Science.gov

Sample records for plant model quarterly

  1. The quarter-power scaling model does not imply size-invariant hydraulic resistance in plants

    Treesearch

    Annikki Makela; Harry T. Valentine

    2006-01-01

    West, Brown, and Enquist (1997, 1999) propose an integrated model of the structure and allometry of plant vascular systems, which has come to be known as the 'WBE model' (Enquist, 2002). The WBE model weaves together area-preserving branching (Leonardo da Vinci), elastic similarity (Greenhill, 1881), the constant ratio of foliage mass to sapwood area (...

  2. Modeling of integrated environmental control systems for coal-fired power plants. Quarterly progress report, [April 1, 1988--June 30, 1988

    SciTech Connect

    Rubin, E.S.

    1988-06-01

    This is the third quarterly report of DOE Contract No. DE-AC22- 87PC79864, entitled ``Modeling of Integrated Environmental Control Systems for Coal-Fired Power Plants.`` This report summarizes accomplishments during the period April 1, 1988 to June 30, 1988. Our efforts during the last quarter focused on, (1) completion of a sulfuric acid plant model (used in conjunction with by-product recovery processes for SO{sub 2}/NO{sub x} removal) and, (2) an update the NOXSO process model. Other accomplishments involved revision and expansion of the enthalpy data algorithms used for process energy balances. The sections below present the details of these developments. References are included at the end of each section.

  3. Coal demonstration plants. Quarterly report, July-September 1979

    SciTech Connect

    1980-07-01

    The status of two coal liquefaction demonstration plants and of four coal gasification demonstration plants is reviewed under the following headings: company involved, contract number, funding, process name, process description, flowsheet, schedule, history and progress during the July-September quarter, 1979. Supporting projects in coal feeding systems, valves, grinding equipment, instrumentation, process control and water treatment are discussed in a similar way. Conceptual design work on commercial plants for coal to methanol and for a HYGAS high BTU gas plant were continued. (LTN)

  4. Coal demonstration plants. Quarterly report, April-June 1979

    SciTech Connect

    1980-04-01

    The objective of the US DOE demonstration program is to demonstrate and verify second-generation technologies and validate the economic, environmental and productive capacity of a near commercial-size plant by integrating and operating a modular unit using commercial size equipment. These facilities are the final stage in the RD and D process aimed at accelerating and reducing the risks of industrial process implementation. Under the DOE program, contracts for the design, construction, and operation of the demonstration plants are awarded through competitive procedures and are cost shared with the industrial partner. The conceptual design phase is funded by the government, with the detailed design, procurement, construction, and operation phases being co-funded between industry and the government. The government share of the cost involved for a demonstration plant depends on the plant size, location, and the desirability and risk of the process to be demonstrated. The various plants and programs are discussed: Description and status, funding, history, flowsheet and progress during the current quarter. (LTN)

  5. An insight into linear quarter car model accuracy

    NASA Astrophysics Data System (ADS)

    Maher, Damien; Young, Paul

    2011-03-01

    The linear quarter car model is the most widely used suspension system model. A number of authors expressed doubts about the accuracy of the linear quarter car model in predicting the movement of a complex nonlinear suspension system. In this investigation, a quarter car rig, designed to mimic the popular MacPherson strut suspension system, is subject to narrowband excitation at a range of frequencies using a motor driven cam. Linear and nonlinear quarter car simulations of the rig are developed. Both isolated and operational testing techniques are used to characterise the individual suspension system components. Simulations carried out using the linear and nonlinear models are compared to measured data from the suspension test rig at selected excitation frequencies. Results show that the linear quarter car model provides a reasonable approximation of unsprung mass acceleration but significantly overpredicts sprung mass acceleration magnitude. The nonlinear simulation, featuring a trilinear shock absorber model and nonlinear tyre, produces results which are significantly more accurate than linear simulation results. The effect of tyre damping on the nonlinear model is also investigated for narrowband excitation. It is found to reduce the magnitude of unsprung mass acceleration peaks and contribute to an overall improvement in simulation accuracy.

  6. Modeling of integrated environmental control systems for coal-fired power plants: Conventional froth flotation for the IEC coal cleaning plant model. Quarterly progress report, [October 1, 1988--December 31, 1988

    SciTech Connect

    Rubin, E.S.

    1989-01-01

    This report describes the addition of a conventional froth flotation circuit into the FORTRAN coal cleaning module of the Integrated Environmental Control (IEC) model. The purpose of this modification is to include froth flotation as an option to clean the coal fines. The current model has three beneficiation: levels (2, 3, and 4) in which different streams are washed by specific gravity equipment. Level 2 washes only the coarse stream. Level 3 washes the coarse and medium streams. Level 4 washes the coarse, medium, and fine streams. This modification adds a fifth level, which uses specific gravity equipment to wash the coarse and medium streams and froth flotation equipment for the fine stream. The specific size fractions in each stream are specified by the model user. As before, the model optimizes the yield of each circuit in order to achieve a target coal quality for the cleaned coal product.

  7. Coal demonstration plants. Quarterly report, January-March 1979. [US DOE-supported

    SciTech Connect

    1980-01-01

    Progress in US DOE-supported demonstration plants for the gasification and liquefaction of coal is reported: company, contract number, process description and flowsheet, history and progress in the current quarter. Related projects involve coal feeders, lock hoppers, values, etc. for feeding coal into high pressure systems, coal grinding equipment and measuring and process control instrumentation. (LTN)

  8. Optimization of nonlinear quarter car suspension-seat-driver model.

    PubMed

    Nagarkar, Mahesh P; Vikhe Patil, Gahininath J; Zaware Patil, Rahul N

    2016-11-01

    In this paper a nonlinear quarter car suspension-seat-driver model was implemented for optimum design. A nonlinear quarter car model comprising of quadratic tyre stiffness and cubic stiffness in suspension spring, frame, and seat cushion with 4 degrees of freedom (DoF) driver model was presented for optimization and analysis. Suspension system was aimed to optimize the comfort and health criterion comprising of Vibration Dose Value (VDV) at head, frequency weighted RMS head acceleration, crest factor, amplitude ratio of head RMS acceleration to seat RMS acceleration and amplitude ratio of upper torso RMS acceleration to seat RMS acceleration along with stability criterion comprising of suspension space deflection and dynamic tyre force. ISO 2631-1 standard was adopted to assess ride and health criterions. Suspension spring stiffness and damping and seat cushion stiffness and damping are the design variables. Non-dominated Sort Genetic Algorithm (NSGA-II) and Multi-Objective Particle Swarm Optimization - Crowding Distance (MOPSO-CD) algorithm are implemented for optimization. Simulation result shows that optimum design improves ride comfort and health criterion over classical design variables.

  9. Pipeline gas demonstration plant, Phase I. Quarterly technical progress report for June 1980-August 1980

    SciTech Connect

    Eby, R.J.

    1980-09-01

    Work was performed in the following tasks in Phase I of the Pipeline Gas Demonstration Plant Program: Demonstration Plant Process Design; Site Evaluation and Selection; Demonstration Plant Environmental Analysis; Feedstock Plans, Licenses, Permits and Easements; Demonstration Plant Definitive Design; Economic Reassessment; Technical Support; Long Lead Procurement List; and Project Management. The following Major Contract Deliverables were submitted to the Government: Process Evaluation Report - TIC Version; Conceptual Commercial Plant Design Report - TIC Version; Demonstration Plant Design Analysis Report - TIC Version; Demonstration Plant Process Design Report; Site Master Plan; and Prevention of Significant Deterioration Documentation. The major work activity has been the effort in Demonstration Plant Definitive Design which commenced following the completion of the Process Design Baseline Packages for the fourteen Demonstration Plant process areas. Task VIII, Economic Reassessment was opened in this quarter. Completion of the TIC copies of the ICGG major deliverables constituted a significant effort in this period. Work has progressed satisfactorily in the other Tasks in support of the Demonstration Plant Program.

  10. Development of the integrated environmental control model. Quarterly progress report, April 1995--June 1995

    SciTech Connect

    Kalagnanam, J.R.; Rubin, E.S.

    1995-06-01

    The purpose of this contract is to develop and refine the Integrated Environmental Control Model (IECM). In its current configuration, the IECM provides a capability to model various conventional and advanced processes for controlling air pollutant emissions from coal-fired power plants before, during, or after combustion. The principal purpose of the model is to calculate the performance, emissions, and cost of power plant configurations employing alternative environmental control methods. The model consists of various control technology modules, which may be integrated into a complete utility plant in any desired combination. In contrast to conventional deterministic models, the IECM offers the unique capability to assign probabilistic values to all model input parameters, and to obtain probabilistic outputs in the form of cumulative distribution functions indicating the likelihood of different costs and performance results. The work in this contract is divided into two phases. Phase I deals with further developing the existing version of the IECM and training PETC personnel on the effective use of the model. Phase H deals with creating new technology modules, linking the IECM with PETC databases, and training PETC personnel on the effective use of the updated model. The present report summarizes recent progress on the Phase I effort during the period April 1, 1995 through June 30, 1995. This report presents additional revisions to the new cost models of flue gas desulfurization (FGD) technology initially reported in our fourth quarterly report. For convenience, the complete description of the revised FGD models are presented here.

  11. The Savannah River Plant`s Groundwater Monitoring Program - second quarter 1987

    SciTech Connect

    1996-10-01

    This report is a summary of the groundwater monitoring program conducted by the Environmental Monitoring Group of the Health Protection Department in the second quarter of 1987 and includes the analytical results, field data, and detailed documentation for this program. The purpose of this report is twofold. First, the report provides a historical record of the activities and the rationale of the program; second, it provides an official document of the analytical results.

  12. Entanglement entropies of the quarter filled Hubbard model

    NASA Astrophysics Data System (ADS)

    Calabrese, Pasquale; Essler, Fabian H. L.; Läuchli, Andreas M.

    2014-09-01

    We study Rényi and von Neumann entanglement entropies in the ground state of the one dimensional quarter-filled Hubbard model with periodic boundary conditions. We show that they exhibit an unexpected dependence on system size: for L = 4mod 8 the results are in agreement with expectations based on conformal field theory, while for L = 0mod 8 additional contributions arise. We show that these can be understood in terms of a ‘shell-filling’ effect and we develop a conformal field theory approach to calculate the additional contributions to the entropies. These analytic results are found to be in excellent agreement with density matrix renormalization group computations for weak Hubbard interactions. We argue that for larger interactions the presence of a marginal irrelevant operator in the spin sector strongly affects the entropies at the finite sizes accessible numerically and we present an effective way to take them into account.

  13. Between simplicity and accuracy: Effect of adding modeling details on quarter vehicle model accuracy.

    PubMed

    Soong, Ming Foong; Ramli, Rahizar; Saifizul, Ahmad

    2017-01-01

    Quarter vehicle model is the simplest representation of a vehicle that belongs to lumped-mass vehicle models. It is widely used in vehicle and suspension analyses, particularly those related to ride dynamics. However, as much as its common adoption, it is also commonly accepted without quantification that this model is not as accurate as many higher-degree-of-freedom models due to its simplicity and limited degrees of freedom. This study investigates the trade-off between simplicity and accuracy within the context of quarter vehicle model by determining the effect of adding various modeling details on model accuracy. In the study, road input detail, tire detail, suspension stiffness detail and suspension damping detail were factored in, and several enhanced models were compared to the base model to assess the significance of these details. The results clearly indicated that these details do have effect on simulated vehicle response, but to various extents. In particular, road input detail and suspension damping detail have the most significance and are worth being added to quarter vehicle model, as the inclusion of these details changed the response quite fundamentally. Overall, when it comes to lumped-mass vehicle modeling, it is reasonable to say that model accuracy depends not just on the number of degrees of freedom employed, but also on the contributions from various modeling details.

  14. Between simplicity and accuracy: Effect of adding modeling details on quarter vehicle model accuracy

    PubMed Central

    2017-01-01

    Quarter vehicle model is the simplest representation of a vehicle that belongs to lumped-mass vehicle models. It is widely used in vehicle and suspension analyses, particularly those related to ride dynamics. However, as much as its common adoption, it is also commonly accepted without quantification that this model is not as accurate as many higher-degree-of-freedom models due to its simplicity and limited degrees of freedom. This study investigates the trade-off between simplicity and accuracy within the context of quarter vehicle model by determining the effect of adding various modeling details on model accuracy. In the study, road input detail, tire detail, suspension stiffness detail and suspension damping detail were factored in, and several enhanced models were compared to the base model to assess the significance of these details. The results clearly indicated that these details do have effect on simulated vehicle response, but to various extents. In particular, road input detail and suspension damping detail have the most significance and are worth being added to quarter vehicle model, as the inclusion of these details changed the response quite fundamentally. Overall, when it comes to lumped-mass vehicle modeling, it is reasonable to say that model accuracy depends not just on the number of degrees of freedom employed, but also on the contributions from various modeling details. PMID:28617819

  15. Specification of hierarchical-model-based fast quarter-pixel motion estimation

    NASA Astrophysics Data System (ADS)

    Cho, Junsang; Suh, Jung W.; Jeon, Gwanggil; Jeong, Jechang

    2010-06-01

    We propose a robust and fast quarter-pixel motion estimation algorithm. This algorithm is an advanced version of the previously proposed model-based quarter-pixel motion estimation (MBQME). MBQME has many advantages in computational complexity, running speed, and hardware implementations. But it has the problem that it does not find the quarter-pixel positions that locate beyond the half-pixel positions. That is one of limitations of model-based motion estimation methods, and it leads to both peak-SNR degradation and bit-rate increase. To solve this problem, we propose a hierarchical mathematical model with minimum interpolations. Through this model, we can determine a motion vector at every quarter-pixel point, which is perfectly compatible with the quarter-pixel motion estimation method within international video coding standards such as MPEG-4 and H.264/AVC. The simulation results show that the proposed method yields almost the same or even better peak-SNR performance than that of full-search quarter-pixel motion estimation, with much lower computational complexity.

  16. Plant Models for DEMO

    NASA Astrophysics Data System (ADS)

    Maisonnier, David

    2008-03-01

    The European Power Plant Conceptual Study (PPCS) has been a study of conceptual designs for commercial fusion power plants. It focused on five power plant models, named PPCS A, B, AB, C and D, which are illustrative of a wider spectrum of possibilities. The PPCS study highlighted the need for specific design and R&D activities as well as the need to clarify the concept of DEMO, the device that will bridge the gap between ITER and the first fusion power plant. An assessment of the PPCS models with limited extrapolations has led to the clarification of the objectives of DEMO. Many parameters will have to be controlled in DEMO in order (1) to control the machine, (2) to satisfy the testing requirements, (3) to satisfy regulatory requirements (primarily safety), and (4) to protect the investment. On the other, DEMO will ulilise one or two plasma scenarios only.

  17. Plant Models for DEMO

    SciTech Connect

    Maisonnier, David

    2008-03-12

    The European Power Plant Conceptual Study (PPCS) has been a study of conceptual designs for commercial fusion power plants. It focused on five power plant models, named PPCS A, B, AB, C and D, which are illustrative of a wider spectrum of possibilities. The PPCS study highlighted the need for specific design and R and D activities as well as the need to clarify the concept of DEMO, the device that will bridge the gap between ITER and the first fusion power plant. An assessment of the PPCS models with limited extrapolations has led to the clarification of the objectives of DEMO. Many parameters will have to be controlled in DEMO in order (1) to control the machine, (2) to satisfy the testing requirements, (3) to satisfy regulatory requirements (primarily safety), and (4) to protect the investment. On the other, DEMO will ulilise one or two plasma scenarios only.

  18. Plant design: Integrating Plant and Equipment Models

    SciTech Connect

    Sloan, David; Fiveland, Woody; Zitney, S.E.; Osawe, Maxwell

    2007-08-01

    Like power plant engineers, process plant engineers must design generating units to operate efficiently, cleanly, and profitably despite fluctuating costs for raw materials and fuels. To do so, they increasingly create virtual plants to enable evaluation of design concepts without the expense of building pilot-scale or demonstration facilities. Existing computational models describe an entire plant either as a network of simplified equipment models or as a single, very detailed equipment model. The Advanced Process Engineering Co-Simulator (APECS) project (Figure 5) sponsored by the U.S. Department of Energy's National Energy Technology Laboratory (NETL) seeks to bridge the gap between models by integrating plant modeling and equipment modeling software. The goal of the effort is to provide greater insight into the performance of proposed plant designs. The software integration was done using the process-industry standard CAPE-OPEN (Computer Aided Process Engineering–Open), or CO interface. Several demonstration cases based on operating power plants confirm the viability of this co-simulation approach.

  19. Development of molten carbonate fuel cell power plant. Quarterly technical progress report, February 1-April 30, 1980

    SciTech Connect

    Peterson, J. R.

    1980-01-01

    Work has been initiated during this first quarter under all four program tasks and by all major participants as described. Task 1.0 activity (establish power plant reference design) concentrated upon definition of user requirements and establishment of power plant subsystem alternatives and characteristics. Task 2.0 work (stack and cell design development and verification) was initiated with a heavy emphasis upon test facilities preparation. A total of 27 laboratory cells were operated during this reporting period and a total of nine cells continued on test at the end of the quarter. Investigation of alternative anode and cathode materials proceeded; a dual-porosity anode was fabricated and tested. Over 10,000 endurance hours on a state-of-the-art cell carried-over from a previous program has been achieved and 1500 hours endurance has been obtained with sheet metal cells. Results presented for electrolyte structure development include comparative data for spray-dried and modified aqueous slurry process powders. Shake-down tests with a rotating disc electrode apparatus for fundamental measurements are described. Concept designs for both prototype and subscale stacks have been identified. Task 3.0 effort (development capability for full-scale stack tests) included preparation of an overall test plan to commercialization for molten carbonate fuel cells and of a functional specification for the tenth-scale stack test facility; drafts of both documents were completed for internal review. Cost-effective manufacturing assessment of available designs and processes was initiated. Task 4.0 work (develop capabilities for operation of stacks on coal-derived gas) included gathering of available contaminants concentration and effects information and preparation of initial projections of contaminant ranges and concentrations. Accomplishments to date and activities planned for the next quarter are described.

  20. Modeling plant growth and development.

    PubMed

    Prusinkiewicz, Przemyslaw

    2004-02-01

    Computational plant models or 'virtual plants' are increasingly seen as a useful tool for comprehending complex relationships between gene function, plant physiology, plant development, and the resulting plant form. The theory of L-systems, which was introduced by Lindemayer in 1968, has led to a well-established methodology for simulating the branching architecture of plants. Many current architectural models provide insights into the mechanisms of plant development by incorporating physiological processes, such as the transport and allocation of carbon. Other models aim at elucidating the geometry of plant organs, including flower petals and apical meristems, and are beginning to address the relationship between patterns of gene expression and the resulting plant form.

  1. Plant response to FBC waste-coal slurry solid mixtures. [Quarterly] technical report, September 1--November 30, 1993

    SciTech Connect

    Darmody, R.G.; Dunker, R.E.; Dreher, G.B.; Roy, W.R.; Steel, J.D.

    1994-03-01

    The goal of this project is to test the feasibility of stabilizing coal slurry solids (CSS) wastes by directly seeding plants into the waste. This is not done conventionally because the waste can generate toxic amounts of sulfuric acid. Our approach is to neutralize the potential acidity by mixing fluidized bed combustion (FBC) waste into the slurry. If successful, this approach would both help dispose of FBC wastes while providing a more economical slurry stabilization technique. The project involves growing forage plants in CSS-FBC mixtures in the greenhouse. This is the first quarter of the project. We have designed the experiment, secured greenhouse space, purchased the seeds, collected and dried the FBC and CSS samples. The samples represent a typical range of properties. We retrieved two FBC and two CSS samples. One CSS sample appears to have a higher pyrite content than the other.

  2. Characterization of air toxics from a laboratory coal-fired combustor and utility scale power plants. Quarterly progress report No. 14, January--March, 1995

    SciTech Connect

    1995-05-01

    This report summarized progress on Task 3, Power Plant Studies, and Task 4, Technical Management and Reporting. Task 3 this quarter involved sampling of flue gas from Units 6 and 7 of the host power plant. The operating parameters during the sampling period are given. Laboratory analyses are in progress. Under Task 4, internal and external QA/QC audits were conducted. A data base management system was prepared. An appendix contains a data compilation of plant operating data.

  3. Quarterly Progress Report: Modeling and Simulation of the Homopolar Motor Test Apparatus

    DTIC Science & Technology

    2006-05-01

    Quarterly Progress Report: Modeling and Simulation of the Homopolar Motor Test Apparatus 5. FUNDING NUMBERS Contract # N00014-1-0588 6. AUTHOR(S) K...superconducting homopolar motor /generator (SCHPMG) machine for ship propulsion. Electrical contact (brush/slip ring) performance is a limiting factor in SCHPMG...SUBJECT TERMS superconducting homopolar motors , inhomogenous brush wear, polarity dependence, destabilized force 15. NUMBER OF PAGES 11 16. PRICE CODE

  4. Modeling, design, and life performance prediction for energy production from geothermal reservoirs. First quarter progress report

    SciTech Connect

    Swenson, D.

    1997-08-15

    The objective of this project is to both transfer existing Hot Dry Rock two-dimensional fractured reservoir analysis capability to the geothermal industry and to extend the analysis concepts to three dimensions. In this quarter, the primary focus has been on interaction with industry, development of the Geocrack3D model, and maintenance of Geocrack2D. It is important to emphasize that the modeling is complementary to current industry modeling, in that they focus on flow in fractured rock and on the coupled effect of thermal cooling, while a primary focus of current modeling technology is multi-phase flow.

  5. Acoustic agglomeration of power plant fly ash: Quarterly technical report, November 5, 1986--February 5, 1987

    SciTech Connect

    Reethof, G.

    1987-03-20

    The objective of this project is to complete the investigations on the use of high intensity acoustic energy to agglomerate micron and submicron sized particulates in fly ash aerosols in order to provide the necessary scientific knowledge and design criteria for the specification of technically and economically viable intermediate flue gas treatment of coal fired power plants. The results of the project are to provide technical and economic information for the better development and evaluation of potential fine particulate control systems. The goals of the proposed work are to further the understanding of certain fundamental processes by means of theoretical and experimental investigations, to include this knowledge in an advanced computerized model of the agglomeration processes. Tests with the two acoustic agglomerators available in Penn State's new High Intensity Acoustics Laboratory will be used to verify the results from the agglomeration simulation. Research work will continue on high power, high efficiency sirens with special emphasis on the nonlinear acoustic phenomena and novel means of significantly increasing siren efficiency. A study will be carried out to evaluate the economics of conventional coal fired power plant clean-up systems using acoustic agglomerators as intermediate flue gas treatment.

  6. [Geothermal system temperature-depth database and model for data analysis]. 5. quarterly technical progress report

    SciTech Connect

    Blackwell, D.D.

    1998-04-25

    During this first quarter of the second year of the contract activity has involved several different tasks. The author has continued to work on three tasks most intensively during this quarter: the task of implementing the data base for geothermal system temperature-depth, the maintenance of the WWW site with the heat flow and gradient data base, and finally the development of a modeling capability for analysis of the geothermal system exploration data. The author has completed the task of developing a data base template for geothermal system temperature-depth data that can be used in conjunction with the regional data base that he had already developed and is now implementing it. Progress is described.

  7. An engineering model for coal devolatilization: Quarterly report, September 15, 1988--December 15, 1988

    SciTech Connect

    Wei Lau, Chun; Niksa, Stephen

    1988-01-01

    During this reporting period, we concentrated on an engineering correlation to represent the enhanced heat transfer predicted from our analysis of the heat and mass transfer around a devolatilizing coal particle. As explained in the last quarterly report, our analysis does not assume that the free stream conditions are reached at infinity, as in the conventional definitions of the Nusselt number and blowing factors for particles in the pulverized fuel grade. Instead, the extent of the thermal and concentration fields are time-dependent, and assigned to satisfy both mass and energy conservation in the film by adapting recent analyses of vapor accumulation effects (VAE) during fuel droplet evaporation. The complete formulation of the model appears in the last quarterly report. 1 ref., 6 figs.

  8. An Evaluation of the Plant Density Estimator the Point-Centred Quarter Method (PCQM) Using Monte Carlo Simulation.

    PubMed

    Khan, Md Nabiul Islam; Hijbeek, Renske; Berger, Uta; Koedam, Nico; Grueters, Uwe; Islam, S M Zahirul; Hasan, Md Asadul; Dahdouh-Guebas, Farid

    2016-01-01

    In the Point-Centred Quarter Method (PCQM), the mean distance of the first nearest plants in each quadrant of a number of random sample points is converted to plant density. It is a quick method for plant density estimation. In recent publications the estimator equations of simple PCQM (PCQM1) and higher order ones (PCQM2 and PCQM3, which uses the distance of the second and third nearest plants, respectively) show discrepancy. This study attempts to review PCQM estimators in order to find the most accurate equation form. We tested the accuracy of different PCQM equations using Monte Carlo Simulations in simulated (having 'random', 'aggregated' and 'regular' spatial patterns) plant populations and empirical ones. PCQM requires at least 50 sample points to ensure a desired level of accuracy. PCQM with a corrected estimator is more accurate than with a previously published estimator. The published PCQM versions (PCQM1, PCQM2 and PCQM3) show significant differences in accuracy of density estimation, i.e. the higher order PCQM provides higher accuracy. However, the corrected PCQM versions show no significant differences among them as tested in various spatial patterns except in plant assemblages with a strong repulsion (plant competition). If N is number of sample points and R is distance, the corrected estimator of PCQM1 is 4(4N - 1)/(π ∑ R2) but not 12N/(π ∑ R2), of PCQM2 is 4(8N - 1)/(π ∑ R2) but not 28N/(π ∑ R2) and of PCQM3 is 4(12N - 1)/(π ∑ R2) but not 44N/(π ∑ R2) as published. If the spatial pattern of a plant association is random, PCQM1 with a corrected equation estimator and over 50 sample points would be sufficient to provide accurate density estimation. PCQM using just the nearest tree in each quadrant is therefore sufficient, which facilitates sampling of trees, particularly in areas with just a few hundred trees per hectare. PCQM3 provides the best density estimations for all types of plant assemblages including the repulsion process

  9. Salmonella prevalence and characterization in a free-range pig processing plant: tracking in trucks, lairage, slaughter line and quartering.

    PubMed

    Hernández, Manuela; Gómez-Laguna, Jaime; Luque, Inmaculada; Herrera-León, Silvia; Maldonado, Alfonso; Reguillo, Lucía; Astorga, Rafael J

    2013-03-01

    New consumer tendencies are focused on products derived from systems which allow both a high animal welfare condition and a high food safety level. However, sometimes animal welfare regulations make the adoption of adequate bio-security measures difficult, representing a barrier for animal health and food safety. Thus the aim of this study was to determine the prevalence of Salmonella at different points of the pig slaughtering process (Trucks, Lairage, Slaughter line and Quartering, TLSQ) from pigs reared in free-range systems. From eight samplings a total of 126 Salmonella isolates out of 1160 different samples were recovered (10.86%). The highest percentage of isolates was detected at the points of pre-scalding (29/80, 36.25%), trucks (13/56, 23.21%), cecal contents (17/80, 21.25%), tonsils (14/80, 17.50%), ileocecal lymph nodes (13/80, 16.25%) and lairage (9/64, 14.06%). Furthermore, eighteen isolates were obtained from different environmental samples from slaughter line and quartering plant (knives and surface of tables) (5.63%) and three isolates at the quartering plant samples (ham, shoulder and loin) (3.75%). Fourteen different serotypes were isolated: Bredeney, Rissen, Derby, Typhimurium, Montevideo, Israel, Anatum, Emek, Monophasic Salmonella Typhimurium (mST), Choleraesuis, Durban, Kentucky, London and Sandiego. S. Typhimurium phage types U311, 193, 104b and UT were identified. Moreover, mST strain was phage typed as U311. From TLSQ1, TLSQ2 and TLSQ4, different strains of S. Derby, S. Rissen and S. Bredeney serotypes were isolated from pig and environmental samples, pointing to a potential cross contamination. Molecular typing (Pulsed-Field Gel Electrophoresis, PFGE) of these strains confirmed the cross contamination. In the remaining samplings, different serotypes were obtained in each sampled point of the chain, assuming that the isolated serotypes belonged to different epidemiological origins. Our results show the isolation of different serotypes of

  10. Pipeline gas demonstration plant, Phase I. Quarterly technical progress report for September 1980-November 1980

    SciTech Connect

    Eby, R.J.

    1980-12-01

    Work was performed in the following tasks in Phase I of the Pipeline Gas Demonstration Plant Program: Site Evaluation and Selection; Demonstration Plant Environmental Analysis; Feedstock Plans, Licenses, Permits and Easements; Demonstration Plant Definitive Design; Construction Planning; Economic Reassessment; Technical Support; Long Lead Procurement List; and Project Management. The Preliminary Construction Schedule was delivered to the Government on October 3, 1980, constituting an early delivery of the construction schedule called for in the scope of work for Task VI. The major work activity continues to be the effort in Task VI, Demonstration Plant Definitive Design, with two 30% Design Review meetings being held with the Government. Work in Task VII, Construction Planning, was initiated. Work has progressed satisfactorily in the other tasks in support of the Demonstration Plant Program. A Cost Change Proposal was submitted because of an increase in the scope of work and an extension of the schedule for Phase I to 47 months.

  11. Development of molten carbonate fuel cell power plant technology. Quarterly technical progress report No. 2, January 1-March 31, 1980

    SciTech Connect

    Healy, H. C.; Sanderson, R. A.; Wertheim, F. J.; Farris, P. F.; Mientek, A. P.; Maricle, D. L.; Briggs, T. A.; Preston, Jr., J. L.; Louis, G. A.; Abrams, M. L.; Bushnell, C. L.; Nickols, R. C.; Gelting, R. L.; Katz, M.; Stewart, R. C.; Kunz, H. R.; Gruver, G. A.; Bregoli, L. J.; Steuernagel, W. H.; Smith, R.; Smith, S. W.; Szymanski, S. T.

    1980-08-01

    The overall objective of this 29-month program is to develop and verify the design of a prototype molten carbonate fuel cell stack which meets the requirements of 1990's competitive coal-fired electrical utility central station or industrial cogeneration power plants. During this quarter, effort was continued in all four major task areas: Task 1 - system studies to define the reference power plant design; Task 2 - cell and stack design, development and verification; Task 3 - preparation for fabrication and testing of the full-scale prototype stack; and Task 4 - developing the capability for operation of stacks on coal-derived gas. In the system study activity of Task 1, preliminary module and cell stack design requirements were completed. Fuel processor characterization has been completed by Bechtel National, Inc. Work under Task 2 defined design approaches for full-scale stack busbars and electrical isolation of reactant manifolds and reactant piping. Preliminary design requirements were completed for the anode. Conductive nickel oxide for cathode fabrication has been made by oxidation and lithiation of porous nickel sheet stock. A method of mechanizing the tape casting process for increased production rates was successfully demonstrated under Task 3. In Task 4, theoretical calculations indicated that hydrogen cyanide and ammonia, when present as impurities in the stack fuel gas, will have no harmful effects. Laboratory experiments using higher than anticipated levels of ethylene showed no harmful effects. Components for the mobile test facility are being ordered.

  12. Plant response to FBC waste-coal slurry solid mixtures. [Quarterly] technical report, December 1--February 28, 1994

    SciTech Connect

    Darmody, R.G.; Dunker, R.E.; Dreher, G.B.; Roy, W.R.; Steel, J.D.

    1994-06-01

    The goal of this project is to test the feasibility of stabilizing coal slurry solids (CSS) wastes by directly seeding plants into the waste. This is not done conventionally because the waste can generate toxic amounts of sulfuric acid. Our approach is to neutralize the potential acidity by mixing fluidized bed combustion (FBC) waste into the slurry. If successful this approach would both help dispose of FBC wastes while providing a more economical slurry stabilization technique. The project involves growing forage plants in CSS-FBC mixtures in the greenhouse. This is the second quarter of the project. We have designed the experiment, secured greenhouse space, purchased the seeds, collected, dried, and are analyzing the FBC and CSS samples. The samples represent a typical range of properties. We retrieved two FBC and two CSS samples. One CSS sample had a relatively high CaCO{sub 3} content relative to the pyrite content and will require no FBC to neutralize the potential acidity. The other CSS sample will require from 4.2 to 2.7% FBC material to neutralize its potential acidity.

  13. Pipeline gas demonstration plant, Phase I. Quarterly technical progress report, December 1980-February 1981

    SciTech Connect

    Eby, R.J.

    1981-03-01

    Work was performed in the following areas of the Pipeline Gas Demonstration Plant Program: site evaluation and selection; demonstration plant environmental analysis; feedstock plans, licenses, permits and easements; demonstration plant definitive design; construction planning; economic reassessment; technical support; long lead procurement list; and project management. Major work activity continued to be the effort on Demonstration Plant Definitive Design. A Construction Readiness Audit was held on January 14 to 16, 1981 by a Government/Procon team to review the project and assess the readiness of the project to proceed into the construction phase. Documents for the 60% Design Review were prepared for ICGG review and submitted to the Contracting Officer's authorized representative prior to transmittal to the Corps of Engineers for review. The Corps of Engineers conducted a design audit. The primary objective of the audit was to prepare an independent estimate of the work remaining to complete Phase I of the project. Work continued on the production of a single bid package for the Demonstration Plant, suitable for release to a single constructor, and organized so it can be easily broken down into subpackages by construction specialty. A formal audit of the ICGG R/QA Plan and implementation thereof was performed February 11-12, 1981 by the Corps of Engineers. The Contract Deliverable Final Feedstock-Product-Waste Disposal Plan was delivered to the Government on February 25, 1981.

  14. Response of a quarter car model with optimal magnetorheological damper parameters

    NASA Astrophysics Data System (ADS)

    Prabakar, R. S.; Sujatha, C.; Narayanan, S.

    2013-04-01

    In this paper, the control of the stationary response of a quarter car model to random road excitation with a Magnetorheological (MR) damper as a semi-active suspension device is considered. The MR damper is a hypothetical analytical damper whose parameters are determined optimally using a multi-objective optimization technique Non-dominated Sorting Genetic Algorithm II (NSGA II). The hysteretic behaviour of the MR damper is characterized using Bingham and modified Bouc-Wen models. The multi-objective optimization problem is solved by minimizing the difference between the root mean square (rms) sprung mass acceleration, suspension stroke and the road holding responses of the quarter car model with the MR damper and those of the active suspension system based on linear quadratic regulator (LQR) control with the constraint that the MR damper control force lies between ±5 percent of the LQR control force. It is observed that the MR damper suspension systems with optimal parameters perform an order of magnitude better than the passive suspension and perform as well as active suspensions with limited state feedback and closer to the performance of fully active suspensions.

  15. Environmental restoration at the Pantex Plant. Quarterly progress report, April 12, 1995--June 30, 1995

    SciTech Connect

    Charbeneau, R.J.

    1995-06-19

    This report summarizes the Work Plans for activities associated with Environmental Restoration of the perched aquifer and contaminated soils at the Pantex Plant. The Higher Education Consortium/Pantex Research Laboratory is participating in the Consortium Grant to evaluate subsurface remediation alternatives for the perched aquifer at the Pantex Plant. Research activities will develop site characterization data and evaluate remediation alternatives for the perched aquifer and the overlying vadose zone. The work plans cover research activities for the remainder of FY95, and proposed activities for FY96 and thereafter. A separate document will present more detailed plans for FY96 activities and budget requirements.

  16. Plant canopy specular reflectance model

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.; Grant, L.

    1985-01-01

    A model is derived for the amount of light specularly reflected and polarized by a plant canopy. The model is based on the morphological and phenological characteristics of the canopy and upon the Fresnel equations of optics. The theory demonstrates that the specular reflectance of the plant canopy is a function of the angle of incidence and potentially contains information to help discriminate between species. The theory relates the specular reflectance to botanical condition of the canopy - to factors such as development stage, plant vigor, and leaf area index (LAI).

  17. Plant canopy specular reflectance model

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.; Grant, L.

    1985-01-01

    A model is derived for the amount of light specularly reflected and polarized by a plant canopy. The model is based on the morphological and phenological characteristics of the canopy and upon the Fresnel equations of optics. The theory demonstrates that the specular reflectance of the plant canopy is a function of the angle of incidence and potentially contains information to help discriminate between species. The theory relates the specular reflectance to botanical condition of the canopy - to factors such as development stage, plant vigor, and leaf area index (LAI).

  18. Development of the integrated environmental control model: Cost models of selective catalytic reduction (SCR) NO{sub x} control systems. Quarterly progress report, October--December 1993

    SciTech Connect

    Frey, H.C.; Rubin, E.S.

    1994-01-31

    Selective catalytic reduction (SCR) is a process for the post-combustion removal of NO{sub x} from the flue gas of fossil-fuel-fired power plants. SCR is capable of NO{sub x} reduction efficiencies of up to 80 or 90 percent. SCR technology has been applied for treatment of flue gases from a variety of emission sources, including natural gas- and oil-fired gas turbines, process steam boilers in refineries, and coal-fired power plants. SCR applications to coal-fired power plants have occurred in Japan and Germany. Full-scale SCR systems have not been applied to coal-fired power plants in the U.S., although there have been small-scale demonstration projects. Increasingly strict NO{sub x} control requirements are being imposed by various state and local regulatory agencies in the U.S. These requirements may lead to U.S. SCR applications, particularly for plants burning low sulfur coals (Robie et al.). Furthermore, implicit in Title IV of the 1990 Clean Air Act Amendment is a national NO{sub x} emission reduction of 2 million tons per year. Thus, there may be other incentives to adapt SCR technology more generally to U.S. coal-fired power plants with varying coal sulfur contents. However, concern remains over the applicability of SCR technology to U.S. plants burning high sulfur coals or coals with significantly different fly ash characteristics than those burned in Germany and Japan. There is also concern regarding the application of SCR to peaking units due to potential startup and shutdown problems (Lowe et al.). In this report, new capital cost models of two SCR systems are developed. These are {open_quotes}hot-side high-dust{close_quotes} and {open_quotes}tail-end low-dust{close_quotes} options. In a previous quarterly report, performance models for these two systems were developed.

  19. Identification and validation of heavy metal and radionuclide accumulating terrestrial plant species. Quarterly technical progress report, June 21, 1995--September 20, 1995

    SciTech Connect

    Kochian, L.

    1995-12-31

    This quarterly report describes experiments on uptake of a variety of heavy metals by plants. Titles of report sections are (1) Alleviation of heavy-metal induced micronutrient deficiency through foliar fertilization, (2) Second screen for Zn, Cu, and Cd accumulation, (3) Characterization of the root Zn hyperaccumulation by Thlaspi caerulescens, (4) Comparison of commercial Brassica accessions obtained from the Iowa seed bank, (5) Second screening experiment for the accumulation of Cs and Sr by plants, (6) Effect of Ca on Cs and Sr accumulation by selected dicot species, and (7) Preliminary investigations into the forms of uranium taken up by plants.

  20. An Evaluation of the Plant Density Estimator the Point-Centred Quarter Method (PCQM) Using Monte Carlo Simulation

    PubMed Central

    Khan, Md Nabiul Islam; Hijbeek, Renske; Berger, Uta; Koedam, Nico; Grueters, Uwe; Islam, S. M. Zahirul; Hasan, Md Asadul; Dahdouh-Guebas, Farid

    2016-01-01

    Background In the Point-Centred Quarter Method (PCQM), the mean distance of the first nearest plants in each quadrant of a number of random sample points is converted to plant density. It is a quick method for plant density estimation. In recent publications the estimator equations of simple PCQM (PCQM1) and higher order ones (PCQM2 and PCQM3, which uses the distance of the second and third nearest plants, respectively) show discrepancy. This study attempts to review PCQM estimators in order to find the most accurate equation form. We tested the accuracy of different PCQM equations using Monte Carlo Simulations in simulated (having ‘random’, ‘aggregated’ and ‘regular’ spatial patterns) plant populations and empirical ones. Principal Findings PCQM requires at least 50 sample points to ensure a desired level of accuracy. PCQM with a corrected estimator is more accurate than with a previously published estimator. The published PCQM versions (PCQM1, PCQM2 and PCQM3) show significant differences in accuracy of density estimation, i.e. the higher order PCQM provides higher accuracy. However, the corrected PCQM versions show no significant differences among them as tested in various spatial patterns except in plant assemblages with a strong repulsion (plant competition). If N is number of sample points and R is distance, the corrected estimator of PCQM1 is 4(4N − 1)/(π ∑ R2) but not 12N/(π ∑ R2), of PCQM2 is 4(8N − 1)/(π ∑ R2) but not 28N/(π ∑ R2) and of PCQM3 is 4(12N − 1)/(π ∑ R2) but not 44N/(π ∑ R2) as published. Significance If the spatial pattern of a plant association is random, PCQM1 with a corrected equation estimator and over 50 sample points would be sufficient to provide accurate density estimation. PCQM using just the nearest tree in each quadrant is therefore sufficient, which facilitates sampling of trees, particularly in areas with just a few hundred trees per hectare. PCQM3 provides the best density estimations for all

  1. Pulverized fuel combustion: modeling and scaleup methodologies. First quarterly report, September 19-December 31, 1980

    SciTech Connect

    Lewis, Paul F.; Wolf, Thomas L.; Gelb, Alan

    1981-01-01

    This document is the first quarterly progress report on the effort to develop an understanding of the stability and carbon carryover characteristics of pulverized fuel combustors. This work is to be accomplished by improving and extending a model developed for entrained flow coal gasifier analysis by including a better description of the finite rate coal pyrolysis, pyrolysis product chemistry, char reactions, particle-particle interactions, radiative transport and recirculation/mixing. The data to be analyzed with the model will include data from simple (cylindrical symmetry) geometry combustors with premixed and mixing reactants, swirl and recirculation. The analysis of these data with the model should lead to an understanding of the effects of fuel type, swirl, recirculation, O/F ratio and mixing rate on the location (stability) of the flame and the carbon carryover from the combustor.

  2. Short-term energy outlook. Quarterly projections, second quarter 1996

    SciTech Connect

    1996-04-01

    The Energy Information Administration prepares quarterly, short-term energy supply, demand, and price projections. The forecasts in this issue cover the second quarter of 1996 through the fourth quarter of 1997. Changes to macroeconomic measures by the Bureau of Economic Analysis have been incorporated into the STIFS model used.

  3. Toward a quarter century of pathogen-derived resistance and practical approaches to plant virus disease control.

    PubMed

    Gottula, J; Fuchs, M

    2009-01-01

    The concept of pathogen-derived resistance (PDR) describes the use of genetic elements from a pathogen's own genome to confer resistance in an otherwise susceptible host via genetic engineering [J. Theor. Biol. 113 (1985) 395]. Illustrated with the bacteriophage Qbeta in Escherichia coli, this strategy was conceived as a broadly applicable approach to engineer resistance against pathogens. For plant viruses, the concept of PDR was validated with the creation of tobacco plants expressing the coat protein gene of Tobacco mosaic virus (TMV) and exhibiting resistance to infection by TMV [Science 232 (1986) 738]. Subsequently, virus-resistant horticultural crops were developed through the expression of viral gene constructs. Among the numerous transgenic crops produced and evaluated in the field, papaya resistant to Papaya ringspot virus (PRSV) [Annu. Rev. Phytopathol. 36 (1998) 415] and summer squash resistant to Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus, and/or Watermelon mosaic virus [Biotechnology 13 (1995) 1458] were released for commercial use in the USA. Although cultivated on limited areas, the adoption rate of cultivars derived from these two crops is increasing steadily. Tomato and sweet pepper resistant to CMV and papaya resistant to PRSV were also released in the People's Republic of China. Applying the concept of PDR provides unique opportunities for developing virus-resistant crops and implementing efficient and environmentally sound management approaches to mitigate the impact of virus diseases. Based on the tremendous progress made during the past quarter century, the prospects of further advancing this innovative technology for practical control of virus diseases are very promising. Copyright 2009 Elsevier Inc. All rights reserved.

  4. Pilot plant testing of Illinois coal for blast furnace injection. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Crelling, J.C.

    1995-12-31

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of Illinois coal in the blast furnace injection process in a new and unique pilot plant test facility. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This study is unique in that it is the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. This proposal is a follow-up to one funded for the 1993--94 period. It is intended to complete the study already underway with the Armco and Inland steel companies and to demonstrate quantitatively the suitability of both the Herrin No. 6 and Springfield No. 5 coals for blast furnace injection. The main feature of the current work is the testing of Illinois coals at CANMET`s (Canadian Centre for Mineral and Energy Technology) pilot plant coal combustion facility. This facility simulates blowpipe-tuyere conditions in an operating blast furnace, including blast temperature (900{degrees}C), flow pattern (hot velocity 200 m/s), geometry, gas composition, coal injection velocity (34 m/s) and residence time (20 ms). The facility is fully instrumented to measure air flow rate, air temperature, temperature in the reactor, wall temperature, preheater coil temperature and flue gas analysis. During this quarter there were two major accomplishments.

  5. Effects of asymmetrical damping on a 2 DOF quarter-car model under harmonic excitation

    NASA Astrophysics Data System (ADS)

    Silveira, M.; Wahi, P.; Fernandes, J. C. M.

    2017-02-01

    The objective of this work is to study the dynamical behavior of vehicle suspension systems employing asymmetrical viscous damping, with a focus on improving passenger comfort. Previous studies have shown that the use of asymmetrical dampers in these types of systems can be advantageous with regard to comfort of the passengers. The modeling and the behavior of a quarter-car model with asymmetrical viscous damping under harmonic excitation is presented. The response is obtained with an analytical approximation via the method of Harmonic Balance. The choice of the asymmetry ratio diminishes the effects that the uneven road causes on the displacement and acceleration of the sprung mass. Although current systems usually adopt larger damping during the expansion phase, it is shown in this work that, for lower frequencies, smaller damping in this phase results in better comfort.

  6. (Development of advanced models of the MCC full expansion (quiet) engine): First quarterly report

    SciTech Connect

    Not Available

    1988-01-01

    This is the first quarterly report to the Department of Energy on the progress associated with the development of advanced models of the MCC full expansion (quiet) engine. These models will be evaluated in successive steps and eventually incorporated into a lawn mower for the purpose of commercializing the engine for small wheeled lawn and garden applications. During the first three months of the program (July 1 thru Sept 30), the Phase I design was basically completed with the exception of some engine/lawn mower interface hardware which will be completed during the final stages of the development program after we have selected a lawn mower deck. Rick Erickson, the design engineer for the program, completed the initial parts drawings utilizing the computer drafting system together with guidance from Fredrick Erickson, the program principal engineer and Jeff Erickson, who is in charge of manufacturing the engines. A miniature copy of these drawings is included in the appendix for your review.

  7. Power Plant Model Validation Tool

    SciTech Connect

    2016-02-12

    The PPMV is used to validate generator model using disturbance recordings. The PPMV tool contains a collection of power plant models and model validation studies, as well as disturbance recordings from a number of historic grid events. The user can import data from a new disturbance into the database, which converts PMU and SCADA data into GE PSLF format, and then run the tool to validate (or invalidate) the model for a specific power plant against its actual performance. The PNNL PPMV tool enables the automation of the process of power plant model validation using disturbance recordings. The tool uses PMU and SCADA measurements as input information. The tool automatically adjusts all required EPCL scripts and interacts with GE PSLF in the batch mode. The main tool features includes: The tool interacts with GE PSLF; The tool uses GE PSLF Play-In Function for generator model validation; Database of projects (model validation studies); Database of the historic events; Database of the power plant; The tool has advanced visualization capabilities; and The tool automatically generates reports

  8. Preliminary design and assessment of a 50,000-BPD coal-to-methanol-to-gasoline plant. Quarterly technical progress report, 1 April 1982-30 June 1982

    SciTech Connect

    Not Available

    1982-01-01

    The technical efforts associated with the Statement of Work for the preliminary design and assessment of a 50,000-BPD Coal-to-Methanol-to-Gasoline Plant continued at an accelerated rate. Physical accomplishment increased from 39.6% (March 1982) to 69.1% (June 1982). All contracts were in place prior to the commencement of this quarter and the only significant contractual action bearing on Statement of Work requirements was DOE's approval of a Grace request for modification of the Dames and Moore Subcontract to recognize certain additions and/or expansions resulting from the scoping meeting process. The narrative of this report discusses progress of work associated with technical activities for both the 50,000-BPD and 12,500-BPD plants. Significant progress in the process and mechanical design was achieved following the receipt of all design packages and data from vendors for incorporation in process design documentation. This information enabled the preparation of all process and utility flow diagrams, plot plans, evaluations, and associated direct capital cost estimates for the 50,000-BPD plant. The basic design of all process units comprising the Gasoline Plant was completed, and engineering efforts directed toward supplying inputs for the development of capital and operating cost estimates and economic assessments. Development of engineering documentation for the 12,500-BPD plant was initiated and progressed significantly during the quarter. Development of capital and operating cost estimates for the smaller plant was also active.

  9. Modeling of solar polygeneration plant

    NASA Astrophysics Data System (ADS)

    Leiva, Roberto; Escobar, Rodrigo; Cardemil, José

    2017-06-01

    In this work, a exergoeconomic analysis of the joint production of electricity, fresh water, cooling and process heat for a simulated concentrated solar power (CSP) based on parabolic trough collector (PTC) with thermal energy storage (TES) and backup energy system (BS), a multi-effect distillation (MED) module, a refrigeration absorption module, and process heat module is carried out. Polygeneration plant is simulated in northern Chile in Crucero with a yearly total DNI of 3,389 kWh/m2/year. The methodology includes designing and modeling a polygeneration plant and applying exergoeconomic evaluations and calculating levelized cost. Solar polygeneration plant is simulated hourly, in a typical meteorological year, for different solar multiple and hour of storage. This study reveals that the total exergy cost rate of products (sum of exergy cost rate of electricity, water, cooling and heat process) is an alternative method to optimize a solar polygeneration plant.

  10. Peierls to superfluid crossover in the one-dimensional, quarter-filled Holstein model.

    PubMed

    Hohenadler, M; Assaad, F F

    2013-01-09

    We use continuous-time quantum Monte Carlo simulations to study retardation effects in the metallic, quarter-filled Holstein model in one dimension. Based on results which include the one- and two-particle spectral functions as well as the optical conductivity, we conclude that with increasing phonon frequency the ground state evolves from one with dominant diagonal order-2k(F) charge correlations-to one with dominant off-diagonal fluctuations, namely s-wave pairing correlations. In the parameter range of this crossover, our numerical results support the existence of a spin gap for all phonon frequencies. The crossover can hence be interpreted in terms of preformed pairs corresponding to bipolarons, which are essentially localized in the Peierls phase, and 'condense' with increasing phonon frequency to generate dominant pairing correlations.

  11. Quarter-filled supersolid and solid phases in the extended Bose-Hubbard model.

    PubMed

    Ng, Kwai-Kong; Chen, Y C; Tzeng, Y C

    2010-05-12

    We numerically study the ground state phase diagram of the two-dimensional hard-core Bose-Hubbard model with nearest-(V(1)) and next-nearest-neighbour (V(2)) repulsions. In particular, we focus on the quarter-filled phases where one supersolid and two solid phases are observed. Using both canonical and grand canonical quantum Monte Carlo (QMC) methods and a mean-field calculation, we provide evidence for the existence of a commensurate supersolid. Despite the two possible diagonal long-range orderings for the solid phase, only one kind of supersolid phase is found to be energetically stable. The competition between the two solid phases manifests itself as a first-order phase transition around 2V(2) ∼ V(1). The change of order parameters as a function of the chemical potential is also presented.

  12. Hydroacoustic Studies Using HydroCAM - Station Centric Integration of Models and Observations Quarterly Report No. 5 October - December 2003

    SciTech Connect

    Upton, Zachary M.; Pulli, Jay J.

    2004-03-29

    OAK-B135 Quarterly Technical Report summarizing BBN's support of the DOE/NNSA GNEM program. This report details BBN's efforts to improve the modeling of explosions and other events underwater and their propagation to hydroacoustic sensor networks. OK to release, no restriction on copyright

  13. BI-GAS pilot plant. Quarterly technical progress report, 1 January 1981-31 March 1981

    SciTech Connect

    Not Available

    1981-01-01

    Test G-16 was conducted on January 20 to 24, 1981, with 58.2 hr of coal feed, 60.5 hr of char feed, and 69.7 hr of char burner firing. During the fuel gas reduction test, it was observed that the plant pressures and temperatures were slightly less steady than during operation with excess fuel gas. The gasifier pressure oscillated plus or minus five psi compared to a normal fluctuation of plus or minus two psi; while the Stage I temperature varied plus or minus 50/sup 0/F compared to plus or minus 20/sup 0/F. Fuel gas was returned to normal flow due to problems with gas washer control and instabilities in char feed. Slag removal from the gasifier was much better during Test G-16 (90%) due to use of the slag breaker, slag agitator, and installation of the grating over both lockhopper legs. Favorable results were obtained during the first test using flocculant addition to the coal fines stream feeding the centrifuge, to aid in solids removal. Installation of the vortex breaker and the drilling of the holes in the lower baffle, to prevent interference with the level control instrumentation, did not improve operation of the gas washer. Test G-16A was conducted on February 23 to March 1, 1981, with 122.0 hr of coal feed, 120.2 hr of char feed, and 133.2 hr of char burner firing. The gasifier was able to be operated stably at an oxygen to fuel gas ratio of two to one in Stage I for a 24-hr period. Testing of the Aurburn flow monitor indicated that this instrument was able to give immediate and consistent responses to changes in char feed valve setting. It will be necessary to make some revisions in the sensor, however, before the monitor can be used to determine flow rate. The modified Kamyr valve successfully controlled char feed through the B leg, with good control occurring between twenty to sixty percent valve position.

  14. Modeling of integrated environmental control systems for coal-fired power plants. Technical progress report, [period ending December 31, 1987

    SciTech Connect

    Rubin, E.S.

    1988-01-01

    This is the first quarterly report of DOE/PETC Contract No. DE-AC22-87PC79864, entitled, ``Modeling of Integrated Environmental Control Systems for Coal-Fired Power Plants.`` Refining, creating, and documenting of computer models concerning coal/flue gas cleaning and desulfurization are discussed. (VC)

  15. Optimization of damping in the passive automotive suspension system with using two quarter-car models

    NASA Astrophysics Data System (ADS)

    Lozia, Z.; Zdanowicz, P.

    2016-09-01

    The paper presents the optimization of damping in the passive suspension system of a motor vehicle moving rectilinearly with a constant speed on a road with rough surface of random irregularities, described according to the ISO classification. Two quarter-car 2DoF models, linear and non-linear, were used; in the latter, nonlinearities of spring characteristics of the suspension system and pneumatic tyres, sliding friction in the suspension system, and wheel lift-off were taken into account. The smoothing properties of vehicle tyres were represented in both models. The calculations were carried out for three roads of different quality, with simulating four vehicle speeds. Statistical measures of vertical vehicle body vibrations and of changes in the vertical tyre/road contact force were used as the criteria of system optimization and model comparison. The design suspension displacement limit was also taken into account. The optimum suspension damping coefficient was determined and the impact of undesirable sliding friction in the suspension system on the calculation results was estimated. The results obtained make it possible to evaluate the impact of the structure and complexity of the model used on the results of the optimization.

  16. Modeling of integrated environmental control systems for coal-fired power plants

    SciTech Connect

    Rubin, E.S.

    1988-06-01

    This is the third quarterly report of DOE Contract No. DE-AC22- 87PC79864, entitled Modeling of Integrated Environmental Control Systems for Coal-Fired Power Plants.'' This report summarizes accomplishments during the period April 1, 1988 to June 30, 1988. Our efforts during the last quarter focused on, (1) completion of a sulfuric acid plant model (used in conjunction with by-product recovery processes for SO{sub 2}/NO{sub x} removal) and, (2) an update the NOXSO process model. Other accomplishments involved revision and expansion of the enthalpy data algorithms used for process energy balances. The sections below present the details of these developments. References are included at the end of each section.

  17. Field Guide to Plant Model Systems.

    PubMed

    Chang, Caren; Bowman, John L; Meyerowitz, Elliot M

    2016-10-06

    For the past several decades, advances in plant development, physiology, cell biology, and genetics have relied heavily on the model (or reference) plant Arabidopsis thaliana. Arabidopsis resembles other plants, including crop plants, in many but by no means all respects. Study of Arabidopsis alone provides little information on the evolutionary history of plants, evolutionary differences between species, plants that survive in different environments, or plants that access nutrients and photosynthesize differently. Empowered by the availability of large-scale sequencing and new technologies for investigating gene function, many new plant models are being proposed and studied.

  18. Establishing the SECME Model in the District of Columbia. Third quarter report, April 1, 1994--June 30, 1994

    SciTech Connect

    Vickers, R.G.

    1995-12-31

    This report contains a description of the planning and activities completed for the third quarter report (April - June 1994) of the 1993-1994 United States Department of Energy/Southeastern Consortium for Minorities in Engineering (SECME) grant for {open_quotes}Establishing the SECME Model in the District of Columbia.{close_quotes} The program continues to have outstanding success in Establishing the SECME Model in the District of Columbia Public Schools. Exhibits of supporting documentation are included.

  19. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model Fourth Quarter 2008

    SciTech Connect

    JH Mather; DA Randall; CJ Flynn

    2008-09-30

    In 2008, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. The first quarter milestone was the initial formulation of the algorithm for retrieval of these properties. The second quarter milestone included the time series of ARM-retrieved cloud properties and a year-long CCPP control simulation. The third quarter milestone included the time series of ARM-retrieved aerosol optical depth and a three-year CCPP control simulation. This final fourth quarter milestone includes the time-series of aerosol and dust properties and a decade-long CCPP control simulation.

  20. Modeling, design, and life performance prediction for energy production from geothermal reservoirs. Quarterly report, January--March 1998

    SciTech Connect

    Swenson, D.

    1998-01-01

    The objective of this project is to maintain and transfer existing Hot Dry Rock two-dimensional fractured reservoir analysis capability to the geothermal industry and to extend the analysis concepts to three dimensions. The project start date was May 22, 1997 and it runs through May 21, 1998. This is the quarterly progress report for January through March of 1998. In this quarter, the primary focus has been on development of the Geocrack3D model, presenting initial results to the industry, and maintenance of Geocrack2D. It is important to emphasize that the modeling is complementary to current industry modeling, in that they focus on the user interface, flow in fractured rock, and the coupled effect of thermal cooling changing fracture aperture.

  1. Plant memory: a tentative model.

    PubMed

    Thellier, M; Lüttge, U

    2013-01-01

    All memory functions have molecular bases, namely in signal reception and transduction, and in storage and recall of information. Thus, at all levels of organisation living organisms have some kind of memory. In plants one may distinguish two types. There are linear pathways from reception of signals and propagation of effectors to a type of memory that may be described by terms such as learning, habituation or priming. There is a storage and recall memory based on a complex network of elements with a high degree of integration and feedback. The most important elements envisaged are calcium waves, epigenetic modifications of DNA and histones, and regulation of timing via a biological clock. Experiments are described that document the occurrence of the two sorts of memory and which show how they can be distinguished. A schematic model of plant memory is derived as emergent from integration of the various modules. Possessing the two forms of memory supports the fitness of plants in response to environmental stimuli and stress.

  2. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model - First Quarter 2008

    SciTech Connect

    JH Mather; D Randall

    2007-12-30

    In 2008, the Atmospheric Radiation Measurement (ARM) program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. The first quarter milestone is ‘initial formulation of the algorithm to produce and make available, new continuous time series of retrieved cloud , aerosol and dust properties, based on results from the ARM Mobile Facility deployment in Niger, Africa. The first quarter milestone has been achieved.

  3. Modeling of integrated environmental control systems for coal-fired power plants

    SciTech Connect

    Rubin, E.S.

    1989-04-01

    This is the sixth quarterly report of DOE Contract No. DE-AC22- 87PC79863, entitled Modeling of Integrated Environmental Control Systems for Coal-Fired Power Plants.'' This report summarizes accomplishments during the period January 1, 1989 to March 31, 1989. Efforts this past quarter focused primarily on the preparation of a computer User's Guide for the Integrated Environmental Control Model (IECM). Drafts of the first two chapters are now complete. These chapters constitute the bulk of this quarterly report. Drafts of the remaining chapters are in preparation, and will appear in a future report this year. We also have been working closely with DOE/PETC to define the computer configuration to be transferred to PETC as a contract deliverable. That process is now complete and the equipment is on order. Delivery of the IECM to PETC is expected during the next calendar quarter. Finally, we are continuing our efforts to develop and refine a number of clean coal technology process models. These efforts will be summarized and reported at a future date.

  4. Mathematical models for plant-herbivore interactions

    USGS Publications Warehouse

    Feng, Zhilan; DeAngelis, Donald L.

    2017-01-01

    Mathematical Models of Plant-Herbivore Interactions addresses mathematical models in the study of practical questions in ecology, particularly factors that affect herbivory, including plant defense, herbivore natural enemies, and adaptive herbivory, as well as the effects of these on plant community dynamics. The result of extensive research on the use of mathematical modeling to investigate the effects of plant defenses on plant-herbivore dynamics, this book describes a toxin-determined functional response model (TDFRM) that helps explains field observations of these interactions. This book is intended for graduate students and researchers interested in mathematical biology and ecology.

  5. Modeling of accelerator systems and experimental verification of Quarter-Wave Resonator steering

    NASA Astrophysics Data System (ADS)

    Benatti, Carla

    Increasingly complicated accelerator systems depend more and more on computing power and computer simulations for their operation as progress in the field has led to cutting-edge advances that require finer control and better understanding to achieve optimal performance. Greater ambitions coupled with the technical complexity of today's state-of-the-art accelerators necessitate corresponding advances in available accelerator modeling resources. Modeling is a critical component of any field of physics, accelerator physics being no exception. It is extremely important to not only understand the basic underlying physics principles but to implement this understanding through the development of relevant modeling tools that provide the ability to investigate and study various complex effects. Moreover, these tools can lead to new insight and applications that facilitate control room operations and enable advances in the field that would not otherwise be possible. The ability to accurately model accelerator systems aids in the successful operation of machines designed specifically to deliver beams to experiments across a wide variety of fields, ranging from material science research to nuclear astrophysics. One such accelerator discussed throughout this work is the ReA facility at the National Superconducting Cyclotron Laboratory (NSCL) which re-accelerates rare isotope beams for nuclear astrophysics experiments. A major component of the ReA facility, as well as the future Facility for Rare Isotope Beams (FRIB) among other accelerators, is the Quarter-Wave Resonator (QWR), a coaxial accelerating cavity convenient for efficient acceleration of low-velocity particles. This device is very important to model accurately as it operates in the critical low-velocity region where the beam's acceleration gains are proportionally larger than they are through the later stages of acceleration. Compounding this matter, QWRs defocus the beam, and are also asymmetric with respect to the

  6. Kinematic and dynamic analysis of the McPherson suspension with a planar quarter-car model

    NASA Astrophysics Data System (ADS)

    Hurel, Jorge; Mandow, Anthony; García-Cerezo, Alfonso

    2013-09-01

    McPherson suspension modelling poses a challenging problem due to its nonlinear asymmetric behaviour. The paper proposes a planar quarter-car analytical model that not only considers vertical motion of the sprung mass (chassis) but also: (i) rotation and translation for the unsprung mass (wheel assembly), (ii) wheel mass and its inertia moment about the longitudinal axis, and (iii) tyre damping and lateral deflection. This kinematic-dynamic model offers a solution to two important shortcomings of the conventional quarter-car model: it accounts for geometry and for tyre modelling. The paper offers a systematic development of the planar model as well as the complete set of mathematical equations. This analytical model can be suitable for fast computation in hardware-in-the-loop applications. Furthermore, a reproducible Simulink implementation is given. The model has been compared with a realistic Adams/View simulation to analyse dynamic behaviour for the jounce and rebound motion of the wheel and two relevant kinematic parameters: camber angle and track width variation.

  7. Acoustic agglomeration of power plant fly ash: Quarterly technical report, 5 November 1986--5 February 1987

    SciTech Connect

    Reethof, G.

    1987-03-20

    High-intensity, high-efficiency sound sources are needed for acoustic agglomeration of particle-laden aerosols in power plant flues and for combustion enhancement. The theory of the linear model is reviewed and show to be in strong disagreement with experimental results. A theoretical study of the sound generation mechanism in sirens is then presented. The various sound attenuation mechanisms are reviewed and a low frequency numerical solution for the frequency response is given which includes arbitrary attenuation, dispersion, horn shape, and mean flow. Next finite-amplitude sound propagation in a horn is studied. Results are presented that agree very well with experimental data. Important nonlinear phenomena such as shock formation, acoustic saturation, and distortion of initially non-sinusoidal finite- amplitude waves are discussed. Finally, a new siren design methodology is presented, including a step-by-step discussion on hot to minimize the acoustic losses. 8 figs.

  8. 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)

  9. (Shippingport Atomic Power Station). Quarterly operating report, third quarter 1980

    SciTech Connect

    Zagorski, J. F.

    1980-01-01

    At the beginning of the third quarter of 1980, the Shippingport Atomic Power Station was operating with the 1A, 1B, 1C, and 1D reactor coolant loops and the 1AC and 1BD purification loops in service. During the quarter, the Station was operated for Duquesne Light Company System grid including base load and swing load operation. Twelve (12) planned swing load operations were performed on the LWBR Core this quarter to complete the LWBR operating plan of fifty (50) during this operating phase. The Station was shutdown on September 12 for the Fall 1980 Shutdown and remained in this mode through the end of the quarter. The LWBR Core has generated 18,297.98 EFPH from start-up through the end of the quarter. There were no radioactive liquid discharges from the Radioactive Waste Processing System to the river this quarter. The radioactive liquid waste effluent line to the river remained blanked off to prevent inadvertent radioactive liquid waste discharges. During the quarter, approximately 0.001 curies of Xe 133 activity were released from the station. The radioactivity released from Shippingport Station is far too small to have any measurable effect on the general background environmental radioactivity outside the plant.

  10. Plant Growth Models Using Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  11. Plant Growth Models Using Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  12. Empty Quarter

    NASA Image and Video Library

    2017-09-27

    Empty Quarter - February 1st, 20003 Description: White pinpricks of cloud cast ebony shadows on the Rub' al Khali, or Empty Quarter, near the border between Saudi Arabia and Yemen. The lines of wind-sculpted sand are characteristic of immense sand deserts, or sand seas, and the Rub' al Khali is the largest desert of this type in the world. A highland ridge is just high enough to disturb the flow of the lines. In the center of that interruption lies the Saudi Arabian town of Sharurah. Credit: USGS/NASA/Landsat 7 To learn more about the Landsat satellite go to: landsat.gsfc.nasa.gov/ NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

  13. Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 2, August--October, 1994

    SciTech Connect

    Rozelle, P.

    1996-01-01

    This report describes the progress made during the second Quarter of a two year project to demonstrate that the air pollution, from a traveling grate stoker being used to heat water at a central heating plant in Krakow Poland, can be reduced significantly by replacing the unwashed, unsized coal now being used with a mechanically cleaned, double sized stoker fuel and by optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost effective and hence be adopted in the other central heating plants in Krakow and indeed throughout Eastern European cities where coal is the primary source of heating fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC a central heating company in Krakow and Naftokrak-Naftobudowa, preparation plant designers and fabricators for this effort. The washability data from a 20mm x 0.5mm size fraction of raw coal from the Staszic Mine were evaluated. The data show that the ash content of this coal can be reduced from 24.4 percent to 6.24 percent by washing in a heavy media cyclone at 1.825 sp.gr.; the actual yield of clean coal would be 76.1 percent. The quest for long-term sources of raw coal to feed the proposed 300 tph stoker coal preparation plant continued throughout the reporting period. Meetings were held with Polish coal preparation equipment suppliers to obtain price and delivery quotations for long lead-time process equipment. Preliminary cost evaluations were the topic of several meetings with financial institutions regarding the cost of producing a quality stoker coal in Poland and for identifying sources of private capital to help cost share the project. The search for markets for surplus production from the new plant continued.

  14. Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles.

    PubMed

    Abid, Haider J; Chen, Jie; Nassar, Ameen A

    2015-01-01

    This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

  15. Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles

    PubMed Central

    Abid, Haider J.; Chen, Jie; Nassar, Ameen A.

    2015-01-01

    This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system. PMID:27351020

  16. Patterns, determinants and models of woody plant diversity in China.

    PubMed

    Wang, Zhiheng; Fang, Jingyun; Tang, Zhiyao; Lin, Xin

    2011-07-22

    What determines large-scale patterns of species richness remains one of the most controversial issues in ecology. Using the distribution maps of 11 405 woody species in China, we compared the effects of habitat heterogeneity, human activities and different aspects of climate, particularly environmental energy, water-energy dynamics and winter frost, and explored how biogeographic affinities (tropical versus temperate) influence richness-climate relationships. We found that the species richness of trees, shrubs, lianas and all woody plants strongly correlated with each other, and more strongly correlated with the species richness of tropical affinity than with that of temperate affinity. The mean temperature of the coldest quarter was the strongest predictor of species richness, and its explanatory power for species richness was significantly higher for tropical affinity than for temperate affinity. These results suggest that the patterns of woody species richness mainly result from the increasing intensity of frost filtering for tropical species from the equator/lowlands towards the poles/highlands, and hence support the freezing-tolerance hypothesis. A model based on these results was developed, which explained 76-85% of species richness variation in China, and reasonably predicted the species richness of woody plants in North America and the Northern Hemisphere.

  17. Thirteen challenges in modelling plant diseases

    USDA-ARS?s Scientific Manuscript database

    The underlying structure of epidemiological models, and the questions that models can be used to address, do not necessarily depend on the identity of the host. This means that certain preoccupations of plant disease modelers are similar to those of modelers of diseases in animals and humans. Howeve...

  18. A pilot plant scale reactor/separator for ethanol from cellulosics. ERIP/DOE quarterly report no. 3 and 4

    SciTech Connect

    Dale, M.C.; Moelhman, M.; Butters, R.

    1998-12-01

    The objective of this project is to develop and demonstrate a continuous, low energy process for the conversion of cellulosics to ethanol. This process involves a pretreatment step followed by enzymatic release of sugars and the consecutive simultaneous saccharification/fermentation (SSF) of cellulose (glucans) followed by hemi-cellulose (pentosans) in a multi-stage continuous stirred reactor separator (CSRS). During quarters 3 and 4, we have completed a literature survey on cellulase production, activated one strain of Trichoderma reesei. We continued developing our proprietary Steep Delignification (SD) process for biomass pretreatment. Some problems with fermentations were traces to bad cellulase enzyme. Using commercial cellulase enzymes from Solvay & Genecor, SSF experiments with wheat straw showed 41 g/L ethanol and free xylose of 20 g/L after completion of the fermentation. From corn stover, we noted 36 g/L ethanol production from the cellulose fraction of the biomass, and 4 g/L free xylose at the completion of the SSF. We also began some work with paper mill sludge as a cellulose source, and in some preliminary experiments obtained 23 g/L ethanol during SSF of the sludge. During year 2, a 130 L process scale unit will be operated to demonstrate the process using straw or cornstalks. Co-sponsors of this project include the Indiana Biomass Grants Program, Bio-Process Innovation.

  19. Model of how plants sense zinc deficiency.

    PubMed

    Assunção, Ana G L; Persson, Daniel P; Husted, Søren; Schjørring, Jan K; Alexander, Ross D; Aarts, Mark G M

    2013-09-01

    Plants are capable of inducing a range of physico-chemical and microbial modifications of the rhizosphere which can mobilize mineral nutrients or prevent toxic elements from entering the roots. Understanding how plants sense and adapt to variations in nutrient availability is essential in order to develop plant-based solutions addressing nutrient-use-efficiency and adaptation to nutrient-limited or -toxic soils. Recently two transcription factors of the bZIP family (basic-region leucine zipper) have been identified in Arabidopsis and shown to be pivotal in the adaptation response to zinc deficiency. They represent not only the first regulators of zinc homeostasis identified in plants, but also a very promising starting-point that can provide new insights into the molecular basis of how plants sense and adapt to the stress of zinc deficiency. Considering the available information thus far we propose in this review a putative model of how plants sense zinc deficiency.

  20. A Comparison of Model Short-Range Forecasts and the ARM Microbase Data Fourth Quarter ARM Science Metric

    SciTech Connect

    Hnilo, J.

    2006-09-19

    For the fourth quarter ARM metric we will make use of new liquid water data that has become available, and called the “Microbase” value added product (referred to as OBS, within the text) at three sites: the North Slope of Alaska (NSA), Tropical West Pacific (TWP) and the Southern Great Plains (SGP) and compare these observations to model forecast data. Two time periods will be analyzed March 2000 for the SGP and October 2004 for both TWP and NSA. The Microbase data have been averaged to 35 pressure levels (e.g., from 1000hPa to 100hPa at 25hPa increments) and time averaged to 3hourly data for direct comparison to our model output.

  1. Association of quarterly average achieved hematocrit with mortality in dialysis patients: a time-dependent comorbidity-adjusted model.

    PubMed

    Messana, Joseph M; Chuang, Chien-Chia; Turenne, Marc; Wheeler, John; Turner, Jason; Sleeman, Kathryn; Tedeschi, Philip; Hirth, Richard

    2009-03-01

    Recent publications suggest that increased mortality is associated with high hematocrit targets in erythropoietin-stimulating agent-treated patients with chronic kidney disease. We aim to further inform the debate about optimal hematocrit targets, advancing the hypothesis that the current hematocrit target may not optimize the survival of patients with end-stage renal disease. Cross-sectional observational study. Medicare dialysis patients from 2002 to 2004 (n = 393,967). Quarterly average hematocrit and erythropoietin alfa (EPO) dose. Mortality hazard ratios from time-dependent Cox proportional hazard models, adjusting for comorbidities. N = 2,712,197 patient-facility quarters. During the study, 100,086 deaths were identified. Percentages of patient quarters within each hematocrit category: hematocrit less than 27% (2.0%), 27% to 28.49% (1.7%), 28.5% to 29.9% (2.9%), 30% to 31.49% (5.2%), 31.5% to 32.99% (9.0%), 33% to 34.49% (14.9%), 34.5% to 35.99% (19.2%), 36% to 37.49% (18.0%), 37.5% to 38.99% (12.0%), 39% to 40.49% (6.4%), 40.5% to 41.99% (3.0%), and 42% or greater (3.1%). Mortality hazard ratios from the fully adjusted model: hematocrit less than 27% (3.11), 27% to 28.49% (2.60), 28.5% to 29.9% (2.14), 30% to 31.49% (1.80), 31.5% to 32.99% (1.44), 33% to 34.49% (1.17), 34.5% to 35.99% (reference), 36% to 37.49% (0.98), 37.5% to 38.99% (1.01), 39% to 40.49% (1.13), 40.5% to 41.99% (1.32), and 42% or greater (1.57). First, potential confounding by indication related to associations between underlying illness and mortality, anemia, and EPO responsiveness. Second, Medicare claims data reflect a range of conditions and degrees of severity not easily translated into the clinical context. Third, for Medicare claims, EPO reporting is not required if EPO is not billed. Greater than 95% of "missing hematocrit" quarters are "EPO = 0" patient quarters. Interpretation of results for the missing hematocrit and EPO = 0 use categories is complicated by data source

  2. SRC-1 quarterly technical report, April-June 1981. [Review of analytical methods needed in SRC Demonstration plants

    SciTech Connect

    Not Available

    1981-10-01

    Twenty-three papers involving the design, materials and equipment for the SRC-1 demonstration coal liquefaction plant near Newman, Daviess County, Kentucky, have been entered individually into EDB and ERA. A number of the papers deal also with the analytical methodology required for the plant, including a rather detailed evaluation of the accuracy requirements and careful evaluation of several methods such as gas chromatography, mass spectroscopy, nuclear magnetic resonance, etc. Flexibility of design is stressed so that products can be optimized for the market and charged if the market requires different products. (LTN)

  3. Sour gas plant subsurface remediation technology research and demonstration project. Quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Stepan, D.J.; Kuehnel, V.

    1994-04-01

    Recognizing the potential impacts of sour gas plant operations on the subsurface environment, the Canadian Association of Petroleum Producers (CAPP), formerly the Canadian Petroleum Association (CPA), and Environment Canada initiated a multiphase study focusing on research related to the development and demonstration of remedial technologies for soil and groundwater contamination at these facilities. The first phase of the project was completed in 1990, and consisted of a comprehensive review of all soil and groundwater monitoring data submitted to Alberta Environment by sour gas plants in accordance with the Clean Water Act (1980). That review indicated that all but one of the 45 sour gas plants for which data were available exhibited some form of impact on soil and groundwater quality. The study identified the most frequently occurring contamination situations at the sites and classified them by source, type of contaminant, and the hydrogeological characteristics of the contaminated setting. The project steering committee subsequently selected the Strachan Gas Plant, located near Rocky Mountain House, Alberta, Canada, as a field research and remediation technology demonstration site. Research to be performed under this agreement is for activities in the areas of soil vapor extraction (SVE), bioventing, and bioremediation, all focusing on residual contamination in the unsaturated, or vadose, zone at the site, as well as evaluations of biological treatment of groundwater and ex situ soil remediation using solvent extraction in conjunction with photooxidation, solvent extraction in conjunction with microwave irradiation, and low-temperature thermal desorption.

  4. Developmental Stages in Dynamic Plant Growth Models

    NASA Astrophysics Data System (ADS)

    Maclean, Heather; Dochain, Denis; Waters, Geoff; Stasiak, Michael; Dixon, Mike; Van Der Straeten, Dominique

    2011-09-01

    During the growth of red beet plants in a closed environment plant growth chamber, a change in metabolism was observed (decreasing photosynthetic quotient) which was not predicted by a previously developed simple dynamic model of photosynthesis and respiration reactions. The incorporation of developmental stages into the model allowed for the representation of this change in metabolism without adding unnecessary complexity. Developmental stages were implemented by dividing the model into two successive sub-models with independent yields. The transition between the phases was detected based on online measurements. Results showed an accurate prediction of carbon dioxide and oxygen fluxes.

  5. Models of plant populations and communities

    SciTech Connect

    Huston, M.

    1990-01-01

    This document is the overview of the plant section in the book, {und Individual-Based Models and Approaches in Ecology}. A brief description of each of the chapters is provided, as well as a comparison of the models presented in each chapter. Four of the six chapters deal with single species interactions, one dealt with a two species system (plants and pollinators) and one deals with multispecies interactions. Both i-state distribution models and i-state configuration models are discussed. (MHB)

  6. In-plant testing of a novel coal cleaning circuit using advanced technologies, Quarterly report, March 1 - May 31, 1996

    SciTech Connect

    Honaker, R.Q.; Reed, S.; Mohanty, M.K.

    1996-12-31

    Research conducted at Southern Illinois University at Carbondale over the past two years has identified highly efficient methods for treating fine coal (i.e., -28 mesh). In this study, a circuit comprised of the three advanced fine coal cleaning technologies is being tested in an operating preparation plant to evaluate circuit performance and to compare the performance with the current technologies used to treat -16 mesh fine coal. The circuit integrated a Floatex hydrosizer, a Falcon concentrator and a Jameson froth flotation cell. The Floatex hydrosizer is being used as a primary cleaner for the nominally -16 mesh Illinois No. 5 fine coal circuit feed. The overflow of the Floatex is screened at 48 mesh using a Sizetec vibratory screen to produce a clean coal product from the screen overflow. The screen overflow is further treated by the Falcon and Jameson Cell. During this reporting period, tests were initiated on the fine coal circuit installed at the Kerr-McGee Galatia preparation plant. The circuit was found to reduce both the ash content and the pyritic sulfur content. Additional in-plant circuitry tests are ongoing.

  7. Tertiary model of a plant cellulose synthase

    PubMed Central

    Sethaphong, Latsavongsakda; Haigler, Candace H.; Kubicki, James D.; Zimmer, Jochen; Bonetta, Dario; DeBolt, Seth; Yingling, Yaroslava G.

    2013-01-01

    A 3D atomistic model of a plant cellulose synthase (CESA) has remained elusive despite over forty years of experimental effort. Here, we report a computationally predicted 3D structure of 506 amino acids of cotton CESA within the cytosolic region. Comparison of the predicted plant CESA structure with the solved structure of a bacterial cellulose-synthesizing protein validates the overall fold of the modeled glycosyltransferase (GT) domain. The coaligned plant and bacterial GT domains share a six-stranded β-sheet, five α-helices, and conserved motifs similar to those required for catalysis in other GT-2 glycosyltransferases. Extending beyond the cross-kingdom similarities related to cellulose polymerization, the predicted structure of cotton CESA reveals that plant-specific modules (plant-conserved region and class-specific region) fold into distinct subdomains on the periphery of the catalytic region. Computational results support the importance of the plant-conserved region and/or class-specific region in CESA oligomerization to form the multimeric cellulose–synthesis complexes that are characteristic of plants. Relatively high sequence conservation between plant CESAs allowed mapping of known mutations and two previously undescribed mutations that perturb cellulose synthesis in Arabidopsis thaliana to their analogous positions in the modeled structure. Most of these mutation sites are near the predicted catalytic region, and the confluence of other mutation sites supports the existence of previously undefined functional nodes within the catalytic core of CESA. Overall, the predicted tertiary structure provides a platform for the biochemical engineering of plant CESAs. PMID:23592721

  8. An analytical model of memristors in plants.

    PubMed

    Markin, Vladislav S; Volkov, Alexander G; Chua, Leon

    2014-01-01

    The memristor, a resistor with memory, was postulated by Chua in 1971 and the first solid-state memristor was built in 2008. Recently, we found memristors in vivo in plants. Here we propose a simple analytical model of 2 types of memristors that can be found within plants. The electrostimulation of plants by bipolar periodic waves induces electrical responses in the Aloe vera and Mimosa pudica with fingerprints of memristors. Memristive properties of the Aloe vera and Mimosa pudica are linked to the properties of voltage gated K(+) ion channels. The potassium channel blocker TEACl transform plant memristors to conventional resistors. The analytical model of a memristor with a capacitor connected in parallel exhibits different characteristic behavior at low and high frequency of applied voltage, which is the same as experimental data obtained by cyclic voltammetry in vivo.

  9. An analytical model of memristors in plants

    PubMed Central

    Markin, Vladislav S; Volkov, Alexander G; Chua, Leon

    2014-01-01

    The memristor, a resistor with memory, was postulated by Chua in 1971 and the first solid-state memristor was built in 2008. Recently, we found memristors in vivo in plants. Here we propose a simple analytical model of 2 types of memristors that can be found within plants. The electrostimulation of plants by bipolar periodic waves induces electrical responses in the Aloe vera and Mimosa pudica with fingerprints of memristors. Memristive properties of the Aloe vera and Mimosa pudica are linked to the properties of voltage gated K+ ion channels. The potassium channel blocker TEACl transform plant memristors to conventional resistors. The analytical model of a memristor with a capacitor connected in parallel exhibits different characteristic behavior at low and high frequency of applied voltage, which is the same as experimental data obtained by cyclic voltammetry in vivo. PMID:25482769

  10. Estimating solar radiation for plant simulation models

    NASA Technical Reports Server (NTRS)

    Hodges, T.; French, V.; Leduc, S.

    1985-01-01

    Five algorithms producing daily solar radiation surrogates using daily temperatures and rainfall were evaluated using measured solar radiation data for seven U.S. locations. The algorithms were compared both in terms of accuracy of daily solar radiation estimates and terms of response when used in a plant growth simulation model (CERES-wheat). Requirements for accuracy of solar radiation for plant growth simulation models are discussed. One algorithm is recommended as being best suited for use in these models when neither measured nor satellite estimated solar radiation values are available.

  11. Sampling results, DNAPL monitoring well GW-727, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Quarterly report, 1995

    SciTech Connect

    1996-05-01

    In January 1990, dense, non aqueous phase liquids (DNAPLs) were discovered at a depth of approximately 274 feet below ground surface along the southern border of the Y-12 Plant Burial Grounds. Immediately after the discovery, an investigation was conducted to assess the occurrence of DNAPL at the site and to make recommendations for further action. A major task in the work plan calls for the construction and installation of five multiport wells. This report summarizes purging and sampling activities for one of these multiport wells, GW-727, and presents analytical results for GW- 727. This report summarizes purging and sampling activities for GW-727 and presents analytical results for GW-727.

  12. In-plant testing of microbubble column flotation. Third quarter technical progress report, April 1, 1990--June 30, 1990

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1990-12-31

    During the past year, a joint project between the US Department of Energy (DOE), the Virginia Center for Coal and Minerals Processing (VCCMP) and the Shell Mining Corporation (SMC) was initiated to implement the testing of a full-scale microbubble flotation column. The work is being carried out at the Marrowbone Preparation Plant, located near Naugatuck in southwestern West Virginia. The primary objective of this effort was to determine the feasibility of using microbubble column flotation for the recovery of coal fines from a classifying cyclone overflow stream that is presently being discarded as refuse.

  13. Plant Growth Modelling and Applications: The Increasing Importance of Plant Architecture in Growth Models

    PubMed Central

    Fourcaud, Thierry; Zhang, Xiaopeng; Stokes, Alexia; Lambers, Hans; Körner, Christian

    2008-01-01

    Background Modelling plant growth allows us to test hypotheses and carry out virtual experiments concerning plant growth processes that could otherwise take years in field conditions. The visualization of growth simulations allows us to see directly and vividly the outcome of a given model and provides us with an instructive tool useful for agronomists and foresters, as well as for teaching. Functional–structural (FS) plant growth models are nowadays particularly important for integrating biological processes with environmental conditions in 3-D virtual plants, and provide the basis for more advanced research in plant sciences. Scope In this viewpoint paper, we ask the following questions. Are we modelling the correct processes that drive plant growth, and is growth driven mostly by sink or source activity? In current models, is the importance of soil resources (nutrients, water, temperature and their interaction with meristematic activity) considered adequately? Do classic models account for architectural adjustment as well as integrating the fundamental principles of development? Whilst answering these questions with the available data in the literature, we put forward the opinion that plant architecture and sink activity must be pushed to the centre of plant growth models. In natural conditions, sinks will more often drive growth than source activity, because sink activity is often controlled by finite soil resources or developmental constraints. PMA06 This viewpoint paper also serves as an introduction to this Special Issue devoted to plant growth modelling, which includes new research covering areas stretching from cell growth to biomechanics. All papers were presented at the Second International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA06), held in Beijing, China, from 13–17 November, 2006. Although a large number of papers are devoted to FS models of agricultural and forest crop species, physiological and genetic

  14. Development of molten carbonate fuel cell power plant technology. Quarterly technical progress report No. 1, October 1, 1979-December 31, 1979

    SciTech Connect

    Healy, H. C.; Sanderson, R. A.; Wertheim, R. J.; Farris, P. F.; Mientek, A. P.; Nickols, R. C.; Katz, M.; Iczkowski, R. P.; Fredley, R. R.; Stewart, R. C.; Kunz, H. R.; Gruver, G. A.; Bregoli, L. J.; Smith, S. W.; Steuernagel, W. H.; Szymanski, S. T.

    1980-03-01

    The overall objective of this 29-month program is to develop and verify the design of a prototype molten carbonate fuel cell stack which meets the requirements of 1990's competitive coal-fired electrical utility central station or industrial cogeneration power plants. During the first quarter, effort was initiated in all four major task areas: Task 1 - system studies to define the reference power plant design; Task 2 - cell and stack design, development and verification; Task 3 - preparation for fabrication and testing of the full-scale prototype stack; and Task-4 developing the capability for operation of stacks on coal-derived gas. In the system study task, a study baseline fuel cell system and module configuration were established. Studies to determine user requirements and to characterize the fuel cell power block and coal gasifier subsystems were initiated. Cell stack design was initiated with completion of preliminary design requirements for the cell cathodes. Laboratory tests were also initiated to identify alternative materials for separator plates, reactant manifold seals, and electrolyte tile fillers. A mechanical tape casting technique for producing 18 x 24 inch sheets of electrolyte matrix tape was successfully demonstrated in Task 3. In Task 4, theoretical and experimental studies were initiated to define the effects of known sulfur contaminants on cell performance. A literature survey was initiated to identify other possible contaminants. Planning and design efforts for construction of a mobile cell test unit were initiated. The mobile unit will be used to verify the molten carbonate cell's ability to operate on gasified coal by tests at a gasifier site.

  15. Measurement and modeling of advanced coal conversion processes. Twenty-second quarterly report, January 2, 1992--March 31, 1992

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S.

    1992-12-01

    The objectives of this proposed study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. This report describes progress during twenty second quarter of the program. Specifically, the paper discusses progress in three task areas: (1) Submodel development and evaluation: coal to char chemistry submodel; fundamental high-pressure reaction rate data; secondary reaction of pyrolysis product and burnout submodels; ash physics and chemistry submodel; large particle submodels; large char particle oxidation at high pressures; and SO{sub x}-NO{sub x} submodel development and evaluation; (2) Comprehensive model development and evaluation: integration of advanced submodels into entrained-flow code, with evaluation and documentation; comprehensive fixed-bed modeling review, development evaluation and implementation; and generalized fuels feedstock submodel; and (3) Application of integrated codes: application of generalized pulverized coal comprehensive code and application of fixed-bed code.

  16. Modeling Production Plant Forming Processes

    SciTech Connect

    Rhee, M; Becker, R; Couch, R; Li, M

    2004-09-22

    Engineering has simulation tools and experience in modeling forming processes. Y-12 personnel have expressed interest in validating our tools and experience against their manufacturing process activities such as rolling, casting, and forging etc. We have demonstrated numerical capabilities in a collaborative DOE/OIT project with ALCOA that is nearing successful completion. The goal was to use ALE3D to model Alcoa's slab rolling process in order to demonstrate a computational tool that would allow Alcoa to define a rolling schedule that would minimize the probability of ingot fracture, thus reducing waste and energy consumption. It is intended to lead to long-term collaboration with Y-12 and perhaps involvement with other components of the weapons production complex. Using simulations to aid in design of forming processes can: decrease time to production; reduce forming trials and associated expenses; and guide development of products with greater uniformity and less scrap.

  17. Safeguards and security modeling for electrochemical plants

    SciTech Connect

    Cipiti, B.B.; Duran, F.A.; Mendoza, L.A.; Parks, M.J.; Dominguez, D.; Le, T.D.

    2013-07-01

    Safeguards and security design for reprocessing plants can lead to excessive costs if not incorporated early in the design process. The design for electrochemical plants is somewhat uncertain since these plants have not been built at a commercial scale in the past. The Separation and Safeguards Performance Model (SSPM), developed at Sandia National Laboratories, has been used for safeguards design and evaluation for multiple reprocessing plant types. The SSPM includes the following capabilities: -) spent fuel source term library, -) mass tracking of elements 1-99 and bulk solid/liquids, -) tracking of heat load and activity, -) customisable measurement points, -) automated calculation of ID and error propagation, -) alarm conditions and statistical tests, and -) user-defined diversion scenarios. Materials accountancy and process monitoring data can provide more timely detection of material loss specifically to protect against the insider threat. While the SSPM is capable of determining detection probabilities and examining detection times for material loss scenarios, it does not model the operations or spatial effects for a plant design. The STAGE software was chosen to model the physical protection system. STAGE provides a framework to create end-to-end scalable force-on-force combat simulations. It allows for a complete 3D model of a facility to be designed along with the design of physical protection elements. This software, then, can be used to model operations and response for various material loss scenarios. The future integration of the SSPM model data with the STAGE software will provide a more complete analysis of diversion scenarios to assist plant designers.

  18. Short-term energy outlook: Quarterly projections. Second quarter 1995

    SciTech Connect

    1995-05-02

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent projections with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the second quarter of 1995 through the fourth quarter of 1996. Values for the first quarter of 1995, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled into the second quarter 1995 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service.

  19. Short-term energy outlook. Quarterly projections, third quarter 1996

    SciTech Connect

    1996-07-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in January, April, July, and October in the Outlook. The forecast period for this issue of the Outlook extends from the third quarter of 1996 through the fourth quarter of 1997. Values for the second quarter of 1996, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled in the third quarter 1996 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service.

  20. A continuous growth model for plant tissue

    NASA Astrophysics Data System (ADS)

    Bozorg, Behruz; Krupinski, Pawel; Jönsson, Henrik

    2016-12-01

    Morphogenesis in plants and animals involves large irreversible deformations. In plants, the response of the cell wall material to internal and external forces is determined by its mechanical properties. An appropriate model for plant tissue growth must include key features such as anisotropic and heterogeneous elasticity and cell dependent evaluation of mechanical variables such as turgor pressure, stress and strain. In addition, a growth model needs to cope with cell divisions as a necessary part of the growth process. Here we develop such a growth model, which is capable of employing not only mechanical signals but also morphogen signals for regulating growth. The model is based on a continuous equation for updating the resting configuration of the tissue. Simultaneously, material properties can be updated at a different time scale. We test the stability of our model by measuring convergence of growth results for a tissue under the same mechanical and material conditions but with different spatial discretization. The model is able to maintain a strain field in the tissue during re-meshing, which is of particular importance for modeling cell division. We confirm the accuracy of our estimations in two and three-dimensional simulations, and show that residual stresses are less prominent if strain or stress is included as input signal to growth. The approach results in a model implementation that can be used to compare different growth hypotheses, while keeping residual stresses and other mechanical variables updated and available for feeding back to the growth and material properties.

  1. Plant bioclimatic models in climate change research.

    PubMed

    Chiou, Chyi-Rong; Hsieh, Tung-Yu; Chien, Chang-Chi

    2015-12-01

    Bioclimatics is an ancient science that was once neglected by many ecologists. However, as climate changes have attracted increasing attention, scientists have reevaluated the relevance of bioclimatology and it has thus become essential for exploring climate changes. Because of the rapidly growing importance of bioclimatic models in climate change studies, we evaluated factors that influence plant bioclimatology, constructed and developed bioclimatic models, and assessed the precautionary effects of the application of the models. The findings obtained by sequentially reviewing the development history and importance of bioclimatic models in climate change studies can be used to enhance the knowledge of bioclimatic models and strengthen their ability to apply them. Consequently, bioclimatic models can be used as a powerful tool and reference in decision-making responses to future climate changes. The objectives of this study were to (1) understand how climatic factors affect plants; (2) describe the sources, construction principles, and development of early plant bioclimatic models (PBMs); and (3) summarize the recent applications of PBMs in climate change research.

  2. Gas Centrifuge Enrichment Plant Safeguards System Modeling

    SciTech Connect

    Elayat, H A; O'Connell, W J; Boyer, B D

    2006-06-05

    The U.S. Department of Energy (DOE) is interested in developing tools and methods for potential U.S. use in designing and evaluating safeguards systems used in enrichment facilities. This research focuses on analyzing the effectiveness of the safeguards in protecting against the range of safeguards concerns for enrichment plants, including diversion of attractive material and unauthorized modes of use. We developed an Extend simulation model for a generic medium-sized centrifuge enrichment plant. We modeled the material flow in normal operation, plant operational upset modes, and selected diversion scenarios, for selected safeguards systems. Simulation modeling is used to analyze both authorized and unauthorized use of a plant and the flow of safeguards information. Simulation tracks the movement of materials and isotopes, identifies the signatures of unauthorized use, tracks the flow and compilation of safeguards data, and evaluates the effectiveness of the safeguards system in detecting misuse signatures. The simulation model developed could be of use to the International Atomic Energy Agency IAEA, enabling the IAEA to observe and draw conclusions that uranium enrichment facilities are being used only within authorized limits for peaceful uses of nuclear energy. It will evaluate improved approaches to nonproliferation concerns, facilitating deployment of enhanced and cost-effective safeguards systems for an important part of the nuclear power fuel cycle.

  3. Establishing the SECME Model in the District of Columbia. Quarterly report, September 1, 1993--December 31, 1993

    SciTech Connect

    Not Available

    1993-12-31

    Technical progress and Federal Cash Transaction reports are presented for the first quarter. The work has been valuable in providing opportunities for greater academic achievement in mathematics and science for minority students in the District of Columbia.

  4. Synthesis of a naphthalene-hydroxynaphthalene polymer model compound. Quarterly report, June 13, 1990--September 12, 1990

    SciTech Connect

    Kwong, C.D.

    1990-10-09

    This goal is to synthesize a new naphthalene hydroxynaphthalene polymer model compound for use in coal combustion studies. na effort will also require the development of a synthetic procedure to synthesize this compound since it is unreported. As a result of our synthesis efforts, a number of potential precursors and Area`s Analytical Section for characterization and identification. The synthesis of the pre-Bakefite intermediate has been identified as being key to the evaluation of our synthetic approach to the target compound. During this quarter, we have been reevaluating our synthetic approach while we have begun trying to synthesize this compound. As a result of our reevaluation, we also have been considering slightly modified target compounds which might be obtained by more direct routes or from commercially available materials. We also targeted simplified intermediates which would expedite our evaluation of the feasibility of the Bakelite process for the final polymerization, the key step of our suggested scheme. The results of our simplified model compound will also provide data to help us determine any modifications that will be required.

  5. Spin, charge, and single-particle spectral functions of the one-dimensional quarter filled Holstein model

    NASA Astrophysics Data System (ADS)

    Assaad, F. F.

    2008-10-01

    We use a recently developed extension of the weak-coupling diagrammatic determinantal quantum Monte Carlo method to investigate the spin, charge, and single-particle spectral functions of the one-dimensional quarter filled Holstein model with phonon frequency ω0=0.1t . As a function of the dimensionless electron-phonon coupling we observe a transition from a Luttinger to a Luther-Emery liquid with dominant 2kf charge fluctuations. Emphasis is placed on the temperature dependence of the single-particle spectral function. At high temperatures and in both phases it is well accounted for within a self-consistent Born approximation. In the low-temperature Luttinger liquid phase we observe features that compare favorably with a bosonization approach retaining only forward scattering. In the Luther-Emery phase, the spectral function at low temperatures shows a quasiparticle gap that matches half the spin gap, whereas at temperatures above which this quasiparticle gap closes characteristic features of the Luttinger liquid model are apparent. Our results are based on lattice simulations on chains up to L=20 for two-particle properties and on cluster dynamical mean-field theory calculations with clusters up to 12 sites for the single-particle spectral function.

  6. Putting the Plants Back into Plant Ecology: Six Pragmatic Models for Understanding and Conserving Plant Diversity

    PubMed Central

    KEDDY, PAUL

    2005-01-01

    • Background There is a compelling need to protect natural plant communities and restore them in degraded landscapes. Activities must be guided by sound scientific principles, practical conservation tools, and clear priorities. With perhaps one-third of the world's flora facing extinction, scientists and conservation managers will need to work rapidly and collaboratively, recognizing each other's strengths and limitations. As a guide to assist managers in maintaining plant diversity, six pragmatic models are introduced that are already available. Although theoretical models continue to receive far more space and headlines in scientific journals, more managers need to understand that pragmatic, rather than theoretical, models have the most promise for yielding results that can be applied immediately to plant communities. • Six Pragmatic Models For each model, key citations and an array of examples are provided, with particular emphasis on wetlands, since ‘wet and wild’ was my assigned theme for the Botanical Society of America in 2003. My own work may seem rather prominent, but the application and refinement of these models has been a theme for me and my many students over decades. The following models are reviewed: (1) species–area: larger areas usually contain more species; (2) species–biomass: plant diversity is maximized at intermediate levels of biomass; (3) centrifugal organization: multiple intersecting environmental gradients maintain regional landscape biodiversity; (4) species–frequency: a few species are frequent while most are infrequent; (5) competitive hierarchies: in the absence of constraints, large canopy-forming species dominate patches of landscape, reducing biological diversity; and (6) intermediate disturbance: perturbations such as water level fluctuations, fire and grazing are essential for maintaining plant diversity. • Conclusions The good news is that managers faced with protecting or restoring landscapes already have this

  7. Plant adaptive behaviour in hydrological models (Invited)

    NASA Astrophysics Data System (ADS)

    van der Ploeg, M. J.; Teuling, R.

    2013-12-01

    Models that will be able to cope with future precipitation and evaporation regimes need a solid base that describes the essence of the processes involved [1]. Micro-behaviour in the soil-vegetation-atmosphere system may have a large impact on patterns emerging at larger scales. A complicating factor in the micro-behaviour is the constant interaction between vegetation and geology in which water plays a key role. The resilience of the coupled vegetation-soil system critically depends on its sensitivity to environmental changes. As a result of environmental changes vegetation may wither and die, but such environmental changes may also trigger gene adaptation. Constant exposure to environmental stresses, biotic or abiotic, influences plant physiology, gene adaptations, and flexibility in gene adaptation [2-6]. Gene expression as a result of different environmental conditions may profoundly impact drought responses across the same plant species. Differences in response to an environmental stress, has consequences for the way species are currently being treated in models (single plant to global scale). In particular, model parameters that control root water uptake and plant transpiration are generally assumed to be a property of the plant functional type. Assigning plant functional types does not allow for local plant adaptation to be reflected in the model parameters, nor does it allow for correlations that might exist between root parameters and soil type. Models potentially provide a means to link root water uptake and transport to large scale processes (e.g. Rosnay and Polcher 1998, Feddes et al. 2001, Jung 2010), especially when powered with an integrated hydrological, ecological and physiological base. We explore the experimental evidence from natural vegetation to formulate possible alternative modeling concepts. [1] Seibert, J. 2000. Multi-criteria calibration of a conceptual runoff model using a genetic algorithm. Hydrology and Earth System Sciences 4(2): 215

  8. Coal gasification. Quarterly report, January-March 1979. [US DOE supported

    SciTech Connect

    1980-01-01

    Progress in DOE-supported coal gasification pilot plant projects is reported: company, location, contract number, funding, process description, history and progress in the current quarter. Two support projects are discussed: preparation of a technical data book and mathematical modeling of gasification reactors. (LTN)

  9. A model for plant lighting system selection

    NASA Technical Reports Server (NTRS)

    Ciolkosz, D. E.; Albright, L. D.; Sager, J. C.; Langhans, R. W.

    2002-01-01

    A decision model is presented that compares lighting systems for a plant growth scenario and chooses the most appropriate system from a given set of possible choices. The model utilizes a Multiple Attribute Utility Theory approach, and incorporates expert input and performance simulations to calculate a utility value for each lighting system being considered. The system with the highest utility is deemed the most appropriate system. The model was applied to a greenhouse scenario, and analyses were conducted to test the model's output for validity. Parameter variation indicates that the model performed as expected. Analysis of model output indicates that differences in utility among the candidate lighting systems were sufficiently large to give confidence that the model's order of selection was valid.

  10. Short-term energy outlook: Quarterly projections, fourth quarter 1997

    SciTech Connect

    1997-10-14

    The Energy Information Administration (EIA) prepares quarterly short-term energy supply, demand, and price projections for printed publication in January, April, July, and October in the Short-Term Energy Outlook. The details of these projections, as well as monthly updates on or about the 6th of each interim month, are available on the internet at: www.eia.doe.gov/emeu/steo/pub/contents.html. The forecast period for this issue of the Outlook extends from the fourth quarter of 1997 through the fourth quarter of 1998. Values for the fourth quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the fourth quarter 1997 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. 19 tabs.

  11. Quarterly coal report, January--March 1993

    SciTech Connect

    Not Available

    1993-08-20

    The United States produced 242 million short tons of coal in the first quarter of 1993, a decrease of 6 percent (14 million short tons) from the amount produced during the first quarter of 1992. The decrease was due to a decline in production east of the Mississippi River. All major coal-producing States in this region had lower coal production levels led by West Virginia, which produced 5 million short tons less coal. The principal reasons for the overall drop in coal output compared to a year earlier were: A decrease in demand for US coal in foreign markets; a slower rate of producer/distributor stock build-up; and a drawn-down of electric utility coal stocks. Distribution of US coal in the first quarter of 1993 was 10 million short tons lower than in the first quarter of 1992, with 5 million short tons less distributed to both electric utilities and overseas markets. The average price of coal delivered to electric utilities during the first quarter of 1993 was $28.65 per short ton, the lowest value since the first quarter of 1980. Coal consumption in the first quarter of 1993 was 230 million short tons, 4 percent higher than in the first quarter of 1992, due primarily to a 5-percent increase in consumption at electric utility plants. Total consumer stocks, at 153 million short tons, and electric utility stocks, at 144 million short tons, were at their lowest quarterly level since the end of 1989. US. coal exports totaled 19 million short tons, 6 million short tons less than in the first quarter of 1992, and the lowest quarterly level since 1988. The decline was primarily due to a 1-million-short-ton drop in exports to each of the following destinations: Italy, France, Belgium and Luxembourg, and Canada.

  12. Non-dimensionalised closed-form parametric analysis of semi-active vehicle suspensions using a quarter-car model

    NASA Astrophysics Data System (ADS)

    Ahmadian, Mehdi; Blanchard, Emmanuel

    2011-02-01

    This article provides a non-dimensionalised closed-form analysis of semi-active vehicle suspensions, using a quarter-car model. The derivation of the closed-form solutions for three indices that can be used for ride comfort, vehicle handling, and stability are presented based on non-dimensionalised suspension parameters. The behaviour of semi-active vehicle suspensions is evaluated using skyhook, groundhook, and hybrid control policies, and compared with passive suspensions. The relationship between vibration isolation, suspension deflection, and road holding is studied, using three performance indices based on the mean square of the sprung mass acceleration, rattle space, and tyre deflection, respectively. The results of the study indicate that the hybrid control policy yields significantly better comfort than a passive suspension, without reducing the road-holding quality or increasing the suspension displacement for typical passenger cars. The results also indicate that for typical passenger cars, the hybrid control policy results in a better compromise between comfort, road holding and suspension travel requirements than both the skyhook and groundhook control methods.

  13. A Quarter-Century of the Transactional Model: How Have Things Changed?

    ERIC Educational Resources Information Center

    Sameroff, Arnold J.; MacKenzie, Michael J.

    2003-01-01

    In this article, the creator of the transactional model and a colleague give an overview of how the model emerged as well as its principal elements. For most of the 20th century, scientists believed that brain damage was the cause of a child's cognitive, social, or emotional problems. Later, researchers found that babies were likely to have…

  14. A model of plant canopy polarization

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.

    1980-01-01

    A model for the amount of linearly polarized light reflected by the shiny leaves of grain crops is based on the morphological and phenological characteristics of the plant canopy and upon the Fresnel equations which describe the light reflection process at the smooth boundary separating two dielectrics. The theory used demonstrates that, potentially, measurements of the linearly polarized light from a crop canopy may be used as an additional feature to discriminate between crops such as wheat and barley, two crops which are so spectrally similar that they are misclassified with unacceptable frequency. Examination of the model suggests that, potentially, satellite polarization measurements may be used to monitor crop development stage, leaf water content, leaf area index, hail damage, and certain plant diseases. The information content of these measurements is needed to evaluate the proposed polarization sensor for the satellite-borne multispectral resource sampler.

  15. An engineering model for coal devolatilization. Quarterly report, September 15, 1989-December 15, 1989

    SciTech Connect

    Hickerson, J.

    1990-01-01

    This research program aims for an engineering model for the evolution of volatile products from coal during pulverized coal combustion. The performance specifications include: (1) compatibility with the computational constraints of large-scale combustor simulators; (2) reliable predictions of the yields of noncondensible gases, tar, char, and unreacted coal for arbitrary thermal histories and ambient conditions; (3) predictions of the tar molecular weight distribution and aromaticity throughout the technological operating domain; and (4) a mathematical framework for the influence of coal type. The program is organized into four tasks. The objective of Task 1 is an engineering model to account for the influence of ambient pressure on the yields and tar molecular weight distributions, including an evaluation against reported devolatilization studies. While the engineering model does not explicitly account for variations in coal type, the theory developed in Task 2 aims for a theoretical framework to handle them. It describes the complete distributions of molecular fragments from a depolymerizing macromolecular network, the reintegration of nonvolatile fragments into a char lattice, and the simultaneous evolution of volatiles by flash distillation. In Task 3, the engineering model is supplemented with descriptions of the chemistry, heat and mass transport in the vicinity of individual coal particles, to model the initial stages of the combustion of entrained coal particles. Task 4 emphasizes heuristic treatments of coal type effects developed from the full depolymerization scheme (Task 2), and their evaluation against data. 14 refs., 8 figs., 2 tabs.

  16. Predictive modelling of boiler fouling. Quarterly technical progress report, July 1, 1991--September 30, 1991

    SciTech Connect

    Not Available

    1991-12-31

    The primary objective of this work is the development of a comprehensive numerical model describing the time evolution of fouling under realistic heat exchanger conditions. As fouling is a complex interaction of gas flow, mineral transport and adhesion mechanisms, understanding and subsequently improved controlling of fouling achieved via appropriate manipulation of the various coupled, nonlinear processes in a complex fluid mechanics environment will undoubtedly help reduce the substantial operating costs incurred by the utilities annually, as well as afford greater flexibility in coal selection and reduce the emission of various pollutants. In a more specialized context, the numerical model to be developed as part of this activity will be used as a tool to address the interaction of the various mechanisms controlling deposit development in specific regimes or correlative relationships. These should prove of direct use to the coal burning industry.

  17. Predictive modelling of boiler fouling. Quarterly technical progress report, October 1, 1990--December 31, 1990

    SciTech Connect

    Not Available

    1990-02-01

    The primary objective of this work is the development of a comprehensive numerical model describing the time evolution of fouling under realistic heat exchanger conditions. As fouling is a complex interaction of gas flow, mineral transport and adhesion mechanisms, understanding and subsequently improved controlling of fouling achieved via appropriate manipulation of the various coupled, nonlinear processes in a complex fluid mechanics environment will undoubtedly help reduce the substantial operating costs incurred by the utilities annually, as well as afford greater flexibility in coal selection and reduce the emission of various pollutants. In a more specialized context the numerical model to be developed as part of this activity will be used as a tool to address the interaction of the various mechanisms controlling deposit development in specific regimes or correlative relationships. These should prove of direct use to the coal burning industry.

  18. Quarter-BPS states in orbifold sigma models with ADE singularities

    NASA Astrophysics Data System (ADS)

    Wong, Kenny

    2017-06-01

    We study the elliptic genera of two-dimensional orbifold CFTs, where the orbifolding procedure introduces du Val surface singularities on the target space. The N=4 characterdecompositionsoftheellipticgenuscontributionsfromthetwistedsectors at the singularities obey a consistent scaling property, and contain information about the arrangement of exceptional rational curves in the resolution. We also discuss how these twisted sector elliptic genera are related to twining genera and Hodge elliptic genera for sigma models with K3 target space.

  19. Finite Element Modeling of Deployment, and Foam Rigidization of Struts and Quarter Scale Shooting Star Experiment

    NASA Technical Reports Server (NTRS)

    Leigh, Larry, Jr.

    2002-01-01

    Inflated cylindrical struts constructed of kapton polyimide film and rigidized with foam have considerable practical application and potential for use as components of inflatable concentrator assemblies, antenna structures and space power systems, Because of their importance, it is of great interest to characterize the dynamic behavior of these components and structures both experimentally and analytically. It is very helpful to take a building-block approach to modeling and understanding inflatable assemblies by first investigating in detail the behavior of the components such as the struts. The foam material used for rigidization of such cylinders has varying modulus, which is a function of different factors, such as density of the foam. Thus, the primary motivation of the tests and analytical modeling efforts was to determine and understand the response of foam-rigidized cylinders for different densities, sizes, and construction methods, In recent years, inflatable structures have been the subject of renewed interest for space applications such as communications antennae, solar thermal propulsion, and space solar power. A major advantage of using inflatable structures in space is that they are extremely lightweight. This makes inflatables a perfect match for solar thermal propulsion because of the low thrust levels available. An obvious second advantage is on-orbit deployability and subsequent space savings in launch configuration. It can be seen that inflatable cylindrical struts and torus are critical components of structural assemblies. In view of this importance, structural dynamic and static behaviors of typical rigidized polyimide struts are investigated in this paper. The paper will focus on the finite element models that were used to model the behavior of the complete solar collector structure, and the results that they provided, as compared to test data.

  20. Short-term energy outlook: Quarterly projections, second quarter 1997

    SciTech Connect

    1997-04-01

    The Energy Information Administration (EIA) prepares quarterly short-term energy supply, demand, and price projections for publication in January, April, July, and October in the Outlook. The forecast period for this issue of the Outlook extends from the second quarter of 1997 through the fourth quarter of 1998. Values for the first quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the second quarter 1997 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the Short-Term Integrated Forecasting System (STIFS). 34 figs., 19 tabs.

  1. Short-term energy outlook. Quarterly projections, first quarter 1996

    SciTech Connect

    1996-02-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Outlook. The forecast period for this issue of the Outlook extends from the first quarter of 1996 through the fourth quarter of 1997. Values for the fourth quarter of 1995, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled into the first quarter 1996 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The cases are produced using the Short-Term Integrated Forecasting System (STIFS). The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook.

  2. Towards a reference plant trait ontology for modeling knowledge of plant traits and phenotypes

    USDA-ARS?s Scientific Manuscript database

    Ontology engineering and knowledge modeling for the plant sciences is expected to contribute to the understanding of the basis of plant traits that determine phenotypic expression in a given environment. Several crop- or clade-specific plant trait ontologies have been developed to describe plant tr...

  3. Plant parameters for plant functional groups of western rangelands to enable process-based simulation modeling

    USDA-ARS?s Scientific Manuscript database

    Regional environmental assessments with process-based models require realistic estimates of plant parameters for the primary plant functional groups in the region. “Functional group” in this context is an operational term, based on similarities in plant type and in plant parameter values. Likewise...

  4. A novel approach to modeling unstable EOR displacements. Quarterly report, January 1993--March 1993

    SciTech Connect

    Peters, E.J.

    1993-07-01

    This research is aimed at developing a methodology for predicting the performance of unstable displacements in heterogeneous reservoirs. A performance prediction approach that combines numerical modeling with laboratory imaging experiments is being developed. Flow visualization experiments are being performed on laboratory corefloods using X-ray Computed Tomography (CT) and other imaging technologies to map the ensitu fluid saturations in time and space. A systematic procedure is being developed to replicate the experimental image data with high-resolution numerical models of the displacements. The well-tuned models will then be used to scale the results of the laboratory coreflood experiments to heterogeneous reservoirs in order to predict the performance of unstable displacements in such reservoirs. There are four major issues in miscible displacements. The first issue is the quantitative description of the mixing or dispersion that occurs in miscible displacements and the attendant problem of measuring the dispersion coefficient for the porous medium. The second issue is the problem of hydrodynamic instability. The third issue is the impact of heterogeneity on the performance of miscible displacements. The fourth and final issue is process optimization and economics. In this report, we address the first issue -- the description of dispersion in porous media. We present an improved method to measure the, longitudinal dispersion coefficient of a porous medium from CT imaging of a tracer test in the medium. The method is demonstrated by measuring the dispersion coefficients for a sandpack and a Berea sandstone. Imaging the tracer test allows the effects of dispersion and heterogeneity to be distinguished.

  5. Short-term energy outlook, quarterly projections, first quarter 1998

    SciTech Connect

    1998-01-01

    The forecast period for this issue of the Outlook extends from the first quarter of 1998 through the fourth quarter of 1999. Values for the fourth quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the first quarter 1998 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are adjusted by EIA to reflect EIA assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the STIFS model. 24 figs., 19 tabs.

  6. Why we need more non-seed plant models.

    PubMed

    Rensing, Stefan A

    2017-02-13

    Contents I. II. III. IV. V. VI. References SUMMARY: Out of a hundred sequenced and published land plant genomes, four are not of flowering plants. This severely skewed taxonomic sampling hinders our comprehension of land plant evolution at large. Moreover, most genetically accessible model species are flowering plants as well. If we are to gain a deeper understanding of how plants evolved and still evolve, and which of their developmental patterns are ancestral or derived, we need to study a more diverse set of plants. Here, I thus argue that we need to sequence genomes of so far neglected lineages, and that we need to develop more non-seed plant model species.

  7. A model of plant canopy polarization response

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.

    1980-01-01

    Sensors to remotely measure the linear polarization of ground scenes have been proposed for the Multispectral Resource Sampler (MRS), a satellite sensor system proposed to complement the Thematic Mapper. At present justification for a sensor on MRS to measure scene polarization is limited. This paper discusses a model for the amount of linearly polarized light reflected by the shiny leaves of such crops as wheat, corn, and sorghum. The theory demonstrates that, potentially, measurements of the linearly polarized light from a crop canopy may be used as an additional feature to discriminate between crops. Examination of the model suggests that, potentially, satellite polarization measurements may be used to monitor crop development stage, leaf water content, leaf area index, hail damage, and certain plant diseases. The model adds to the understanding of the potential information content of scene polarization measurements acquired by future satellite sensor systems such as MRS.

  8. A model of plant canopy polarization response

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.

    1980-01-01

    Sensors to remotely measure the linear polarization of ground scenes have been proposed for the Multispectral Resource Sampler (MRS), a satellite sensor system proposed to complement the Thematic Mapper. At present justification for a sensor on MRS to measure scene polarization is limited. This paper discusses a model for the amount of linearly polarized light reflected by the shiny leaves of such crops as wheat, corn, and sorghum. The theory demonstrates that, potentially, measurements of the linearly polarized light from a crop canopy may be used as an additional feature to discriminate between crops. Examination of the model suggests that, potentially, satellite polarization measurements may be used to monitor crop development stage, leaf water content, leaf area index, hail damage, and certain plant diseases. The model adds to the understanding of the potential information content of scene polarization measurements acquired by future satellite sensor systems such as MRS.

  9. Hydroacoustic Studies Using HydroCAM - Station-centric Integration of Models and Observations Quarterly Report No.4 July 2003 - September 2003

    SciTech Connect

    Upton, Zachary, M.; Pulli, Jay, J.

    2003-10-13

    OAK B272 Quarterly technical report summarizing BBN's efforts to improve DOE's hydroacoustic modeling and analysis capability for nuclear explosion monitoring. BBN's work during the third quarter of 2003 was focused on preparations for and participation in the 2003 Seismic Research Review Meeting, unit testing and bug fixes to HydroCAM 4.1, data collection and analysis, and procuring high-resolution bathymetric data. In an attempt to save money, BBN scaled back its labor in the third quarter, delaying some deliverables but saving contract funding in case our next increment is delayed. We have succeeded in finding the correct Naval contact that can help us procure high-resolution bathymetry data. Although these data may require the release of a classified version of HydroCAM, we are optimistic that we will be able to acquire and integrate high-resolution bathymetric data near the Indian Ocean IMS stations. HydroCAM 4.1, which includes the ability to make blockage predictions using varying resolution bathymetric data, has completed unit testing and is now under integration (release) testing. We hope to deliver that functionality to DOE and AFTAC in November. BBN improved its database of hydroacoustic events in the Indian Ocean by including meta-data for associated arrivals. For each earthquake event, BBN is now picking the direct arrival at each station (Diego Garcia North and South, and Cape Leeuwin) and associating that arrival with the origin information that we are compiling. The data for 2001, 2002 and 2003 (to date) will be delivered to LLNL for integration into the Knowledge Base during the fourth quarter of 2003.

  10. Plant actin cytoskeleton re-modeling by plant parasitic nematodes.

    PubMed

    Engler, Janice de Almeida; Rodiuc, Natalia; Smertenko, Andrei; Abad, Pierre

    2010-03-01

    The cytoskeleton is an important component of the plant's defense mechanism against the attack of pathogenic organisms. Plants however, are defenseless against parasitic root-knot and cyst nematodes and respond to the invasion by the development of a special feeding site that supplies the parasite with nutrients required for the completion of its life cycle. Recent studies of nematode invasion under treatment with cytoskeletal drugs and in mutant plants where normal functions of the cytoskeleton have been affected, demonstrate the importance of the cytoskeleton in the establishment of a feeding site and successful nematode reproduction. It appears that in the case of microfilaments, nematodes hijack the intracellular machinery that regulates actin dynamics and modulate the organization and properties of the actin filament network. Intervening with this process reduces the nematode infection efficiency and inhibits its life cycle. This discovery uncovers a new pathway that can be exploited for the protection of plants against nematodes.

  11. Using functional–structural plant models to study, understand and integrate plant development and ecophysiology

    PubMed Central

    DeJong, Theodore M.; Da Silva, David; Vos, Jan; Escobar-Gutiérrez, Abraham J.

    2011-01-01

    Functional–structural plant models (FSPMs) explore and integrate relationships between a plant's structure and processes that underlie its growth and development. In recent years, the range of topics being addressed by scientists interested in functional–structural plant modelling has expanded greatly. FSPM techniques are now being used to dynamically simulate growth and development occurring at the microscopic scale involving cell division in plant meristems to the macroscopic scales of whole plants and plant communities. The plant types studied also cover a broad spectrum from algae to trees. FSPM is highly interdisciplinary and involves scientists with backgrounds in plant physiology, plant anatomy, plant morphology, mathematics, computer science, cellular biology, ecology and agronomy. This special issue of Annals of Botany features selected papers that provide examples of comprehensive functional–structural models, models of key processes such as partitioning of resources, software for modelling plants and plant environments, data acquisition and processing techniques and applications of functional–structural plant models for agronomic purposes. PMID:22084818

  12. Functional–structural plant models: a growing paradigm for plant studies

    PubMed Central

    Sievänen, Risto; Godin, Christophe; DeJong, Theodore M.; Nikinmaa, Eero

    2014-01-01

    A number of research groups in various areas of plant biology as well as computer science and applied mathematics have addressed modelling the spatiotemporal dynamics of growth and development of plants. This has resulted in development of functional–structural plant models (FSPMs). In FSPMs, the plant structure is always explicitly represented in terms of a network of elementary units. In this respect, FSPMs are different from more abstract models in which a simplified representation of the plant structure is frequently used (e.g. spatial density of leaves, total biomass, etc.). This key feature makes it possible to build modular models and creates avenues for efficient exchange of model components and experimental data. They are being used to deal with the complex 3-D structure of plants and to simulate growth and development occurring at spatial scales from cells to forest areas, and temporal scales from seconds to decades and many plant generations. The plant types studied also cover a broad spectrum, from algae to trees. This special issue of Annals of Botany features selected papers on FSPM topics such as models of morphological development, models of physical and biological processes, integrated models predicting dynamics of plants and plant communities, modelling platforms, methods for acquiring the 3-D structures of plants using automated measurements, and practical applications for agronomic purposes. PMID:25469374

  13. Functional-structural plant models: a growing paradigm for plant studies.

    PubMed

    Sievänen, Risto; Godin, Christophe; DeJong, Theodore M; Nikinmaa, Eero

    2014-09-01

    A number of research groups in various areas of plant biology as well as computer science and applied mathematics have addressed modelling the spatiotemporal dynamics of growth and development of plants. This has resulted in development of functional-structural plant models (FSPMs). In FSPMs, the plant structure is always explicitly represented in terms of a network of elementary units. In this respect, FSPMs are different from more abstract models in which a simplified representation of the plant structure is frequently used (e.g. spatial density of leaves, total biomass, etc.). This key feature makes it possible to build modular models and creates avenues for efficient exchange of model components and experimental data. They are being used to deal with the complex 3-D structure of plants and to simulate growth and development occurring at spatial scales from cells to forest areas, and temporal scales from seconds to decades and many plant generations. The plant types studied also cover a broad spectrum, from algae to trees. This special issue of Annals of Botany features selected papers on FSPM topics such as models of morphological development, models of physical and biological processes, integrated models predicting dynamics of plants and plant communities, modelling platforms, methods for acquiring the 3-D structures of plants using automated measurements, and practical applications for agronomic purposes.

  14. Using functional–structural plant models to study, understand and integrate plant development and ecophysiology.

    PubMed

    DeJong, Theodore M; Da Silva, David; Vos, Jan; Escobar-Gutiérrez, Abraham J

    2011-10-01

    Functional–structural plant models (FSPMs) explore and integrate relationships between a plant’s structure and processes that underlie its growth and development. In recent years, the range of topics being addressed by scientists interested in functional–structural plant modelling has expanded greatly. FSPM techniques are now being used to dynamically simulate growth and development occurring at the microscopic scale involving cell division in plant meristems to the macroscopic scales of whole plants and plant communities. The plant types studied also cover a broad spectrum from algae to trees. FSPM is highly interdisciplinary and involves scientists with backgrounds in plant physiology, plant anatomy, plant morphology, mathematics, computer science, cellular biology, ecology and agronomy. This special issue of Annals of Botany features selected papers that provide examples of comprehensive functional–structural models, models of key processes such as partitioning of resources, software for modelling plants and plant environments, data acquisition and processing techniques and applications of functional–structural plant models for agronomic purposes.

  15. Development of the integrated environmental control model: Performance and cost models for fabric filters. Quarterly progress report, January--March 1994

    SciTech Connect

    Kalagnanam, J.R.; Rubin, E.S.

    1994-04-27

    The present report summarizes recent progress on the Phase I effort during the period January 1, 1994 through March 30, 1994. This report summarizes progress to date in refining the existing analytical models implemented in the IECM. In this report, the authors described the development of analytical models for the performance and costs of high-performance particulate control technologies, focusing on fabric filters. They pay special attention to developing models which can be used to estimate costs for systems whose performance is up to a factor of three below the present NSPS standards of 0.03 lb/MMBtu. Typically, the cost models relate the capital costs and the operating and maintenance (O&M) costs to process parameters and the costs of labor and materials. The capital cost models are anchored to a base capital cost for a specific size unit and adjusted according to the actual or design parameters. The performance models are constructed to estimate the process parameters for a desired level of emission control. The primary motivation for these models is to estimate the costs of complying with environmental standards on a basis which reflects recent advances in control technology. Finally, the authors incorporate the uncertainties in various process parameters and inputs costs so as to allow a more rational and robust basis for comparing different technologies. In the following sections the authors discuss the initial development of the performance and cost models for fabric filters followed by a numerical example which illustrates the use of these new models. The next quarterly report will provide a similar update of the IECM electrostatic precipitator models, plus a brief discussion of the comparative advantages of different particulate control.

  16. Quarterly coal report

    SciTech Connect

    Young, P.

    1996-05-01

    The Quarterly Coal Report (QCR) provides comprehensive information about U.S. coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. The data presented in the QCR are collected and published by the Energy Information Administration (EIA) to fulfill data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275), as amended. This report presents detailed quarterly data for October through December 1995 and aggregated quarterly historical data for 1987 through the third quarter of 1995. Appendix A displays, from 1987 on, detailed quarterly historical coal imports data, as specified in Section 202 of the Energy Policy and Conservation Amendments Act of 1985 (Public Law 99-58). Appendix B gives selected quarterly tables converted to metric tons.

  17. Waste isolation pilot plant disposal room model

    SciTech Connect

    Butcher, B.M.

    1997-08-01

    This paper describes development of the conceptual and mathematical models for the part of the Waste Isolation Pilot Plant (WIPP) repository performance assessment that is concerned with what happens to the waste over long times after the repository is decommissioned. These models, collectively referred to as the {open_quotes}Disposal Room Model,{close_quotes} describe the repository closure process during which deformation of the surrounding salt consolidates the waste. First, the relationship of repository closure to demonstration of compliance with the Environmental Protection Agency (EPA) standard (40 CFR 191 Appendix C) and how sensitive performance results are to it are examined. Next, a detailed description is provided of the elements of the disposal region, and properties selected for the salt, waste, and other potential disposal features such as backfill. Included in the discussion is an explanation of how the various models were developed over time. Other aspects of closure analysis, such as the waste flow model and method of analysis, are also described. Finally, the closure predictions used in the final performance assessment analysis for the WIPP Compliance Certification Application are summarized.

  18. Modeling of integrated environmental control systems for coal-fired power plants. Technical progress report, [January 1, 1989--March 31, 1989

    SciTech Connect

    Rubin, E.S.

    1989-04-01

    This is the sixth quarterly report of DOE Contract No. DE-AC22- 87PC79863, entitled ``Modeling of Integrated Environmental Control Systems for Coal-Fired Power Plants.`` This report summarizes accomplishments during the period January 1, 1989 to March 31, 1989. Efforts this past quarter focused primarily on the preparation of a computer User`s Guide for the Integrated Environmental Control Model (IECM). Drafts of the first two chapters are now complete. These chapters constitute the bulk of this quarterly report. Drafts of the remaining chapters are in preparation, and will appear in a future report this year. We also have been working closely with DOE/PETC to define the computer configuration to be transferred to PETC as a contract deliverable. That process is now complete and the equipment is on order. Delivery of the IECM to PETC is expected during the next calendar quarter. Finally, we are continuing our efforts to develop and refine a number of clean coal technology process models. These efforts will be summarized and reported at a future date.

  19. Plant growth and architectural modelling and its applications

    PubMed Central

    Guo, Yan; Fourcaud, Thierry; Jaeger, Marc; Zhang, Xiaopeng; Li, Baoguo

    2011-01-01

    Over the last decade, a growing number of scientists around the world have invested in research on plant growth and architectural modelling and applications (often abbreviated to plant modelling and applications, PMA). By combining physical and biological processes, spatially explicit models have shown their ability to help in understanding plant–environment interactions. This Special Issue on plant growth modelling presents new information within this topic, which are summarized in this preface. Research results for a variety of plant species growing in the field, in greenhouses and in natural environments are presented. Various models and simulation platforms are developed in this field of research, opening new features to a wider community of researchers and end users. New modelling technologies relating to the structure and function of plant shoots and root systems are explored from the cellular to the whole-plant and plant-community levels. PMID:21638797

  20. Establishing the SECME model in the District of Columbia. Quarterly report, 1 January 1994--31 March 1994

    SciTech Connect

    Vikers, R.G.

    1994-05-01

    During this quarter, many program activities were held to help SECME teachers and counselors implement, improve and strengthen SECME school programs in the District of Columbia. Teachers were actively engaged in enhanced instructional techniques, ideas, processes and resources to help them enrich their students` learning experience. Students are busily participating in hands-on instructional activities and preparing for the SECME competition where they are learning to excel in a competitive environment designed to help them make the most of their school experience.

  1. Short-term energy outlook, Quarterly projections. Third quarter 1993

    SciTech Connect

    1993-08-04

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the third quarter of 1993 through the fourth quarter of 1994. Values for the second quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding.

  2. Crop plants as models for understanding plant adaptation and diversification

    PubMed Central

    Olsen, Kenneth M.; Wendel, Jonathan F.

    2013-01-01

    Since the time of Darwin, biologists have understood the promise of crop plants and their wild relatives for providing insight into the mechanisms of phenotypic evolution. The intense selection imposed by our ancestors during plant domestication and subsequent crop improvement has generated remarkable transformations of plant phenotypes. Unlike evolution in natural settings, descendent and antecedent conditions for crop plants are often both extant, providing opportunities for direct comparisons through crossing and other experimental approaches. Moreover, since domestication has repeatedly generated a suite of “domestication syndrome” traits that are shared among crops, opportunities exist for gaining insight into the genetic and developmental mechanisms that underlie parallel adaptive evolution. Advances in our understanding of the genetic architecture of domestication-related traits have emerged from combining powerful molecular technologies with advanced experimental designs, including nested association mapping, genome-wide association studies, population genetic screens for signatures of selection, and candidate gene approaches. These studies may be combined with high-throughput evaluations of the various “omics” involved in trait transformation, revealing a diversity of underlying causative mutations affecting phenotypes and their downstream propagation through biological networks. We summarize the state of our knowledge of the mutational spectrum that generates phenotypic novelty in domesticated plant species, and our current understanding of how domestication can reshape gene expression networks and emergent phenotypes. An exploration of traits that have been subject to similar selective pressures across crops (e.g., flowering time) suggests that a diversity of targeted genes and causative mutational changes can underlie parallel adaptation in the context of crop evolution. PMID:23914199

  3. 6. Interior of quarters (executive officer's quarters), living room, looking ...

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

    6. Interior of quarters (executive officer's quarters), living room, looking west - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  4. 1. North side of quarters (executive officer's quarters), looking southeast ...

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

    1. North side of quarters (executive officer's quarters), looking southeast - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  5. 5. East side of quarters (executive officer's quarters), looking west ...

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

    5. East side of quarters (executive officer's quarters), looking west - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  6. 4. South side of quarters (executive officer's quarters), looking north ...

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

    4. South side of quarters (executive officer's quarters), looking north - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  7. 2. West side of quarters (executive officer's quarters), looking east ...

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

    2. West side of quarters (executive officer's quarters), looking east - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  8. 3. Southwest side of quarters (executive officer's quarters), looking northeast ...

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

    3. Southwest side of quarters (executive officer's quarters), looking northeast - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  9. 2. Southeast side of Quarters R (commanding officer's quarters), looking ...

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

    2. Southeast side of Quarters R (commanding officer's quarters), looking northwest - Naval Air Station Chase Field, Quarters R, Essex Street, .43 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  10. 5. Interior of Quarters R (commanding officer's quarters), living room, ...

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

    5. Interior of Quarters R (commanding officer's quarters), living room, looking northwest - Naval Air Station Chase Field, Quarters R, Essex Street, .43 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  11. 4. Northwest side of Quarters R (commanding officer's quarters), looking ...

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

    4. Northwest side of Quarters R (commanding officer's quarters), looking southeast - Naval Air Station Chase Field, Quarters R, Essex Street, .43 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  12. 3. Southwest side of quarters R (commanding officer's quarters), looking ...

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

    3. Southwest side of quarters R (commanding officer's quarters), looking east - Naval Air Station Chase Field, Quarters R, Essex Street, .43 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  13. 1. Northeast side of Quarters R (commanding officer's quarters), looking ...

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

    1. Northeast side of Quarters R (commanding officer's quarters), looking west - Naval Air Station Chase Field, Quarters R, Essex Street, .43 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  14. Contextual view of quarters no. 2 quarters no. 1, and ...

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

    Contextual view of quarters no. 2 quarters no. 1, and water tower, looking southwest. - Sacramento National Wildlife Refuge, Headquarters Complex, Quarters No. 2, 752 County Road 99W, Willows, Glenn County, CA

  15. Plant growth simulation for landscape scale hydrologic modeling

    USDA-ARS?s Scientific Manuscript database

    Landscape scale hydrologic models can be improved by incorporating realistic, process-oriented plant models for simulating crops, grasses, and woody species. The objective of this project was to present some approaches for plant modeling applicable to hydrologic models like SWAT that can affect the...

  16. Computational modeling and experimental studies on NO{sub x} reduction under pulverized coal combustion conditions. Technical progress report, sixth quarter, April 1--June 30, 1996

    SciTech Connect

    Kumpaty, S.K.; Subramanian, K.; Nokku, V.P.; Hodges, T.L.

    1996-12-31

    During this quarter, the experiments for nitric oxide reburning with a combination of methane and acetylene were conducted successfully. With the failure of ozonator lamp in the NOx analyzer shortly thereafter, the experimental study of nitric oxide reburning with a combination of methane and ammonia could not be completed. In the meantime, a coal feeder was designed and a purchase order was sent out for the building of the coal feeder. Presented herein are the experimental results of NO reburning with methane/acetylene. The results are consistent with model predictions.

  17. (Shippingport Atomic Power Station). Quarterly operating report, first quarter 1982

    SciTech Connect

    Not Available

    1982-01-01

    At the beginning of the first quarter of 1982, the Shippingport Atomic Power Station remained shutdown for the planned 1981 to 1982 Winter Shutdown, initiated December 11, 1981. The station was in a cooldown condition at approximately 150/sup 0/F and 280 psig with a steam bubble maintained in the pressurizer and the reactor coolant pumps in slow speed. The reactor plant cooldown heat exchanger was in service to maintain coolant temperature. The 1A, 1B, 1C, and 1D reactor coolant loops and the 1AC and 18D purification loops remained in service. The 1A, 1B, and 1C 991 psig self-actuated steam relief valves remained gagged during the quarter to prevent leakage through the valve seats. The 1D steam relief valve was removed during the Spring 1980 Shutdown for repairs and a blind flange was installed in its place. Gagging and/or removing of redundant relief valves is permitted by ASME Code and approved operating procedures. During the first quarter of 1982, a total of 1028 cubic feet of radioactive solid waste was shipped out of state for burial. The shipments contained 0.032 curies of radioactivity.

  18. Modeling Sugar Allocations in Plants using Radioisotope Tracer Data

    NASA Astrophysics Data System (ADS)

    Bai, Mingru

    2013-10-01

    The allocations of carbon and nitrogen are major factors in determining growth priorities in plants. The mechanisms that regulate resource allocation in plants are poorly understood. We use radiotracer techniques to identify and quantify dynamical feedback responses of plants to changes in environmental conditions. A major goal of this research is to investigate shifts in sugar allocations as part of the plant's response to changes in environmental conditions. These observations are used to develop mechanistic models that simulate the feedback for adjustments to resource allocations based on the environment-plant interface. By writing a software module in C + + based on the models, we are able to conduct a computer simulation of plant's intake of carbon dioxide and sugar allocation inside plant body. By comparing and matching the simulation results and experimental data through adjusting model parameters, we are able to gain knowledge of the mechanisms that regulate resource allocation in plants.

  19. Modeling of advanced fossil fuel power plants

    NASA Astrophysics Data System (ADS)

    Zabihian, Farshid

    The first part of this thesis deals with greenhouse gas (GHG) emissions from fossil fuel-fired power stations. The GHG emission estimation from fossil fuel power generation industry signifies that emissions from this industry can be significantly reduced by fuel switching and adaption of advanced power generation technologies. In the second part of the thesis, steady-state models of some of the advanced fossil fuel power generation technologies are presented. The impacts of various parameters on the solid oxide fuel cell (SOFC) overpotentials and outputs are investigated. The detail analyses of operation of the hybrid SOFC-gas turbine (GT) cycle when fuelled with methane and syngas demonstrate that the efficiencies of the cycles with and without anode exhaust recirculation are close, but the specific power of the former is much higher. The parametric analysis of the performance of the hybrid SOFC-GT cycle indicates that increasing the system operating pressure and SOFC operating temperature and fuel utilization factor improves cycle efficiency, but the effects of the increasing SOFC current density and turbine inlet temperature are not favourable. The analysis of the operation of the system when fuelled with a wide range of fuel types demonstrates that the hybrid SOFC-GT cycle efficiency can be between 59% and 75%, depending on the inlet fuel type. Then, the system performance is investigated when methane as a reference fuel is replaced with various species that can be found in the fuel, i.e., H2, CO2, CO, and N 2. The results point out that influence of various species can be significant and different for each case. The experimental and numerical analyses of a biodiesel fuelled micro gas turbine indicate that fuel switching from petrodiesel to biodiesel can influence operational parameters of the system. The modeling results of gas turbine-based power plants signify that relatively simple models can predict plant performance with acceptable accuracy. The unique

  20. CSSEDC Quarterly. 1989.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1989-01-01

    These four issues of the CSSEDC Quarterly (Conference for Secondary School English Department Chairpersons) represent the quarterly for 1989. Articles in number 1 deal with professional development, and include: "Sharing Expertise within a Department" (Martha R. Dolly); "Empowerment Develops a Computer Writing Center" (Norman…

  1. English Leadership Quarterly. 1991.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1991-01-01

    These four issues of the English Leadership Quarterly represent the quarterly for 1991. Articles in number 1 deal with whole language and include: "CEL: Shorter and Better" (Myles D. Eley); "Toward a New Philosophy of Language Learning" (Kathleen Strickland); "Whole Language: Implications for Secondary Classrooms"…

  2. CSSEDC Quarterly. 1988.

    ERIC Educational Resources Information Center

    Zirinsky, Driek, Ed.; Strickland, James, Ed.

    1988-01-01

    These four issues of the CSSEDC Quarterly (Conference for Secondary School English Department Chairpersons) represent the quarterly for 1988. Articles in number 1 include: "Relearning Leadership" (Tom Jones); "The English Coalition Conference" (Robert Denham); "The Reluctant Writer and Word Processing" (James…

  3. CSSEDC Quarterly. 1990.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1990-01-01

    These four issues of the CSSEDC Quarterly (Conference for Secondary School English Department Chairpersons) represent the quarterly for 1990. Articles in number 1 deal with student teachers and include: "Student Teaching: Smoothing Out the Rough Spots" (Susan B. Argyle and Fred C. Feitler); "A Partnership for Urban Student…

  4. Modelling soil-plant-atmosphere interactions by coupling the regional weather model WRF to mechanistic plant models

    NASA Astrophysics Data System (ADS)

    Klein, C.; Hoffmann, P.; Priesack, E.

    2012-04-01

    Climate change causes altering distributions of meteorological factors influencing plant growth and its interactions between the land surface and the atmosphere. Recent studies show, that uncertainties in regional and global climate simulations are also caused by lacking descriptions of the soil-plant-atmosphere system. Therefore, we couple a mechanistic soil-plant model to a regional climate and forecast model. The detailed simulation of the water and energy exchanges, especially the transpiration of grassland and forests stands, are the key features of the modelling framework. The Weather Research and Forecasting model (WRF) (Skamarock 2008) is an open source mesoscale numerical weather prediction model. The WRF model was modified in a way, to either choose its native, static land surface model NOAH or the mechanistic eco-system model Expert-N 5.0 individually for every single grid point within the simulation domain. The Expert-N 5.0 modelling framework provides a highly modular structure, enabling the development and use of a large variety of different plant and soil models, including heat transfer, nitrogen uptake/turnover/transport as well as water uptake/transport and crop management. To represent the key landuse types grassland and forest, we selected two mechanistic plant models: The Hurley Pasture model (Thornley 1998) and a modified TREEDYN3 forest simulation model (Bossel 1996). The models simulate plant growth, water, nitrogen and carbon flows for grassland and forest stands. A mosaic approach enables Expert-N to use high resolution land use data e.g. CORINE Land Cover data (CLC, 2006) for the simulation, making it possible to simulate different land use distributions within a single grid cell. The coupling results are analyzed for plausibility and compared with the results of the default land surface model NOAH (Fei Chen and Jimy Dudhia 2010). We show differences between the mechanistic and the static model coupling, with focus on the feedback effects

  5. Working toward integrated models of alpine plant distribution

    PubMed Central

    Carlson, Bradley Z.; Randin, Christophe F.; Boulangeat, Isabelle; Lavergne, Sébastien; Thuiller, Wilfried; Choler, Philippe

    2014-01-01

    Species distribution models (SDMs) have been frequently employed to forecast the response of alpine plants to global changes. Efforts to model alpine plant distribution have thus far been primarily based on a correlative approach, in which ecological processes are implicitly addressed through a statistical relationship between observed species occurrences and environmental predictors. Recent evidence, however, highlights the shortcomings of correlative SDMs, especially in alpine landscapes where plant species tend to be decoupled from atmospheric conditions in micro-topographic habitats and are particularly exposed to geomorphic disturbances. While alpine plants respond to the same limiting factors as plants found at lower elevations, alpine environments impose a particular set of scale-dependent and hierarchical drivers that shape the realized niche of species and that require explicit consideration in a modelling context. Several recent studies in the European Alps have successfully integrated both correlative and process-based elements into distribution models of alpine plants, but for the time being a single integrative modelling framework that includes all key drivers remains elusive. As a first step in working toward a comprehensive integrated model applicable to alpine plant communities, we propose a conceptual framework that structures the primary mechanisms affecting alpine plant distributions. We group processes into four categories, including multi-scalar abiotic drivers, gradient dependent species interactions, dispersal and spatial–temporal plant responses to disturbance. Finally, we propose a methodological framework aimed at developing an integrated model to better predict alpine plant distribution. PMID:24790594

  6. Effect of quartering and sampling method on recovery of bacteria from broiler carcasses

    USDA-ARS?s Scientific Manuscript database

    Four eviscerated broiler carcasses were obtained from a commercial processing plant just prior to the final inside-outside bird washer in each of three replicate trials. Carcasses were separated into leg quarters and breast quarters (n=48) and weighed. One breast and leg quarter from the same carc...

  7. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Framed by wispy contrails left by passing jets high above, a quarter-scale model of the Centurion solar-electric flying wing shows off its graceful lines during a March 1997 test flight at El Mirage Dry Lake in California's Mojave Desert. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  8. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    With the snow-covered San Gabriel Mountains as a backdrop and a motorcycle-mounted chase crew alongside, a quarter-scale model of the Centurion solar-powered flying wing soars over El Mirage Dry Lake on an early test flight in March 1997. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  9. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of of a March 1997 flight test. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

  10. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing Landing during First

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the future Centurion solar-powered high-altitude research aircraft settles in for landing after a March 1997 test flight at El Mirage Dry Lake, California. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he

  11. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its internal rib structure as it floats over the El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  12. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft

  13. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its long, narrow wing as it flies over the broad expanse of El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del

  14. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Trailed by a van carrying the remote pilot and observers, a radio-controlled quarter-scale model of the Centurion solar-electric flying wing makes a low pass over El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  15. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Trailed by a van carrying the remote pilot and observers, a radio-controlled quarter-scale model of the Centurion solar-electric flying wing makes a low pass over El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  16. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Illuminated by early-morning sunlight, a quarter-scale model of the solar-powered, remotely piloted Centurion ultra-high-altitude flying wing soars over California's Mojave Desert on a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for

  17. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of of a March 1997 flight test. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

  18. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its internal rib structure as it floats over the El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  19. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Illuminated by early-morning sunlight, a quarter-scale model of the Solar-powered, remotely piloted Centurion ultra-high-altitude flying wing demonstrates its abilities during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

  20. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Illuminated by early-morning sunlight, a quarter-scale model of the solar-powered, remotely piloted Centurion ultra-high-altitude flying wing soars over California's Mojave Desert on a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for

  1. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing Landing during First

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the future Centurion solar-powered high-altitude research aircraft settles in for landing after a March 1997 test flight at El Mirage Dry Lake, California. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he

  2. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    With the snow-covered San Gabriel Mountains as a backdrop and a motorcycle-mounted chase crew alongside, a quarter-scale model of the Centurion solar-powered flying wing soars over El Mirage Dry Lake on an early test flight in March 1997. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  3. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its long, narrow wing as it flies over the broad expanse of El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del

  4. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Framed by wispy contrails left by passing jets high above, a quarter-scale model of the Centurion solar-electric flying wing shows off its graceful lines during a March 1997 test flight at El Mirage Dry Lake in California's Mojave Desert. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate

  5. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft

  6. Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Illuminated by early-morning sunlight, a quarter-scale model of the Solar-powered, remotely piloted Centurion ultra-high-altitude flying wing demonstrates its abilities during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar

  7. The theater management model of plant memory

    PubMed Central

    Norris, Vic; Ripoll, Camille; Thellier, Michel

    2015-01-01

    The existence of a memory in plants raises several fundamental questions. What might be the function of a plant memory? How might it work? Which molecular mechanisms might be responsible? Here, we sketch out the landscape of plant memory with particular reference to the concepts of functioning-dependent structures and competitive coherence. We illustrate how these concepts might be relevant with reference to the metaphor of a traveling, avant-garde theater company and we suggest how using a program that simulates competitive coherence might help answer some of the questions about plant memory. PMID:25482789

  8. 4. Northeast corner of quarters (executive officer's quarters), looking onto ...

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

    4. Northeast corner of quarters (executive officer's quarters), looking onto Quarter R (commanding officer's quarters), looking southeast - Naval Air Station Chase Field, Texas State Highway 202, 4.8 miles east of intersection of Texas State Highway 202 & U.S. State Highway 181, Beeville, Bee County, TX

  9. Dynamic modeling of Badaling molten salt tower CSP pilot plant

    NASA Astrophysics Data System (ADS)

    Yang, Zijiang; Lu, Jiahui; Zhang, Qiangqiang; Li, Zhi; Li, Xin; Wang, Zhifeng

    2017-06-01

    Under the collaboration framework between EDF China R&D Centre and CAS-IEE, a preliminary numerical model of 1MWth molten salt tower solar power demonstration plant in Badaling, Beijing is presented in this paper. All key components in the plant are presented throughout detailed modules in the model according to its design specifications. Control strategies are also implemented to maintain the design system performance at transient scenario. By this model some key design figures of plant has been validated and it will be used to guide experiment set-up and plant commissioning.

  10. Spiral Growth in Plants: Models and Simulations

    ERIC Educational Resources Information Center

    Allen, Bradford D.

    2004-01-01

    The analysis and simulation of spiral growth in plants integrates algebra and trigonometry in a botanical setting. When the ideas presented here are used in a mathematics classroom/computer lab, students can better understand how basic assumptions about plant growth lead to the golden ratio and how the use of circular functions leads to accurate…

  11. Spiral Growth in Plants: Models and Simulations

    ERIC Educational Resources Information Center

    Allen, Bradford D.

    2004-01-01

    The analysis and simulation of spiral growth in plants integrates algebra and trigonometry in a botanical setting. When the ideas presented here are used in a mathematics classroom/computer lab, students can better understand how basic assumptions about plant growth lead to the golden ratio and how the use of circular functions leads to accurate…

  12. Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences.

    PubMed

    Bucksch, Alexander; Atta-Boateng, Acheampong; Azihou, Akomian F; Battogtokh, Dorjsuren; Baumgartner, Aly; Binder, Brad M; Braybrook, Siobhan A; Chang, Cynthia; Coneva, Viktoirya; DeWitt, Thomas J; Fletcher, Alexander G; Gehan, Malia A; Diaz-Martinez, Diego Hernan; Hong, Lilan; Iyer-Pascuzzi, Anjali S; Klein, Laura L; Leiboff, Samuel; Li, Mao; Lynch, Jonathan P; Maizel, Alexis; Maloof, Julin N; Markelz, R J Cody; Martinez, Ciera C; Miller, Laura A; Mio, Washington; Palubicki, Wojtek; Poorter, Hendrik; Pradal, Christophe; Price, Charles A; Puttonen, Eetu; Reese, John B; Rellán-Álvarez, Rubén; Spalding, Edgar P; Sparks, Erin E; Topp, Christopher N; Williams, Joseph H; Chitwood, Daniel H

    2017-01-01

    The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics.

  13. Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences

    PubMed Central

    Bucksch, Alexander; Atta-Boateng, Acheampong; Azihou, Akomian F.; Battogtokh, Dorjsuren; Baumgartner, Aly; Binder, Brad M.; Braybrook, Siobhan A.; Chang, Cynthia; Coneva, Viktoirya; DeWitt, Thomas J.; Fletcher, Alexander G.; Gehan, Malia A.; Diaz-Martinez, Diego Hernan; Hong, Lilan; Iyer-Pascuzzi, Anjali S.; Klein, Laura L.; Leiboff, Samuel; Li, Mao; Lynch, Jonathan P.; Maizel, Alexis; Maloof, Julin N.; Markelz, R. J. Cody; Martinez, Ciera C.; Miller, Laura A.; Mio, Washington; Palubicki, Wojtek; Poorter, Hendrik; Pradal, Christophe; Price, Charles A.; Puttonen, Eetu; Reese, John B.; Rellán-Álvarez, Rubén; Spalding, Edgar P.; Sparks, Erin E.; Topp, Christopher N.; Williams, Joseph H.; Chitwood, Daniel H.

    2017-01-01

    The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics. PMID:28659934

  14. Modelling of nuclear power plant decommissioning financing.

    PubMed

    Bemš, J; Knápek, J; Králík, T; Hejhal, M; Kubančák, J; Vašíček, J

    2015-06-01

    Costs related to the decommissioning of nuclear power plants create a significant financial burden for nuclear power plant operators. This article discusses the various methodologies employed by selected European countries for financing of the liabilities related to the nuclear power plant decommissioning. The article also presents methodology of allocation of future decommissioning costs to the running costs of nuclear power plant in the form of fee imposed on each megawatt hour generated. The application of the methodology is presented in the form of a case study on a new nuclear power plant with installed capacity 1000 MW. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Computational Modeling of Auxin: A Foundation for Plant Engineering.

    PubMed

    Morales-Tapia, Alejandro; Cruz-Ramírez, Alfredo

    2016-01-01

    Since the development of agriculture, humans have relied on the cultivation of plants to satisfy our increasing demand for food, natural products, and other raw materials. As we understand more about plant development, we can better manipulate plants to fulfill our particular needs. Auxins are a class of simple metabolites that coordinate many developmental activities like growth and the appearance of functional structures in plants. Computational modeling of auxin has proven to be an excellent tool in elucidating many mechanisms that underlie these developmental events. Due to the complexity of these mechanisms, current modeling efforts are concerned only with single phenomena focused on narrow spatial and developmental contexts; but a general model of plant development could be assembled by integrating the insights from all of them. In this perspective, we summarize the current collection of auxin-driven computational models, focusing on how they could come together into a single model for plant development. A model of this nature would allow researchers to test hypotheses in silico and yield accurate predictions about the behavior of a plant under a given set of physical and biochemical constraints. It would also provide a solid foundation toward the establishment of plant engineering, a proposed discipline intended to enable the design and production of plants that exhibit an arbitrarily defined set of features.

  16. Computational Modeling of Auxin: A Foundation for Plant Engineering

    PubMed Central

    Morales-Tapia, Alejandro; Cruz-Ramírez, Alfredo

    2016-01-01

    Since the development of agriculture, humans have relied on the cultivation of plants to satisfy our increasing demand for food, natural products, and other raw materials. As we understand more about plant development, we can better manipulate plants to fulfill our particular needs. Auxins are a class of simple metabolites that coordinate many developmental activities like growth and the appearance of functional structures in plants. Computational modeling of auxin has proven to be an excellent tool in elucidating many mechanisms that underlie these developmental events. Due to the complexity of these mechanisms, current modeling efforts are concerned only with single phenomena focused on narrow spatial and developmental contexts; but a general model of plant development could be assembled by integrating the insights from all of them. In this perspective, we summarize the current collection of auxin-driven computational models, focusing on how they could come together into a single model for plant development. A model of this nature would allow researchers to test hypotheses in silico and yield accurate predictions about the behavior of a plant under a given set of physical and biochemical constraints. It would also provide a solid foundation toward the establishment of plant engineering, a proposed discipline intended to enable the design and production of plants that exhibit an arbitrarily defined set of features. PMID:28066453

  17. Systems Modeling for Z-IFE Power Plants

    SciTech Connect

    Meier, W R

    2006-11-08

    A preliminary systems model has been developed for Z-IFE power plants. The model includes cost and performance scaling for the target physics, z-pinch driver, chamber, power conversion system and target/RTL manufacturing plant. As the base case we consider the dynamic hohlraum target and a thick liquid wall chamber with flibe as the working fluid. Driver cost and efficiency are evaluated parametrically since various options are still being considered. The model allows for power plants made up of multiple chambers and power conversion units supplied by a central target/RTL manufacturing plant. Initial results indicate that plants with few chambers operating at high yield are economically more attractive than the 10-unit plant previously proposed. Various parametric and sensitivity studies have been completed and are discussed.

  18. A Dynamic, Architectural Plant Model Simulating Resource‐dependent Growth

    PubMed Central

    YAN, HONG‐PING; KANG, MENG ZHEN; DE REFFYE, PHILIPPE; DINGKUHN, MICHAEL

    2004-01-01

    • Background and Aims Physiological and architectural plant models have originally been developed for different purposes and therefore have little in common, thus making combined applications difficult. There is, however, an increasing demand for crop models that simulate the genetic and resource‐dependent variability of plant geometry and architecture, because man is increasingly able to transform plant production systems through combined genetic and environmental engineering. • Model GREENLAB is presented, a mathematical plant model that simulates interactions between plant structure and function. Dual‐scale automaton is used to simulate plant organogenesis from germination to maturity on the basis of organogenetic growth cycles that have constant thermal time. Plant fresh biomass production is computed from transpiration, assuming transpiration efficiency to be constant and atmospheric demand to be the driving force, under non‐limiting water supply. The fresh biomass is then distributed among expanding organs according to their relative demand. Demand for organ growth is estimated from allometric relationships (e.g. leaf surface to weight ratios) and kinetics of potential growth rate for each organ type. These are obtained through parameter optimization against empirical, morphological data sets by running the model in inverted mode. Potential growth rates are then used as estimates of relative sink strength in the model. These and other ‘hidden’ plant parameters are calibrated using the non‐linear, least‐square method. • Key Results and Conclusions The model reproduced accurately the dynamics of plant growth, architecture and geometry of various annual and woody plants, enabling 3D visualization. It was also able to simulate the variability of leaf size on the plant and compensatory growth following pruning, as a result of internal competition for resources. The potential of the model’s underlying concepts to predict the plant

  19. Dynamic simulation models and performance of an OTEC power plant

    SciTech Connect

    Wormley, D.N.; Carmichael, D.A.; Umans, S.

    1983-08-01

    In this study, the aspects of plant performance which influence the potential for integration of an OTEC plant into a utility grid are considered. A set of simulation models have been developed for the evaluation of OTEC dynamic plant performance. A detailed nonlinear dynamic model has been forumlated which is useful for the assessment of component performance including heat exchangers, turbines, pumps and control systems. A reduced order linear model has been developed which is useful for studies of plant stability, control system development and transient performance of the plant connected to a utility grid. This model is particularly suitable for transient dynamic studies of an OTEC plant as a unit in a utility grid. A quasi-steady power availability model has also been developed which is useful to determine plant ouput power as a function of ocean thermal gradients so that the influence of daily and seasonal temperature variations may be easily computed. The study has found no fundamental technical barriers which would prohibit the interconnection of an OTEC plant into a utility grid. It has also shown that detailed consideration of turbine nozzle angle control is merited and such a control has the potential to provide superior performance in comparison to turbine bypass valve control.

  20. USE OF MODELING APPROACHES TO UNDERSTAND POTENTIAL IMPACTS OF GENETICALLY MODIFIED PLANTS ON PLANT COMMUNITIES

    EPA Science Inventory

    Model development is of interest to ecologists, regulators and developers, since it may assist theoretical understanding, decision making in experimental design, product development and risk assessment. In order to predict the potential impacts of genetically modified (GM) plants...

  1. USE OF MODELING APPROACHES TO UNDERSTAND POTENTIAL IMPACTS OF GENETICALLY MODIFIED PLANTS ON PLANT COMMUNITIES

    EPA Science Inventory

    Model development is of interest to ecologists, regulators and developers, since it may assist theoretical understanding, decision making in experimental design, product development and risk assessment. In order to predict the potential impacts of genetically modified (GM) plants...

  2. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1995--June 20, 1995

    SciTech Connect

    Kochian, L.

    1995-12-01

    The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.

  3. CHARACTERIZATION AND MODELING OF THE FORMS OF MERCURY FROM COAL-FIRED POWER PLANTS

    SciTech Connect

    Dennis L. Laudal

    2001-08-01

    The 1990 Clean Air Act Amendments (CAAAs) required the U.S. Environmental Protection Agency (EPA) to determine whether the presence of mercury in the stack emissions from fossil fuel-fired electric utility power plants poses an unacceptable public health risk. EPA's conclusions and recommendations were presented in the Mercury Study Report to Congress (1) and the Utility Air Toxics Report to Congress (1). The first report addressed both the human health and environmental effects of anthropogenic mercury emissions, while the second addressed the risk to public health posed by the emission of mercury and other hazardous air pollutants from steam-electric generating units. Given the current state of the art, these reports did not state that mercury controls on coal-fired electric power stations would be required. However, they did indicate that EPA views mercury as a potential threat to human health. In fact, in December 2000, the EPA issued an intent to regulate for mercury from coal-fired boilers. However, it is clear that additional research needs to be done in order to develop economical and effective mercury control strategies. To accomplish this objective, it is necessary to understand mercury behavior in coal-fired power plants. The markedly different chemical and physical properties of the different mercury forms generated during coal combustion appear to impact the effectiveness of various mercury control strategies. The original Characterization and Modeling of the Forms of Mercury from Coal-Fired Power Plants project had two tasks. The first was to collect enough data such that mercury speciation could be predicted based on relatively simple inputs such as coal analyses and plant configuration. The second was to field-validate the Ontario Hydro mercury speciation method (at the time, it had only been validated at the pilot-scale level). However, after sampling at two power plants (the Ontario Hydro method was validated at one of them), the EPA issued an

  4. Single Plant Root System Modeling under Soil Moisture Variation

    NASA Astrophysics Data System (ADS)

    Yabusaki, S.; Fang, Y.; Chen, X.; Scheibe, T. D.

    2016-12-01

    A prognostic Virtual Plant-Atmosphere-Soil System (vPASS) model is being developed that integrates comprehensively detailed mechanistic single plant modeling with microbial, atmospheric, and soil system processes in its immediate environment. Three broad areas of process module development are targeted: Incorporating models for root growth and function, rhizosphere interactions with bacteria and other organisms, litter decomposition and soil respiration into established porous media flow and reactive transport models Incorporating root/shoot transport, growth, photosynthesis and carbon allocation process models into an integrated plant physiology model Incorporating transpiration, Volatile Organic Compounds (VOC) emission, particulate deposition and local atmospheric processes into a coupled plant/atmosphere model. The integrated plant ecosystem simulation capability is being developed as open source process modules and associated interfaces under a modeling framework. The initial focus addresses the coupling of root growth, vascular transport system, and soil under drought scenarios. Two types of root water uptake modeling approaches are tested: continuous root distribution and constitutive root system architecture. The continuous root distribution models are based on spatially averaged root development process parameters, which are relatively straightforward to accommodate in the continuum soil flow and reactive transport module. Conversely, the constitutive root system architecture models use root growth rates, root growth direction, and root branching to evolve explicit root geometries. The branching topologies require more complex data structures and additional input parameters. Preliminary results are presented for root model development and the vascular response to temporal and spatial variations in soil conditions.

  5. Measurement and modelling of sap flow in maize plants

    NASA Astrophysics Data System (ADS)

    Heinlein, Florian; Biernath, Christian; Hoffmann, Peter; Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2014-05-01

    Climate change as well as the changing composition of the atmosphere will have an impact on future yield of agricultural plants. In order to better estimate these impacts new, mechanistic plant growth models are needed. These models should be able to dynamically reproduce the plants' reactions to modified climate state variables like temperature, atmospheric CO2-concentration and water availability. In particular, to better describe the crop response to more strongly changing water availability the simulation of plant-internal water and solute transport processes in xylem and phloem needs to be improved. Our existing water transport model consists of two coupled 1-D Richards equations to calculate water transport in the soil and in the plants. This model has already been successfully applied to single Fagus sylvatica L. trees. At present it is adapted to agricultural plants such as maize. To simulate the water transport within the plants a representation of the flow paths, i.e. the plant architecture, is required. Aboveground plant structures are obtained from terrestrial laser scan (TLS) measurements at different development stages. These TLSs have been executed at the lysimeter facilities of Helmholtz Zentrum München and at the TERENO (Terrestrial Environmental Observatories) research farm Scheyern. Additionally, an L-system model is used to simulate aboveground and belowground plant architectures. In a further step, the quality of the explicit water flow model has to be tested using measurements. The Heat-Ratio-Method has been employed to directly measure sap flow in larger maize plants during a two-months-period in summer 2013 with a resolution of 10 minutes and thus, the plants' transpiration can be assessed. Water losses from the soil are determined by measuring the weight of lysimeters. From this evapotranspiration can be calculated. Transpiration and evapotranspiration are also simulated by application of the modelling system Expert-N. This framework

  6. FETC/EPRI Biomass Cofiring Cooperative Agreement. Quarterly technical report, April 1-June 30, 1997

    SciTech Connect

    Hughes, E.; Tillman, D.

    1997-12-01

    The FETC/EPRI Biomass Cofiring Program has accelerated the pace of cofiring development by increasing the testing activities plus the support activities for interpreting test results. Past tests conducted and analyzed include the Allen Fossil Plant and Seward Generating Station programs. On-going tests include the Colbert Fossil Plant precommercial test program, the Greenidge Station commercialization program, and the Blount St. Station switchgrass program. Tests in the formative stages included the NIPSCO cofiring test at Michigan City Generating Station. Analytical activities included modeling and related support functions required to analyze the cofiring test results, and to place those results into context. Among these activities is the fuel availability study in the Pittsburgh, PA area. This study, conducted for Duquesne Light, supports their initial investigation into reburn technology using wood waste as a fuel. This Quarterly Report, covering the third quarter of the FETC/EPRI Biomass Cofiring Program, highlights the progress made on the 16 projects funded under this cooperative agreement.

  7. Modeling of bleach plant washer mineral scale

    Treesearch

    Alan Rudie; Peter Hart

    2004-01-01

    One of the more common areas of mineral scale formation in bleach plants is on washer face wires and the extraction rings of diffusion washers. Whereas most scale problems can be understood as a mixing of two streams that increase the concentrations of anions and cations and exceed a solubility product, washer problems are often more difficult to understand. The...

  8. Editorial: Plant organ abscission: from models to crops

    USDA-ARS?s Scientific Manuscript database

    The shedding of plant organs is a highly coordinated process essential for both vegetative and reproductive development (Addicott, 1982; Sexton and Roberts, 1982; Roberts et al., 2002; Leslie et al., 2007; Roberts and Gonzalez-Carranza, 2007; Estornell et al., 2013). Research with model plants, name...

  9. Multiscale Models in the Biomechanics of Plant Growth

    PubMed Central

    Fozard, John A.

    2015-01-01

    Plant growth occurs through the coordinated expansion of tightly adherent cells, driven by regulated softening of cell walls. It is an intrinsically multiscale process, with the integrated properties of multiple cell walls shaping the whole tissue. Multiscale models encode physical relationships to bring new understanding to plant physiology and development. PMID:25729061

  10. Plant Phenotyping using Probabilistic Topic Models: Uncovering the Hyperspectral Language of Plants.

    PubMed

    Wahabzada, Mirwaes; Mahlein, Anne-Katrin; Bauckhage, Christian; Steiner, Ulrike; Oerke, Erich-Christian; Kersting, Kristian

    2016-03-09

    Modern phenotyping and plant disease detection methods, based on optical sensors and information technology, provide promising approaches to plant research and precision farming. In particular, hyperspectral imaging have been found to reveal physiological and structural characteristics in plants and to allow for tracking physiological dynamics due to environmental effects. In this work, we present an approach to plant phenotyping that integrates non-invasive sensors, computer vision, as well as data mining techniques and allows for monitoring how plants respond to stress. To uncover latent hyperspectral characteristics of diseased plants reliably and in an easy-to-understand way, we "wordify" the hyperspectral images, i.e., we turn the images into a corpus of text documents. Then, we apply probabilistic topic models, a well-established natural language processing technique that identifies content and topics of documents. Based on recent regularized topic models, we demonstrate that one can track automatically the development of three foliar diseases of barley. We also present a visualization of the topics that provides plant scientists an intuitive tool for hyperspectral imaging. In short, our analysis and visualization of characteristic topics found during symptom development and disease progress reveal the hyperspectral language of plant diseases.

  11. Plant Phenotyping using Probabilistic Topic Models: Uncovering the Hyperspectral Language of Plants

    PubMed Central

    Wahabzada, Mirwaes; Mahlein, Anne-Katrin; Bauckhage, Christian; Steiner, Ulrike; Oerke, Erich-Christian; Kersting, Kristian

    2016-01-01

    Modern phenotyping and plant disease detection methods, based on optical sensors and information technology, provide promising approaches to plant research and precision farming. In particular, hyperspectral imaging have been found to reveal physiological and structural characteristics in plants and to allow for tracking physiological dynamics due to environmental effects. In this work, we present an approach to plant phenotyping that integrates non-invasive sensors, computer vision, as well as data mining techniques and allows for monitoring how plants respond to stress. To uncover latent hyperspectral characteristics of diseased plants reliably and in an easy-to-understand way, we “wordify” the hyperspectral images, i.e., we turn the images into a corpus of text documents. Then, we apply probabilistic topic models, a well-established natural language processing technique that identifies content and topics of documents. Based on recent regularized topic models, we demonstrate that one can track automatically the development of three foliar diseases of barley. We also present a visualization of the topics that provides plant scientists an intuitive tool for hyperspectral imaging. In short, our analysis and visualization of characteristic topics found during symptom development and disease progress reveal the hyperspectral language of plant diseases. PMID:26957018

  12. Dynamics of an ant-plant-pollinator model

    NASA Astrophysics Data System (ADS)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  13. EMSL Quarterly Highlights Report: 1st Quarter, FY08

    SciTech Connect

    Showalter, Mary Ann

    2008-01-28

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  14. EMSL Quarterly Highlights Report: 1st Quarter, Fiscal Year 2009

    SciTech Connect

    Showalter, Mary Ann; Kathmann, Loel E.; Manke, Kristin L.

    2009-02-02

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2008 - December 2008) of Fiscal Year 2009.

  15. EMSL Quarterly Highlights Report: FY 2008, 3rd Quarter

    SciTech Connect

    Showalter, Mary Ann

    2008-09-16

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  16. Time-delayed model of immune response in plants.

    PubMed

    Neofytou, G; Kyrychko, Y N; Blyuss, K B

    2016-01-21

    In the studies of plant infections, the plant immune response is known to play an essential role. In this paper we derive and analyse a new mathematical model of plant immune response with particular account for post-transcriptional gene silencing (PTGS). Besides biologically accurate representation of the PTGS dynamics, the model explicitly includes two time delays to represent the maturation time of the growing plant tissue and the non-instantaneous nature of the PTGS. Through analytical and numerical analysis of stability of the steady states of the model we identify parameter regions associated with recovery and resistant phenotypes, as well as possible chronic infections. Dynamics of the system in these regimes is illustrated by numerical simulations of the model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Fire models for assessment of nuclear power plant fires

    SciTech Connect

    Nicolette, V.F.; Nowlen, S.P.

    1989-01-01

    This paper reviews the state-of-the-art in available fire models for the assessment of nuclear power plants fires. The advantages and disadvantages of three basic types of fire models (zone, field, and control volume) and Sandia's experience with these models will be discussed. It is shown that the type of fire model selected to solve a particular problem should be based on the information that is required. Areas of concern which relate to all nuclear power plant fire models are identified. 17 refs., 6 figs.

  18. Model intercomparison for the uptake of organic chemicals by plants.

    PubMed

    Collins, Christopher D; Fryer, Mike E

    2003-04-15

    Currently, a variety of models are available for predicting the uptake, translocation, and elimination of organic contaminants by plants. These models range from simple deterministic risk assessment screening tools to more complex models that consider physical, chemical, and biological processes in a mechanistic manner. This study evaluates the performance of a range of such models and model types against experimental data sets. Three dynamic, three regression-based, and three steady-state and equilibrium models have been selected for evaluation. These models differ in terms of their scope, methodological approach, and complexity. Data from nine published experiments were used to create scenarios to test model performance. These experiments consider plant contamination via both soil and aerial exposure pathways. A total of 19 different organic chemicals were used in the experiments along with 7 different plant species. Model predictions of chemical concentrations in the relevant plant compartments were compared with the experimentally recorded values. The results indicate that dynamic models offer performance advantages for acute exposure durations and for rapidly changing environmental media. Equilibrium/steady-state and regression-based models perform better for chronic exposure durations, where stable conditions are more likely to exist. The selection of an appropriate plant uptake model will therefore be dependent on the requirements of the assessment, the nature of the environmental media, and the duration of the source term. The results generated by the regression-based models suggest that in their current form these models are unsuitable for evaluating the uptake of organic chemicals from the air into plants.

  19. Modeling of air pollution from the power plant ash dumps

    NASA Astrophysics Data System (ADS)

    Aleksic, Nenad M.; Balać, Nedeljko

    A simple model of air pollution from power plant ash dumps is presented, with emission rates calculated from the Bagnold formula and transport simulated by the ATDL type model. Moisture effects are accounted for by assumption that there is no pollution on rain days. Annual mean daily sedimentation rates, calculated for the area around the 'Nikola Tesla' power plants near Belgrade for 1987, show reasonably good agreement with observations.

  20. Past, present, and future of Brachypodium as a model plant

    USDA-ARS?s Scientific Manuscript database

    Biologists rely on a plethora of model systems to study an exceptionally broad range of questions in biology. These model systems range from simple prokaryotes to complex animal species. In plants, the most powerful model system has been Arabidopsis thaliana (Arabidopsis), a small dicotyledonous wee...

  1. Model of annual plants dynamics with facilitation and competition.

    PubMed

    Droz, Michel; Pękalski, Andrzej

    2013-10-21

    An individual-based model describing the dynamics of one type of annual plants is presented. We use Monte Carlo simulations where each plant has its own history and the interactions among plants are between nearest neighbours. The character of the interaction (positive or negative) depends on local conditions. The plants compete for two external resources-water and light. The amount of water and/or light a plant receives depends on the external factor but also on local arrangement. Survival, growth and seed production of plants are determined by how well their demands for the resources are met. The survival and seeds production tests have a probabilistic character, which makes the dynamics more realistic than by using a deterministic approach. There is a non-linear coupling between the external supplies. Water evaporates from the soil at a rate depending on constant evaporation rate, local conditions and the amount of light. We examine the dynamics of the plant population along two environmental gradients, allowing also for surplus of water and/or light. We show that the largest number of plants is when the demands for both resources are equal to the supplies. We estimate also the role of evaporation and we find that it depends on the situation. It could be negative, but sometimes it has a positive character. We show that the link between the type of interaction (positive or negative) and external conditions has a complex character. In general in favourable environment plants have a stronger tendency for competitive interactions, leading to mostly isolated plants. When the conditions are getting more difficult, cooperation becomes the dominant type of interactions and the plants grow in clusters. The type of plants-sun-loving or shade tolerating, plays also an important role.

  2. A plant-wide energy model for wastewater treatment plants: application to anaerobic membrane bioreactor technology.

    PubMed

    Pretel, R; Robles, A; Ruano, M V; Seco, A; Ferrer, J

    2016-09-01

    The aim of this study is to propose a detailed and comprehensive plant-wide model for assessing the energy demand of different wastewater treatment systems (beyond the traditional activated sludge) in both steady- and unsteady-state conditions. The proposed model makes it possible to calculate power and heat requirements (W and Q, respectively), and to recover both power and heat from methane and hydrogen capture. In order to account for the effect of biological processes on heat requirements, the model has been coupled to the extended version of the BNRM2 plant-wide mathematical model, which is implemented in DESSAS simulation software. Two case studies have been evaluated to assess the model's performance: (1) modelling the energy demand of two urban wastewater treatment plants based on conventional activated sludge and submerged anaerobic membrane bioreactor (AnMBR) technologies in steady-state conditions and (2) modelling the dynamics of reactor temperature and heat requirements in an AnMBR plant in unsteady-state conditions. The results indicate that the proposed model can be used to assess the energy performance of different wastewater treatment processes and would thus be useful, for example, WWTP design or upgrading or the development of new control strategies for energy savings.

  3. A dynamical systems model for nuclear power plant risk

    NASA Astrophysics Data System (ADS)

    Hess, Stephen Michael

    The recent transition to an open access generation marketplace has forced nuclear plant operators to become much more cost conscious and focused on plant performance. Coincidentally, the regulatory perspective also is in a state of transition from a command and control framework to one that is risk-informed and performance-based. Due to these structural changes in the economics and regulatory system associated with commercial nuclear power plant operation, there is an increased need for plant management to explicitly manage nuclear safety risk. Application of probabilistic risk assessment techniques to model plant hardware has provided a significant contribution to understanding the potential initiating events and equipment failures that can lead to core damage accidents. Application of the lessons learned from these analyses has supported improved plant operation and safety over the previous decade. However, this analytical approach has not been nearly as successful in addressing the impact of plant processes and management effectiveness on the risks of plant operation. Thus, the research described in this dissertation presents a different approach to address this issue. Here we propose a dynamical model that describes the interaction of important plant processes among themselves and their overall impact on nuclear safety risk. We first provide a review of the techniques that are applied in a conventional probabilistic risk assessment of commercially operating nuclear power plants and summarize the typical results obtained. The limitations of the conventional approach and the status of research previously performed to address these limitations also are presented. Next, we present the case for the application of an alternative approach using dynamical systems theory. This includes a discussion of previous applications of dynamical models to study other important socio-economic issues. Next, we review the analytical techniques that are applicable to analysis of

  4. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species, Quarterly technical progress report, December 20, 1995--March 20, 1995

    SciTech Connect

    Kochian, L.; Brady, D.; Last, M.; Ebbs, S.

    1995-12-01

    Although the period covered by this progress report began on December 20, 1994, which was the date that DOE approved the Interagency Agreement, the agreement was not approved by USDA until January 9, 1995 and the first scientists working on the project were not hired until February 1, 1995. The first goal of the research supported by the Interagency Agreement is to use hydroponic techniques to identify plant species and genotypes with potential for heavy metal hyperaccumulation for planting on a test site at Silverbow Creek and for radionuclide ({sup 90}Sr and {sup 137}Cs) accumulation on a test site at INEL, Idaho, later this year. The second goal of this research is to identify soil amendment procedures that will enhance the bioavailability of heavy metals and radionuclides in the soil without increasing the movement of the contaminants of concern (COC`s) into the groundwater. Our initial research covered in this report focuses on the first goal.

  5. Sampling results, DNAPL monitoring well GW-726, Oak Ridge Y-12 plant, Oak Ridge, Tennessee. Quarterly report, April 1, 1994--September 30, 1994.

    SciTech Connect

    1995-12-31

    In January 1990, dense, non aqueous phase liquids (DNAPLs) were discovered at a depth of approximately 274 foot below ground surface along the southern border of the Y-12 Plant Burial Grounds. Immediately after the discovery, an investigation was conducted to assess the occurrence of DNAPL at the site and to make recommendations for further action. This report summarizes purging and sampling activities for one of these multiport wells, GW-726, and presents analytical results for GW-726.

  6. Combustion characterization of coal fines recovered from the handling plant. Quarterly technical progress report No. 2, January 1, 1995--March 31, 1995

    SciTech Connect

    Houshang, Masudi

    1995-04-01

    The main goal of this research project is to evaluate the combustion characteristics of the slurry fuels prepared from the recovered coal fines and plant coal fines. A specific study will include the combustion behavior, flame stability, ash behavior and emissions of SO{sub x}, NO{sub x} and particulate in a well insulated laboratory scale furnace in which the residence time and temperature history of the burning particles are similar to that of utility boiler furnace at 750,000 Btu/hr input and 20% excess air. The slurry fuel will be prepared at 60% solid to match the generic slurry properties, i.e., viscosity less than 500 cp, 100% of particles passing through 100 mesh and 80-90% of solid particles passing through 200 mesh. The coal blend is prepared using a mix of 15% effluent recovered coal and 85% plant fines. Combustion characteristics of the slurry fuels is determined at three different firing rates 750K, 625K, 500K Btu/hr. Finally a comparison of the results is made to determine the advantages of coal water slurry fuel over the plant coal blended form.

  7. Cristoforetti in Crew quarters

    NASA Image and Video Library

    2014-12-06

    iss042e023422 (12/6/14) --- Expedition 42 Flight Engineer Samantha Cristoforetti of the European Space Agency (ESA) on 6 December 2014 is seen inside of a sleeping bag in her personal crew quarters on the International Space Station. Astronauts will strap the bag to the wall to prevent from free floating and potentially bumping into equipment while sleeping.

  8. Coleman in sleeping quarters

    NASA Image and Video Library

    2010-12-25

    ISS026-E-012158 (25 Dec. 2010) --- NASA astronaut Catherine (Cady) Coleman, Expedition 26 flight engineer, and one of six crew members currently aboard the International Space Station, peeks out of her sleeping quarters on Christmas morning to view the station’s decorations and gifts.

  9. Gifted Education Quarterly, 1998.

    ERIC Educational Resources Information Center

    Fisher, Maurice, Ed.

    1998-01-01

    These four issues of "Gifted Education Quarterly" include the following articles: (1) "Using Test Results To Support Clinical Judgment" (Linda Kreger Silverman), which discusses some of the difficulties in obtaining accurate indications of a child's level of giftedness and the importance of using professional judgment in…

  10. English Leadership Quarterly, 1995.

    ERIC Educational Resources Information Center

    Kiernan, Henry, Ed.

    1995-01-01

    These 4 issues of the English Leadership Quarterly comprise volume 17, published during 1995. Articles in number 1 deal with multicultural and multiethnic literature, and are, as follows: "Guidelines for Selecting European Ethnic Literature for Interdisciplinary Courses" (Sandra Stotsky); "Striving for Kinship within Diverse Communities" (Peter…

  11. Trustee Quarterly, 1997.

    ERIC Educational Resources Information Center

    Hutchins, Sally, Ed.

    1997-01-01

    These four issues of "Trustee Quarterly" focus on current topics affecting community college trustees. Issue 1 focuses on the learning revolution and serves as a guide for community college trustees. It offers the following feature articles by Terry O'Banion: "Education Reform: Two Waves,""The Second Wave and the Community…

  12. English Leadership Quarterly, 1994.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.; Kiernan, Henry, Ed.

    1994-01-01

    These 4 issues of the English Leadership Quarterly comprise volume 16, published during 1994. Articles in number 1 deal with practical advice, and include: "The Law of Privacy and the Writing Teacher" (Ben T. Allen); Beware of Teachers Who Laminate Their Lesson Plans and Other Useful Suggestions about Teaching" (Robert Perrin);…

  13. English Leadership Quarterly, 1993.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1993-01-01

    These four issues of the English Leadership Quarterly represent those published during 1993. Articles in number 1 deal with parent involvement and participation, and include: "Opening the Doors to Open House" (Jolene A. Borgese); "Parent/Teacher Conferences: Avoiding the Collision Course" (Robert Perrin); "Expanding Human…

  14. Trustee Quarterly, 1994.

    ERIC Educational Resources Information Center

    Trustee Quarterly, 1994

    1994-01-01

    The four issues of "Trustee Quarterly" combined here focus on topics of current concern to community college trustees. The winter 1994 issues offers these feature articles: "Honoring Retiring Presidents," by Terry O'Banion; "Trustees as Reluctant Leaders: The Board/CEO Relationship," Norma Jean Germond, John Keyser, and Vaughn A. Sherman; and…

  15. Trustee Quarterly, 1994.

    ERIC Educational Resources Information Center

    Trustee Quarterly, 1994

    1994-01-01

    The four issues of "Trustee Quarterly" combined here focus on topics of current concern to community college trustees. The winter 1994 issues offers these feature articles: "Honoring Retiring Presidents," by Terry O'Banion; "Trustees as Reluctant Leaders: The Board/CEO Relationship," Norma Jean Germond, John Keyser, and Vaughn A. Sherman; and…

  16. English Leadership Quarterly, 1992.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1992-01-01

    These four issues of the English Leadership Quarterly represent those published during 1992. Articles in number 1 deal with testing assessing, and measuring student performance, and include: "Real Evaluation: Portfolios as an Effective Alternative to Standardized Testing" (Kate Kiefer); "No More Objective Tests, Ever" (Carol…

  17. Trustee Quarterly, 1992.

    ERIC Educational Resources Information Center

    Trustee Quarterly, 1992

    1992-01-01

    The four issues of "Trustee Quarterly" contained in this document focus on topics of current concern to community college trustees. The winter 1992 issue offers articles on the trustee's role in politics, community colleges as community catalysts, Lewis and Clark Community College's (Illinois) strategic planning process, staff development…

  18. Trustee Quarterly, 1993.

    ERIC Educational Resources Information Center

    Trustee Quarterly, 1993

    1993-01-01

    The four issues of "Trustee Quarterly" contained in this document focus on topics of current concern to community college trustees. The winter 1993 issue offers articles on the prospects for educational reform under the Clinton administration and the current Congress, strategies for obtaining needed resources from the state legislature, and the…

  19. Applications of metabolic modelling to plant metabolism.

    PubMed

    Poolman, M G; Assmus, H E; Fell, D A

    2004-05-01

    In this paper some of the general concepts underpinning the computer modelling of metabolic systems are introduced. The difference between kinetic and structural modelling is emphasized, and the more important techniques from both, along with the physiological implications, are described. These approaches are then illustrated by descriptions of other work, in which they have been applied to models of the Calvin cycle, sucrose metabolism in sugar cane, and starch metabolism in potatoes. Copyright 2004 Society for Experimental Biology

  20. Mesoscale to plant-scale models of nuclear waste reprocessing.

    SciTech Connect

    Noble, David Frederick; O'Hern, Timothy John; Moffat, Harry K.; Nemer, Martin B.; Domino, Stefan Paul; Rao, Rekha Ranjana; Cipiti, Benjamin B.; Brotherton, Christopher M.; Jove-Colon, Carlos F.; Pawlowski, Roger Patrick

    2010-09-01

    Imported oil exacerabates our trade deficit and funds anti-American regimes. Nuclear Energy (NE) is a demonstrated technology with high efficiency. NE's two biggest political detriments are possible accidents and nuclear waste disposal. For NE policy, proliferation is the biggest obstacle. Nuclear waste can be reduced through reprocessing, where fuel rods are separated into various streams, some of which can be reused in reactors. Current process developed in the 1950s is dirty and expensive, U/Pu separation is the most critical. Fuel rods are sheared and dissolved in acid to extract fissile material in a centrifugal contactor. Plants have many contacts in series with other separations. We have taken a science and simulation-based approach to develop a modern reprocessing plant. Models of reprocessing plants are needed to support nuclear materials accountancy, nonproliferation, plant design, and plant scale-up.

  1. Estimating regional plant biodiversity with GIS modelling

    Treesearch

    Louis R. Iverson; Anantha M. Prasad; Anantha M. Prasad

    1998-01-01

    We analyzed a statewide species database together with a county-level geographic information system to build a model based on well-surveyed areas to estimate species richness in less surveyed counties. The model involved GIS (Arc/Info) and statistics (S-PLUS), including spatial statistics (S+SpatialStats).

  2. Towards aspect-oriented functional–structural plant modelling

    PubMed Central

    Cieslak, Mikolaj; Seleznyova, Alla N.; Prusinkiewicz, Przemyslaw; Hanan, Jim

    2011-01-01

    Background and Aims Functional–structural plant models (FSPMs) are used to integrate knowledge and test hypotheses of plant behaviour, and to aid in the development of decision support systems. A significant amount of effort is being put into providing a sound methodology for building them. Standard techniques, such as procedural or object-oriented programming, are not suited for clearly separating aspects of plant function that criss-cross between different components of plant structure, which makes it difficult to reuse and share their implementations. The aim of this paper is to present an aspect-oriented programming approach that helps to overcome this difficulty. Methods The L-system-based plant modelling language L+C was used to develop an aspect-oriented approach to plant modelling based on multi-modules. Each element of the plant structure was represented by a sequence of L-system modules (rather than a single module), with each module representing an aspect of the element's function. Separate sets of productions were used for modelling each aspect, with context-sensitive rules facilitated by local lists of modules to consider/ignore. Aspect weaving or communication between aspects was made possible through the use of pseudo-L-systems, where the strict-predecessor of a production rule was specified as a multi-module. Key Results The new approach was used to integrate previously modelled aspects of carbon dynamics, apical dominance and biomechanics with a model of a developing kiwifruit shoot. These aspects were specified independently and their implementation was based on source code provided by the original authors without major changes. Conclusions This new aspect-oriented approach to plant modelling is well suited for studying complex phenomena in plant science, because it can be used to integrate separate models of individual aspects of plant development and function, both previously constructed and new, into clearly organized, comprehensive FSPMs. In

  3. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    NASA Astrophysics Data System (ADS)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  4. Public lakes, private lakeshore: modeling protection of native aquatic plants.

    PubMed

    Schroeder, Susan A; Fulton, David C

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  5. Commercial second-generation PFBC plant transient model: Task 15

    SciTech Connect

    White, J.S.; Getty, R.T.; Torpey, M.R.

    1995-04-01

    The advanced pressurized fluidized bed combustor (APFBC) power plant combines an efficient gas-fired combined cycle, a low-emission PFB combustor, and a coal pyrolysis unit (carbonizer) that converts coal, America`s most plentiful fuel, into the gas turbine fuel. From an operation standpoint, the APFBC plant is similar to an integrated gasification combined cycle (IGCC) plant, except that the PFBC and fluid bed heat exchanger (FBHE) allow a considerable fraction of coal energy to be shunted around the gas turbine and sent directly to the steam turbine. By contrast, the fuel energy in IGCC plants and most other combined cycles is primarily delivered to the gas turbine and then to the steam turbine. Another characteristic of the APFBC plant is the interaction among three large thermal inertias--carbonizer, PFBC, and FBHE--that presents unique operational challenges for modeling and operation of this type of plant. This report describes the operating characteristics and dynamic responses of the APFBC plant and discusses the advantages and shortcomings of several alternative control strategies for the plant. In particular, interactions between PFBC, FBHE, and steam bottoming cycle are analyzed and the effect of their interactions on plant operation is discussed. The technical approach used in the study is described in Section 2. The dynamic model is introduced in Section 3 and described is detail in the appendices. Steady-state calibration and transient simulations are presented in Sections 4 and 5. The development of the operating philosophy is discussed in Section 6. Potential design changes to the dynamic model and trial control schemes are listed in Sections 7 and 8. Conclusions derived from the study are presented in Section 9.

  6. Ocean thermal energy. Quarterly report, October-December 1981

    SciTech Connect

    Not Available

    1981-12-30

    This quarterly report summarizes work on the following tasks: OTEC methanol; approaches for financing OTEC proof-of-concept experimental vessels; investigation of OTEC-ammonia as an alternative fuel; review of electrolyzer development programs and requirements; hybrid geothermal-OTEC power plants: single-cycle performance; estimates; and hybrid geothermal-OTEC power plants: dual-cycle performance estimates.

  7. Coal liquefaction. Quarterly report, July-September 1979

    SciTech Connect

    1980-07-01

    The status of coal liquefaction pilot plants supported by US DOE is reviewed under the following headings: company involved, location, contract, funding, process name, process description, flowsheet, history and progress during the July-September 1979 quarter. Supporting projects such as test facilities, refining and upgrading coal liquids, catalyst development, and gasification of residues from coal gasification plants are discussed similarly. (LTN)

  8. Ocean energy systems. Quarterly report, July-September 1982

    SciTech Connect

    Not Available

    1982-09-30

    This quarterly report summarizes work on the following tasks as of September 30, 1982: (1) OTEC pilot plant conceptual design review; (2) OTEC methanol; (3) financial and legal considerations in OTEC implementation; (4) GEOTEC resource exploration at Adak, Alaska, and Lualualei, Hawaii; (5) preliminary GEOTEC plant cost estimates; and (6) supervision of testing of pneumatic wave energy conversion system.

  9. Ocean thermal energy. Quarterly report, April-June 1982

    SciTech Connect

    Not Available

    1982-06-30

    This quarterly report includes summaries of the following tasks: (1) OTEC pilot plant conceptual design review; (2) OTEC methanol; (3) management decision requirements for OTEC construction; (4) hybrid geothermal - OTEC (GEOTEC) power plant performance estimates; and (5) supervision of testing of pneumatic wave energy conversion system.

  10. Ocean thermal energy. Quarterly report, January-March 1982

    SciTech Connect

    Not Available

    1982-03-30

    This quarterly report summarizes work of the following tasks as of March 31, 1982: OTEC pilot plant conceptual design review; OTEC methanol; review of electrolyzer development programs and requirements; financial and legal considerations in OTEC implementation; potential Navy sites for GEOTEC systems; hybrid geothermal-OTEC power plants: single-cycle performance estimates; and supervision of testing of pneumatic wave energy conversion system.

  11. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly progress report, July 1, 1996--September 30, 1996

    SciTech Connect

    Kochian, L.

    1997-05-01

    Potential for phytoremediation of an aged radiocesium-contaminated soil from Brookhaven National Laboratory was investigated in three phases: (1) hydroponic screening for plant species capable of accumulating elevated levels of cesium in shoots, (2) amending contaminated soil to enhance {sup 137}Cs bioavailability, and (3) phytoextracting radiocesium with plant roots and its removal in harvested shoots. The bioaccumulation ratio of Cs in shoots of hydroponically grown plants ranged between 38 and 165. From solution, dicot species accumulated 2- to 4-fold more cesium in shoots than grasses. The effect of several chemical compounds on {sup 137}Cs desorption from the contaminated soil was investigated. Ammonium salts were the most effective at desorbing Cs from contaminated soil, but only 25% of radiocesium could be desorbed. Although release of radiocesium from the soil was concentration-dependent, this effect appeared to level off above 0.2 M ammonium in solution. In a pot study, from the soil contaminated with 400 pCi g{sup -1} soil, the greatest amount of {sup 137}Cs, 140 pCi, was removed in shoots of cabbage (Brassica oleracea var. capitata). {sup 137}Cs accumulation in shoots was significantly increased by the addition of 40 NH{sub 4}NO{sub 3} kg{sup -1} soil. Increasing NH{sub 4}NO{sub 3} application from 40 to 80 mmoles kg{sup -1} soil did not further increase radiocesium phytoextraction. The ability to accumulate radiocesium from soil in shoots was significantly different among species tested. This ability increased in order: reed Canary grass (Phalaris arundinacea) < Indian mustard (Brassica juncea) < tepary bean (Phaseolus acutifolius) < cabbage.

  12. A collaborative effort to model plant response to acidic rain

    SciTech Connect

    Jacobson, J.; Irving, P.; Kuja, A.; Lee, J.; Shriner, D.; Troiano, J.; Perrigan, S.; Cullinan, V.

    1989-01-01

    Radish plants were exposed three times per week to simulated acidic rain at pH values of 2.6 to 5.4 over the course of four weeks in trials performed at Argonne, Illinois; Ithaca and Upton, New York; Corvallis, Oregon; Oak Ridge, Tennessee; and Toronto, Canada. Uniform genotype, soil media and planting techniques, treatment procedures, biological measurements, and experimental design were employed. Growth of plants differed among trials as a result of variation in greenhouse environmental conditions according to location and facilities. Larger plants underwent greater absolute but lower relative reductions in biomass after exposure to the higher levels of acidity. A generalized Mitscherlich function was used to model the effects of acidity of simulated rain on dry mass of hypocotyls using data from three laboratories that performed duplicate trials. The remaining data, from three other laboratories that performed only one trial each, were used to test the model. 14 refs., 2 figs., 7 tabs.

  13. The components of crop productivity: measuring and modeling plant metabolism

    NASA Technical Reports Server (NTRS)

    Bugbee, B.

    1995-01-01

    Several investigators in the CELSS program have demonstrated that crop plants can be remarkably productive in optimal environments where plants are limited only by incident radiation. Radiation use efficiencies of 0.4 to 0.7 g biomass per mol of incident photons have been measured for crops in several laboratories. Some early published values for radiation use efficiency (1 g mol-1) were inflated due to the effect of side lighting. Sealed chambers are the basic research module for crop studies for space. Such chambers allow the measurement of radiation and CO2 fluxes, thus providing values for three determinants of plant growth: radiation absorption, photosynthetic efficiency (quantum yield), and respiration efficiency (carbon use efficiency). Continuous measurement of each of these parameters over the plant life cycle has provided a blueprint for daily growth rates, and is the basis for modeling crop productivity based on component metabolic processes. Much of what has been interpreted as low photosynthetic efficiency is really the result of reduced leaf expansion and poor radiation absorption. Measurements and models of short-term (minutes to hours) and long-term (days to weeks) plant metabolic rates have enormously improved our understanding of plant environment interactions in ground-based growth chambers and are critical to understanding plant responses to the space environment.

  14. The components of crop productivity: measuring and modeling plant metabolism

    NASA Technical Reports Server (NTRS)

    Bugbee, B.

    1995-01-01

    Several investigators in the CELSS program have demonstrated that crop plants can be remarkably productive in optimal environments where plants are limited only by incident radiation. Radiation use efficiencies of 0.4 to 0.7 g biomass per mol of incident photons have been measured for crops in several laboratories. Some early published values for radiation use efficiency (1 g mol-1) were inflated due to the effect of side lighting. Sealed chambers are the basic research module for crop studies for space. Such chambers allow the measurement of radiation and CO2 fluxes, thus providing values for three determinants of plant growth: radiation absorption, photosynthetic efficiency (quantum yield), and respiration efficiency (carbon use efficiency). Continuous measurement of each of these parameters over the plant life cycle has provided a blueprint for daily growth rates, and is the basis for modeling crop productivity based on component metabolic processes. Much of what has been interpreted as low photosynthetic efficiency is really the result of reduced leaf expansion and poor radiation absorption. Measurements and models of short-term (minutes to hours) and long-term (days to weeks) plant metabolic rates have enormously improved our understanding of plant environment interactions in ground-based growth chambers and are critical to understanding plant responses to the space environment.

  15. Non-smooth plant disease models with economic thresholds.

    PubMed

    Zhao, Tingting; Xiao, Yanni; Smith, Robert J

    2013-01-01

    In order to control plant diseases and eventually maintain the number of infected plants below an economic threshold, a specific management strategy called the threshold policy is proposed, resulting in Filippov systems. These are a class of piecewise smooth systems of differential equations with a discontinuous right-hand side. The aim of this work is to investigate the global dynamic behavior including sliding dynamics of one Filippov plant disease model with cultural control strategy. We examine a Lotka-Volterra Filippov plant disease model with proportional planting rate, which is globally studied in terms of five types of equilibria. For one type of equilibrium, the global structure is discussed by the iterative equations for initial numbers of plants. For the other four types of equilibria, the bounded global attractor of each type is obtained by constructing appropriate Lyapunov functions. The ideas of constructing Lyapunov functions for Filippov systems, the methods of analyzing such systems and the main results presented here provide scientific support for completing control regimens on plant diseases in integrated disease management. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Steady-state plant model to predict hydrogen levels in power plant components

    NASA Astrophysics Data System (ADS)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    2017-06-01

    The National Renewable Energy Laboratory (NREL) and Acciona Energy North America developed a full-plant steady-state computational model that estimates levels of hydrogen in parabolic trough power plant components. The model estimated dissolved hydrogen concentrations in the circulating heat transfer fluid (HTF), and corresponding partial pressures within each component. Additionally for collector field receivers, the model estimated hydrogen pressure in the receiver annuli. The model was developed to estimate long-term equilibrium hydrogen levels in power plant components, and to predict the benefit of hydrogen mitigation strategies for commercial power plants. Specifically, the model predicted reductions in hydrogen levels within the circulating HTF that result from purging hydrogen from the power plant expansion tanks at a specified target rate. Our model predicted hydrogen partial pressures from 8.3 mbar to 9.6 mbar in the power plant components when no mitigation treatment was employed at the expansion tanks. Hydrogen pressures in the receiver annuli were 8.3 to 8.4 mbar. When hydrogen partial pressure was reduced to 0.001 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.001 mbar to 0.02 mbar. When hydrogen partial pressure was reduced to 0.3 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.25 mbar to 0.28 mbar. Our results show that controlling hydrogen partial pressure in the expansion tanks allows us to reduce and maintain hydrogen pressures in the receiver annuli to any practical level.

  17. Modelling of an oil refinery wastewater treatment plant.

    PubMed

    Pinzón Pardo, A L; Brdjanovic, D; Moussa, M S; López-Vázquez, C M; Meijer, S C F; Van Straten, H H A; Janssen, A J H; Amy, G; Van Loosdrecht, M C M

    2007-11-01

    The Activated Sludge Model No. 3 (ASM3) and Dutch calibration guidelines (STOWA) were evaluated in the modelling of an activated sludge system treating effluents from a large oil refinery. The plant was designed to remove suspended solids, organic matter and nitrogen from wastewater at an average water temperature of 34 degrees C. The plant consists of three tanks in series; the first two tanks operate in on-off aeration mode with pure oxygen for N-removal, whilst extra methanol is added for the denitrification, and the third tank is maintained as constantly aerobic. Calibration was performed based on a simplified influent characterisation and extra batch experiments (nitrification and denitrification). With the adjustment of only four parameters the model proved capable of describing the performance of the plant concerning both the liquid phase and the biomass. The model was further used to analyse possible modifications in the plant layout and optimize operational conditions in order to reduce operating costs. Modelling results indicated reduction in methanol dosage by implementing an idle time between aerobic and anoxic phases. In this way, surplus methanol was prevented from entering during the aerobic period. Moreover, simulations showed that the most cost-effective option regarding the denitrification process was a combined pre-post-denitrification scheme, without the need for enlarging existing basins. It can be concluded that although ASM3 and STOWA guidelines were originally developed for domestic wastewater application at a temperature range of 10 to 20 degrees C, they proved well capable of describing the performance of an oil refinery wastewater treatment plant operating at 34 degrees C. Moreover, the plant model proved useful for optimization of the plant performance regarding operational costs.

  18. AN ECONOMETRIC MODEL OF THE CALIFORNIA PUBLIC JUNIOR COLLEGE OPERATING YEAR-ROUND.

    ERIC Educational Resources Information Center

    KEENE, JAMES W.

    BASED ON EMPIRICAL DATA ACCUMULATED FROM TWELVE JUNIOR COLLEGES UNDER THE 2-SEMESTER CALENDAR, THE MODEL DEVELOPED IN THIS STUDY CAN BE USEFUL IN PREDICTING CHANGES IN PLANT USE UNDER THE 4-QUARTER CALENDAR. THIS CALENDAR REVISION HAS FOUR CONSTRAINTS--(1) THE SENIOR INSTITUTIONS IN THE STATE HAVE ADOPTED IT, (2) THE STUDENT'S CHOICE OF QUARTER IN…

  19. Modeling of water treatment plant using timed continuous Petri nets

    NASA Astrophysics Data System (ADS)

    Nurul Fuady Adhalia, H.; Subiono, Adzkiya, Dieky

    2017-08-01

    Petri nets represent graphically certain conditions and rules. In this paper, we construct a model of the Water Treatment Plant (WTP) using timed continuous Petri nets. Specifically, we consider that (1) the water pump always active and (2) the water source is always available. After obtaining the model, the flow through the transitions and token conservation laws are calculated.

  20. Simulation model for plant growth in controlled environment systems

    NASA Technical Reports Server (NTRS)

    Raper, C. D., Jr.; Wann, M.

    1986-01-01

    The role of the mathematical model is to relate the individual processes to environmental conditions and the behavior of the whole plant. Using the controlled-environment facilities of the phytotron at North Carolina State University for experimentation at the whole-plant level and methods for handling complex models, researchers developed a plant growth model to describe the relationships between hierarchial levels of the crop production system. The fundamental processes that are considered are: (1) interception of photosynthetically active radiation by leaves, (2) absorption of photosynthetically active radiation, (3) photosynthetic transformation of absorbed radiation into chemical energy of carbon bonding in solube carbohydrates in the leaves, (4) translocation between carbohydrate pools in leaves, stems, and roots, (5) flow of energy from carbohydrate pools for respiration, (6) flow from carbohydrate pools for growth, and (7) aging of tissues. These processes are described at the level of organ structure and of elementary function processes. The driving variables of incident photosynthetically active radiation and ambient temperature as inputs pertain to characterization at the whole-plant level. The output of the model is accumulated dry matter partitioned among leaves, stems, and roots; thus, the elementary processes clearly operate under the constraints of the plant structure which is itself the output of the model.

  1. 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.

  2. Computational Morphodynamics: A modeling framework to understand plant growth

    PubMed Central

    Chickarmane, Vijay; Roeder, Adrienne H.K.; Tarr, Paul T.; Cunha, Alexandre; Tobin, Cory; Meyerowitz, Elliot M.

    2014-01-01

    Computational morphodynamics utilizes computer modeling to understand the development of living organisms over space and time. Results from biological experiments are used to construct accurate and predictive models of growth. These models are then used to make novel predictions providing further insight into the processes in question, which can be tested experimentally to either confirm or rule out the validity of the computational models. This review highlights two fundamental issues: (1.) models should span and integrate single cell behavior with tissue development and (2.) the necessity to understand the feedback between mechanics of growth and chemical or molecular signaling. We review different approaches to model plant growth and discuss a variety of model types that can be implemented, with the aim of demonstrating how this methodology can be used, to explore the morphodynamics of plant development. PMID:20192756

  3. Strategic Petroleum Reserve quarterly report

    SciTech Connect

    Not Available

    1993-08-15

    This Quarterly Report highlights activities undertaken during the second quarter of calendar year 1993, including: inventory of petroleum products stored in the Reserve, under contract and in transit at the end of the calendar quarter; fill rate for the current quarter and projected fill rate for the next calendar quarter; average price of the petroleum products acquired during the calendar quarter; current and projected storage capacity and plans to accelerate the acquisition or construction of such capacity; analysis of existing or anticipated problems with the acquisition and storage of petroleum products, and future expansion of storage capacity; funds obligated by the Secretary from the SPR Petroleum Account and the Strategic Petroleum Reserve Account during the prior calendar quarter and in total; and major environmental actions completed, in progress, or anticipated.

  4. Are we ready for genome-scale modeling in plants?

    PubMed

    Collakova, Eva; Yen, Jiun Y; Senger, Ryan S

    2012-08-01

    As it is becoming easier and faster to generate various types of high-throughput data, one would expect that by now we should have a comprehensive systems-level understanding of biology, biochemistry, and physiology at least in major prokaryotic and eukaryotic model systems. Despite the wealth of available data, we only get a glimpse of what is going on at the molecular level from the global perspective. The major reason is the high level of cellular complexity and our limited ability to identify all (or at least important) components and their interactions in virtually infinite number of internal and external conditions. Metabolism can be modeled mathematically by the use of genome-scale models (GEMs). GEMs are in silico metabolic flux models derived from available genome annotation. These models predict the combination of flux values of a defined metabolic network given the influence of internal and external signals. GEMs have been successfully implemented to model bacterial metabolism for over a decade. However, it was not until 2009 when the first GEM for Arabidopsis thaliana cell-suspension cultures was generated. Genome-scale modeling ("GEMing") in plants brings new challenges primarily due to the missing components and complexity of plant cells represented by the existence of: (i) photosynthesis; (ii) compartmentation; (iii) variety of cell and tissue types; and (iv) diverse metabolic responses to environmental and developmental cues as well as pathogens, insects, and competing weeds. This review presents a critical discussion of the advantages of existing plant GEMs, while identifies key targets for future improvements. Plant GEMs tend to be accurate in predicting qualitative changes in selected aspects of central carbon metabolism, while secondary metabolism is largely neglected mainly due to the missing (unknown) genes and metabolites. As such, these models are suitable for exploring metabolism in plants grown in favorable conditions, but not in field

  5. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1997--June 19, 1997

    SciTech Connect

    Kochian, L.

    1997-11-01

    This laboratory has been involved in a collaborative project focusing on a range of issues related to the phytoremediation of heavy metal-and radionuclide- contaminated soils. While much of the research has been fundamental in nature, involving physiological and molecular characterizations of the mechanisms of hyperaccumulation in plants, the laboratory is also investigating more practical issues related to phytoremediation. A central issue in this latter research has been the identification of amendments capable of increasing the bioavailability and subsequent phytoextraction of radionuclides. The results described here detail these efforts for uranium and Cs-137. A study was also conducted on a Cs-137 contaminated site at Brookhaven National Laboratory (BNL), which allowed application of the laboratory and greenhouse results to a field setting.

  6. How Plant Hydraulics can Improve the Modeling of Plant and Ecosystem Responses to Environment

    NASA Astrophysics Data System (ADS)

    Sperry, J.; Anderegg, W.; Mackay, D. S.; Venturas, M.

    2016-12-01

    Stomatal regulation is an important, yet problematic component in modeling plant-environment interactions. The problem is that stomata respond to so many environmental cues via complex and uncertain mechanisms. But the assumed end result of regulation is conceptually simple: an optimization of CO2 for H2O exchange in response to changing conditions. Stomata open when photosynthetic opportunity is high and water is cheap. They close if photosynthetic opportunity is low or water is very expensive. Photosynthetic opportunity is relatively easy to model. The cost of water loss is also easy to model if it is assumed to rise with greater proximity to hydraulic failure and desiccation. Unsaturated hydraulic conductivity curves of soil- and plant are used to estimate proximity to failure. At any given instant, a model can calculate opportunity and cost curves associated with greater stomatal opening. If stomata regulate to maximize the instantaneous difference between photosynthetic gain and hydraulic cost, then a model can predict the trajectory of stomatal responses to changes in environment across time. Results of this optimization routine extend the utility of hydraulic predecessor models, and are consistent with widely used empirical models across a wide range of vapor pressure deficit and ambient CO2 concentrations for wet soil. The advantage of the optimization approach is the absence of empirical coefficients, applicability to dry as well as wet soil, and prediction of plant hydraulic status along with gas exchange. The optimization algorithm is a trait- and process-based approach that could improve next generation land surface models.

  7. Analysis of axial-induction-based wind plant control using an engineering and a high-order wind plant model

    SciTech Connect

    Annoni, Jennifer; Gebraad, Pieter M. O.; Scholbrock, Andrew K.; Fleming, Paul A.; Wingerden, Jan-Willem van

    2015-08-14

    Wind turbines are typically operated to maximize their performance without considering the impact of wake effects on nearby turbines. Wind plant control concepts aim to increase overall wind plant performance by coordinating the operation of the turbines. This paper focuses on axial-induction-based wind plant control techniques, in which the generator torque or blade pitch degrees of freedom of the wind turbines are adjusted. The paper addresses discrepancies between a high-order wind plant model and an engineering wind plant model. Changes in the engineering model are proposed to better capture the effects of axial-induction-based control shown in the high-order model.

  8. Trustee Quarterly, Issues 1-3, 1996.

    ERIC Educational Resources Information Center

    Hutchins, Sally, Ed.

    1996-01-01

    The three issues of "Trustee Quarterly" contained in this document focus on topics of current concern to community college trustees. Issue 1 for 1996 focuses on the policy governance model of community college board leadership, offering the following feature articles: "John Carver...and His Contribution to Community College…

  9. Augmented Reality for Close Quarters Combat

    ScienceCinema

    None

    2016-07-12

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  10. Augmented Reality for Close Quarters Combat

    SciTech Connect

    2013-09-20

    Sandia National Laboratories has developed a state-of-the-art augmented reality training system for close-quarters combat (CQB). This system uses a wearable augmented reality system to place the user in a real environment while engaging enemy combatants in virtual space (Boston Dynamics DI-Guy). Umbra modeling and simulation environment is used to integrate and control the AR system.

  11. Gasification CFD Modeling for Advanced Power Plant Simulations

    SciTech Connect

    Zitney, S.E.; Guenther, C.P.

    2005-09-01

    In this paper we have described recent progress on developing CFD models for two commercial-scale gasifiers, including a two-stage, coal slurry-fed, oxygen-blown, pressurized, entrained-flow gasifier and a scaled-up design of the PSDF transport gasifier. Also highlighted was NETL’s Advanced Process Engineering Co-Simulator for coupling high-fidelity equipment models with process simulation for the design, analysis, and optimization of advanced power plants. Using APECS, we have coupled the entrained-flow gasifier CFD model into a coal-fired, gasification-based FutureGen power and hydrogen production plant. The results for the FutureGen co-simulation illustrate how the APECS technology can help engineers better understand and optimize gasifier fluid dynamics and related phenomena that impact overall power plant performance.

  12. Incorporating Plant Phenology Dynamics in a Biophysical Canopy Model

    NASA Technical Reports Server (NTRS)

    Barata, Raquel A.; Drewry, Darren

    2012-01-01

    The Multi-Layer Canopy Model (MLCan) is a vegetation model created to capture plant responses to environmental change. Themodel vertically resolves carbon uptake, water vapor and energy exchange at each canopy level by coupling photosynthesis, stomatal conductance and leaf energy balance. The model is forced by incoming shortwave and longwave radiation, as well as near-surface meteorological conditions. The original formulation of MLCan utilized canopy structural traits derived from observations. This project aims to incorporate a plant phenology scheme within MLCan allowing these structural traits to vary dynamically. In the plant phenology scheme implemented here, plant growth is dependent on environmental conditions such as air temperature and soil moisture. The scheme includes functionality that models plant germination, growth, and senescence. These growth stages dictate the variation in six different vegetative carbon pools: storage, leaves, stem, coarse roots, fine roots, and reproductive. The magnitudes of these carbon pools determine land surface parameters such as leaf area index, canopy height, rooting depth and root water uptake capacity. Coupling this phenology scheme with MLCan allows for a more flexible representation of the structure and function of vegetation as it responds to changing environmental conditions.

  13. Incorporating Plant Phenology Dynamics in a Biophysical Canopy Model

    NASA Technical Reports Server (NTRS)

    Barata, Raquel A.; Drewry, Darren

    2012-01-01

    The Multi-Layer Canopy Model (MLCan) is a vegetation model created to capture plant responses to environmental change. Themodel vertically resolves carbon uptake, water vapor and energy exchange at each canopy level by coupling photosynthesis, stomatal conductance and leaf energy balance. The model is forced by incoming shortwave and longwave radiation, as well as near-surface meteorological conditions. The original formulation of MLCan utilized canopy structural traits derived from observations. This project aims to incorporate a plant phenology scheme within MLCan allowing these structural traits to vary dynamically. In the plant phenology scheme implemented here, plant growth is dependent on environmental conditions such as air temperature and soil moisture. The scheme includes functionality that models plant germination, growth, and senescence. These growth stages dictate the variation in six different vegetative carbon pools: storage, leaves, stem, coarse roots, fine roots, and reproductive. The magnitudes of these carbon pools determine land surface parameters such as leaf area index, canopy height, rooting depth and root water uptake capacity. Coupling this phenology scheme with MLCan allows for a more flexible representation of the structure and function of vegetation as it responds to changing environmental conditions.

  14. A stoichiometric model of early plant primary succession.

    PubMed

    Marleau, Justin N; Jin, Yu; Bishop, John G; Fagan, William F; Lewis, Mark A

    2011-02-01

    The relative importance of plant facilitation and competition during primary succession depends on the development of ecosystem nutrient pools, yet the interaction of these processes remains poorly understood. To explore how these mechanisms interact to drive successional dynamics, we devised a stoichiometric ecosystem-level model that considers the role of nitrogen and phosphorus limitation in plant primary succession. We applied this model to the primary plant community on Mount St. Helens, Washington State, to check the validity of the proposed mechanisms. Our results show that the plant community is colimited by nitrogen and phosphorus, and they confirm previous suggestions that the presence of a nitrogen-fixing legume, Lupinus lepidus, can enhance community biomass. In addition, the observed nutrient supply rates may promote alternative successional trajectories that depend on the initial plant abundances, which may explain the observed heterogeneity in community development. The model further indicates the importance of mineralization rates and other ecosystem parameters to successional rates. We conclude that a model framework based on ecological stoichiometry allows integration of key biotic processes that interact nonlinearly with biogeochemical aspects of succession. Extension of this approach will improve the understanding of the process of primary succession and its application to ecosystem rehabilitation.

  15. Chemotaxis signaling systems in model beneficial plant-bacteria associations.

    PubMed

    Scharf, Birgit E; Hynes, Michael F; Alexandre, Gladys M

    2016-04-01

    Beneficial plant-microbe associations play critical roles in plant health. Bacterial chemotaxis provides a competitive advantage to motile flagellated bacteria in colonization of plant root surfaces, which is a prerequisite for the establishment of beneficial associations. Chemotaxis signaling enables motile soil bacteria to sense and respond to gradients of chemical compounds released by plant roots. This process allows bacteria to actively swim towards plant roots and is thus critical for competitive root surface colonization. The complete genome sequences of several plant-associated bacterial species indicate the presence of multiple chemotaxis systems and a large number of chemoreceptors. Further, most soil bacteria are motile and capable of chemotaxis, and chemotaxis-encoding genes are enriched in the bacteria found in the rhizosphere compared to the bulk soil. This review compares the architecture and diversity of chemotaxis signaling systems in model beneficial plant-associated bacteria and discusses their relevance to the rhizosphere lifestyle. While it is unclear how controlling chemotaxis via multiple parallel chemotaxis systems provides a competitive advantage to certain bacterial species, the presence of a larger number of chemoreceptors is likely to contribute to the ability of motile bacteria to survive in the soil and to compete for root surface colonization.

  16. Hydroacoustic Studies Using HydroCAM - Station-centric Integration of Models and Observations Quarterly Report No. 3 April 2003 - June 2003

    SciTech Connect

    Pulli, Jay J.; Upton, Zachary M.

    2003-07-14

    OAK A271 Hydroacoustic Studies Using HydroCAM - Station-centric Integration of Models and Observations Quarterly Report No. 3 April 2003 - June 2003. BBN's work from April through June of 2003 was focused on the testing and release of HydroCAM 4.0, development of HydroCAM 4.1 software, continued data collection and analysis, and initial preparations for the 2003 Seismic Research Review. HydroCAM 4.0 was released and sent to DOE and AFTAC on June 9. This is the first release of new software on this contract. The code addresses the problems and issues that BBN and AFTAC had identified in the Fall of 2003. HydroCAM 4.1 is under development. A description of that development is shown in section 3.2. We continued our efforts to collect ground truth hydroacoustic data from sub-sea earthquakes in the Indian Ocean. To date, we have collected over 130 events. These data are recorded on the International Monitoring System stations at Diego Garcia and Cape Leeuwin. Finally, BBN submitted an abstract for the 2003 Seismic Research Review meeting. However, after discussions with Phil Harben at Lawrence Livermore Labs, we have decided to collaborate on one program-wide paper for the meeting.

  17. Hydroacoustic Studies Using HydroCAM - Station-centric Integration of Models and Observations Quarterly Report No. 2 January 2003 - March 2003

    SciTech Connect

    Pulli, Jay J.; Upton, Zachary M.

    2003-04-21

    OAK A271 Hydroacoustic Studies Using HydroCAM - Station-centric Integration of Models and Observations Quarterly Report No. 2 January 2003 - March 2003. BBN's work from January through March of 2003 was focused on data collection, data analysis and software development. We continued our efforts to collect ground truth hydroacoustic data from sub-sea earthquakes in the Indian Ocean. These data are recorded on the International Monitoring System stations at Diego Garcia and Cape Leeuwin. The software development effort spanned two areas. Fixing problems and making small improvements to HydroCAM based on meetings at AFTAC in September 2002. We have also begun development of the software that will integrate local high-resolution bathymetry into lower-resolution global bathymetry for acoustic path predictions in HydroCAM. We hope that this will improve HydroCAM's ability to predict acoustic blockage. Unfortunately, due to corporate travel restrictions stemming from the war with Iraq, BBN will not be able to participate in the International Hydroacoustics Meeting in Hobart, Tasmania in May. However, we plan to provide Phil Harben with material to present and we plan to participate in the annual Seismic Research Review in Arizona this September.

  18. Development of plant condition measurement - The Jimah Model

    NASA Astrophysics Data System (ADS)

    Evans, Roy F.; Syuhaimi, Mohd; Mazli, Mohammad; Kamarudin, Nurliyana; Maniza Othman, Faiz

    2012-05-01

    The Jimah Model is an information management model. The model has been designed to facilitate analysis of machine condition by integrating diagnostic data with quantitative and qualitative information. The model treats data as a single strand of information - metaphorically a 'genome' of data. The 'Genome' is structured to be representative of plant function and identifies the condition of selected components (or genes) in each machine. To date in industry, computer aided work processes used with traditional industrial practices, have been unable to consistently deliver a standard of information suitable for holistic evaluation of machine condition and change. Significantly the reengineered site strategies necessary for implementation of this "data genome concept" have resulted in enhanced knowledge and management of plant condition. In large plant with high initial equipment cost and subsequent high maintenance costs, accurate measurement of major component condition becomes central to whole of life management and replacement decisions. A case study following implementation of the model at a major power station site in Malaysia (Jimah) shows that modeling of plant condition and wear (in real time) can be made a practical reality.

  19. Close Quarters Combat Shooting

    DTIC Science & Technology

    2010-04-14

    1994.at the Palm Beach Community College Criminal Justice Institute ofLakeworth, Florida to the more dynamic force-on-force, realistic scenario...Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington, DC...Shooting is the Superior Method for Close Quarters Combat 5b. GRANT NUMBER Shooting" N/A Sc. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR( S ) Sd. PROJECT

  20. Empty Quarter, Saudi Arabia

    NASA Technical Reports Server (NTRS)

    1981-01-01

    In the northeast end of the Saudi Arabian desert called the Rub-Al-Khali (Empty Quarter) (21.0N, 53.0E) is the great sand dune field known as the Ash Shaiba. Here, the dunes reach great heights and are held at the maximum angle of repose by the wind. Any disturbance of the base will cause a great cascade of sand burying an intruder like a great wave. The dunes are of a classic style known as 'Barcans'.

  1. Measurement and modeling of advanced coal conversion processes. 19th quarterly report, April 1, 1991--June 30, 1991

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S.

    1991-09-25

    The objectives of this study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. (VC)

  2. Predicting plants -modeling traits as a function of environment

    NASA Astrophysics Data System (ADS)

    Franklin, Oskar

    2016-04-01

    A central problem in understanding and modeling vegetation dynamics is how to represent the variation in plant properties and function across different environments. Addressing this problem there is a strong trend towards trait-based approaches, where vegetation properties are functions of the distributions of functional traits rather than of species. Recently there has been enormous progress in in quantifying trait variability and its drivers and effects (Van Bodegom et al. 2012; Adier et al. 2014; Kunstler et al. 2015) based on wide ranging datasets on a small number of easily measured traits, such as specific leaf area (SLA), wood density and maximum plant height. However, plant function depends on many other traits and while the commonly measured trait data are valuable, they are not sufficient for driving predictive and mechanistic models of vegetation dynamics -especially under novel climate or management conditions. For this purpose we need a model to predict functional traits, also those not easily measured, and how they depend on the plants' environment. Here I present such a mechanistic model based on fitness concepts and focused on traits related to water and light limitation of trees, including: wood density, drought response, allocation to defense, and leaf traits. The model is able to predict observed patterns of variability in these traits in relation to growth and mortality, and their responses to a gradient of water limitation. The results demonstrate that it is possible to mechanistically predict plant traits as a function of the environment based on an eco-physiological model of plant fitness. References Adier, P.B., Salguero-Gómez, R., Compagnoni, A., Hsu, J.S., Ray-Mukherjee, J., Mbeau-Ache, C. et al. (2014). Functional traits explain variation in plant lifehistory strategies. Proc. Natl. Acad. Sci. U. S. A., 111, 740-745. Kunstler, G., Falster, D., Coomes, D.A., Hui, F., Kooyman, R.M., Laughlin, D.C. et al. (2015). Plant functional traits

  3. The development of Arabidopsis as a model plant.

    PubMed

    Koornneef, Maarten; Meinke, David

    2010-03-01

    Twenty-five years ago, Arabidopsis thaliana emerged as the model organism of choice for research in plant biology. A consensus was reached about the need to focus on a single organism to integrate the classical disciplines of plant science with the expanding fields of genetics and molecular biology. Ten years after publication of its genome sequence, Arabidopsis remains the standard reference plant for all of biology. We reflect here on the major advances and shared resources that led to the extraordinary growth of the Arabidopsis research community. We also underscore the importance of continuing to expand and refine our detailed knowledge of Arabidopsis while seeking to appreciate the remarkable diversity that characterizes the plant kingdom.

  4. 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.

  5. Dynamic Models for Wind Turbines and Wind Power Plants

    SciTech Connect

    Singh, M.; Santoso, S.

    2011-10-01

    The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

  6. Sampling results, DNAPL monitoring well GW-790, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, first-third quarter, FY 1995

    SciTech Connect

    1996-05-01

    In January 1990, dense, non aqueous phase liquids (DNAPLs) were discovered at a depth of approximately 274 ft. below ground surface along the southern border of the Y-12 Plant Burial Grounds. Immediately after the discovery, an investigation was conducted to assess the occurrence of DNAPL at the site and to make recommendations for further action. To date, free-phase DNAPL contamination has been encountered in GW-625 (the discovery well), and is suspected to occur in GW-628 and GW-629. In addition, groundwater from GW-117 shows levels of volatile organic compounds suggestive of a dissolved contaminant plume. Results of the preliminary DNAPL investigation are presented in detail, and a work plan for assessment and characterization of the DNAPL is presented. A major task in the work plan calls for the construction and installation of five multipart wells. These wells (GW-726, GW-727, GW-729, GW-730, GW-730 and GW- 790) were constructed and instrumented with multipart components from August, 1991 to April, 1993. Subsequently, purging and sampling activities were started in each well. This report summarizes purging and sampling activities for GW-790 and presents analytical results for GW-790.

  7. Collaborative effort to model plant response to acidic rain

    SciTech Connect

    Jacobson, J.; Kuja, A.; Shriner, D.; Perrigan, S.; Irving, P.; Lee, J.; Troiano, J.; Cullinan, V.

    1988-06-01

    Radish plants were exposed three times per week to simulated acidic rain at pH values of 2.6 to 5.4 over the course of four weeks in trials performed at Argonne, Illinois; Ithaca and Upton, New York; Corvallis, Oregon; Oak Ridge, Tennessee; and Toronto, Canada. Uniform genotype, soil media and planting techniques, treatment procedures, biological measurements, and experimental design were employed. Growth of plants differed among trials as a result of variation in greenhouse environmental conditions according to location and facilities. Larger plants underwent greater absolute but lower relative reductions in biomass after exposure to the higher levels of acidity. A generalized Mitscherlich function was used to model the effects of acidity of simulated rain or dry mass of hypocotyls using data from three laboratories that performed duplicate trials. The remaining data, from three other laboratories that performed only one trial each, were used to test the model. When the laboratory by trial effect was removed, lack of fit to the Mitscherlich function was insignificant. Thus, a single mathematical model satisfactorily characterized the relationship between acidity and mean plant response.

  8. Simulation of wastewater treatment plant within integrated urban wastewater models.

    PubMed

    Heusch, S; Kamradt, B; Ostrowski, M

    2010-01-01

    In the federal state of Hesse in Germany the application of an integrated software modelling framework is becoming part of the planning process to attain legal approval for the operation of combined sewer systems. The software allows for parallel simulation of flow and water quality routing in the sewer system and in receiving rivers. It combines existing pollution load model approaches with a simplified version of the River Water Quality Model No. 1 (RWQM1). Comprehensive simulation of the wastewater treatment plant (WWTP) is not considered yet. The paper analyses alternatives for the implementation of a WWTP module to model activated sludge plants. For both primary and secondary clarifiers as well as for the activated sludge process concepts for the integration into the existing software framework were developed. The activated sludge concept which uses a linearized version of the well known ASM1 model is presented in detail.

  9. [Evaluation of Fusarium spp. pathogenicity in plant and murine models].

    PubMed

    Forero-Reyes, Consuelo M; Alvarado-Fernández, Angela M; Ceballos-Rojas, Ana M; González-Carmona, Lady C; Linares-Linares, Melva Y; Castañeda-Salazar, Rubiela; Pulido-Villamarín, Adriana; Góngora-Medina, Manuel E; Cortés-Vecino, Jesús A; Rodríguez-Bocanegra, María X

    2017-10-05

    The genus Fusarium is widely recognized for its phytopathogenic capacity. However, it has been reported as an opportunistic pathogen in immunocompetent and immunocompromised patients. Thus, it can be considered a microorganism of interest in pathogenicity studies on different hosts. Therefore, this work evaluated the pathogenicity of Fusarium spp. isolates from different origins in plants and animals (murine hosts). Twelve isolates of Fusarium spp. from plants, animal superficial mycoses, and human superficial and systemic mycoses were inoculated in tomato, passion fruit and carnation plants, and in immunocompetent and immunosuppressed BALB/c mice. Pathogenicity tests in plants did not show all the symptoms associated with vascular wilt in the three plant models; however, colonization and necrosis of the vascular bundles, regardless of the species and origin of the isolates, showed the infective potential of Fusarium spp. in different plant species. Moreover, the pathogenicity tests in the murine model revealed behavioral changes. It was noteworthy that only five isolates (different origin and species) caused mortality. Additionally, it was observed that all isolates infected and colonized different organs, regardless of the species and origin of the isolates or host immune status. In contrast, the superficial inoculation test showed no evidence of epidermal injury or colonization. The observed results in plant and murine models suggest the pathogenic potential of Fusarium spp. isolates in different types of hosts. However, further studies on pathogenicity are needed to confirm the multihost capacity of this genus. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Short-term energy outlook. Quarterly projections, Third quarter 1995

    SciTech Connect

    1995-08-02

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent projections with those of other forecasting services, and discusses current topics related to the short-term energy markets. The forecast period for this issue of the Outlook extends from the third quarter of 1995 through the fourth quarter of 1996. Values for the second quarter of 1995, however, are preliminary EIA estimates.

  11. Representing plants as rigid cylinders in experiments and models

    NASA Astrophysics Data System (ADS)

    Vargas-Luna, Andrés; Crosato, Alessandra; Calvani, Giulio; Uijttewaal, Wim S. J.

    2016-07-01

    Simulating the morphological adaptation of water systems often requires including the effects of plants on water and sediment dynamics. Physical and numerical models need representing vegetation in a schematic easily-quantifiable way despite the variety of sizes, shapes and flexibility of real plants. Common approaches represent plants as rigid cylinders, but the ability of these schematizations to reproduce the effects of vegetation on morphodynamic processes has never been analyzed systematically. This work focuses on the consequences of representing plants as rigid cylinders in laboratory tests and numerical simulations. New experiments show that the flow resistance decreases for increasing element Reynolds numbers for both plants and rigid cylinders. Cylinders on river banks can qualitatively reproduce vegetation effects on channel width and bank-related processes. A comparative review of numerical simulations shows that Baptist's method that sums the contribution of bed shear stress and vegetation drag, underestimates bed erosion within sparse vegetation in real rivers and overestimates the mean flow velocity in laboratory experiments. This is due to assuming uniform flow among plants and to an overestimation of the role of the submergence ratio.

  12. Plants as Model in Biomimetics and Biorobotics: New Perspectives

    PubMed Central

    Mazzolai, Barbara; Beccai, Lucia; Mattoli, Virgilio

    2013-01-01

    Especially in robotics, rarely plants have been considered as a model of inspiration for designing and developing new technology. This is probably due to their radically different operational principles compared to animals and the difficulty to study their movements and features. Owing to the sessile nature of their lifestyle, plants have evolved the capability to respond to a wide range of signals and efficiently adapt to changing environmental conditions. Plants in fact are able to show considerable plasticity in their morphology and physiology in response to variability within their environment. This results in movements that are characterized by energy efficiency and high density. Plant materials are optimized to reduce energy consumption during motion and these capabilities offer a plethora of solutions in the artificial world, exploiting approaches that are muscle-free and thus not necessarily animal-like. Plant roots then are excellent natural diggers, and their characteristics such as adaptive growth, low energy consumption movements, and the capability of penetrating soil at any angle are interesting from an engineering perspective. A few examples are described to lay the perspectives of plants in the artificial world. PMID:25152878

  13. Forecast and virtual weather driven plant disease risk modeling system

    USDA-ARS?s Scientific Manuscript database

    We describe a system in use and development that leverages public weather station data, several spatialized weather forecast types, leaf wetness estimation, generic plant disease models, and online statistical evaluation. Convergent technological developments in all these areas allow, with funding f...

  14. Applied Meteorology Unit (AMU) Quarterly Report - Fourth Quarter FY-10

    NASA Technical Reports Server (NTRS)

    Bauman, William; Crawford, Winifred; Barrett, Joe; Watson, Leela; Wheeler, Mark

    2010-01-01

    Three AMU tasks were completed in this Quarter, each resulting in a forecast tool now being used in operations and a final report documenting how the work was done. AMU personnel completed the following tasks (1) Phase II of the Peak Wind Tool for General Forecasting task by delivering an improved wind forecasting tool to operations and providing training on its use; (2) a graphical user interface (GUI) she updated with new scripts to complete the ADAS Update and Maintainability task, and delivered the scripts to the Spaceflight Meteorology Group on Johnson Space Center, Texas and National Weather Service in Melbourne, Fla.; and (3) the Verify MesoNAM Performance task after we created and delivered a GUI that forecasters will use to determine the performance of the operational MesoNAM weather model forecast.

  15. Sex determination in flowering plants: papaya as a model system.

    PubMed

    Aryal, Rishi; Ming, Ray

    2014-03-01

    Unisexuality in flowering plants evolved from a hermaphrodite ancestor. Transition from hermaphrodite to unisexual flowers has occurred multiple times across the different lineages of the angiosperms. Sexuality in plants is regulated by genetic, epigenetic and physiological mechanisms. The most specialized mechanism of sex determination is sex chromosomes. The sex chromosomes ensure the stable segregation of sexual phenotypes by preventing the recombination of sex determining genes. Despite continuous efforts, sex determining genes of dioecious plants have not yet been cloned. Concerted efforts with various model systems are necessary to understand the complex mechanism of sex determination in plants. Papaya (Carica papaya L.) is a tropical fruit tree with three sex forms, male, hermaphrodite, and female. Sexuality in papaya is determined by an XY chromosome system that is in an early evolutionary stage. The male and hermaphrodite of papaya are controlled by two different types of Y chromosomes: Y and Y(h). Large amounts of information in the area of genetics, genomics, and epigenetics of papaya have been accumulated over the last few decades. Relatively short lifecycle, small genome size, and readily available genetic and genomic resources render papaya an excellent model system to study sex determination and sex chromosomes in flowering plants.

  16. Trichomes as models for studying plant cell differentiation.

    PubMed

    Yang, Changxian; Ye, Zhibiao

    2013-06-01

    Trichomes, originating from epidermal cells, are present on nearly all terrestrial plants. They exist in diverse forms, are readily accessible, and serve as an excellent model system for analyzing the molecular mechanisms in plant cell differentiation, including cell fate choices, cell cycle control, and cell morphogenesis. In Arabidopsis, two regulatory models have been identified that function in parallel in trichome formation; the activator-inhibitor model and the activator-depletion model. Cotton fiber, a similar unicellular structure, is controlled by some functional homologues of Arabidopsis trichome-patterning genes. Multicellular trichomes, as in tobacco and tomato, may form through a distinct pathway from unicellular trichomes. Recent research has shown that cell cycle control participates in trichome formation. In this review, we summarize the molecular mechanisms involved in the formation of unicellular and multicellular trichomes, and discuss the integration of the cell cycle in its initiation and morphogenesis.

  17. Modeling Regulatory Networks to Understand Plant Development: Small Is Beautiful

    PubMed Central

    Middleton, Alistair M.; Farcot, Etienne; Owen, Markus R.; Vernoux, Teva

    2012-01-01

    We now have unprecedented capability to generate large data sets on the myriad genes and molecular players that regulate plant development. Networks of interactions between systems components can be derived from that data in various ways and can be used to develop mathematical models of various degrees of sophistication. Here, we discuss why, in many cases, it is productive to focus on small networks. We provide a brief and accessible introduction to relevant mathematical and computational approaches to model regulatory networks and discuss examples of small network models that have helped generate new insights into plant biology (where small is beautiful), such as in circadian rhythms, hormone signaling, and tissue patterning. We conclude by outlining some of the key technical and modeling challenges for the future. PMID:23110896

  18. Matrix population models from 20 studies of perennial plant populations

    USGS Publications Warehouse

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the "Testing Matrix Models" working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  19. Matrix population models from 20 studies of perennial plant populations

    USGS Publications Warehouse

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  20. Strategic Petroleum Reserve quarterly report

    SciTech Connect

    Not Available

    1990-08-15

    The Strategic Petroleum Reserve Quarterly Report is submitted in accordance with section 165(b) of the Energy Policy and Conservation Act, as amended, which requires that the Secretary of Energy submit quarterly reports to Congress on Activities undertaken with respect to the Strategic Petroleum Reserve. This August 15, 1990, Strategic Petroleum Reserve Quarterly Report describes activities related to the site development, oil acquisition, budget and cost of the Reserve during the period April 1, 1990, through June 30, 1990. 3 tabs.

  1. Computational Modeling and Experimental Studies on NO(x) Reduction Under Pulveerized Coal Combustion Conditions. Quarterly technical progress report, July 1 - September 30, 1997

    SciTech Connect

    Kumpaty, S.K.; Subramanian, K.; Darboe, A.; Kumpati, S.K.

    1997-12-31

    Several experiments were conducted during this quarter to study the NO{sub x} reduction effectiveness of lignite coal, activated carbon and catalytic sites such as calcium sulfide and calcium carbide. While some of the coals/chemicals could be fed easily, some needed the mixing with silica gel to result in a uniform flow through the feeder. Several trial runs were performed to ensure proper feeding of the material before conducting the actual experiment to record NO{sub x} reduction. The experimental approach has been the same as presented in the past two quarterly reports with the coal reburning experiments. Partial reduction is achieved through methane addition for SR2=0.95 conditions and then coal or the catalyst is introduced to see if there is further reduction. Presented below are the results of the experiments conducted during this quarter.

  2. An experimental test of plant canopy reflectance models on cotton

    NASA Technical Reports Server (NTRS)

    Lemaster, E. W.

    1974-01-01

    Extensive data on the plant parameters necessary to evaluate any model are presented for a cotton crop. The variation of the bidirectional reflectance function with observer altitude, observer azimuth, and sun altitude angle is presented for a high density cotton crop having leaf index of 19. A comparison with the quantitative behavior obtained from the Suits model is accomplished in the wavelength region from 400 nm to 1050 nm.

  3. Plant model of KIPT neutron source facility simulator

    SciTech Connect

    Cao, Yan; Wei, Thomas Y.; Grelle, Austin L.; Gohar, Yousry

    2016-02-01

    Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine are collaborating on constructing a neutron source facility at KIPT, Kharkov, Ukraine. The facility has 100-kW electron beam driving a subcritical assembly (SCA). The electron beam interacts with a natural uranium target or a tungsten target to generate neutrons, and deposits its power in the target zone. The total fission power generated in SCA is about 300 kW. Two primary cooling loops are designed to remove 100-kW and 300-kW from the target zone and the SCA, respectively. A secondary cooling system is coupled with the primary cooling system to dispose of the generated heat outside the facility buildings to the atmosphere. In addition, the electron accelerator has a low efficiency for generating the electron beam, which uses another secondary cooling loop to remove the generated heat from the accelerator primary cooling loop. One of the main functions the KIPT neutron source facility is to train young nuclear specialists; therefore, ANL has developed the KIPT Neutron Source Facility Simulator for this function. In this simulator, a Plant Control System and a Plant Protection System were developed to perform proper control and to provide automatic protection against unsafe and improper operation of the facility during the steady-state and the transient states using a facility plant model. This report focuses on describing the physics of the plant model and provides several test cases to demonstrate its capabilities. The plant facility model uses the PYTHON script language. It is consistent with the computer language of the plant control system. It is easy to integrate with the simulator without an additional interface, and it is able to simulate the transients of the cooling systems with system control variables changing on real-time.

  4. Model parameters for representative wetland plant functional groups

    USGS Publications Warehouse

    Williams, Amber S.; Kiniry, James R.; Mushet, David M.; Smith, Loren M.; McMurry, Scott T.; Attebury, Kelly; Lang, Megan; McCarty, Gregory W.; Shaffer, Jill A.; Effland, William R.; Johnson, Mari-Vaughn V.

    2017-01-01

    Wetlands provide a wide variety of ecosystem services including water quality remediation, biodiversity refugia, groundwater recharge, and floodwater storage. Realistic estimation of ecosystem service benefits associated with wetlands requires reasonable simulation of the hydrology of each site and realistic simulation of the upland and wetland plant growth cycles. Objectives of this study were to quantify leaf area index (LAI), light extinction coefficient (k), and plant nitrogen (N), phosphorus (P), and potassium (K) concentrations in natural stands of representative plant species for some major plant functional groups in the United States. Functional groups in this study were based on these parameters and plant growth types to enable process-based modeling. We collected data at four locations representing some of the main wetland regions of the United States. At each site, we collected on-the-ground measurements of fraction of light intercepted, LAI, and dry matter within the 2013–2015 growing seasons. Maximum LAI and k variables showed noticeable variations among sites and years, while overall averages and functional group averages give useful estimates for multisite simulation modeling. Variation within each species gives an indication of what can be expected in such natural ecosystems. For P and K, the concentrations from highest to lowest were spikerush (Eleocharis macrostachya), reed canary grass (Phalaris arundinacea), smartweed (Polygonum spp.), cattail (Typha spp.), and hardstem bulrush (Schoenoplectus acutus). Spikerush had the highest N concentration, followed by smartweed, bulrush, reed canary grass, and then cattail. These parameters will be useful for the actual wetland species measured and for the wetland plant functional groups they represent. These parameters and the associated process-based models offer promise as valuable tools for evaluating environmental benefits of wetlands and for evaluating impacts of various agronomic practices in

  5. Signalling network construction for modelling plant defence response.

    PubMed

    Miljkovic, Dragana; Stare, Tjaša; Mozetič, Igor; Podpečan, Vid; Petek, Marko; Witek, Kamil; Dermastia, Marina; Lavrač, Nada; Gruden, Kristina

    2012-01-01

    Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2) triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be utilised for

  6. Plant water potential improves prediction of empirical stomatal models.

    PubMed

    Anderegg, William R L; Wolf, Adam; Arango-Velez, Adriana; Choat, Brendan; Chmura, Daniel J; Jansen, Steven; Kolb, Thomas; Li, Shan; Meinzer, Frederick; Pita, Pilar; Resco de Dios, Víctor; Sperry, John S; Wolfe, Brett T; Pacala, Stephen

    2017-01-01

    Climate change is expected to lead to increases in drought frequency and severity, with deleterious effects on many ecosystems. Stomatal responses to changing environmental conditions form the backbone of all ecosystem models, but are based on empirical relationships and are not well-tested during drought conditions. Here, we use a dataset of 34 woody plant species spanning global forest biomes to examine the effect of leaf water potential on stomatal conductance and test the predictive accuracy of three major stomatal models and a recently proposed model. We find that current leaf-level empirical models have consistent biases of over-prediction of stomatal conductance during dry conditions, particularly at low soil water potentials. Furthermore, the recently proposed stomatal conductance model yields increases in predictive capability compared to current models, and with particular improvement during drought conditions. Our results reveal that including stomatal sensitivity to declining water potential and consequent impairment of plant water transport will improve predictions during drought conditions and show that many biomes contain a diversity of plant stomatal strategies that range from risky to conservative stomatal regulation during water stress. Such improvements in stomatal simulation are greatly needed to help unravel and predict the response of ecosystems to future climate extremes.

  7. Computational modeling and experimental studies on NO{sub x} reduction under pulverized coal combustion conditions. Technical progress report, second quarter, April 1, 1995--June 30, 1995

    SciTech Connect

    Kumpaty, S.K.

    1995-12-01

    Presented in this second quarterly report are the computational results of NO reburning with (a) a combination of methane and acetylene (i) with the reaction mechanism listed in the first quarterly report and (ii) with the updated reaction mechanism (Table 1 of this report); and (b) a combination of methane and ammonia. The impact of the updated reaction scheme was not significant on the results of NO reburning with methane/acetylene; however, the reaction scheme needed changes to improve the accuracy of some reactions of crucial intermediates in methane/ammonia reburning. An extensive literature survey was made in order to update the mechanism.

  8. Computational modeling and experimental studies on NO{sub x} reduction under pulverized coal combustion conditions. Seventh quarterly technical progress report, July 1, 1996--September 30, 1996

    SciTech Connect

    Kumpaty, S.K.; Subramanian, K.; Nokku, V.P.; Hodges, T.L.

    1996-12-31

    During this quarter (July-August 1996), the experiments for nitric oxide reburning with a combination of methane and ammonia were conducted successfully. This marked the completion of gaseous phase experiments. Preparations are underway for the reburning studies with coal. A coal feeder was designed to suit our reactor facility which is being built by MK Fabrication. The coal feeder should be operational in the coming quarter. Presented here are the experimental results of NO reburning with methane/ammonia. The results are consistent with the computational work submitted in previous reports.

  9. Output-Feedback Model Predictive Control of a Pasteurization Pilot Plant based on an LPV model

    NASA Astrophysics Data System (ADS)

    Karimi Pour, Fatemeh; Ocampo-Martinez, Carlos; Puig, Vicenç

    2017-01-01

    This paper presents a model predictive control (MPC) of a pasteurization pilot plant based on an LPV model. Since not all the states are measured, an observer is also designed, which allows implementing an output-feedback MPC scheme. However, the model of the plant is not completely observable when augmented with the disturbance models. In order to solve this problem, the following strategies are used: (i) the whole system is decoupled into two subsystems, (ii) an inner state-feedback controller is implemented into the MPC control scheme. A real-time example based on the pasteurization pilot plant is simulated as a case study for testing the behavior of the approaches.

  10. Model-free adaptive control of advanced power plants

    DOEpatents

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  11. 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

  12. Atmospheric Properties from the 2006 Niamey Deployment and Climate Simulation with a Geodesic Grid Coupled Climate Model Third Quarter 2008

    SciTech Connect

    JH Mather; DA Randall; CJ Flynn

    2008-06-30

    In 2008, the Atmospheric Radiation Measurement (ARM) Program and the Climate Change Prediction Program (CCPP) have been asked to produce joint science metrics. For CCPP, the metrics will deal with a decade-long control simulation using geodesic grid-coupled climate model. For ARM, the metrics will deal with observations associated with the 2006 deployment of the ARM Mobile Facility (AMF) to Niamey, Niger. Specifically, ARM has been asked to deliver data products for Niamey that describe cloud, aerosol, and dust properties. This report describes the aerosol optical depth (AOD) product.

  13. ENEL overall PWR plant models and neutronic integrated computing systems

    SciTech Connect

    Pedroni, G.; Pollachini, L.; Vimercati, G.; Cori, R.; Pretolani, F.; Spelta, S.

    1987-01-01

    To support the design activity of the Italian nuclear energy program for the construction of pressurized water reactors, the Italian Electricity Board (ENEL) needs to verify the design as a whole (that is, the nuclear steam supply system and balance of plant) both in steady-state operation and in transient. The ENEL has therefore developed two computer models to analyze both operational and incidental transients. The models, named STRIP and SFINCS, perform the analysis of the nuclear as well as the conventional part of the plant (the control system being properly taken into account). The STRIP model has been developed by means of the French (Electricite de France) modular code SICLE, while SFINCS is based on the Italian (ENEL) modular code LEGO. STRIP validation was performed with respect to Fessenheim French power plant experimental data. Two significant transients were chosen: load step and total load rejection. SFINCS validation was performed with respect to Saint-Laurent French power plant experimental data and also by comparing the SFINCS-STRIP responses.

  14. Measurement and modeling of advanced coal conversion processes. Twenty-seventh quarterly report, April 1, 1993--June 30, 1993

    SciTech Connect

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D.; Brewster, B.S.

    1993-09-01

    Significant advances have been made at Brigham Young University (BYU) in comprehensive two-dimensional computer codes for mechanistic modeling of entrained-bed gasification and pulverized coal combustion. During the same time period, significant advances have been made at Advanced Fuel Research, Inc. (AFR) in the mechanisms and kinetics of coal pyrolysis and secondary reactions of pyrolysis products. This program presents a unique opportunity to merge the technology developed by each organization to provide detailed predictive capability for advanced coal characterization techniques in conjunction with comprehensive computer models to provide accurate process simulations. The program will streamline submodels existing or under development for coal pyrolysis chemistry, volatile secondary reactions, tar formation, soot formation, char reactivity, and SO{sub x}-NO{sub x} pollutant formation. Submodels for coal viscosity, agglomeration, tar/char secondary reactions, sulfur capture, and ash physics and chemistry will be developed or adapted. The submodels will first be incorporated into the BYU entrained-bed gasification code and subsequently, into a fixed-bed gasification code (to be selected and adapted). These codes will be validated by comparison with small scale laboratory and PDU-scale experiments. Progress is described.

  15. Department of Defense Quarterly Suicide Report, Calendar Year 2015 Third Quarter

    DTIC Science & Technology

    2015-02-01

    Quarter 3, 2015 0 Department of Defense Quarterly Suicide Report Calendar Year 2015 3rd Quarter Defense Suicide Prevention...Office (DSPO) Keita Franklin, Ph.D. Director, DSPO Quarter 3, 2015 1 Department of Defense Quarterly Suicide Report Calendar Year 2015...Third Quarter Introduction Timely and accurate suicide data reporting allows leaders at all levels to have near real time

  16. Verification of Geometric Model-Based Plant Phenotyping Methods for Studies of Xerophytic Plants

    PubMed Central

    Drapikowski, Paweł; Kazimierczak-Grygiel, Ewa; Korecki, Dominik; Wiland-Szymańska, Justyna

    2016-01-01

    This paper presents the results of verification of certain non-contact measurement methods of plant scanning to estimate morphological parameters such as length, width, area, volume of leaves and/or stems on the basis of computer models. The best results in reproducing the shape of scanned objects up to 50 cm in height were obtained with the structured-light DAVID Laserscanner. The optimal triangle mesh resolution for scanned surfaces was determined with the measurement error taken into account. The research suggests that measuring morphological parameters from computer models can supplement or even replace phenotyping with classic methods. Calculating precise values of area and volume makes determination of the S/V (surface/volume) ratio for cacti and other succulents possible, whereas for classic methods the result is an approximation only. In addition, the possibility of scanning and measuring plant species which differ in morphology was investigated. PMID:27355949

  17. Verification of Geometric Model-Based Plant Phenotyping Methods for Studies of Xerophytic Plants.

    PubMed

    Drapikowski, Paweł; Kazimierczak-Grygiel, Ewa; Korecki, Dominik; Wiland-Szymańska, Justyna

    2016-06-27

    This paper presents the results of verification of certain non-contact measurement methods of plant scanning to estimate morphological parameters such as length, width, area, volume of leaves and/or stems on the basis of computer models. The best results in reproducing the shape of scanned objects up to 50 cm in height were obtained with the structured-light DAVID Laserscanner. The optimal triangle mesh resolution for scanned surfaces was determined with the measurement error taken into account. The research suggests that measuring morphological parameters from computer models can supplement or even replace phenotyping with classic methods. Calculating precise values of area and volume makes determination of the S/V (surface/volume) ratio for cacti and other succulents possible, whereas for classic methods the result is an approximation only. In addition, the possibility of scanning and measuring plant species which differ in morphology was investigated.

  18. Mathematical modeling of physical-chemical wastewater treatment plant

    SciTech Connect

    Torruellas, E.D.

    1987-01-01

    The scheme of treatment modeled includes processes such as coagulation, flocculation, sedimentation, sand filtration, adsorption on granular activated carbon, and surge storage. Sludge treatment processes such as gravity thickening, vacuum filter dewatering, and hauling and disposal were also simulated. The primary objective of this work is to demonstrate that an optimization scheme can be used to determine the minimum total cost of a complex physical-chemical treatment system with models representing the individual unit processes. A method for determining the minimum cost design of a physical-chemical treatment plant is presented. The method utilizes an existing search technique (Box complex algorithm) to optimize a non-linear cost function for the physical-chemical processes. Thus, the physical-chemical treatment plant design is formulated as an optimization problem with non-linear cost functions and realistic mathematical models for each of its constituent unit processes. The level of cost resolution adopted derives from a series of economic models developed which basically make a Present Worth Analysis of each unit within the system. The economic data are based mostly on updated cost information obtained from Environmental Protection Agency Technology Transfer Manuals. Among the benefits directly derived from this study are the following: optimum economic design and operation of a typical physical-chemical treatment plant, simplified and directly oriented pilot plant studies, and the cost savings associated with it. Also, the formulation of a relatively new design concept is developed which underlines the need of the simultaneous consideration of all the components of a physical-chemical treatment plant for the most economic design.

  19. Synthesis of a naphthalene-hydroxynaphthalene polymer model compound. Quarterly report, December 13, 1990--March 12, 1991

    SciTech Connect

    Kwong, C.D.

    1991-04-15

    The objective of this contract is the synthesis of a new naphthalene-hydroxynaphthalene polymer model compound for coal combustion studies. This effort also requires the development of a synthetic procedure for this compound since it has not been reported before. We can only report that we are still unable to provide the target polymer or even any of the key intermediates leading to this target Dr. Rao has been informed of our progress (or lack of progress), and he has suggested that we begin to design other alternative compounds which contain the functionalities required by the target compound. In response to this suggestion, we have quickly designed the potential targets shown in Scheme VIL We are currently evaluating the schemes further and we will continue designing routes to the other analogous compounds.

  20. Synthesis of a naphthalene-hydroxynaphthalene polymer model compound. Quarterly report, September 13, 1990--December 12, 1990

    SciTech Connect

    Kwong, C.D.

    1991-01-15

    The goal is to synthesize a new naphthalene-hydroxynaphthalene polymer model compound for use in coal combustion studies. This effort will also require the development of a synthetic procedure to synthesize this compound since it is unreported. Our synthesis efforts have resulted in the preparation of a number of potential precursors and intermediates. These compounds were submitted to the Organic Chemistry Research Area`s Analytical Section for characterization and identification. The synthesis of the pre-Bakelite intermediate has continued to be the focus of our efforts. We first modified the target intermediate slightly to allow this compound to be obtained by a more direct route, using commercially available materials. Since then, we have further simplified intermediate to expedite our evaluation of the feasibility of the Bakelite process for the final polymerization, the key step of our suggested scheme.

  1. Modelling of some parameters from thermoelectric power plants

    NASA Astrophysics Data System (ADS)

    Popa, G. N.; Diniş, C. M.; Deaconu, S. I.; Maksay, Şt; Popa, I.

    2016-02-01

    Paper proposing new mathematical models for the main electrical parameters (active power P, reactive power Q of power supplies) and technological (mass flow rate of steam M from boiler and dust emission E from the output of precipitator) from a thermoelectric power plants using industrial plate-type electrostatic precipitators with three sections used in electrical power plants. The mathematical models were used experimental results taken from industrial facility, from boiler and plate-type electrostatic precipitators with three sections, and has used the least squares method for their determination. The modelling has been used equations of degree 1, 2 and 3. The equations were determined between dust emission depending on active power of power supplies and mass flow rate of steam from boiler, and, also, depending on reactive power of power supplies and mass flow rate of steam from boiler. These equations can be used to control the process from electrostatic precipitators.

  2. Plant hormone signaling during development: insights from computational models.

    PubMed

    Oliva, Marina; Farcot, Etienne; Vernoux, Teva

    2013-02-01

    Recent years have seen an impressive increase in our knowledge of the topology of plant hormone signaling networks. The complexity of these topologies has motivated the development of models for several hormones to aid understanding of how signaling networks process hormonal inputs. Such work has generated essential insights into the mechanisms of hormone perception and of regulation of cellular responses such as transcription in response to hormones. In addition, modeling approaches have contributed significantly to exploring how spatio-temporal regulation of hormone signaling contributes to plant growth and patterning. New tools have also been developed to obtain quantitative information on hormone distribution during development and to test model predictions, opening the way for quantitative understanding of the developmental roles of hormones.

  3. Modeling Halophytic Plants in APEX for Sustainable Water and Agriculture

    NASA Astrophysics Data System (ADS)

    DeRuyter, T.; Saito, L.; Nowak, B.; Rossi, C.; Toderich, K.

    2013-12-01

    A major problem for irrigated agricultural production is soil salinization, which can occur naturally or can be human-induced. Human-induced, or secondary salinization, is particularly a problem in arid and semi-arid regions, especially in irrigated areas. Irrigated land has more than twice the production of rainfed land, and accounts for about one third of the world's food, but nearly 20% of irrigated lands are salt-affected. Many farmers worldwide currently seasonally leach their land to reduce the soil salt content. These practices, however, create further problems such as a raised groundwater table, and salt, fertilizer, and pesticide pollution of nearby lakes and groundwater. In Uzbekistan, a combination of these management practices and a propensity to cultivate 'thirsty' crops such as cotton has also contributed to the Aral Sea shrinking nearly 90% by volume since the 1950s. Most common agricultural crops are glycophytes that have reduced yields when subjected to salt-stress. Some plants, however, are known as halophytic or 'salt-loving' plants and are capable of completing their life-cycle in higher saline soil or water environments. Halophytes may be useful for human consumption, livestock fodder, or biofuel, and may also be able to reduce or maintain salt levels in soil and water. To assess the potential for these halophytes to assist with salinity management, we are developing a model that is capable of tracking salinity under different management practices in agricultural environments. This model is interdisciplinary as it combines fields such as plant ecology, hydrology, and soil science. The US Department of Agriculture (USDA) model, Agricultural Policy/Environmental Extender (APEX), is being augmented with a salinity module that tracks salinity as separate ions across the soil-plant-water interface. The halophytes Atriplex nitens, Climacoptera lanata, and Salicornia europaea are being parameterized and added into the APEX model database. Field sites

  4. Plants Living on Gypsum: Beyond the Specialist Model

    PubMed Central

    Palacio, Sara; Escudero, Adrián; Montserrat-Martí, Gabriel; Maestro, Melchor; Milla, Rubén; Albert, MarÍa J.

    2007-01-01

    Background and Aims Plants from gypsum habitats are classified as gypsophiles and gypsovags. The former include both narrow endemics limited to small gypsum areas and regionally dominant gypsophiles growing in gypsum areas of large regions, whereas gypsovags are plants that can grow both in gypsum and non-gypsum soils. Factors controlling the distribution of gypsum plants are still not fully understood. Methods To assess how the different types of gypsum plants deal with the stressful conditions of gypsum substrates, comparisons were made of the leaf chemical composition of four gypsovags, five regionally dominant gypsophiles and four narrow gypsum endemics growing in two massive gypsum areas of the Iberian Peninsula. Key Results The chemical composition of gypsovags was clearly different from regionally dominant gypsophiles, while the chemical composition of narrow-gypsophile endemics was more similar to the chemical composition of gypsovags than to that of regionally dominant gypsophiles. Regionally dominant gypsophiles showed higher concentrations of ash, Ca, S, N, Mg P and Na, whereas gypsovags and local gypsophile endemics displayed higher concentrations of C and greater C : N ratios. Conclusions Such differences suggest that the three groups of gypsum plants follow diverse ecological strategies. It is suggested that regionally dominant gypsophiles might fit the ‘specialist’ model, being species specifically adapted to gypsum, whereas both gypsovags and narrow-gypsophile endemics might fit the ‘refuge’ model, being stress-tolerant species that find refuge on gypsum soils from competition. The analysis of the leaf chemical composition could be a good predictor of the degree of plants specialization to gypsum soils. PMID:17204537

  5. (Shippingport Atomic Power Station). Quarterly operating report, fourth quarter 1980

    SciTech Connect

    Not Available

    1980-01-01

    At the beginning of the fourth quarter of 1980, the Shippingport Atomic Power Station remained shutdown for the normally planned semiannual maintenance and testing program, initiated September 12, 1980. Operational testing began on November 7. Maximum power was achieved November 28 and was maintained throughout the remainder of the quarter except as noted. The LWBR Core has generated 19,046.07 EFPH from start-up through the end of the quarter. During this quarter, approximately 0.000025 curies of Xe 133 activity were released from the station. During the fourth quarter of 1980, 1081 cubic feet of radioactive solid waste was shipped out of state for burial. These shipments contained 0.037 curies of radioactivity.

  6. Stochastic modeling of deterioration in nuclear power plant components

    NASA Astrophysics Data System (ADS)

    Yuan, Xianxun

    2007-12-01

    The risk-based life-cycle management of engineering systems in a nuclear power plant is intended to ensure safe and economically efficient operation of energy generation infrastructure over its entire service life. An important element of life-cycle management is to understand, model and forecast the effect of various degradation mechanisms affecting the performance of engineering systems, structures and components. The modeling of degradation in nuclear plant components is confounded by large sampling and temporal uncertainties. The reason is that nuclear systems are not readily accessible for inspections due to high level of radiation and large costs associated with remote data collection methods. The models of degradation used by industry are largely derived from ordinary linear regression methods. The main objective of this thesis is to develop more advanced techniques based on stochastic process theory to model deterioration in engineering components with the purpose of providing more scientific basis to life-cycle management of aging nuclear power plants. This thesis proposes a stochastic gamma process (GP) model for deterioration and develops a suite of statistical techniques for calibrating the model parameters. The gamma process is a versatile and mathematically tractable stochastic model for a wide variety of degradation phenomena, and another desirable property is its nonnegative, monotonically increasing sample paths. In the thesis, the GP model is extended by including additional covariates and also modeling for random effects. The optimization of age-based replacement and condition-based maintenance strategies is also presented. The thesis also investigates improved regression techniques for modeling deterioration. A linear mixed-effects (LME) regression model is presented to resolve an inconsistency of the traditional regression models. The proposed LME model assumes that the randomness in deterioration is decomposed into two parts: the unobserved

  7. Development of a reburning boiler process model. First quarterly progress report, October 1, 1991--December 31, 1991

    SciTech Connect

    Wu, K.T.

    1992-01-30

    The overall objective of this program is to integrate EER`s expertise in boiler reburning performance evaluation into a package of analytical computer tools. Specific objectives of the program are to develop a computational capability with the following features: (1) can be used to predict the impact of gas reburning application on thermal conditions in the boiler radiant furnace, and on overall boiler performance; (2) can estimate gas reburning NO{sub x} reduction effectiveness based on specific reburning configurations and furnace/boiler configurations; (3) can be used as an analytical tool to evaluate the impact of boiler process parameters (e.g., fuel switching and changes in boiler operating conditions) on boiler thermal performance; (4) is adaptable to most boiler designs (tangential and wall fire boilers) and a variety of fuels (solid, liquid, gaseous and slurried fuels); (5) is sufficiently user friendly to be exercisable by engineers with a reasonable knowledge of boilers, and with reasonable computer skills. Here, ``user friendly`` means that the user will be guided by computer codes during the course of setting up individual input files for the boiler performance model.

  8. Comprehensive silicon solar cell computer modeling. Quarterly progress report No. 1, January 5, 1984-April 4, 1984

    SciTech Connect

    Lamorte, M.F.

    1984-06-01

    The general method to solve the transport equations for a solar cell is discussed. To obtain an accurate representation of a physical system, the system geometry is divided into a number of segments (mesh points). In a one-dimensional geometry, the segments are defined by a series of parallel planes. The separation of the planes defining the segments determines the simulation accuracy. The segments may be taken as thin as required to obtain the accuracy desired. The transport equations, governing the behavior of the physical system, are applied to each segment, and a closed-form solution is obtained in each of the segments. A brief discussion is presented of some of the phenomena submodels in the model and the representations used in the simulation program. The submodels cover such phenomena as mobility, diffusivities, boundary conditions at depletion region edges and those imposed at the mesh points, bandgap narrowing and intrinsic concentration, carrier lifetime, induced surface electric field, and built-in fields. (LEW)

  9. Deployable Crew Quarters

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo

    2008-01-01

    The deployable crew quarters (DCQ) have been designed for the International Space Station (ISS). Each DCQ would be a relatively inexpensive, deployable boxlike structure that is designed to fit in a rack bay. It is to be occupied by one crewmember to provide privacy and sleeping functions for the crew. A DCQ comprises mostly hard panels, made of a lightweight honeycomb or matrix/fiber material, attached to each other by cloth hinges. Both faces of each panel are covered with a layer of Nomex cloth and noise-suppression material to provide noise isolation from ISS. On Earth, the unit is folded flat and attached to a rigid pallet for transport to the ISS. On the ISS, crewmembers unfold the unit and install it in place, attaching it to ISS structural members by use of soft cords (which also help to isolate noise and vibration). A few hard pieces of equipment (principally, a ventilator and a smoke detector) are shipped separately and installed in the DCQ unit by use of a system of holes, slots, and quarter-turn fasteners. Full-scale tests showed that the time required to install a DCQ unit amounts to tens of minutes. The basic DCQ design could be adapted to terrestrial applications to satisfy requirements for rapid deployable emergency shelters that would be lightweight, portable, and quickly erected. The Temporary Early Sleep Station (TeSS) currently on-orbit is a spin-off of the DCQ.

  10. Short-term energy outlook. Quarterly projections, 2nd quarter 1994

    SciTech Connect

    Not Available

    1994-05-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. The forecast period for this issue of the Outlook extends from the second quarter of 1994 through the fourth quarter of 1995. Values for the first quarter of 1994, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available. The historical energy data, compiled into the second quarter 1994 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The cases are produced using the STIFS. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. The EIA model is available on computer tape from the National Technical Information Service.

  11. A Compact Model for the Complex Plant Circadian Clock

    PubMed Central

    De Caluwé, Joëlle; Xiao, Qiying; Hermans, Christian; Verbruggen, Nathalie; Leloup, Jean-Christophe; Gonze, Didier

    2016-01-01

    The circadian clock is an endogenous timekeeper that allows organisms to anticipate and adapt to the daily variations of their environment. The plant clock is an intricate network of interlocked feedback loops, in which transcription factors regulate each other to generate oscillations with expression peaks at specific times of the day. Over the last decade, mathematical modeling approaches have been used to understand the inner workings of the clock in the model plant Arabidopsis thaliana. Those efforts have produced a number of models of ever increasing complexity. Here, we present an alternative model that combines a low number of equations and parameters, similar to the very earliest models, with the complex network structure found in more recent ones. This simple model describes the temporal evolution of the abundance of eight clock gene mRNA/protein and captures key features of the clock on a qualitative level, namely the entrained and free-running behaviors of the wild type clock, as well as the defects found in knockout mutants (such as altered free-running periods, lack of entrainment, or changes in the expression of other clock genes). Additionally, our model produces complex responses to various light cues, such as extreme photoperiods and non-24 h environmental cycles, and can describe the control of hypocotyl growth by the clock. Our model constitutes a useful tool to probe dynamical properties of the core clock as well as clock-dependent processes. PMID:26904049

  12. Modeling gas exchange in a closed plant growth chamber

    NASA Technical Reports Server (NTRS)

    Cornett, J. D.; Hendrix, J. E.; Wheeler, R. M.; Ross, C. W.; Sadeh, W. Z.

    1994-01-01

    Fluid transport models for fluxes of water vapor and CO2 have been developed for one crop of wheat and three crops of soybean grown in a closed plant growth chamber. Correspondence among these fluxes is discussed. Maximum fluxes of gases are provided for engineering design requirements of fluid recycling equipment in growth chambers. Furthermore, to investigate the feasibility of generalized crop models, dimensionless representations of water vapor fluxes are presented. The feasibility of such generalized models and the need for additional data are discussed.

  13. Modeling Gas Exchange in a Closed Plant Growth Chamber

    NASA Technical Reports Server (NTRS)

    Cornett, J. D.; Hendrix, J. E.; Wheeler, R. M.; Ross, C. W.; Sadeh, W. Z.

    1994-01-01

    Fluid transport models for fluxes of water vapor and CO2 have been developed for one crop of wheat and three crops of soybean grown in a closed plant a growth chamber. Correspondence among these fluxes is discussed. Maximum fluxes of gases are provided for engineering design requirements of fluid recycling equipment in growth chambers. Furthermore, to investigate the feasibility of generalized crop models, dimensionless representations of water vapor fluxes are presented. The feasibility of such generalized models and the need for additional data are discussed.

  14. [Temperature dependence of parameters of plant photosynthesis models: a review].

    PubMed

    Borjigidai, Almaz; Yu, Gui-Rui

    2013-12-01

    This paper reviewed the progress on the temperature response models of plant photosynthesis. Mechanisms involved in changes in the photosynthesis-temperature curve were discussed based on four parameters, intercellular CO2 concentration, activation energy of the maximum rate of RuBP (ribulose-1,5-bisphosphate) carboxylation (V (c max)), activation energy of the rate of RuBP regeneration (J(max)), and the ratio of J(max) to V(c max) All species increased the activation energy of V(c max) with increasing growth temperature, while other parameters changed but differed among species, suggesting the activation energy of V(c max) might be the most important parameter for the temperature response of plant photosynthesis. In addition, research problems and prospects were proposed. It's necessary to combine the photosynthesis models at foliage and community levels, and to investigate the mechanism of plants in response to global change from aspects of leaf area, solar radiation, canopy structure, canopy microclimate and photosynthetic capacity. It would benefit the understanding and quantitative assessment of plant growth, carbon balance of communities and primary productivity of ecosystems.

  15. Global asymptotic stability of plant-seed bank models.

    PubMed

    Eager, Eric Alan; Rebarber, Richard; Tenhumberg, Brigitte

    2014-07-01

    Many plant populations have persistent seed banks, which consist of viable seeds that remain dormant in the soil for many years. Seed banks are important for plant population dynamics because they buffer against environmental perturbations and reduce the probability of extinction. Viability of the seeds in the seed bank can depend on the seed's age, hence it is important to keep track of the age distribution of seeds in the seed bank. In this paper we construct a general density-dependent plant-seed bank model where the seed bank is age-structured. We consider density dependence in both seedling establishment and seed production, since previous work has highlighted that overcrowding can suppress both of these processes. Under certain assumptions on the density dependence, we prove that there is a globally stable equilibrium population vector which is independent of the initial state. We derive an analytical formula for the equilibrium population using methods from feedback control theory. We apply these results to a model for the plant species Cirsium palustre and its seed bank.

  16. Lignin variability in plant cell walls: contribution of new models.

    PubMed

    Neutelings, Godfrey

    2011-10-01

    Lignin is a major component of certain plant cell walls. The enzymes and corresponding genes associated with the metabolic pathway leading to the production of this complex phenolic polymer have been studied for many years now and are relatively well characterized. The use of genetically modified model plants (Arabidopsis, tobacco, poplar.) and mutants has contributed greatly to our current understanding of this process. The recent utilisation and/or development of a number of dedicated genomic and transcriptomic tools for other species opens new perspectives for advancing our knowledge of the biological role of this important polymer in less typical situations and/or species. In this context, studies on the formation of hypolignified G-type fibres in angiosperm tension wood, and the natural hypolignification of secondary cell walls in plant bast fibre species such as hemp (Cannabis sativa), flax (Linum usitatissimum) or ramie (Boehmeria nivea) are starting to provide novel information about how plants control secondary cell wall formation. Finally, other biologically interesting species for which few molecular resources currently exist could also represent interesting future models.

  17. Empirical Modeling of Plant Gas Fluxes in Controlled Environments

    NASA Technical Reports Server (NTRS)

    Cornett, Jessie David

    1994-01-01

    As humans extend their reach beyond the earth, bioregenerative life support systems must replace the resupply and physical/chemical systems now used. The Controlled Ecological Life Support System (CELSS) will utilize plants to recycle the carbon dioxide (CO2) and excrement produced by humans and return oxygen (O2), purified water and food. CELSS design requires knowledge of gas flux levels for net photosynthesis (PS(sub n)), dark respiration (R(sub d)) and evapotranspiration (ET). Full season gas flux data regarding these processes for wheat (Triticum aestivum), soybean (Glycine max) and rice (Oryza sativa) from published sources were used to develop empirical models. Univariate models relating crop age (days after planting) and gas flux were fit by simple regression. Models are either high order (5th to 8th) or more complex polynomials whose curves describe crop development characteristics. The models provide good estimates of gas flux maxima, but are of limited utility. To broaden the applicability, data were transformed to dimensionless or correlation formats and, again, fit by regression. Polynomials, similar to those in the initial effort, were selected as the most appropriate models. These models indicate that, within a cultivar, gas flux patterns appear remarkably similar prior to maximum flux, but exhibit considerable variation beyond this point. This suggests that more broadly applicable models of plant gas flux are feasible, but univariate models defining gas flux as a function of crop age are too simplistic. Multivariate models using CO2 and crop age were fit for PS(sub n), and R(sub d) by multiple regression. In each case, the selected model is a subset of a full third order model with all possible interactions. These models are improvements over the univariate models because they incorporate more than the single factor, crop age, as the primary variable governing gas flux. They are still limited, however, by their reliance on the other environmental

  18. Empirical Modeling of Plant Gas Fluxes in Controlled Environments

    NASA Technical Reports Server (NTRS)

    Cornett, Jessie David

    1994-01-01

    As humans extend their reach beyond the earth, bioregenerative life support systems must replace the resupply and physical/chemical systems now used. The Controlled Ecological Life Support System (CELSS) will utilize plants to recycle the carbon dioxide (CO2) and excrement produced by humans and return oxygen (O2), purified water and food. CELSS design requires knowledge of gas flux levels for net photosynthesis (PS(sub n)), dark respiration (R(sub d)) and evapotranspiration (ET). Full season gas flux data regarding these processes for wheat (Triticum aestivum), soybean (Glycine max) and rice (Oryza sativa) from published sources were used to develop empirical models. Univariate models relating crop age (days after planting) and gas flux were fit by simple regression. Models are either high order (5th to 8th) or more complex polynomials whose curves describe crop development characteristics. The models provide good estimates of gas flux maxima, but are of limited utility. To broaden the applicability, data were transformed to dimensionless or correlation formats and, again, fit by regression. Polynomials, similar to those in the initial effort, were selected as the most appropriate models. These models indicate that, within a cultivar, gas flux patterns appear remarkably similar prior to maximum flux, but exhibit considerable variation beyond this point. This suggests that more broadly applicable models of plant gas flux are feasible, but univariate models defining gas flux as a function of crop age are too simplistic. Multivariate models using CO2 and crop age were fit for PS(sub n), and R(sub d) by multiple regression. In each case, the selected model is a subset of a full third order model with all possible interactions. These models are improvements over the univariate models because they incorporate more than the single factor, crop age, as the primary variable governing gas flux. They are still limited, however, by their reliance on the other environmental

  19. Strategic petroleum reserve. Quarterly report

    SciTech Connect

    Not Available

    1994-05-15

    The Strategic Petroleum Reserve serves as one of our most important investments in reducing the Nation`s vulnerability to oil supply disruptions. Its existence provides an effective response mechanism should a disruption occur and a formidable deterrent to the use of oil as a political instrument. The Strategic Petroleum Reserve was created pursuant to the Energy Policy and Conservation Act of December 22, 1975, (Public Law 94-163) as amended, to reduce the impact of disruptions in supplies of petroleum products and to carry out obligations of the United States under the Agreement on an International Energy Program. Section 165(a) of the Act requires the submission of Annual Reports and Section 165(b)(1) requires the submission of Quarterly Reports. This Quarterly Report highlights activities undertaken during the first quarter of calendar year 1994, including: (1) inventory of petroleum products stored in the Reserve, under contract and in transit at the end of the calendar quarter; (2) fill rate for the current quarter and projected fill rate for the next calendar quarter; (3) average price of the petroleum products acquired during the calendar quarter; (4) current and projected storage capacity; (5) analysis of existing or anticipated problems with the acquisition and storage of petroleum products, and future expansion of storage capacity; (6) funds obligated by the Secretary from the SPR Petroleum Account and the Strategic Petroleum Reserve Account during the prior calendar quarter and in total; and (7) major environmental actions completed, in progress, or anticipated.

  20. Future of Plant Functional Types in Terrestrial Biosphere Models

    NASA Astrophysics Data System (ADS)

    Wullschleger, S. D.; Euskirchen, E. S.; Iversen, C. M.; Rogers, A.; Serbin, S.

    2015-12-01

    Earth system models describe the physical, chemical, and biological processes that govern our global climate. While it is difficult to single out one component as being more important than another in these sophisticated models, terrestrial vegetation is a critical player in the biogeochemical and biophysical dynamics of the Earth system. There is much debate, however, as to how plant diversity and function should be represented in these models. Plant functional types (PFTs) have been adopted by modelers to represent broad groupings of plant species that share similar characteristics (e.g. growth form) and roles (e.g. photosynthetic pathway) in ecosystem function. In this review the PFT concept is traced from its origin in the early 1800s to its current use in regional and global dynamic vegetation models (DVMs). Special attention is given to the representation and parameterization of PFTs and to validation and benchmarking of predicted patterns of vegetation distribution in high-latitude ecosystems. These ecosystems are sensitive to changing climate and thus provide a useful test case for model-based simulations of past, current, and future distribution of vegetation. Models that incorporate the PFT concept predict many of the emerging patterns of vegetation change in tundra and boreal forests, given known processes of tree mortality, treeline migration, and shrub expansion. However, representation of above- and especially belowground traits for specific PFTs continues to be problematic. Potential solutions include developing trait databases and replacing fixed parameters for PFTs with formulations based on trait co-variance and empirical trait-environment relationships. Surprisingly, despite being important to land-atmosphere interactions of carbon, water, and energy, PFTs such as moss and lichen are largely absent from DVMs. Close collaboration among those involved in modelling with the disciplines of taxonomy, biogeography, ecology, and remote sensing will be

  1. Model predictive control of a combined heat and power plant using local linear models

    SciTech Connect

    Kikstra, J.F.; Roffel, B.; Schoen, P.

    1998-10-01

    Model predictive control has been applied to control of a combined heat and power plant. One of the main features of this plant is that it exhibits nonlinear process behavior due to large throughput swings. In this application, the operating window of the plant has been divided into a number of smaller windows in which the nonlinear process behavior has been approximated by linear behavior. For each operating window, linear step weight models were developed from a detailed nonlinear first principles model, and the model prediction is calculated based on interpolation between these linear models. The model output at each operating point can then be calculated from four basic linear models, and the required control action can subsequently be calculated with the standard model predictive control approach using quadratic programming.

  2. Modelling of the Nutrient Medium for Plants Cultivation in Spaceflight

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.

    2016-07-01

    MODELLING OF THE NUTRIENT MEDIUM FOR PLANTS CULTIVATION IN SPACEFLIGHT Nechitajlo G.S.*, Rakhmetova A.A.**, Bogoslovskaja O.A.**, Ol'hovskay I.P.**, Glushchenko N.N.** *Emanuel Institute of Biochemical Physics of Russian Academy of Sciences (IBCP RAS) mail: spacemal@mail.ru **V.L. Talrose Institute for Energy Problems of Chemical Physics of Russian Academy of Science (INEPCP RAS) mail: nnglu@ mail.ru The valuable life and fruitful activity of cosmonauts and researchers in conditions of spaceflights and prolonged work at space stations are only possible with creating life area providing fresh air, natural food, comfortable psychological conditions, etc. The solution of that problem under space conditions seems impossible without use of high nano- and biotechnologies for plants growth. A priority should be given not only to choose species of growth plants in space, but also to improve conditions for their growth which includes optimal nourishing components for plants, preparation of nutrient mediums, illumination and temperature. We are deeply convinced that just manipulations with growing conditions for cultivated plants, but not genes changes, is a guarantee of success in the decision of this problem. For improving the method of plants growing on the artificial nutrient medium with balanced content of components, being necessary for growth and development of plants, we added essential metal elements: Fe, Zn, Cu - in an electroneutral state in the form of nanoparticles instead of sulfates or other easily dissolving salts. Nanoparticulated metals are known to have a number of advantages in comparison with salts: metals in an electroneutral form are characterized with the prolonged and multifunctional action, low toxicity per se and appearing to be much below the toxicity of the same metals in the ionic forms, accumulation as a reserve being used in biotic dozes, active distribution in bodies and organs of plants and stimulation of vital processes. A high reactivity

  3. " Using the impact model in order to predict the Danube river flow in the last quarter of the XXI century

    NASA Astrophysics Data System (ADS)

    Adamovic, M.

    2009-04-01

    The paper has intercompared and verified Regional Climate Model (RCM) EBU-POM in its representation of the hydrological balance over the Danube river basin along Iron Gate gorge, for the time frame 1961-1990 and 2071-2100 according to the IPCC SRES scenario A1B. The Danube has been chosen as a case study because of its multiple relevance for socioeconomical, as well as environmental and climatic level. This part of the Danube river basin has a direct relevance to the Mediterranean region, since it provides a relevant input of freshwater to the sea, as well as being fuelled mostly by precipitations due to the water of Mediterranean origin. On the other, the Dinaric-Balkan mountain chains in the west and the Carpathian mountain bow in the north and east, present distinctive morphological and climatic regions and barriers. Having been aware of the climatic-hydrologic and hydrographic homogeneity of regions, the whole territory of Serbia is divided into 20 units basins. The part of Danube basin in its eastern part present one of them, and was subject of the research. For this balance unit, the main components of the balance equation of the water that included into the calculation are: precipitation P (mm), flow Q (m3/s), runoff depth h (mm), evaporation E (mm) and annual air temperature T (0C). The hydrological balance has been computed in two different, but in principle equivalent ways. The first approach, which has a more hydrological nuance, relies on establishing relationships between annual averages of the hydrological balance parameters (E, P, T) in order to get relevant coefficients. The second approach, which is more typically meteorological, relies on the calculation of the E for the time frame 2071-2100 by using the previous coefficients. On the basis of the assessment of climate parameters in the XXI century and with help of the established relationships, the water flow of Danube river and runoff depth were defined for this century. The outcomes are very

  4. A vegetation-focused soil-plant-atmospheric continuum model to study hydrodynamic soil-plant water relations

    NASA Astrophysics Data System (ADS)

    Deng, Zijuan; Guan, Huade; Hutson, John; Forster, Michael A.; Wang, Yunquan; Simmons, Craig T.

    2017-06-01

    A novel simple soil-plant-atmospheric continuum model that emphasizes the vegetation's role in controlling water transfer (v-SPAC) has been developed in this study. The v-SPAC model aims to incorporate both plant and soil hydrological measurements into plant water transfer modeling. The model is different from previous SPAC models in which v-SPAC uses (1) a dynamic plant resistance system in the form of a vulnerability curve that can be easily obtained from sap flow and stem xylem water potential time series and (2) a plant capacitance parameter to buffer the effects of transpiration on root water uptake. The unique representation of root resistance and capacitance allows the model to embrace SPAC hydraulic pathway from bulk soil, to soil-root interface, to root xylem, and finally to stem xylem where the xylem water potential is measured. The v-SPAC model was tested on a native tree species in Australia, Eucalyptus crenulata saplings, with controlled drought treatment. To further validate the robustness of the v-SPAC model, it was compared against a soil-focused SPAC model, LEACHM. The v-SPAC model simulation results closely matched the observed sap flow and stem water potential time series, as well as the soil moisture variation of the experiment. The v-SPAC model was found to be more accurate in predicting measured data than the LEACHM model, underscoring the importance of incorporating root resistance into SPAC models and the benefit of integrating plant measurements to constrain SPAC modeling.

  5. Health-aware Model Predictive Control of Pasteurization Plant

    NASA Astrophysics Data System (ADS)

    Karimi Pour, Fatemeh; Puig, Vicenç; Ocampo-Martinez, Carlos

    2017-01-01

    In order to optimize the trade-off between components life and energy consumption, the integration of a system health management and control modules is required. This paper proposes the integration of model predictive control (MPC) with a fatigue estimation approach that minimizes the damage of the components of a pasteurization plant. The fatigue estimation is assessed with the rainflow counting algorithm. Using data from this algorithm, a simplified model that characterizes the health of the system is developed and integrated with MPC. The MPC controller objective is modified by adding an extra criterion that takes into account the accumulated damage. But, a steady-state offset is created by adding this extra criterion. Finally, by including an integral action in the MPC controller, the steady-state error for regulation purpose is eliminated. The proposed control scheme is validated in simulation using a simulator of a utility-scale pasteurization plant.

  6. Selected bibliography on the modeling and control of plant processes

    NASA Technical Reports Server (NTRS)

    Viswanathan, M. M.; Julich, P. M.

    1972-01-01

    A bibliography of information pertinent to the problem of simulating plants is presented. Detailed simulations of constituent pieces are necessary to justify simple models which may be used for analysis. Thus, this area of study is necessary to support the Earth Resources Program. The report sums up the present state of the problem of simulating vegetation. This area holds the hope of major benefits to mankind through understanding the ecology of a region and in improving agricultural yield.

  7. Assessment of uncertainty in functional–structural plant models

    PubMed Central

    Ford, E. David; Kennedy, Maureen C.

    2011-01-01

    Background and Aims Constructing functional–structural plant models (FSPMs) is a valuable method for examining how physiology and morphology interact in determining plant processes. However, such models always have uncertainty concerned with whether model components have been selected and represented effectively, with the number of model outputs simulated and with the quality of data used in assessment. We provide a procedure for defining uncertainty of an FSPM and how this uncertainty can be reduced. Methods An important characteristic of FSPMs is that typically they calculate many variables. These can be variables that the model is designed to predict and also variables that give indications of how the model functions. Together these variables are used as criteria in a method of multi-criteria assessment. Expected ranges are defined and an evolutionary computation algorithm searches for model parameters that achieve criteria within these ranges. Typically, different combinations of model parameter values provide solutions achieving different combinations of variables within their specified ranges. We show how these solutions define a Pareto Frontier that can inform about the functioning of the model. Key Results The method of multi-criteria assessment is applied to development of BRANCHPRO, an FSPM for foliage reiteration on old-growth branches of Pseudotsuga menziesii. A geometric model utilizing probabilities for bud growth is developed into a causal explanation for the pattern of reiteration found on these branches and how this pattern may contribute to the longevity of this species. Conclusions FSPMs should be assessed by their ability to simulate multiple criteria simultaneously. When different combinations of parameter values achieve different groups of assessment criteria effectively a Pareto Frontier can be calculated and used to define the sources of model uncertainty. PMID:21593061

  8. Metabolomics, Standards, and Metabolic Modeling for Synthetic Biology in Plants

    PubMed Central

    Hill, Camilla Beate; Czauderna, Tobias; Klapperstück, Matthias; Roessner, Ute; Schreiber, Falk

    2015-01-01

    Life on earth depends on dynamic chemical transformations that enable cellular functions, including electron transfer reactions, as well as synthesis and degradation of biomolecules. Biochemical reactions are coordinated in metabolic pathways that interact in a complex way to allow adequate regulation. Biotechnology, food, biofuel, agricultural, and pharmaceutical industries are highly interested in metabolic engineering as an enabling technology of synthetic biology to exploit cells for the controlled production of metabolites of interest. These approaches have only recently been extended to plants due to their greater metabolic complexity (such as primary and secondary metabolism) and highly compartmentalized cellular structures and functions (including plant-specific organelles) compared with bacteria and other microorganisms. Technological advances in analytical instrumentation in combination with advances in data analysis and modeling have opened up new approaches to engineer plant metabolic pathways and allow the impact of modifications to be predicted more accurately. In this article, we review challenges in the integration and analysis of large-scale metabolic data, present an overview of current bioinformatics methods for the modeling and visualization of metabolic networks, and discuss approaches for interfacing bioinformatics approaches with metabolic models of cellular processes and flux distributions in order to predict phenotypes derived from specific genetic modifications or subjected to different environmental conditions. PMID:26557642

  9. Stochastic models for plant microtubule self-organization and structure.

    PubMed

    Eren, Ezgi C; Dixit, Ram; Gautam, Natarajan

    2015-12-01

    One of the key enablers of shape and growth in plant cells is the cortical microtubule (CMT) system, which is a polymer array that forms an appropriately-structured scaffolding in each cell. Plant biologists have shown that stochastic dynamics and simple rules of interactions between CMTs can lead to a coaligned CMT array structure. However, the mechanisms and conditions that cause CMT arrays to become organized are not well understood. It is prohibitively time-consuming to use actual plants to study the effect of various genetic mutations and environmental conditions on CMT self-organization. In fact, even computer simulations with multiple replications are not fast enough due to the spatio-temporal complexity of the system. To redress this shortcoming, we develop analytical models and methods for expeditiously computing CMT system metrics that are related to self-organization and array structure. In particular, we formulate a mean-field model to derive sufficient conditions for the organization to occur. We show that growth-prone dynamics itself is sufficient to lead to organization in presence of interactions in the system. In addition, for such systems, we develop predictive methods for estimation of system metrics such as expected average length and number of CMTs over time, using a stochastic fluid-flow model, transient analysis, and approximation algorithms tailored to our problem. We illustrate the effectiveness of our approach through numerical test instances and discuss biological insights.

  10. Coal gasification. Quarterly report, July-September 1979

    SciTech Connect

    1980-07-01

    The status of 18 coal gasification pilot plants or supporting projects supported by US DOE is reviewed under the following headings: company involved, location, contract number, funding, gasification process, history, process description, flowsheet and progress in the July-September 1979 quarter. (LTN)

  11. Phylogeny and a structural model of plant MHX transporters

    PubMed Central

    2013-01-01

    Background The Arabidopsis thaliana MHX gene (AtMHX) encodes a Mg2+/H+ exchanger. Among non-plant proteins, AtMHX showed the highest similarity to mammalian Na+/Ca2+ exchanger (NCX) transporters, which are part of the Ca2+/cation (CaCA) exchanger superfamily. Results Sequences showing similarity to AtMHX were searched in the databases or sequenced from cDNA clones. Phylogenetic analysis showed that the MHX family is limited to plants, and constitutes a sixth family within the CaCA superfamily. Some plants include, besides a full MHX gene, partial MHX-related sequences. More than one full MHX gene was currently identified only in Oryza sativa and Mimulus guttatus, but an EST for more than one MHX was identified only in M. guttatus. MHX genes are not present in the currently available chlorophyte genomes. The prevalence of upstream ORFs in MHX genes is much higher than in most plant genes, and can limit their expression. A structural model of the MHXs, based on the resolved structure of NCX1, implies that the MHXs include nine transmembrane segments. The MHXs and NCXs share 32 conserved residues, including a GXG motif implicated in the formation of a tight-turn in a reentrant-loop. Three residues differ between all MHX and NCX proteins. Altered mobility under reducing and non-reducing conditions suggests the presence of an intramolecular disulfide-bond in AtMHX. Conclusions The absence of MHX genes in non-plant genomes and in the currently available chlorophyte genomes, and the presence of an NCX in Chlamydomonas, are consistent with the suggestion that the MHXs evolved from the NCXs after the split of the chlorophyte and streptophyte lineages of the plant kingdom. The MHXs underwent functional diploidization in most plant species. De novo duplication of MHX occurred in O. sativa before the split between the Indica and Japonica subspecies, and was apparently followed by translocation of one MHX paralog from chromosome 2 to chromosome 11 in Japonica. The structural

  12. Environemental Planning Quarterly

    NASA Astrophysics Data System (ADS)

    Anderson, Mary P.

    The Environmental Planning Quarterly is a publication of the Environmental Planning Division of the American Planning Association (APA). Its current editor is G. William Page (Department of Urban Planning, University of Wisconsin-Milwaukee). A recent issue included a feature article on forest management in the state of Washington and several lengthy and informative news items about activities of the Environmental Protection Agency related to groundwater contamination and hazardous waste. Other news items contained information on air pollution and acid rain as well as on surface water pollution. Subscriptions can be obtained by writing to the Environmental Planning Division. American Planning Association, Lock Box 97774, Chicago, IL 60690. Annual fees are as follows: $ 15 (APA member), $25 (affiliate), $5 (student), $30 (subscribing).

  13. Modeling Forest Structure and Vascular Plant Diversity in Piedmont Forests

    NASA Astrophysics Data System (ADS)

    Hakkenberg, C.

    2014-12-01

    When the interacting stressors of climate change and land cover/land use change (LCLUC) overwhelm ecosystem resilience to environmental and climatic variability, forest ecosystems are at increased risk of regime shifts and hyperdynamism in process rates. To meet the growing range of novel biotic and environmental stressors on human-impacted ecosystems, the maintenance of taxonomic diversity and functional redundancy in metacommunities has been proposed as a risk spreading measure ensuring that species critical to landscape ecosystem functioning are available for recruitment as local systems respond to novel conditions. This research is the first in a multi-part study to establish a dynamic, predictive model of the spatio-temporal dynamics of vascular plant diversity in North Carolina Piedmont mixed forests using remotely sensed data inputs. While remote sensing technologies are optimally suited to monitor LCLUC over large areas, direct approaches to the remote measurement of plant diversity remain a challenge. This study tests the efficacy of predicting indices of vascular plant diversity using remotely derived measures of forest structural heterogeneity from aerial LiDAR and high spatial resolution broadband optical imagery in addition to derived topo-environmental variables. Diversity distribution modelling of this sort is predicated upon the idea that environmental filtering of dispersing species help define fine-scale (permeable) environmental envelopes within which biotic structural and compositional factors drive competitive interactions that, in addition to background stochasticity, determine fine-scale alpha diversity. Results reveal that over a range of Piedmont forest communities, increasing structural complexity is positively correlated with measures of plant diversity, though the nature of this relationship varies by environmental conditions and community type. The diversity distribution model is parameterized and cross-validated using three high

  14. An implicit approach to model plant infestation by insect pests.

    PubMed

    Lopes, Christelle; Spataro, Thierry; Doursat, Christophe; Lapchin, Laurent; Arditi, Roger

    2007-09-07

    Various spatial approaches were developed to study the effect of spatial heterogeneities on population dynamics. We present in this paper a flux-based model to describe an aphid-parasitoid system in a closed and spatially structured environment, i.e. a greenhouse. Derived from previous work and adapted to host-parasitoid interactions, our model represents the level of plant infestation as a continuous variable corresponding to the number of plants bearing a given density of pests at a given time. The variation of this variable is described by a partial differential equation. It is coupled to an ordinary differential equation and a delay-differential equation that describe the parasitized host population and the parasitoid population, respectively. We have applied our approach to the pest Aphis gossypii and to one of its parasitoids, Lysiphlebus testaceipes, in a melon greenhouse. Numerical simulations showed that, regardless of the number and distribution of hosts in the greenhouse, the aphid population is slightly larger if parasitoids display a type III rather than a type II functional response. However, the population dynamics depend on the initial distribution of hosts and the initial density of parasitoids released, which is interesting for biological control strategies. Sensitivity analysis showed that the delay in the parasitoid equation and the growth rate of the pest population are crucial parameters for predicting the dynamics. We demonstrate here that such a flux-based approach generates relevant predictions with a more synthetic formalism than a common plant-by-plant model. We also explain how this approach can be better adapted to test different management strategies and to manage crops of several greenhouses.

  15. National Bioenergy Center Biochemical Platform Integration Project: Quarterly Update #26, January - March 2010

    SciTech Connect

    Schell, D.

    2010-04-01

    January-March, 2010 edition of the National Bioenergy Center's Biochemical Platform Integration Project quarterly newsletter. Issue topics: understanding and improving sugar measurements in biomass hydrolysates; expansion of the NREL/DOE Biochemical Pilot Plant.

  16. The Unified Plant Growth Model (UPGM): software framework overview and model application

    USDA-ARS?s Scientific Manuscript database

    Since the Environmental Policy Integrated Climate (EPIC) model was developed in 1989, the EPIC plant growth component has been incorporated into other erosion and crop management models (e.g., WEPS, WEPP, SWAT, ALMANAC, and APEX) and modified to meet model developer research objectives. This has re...

  17. Modeling the leaf angle dynamics in rice plant

    PubMed Central

    Zhang, Yonghui; Tang, Liang; Liu, Xiaojun; Liu, Leilei; Cao, Weixing; Zhu, Yan

    2017-01-01

    The leaf angle between stem and sheath (SSA) is an important rice morphological trait. The objective of this study was to develop and validate a dynamic SSA model under different nitrogen (N) rates for selected rice cultivars. The time-course data of SSA were collected in three years, and a dynamic SSA model was developed for different main stem leaf ranks under different N rates for two selected rice cultivars. SSA increased with tiller age. The SSA of the same leaf rank increased with increase in N rate. The maximum SSA increased with leaf rank from the first to the third leaf, then decreased from the third to the final leaf. The relationship between the maximum SSA and leaf rank on main stem could be described with a linear piecewise function. The change of SSA with thermal time (TT) was described by a logistic equation. A variety parameter (the maximum SSA of the 3rd leaf on main stem) and a nitrogen factor were introduced to quantify the effect of cultivar and N rate on SSA. The model was validated against data collected from both pot and field experiments. The relative root mean square error (RRMSE) was 11.56% and 14.05%, respectively. The resulting models could be used for virtual rice plant modeling and plant-type design. PMID:28207799

  18. Modeling the leaf angle dynamics in rice plant.

    PubMed

    Zhang, Yonghui; Tang, Liang; Liu, Xiaojun; Liu, Leilei; Cao, Weixing; Zhu, Yan

    2017-01-01

    The leaf angle between stem and sheath (SSA) is an important rice morphological trait. The objective of this study was to develop and validate a dynamic SSA model under different nitrogen (N) rates for selected rice cultivars. The time-course data of SSA were collected in three years, and a dynamic SSA model was developed for different main stem leaf ranks under different N rates for two selected rice cultivars. SSA increased with tiller age. The SSA of the same leaf rank increased with increase in N rate. The maximum SSA increased with leaf rank from the first to the third leaf, then decreased from the third to the final leaf. The relationship between the maximum SSA and leaf rank on main stem could be described with a linear piecewise function. The change of SSA with thermal time (TT) was described by a logistic equation. A variety parameter (the maximum SSA of the 3rd leaf on main stem) and a nitrogen factor were introduced to quantify the effect of cultivar and N rate on SSA. The model was validated against data collected from both pot and field experiments. The relative root mean square error (RRMSE) was 11.56% and 14.05%, respectively. The resulting models could be used for virtual rice plant modeling and plant-type design.

  19. Conceptual hierarchical modeling to describe wetland plant community organization

    USGS Publications Warehouse

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

  20. Phytoremediation: modeling plant uptake and contaminant transport in the soil plant atmosphere continuum

    NASA Astrophysics Data System (ADS)

    Ouyang, Ying

    2002-09-01

    Phytoremediation is an emerging technology that uses plants and their associated rhizospheric microorganisms to remove, degrade, detoxify, or contain contaminants located in the soil, sediments, groundwater, surface water, and even the atmosphere. This study investigates phytoremediation of 1,4-dioxane from a contaminated sandy soil by a poplar cutting, which is associated with water flow in the soil as well as water movement and 1,4-dioxane translocation in the xylem and phloem systems. An existing one-dimensional mathematical model for coupled transport of water, heat, and solutes in the soil-plant-atmosphere continuum (CTSPAC) is modified for the purpose of this study. The model is calibrated with the laboratory experimental measurements prior to its applications. A simulation scenario is then performed to investigate phytoremediation of 1,4-dioxane by a poplar cutting in response to daily water flow and 1,4-dioxane transport for a simulation period of 7 days. Simulation shows that 1,4-dioxane concentration is high in leaves and low in roots with the stem in between. However, 1,4-dioxane mass in the stem (60%) is higher than that of leaves (28%) and roots (12%). This occurs because the stem volume used in this study is larger than those of leaves and roots. The simulation further reveals that about 30% of the soil 1,4-dioxane is removed within 7 days, resulting mainly from root uptake. A plot of the 1,4-dioxane concentrations in plant compartments as a function of time shows that the highest concentration in leaves is about 2600 μg/cm 3 and the lowest concentration in roots is about 350 μg/cm 3 at the end of the simulation. Results indicate that leaves are an important compartment for 1,4-dioxane accumulation and transpiration. This study suggests that the modified CTSPAC model could be a useful tool for phytoremediation estimations.

  1. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  2. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

    EPA Science Inventory

    Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

  3. Modeling and experimental verification of a new muffler based on the theory of quarter-wavelength tube and the Helmholtz muffler.

    PubMed

    Wu, Can; Chen, Lei; Ni, Jing; Xu, Jing

    2016-01-01

    To address the problem of low frequency noise of the internal combustion engine, several existing muffler design methods, such as the theory of the quarter-wavelength tube and the Helmholtz muffler, were examined and compared. This paper proposes a new type of muffler design method, which has the advantages of both the quarter-wavelength tube and the Helmholtz muffler. An example is carried out to illustrate the analysis of original signal, the design of the new muffler and the improvement of the in-car noise. The transmission loss of the new muffler is studied by theoretical method and finite element method. The vehicle test of the new muffler demonstrates excellent performance with a wider noise elimination frequency band and smaller radial size.

  4. The role of plant phenology in stomatal ozone flux modeling.

    PubMed

    Anav, Alessandro; Liu, Qiang; De Marco, Alessandra; Proietti, Chiara; Savi, Flavia; Paoletti, Elena; Piao, Shilong

    2017-07-19

    Plant phenology plays a pivotal role in the climate system as it regulates the gas exchange between the biosphere and the atmosphere. The uptake of ozone by forest is estimated through several meteorological variables and a specific function describing the beginning and the termination of plant growing season; actually, in many risk assessment studies, this function is based on a simple latitude and topography model. In this study, using two satellite datasets, we apply and compare six methods to estimate the start and the end dates of the growing season across a large region covering all Europe for the year 2011. Results show a large variability between the green-up and dormancy dates estimated using the six different methods, with differences greater than one month. However, interestingly, all the methods display a common spatial pattern in the uptake of ozone by forests with a marked change in the magnitude, up to 1.9 TgO3 /year, and corresponding to a difference of 25% in the amount of ozone that enters the leaves. Our results indicate that improved estimates of ozone fluxes require a better representation of plant phenology in the models used for O3 risk assessment. © 2017 John Wiley & Sons Ltd.

  5. Mathematical modelling of the cellular mechanics of plants.

    PubMed Central

    Bruce, David M

    2003-01-01

    The complex mechanical behaviour of plant tissues reflects the complexity of their structure and material properties. Modelling has been widely used in studies of how cell walls, single cells and tissue respond to loading, both externally applied loading and loads on the cell wall resulting from changes in the pressure within fluid-filled cells. This paper reviews what approaches have been taken to modelling and simulation of cell wall, cell and tissue mechanics, and to what extent models have been successful in predicting mechanical behaviour. Advances in understanding of cell wall ultrastructure and the control of cell growth present opportunities for modelling to clarify how growth-related mechanical properties arise from wall polymeric structure and biochemistry. PMID:14561334

  6. Kinetic model for the chlorination of power plant cooling waters

    SciTech Connect

    Johnson, J.D.; Qualls, R.G.

    1983-01-01

    Concern over the environmental effects of chlorination has prompted efforts to minimize the amount of chlorine necessary to prevent fouling of power-plant condensers. Kinetic expressions are developed for the short-term reactions of chlorine consumption by organic substances in natural freshwater. These expressions were developed to use in a kinetic model to predict the free and total available chlorine discharged in cooling water. This model uses commonly available water-quality data. It assumes that most of the chlorine-consuming substances are: (1) NH/sub 3/, (2) chloramine-forming organic-N, and (3) humic substances. It uses the Morris-Wei model of chlorine-ammonia reactions. Chloramine formation from organic-N was represented by a model compound, glycylglycine.

  7. Geochemical modeling of cyanide in tailing dam gold processing plant

    NASA Astrophysics Data System (ADS)

    Khodadadi, Ahmad; Monjezi, M.; Mehrpouya, H.; Dehghani, H.

    2009-09-01

    This research is aimed at investigating possible neutralization of cyanide in tailing dam of Muteh gold processing plant in Isfahan, Iran at various conditions such as pH and temperature using USEPA Visual MINTEQ geochemical model simulation. The model is based on geochemical equilibrium which uses the simultaneous solution of the non-linear mass action expressions and linear mass balance relationships to formulate and solve the multiple-component chemical equilibrium problems. In this study the concentration of aqueous species in tailing dam as an aqueous, solid and gaseous were used as input in the model. Temperature and pH variation were simulated. The results of the model indicated that cyanide may be complexes in 10 < pH < 5. In other pH values complexation is not important. The results also indicated that cyanide reduction mechanism in acidic pH and temperature above 30°C is due to cyanide acid formation which is vaporized.

  8. Modelling of aeration systems at wastewater treatment plants.

    PubMed

    Rieger, L; Alex, J; Gujer, W; Siegrist, H

    2006-01-01

    A model for the response time of aeration systems at WWTPs is proposed. It includes the delays caused by the air supply system (consisting of blowers, throttles and pipes), the rise time of the air bubbles and all control loops except the master DO controller. Beside a description of the required step-change experiments, different approaches for model calibration are given depending on the available data. Moreover, the parameters for the oxygen transfer and the response time of the aeration system model are not clearly identifiable. The model can be used for simulation studies which compare different types of controllers under changing loading and process conditions. The results from full-scale experiments at three different plants show that the response times of the aeration systems are in the range of 4-5 min. Taking all processes and time constants into account, some 30 min are needed to reach a new steady state after a step change of the airflow rate.

  9. Computational modeling and experimental studies on NOx reduction under pulverized coal combustion conditions. Technical progress report, fifth quarter, 1 January 1996--31 March 1996

    SciTech Connect

    Kumpaty, S.K.; Subramanian, K.; Nokku, V.P.; Hodges, T.L.

    1996-02-01

    During this quarter, the focus was on getting the experimental facility ready for operation. Upon receiving all the pieces of equipment, the research team first spent a great deal of time in calibration of various instruments and then began assembling the pieces for the experimental work. The use of Swage-lock fittings helped in arresting the gas leaks fairly easily. The entire assembly consisted of teflon tube connections (a) from gas cylinders to the flow meters, manifold and buffer vessel, (b) from buffer vessel to the inlet of the reactor enclosed in the middle, by a furnace, (c) from the exhaust end of the reactor to the NOx analyzer via gas dryer and (d) from the analyzer to the vent. Details of the experimental setup are given in the subsequent section. Once the setup was checked for leaks and the leaks were arrested, the facility was operational. Several experiments on NO reburning with methane were undertaken. The flow rates for various gases were calculated for five reburning stoichiometric ratios and the experiments were conducted for three different reaction temperatures. The results are presented later on in this report. These results indicate favorable reduction of NO by reburning with methane, consistent with their computer projections, and hence, present a good base for investigating further on nitric oxide reburning with other fuels as well. Experiments on nitric oxide reburning with (1) a combination of methane and acetylene, and (2) a combination of methane and ammonia, will be considered in the next quarter. The computer simulation results submitted in the Second Quarterly Report indicate further reduction of NO with the addition of acetylene/ammonia to methane as reburn fuel. These results will be verified experimentally in the ensuing quarter.

  10. Toxic substances from coal combustion -- A comprehensive assessment. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    Bool, L.E. III; Senior, C.L.; Huggins, F.; Huffman, G.P.; Shah, N.

    1997-01-31

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UKy), the University of Connecticut, and Princeton University to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI`s existing Engineering Model for Ash Formation (EMAF). During the past quarter the final program coal, from the Wyodak seam in the Powder River Basin, was acquired and distributed. Extensive coal characterization and laboratory work is underway to develop and test new sub-models. Coal characterization in the past quarter included direct identification of the modes of occurrence of various trace inorganic species in coal and ash using unique analytical techniques such as XAFS analysis and selective leaching. Combustion testing of the bituminous coals continued and additional data were obtained on trace element vaporization in the combustion zone. Studies of post-combustion trace element transformations, such as mercury speciation in the flue gas, were also begun in the last quarter.

  11. Genotoxin induced mutagenesis in the model plant Physcomitrella patens.

    PubMed

    Holá, Marcela; Kozák, Jaroslav; Vágnerová, Radka; Angelis, Karel J

    2013-01-01

    The moss Physcomitrella patens is unique for the high frequency of homologous recombination, haploid state, and filamentous growth during early stages of the vegetative growth, which makes it an excellent model plant to study DNA damage responses. We used single cell gel electrophoresis (comet) assay to determine kinetics of response to Bleomycin induced DNA oxidative damage and single and double strand breaks in wild type and mutant lig4 Physcomitrella lines. Moreover, APT gene when inactivated by induced mutations was used as selectable marker to ascertain mutational background at nucleotide level by sequencing of the APT locus. We show that extensive repair of DSBs occurs also in the absence of the functional LIG4, whereas repair of SSBs is seriously compromised. From analysis of induced mutations we conclude that their accumulation rather than remaining lesions in DNA and blocking progression through cell cycle is incompatible with normal plant growth and development and leads to sensitive phenotype.

  12. Genotoxin Induced Mutagenesis in the Model Plant Physcomitrella patens

    PubMed Central

    Holá, Marcela; Kozák, Jaroslav; Vágnerová, Radka; Angelis, Karel J.

    2013-01-01

    The moss Physcomitrella patens is unique for the high frequency of homologous recombination, haploid state, and filamentous growth during early stages of the vegetative growth, which makes it an excellent model plant to study DNA damage responses. We used single cell gel electrophoresis (comet) assay to determine kinetics of response to Bleomycin induced DNA oxidative damage and single and double strand breaks in wild type and mutant lig4 Physcomitrella lines. Moreover, APT gene when inactivated by induced mutations was used as selectable marker to ascertain mutational background at nucleotide level by sequencing of the APT locus. We show that extensive repair of DSBs occurs also in the absence of the functional LIG4, whereas repair of SSBs is seriously compromised. From analysis of induced mutations we conclude that their accumulation rather than remaining lesions in DNA and blocking progression through cell cycle is incompatible with normal plant growth and development and leads to sensitive phenotype. PMID:24383055

  13. Quarterly environmental data summary for first quarter 1997

    SciTech Connect

    McCracken, S.H.

    1997-05-09

    This report supports the Weldon Spring Site Remedial Action Project Federal Facilities Agreement. All data received and verified during the fourth quarter were within a permissible range of variability except for those detailed in this support. Above normal occurrences are cited for groundwater data and NPDES. There were none for air, surface water or springs. A brief summary is presented of the data that met the above normal criteria merged during the first quarter and updates on past reported above normal data.

  14. Joint Force Quarterly. Issue 56, 1st Quarter, January 2010

    DTIC Science & Technology

    2010-01-01

    between single - and double-loop learning.17 The contrast pertains to knowledge about improving what one is already doing based on a given set of...how they should be developed, and why many recent attempts at theories are really shallow approaches based on a single governing idea, ignor...Quarterly should be acknowledged whenever material is quoted from or based on its content. COMMUNICATIONS Please visit NDU Press and Joint Force Quarterly

  15. Modeling temperature variations in a pilot plant thermophilic anaerobic digester.

    PubMed

    Valle-Guadarrama, Salvador; Espinosa-Solares, Teodoro; López-Cruz, Irineo L; Domaschko, Max

    2011-05-01

    A model that predicts temperature changes in a pilot plant thermophilic anaerobic digester was developed based on fundamental thermodynamic laws. The methodology utilized two simulation strategies. In the first, model equations were solved through a searching routine based on a minimal square optimization criterion, from which the overall heat transfer coefficient values, for both biodigester and heat exchanger, were determined. In the second, the simulation was performed with variable values of these overall coefficients. The prediction with both strategies allowed reproducing experimental data within 5% of the temperature span permitted in the equipment by the system control, which validated the model. The temperature variation was affected by the heterogeneity of the feeding and extraction processes, by the heterogeneity of the digestate recirculation through the heating system and by the lack of a perfect mixing inside the biodigester tank. The use of variable overall heat transfer coefficients improved the temperature change prediction and reduced the effect of a non-ideal performance of the pilot plant modeled.

  16. Experimental validation of a solar-chimney power plant model

    NASA Astrophysics Data System (ADS)

    Fathi, Nima; Wayne, Patrick; Trueba Monje, Ignacio; Vorobieff, Peter

    2016-11-01

    In a solar chimney power plant system (SCPPS), the energy of buoyant hot air is converted to electrical energy. SCPPS includes a collector at ground level covered with a transparent roof. Solar radiation heats the air inside and the ground underneath. There is a tall chimney at the center of the collector, and a turbine located at the base of the chimney. Lack of detailed experimental data for validation is one of the important issues in modeling this type of power plants. We present a small-scale experimental prototype developed to perform validation analysis for modeling and simulation of SCCPS. Detailed velocity measurements are acquired using particle image velocimetry (PIV) at a prescribed Reynolds number. Convection is driven by a temperature-controlled hot plate at the bottom of the prototype. Velocity field data are used to perform validation analysis and measure any mismatch of the experimental results and the CFD data. CFD Code verification is also performed, to assess the uncertainly of the numerical model with respect to our grid and the applied mathematical model. The dimensionless output power of the prototype is calculated and compared with a recent analytical solution and the experimental results.

  17. A soil-plant model applied to phytoremediation of metals.

    PubMed

    Lugli, Francesco; Mahler, Claudio Fernando

    2016-01-01

    This study reports a phytoremediation pot experiment using an open-source program. Unsaturated water flow was described by the Richards' equation and solute transport by the advection-dispersion equation. Sink terms in the governing flow and transport equations accounted for root water and solute uptake, respectively. Experimental data were related to application of Vetiver grass to soil contaminated by metal ions. Sensitivity analysis revealed that due to the specific experimental set-up (bottom flux not allowed), hydraulic model parameters did not influence root water (and contaminant) uptake. In contrast, the results were highly correlated with plant solar radiation interception efficiency (leaf area index). The amounts of metals accumulated in the plant tissue were compared to numerical values of cumulative uptake. Pb(2+) and Zn(2+) uptake was satisfactorily described using a passive model. However, for Ni(2+) and Cd(2+), a specific calibration of the active uptake model was necessary. Calibrated MM parameters for Ni(2+), Cd(2+), and Pb(2+) were compared to values in the literature, generally suggesting lower rates and saturation advance. A parameter (saturation ratio) was introduced to assess the efficiency of contaminant uptake. Numerical analysis, applying actual field conditions, showed the limitation of the active model for being independent of the transpiration rate.

  18. Change of plant phenophases explained by survival modeling

    NASA Astrophysics Data System (ADS)

    Templ, Barbara; Fleck, Stefan; Templ, Matthias

    2017-05-01

    It is known from many studies that plant species show a delay in the timing of flowering events with an increase in latitude and altitude, and an advance with an increase in temperature. Furthermore, in many locations and for many species, flowering dates have advanced over the long-term. New insights using survival modeling are given based on data collected (1970-2010) along a 3000-km long transect from northern to eastern central Europe. We could clearly observe that in the case of dandelion ( Taraxacum officinale) the risk of flowering time, in other words the probability that flowering occurs, is higher for an earlier day of year in later decades. Our approach assume that temperature has greater influence than precipitation on the timing of flowering. Evaluation of the predictive power of tested models suggests that Cox models may be used in plant phenological research. The applied Cox model provides improved predictions of flowering dates compared to traditional regression methods and gives further insights into drivers of phenological events.

  19. Change of plant phenophases explained by survival modeling

    NASA Astrophysics Data System (ADS)

    Templ, Barbara; Fleck, Stefan; Templ, Matthias

    2016-11-01

    It is known from many studies that plant species show a delay in the timing of flowering events with an increase in latitude and altitude, and an advance with an increase in temperature. Furthermore, in many locations and for many species, flowering dates have advanced over the long-term. New insights using survival modeling are given based on data collected (1970-2010) along a 3000-km long transect from northern to eastern central Europe. We could clearly observe that in the case of dandelion (Taraxacum officinale) the risk of flowering time, in other words the probability that flowering occurs, is higher for an earlier day of year in later decades. Our approach assume that temperature has greater influence than precipitation on the timing of flowering. Evaluation of the predictive power of tested models suggests that Cox models may be used in plant phenological research. The applied Cox model provides improved predictions of flowering dates compared to traditional regression methods and gives further insights into drivers of phenological events.

  20. Process simulation and modeling for gas processing plant

    NASA Astrophysics Data System (ADS)

    Alhameli, Falah Obaid Kenish Mubarak

    Natural gas is one of the major energy sources and its demand is increasing rapidly due to its environmental and economic advantages over other fuels. Gas processing is an essential component of natural gas system. In this work, gas processing plant is introduced with the objective of meeting pipeline gas quality. It consists of separation, sweetening and dehydration units. The separation unit contains phase separators along with stabilizer (conventional distillation column). The sweetening unit is an amine process with MDEA (Methyl DiEthanol Amine) solvent. The dehydration unit is glycol absorption with TEG (TriEthyleneGlycol) solvent. ProMaxRTM 3.2 was used to simulate the plant. Box-Behnken design was applied to build a black-box model using design of experiments (DoE). MinitabRTM 15 was used to generate and analyse the design. The chosen variables for the model were 10. They represent the gas feed conditions and units' parameters. The total runs were 170. They were successfully implemented and analysed. Total energy of the plant and water content for the product gas models were obtained. Case study was conducted to investigate the impact of H2S composition increase in the feed gas. The models were used for the case study with the objective of total energy minimization and constraint of 4 lb/MMscf for water content in the product gas. Lingo 13 was used for the optimization. It was observed that the feed pressure had the highest influence among the other parameters. Finally, some recommendations were pointed out for the future works.

  1. 20 CFR 404.146 - When a calendar quarter cannot be a quarter of coverage.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false When a calendar quarter cannot be a quarter... Coverage § 404.146 When a calendar quarter cannot be a quarter of coverage. This section applies when we credit you with quarters of coverage (QCs) under § 404.141 for calendar years before 1978 and under §...

  2. 20 CFR 404.146 - When a calendar quarter cannot be a quarter of coverage.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false When a calendar quarter cannot be a quarter... Coverage § 404.146 When a calendar quarter cannot be a quarter of coverage. This section applies when we credit you with quarters of coverage (QCs) under § 404.141 for calendar years before 1978 and under §...

  3. 20 CFR 404.146 - When a calendar quarter cannot be a quarter of coverage.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false When a calendar quarter cannot be a quarter... Coverage § 404.146 When a calendar quarter cannot be a quarter of coverage. This section applies when we credit you with quarters of coverage (QCs) under § 404.141 for calendar years before 1978 and under §...

  4. 20 CFR 404.146 - When a calendar quarter cannot be a quarter of coverage.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false When a calendar quarter cannot be a quarter... Coverage § 404.146 When a calendar quarter cannot be a quarter of coverage. This section applies when we credit you with quarters of coverage (QCs) under § 404.141 for calendar years before 1978 and under §...

  5. 20 CFR 404.146 - When a calendar quarter cannot be a quarter of coverage.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false When a calendar quarter cannot be a quarter... Coverage § 404.146 When a calendar quarter cannot be a quarter of coverage. This section applies when we credit you with quarters of coverage (QCs) under § 404.141 for calendar years before 1978 and under §...

  6. Strategic Petroleum Reserve quarterly report

    SciTech Connect

    1995-11-15

    The Strategic Petroleum Reserve was created pursuant to the Energy Policy and Conservation Act of December 22, 1975 (Public Law 94-163). Its purposes are to reduce the impact of disruptions in supplies of petroleum products and to carry out obligations of the United States under the Agreement on an International Energy Program. Section 165(a) of the Act requires the submission of Annual Reports and Section 165(b)(1) requires the submission of Quarterly Reports. This Quarterly Report highlights activities undertaken during the third quarter of calendar year 1995, including: inventory of petroleum products stored in the Reserve; current storage capacity and ullage available; current status of the Strategic Petroleum Reserve storage facilities, major projects and the acquisition of petroleum products; funds obligated by the Secretary from the SPR Petroleum Account and the Strategic Petroleum Reserve Account during the prior calendar quarter and in total; and major environmental actions completed, in progress, or anticipated.

  7. The Ustilaginales as plant pests and model systems.

    PubMed

    Martínez-Espinoza, Alfredo D; García-Pedrajas, María D; Gold, Scott E

    2002-02-01

    The Ustilaginales are a vast and diverse group of fungi, which includes the plant pathogenic smuts that cause significant losses to crops worldwide. Members of the Ustilaginales are also valuable models for the unraveling of fundamental mechanisms controlling important biological processes. Ustilago maydis is an important fungal model system and has been well studied with regard to mating, morphogenesis, pathogenicity, signal transduction, mycoviruses, DNA recombination, and, recently, genomics. In this review we discuss the life cycles of members of the Ustilaginales and provide background on their economic impact as agricultural pests. We then focus on providing a summary of the literature with special attention to topics not well covered in recent reviews such as the use of U. maydis in mycovirus research and as a model for understanding the molecular mechanisms of fungicide resistance and DNA recombination and repair.

  8. High-throughput comparison, functional annotation, and metabolic modeling of plant genomes using the PlantSEED resource

    PubMed Central

    Seaver, Samuel M. D.; Gerdes, Svetlana; Frelin, Océane; Lerma-Ortiz, Claudia; Bradbury, Louis M. T.; Zallot, Rémi; Hasnain, Ghulam; Niehaus, Thomas D.; El Yacoubi, Basma; Pasternak, Shiran; Olson, Robert; Pusch, Gordon; Overbeek, Ross; Stevens, Rick; de Crécy-Lagard, Valérie; Ware, Doreen; Hanson, Andrew D.; Henry, Christopher S.

    2014-01-01

    The increasing number of sequenced plant genomes is placing new demands on the methods applied to analyze, annotate, and model these genomes. Today’s annotation pipelines result in inconsistent gene assignments that complicate comparative analyses and prevent efficient construction of metabolic models. To overcome these problems, we have developed the PlantSEED, an integrated, metabolism-centric database to support subsystems-based annotation and metabolic model reconstruction for plant genomes. PlantSEED combines SEED subsystems technology, first developed for microbial genomes, with refined protein families and biochemical data to assign fully consistent functional annotations to orthologous genes, particularly those encoding primary metabolic pathways. Seamless integration with its parent, the prokaryotic SEED database, makes PlantSEED a unique environment for cross-kingdom comparative analysis of plant and bacterial genomes. The consistent annotations imposed by PlantSEED permit rapid reconstruction and modeling of primary metabolism for all plant genomes in the database. This feature opens the unique possibility of model-based assessment of the completeness and accuracy of gene annotation and thus allows computational identification of genes and pathways that are restricted to certain genomes or need better curation. We demonstrate the PlantSEED system by producing consistent annotations for 10 reference genomes. We also produce a functioning metabolic model for each genome, gapfilling to identify missing annotations and proposing gene candidates for missing annotations. Models are built around an extended biomass composition representing the most comprehensive published to date. To our knowledge, our models are the first to be published for seven of the genomes analyzed. PMID:24927599

  9. High-throughput comparison, functional annotation, and metabolic modeling of plant genomes using the PlantSEED resource.

    PubMed

    Seaver, Samuel M D; Gerdes, Svetlana; Frelin, Océane; Lerma-Ortiz, Claudia; Bradbury, Louis M T; Zallot, Rémi; Hasnain, Ghulam; Niehaus, Thomas D; El Yacoubi, Basma; Pasternak, Shiran; Olson, Robert; Pusch, Gordon; Overbeek, Ross; Stevens, Rick; de Crécy-Lagard, Valérie; Ware, Doreen; Hanson, Andrew D; Henry, Christopher S

    2014-07-01

    The increasing number of sequenced plant genomes is placing new demands on the methods applied to analyze, annotate, and model these genomes. Today's annotation pipelines result in inconsistent gene assignments that complicate comparative analyses and prevent efficient construction of metabolic models. To overcome these problems, we have developed the PlantSEED, an integrated, metabolism-centric database to support subsystems-based annotation and metabolic model reconstruction for plant genomes. PlantSEED combines SEED subsystems technology, first developed for microbial genomes, with refined protein families and biochemical data to assign fully consistent functional annotations to orthologous genes, particularly those encoding primary metabolic pathways. Seamless integration with its parent, the prokaryotic SEED database, makes PlantSEED a unique environment for cross-kingdom comparative analysis of plant and bacterial genomes. The consistent annotations imposed by PlantSEED permit rapid reconstruction and modeling of primary metabolism for all plant genomes in the database. This feature opens the unique possibility of model-based assessment of the completeness and accuracy of gene annotation and thus allows computational identification of genes and pathways that are restricted to certain genomes or need better curation. We demonstrate the PlantSEED system by producing consistent annotations for 10 reference genomes. We also produce a functioning metabolic model for each genome, gapfilling to identify missing annotations and proposing gene candidates for missing annotations. Models are built around an extended biomass composition representing the most comprehensive published to date. To our knowledge, our models are the first to be published for seven of the genomes analyzed.

  10. Micrasterias as a Model System in Plant Cell Biology

    PubMed Central

    Lütz-Meindl, Ursula

    2016-01-01

    The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells. PMID:27462330

  11. Biomimetic polymers of plant cutin: an approach from molecular modeling.

    PubMed

    San-Miguel, Miguel A; Oviedo, Jaime; Heredia-Guerrero, Jose Alejandro; Heredia, Antonio; Benitez, Jose Jesus

    2014-07-01

    Biomimetics of materials is based on adopting and reproducing a model in nature with a well-defined functionality optimized through evolution. An example is barrier polymers that protect living tissues from the environment. The protecting layer of fruits, leaves, and non-lignified stems is the plant cuticle. The cuticle is a complex system in which the cutin is the main component. Cutin is a biopolyester made of polyhydroxylated carboxylic acids of 16 and 18 carbon atoms. The biosynthesis of cutin in plants is not well understood yet, but a direct chemical route involving the self-assembly of either molecules or molecular aggregates has been proposed. In this work, we present a combined study using experimental and simulation techniques on self-assembled layers of monomers selectively functionalized with hydroxyl groups. Our results demonstrate that the number and position of the hydroxyl groups are critical for the interaction between single molecules and the further rearrangement. Also, the presence of lateral hydroxyl groups reinforces lateral interactions and favors the bi-dimensional growth (2D), while terminal hydroxyl groups facilitate the formation of a second layer caused by head-tail interactions. The balance of 2D/3D growth is fundamental for the plant to create a protecting layer both large enough in 2D and thick enough in 3D.

  12. Brown algae as a model for plant organogenesis.

    PubMed

    Bogaert, Kenny A; Arun, Alok; Coelho, Susana M; De Clerck, Olivier

    2013-01-01

    Brown algae are an extremely interesting, but surprisingly poorly explored, group of organisms. They are one of only five eukaryotic lineages to have independently evolved complex multicellularity, which they express through a wide variety of morphologies ranging from uniseriate branched filaments to complex parenchymatous thalli with multiple cell types. Despite their very distinct evolutionary history, brown algae and land plants share a striking amount of developmental features. This has led to an interest in several aspects of brown algal development, including embryogenesis, polarity, cell cycle, asymmetric cell division and a putative role for plant hormone signalling. This review describes how investigations using brown algal models have helped to increase our understanding of the processes controlling early embryo development, in particular polarization, axis formation and asymmetric cell division. Additionally, the diversity of life cycles in the brown lineage and the emergence of Ectocarpus as a powerful model organism, are affording interesting insights on the molecular mechanisms underlying haploid-diploid life cycles. The use of these and other emerging brown algal models will undoubtedly add to our knowledge on the mechanisms that regulate development in multicellular photosynthetic organisms.

  13. Modeling Offgas Systems for the Hanford Waste Treatment Plant

    SciTech Connect

    Smith, Frank G., III

    2005-09-02

    To augment steady-state design calculations, dynamic models of three offgas systems that will be used in the Waste Treatment Plant now under construction at the Hanford Site were developed using Aspen Custom Modeler{trademark}. The offgas systems modeled were those for the High Level Waste (HLW) melters, Low Activity Waste (LAW) melters and HLW Pulse Jet Ventilation (PJV) system. The models do not include offgas chemistry but only consider the two major species in the offgas stream which are air and water vapor. This is sufficient to perform material and energy balance calculations that accurately show the dynamic behavior of gas pressure, temperature, humidity and flow throughout the systems. The models are structured to perform pressure drop calculations across the various unit operations using a combination of standard engineering calculations and empirical data based correlations for specific pieces of equipment. The models include process controllers, gas ducting, control valves, exhaust fans and the offgas treatment equipment. The models were successfully used to analyze a large number of operating scenarios including both normal and off-normal conditions.

  14. Quarterly coal report, July--September 1997

    SciTech Connect

    1998-02-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks. Coke production consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for July through September 1997 and aggregated quarterly historical data for 1991 through the second quarter of 1997. Appendix A displays, from 1991 on, detailed quarterly historical coal imports data. 72 tabs.

  15. Plant functional type mapping for earth system models

    NASA Astrophysics Data System (ADS)

    Poulter, B.; Ciais, P.; Hodson, E.; Lischke, H.; Maignan, F.; Plummer, S.; Zimmermann, N. E.

    2011-08-01

    The sensitivity of global carbon and water cycling to climate variability is coupled directly to land cover and the distribution of vegetation. To investigate biogeochemistry-climate interactions, earth system models require a representation of vegetation distributions that are either prescribed from remote sensing data or simulated via biogeography models. However, the abstraction of earth system state variables in models means that data products derived from remote sensing need to be post-processed for model-data assimilation. Dynamic global vegetation models (DGVM) rely on the concept of plant functional types (PFT) to group shared traits of thousands of plant species into just several classes. Available databases of observed PFT distributions must be relevant to existing satellite sensors and their derived products, and to the present day distribution of managed lands. Here, we develop four PFT datasets based on land-cover information from three satellite sensors (EOS-MODIS 1 km and 0.5 km, SPOT4-VEGETATION 1 km, and ENVISAT-MERIS 0.3 km spatial resolution) that are merged with spatially-consistent Köppen-Geiger climate zones. Using a beta (β) diversity metric to assess reclassification similarity, we find that the greatest uncertainty in PFT classifications occur most frequently between cropland and grassland categories, and in dryland systems between shrubland, grassland and forest categories because of differences in the minimum threshold required for forest cover. The biogeography-biogeochemistry DGVM, LPJmL, is used in diagnostic mode with the four PFT datasets prescribed to quantify the effect of land-cover uncertainty on climatic sensitivity of gross primary productivity (GPP) and transpiration fluxes. Our results show that land-cover uncertainty has large effects in arid regions, contributing up to 30 % (20 %) uncertainty in the sensitivity of GPP (transpiration) to precipitation. The availability of plant functional type datasets that are consistent

  16. Quarterly environmental data summary for first quarter 1998

    SciTech Connect

    1998-05-01

    In support of the Weldon Spring Site Remedial Action Project Federal Facilities Agreement, a copy of the Quarterly Environmental Data Summary (QEDS) for the first quarter of 1998 is enclosed. The data presented in this letter and attachment constitute the QEDS. The data were received from the contract laboratories, verified by the Weldon Spring Site verification group and, except for air monitoring data and site KPA generated data (uranium analyses), merged into the data base during the first quarter of 1998. Air monitoring data presented are the most recent complete sets of quarterly data. Air data are not stored in the data base, and KPA data are not merged into the regular data base. Significant data, defined as data values that have exceeded defined {open_quotes}above normal{close_quotes} Level 2 values, are discussed in this letter for Environmental Monitoring Plan (EMP) generated data only. Above normal Level 2 values are based, in ES&H procedures, on historical high values, DOE Derived Concentration Guides (DCGs), NPDES limits and other guidelines. The procedures also establish actions to be taken in the event that {open_quotes}above normal{close_quotes} data occur. All data received and verified during the first quarter were within a permissible range of variability except for those detailed below. Above normal occurrences are cited for groundwater, air, and NPDES data. There were none for springs or surface water. The following discussion offers a brief summary of the data merged during the first quarter that exceeded the above normal criteria and updates on past reported above normal data. The attached tables present the most recent data for air and the data merged into the data base during the first quarter 1998 for groundwater, NPDES, surface water, and springs. Graphs showing concentrations of selected contaminants of concern at some of the critical locations have also been included in this QEDS. The graphs are discussed in the separate sections.

  17. Modelling the impact and control of an infectious disease in a plant nursery with infected plant material inputs.

    PubMed

    Bate, Andrew M; Jones, Glyn; Kleczkowski, Adam; MacLeod, Alan; Naylor, Rebecca; Timmis, Jon; Touza, Julia; White, Piran C L

    2016-08-24

    The ornamental plant trade has been identified as a key introduction pathway for plant pathogens. Establishing effective biosecurity measures to reduce the risk of plant pathogen outbreaks in the live plant trade is therefore important. Management of invasive pathogens has been identified as a weakest link public good, and thus is reliant on the actions of individual private agents. This paper therefore provides an analysis of the impact of the private agents' biosecurity decisions on pathogen prevention and control within the plant trade. We model the impact that an infectious disease has on a plant nursery under a constant pressure of potentially infected input plant materials, like seeds and saplings, where the spread of the disease reduces the value of mature plants. We explore six scenarios to understand the influence of three key bioeconomic parameters; the disease's basic reproductive number, the loss in value of a mature plant from acquiring an infection and the cost-effectiveness of restriction. The results characterise the disease dynamics within the nursery and explore the trade-offs and synergies between the optimal level of efforts on restriction strategies (actions to prevent buying infected inputs), and on removal of infected plants in the nursery. For diseases that can be easily controlled, restriction and removal are substitutable strategies. In contrast, for highly infectious diseases, restriction and removal are often found to be complementary, provided that restriction is cost-effective and the optimal level of removal is non-zero.

  18. Higher plant modelling for life support applications: first results of a simple mechanistic model

    NASA Astrophysics Data System (ADS)

    Hezard, Pauline; Dussap, Claude-Gilles; Sasidharan L, Swathy

    2012-07-01

    In the case of closed ecological life support systems, the air and water regeneration and food production are performed using microorganisms and higher plants. Wheat, rice, soybean, lettuce, tomato or other types of eatable annual plants produce fresh food while recycling CO2 into breathable oxygen. Additionally, they evaporate a large quantity of water, which can be condensed and used as potable water. This shows that recycling functions of air revitalization and food production are completely linked. Consequently, the control of a growth chamber for higher plant production has to be performed with efficient mechanistic models, in order to ensure a realistic prediction of plant behaviour, water and gas recycling whatever the environmental conditions. Purely mechanistic models of plant production in controlled environments are not available yet. This is the reason why new models must be developed and validated. This work concerns the design and test of a simplified version of a mathematical model coupling plant architecture and mass balance purposes in order to compare its results with available data of lettuce grown in closed and controlled chambers. The carbon exchange rate, water absorption and evaporation rate, biomass fresh weight as well as leaf surface are modelled and compared with available data. The model consists of four modules. The first one evaluates plant architecture, like total leaf surface, leaf area index and stem length data. The second one calculates the rate of matter and energy exchange depending on architectural and environmental data: light absorption in the canopy, CO2 uptake or release, water uptake and evapotranspiration. The third module evaluates which of the previous rates is limiting overall biomass growth; and the last one calculates biomass growth rate depending on matter exchange rates, using a global stoichiometric equation. All these rates are a set of differential equations, which are integrated with time in order to provide

  19. A quantitative and dynamic model for plant stem cell regulation.

    PubMed

    Geier, Florian; Lohmann, Jan U; Gerstung, Moritz; Maier, Annette T; Timmer, Jens; Fleck, Christian

    2008-01-01

    Plants maintain pools of totipotent stem cells throughout their entire life. These stem cells are embedded within specialized tissues called meristems, which form the growing points of the organism. The shoot apical meristem of the reference plant Arabidopsis thaliana is subdivided into several distinct domains, which execute diverse biological functions, such as tissue organization, cell-proliferation and differentiation. The number of cells required for growth and organ formation changes over the course of a plants life, while the structure of the meristem remains remarkably constant. Thus, regulatory systems must be in place, which allow for an adaptation of cell proliferation within the shoot apical meristem, while maintaining the organization at the tissue level. To advance our understanding of this dynamic tissue behavior, we measured domain sizes as well as cell division rates of the shoot apical meristem under various environmental conditions, which cause adaptations in meristem size. Based on our results we developed a mathematical model to explain the observed changes by a cell pool size dependent regulation of cell proliferation and differentiation, which is able to correctly predict CLV3 and WUS over-expression phenotypes. While the model shows stem cell homeostasis under constant growth conditions, it predicts a variation in stem cell number under changing conditions. Consistent with our experimental data this behavior is correlated with variations in cell proliferation. Therefore, we investigate different signaling mechanisms, which could stabilize stem cell number despite variations in cell proliferation. Our results shed light onto the dynamic constraints of stem cell pool maintenance in the shoot apical meristem of Arabidopsis in different environmental conditions and developmental states.

  20. Drosophila melanogaster "a potential model organism" for identification of pharmacological properties of plants/plant-derived components.

    PubMed

    Panchal, Komal; Tiwari, Anand K

    2017-03-18

    Plants/plant-derived components have been used from ancient times to treat/cure several human diseases. Plants and their parts possess several chemical components that play the vital role in the improvement of human health and their life expectancy. Allopathic medicines have been playing a key role in the treatment of several diseases. Though allopathic medicines provide fast relief, long time consumption cause serious health concerns such as hyperallergic reactions, liver damage, etc. So, the study of medicinal plants which rarely cause any side effect is very important to mankind. Plants contain many health benefit properties like antioxidant, anti-aging, neuroprotective, anti-genotoxic, anti-mutagenic and bioinsecticidal activity. Thus, identification of pharmacological properties of plants/plant-derived components are of utmost importance to be explored. Several model organisms have been used to identify the pharmacological properties of the different plants or active components therein and Drosophila is one of them. Drosophila melanogaster "fruit fly" is a well understood, high-throughput model organism being used more than 110 years to study the different biological aspects related to the development and diseases. Most of the developmental and cell signaling pathways and ∼75% human disease-related genes are conserved between human and Drosophila. Using Drosophila, one can easily analyze the pharmacological properties of plants/plant-derived components by performing several assays available with flies such as survivorship, locomotor, antioxidant, cell death, etc. The current review focuses on the potential of Drosophila melanogaster for the identification of medicinal/pharmacological properties associated with plants/plant-derived components.

  1. Modelling Hotspots for Invasive Alien Plants in India

    PubMed Central

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species. PMID:26230513

  2. Temperature-dependent bursting pattern analysis by modified Plant model

    PubMed Central

    2014-01-01

    Many electrophysiological properties of neuron including firing rates and rhythmical oscillation change in response to a temperature variation, but the mechanism underlying these correlations remains unverified. In this study, we analyzed various action potential (AP) parameters of bursting pacemaker neurons in the abdominal ganglion of Aplysia juliana to examine whether or not bursting patterns are altered in response to temperature change. Here we found that the inter-burst interval, burst duration, and number of spike during burst decreased as temperature increased. On the other hand, the numbers of bursts per minute and numbers of spikes per minute increased and then decreased, but interspike interval during burst firstly decreased and then increased. We also tested the reproducibility of temperature-dependent changes in bursting patterns and AP parameters. Finally we performed computational simulations of these phenomena by using a modified Plant model composed of equations with temperature-dependent scaling factors to mathematically clarify the temperature-dependent changes of bursting patterns in burst-firing neurons. Taken together, we found that the modified Plant model could trace the ionic mechanism underlying the temperature-dependent change in bursting pattern from experiments with bursting pacemaker neurons in the abdominal ganglia of Aplysia juliana. PMID:25051923

  3. Modelling Hotspots for Invasive Alien Plants in India.

    PubMed

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species.

  4. An allometric model for mapping seed development in plants.

    PubMed

    Huang, Zhongwen; Tong, Chunfa; Bo, Wenhao; Pang, Xiaoming; Wang, Zhong; Xu, Jichen; Gai, Junyi; Wu, Rongling

    2014-07-01

    Despite a tremendous effort to map quantitative trait loci (QTLs) responsible for agriculturally and biologically important traits in plants, our understanding of how a QTL governs the developmental process of plant seeds remains elusive. In this article, we address this issue by describing a model for functional mapping of seed development through the incorporation of the relationship between vegetative and reproductive growth. The time difference of reproductive from vegetative growth is described by Reeve and Huxley’s allometric equation. Thus, the implementation of this equation into the framework of functional mapping allows dynamic QTLs for seed development to be identified more precisely. By estimating and testing mathematical parameters that define Reeve and Huxley’s allometric equations of seed growth, the dynamic pattern of the genetic effects of the QTLs identified can be analyzed. We used the model to analyze a soybean data, leading to the detection of QTLs that control the growth of seed dry weight. Three dynamic QTLs, located in two different linkage groups, were detected to affect growth curves of seed dry weight. The QTLs detected may be used to improve seed yield with marker-assisted selection by altering the pattern of seed development in a hope to achieve a maximum size of seeds at a harvest time.

  5. Parachute Creek Shale Oil Program Environmental Monitoring Program. Quarterly report, fourth quarter, October 1-December 31, 1991

    SciTech Connect

    Not Available

    1992-02-28

    The Energy Security Act of 1980 established a program to provide financial assistance to private industry in the construction and operation of commercial-scale synthetic fuels plants. The Parachute Creek Shale Oil Program is one of four projects awarded financial assistance. The Program agreed to comply with existing environmental monitoring regulations and to develop an Environmental Monitoring Plan (EMP) incorporating supplemental monitoring in the areas of water, air, solid waste, and worker health and safety during the period 1985-1992. These activities are described in a series of quarterly and annual reports. The document contains environmental compliance data collected in the fourth quarter of 1991, contents of reports on compliance data submitted to regulatory agencies, and supplemental analytical results from retorted shale pile runoff water collected following a storm event during the third quarter of 1991.

  6. Thermal IR exitance model of a plant canopy

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Smith, J. A.; Link, L. E.

    1981-01-01

    A thermal IR exitance model of a plant canopy based on a mathematical abstraction of three horizontal layers of vegetation was developed. Canopy geometry within each layer is quantitatively described by the foliage and branch orientation distributions and number density. Given this geometric information for each layer and the driving meteorological variables, a system of energy budget equations was determined and solved for average layer temperatures. These estimated layer temperatures, together with the angular distributions of radiating elements, were used to calculate the emitted thermal IR radiation as a function of view angle above the canopy. The model was applied to a lodgepole pine (Pinus contorta) canopy over a diurnal cycle. Simulated vs measured radiometric average temperatures of the midcanopy layer corresponded with 2 C. Simulation results suggested that canopy geometry can significantly influence the effective radiant temperature recorded at varying sensor view angles.

  7. Thermal IR exitance model of a plant canopy

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Smith, J. A.; Link, L. E.

    1981-01-01

    A thermal IR exitance model of a plant canopy based on a mathematical abstraction of three horizontal layers of vegetation was developed. Canopy geometry within each layer is quantitatively described by the foliage and branch orientation distributions and number density. Given this geometric information for each layer and the driving meteorological variables, a system of energy budget equations was determined and solved for average layer temperatures. These estimated layer temperatures, together with the angular distributions of radiating elements, were used to calculate the emitted thermal IR radiation as a function of view angle above the canopy. The model was applied to a lodgepole pine (Pinus contorta) canopy over a diurnal cycle. Simulated vs measured radiometric average temperatures of the midcanopy layer corresponded with 2 C. Simulation results suggested that canopy geometry can significantly influence the effective radiant temperature recorded at varying sensor view angles.

  8. Modeling of optical radiation energy distribution in plant tissue

    NASA Astrophysics Data System (ADS)

    Zakharov, V. P.; Bratchenko, I. A.; Sindyaeva, A. R.; Timchenko, E. V.

    2009-12-01

    A three-dimensional mathematical model of interactions of optical radiation with plant tissue taking into account its structural inhomogeneity, spectral properties, and the effects of fluorescence is constructed. The developed model is implemented using the statistical Monte Carlo method for the Henyey-Greenstein phase function. The dependence of differential backscattering and fluorescence coefficients on the concentration of photosynthetic pigments (chlorophylls) is numerically studied. It is demonstrated that numerical characteristics agree with results of physical experiment. The approximate solution based on the expansion of the diffusion and fluorescence radiation fluxes into a series in terms of a small parameter is found. This expansion makes it possible to calculate the field of backscattered radiation with satisfactory accuracy and to qualitatively correctly describe the experimentally observed dependences of the fluorescence coefficient in the region of high chlorophyll concentration.

  9. Peer Review of NRC Standardized Plant Analysis Risk Models

    SciTech Connect

    Anthony Koonce; James Knudsen; Robert Buell

    2011-03-01

    The Nuclear Regulatory Commission (NRC) Standardized Plant Analysis Risk (SPAR) Models underwent a Peer Review using ASME PRA standard (Addendum C) as endorsed by NRC in Regulatory Guide (RG) 1.200. The review was performed by a mix of industry probabilistic risk analysis (PRA) experts and NRC PRA experts. Representative SPAR models, one PWR and one BWR, were reviewed against Capability Category I of the ASME PRA standard. Capability Category I was selected as the basis for review due to the specific uses/applications of the SPAR models. The BWR SPAR model was reviewed against 331 ASME PRA Standard Supporting Requirements; however, based on the Capability Category I level of review and the absence of internal flooding and containment performance (LERF) logic only 216 requirements were determined to be applicable. Based on the review, the BWR SPAR model met 139 of the 216 supporting requirements. The review also generated 200 findings or suggestions. Of these 200 findings and suggestions 142 were findings and 58 were suggestions. The PWR SPAR model was also evaluated against the same 331 ASME PRA Standard Supporting Requirements. Of these requirements only 215 were deemed appropriate for the review (for the same reason as noted for the BWR). The PWR review determined that 125 of the 215 supporting requirements met Capability Category I or greater. The review identified 101 findings or suggestions (76 findings and 25 suggestions). These findings or suggestions were developed to identify areas where SPAR models could be enhanced. A process to prioritize and incorporate the findings/suggestions supporting requirements into the SPAR models is being developed. The prioritization process focuses on those findings that will enhance the accuracy, completeness and usability of the SPAR models.

  10. Modeling the radiation balance within a planted trench system

    NASA Astrophysics Data System (ADS)

    Kramer, Isaac; Agam, Nurit; Berliner, Pedro

    2017-04-01

    Micro-catchment systems (MCs) are designed to harvest and utilize rainwater, with the aim of supporting tree growth in arid regions. While MCs were traditionally built with shallow infiltration basins, recent research indicates that MCs with deeper basins retain more water than MCs with shallower basins, and that trees grown in deeper MCs outperform those grown in shallow MCs. This may be partially because the flux of incoming shortwave radiation reaching the surface is decreased in deeper basins. The degree to which the incoming radiation reaching the floor of the MC is reduced, however, depends on the system's dimensions and orientation, geographical location, canopy geometry, soil properties, date, and time. Existing radiation models are either capable of modeling radiation penetration into trenches, or describe transmission of radiation through canopy. None can describe the penetration of radiation through canopy into a trench. The goal of our research was to model the incoming shortwave and longwave radiation flux densities reaching a MC floor in which trees are planted. The model calculates the incoming shortwave and longwave radiation at any given point on the trench floor. In calculating the incoming shortwave radiation, the model considers direct radiation, diffuse radiation, and direct and diffuse radiation reflected from the walls of the MC system. The model also accounts for possible shading and attenuation of the radiation caused by the presence of a canopy in the system. Validation of the model is performed by comparing measured incoming shortwave radiation to modeled outputs. The measurements are conducted at various positions within existing trenches with width of 1 m and length of 12 m, in which three 6-year old olive trees are grown, with 4 m spacing between trees. The flexibility of the model and the ability to change the trench configurations will help enable the maximization of water use efficiency inside MC systems.

  11. A SIMPLE MODEL FOR THE UPTAKE, TRANSLOCATION, AND ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS

    EPA Science Inventory

    A simple mathematical model is being developed to describe the uptake, translocation, and accumulation of perchlorate in tobacco plants. The model defines a plant as a set of compartments, consisting of mass balance differential equations and plant-specific physiological paramet...

  12. A SIMPLE MODEL FOR THE UPTAKE, TRANSLOCATION, AND ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS

    EPA Science Inventory

    A simple mathematical model is being developed to describe the uptake, translocation, and accumulation of perchlorate in tobacco plants. The model defines a plant as a set of compartments, consisting of mass balance differential equations and plant-specific physiological paramet...

  13. Quarterly environmental data summary for fourth quarter 1997

    SciTech Connect

    1997-12-31

    The Quarterly Environmental Data Summary (QEDS) for the fourth quarter of 1997 is prepared in support of the Weldon Spring Site Remedial Action Project Federal Facilities Agreement. The data presented constitute the QEDS. The data were received from the contract laboratories, verified by the Weldon Spring Site verification group and, except for air monitoring data and site KPA generated data (uranium analyses), merged into the data base during the fourth quarter of 1997. Air monitoring data presented are the most recent complete sets of quarterly data. Air data are not stored in the data base and KPA data are not merged into the regular data base. Significant data, defined as data values that have exceeded defined ``above normal`` level 2 values, are discussed in this letter for Environmental Monitoring Plan (EMP) generated data only. Above normal level 2 values are based, in ES and H procedures, on historical high values, DOE Derived Concentration Guides (DCGs), NPDES limits and other guidelines. The procedures also establish actions to be taken in response to such data. Data received and verified during the fourth quarter were within a permissible range of variability except for those which are detailed.

  14. Infrastructure development assistance modeling for nuclear power plant

    SciTech Connect

    Park, J. H.; Hwang, K.; Park, K. M.; Kim, S. W.; Lee, S. M.

    2012-07-01

    The purpose of this paper is to develop a model, a general frame to be utilized in assisting newcomer countries to start a nuclear power program. A nuclear power plant project involves technical complexity and high level of investment with long duration. Considering newcomers are mostly developing countries that lack the national infrastructure, key infrastructure issues may constitute the principal constraints to the development of a nuclear power program. In this regard, it is important to provide guidance and support to set up an appropriate infrastructure when we help them with the first launch of nuclear power plant project. To date, as a sole nuclear power generation company, KHNP has been invited many times to mentor or assist newcomer countries for their successful start of a nuclear power program since Republic of Korea is an exemplary case of a developing country which began nuclear power program from scratch and became a major world nuclear energy country in a short period of time. Through hosting events organized to aid newcomer countries' initiation of nuclear power projects, difficulties have been recognized. Each event had different contents according to circumstances because they were held as an unstructured and one-off thing. By developing a general model, we can give more adequate and effective aid in an efficient way. In this paper, we created a model to identify necessary infrastructures at the right stage, which was mainly based on a case of Korea. Taking into account the assistance we received from foreign companies and our own efforts for technological self-reliance, we have developed a general time table and specified activities required to do at each stage. From a donor's perspective, we explored various ways to help nuclear infrastructure development including technical support programs, training courses, and participating in IAEA technical cooperation programs on a regular basis. If we further develop the model, the next task would be to

  15. Modeling and control for closed environment plant production systems

    NASA Technical Reports Server (NTRS)

    Fleisher, David H.; Ting, K. C.; Janes, H. W. (Principal Investigator)

    2002-01-01

    A computer program was developed to study multiple crop production and control in controlled environment plant production systems. The program simulates crop growth and development under nominal and off-nominal environments. Time-series crop models for wheat (Triticum aestivum), soybean (Glycine max), and white potato (Solanum tuberosum) are integrated with a model-based predictive controller. The controller evaluates and compensates for effects of environmental disturbances on crop production scheduling. The crop models consist of a set of nonlinear polynomial equations, six for each crop, developed using multivariate polynomial regression (MPR). Simulated data from DSSAT crop models, previously modified for crop production in controlled environments with hydroponics under elevated atmospheric carbon dioxide concentration, were used for the MPR fitting. The model-based predictive controller adjusts light intensity, air temperature, and carbon dioxide concentration set points in response to environmental perturbations. Control signals are determined from minimization of a cost function, which is based on the weighted control effort and squared-error between the system response and desired reference signal.

  16. Modeling and control for closed environment plant production systems

    NASA Technical Reports Server (NTRS)

    Fleisher, David H.; Ting, K. C.; Janes, H. W. (Principal Investigator)

    2002-01-01

    A computer program was developed to study multiple crop production and control in controlled environment plant production systems. The program simulates crop growth and development under nominal and off-nominal environments. Time-series crop models for wheat (Triticum aestivum), soybean (Glycine max), and white potato (Solanum tuberosum) are integrated with a model-based predictive controller. The controller evaluates and compensates for effects of environmental disturbances on crop production scheduling. The crop models consist of a set of nonlinear polynomial equations, six for each crop, developed using multivariate polynomial regression (MPR). Simulated data from DSSAT crop models, previously modified for crop production in controlled environments with hydroponics under elevated atmospheric carbon dioxide concentration, were used for the MPR fitting. The model-based predictive controller adjusts light intensity, air temperature, and carbon dioxide concentration set points in response to environmental perturbations. Control signals are determined from minimization of a cost function, which is based on the weighted control effort and squared-error between the system response and desired reference signal.

  17. Behind their Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 46-47 crewmember Tim Kopra of NASA (left), Yuri Malenchenko of the Russian Federal Space Agency (Roscosmos, center) and Tim Peake of the European Space Agency (right) pose for pictures Dec. 9 after a traditional tree-planting ceremony. The trio will launch Dec. 15 on their Soyuz TMA-19M spacecraft for a six-month mission on the International Space Station...NASA/Victor Zelentsov.

    NASA Image and Video Library

    2015-12-09

    Behind their Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 46-47 crewmember Tim Kopra of NASA (left), Yuri Malenchenko of the Russian Federal Space Agency (Roscosmos, center) and Tim Peake of the European Space Agency (right) pose for pictures Dec. 9 after a traditional tree-planting ceremony. The trio will launch Dec. 15 on their Soyuz TMA-19M spacecraft for a six-month mission on the International Space Station. NASA/Victor Zelentsov

  18. 77 FR 27814 - Model Safety Evaluation for Plant-Specific Adoption of Technical Specifications Task Force...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... COMMISSION Model Safety Evaluation for Plant-Specific Adoption of Technical Specifications Task Force... Consolidated Line Item Improvement Process AGENCY: Nuclear Regulatory Commission. ACTION: Notice of... safety evaluation (SE) for plant-specific adoption of Technical Specifications (TSs) Task Force...

  19. Modelling and characterization of primary settlers in view of whole plant and resource recovery modelling.

    PubMed

    Bachis, Giulia; Maruéjouls, Thibaud; Tik, Sovanna; Amerlinck, Youri; Melcer, Henryk; Nopens, Ingmar; Lessard, Paul; Vanrolleghem, Peter A

    2015-01-01

    Characterization and modelling of primary settlers have been neglected pretty much to date. However, whole plant and resource recovery modelling requires primary settler model development, as current models lack detail in describing the dynamics and the diversity of the removal process for different particulate fractions. This paper focuses on the improved modelling and experimental characterization of primary settlers. First, a new modelling concept based on particle settling velocity distribution is proposed which is then applied for the development of an improved primary settler model as well as for its characterization under addition of chemicals (chemically enhanced primary treatment, CEPT). This model is compared to two existing simple primary settler models (Otterpohl and Freund; Lessard and Beck), showing to be better than the first one and statistically comparable to the second one, but with easier calibration thanks to the ease with which wastewater characteristics can be translated into model parameters. Second, the changes in the activated sludge model (ASM)-based chemical oxygen demand fractionation between inlet and outlet induced by primary settling is investigated, showing that typical wastewater fractions are modified by primary treatment. As they clearly impact the downstream processes, both model improvements demonstrate the need for more detailed primary settler models in view of whole plant modelling.

  20. Has the plant genetic variability any role in models of water transfer in the soil-plant-atmosphere continuum ?

    NASA Astrophysics Data System (ADS)

    Tardieu, F.

    2012-04-01

    Water transfer in the SPAC is essentially linked to environmental conditions such as evaporative demand or soil water potential, and physical parameters such as soil hydraulic capacity or hydraulic conductivity. Models used in soil science most often represent the plant via a small number of variables such as the water flux that crosses the base of the stem or the root length (or area) in each soil layer. Because there is an increasing demand for computer simulations of plants that would perform better under water deficit, models of SPA water transfer are needed that could better take into account the genetic variability of traits involved in plant hydraulics. (i) The water flux through the plant is essentially limited by stomata, which present a much higher resistance to water flow than those in the soil - root continuum. This can lead to unexpected relations between flux, leaf water potential and root hydraulic conductance. (ii) A large genetic variability exists within and between species for stomatal control, with important consequences for the minimum soil water potential that is accessible to the plant. In particular, isohydric plants that maintain leaf water potential in a narrow range via stomatal control have a higher (nearer to 0) 'wilting point' than anisohydric plants that allow leaf water potential to reach very low values. (iii) The conductivity for water transfer in roots and shoots is controlled by plants via aquaporins. It largely varies with time of the day, water and nutrient status, in particular via plant hormones and circadian rhythms. Models of SPA water transfer with a time definition of minutes to hour should probably not ignore this, while those with longer time steps are probably less sensitive to changes in plant hydraulic conductivity. (iv) The "dogma" that dense root systems provide tolerance to water deficit is profoundly affected when the balance "H2O gain vs C investment" is taken into account. At least three programmes of recurrent

  1. Tidd PFBC Demonstration Project. Quarterly report, January--March 1994

    SciTech Connect

    Not Available

    1994-04-01

    This is the 28th Technical Progress Report submitted to the Department of Energy in connection with the Cooperative Agreement between the DOE and the Ohio Power Company for the Tidd PFBC Demonstration Plant. This report covers the period of January 1, 1994 to March 31, 1994. Major activities during this period include: (1) The unit operated for 850 hours on coal, bringing the grand total for coal fire through the end of the quarter to 6318 hours. (2) The unit availability for the first quarter was 40.1%. (3) There were twelve gas turbine starts, eight bed preheater starts, and six operating periods on coal. (4) During this quarter, total gross generation was 40,721 MWH, the peak unit output for one hour was 62 MWH, and the coal consumption was 19,370 tons. (5) Three performance tests were conducted during this quarter; and (6) the plant was able to remain in service during the sub-zero weather in January, providing power to the critically short grid.

  2. Modeling plasmalemma ion transport of the aquatic plant Egeria densa.

    PubMed

    Buschmann, P; Sack, H; Köhler, A E; Dahse, I

    1996-11-01

    Fresh-water plants generate extraordinarily high electric potential differences at the plasma membrane. For a deeper understanding of the underlying transport processes a mathematical model of the electrogenic plasmalemma ion transport was developed based on experimental data mainly obtained from Egeria densa. The model uses a general nonlinear network approach and assumes coupling of the transporters via membrane potential. A proton pump, an outward-rectifying K+ channel, an inward-rectifying K+ channel, a Cl- channel and a (2H-Cl)+ symporter are considered to be elements of the system. The model takes into consideration the effects of light, external pH and ionic content of the bath medium on ion transport. As a result it does not only satisfactorily describe the membrane potential as a function of these external physiological factors but also succeeds in simulating the effects of specific inhibitors as well as I-V-curves obtained with the patch-clamp technique in the whole cell mode. The quality of the model was checked by stability and sensitivity analyses.

  3. Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions.

    PubMed

    Khayet, Mohamed; Fernández, Victoria

    2012-11-14

    Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions.

  4. Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

    PubMed Central

    2012-01-01

    Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions. PMID:23151272

  5. Plant functional type mapping for earth system models

    NASA Astrophysics Data System (ADS)

    Poulter, B.; Ciais, P.; Hodson, E.; Lischke, H.; Maignan, F.; Plummer, S.; Zimmermann, N. E.

    2011-11-01

    The sensitivity of global carbon and water cycling to climate variability is coupled directly to land cover and the distribution of vegetation. To investigate biogeochemistry-climate interactions, earth system models require a representation of vegetation distributions that are either prescribed from remote sensing data or simulated via biogeography models. However, the abstraction of earth system state variables in models means that data products derived from remote sensing need to be post-processed for model-data assimilation. Dynamic global vegetation models (DGVM) rely on the concept of plant functional types (PFT) to group shared traits of thousands of plant species into usually only 10-20 classes. Available databases of observed PFT distributions must be relevant to existing satellite sensors and their derived products, and to the present day distribution of managed lands. Here, we develop four PFT datasets based on land-cover information from three satellite sensors (EOS-MODIS 1 km and 0.5 km, SPOT4-VEGETATION 1 km, and ENVISAT-MERIS 0.3 km spatial resolution) that are merged with spatially-consistent Köppen-Geiger climate zones. Using a beta (ß) diversity metric to assess reclassification similarity, we find that the greatest uncertainty in PFT classifications occur most frequently between cropland and grassland categories, and in dryland systems between shrubland, grassland and forest categories because of differences in the minimum threshold required for forest cover. The biogeography-biogeochemistry DGVM, LPJmL, is used in diagnostic mode with the four PFT datasets prescribed to quantify the effect of land-cover uncertainty on climatic sensitivity of gross primary productivity (GPP) and transpiration fluxes. Our results show that land-cover uncertainty has large effects in arid regions, contributing up to 30% (20%) uncertainty in the sensitivity of GPP (transpiration) to precipitation. The availability of PFT datasets that are consistent with current

  6. Quarterly coal report, April--June 1997

    SciTech Connect

    1997-11-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for April through June 1997 and aggregated quarterly historical data for 1991 through the first quarter of 1997. Appendix A displays, from 1991 on, detailed quarterly historical coal imports data. Appendix B gives selected quarterly tables converted to metric tons. To provide a complete picture of coal supply and demand in the US, historical information has been integrated in this report. 8 figs., 73 tabs.

  7. A model framework to represent plant-physiology and rhizosphere processes in soil profile simulation models

    NASA Astrophysics Data System (ADS)

    Vanderborght, J.; Javaux, M.; Couvreur, V.; Schröder, N.; Huber, K.; Abesha, B.; Schnepf, A.; Vereecken, H.

    2013-12-01

    Plant roots play a crucial role in several key processes in soils. Besides their impact on biogeochemical cycles and processes, they also have an important influence on physical processes such as water flow and transport of dissolved substances in soils. Interaction between plant roots and soil processes takes place at different scales and ranges from the scale of an individual root and its directly surrounding soil or rhizosphere over the scale of a root system of an individual plant in a soil profile to the scale of vegetation patterns in landscapes. Simulation models that are used to predict water flow and solute transport in soil-plant systems mainly focus on the individual plant root system scale, parameterize single-root scale phenomena, and aggregate the root system scale to the vegetation scale. In this presentation, we will focus on the transition from the single root to the root system scale. Using high resolution non-invasive imaging techniques and methods, gradients in soil properties and states around roots and their difference from the bulk soil properties could be demonstrated. Recent developments in plant sciences provide new insights in the mechanisms that control water fluxes in plants and in the adaptation of root properties or root plasticity to changing soil conditions. However, since currently used approaches to simulate root water uptake neither resolve these small scale processes nor represent processes and controls within the root system, transferring this information to the whole soil-plant system scale is a challenge. Using a simulation model that describes flow and transport processes in the soil, resolves flow and transport towards individual roots, and describes flow and transport within the root system, such a transfer could be achieved. We present a few examples that illustrate: (i) the impact of changed rhizosphere hydraulic properties, (ii) the effect of root hydraulic properties and root system architecture, (iii) the regulation

  8. Review of a Proposed Quarterly Coal Publication

    SciTech Connect

    Not Available

    1981-01-01

    This Review of a Proposed Quartery Coal Publication contains findings and recommendations regarding the content of a new summary Energy Information Administration (EIA) coal and coke publication entitled The Quarterly Coal Review (QCR). It is divided into five sections: results of interviews with selected EIA data users; identification of major functions of the coal and coke industries; analysis of coal and coke data collection activities; evaluation of issues conerning data presentation including recommendations for the content of the proposed QCR; and comparison of the proposed QCR with other EIA publications. Major findings and recommendations are as follows: (1) User interviews indicate a definite need for a compehensive publication that would support analyses and examine economic, supply and demand trends in the coal industry; (2) the organization of the publication should reflect the natural order of activities of the coal and coke industries. Based on an analysis of the industries, these functions are: production, stocks, imports, exports, distribution, and consumption; (3) current EIA coal and coke surveys collect sufficient data to provide a summary of the coal and coke industries on a quarterly basis; (4) coal and coke data should be presented separately. Coke data could be presented as an appendix; (5) three geographic aggregations are recommended in the QCR. These are: US total, coal producing districts, and state; (6) coal consumption data should be consolidated into four major consumer categories: electric utilities, coke plants, other industrial, and residential commercial; (7) several EIA publications could be eliminated by the proposed QCR.

  9. [Hydrodyne quarterly report

    SciTech Connect

    1996-03-01

    In order that this report might stand by itself, a brief description of its goals is as follows. The equipment to tenderize meat by immersing the meat in water in which a small amount of high explosive is detonated was to be designed, fabricated and tested. The equipment was then to be shipped and installed near the ARS Meat Science Laboratory in Beltsville, MD. There further testing was to be done to establish performance characteristics. It was to be shown as an operating plant to meat producers who were potential customers. This document is in letter format; main headings include design of the equipment; new patent; fabrication; testing of unit; prototype plant in Virginia; new developments; tests and potential users; basic investigation.

  10. Modeling photosynthesis of discontinuous plant canopies by linking Geometric Optical Radiative Transfer model with biochemical processes

    NASA Astrophysics Data System (ADS)

    Xin, Q.; Gong, P.; Li, W.

    2015-02-01

    Modeling vegetation photosynthesis is essential for understanding carbon exchanges between terrestrial ecosystems and the atmosphere. The radiative transfer process within plant canopies is one of the key drivers that regulate canopy photosynthesis. Most vegetation cover consists of discrete plant crowns, of which the physical observation departs from the underlying assumption of a homogenous and uniform medium in classic radiative transfer theory. Here we advance the Geometric Optical Radiative Transfer (GORT) model to simulate photosynthesis activities for discontinuous plant canopies. We separate radiation absorption into two components that are absorbed by sunlit and shaded leaves, and derive analytical solutions by integrating over the canopy layer. To model leaf-level and canopy-level photosynthesis, leaf light absorption is then linked to the biochemical process of gas diffusion through leaf stomata. The canopy gap probability derived from GORT differs from classic radiative transfer theory, especially when the leaf area index is high, due to leaf clumping effects. Tree characteristics such as tree density, crown shape, and canopy length affect leaf clumping and regulate radiation interception. Modeled gross primary production (GPP) for two deciduous forest stands could explain more than 80% of the variance of flux tower measurements at both near hourly and daily time scales. We also demonstrate that the ambient CO2 concentration influences daytime vegetation photosynthesis, which needs to be considered in state-of-the-art biogeochemical models. The proposed model is complementary to classic radiative transfer theory and shows promise in modeling the radiative transfer process and photosynthetic activities over discontinuous forest canopies.

  11. Calibration of model constants in a biological reaction model for sewage treatment plants.

    PubMed

    Amano, Ken; Kageyama, Kohji; Watanabe, Shoji; Takemoto, Takeshi

    2002-02-01

    Various biological reaction models have been proposed which estimate concentrations of soluble and insoluble components in effluent of sewage treatment plants. These models should be effective to develop a better operation system and plant design, but their formulas consist of nonlinear equations, and there are many model constants, which are not easy to calibrate. A technique has been proposed to decide the model constants by precise experiments, but it is not practical for design engineers or process operators to perform these experiments regularly. Other approaches which calibrate the model constants by mathematical techniques should be used. In this paper, the optimal regulator method of modern control theory is applied as a mathematical technique to calibrate the model constants. This method is applied in a small sewage treatment testing facility. Calibration of the model constants is examined to decrease the deviations between calculated and measured concentrations. Results show that calculated values of component concentrations approach measured values and the method is useful for actual plants.

  12. Species distribution modelling for plant communities: Stacked single species or multivariate modelling approaches?

    Treesearch

    Emilie B. Henderson; Janet L. Ohmann; Matthew J. Gregory; Heather M. Roberts; Harold S.J. Zald

    2014-01-01

    Landscape management and conservation planning require maps of vegetation composition and structure over large regions. Species distribution models (SDMs) are often used for individual species, but projects mapping multiple species are rarer. We compare maps of plant community composition assembled by stacking results from many SDMs with multivariate maps constructed...

  13. Modelling utility-scale wind power plants. Part 1: Economics

    NASA Astrophysics Data System (ADS)

    Milligan, Michael R.

    1999-10-01

    As the worldwide use of wind turbine generators continues to increase in utility-scale applications, it will become increasingly important to assess the economic and reliability impact of these intermittent resources. Although the utility industry in the United States appears to be moving towards a restructured environment, basic economic and reliability issues will continue to be relevant to companies involved with electricity generation. This article is the first of two which address modelling approaches and results obtained in several case studies and research projects at the National Renewable Energy Laboratory (NREL). This first article addresses the basic economic issues associated with electricity production from several generators that include large-scale wind power plants. An important part of this discussion is the role of unit commitment and economic dispatch in production cost models. This paper includes overviews and comparisons of the prevalent production cost modelling methods, including several case studies applied to a variety of electric utilities. The second article discusses various methods of assessing capacity credit and results from several reliability-based studies performed at NREL.

  14. Study of soluble scale fouling control in high solids black liquor concentrators. Progress report, quarter 5 (October 1, 1999 - December 31, 1999)

    SciTech Connect

    W.J. Frederick; F. Chen; G. Hsieh; S. Lien; R.W. Murphy; R.W. Rousseau; W. Schmidl

    2000-01-01

    During this quarter, work has finally resumed on the black liquor solubility experiments, but no new data have been generated. The crystallization experiments with inorganic model solutions have been completed, and crystallization experiments with kraft black liquor have been started. The Annular Test Cell apparatus is now fully operational, while construction of the falling film evaporator pilot plant is nearly complete. Startup of this unit is planned for late in Quarter 6. In the CFD model development work, the relaxation of simplifying assumptions in the falling film model have been completed, and expressions were developed to estimate film velocity/film Reynolds number relations. Also, thin film data taken for a range of conventional fluids were compared to predictions using selected methods, and attempts were initiated to extrapolate to approximate black liquor evaporator conditions.

  15. Modeling the atomtronic analog of an optical polarizing beam splitter, a half-wave plate, and a quarter-wave plate for phonons of the motional state of two trapped atoms

    NASA Astrophysics Data System (ADS)

    Mohseni, Naeimeh; Fani, Marjan; Dowling, Jonathan P.; Saeidian, Shahpoor

    2017-07-01

    In this paper we propose a scheme to model the phonon analog of optical elements, including a polarizing beam splitter, a half-wave plate, and a quarter-wave plate, as well as an implementation of cnot and Pauli gates, by using two atoms confined in a two-dimensional plane. The internal states of the atoms are taken to be Rydberg circular states. Using this model we can manipulate the motional state of the atom, with possible applications in optomechanical integrated circuits for quantum information processing and quantum simulation. Towards this aim, we consider two trapped atoms and let only one of them interact simultaneously with two circularly polarized Laguerre-Gaussian beams.

  16. Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

    SciTech Connect

    Turchi, C.

    2010-07-01

    This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

  17. A plant-growth stress model: Conceptual model and development plan

    SciTech Connect

    Chen, C.W. )

    1989-12-01

    This report begins with a literature review of existing models for crops and forest trees. The models were analyzed for their assumptions, formulations, inputs, outputs, calibrations and verifications. The formulations of crop models (e.g. corn, sugar beet, soybean, and red radish) included detailed hypotheses of carbon uptake, light attenuation through leaves, photosynthesis, chemical synthesis of organics, material transport between plant parts and production of havestable dry matter. Most crop models performed simulations with a time step of 15 minutes to an hour for a total period of 100 to 150 days. Tree models were developed, mostly without verification, for forest management practices, ecological studies of species succession, and assessment of air pollution effects. None are physiologically based models that can simulate mechanistically tree responses to interacting natural and anthropogenic stresses. A new generation tree model was formulated. The model incorporated subroutines from an existing model (ILWAS) to calculate daily soil temperature, soil moisture, cations (including aluminum species) and anion concentrations in the soil solution at the root zone. It also includes a new plant module to simulate daily physiological and growth responses of trees, subjected to the dynamic impacts of air pollution, aluminum toxicity, nutrient deficiency, and drought. Model coefficient will be calibrated with data from exposure experiments where environmental conditions are controlled. The model can then be extended to the field where environmental conditions change dynamically. 90 refs., 11 figs.

  18. Lessons Learned from a Past Series of Bayesian Model Averaging studies for Soil/Plant Models

    NASA Astrophysics Data System (ADS)

    Nowak, Wolfgang; Wöhling, Thomas; Schöniger, Anneli

    2015-04-01

    In this study we evaluate the lessons learned about modelling soil/plant systems from analyzing evapotranspiration data, soil moisture and leaf area index. The data were analyzed with advanced tools from the area of Bayesian Model Averaging, model ranking and Bayesian Model Selection. We have generated a large variety of model conceptualizations by sampling random parameter sets from the vegetation components of the CERES, SUCROS, GECROS, and SPASS models and a common model for soil water movement via Monte-Carlo simulations. We used data from a one vegetation period of winter wheat at a field site in Nellingen, Germany. The data set includes soil moisture, actual evapotranspiration (ETa) from an eddy covariance tower, and leaf-area index (LAI). The focus of data analysis was on how one can do model ranking and model selection. Further analysis steps included the predictive reliability of different soil/plant models calibrated on different subsets of the available data. Our main conclusion is that model selection between different competing soil-plant models remains a large challenge, because 1. different data types and their combinations favor different models, because competing models are more or less good in simulating the coupling processes between the various compartments and their states, 2. singular events (such as the evolution of LAI during plant senescence) can dominate an entire time series, and long time series can be represented well by the few data values where the models disagree most, 3. the different data types differ in their discriminating power for model selection, 4. the level of noise present in ETa and LAI data, and the level of systematic model bias through simplifications of the complex system (e.g., assuming a few internally homogeneous soil layers) substantially reduce the confidence in model ranking and model selection, 5. none of the models withstands a hypothesis test against the available data, 6. even the assumed level of measurement

  19. Applied Meteorology Unit (AMU) Quarterly Report First Quarter FY-04

    NASA Technical Reports Server (NTRS)

    Bauman, William; Wheeler, Mark; Labert, Winifred; Jonathan Case; Short, David

    2004-01-01

    This report summarizes the Applied Meteorology Unit (AMU) activities for the First Quarter of Fiscal Year 2004 (October - December 2003). Tasks reviewed are: (1) Objective Lightning Probability Forecast, (2) Mesonet Temperature and Wind Climatology, (3) Severe Weather Forecast Decision Aid and (4) Anvil Transparency Relationship to Radar Reflectivity

  20. Short-term energy outlook quarterly projections. First quarter 1994

    SciTech Connect

    Not Available

    1994-02-07

    The Energy Information Administration (EIA) prepares quarterly, short- term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets.

  1. A modelling framework to simulate foliar fungal epidemics using functional-structural plant models.

    PubMed

    Garin, Guillaume; Fournier, Christian; Andrieu, Bruno; Houlès, Vianney; Robert, Corinne; Pradal, Christophe

    2014-09-01

    Sustainable agriculture requires the identification of new, environmentally responsible strategies of crop protection. Modelling of pathosystems can allow a better understanding of the major interactions inside these dynamic systems and may lead to innovative protection strategies. In particular, functional-structural plant models (FSPMs) have been identified as a means to optimize the use of architecture-related traits. A current limitation lies in the inherent complexity of this type of modelling, and thus the purpose of this paper is to provide a framework to both extend and simplify the modelling of pathosystems using FSPMs. Different entities and interactions occurring in pathosystems were formalized in a conceptual model. A framework based on these concepts was then implemented within the open-source OpenAlea modelling platform, using the platform's general strategy of modelling plant-environment interactions and extending it to handle plant interactions with pathogens. New developments include a generic data structure for representing lesions and dispersal units, and a series of generic protocols to communicate with objects representing the canopy and its microenvironment in the OpenAlea platform. Another development is the addition of a library of elementary models involved in pathosystem modelling. Several plant and physical models are already available in OpenAlea and can be combined in models of pathosystems using this framework approach. Two contrasting pathosystems are implemented using the framework and illustrate its generic utility. Simulations demonstrate the framework's ability to simulate multiscaled interactions within pathosystems, and also show that models are modular components within the framework and can be extended. This is illustrated by testing the impact of canopy architectural traits on fungal dispersal. This study provides a framework for modelling a large number of pathosystems using FSPMs. This structure can accommodate both

  2. 49 CFR 573.7 - Quarterly reports.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; (2) For the second calendar quarter (April 1 through June 30), on or before July 30; (3) For the third calendar quarter (July 1 through September 30), on or before October 30; and (4) For the fourth...

  3. 49 CFR 573.7 - Quarterly reports.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; (2) For the second calendar quarter (April 1 through June 30), on or before July 30; (3) For the third calendar quarter (July 1 through September 30), on or before October 30; and (4) For the fourth...

  4. Pathogen group specific risk factors for clinical mastitis, intramammary infection and blind quarters at the herd, cow and quarter level in smallholder dairy farms in Jimma, Ethiopia.

    PubMed

    Tolosa, T; Verbeke, J; Ayana, Z; Piepers, S; Supré, K; De Vliegher, S

    2015-07-01

    A cross-sectional study on clinical mastitis, intramammary infection (IMI) and blind quarters was conducted on 50 smallholder dairy farms in Jimma, Ethiopia. A questionnaire was performed, and quarters of 211 cows were sampled and bacteriologically cultured. Risk factors at the herd, cow, and quarter level for clinical mastitis and (pathogen-specific) intramammary infection were studied using multilevel modeling. As well, factors associated with quarters being blind were studied. Eleven percent of the cows and 4% of the quarters had clinical mastitis whereas 85% of the cows and 51% of the quarters were infected. Eighteen percent of the cows had one or more blind quarter(s), whereas 6% of the quarters was blind. Non-aureus staphylococci were the most frequently isolated pathogens in both clinical mastitis cases and IMI. The odds of clinical mastitis was lower in herds where heifers were purchased in the last year [odds ratio (OR) with 95% confidence interval: 0.11 (0.01-0.90)], old cows (>4 years) [OR: 0.45 (0.18-1.14)], and quarters not showing teat injury [OR: 0.23 (0.07-0.77)]. The odds of IMI caused by any pathogen was higher in herds not practicing teat drying before milking (opposed to drying teats with 1 towel per cow) [OR: 1.68 (1.05-2.69)], cows in later lactation (>180 DIM opposed to ≤90 DIM) [OR: 1.81 (1.14-2.88)], cows with a high (>3) body condition score (BCS) [OR: 1.57 (1.06-2.31)], right quarters (opposed to a left quarter position) [OR: 1.47 (1.10-1.98)], and quarters showing teat injury [OR: 2.30 (0.97-5.43)]. Quarters of cows in herds practicing bucket-fed calf feeding (opposed to suckling) had higher odds of IMI caused by Staphylococcus aureus [OR: 6.05 (1.31-27.90)]. Except for BCS, IMI caused by non-aureus staphylococci was associated with the same risk factors as IMI caused by any pathogen. No access to feed and water immediately after milking [OR: 2.41 (1.26-4.60)], higher parity [OR: 3.60 (1.20-10.82)] and tick infestation [OR: 2.42 (1

  5. Development of models for thermal infrared radiation above and within plant canopies

    NASA Technical Reports Server (NTRS)

    Paw u, Kyaw T.

    1992-01-01

    Any significant angular dependence of the emitted longwave radiation could result in errors in remotely estimated energy budgets or evapotranspiration. Empirical data and thermal infrared radiation models are reviewed in reference to anisotropic emissions from the plant canopy. The biometeorological aspects of linking longwave models with plant canopy energy budgets and micrometeorology are discussed. A new soil plant atmosphere model applied to anisotropic longwave emissions from a canopy is presented. Time variation of thermal infrared emission measurements is discussed.

  6. Development of models for thermal infrared radiation above and within plant canopies

    NASA Technical Reports Server (NTRS)

    Paw u, Kyaw T.

    1992-01-01

    Any significant angular dependence of the emitted longwave radiation could result in errors in remotely estimated energy budgets or evapotranspiration. Empirical data and thermal infrared radiation models are reviewed in reference to anisotropic emissions from the plant canopy. The biometeorological aspects of linking longwave models with plant canopy energy budgets and micrometeorology are discussed. A new soil plant atmosphere model applied to anisotropic longwave emissions from a canopy is presented. Time variation of thermal infrared emission measurements is discussed.

  7. Mixed Waste Management Facility (MWMF) groundwater monitoring report. Second quarter 1993

    SciTech Connect

    Not Available

    1993-09-01

    Groundwater monitoring continued at the Savannah River Plant. During second quarter 1993, nine constituents exceeded final Primary Drinking Water Standards in groundwater samples from downgradient monitoring wells at the Mixed Waste Management Facility, the Old Burial Ground, the E-Area Vaults, and the proposed Hazardous Waste/Mixed Waste Disposal Vaults. As in previous quarters, tritium and trichloroethylene were the most widespread constituents. Chloroethene (vinyl chloride), dichloromethane (methylene chloride), 1,1-dichloroethylene, gross alpha, lead, nonvolatile beta, or tetrachloroethylene also exceeded standards in one or more wells. The groundwater flow directions and rates in the three hydrostratigraphic units were similar to those of previous quarters.

  8. Quarterly coal report, July--September 1998

    SciTech Connect

    1999-02-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for July through September 1998 and aggregated quarterly historical data for 1992 through the second quarter of 1998. 58 tabs.

  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. Modelling production processes in a vehicle recycling plant.

    PubMed

    Simic, Vladimir; Dimitrijevic, Branka

    2012-09-01

    The European Directive on end-of-life vehicles (ELVs) fundamentally changed the business philosophy of the European vehicle recycling system, which was exclusively profit-oriented. As the dominant participants of this system, vehicle recycling plants (VRPs) are especially affected by its implementation. For VRPs to successfully respond to the prescribed eco-efficiency quotas, investment will be needed to procure modern sorting equipment as well as to achieve full transformation of their production process. However, before VRPs decide to make this very important investment decision, it is necessary to determine the adequacy of such a decision in detail. Consequently, the following questions become unavoidable: Can modernly equipped VRPs conduct profitable business? Are eco-efficiency quotas actually attainable? How will the new changes in vehicle design influence VRPs? To provide answers to these essential questions, a production planning model of a modernly equipped VRP was first developed and then tested extensively using real data. Based on the answers provided by the proposed model testing analysis it was concluded that VRP transformation is not only necessary but completely justified and that the final success of the ELV Directive is realistic.

  11. Multiscale model of light harvesting by photosystem II in plants

    PubMed Central

    Amarnath, Kapil; Bennett, Doran I. G.; Schneider, Anna R.; Fleming, Graham R.

    2016-01-01

    The first step of photosynthesis in plants is the absorption of sunlight by pigments in the antenna complexes of photosystem II (PSII), followed by transfer of the nascent excitation energy to the reaction centers, where long-term storage as chemical energy is initiated. Quantum mechanical mechanisms must be invoked to explain the transport of excitation within individual antenna. However, it is unclear how these mechanisms influence transfer across assemblies of antenna and thus the photochemical yield at reaction centers in the functional thylakoid membrane. Here, we model light harvesting at the several-hundred-nanometer scale of the PSII membrane, while preserving the dominant quantum effects previously observed in individual complexes. We show that excitation moves diffusively through the antenna with a diffusion length of 50 nm until it reaches a reaction center, where charge separation serves as an energetic trap. The diffusion length is a single parameter that incorporates the enhancing effect of excited state delocalization on individual rates of energy transfer as well as the complex kinetics that arise due to energy transfer and loss by decay to the ground state. The diffusion length determines PSII’s high quantum efficiency in ideal conditions, as well as how it is altered by the membrane morphology and the closure of reaction centers. We anticipate that the model will be useful in resolving the nonphotochemical quenching mechanisms that PSII employs in conditions of high light stress. PMID:26787911

  12. Plant canopy light absorption model with application to wheat

    NASA Technical Reports Server (NTRS)

    Chance, J. E.; Lemaster, E. W.

    1978-01-01

    A light absorption model (LAM) for vegetative plant canopies has been derived from the Suits reflectance model. From the LAM the absorption of light in the photosynthetically active region of the spectrum (400-700 nm) has been calculated for a Penjamo wheat crop for several situations including (a) the percent absorption of the incident radiation by a canopy of LAI 3.1 having a four-layer structure, (b) the percent absorption of light by the individual layers within a four-layer canopy and by the underlying soil, (c) the percent absorption of light by each vegetative canopy layer for variable sun angle, and (d) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three-layer canopy. This calculation is also presented as a function of the leaf area index and is shown to be in agreement with experimental data reported by Kanemasu on Plainsman V wheat.

  13. An Idealized Model of Plant and Soil Dynamics

    NASA Astrophysics Data System (ADS)

    Burg, David; Malkinson, Dan; Wittenberg, Lea

    2014-05-01

    Following wildfire events the landscape commonly becomes denuded of vegetation cover, resulting in systems prone to soil loss and degradation. In this context soil dynamics are an intricate process balanced between pedogenesis, which is a relatively slow process and erosion which depends on many inert (e.g. soil texture, slope, precipitation and wind) and biological factors such as vegetation properties, grazing intensity, and human disturbance. We develop a simple homogenous, spatially implicit, theoretical model of the global dynamics of the interactions between vegetation and soil using a system of two nonlinear differential equations describing this interdependence, assuming a double feedback between them - plants control erosion and soil availability facilitates plants growth: ( ) dV- -K-- dt = rV K - 1+ aS - V (1) dS-= σ - ɛSe-cT dt (2) where V and S represent vegetation cover and soil availability, respectively. Vegetation growth is similar to the classical logistic model with a growth rate of r(yr1), however, the "carrying capacity" (K) is dependent on soil availability (a1 is the amount of soil where V is reduced by half). Soil influxes at a constant rate σ(mm×yr1) and is eroded at a constant rategɛ (yr-1), while vegetation abates this process modeled as a decreasing exponent as the effectiveness of vegetation in reducing soil erosion (c). Parameter values were chosen from a variable range found in the literature: r=0.01 yr1, K=75%, a1=1, σ=1 mm×yr1, ɛ=0.1 yr1, c=0.08. Complex properties emerge from this model. At certain parameter values (cK≤4) the model predicts one of two steady states - full recovery of vegetation cover or a degraded barren system. However, at certain boundary conditions (cK>4 and Λ1 ≤ σ/ɛ ≤ Λ2, see Article for terms of Λ1 and Λ2) bistability may be observed. We also show that erosion seems to be the determining factor in this system, and we identify the threshold values from which beyond the systems become unstable

  14. P-Area Acid/Caustic Basin groundwater monitoring report, fourth quarter 1991 and 1991 summary

    SciTech Connect

    Not Available

    1992-03-01

    During fourth quarter 1991, samples from the PAC monitoring wells at the P-Area Acid/Caustic Basin of Savannah River Plant were analyzed for indicator parameters, turbidity, major ions, volatile organic compounds, radionuclides, and other constituents. Monitoring results that exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) and the Savannah River Site (SRS) flagging criteria and turbidity standards during the quarter, with summary results for the year, are presented in this report.

  15. Global land model development: time to shift from a plant functional type to a plant functional trait approach

    NASA Astrophysics Data System (ADS)

    Reich, P. B.; Butler, E. E.

    2015-12-01

    This project will advance global land models by shifting from the current plant functional type approach to one that better utilizes what is known about the importance and variability of plant traits, within a framework of simultaneously improving fundamental physiological relations that are at the core of model carbon cycling algorithms. Existing models represent the global distribution of vegetation types using the Plant Functional Typeconcept. Plant Functional Types are classes of plant species with similar evolutionary and life history withpresumably similar responses to environmental conditions like CO2, water and nutrient availability. Fixedproperties for each Plant Functional Type are specified through a collection of physiological parameters, or traits.These traits, mostly physiological in nature (e.g., leaf nitrogen and longevity) are used in model algorithms to estimate ecosystem properties and/or drive calculated process rates. In most models, 5 to 15 functional types represent terrestrial vegetation; in essence, they assume there are a total of only 5 to 15 different kinds of plants on the entire globe. This assumption of constant plant traits captured within the functional type concept has serious limitations, as a single set of traits does not reflect trait variation observed within and between species and communities. While this simplification was necessary decades past, substantial improvement is now possible. Rather than assigning a small number of constant parameter values to all grid cells in a model, procedures will be developed that predict a frequency distribution of values for any given grid cell. Thus, the mean and variance, and how these change with time, will inform and improve model performance. The trait-based approach will improve land modeling by (1) incorporating patterns and heterogeneity of traits into model parameterization, thus evolving away from a framework that considers large areas of vegetation to have near identical trait

  16. Education Statistics Quarterly, Fall 2000.

    ERIC Educational Resources Information Center

    Dillow, Sally, Ed.

    2000-01-01

    The "Education Statistics Quarterly" gives a comprehensive overview of work done across all parts of the National Center for Education Statistics (NCES). Each issue contains short publications, summaries, and descriptions that cover all NCES publications and data products released during a 3-month period. Each message also contains a…

  17. Trustee Quarterly, 2000-2001.

    ERIC Educational Resources Information Center

    Trustee Quarterly, 2001

    2001-01-01

    This document contains 4 issues of the Trustee Quarterly: fall 2000, spring 2001, summer 2001, and fall 2001. The fall 2000 issue contains seven features and six departments. Among the features are: "The New Economy: Who Will Lead the Education Movement," by Rucker; "Community Colleges Tackle IT Staffing Challenges," by Matina; and "Looking at…

  18. JLTN Quarterly, 1995-1996.

    ERIC Educational Resources Information Center

    JLTN Quarterly, 1996

    1996-01-01

    This document consists of the four issues of the "JLTN Quarterly" issued from December 1995 to October 1996. This journal for high school Japanese language teachers contain articles on class activities and classroom teaching techniques. These include: exercises in interpretation of a Toys "R" Us store map and advertising; a weather discussion…

  19. Gifted Education Press Quarterly, 2002.

    ERIC Educational Resources Information Center

    Fisher, Maurice D., Ed.

    2002-01-01

    These four issues of a quarterly publication for gifted educators and parents of gifted children span winter 2002 through fall 2002. Featured articles include: (1) "Cultivating Courage, Creativity, and Caring" (James T. Webb), which discusses the need to encourage the development of courage and caring, as well as creativity in gifted students; (2)…

  20. Gifted Education Press Quarterly, 1999.

    ERIC Educational Resources Information Center

    Fisher, Maurice D., Ed.

    1999-01-01

    This document consists of the four 1999 issues of a quarterly newsletter publication on gifted education. Issues regularly include major articles, book reviews, announcements, and letters. The major articles in these issues are: "The Mathematically Gifted: Bridging the Gender Gap" (Lynn H. Fox and Janet F. Soller); "Parenting for Education:…

  1. Apprentices & Trainees: September Quarter, 2012

    ERIC Educational Resources Information Center

    National Centre for Vocational Education Research (NCVER), 2013

    2013-01-01

    This publication presents estimates of apprentice and trainee activity in Australia for the September quarter 2012. The figures in this publication are derived from the National Apprentice and Trainee Collection no.74 (December 2012 estimates). The most recent figures in this publication are estimated (those for training activity from the March…

  2. Gifted Education Press Quarterly, 1995.

    ERIC Educational Resources Information Center

    Fisher, Maurice D., Ed.

    1995-01-01

    This document consists of the four issues of the newsletter "Gifted Education Press Quarterly" published during 1995. This newsletter addresses issues in the education of gifted children and youth. The major articles are: (1) "Using Today's Technology: Parents Can Help Challenge Gifted Children" (Adrienne O'Neill); (2)…

  3. Gifted Education Press Quarterly, 2000.

    ERIC Educational Resources Information Center

    Fisher, Maurice D., Ed.

    2000-01-01

    Four issues of this quarterly publications on gifted education include the following articles: "Unrecognized Giftedness: The Frustrating Case of the Gifted Adult" (Marylou Kelly Streznewski); "Shakespeare in the Classroom: The Bard is Back!" (Rosanna DiMillo Sandell); "What Teachers, Parents, and Administrators Need To…

  4. Gifted Education Press Quarterly, 2001.

    ERIC Educational Resources Information Center

    Fisher, Maurice D., Ed.

    2001-01-01

    These four issues of this quarterly publication on the education of gifted students contain the following featured articles: (1) "Reflections on China: Implications for Gifted Education" (Andrea I. Prejean and Lynn H. Fox); (2) "Differentiating Instruction for Gifted Middle School Students in Heterogeneous Science Classes"…

  5. Education Statistics Quarterly, Spring 2001.

    ERIC Educational Resources Information Center

    Education Statistics Quarterly, 2001

    2001-01-01

    The "Education Statistics Quarterly" gives a comprehensive overview of work done across all parts of the National Center for Education Statistics (NCES). Each issue contains short publications, summaries, and descriptions that cover all NCES publications, data products and funding opportunities developed over a 3-month period. Each issue…

  6. Strategic Studies Quarterly. Winter 2015

    DTIC Science & Technology

    2016-09-19

    machines and unknown Resiliency in Future Cyber Combat Strategic Studies Quarterly ♦ Winter 2015 [ 91 ] vulnerabilities. Aristotle taught that virtue...27 November 2012, II-9. 7. Edward N. Luttwak, Strategy: The Logic of War and Peace (Cambridge, MA: Belknap Press, 2003), 39–40. 8. Aristotle

  7. Writing: The Quarterly as Text

    ERIC Educational Resources Information Center

    Locke, Lawrence F.

    2005-01-01

    The purpose of this essay is to examine how writing has shaped the nature of the Quarterly over 75 years. Here the author explores how stylistic elements have changed over time, how form has interacted with function and content, and how well the resulting text has served the several communities within physical education. He makes the following…

  8. Strategic petroleum reserve. Quarterly report

    SciTech Connect

    1995-08-15

    The Strategic Petroleum Reserve reduces the Nation`s vulnerability to oil supply disruptions. Its existence provides a formidable deterrent to the use of oil as a political instrument and an effective response mechanism should a disruption occur. The Strategic Petroleum Reserve was created pursuant to the Energy Policy and Conservation Act of December 22, 1975 (Public Law 94-163). Its purposes are to reduce the impact of disruptions in supplies of petroleum products and to carry out obligations of the United States under the Agreement on an International Energy Program. Section 165(a) of the Act requires the submission of Annual Reports and Section 165(b)(1) requires the submission of Quarterly Reports. This Quarterly Report highlights activities undertaken during the second quarter of calendar year 1995, including: inventory of petroleum products stored in the Reserve; current and projected storage capacity, analysis of existing or anticipated problems with the acquisition and storage of petroleum products, and future expansion of storage capacity; funds obligated by the Secretary from the SPR Petroleum Account and the Strategic Petroleum Reserve Account during the prior calendar quarter and in total; and major environmental actions completed, in progress, or anticipated.

  9. Heartbeat Model for Component Failure in Simulation of Plant Behavior

    SciTech Connect

    R. W. Youngblood; R. R. Nourgaliev; D. L. Kelly; C. L. Smith; T-N. Dinh

    2011-03-01

    As part of the Department of Energy’s “Light Water Reactor Sustainability Program” (LWRSP), tools and methodology for risk-informed characterization of safety margin are being developed for use in supporting decision-making on plant life extension after the first license renewal. Beginning with the traditional discussion of “margin” in terms of a “load” (a physical challenge to system or component function) and a “capacity” (the capability of that system or component to accommodate the challenge), we are developing the capability to characterize realistic probabilistic load and capacity spectra, reflecting both aleatory and epistemic uncertainty in system behavior. This way of thinking about margin comports with work done in the last 10 years. However, current capabilities to model in this way are limited: it is currently possible, but difficult, to validly simulate enough time histories to support quantification in realistic problems, and the treatment of environmental influences on reliability is relatively artificial in many existing applications. The INL is working on a next-generation safety analysis capability (widely referred to as “R7”) that will enable a much better integration of reliability-related and phenomenology-related aspects of margin. In this paper, we show how to implement cumulative damage (“heartbeat”) models for component reliability that lend themselves naturally to being included as part of the phenomenology simulation. Implementation of this modeling approach relies on the way in which the phenomenology simulation implements its dynamic time step management. Within this approach, component failures influence the phenomenology, and the phenomenology influences the component failures.

  10. A 20-state empirical amino-acid substitution model for green plant chloroplasts.

    PubMed

    Cox, Cymon J; Foster, Peter G

    2013-08-01

    We introduce a new empirical amino-acid substitution model intended for use with for green plant (Viridiplantae) chloroplast protein data, which we call gcpREV (green chloroplast reversible model). Relative exchange rates and base composition frequencies among amino-acids were calculated using a Markov-chain Monte Carlo analysis on a combined data set of 34 proteins sampled among 27 taxa of green plants. The gcpREV model is a better fit than the commonly-used cpREV model to five previously published chloroplast protein test data sets of green plants, but is not a better fit to test data consisting mostly of non-green plant chloroplasts. Consequently, our analyses suggest a degree of specificity of the new model to green plant chloroplast data. The new model is implemented in the software P4, and model description files are available for other popular phylogenetic analysis software. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Plant metabolic modeling: achieving new insight into metabolism and metabolic engineering.

    PubMed

    Baghalian, Kambiz; Hajirezaei, Mohammad-Reza; Schreiber, Falk

    2014-10-01

    Models are used to represent aspects of the real world for specific purposes, and mathematical models have opened up new approaches in studying the behavior and complexity of biological systems. However, modeling is often time-consuming and requires significant computational resources for data development, data analysis, and simulation. Computational modeling has been successfully applied as an aid for metabolic engineering in microorganisms. But such model-based approaches have only recently been extended to plant metabolic engineering, mainly due to greater pathway complexity in plants and their highly compartmentalized cellular structure. Recent progress in plant systems biology and bioinformatics has begun to disentangle this complexity and facilitate the creation of efficient plant metabolic models. This review highlights several aspects of plant metabolic modeling in the context of understanding, predicting and modifying complex plant metabolism. We discuss opportunities for engineering photosynthetic carbon metabolism, sucrose synthesis, and the tricarboxylic acid cycle in leaves and oil synthesis in seeds and the application of metabolic modeling to the study of plant acclimation to the environment. The aim of the review is to offer a current perspective for plant biologists without requiring specialized knowledge of bioinformatics or systems biology. © 2014 American Society of Plant Biologists. All rights reserved.

  12. TIDD PFBC demonstration project. Quarterly report, January--March 1995

    SciTech Connect

    1995-04-01

    This is the thirty-second Technical Progress Report submitted to the Department of Energy in connection with the Cooperative Agreement between the DOE and the Ohio Power Company for the Tidd PFBC Demonstration Plant. This report covers the period from January 1, 1995 to March 31, 1995. Major Activities during this period include: The unit operated for 718 hours on coal, bringing the grand total for coal fire through the end of the quarter to 11,442 hours. There were seven gas turbine starts, nine bed preheater starts, and nine operating periods on coal. During this quarter, total gross generation was 57,693 MWH, the peak unit output for one hour was 74 MWH, and the coal consumption was 27,866 tons. Twelve performance tests were conducted during this quarter, bringing the total number of tests for the plant to 95. On March 30,1995, at 8:27 am, the Tidd PFBC Demonstration Plant was manually tripped for the last time.

  13. Modeling terrestrial carbon and water dynamics across climatic gradients: does plant trait diversity matter?

    PubMed

    Pappas, Christoforos; Fatichi, Simone; Burlando, Paolo

    2016-01-01

    Plant trait diversity in many vegetation models is crudely represented using a discrete classification of a handful of 'plant types' (named plant functional types; PFTs). The parameterization of PFTs reflects mean properties of observed plant traits over broad categories ignoring most of the inter- and intraspecific plant trait variability. Taking advantage of a multivariate leaf-trait distribution (leaf economics spectrum), as well as documented plant drought strategies, we generate an ensemble of hypothetical species with coordinated attributes, rather than using few PFTs. The behavior of these proxy species is tested using a mechanistic ecohydrological model that translates plant traits into plant performance. Simulations are carried out for a range of climates representative of different elevations and wetness conditions in the European Alps. Using this framework we investigate the sensitivity of ecosystem response to plant trait diversity and compare it with the sensitivity to climate variability. Plant trait diversity leads to highly divergent vegetation carbon dynamics (fluxes and pools) and to a lesser extent water fluxes (transpiration). Abiotic variables, such as soil water content and evaporation, are only marginally affected. These results highlight the need for revising the representation of plant attributes in vegetation models. Probabilistic approaches, based on observed multivariate whole-plant trait distributions, provide a viable alternative.

  14. Detoxification and generation of useful products from coal combustion wastes: Quarterly technical report, (October--December 1988)

    SciTech Connect

    Not Available

    1988-01-01

    This quarter, samples of dry fly ash, wet bottom ash, and desulfurization gypsum slurry were provided from an Ohio Edison power plant. Chemical analysis mineralogical examination, and an anion analysis were performed on the samples. 2 figs., 1 tab. (CBS)

  15. Coal liquefaction. Quarterly report, January-March 1979. [US DOE supported

    SciTech Connect

    1980-01-01

    Progress in DOE-supported coal liquefaction pilot plant projects is reported: company, location, contract, funding, process description, history and progress in the current quarter. Related projects discussed are: coking and gasification of liquefaction plant residues, filtration of coal liquids and refining of coal liquids by hydrogenation. (LTN)

  16. A modelling framework to simulate foliar fungal epidemics using functional–structural plant models

    PubMed Central

    Garin, Guillaume; Fournier, Christian; Andrieu, Bruno; Houlès, Vianney; Robert, Corinne; Pradal, Christophe

    2014-01-01

    Background and Aims Sustainable agriculture requires the identification of new, environmentally responsible strategies of crop protection. Modelling of pathosystems can allow a better understanding of the major interactions inside these dynamic systems and may lead to innovative protection strategies. In particular, functional–structural plant models (FSPMs) have been identified as a means to optimize the use of architecture-related traits. A current limitation lies in the inherent complexity of this type of modelling, and thus the purpose of this paper is to provide a framework to both extend and simplify the modelling of pathosystems using FSPMs. Methods Different entities and interactions occurring in pathosystems were formalized in a conceptual model. A framework based on these concepts was then implemented within the open-source OpenAlea modelling platform, using the platform's general strategy of modelling plant–environment interactions and extending it to handle plant interactions with pathogens. New developments include a generic data structure for representing lesions and dispersal units, and a series of generic protocols to communicate with objects representing the canopy and its microenvironment in the OpenAlea platform. Another development is the addition of a library of elementary models involved in pathosystem modelling. Several plant and physical models are already available in OpenAlea and can be combined in models of pathosystems using this framework approach. Key Results Two contrasting pathosystems are implemented using the framework and illustrate its generic utility. Simulations demonstrate the framework's ability to simulate multiscaled interactions within pathosystems, and also show that models are modular components within the framework and can be extended. This is illustrated by testing the impact of canopy architectural traits on fungal dispersal. Conclusions This study provides a framework for modelling a large number of pathosystems

  17. Understanding linkage rules in plant-pollinator networks by using hierarchical models that incorporate pollinator detectability and plant traits.

    PubMed

    Bartomeus, Ignasi

    2013-01-01

    The analysis of mutualistic networks has become a central tool in answering theoretical and applied questions regarding our understanding of ecological processes. Significant gaps in knowledge do however need to be bridged in order to effectively and accurately be able to describe networks. Main concern are the incorporation of species level information, accounting for sampling limitations and understanding linkage rules. Here I propose a simple method to combine plant pollinator effort-limited sampling with information about plant community to gain understanding of what drives linkage rules, while accounting for possible undetected linkages. I use hierarchical models to estimate the probability of detection of each plant-pollinator interaction in 12 Mediterranean plant-pollinator networks. As it is possible to incorporate plant traits as co-variables in the models, this method has the potential to be used for predictive purposes, such as identifying undetected links among existing species, as well as potential interactions with new plant species. Results show that pollinator detectability is very skewed and usually low. Nevertheless, 84% of the models are enhanced by the inclusion of co-variables, with flower abundance and inflorescence type being the most commonly retained co-variables. The predicted networks increase network Connectance by 13%, but not Nestedness, which is known to be robust to sampling effects. However, 46% of the pollinator interactions in the studied networks comprised a single observation and hence could not be modeled. The hierarchical modeling approach suggested here is highly flexible and can be used on binary or frequency networks, accommodate different observers or include collection day weather variables as confounding factors. An R script is provided for a rapid adoption of this method.

  18. Understanding Linkage Rules in Plant-Pollinator Networks by Using Hierarchical Models That Incorporate Pollinator Detectability and Plant Traits

    PubMed Central

    Bartomeus, Ignasi

    2013-01-01

    The analysis of mutualistic networks has become a central tool in answering theoretical and applied questions regarding our understanding of ecological processes. Significant gaps in knowledge do however need to be bridged in order to effectively and accurately be able to describe networks. Main concern are the incorporation of species level information, accounting for sampling limitations and understanding linkage rules. Here I propose a simple method to combine plant pollinator effort-limited sampling with information about plant community to gain understanding of what drives linkage rules, while accounting for possible undetected linkages. I use hierarchical models to estimate the probability of detection of each plant-pollinator interaction in 12 Mediterranean plant-pollinator networks. As it is possible to incorporate plant traits as co-variables in the models, this method has the potential to be used for predictive purposes, such as identifying undetected links among existing species, as well as potential interactions with new plant species. Results show that pollinator detectability is very skewed and usually low. Nevertheless, 84% of the models are enhanced by the inclusion of co-variables, with flower abundance and inflorescence type being the most commonly retained co-variables. The predicted networks increase network Connectance by 13%, but not Nestedness, which is known to be robust to sampling effects. However, 46% of the pollinator interactions in the studied networks comprised a single observation and hence could not be modeled. The hierarchical modeling approach suggested here is highly flexible and can be used on binary or frequency networks, accommodate different observers or include collection day weather variables as confounding factors. An R script is provided for a rapid adoption of this method. PMID:23840909

  19. Wild Plants Used by the Native Americans.

    ERIC Educational Resources Information Center

    Nature Study, 1984

    1984-01-01

    Describes 10 wild plants used by Native Americans. They include: rose hips; the common milkweed; cattails; elderberries; cactus fruits; lamb's quarters pigweeds (Chenopodium sp.); persimmons; mints (Monardo sp.); the yucca; and the hawthorn. Illustrations of each plant are included. (JN)

  20. Wild Plants Used by the Native Americans.

    ERIC Educational Resources Information Center

    Nature Study, 1984

    1984-01-01

    Describes 10 wild plants used by Native Americans. They include: rose hips; the common milkweed; cattails; elderberries; cactus fruits; lamb's quarters pigweeds (Chenopodium sp.); persimmons; mints (Monardo sp.); the yucca; and the hawthorn. Illustrations of each plant are included. (JN)

  1. TIDD PFBC Demonstration Project. Quarterly report, July--September 1994

    SciTech Connect

    1995-01-01

    This is the thirty-first Technical Progress Report submitted to the Department of Energy in connection with the Cooperative Agreement between the DOE and the Ohio Power Company for the Tidd PFBC Demonstration Plant. This report covers the period from October 1, 1994, to December 31, 1994. Major activities during this period include: the unit operated for 1216 hours on coal, bringing the grand total for coal fire through the end of the quarter to 10,297 hours; the unit availability for the fourth quarter was 54.15%. The unit availability for 1994 was 54.7%; there were two gas turbine starts, two bed preheater starts, and three operating periods on coal; during this quarter, total gross generation was 64,439 MWH, the peak unit output for one hour was 68 MWH, and the coal consumption was 31,846 tons; six performance tests were conducted during this quarter; and the draft report on the first three years of operation was submitted to the DOE.

  2. Quarterly coal report, October--December 1996

    SciTech Connect

    1997-05-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for October through December 1996 and aggregated quarterly historical data for 1990 through the third quarter of 1996. Appendix A displays, from 1988 on, detailed quarterly historical coal imports data. To provide a complete picture of coal supply and demand in the US, historical information has been integrated in this report. 8 figs., 72 tabs.

  3. Quarterly coal report, April--June, 1998

    SciTech Connect

    1998-11-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for April through June 1998 and aggregated quarterly historical data for 1992 through the first quarter of 1998. Appendix A displays, from 1992 on, detailed quarterly historical coal imports data. 58 tabs.

  4. Quarterly coal report, January--March 1998

    SciTech Connect

    Young, P.

    1998-08-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for January through March 1998 and aggregated quarterly historical data for 1992 through the fourth quarter of 1997. Appendix A displays, from 1992 on, detailed quarterly historical coal imports data. To provide a complete picture of coal supply and demand in the United States, historical information has been integrated in this report. 58 tabs.

  5. Quarterly coal report, October--December 1998

    SciTech Connect

    1999-07-01

    The Quarterly Coal Report (QCR) provides comprehensive information about US coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. This report presents detailed quarterly data for October through December 1998 and aggregated quarterly historical data for 1992 through the third quarter of 1998. Appendix A displays, from 1992 on, detailed quarterly historical coal imports data. 58 tabs.

  6. Animal Models of Brain Maldevelopment Induced by Cycad Plant Genotoxins

    PubMed Central

    Kisby, Glen E.; Moore, Holly; Spencer, Peter S.

    2014-01-01

    Cycads are long-lived tropical and subtropical plants that contain azoxyglycosides (e.g., cycasin, macrozamin) and neurotoxic amino acids (notably β-N-methylamino-L-alanine L-BMAA), toxins that have been implicated in the etiology of a disappearing neurodegenerative disease, amyotrophic lateral sclerosis and parkinsonism-dementia complex that has been present in high incidence among three genetically distinct populations in the western Pacific. The neuropathology of amyotrophic lateral sclerosis/parkinsonism-dementia complex includes features suggestive of brain maldevelopment, an experimentally proven property of cycasin attributable to the genotoxic action of its aglycone methylazoxymethanol (MAM). This property of MAM has been exploited by neurobiologists as a tool to study perturbations of brain development. Depending on the neurodevelopmental stage, MAM can induce features in laboratory animals that model certain characteristics of epilepsy, schizophrenia, or ataxia. Studies in DNA repair-deficient mice show that MAM perturbs brain development through a DNA damage-mediated mechanism. The brain DNA lesions produced by systemic MAM appear to modulate the expression of genes that regulate neurodevelopment and contribute to neurodegeneration. Epigenetic changes (histone lysine methylation) have also been detected in the underdeveloped brain after MAM administration. The DNA damage and epigenetic changes produced by MAM and, perhaps by chemically related substances (e.g., nitrosamines, nitrosoureas, hydrazines), might be an important mechanism by which early-life exposure to genotoxicants can induce long-term brain dysfunction. PMID:24339036

  7. 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.

  8. Validation of the FLAGSOL parabolic trough solar power plant performance model

    SciTech Connect

    Price, H.W.; Svoboda, P.; Kearney, D.

    1994-10-01

    This paper describes the results of a validation of the FLAGSOL parabolic trough solar power plant performance model. The validation was accomplished by simulating an operating solar electric generating system (SEGS) parabolic trough solar thermal power plant and comparing the model output results with actual plant operating data. This comparison includes instantaneous, daily, and annual total solar thermal electric output, gross solar electric generation, and solar mode parasitic electric consumption. The results indicate that the FLAGSOL model adequately predicts the gross solar electric output of an operating plant, both on a daily and an annual basis.

  9. Microbiota of Cow’s Milk; Distinguishing Healthy, Sub-Clinically and Clinically Diseased Quarters

    PubMed Central

    Oikonomou, Georgios; Bicalho, Marcela Lucas; Meira, Enoch; Rossi, Rodolfo Elke; Foditsch, Carla; Machado, Vinicius Silva; Teixeira, Andre Gustavo Vieira; Santisteban, Carlos; Schukken, Ynte Hein; Bicalho, Rodrigo Carvalho

    2014-01-01

    The objective of this study was to use pyrosequencing of the 16S rRNA genes to describe the microbial diversity of bovine milk samples derived from clinically unaffected quarters across a range of somatic cell counts (SCC) values or from clinical mastitis, culture negative quarters. The obtained microbiota profiles were used to distinguish healthy, subclinically and clinically affected quarters. Two dairy farms were used for the collection of milk samples. A total of 177 samples were used. Fifty samples derived from healthy, culture negative quarters with a SCC of less than 20,000 cells/ml (group 1); 34 samples derived from healthy, culture negative quarters, with a SCC ranging from 21,000 to 50,000 cells/ml (group 2); 26 samples derived from healthy, culture negative quarters with a SCC greater than 50,000 cells/ml (group 3); 34 samples derived from healthy, culture positive quarters, with a SCC greater than 400,000 (group 4, subclinical); and 33 samples derived from clinical mastitis, culture negative quarters (group 5, clinical). Bacterial DNA was isolated from these samples and the 16S rRNA genes were individually amplified and pyrosequenced. All samples analyzed revealed great microbial diversity. Four bacterial genera were present in every sample obtained from healthy quarters (Faecalibacterium spp., unclassified Lachnospiraceae, Propionibacterium spp. and Aeribacillus spp.). Discriminant analysis models showed that samples derived from healthy quarters were easily discriminated based on their microbiota profiles from samples derived from clinical mastitis, culture negative quarters; that was also the case for samples obtained from different farms. Staphylococcus spp. and Streptococcus spp. were among the most prevalent genera in all groups while a general multivariable linear model revealed that Sphingobacterium and Streptococcus prevalences were associated with increased 10 log SCC. Conversely, Nocardiodes and Paenibacillus were negatively correlated, and a

  10. Life table parameters for tarnished plant bug models

    USDA-ARS?s Scientific Manuscript database

    The tarnished plant bug, Lygus lineolaris (Palisot De Beauvois) is a highly polyphagous insect that feeds on numerous wild and cultivated host plants. Previous papers have reported the survival and developmental times of immature stages of TPB and the fecundity and longevity of adults on various ho...

  11. Palaeogenomics of plants: synteny-based modelling of extinct ancestors.

    PubMed

    Abrouk, Michael; Murat, Florent; Pont, Caroline; Messing, Joachim; Jackson, Scott; Faraut, Thomas; Tannier, Eric; Plomion, Christophe; Cooke, Richard; Feuillet, Catherine; Salse, Jérôme

    2010-09-01

    In the past ten years, international initiatives have led to the development of large sets of genomic resources that allow comparative genomic studies between plant genomes at a high level of resolution. Comparison of map-based genomic sequences revealed shared intra-genomic duplications, providing new insights into the evolution of flowering plant genomes from common ancestors. Plant genomes can be presented as concentric circles, providing a new reference for plant chromosome evolutionary relationships and an efficient tool for gene annotation and cross-genome markers development. Recent palaeogenomic data demonstrate that whole-genome duplications have provided a motor for the evolutionary success of flowering plants over the last 50-70 million years. 2010 Elsevier Ltd. All rights reserved.

  12. Quarter-Filled Honeycomb Lattice with a Quantized Hall Conductance

    NASA Astrophysics Data System (ADS)

    Shimshoni, Efrat; Murthy, Ganpathy; Shankar, Ramamurti; Fertig, Herbert

    2012-02-01

    We study a generic two-dimensional hopping model on a honeycomb lattice with strong spin-orbit coupling, without the requirement that the half-filled lattice be a Topological Insulator. For quarter-(or three-quarter) filling, we show that a state with a quantized Hall conductance generically arises in the presence of a Zeeman field of sufficient strength. We discuss the influence of Hubbard interactions and argue that spontaneous ferromagnetism (which breaks time-reversal) will occur, leading to a quantized anomalous Hall effect. G. Murthy, E. Shimshoni, R. Shankar, and H. A. Fertig, arxiv:1108.2010[cond-mat.mes-hall

  13. Joint Force Quarterly. Issue 52, 1st Quarter, January 2009

    DTIC Science & Technology

    2009-01-01

    Quarter 2009 Inside JFQ dialogue 2 The National Defense Strategy: Striking the Right Balance By Robert M. Gates 8 From the Chairman 10 Open Letter...Striking the Right Balance By R o b e R t M . G a t e s T he defining principle driving our strategy is balance . Balance is not the same as treating all...Resources are scarce, yet we still must set priorities and consider inescapable tradeoffs and opportunity costs. We currently strive for balance

  14. Applied Meteorology Unit (AMU) Quarterly Report Fourth Quarter FY-04

    NASA Technical Reports Server (NTRS)

    Bauman, William; Wheeler, Mark; Lambert, Winifred; Case, Jonathan; Short, David

    2004-01-01

    This report summarizes the Applied Meteorology Unit (A MU) activities for the fourth quarter of Fiscal Year 2004 (July -Sept 2004). Tasks covered are: (1) Objective Lightning Probability Forecast: Phase I, (2) Severe Weather Forecast Decision Aid, (3) Hail Index, (4) Shuttle Ascent Camera Cloud Obstruction Forecast, (5) Advanced Regional Prediction System (ARPS) Optimization and Training Extension and (5) User Control Interface for ARPS Data Analysis System (ADAS) Data Ingest.

  15. Joint Force Quarterly. Issue 63, 4th Quarter 2011

    DTIC Science & Technology

    2011-10-01

    is quoted from or based on its content. COMMUNICATIONS Please visit NDU Press and Joint Force Quarterly online at ndupress.ndu.edu for more on...His final arguments are directed at the noncommissioned officer (NCO) corps (not petty officers), so I would like to know if his data are based ...on his experiences across the Services, or mainly based on his observations and study within his own branch. Though observant of and an occasional

  16. Stability analysis and optimal control of plant fungal epidemic: An explicit model with curative factor

    NASA Astrophysics Data System (ADS)

    Anggriani, N.; Putri, L. Nurul; Supriatna, A. K.

    2015-03-01

    Many plants could not escape from diseases caused by fungi. The use of fungicide can help to reduce the spread of the fungi but if it used continuously with the same dosage, the fungi would be invulnerable to fungicide eventually. Hence, it is critical to know the appropriate level of fungicide application and its impact on the dynamics of the plants. In this paper we use an explicit model of fungal outbreaks of plant by taking into account a curative factor including the dynamic of fungicides itself. Granting of fungicide on crops is useful to control the infected plants as well as protecting the vulnerable plants. Optimal control is used to find out how many doses of the appropriate fungicide should be used to cure infected plants. Optimal control is obtained by applying Pontryagin's Minimum Principle. We found that the presence of appropriate level of fungicide speeds up the reduction of infected plants as well as accelerates the growth of healthy plants.

  17. Development of a CSP plant energy yield calculation tool applying predictive models to analyze plant performance sensitivities

    NASA Astrophysics Data System (ADS)

    Haack, Lukas; Peniche, Ricardo; Sommer, Lutz; Kather, Alfons

    2017-06-01

    At early project stages, the main CSP plant design parameters such as turbine capacity, solar field size, and thermal storage capacity are varied during the techno-economic optimization to determine most suitable plant configurations. In general, a typical meteorological year with at least hourly time resolution is used to analyze each plant configuration. Different software tools are available to simulate the annual energy yield. Software tools offering a thermodynamic modeling approach of the power block and the CSP thermal cycle, such as EBSILONProfessional®, allow a flexible definition of plant topologies. In EBSILON, the thermodynamic equilibrium for each time step is calculated iteratively (quasi steady state), which requires approximately 45 minutes to process one year with hourly time resolution. For better presentation of gradients, 10 min time resolution is recommended, which increases processing time by a factor of 5. Therefore, analyzing a large number of plant sensitivities, as required during the techno-economic optimization procedure, the detailed thermodynamic simulation approach becomes impracticable. Suntrace has developed an in-house CSP-Simulation tool (CSPsim), based on EBSILON and applying predictive models, to approximate the CSP plant performance for central receiver and parabolic trough technology. CSPsim significantly increases the speed of energy yield calculations by factor ≥ 35 and has automated the simulation run of all predefined design configurations in sequential order during the optimization procedure. To develop the predictive models, multiple linear regression techniques and Design of Experiment methods are applied. The annual energy yield and derived LCOE calculated by the predictive model deviates less than ±1.5 % from the thermodynamic simulation in EBSILON and effectively identifies the optimal range of main design parameters for further, more specific analysis.

  18. Evolution of crop production under a pseudo-space environment using model plants, Lotus japonicus

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Motohashi, Kyohei; Omi, Naomi; Sato, Seigo; Aoki, Toshio; Hashimoto, Hirofumi; Yamashita, Masamichi

    Habitation in outer space is one of our challenges. We have been studying space agriculture and/or spacecraft agriculture to provide food and oxygen for the habitation area in the space environment. However, careful investigation should be made concerning the results of exotic environmental effects on the endogenous production of biologically active substances in indi-vidual cultivated plants in a space environment. We have already reported that the production of functional substances in cultivated plants as crops are affected by gravity. The amounts of the main physiological substances in these plants grown under terrestrial control were different from that grown in a pseudo-microgravity. These results suggested that the nutrition would be changed in the plants/crops grown in the space environment when human beings eat in space. This estimation required us to investigate each of the useful components produced by each plant grown in the space environment. These estimations involved several study fields, includ-ing nutrition, plant physiology, etc. On the other hand, the analysis of model plant genomes has recently been remarkably advanced. Lotus japonicus, a leguminous plant, is also one of the model plant. The leguminosae is a large family in the plant vegetable kingdom and almost the entire genome sequence of Lotus japonicus has been determined. Nitrogen fixation would be possible even in a space environment. We are trying to determine the best conditions and evolution for crop production using the model plants.

  19. Model of yield response of corn to plant population and absorption of solar energy.

    PubMed

    Overman, Allen R; Scholtz, Richard V

    2011-01-31

    Biomass yield of agronomic crops is influenced by a number of factors, including crop species, soil type, applied nutrients, water availability, and plant population. This article is focused on dependence of biomass yield (Mg ha(-1) and g plant(-1)) on plant population (plants m(-2)). Analysis includes data from the literature for three independent studies with the warm-season annual corn (Zea mays L.) grown in the United States. Data are analyzed with a simple exponential mathematical model which contains two parameters, viz. Y(m) (Mg ha(-1)) for maximum yield at high plant population and c (m(2) plant(-1)) for the population response coefficient. This analysis leads to a new parameter called characteristic plant population, x(c) = 1/c (plants m(-2)). The model is shown to describe the data rather well for the three field studies. In one study measurements were made of solar radiation at different positions in the plant canopy. The coefficient of absorption of solar energy was assumed to be the same as c and provided a physical basis for the exponential model. The three studies showed no definitive peak in yield with plant population, but generally exhibited asymptotic approach to maximum yield with increased plant population. Values of x(c) were very similar for the three field studies with the same crop species.

  20. Visualized modeling platform for virtual plant growth and monitoring on the internet

    NASA Astrophysics Data System (ADS)

    Zhou, De-fu; Tian, Feng-qui; Ren, Ping

    2009-07-01

    Virtual plant growth is a key research topic in Agriculture Information Technique and Computer Graphics. It has been applied in botany, agronomy, environmental sciences, computre sciences and applied mathematics. Modeling leaf color dynamics in plant is of significant importance for realizing virtual plant growth. Using systematic analysis method and dynamic modeling technology, a SPAD-based leaf color dynamic model was developed to simulate time-course change characters of leaf SPAD on the plant. In addition, process of plant growth can be computer-stimulated using Virtual Reality Modeling Language (VRML) to establish a vivid and visible model, including shooting, rooting, blooming, as well as growth of the stems and leaves. In the resistance environment, e.g., lacking of water, air or nutrient substances, high salt or alkaline, freezing injury, high temperature, suffering from diseases and insect pests, the changes from the level of whole plant to organs, tissues and cells could be computer-stimulated. Changes from physiological and biochemistry could also be described. When a series of indexes were input by the costumers, direct view and microcosmic changes could be shown. Thus, the model has a good performance in predicting growth condition of the plant, laying a foundation for further constructing virtual plant growth system. The results revealed that realistic physiological and pathological processes of 3D virtual plants could be demonstrated by proper design and effectively realized in the internet.