A discrete control model of PLANT

Science.gov (United States)

Mitchell, C. M.

1985-01-01

A model of the PLANT system using the discrete control modeling techniques developed by Miller is described. Discrete control models attempt to represent in a mathematical form how a human operator might decompose a complex system into simpler parts and how the control actions and system configuration are coordinated so that acceptable overall system performance is achieved. Basic questions include knowledge representation, information flow, and decision making in complex systems. The structure of the model is a general hierarchical/heterarchical scheme which structurally accounts for coordination and dynamic focus of attention. Mathematically, the discrete control model is defined in terms of a network of finite state systems. Specifically, the discrete control model accounts for how specific control actions are selected from information about the controlled system, the environment, and the context of the situation. The objective is to provide a plausible and empirically testable accounting and, if possible, explanation of control behavior.

Design process and philosophy of TVA's latest advance control room complex

International Nuclear Information System (INIS)

Owens, G.R.; Masters, D.W.

1979-01-01

TVA's latest nuclear power plant control room design includes a greater emphasis on human factors as compared to their earlier plant designs. This emphasis has resulted in changes in the overall design philosophy and design process. This paper discusses some of the prominent design features of both the control room and the surrounding control room complex. In addition, it also presents some of the important activities involved in the process of developing the advanced control room design

Pythium invasion of plant-based life support systems: biological control and sources

Science.gov (United States)

Jenkins, D. G.; Cook, K. L.; Garland, J. L.; Board, K. F.; Sager, J. C. (Principal Investigator)

2000-01-01

Invasion of plant-based life support systems by plant pathogens could cause plant disease and disruption of life support capability. Root rot caused by the fungus, Pythium, was observed during tests of prototype plant growth systems containing wheat at the Kennedy Space Center (KSC). We conducted experiments to determine if the presence of complex microbial communities in the plant root zone (rhizosphere) resisted invasion by the Pythium species isolated from the wheat root. Rhizosphere inocula of different complexity (as assayed by community-level physiological profile: CLPP) were developed using a dilution/extinction approach, followed by growth in hydroponic rhizosphere. Pythium growth on wheat roots and concomitant decreases in plant growth were inversely related to the complexity of the inocula during 20-day experiments in static hydroponic systems. Pythium was found on the seeds of several different wheat cultivars used in controlled environmental studies, but it is unclear if the seed-borne fungal strain(s) were identical to the pathogenic strain recovered from the KSC studies. Attempts to control pathogens and their effects in hydroponic life support systems should include early inoculation with complex microbial communities, which is consistent with ecological theory.

Distributed control and data processing system with a centralized database for a BWR power plant

International Nuclear Information System (INIS)

Fujii, K.; Neda, T.; Kawamura, A.; Monta, K.; Satoh, K.

1980-01-01

Recent digital techniques based on changes in electronics and computer technologies have realized a very wide scale of computer application to BWR Power Plant control and instrumentation. Multifarious computers, from micro to mega, are introduced separately. And to get better control and instrumentation system performance, hierarchical computer complex system architecture has been developed. This paper addresses the hierarchical computer complex system architecture which enables more efficient introduction of computer systems to a Nuclear Power Plant. Distributed control and processing systems, which are the components of the hierarchical computer complex, are described in some detail, and the database for the hierarchical computer complex is also discussed. The hierarchical computer complex system has been developed and is now in the detailed design stage for actual power plant application. (auth)

Multilevel flow modelling of process plant for diagnosis and control

International Nuclear Information System (INIS)

Lind, M.

1982-08-01

The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as basic for design of control strategies and for the allocation of control tasks to the computer and the plant operator. (author)

Multilevel Flow Modelling of Process Plant for Diagnosis and Control

DEFF Research Database (Denmark)

Lind, Morten

1982-01-01

The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure...... of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant...... operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as a basis for design of control strategies and for the allocation of control tasks to the computer and the plant operator....

Criteria for the design of the control room complex for a nuclear power generating station

International Nuclear Information System (INIS)

Anon.

1981-01-01

This Standard addresses the central control room of a nuclear power generating station and the overall complex in which this room is housed. It is not intended to cover special or normally unattended control rooms, such as those provided for radioactive waste handling or for emergency shutdown operations. The nuclear power generating station control room complex provides a protective envelope for plant operating personnel and for instrument and control equipment vital to the operation of the plant during normal and abnormal conditions. In this capacity, the control room complex must be designed and constructed to meet the following criteria contained in Appendix A of 10CFR50, General Design criteria for Nuclear Power Plants: (1) Criterion 2: design bases for protection against natural phenomena; (2) Criterion 3: fire protection; (3) Criterion 4: environmental and missile design bases; (4) Criterion 5: sharing of structures, systems and components (multiunit stations only); and (5) Criterion 19: control room

Exotic plant species around Jeongeup Research Complex and RFT industrial complex

International Nuclear Information System (INIS)

Kim, Jin Kyu; Cha, Min Kyoung; Ryu, Tae Ho; Lee, Yun Jong; Kim, Jin Hong

2015-01-01

In Shinjeong-dong of Jeongeup, there are three government-supported research institutes and an RFT industrial complex which is currently being established. Increased human activities can affect flora and fauna as a man-made pressure onto the region. As a baseline study, status of exotic plants was investigated prior to a full operation of the RFT industrial complex. A total of 54 species and 1 variety of naturalized or introduced plants were found in the study area. Among them, three species (Ambrosia artemisifolia var. elatior, Rumex acetocella and Aster pilosus) belong to 'nuisance species', and four species (Phytolacca americana, Iopomoea hederacea, Ereechtites hieracifolia and Rudbeckia laciniata) to ‘monitor species’ designated by the ministry of Environment. Some of naturalized trees and plants were intentionally introduced in this area, while others naturally immigrated. Physalis angulata seems to immigrate in the study area in the form of mixture with animal feeds as its distribution coincided with the transportation route of the animal feeds. Liquidambar styraciflua is amenable to the ecological investigation on the possible expansion of the species to the nearby Naejang National Park as its leave shape and autumn color are very similar to those of maple trees. The number of naturalized plants around the RFT industrial complex will increase with an increase in floating population, in human activities in association with constructions of factories and operations of the complex. The result of this study provides baseline data for assessing the ecological change of the region according to the operation of the RFT industrial complex

Exotic plant species around Jeongeup Research Complex and RFT industrial complex

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Kyu; Cha, Min Kyoung; Ryu, Tae Ho; Lee, Yun Jong; Kim, Jin Hong [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

2015-08-15

In Shinjeong-dong of Jeongeup, there are three government-supported research institutes and an RFT industrial complex which is currently being established. Increased human activities can affect flora and fauna as a man-made pressure onto the region. As a baseline study, status of exotic plants was investigated prior to a full operation of the RFT industrial complex. A total of 54 species and 1 variety of naturalized or introduced plants were found in the study area. Among them, three species (Ambrosia artemisifolia var. elatior, Rumex acetocella and Aster pilosus) belong to 'nuisance species', and four species (Phytolacca americana, Iopomoea hederacea, Ereechtites hieracifolia and Rudbeckia laciniata) to ‘monitor species’ designated by the ministry of Environment. Some of naturalized trees and plants were intentionally introduced in this area, while others naturally immigrated. Physalis angulata seems to immigrate in the study area in the form of mixture with animal feeds as its distribution coincided with the transportation route of the animal feeds. Liquidambar styraciflua is amenable to the ecological investigation on the possible expansion of the species to the nearby Naejang National Park as its leave shape and autumn color are very similar to those of maple trees. The number of naturalized plants around the RFT industrial complex will increase with an increase in floating population, in human activities in association with constructions of factories and operations of the complex. The result of this study provides baseline data for assessing the ecological change of the region according to the operation of the RFT industrial complex.

Internal transport control in pot plant production

NARCIS (Netherlands)

Annevelink, E.

1999-01-01

Drawing up internal transport schedules in pot plant production is a very complex task. Scheduling internal transport at the operational level and providing control on a day-to-day or even hour-to-hour basis in particular requires a new approach. A hierarchical planning approach based on

Plant Phenotyping through the Eyes of Complex Systems: Theoretical Considerations

Science.gov (United States)

Kim, J.

2017-12-01

Plant phenotyping is an emerging transdisciplinary research which necessitates not only the communication and collaboration of scientists from different disciplines but also the paradigm shift to a holistic approach. Complex system is defined as a system having a large number of interacting parts (or particles, agents), whose interactions give rise to non-trivial properties like self-organization and emergence. Plant ecosystems are complex systems which are continually morphing dynamical systems, i.e. self-organizing hierarchical open systems. Such systems are composed of many subunits/subsystems with nonlinear interactions and feedback. The throughput such as the flow of energy, matter and information is the key control parameter in complex systems. Information theoretic approaches can be used to understand and identify such interactions, structures and dynamics through reductions in uncertainty (i.e. entropy). The theoretical considerations based on network and thermodynamic thinking and exemplary analyses (e.g. dynamic process network, spectral entropy) of the throughput time series will be presented. These can be used as a framework to develop more discipline-specific fundamental approaches to provide tools for the transferability of traits between measurement scales in plant phenotyping. Acknowledgment: This work was funded by the Weather Information Service Engine Program of the Korea Meteorological Administration under Grant KMIPA-2012-0001.

Advanced control room design for nuclear power plants

International Nuclear Information System (INIS)

Scarola, K.

1987-01-01

The power industry has seen a continuous growth of size and complexity of nuclear power plants. Accompanying these changes have been extensive regulatory requirements resulting in significant construction, operation and maintenance costs. In response to related concerns raised by industry members, Combustion Engineering developed the NUPLEX 80 Advanced Control Room. The goal of NUPLEX 80 TM is to: reduce design and construction costs; increase plant safety and availability through improvements in the man-machine interface; and reduce maintenance costs. This paper provides an overview of the NUPLEX 80 Advanced Control Room and explains how the stated goals are achieved. (author)

Dynamic complexity: plant receptor complexes at the plasma membrane.

Science.gov (United States)

Burkart, Rebecca C; Stahl, Yvonne

2017-12-01

Plant receptor complexes at the cell surface perceive many different external and internal signalling molecules and relay these signals into the cell to regulate development, growth and immunity. Recent progress in the analyses of receptor complexes using different live cell imaging approaches have shown that receptor complex formation and composition are dynamic and take place at specific microdomains at the plasma membrane. In this review we focus on three prominent examples of Arabidopsis thaliana receptor complexes and how their dynamic spatio-temporal distribution at the PM has been studied recently. We will elaborate on the newly emerging concept of plasma membrane microdomains as potential hubs for specific receptor complex assembly and signalling outputs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Perception of tomorrow's nuclear power plant control rooms

International Nuclear Information System (INIS)

Meyer, O.R.

1986-01-01

Major development programs are upgrading today's light water reactor nuclear power plant (NPP) control rooms. These programs involve displays, control panel architecture, procedures, staffing, and training, and are supported by analytical efforts to refine the definitions of the dynamics and the functional requirements of NPP operation. These programs demonstrate that the NPP control room is the visible command/control/communications center of the complex man/machine system that operates the plant. These development programs are primarily plant specific, although the owners' groups and the Institute of Nuclear Power Operations (INPO) do provide some standardization. The Idaho National Engineering Laboratory recently completed a project to categorize control room changes and estimate the degree of change. That project, plus related studies, provides the basis for this image of the next generation of NPP control rooms. The next generation of NPP control rooms is envisioned as being dominated by three current trends: (1) application of state-of-the-art computer hardware and software; (2) use of NPP dynamic analyses to provide the basis for the control room man/machine system design; and (3) application of empirical principles of human performance

Man-machine considerations in nuclear power plant control room design

International Nuclear Information System (INIS)

Tennant, D.V.

1987-01-01

Although human factors is a subject that has been around for a number of years, this area of design has only recently become known to the power industry. As power plants have grown in size and complexity, the instrumentation required to control and monitor plant processes has increased tremendously. This has been especially true in nuclear power facilities. Although operators are better trained and qualified, very little consideration has been devoted to man-machine interface and the limitations of human operators. This paper explores the historic aspects and design philosophy associated with nuclear plant control rooms. Current problems and solutions are explored along with the components of a control room review. Finally, a survey of future advances in control room design are offered. This paper is concerned with instrumentation, controls, and displays

An Assessment of Wind Plant Complex Flows Using Advanced Doppler Radar Measurements

Science.gov (United States)

Gunter, W. S.; Schroeder, J.; Hirth, B.; Duncan, J.; Guynes, J.

2015-12-01

As installed wind energy capacity continues to steadily increase, the need for comprehensive measurements of wind plant complex flows to further reduce the cost of wind energy has been well advertised by the industry as a whole. Such measurements serve diverse perspectives including resource assessment, turbine inflow and power curve validation, wake and wind plant layout model verification, operations and maintenance, and the development of future advanced wind plant control schemes. While various measurement devices have been matured for wind energy applications (e.g. meteorological towers, LIDAR, SODAR), this presentation will focus on the use of advanced Doppler radar systems to observe the complex wind flows within and surrounding wind plants. Advanced Doppler radars can provide the combined advantage of a large analysis footprint (tens of square kilometers) with rapid data analysis updates (a few seconds to one minute) using both single- and dual-Doppler data collection methods. This presentation demonstrates the utility of measurements collected by the Texas Tech University Ka-band (TTUKa) radars to identify complex wind flows occurring within and nearby operational wind plants, and provide reliable forecasts of wind speeds and directions at given locations (i.e. turbine or instrumented tower sites) 45+ seconds in advance. Radar-derived wind maps reveal commonly observed features such as turbine wakes and turbine-to-turbine interaction, high momentum wind speed channels between turbine wakes, turbine array edge effects, transient boundary layer flow structures (such as wind streaks, frontal boundaries, etc.), and the impact of local terrain. Operational turbine or instrumented tower data are merged with the radar analysis to link the observed complex flow features to turbine and wind plant performance.

Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity.

Science.gov (United States)

Stefanaki, Anastasia; Kantsa, Aphrodite; Tscheulin, Thomas; Charitonidou, Martha; Petanidou, Theodora

2015-01-01

The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant's proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant-pollinator specializations to identify plant species particularly at

Biological significance of complex N-glycans in plants and their impact on plant physiology.

Science.gov (United States)

Strasser, Richard

2014-01-01

Asparagine (N)-linked protein glycosylation is a ubiquitous co- and post-translational modification which can alter the biological function of proteins and consequently affects the development, growth, and physiology of organisms. Despite an increasing knowledge of N-glycan biosynthesis and processing, we still understand very little about the biological function of individual N-glycan structures in plants. In particular, the N-glycan-processing steps mediated by Golgi-resident enzymes create a structurally diverse set of protein-linked carbohydrate structures. Some of these complex N-glycan modifications like the presence of β1,2-xylose, core α1,3-fucose or the Lewis a-epitope are characteristic for plants and are evolutionary highly conserved. In mammals, complex N-glycans are involved in different cellular processes including molecular recognition and signaling events. In contrast, the complex N-glycan function is still largely unknown in plants. Here, in this short review, I focus on important recent developments and discuss their implications for future research in plant glycobiology and plant biotechnology.

Plant Mediator complex and its critical functions in transcription regulation.

Science.gov (United States)

Yang, Yan; Li, Ling; Qu, Li-Jia

2016-02-01

The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to genes involved in different pathways. The plant Mediator complex was recently purified and comprises conserved and specific subunits. It functions in concert with transcription factors to modulate various responses. In this review, we summarize the recent advances in understanding the plant Mediator complex and its diverse roles in plant growth, development, defense, non-coding RNA production, response to abiotic stresses, flowering, genomic stability and metabolic homeostasis. In addition, the transcription factors interacting with the Mediator complex are also highlighted. © 2015 Institute of Botany, Chinese Academy of Sciences.

Effect evaluation of carbendazim-β-ciclodextrin complex for controling filamentous contaminants of plant in vitro cultura

Directory of Open Access Journals (Sweden)

Mileidy Cruz-Martín

2002-04-01

Full Text Available The majority of in vitro contaminant microorganisms affecting plant in vitro culture are bacterias and fungus. These are commonly observed in vivo on plants, but they could cause harmful effect on plant propagated in vitro. The search of new alternatives for their prevention and control is a priority. Carbendazim is the active ingredient of some systemic fungicides, it´s application for fungus contamination on in vitro propagation of plant it has been constrained for their lowsolubilityonwater.Thisproblemcouldbesolvedbycombiningthisproductwitha β-ciclodextrina.Thispaperwas focusedtodeterminetheeffectofcarbendazim-β-ciclodextrinaversusthecontaminantfungiofplantinvitroculture. It was determined the Minimum Inhibitory Concentration (MIC by the agar dilution method. Thirty four strains were analysed.Thecarbendazim-β-ciclodextrinacomplexshowedanacceptableantifungalactivityversuscontaminant. This result could be an useful alternative to control the fungi contamination on plant propagated in vitro. Key words: fungal contamination, antifungal compounds, minimum inhibitory concentration

Recent control and instrumentation systems for BWR nuclear power plant

International Nuclear Information System (INIS)

Fujii, Hiroaki; Higashikawa, Yuichi; Sato, Hideyuki

1990-01-01

For the needs of the more stable operation of nuclear power stations, the upgrading of the measurement and control system for BWRs has been promoted by positively introducing remarkably advancing electronic technology. Further, it is aimed at to construct the synthetic digitized measurement and control system for nuclear power stations to heighten the operation reliability in ABWRs. As the first step of the development in the synthetic digitization, the monitoring and control system for radioactive waste treatment was put in practical use for No.5 plant of Kashiwazaki, Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. Hitachi Ltd. has promoted the development and the application to actual plants of the measurement and control system for BWRs, in which digital control technology, optical information transmission technology and the operation-supporting technology using a computer were utilized. Hereafter, it is intended to expand the application of digital measurement and control aiming at improving the reliability, operation performance and maintainability. The nuclear power plant control complex with advanced man-machine interface-90 (NUCAMM-90) was developed, and its application to actual plants is planned. (K.I.)

Composition of the SAGA complex in plants and its role in controlling gene expression in response to abiotic stresses.

Directory of Open Access Journals (Sweden)

Felipe eMoraga

2015-10-01

Full Text Available Protein complexes involved in epigenetic regulation of transcription have evolved as molecular strategies to face environmental stress in plants. SAGA (Spt–Ada–Gcn5 Acetyltransferase is a transcriptional co-activator complex that regulates numerous cellular processes through the coordination of multiple post-translational histone modifications, including acetylation, deubiquitination, and chromatin recognition. The diverse functions of the SAGA complex involve distinct modules that are highly conserved between yeast, flies, and mammals. In this review, the composition of the SAGA complex in plants is described and its role in gene expression regulation under stress conditions summarized. Some of these proteins are likely involved in the regulation of the inducible expression of genes under light, cold, drought, salt, and iron stress, although the functions of several of its components remain unknown.

Balancing the roles of humans and machines in power plant control

International Nuclear Information System (INIS)

Lipsett, J.J.

1989-05-01

A number of factors are leading to a re-examination of the balance between the roles of the operators and the machine in controlling nuclear power plants. Some of these factors are: the advent of new and advanced computer technologies; increased plant complexity, placing heavy workloads and stress on the control room operator; and increasing concerns about the role of human reliability in industrial mishaps. In light of the changing control aspects, we examine the meaning of automation, we discuss a proposed model of the control process, the concept of control within a few defined reactor states, a decision-making sequence; and we identify some possible problem areas in implementing new control technologies. Significant benefits should come from the new control methods and these opportunities should be exploited as soon as prudence allows, taking great care that the safety of the plants is improved

Optimization of controlled processes in combined-cycle plant (new developments and researches)

Science.gov (United States)

Tverskoy, Yu S.; Muravev, I. K.

2017-11-01

All modern complex technical systems, including power units of TPP and nuclear power plants, work in the system-forming structure of multifunctional APCS. The development of the modern APCS mathematical support allows bringing the automation degree to the solution of complex optimization problems of equipment heat-mass-exchange processes in real time. The difficulty of efficient management of a binary power unit is related to the need to solve jointly at least three problems. The first problem is related to the physical issues of combined-cycle technologies. The second problem is determined by the criticality of the CCGT operation to changes in the regime and climatic factors. The third problem is related to a precise description of a vector of controlled coordinates of a complex technological object. To obtain a joint solution of this complex of interconnected problems, the methodology of generalized thermodynamic analysis, methods of the theory of automatic control and mathematical modeling are used. In the present report, results of new developments and studies are shown. These results allow improving the principles of process control and the automatic control systems structural synthesis of power units with combined-cycle plants that provide attainable technical and economic efficiency and operational reliability of equipment.

Dipping Strawberry Plants in Fungicides before Planting to Control Anthracnose

Directory of Open Access Journals (Sweden)

Myeong Hyeon Nam

2014-03-01

Full Text Available Anthracnose crown rot (ACR, caused by Colletotrichum fructicola, is a serious disease of strawberry in Korea. The primary inoculums of ACR were symptomless strawberry plants, plant debris, and other host plants. To effectively control anthracnose in symptomless transplanted strawberries, it is necessary to use diseasefree plants, detect the disease early, and apply a fungicide. Therefore, in 2010 and 2011, we evaluated the efficacy of pre-plant fungicide dips by using strawberry transplants infected by C. fructicola for the control of anthracnose. Dipping plants in prochloraz-Mn for 10 min before planting was most effective for controlling anthracnose in symptomless strawberry plants and resulted in more than 76% control efficacy. Azoxystrobin showed a control efficacy of over 40%, but plants treated with pyraclostrobin, mancozeb and iminoctadine tris showed high disease severity. The control efficacy of the dip treatment with prochloraz-Mn did not differ with temperature and time. Treatment with prochloraz-Mn for more than an hour caused growth suppression in strawberry plants. Therefore, the development of anthracnose can be effectively reduced by dipping strawberry plants for 10 min in prochloraz-Mn before planting.

Virtual reality applied in the ergonomic evaluation of nuclear power plant control room

International Nuclear Information System (INIS)

Gatto, Leandro Barbosa da Silveira

2012-01-01

A nuclear power plant control room is a complex system that controls a nuclear and thermodynamic process used to produce electrical energy. The operators interact with the control room through interfaces that have significant implications to nuclear power plant safety and influence the operator activity. The operator activity presents complexity features and shows a series of mechanisms absents from the human factors guidelines, important to the evaluation and update of control rooms. The ergonomics approach considers the operation strategies, the interaction between the operators, the operator-system interaction, and interaction between operators and support groups. The main objective of this paper is propose the modeling of a nuclear control room, with the support of a game engine core. This tool will be used in the ergonomic evaluation of nuclear control room, generating information and data that will make possible the adequacy of control rooms features to the legal requirements of the regulating agency, assisting the nuclear licensing. (author)

Functional genomics tools applied to plant metabolism: a survey on plant respiration, its connections and the annotation of complex gene functions

Directory of Open Access Journals (Sweden)

Wagner L. Araújo

2012-09-01

Full Text Available The application of post-genomic techniques in plant respiration studies has greatly improved our ability to assign functions to gene products. In addition it has also revealed previously unappreciated interactions between distal elements of metabolism. Such results have reinforced the need to consider plant respiratory metabolism as part of a complex network and making sense of such interactions will ultimately require the construction of predictive and mechanistic models. Transcriptomics, proteomics, metabolomics and the quantification of metabolic flux will be of great value in creating such models both by facilitating the annotation of complex gene function, determining their structure and by furnishing the quantitative data required to test them. In this review we highlight how these experimental approaches have contributed to our current understanding of plant respiratory metabolism and its interplay with associated process (e.g. photosynthesis, photorespiration and nitrogen metabolism. We also discuss how data from these techniques may be integrated, with the ultimate aim of identifying mechanisms that control and regulate plant respiration and discovering novel gene functions with potential biotechnological implications.

Does plant architectural complexity increase with increasing habitat complexity? A test with a pioneer shrub in the Brazilian Cerrado

Directory of Open Access Journals (Sweden)

FAO Silveira

Full Text Available Understanding variation in plant traits in heterogeneous habitats is important to predict responses to changing environments, but trait-environment associations are poorly known along ecological gradients. We tested the hypothesis that plant architectural complexity increases with habitat complexity along a soil fertility gradient in a Cerrado (Neotropical savanna area in southeastern Brazil. Plant architecture and productivity (estimated as the total number of healthy infructescences of Miconia albicans (SW. Triana were examined in three types of vegetation which together form a natural gradient of increasing soil fertility, tree density and canopy cover: grasslands (campo sujo, CS, shrublands (cerrado sensu strico, CE and woodlands (cerradão, CD. As expected, plants growing at the CS were shorter and had a lower branching pattern, whereas plants at the CD were the tallest. Unexpectedly, however, CD plants did not show higher architectural complexity compared to CE plants. Higher architectural similarity between CE and CD plants compared to similarity between CS and CE plants suggests reduced expression of functional architectural traits under shade. Plants growing at the CE produced more quaternary shoots, leading to a larger number of infructescences. This higher plant productivity in CE indicates that trait variation in ecological gradients is more complex than previously thought. Nematode-induced galls accounted for fruit destruction in 76.5% infructescences across physiognomies, but percentage of attack was poorly related to architectural variables. Our data suggest shade-induced limitation in M. albicans architecture, and point to complex phenotypic variation in heterogeneous habitats in Neotropical savannas.

Trophic complexity and the adaptive value of damage-induced plant volatiles.

Directory of Open Access Journals (Sweden)

Ian Kaplan

Full Text Available Indirect plant defenses are those facilitating the action of carnivores in ridding plants of their herbivorous consumers, as opposed to directly poisoning or repelling them. Of the numerous and diverse indirect defensive strategies employed by plants, inducible volatile production has garnered the most fascination among plant-insect ecologists. These volatile chemicals are emitted in response to feeding by herbivorous arthropods and serve to guide predators and parasitic wasps to their prey. Implicit in virtually all discussions of plant volatile-carnivore interactions is the premise that plants "call for help" to bodyguards that serve to boost plant fitness by limiting herbivore damage. This, by necessity, assumes a three-trophic level food chain where carnivores benefit plants, a theoretical framework that is conceptually tractable and convenient, but poorly depicts the complexity of food-web dynamics occurring in real communities. Recent work suggests that hyperparasitoids, top consumers acting from the fourth trophic level, exploit the same plant volatile cues used by third trophic level carnivores. Further, hyperparasitoids shift their foraging preferences, specifically cueing in to the odor profile of a plant being damaged by a parasitized herbivore that contains their host compared with damage from an unparasitized herbivore. If this outcome is broadly representative of plant-insect food webs at large, it suggests that damage-induced volatiles may not always be beneficial to plants with major implications for the evolution of anti-herbivore defense and manipulating plant traits to improve biological control in agricultural crops.

Concept and structure of instrumentation and control of the Atucha II nuclear power plant

International Nuclear Information System (INIS)

Garzon, D.; Roca, J.L.

1987-01-01

The general structure of instrumentation and control of Atucha II nuclear power plant as well as the technologies used, are described: concepts of functional decentralization and physical centralization; concept of functional group and functional complex; description of the technologies used (physical support) in the project of plant instrumentation and control; description of the different automation levels on the basis of concepts of control interface, automatism, regulation, group and subgroup controls; principles of signal conditioning; concept of announcement of alarms and state: supervisory computer, description of HAS (Hard wired Alarm System) and CAS (Computer Alarm System); application of the above mentioned structure to the project of another type of plants. (Author)

On fuzzy control of water desalination plants

Energy Technology Data Exchange (ETDEWEB)

Titli, A. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France); Jamshidi, M. [New Mexico Univ., Albuquerque, NM (United States); Olafsson, F. [Institute of Technology, Norway (Norway)

1995-12-31

In this report we have chosen a sub-system of an MSF water desalination plant, the brine heater, for analysis, synthesis, and simulation. This system has been modelled and implemented on computer. A fuzzy logic controller (FLC) for the top brine temperature control loop has been designed and implemented on the computer. The performance of the proposed FLC is compared with three other conventional control strategies: PID, cascade and disturbance rejection control. One major concern on FLC`s has been the lack of stability criteria. An up to-date survey of stability of fuzzy control systems is given. We have shown stability of the proposed FLC using the Sinusoidal Input Describing Functions (SIDF) method. The potential applications of fuzzy controllers for complex and large-scale systems through hierarchy of rule sets and hybridization with conventional approaches are also investigated. (authors)

On fuzzy control of water desalination plants

Energy Technology Data Exchange (ETDEWEB)

Titli, A [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France); Jamshidi, M [New Mexico Univ., Albuquerque, NM (United States); Olafsson, F [Institute of Technology, Norway (Norway)

1996-12-31

In this report we have chosen a sub-system of an MSF water desalination plant, the brine heater, for analysis, synthesis, and simulation. This system has been modelled and implemented on computer. A fuzzy logic controller (FLC) for the top brine temperature control loop has been designed and implemented on the computer. The performance of the proposed FLC is compared with three other conventional control strategies: PID, cascade and disturbance rejection control. One major concern on FLC`s has been the lack of stability criteria. An up to-date survey of stability of fuzzy control systems is given. We have shown stability of the proposed FLC using the Sinusoidal Input Describing Functions (SIDF) method. The potential applications of fuzzy controllers for complex and large-scale systems through hierarchy of rule sets and hybridization with conventional approaches are also investigated. (authors)

Demonstration of a Porous Tube Hydroponic System to Control Plant Moisture and Growth

Science.gov (United States)

Dreschel, T. W.; Hall, C. R.; Foster, T. E.

2003-01-01

Accurate remote detection of plant health indicators such as moisture, plant pigment concentrations, photosynthetic flux, and other biochemicals in canopies is a major goal in plant research. Influencing factors include complex interactions between wavelength dependent absorbing and scattering features from backgrounds as well as canopy biochemical and biophysical constituents. Accurately controlling these factors in outdoor field studies is difficult. Early testing of a porous tube plant culture system has indicated that plant biomass production, biomass partitioning, and leaf moisture of plants can be controlled by precisely managing the root water potential. Managing nutrient solution chemistry can also control plant pigments, biochemical concentrations, plant biomass production, and photosynthetic rates. A test bed was developed which utilized the porous tube technology with the intent of evaluating remote sensing systems, spectral analyses procedures, gas-exchange, and fluorescence measurements for their ability to detect small differences in plant water status. Spectral analysis was able to detect small differences in the mean leaf water content between the treatments. However these small differences were not detectable in the gas-exchange or fluorescence measurements.

Methodology for risk-based configuration control of nuclear power plant operation

International Nuclear Information System (INIS)

Valle, Antonio Torres; Oliva, Jose de Jesus Rivero

2012-01-01

The hazardous configurations control in Nuclear Power Plants is an application of a previous Probabilistic Safety Analysis (PSA). A more complete option would be the risk monitoring for the online detection of these configurations but expert personnel would be required to deal with the complexities of PSA and risk monitor. The paper presents a simpler but effective approach: a method of configuration control, based on dependencies matrixes. The algorithm is included in a computer code called SECURE A-Z. The configuration control is carried out in a qualitative way, without previous PSA results and not using a Risk Monitor. The simplicity of the method warrants its application to facilities where these tools have not been developed, allowing the detection of hazardous configurations during operation and increasing plant safety. This configuration control system was implemented in the Embalse Nuclear Power Plant in Argentina. The paper shows the application of the algorithm to the analysis of a simplified safety system. (author)

Model-based reasoning and the control of process plants

International Nuclear Information System (INIS)

Vaelisuo, Heikki

1993-02-01

In addition to feedback control, safe and economic operation of industrial process plants requires discrete-event type logic control like for example automatic control sequences, interlocks, etc. A lot of complex routine reasoning is involved in the design and verification and validation (VandV) of such automatics. Similar reasoning tasks are encountered during plant operation in action planning and fault diagnosis. The low-level part of the required problem solving is so straightforward that it could be accomplished by a computer if only there were plant models which allow versatile mechanised reasoning. Such plant models and corresponding inference algorithms are the main subject of this report. Deep knowledge and qualitative modelling play an essential role in this work. Deep knowledge refers to mechanised reasoning based on the first principles of the phenomena in the problem domain. Qualitative modelling refers to knowledge representation formalism and related reasoning methods which allow solving problems on an abstraction level higher than for example traditional simulation and optimisation. Prolog is a commonly used platform for artificial intelligence (Al) applications. Constraint logic languages like CLP(R) and Prolog-III extend the scope of logic programming to numeric problem solving. In addition they allow a programming style which often reduces the computational complexity significantly. An approach to model-based reasoning implemented in constraint logic programming language CLP(R) is presented. The approach is based on some of the principles of QSIM, an algorithm for qualitative simulation. It is discussed how model-based reasoning can be applied in the design and VandV of plant automatics and in action planning during plant operation. A prototype tool called ISIR is discussed and some initial results obtained during the development of the tool are presented. The results presented originate from preliminary test results of the prototype obtained

Control oriented concentrating solar power (CSP) plant model and its applications

Science.gov (United States)

Luo, Qi

Solar receivers in concentrating solar thermal power plants (CSP) undergo over 10,000 start-ups and shutdowns, and over 25,000 rapid rate of change in temperature on receivers due to cloud transients resulting in performance degradation and material fatigue in their expected lifetime of over 30 years. The research proposes to develop a three-level controller that uses multi-input-multi-output (MIMO) control technology to minimize the effect of these disturbances, improve plant performance, and extend plant life. The controller can be readily installed on any vendor supplied state-of-the-art control hardware. We propose a three-level controller architecture using multi-input-multi-output (MIMO) control for CSP plants that can be implemented on existing plants to improve performance, reliability, and extend the life of the plant. This architecture optimizes the performance on multiple time scalesreactive level (regulation to temperature set points), tactical level (adaptation of temperature set points), and strategic level (trading off fatigue life due to thermal cycling and current production). This controller unique to CSP plants operating at temperatures greater than 550 °C, will make CSPs competitive with conventional power plants and contribute significantly towards the Sunshot goal of 0.06/kWh(e), while responding with agility to both market dynamics and changes in solar irradiance such as due to passing clouds. Moreover, our development of control software with performance guarantees will avoid early stage failures and permit smooth grid integration of the CSP power plants. The proposed controller can be implemented with existing control hardware infrastructure with little or no additional equipment. In the thesis, we demonstrate a dynamics model of CSP, of which different components are modelled with different time scales. We also show a real time control strategy of CSP control oriented model in steady state. Furthermore, we shown different controllers

Application of Multivariable Statistical Techniques in Plant-wide WWTP Control Strategies Analysis

DEFF Research Database (Denmark)

Flores Alsina, Xavier; Comas, J.; Rodríguez-Roda, I.

2007-01-01

The main objective of this paper is to present the application of selected multivariable statistical techniques in plant-wide wastewater treatment plant (WWTP) control strategies analysis. In this study, cluster analysis (CA), principal component analysis/factor analysis (PCA/FA) and discriminant...... analysis (DA) are applied to the evaluation matrix data set obtained by simulation of several control strategies applied to the plant-wide IWA Benchmark Simulation Model No 2 (BSM2). These techniques allow i) to determine natural groups or clusters of control strategies with a similar behaviour, ii......) to find and interpret hidden, complex and casual relation features in the data set and iii) to identify important discriminant variables within the groups found by the cluster analysis. This study illustrates the usefulness of multivariable statistical techniques for both analysis and interpretation...

Multi-criteria evaluation of wastewater treatment plant control strategies under uncertainty

DEFF Research Database (Denmark)

Flores Alsina, Xavier; Rodriguez-Roda, Ignasi; Sin, Gürkan

2008-01-01

The evaluation of activated sludge control strategies in wastewater treatment plants (WWTP) via mathematical modelling is a complex activity because several objectives; e.g. economic, environmental, technical and legal; must be taken into account at the same time, i.e. the evaluation of the alter...

Evolved Control of Natural Plants: Crossing the Reality Gap for User-Defined Steering of Growth and Motion

DEFF Research Database (Denmark)

Hofstadler, Daniel Nicolas; Wahby, Mostafa; Heinrich, Mary Katherine

2017-01-01

Mixing societies of natural and artificial systems can provide interesting and potentially fruitful research targets. Here we mix robotic setups and natural plants in order to steer the motion behavior of plants while growing. The robotic setup uses a camera to observe the plant and uses a pair...... of light sources to trigger phototropic response, steering the plant to user-defined targets. An evolutionary robotic approach is used to design a controller for the setup. Initially, preliminary experiments are performed with a simple predetermined controller and a growing bean plant. The plant behavior......-evolved controller in the real setup controlling a natural bean plant. The results demonstrate a successful crossing of the reality gap in the setup. The success of the approach allows for future extensions to more complex tasks including control of the shape of plants and pattern formation in multiple plant setups....

Control and decision strategies in wastewater treatment plants for operation improvement

CERN Document Server

Santín, Ignacio; Vilanova, Ramón

2017-01-01

This book examines the operation of biological wastewater treatment plants (WWTPs), with a focus on maintaining effluent water quality while keeping operational costs within constrained limits. It includes control operation and decision schemes and is based on the use of benchmarking scenarios that yield easily reproducible results that readers can implement for their own solutions. The final criterion is the effect of the applied control strategy on plant performance – specifically, improving effluent quality, reducing costs and avoiding violations of established effluent limits. The evaluation of the different control strategies is achieved with the help of two Benchmark Simulation Models (BSM1, BSM2). Given the complexity of the biological and biochemical processes involved and the major fluctuations in the influent flow rate, controlling WWTPs poses a serious challenge. Further, the importance of control goal formulation and control structure design in relation to WWTP process control is widely recogniz...

Quantification of complex modular architecture in plants.

Science.gov (United States)

Reeb, Catherine; Kaandorp, Jaap; Jansson, Fredrik; Puillandre, Nicolas; Dubuisson, Jean-Yves; Cornette, Raphaël; Jabbour, Florian; Coudert, Yoan; Patiño, Jairo; Flot, Jean-François; Vanderpoorten, Alain

2018-04-01

Morphometrics, the assignment of quantities to biological shapes, is a powerful tool to address taxonomic, evolutionary, functional and developmental questions. We propose a novel method for shape quantification of complex modular architecture in thalloid plants, whose extremely reduced morphologies, combined with the lack of a formal framework for thallus description, have long rendered taxonomic and evolutionary studies extremely challenging. Using graph theory, thalli are described as hierarchical series of nodes and edges, allowing for accurate, homologous and repeatable measurements of widths, lengths and angles. The computer program MorphoSnake was developed to extract the skeleton and contours of a thallus and automatically acquire, at each level of organization, width, length, angle and sinuosity measurements. Through the quantification of leaf architecture in Hymenophyllum ferns (Polypodiopsida) and a fully worked example of integrative taxonomy in the taxonomically challenging thalloid liverwort genus Riccardia, we show that MorphoSnake is applicable to all ramified plants. This new possibility of acquiring large numbers of quantitative traits in plants with complex modular architectures opens new perspectives of applications, from the development of rapid species identification tools to evolutionary analyses of adaptive plasticity. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Cascade plant control by timer method

International Nuclear Information System (INIS)

Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

1970-01-01

The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

Deep Plant Phenomics: A Deep Learning Platform for Complex Plant Phenotyping Tasks

Science.gov (United States)

Ubbens, Jordan R.; Stavness, Ian

2017-01-01

Plant phenomics has received increasing interest in recent years in an attempt to bridge the genotype-to-phenotype knowledge gap. There is a need for expanded high-throughput phenotyping capabilities to keep up with an increasing amount of data from high-dimensional imaging sensors and the desire to measure more complex phenotypic traits (Knecht et al., 2016). In this paper, we introduce an open-source deep learning tool called Deep Plant Phenomics. This tool provides pre-trained neural networks for several common plant phenotyping tasks, as well as an easy platform that can be used by plant scientists to train models for their own phenotyping applications. We report performance results on three plant phenotyping benchmarks from the literature, including state of the art performance on leaf counting, as well as the first published results for the mutant classification and age regression tasks for Arabidopsis thaliana. PMID:28736569

Design and implementation of the control system for nuclear plant VVER-1000. Instrumentation (program technical complexes)

International Nuclear Information System (INIS)

Siora, A.; Tokarev, V.; Bakhmach, E.

2004-01-01

Program-technical complexes (PTC) are designed as control and protection systems in water-moderated atomic reactors, including emergency and preventive systems, automatic control, unloading, reactor capacity limitation and accelerated preventive protection systems. Utilization of programmable logic integrated circuits from world leading manufacturers makes the complexes simple in structure, compact, with low energy demands and mutually independent for key and supporting functions The results of PTC assessment and implementation in Ukraine are outlined. Opportunities for a future development of RADIJ company in the area of control and protection systems for VVER reactors are also discussed

Methodology for allocating nuclear power plant control functions to human or automatic control

International Nuclear Information System (INIS)

Pulliam, R.; Price, H.E.; Bongarra, J.; Sawyer, C.R.; Kisner, R.A.

1983-08-01

This report describes a general method for allocating control functions to man or machine during nuclear power plant (NPP) design, or for evaluating their allocation in an existing design. The research examined some important characeristics of the systems design process, and the results make it clear that allocation of control functions is an intractable problem, one which increases complexity of systems. The method is reported in terms of specific steps which should be taken during early stages of a new system design, and which will lead to an optimal allocation at the functional design level of detail

Hybrid Model Predictive Control as a LFC solution in Hydropower Plants

Directory of Open Access Journals (Sweden)

Donaisky Emerson

2015-01-01

Full Text Available For Electric Power System safety and stable operation, planning and analysis by using simulation environments are necessary. An important point for frequency stability analysis is, on one hand, an adequate representation of Load-Frequency Control (LFC loops and, on the other hand, the design of advanced control strategies to deal with the power system dynamic complexity. Therefore, in this paper we propose to represent the group turbine/penstock, found in hydropower plants, in a Piecewise Affine (PWA modelling structure. Based on such modelling, we also propose the use of a Hybrid Model Predictive algorithm to be use as a control law in LFC loops. Among the advantages of this PWA representation is the use of this model in the controller algorithm, thereby improving the Load-Frequency Control performance. Simulation results, on a 200 MW hydropower plant compares the performance of predictive control strategy presented with the classical PID control strategy in an isolated condition.

Model-Based Power Plant Master Control

Energy Technology Data Exchange (ETDEWEB)

Boman, Katarina; Thomas, Jean; Funkquist, Jonas

2010-08-15

The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

Complex nuclear safety evaluation of the Bohunice V-1 nuclear power plant

International Nuclear Information System (INIS)

Kriz, Z.

1991-01-01

The safety concept of V-230 type reactor units dates back to the late 1960s. The units fail to be sufficiently dimensioned for emergency cooling of the reactor core and are fitted with no containment. So far, operating experience is good. The availability factor is 71.5% for unit 1 and 77.8% for unit 2. There occur 1 to 3 unscheduled shutdowns annually. The quality of steam generator tubes is very good. A complex safety assessment of the plant was accomplished in 1990. It concerned the concept and criteria of safety assessment, the earthquake situation, the condition of the primary coolant circuit equipment, the control system, the effect of the human factor, and preparedness of emergency plans. OSART and ASSET missions were accomplished at the plant. Based on the results of the missions as well as of inspections by the State Surveillance over Nuclear Safety, the decision has been adopted to operate the plant not longer than till 1995; the further fate of the plant will be decided on according to a future technical and economic analysis. (M.D.)

Design and simulation of a plant control system for a GCFR demonstration plant

International Nuclear Information System (INIS)

Estrine, E.A.; Greiner, H.G.

1980-02-01

A plant control system is being designed for a 300 MW(e) Gas Cooled Fast Breeder Reactor (GCFR) demonstration plant. Control analysis is being performed as an integral part of the plant design process to ensure that control requirements are satisfied as the plant design evolves. Plant models and simulations are being developed to generate information necessary to further define control system requirements for subsequent plant design iterations

Awarable complexity: a study on CRT picture design based on plant images by NPP operators

International Nuclear Information System (INIS)

Kawano, Ryutaro; Ohtsuka, Tsutomu; Masugi, Tsuyoshi

2000-01-01

Original pictures installed in the 1st and 2nd generation type central control panels (CCP) and new 'Awarable and Complex' pictures were made on personal computers and evaluated. A total 18 of actual plant operators (M=32.3, SD=10.5 years old) participated in the evaluation. The operators rated the new CRT pictures highly. The response times using the new CRT pictures were shorter than those by the original pictures. Both results suggested that the CRT picture design guidelines based on the operators' plant images were effective for improving their performance. (author)

Operation control device for nuclear power plants

International Nuclear Information System (INIS)

Suto, Osamu.

1982-01-01

Purpose: To render the controlling functions of a central control console more centralized by constituting the operation controls for a nuclear power plant with computer systems having substantially independent functions such as those of plant monitor controls, reactor monitor management and CRT display and decreasing interactions between each of the systems. Constitution: An input/output device for the input of process data for a nuclear power plant and indication data for a plant control console is connected to a plant supervisory and control computer system and a display computer system, the plant supervisory control computer system and a reactor and management computer system are connected with a CRT display control device, a printer and a CRT display input/output device, and the display computer system is connected with the CRT display control device and the CRT display unit on the central control console, whereby process input can be processed and displayed at high speed. (Yoshino, Y.)

Structure and function of complex carbohydrates active in regulating plant-microbe interactions

Energy Technology Data Exchange (ETDEWEB)

Albersheim, P; Darvill, A G; McNeil, M

1981-01-01

A key regulatory role of complex carbohydrates in the interactions between plants and microbes has been established. The complex carbohydrates act as regulatory molecules or hormones in that the carbohydrates induce de novo protein synthesis in receptive cells. The first complex carbohydrate recognized to possess such regulatory properties is a polysaccharide (PS) present in the walls of fungi. Hormonal concentrations of this PS elicit plant cells to accumulate phytoalexins (antibiotics). More recently we have recognized that a PS in the walls of growing plant cells also elicits phytoalexin accumulation; microbes and viruses may cause the release of active fragments of this endogenous elicitor. Another PS in plant cell walls is the Proteinase Inhibitor Inducing Factor (PIIF). This hormone appears to protect plants by inducing synthesis in plants of proteins which specifically inhibit digestive enzymes of insects and bacteria. Glycoproteins secreted by incompatible races (races that do not infect the plant) of a fungal pathogen of soybeans protect seedlings from attack by compatible races. Glycoproteins from compatible races do not protect the seedlings. The acidic PS secreted by the nitrogen-fixing rhizobia appear to function in the infection of legumes by the rhizobia. W.D. Bauer and his co-workers have evidence that these PS are required for the development of root hairs capable of being infected by symbiont rhizobia. Current knowledge of the structures of these biologically active complex carbohydrates will be presented.

Reliability and maintenance in European nuclear power plants: A structural analysis of a controlled stochastic process

International Nuclear Information System (INIS)

Sturm, R.

1991-01-01

Two aspects of performance are of main concern: plant availability and plant reliability (defined as the conditional probability of an unplanned shutdown). The goal of the research is a unified framework that combines behavioral models of optimizing agents with models of complex technical systems that take into account the dynamic and stochastic features of the system. In order to achieve this synthesis, two liens of work are necessary. One line requires a deeper understanding of complex production systems and the type of data they give rise to; the other line involves the specification and estimation of a rigorously specified behavioral model. Plant operations are modeled as a controlled stochastic process, and the sequence of up and downtime spells is analyzed during failure time and point process models. Similar to work on rational expectations and structural econometric models, the behavior model of how the plant process is controlled is formulated at the level of basic processes, i.e., the objective function of the plant manager, technical constraints, and stochastic disturbances

Structure and function of complex I in animals and plants - a comparative view.

Science.gov (United States)

Senkler, Jennifer; Senkler, Michael; Braun, Hans-Peter

2017-09-01

The mitochondrial NADH dehydrogenase complex (complex I) has a molecular mass of about 1000 kDa and includes 40-50 subunits in animals, fungi and plants. It is composed of a membrane arm and a peripheral arm and has a conserved L-like shape in all species investigated. However, in plants and possibly some protists it has a second peripheral domain which is attached to the membrane arm on its matrix exposed side at a central position. The extra domain includes proteins resembling prokaryotic gamma-type carbonic anhydrases. We here present a detailed comparison of complex I from mammals and flowering plants. Forty homologous subunits are present in complex I of both groups of species. In addition, five subunits are present in mammalian complex I, which are absent in plants, and eight to nine subunits are present in plant complex I which do not occur in mammals. Based on the atomic structure of mammalian complex I and biochemical insights into complex I architecture from plants we mapped the species-specific subunits. Interestingly, four of the five animal-specific and five of the eight to nine plant-specific subunits are localized at the inner surface of the membrane arm of complex I in close proximity. We propose that the inner surface of the membrane arm represents a workbench for attaching proteins to complex I, which are not directly related to respiratory electron transport, like nucleoside kinases, acyl-carrier proteins or carbonic anhydrases. We speculate that further enzyme activities might be bound to this micro-location in other groups of organisms. © 2017 Scandinavian Plant Physiology Society.

Idiomatic Control used in Sugar Plants

DEFF Research Database (Denmark)

Nielsen, Kirsten Mølgaard; Nielsen, Jens Frederik Dalsgaard; Pedersen, Tom Søndergaard

1993-01-01

A description of a control system for a large scale industrial plant - the evaporator section of a sugar plant. The control system is based on the idiomatic control concept, causing decomposition into loop control units - idioms. Dynamic decoupling, feedforward- and feedback loops eg. have been...

Advanced liquid metal reactor plant control system

International Nuclear Information System (INIS)

Dayal, Y.; Wagner, W.; Zizzo, D.; Carroll, D.

1993-01-01

The modular Advanced Liquid Metal Reactor (ALMR) power plant is controlled by an advanced state-of-the-art control system designed to facilitate plant operation, optimize availability, and protect plant investment. The control system features a high degree of automatic control and extensive amount of on-line diagnostics and operator aids. It can be built with today's control technology, and has the flexibility of adding new features that benefit plant operation and reduce O ampersand M costs as the technology matures

Complex effects of fertilization on plant and herbivore performance in the presence of a plant competitor and activated carbon.

Science.gov (United States)

Mahdavi-Arab, Nafiseh; Meyer, Sebastian T; Mehrparvar, Mohsen; Weisser, Wolfgang W

2014-01-01

Plant-herbivore interactions are influenced by host plant quality which in turn is affected by plant growth conditions. Competition is the major biotic and nutrient availability a major abiotic component of a plant's growth environment. Yet, surprisingly few studies have investigated impacts of competition and nutrient availability on herbivore performance and reciprocal herbivore effects on plants. We studied growth of the specialist aphid, Macrosiphoniella tanacetaria, and its host plant tansy, Tanacetum vulgare, under experimental addition of inorganic and organic fertilizer crossed with competition by goldenrod, Solidago canadensis. Because of evidence that competition by goldenrod is mediated by allelopathic compounds, we also added a treatment with activated carbon. Results showed that fertilization increased, and competition with goldenrod decreased, plant biomass, but this was likely mediated by resource competition. There was no evidence from the activated carbon treatment that allelopathy played a role which instead had a fertilizing effect. Aphid performance increased with higher plant biomass and depended on plant growth conditions, with fertilization and AC increasing, and plant competition decreasing aphid numbers. Feedbacks of aphids on plant performance interacted with plant growth conditions in complex ways depending on the relative magnitude of the effects on plant biomass and aphid numbers. In the basic fertilization treatment, tansy plants profited from increased nutrient availability by accumulating more biomass than they lost due to an increased number of aphids under fertilization. When adding additional fertilizer, aphid numbers increased so high that tansy plants suffered and showed reduced biomass compared with controls without aphids. Thus, the ecological cost of an infestation with aphids depends on the balance of effects of growth conditions on plant and herbivore performance. These results emphasize the importance to investigate both

Complex effects of fertilization on plant and herbivore performance in the presence of a plant competitor and activated carbon.

Directory of Open Access Journals (Sweden)

Nafiseh Mahdavi-Arab

Full Text Available Plant-herbivore interactions are influenced by host plant quality which in turn is affected by plant growth conditions. Competition is the major biotic and nutrient availability a major abiotic component of a plant's growth environment. Yet, surprisingly few studies have investigated impacts of competition and nutrient availability on herbivore performance and reciprocal herbivore effects on plants. We studied growth of the specialist aphid, Macrosiphoniella tanacetaria, and its host plant tansy, Tanacetum vulgare, under experimental addition of inorganic and organic fertilizer crossed with competition by goldenrod, Solidago canadensis. Because of evidence that competition by goldenrod is mediated by allelopathic compounds, we also added a treatment with activated carbon. Results showed that fertilization increased, and competition with goldenrod decreased, plant biomass, but this was likely mediated by resource competition. There was no evidence from the activated carbon treatment that allelopathy played a role which instead had a fertilizing effect. Aphid performance increased with higher plant biomass and depended on plant growth conditions, with fertilization and AC increasing, and plant competition decreasing aphid numbers. Feedbacks of aphids on plant performance interacted with plant growth conditions in complex ways depending on the relative magnitude of the effects on plant biomass and aphid numbers. In the basic fertilization treatment, tansy plants profited from increased nutrient availability by accumulating more biomass than they lost due to an increased number of aphids under fertilization. When adding additional fertilizer, aphid numbers increased so high that tansy plants suffered and showed reduced biomass compared with controls without aphids. Thus, the ecological cost of an infestation with aphids depends on the balance of effects of growth conditions on plant and herbivore performance. These results emphasize the importance

B Plant Complex generator dangerous waste storage areas inspection plan: Revision 1

International Nuclear Information System (INIS)

Beam, T.G.

1994-01-01

This document contains the inspection plan for the <90 day dangerous/mixed waste storage areas and satellite accumulation areas at B Plant Complex. This inspection plan is designed to comply with all applicable federal, state and US Department of Energy-Richland Operations Office training requirements. In particular, the requirements of WAC 173-303 ''Dangerous Waste Regulations'' are met by this inspection plan. This inspection plan is designed to provide B Plant Complex with the records and documentation showing that the waste storage and handling program is in compliance with applicable regulations. The plan also includes the requirements for becoming a qualified inspector of waste storage areas and the responsibilities of various individuals and groups at B Plant Complex

The factors controlling species density in herbaceous plant communities: An assessment

Science.gov (United States)

Grace, J.B.

1999-01-01

This paper evaluates both the ideas and empirical evidence pertaining to the control of species density in herbaceous plant communities. While most theoretical discussions of species density have emphasized the importance of habitat productivity and disturbance regimes, many other factors (e.g. species pools, plant litter accumulation, plant morphology) have been proposed to be important. A review of literature presenting observations on the density of species in small plots (in the vicinity of a few square meters or less), as well as experimental studies, suggests several generalizations: (1) Available data are consistent with an underlying unimodal relationship between species density and total community biomass. While variance in species density is often poorly explained by predictor variables, there is strong evidence that high levels of community biomass are antagonistic to high species density. (2) Community biomass is just one of several factors affecting variations in species density. Multivariate analyses typically explain more than twice as much variance in species density as can be explained by community biomass alone. (3) Disturbance has important and sometimes complex effects on species density. In general, the evidence is consistent with the intermediate disturbance hypothesis but exceptions exist and effects can be complex. (4) Gradients in the species pool can have important influences on patterns of species density. Evidence is mounting that a considerable amount of the observed variability in species density within a landscape or region may result from environmental effects on the species pool. (5) Several additional factors deserve greater consideration, including time lags, species composition, plant morphology, plant density and soil microbial effects. Based on the available evidence, a conceptual model of the primary factors controlling species density is presented here. This model suggests that species density is controlled by the effects of

Design Of Feedforward Controllers For Multivariable Plants

Science.gov (United States)

Seraji, Homayoun

1989-01-01

Controllers based on simple low-order transfer functions. Mathematical criteria derived for design of feedforward controllers for class of multiple-input/multiple-output linear plants. Represented by simple low-order transfer functions, obtained without reconstruction of states of commands and disturbances. Enables plant to track command while remaining unresponsive to disturbance in steady state. Feedback controller added independently to stabilize plant or to make control system less susceptible to variations in parameters of plant.

Configuration control during plant outages. A review of operating experience

Energy Technology Data Exchange (ETDEWEB)

Peinador Veira, Miguel; El Kanbi, Semir [European Commission Joint Research Centre, Petten (Netherlands). Inst. for Energy and Transport; Stephan, Jean-Luc [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Martens, Johannes [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Koeln (Germany)

2015-03-15

After the occurrence of several significant events in nuclear power plants during shut-down modes of operation in the eighties, and from the results of probabilistic safety assessments completed in the nineties, it was clear that risk from low power and shutdown operational modes could not be neglected and had to be addressed by appropriate safety programs. A comprehensive review of operating experience from the last ten years has been conducted by the Joint Research Centre with the objective of deriving lessons learned and recommendations useful for nuclear regulatory bodies and utilities alike. This paper is focused on one particular challenge that any nuclear plant faces whenever it plans its next outage period: how to manage the configuration of all systems under a complex environment involving numerous concurrent activities, and how to make sure that systems are returned to their valid configuration before the plant resumes power operation. This study highlights the importance of conveying accurate but synthesized information on the status of the plant to the operators in the main control room. Many of the lessons learned are related to the alarm display in the control room and to the use of check lists to control the status of systems. Members of the industry and safety authorities may now use these recommendations and lessons learned to feed their own operating experience feedback programs, and check their applicability for specific sites.

Plant control device

International Nuclear Information System (INIS)

Sato, Masuo; Ono, Makoto.

1995-01-01

A plant control device comprises an intellectual instrumentation group for measuring a predetermined process amount, an intellectual equipment group operating in accordance with a self-countermeasure, a system information space for outputting system information, a system level monitoring and diagnosing information generalization section for outputting system information, a system level maintenance information generalization section for outputting information concerning maintenance, a plant level information space and a plant level information generalization section. Each of them determines a state of the plant autonomously, and when abnormality is detected, each of the intellectual instrumentation, equipments and systems exchange information with each other, to conduct required operations including operations of intellectual robots, as required. Appropriate countermeasures for gauges, equipments and systems can be conducted autonomously at a place where operators can not access to improve reliability of complicate operations in the working site, as well as improve plant safety and reliability. (N.H.)

Complex Dietary Supplements from Raw Plants Provide Nutrition for Athletes

Directory of Open Access Journals (Sweden)

Dmitriy M. Uvarov

2017-03-01

Full Text Available The aim of this study was to investigate the effectiveness of mechanically activated complexes from plant substances to enhance athletes’ adaptability to intense physical activity. Methods: The object of the study was the dietary supplement Kladorod, which is based on the reindeer lichen Cladonia rangiferina and Rhodiola rosea in weight ratio of 10:1. To test the dietary supplement, we developed a special scheme for the experiment and selected 10 elite athletes (boxers and mixfighters. Athletes were divided into 2 groups and were under the same conditions (nutrition, medical monitoring, living conditions and training process. Athletes of the experimental group were given the dietary supplement Kladorod (capsule of 0.4 g by mouth between meals 4 times a day for 28 days. The control group was given placebo (Ringer-Locke powder capsules in the same terms in a similar way. During the experiment, the athletes were medically examined 3 times: at the beginning, in the middle, and after the course of intervention. We measured muscle performance, fat mass, muscle mass, and serum concentrations of cortisol and total testosterone. Results: It was established that during the intensive training of boxers and mixfighters for rating fights, administration of the dietary supplement Kladorod for 28 days stabilized the absolute and relative muscle mass, preventing its reduction, in comparison with the placebo group. At the same time, indicators of fat mass decreased significantly in the experimental group. After administering the course of Kladorod, we did not observe a significant decrease in testosterone/cortisol ratio, compared to the control group Thus, the use of biologically active supplements based on lichen raw materials and complexes of lichen raw materials with different plant substances enables the body to increase its adaptive potential and physical capacity.

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1993-01-01

This project was initiated in September 1989 as a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. There were two primary goals of this research project. The first goal was to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz. The second goal was to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-2 steam plant. Described in this Final (Third Annual) Technical Progress Report is the accomplishment of the project's final milestone, an in-plant intelligent control experiment conducted on April 1, 1993. The development of the experiment included: simulation validation, experiment formulation and final programming, procedure development and approval, and experimental results. Other third year developments summarized in this report are: (1) a theoretical foundation for Reconfigurable Hybrid Supervisory Control, (2) a steam plant diagnostic system, (3) control console design tools and (4) other advanced and intelligent control

Emergency control centers for nuclear power plants

International Nuclear Information System (INIS)

Anon.

1979-01-01

Guidance is provided for the development and implementation of emergency control centers for nuclear power plants, including nuclear plant control room, nuclear plant company headquarters, emergency control center, and nuclear plant alternate emergency control center. Requirements and recommendations are presented for the mission, communications, instrumentation and equipment associated with each type of control center. Decisional aids, manning requirements and resources are also given; the decision aids cover both the accident assessment and protective action areas. Both normal and alternate means of communications are considered. Off-site emergency control centers, although not covered in the strict sense by this standard, are considered in an appendix

Ternary WD40 repeat-containing protein complexes: evolution, composition and roles in plant immunity

Directory of Open Access Journals (Sweden)

Jimi C. Miller

2016-01-01

Full Text Available Plants, like mammals, rely on their innate immune system to perceive and discriminate among the majority of their microbial pathogens. Unlike mammals, plants respond to this molecular dialogue by unleashing a complex chemical arsenal of defense metabolites to resist or evade pathogen infection. In basal or non-host resistance, plants utilize signal transduction pathways to detect non-self, damaged-self and altered-self-associated molecular patterns and translate these danger signals into largely inducible chemical defenses. The WD40 repeat (WDR-containing proteins Gβ and TTG1 are constituents of two independent ternary protein complexes functioning at opposite ends of a plant immune signaling pathway. Gβ and TTG1 are also encoded by single-copy genes that are ubiquitous in higher plants, implying the limited diversity and functional conservation of their respective complexes. In this review, we summarize what is currently known about the evolutionary history of these WDR-containing ternary complexes, their repertoire and combinatorial interactions, and their downstream effectors and pathways in plant defense.

Chemical Control of Plant Growth.

Science.gov (United States)

Agricultural Research Center (USDA), Beltsville, MD.

Seven experiments are presented in this Science Study Aid to help students investigate the control of plant growth with chemicals. Plant growth regulators, weed control, and chemical pruning are the topics studied in the experiments which are based on investigations that have been and are being conducted at the U. S. Agricultural Research Center,…

Emerging functions of multi-protein complex Mediator with special emphasis on plants.

Science.gov (United States)

Malik, Naveen; Agarwal, Pinky; Tyagi, Akhilesh

2017-10-01

Mediator is a multi-subunit protein complex which is involved in transcriptional regulation in yeast and other eukaryotes. As a co-activator, it connects information from transcriptional activators/repressors to transcriptional machinery including RNA polymerase II and general transcription factors. It is not only involved in transcription initiation but also has important roles to play in transcription elongation and termination. Functional attributes of different Mediator subunits have been largely defined in yeast and mammalian systems earlier, while such studies in plants have gained momentum recently. Mediator regulates various processes related to plant development and is also involved in biotic and abiotic stress response. Thus, plant Mediator, like yeast and mammalian Mediator complex, is indispensable for plant growth and survival. Interaction of its multiple subunits with other regulatory proteins and their ectopic expression or knockdown in model plant like Arabidopsis and certain crop plants are paving the way to biochemical analysis and unravel molecular mechanisms of action of Mediator in plants.

Plants lacking the main light-harvesting complex retain photosystem II macro-organization.

Science.gov (United States)

Ruban, A V; Wentworth, M; Yakushevska, A E; Andersson, J; Lee, P J; Keegstra, W; Dekker, J P; Boekema, E J; Jansson, S; Horton, P

2003-02-06

Photosystem II (PSII) is a key component of photosynthesis, the process of converting sunlight into the chemical energy of life. In plant cells, it forms a unique oligomeric macrostructure in membranes of the chloroplasts. Several light-harvesting antenna complexes are organized precisely in the PSII macrostructure-the major trimeric complexes (LHCII) that bind 70% of PSII chlorophyll and three minor monomeric complexes-which together form PSII supercomplexes. The antenna complexes are essential for collecting sunlight and regulating photosynthesis, but the relationship between these functions and their molecular architecture is unresolved. Here we report that antisense Arabidopsis plants lacking the proteins that form LHCII trimers have PSII supercomplexes with almost identical abundance and structure to those found in wild-type plants. The place of LHCII is taken by a normally minor and monomeric complex, CP26, which is synthesized in large amounts and organized into trimers. Trimerization is clearly not a specific attribute of LHCII. Our results highlight the importance of the PSII macrostructure: in the absence of one of its main components, another protein is recruited to allow it to assemble and function.

A plant control system development approach for IRIS

International Nuclear Information System (INIS)

Wood, R.T.; Brittain, C.R.; March-Leuba, J.A.; Conway, L.E.; Oriani, L.

2003-01-01

The plant control system concept for the International Reactor Innovative and Secure (IRIS) will make use of integrated control, diagnostic, and decision modules to provide a highly automated intelligent control capability. The plant control system development approach established for IRIS involves determination and verification of control strategies based on whole-plant simulation; identification of measurement, control, and diagnostic needs; development of an architectural framework in which to integrate an intelligent plant control system; and design of the necessary control and diagnostic elements for implementation and validation. This paper describes key elements of the plant control system development approach established for IRIS and presents some of the strategies and methods investigated to support the desired control capabilities. (author)

Plants cultivation in controlled containments

International Nuclear Information System (INIS)

2000-01-01

The plants cultivation in controlled containments permits to the - Departement d'Ecophysiologie Vegetale et de Microbiologie (DVEM) - of the CEA to lead several topics of research. The works of DVEM which are based on the molecular labelling, technique adapted to plants, contribute to understand the plant - soil relationships and the plant growth process. In addition, the staff of DVEM study the impact of pollutant heavy metals, existing in the soil, on plants and the plant stress induced by oxygen, light, ionizing radiations,... and defence mechanisms of plants (F. M.)

Using Plants to Explore the Nature & Structural Complexity of Life

Science.gov (United States)

Howard, Ava R.

2014-01-01

Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

Gain-Scheduled Control of a Fossil-Fired Power Plant Boiler

DEFF Research Database (Denmark)

Hangstrup, M.; Stoustrup, Jakob; Andersen, Palle

1999-01-01

-scheduling which interpolates between unstable controllers is not allowed using traditional schemes. The results show that a considerable optimization of the conventional controlled system is obtainable. Also the gain-scheduled optimizing controller is seen to have a superior performance compared to the fixed LTI......In this paper the objective is to optimize the control of a coal fired 250 MW power plant boiler. The conventional control system is supplemented with a multivariable optimizing controller operating in parallel with the conventional control system. Due to the strong dependence of the gains...... and dynamics upon the load, it is beneficial to consider a gain-scheduling control approach. Optimization using complex mu synthesis results in unstable LTI controllers in some operating points of the boiler. A recent gain-scheduling approach allowing for unstable fixed LTI controllers is applied. Gain...

Nuclear power desalinating complex with IRIS reactor plant and Russian distillation desalinating unit

International Nuclear Information System (INIS)

Kostin, V. I.; Panov, Yu.K.; Polunichev, V. I.; Fateev, S. A.; Gureeva, L. V.

2004-01-01

This paper has been prepared as a result of Russian activities on the development of nuclear power desalinating complex (NPDC) with the IRIS reactor plant (RP). The purpose of the activities was to develop the conceptual design of power desalinating complex (PDC) and to evaluate technical and economical indices, commercial attractiveness and economical efficiency of PDC based on an IRIS RP with distillation desalinating plants. The paper presents the main results of studies as applied to dual-purpose PDC based on IRIS RP with different types of desalinating plants, namely: characteristics of nuclear power desalinating complex based on IRIS reactor plant using Russian distillation desalinating technologies; prospective options of interface circuits of the IRIS RP with desalinating plants; evaluations of NPDC with IRIS RP output based on selected desalinating technologies for water and electric power supplied to the grid; cost of water generated by NPDC for selected interface circuits made by the IAEA DEEP code as well as by the Russian TEO-INVEST code; cost evaluation results for desalinated water of PDC operating on fossil fuel and conditions for competitiveness of the nuclear PDC based on IRIS RP compared with analog desalinating complexes operating on fossil fuel.(author)

Application of process computers and colour CRT displays in the plant control room of a BWR

International Nuclear Information System (INIS)

Itoh, M.; Hayakawa, H.; Kawahara, H.; Neda, T.; Wakabayashi, Y.

1983-01-01

The recent application of a CRT display system in an 1100-MW(e) BWR plant control room and the design features of a new control room whose installation is planned for the next generation are discussed. As reactor unit capacity and the need for plant safety and reliability continue to increase, instrumentation and control equipment is growing in number and complexity. In consequence, control and supervision of plant operations require improvement. Thus, because of recent progress in the field of process computers and display equipment (colour CRTs), efficient improvements of the control room are under way in the Japanese BWR plant. In the recently constructed BWR plant (1100 MW(e)), five CRTs on the bench board and two process computers were additionally installed in the control room during the construction stage to improve plant control and supervisory functions by implementing the lessons learned from the Three Mile Island incident. The major functions of the new computers and display systems are to show integrated graphic displays of the plant status, to monitor the standby condition of the safety system, to show the condition of the integrated alarm system, etc. In practice, in the actual plant, this newly installed system performs well. On the basis of the experience gained in these activities, a new computerized control and monitoring system is now being designed for subsequent domestic BWR plants. This advanced system will incorporate not only the functions already mentioned, but also a surveillance guide system and plant automation. For future plants, a diagnostic system and an instructional system that can analyse a disturbance and give operational guidance to the plant operator are being developed in a government-sponsored programme. (author)

Research on control function switch of nuclear power plant control room

International Nuclear Information System (INIS)

Mei Shibo; Mao Ting; Cheng Bo; Zhang Gang

2014-01-01

The nuclear power plant provides main control room (MCR) to the unit operators for the plant monitoring and control, and provides the remote shutdown station (RSS) as the back-up control room, which is used only when MCR is unavailable. The RSS could be used to monitor and control the plant, bring the plant into shutdown state and remove the residual heat. The command from MCR and RSS is blocked by each other and can not be executed at the same time. The operation mode switch function between MCR and RSS is carried out by MCR/RSS mode switches. The operation mode switch scheme of CPR1000, ERP and AP1000 were compared and researched, and some design bases for new nuclear power plant were submitted in this paper. These design bases could be referred during the design of control function switch for the new nuclear power plants, in order to put forward a more practical, simple, safe and convenient scheme. (authors)

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1992-01-01

This project was initiated in September 1989 as a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this Third Annual Technical Progress report summarizes the period from September 1991 to October 1992. There were two primary goals of this research project. The first goal was to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz. His philosophy, is to improve public perception of the safety of nuclear power plants by incorporating a high degree of automation where a greatly simplified operator control console minimizes the possibility of human error in power plant operations. To achieve this goal, a hierarchically distributed control system with automated responses to plant upset conditions was pursued in this research. The second goal was to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-2 stem plant. Emphasized in this Third Annual Technical Progress Report is the continuing development of the in-plant intelligent control demonstration for the final project milestone and includes: simulation validation and the initial approach to experiment formulation

Fuzzy logic control of nuclear power plant

International Nuclear Information System (INIS)

Yao Liangzhong; Guo Renjun; Ma Changwen

1996-01-01

The main advantage of the fuzzy logic control is that the method does not require a detailed mathematical model of the object to be controlled. In this paper, the shortcomings and limitations of the model-based method in nuclear power plant control were presented, the theory of the fuzzy logic control was briefly introduced, and the applications of the fuzzy logic control technology in nuclear power plant controls were surveyed. Finally, the problems to be solved by using the fuzzy logic control in nuclear power plants were discussed

Implications of the degree of controllability of controlled plants in the sense of LQR optimal control

Science.gov (United States)

Xia, Yaping; Yin, Minghui; Zou, Yun

2018-01-01

In this paper, the relationship between the degree of controllability (DOC) of controlled plants and the corresponding quadratic optimal performance index in LQR control is investigated for the electro-hydraulic synchronising servo control systems and wind turbine systems, respectively. It is shown that for these two types of systems, the higher the DOC of a controlled plant is, the better the quadratic optimal performance index is. It implies that in some LQR controller designs, the measure of the DOC of a controlled plant can be used as an index for the optimisation of adjustable plant parameters, by which the plant can be controlled more effectively.

Nuclear power plant control room operator control and monitoring tasks

International Nuclear Information System (INIS)

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

1998-01-01

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

Control of power plants and power systems. Proceedings

International Nuclear Information System (INIS)

Canales-Ruiz, R.

1996-01-01

The 88 papers in this volume constitute the proceedings of the International Federation of Automatic Control Symposium held in Mexico in 1995. The broad areas which they cover are: self tuning control; power plant operations; dynamic stability; fuzzy logic applications; power plants modelling; artificial intelligence applications; power plants simulation; voltage control; control of hydro electric units; state estimation; fault diagnosis and monitoring systems; system expansion and operation planning; security assessment; economic dispatch and optimal load flow; adaptive control; distribution; transient stability and preventive control; modelling and control of nuclear plant; knowledge data bases for automatic learning methods applied to power system dynamic security assessment; control of combined cycle units; power control centres. Separate abstracts have been prepared for the three papers relating to nuclear power plants. (UK)

The control of operational risk in nuclear power plant operations - Some cross-cultural perspectives

International Nuclear Information System (INIS)

Suchard, A.; Rochlin, G.

1992-01-01

The operation of nuclear power plants requires the management of a complex technology under exacting performance and safety criteria. Organizations operating nuclear power plants are faced with the challenge of simultaneously meeting technical, organizational, and social demands, striving toward perfection in a situation where learning by trial and error can be too costly. In this process, they interact with regulatory bodies who seek to help minimize operational risk by imposing and upholding safety standards. The character of this interaction differs in various countries, as does the larger cultural setting. The study generally pursued the question of how organizations operating complex and demanding technologies adapt to such requirements and circumstances, and how they can succeed in delivering nearly error-free performance. One aspect of this study includes the comparison of organizational and cultural environments for nuclear power plant operations in the US, France, Germany, Sweden, and Switzerland. The research involved in-depth, continuous observations on location and interviews with plant personnel, especially control operators, at one plant in each country

Linguistic control of a nuclear power plant

International Nuclear Information System (INIS)

Feeley, J.J.; Johnson, J.C.

1987-01-01

A multivariable linguistic controller based on fuzzy set theory is discussed and its application to a pressurized water nuclear power plant control is illustrated by computer simulation. The nonlinear power plant simulation model has nine states, two control inputs, one disturbance input, and two outputs. Although relatively simple, the model captures the essential coupled nonlinear plant dynamics and is convenient to use for control system studies. The use of an adaptive version of the controller is also demonstrated by computer simulation

Optimal control systems in hydro power plants

International Nuclear Information System (INIS)

Babunski, Darko L.

2012-01-01

The aim of the research done in this work is focused on obtaining the optimal models of hydro turbine including auxiliary equipment, analysis of governors for hydro power plants and analysis and design of optimal control laws that can be easily applicable in real hydro power plants. The methodology of the research and realization of the set goals consist of the following steps: scope of the models of hydro turbine, and their modification using experimental data; verification of analyzed models and comparison of advantages and disadvantages of analyzed models, with proposal of turbine model for design of control low; analysis of proportional-integral-derivative control with fixed parameters and gain scheduling and nonlinear control; analysis of dynamic characteristics of turbine model including control and comparison of parameters of simulated system with experimental data; design of optimal control of hydro power plant considering proposed cost function and verification of optimal control law with load rejection measured data. The hydro power plant models, including model of power grid are simulated in case of island ing and restoration after breakup and load rejection with consideration of real loading and unloading of hydro power plant. Finally, simulations provide optimal values of control parameters, stability boundaries and results easily applicable to real hydro power plants. (author)

Control of complex systems

CERN Document Server

Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo

2001-01-01

The world of artificial systems is reaching complexity levels that es­ cape human understanding. Surface traffic, electricity distribution, air­ planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi­ neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re­ search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu­ ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...

Design of coordinated controller in nuclear power plant based on digital instrument and control technology

International Nuclear Information System (INIS)

Cheng Shouyu; Peng Minjun; Liu Xinkai; Zhao Qiang; Deng Xiangxin

2014-01-01

Nuclear power plant (NPP) is a multi-input and multi-output, no-linear and time-varying complex system. The conventional PID controller is usually used in NPP control system which is based on analog instrument. The system parameters are easy to overshoot and the response time is longer in the control mode of the conventional PID. In order to improve this condition, a new coordinated control strategy which is based on expert system and the original controllers in the digital instrument and control technology was presented. In order to verify and validate it, the proposed coordinated control technology was tested by the full-scope real-time simulation system. The results prove that using digital instrument and control technology to achieve coordinated controller is feasible, the coordinated controller can effectively improve the dynamic operating characteristics of the system, and the coordinated controller is superior to the conventional PID controller in control performance. (authors)

Design of a multivariable controller for a CANDU 600 MWe nuclear power plant using the INA method

International Nuclear Information System (INIS)

Roy, N.; Boisvert, J.; Mensah, S.

1984-04-01

The development of large and complex nuclear and process plants requires high-performance control systems, designed with rigorous multivariable techniques. This work is part of an analytical study demonstrating the real potential of multivariable methods. It covers every step in the design of a multi-variable controller for a Gentilly-2 type CANDU 600 MWe nuclear power plant using the Inverse Nyquist Array (INA) method. First the linear design model and its preliminary modifications are described. The design tools are reviewed and the operations required to achieve open-loop diagonal dominance are thoroughly described. Analysis of the closed-loop system is then performed and a feedback matrix is selected to meet the design specifications. The performance of the controller on the linear model is verified by simulation. Finally, the controller is implemented on the reference non-linear model to assess its overall performance. The results show that the INA method can be used successfully to design controllers for large and complex systems

Inter-plant communication through mycorrhizal networks mediates complex adaptive behaviour in plant communities.

Science.gov (United States)

Gorzelak, Monika A; Asay, Amanda K; Pickles, Brian J; Simard, Suzanne W

2015-05-15

Adaptive behaviour of plants, including rapid changes in physiology, gene regulation and defence response, can be altered when linked to neighbouring plants by a mycorrhizal network (MN). Mechanisms underlying the behavioural changes include mycorrhizal fungal colonization by the MN or interplant communication via transfer of nutrients, defence signals or allelochemicals. We focus this review on our new findings in ectomycorrhizal ecosystems, and also review recent advances in arbuscular mycorrhizal systems. We have found that the behavioural changes in ectomycorrhizal plants depend on environmental cues, the identity of the plant neighbour and the characteristics of the MN. The hierarchical integration of this phenomenon with other biological networks at broader scales in forest ecosystems, and the consequences we have observed when it is interrupted, indicate that underground 'tree talk' is a foundational process in the complex adaptive nature of forest ecosystems. Published by Oxford University Press on behalf of the Annals of Botany Company.

Optimal estimation and control in nuclear power plants

International Nuclear Information System (INIS)

Purviance, J.E.; Tylee, J.L.

1982-08-01

Optimal estimation and control theories offer the potential for more precise control and diagnosis of nuclear power plants. The important element of these theories is that a mathematical plant model is used in conjunction with the actual plant data to optimize some performance criteria. These criteria involve important plant variables and incorporate a sense of the desired plant performance. Several applications of optimal estimation and control to nuclear systems are discussed

Studies on the coordinated operation and autonomous control for multi-modular nuclear power plants

International Nuclear Information System (INIS)

Hui Chao; Huang Xiaojin; Wang Jie

2011-01-01

The tendency has always been to build ever larger single-modular reactor plants with the objective of benefiting from economies of scale. These plants have compiled admirable safety records. Nevertheless, there is concern that conventional large single reactors have become too complex by reason of placing too much reliance on engineered safeguards. The multi-modular approach offers a solution in that its use of many small reactors in conjunction with several shared turbines permits a simpler core design while, at the same time, at least partially retaining economies of scale by increasing the number of modules. Specific advantages to the multi-modular approach are as follows. First, the small-sized of the reactor core may allow the incorporation of passive safety features such as natural circulation cooling on loss of off-site electricity. Second, the individual modules are to be sized so that components related to nuclear safety can be factory-fabricated. Moreover, once the major components are made, they are to be transported to the site for rapid installation. This construction method is expected to reduce the licensing effort because the modules will be pre-licensed, and only site-specific issues will have to be considered in the final licensing process. At present, related studies show that the multi-modular approach for Generation IV can retain both the inherent safety and good economies of scale. However, the unbalanced load operation of the multi-modular power plant in which each module operates at a different power level and strong coupling between multi modules creates a complex control challenge to safe operation and control. Firstly, this paper summarizes the unbalanced load operation characteristics and challenges faced by operation and control of multi-modular power plant in the dynamic operational characteristics and requirements of coordinated control between multi modules. Secondly, detailed analysis and comparison are given in the integral

Decentralized control of complex systems

CERN Document Server

Siljak, Dragoslav D

2011-01-01

Complex systems require fast control action in response to local input, and perturbations dictate the use of decentralized information and control structures. This much-cited reference book explores the approaches to synthesizing control laws under decentralized information structure constraints.Starting with a graph-theoretic framework for structural modeling of complex systems, the text presents results related to robust stabilization via decentralized state feedback. Subsequent chapters explore optimization, output feedback, the manipulative power of graphs, overlapping decompositions and t

Biology, ecology and control of the Penthaleus species complex (Acari: Penthaleidae).

Science.gov (United States)

Umina, Paul A; Hoffmann, Ary A; Weeks, Andrew R

2004-01-01

Blue oat mites, Penthaleus spp. (Acari: Penthaleidae), are major agricultural pests in southern Australia and other parts of the world, attacking various pasture, vegetable and crop plants. Management of these mites has been complicated by the recent discovery of three cryptic pest species of Penthaleus, whereas prior research had assumed a single species. The taxonomy, population genetics, ecology, biology and control of the Penthaleus spp. complex are reviewed. Adult Penthaleus have a dark blue-black body approximately 1 mm in length, and eight red-orange legs. Within Australia, they are winter pests completing two or three generations a season, depending on conditions. The summer is passed as diapausing eggs, when long-distance dispersal is thought to occur. The Penthaleus spp. reproduce by thelytokous parthenogenesis, with populations comprising clones that differ ecologically. The three pest Penthaleus spp. differ markedly in their distributions, plant hosts, timing of diapause egg production and response to pesticides, highlighting the need to develop control strategies that consider each species separately. Chemicals are the main weapons used in current control programs, however research continues into alternative more sustainable management options. Host plant resistance, crop rotations, conservation of natural enemies, and improved timing of pesticide application would improve the management of these pests. The most cost-effective and environmentally acceptable means of control will result from the integration of these practices combined with the development of a simple field-based kit to distinguish the different mite species.

Evaluation of an Extremum Seeking Control Based Optimization and Sequencing Strategy for a Chilled-water Plant

OpenAIRE

Zhao, Zhongfan; Li, Yaoyu; Mu, Baojie; Salsbury, Timothy I.; House, John M.

2016-01-01

Chilled-water plants with multiple chillers account for a significant fraction of energy use in large commercial buildings. Real-time optimization and sequencing of such plants is thus critical for building energy efficiency. Due to the cost and complexity associated with calibrating a chiller plant model to field operation, model-free control has become an attractive solution. Recently, Mu et al. (2015) proposed a model-free real-time optimization and sequencing strategy based on extremum se...

Plant control system upgrades in the context of industry trends towards plant life-extension

International Nuclear Information System (INIS)

De Grosbois, J.; Basso, R.; Hepburn, A.; Kumar, V.

2002-01-01

Domestic CANDU nuclear plants were brought online between 1972 and 1986. Over the next decade, most of these stations will be nearing the end of their designed operating life. Effort has traditionally been placed on ensuring that the existing installed plant control system equipment could operate reliably until the end of this design life. Until recently, little attention has been given to plant control system upgrades or replacements to meet the expected requirement for 30+ years of additional plant operation following potential plant refurbishments. Industry developments are changing this thinking. The combination of expected increases in electricity demand (and prices), and the many recent successful turnaround stories of U.S. nuclear power plants has resulted in new interest in plant life improvement and plant life extension programs. Plant control system upgrade decisions are now being driven by the need to replace or upgrade these systems to support plant life extension. This article is the first of several that investigate aspects of plant control system upgrades or replacement, specifically in the context of the CANDU station digital control computers (DCCs). It sets the context for the discussion in the subsequent articles by providing a brief review of industry trends favouring plant refurbishment, by outlining the basic issues of aging and obsolescence of control system equipment, by establishing the need for upgrades and replacements, and by introducing some of the basic challenges to be addressed by the industry as it moves forward. (author)

Ecological significance and complexity of N-source preference in plants.

Science.gov (United States)

Britto, Dev T; Kronzucker, Herbert J

2013-10-01

Plants can utilize two major forms of inorganic N: NO3(-) (nitrate) and NH4(+) (ammonium). In some cases, the preference of one form over another (denoted as β) can appear to be quite pronounced for a plant species, and can be an important determinant and predictor of its distribution and interactions with other species. In many other cases, however, assignment of preference is not so straightforward and must take into account a wide array of complex physiological and environmental features, which interact in ways that are still not well understood. This Viewpoint presents a discussion of the key, and often co-occurring, factors that join to produce the complex phenotypic composite referred to by the deceptively simple term 'N-source preference'. N-source preference is much more complex a biological phenomenon than is often assumed, and general models predicting how it will influence ecological processes will need to be much more sophisticated than those that have been so far developed.

Physical environment design criteria for the new control room in the ENEA TRIGA-RC1 plant

International Nuclear Information System (INIS)

Alberti, M.; Di Giulio, A.

1986-01-01

Parallelly to the plant modifications, many changes of the instrumentation in the Control Room (CR) were necessary in order to deal with the various aged components and the completion and integration needs turning out from the experience in reactor running. In the room, besides the control activity of the RC1 plant, continuous training and updating activities are currently performed which are intended for the operators working in the control rooms of nuclear power plants. The design of the physical environment of the new CR - carried out in a more general research project between ENEA and Politecnico di Milano - was based on the following fundamental criteria: - to ensure conditions fit for the performance of the suspervision, diagnosis and control tasks the operators are entrusted with; - to set up a model of control room for the more complex power plants. First of all a detailed analysis of the environmental conditions relating to microclimate, lighting and noise was accomplished. Afterwards, the goals to be attained were defined as well as the technical means necessary for providing the operators with comfortable working conditions

Application of digital control in Japanese PWR Plants

International Nuclear Information System (INIS)

Taguchi, S.; Kondo, Y.; Teranishi, S.; Matsumiya, M.; Takashima, M.; Nagai, T.

1986-01-01

More reliable and flexible control system to improve the plant availability and operability is constantly demanded. In order to answer the demands, digital control systems are being applied to Japanese PWR plants. Microprocessor-based digital control systems are widely used in other industries and show good performance. The digital control system has been already applied to the chemical and volume control system and the radioactive waste disposal system in the operating plants. These systems have been working as expected and demonstrating good performances. The digital control system for the reactor control system, which is the main control system of the PWR plants, is being developed. The design of the system has been already finished and the verification/validation process is now in progress

Suboptimal control of pressurized water reactor power plant using approximate model-following method

International Nuclear Information System (INIS)

Tsuji, Masashi; Ogawa, Yuichi

1987-01-01

We attempted to develop an effective control system that can successfully manage the nuclear steam supply (NSS) system of a PWR power plant in an operational mode requiring relatively small variations of power. A procedure is proposed for synthesizing control system that is a simple, yet practiced, suboptimal control system. The suboptimal control system is designed in two steps; application of the optimal control theory, based on the linear state-feedback control and the use of an approximate model-following method. This procedure can appreciably reduce the complexity of the structure of the controller by accepting a slight deviation from the optimality and by the use of the output-feedback control. This eliminates the engineering difficulty caused by an incompletely state-feedback that is sometimes encountered in practical applications of the optimal state-feedback control theory to complex large-scale dynamical systems. Digital simulations and graphical studies based on the Bode-diagram demonstrate the effectiveness of the suboptimal control, and the applicability of the proposed design method as well. (author)

Gametophyte differentiation and imprinting control in plants: Crosstalk between RBR and chromatin.

Science.gov (United States)

Johnston, Amal J; Gruissem, Wilhelm

2009-01-01

The Retinoblastoma (pRb) pathway has been implicated as a convergent regulatory unit in the control of cell cycle and disease. We have shown that a crosstalk between RETINOBLASTOMA RELATED (RBR), the Arabidopsis homologue of pRb, and the genes encoding proteins of the chromatin complexes involved in DNA or histone methylation, controls gametophytic and post-fertilization differentiation events and a subset of imprinting effects. We describe here a plausible model that incorporates several components of the plant Retinoblastoma pathway, thus offering a novel paradigm that merges the traditional cell cycle and the chromatin components in the control of cell differentiation and imprinting.

Nuclear power plant control and instrumentation 1982. Proceedings of an international symposium on nuclear power plant control and instrumentation

International Nuclear Information System (INIS)

1983-01-01

Ever increasing demands for nuclear power plant safety and availability imply a need for the introduction of modern measurement and control methods, together with data processing techniques based on the latest advances in electronic components, transducers and computers. Nuclear power plant control and instrumentation is therefore an extremely rapidly developing field. The present symposium, held in Munich, FR Germany, was prepared with the help of the IAEA International Working Group on Nuclear Power Plant Control and Instrumentation and organized in close co-operation with the Gesellschaft fur Reaktorsicherheit, Federal Republic of Germany. A number of developments were highlighted at the Munich symposium: - The increased use of computers can bring clear advantages and this technique is now proven as a tool for supervising and controlling plant operation. Advanced computerized systems for operator support are being developed on a large scale in many countries. The progress in this field is quite obvious, especially in disturbance analysis, safety parameter display, plant operator guidance and plant diagnostics. The new trend of introducing computers and microprocessors in protection systems makes it easy to implement 'defence-in-depth' strategies which give better assurance of correct system responses and also prevent unnecessary reactor trips, thus improving plant availability. The introduction of computerized systems for control of reactor power, reactor water level and reactor pressure as well as for reactor start-up and shut-down could improve the reliability and availability of nuclear power plants. The rapid technical development in the area of control and instrumentation makes it necessary to plan for at least one replacement of obsolete equipment in the course of the 30 years lifetime of a nuclear power plant and retrofitting of currently operating reactors with new control systems. Major design improvements and regulatory requirements also require

Medicinal plants and secondary metabolites for diabetes mellitus control

Directory of Open Access Journals (Sweden)

Mahmoud Bahmani

2014-09-01

Full Text Available Diabetes mellitus is one of the most common and complex problems of modern societies which has caused many economic and social problems. Because diabetes has no definite treatment, the use of traditional medicine seems to be an appropriate solution to control and manage it. Studies revealed that Vaccinium Arctostaphylos L., Securigera securidaca L., Gymnema sylvestre L., Atriplex halimus L., Camellia sinensis L., Ginkgo biloba L., Mamordica charantia L., Citrullus colocynthis (L. Schrad., Allium cepa L., Allium sativum L., Silybum marianum (L., Gaertn and Trigonella foenum graecum L. are effective against diabetes. Flavonoids, quercin, metformin, quinolizidine, anthocyanin, catechin and flavone, phenylpropanoids, lipoic acid and coumarin metabolites were introduced major impact on diabetes. With regard to the study of plants and their metabolites and the mechanisms of their influence, it is clear that these plants have the potential to reduce blood sugar and diabetes and be considered as candidates for preparing new drugs. Combination of plants extracts or their components may also have synergistic effects to better act on diabetes.

Add Control: plant virtualization for control solutions in WWTP.

Science.gov (United States)

Maiza, M; Bengoechea, A; Grau, P; De Keyser, W; Nopens, I; Brockmann, D; Steyer, J P; Claeys, F; Urchegui, G; Fernández, O; Ayesa, E

2013-01-01

This paper summarizes part of the research work carried out in the Add Control project, which proposes an extension of the wastewater treatment plant (WWTP) models and modelling architectures used in traditional WWTP simulation tools, addressing, in addition to the classical mass transformations (transport, physico-chemical phenomena, biological reactions), all the instrumentation, actuation and automation & control components (sensors, actuators, controllers), considering their real behaviour (signal delays, noise, failures and power consumption of actuators). Its ultimate objective is to allow a rapid transition from the simulation of the control strategy to its implementation at full-scale plants. Thus, this paper presents the application of the Add Control simulation platform for the design and implementation of new control strategies at the WWTP of Mekolalde.

Performance test of nutrient control equipment for hydroponic plants

Science.gov (United States)

Rahman, Nurhaidar; Kuala, S. I.; Tribowo, R. I.; Anggara, C. E. W.; Susanti, N. D.

2017-11-01

Automatic control equipment has been made for the nutrient content in irrigation water for hydroponic plants. Automatic control equipment with CCT53200E conductivity controller to nutrient content in irrigation water for hydroponic plants, can be used to control the amount of TDS of nutrient solution in the range of TDS numbers that can be set according to the range of TDS requirements for the growth of hydroponically cultivated crops. This equipment can minimize the work time of hydroponic crop cultivators. The equipment measurement range is set between 1260 ppm up to 1610 ppm for spinach plants. Caisim plants were included in this experiment along with spinach plants with a spinach plants TDS range. The average of TDS device is 1450 ppm, while manual (conventional) is 1610 ppm. Nutrient solution in TDS controller has pH 5,5 and temperature 29,2 °C, while manual is pH 5,6 and temperature 31,3 °C. Manually treatment to hydroponic plant crop, yields in an average of 39.6 grams/plant, greater than the yield of spinach plants with TDS control equipment, which is in an average of 24.6 grams / plant. The yield of caisim plants by manual treatment is in an average of 32.3 grams/crop, less than caisim crop yields with TDS control equipment, which is in an average of 49.4 grams/plant.

The water desalination complex based on ABV-type reactor plant

International Nuclear Information System (INIS)

Panov, Yu.K.; Fadeev, Yu.P.; Vorobiev, V.M.; Baranaev, Yu.D.

1997-01-01

A floating nuclear desalination complex with two barges, one for ABV type reactor plant, with twin reactor 2 x 6 MW(e), and one for reverse osmosis desalination plant, was described. The principal specifications of the ABV type reactor plant and desalination barge were given. The ABV type reactor has a traditional two-circuit layout using an integral type reactor vessel with all mode natural convection of primary coolant. The desalted water cost was estimated to be around US $0.86 per cubic meter. R and D work has been performed and preparations for commercial production are under way. (author)

Instrumentation, control and modellisation/simulation in waste water treatment plants; Instrumentacion, control y modelizacion/simulacion en plantas depuradoras de aguas residuales

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, E.; Martinez, J. L.; Llorente, V.

2002-07-01

Controlling waste water treatment plants presents numerous problems as a result of the complexity of the task involved in managing them. The different instruments used in monitoring and controlling the flow, dissolved oxygen, pH, cloudiness and other parameters involved in the treatment process at level 0 are listed and described. The control and regulation equipment comprising level 1 is operated by the process computers of level 2. The different types of instruments are studied in relation to monitoring and control and the analysis and management o the data supplied by the instrumentation, the control strategies, operational margins and applicable software. Several case studies of activated sludge treatment processes are included to facilitate comprehension. Finally, the simulation models are presented with a view to aiding understanding, management and prediction of the operation of waste water treatment plants, particularly in regard to the problems of bulking and/or foaming. (Author)

Integrating environmental control for coal plant efficiency

Energy Technology Data Exchange (ETDEWEB)

Shepard, M

1986-01-01

As emission control requirements for power plants have grown more stringent, utilities have added new environmental protection technology. As environmental controls have been added one after another, plant designers have rarely had the opportunity to integrate these components with each other and the balance of the plant. Consequently they often cost more to build and operate and can reduce power plant efficiency and availability. With the aim of lowering the cost of environmental systems, a design approach known as integrated environmental control (IEC) has emerged. This is based on the premise that environmental controls can function most economically if they are designed integrally with other power generation equipment. EPRI has established an IEC progam to develop integrated design strategies and evaluate their net worth to utilities. Various aspects of this program are described. (3 refs.)

The control and automation of a complex experimental plant: The Sesta test facility; L`automazione di un impiuanto sperimentale complesso: La stazione di Sesta

Energy Technology Data Exchange (ETDEWEB)

Maini, Michele; Prandoni, Walter [ENEL Spa, Cologno Monzese (Italy). Polo Elettrico e Automazione. Unita` Robotica

1997-05-01

The running of complex experimental plants in the field of energetic sources involves a strong component of automation. Since they are unique and innovative plants there are not well defined ways to run them. So it is necessary to design the automation each time and then to select the proper resources for the implementation. The plant for the testing of gas turbine components of Sesta is an important example of this type of approach.

UNDERSTANDING PLANT-SOIL RELATIONSHIPS USING CONTROLLED ENVIRONMENT FACILITIES

Science.gov (United States)

Although soil is a component of terrestrial ecosystems, it is comprised of a complex web of interacting organisms, and therefore, can be considered itself as an ecosystem. Soil microflora and fauna derive energy from plants and plant residues and serve important functions in mai...

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.; Edwards, R.M.; Ray, A.; Lee, K.Y.; Garcia, H.E.: Chavez, C.M.; Turso, J.A.; BenAbdennour, A.

1991-01-01

In September of 1989 work began on the DOE University Program grant DE-FG07-89ER12889. The grant provides support for a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this Second Annual Technical Progress report covers the period from September 1990 to September 1991. It summarizes the second year accomplishments while the appendices provide detailed information presented at conference meetings. These are two primary goals of this research. The first is to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz, a project consultant during the first year of the project. This philosophy, as presented in the first annual technical progress report, is to improve public perception of the safety of nuclear power plants by incorporating a high degree automation where greatly simplified operator control console minimizes the possibility of human error in power plant operations. A hierarchically distributed control system with automated responses to plant upset conditions is the focus of our research to achieve this goal. The second goal is to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-II steam plant

BWR plant advanced central control panel PODIA

International Nuclear Information System (INIS)

Fujii, K.; Hayakawa, H.; Ikeda, Y.; Neda, T.; Suto, O.; Takamiya, S.

1983-01-01

BWR plant central control panels have become more and more enlarged and complicated recently due to the magnification of the scale of a plant and the requirement to reinforce safety. So, it is important to make communication between men and the complicated central control panel smooth. Toshiba has developed an advanced central control panel, named PODIA, which uses many computers and color CRTs, and PODIA is now in the stage of application to practical plants. In this article, the writers first touch upon control functions transition in the central control room, the PODIA position concerning the world-wide trend in this technology phase and the human engineering on the design. Then they present concrete design concepts for the control board and computer system which constitute PODIA

Analysis and control of complex dynamical systems robust bifurcation, dynamic attractors, and network complexity

CERN Document Server

Imura, Jun-ichi; Ueta, Tetsushi

2015-01-01

This book is the first to report on theoretical breakthroughs on control of complex dynamical systems developed by collaborative researchers in the two fields of dynamical systems theory and control theory. As well, its basic point of view is of three kinds of complexity: bifurcation phenomena subject to model uncertainty, complex behavior including periodic/quasi-periodic orbits as well as chaotic orbits, and network complexity emerging from dynamical interactions between subsystems. Analysis and Control of Complex Dynamical Systems offers a valuable resource for mathematicians, physicists, and biophysicists, as well as for researchers in nonlinear science and control engineering, allowing them to develop a better fundamental understanding of the analysis and control synthesis of such complex systems.

Improvement on reliability of control system in power plant

International Nuclear Information System (INIS)

Taguchi, S.; Mizumoto, T.; Hirose, Y.; Kashiwai, J.; Takami, I.; Shono, M.; Roji, Y.; Kizaki, S.

1985-01-01

Studies made of Japanese PWR operating experiences have revealed that failures in the control system are the primary causes of unscheduled shutdowns. An attempt has, therefore, been made to improve the reliability of the control system in order to raise the plant reliability. The following are the procedures applied to solve the issue; study of operating experiences, fault tree analysis and failure mode and effects analysis. Improvement measures are developed for the control system whose failure threatens to cause the plant trip during the plant life. These systems are the main feedwater control system, rod control system, pressurizer control system and main steam control system in the primary control system. As a result, the plant unavailability is expected to be reduced significantly by applying the improvements. The improvements are applied to the plants under construction and the operating plants in co-operation with utilities and vendors. (author)

Scada Systems – Control, Supervision and Data Acquisition for the Power Plants Settled on a Stream (Part 2

Directory of Open Access Journals (Sweden)

Cosmin Ursoniu

2015-09-01

Full Text Available Scada (supervisory control and data acquisition is a complex system that supervises and controls an industrial process and performs several functions. A human machine interface will also be presented and how the process in a power plant is controlled and supervised through it by the operator. The main screen will be described (which is a global view of the hydro unit and what the operator can see and what he can press to control the power plants process also a few more screens will be presented for auxiliary installations and it will be described what the operator can see and what he can do to control the installation.

Scada Systems – Control, Supervision and Data Acquisition for the Power Plants Settled on a Stream (Part 1

Directory of Open Access Journals (Sweden)

Cosmin Ursoniu

2015-09-01

Full Text Available Scada (supervisory control and data acquisition is a complex system that supervises and control an industrial process and performs several functions. A human machine interface will also be presented and how the process in a power plant is controlled and supervised through it by the operator. The main screen will be described (which is a global view of the hydro unit and what the operator can see and what he can press to control the power plants process also a few more screens will be presented for auxiliary installations and it will be described what the operator can see and what he can do to control the installation.

Identifying cognitive complexity factors affecting the complexity of procedural steps in emergency operating procedures of a nuclear power plant

International Nuclear Information System (INIS)

Park, Jinkyun; Jeong, Kwangsup; Jung, Wondea

2005-01-01

In complex systems such as a nuclear and chemical plant, it is well known that the provision of understandable procedures that allow operators to clarify what needs to be done and how to do it is one of the requisites to secure their safety. As a previous study in providing understandable procedures, the step complexity (SC) measure that can quantify the complexity of procedural steps in emergency operating procedures (EOPs) of a nuclear power plant (NPP) was suggested. However, the necessity of additional complexity factors that can consider a cognitive aspect in evaluating the complexity of procedural steps is raised. To this end, the comparisons between operators' performance data measured by the form of a step performance time with their behavior in carrying out the prescribed activities of procedural steps are conducted in this study. As a result, two kinds of complexity factors (the abstraction level of knowledge and the level of engineering decision) that could affect an operator's cognitive burden are identified. Although a well-designed experiment is indispensable for confirming the appropriateness of the additional complexity factors, it is strongly believed that the change of operators' performance data can be more authentically explained if the additional complexity factors are taken into consideration

Identifying cognitive complexity factors affecting the complexity of procedural steps in emergency operating procedures of a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Park, Jinkyun [Integrated Safety Assessment Division, Korea Atomic Energy Research Institute, P.O. Box 105, Duckjin-Dong, Yusong-Ku, Taejon 305-600 (Korea, Republic of)]. E-mail: kshpjk@kaeri.re.kr; Jeong, Kwangsup [Integrated Safety Assessment Division, Korea Atomic Energy Research Institute, P.O. Box 105, Duckjin-Dong, Yusong-Ku, Taejon 305-600 (Korea, Republic of); Jung, Wondea [Integrated Safety Assessment Division, Korea Atomic Energy Research Institute, P.O. Box 105, Duckjin-Dong, Yusong-Ku, Taejon 305-600 (Korea, Republic of)

2005-08-01

In complex systems such as a nuclear and chemical plant, it is well known that the provision of understandable procedures that allow operators to clarify what needs to be done and how to do it is one of the requisites to secure their safety. As a previous study in providing understandable procedures, the step complexity (SC) measure that can quantify the complexity of procedural steps in emergency operating procedures (EOPs) of a nuclear power plant (NPP) was suggested. However, the necessity of additional complexity factors that can consider a cognitive aspect in evaluating the complexity of procedural steps is raised. To this end, the comparisons between operators' performance data measured by the form of a step performance time with their behavior in carrying out the prescribed activities of procedural steps are conducted in this study. As a result, two kinds of complexity factors (the abstraction level of knowledge and the level of engineering decision) that could affect an operator's cognitive burden are identified. Although a well-designed experiment is indispensable for confirming the appropriateness of the additional complexity factors, it is strongly believed that the change of operators' performance data can be more authentically explained if the additional complexity factors are taken into consideration.

Identifying cognitive complexity factors affecting the complexity of procedural steps in emergency operating procedures of a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Jinkyun Park; Kwangsup Jeong; Wondea Jung [Korea Atomic Energy Research Institute, Taejon (Korea). Integrated Safety Assessment Division

2005-08-15

In complex systems such as a nuclear and chemical plant, it is well known that the provision of understandable procedures that allow operators to clarify what needs to be done and how to do it is one of the requisites to secure their safety. As a previous study in providing understandable procedures, the step complexity (SC) measure that can quantify the complexity of procedural steps in emergency operating procedures (EOPs) of a nuclear power plant (NPP) was suggested. However, the necessity of additional complexity factors that can consider a cognitive aspect in evaluating the complexity of procedural steps is raised. To this end, the comparisons between operator' performance data measured by the form of a step performance time with their behavior in carrying out the prescribed activities of procedural steps are conducted in this study. As a result, two kinds of complexity factors (the abstraction level of knowledge and the level of engineering decision) that could affect an operator's cognitive burden are identified. Although a well-designed experiment is indispensable for confirming the appropriateness of the additional complexity factors, it is strongly believed that the change of operators' performance data can be more authentically explained if the additional complexity factors are taken into consideration. (author)

Plant control using embedded predictive models

International Nuclear Information System (INIS)

Godbole, S.S.; Gabler, W.E.; Eschbach, S.L.

1990-01-01

B and W recently undertook the design of an advanced light water reactor control system. A concept new to nuclear steam system (NSS) control was developed. The concept, which is called the Predictor-Corrector, uses mathematical models of portions of the controlled NSS to calculate, at various levels within the system, demand and control element position signals necessary to satisfy electrical demand. The models give the control system the ability to reduce overcooling and undercooling of the reactor coolant system during transients and upsets. Two types of mathematical models were developed for use in designing and testing the control system. One model was a conventional, comprehensive NSS model that responds to control system outputs and calculates the resultant changes in plant variables that are then used as inputs to the control system. Two other models, embedded in the control system, were less conventional, inverse models. These models accept as inputs plant variables, equipment states, and demand signals and predict plant operating conditions and control element states that will satisfy the demands. This paper reports preliminary results of closed-loop Reactor Coolant (RC) pump trip and normal load reduction testing of the advanced concept. Results of additional transient testing, and of open and closed loop stability analyses will be reported as they are available

The function of the Mediator complex in plant immunity.

Science.gov (United States)

An, Chuanfu; Mou, Zhonglin

2013-03-01

Upon pathogen infection, plants undergo dramatic transcriptome reprogramming to shift from normal growth and development to immune response. During this rapid process, the multiprotein Mediator complex has been recognized as an important player to fine-tune gene-specific and pathway-specific transcriptional reprogramming by acting as an adaptor/coregulator between sequence-specific transcription factor and RNA polymerase II (RNAPII). Here, we review current understanding of the role of five functionally characterized Mediator subunits (MED8, MED15, MED16, MED21 and MED25) in plant immunity. All these Mediator subunits positively regulate resistance against leaf-infecting biotrophic bacteria or necrotrophic fungi. While MED21 appears to regulate defense against fungal pathogens via relaying signals from upstream regulators and chromatin modification to RNAPII, the other four Mediator subunits locate at different positions of the defense network to convey phytohormone signal(s). Fully understanding the role of Mediator in plant immunity needs to characterize more Mediator subunits in both Arabidopsis and other plant species. Identification of interacting proteins of Mediator subunits will further help to reveal their specific regulatory mechanisms in plant immunity.

An overview of the gene regulatory network controlling trichome development in the model plant, Arabidopsis

Directory of Open Access Journals (Sweden)

Sitakanta ePattanaik

2014-06-01

Full Text Available Trichomes are specialized epidermal cells located on aerial parts of plants and are associated with a wide array of biological processes. Trichomes protect plants from adverse conditions including UV light and herbivore attack and are also an important source of a number of phytochemicals. The simple unicellular trichomes of Arabidopsis serve as an excellent model to study molecular mechanism of cell differentiation and pattern formation in plants. The emerging picture suggests that the developmental process is controlled by a transcriptional network involving three major groups of transcription factors: the R2R3 MYB, basic helix-loop-helix (bHLH and WD40 repeat (WDR protein. These regulatory proteins form a trimeric activator complex that positively regulates trichome development. The single repeat R3 MYBs act as negative regulators of trichome development. They compete with the R2R3 MYBs to bind the bHLH factor and form a repressor complex. In addition to activator-repressor mechanism, a depletion mechanism may operate in parallel during trichome development. In this mechanism, the bHLH factor traps the WDR protein which results in depletion of WDR protein in neighboring cells. Consequently, the cells with high levels of bHLH and WDR proteins are developed into trichomes. A group of C2H2 zinc finger TFs has also been implicated in trichome development. Phytohormones, including gibberellins and jasmonic acid, play significant roles in this developmental process. Recently, microRNAs have been shown to be involved in trichome development. Furthermore, it has been demonstrated that the activities of the key regulatory proteins involved in trichome development are controlled by the 26S/ubiquitin proteasome system (UPS, highlighting the complexity of the regulatory network controlling this developmental process. To complement several excellent recent relevant reviews, this review focuses on the transcriptional network and hormonal interplay

Configuration management of plant modifications for nuclear power plants

International Nuclear Information System (INIS)

Ritsch, W.J.

1987-01-01

Due to the increasing complexity of nuclear power plant operation, regulatory pressure, and the large numbers of people required to operate and support the stations, the control of plant modifications at these plants needs to be expanded and improved. The aerospace and defense industries, as well as the owners or operators of large energy projects have established configuration management programs (CMPs) to control plant design changes. These programs are composed of well-defined functions for identifying, evaluating, recording, tracking, issuing, and documenting the established baseline conditions, as well as required changes to these baseline conditions. The purpose of this paper is to describe a recommended CMP for plant modifications consisting of a computerized data base installed on the utility's computer to provide a central storage of plant design and operations data necessary to control the following activities as they are affected by plant design changes: training; record management; operations; maintenance; health physics; planning/scheduling; procurement/inventory control; outage management (including modifications); and emergency response

Instrumentation and control system upgrade plan for operating PWR plants in Japan

International Nuclear Information System (INIS)

Ishii, Hirofumi

1993-01-01

Digital technology has been applied to all non-safety grade instrumentation and control (I ampersand C) systems in the latest Japanese PWR plants, and has achieved more reliable and operable systems, easier maintenance and cable reductions. In the next stage APWR plants, the digital technology will be also applied to all the I ampersand C systems including safety grade systems. Parallel to the above efforts, many backfitting programs in which the digital technology is applied to operating plants are under way to improve reliability and operability. The backfitting programs for operating plants are proceeded in two phases, synthesizing various utility's needs to improve plant availability and operability, improvement of digital technology, and complexity of the practicable replacement procedures. Phase 1 is a partial application of digital technology, while Phase 2 is a complete application of digital technology. Phase 1 has been implemented in a number of operation plants, while Phase 2 studies are in the design stage, but have not been implemented at this point. This paper presents examples of the partial application of digital technology to operating plants, and the contents of basic design for the complete application of digital technology

Modelling and controlling hydropower plants

CERN Document Server

Munoz-Hernandez, German Ardul; Jones, Dewi Ieuan

2013-01-01

Hydroelectric power stations are a major source of electricity around the world; understanding their dynamics is crucial to achieving good performance.  Modelling and Controlling Hydropower Plants discusses practical and well-documented cases of modelling and controlling hydropower station modelling and control, focussing on a pumped storage scheme based in Dinorwig, North Wales.  Single-input-single-output and multiple-input-multiple-output models, which cover the linear and nonlinear characteristics of pump-storage hydroelectric power stations, are reviewed. The most important dynamic features are discussed, and the verification of these models by hardware in the loop simulation is described. To show how the performance of a pump-storage hydroelectric power station can be improved, classical and modern controllers are applied to simulated models of the Dinorwig power plant. These include PID, fuzzy approximation, feed-forward and model-based predictive control with linear and hybrid prediction models. Mod...

B Plant complex hazardous, mixed and low level waste certification plan

International Nuclear Information System (INIS)

Beam, T.G.

1994-11-01

This plan describes the administrative steps and handling methodology for certification of hazardous waste, mixed waste, and low level waste generated at B Plant Complex. The plan also provides the applicable elements of waste reduction and pollution prevention, including up front minimization and end product reduction of volume and/or toxicity. The plan is written to satisfy requirements for Hanford Site waste generators to have a waste certification program in place at their facility. This plan, as described, applies only to waste which is generated at, or is the responsibility of, B Plant Complex. The scope of this plan is derived from the requirements found in WHC-EP-0063, Hanford Site Solid Waste Acceptance Criteria

B Plant complex hazardous, mixed and low level waste certification plan

Energy Technology Data Exchange (ETDEWEB)

Beam, T.G.

1994-11-01

This plan describes the administrative steps and handling methodology for certification of hazardous waste, mixed waste, and low level waste generated at B Plant Complex. The plan also provides the applicable elements of waste reduction and pollution prevention, including up front minimization and end product reduction of volume and/or toxicity. The plan is written to satisfy requirements for Hanford Site waste generators to have a waste certification program in place at their facility. This plan, as described, applies only to waste which is generated at, or is the responsibility of, B Plant Complex. The scope of this plan is derived from the requirements found in WHC-EP-0063, Hanford Site Solid Waste Acceptance Criteria.

Complexity factors and prediction of performance

International Nuclear Information System (INIS)

Braarud, Per Oeyvind

1998-03-01

Understanding of what makes a control room situation difficult to handle is important when studying operator performance, both with respect to prediction as well as improvement of the human performance. A factor analytic approach identified eight factors from operators' answers to an 39 item questionnaire about complexity of the operator's task in the control room. A Complexity Profiling Questionnaire was developed, based on the factor analytic results from the operators' conception of complexity. The validity of the identified complexity factors was studied by prediction of crew performance and prediction of plant performance from ratings of the complexity of scenarios. The scenarios were rated by both process experts and the operators participating in the scenarios, using the Complexity Profiling Questionnaire. The process experts' complexity ratings predicted both crew performance and plant performance, while the operators' rating predicted plant performance only. The results reported are from initial studies of complexity, and imply a promising potential for further studies of the concept. The approach used in the study as well as the reported results are discussed. A chapter about the structure of the conception of complexity, and a chapter about further research conclude the report. (author)

Systemic delivery of siRNA in pumpkin by a plant PHLOEM SMALL RNA-BINDING PROTEIN 1-ribonucleoprotein complex.

Science.gov (United States)

Ham, Byung-Kook; Li, Gang; Jia, Weitao; Leary, Julie A; Lucas, William J

2014-11-01

In plants, the vascular system, specifically the phloem, functions in delivery of small RNA (sRNA) to exert epigenetic control over developmental and defense-related processes. Although the importance of systemic sRNA delivery has been established, information is currently lacking concerning the nature of the protein machinery involved in this process. Here, we show that a PHLOEM SMALL-RNA BINDING PROTEIN 1 (PSRP1) serves as the basis for formation of an sRNA ribonucleoprotein complex (sRNPC) that delivers sRNA (primarily 24 nt) to sink organs. Assembly of this complex is facilitated through PSRP1 phosphorylation by a phloem-localized protein kinase, PSRPK1. During long-distance transport, PSRP1-sRNPC is stable against phloem phosphatase activity. Within target tissues, phosphatase activity results in disassembly of PSRP1-sRNPC, a process that is probably required for unloading cargo sRNA into surrounding cells. These findings provide an insight into the mechanism involved in delivery of sRNA associated with systemic gene silencing in plants. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Modeling complex flow structures and drag around a submerged plant of varied posture

Science.gov (United States)

Boothroyd, Richard J.; Hardy, Richard J.; Warburton, Jeff; Marjoribanks, Timothy I.

2017-04-01

Although vegetation is present in many rivers, the bulk of past work concerned with modeling the influence of vegetation on flow has considered vegetation to be morphologically simple and has generally neglected the complexity of natural plants. Here we report on a combined flume and numerical model experiment which incorporates time-averaged plant posture, collected through terrestrial laser scanning, into a computational fluid dynamics model to predict flow around a submerged riparian plant. For three depth-limited flow conditions (Reynolds number = 65,000-110,000), plant dynamics were recorded through high-definition video imagery, and the numerical model was validated against flow velocities collected with an acoustic Doppler velocimeter. The plant morphology shows an 18% reduction in plant height and a 14% increase in plant length, compressing and reducing the volumetric canopy morphology as the Reynolds number increases. Plant shear layer turbulence is dominated by Kelvin-Helmholtz type vortices generated through shear instability, the frequency of which is estimated to be between 0.20 and 0.30 Hz, increasing with Reynolds number. These results demonstrate the significant effect that the complex morphology of natural plants has on in-stream drag, and allow a physically determined, species-dependent drag coefficient to be calculated. Given the importance of vegetation in river corridor management, the approach developed here demonstrates the necessity to account for plant motion when calculating vegetative resistance.

Intelligent control system Cellular Robotics Approach to Nuclear Plant control and maintenance

International Nuclear Information System (INIS)

Fukuda, Toshio; Sekiyama, Kousuke; Xue Guoqing; Ueyama, Tsuyoshi.

1994-01-01

This paper presents the concept of Cellular Robotic System (CEBOT) and describe the strategy of a distributed sensing, control and planning as a Cellular Robotics Approach to the Nuclear Plant control and maintenance. Decentralized System is effective in large plant and The CEBOT possesses desirable features for realization of Nuclear Plant control and maintenance because of its flexibility and adaptability. Also, as related on going research work, self-organizing manipulator and communication issues are mentioned. (author)

Nuclear power plant monitoring and control system software: verification and validation

International Nuclear Information System (INIS)

Kaneda, M.; Niki, K.; Shibata, K.

1986-01-01

The design philosophy, configuration, and production of process computer system software used for the monitoring and control of nuclear power plants are presented in detail. To achieve a very complex software system that not only has excellent performance, high reliability, and full fail safe protection, but also is easy to produce, verify, and validate, and has flexibility for future modifications, we developed the following software production system to support safe operation of nuclear power stations. The fundamental design philosophy of our monitoring and control system software is the complete separation of program logic from the data base. The logic section is highly standardized and applicable to a wide range of power generation plant computer application systems. The plant-unique properties and characteristics are all described in the data base. This separation of logic and data base has a dramatic effect on the reliability and productivity of the software system. One of the main features of the data base system is the use of easy-to-learn, easy-to-use, problem-oriented language that enables non-programmers to build up the data base using simple fill-in-the-blank type tables. The generation of these tables is fully automated, and the full set of online table editing utility software, which runs on the target plant process computer, has proven very effective in incorporation of changes and modifications at the site. (author)

Neuro-fuzzy controller of low head hydropower plants using adaptive-network based fuzzy inference system

Energy Technology Data Exchange (ETDEWEB)

Djukanovic, M.B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M.S. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Vesovic, B.V. [Inst. Mihajlo Pupin, Belgrade (Yugoslavia). Dept. of Automatic Control; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

1997-12-01

This paper presents an attempt of nonlinear, multivariable control of low-head hydropower plants, by using adaptive-network based fuzzy inference system (ANFIS). The new design technique enhances fuzzy controllers with self-learning capability for achieving prescribed control objectives in a near optimal manner. The controller has flexibility for accepting more sensory information, with the main goal to improve the generator unit transients, by adjusting the exciter input, the wicket gate and runner blade positions. The developed ANFIS controller whose control signals are adjusted by using incomplete on-line measurements, can offer better damping effects to generator oscillations over a wide range of operating conditions, than conventional controllers. Digital simulations of hydropower plant equipped with low-head Kaplan turbine are performed and the comparisons of conventional excitation-governor control, state-feedback optimal control and ANFIS based output feedback control are presented. To demonstrate the effectiveness of the proposed control scheme and the robustness of the acquired neuro-fuzzy controller, the controller has been implemented on a complex high-order non-linear hydrogenerator model.

Screen-based process control in nuclear plants

International Nuclear Information System (INIS)

Hinz, W.; Arnoldt, C.; Hessler, C.

1993-01-01

Requirements, development and conceptual design of a screen-based control room for nuclear power plants are outlined. The control room consists of three or four equally equipped operator workstations comprising screens for process information and manual process control. A plant overview will assist the coordination among the operators. A safety classified backup system (safety control area) is provided to cover postulated failures of the control means. Some aspects of ergonomical validation and of future development trends are discussed. (orig.) [de

Virtual control desk for operators training: a case study for a nuclear power plant simulator

International Nuclear Information System (INIS)

Aghina, Mauricio Alves da Cunha e

2009-03-01

Nuclear Power Plant (NPP) is a facility for electrical energy generation. Because of its high degree of complexity and very rigid norms of security it is extremely necessary that operators are very well trained for the NPP operation. A mistaken operation by a human operator may cause a shutdown of the NPP, incurring in a huge economical damage for the owner and for the population in the case of a electric net black out. To reduce the possibility of a mistaken operation, the NPP usually have a full scope simulator of the plant's control room, which is the physical copy of the original control room. The control of this simulator is a computer program that can generate the equal functioning of the normal one or some scenarios of accidents to train the operators in many abnormal conditions of the plant. A physical copy of the control room has a high cost for its construction, not only of its facilities but also for its physical components. The proposal of this work is to present a project of a virtual simulator with the modeling in 3D stereo of a control room of a given nuclear plant with the same operation functions of the original simulator. This virtual simulator will have a lower cost and serves for pretraining of operators with the intention of making them familiar to the original control room. (author)

Flower-Visiting Social Wasps and Plants Interaction: Network Pattern and Environmental Complexity

Directory of Open Access Journals (Sweden)

Mateus Aparecido Clemente

2012-01-01

Full Text Available Network analysis as a tool for ecological interactions studies has been widely used since last decade. However, there are few studies on the factors that shape network patterns in communities. In this sense, we compared the topological properties of the interaction network between flower-visiting social wasps and plants in two distinct phytophysiognomies in a Brazilian savanna (Riparian Forest and Rocky Grassland. Results showed that the landscapes differed in species richness and composition, and also the interaction networks between wasps and plants had different patterns. The network was more complex in the Riparian Forest, with a larger number of species and individuals and a greater amount of connections between them. The network specialization degree was more generalist in the Riparian Forest than in the Rocky Grassland. This result was corroborated by means of the nestedness index. In both networks was found asymmetry, with a large number of wasps per plant species. In general aspects, most wasps had low niche amplitude, visiting from one to three plant species. Our results suggest that differences in structural complexity of the environment directly influence the structure of the interaction network between flower-visiting social wasps and plants.

Plant Control Concept for the Sodium Cooled Fast Reactor

International Nuclear Information System (INIS)

Kim, Eui Kwang; Kim, S. O.

2010-12-01

A power plant is designed for incorporation into a utility's grid system and follows the load demand through the steam generator, intermediate heat exchanger(IHX), from the nuclear core. During the load-following transients, various plant parameters must be controlled to protect the reactor core and other components in the plant. The purpose of this report is to review design considerations to establish SFR plant control and to design plant control concepts. The governing equations and solution procedure of the computer code to calculate plant temperature conditions during the part-load operation was reviewed and 4 types of plant operation concepts were designed, and the results of the calculations were compared

Improved design architecture to minimize functional complexity of plant protection system for nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Jung, JaeCheon, E-mail: jcjung@kings.ac.kr

2016-12-01

An improved design architecture method to minimize the functional complexity of PPS (Plant Protection System) is proposed in this work. Firstly, the design concerns are identified with both AHP (Analytic Hierarchy Process) analysis. AHP is able to identify the source of design concerns using pairwise comparison. AHP result shows CCF is the primary concern and the complexity is the secondly. Even though complexity is the second largest concern to the effectiveness of digital I&C system, but it has not been highlighted as CCF. This is the reason why this work focuses on the sources of complexity to maximize the effectiveness of digital system in the viewpoint of design architecture. The proposed methods are, separating non-safety functions from bistable logics and simplifying communication links and network. In order to verify the new concept, EFFBD (Enhanced Functional Flow Block Diagram) models are developed for two bistable logics of PPS and the complexities are measured using Halstead’s program maintainability measures. This measure specifies what provokes functional complexity. Periodic testing and operating bypass function are the source of complexity in this analysis.

Improved design architecture to minimize functional complexity of plant protection system for nuclear power plant

International Nuclear Information System (INIS)

Jung, JaeCheon

2016-01-01

An improved design architecture method to minimize the functional complexity of PPS (Plant Protection System) is proposed in this work. Firstly, the design concerns are identified with both AHP (Analytic Hierarchy Process) analysis. AHP is able to identify the source of design concerns using pairwise comparison. AHP result shows CCF is the primary concern and the complexity is the secondly. Even though complexity is the second largest concern to the effectiveness of digital I&C system, but it has not been highlighted as CCF. This is the reason why this work focuses on the sources of complexity to maximize the effectiveness of digital system in the viewpoint of design architecture. The proposed methods are, separating non-safety functions from bistable logics and simplifying communication links and network. In order to verify the new concept, EFFBD (Enhanced Functional Flow Block Diagram) models are developed for two bistable logics of PPS and the complexities are measured using Halstead’s program maintainability measures. This measure specifies what provokes functional complexity. Periodic testing and operating bypass function are the source of complexity in this analysis.

A computerized diagnostic system for nuclear plant control rooms based on statistical quality control

International Nuclear Information System (INIS)

Heising, C.D.; Grenzebach, W.S.

1990-01-01

In engineering science, statistical quality control techniques have traditionally been applied to control manufacturing processes. An application to commercial nuclear power plant maintenance and control is presented that can greatly improve safety. As a demonstration of such an approach to plant maintenance and control, a specific system is analyzed: the reactor coolant pumps of the St. Lucie Unit 2 nuclear power plant located in Florida. A 30-day history of the four pumps prior to a plant shutdown caused by pump failure and a related fire within the containment was analyzed. Statistical quality control charts of recorded variables were constructed for each pump, which were shown to go out of statistical control many days before the plant trip. The analysis shows that statistical process control methods can be applied as an early warning system capable of identifying significant equipment problems well in advance of traditional control room alarm indicators

Compartmentation and complexation of metals in hyperaccumulator plants

Directory of Open Access Journals (Sweden)

Barbara eLeitenmaier

2013-09-01

Full Text Available Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their strange behaviour in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defence against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e. detoxified by binding to strong ligands such as metallothioneins.

Research of polysaccharide complexes from asteraceae family plants

Directory of Open Access Journals (Sweden)

Світлана Михайлівна Марчишин

2015-10-01

Full Text Available Aim of research. Depth study of polysaccharides in some little-known plant species of Asteraceae family is pressing question, considering that polysaccharides are important biologically active compounds widely used in pharmaceutical and medical practice as remedies and preventive medications. The aim of research was to determinate both quantitative content and monomeric composition of polysaccharide complexes from Asteraceae family plant species – Tagetes genus, Arnica genus, and Bellis genus.Materials and methods. Determination of polysaccharides was carried out by the precipitation reaction, using 96 % ethyl alcohol P and Fehling's solution after acid hydrolysis; quantitative content of this group of compounds was determined by gravimetric analysis. On purpose to identify the monomeric composition hydrolysis under sulfuric acid conditions was conducted. Qualitative monomeric composition of polysaccharides after hydrolysis was carried out by paper chromatography method in n-Butanol – Pyridine – Distilled water P (6:4:3 system along with saccharides reference samples.Results. Polysaccharide complexes from Tagetes erecta, Tagetes patula, Tagetes tenuifolia, Arnica montana, Arnica foliosa, wild and cultivated Bellis perennis herbs were studied. Water-soluble polysaccharides and pectin fractions were isolated from studied objects; their quantitative content and monomeric composition were determined.Conclusion. The highest amount of water-soluble polysaccharides was found in cultivated Bellis perennis herb (10,13 %, the highest amount of pectin compounds – in Tagetes tenuifolia herb (13,62 %; the lowest amount of water-soluble polysaccharides and pectin compounds was found in Arnica montana herb (4,61 % and Tagetes patula herb (3,62 %, respectively. It was found that polysaccharide complexes from all studied species include glucose and arabinose

New technology in nuclear power plant instrumentation and control

International Nuclear Information System (INIS)

Anon.

1985-01-01

The primary topic of this book is what can be done to improve nuclear power plant operation safety and the economic benefits that can be gained with the utilization of advance instrumentation and control technology. Other topics discussed are the industry's reluctance to accept new designs determining cost effective improvements, and difficulties in meeting regulatory standards with new technology control. The subjects will be useful when considering the area of instrumentation and control for enhancing plant operation and safety. Contents: Advanced Instrumention, Plant Control and Monitoring, Plant Diagnostics and Failure Detection, Human Factors Considerations in Instrumentation and Control, NRC and Industry Perspective on Advanced Instrumentation and Control

Process control in biogas plants

DEFF Research Database (Denmark)

Holm-Nielsen, Jens Bo; Oleskowicz-Popiel, Piotr

2013-01-01

Efficient monitoring and control of anaerobic digestion (AD) processes are necessary in order to enhance biogas plant performance. The aim of monitoring and controlling the biological processes is to stabilise and optimise the production of biogas. The principles of process analytical technology...

Tissue-Specific Control of the Endocycle by the Anaphase Promoting Complex/Cyclosome Inhibitors UVI4 and DEL1.

Science.gov (United States)

Heyman, Jefri; Polyn, Stefanie; Eekhout, Thomas; De Veylder, Lieven

2017-09-01

The endocycle represents a modified mitotic cell cycle that in plants is often coupled to cell enlargement and differentiation. Endocycle onset is controlled by activity of the Anaphase Promoting Complex/Cyclosome (APC/C), a multisubunit E3 ubiquitin ligase targeting cell-cycle factors for destruction. CELL CYCLE SWITCH52 (CCS52) proteins represent rate-limiting activator subunits of the APC/C. In Arabidopsis ( Arabidopsis thaliana ), mutations in either CCS52A1 or CCS52A2 activators result in a delayed endocycle onset, whereas their overexpression triggers increased DNA ploidy levels. Here, the relative contribution of the APC/C CCS52A1 and APC/C CCS52A2 complexes to different developmental processes was studied through analysis of their negative regulators, being the ULTRAVIOLET-B-INSENSITIVE4 protein and the DP-E2F-Like1 transcriptional repressor, respectively. Our data illustrate cooperative activity of the APC/C CCS52A1 and APC/C CCS52A2 complexes during root and trichome development, but functional interdependency during leaf development. Furthermore, we found APC/C CCS52A1 activity to control CCS52A2 expression. We conclude that interdependency of CCS52A-controlled APC/C activity is controlled in a tissue-specific manner. © 2017 American Society of Plant Biologists. All Rights Reserved.

Optimal control of wind power plants

NARCIS (Netherlands)

Steinbuch, M.; Boer, de W.W.; Bosgra, O.H.; Peeters, S.A.W.M.; Ploeg, J.

1988-01-01

The control system design for a wind power plant is investigated. Both theoverall wind farm control and the individual wind turbine control effect thewind farm dynamic performance.For a wind turbine with a synchronous generator and rectifier/invertersystem a multivariable controller is designed.

Automatic diagnosis of oscillating control loops in complex industrial plants; Automatische Diagnose oszillierender Regelkreise in komplexen industriellen Anlagen

Energy Technology Data Exchange (ETDEWEB)

Jelali, Mohieddine [VDEh-Betriebsforschungsinstitut GmbH, Duesseldorf (Germany). Abt. Prozess- und Anlagenautomatisierung; Karra, Srinivas [Applied Manufacturing Technologies, Houston, TX (United States)

2010-07-15

Oscillations in control loops are one of the widespread problems in the process industry. Oscillations lead to increased variability in product quality, higher energy consumption, productivity losses and increased wear of plant components. This paper presents a new approach for the automatic and comprehensive diagnosis of oscillating valve-controlled processes, based on the identification of a Hammerstein model. The proposed method not only detects and quantifies valve stiction, but is also able to find out and distinguish between faults, such as aggressive controller tuning or external oscillatory disturbances, which may occur simultaneously to stiction. (orig.)

Progress of nuclear safety for symbiosis and sustainability advanced digital instrumentation, control and information systems for nuclear power plants

CERN Document Server

Yoshikawa, Hidekazu

2014-01-01

This book introduces advanced methods of computational and information systems allowing readers to better understand the state-of-the-art design and implementation technology needed to maintain and enhance the safe operation of nuclear power plants. The subjects dealt with in the book are (i) Full digital instrumentation and control systems and human?machine interface technologies (ii) Risk? monitoring methods for large and? complex? plants (iii) Condition monitors for plant components (iv) Virtual and augmented reality for nuclear power plants and (v) Software reliability verification and val

An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

Science.gov (United States)

Beck, John J; Smith, Lincoln; Baig, Nausheena

2014-01-01

The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

Power plant instrumentation and control handbook a guide to thermal power plants

CERN Document Server

Basu, Swapan

2014-01-01

The book discusses instrumentation and control in modern fossil fuel power plants, with an emphasis on selecting the most appropriate systems subject to constraints engineers have for their projects. It provides all the plant process and design details, including specification sheets and standards currently followed in the plant. Among the unique features of the book are the inclusion of control loop strategies and BMS/FSSS step by step logic, coverage of analytical instruments and technologies for pollution and energy savings, and coverage of the trends toward filed bus systems and integratio

Control of volunteer soybean plants in sunflower crop

Directory of Open Access Journals (Sweden)

Alexandre Magno Brighenti

2015-09-01

Full Text Available Sunflower (Helianthus annuus sown offseason, after soybean crop (Glycine max, is affected by the competition imposed by volunteer plants. Two experiments were carried out to evaluate the control of volunteer soybean plants in sunflower crops. The sulfentrazone herbicide (75 g ha-1, 100 g ha-1 and 250 g ha-1 causes phytotoxicity to sunflower immediately after application, however, plants recover, with no yield losses. These doses do not cause the total death of volunteer soybean plants, but temporarily paralyzes their growth, avoiding the competition with the sunflower crop. The glufosinate ammonium and ametryn herbicides are effective in controlling volunteer soybean plants, however, symptoms of phytotoxicity in the sunflower crop are high, reflecting in losses of dry weight biomass and crop yield. The other treatments do not provide satisfactory control of volunteer soybean plants and even reduce the sunflower dry weight biomass and yield.

Practice in development and utilization of program-technical complex (PTK) in in-reactor control systems

International Nuclear Information System (INIS)

Gribov, A.A.; Kuzil, A.C.; Padun, S.P.; Surnachov, S.I.; Jakovlev, G.V.

2001-01-01

Experience with the development and utilization of the program-technical complex PTK 'KRUIZ' is analyzed in the paper. A peculiarity of PTK is the orientation on acquisition, processing and diagnostics of signals from in-reactor sensors (thermocouples and SPD). The PTK 'KRUIZ' represents a new generation of tools open for further development, oriented specifically on the use in in-reactor control systems in modernized and built power units of the WWER type. In the PTK 'KRUIZ', methods, models and algorithms proved in nuclear power plants are used accounting for the utilization of up to date technical tools and systematic technical solutions. Experience with the use of basic elements of the PTK 'KRUIZ' at existing WWER reactors including peculiarities of temperature control in nuclear power plants are also dealt within the paper. (Authors)

Plant Modeling for Human Supervisory Control

DEFF Research Database (Denmark)

Lind, Morten

1999-01-01

This paper provides an overview of multilevel flow modelling (MFM) and its application for design of displays for the supervisory control of industrial plant. The problem of designing the inforrrzatian content of sacpervisory displays is discussed and plant representations like MFM using levels...

Complex programmable logic device based alarm sequencer for nuclear power plants

International Nuclear Information System (INIS)

Khedkar, Ravindra; Solomon, J. Selva; KrishnaKumar, B.

2001-01-01

Complex Programmable Logic Device based Alarm Sequencer is an instrument, which detects alarms, memorizes them and displays the sequences of occurrence of alarms. It caters to sixteen alarm signals and distinguishes the sequence among any two alarms with a time resolution of 1 ms. The system described has been designed for continuous operation in process plants, nuclear power plants etc. The system has been tested and found to be working satisfactorily. (author)

Support for cooperative control and maintenance operation in advanced nuclear power plant from generalized and intuitive viewpoints

International Nuclear Information System (INIS)

Numano, Masayoshi; Niwa, Yasuyuki; Miyazaki, Keiko; Fukuto, Junji; Tanaka, Kunihiko; Okazaki, Tadatsugi; Itoh, Hiroko; Matsuoka, Takeshi

2002-01-01

To keep safety and effectiveness in control and maintenance operations of large and complex plants like nuclear power plants, cooperative operation among human and machine agents is proposed. The concept is that the cooperation augments human capability as an individual by closely related team members with adequate interfaces. This paper describes a basic concept of the cooperation, necessary interface functions, infrastructure of the cooperation and communication logging for accumulation and sharing of knowledge. (author)

STUDY OF PLANT-WIDE CONTROL IMPLEMENTATION IN PRODUCTION PROCESS OF GEOTHERMAL POWER PLANT

Directory of Open Access Journals (Sweden)

KATHERIN INDRIAWATI

2017-02-01

Full Text Available The design of plant-wide control system to optimize electricity production in geothermal power plant is proposed in this research. The objective is to overcome the deficiency due to changes in the characteristics of production well and fluctuation in electricity demand load. The proposed plant-wide control system has two main tasks; to maintain production process at optimum value and to increase efficiency. The pressure in separator and condenser is maintained at the respective set points under electrical load fluctuations in order to ensure optimum efficiency. The control system also reduce the usage of auxialiary electrical power and increase efficiency. The task was performed by controlling inlet cooling water temperatures to the condenser. It was concluded that the proposed control structure was able to increase efficiency and maintain production.

Plants lacking the main light-harvesting complex retain photosystem II macro-organization

OpenAIRE

Ruban, AV; Wentworth, M; Yakushevska, AE; Andersson, J; Lee, PJ; Keegstra, W; Dekker, JP; Boekema, EJ; Jansson, S; Horton, P

2003-01-01

Photosystem II (PSII) is a key component of photosynthesis, the process of converting sunlight into the chemical energy of life. In plant cells, it forms a unique oligomeric macrostructure in membranes of the chloroplasts(1). Several light-harvesting antenna complexes are organized precisely in the PSII macrostructure-the major trimeric complexes (LHCII)(2) that bind 70% of PSII chlorophyll and three minor monomeric complexes(3)-which together form PSII supercomplexes(4-6). The antenna comple...

Novel Micro-organisms controlling plant pathogens

NARCIS (Netherlands)

Köhl, J.

2009-01-01

The invention relates to control of pathogen caused diseases on leaves, fruits and ears in plants, such as apple scab (Venturia inaequalis by treatment of plant with an isolate of Cladosporium cladosporioides. The treatment is effective in both prevention and treatment of the fungal infection

Novel Micro-organisms controlling plant pathogens

NARCIS (Netherlands)

Köhl, J.

2010-01-01

The invention relates to control of pathogen caused diseases on leaves, fruits and ears in plants, such as apple scab (Venturia inaequalis by treatment of plant with an isolate of Cladosporium cladosporioides. The treatment is effective in both prevention and treatment of the fungal infection

Effects of reactive Mn(III)-oxalate complexes on structurally intact plant cell walls

Science.gov (United States)

Summering, J. A.; Keiluweit, M.; Goni, M. A.; Nico, P. S.; Kleber, M.

2011-12-01

Lignin components in the in plant litter are commonly assumed to have longer residence times in soil than many other compounds, which are supposedly, more easily degradable. The supposed resistance of lignin compounds to decomposition is generally attributed to the complex chain of biochemical steps required to create footholds in the non-porous structure of ligno-cellulose in cell walls. Interestingly, Mn(III) complexes have shown the ability to degrade ligno-cellulose. Mn(III) chelated by ligands such as oxalate are soluble oxidizers with a high affinity for lignin structures. Here we determined (i) the formation and decay kinetics of the Mn(III)-oxalate complexes in aqueous solution and (ii) the effects that these complexes have on intact ligno-cellulose. UV/vis spectroscopy and iodometric titrations confirmed the transient nature of Mn(III)-oxalate complexes with decay rates being in the order of hours. Zinnia elegans tracheary elements - a model ligno-cellulose substrate - were treated with Mn(III)-oxalate complexes in a newly developed flow-through reactor. Soluble decomposition products released during the treatment were analyzed by GC/MS and the degree of cell integrity was measured by cell counts, pre- and post-treatment counts indicate a decrease in intact Zinnia elegans as a result of Mn(III)-treatment. GC/MS results showed the release of a multitude of solubilized lignin breakdown products from plant cell walls. We conclude that Mn(III)-oxalate complexes have the ability to lyse intact plant cells and solubilize lignin. Lignin decomposition may thus be seen as resource dependent, with Mn(III) a powerful resource that should be abundant in terrestrial characterized by frequent redox fluctuations.

Complex systems and networks dynamics, controls and applications

CERN Document Server

Yu, Xinghuo; Chen, Guanrong; Yu, Wenwu

2016-01-01

This elementary book provides some state-of-the-art research results on broad disciplinary sciences on complex networks. It presents an in-depth study with detailed description of dynamics, controls and applications of complex networks. The contents of this book can be summarized as follows. First, the dynamics of complex networks, for example, the cluster dynamic analysis by using kernel spectral methods, community detection algorithms in bipartite networks, epidemiological modeling with demographics and epidemic spreading on multi-layer networks, are studied. Second, the controls of complex networks are investigated including topics like distributed finite-time cooperative control of multi-agent systems by applying homogenous-degree and Lyapunov methods, composite finite-time containment control for disturbed second-order multi-agent systems, fractional-order observer design of multi-agent systems, chaos control and anticontrol of complex systems via Parrondos game and many more. Third, the applications of ...

Complexity Control of Fast Motion Estimation in H.264/MPEG-4 AVC with Rate-Distortion-Complexity optimization

DEFF Research Database (Denmark)

Wu, Mo; Forchhammer, Søren; Aghito, Shankar Manuel

2007-01-01

A complexity control algorithm for H.264 advanced video coding is proposed. The algorithm can control the complexity of integer inter motion estimation for a given target complexity. The Rate-Distortion-Complexity performance is improved by a complexity prediction model, simple analysis of the pa...... statistics and a control scheme. The algorithm also works well for scene change condition. Test results for coding interlaced video (720x576 PAL) are reported.......A complexity control algorithm for H.264 advanced video coding is proposed. The algorithm can control the complexity of integer inter motion estimation for a given target complexity. The Rate-Distortion-Complexity performance is improved by a complexity prediction model, simple analysis of the past...

Possible evidence for transport of an iron cyanide complex by plants

International Nuclear Information System (INIS)

Samiotakis, M.; Ebbs, S.D.

2004-01-01

Barley (Hordeum vulgare L.), oat (Avena sativa L.), and wild cane (Sorghum bicolor L.), were exposed to 15 N-labeled ferrocyanide to determine whether these plant species can transport this iron cyanide complex. Plants were treated with ferrocyanide in a nutrient solution that simulated iron cyanide contaminated groundwater and soil solutions. This nutrient solution has been shown to maintain ferrocyanide speciation with minimal dissociation to free cyanide. Following treatment, all three plants showed dramatic enrichments in roots (δ 15 N%o=1000-1500) and shoots (δ 15 N%o=500). Barley and oat showed enrichment primarily in roots while wild cane showed a near equal enrichment in root and shoot tissues. Nitrogen-deficient barley plants treated with ferrocyanide showed a significantly greater 15 N enrichment as compared to nitrogen-sufficient plants. While the results are suggestive of ferrocyanide transport by these plant species, additional study will be required to verify these results. - Results suggest ferrocyanide transport by barley, oat and wild cane

Possible evidence for transport of an iron cyanide complex by plants

Energy Technology Data Exchange (ETDEWEB)

Samiotakis, M.; Ebbs, S.D

2004-01-01

Barley (Hordeum vulgare L.), oat (Avena sativa L.), and wild cane (Sorghum bicolor L.), were exposed to {sup 15}N-labeled ferrocyanide to determine whether these plant species can transport this iron cyanide complex. Plants were treated with ferrocyanide in a nutrient solution that simulated iron cyanide contaminated groundwater and soil solutions. This nutrient solution has been shown to maintain ferrocyanide speciation with minimal dissociation to free cyanide. Following treatment, all three plants showed dramatic enrichments in roots ({delta} {sup 15}N%o=1000-1500) and shoots ({delta} {sup 15}N%o=500). Barley and oat showed enrichment primarily in roots while wild cane showed a near equal enrichment in root and shoot tissues. Nitrogen-deficient barley plants treated with ferrocyanide showed a significantly greater {sup 15}N enrichment as compared to nitrogen-sufficient plants. While the results are suggestive of ferrocyanide transport by these plant species, additional study will be required to verify these results. - Results suggest ferrocyanide transport by barley, oat and wild cane.

Pollution control activities for waste-water treatment plants: planning, integrated approach, functionality controls and small plants

International Nuclear Information System (INIS)

Serena, F.; Tomiato, L.; Ostoich, M.; Falletti, L.

2009-01-01

The work presents the problem of the Wastewater Treatment Plants' (WWTPs) controls and the organization of the consequential activities with reference to the priorities of the Environmental Agencies through a hierarchy assessment according to the environmental importance of the pressure sources. The European Recommendation 2001/331/EC bases the environmental controls of industrial sites and also of WWTPs on an integrated approach overtaking the simple analytic control; the integrated approach requires documentary, technical, management and analytic controls. The Veneto Regional Environmental Prevention and Protection Agency (ARPAV) has recently developed and applied a check-list for the implementation of the European Recommendation for WWTPs. The check-list includes the functionality assessment of the WWTP in case of discharge control delegation to the plant manager as consented with Annex 5 third part Italian Decree 3/04/2006 n. 152. In the paper the general framework of environmental controls on public WWTPs in the Veneto region is described. Particular importance for the numerousness and for the required control typology is referred to the small WWTP ( [it

Babaco (Vasconcellea heilbornii var. pentagona Badillo. Major plant pathogens and control strategies

Directory of Open Access Journals (Sweden)

Angel Rolando Robles-Carrión

2016-04-01

Full Text Available This work was carried out with the aim of documenting the importance of Babaco for the Andean region, its main plant pathogens, and possible control strategies and integrated management, emphasizing the MVB. Was performed a systematic review of scientific papers published in prestigious journals and thesis diplomas, masters and doctorates from various universities. As a criterion for inclusion-exclusion studies were taken into account in the genus Vasconcellea. Ecuador has 15 of the 21 described species, of which more than half are located in the province of Loja. Vascular Wilt Babaco (MVB is caused by a complex of Fusarium fungi that interact with the plant. There are no integrated management strategies for Vascular Wilt Babaco scientifically proven.

Computer-based control systems of nuclear power plants

International Nuclear Information System (INIS)

Kalashnikov, V.K.; Shugam, R.A.; Ol'shevsky, Yu.N.

1975-01-01

Computer-based control systems of nuclear power plants may be classified into those using computers for data acquisition only, those using computers for data acquisition and data processing, and those using computers for process control. In the present paper a brief review is given of the functions the systems above mentioned perform, their applications in different nuclear power plants, and some of their characteristics. The trend towards hierarchic systems using control computers with reserves already becomes clear when consideration is made of the control systems applied in the Canadian nuclear power plants that pertain to the first ones equipped with process computers. The control system being now under development for the large Soviet reactors of WWER type will also be based on the use of control computers. That part of the system concerned with controlling the reactor assembly is described in detail

Plant Research '75

Energy Technology Data Exchange (ETDEWEB)

1975-01-01

Research is reported on stomatal regulation of the gas exchanges between plant and environment; inhibitory effects in flower formation; plant growth and development through hormones; hormone action; development and nitrogen fixation in algae; primary cell wall glycoprotein ectensin; enzymic mechanisms and control of polysaccharide and glycoprotein synthesis; molecular studies of membrane studies; sensory transduction in plants; regulation of formation of protein complexes and enzymes in higher plant cell and mechanism of sulfur dioxide toxicity in plants. (PCS)

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants

Directory of Open Access Journals (Sweden)

Subhasis eSamanta

2015-09-01

Full Text Available Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channelling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic and molecular analyses have unravelled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator’s involvement in these processes.

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants.

Science.gov (United States)

Samanta, Subhasis; Thakur, Jitendra K

2015-01-01

Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes.

Control characteristics of inert gas recovery plant

International Nuclear Information System (INIS)

Mikawa, Hiroji; Kato, Yomei; Kamiya, Kunio

1980-01-01

This paper presents a dynamic simulator and the control characteristics for a radioactive inert gas recovery plant which uses a cryogenic liquefying process. The simulator was developed to analyze the operational characteristics and is applicable to gas streams which contain nitrogen, argon, oxygen and krypton. The characteristics analysis of the pilot plant was performed after the accuracy of the simulator was checked using data obtained in fundamental experiments. The relationship between the reflux ratio and krypton concentration in the effluent gas was obtained. The decontamination factor is larger than 10 9 when the reflux ratio is more than 2. 0. The control characteristics of the plant were examined by changing its various parameters. These included the amount of gas to be treated, the heater power inside the evaporator and the liquid nitrogen level in the condenser. These characteristics agreed well with the values obtained in the pilot plant. The results show that the krypton concentration in the effluent gas increases when the liquid nitrogen level is decreased. However, in this case, the krypton concentration can be minimized by applying a feed forward control to the evaporator liquid level controller. (author)

SciLab Based Remote Control of Thermo-Optical Plant

Directory of Open Access Journals (Sweden)

Miroslav Jano

2011-11-01

Full Text Available The paper deals with the web-based implementation of the control system of a thermo-optical plant. The control of the plant is based on the SciLab software which originally is not designed for web-based applications. The paper shows a possible way to circumvent this limitation. The ultimate goal is to enable remote controlled experiment using SciLab. The paper also describes possible tools for communication and control of the real plant and visualization of results.

Intelligent control and maintenance of management integrated system based on multi-agents for coal preparation plant

Energy Technology Data Exchange (ETDEWEB)

Meng, F.; Wang, Y. [China University of Mining and technology, Xuzhou (China). School of Information and Electrical Engineering

2006-06-15

This paper discusses the progress of computer integrated processing (CIPS) of coal preparation and then presents an intelligence controlled production process, device-maintenance and production-management system of coal preparation based on multi-agents (IICMMS-CP). The construction of the IICMMS-CP, the distributed network control system based on live intelligence control stations and the strategy of implementing a distributed intelligence control system are studied in order to overcome the disadvantages brought about by the wide use of the PLC system by coal preparation plants. The software frame, based on a Multi-Agent Intelligence Control and Maintenance Management integrated system, is studied and the implementation methods of IICMMS-CP are discussed. The characteristics of distributed architecture, cooperation and parallel computing meet the needs of integrated control of coal preparation plants with large-scale spatial production distribution, densely-related processes and complex systems. Its application further improves the reliability and precision of process control, accuracy of fault identification and intelligence of production adjustment, establishes a technical basis for system integration and flexible production. The main function of the system has been tested in a coal preparation plant to good effect in stabilizing product quality, improving efficiency and reducing consumption. 17 refs., 4 figs.

Pinning impulsive control algorithms for complex network

Energy Technology Data Exchange (ETDEWEB)

Sun, Wen [School of Information and Mathematics, Yangtze University, Jingzhou 434023 (China); Lü, Jinhu [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Chen, Shihua [College of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China); Yu, Xinghuo [School of Electrical and Computer Engineering, RMIT University, Melbourne VIC 3001 (Australia)

2014-03-15

In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms.

Pinning impulsive control algorithms for complex network

International Nuclear Information System (INIS)

Sun, Wen; Lü, Jinhu; Chen, Shihua; Yu, Xinghuo

2014-01-01

In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms

Nuclear reactor kinetics and plant control

CERN Document Server

Oka, Yoshiaki

2013-01-01

Understanding time-dependent behaviors of nuclear reactors and the methods of their control is essential to the operation and safety of nuclear power plants. This book provides graduate students, researchers, and engineers in nuclear engineering comprehensive information on both the fundamental theory of nuclear reactor kinetics and control and the state-of-the-art practice in actual plants, as well as the idea of how to bridge the two. The first part focuses on understanding fundamental nuclear kinetics. It introduces delayed neutrons, fission chain reactions, point kinetics theory, reactivit

Enabling Controlling Complex Networks with Local Topological Information.

Science.gov (United States)

Li, Guoqi; Deng, Lei; Xiao, Gaoxi; Tang, Pei; Wen, Changyun; Hu, Wuhua; Pei, Jing; Shi, Luping; Stanley, H Eugene

2018-03-15

Complex networks characterize the nature of internal/external interactions in real-world systems including social, economic, biological, ecological, and technological networks. Two issues keep as obstacles to fulfilling control of large-scale networks: structural controllability which describes the ability to guide a dynamical system from any initial state to any desired final state in finite time, with a suitable choice of inputs; and optimal control, which is a typical control approach to minimize the cost for driving the network to a predefined state with a given number of control inputs. For large complex networks without global information of network topology, both problems remain essentially open. Here we combine graph theory and control theory for tackling the two problems in one go, using only local network topology information. For the structural controllability problem, a distributed local-game matching method is proposed, where every node plays a simple Bayesian game with local information and local interactions with adjacent nodes, ensuring a suboptimal solution at a linear complexity. Starring from any structural controllability solution, a minimizing longest control path method can efficiently reach a good solution for the optimal control in large networks. Our results provide solutions for distributed complex network control and demonstrate a way to link the structural controllability and optimal control together.

Computerized control and management at the Temelin nuclear power plant

International Nuclear Information System (INIS)

Mitosinka, J.; Korec, J.

1992-01-01

The proposed automation of the nuclear power plant control system includes a division of the control system into three hierarchic levels, supplemented with an additional level. These comprise the automated system of control of technological processes, the all-plant control of the power-generating process, the control of backup activities and of technical and economic activities, and top managerial control. The efficiency of the nuclear power plant operation, i.e. attainment of the maximum electricity output with minimum costs while securing the required safety, is the principal criterion in the design of the data model. Listed are tasks that would lend themselves to automation within the automated system of nuclear power plant control, and the basic scheme of their automation as follows from an analysis performed at the Temelin nuclear power plant. (Z.S). 2 figs., 2 refs

ROBUST CONTROL ALGORITHM FOR MULTIVARIABLE PLANTS WITH QUANTIZED OUTPUT

Directory of Open Access Journals (Sweden)

A. A. Margun

2017-01-01

Full Text Available The paper deals with robust output control algorithm for multivariable plants under disturbances. A plant is described by the system of linear differential equations with known relative degrees. Plant parameters are unknown but belong to the known closed bounded set. Plant state vector is unmeasured. Plant output is measured only via static quantizer. Control system algorithm is based on the high gain feedback method. Developed controller provides exponential convergence of tracking error to the bounded area. The area bounds depend on quantizer parameters and the value of external disturbances. Experimental approbation of the proposed control algorithm is performed with the use of Twin Rotor MIMO System laboratory bench. This bench is a helicopter like model with two degrees of freedom (pitch and yaw. DC motors are used as actuators. The output signals are measured via optical encoders. Mathematical model of laboratory bench is obtained. Proposed algorithm was compared with proportional - integral – differential controller in conditions of output quantization. Obtained results have confirmed the efficiency of proposed controller.

Model complexity control for hydrologic prediction

NARCIS (Netherlands)

Schoups, G.; Van de Giesen, N.C.; Savenije, H.H.G.

2008-01-01

A common concern in hydrologic modeling is overparameterization of complex models given limited and noisy data. This leads to problems of parameter nonuniqueness and equifinality, which may negatively affect prediction uncertainties. A systematic way of controlling model complexity is therefore

MECHANISM AND REGULATION OF NONSENSE-MEDIATED MRNA DECAY (NMD, AN ESSENTIAL QUALITY CONTROL SYSTEM OF PLANTS

Directory of Open Access Journals (Sweden)

D. Silhavy

2008-09-01

Full Text Available In eukaryotic cell, various quality control mechanisms have evolved to ensure that only perfect mRNAs could be translated. Nonsense-mediated mRNA decay (NMD is a quality control system that identifies and eliminates mRNAs containing premature termination codons, thereby preventing the accumulation of potentially harmful truncated proteins. While NMD is well-characterized in yeast, in invertebrates and in mammals, plant NMD is poorly understood. In yeast and in invertebrates unusually long 3'untranslated regions (3'UTRs render an mRNA subject to NMD, while in mammals' 3'UTR located introns trigger NMD. UPF1, 2 and 3 are the key trans-acting NMD factors in yeast as well as in animals. However, in mammals, the core components of the Exon Junction Complex (Mago, Y14, eIF4A3 and MLN51 are also required for NMD. It was proposed that long 3’UTR-induced NMD is the ancient type and that it was changed to a more complex intron-based NMD in mammals. To better understand the evolution of eukaryotic NMD systems, we have studied the NMD machinery of plants, as plants are outgroup relative to fungi and animals. We have elaborated various transient assays to analyze plant NMD. Using these assays we defined the cis elements of plant NMD and characterized several trans-acting plant NMD factors. We demonstrated that two plant NMD pathways co-exist, one pathway, as yeast or invertebrate NMD systems, eliminates mRNAs with long 3'UTRs, while a distinct pathway, like mammalian NMD, degrades mRNAs harbouring 3'UTR-located introns. We showed that UPF1, UPF2, and SMG-7 are involved in both plant NMD pathways, whereas Mago and Y14 are required only for intron-based NMD. We also provide evidence that the molecular mechanism of long 3'UTR-based plant NMD resembles yeast NMD, while the intron-based NMD is similar to mammalian NMD. Moreover we have found that the SMG-7 component of plant NMD is targeted by NMD suggesting that plant NMD is autoregulated. We propose that in

Influence of in-plant air pollution control measures on power plant and system operation

International Nuclear Information System (INIS)

Kurten, H.

1990-01-01

The burning of fossil fuels causes the emission of air pollutants which have harmful environmental impact. Consequently many nations have in the last few years established regulations for air pollution control and have initiated the development and deployment of air pollution control systems in power plants. The paper describes the methods used for reducing particulate, SO 2 and NO x emissions, their application as backfit systems and in new plants, the power plant capacity equipped with such systems in the Federal Republic of Germany and abroad and the additional investment and operating costs incurred. It is to be anticipated that advanced power plant designs will produce lower pollutant emissions and less waste at enhanced efficiency levels. A comparison with power generation in nuclear power plants completes the first part of the paper. This paper covers the impact of the above-mentioned air pollution control measures on unit commitment in daily operation

Limitation for performance of jobs in power unit control room of nuclear power plant

International Nuclear Information System (INIS)

Janas, D.

1988-01-01

The procedure is described for an analysis of the somatic and mental health condition of operating personnel in the unit control room of a nuclear power plant. It was divided into three stages, viz.: (1) determination of adverse and favorable effects of work; (2) the recording of social, psychological, physiological and biochemical changes in the personnel; (3) determination of possibilities of controlling the limit for performance of a job. The analysis showed that the problem is complex and should permanently remain in the centre of attention. (J.B.). 3 refs

Engineering Design of ITER Prototype Fast Plant System Controller

Science.gov (United States)

Goncalves, B.; Sousa, J.; Carvalho, B.; Rodrigues, A. P.; Correia, M.; Batista, A.; Vega, J.; Ruiz, M.; Lopez, J. M.; Rojo, R. Castro; Wallander, A.; Utzel, N.; Neto, A.; Alves, D.; Valcarcel, D.

2011-08-01

The ITER control, data access and communication (CODAC) design team identified the need for two types of plant systems. A slow control plant system is based on industrial automation technology with maximum sampling rates below 100 Hz, and a fast control plant system is based on embedded technology with higher sampling rates and more stringent real-time requirements than that required for slow controllers. The latter is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and, if necessary, high performance networks. Two prototypes of a fast plant system controller specialized for data acquisition and constrained by ITER technological choices are being built using two different form factors. This prototyping activity contributes to the Plant Control Design Handbook effort of standardization, specifically regarding fast controller characteristics. Envisaging a general purpose fast controller design, diagnostic use cases with specific requirements were analyzed and will be presented along with the interface with CODAC and sensors. The requirements and constraints that real-time plasma control imposes on the design were also taken into consideration. Functional specifications and technology neutral architecture, together with its implications on the engineering design, were considered. The detailed engineering design compliant with ITER standards was performed and will be discussed in detail. Emphasis will be given to the integration of the controller in the standard CODAC environment. Requirements for the EPICS IOC providing the interface to the outside world, the prototype decisions on form factor, real-time operating system, and high-performance networks will also be discussed, as well as the requirements for data streaming to CODAC for visualization and

Control system for technological processes in tritium processing plants with process analysis

International Nuclear Information System (INIS)

Retevoi, Carmen Maria; Stefan, Iuliana; Balteanu, Ovidiu; Stefan, Liviu; Bucur, Ciprian

2005-01-01

Integration of a large variety of installations and equipment into a unitary system for controlling the technological process in tritium processing nuclear facilities appears to be a rather complex approach particularly when experimental or new technologies are developed. Ensuring a high degree of versatility allowing easy modifications in configurations and process parameters is a major requirement imposed on experimental installations. The large amount of data which must be processed, stored and easily accessed for subsequent analyses imposes development of a large information network based on a highly integrated system containing the acquisition, control and technological process analysis data as well as data base system. On such a basis integrated systems of computation and control able to conduct the technological process could be developed as well protection systems for cases of failures or break down. The integrated system responds to the control and security requirements in case of emergency and of the technological processes specific to the industry that processes radioactive or toxic substances with severe consequences in case of technological failure as in the case of tritium processing nuclear plant. In order to lower the risk technological failure of these processes an integrated software, data base and process analysis system are developed, which, based on identification algorithm of the important parameters for protection and security systems, will display the process evolution trend. The system was checked on a existing plant that includes a removal tritium unit, finally used in a nuclear power plant, by simulating the failure events as well as the process. The system will also include a complete data base monitoring all the parameters and a process analysis software for the main modules of the tritium processing plant, namely, isotope separation, catalytic purification and cryogenic distillation

Considerations on safety against seismic excitations in the project of reactor auxiliary building and control building in nuclear power plants

International Nuclear Information System (INIS)

Santos, S.H.C.; Castro Monteiro, I. de

1986-01-01

The seismic requests to be considered in the project of main buildings of a nuclear power plant are discussed. The models for global seismic analysis of nuclear power plant structures, as well as models for global strength distribution are presented. The models for analysing reactor auxiliary building and control building, which together with the reactor building and turbine building form the main energy generation complex in a nuclear power plant, are described. (M.C.K.) [pt

Distributed control system for CANDU 9 nuclear power plant

International Nuclear Information System (INIS)

Harber, J.E.; Kattan, M.K.; Macbeth, M.J.

1996-01-01

Canadian designed CANDU pressurized heavy water nuclear reactors have been world leaders in electrical power generation. The CANDU 9 project is AECL's next reactor design. The CANDU 9 plant monitoring, annunciation, and control functions are implemented in two evolutionary systems; the distributed control system (DCS) and the plant display system (PDS). The CDS implements most of the plant control functions in a single hardware platform. The DCS communicates with the PDS to provide the main operator interface and annunciation capabilities of the previous control computer designs along with human interface enhancements required in a modern control system. (author)

Mechanics of Cellulose Synthase Complexes in Living Plant Cells

Science.gov (United States)

Zehfroosh, Nina; Liu, Derui; Ramos, Kieran P.; Yang, Xiaoli; Goldner, Lori S.; Baskin, Tobias I.

The polymer cellulose is one of the major components of the world's biomass with unique and fascinating characteristics such as its high tensile strength, renewability, biodegradability, and biocompatibility. Because of these distinctive aspects, cellulose has been the subject of enormous scientific and industrial interest, yet there are still fundamental open questions about cellulose biosynthesis. Cellulose is synthesized by a complex of transmembrane proteins called ``Cellulose Synthase A'' (CESA) in the plasma membrane. Studying the dynamics and kinematics of the CESA complex will help reveal the mechanism of cellulose synthesis and permit the development and validation of models of CESA motility. To understand what drives these complexes through the cell membrane, we used total internal reflection fluorescence microscopy (TIRFM) and variable angle epi-fluorescence microscopy to track individual, fluorescently-labeled CESA complexes as they move in the hypocotyl and root of living plants. A mean square displacement analysis will be applied to distinguish ballistic, diffusional, and other forms of motion. We report on the results of these tracking experiments. This work was funded by NSF/PHY-1205989.

A Cryo Complex Control

CERN Document Server

Alferov, V; Fedorchenko, V; Ivanova, N; Kholkin, A; Klimov, S; Krendelev, V; Kuznetsov, S; Lukyantsev, A; Lutchev, A; Milutkin, V; Sytin, A N; Vasilev, D

2004-01-01

A Cryogenic complex is being constructed to provide by liquid helium and nitrogen the RF-separator of kaons. About 500 parameters including temperature (1,8…300)K, liquid helium/nitrogen level, vacuum, 300 digital signals have to be measured, 70 commands generated, 20 closed loops activated. The paper describes controls electronics which includes home made I8051 compatible controllers connected by the CAN field bus to a bus controller and interface electronic modules for: - temperature measurements; - liquid Ni and He level measurements; - vacuum pumps current measurements; - analog and digital signals measurements and generations. The modules are tested together with signal imitators within a vertical slice of the Control System based on EPICS tools.

Complex Projective Synchronization in Drive-Response Stochastic Complex Networks by Impulsive Pinning Control

Directory of Open Access Journals (Sweden)

Xuefei Wu

2014-01-01

Full Text Available The complex projective synchronization in drive-response stochastic coupled networks with complex-variable systems is considered. The impulsive pinning control scheme is adopted to achieve complex projective synchronization and several simple and practical sufficient conditions are obtained in a general drive-response network. In addition, the adaptive feedback algorithms are proposed to adjust the control strength. Several numerical simulations are provided to show the effectiveness and feasibility of the proposed methods.

3D visualization based customer experiences of nuclear plant control room

International Nuclear Information System (INIS)

Sun Tienlung; Chou Chinmei; Hung Tamin; Cheng Tsungchieh; Yang Chihwei; Yang Lichen

2011-01-01

This paper employs virtual reality (VR) technology to develop an interactive virtual nuclear plant control room in which the general public could easily walk into the 'red zone' and play with the control buttons. The VR-based approach allows deeper and richer customer experiences that the real nuclear plant control room could not offer. When people know more about the serious process control procedures enforced in the nuclear plant control room, they will appropriate more about the safety efforts imposed by the nuclear plant and become more comfortable about the nuclear plant. The virtual nuclear plant control room is built using a 3D game development tool called Unity3D. The 3D scene is connected to a nuclear plant simulation system through Windows API programs. To evaluate the usability of the virtual control room, an experiment will be conducted to see how much 'immersion' the users could feel when they played with the virtual control room. (author)

Automated detection and control of volunteer potato plants

NARCIS (Netherlands)

Nieuwenhuizen, A.T.

2009-01-01

High amounts of manual labor are needed to control volunteer potato plants in arable fields. Due to the high costs, this leads to incomplete control of these weed plants, and they spread diseases like Phytophthora infestans to other fields. This results in higher environmental loads by curative

Habitats as complex odour environments: how does plant diversity affect herbivore and parasitoid orientation?

Directory of Open Access Journals (Sweden)

Nicole Wäschke

Full Text Available Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts.

Mediated Plastid RNA Editing in Plant Immunity

Science.gov (United States)

García-Andrade, Javier; Ramírez, Vicente; López, Ana; Vera, Pablo

2013-01-01

Plant regulatory circuits coordinating nuclear and plastid gene expression have evolved in response to external stimuli. RNA editing is one of such control mechanisms. We determined the Arabidopsis nuclear-encoded homeodomain-containing protein OCP3 is incorporated into the chloroplast, and contributes to control over the extent of ndhB transcript editing. ndhB encodes the B subunit of the chloroplast NADH dehydrogenase-like complex (NDH) involved in cyclic electron flow (CEF) around photosystem I. In ocp3 mutant strains, ndhB editing efficiency decays, CEF is impaired and disease resistance to fungal pathogens substantially enhanced, a process recapitulated in plants defective in editing plastid RNAs encoding NDH complex subunits due to mutations in previously described nuclear-encoded pentatricopeptide-related proteins (i.e. CRR21, CRR2). Furthermore, we observed that following a pathogenic challenge, wild type plants respond with editing inhibition of ndhB transcript. In parallel, rapid destabilization of the plastidial NDH complex is also observed in the plant following perception of a pathogenic cue. Therefore, NDH complex activity and plant immunity appear as interlinked processes. PMID:24204264

New Process Controls for the Hera Cryogenic Plant

Science.gov (United States)

Böckmann, T.; Clausen, M.; Gerke, Chr.; Prüß, K.; Schoeneburg, B.; Urbschat, P.

2010-04-01

The cryogenic plant built for the HERA accelerator at DESY in Hamburg (Germany) is now in operation for more than two decades. The commercial process control system for the cryogenic plant is in operation for the same time period. Ever since the operator stations, the control network and the CPU boards in the process controllers went through several upgrade stages. Only the centralized Input/Output system was kept unchanged. Many components have been running beyond the expected lifetime. The control system for one at the three parts of the cryogenic plant has been replaced recently by a distributed I/O system. The I/O nodes are connected to several Profibus-DP field busses. Profibus provides the infrastructure to attach intelligent sensors and actuators directly to the process controllers which run the open source process control software EPICS. This paper describes the modification process on all levels from cabling through I/O configuration, the process control software up to the operator displays.

Control of complex physically simulated robot groups

Science.gov (United States)

Brogan, David C.

2001-10-01

Actuated systems such as robots take many forms and sizes but each requires solving the difficult task of utilizing available control inputs to accomplish desired system performance. Coordinated groups of robots provide the opportunity to accomplish more complex tasks, to adapt to changing environmental conditions, and to survive individual failures. Similarly, groups of simulated robots, represented as graphical characters, can test the design of experimental scenarios and provide autonomous interactive counterparts for video games. The complexity of writing control algorithms for these groups currently hinders their use. A combination of biologically inspired heuristics, search strategies, and optimization techniques serve to reduce the complexity of controlling these real and simulated characters and to provide computationally feasible solutions.

Control system security in nuclear power plant

International Nuclear Information System (INIS)

Li Jianghai; Huang Xiaojin

2012-01-01

The digitalization and networking of control systems in nuclear power plants has brought significant improvements in system control, operation and maintenance. However, the highly digitalized control system also introduces additional security vulnerabilities. Moreover, the replacement of conventional proprietary systems with common protocols, software and devices makes these vulnerabilities easy to be exploited. Through the interaction between control systems and the physical world, security issues in control systems impose high risks on health, safety and environment. These security issues may even cause damages of critical infrastructures and threaten national security. The importance of control system security by reviewing several control system security incidents that happened in nuclear power plants was showed in recent years. Several key difficulties in addressing these security issues were described. Finally, existing researches on control system security and propose several promising research directions were reviewed. (authors)

Integrated control algorithms for plant environment in greenhouse

Science.gov (United States)

Zhang, Kanyu; Deng, Lujuan; Gong, Youmin; Wang, Shengxue

2003-09-01

In this paper a survey of plant environment control in artificial greenhouse was put forward for discussing the future development. Firstly, plant environment control started with the closed loop control of air temperature in greenhouse. With the emergence of higher property computer, the adaptive control algorithm and system identification were integrated into the control system. As adaptation control is more depending on observation of variables by sensors and yet many variables are unobservable or difficult to observe, especially for observation of crop growth status, so model-based control algorithm were developed. In order to evade modeling difficulty, one method is predigesting the models and the other method is utilizing fuzzy logic and neural network technology that realize the models by the black box and gray box theory. Studies on control method of plant environment in greenhouse by means of expert system (ES) and artificial intelligence (AI) have been initiated and developed. Nowadays, the research of greenhouse environment control focus on energy saving, optimal economic profit, enviornment protection and continualy develop.

Angra nuclear plant - environmental control program

International Nuclear Information System (INIS)

Kircher, E.; Cruz, E.S. da

1989-01-01

The pre-operational studies, that were elaborated before the beginning of Angra I Power Plant operation, are described in particular the environmental radiological safety area till the fuel loading in the core reactor. Several aspects are included, as socio-economic survey, seismological analysis, Meteorological Program, marine biology, water cooling system, exposure measures of natural radiation, marine sediments characterization in the effluent dispersion area and Environmental Radiological Monitoring Program. The main environmental programs developed for the operational phase of the Angra I Plant are also presented, citing some considerations about the Meteorological Program, Marine Biology Control Program, Temperature and Chlorine Control in Piraquara de Fora Bay, Radiological Environmental Monitoring Program, Sanitary Effluent Control Program and Radiological Emergency Program. (C.G.C.). 2 refs

Subjective task complexity in the control room

International Nuclear Information System (INIS)

Braarud, Per Oeivind

2000-05-01

Understanding of what makes a control room situation difficult to handle is important when studying operator performance, both with respect to prediction as well as improvement of the human performance. Previous exploratory work on complexity showed a potential for prediction and explanation of operator performance. This report investigates in further detail the theoretical background and the structure of operator rated task complexity. The report complements the previous work on complexity to make a basis for development of operator performance analysis tools. The first part of the report outlines an approach for studying the complexity of the control room crew's work. The approach draws upon man-machine research as well as problem solving research. The approach identifies five complexity-shaping components: 'task work characteristics', 'teamwork characteristics', 'individual skill', 'teamwork skill', and 'interface and support systems'. The crew's work complexity is related to concepts of human performance quality and human error. The second part of the report is a post-hoc exploratory analysis of four empirical HRP studies, where operators' conception of the complexity of control room work is assessed by questionnaires. The analysis deals with the structure of complexity questionnaire ratings, and the relationship between complexity ratings and human performance measures. The main findings from the analysis of structure was the identification of three task work factors which were named Masking, Information load and Temporal demand, and in addition the identification of one interface factor which was named Navigation. Post-hoc analysis suggests that operator's subjective complexity, which was assessed by questionnaires, is related to workload, task and system performance, and operator's self-rated performance. (Author). 28 refs., 47 tabs

DISPATCHING CONTROL SYSTEM OF THE CONCRETE BATCHING PLANTS

Directory of Open Access Journals (Sweden)

Andrey Vladimirovich Ostroukh

2015-09-01

Full Text Available This paper proposes an approach to the design of dispatching control system of the concrete batching plant, which is a set of hardware maintenance, information, mathematical and software for control of technological objects. The proposed system is scalable and can include a control subsystem of mobile concrete plant, laboratory, subsystems, access control, and personnel management jobs. The system provides optimum automating the collection and processing of information for generating control signals and transmitting them without loss and distortion to the actuators in order to achieve the most efficient operation of process control object as a whole.

Control strategy optimization of HVAC plants

Energy Technology Data Exchange (ETDEWEB)

Facci, Andrea Luigi; Zanfardino, Antonella [Department of Engineering, University of Napoli “Parthenope” (Italy); Martini, Fabrizio [Green Energy Plus srl (Italy); Pirozzi, Salvatore [SIAT Installazioni spa (Italy); Ubertini, Stefano [School of Engineering (DEIM) University of Tuscia (Italy)

2015-03-10

In this paper we present a methodology to optimize the operating conditions of heating, ventilation and air conditioning (HVAC) plants to achieve a higher energy efficiency in use. Semi-empiric numerical models of the plant components are used to predict their performances as a function of their set-point and the environmental and occupied space conditions. The optimization is performed through a graph-based algorithm that finds the set-points of the system components that minimize energy consumption and/or energy costs, while matching the user energy demands. The resulting model can be used with systems of almost any complexity, featuring both HVAC components and energy systems, and is sufficiently fast to make it applicable to real-time setting.

Control strategy optimization of HVAC plants

International Nuclear Information System (INIS)

Facci, Andrea Luigi; Zanfardino, Antonella; Martini, Fabrizio; Pirozzi, Salvatore; Ubertini, Stefano

2015-01-01

In this paper we present a methodology to optimize the operating conditions of heating, ventilation and air conditioning (HVAC) plants to achieve a higher energy efficiency in use. Semi-empiric numerical models of the plant components are used to predict their performances as a function of their set-point and the environmental and occupied space conditions. The optimization is performed through a graph-based algorithm that finds the set-points of the system components that minimize energy consumption and/or energy costs, while matching the user energy demands. The resulting model can be used with systems of almost any complexity, featuring both HVAC components and energy systems, and is sufficiently fast to make it applicable to real-time setting

Development of technology for creating intelligent control systems for power plants and propulsion systems for marine robotic systems

Science.gov (United States)

Iakovleva, E. V.; Momot, B. A.

2017-10-01

The object of this study is to develop a power plant and an electric propulsion control system for autonomous remotely controlled vessels. The tasks of the study are as follows: to assess remotely controlled vessels usage reasonability, to define the requirements for this type of vessel navigation. In addition, the paper presents the analysis of technical diagnostics systems. The developed electric propulsion control systems for vessels should provide improved reliability and efficiency of the propulsion complex to ensure the profitability of remotely controlled vessels.

Efficiency mark of the two-product power complex of nuclear power plant

Science.gov (United States)

Khrustalev, V. A.; Suchkov, V. M.

2017-11-01

The article discusses the combining nuclear power plants (NPP) with pressurized water reactors and distillation-desalination plants (DDP), their joint mode of operation during periods of coating failures of the electric power load graphs and thermo-economical efficiency. Along with the release of heat and generation of electric energy a desalination complex with the nuclear power plant produces distillate. Part of the selected steam “irretrievably lost” with a mix of condensation of this vapor in a desalination machine with a flow of water for distillation. It means that this steam transforms into condition of acquired product - distillate. The article presents technical solutions for the return of the working fluid for turbine К-1000-60/1500-2 и К-1200-6,8/50, as well as permissible part of low pressure regime according to the number of desalination units for each turbine. Patent for the proposed two-product energy complex, obtained by Gagarin State Technical University is analyzed. The energy complex has such system advantages as increasing the capacity factor of a nuclear reactor and also allows to solve the problem of shortage of fresh water. Thermo-economics effectiveness of this complex is determined by introducing a factor-“thermo-economic index”. During analyzing of the results of the calculations of a thermo-economic index we can see a strong influence of the cost factor of the distillate on the market. Then higher participation of the desalination plant in coverage of the failures of the graphs of the electric loading then smaller the payback period of the NPP. It is manifested more clearly, as it’s shown in the article, when pricing options depend on time of day and the configuration of the daily electric load diagram. In the geographical locations of the NPPs with PWR the Russian performance in a number of regions with low freshwater resources and weak internal electrical connections combined with DDP might be one of the ways to improve the

Interference lithographic nanopatterning of plant and bacterial light-harvesting complexes on gold substrates

Energy Technology Data Exchange (ETDEWEB)

Patole, S.; Vasilev, C.; El-Zubir, O.; Wang, L.; Johnson, M. P.; Cadby, A. J.; Leggett, G. J.; Hunter, C. N.

2015-05-15

We describe a facile approach for nanopatterning of photosynthetic light-harvesting complexes over macroscopic areas, and use optical spectroscopy to demonstrate retention of native properties by both site-specifically and non-specifically attached photosynthetic membrane proteins. A Lloyd's mirror dual-beam interferometer was used to expose self-assembled monolayers of amine-terminated alkylthiolates on gold to laser irradiation. Following exposure, photo-oxidized adsorbates were replaced by oligo(ethylene glycol) terminated thiols, and the remaining intact amine-functionalized regions were used for attachment of the major light-harvesting chlorophyll–protein complex from plants, LHCII. These amine patterns could be derivatized with nitrilotriacetic acid (NTA), so that polyhistidine-tagged bacteriochlorophyll–protein complexes from phototrophic bacteria could be attached with a defined surface orientation. By varying parameters such as the angle between the interfering beams and the laser irradiation dose, it was possible to vary the period and widths of NTA and amine-functionalized lines on the surfaces; periods varied from 1200 to 240 nm and linewidths as small as 60 nm (λ/4) were achieved. This level of control over the surface chemistry was reflected in the surface topology of the protein nanostructures imaged by atomic force microscopy; fluorescence imaging and spectral measurements demonstrated that the surface-attached proteins had retained their native functionality.

Potential utilities of optimal estimation and control in nuclear power plants

International Nuclear Information System (INIS)

Tylee, J.L.; Purviance, J.E.

1983-01-01

Optimal estimation and control theories offer the potential for more precise control and diagnosis of nuclear power plants. The important element of these theories is that a mathematical plant model is used in conjunction with the actual plant data to optimize some performance criteria. These criteria involve important plant variables and incorporate a sense of the desired plant performance. Several applications of optimal estimation and control to nuclear systems are discussed

Fire hazard analysis for Plutonium Finishing Plant complex

International Nuclear Information System (INIS)

MCKINNIS, D.L.

1999-01-01

A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards

Nonlinear Fuzzy Model Predictive Control for a PWR Nuclear Power Plant

Directory of Open Access Journals (Sweden)

Xiangjie Liu

2014-01-01

Full Text Available Reliable power and temperature control in pressurized water reactor (PWR nuclear power plant is necessary to guarantee high efficiency and plant safety. Since the nuclear plants are quite nonlinear, the paper presents nonlinear fuzzy model predictive control (MPC, by incorporating the realistic constraints, to realize the plant optimization. T-S fuzzy modeling on nuclear power plant is utilized to approximate the nonlinear plant, based on which the nonlinear MPC controller is devised via parallel distributed compensation (PDC scheme in order to solve the nonlinear constraint optimization problem. Improved performance compared to the traditional PID controller for a TMI-type PWR is obtained in the simulation.

Model-free adaptive control of advanced power plants

Science.gov (United States)

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.

Improved iodine and tritium control in reprocessing plants

International Nuclear Information System (INIS)

Henrich, E.; Schmieder, H.; Roesch, W.; Weirich, F.

1981-01-01

During spent fuel processing, iodine and tritium are distributed in many aqueous, organic and gaseous process streams, which complicates their control. Small modifications of conventional purex flow sheets, compatible with processing in the headend and the first extraction cycle are necessary to confine the iodine and the tritium to smaller plant areas. The plant area connected to the dissolver off-gas (DOG) system is suited to confine the iodine and the plant area connected to the first aqueous cycle is suited to confine the tritium. A more clear and convenient iodine and tritium control will be achieved. Relevant process steps have been studied on a lab or a pilot plant scale using I-123 and H-3 tracer

Adaptive control for a class of nonlinear complex dynamical systems with uncertain complex parameters and perturbations.

Directory of Open Access Journals (Sweden)

Jian Liu

Full Text Available In this paper, adaptive control is extended from real space to complex space, resulting in a new control scheme for a class of n-dimensional time-dependent strict-feedback complex-variable chaotic (hyperchaotic systems (CVCSs in the presence of uncertain complex parameters and perturbations, which has not been previously reported in the literature. In detail, we have developed a unified framework for designing the adaptive complex scalar controller to ensure this type of CVCSs asymptotically stable and for selecting complex update laws to estimate unknown complex parameters. In particular, combining Lyapunov functions dependent on complex-valued vectors and back-stepping technique, sufficient criteria on stabilization of CVCSs are derived in the sense of Wirtinger calculus in complex space. Finally, numerical simulation is presented to validate our theoretical results.

Adaptive control for a class of nonlinear complex dynamical systems with uncertain complex parameters and perturbations.

Science.gov (United States)

Liu, Jian; Liu, Kexin; Liu, Shutang

2017-01-01

In this paper, adaptive control is extended from real space to complex space, resulting in a new control scheme for a class of n-dimensional time-dependent strict-feedback complex-variable chaotic (hyperchaotic) systems (CVCSs) in the presence of uncertain complex parameters and perturbations, which has not been previously reported in the literature. In detail, we have developed a unified framework for designing the adaptive complex scalar controller to ensure this type of CVCSs asymptotically stable and for selecting complex update laws to estimate unknown complex parameters. In particular, combining Lyapunov functions dependent on complex-valued vectors and back-stepping technique, sufficient criteria on stabilization of CVCSs are derived in the sense of Wirtinger calculus in complex space. Finally, numerical simulation is presented to validate our theoretical results.

Material control for a reprocessing plant

International Nuclear Information System (INIS)

Rundquist, D.; Bray, G.; Donelson, S.; Glancy, J.; Gozani, T.; Harris, L.; McNamera, R.; Pence, D.; Ringham, M.

1976-01-01

Adequate control of special nuclear material (SNM) implies a basic knowledge of the quantities of SNM processed through or contained within a fuels processing facility with sufficient accuracy that diversion of the SNM for deleterious purposes can be detected in a timely manner. This report to the Lawrence Livermore Laboratory (LLL) describes the primary process streams containing plutonium that are handled routinely within a spent fuel reprocessing plant and conversion facility. As an aid in implementing the objectives of the accountability system in a realistic situation, the Allied General Nuclear Services (AGNS) reprocessing plant now under construction near Barnwell, South Carolina, was chosen as the study model. The AGNS plant processes are discussed in detail emphasizing those portions of the process that contain significant quantities of plutonium. The unit processes within the separations plant, nitrate storage, plutonium product facility and the analytical laboratory are described with regard to the SNM control system currently planned for use in the facilities. A general discussion of laboratory techniques, nondestructive assay and process instrumentation for plutonium process and product material from a reprocessing plant is included. A comprehensive discussion is given of holdup measurements in plutonium recycle facilities. A brief preliminary overview is presented of alternative processing strategies for LWR fuel. An extensive review and summary of modeling efforts for liquid-liquid extraction cycles is included. A comprehensive bibliography of previous modeling efforts is covered

Power control of the Angra-2 Nuclear Power Plant

International Nuclear Information System (INIS)

Souza Mendes, J.E. de

1986-01-01

The systems for the power control of the Nuclear Power Plant Angra 2 have a high degree of automation so that few operator actions are required during power operation. The power control strategy and the operation principles of the control systems, here presented, make possible a great flexibility of the Plant operation. (Author) [pt

An expert display system and nuclear power plant control rooms

International Nuclear Information System (INIS)

Beltracchi, L.

1988-01-01

An expert display system controls automatically the display of segments on a cathode ray tube's screen to form an image of plant operations. The image consists of an icon of: 1) the process (heat engine cycle), 2) plant control systems, and 3) safety systems. A set of data-driven, forward-chaining computer stored rules control the display of segments. As plant operation changes, measured plant data are processed through the rules, and the results control the deletion and addition of segments to the display format. The icon contains information needed by control rooms operators to monitor plant operations. One example of an expert display is illustrated for the operator's task of monitoring leakage from a safety valve in a steam line of a boiling water reactor (BWR). In another example, the use of an expert display to monitor plant operations during pre-trip, trip, and post-trip operations is discussed as a universal display. The viewpoints and opinions expressed herein are the author's personal ones, and they are not to be interpreted as Nuclear Regulatory Commission criteria, requirements, or guidelines

The RTR complex as caretaker of genome stability and its unique meiotic function in plants

Directory of Open Access Journals (Sweden)

Alexander eKnoll

2014-02-01

Full Text Available The RTR complex consisting of a RecQ helicase, a type IA topoisomerase and the structural protein RMI1 is involved in the processing of DNA recombination intermediates in all eukaryotes. In Arabidopsis thaliana the complex partners RECQ4A, topoisomerase 3α and RMI1 have been shown to be involved in DNA repair and in the suppression of homologous recombination (HR in somatic cells. Interestingly, mutants of AtTOP3A and AtRMI1 are also sterile due to extensive chromosome breakage in meiosis I, a phenotype that seems to be specific for plants. Although both proteins are essential for meiotic recombination it is still elusive on what kind of intermediates they are acting on. Recent data indicate that the pattern of non-crossover (NCO-associated meiotic gene conversion (GC differs between plants and other eukaryotes, as less NCOs in comparison to crossovers (CO could be detected in Arabidopsis. This indicates that NCOs happen either more rarely in plants or that the conversion tract length is significantly shorter than in other organisms. As the TOP3α/RMI1-mediated dissolution of recombination intermediates results exclusively in NCOs, we suggest that the peculiar GC pattern found in plants is connected to the unique role, members of the RTR complex play in plant meiosis.

Reactor power control device in BWR power plant

International Nuclear Information System (INIS)

Kurosawa, Tsuneo.

1997-01-01

The present invention provides a device for controlling reactor power based on a start-up/shut down program in a BWR type reactor, as well as for detecting deviation, if occurs, of the power from the start-up/shut down program, to control a recycling flow rate control system or control rod drive mechanisms. Namely, a power instruction section successively executes the start-up/shut down program and controls the coolant recycling system and the control rod driving mechanisms to control the power. A current state monitoring and calculation section receives a process amount, calculates parameters showing the plant state, compares/monitors them with predetermined values, detecting the deviation, if occurs, of the plant state from the start-up/shut down program, and prevents output of a power increase control signal which leads to power increase. A forecasting and monitoring/calculation section forecasts and calculates the plant state when not yet executed steps of the start-up/shut down program are performed, stops the execution of the start-up/shut down program in the next step in a case of forecasting that the results of the calculation will deviate from the start-up/shut down program. (I.S.)

Recent progress in SG level control in French PWR plants

International Nuclear Information System (INIS)

Parry, A.; Petetrot, J.F.; Vivier, M.J.

1985-10-01

Controlling the steam generator (SG) level is of major importance in a large PWR plant. This has led to extensive work on SG computer models. This paper presents results of the comparison between calculations and tests on the first four-loop plant in France. Four-loop plants started up after 1985 will be equipped with digital instead of analog controllers. A new SG level control has been designed and then optimised using the validated SG model. A prototype of this new system has been successfully tested on a three-loop plant. 4 refs

Expert systems with fuzzy logic for intelligent diagnosis and control of nuclear power plants

International Nuclear Information System (INIS)

Abdelhai, M.I.; Upadhyaya, B.R.

1990-01-01

A model-based production-rule analysis system was developed for the tracking and diagnosis of the condition of a reactor coolant system (RCS) using a fuzzy logic algorithm. Since nuclear power plants are large and complex systems, it is natural that vagueness, uncertainty, and imprecision are introduced to such systems. Even in fully automated power plants, the critical diagnostic and control changes must be made by operators who usually express their diagnostic and control strategies linguistically as sets of heuristic decision rules. Therefore, additional imprecisions are introduced into the systems because of the imprecise nature of such qualitative strategies when they are converted into quantitative rules. Such problems, in which the source of imprecision is the absence of sharply defined criteria of class membership, could be dealt with using fuzzy set theory. Hence, a fuzzy logic algorithm could be initiated to implement a known heuristic whenever the given information is vague and qualitative, and it will allow operators to introduce certain linguistic assertions and commands to diagnose and control the system

Savannah River Plant airborne emissions and controls

International Nuclear Information System (INIS)

Dukes, E.K.; Benjamin, R.W.

1982-12-01

The Savannah River Plant (SRP) was established to produce special nuclear materials, principally plutonium and tritium, for national defense needs. Major operating facilities include three nuclear reactors, two chemical separations plants, a fuel and target fabrication plant, and a heavy-water rework plant. An extensive environmental surveillance program has been maintained continuously since 1951 (before SRP startup) to determine the concentrations of radionuclides in a 1200-square-mile area centered on the plant, and the radiation exposure of the population resulting from SRP operations. This report provides data on SRP emissions, controls systems, and airborne radioactive releases. The report includes descriptions of current measurement technology. 10 references, 14 figures, 9 tables

Discrimination of plant-parasitic nematodes from complex soil communities using ecometagenetics.

Science.gov (United States)

Porazinska, Dorota L; Morgan, Matthew J; Gaspar, John M; Court, Leon N; Hardy, Christopher M; Hodda, Mike

2014-07-01

Many plant pathogens are microscopic, cryptic, and difficult to diagnose. The new approach of ecometagenetics, involving ultrasequencing, bioinformatics, and biostatistics, has the potential to improve diagnoses of plant pathogens such as nematodes from the complex mixtures found in many agricultural and biosecurity situations. We tested this approach on a gradient of complexity ranging from a few individuals from a few species of known nematode pathogens in a relatively defined substrate to a complex and poorly known suite of nematode pathogens in a complex forest soil, including its associated biota of unknown protists, fungi, and other microscopic eukaryotes. We added three known but contrasting species (Pratylenchus neglectus, the closely related P. thornei, and Heterodera avenae) to half the set of substrates, leaving the other half without them. We then tested whether all nematode pathogens-known and unknown, indigenous, and experimentally added-were detected consistently present or absent. We always detected the Pratylenchus spp. correctly and with the number of sequence reads proportional to the numbers added. However, a single cyst of H. avenae was only identified approximately half the time it was present. Other plant-parasitic nematodes and nematodes from other trophic groups were detected well but other eukaryotes were detected less consistently. DNA sampling errors or informatic errors or both were involved in misidentification of H. avenae; however, the proportions of each varied in the different bioinformatic pipelines and with different parameters used. To a large extent, false-positive and false-negative errors were complementary: pipelines and parameters with the highest false-positive rates had the lowest false-negative rates and vice versa. Sources of error identified included assumptions in the bioinformatic pipelines, slight differences in primer regions, the number of sequence reads regarded as the minimum threshold for inclusion in analysis

Toward risk-based control of nuclear power plant configurations

International Nuclear Information System (INIS)

Samanta, P.K.; Veseley, W.E.; Kim, I.S.

1992-01-01

This paper presents an evaluation of the configuration risks associated with the operation of a nuclear power plant and the approaches to control these risks using risk-based configuration control considerations. In that context, the actual and maximum potential configuration risks at a plant are analyzed and the alternative types criteria for a risk-based configuration control systems are described. The risk-based configuration calculations which are studied here focus on the core-melt frequency impacts from given plant configurations, the configurations which cause large core-melt frequency increases can be identified and controlled. The duration time in which the configuration can exist can then be limited or the core-melt frequency level associated with the configuration can be reduced by various actions. Futhermore, maintenances and tests can be scheduled to avoid the configurations which cause large core-melt frequency increases. Present technical specifications do not control many of these configurations which can cause large core-melt frequency increases but instead focus on many risk-unimportant allowed outage times. Hence, risk-based configuration management can be effectively used to reduce core-melt frequency associated risks at a plant and at the same time can provide flexibility in plant operation. The alternative strategies for controlling the core-melt frequency and other risk contributions include: (1) controlling the increased risk level which is associated with the configuration; (2) controlling the individual configuration risk which is associated with a given duration of a configuration; (3) controlling the time period configuration risk from configurations which occur in a time period. (orig.)

Smart — STATCOM control strategy implementation in wind power plants

DEFF Research Database (Denmark)

Sintamarean, Nicolae Christian; Cantarellas, Antoni Mir; Miranda, H.

2012-01-01

High penetration of wind energy into the grid may introduce stability and power quality problems due to the fluctuating nature of the wind and the increasing complexity of the power system. By implementing advanced functionalities in power converters, it is possible to improve the performance...... of the wind farm and also to provide grid support, as it is required by the grid codes. One of the main compliance difficulties that can be found in such power plants are related to reactive power compensation and to keep the harmonics content between the allowed limits, even if the power of the WPP...... converters is increasing. This paper deals with an advanced control strategy design of a three-level converter performing STATCOM and Active Filter functionalities. The proposed system is called Smart-STATCOM since it has the capability of self-controlling reactive power and harmonic voltages at the same...

The effects of overtime work and task complexity on the performance of nuclear plant operators: A proposed methodology

International Nuclear Information System (INIS)

Banks, W.W.; Potash, L.

1985-01-01

This document presents a very general methodology for determining the effect of overtime work and task complexity on operator performance in response to simulated out-of-limit nuclear plant conditions. The independent variables consist of three levels of overtime work and three levels of task complexity. Multiple dependent performance measures are proposed for use and discussion. Overtime work is operationally defined in terms of the number of hours worked by nuclear plant operators beyond the traditional 8 hours per shift. Task complexity is operationalized in terms of the number of operator tasks required to remedy a given plant anomalous condition and bring the plant back to a ''within limits'' or ''normal'' steady-state condition. The proposed methodology would employ a 2 factor repeated measures design along with the analysis of variance (linear) model

Complexity and Control: Towards a Rigorous Behavioral Theory of Complex Dynamical Systems

Science.gov (United States)

Ivancevic, Vladimir G.; Reid, Darryn J.

We introduce our motive for writing this book on complexity and control with a popular "complexity myth," which seems to be quite wide spread among chaos and complexity theory fashionistas: quote>Low-dimensional systems usually exhibit complex behaviours (which we know fromMay's studies of the Logisticmap), while high-dimensional systems usually exhibit simple behaviours (which we know from synchronisation studies of the Kuramoto model)...quote> We admit that this naive view on complex (e.g., human) systems versus simple (e.g., physical) systems might seem compelling to various technocratic managers and politicians; indeed, the idea makes for appealing sound-bites. However, it is enough to see both in the equations and computer simulations of pendula of various degree - (i) a single pendulum, (ii) a double pendulum, and (iii) a triple pendulum - that this popular myth is plain nonsense. The only thing that we can learn from it is what every tyrant already knows: by using force as a strong means of control, it is possible to effectively synchronise even hundreds of millions of people, at least for a while.

Control room design and human engineering in power plants

International Nuclear Information System (INIS)

Herbst, L.; Hinz, W.

1982-01-01

The concept for modern plant control rooms is primary influenced by: The automation of protection, binary control and closed loop control functions; organization employing functional areas; computer based information processing; human engineered design. Automation reduces the human work load. Employment of functional areas permits optimization of operational sequences. Computer based information processing makes it possible to output information in accordance with operating requirements. Design based on human engineering principles assures the quality of the interaction between the operator and the equipment. The degree to which these conceptional features play a role in design of power plant control rooms depends on the unit rating, the mode of operation and on the requirements respecting safety and availability of the plant. (orig.)

An Evolutionary Robotics Approach to the Control of Plant Growth and Motion: Modeling Plants and Crossing the Reality Gap

DEFF Research Database (Denmark)

Wahby, Mostafa; Hofstadler, Daniel Nicolas; Heinrich, Mary Katherine

2016-01-01

approach where task performance is determined by monitoring the plant's reaction. First, we do initial plant experiments with simple, predetermined controllers. Then we use image sampling data as a model of the dynamics of the plant tip xy position. Second, we use this approach to evolve robot controllers...... in simulation. The task is to make the plant approach three predetermined, distinct points in an xy-plane. Finally, we test the evolved controllers in real plant experiments and find that we cross the reality gap successfully. We shortly describe how we have extended from plant tip to many points on the plant...

Nuclear Power Plant Control and Instrumentation 1989

International Nuclear Information System (INIS)

1990-11-01

The meeting of the International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI) was organized in order to summarize operating experience of nuclear power plant control systems, gain a general overview of activities in development of modern control systems and receive recommendations on the further directions and particular measures within the Agency's programme. The meeting was held at the IAEA Headquarters in Vienna and was attended by 21 national delegates and observers from 18 countries. The present volume contains: (1) report on the meeting of the IWG-NPPCI, Vienna, 8-10 May 1989, (2) report of the scientific secretary on the major activities of IAEA during 1987-89 in the NPPCI area, (3) terms of reference International Working Group on NPPCI and (4) reports of the national representatives to the International Working Group on NPPCI. The paper and discussions with practical experience and described actual problems encountered. Emphasis was placed on the technical, industrial and economical aspects of the introduction of modern control systems and on the improvement of plant availability and safety. A separate abstract was prepared for each of the 19 papers presented by members of the International Working Group. Refs, figs and tabs

Control of uranium hazards - Portsmouth uranium enrichment plant

International Nuclear Information System (INIS)

Wagner, E.R.

1985-01-01

This report summarizes the Environmental, Safety and Health programs to control uranium hazards at the Portsmouth Gaseous Diffusion Plant. A description of the physical plant, the facility processes and the attendant uranium flows and effluents are provided. The hazards of uranium are discussed and the control systems are outlined. Finally, the monitoring programs are described and summaries of recent data are provided. 11 figs., 20 tabs

Retrofit of safety and control systems in nuclear power plants

International Nuclear Information System (INIS)

Keiper, J.T.; Fassett, G.B.

1986-01-01

The modularity, compactness, compatibility, and licensability of the microcontrol system make it a cost-effective approach to obtain the benefits of digital control technology in the retrofit of nuclear power plants. Retrofit of individual loops or complete systems can be scheduled to meet the operational needs of the plant. The existing racks, panels, and cable systems can be utilized to the maximum extent to minimize the installed cost. Future expansion to total plant control or plant management is supported by the network communication module or gateway. The microcontrol module provides benefits now in improved operation, and future benefits in planned, controlled upgrading

Historical development of automation and control of thermal power plants''; Historische Entwicklung der Leittechnik von Dampfkraftwerken

Energy Technology Data Exchange (ETDEWEB)

Welfonder, E. [Stuttgart Univ. (DE). Abt. Stromerzeugung und Automatisierungstechnik (IVD); Sterff, J.

2006-07-01

Historically early steam power plants were developed to replace muscular power of men and animals and to gain independence from wind and water power. The further development of power plant technology was driven by the demand to meet the fast growing consumption of electric power with a higher degree of efficiency. In the nineteenth century steam power was the key element for industrialisation. Instrumentation and control equipments were the key factors for the safe operation of power generating processes, becoming more and more complex during the twentieth century. The use of control concepts with increasing performance induced the development of adequate instrumentation and control systems. This paper outlines the history of steam power from the beginning to the seventies and focuses on automation concepts, without further regarding details of apparatus und system technology. (orig.)

Fire hazard analysis for Plutonium Finishing Plant complex

Energy Technology Data Exchange (ETDEWEB)

MCKINNIS, D.L.

1999-02-23

A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards.

Analysis on Single Point Vulnerabilities of Plant Control System

International Nuclear Information System (INIS)

Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung

2011-01-01

The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities

Analysis on Single Point Vulnerabilities of Plant Control System

Energy Technology Data Exchange (ETDEWEB)

Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2011-08-15

The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities.

Distributed and hierarchical control techniques for large-scale power plant systems

International Nuclear Information System (INIS)

Raju, G.V.S.; Kisner, R.A.

1985-08-01

In large-scale systems, integrated and coordinated control functions are required to maximize plant availability, to allow maneuverability through various power levels, and to meet externally imposed regulatory limitations. Nuclear power plants are large-scale systems. Prime subsystems are those that contribute directly to the behavior of the plant's ultimate output. The prime subsystems in a nuclear power plant include reactor, primary and intermediate heat transport, steam generator, turbine generator, and feedwater system. This paper describes and discusses the continuous-variable control system developed to supervise prime plant subsystems for optimal control and coordination

Controlling extreme events on complex networks

Science.gov (United States)

Chen, Yu-Zhong; Huang, Zi-Gang; Lai, Ying-Cheng

2014-08-01

Extreme events, a type of collective behavior in complex networked dynamical systems, often can have catastrophic consequences. To develop effective strategies to control extreme events is of fundamental importance and practical interest. Utilizing transportation dynamics on complex networks as a prototypical setting, we find that making the network ``mobile'' can effectively suppress extreme events. A striking, resonance-like phenomenon is uncovered, where an optimal degree of mobility exists for which the probability of extreme events is minimized. We derive an analytic theory to understand the mechanism of control at a detailed and quantitative level, and validate the theory numerically. Implications of our finding to current areas such as cybersecurity are discussed.

Control room habitability in Spanish Nuclear Power Plants

International Nuclear Information System (INIS)

Mediavilla, F.; Sierra, J. J.

2007-01-01

Since the NRC published in 2003 the Generic Letter 2003-01 Control room Habitability and the Regulatory guide 1.197 Demonstrating Control Room Envelope Integrity at Nuclear Power Reactors, where it is emphasized the importance of verifying the control room habitability by means of alternative methods, Spanish Nuclear Power Plants are undertaking the different necessary activities to fulfill the requirements of the regulatory commission. This paper describes the main mechanisms included in NEI 99-03 Nuclear Energy Institute publication Control room Habitability Assessment guidance, to demonstrate and maintain Control room Habitability. In addition, in this article it Ds shown the theoretical principle of the test used to quantify air in-leakage in a control room envelope by using tracer gas techniques. The necessary activities to perform the initial in leakage testing are also put forward. Since 2006 Tecnatom, S. A. has performed the baseline testing in four Spanish Units, all of them with successful results. The rest of the Plants are scheduled to perform the tests during the second half of this year. Finally, this document summarises the more important aspects to be taken into account in the development of control room Habitability Programs, which are expected to ensure the integral maintenance of the Control room Envelope during the life a plant. (Author)

Development of model reference adaptive control theory for electric power plant control applications

Energy Technology Data Exchange (ETDEWEB)

Mabius, L.E.

1982-09-15

The scope of this effort includes the theoretical development of a multi-input, multi-output (MIMO) Model Reference Control (MRC) algorithm, (i.e., model following control law), Model Reference Adaptive Control (MRAC) algorithm and the formulation of a nonlinear model of a typical electric power plant. Previous single-input, single-output MRAC algorithm designs have been generalized to MIMO MRAC designs using the MIMO MRC algorithm. This MRC algorithm, which has been developed using Command Generator Tracker methodologies, represents the steady state behavior (in the adaptive sense) of the MRAC algorithm. The MRC algorithm is a fundamental component in the MRAC design and stability analysis. An enhanced MRC algorithm, which has been developed for systems with more controls than regulated outputs, alleviates the MRC stability constraint of stable plant transmission zeroes. The nonlinear power plant model is based on the Cromby model with the addition of a governor valve management algorithm, turbine dynamics and turbine interactions with extraction flows. An application of the MRC algorithm to a linearization of this model demonstrates its applicability to power plant systems. In particular, the generated power changes at 7% per minute while throttle pressure and temperature, reheat temperature and drum level are held constant with a reasonable level of control. The enhanced algorithm reduces significantly control fluctuations without modifying the output response.

EFFECT OF PLANT EXTRACTS AND GROWTH SUBSTRATES ON CONTROLLING DAMPING-OFF IN PINUS TECUNUMANII SEEDLINGS

Directory of Open Access Journals (Sweden)

Maria Alejandra Fajardo-Mejía

2016-09-01

Full Text Available Damping-off is considered one of the most limiting phytosanitary problems in conifer seedling production because it may cause massive damage or total plant death in short time periods. This pathology is caused by a complex of microorganisms, the most common of which are Fusarium spp. and Rhizoctonia spp. This study evaluated the effect of growth substrates and plant extracts at different concentrations on germination and incidence of disease in Pinus tecunumanii plants. The plants were inoculated with the damping-off pathogen Fusarium oxysporum and treatments were applied in a completely randomized design with a factorial arrangement of 4x2x3. This corresponded to four substrates (pine bark, rice hull, coconut husk and sandy soil (4:1; two plant extracts (Matricaria chamomilla and Datura stramonium, andthree concentrations of each extract (Control concentration: 0%, Concentration 1: 50 % and Concentration 2: Undiluted. Each treatment had three repetitions, with 25 plants per repetition. The growth substrates affected germination; the most effective of these were sandy soil (4:1 and pine bark, with 90% and 92% germination at day 20, respectively. No significant difference was observed between the germination obtained with these substrates and that obtained with coconut husk after day 19. Meanwhile, all of the extracts had a significant effect on controlling the disease when they were combined with the substrates, with the exception of coconut husk. With this last substrate the incidence of disease was lower than 4% without the application of plant extracts; this indicates that coconut husk discourages the development of the disease on its own.

Synchronizability on complex networks via pinning control

Indian Academy of Sciences (India)

Keywords. Complex network; the pinning synchronization; synchronizability. ... The findings reveal the relationship between the decreasing speed of maximum eigenvalue sequence of the principal submatrices for coupling matrix and the synchronizability on complex networks via pinning control. We discuss the ...

Wind Plant Power Optimization and Control under Uncertainty

Science.gov (United States)

Jha, Pankaj; Ulker, Demet; Hutchings, Kyle; Oxley, Gregory

2017-11-01

The development of optimized cooperative wind plant control involves the coordinated operation of individual turbines co-located within a wind plant to improve the overall power production. This is typically achieved by manipulating the trajectory and intensity of wake interactions between nearby turbines, thereby reducing wake losses. However, there are various types of uncertainties involved, such as turbulent inflow and microscale and turbine model input parameters. In a recent NREL-Envision collaboration, a controller that performs wake steering was designed and implemented for the Longyuan Rudong offshore wind plant in Jiangsu, China. The Rudong site contains 25 Envision EN136-4 MW turbines, of which a subset was selected for the field test campaign consisting of the front two rows for the northeasterly wind direction. In the first row, a turbine was selected as the reference turbine, providing comparison power data, while another was selected as the controlled turbine. This controlled turbine wakes three different turbines in the second row depending on the wind direction. A yaw misalignment strategy was designed using Envision's GWCFD, a multi-fidelity plant-scale CFD tool based on SOWFA with a generalized actuator disc (GAD) turbine model, which, in turn, was used to tune NREL's FLORIS model used for wake steering and yaw control optimization. The presentation will account for some associated uncertainties, such as those in atmospheric turbulence and wake profile.

Monitor and control device in a nuclear power plant

International Nuclear Information System (INIS)

Neda, Toshikatsu.

1980-01-01

Purpose: To facilitate and ensure monitor and control, as well as improve the operation efficiency and save man power, by render the operation automatic utilizing a process computer and centralizing the monitor and control functions. Constitution: All of the operations from the start up to stop in a nuclear power plant are conducted by way of a monitor and control board. The process data for the nuclear power plant are read into the process computer and displayed on a CRT display. Controls are carried out respectively for the control rod on a control rod panel, for the feedwater rate on a feedwater control panel, for the recycling flow rate on a recycling control panel and for the turbine generator on a turbine control panel. When the operation is conducted by an automatic console, operation signals from the console are imputted into the process computer and the state of the power plant is monitored and automatic operation is carried out based on the operation signals and from signals from each of the panels. (Moriyama, K.)

Solar field control for desalination plants

Energy Technology Data Exchange (ETDEWEB)

Roca, Lidia [Convenio Universidad de Almeria, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain); Berenguel, Manuel [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, 04120 Almeria (Spain); Yebra, Luis; Alarcon-Padilla, Diego C. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain)

2008-09-15

This paper presents the development and application of a feedback linearization control strategy for a solar collector field supplying process heat to a multi-effect seawater distillation plant. Since one objective is to use as much as possible the solar resource, control techniques can be used to produce the maximum heat process in the solar field. The main purpose of the controller presented in this paper is to manipulate the water flow rate to maintain an outlet-inlet temperature gradient in the collectors, thereby ensuring continuous process heating, or in other words, continuous production of fresh water in spite of disturbances. The dynamic behaviour of this solar field was approximated by a simplified lumped-parameters nonlinear model based on differential equations, validated with real data and used in the feedback linearization control design. Experimental results in the seawater desalination plant at the Plataforma Solar de Almeria (Spain) show good agreement of the model and real data despite the approximations included. Moreover, by using feedback linearization control it is possible to track a constant gradient temperature reference in the solar field with good results. (author)

Production of complex multiantennary N-glycans in Nicotiana benthamiana plants.

Science.gov (United States)

Nagels, Bieke; Van Damme, Els J M; Pabst, Martin; Callewaert, Nico; Weterings, Koen

2011-03-01

In recent years, plants have been developed as an alternative expression system to mammalian hosts for the production of therapeutic proteins. Many modifications to the plant glycosylation machinery have been made to render it more human because of the importance of glycosylation for functionality, serum half-life, and the safety profile of the expressed proteins. These modifications include removal of plant-specific β1,2-xylose and core α1,3-fucose, and addition of bisecting N-acetylglucosamine, β1,4-galactoses, and sialic acid residues. Another glycosylation step that is essential for the production of complex human-type glycans is the synthesis of multiantennary structures, which are frequently found on human N-glycans but are not generated by wild-type plants. Here, we report both the magnICON-based transient as well as stable introduction of the α1,3-mannosyl-β1,4-N-acetylglucosaminyltransferase (GnT-IV isozymes a and b) and α1,6-mannosyl-β1,6-N-acetylglucosaminyltransferase (GnT-V) in Nicotiana benthamiana plants. The enzymes were targeted to the Golgi apparatus by fusing their catalytic domains to the plant-specific localization signals of xylosyltransferase and fucosyltransferase. The GnT-IV and -V modifications were tested in the wild-type background, but were also combined with the RNA interference-mediated knockdown of β1,2-xylosyltransferase and α1,3-fucosyltransferase. Results showed that triantennary Gn[GnGn] and [GnGn]Gn N-glycans could be produced according to the expected activities of the respective enzymes. Combination of the two enzymes by crossing stably transformed GnT-IV and GnT-V plants showed that up to 10% tetraantennary [GnGn][GnGn], 25% triantennary, and 35% biantennary N-glycans were synthesized. All transgenic plants were viable and showed no aberrant phenotype under standard growth conditions.

Plant response-based sensing for control starategies in sustainable greenhouse production

International Nuclear Information System (INIS)

Kacira, M.; Sase, S.; Okushima, L.; Ling, P.P.

2005-01-01

The effect of environmental variability is one of the major concerns in experimental design for both research in plant systems and greenhouse plant production. Microclimates surrounding plants are not usually uniform. Therefore, many samples and sensors are required to obtain a true representation of the plant population. A plant monitoring system capable of reducing the required number of samples by reducing environmental variability would be more advantageous. To better understand plant-environment interaction, it is essential to study plants, microclimate surrounding the plants and the growth media. To achieve this, the monitoring system must be equipped with proper instrumentation. To achieve proper management practices and sustainable greenhouse production, it is essential first to understand plants and their interactions with their surroundings and then establish plant response-based sensing and control strategies for greenhouse processes. Therefore, an effort was conducted to review and discuss current sensing and control strategies in greenhouse research and plant production and provide recommendations on plant response-based sensing and control strategies for sustainable greenhouse production

Major intrinsic proteins (MIPs) in plants: a complex gene family with major impacts on plant phenotype.

Science.gov (United States)

Forrest, Kerrie L; Bhave, Mrinal

2007-10-01

The ubiquitous cell membrane proteins called aquaporins are now firmly established as channel proteins that control the specific transport of water molecules across cell membranes in all living organisms. The aquaporins are thus likely to be of fundamental significance to all facets of plant growth and development affected by plant-water relations. A majority of plant aquaporins have been found to share essential structural features with the human aquaporin and exhibit water-transporting ability in various functional assays, and some have been shown experimentally to be of critical importance to plant survival. Furthermore, substantial evidence is now available from a number of plant species that shows differential gene expression of aquaporins in response to abiotic stresses such as salinity, drought, or cold and clearly establishes the aquaporins as major players in the response of plants to conditions that affect water availability. This review summarizes the function and regulation of these genes to develop a greater understanding of the response of plants to water insufficiency, and particularly, to identify tolerant genotypes of major crop species including wheat and rice and plants that are important in agroforestry.

Plants lacking the main light-harvesting complex retain photosystem II macro-organization

NARCIS (Netherlands)

Ruban, A.V.; Wentworth, M.; Yakushevska, A.E.; Andersson, J.; Lee, P.J.; Keegstra, W.; Dekker, J.P.; Boekema, E.J.; Jansson, S.; Horton, P.

2003-01-01

Photosystem II (PSII) is a key component of photosynthesis, the process of converting sunlight into the chemical energy of life. In plant cells, it forms a unique oligomeric macrostructure in membranes of the chloroplasts. Several light-harvesting antenna complexes are organized precisely in the

Plants lacking the main light-harvesting complex retain photosystem II macro-organization

NARCIS (Netherlands)

Ruban, AV; Wentworth, M; Yakushevska, AE; Andersson, J; Lee, PJ; Keegstra, W; Dekker, JP; Boekema, EJ; Jansson, S; Horton, P

2003-01-01

Photosystem II (PSII) is a key component of photosynthesis, the process of converting sunlight into the chemical energy of life. In plant cells, it forms a unique oligomeric macrostructure in membranes of the chloroplasts(1). Several light-harvesting antenna complexes are organized precisely in the

Study on a quantitative evaluation method of equipment maintenance level and plant safety level for giant complex plant system

International Nuclear Information System (INIS)

Aoki, Takayuki

2010-01-01

In this study, a quantitative method on maintenance level which is determined by the two factors, maintenance plan and field work implementation ability by maintenance crew is discussed. And also a quantitative evaluation method on safety level for giant complex plant system is discussed. As a result of consideration, the following results were obtained. (1) It was considered that equipment condition after maintenance work was determined by the two factors, maintenance plan and field work implementation ability possessed by maintenance crew. The equipment condition determined by the two factors was named as 'equipment maintenance level' and its quantitative evaluation method was clarified. (2) It was considered that CDF in a nuclear power plant, evaluated by using a failure rate counting the above maintenance level was quite different from CDF evaluated by using existing failure rates including a safety margin. Then, the former CDF was named as 'plant safety level' of plant system and its quantitative evaluation method was clarified. (3) Enhancing equipment maintenance level means an improvement of maintenance quality. That results in the enhancement of plant safety level. Therefore, plant safety level should be always watched as a plant performance indicator. (author)

Role of post-translational modifications at the β-subunit ectodomain in complex association with a promiscuous plant P4-ATPase.

Science.gov (United States)

Costa, Sara R; Marek, Magdalena; Axelsen, Kristian B; Theorin, Lisa; Pomorski, Thomas G; López-Marqués, Rosa L

2016-06-01

P-type ATPases of subfamily IV (P4-ATPases) constitute a major group of phospholipid flippases that form heteromeric complexes with members of the Cdc50 (cell division control 50) protein family. Some P4-ATPases interact specifically with only one β-subunit isoform, whereas others are promiscuous and can interact with several isoforms. In the present study, we used a site-directed mutagenesis approach to assess the role of post-translational modifications at the plant ALIS5 β-subunit ectodomain in the functionality of the promiscuous plant P4-ATPase ALA2. We identified two N-glycosylated residues, Asn(181) and Asn(231) Whereas mutation of Asn(231) seems to have a small effect on P4-ATPase complex formation, mutation of evolutionarily conserved Asn(181) disrupts interaction between the two subunits. Of the four cysteine residues located in the ALIS5 ectodomain, mutation of Cys(86) and Cys(107) compromises complex association, but the mutant β-subunits still promote complex trafficking and activity to some extent. In contrast, disruption of a conserved disulfide bond between Cys(158) and Cys(172) has no effect on the P4-ATPase complex. Our results demonstrate that post-translational modifications in the β-subunit have different functional roles in different organisms, which may be related to the promiscuity of the P4-ATPase. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Reactive power control with CHP plants - A demonstration

DEFF Research Database (Denmark)

Nyeng, Preben; Østergaard, Jacob; Andersen, Claus A.

2010-01-01

power rating of 7.3 MW on two synchronous generators. A closed-loop control is implemented, that remote controls the CHP plant to achieve a certain reactive power flow in a near-by substation. The solution communicates with the grid operator’s existing SCADA system to obtain measurements from...... lines to underground cables has changed the reactive power balance, and third, the TSO has introduced restrictions in the allowed exchange of reactive power between the transmission system and distribution grids (known as the Mvar-arrangement). The demonstration includes a CHP plant with an electric......In this project the potential for ancillary services provision by distributed energy resources is investigated. Specifically, the provision of reactive power control by combined heat and power plants is examined, and the application of the new standard for DER communication systems, IEC 61850...

Environmental radioactive contamination and its control for nuclear power plants

International Nuclear Information System (INIS)

Shi Zhongqi; Qu Jingyuan; Cui Yongli

1998-01-01

The environmental radioactive releases and exposure to human being due to operation of nuclear power plants in the world and in China, environmental contamination and consequences caused by severe nuclear power plant accidents in the history, control of the radioactive contamination in China, and some nuclear laws on the radioactive contamination control established by international organizations and USA etc. are described according to literature investigation and research. Some problems and comments in radioactive contamination control for nuclear power plants in China are presented. Therefore, perfecting laws and regulations and enhancing surveillances on the contamination control are recommended

Arabidopsis thaliana plants lacking the ARP2/3 complex show defects in cell wall assembly and auxin distribution.

Science.gov (United States)

Pratap Sahi, Vaidurya; Cifrová, Petra; García-González, Judith; Kotannal Baby, Innu; Mouillé, Gregory; Gineau, Emilie; Müller, Karel; Baluška, František; Soukup, Aleš; Petrášek, Jan; Schwarzerová, Katerina

2017-12-25

The cytoskeleton plays an important role in the synthesis of plant cell walls. Both microtubules and actin cytoskeleton are known to be involved in the morphogenesis of plant cells through their role in cell wall building. The role of ARP2/3-nucleated actin cytoskeleton in the morphogenesis of cotyledon pavement cells has been described before. Seedlings of Arabidopsis mutants lacking a functional ARP2/3 complex display specific cell wall-associated defects. In three independent Arabidopsis mutant lines lacking subunits of the ARP2/3 complex, phenotypes associated with the loss of the complex were analysed throughout plant development. Organ size and anatomy, cell wall composition, and auxin distribution were investigated. ARP2/3-related phenotype is associated with changes in cell wall composition, and the phenotype is manifested especially in mature tissues. Cell walls of mature plants contain less cellulose and a higher amount of homogalacturonan, and display changes in cell wall lignification. Vascular bundles of mutant inflorescence stems show a changed pattern of AUX1-YFP expression. Plants lacking a functional ARP2/3 complex have decreased basipetal auxin transport. The results suggest that the ARP2/3 complex has a morphogenetic function related to cell wall synthesis and auxin transport. © The Author(s) 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Voltage Control in Wind Power Plants with Doubly Fed Generators

DEFF Research Database (Denmark)

Garcia, Jorge Martinez

In this work, the process of designing a wind power plant composed of; doubly fed induction generators, a static compensator unit, mechanically switched capacitors and on-load tap changer, for voltage control is shown. The selected control structure is based on a decentralized system, since...... supplied by the doubly fed induction generator wind turbines is overcome by installing a reactive power compensator, i.e. a static compensator unit, which is coordinated with the plant control by a specific dispatcher. This dispatcher is set according to the result of the wind power plant load flow....... To release the operation of the converters during steady-state disturbances, mechanically switched capacitors are installed in the wind power plant, which due to their characteristics, they are appropriate for permanent disturbances compensation. The mechanically switched capacitors are controlled to allow...

Automated logic conversion method for plant controller systems

International Nuclear Information System (INIS)

Wada, Yutaka; Kobayashi, Yasuhiro; Miyo, Tsunemasa; Okano, Masato.

1990-01-01

An automated method is proposed for logic conversion from functional description diagrams to detailed logic schematics by incorporating expertise knowledge in plant controller systems design. The method uses connection data of function elements in the functional description diagram as input, and synthesizes a detailed logic structure by adding elements to the given connection data incrementally, and to generate detailed logic schematics. In logic synthesis, for building up complex synthesis procedures by combining generally-described knowledge, knowledge is applied by groups. The search order of the groups is given by upper-level knowledge. Furthermore, the knowledge is expressed in terms of two classes of rules; one for generating a hypothesis of individual synthesis operations and the other for considering several hypotheses to determine the connection ordering of elements to be added. In the generation of detailed logic schematics, knowledge is used as rules for deriving various kinds of layout conditions on schematics, and rules for generating two-dimensional coordinates of layout objects. Rules in the latter class use layout conditions to predict intersections among layout objects without their coordinates being fixed. The effectiveness of the method with 150 rules was verified by its experimental application to some logic conversions in a real power plant design. Evaluation of the results showed them to be equivalent to those obtained by well qualified designers. (author)

A Plant Control Technology Using Reinforcement Learning Method with Automatic Reward Adjustment

Science.gov (United States)

Eguchi, Toru; Sekiai, Takaaki; Yamada, Akihiro; Shimizu, Satoru; Fukai, Masayuki

A control technology using Reinforcement Learning (RL) and Radial Basis Function (RBF) Network has been developed to reduce environmental load substances exhausted from power and industrial plants. This technology consists of the statistic model using RBF Network, which estimates characteristics of plants with respect to environmental load substances, and RL agent, which learns the control logic for the plants using the statistic model. In this technology, it is necessary to design an appropriate reward function given to the agent immediately according to operation conditions and control goals to control plants flexibly. Therefore, we propose an automatic reward adjusting method of RL for plant control. This method adjusts the reward function automatically using information of the statistic model obtained in its learning process. In the simulations, it is confirmed that the proposed method can adjust the reward function adaptively for several test functions, and executes robust control toward the thermal power plant considering the change of operation conditions and control goals.

Transient behaviour and control of the ACACIA plant

International Nuclear Information System (INIS)

Kikstra, J.F.; Heek, A.I. van; Verkooijen, A.H.M.

2001-01-01

This article deals with dynamic modelling and control of the ACACIA plant. A one-dimensional flow model describing the helium flow and the two-phase water flow is used through the whole plant, with different source terms in different pieces of equipment. A stage-by-stage model is produced for the radial compressor and axial turbine. Other models include the recuperator, water/helium heat exchangers, a natural convection evaporator, valves, etc. The models have been checked by comparison of the transient behavior with several other models, e.g. produced in RELAP. The dynamic behavior of this plant is analysed and a control structure is designed. First the requirements and options for a control system design are investigated. A number of possible control valve positions in the flowsheet are tested with transients in order to make an argued choice. The model is subsequently used to determine the optimal working conditions for different heat and power demands, these are used as set-points for the control system. Then the interaction between manipulated and controlled variables is mapped and based on this information a choice for coupling them in decentralised feedback control loops is made. This control structure is then tuned and tested. It can be concluded that both heat and power demand can be followed with acceptable performance over a wide range. (author)

A protochlorophyllide light-harvesting complex involved in de-etiolation of higher plants

International Nuclear Information System (INIS)

Reinbothe, C.; Lebedev, N.; Reinbothe, S.

1999-01-01

When etiolated angiosperm seedlings break through the soil after germination, they are immediately exposed to sunlight, but at this stage they are unable to perform photosynthesis1. In the absence of chlorophyll a and chlorophyll b, two other porphyrin species cooperate as the basic light-harvesting structure of etiolated plants. Protochlorophyllide a and protochlorophyllide b (ref. 2) form supramolecular complexes with NADPH and two closely related NADPH:protochlorophyllide oxidoreductase (POR) proteins—PORA and PORB (ref. 3)—in the prolamellar body of etioplasts. Here we report that these light-harvesting POR–protochlorophyllide complexes, named LHPP, are essential for the establishment of the photosynthetic apparatus and also confer photoprotection on the plant. They collect sunlight for rapid chlorophyll a biosynthesis and, simultaneously, dissipate excess light energy in the bulk of non-photoreducible protochlorophyllide b. Based on this dual function, it seems that LHPP provides the link between skotomorphogenesis and photosynthesis that is required for efficient de-etiolation

Optimization control of LNG regasification plant using Model Predictive Control

Science.gov (United States)

Wahid, A.; Adicandra, F. F.

2018-03-01

Optimization of liquified natural gas (LNG) regasification plant is important to minimize costs, especially operational costs. Therefore, it is important to choose optimum LNG regasification plant design and maintaining the optimum operating conditions through the implementation of model predictive control (MPC). Optimal tuning parameter for MPC such as P (prediction horizon), M (control of the horizon) and T (sampling time) are achieved by using fine-tuning method. The optimal criterion for design is the minimum amount of energy used and for control is integral of square error (ISE). As a result, the optimum design is scheme 2 which is developed by Devold with an energy savings of 40%. To maintain the optimum conditions, required MPC with P, M and T as follows: tank storage pressure: 90, 2, 1; product pressure: 95, 2, 1; temperature vaporizer: 65, 2, 2; and temperature heater: 35, 6, 5, with ISE value at set point tracking respectively 0.99, 1792.78, 34.89 and 7.54, or improvement of control performance respectively 4.6%, 63.5%, 3.1% and 58.2% compared to PI controller performance. The energy savings that MPC controllers can make when there is a disturbance in temperature rise 1°C of sea water is 0.02 MW.

Controlling Complex Systems and Developing Dynamic Technology

Science.gov (United States)

Avizienis, Audrius Victor

In complex systems, control and understanding become intertwined. Following Ilya Prigogine, we define complex systems as having control parameters which mediate transitions between distinct modes of dynamical behavior. From this perspective, determining the nature of control parameters and demonstrating the associated dynamical phase transitions are practically equivalent and fundamental to engaging with complexity. In the first part of this work, a control parameter is determined for a non-equilibrium electrochemical system by studying a transition in the morphology of structures produced by an electroless deposition reaction. Specifically, changing the size of copper posts used as the substrate for growing metallic silver structures by the reduction of Ag+ from solution under diffusion-limited reaction conditions causes a dynamical phase transition in the crystal growth process. For Cu posts with edge lengths on the order of one micron, local forces promoting anisotropic growth predominate, and the reaction produces interconnected networks of Ag nanowires. As the post size is increased above 10 microns, the local interfacial growth reaction dynamics couple with the macroscopic diffusion field, leading to spatially propagating instabilities in the electrochemical potential which induce periodic branching during crystal growth, producing dendritic deposits. This result is interesting both as an example of control and understanding in a complex system, and as a useful combination of top-down lithography with bottom-up electrochemical self-assembly. The second part of this work focuses on the technological development of devices fabricated using this non-equilibrium electrochemical process, towards a goal of integrating a complex network as a dynamic functional component in a neuromorphic computing device. Self-assembled networks of silver nanowires were reacted with sulfur to produce interfacial "atomic switches": silver-silver sulfide junctions, which exhibit

Benchmarking of Control Strategies for Wastewater Treatment Plants

DEFF Research Database (Denmark)

Wastewater treatment plants are large non-linear systems subject to large perturbations in wastewater flow rate, load and composition. Nevertheless these plants have to be operated continuously, meeting stricter and stricter regulations. Many control strategies have been proposed in the literature...

Atmospheric dispersion in complex terrain: Angra-1 nuclear power plant

International Nuclear Information System (INIS)

Lima e Silva Filho, P.P. de

1986-01-01

The Angra 1 plant is located in a very complex terrain, what makes the environmental impact assessment very difficult, regarding to the atmospheric transport problem as well as to the diffusion problem. Three main characteristics are responsible for that situation: the location at the shoreline, the complex topography and the high roughness of the terrain. Those characteristics generate specific phenomena and utilization of parameters from other sites are not convenient. Considering financial and technical viabilities, we must look for the local parameters, disregarding the easy, although risky, attitude of applying parameters and models incovenient to the Angra site. Some of those aspects are more important, and among them we will discuss the Plume Rise, the Critical Height, the Drainage Flow and the Atmospheric Dispersion Coefficients. (Author) [pt

Recent experience in water chemistry control at PWR plants

International Nuclear Information System (INIS)

Makino, Ichiro

2000-01-01

At present, 23 units of PWRs are under operation in all of Japan, among which 11 units are operated by the Kansai Electric Power Co., Inc. (KEP). Plant availability in KEP's PWRs has been improved for the past several years, through their successive stable operation. Recently, a focus is given not only to maintenance of plant integrity, but also to preventive maintenance and water chemistry control. Various measures have been carried out to enhance exposure reduction of the primary water chemistry control in the Japanese PWRs. As a result, environmental dose equivalent rate is decreasing. A secondary system is now under excellent condition because of application of diversified measures for prevention of the SG tube corrosion. At present, the water chemistry control measures which take into account of efficient chemistry control and plant aging deterioration prevention, are being examined to use for both primary and secondary systems in Japanese PWRs, to further enhance their plant integrity and availability. And, some of them are currently being actually applied. (G.K.)

Multi-variable systems in nuclear power plant

International Nuclear Information System (INIS)

Collins, G.B.; Howell, J.

1982-01-01

Nuclear power plant are complex multi-variable dynamically interactive systems which employ many facets of systems and control theory in their analysis and design. Whole plant mathematical models must be developed and validated and in addition to their obvious role in control system synthesis and design, they are also widely used for operational constraint and plant malfunction analysis. The need for and scope of an integrated power plant control system is discussed and, as a specific example, the design of an integrated feedwater regulator is reviewed. The multi-variable frequency response analysis employed in the design is described in detail. (author)

Automated systems for control of technological processes at nuclear power plants and their use in putting the plant into operation

International Nuclear Information System (INIS)

Majtan, L.

1987-01-01

The systems of testing and control of technological processes in WWER-440 units in nuclear power plants which have so far been constructed in Czechoslovakia have been based on the conceptual principles and hardware used in the USSR. For the Mochovce nuclear power plant an automated process control system is to be introduced which proceeds from experiences gained with new Czechoslovak conventional power plants with 200 MW units. The control system consists of two levels: unit control and the control of the whole power plant the unit control consists of the DERIS-900 decentralized control system and the SM 1804 microcomputer and SM 1420 minicomputer based information and control system. A data processing system based on the SM 52/11.M1 minicomputer system will be used for power plant start-up and commissioning. (Z.M.). 2 figs., 4 refs

A minimum attention control center for nuclear power plants

International Nuclear Information System (INIS)

Meijer, C.H.

1986-01-01

Control Centers for Nuclear Power Plants have characteristically been designed for maximum attention by the operating staffs of these plants. Consequently, the monitoring, control and diagnostics oriented cognitive activities by these staffs, were mostly ''data-driven'' in nature. This paper addresses a control center concept, under development by Combustion Engineering, that promotes a more ''information-driven'' cognitive interaction process between the operator and the plant. The more ''intelligent'' and therefore less attentive nature of such interactive process utilizes computer implemented cognitive engineered algorithms. The underlying structure of these algorithms is based upon the Critical Function/Success Path monitoring principle. The paper highlights a typical implementation of the minimum attention concept for the handling of unfamiliar safety related events. (author)

Impact of Advanced Alarm Systems and Information Displays on Human Reliability in the Digital Control Room of Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Jong Hyun; Dang, Vinh N

2011-01-01

This paper discusses the potential impacts of two advanced features of digital control rooms, alarm systems and information display systems, on the Human Reliability Analysis (HRA) in nuclear power plants. Although the features of digital control rooms have already been implemented in new or upgraded nuclear power plants, HRAs have so far not taken much credit for these features. In this circumstance, this paper aims at examining the potential effects of these features on human performance and discussing how these effects can be addressed with existing HRA methods. A conclusion derivable from past experimental studies is that those features are supportive in the severe conditions such as complex scenarios and knowledge-based works. However, in the less complex scenarios and rule-based work, they may have no difference with or sometimes negative impacts on operator performance. The discussion about the impact on the HRA is provided on the basis on the THERP method

Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

Energy Technology Data Exchange (ETDEWEB)

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.

Fuzzy control applied to nuclear power plant pressurizer system

International Nuclear Information System (INIS)

Oliveira, Mauro V.; Almeida, Jose C.S.

2011-01-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Fuzzy control applied to nuclear power plant pressurizer system

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Temporal dynamics of stomatal conductance of plants under water deficit: can homeostasis be improved by more complex dynamics?

Directory of Open Access Journals (Sweden)

Gustavo Maia Souza

2004-07-01

Full Text Available In this study we hypothesized that chaotic or complex behavior of stomatal conductance could improve plant homeostasis after water deficit. Stomatal conductance of sunflower and sugar beet leaves was measured in plants grown either daily irrigation or under water deficit using an infrared gas analyzer. All measurements were performed under controlled environmental conditions. In order to measure a consistent time series, data were scored with time intervals of 20s during 6h. Lyapunov exponents, fractal dimensions, KS entropy and relative LZ complexity were calculated. Stomatal conductance in both irrigated and non-irrigated plants was chaotic-like. Plants under water deficit showed a trend to a more complex behaviour, mainly in sunflower that showed better homeostasis than in sugar beet. Some biological implications are discussed.Este estudo testou a hipótese de que a condutância estomática de uma população de estômatos em uma folha poderia apresentar um comportamento caótico ou complexo sob diferentes condições hídricas, o que poderia favorecer a capacidade homeostática das plantas. A condutância estomática em folhas de girassol e de beterraba cultivadas com irrigação diária e sob deficiência hídrica foi medida com um analisador de gás por infra-vermelho em condições controladas. Os dados foram registrados a cada 20s durante 6h. As séries temporais obtidas foram analisadas por meio dos coeficientes de Lyapunov, dimensão fractal, entropia KS e complexidade LZ relativa. A condutância estomática nas plantas cultivadas com e sem deficiência hídrica exibiu um comportamento provavelmente caótico. As plantas sob estresse hídrico mostraram uma tendência para um comportamento mais complexo, principalmente as plantas de girassol cuja capacidade homeostática foi superior. Algumas implicações biológicas destes comportamentos são discutidas no texto.

Position control of a floating nuclear power plant

International Nuclear Information System (INIS)

Motohashi, K.; Hamamoto, T.; Sasaki, R.; Kojima, M.

1993-01-01

In spite of the increasing demand of electricity in Japan, the sites of nuclear power plants suitable for conventional seismic regulations become severely limited. Under these circumstances, several types of advanced siting technology have been developed. Among them, floating power plants have a great advantage of seismic isolation that leads to the seismic design standardization and factory fabrication. The feasibility studies or preliminary designs of floating power plants enclosed by breakwaters in the shallow sea have been carried out last two decades in U.S. and Japan. On the other hand, there are few investigations on the dynamic behavior of floating power plants in the deep sea. The offshore floating nuclear power plants have an additional advantage in that large breakwaters are not required, although the safety checking is inevitable against wind-induced waves. The tension-leg platforms which have been constructed for oil drilling in the deep sea seem to be a promising offshore siting technology of nuclear power plants. The tension-leg mooring system can considerably restrain the heave and pitch of a floating power plant because of significant stiffness in the vertical direction. Different from seismic effects, wind-induced waves may be predicted in advance by making use of ocean weather forecasts using artificial satellites. According to the wave prediction, the position of the floating plant may be controlled by adjusting the water content in ballast tanks and the length of tension-legs before the expected load arrives. The position control system can reduce the wave force acting on the plant and to avoid the unfavorable response behavior of the plant. In this study a semi-submerged circular cylinder with tension-legs is considered as a mathematical model. The configuration of circular cylinder is effective because the dynamic behavior does not depend on incident wave directions. It is also unique in that it can obtain the closed-form solution of

Development of Plant Control Diagnosis Technology and Increasing Its Applications

Science.gov (United States)

Kugemoto, Hidekazu; Yoshimura, Satoshi; Hashizume, Satoru; Kageyama, Takashi; Yamamoto, Toru

A plant control diagnosis technology was developed to improve the performance of plant-wide control and maintain high productivity of plants. The control performance diagnosis system containing this technology picks out the poor performance loop, analyzes the cause, and outputs the result on the Web page. Meanwhile, the PID tuning tool is used to tune extracted loops from the control performance diagnosis system. It has an advantage of tuning safely without process changes. These systems are powerful tools to do Kaizen (continuous improvement efforts) step by step, coordinating with the operator. This paper describes a practical technique regarding the diagnosis system and its industrial applications.

Reciprocal diversification in a complex plant-herbivore-parasitoid food web

Directory of Open Access Journals (Sweden)

Bokma Folmer

2007-11-01

Full Text Available Abstract Background Plants, plant-feeding insects, and insect parasitoids form some of the most complex and species-rich food webs. According to the classic escape-and-radiate (EAR hypothesis, these hyperdiverse communities result from coevolutionary arms races consisting of successive cycles of enemy escape, radiation, and colonization by new enemy lineages. It has also been suggested that "enemy-free space" provided by novel host plants could promote host shifts by herbivores, and that parasitoids could similarly drive diversification of gall form in insects that induce galls on plants. Because these central coevolutionary hypotheses have never been tested in a phylogenetic framework, we combined phylogenetic information on willow-galling sawflies with data on their host plants, gall types, and enemy communities. Results We found that evolutionary shifts in host plant use and habitat have led to dramatic prunings of parasitoid communities, and that changes in gall phenotype can provide "enemy-free morphospace" for millions of years even in the absence of host plant shifts. Some parasites have nevertheless managed to colonize recently-evolved gall types, and this has apparently led to adaptive speciation in several enemy groups. However, having fewer enemies does not in itself increase speciation probabilities in individual sawfly lineages, partly because the high diversity of the enemy community facilitates compensatory attack by remaining parasite taxa. Conclusion Taken together, our results indicate that niche-dependent parasitism is a major force promoting ecological divergence in herbivorous insects, and that prey divergence can cause speciation in parasite lineages. However, the results also show that the EAR hypothesis is too simplistic for species-rich food webs: instead, diversification seems to be spurred by a continuous stepwise process, in which ecological and phenotypic shifts in prey lineages are followed by a lagged evolutionary

The operational benefits of integrated PC control of gamma irradiation plants

International Nuclear Information System (INIS)

Comben, M.; Stephens, P.

1998-01-01

Compared with the traditional PLC control systems used on many gamma irradiation plants, the semi-intelligent decision making capabilities of a fully integrated PC control system can bring many benefits to the plant operator. The authors will describe how plant operation is fully automatic with the PC control providing all the input-output data required to run the plant efficiently and safely. Detailed product tracking, with live on-screen data, can be incorporated to give both plant operator and product manufacturer complete confidence in the irradiation process. Advanced features such as on-line diagnostics and mechanical part failure prediction are also described. Also available is automated dosimetry, reducing the opportunity for human error, whilst at the same time saving on staff costs and providing highly professional dose validation reports and comprehensive routine dosimetry documentation. The benefits of PURIDEC's PC control system are not only available with its new plants. The system can be supplied as an upgrade to plants of all ages and design giving the current operator all the benefits described in the paper

Utility of low-order linear nuclear-power-plant models in plant diagnostics and control

International Nuclear Information System (INIS)

Tylee, J.L.

1981-01-01

A low-order, linear model of a pressurized water reactor (PWR) plant is described and evaluated. The model consists of 23 linear, first-order difference equations and simulates all subsystems of both the primary and secondary sides of the plant. Comparisons between the calculated model response and available test data show the model to be an adequate representation of the actual plant dynamics. Suggested use for the model in an on-line digital plant diagnostics and control system are presented

Preparation for commissioning of nuclear plant with reference to British Nuclear Fuels Plc fuel handling plant project

International Nuclear Information System (INIS)

Bamber, D.R.

1987-01-01

The new Fuel Handling Plant at British Nuclear Fuels Sellafield is part of a Pound 550M complex which provides facilities for the receipt, storage and mechanical preparation of both Magnox and A.G.R. fuel. The plant is very large and complex with considerable use of computer based process control systems, providing for physical and nuclear safety. The preparation of such plant for active commissioning necessitates a great many physical checks and technical evaluations in support of its safety case. This paper describes arrangements for plant commissioning checks, against the regulatory framework and explains the physical preparations necessary for their timely accomplishment. (author)

Preparation for commissioning of nuclear plant with reference to British Nuclear Fuels Plc fuel handling plant project

International Nuclear Information System (INIS)

Bamber, D.

1987-01-01

The new Fuel Handing Plant at British Nuclear Fuels Sellafield is part of a Pound 550M complex which provides facilities for the receipt, storage and mechanical preparation of both magnox and A.G.R. fuel. The plant is very large and complex with considerable use of computer based process control systems, providing for physical and nuclear safety. The preparation of such plant for ''active'' commissioning necessitates a great many physical checks and technical evaluations in support of its safety case. This paper describes arrangements for plant commissioning checks, against the regulatory framework and explains the physical preparations necessary for their timely accomplishment. (author)

Aquatic plant control research

Energy Technology Data Exchange (ETDEWEB)

Pryfogle, P.A.; Rinehart, B.N. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, E.G. [Pacific Gas & Electric Company, San Francisco, CA (United States). Hydro Generation Engineering

1997-05-01

The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

Planning and evaluation of plant under safety aspects

International Nuclear Information System (INIS)

Strnad, H.

1985-01-01

Plant denotes a technical product characterized as being structured, complex, comprising the use of energy, and that of measuring, automatic control and monitoring systems to keep track of present, control and monitor processes. Particular attention is paid to methods of developing plant concepts, measures to exclude or detect risks, integration of safety engineering into the course of planning, safety concept and ergonomics in plant design. (DG) [de

Complex monitoring of the surroundings of the Dukovany nuclear power plant

International Nuclear Information System (INIS)

Tylova, E.

1993-01-01

Based on a Resolution of the Government of the Czech Republic, the Ministry of the Environment and the Ministry of Health of the Czech Republic shall develop a project of complex environmental pollution and contamination monitoring in the surroundings of the Dukovany nuclear power plant and shall discuss this project with municipalities there till the end of 1993. The objective of the project is to assess in a complex manner the situation in the Dukovany area with respect to all risks and their simultaneous effects, so as to ensure that the population in the area concerned is not burdened to an intolerable extent. (Z.S.)

An Evolutionary Robotics Approach to the Control of Plant Growth and Motion: Modeling Plants and Crossing the Reality Gap

DEFF Research Database (Denmark)

Wahby, Mostafa; Hofstadler, Daniel Nicolas; Heinrich, Mary Katherine

2016-01-01

The self-organizing bio-hybrid collaboration of robots and natural plants allows for a variety of interesting applications. As an example we investigate how robots can be used to control the growth and motion of a natural plant, using LEDs to provide stimuli. We follow an evolutionary robotics...... approach where task performance is determined by monitoring the plant's reaction. First, we do initial plant experiments with simple, predetermined controllers. Then we use image sampling data as a model of the dynamics of the plant tip xy position. Second, we use this approach to evolve robot controllers...

Comparison of two voltage control strategies for a wind power plant

DEFF Research Database (Denmark)

Martinez, Jorge; Kjær, Philip C.; Rodriguez, Pedro

2011-01-01

plants. This paper addresses the analysis of two different voltage control strategies for a wind power plant, i.e. decentralized and centralized voltage control schemes. The analysis has been performed using the equivalent and simplified transfer functions of the system. Using this representation......Larger percentages of wind power penetration translate to more demanding requirements from grid codes. Recently, voltage support at the point of connection has been introduced by several grid codes from around the world, thus, making it important to analyze this control when applied to wind power......, it is possible to investigate the influence of the plant control gain, short circuit ratio, and time delays on the system stability, as well as the fulfillment of the design requirements. The implemented plant voltage control is based on a slope voltage controller, which calculates the references to be sent...

Controlled molecular self-assembly of complex three-dimensional structures in soft materials.

Science.gov (United States)

Huang, Changjin; Quinn, David; Suresh, Subra; Hsia, K Jimmy

2018-01-02

Many applications in tissue engineering, flexible electronics, and soft robotics call for approaches that are capable of producing complex 3D architectures in soft materials. Here we present a method using molecular self-assembly to generate hydrogel-based 3D architectures that resembles the appealing features of the bottom-up process in morphogenesis of living tissues. Our strategy effectively utilizes the three essential components dictating living tissue morphogenesis to produce complex 3D architectures: modulation of local chemistry, material transport, and mechanics, which can be engineered by controlling the local distribution of polymerization inhibitor (i.e., oxygen), diffusion of monomers/cross-linkers through the porous structures of cross-linked polymer network, and mechanical constraints, respectively. We show that oxygen plays a role in hydrogel polymerization which is mechanistically similar to the role of growth factors in tissue growth, and the continued growth of hydrogel enabled by diffusion of monomers/cross-linkers into the porous hydrogel similar to the mechanisms of tissue growth enabled by material transport. The capability and versatility of our strategy are demonstrated through biomimetics of tissue morphogenesis for both plants and animals, and its application to generate other complex 3D architectures. Our technique opens avenues to studying many growth phenomena found in nature and generating complex 3D structures to benefit diverse applications. Copyright © 2017 the Author(s). Published by PNAS.

Backfitting of the nuclear plant V1 power control system

International Nuclear Information System (INIS)

Karpeta, C.; Rubek, J.; Stirsky, P.

1985-01-01

The paper deals with some aspects of implementation of modifications into the Czechoslovak nuclear plant V1 control system as called for on the basis of experience gained during the first period of the plant operation. Brief description of the plant power control system and its main functions is given. Some deficiencies in the system performance during abnormal conditions are outlined and measures taken to overcome them are presented. (author)

Reactor instrumentation and control in nuclear power plants in Germany

International Nuclear Information System (INIS)

Aleite, W.

1993-01-01

The pertinent legislation, guidelines and standards of importance for nuclear power plant construction as well as the relevant committees in Germany are covered. The impact of international developments on the German regulatory scene is mentioned. A series of 15 data sheets on reactor control, followed by 5 data sheets on instrumentation and control in nuclear power plants, which were drawn up for German plants, are compared and commented in some detail. Digitalization of instrumentation and control systems continues apace. To illustrate the results that can be achieved with a digitalized information system, a picture series that documents a plant test of behavior on simulated steam generator tube rupture is elaborately commented. An outlook on backfitting and upgrading applications concludes this paper. (orig.) [de

Applications of modern control systems in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Wilhelm, H [Brown, Boveri und Cie A.G., Mannheim (Germany, F.R.). Abt. GK/TE

1980-10-01

A new generation of automation and control systems are currently becoming commercially available in the power plant market which, because of their incorporation of microprocessors and bus data transmission systems, represent a major step forward in innovation. The application of these systems meets today's requirements and solutions, for the number of measurements to be performed has increased five or sixfold in the past few years, and the number of drive systems to be controlled has doubled or even tripled. Requirements to be met by process management systems have become vastly more complicated: peak load operation, short startup times, improved communication, and rising safety and reliability requirements, especially in nuclear power plants. Control concepts have been developed for the area relevant to reactor safety and for the whole of the plant, which make full use of the possibilities offered by plant systems. More stringent demands must be met especially in the areas of handling, communication, testing capability, improved function, and flexibility and modular design in the safety sector.

New technology for BWR power plant control and instrumentation

International Nuclear Information System (INIS)

Takano, Yoshiyuki; Nakamura, Makoto; Murata, Fumio.

1992-01-01

Nuclear power plants are facing strong demands for higher reliability and cost-performance in their control and instrumentation systems. To meet these needs, Hitachi is developing advanced control and instrumentation technology by rationalizing the conventional technology in that field. The rationalization is done through the utilization of reliable digital technology and optical transmission technology, and others, which are now commonly used in computer applications. The goal of the development work is to ensure safe, stable operation of the plant facilities and to secure harmony between man and machine. To alleviate the burdens of the operators, the latest electronic devices are being employed to create an advanced man-machine interface, and to promote automatic operation of the plant based upon the automatic operation of individual systems. In addition, the control and instrumentation system, including the safety system, incorporates more and more digital components in order to further enhance the reliability and maintainability of the plant. (author)

Plant status control - with an operational focus

International Nuclear Information System (INIS)

Lane, L.A.

2000-01-01

In the Nuclear industry, we have done a very good job of designing, developing, constructing, and improving our nuclear facilities. We have, however, often been inconsistent in documenting the details of our facilities, clearly addressing the rules around facility operation, and controlling and tracking the temporary, or permanent changes to our facilities. The reality is, that once we build a facility, we then must operate the facility, for it to be viable. Further we must operate it safely and efficiently for the facility to produce its product, and be acceptable to the public. Unfortunately, when we design and build these large, complicated facilities, we cannot project all the nuances of facility operation, although we can recognize this potential gap, and prepare for it. In order to allow for the complexities of the real world, we must provide the individuals who are tasked with operating our nuclear facilities, with the tools and processes to deal with 'all the nuances' of facility operation. This discussion will focus on the concepts behind a key process for ensuring that we meet our design and operating needs for our facilities, as well as recognizing and dealing with the potential gaps. The key process is 'Plant Status Control', and the discussion will have a primary focus on the needs of the end users, that being the individuals that have the immediate and current accountability for control and safety of the facility, the equipment, the staff, and ultimately the public, that being our Operations staff, and the Shift Manager. (author)

Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

Science.gov (United States)

Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

2017-04-01

The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

Implementation considerations for digital control systems in power plants: Final report

International Nuclear Information System (INIS)

Shah, S.C.; Lehman, L.L.; Sarchet, M.M.

1988-09-01

Conversion of nuclear power plants fron analog to digital control systems will require careful design, testing, and integration of the control algorithms, the software which implements the algorithms, the digital instrumentation, the digital communications network, and analog/digital device interfaces. Digital control systems are more flexible than their analog counterparts, and therefore greater attention must be paid by the customer to all stages of the control system design process. This flexibility also provides the framework for development of significant safety and reliability are inherant aspects of the chosen design processes. Digital control algorithms are capable of improving their performance by on-line self-tuning of the control parameters. It is therefore incumbant on system designers to choose self-tuning algorithms for power plant control. Implementation of these algorithms in software required a careful software design and development process to minimize errors in interpretation of the engineering design and prevent the inclusion of programming errors during software production. Digital control system and communications software must exhibit sufficient ''fault tolerance'' to maintain some level of safe plant operation or execute a safe plant shutdown in the event of both hard equipment failures and the appearance of software design faults. A number of standardized digital communications protocols are available to designers of digital control systems. These standardized digital communications protocols provide reliable fault tolerant communication between all digital elements of the plant control system and can be implemented redundantly to further enhance power plant operational safety. 5 refs., 11 figs., 1 tab

Digital control in nuclear power plants

International Nuclear Information System (INIS)

Bouzon, B.

1984-01-01

This document presents the latest automatic control structures used in the programmable control systems of 13.00 MW nuclear power plants constructed by Electricite de France. The impact of this technological innovation goes beyond a straightforward design modification; in addition to the new range of processes made possible, it permits far-reaching changes in the working method employed at the design office and in the field. (author)

Chapter 8. Controlling plant competition

Science.gov (United States)

Stephen B. Monsen

2004-01-01

Generally, range or wildlife habitat improvement projects seek to achieve desirable plants through the elimination or replacement of undesirable species or both. Control measures are thus designed to: (1) reduce the competitive effects of existing species (Evans and Young 1987a,b; Robertson and Pearse 1945), (2) allow the establishment of seeded species (Harper and...

ANS main control complex three-dimensional computer model development

International Nuclear Information System (INIS)

Cleaves, J.E.; Fletcher, W.M.

1993-01-01

A three-dimensional (3-D) computer model of the Advanced Neutron Source (ANS) main control complex is being developed. The main control complex includes the main control room, the technical support center, the materials irradiation control room, computer equipment rooms, communications equipment rooms, cable-spreading rooms, and some support offices and breakroom facilities. The model will be used to provide facility designers and operations personnel with capabilities for fit-up/interference analysis, visual ''walk-throughs'' for optimizing maintain-ability, and human factors and operability analyses. It will be used to determine performance design characteristics, to generate construction drawings, and to integrate control room layout, equipment mounting, grounding equipment, electrical cabling, and utility services into ANS building designs. This paper describes the development of the initial phase of the 3-D computer model for the ANS main control complex and plans for its development and use

Mathematical models of power plant units with once-through steam generators

International Nuclear Information System (INIS)

Hofmeister, W.; Kantner, A.

1977-01-01

An optimization of effective control functions with the current complex control loop structures and control algorithms is practically not possible. Therefore computer models are required which may be optimized with the process and plant data known before start-up of thermal power plants. The application of process computers allows additional predictions on the control-dynamic behavior of a thermal power plant unit. (TK) [de

50 CFR 35.7 - Control of wildfires, insects, pest plants, and disease.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Control of wildfires, insects, pest plants... MANAGEMENT General Rules § 35.7 Control of wildfires, insects, pest plants, and disease. To the extent necessary, the Director shall prescribe measures to control wildfires, insects, pest plants, and disease to...

Nuclear techniques in plant pathology 1. Plant disease control and physiology of parasitism

International Nuclear Information System (INIS)

Menten, J.O.M.; Ando, A.; Tulmann Neto, A.

1986-01-01

Nuclear techniques are advantageously used in several areas of plant pathology. Among them are: induction of mutation for disease resistance, studies with pesticides, disease control through pathogen inactivation, induction of variability and stimulation in pathogens and natural enemies, studies of microorganism physiology and diseased plant physiology, effect of gamma radiation on pesticides, technology of pesticides application, etc. (Author) [pt

Rapid Control Prototyping Plataform for Didactic Plant Motor DC

Directory of Open Access Journals (Sweden)

Cristian Bazán-Orobio

2013-06-01

Full Text Available In this paper a design, implementation and validation of a Rapid Control Prototype platform for a plant based on a DC motor is proposed. This low-cost prototype provides of an electronic card (with a motor DC and sensors manipulated by PC with free software tools using Linux, Scilab / Scicos and RTAI-Lab. This RCP System allows developing speed -position control trainings by using different types of PID industrial controllers with anti – wind up and bump less transfer schemes. We develop a speed control application structured in four steps: identification, controller design, simulation and real time control, where there are pedagogical advantages of a platform that not only allows simulation but also real-time control of a plant.

Automated complex for research of electric drives control

Science.gov (United States)

Avlasko, P. V.; Antonenko, D. A.

2018-05-01

In the article, the automated complex intended for research of various control modes of electric motors including the inductor motor of double-way feed is described. As a basis of the created complex, the National Instruments platform is chosen. The operating controller built in a platform is delivered with an operating system of real-time for creation of systems of measurement and management. The software developed in the environment of LabVIEW consists of several connected modules which are in different elements of a complex. Besides the software for automated management by experimental installation, the program complex is developed for modelling of processes in the electric drive. As a result there is an opportunity to compare simulated and received experimentally transitional characteristics of the electric drive in various operating modes.

A modeling and control approach to advanced nuclear power plants with gas turbines

International Nuclear Information System (INIS)

Ablay, Günyaz

2013-01-01

Highlights: • Load frequency control strategies in nuclear plants are researched. • Nuclear reactor-centered control system may not be suitable for load control. • Local unit controllers improve stability and overall time constant. • Coolant loops in nuclear plants should be controlled locally. - Abstract: Advanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach and load following control strategy for gas turbine nuclear power plants in order to provide an assessment way to the concept designs. A load frequency control strategy and average temperature control mechanism are studied to get load following nuclear power plants. The suitability of the control strategies and concept designs are assessed through linear stability analysis methods. Numerical results are presented on an advanced molten salt reactor concept as an example nuclear power plant system to demonstrate the validity and effectiveness of the proposed modeling and load following control strategies

Complexity control in statistical learning

Indian Academy of Sciences (India)

Then we describe how the method of regularization is used to control complexity in learning. We discuss two examples of regularization, one in which the function space used is finite dimensional, and another in which it is a reproducing kernel Hilbert space. Our exposition follows the formulation of Cucker and Smale.

Modelling, Estimation and Control of Networked Complex Systems

CERN Document Server

Chiuso, Alessandro; Frasca, Mattia; Rizzo, Alessandro; Schenato, Luca; Zampieri, Sandro

2009-01-01

The paradigm of complexity is pervading both science and engineering, leading to the emergence of novel approaches oriented at the development of a systemic view of the phenomena under study; the definition of powerful tools for modelling, estimation, and control; and the cross-fertilization of different disciplines and approaches. This book is devoted to networked systems which are one of the most promising paradigms of complexity. It is demonstrated that complex, dynamical networks are powerful tools to model, estimate, and control many interesting phenomena, like agent coordination, synchronization, social and economics events, networks of critical infrastructures, resources allocation, information processing, or control over communication networks. Moreover, it is shown how the recent technological advances in wireless communication and decreasing in cost and size of electronic devices are promoting the appearance of large inexpensive interconnected systems, each with computational, sensing and mobile cap...

Identification of Potential Plants Producing Tannin-protein Complex for a-amylase as Botanical Pesticide

Directory of Open Access Journals (Sweden)

Asriyah Firdausi

2013-05-01

Full Text Available Research  on  the  development  of  botanical  pesticides  should  be developed  through  new  methods,  such  as  by  inhibiting the  activity  of  digestive enzymes  by  secondary  metabolites.  The  aim  of  this  study  was  to  identify some  of  potential  plants  as  a  source  of  tannin-protein  complexes  to  inhibitthe  activity  of  - amylase.  The  study  of  identification  of  potential  plants producing  the  active  ingredient  tannin-protein  complex  was  divided  into  three stages,  1  identification  of  potential  plants  producing  tannin,  2  isolation  of tannin-protein  complexes,  and  3  in  vitro  test  of  tannin-protein  complexes effect  of  the  -amylase activity.  Some  of  the observed  plants  were  sidaguri  leaf (Sida rhombifolia, melinjo leaf (Gnetum gnemon, gamal leaf (Gliricidia sepium,lamtoro  leaf  (Leucaena  leucocephala ,  betel  nut  (Areca  catechu ,  and  crude gambier  (Uncaria  gambir a s  a  source of  tannins  and  melinjo  seed was  used  asprotein  source.  Betel  nut  and  melinjo  seed  were  the  best  source  of  tannin-protein  complex,  tannin  content  1.77  mg  TAE/mL  with  antioxidant  activity  of  90%,the  ability  to  inhibit  the  activity  of  -amylase by  95%  with  IC 50  values  of 10 mg/mL.Key words: Tannin, protein, -amylase, botanical pesticides,Areca catechu, Gnetum gnemon.

Handbook for replacement of process control systems in thermal power plants; Handbok - Utbytesbehov i kontrollsystem foer vaermekraftverk

Energy Technology Data Exchange (ETDEWEB)

Tuszynski, J. [Sydkraft Konsult AB, Malmoe (Sweden); Eriksson, Tage [Vattenfall Energisystem AB, Stockholm (Sweden)

1996-12-01

Modernization of control equipment in more complex power plants, such as thermal power plants, requires special attention due to the almost complete change-over to new computerised technology. The introduction of new technology gives rise to great changes in both the process control systems and in operation and maintenance routines. The change-over to computerised technology also causes lack of spare parts and service for older equipment. The older technology becomes obsolete due to the great advantages that comes with new technology. Therefore, the lifetime of control equipment is not only coupled to traditional ageing and wear, such as oxidation and fatigue of material, but also to the fact that the old equipment is getting out of date. It becomes more and more common that this out-of-date factor, rather than ageing, sets the limit for the useful life of the equipment. The Handbook for replacement of process control systems in thermal power plants is thought to be a first help for engineers and managers who has the responsibility for process control modernization. The Handbook points out the factors that determines the service life of the control equipment. It also suggests what information is required in order to take a decision on modernization. The Handbook at its present form constitutes a first approach that leaves room for an extension later on. Any request to expand the Handbook should be put forward to Vaermeforsk or its partners

Dynamic modeling, simulation and control design of an advanced micro-hydro power plant for distributed generation applications

Energy Technology Data Exchange (ETDEWEB)

Marquez, J.L. [Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste 1109, J5400ARL San Juan (Argentina); Molina, M.G. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste 1109, J5400ARL San Juan (Argentina); Pacas, J.M. [Institut fuer Leistungselektronik und Elektrische Antriebe, Universitaet Siegen, Fachbereich 12 Hoelderlinstr 3, D 57068 Siegen (Germany)

2010-06-15

A small-scale hydropower station is usually a run-of-river plant that uses a fixed speed drive with mechanical regulation of the turbine water flow rate for controlling the active power generation. This design enables to reach high efficiency over a wide range of water flows but using a complex operating mechanism, which is in consequence expensive and tend to be more affordable for large systems. This paper proposes an advanced structure of a micro-hydro power plant (MHPP) based on a smaller, lighter, more robust and more efficient higher-speed turbine. The suggested design is much simpler and eliminates all mechanical adjustments through a novel electronic power conditioning system for connection to the electric grid. In this way, it allows obtaining higher reliability and lower cost of the power plant. A full detailed model of the MHPP is derived and a new three-level control scheme is designed. The dynamic performance of the proposed MHPP is validated through digital simulations and employing a small-scale experimental set-up. (author)

Distributed Control Systems in New Nuclear Power Plants

International Nuclear Information System (INIS)

Doerfler, Joseph

2008-01-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Distributed Control Systems in New Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Doerfler, Joseph [Westinghouse Electric Company, 4350 Northern Pike, Monroeville, PA 15146 (United States)

2008-07-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Modeling Operating Modes for the Monju Nuclear Power Plant

DEFF Research Database (Denmark)

Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

2012-01-01

The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...... for the Japanese fast breeder reactor plant MONJU....

Development of Rotational Smart Lighting Control System for Plant Factory

OpenAIRE

Won-Sub Lee; Sung-Gaun Kim

2012-01-01

Rotational Smart Lighting Control System can supply the quantity of lighting which is required to run plants by rotating few LED and Fluorescent instead of that are used in the existing plant factories.The initial installation of the existing plants factory is expensive, so in order to solve the problem with smart lighting control system was developed. The beam required intensity for the growth of crops, Photosynthetic Photon Flux Density(PPFD)is calculated; and the numbe...

Complexity, Analysis and Control of Singular Biological Systems

CERN Document Server

Zhang, Qingling; Zhang, Xue

2012-01-01

Complexity, Analysis and Control of Singular Biological Systems follows the control of real-world biological systems at both ecological and phyisological levels concentrating on the application of now-extensively-investigated singular system theory. Much effort has recently been dedicated to the modelling and analysis of developing bioeconomic systems and the text establishes singular examples of these, showing how proper control can help to maintain sustainable economic development of biological resources. The book begins from the essentials of singular systems theory and bifurcations before tackling  the use of various forms of control in singular biological systems using examples including predator-prey relationships and viral vaccination and quarantine control. Researchers and graduate students studying the control of complex biological systems are shown how a variety of methods can be brought to bear and practitioners working with the economics of biological systems and their control will also find the ...

A coordinated MIMO control design for a power plant using improved sliding mode controller.

Science.gov (United States)

Ataei, Mohammad; Hooshmand, Rahmat-Allah; Samani, Siavash Golmohammadi

2014-03-01

For the participation of the steam power plants in regulating the network frequency, boilers and turbines should be co-ordinately controlled in addition to the base load productions. Lack of coordinated control over boiler-turbine may lead to instability; oscillation in producing power and boiler parameters; reduction in the reliability of the unit; and inflicting thermodynamic tension on devices. This paper proposes a boiler-turbine coordinated multivariable control system based on improved sliding mode controller (ISMC). The system controls two main boiler-turbine parameters i.e., the turbine revolution and superheated steam pressure of the boiler output. For this purpose, a comprehensive model of the system including complete and exact description of the subsystems is extracted. The parameters of this model are determined according to our case study that is the 320MW unit of Islam-Abad power plant in Isfahan/Iran. The ISMC method is simulated on the power plant and its performance is compared with the related real PI (proportional-integral) controllers which have been used in this unit. The simulation results show the capability of the proposed controller system in controlling local network frequency and superheated steam pressure in the presence of load variations and disturbances of boiler. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Development of assessment methodology for plant configuration control

Energy Technology Data Exchange (ETDEWEB)

Chung, Chang Hyun; You, Young Woo; Kim, Yoon Ik; Yang, Hui Chang; Huh, Byeong Gill; Lee, Dong Won; Ahn, Gwan Won [Seoul National Univ., Seoul (Korea, Republic of)

2001-03-15

The purpose of this study IS the development of effective and overall assessment methodology which reflects the characteristics of plants for the surveillance, maintenance, repair and operation of nuclear power plants. In this study, recent researches are surveyed and concept definition, procedures, current PSA methodologies, implementation of various models are evaluated. Through this survey, systematic assessment methodology is suggested. Configuration control assessment methodology suggested in this study for the purpose of the development of configuration control methodology reflecting the characteristics of Korean NPPs, can be utilized as the supplement of current PSA methodologies.

Mixed-waste minimization activities in the nuclear weapons complex

International Nuclear Information System (INIS)

Marchetti, J.A.; Suffern, J.S.

1991-01-01

Over the past 40 years, the US Department of Energy (DOE) and the nuclear weapons complex have successfully executed their mission of providing the country with a strong nuclear deterrent. Now, however, they must attain another mission at the same time: to eliminate or greatly reduce the environmental, safety, and health problems in the complex. Mixed-waste minimization activities have taken place in 11 of the complex production plants and laboratories: the Pinellas plant, the Mount plant, the Kansas City plant, the Y-12 plant, the Rocky Flats plant, the Savannah River Site (SRS), the Savannah River Site (SRS), the Pantex plant, the Nevada Test Site, Sandia National Laboratories, Los Alamos National Laboratory, and the Lawrence Livermore National Laboratory. The mixed-waste minimization opportunities that have been implemented to date by the production facilities are different from those that have been implemented by the laboratories. Areas of opportunity at the plants involve the following activities: (1) process design or improvement; (2) substitution of materials; (3) waste segregation; (4) recycling; and (5) administrative controls

From control switches to integrated process control systems. 60 years of power plant control technology; Vom Steuerquittierschalter zum integrierten Prozessleitsystem. 60 Jahre Kraftwerksleittechnik

Energy Technology Data Exchange (ETDEWEB)

Pagel, Peter [ABB AG, Mannheim (Germany). Marketing

2009-07-01

Power plant control has always been based on the process requirements and on the need to reduce the process cost. Modern power plant control systems also take account of the need for emission reduction. They have developed into integrated navigation platforms with functional confectioning of workstations, focusing on the aspects of functionality, efficiency, ergonomics, plant availability and life cycle cost. The contribution outlines important developments of power plant control technology during the past few decades. (orig.)

Expert System Control of Plant Growth in an Enclosed Space

Science.gov (United States)

May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

2008-01-01

The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

Buildings 104 and 142 Complex Physical Protection and Material Control and Accounting Upgrades at the Mayak Production Association

International Nuclear Information System (INIS)

Aichele, Walter T.; Dwyer, Gregory M.; Larsen, R.; Malone, Tim

2004-01-01

The Federal State Unitary Enterprise Mayak Production Association (Mayak) and the U.S. Material Protection, Control and Accounting (MPC and A) United States Project Team (USPT) have worked together for a number of years as part of the U.S. national Nuclear Security Administration's (NNSA) MPC and A program to implement both Physical Protection (PP) and Material Control and Accounting (MC and A) upgrades within the Buildings 104 and 142 Complex, a long-term storage area for uranium and plutonium oxide located within Mayak's RT-1 Spent Fuel Reprocessing Plant. This paper focuses on the successes and areas for improvement in the analysis, planning, construction, implementation, and completion of a complex and labor-intensive project aimed at the refurbishment of two existing, in service, long-term special nuclear material (SNM) storage buildings within a Russian SNM production facility

Process control and monitoring system: Thermal Power Plant Gacko

International Nuclear Information System (INIS)

Jeremovic, Dragan; Skoko, Maksim; Gjokanovic, Zdravko

2004-01-01

DCS Ovation system, manufactured by Westinghouse, USA, is described in this paper. Emphasize on concept of realization and basic characteristic in Thermal Power Plant Gacko is given in this paper. The most important, noticed by now, comparative effects and performances of new monitoring and control system according to classical monitoring and control system of 300 MW units Thermal Power Plant Gacko in Gacko, are given in the conclusion. (Author)

Health-aware Model Predictive Control of Pasteurization Plant

Science.gov (United States)

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.

Complex genetics controls natural variation among seed quality phenotypes in a recombinant inbred population of an interspecific cross between Solanum lycopersicum × Solanum pimpinellifolium

NARCIS (Netherlands)

Kazmi, R.H.; Khan, N.; Willems, L.A.J.; Heusden, van A.W.; Ligterink, J.W.; Hilhorst, H.W.M.

2012-01-01

Seed quality in tomato is associated with many complex physiological and genetic traits. While plant processes are frequently controlled by the action of small- to large-effect genes that follow classic Mendelian inheritance, our study suggests that seed quality is primarily quantitative and

Applications of modern control systems in nuclear power plants

International Nuclear Information System (INIS)

Wilhelm, H.

1980-01-01

A new generation of automation and control systems are currently becoming commercially available in the power plant market which, because of their incorporation of microprocessors and bus data transmission systems, represent a major step forward in innovation. The application of these systems meets today's requirements and solutions, for the number of measurements to be performed has increased five or sixfold in the past few years, and the number of drive systems to be controlled has doubled or even tripled. Requirements to be met by process management systems have become vastly more complicated: peak load operation, short startup times, improved communication, and rising safety and reliability requirements, especially in nuclear power plants. Control concepts have been developed for the area relevant to reactor safety and for the whole of the plant, which make full use of the possibilities offered by plant systems. More stringent demands must be met especially in the areas of handling, communication, testing capability, improved function, and flexibility and modular design in the safety sector. (orig.) [de

Results from an in-plant demonstration of intelligent control

International Nuclear Information System (INIS)

Edwards, R.M.; Garcia, H.E.; Messick, N.

1993-01-01

A learning systems-based reconfigurable controller was demonstrated on the deaerating feedwater heater at the Experimental Breeder Reactor II (EBR-II) on April 1, 1993. Failures of the normal pressure regulating process were introduced by reducing the steam flow to the heater by as much as 10%. The controller maintained pressure in the heater at acceptable levels for several minutes, whereas operator intervention would have otherwise been required within a few seconds. This experiment demonstrates the potential of advanced control techniques for improving safety, reliability, and performance of power plant operations as well as the utility of EBR-II as an experimental power plant controls facility

Plant Transporter Identification

DEFF Research Database (Denmark)

Larsen, Bo

Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

B Plant Complex pollution prevention plan. Revision 1

International Nuclear Information System (INIS)

Beam, T.G.

1994-01-01

The US Department of Energy (DOE) has directed Westinghouse Hanford Company (WHC) to develop an effective strategy to minimize the generation of hazardous, radioactive, and mixed wastes at Hanford in compliance with state and federal regulations. WHC has formalized a pollution prevention program composed of management policies, management requirements and procedures. This plan addresses pollution prevention for B Plant Complex. A pollution prevention team is in place and has been assigned responsibility for implementing the plan. This plan includes actions and goals for reducing volume and toxicity of waste generated, as well as a basis for evaluation of progress. Descriptions of waste streams, current specific goals, general pollution prevention methods, and specific accomplishments are in the appendices of this plan

Improvement on main control room for Japanese PWR plants

International Nuclear Information System (INIS)

Matsumiya, Masayuki

1996-01-01

The main control room which is the information center of nuclear power plant has been continuously improved utilizing the state of the art ergonomics, a high performance computer, computer graphic technologies, etc. For the latest Japanese Pressurized Water Reactor (PWR) plant, the CRT monitoring system is applied as the major information source for facilitating operators' plant monitoring tasks. For an operating plant, enhancement of monitoring and logging functions has been made adopting a high performance computer

Using H∞ to design robust POD controllers for wind power plants

DEFF Research Database (Denmark)

Mehmedalic, Jasmin; Knüppel, Thyge; Østergaard, Jacob

2012-01-01

Large wind power plants (WPPs) can help to improve small signal stability by increasing the damping of electromechanical modes of oscillation. This can be done by adding a power system oscillation damping (POD) controller to the wind power plants, similar to power system stabilizer (PSS......) controllers on conventional generation. Here two different design methods are evaluated for their suitability in producing a robust power system oscillation damping controller for wind power plants with full-load converter wind turbine generators (WTGs). Controllers are designed using classic PSS design and H......∞ methods and the designed controllers evaluated on both performance and robustness. It is found that the choice of control signal has a large influence on the robustness of the controllers, and the best performance and robustness is found when the converter active power command is used as control signal...

Border control: selectivity of chloroplast protein import and regulation at the TOC-complex.

Science.gov (United States)

Demarsy, Emilie; Lakshmanan, Ashok M; Kessler, Felix

2014-01-01

Plants have evolved complex and sophisticated molecular mechanisms to regulate their development and adapt to their surrounding environment. Particularly the development of their specific organelles, chloroplasts and other plastid-types, is finely tuned in accordance with the metabolic needs of the cell. The normal development and functioning of plastids require import of particular subsets of nuclear encoded proteins. Most preproteins contain a cleavable sequence at their N terminal (transit peptide) serving as a signal for targeting to the organelle and recognition by the translocation machinery TOC-TIC (translocon of outer membrane complex-translocon of inner membrane complex) spanning the dual membrane envelope. The plastid proteome needs constant remodeling in response to developmental and environmental factors. Therefore selective regulation of preprotein import plays a crucial role in plant development. In this review we describe the diversity of transit peptides and TOC receptor complexes, and summarize the current knowledge and potential directions for future research concerning regulation of the different Toc isoforms.

Development of Automatic Control of Bayer Plant Digestion

Science.gov (United States)

Riffaud, J. P.

Supervisory computer control has been achieved in Alcan's Bayer Plants at Arvida, Quebec, Canada. The purpose of the automatic control system is to stabilize and consequently increase, the alumina/caustic ratio within the digester train and in the blow-off liquor. Measurements of the electrical conductivity of the liquor are obtained from electrodeless conductivity meters. These signals, along with several others are scanned by the computer and converted to engineering units, using specific relationships which are updated periodically for calibration purposes. On regular time intervals, values of ratio are compared to target values and adjustments are made to the bauxite flow entering the digesters. Dead time compensation included in the control algorithm enables a faster rate for corrections. Modification of production rate is achieved through careful timing of various flow changes. Calibration of the conductivity meters is achieved by sampling at intervals the liquor flowing through them, and analysing it with a thermometric titrator. Calibration of the thermometric titrator is done at intervals with a standard solution. Calculations for both calibrations are performed by computer from data entered by the analyst. The computer was used for on-line data collection, modelling of the digester system, calculation of disturbances and simulation of control strategies before implementing the most successful strategy in the Plant. Control of ratio has been improved by the integrated system, resulting in increased Plant productivity.

Roles of programmable logic controllers in fuel reprocessing plants

International Nuclear Information System (INIS)

Mishra, Hrishikesh; Balakrishnan, V.P.; Pandya, G.J.

1999-01-01

Fuel charging facility is another application of Programmable Logic Controllers (PLC) in fuel reprocessing plants, that involves automatic operation of fuel cask dolly, charging motor, pneumatic doors, clutches, clamps, stepper motors and rod pushers in a pre-determined sequence. Block diagram of ACF system is given for underlining the scope of control and interlocks requirements involved for automation of the fuel charging system has been provided for the purpose at KARP Plant, Kalpakkam

An adaptive control application in a large thermal combined power plant

International Nuclear Information System (INIS)

Kocaarslan, Ilhan; Cam, Ertugrul

2007-01-01

In this paper, an adaptive controller was applied to a 765 MW large thermal power plant to decrease operating costs, increase quality of generated electricity and satisfy environmental concerns. Since power plants may present several operating problems such as disturbances and severe effects at operating points, design of their controllers needs to be carried out adequately. For these reasons, first, a reduced mathematical model was developed under Computer Aided Analysis and Design Package for Control (CADACS), so that the results of the experimental model have briefly been discussed. Second, conventional PID and adaptive controllers were designed and implemented under the real-time environment of the CADACS software. Additionally, the design of the adaptive model-reference and conventional PID controllers used in the power plant for real-time control were theoretically presented. All processes were realized in real-time. Due to safety restrictions, a direct connection to the sensors and actuators of the plant was not allowed. Instead a coupling to the control system was realized. This offers, in addition, the usage of the supervisory functions of an industrial process computer system. Application of the controllers indicated that the proposed adaptive controller has better performances for rise and settling times of electrical power, and enthalpy outputs than the conventional PID controller does

DESIGN OF THE THREE-LEVEL MULTICRITERIAL STRATEGY OF HYBRID MARINE POWER PLANT CONTROL FOR A COMBINED PROPULSION COMPLEX

Directory of Open Access Journals (Sweden)

V.V. Budashko

2017-04-01

Full Text Available Purpose. Efficiency of hybrid ships power plants (SPP combined propulsion complexes (CPC by various criteria for energy management systems strategies. Methodology. Based on the classification system topologies SPP CPC for mechanical, electrical and hybrid types of motors schematic diagrams of management strategies for the criterion of minimum power consumption are defined. Changing the technical component of the traditional approach to building hybrid ships electric power systems (SEPS SPP CPC the principle of modifying the structure of SEPS is applied with the integration of additional static alternative power source as dynamic reserve, which allowed to meet modern requirements for energy efficiency, levels of vibration, noise and degradation effects produced to SPP CPC, in all areas of the energy for the transfer of power from energy to propellers. Modeling of power transmission of energy to propellers in MatLab/Simulink is conducted, using blocks of optimization library and definition of identity markers. Results. Major advantages and disadvantages SPP CPC depending on the topology of energy distribution systems are determined. According to the chosen structure system electricity characteristics were obtained in the process of power transmission SPP CPC and power systems and their control strategies in terms of increased efficiency and eliminate these drawbacks. And finally, mathematical apparatus for research in terms of the development of methods for designing and managing SPP hybrid CPC to reduced fuel consumption, emissions into the environment and improving maintainability, flexibility and comfort level are improved. Originality. The methodology for improving SPP CPC implementation by developing methods of identification markers mutually influencing processes in SPP CPC and the development of implementing these methods of settlement and information systems. Practical value. The method enables iterative optimization parameters SPP CPC, it

A small diffusible signal molecule is responsible for the global control of virulence and exoenzyme production in the plant pathogen Erwinia carotovora.

OpenAIRE

Pirhonen, M; Flego, D; Heikinheimo, R; Palva, E T

1993-01-01

Virulence of the plant pathogen Erwinia carotovora subsp. carotovora is dependent on the production and secretion of a complex arsenal of plant cell wall-degrading enzymes. Production of these exoenzymes is controlled by a global regulatory mechanism. A virulent mutants in one of the regulatory loci, expI, show a pleiotropic defect in the growth phase-dependent transcriptional activation of exoenzyme gene expression. The expI gene encodes a 26 kDa polypeptide that is structurally and function...

Plant parasite control and soil fauna diversity.

Science.gov (United States)

Lavelle, Patrick; Blouin, Manuel; Boyer, Johnny; Cadet, Patrice; Laffray, Daniel; Pham-Thi, Anh-Thu; Reversat, Georges; Settle, William; Zuily, Yasmine

2004-07-01

The use of pesticides to control plant parasites and diseases has generated serious problems of public health and environmental quality, leading to the promotion of alternative Integrated Pest Management strategies that tend to rely more on natural processes and the active participation of farmers as observers and experimenters in their own fields. We present three case studies that point at different options provided by locally available populations of soil organisms, the maintenance of diverse populations of pests or increased resistance of plants to pest attacks by their interactions with earthworms and other useful soil organisms. These examples demonstrate the diversity of options offered by the non-planned agro-ecosystem diversity in pest control and the need to identify management options that maintain this biodiversity.

Plant control impact on IFR power plant passive safety response

International Nuclear Information System (INIS)

Vilim, R.B.

1993-01-01

A method is described for optimizing the closed-loop plant control strategy with respect to safety margins sustained in the unprotected upset response of a liquid metal reactor. The optimization is performed subject to the normal requirements for reactor startup, load change and compensation for reactivity changes over the cycle. The method provides a formal approach to the process of exploiting the innate self-regulating property of a metal fueled reactor to make it less dependent on operator action and less vulnerable to automatic control system fault and/or operator error

The role of human performance in safe operation of complex plants

International Nuclear Information System (INIS)

Preda, Irina Aida; Lazar, Roxana Elena; Croitoru, Cornelia

1999-01-01

According to statistics, about 20-30% from the failures occurring in plants are caused directly or indirectly by human errors. Furthermore, it was established that 10-15 percents of the global failures are related to the human errors. These are mainly due to the wrong actions, maintenance errors, and misinterpretation of instruments. The human performance is influenced by: professional ability, complexity and danger of the plant, experience in the same working place, level of skills, events in personal and/or professional life, discipline, social ambience and somatic health. The human performances assessment in the probabilistic safety assessment offers the possibility of evaluation for human contribution to the events sequences outcome. A human error may be recovered before the unwanted consequences had been occurred on system. This paper presents the possibilities to use the probabilistic methods (event tree, fault tree) to identify the solution for human reliability improvement in order to minimise the risk in industrial plant operation. Also, are defined the human error types and their causes and the 'decision tree method' is presented as technique in our analyses for human reliability assessment. The exemplification of human error analysis method was achieved based on operation data for Valcea heavy water pilot plant. (authors)

Pollution control in oil, gas and chemical plants

CERN Document Server

Bahadori, Alireza

2014-01-01

This unique book covers the fundamental requirements for air, soil, noise and water pollution control in oil and gas refineries, chemical plants, oil terminals, petrochemical plants, and related facilities. Coverage includes design and operational considerations relevant to critical systems such as monitoring of water pollution control, equipment, and engineering techniques as well as engineering/technological methods related to soil, noise and air pollution control. This book also: ·         Covers a diverse list of pollution control strategies important to practitioners, ranging from waste water gathering systems and oil/suspended solids removal to chemical flocculation units, biological treatment, and sludge handling and treatment ·         Provides numerous step-by-step tutorials that orient both entry level and veteran engineers to the essentials of pollution control methods in petroleum and chemical industries ·         Includes a comprehensive glossary providing readers with...

Mercury controls for coal-fired power plants - status and challenges

Energy Technology Data Exchange (ETDEWEB)

Offen, G.; Shick, N.; Chang, R.; Chu, P.; Dene, C.; Rhudy, R. [EPRI, Palo Alto (US)

2005-05-01

Although the US Environmental Protection Agency has issued its mercury rule, setting limits for emissions from new power plants and placing an eventual cap on emissions from all plants, mercury control technologies offering sustainable performance and known applicability, impact, and cost are still in the future. Co-operative funding for long-term, full-scale tests of technologies in advanced stages of development, and support for emerging ones, promises to close the gap. The goal is to learn how to tailor control technologies to flue gas environments at individual power plants. In this paper the authors describe the current performance of mercury control technologies and outline the research needed to demonstrate their easiness for commercial deployment. 4 figs.

Developments in data acquisition systems with LabView datalogging and supervisory control module for tritium removal plant, with data base and process analysis

International Nuclear Information System (INIS)

Moraru, Carmen Maria; Stefan, Iuliana; Balteanu, Ovidiu; Stefan, Liviu; Bucur, Ciprian; Hartescu, Florin

2006-01-01

Full text: The implementation of the new trends for tritium processing nuclear plants, and especially those with an experimental character or of new technology development, shows a very high complexity due to issues raised by the integration of a high diversity of instrumentation and equipment into a unitary control system of the technological process. Keeping the system's flexibility is a demand of the experimental plants for which the change of configuration, process and parameters is something usual. The big amount of data that needs to be monitored, stored and accessed for ulterior analyses demands the achievement of an information network where the data acquiring, control and analysis systems of the technological process can be integrated with a data base system. Thus, integrated computing and control systems needed for the control of the technological process will be executed, to be continued with the execution of failure protection system, by choosing methods corresponding to the technological processes within the tritium processing nuclear plants. (authors)

Control room systems design for nuclear power plants

International Nuclear Information System (INIS)

1995-07-01

This publication provides a resource for those who are involved in researching, managing, conceptualizing, designing, manufacturing or backfitting power plant control room systems. It will also be useful to those responsible for performing reviews or evaluations of the design and facilities associated with existing power plant control room systems. The ultimate worth of the publication, however, will depend upon how well it can support its users. Readers are invited to provide comments and observations to the IAEA, Division of Nuclear Power. If appropriate, the report will subsequently be re-issued, taking such feedback into account. Refs, figs and tabs

Control room systems design for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

This publication provides a resource for those who are involved in researching, managing, conceptualizing, designing, manufacturing or backfitting power plant control room systems. It will also be useful to those responsible for performing reviews or evaluations of the design and facilities associated with existing power plant control room systems. The ultimate worth of the publication, however, will depend upon how well it can support its users. Readers are invited to provide comments and observations to the IAEA, Division of Nuclear Power. If appropriate, the report will subsequently be re-issued, taking such feedback into account. Refs, figs and tabs.

Material control and accountancy at EDF PWR plants

International Nuclear Information System (INIS)

de Cormis, F.

1991-01-01

The paper describes the comprehensive system which is developed and implemented at Electricite de France to provide a single reliable nuclear material control and accounting system for all nuclear plants. This software aims at several objectives among which are: the control and the accountancy of nuclear material at the plant, the optimization of the consistency of data by minimizing the possibility of transcription errors, the fulfillment of the statutory requirements by automatic transfer of reports to national and international safeguards authorities, the servicing of other EDF users of nuclear material data for technical or commercial purposes

Optimal control of a waste water cleaning plant

Directory of Open Access Journals (Sweden)

Ellina V. Grigorieva

2010-09-01

Full Text Available In this work, a model of a waste water treatment plant is investigated. The model is described by a nonlinear system of two differential equations with one bounded control. An optimal control problem of minimizing concentration of the polluted water at the terminal time T is stated and solved analytically with the use of the Pontryagin Maximum Principle. Dependence of the optimal solution on the initial conditions is established. Computer simulations of a model of an industrial waste water treatment plant show the advantage of using our optimal strategy. Possible applications are discussed.

Computer simulations of discharges from a lignite power plant complex

International Nuclear Information System (INIS)

Koukouliou, V.; Horyna, J.; Perez-Sanchez, D.

2008-01-01

This paper describes work carried out within the IAEA EMRAS program NORM working group to test the predictions of three computer models against measured radionuclide concentrations resulting from discharges from a lignite power plant complex. This complex consists of two power plants with a total of five discharge stacks, situated approximately 2-5 kilometres from a city of approximately 10,000 inhabitants. Monthly measurements of mean wind speed and direction, dust loading, and 238 U activities in fallout samples, as well as mean annual values of 232 Th activity in the nearest city sampling sites were available for the study. The models used in the study were Pc-CREAM (a detailed impact assessment model), and COMPLY and CROM (screening models). In applying the models to this scenario it was noted that the meteorological data provided was not ideal for testing, and that a number of assumptions had to be made, particularly for the simpler models. However, taking the gaps and uncertainties in the data into account, the model predictions from PC-CREAM were generally in good agreement with the measured data, and the results from different models were also generally consistent with each other. However, the COMPLY predictions were generally lower than those from PC-CREAM. This is of concern, as the aim of a screening model (COMPLY) is to provide conservative estimates of contaminant concentrations. Further investigation of this problem is required. The general implications of the results for further model development are discussed. (author)

Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

Science.gov (United States)

Gigli-Bisceglia, Nora; Hamann, Thorsten

2018-04-13

During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

Mechanisms of energy transfer and conversion in plant Light-Harvesting Complex II

Energy Technology Data Exchange (ETDEWEB)

Barros, Tiago Ferreira de

2009-09-24

The light-harvesting complex of photosystem II (LHC-II) is the major antenna complex in plant photosynthesis. It accounts for roughly 30% of the total protein in plant chloroplasts, which makes it arguably the most abundant membrane protein on Earth, and binds about half of plant chlorophyll (Chl). The complex assembles as a trimer in the thylakoid membrane and binds a total of 54 pigment molecules, including 24 Chl a, 18 Chl b, 6 lutein (Lut), 3 neoxanthin (Neo) and 3 violaxanthin (Vio). LHC-II has five key roles in plant photosynthesis. It: (1) harvests sunlight and transmits excitation energy to the reaction centres of photosystems II and I, (2) regulates the amount of excitation energy reaching each of the two photosystems, (3) has a structural role in the architecture of the photosynthetic supercomplexes, (4) contributes to the tight appression of thylakoid membranes in chloroplast grana, and (5) protects the photosynthetic apparatus from photo damage by non photochemical quenching (NPQ). A major fraction of NPQ is accounted for its energy-dependent component qE. Despite being critical for plant survival and having been studied for decades, the exact details of how excess absorbed light energy is dissipated under qE conditions remain enigmatic. Today it is accepted that qE is regulated by the magnitude of the pH gradient ({delta}pH) across the thylakoid membrane. It is also well documented that the drop in pH in the thylakoid lumen during high-light conditions activates the enzyme violaxanthin de-epoxidase (VDE), which converts the carotenoid Vio into zeaxanthin (Zea) as part of the xanthophyll cycle. Additionally, studies with Arabidopsis mutants revealed that the photosystem II subunit PsbS is necessary for qE. How these physiological responses switch LHC-II from the active, energy transmitting to the quenched, energy-dissipating state, in which the solar energy is not transmitted to the photosystems but instead dissipated as heat, remains unclear and is the

Distributed computer control systems in future nuclear power plants

International Nuclear Information System (INIS)

Yan, G.; L'Archeveque, J.V.R.; Watkins, L.M.

1978-09-01

Good operating experience with computer control in CANDU reactors over the last decade justifies a broadening of the role of digital electronic and computer related technologies in future plants. Functions of electronic systems in the total plant context are reappraised to help evolve an appropriate match between technology and future applications. The systems research, development and demonstration program at CRNL is described, focusing on the projects pertinent to the real-time data acquisition and process control requirements. (author)

Distributed control software of high-performance control-loop algorithm

CERN Document Server

Blanc, D

1999-01-01

The majority of industrial cooling and ventilation plants require the control of complex processes. All these processes are highly important for the operation of the machines. The stability and reliability of these processes are leading factors identifying the quality of the service provided. The control system architecture and software structure, as well, are required to have high dynamical performance and robust behaviour. The intelligent systems based on PID or RST controllers are used for their high level of stability and accuracy. The design and tuning of these complex controllers require the dynamic model of the plant to be known (generally obtained by identification) and the desired performance of the various control loops to be specified for achieving good performances. The concept of having a distributed control algorithm software provides full automation facilities with well-adapted functionality and good performances, giving methodology, means and tools to master the dynamic process optimization an...

Augmenting Plant Immune Responses and Biological Control by Microbial Determinants

Directory of Open Access Journals (Sweden)

Sang Moo Lee

2015-09-01

Full Text Available Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

Wind Power Plant Control Optimisation with Incorporation of Wind Turbines and STATCOMs

DEFF Research Database (Denmark)

Petersen, Lennart; Kryezi, Fitim; Iov, Florin

2015-01-01

This paper addresses a detailed design and tuning of a wind power plant slope voltage control with reactive power contribution of wind turbines and STATCOMS. First, small-signal models of a single wind turbine and the whole wind power plant are developed, being appropriate for voltage control...... assessment. An exemplary wind power plant located in the United Kingdom and the corresponding grid code requirements are used as a base case. The final design and tuning process of the voltage controller results in a guidance, proposed for this particular control architecture. It provides qualitative...... outcomes regarding the impact of system delays, grid conditions and various operating conditions of the wind power plant, with and without incorporation of STATCOMS....

Time scaling internal state predictive control of a solar plant

Energy Technology Data Exchange (ETDEWEB)

Silva, R.N. [DEE-FCT/UNL, Caparica (Portugal); Rato, L.M. [INESC-ID/University, Evora (Portugal); Lemos, J.M. [INESC-ID/IST, Lisboa (Portugal)

2003-12-01

The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration. (author)

Nuclear power plant control and instrumentation 1993. Working material

International Nuclear Information System (INIS)

1994-01-01

The regular meeting of the International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI) was organized in order to summarize operating experience of nuclear power plant control systems, gain a general overview of activities in development of modern control systems and receive recommendations on the further directions and particular measures within the Agency's programme. The meeting was held at the Merlin-Gerin Headquarters in Paris and was attended by twenty one national delegates and observers from 17 countries. The present volume contains: (1) report on the meeting of the IWG-NPPCI, Paris, 21-22 October 1993, (2) report by the scientific secretary on the major activities of IAEA during 1991-1993 in the NPPCI area, and (3) reports of the national representatives to the International Working Group on NPPCI. The papers and discussions with practical experience and described actual problems encountered. Emphasis was placed on the technical, industrial and economic aspects of the introduction of modern control systems and on the improvement of plant availability and safety. Refs, figs and tabs

Agricultural Plant Pest Control. Manual 93.