Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis weeds and plant community composition.

Directory of Open Access Journals (Sweden)

Collin W Ahrens

Full Text Available Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB and redtop (RT, where the glyphosate resistance (GR trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

Species composition, plant cover and diversity of recently reforested ...

African Journals Online (AJOL)

SERVER

2007-12-17

Dec 17, 2007 ... Deforestation, over-cultivation and rural growth have severely ... over-cultivation, plant populations changed, and biolo- ... Restoring community structure (e.g. species composi-tion ... plant diversity at all spatial scales are the criteria that should ..... taxonomic groups in recovering and restored forests.

Dipping Strawberry Plants in Fungicides before Planting to Control Anthracnose

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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.

The significance of different diacylgycerol synthesis pathways on plant oil composition and bioengineering

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Philip David Bates

2012-07-01

Full Text Available The unique properties of vegetable oils from different plants utilized for food, industrial feedstocks, and fuel is dependent on the fatty acid (FA composition of triacylglycerol (TAG. Plants can use two main pathways to produce diacylglycerol (DAG, the immediate precursor molecule to TAG synthesis: 1 De novo DAG synthesis, and 2 conversion of the membrane lipid phosphatidylcholine (PC to DAG. The FA esterified to PC are also the substrate for FA modification (e.g. desaturation, hydroxylation, etc., such that the FA composition of PC-derived DAG can be substantially different than that of de novo DAG. Since DAG provides two of the three FA in TAG, the relative flux of TAG synthesis from de novo DAG or PC-derived DAG can greatly affect the final oil FA composition. Here we review how the fluxes through these two alternate pathways of DAG/TAG synthesis are determined and present evidence that suggests which pathway is utilized in different plants. Additionally, we present examples of how the endogenous DAG synthesis pathway in a transgenic host plant can produce bottlenecks for engineering of plant oil FA composition, and discuss alternative strategies to overcome these bottlenecks to produce crop plants with designer vegetable oil compositions.

Microorganisms transported by ants induce changes in floral nectar composition of an ant-pollinated plant.

Science.gov (United States)

de Vega, Clara; Herrera, Carlos M

2013-04-01

Interactions between plants and ants abound in nature and have significant consequences for ecosystem functioning. Recently, it has been suggested that nectar-foraging ants transport microorganisms to flowers; more specifically, they transport yeasts, which can potentially consume sugars and alter nectar composition. Therefore, ants could indirectly change nectar sugar profile, an important floral feature involved in the plant-pollinator mutualism. But this novel role for ants has never been tested. We here investigate the effects of nectarivorous ants and their associated yeasts on the floral nectar sugar composition of an ant-pollinated plant. Differences in the nectar sugar composition of ant-excluded and ant-visited flowers were examined in 278 samples by using high-performance liquid-chromatography. The importance of the genetic identity and density of ant-transported basidiomycetous and ascomycetous yeasts on the variation of nectar traits was also evaluated. Ant visitation had significant effects on nectar sugar composition. The nectar of ant-visited flowers contained significantly more fructose, more glucose, and less sucrose than the nectar of ant-excluded flowers, but these effects were context dependent. Nectar changes were correlated with the density of yeast cells in nectar. The magnitude of the effects of ant-transported ascomycetes was much higher than that of basiodiomycetes. Ants and their associated yeasts induce changes in nectar sugar traits, reducing the chemical control of the plant over this important floral trait. The potential relevance of this new role for ants as indirect nectar modifiers is a rich topic for future research into the ecology of ant-flower interactions.

Study on caralluma tuberculata nutritional composition and its importance as medicinal plant

International Nuclear Information System (INIS)

Ahmad, B.; Abbasi, S.J.; Hussain, F.

2014-01-01

This study was conducted on Caralluma tuberculata, a famous traditional medicinal plant in the northern territory of Pakistan to assess its importance. Analysis were performed on its nutritional, proximate and microchemical composition for evaluation as food plant, while experiments of cytotoxicity, phytotoxicity and as phytobiocide were conducted to study its importance as medicinal plant. A method for vegetative propagation of C. tuberculata was optimized using cut stems without roots give better result and also more economical, from single stem multiple plant can be produced. It contains good amount of nutrients and proximate contents. Due to high inhibitory effect results of C. tuberculata against Alternaria alternata it can be recommended as selective fungicide for controlling Alternaria sp., born diseases. From the results it becomes clear that C. tuberculata had some anti-bacterial compounds which had very minimum inhibitory effect on the growth of bacterial species. This plant also showed significant activity against Artemia salina, Lemna minor and can be used as cytotoxic and phytotoxic agents in concentrated states. (author)

HYSSOP COMPOSITION DEPENDING ON AGE AND PLANTS DEVELOPMENT PHASES

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L. A. Kotyuk

2015-10-01

Full Text Available The aim of the paper is to research biochemical composition of Hyssopus officinalis L. (Lamiaceae in relation to plant age and phenological growth stage under conditions of Ukrainian Polissya, bin order to determine the optimal harvest dates of the herbal material and its application spheres. The raw material samples under analysis were cut at various growth stages: the vegetative, budding, blooming, ripening stages. To study the hyssop oil composition, areal parts of H. officinalis were used. The composition analysis was aimed at determining absolute dry matter (by drying samples at 105 °C up to the constant mass, “crude” cellulose, amounts of protein, fats, calcium, potassium, phosphorus, ascorbic acid, carotene, discernible sugars and tannins and essential oil. The present study has proved that in the plant ontogenesis the amount of essential oil, obtained from H. officinalis areal parts, does not markedly decrease: volatile oil yield in plants of the first, second and third years of life amounted to 1.007%, 0.75% and 0.71% respectively. The composition of volatile oil in the plants of the first year of life reveals 46 components, of which pinocampone (53.73%, isopinocampone (4.66% myrtenol (9.35% and camphor (3.86% prevailed. In H. officinalis volatile oil of the third year 30 components were identified, the prevailing of which were isopinocampone (44.43%, pinocampone (35.49%, myrtenol (5.26%, germacrene D (3.15%, pulegone (2.93% and bicyclogermacrene (1.35%. We could observe the change in the quantitative and qualitative composition of H. officinalis volatile oil throughout the entire vegetation period. Thus, in the phase of vegetative growth one can identify 25 compounds, the most predominant being elemol (33.25%, germacren D (21.59% and bicyclogermacrene (15.78%. In the phase of blossoming 30 components can be identified, a high amount of isopinocampone and pinocampone (44.43% and 35.49% and somewhat lover amount of myrtenol (5

Studies on source sink relationship of composite tea plants using 14C

International Nuclear Information System (INIS)

Marimuthu, S.; Raj Kumar, R.; Jayakumar, D.; Cox, Spurgeon

2000-01-01

An experiment on sink capacity of grafted tea plants was carried out adopting radiotracer technique under nursery conditions with two different graft combinations besides the un-grafted control plants. Among the control plants, UPASI-3 translocated higher quantum of photosynthates towards the growing shoot followed by UPASI-9 and ATK-I. In order to confirm the sink capacity of axillary shoot of rootstock, shoot arising from rootstock has been removed prior to exposure of root stock mother leaf. This led to a dramatic enhancement in assimilates translocation towards UPASI-3 scions. ATK- I rootstock mother leaves retained higher amount of photoassimilates when UPASI-9 was used as scion. Variation existed in partitioning of dry matter in response to cultivar type used for composite plant product. Axillary shoot of rootstock, ATK-I drained about seven per cent of total dry matter production irrespective of the scions. UPASI-3 scions drew about 40 per cent of total dry matter and it enhanced to 60 per cent on removal of axillary shoot of ATK-I. Results highlight that the removal of axillary shoot of the rootstock should be practiced at nursery level, immediately after initiation of its growth to obtain the balanced shoot : root ratio. (author)

Contrasting growth responses of dominant peatland plants to warming and vegetation composition.

Science.gov (United States)

Walker, Tom N; Ward, Susan E; Ostle, Nicholas J; Bardgett, Richard D

2015-05-01

There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and vegetation change are unknown. Here, we used a field warming and vegetation removal experiment to test the hypothesis that dominant species from the three plant functional types present (dwarf-shrubs: Calluna vulgaris; graminoids: Eriophorum vaginatum; bryophytes: Sphagnum capillifolium) contrast in their growth responses to warming and the presence or absence of other plant functional types. Warming was accomplished using open top chambers, which raised air temperature by approximately 0.35 °C, and we measured air and soil microclimate as potential mechanisms through which both experimental factors could influence growth. We found that only Calluna growth increased with experimental warming (by 20%), whereas the presence of dwarf-shrubs and bryophytes increased growth of Sphagnum (46%) and Eriophorum (20%), respectively. Sphagnum growth was also negatively related to soil temperature, which was lower when dwarf-shrubs were present. Dwarf-shrubs may therefore promote Sphagnum growth by cooling the peat surface. Conversely, the effect of bryophyte presence on Eriophorum growth was not related to any change in microclimate, suggesting other factors play a role. In conclusion, our findings reveal contrasting abiotic and biotic controls over dominant peatland plant growth, suggesting that community composition and carbon cycling could be modified by simultaneous climate and vegetation change.

Aroma of some plants cultivated in Lithuania : composition, processing and release

NARCIS (Netherlands)

Bylaite, E.

2000-01-01

In this study, some factors affecting the aroma of some plants of the families Umbelliferae and Asteraceae were evaluated. The composition of the aromas is influenced by several factors: plant family, harvesting time, anatomical part of plant,

Plant proteins as binders in cellulosic paper composites.

Science.gov (United States)

Fahmy, Yehia; El-Wakil, Nahla A; El-Gendy, Ahmed A; Abou-Zeid, Ragab E; Youssef, M A

2010-07-01

Plant proteins are used - for the first time - in this work as bulk binders for cellulosic fibers in paper composites. Soy bean protein and wheat gluten were denatured by two methods, namely by: urea+NaOH and by urea+NaOH+acrylamide. Addition of increased amounts of the denatured proteins resulted in a significant increase in all paper strength properties. Soy protein led, in addition, to a remarkable enhancement in opacity. The use of proteins increased kaolin retention in the paper composites, while keeping the paper strength higher than the blank protein-free paper. The results show that plant proteins are favorable than synthetic adhesives; because they are biodegradable and do not cause troubles in paper recycling i.e. they are environmentally friendly. (c) 2010 Elsevier B.V. All rights reserved.

Connectivity and propagule sources composition drive ditch plant metacommunity structure

Science.gov (United States)

Favre-Bac, Lisa; Ernoult, Aude; Mony, Cendrine; Rantier, Yann; Nabucet, Jean; Burel, Françoise

2014-11-01

The fragmentation of agricultural landscapes has a major impact on biodiversity. In addition to habitat loss, dispersal limitation increasingly appears as a significant driver of biodiversity decline. Landscape linear elements, like ditches, may reduce the negative impacts of fragmentation by enhancing connectivity for many organisms, in addition to providing refuge habitats. To characterize these effects, we investigated the respective roles of propagule source composition and connectivity at the landscape scale on hydrochorous and non-hydrochorous ditch bank plant metacommunities. Twenty-seven square sites (0.5 km2 each) were selected in an agricultural lowland of northern France. At each site, plant communities were sampled on nine ditch banks (totaling 243 ditches). Variables characterizing propagule sources composition and connectivity were calculated for landscape mosaic and ditch network models. The landscape mosaic influenced only non-hydrochorous species, while the ditch network impacted both hydrochorous and non-hydrochorous species. Non-hydrochorous metacommunities were dependent on a large set of land-use elements, either within the landscape mosaic or adjacent to the ditch network, whereas hydrochorous plant metacommunities were only impacted by the presence of ditches adjacent to crops and roads. Ditch network connectivity also influenced both hydrochorous and non-hydrochorous ditch bank plant metacommunity structure, suggesting that beyond favoring hydrochory, ditches may also enhance plant dispersal by acting on other dispersal vectors. Increasing propagule sources heterogeneity and connectivity appeared to decrease within-metacommunity similarity within landscapes. Altogether, our results suggest that the ditch network's composition and configuration impacts plant metacommunity structure by affecting propagule dispersal possibilities, with contrasted consequences depending on species' dispersal vectors.

WATER BINDING IN COMPOSITE SYSTEMS BASED ON MILLED MEDICINAL PLANTS AND NANOSILICA

Directory of Open Access Journals (Sweden)

V. V. Turov

2017-04-01

Full Text Available The aim of the study was to identify the influence of hydrodensified nanosilica particles on the binding of water by milled plant raw materials in neutral and acidic media. Flowers of Hibiscus sabdariffa and Calendula officinalis were used as the model materials. According to the microphotographs and low temperature 1H NMR spectroscopy data, the silica film forms on the surface of the milled plant particles, and it can significantly influence their hydration. According to the suggested scheme, some of the water from the inner cavities of plant raw materials moves (as evidenced by the decreasing radius of water-filled pores to the zone of contact of the composite components (the radius of clusters of adsorbed water increases. In studies of desorption of active substances from milled medicinal herbs and their composites by the initial and hydrodensified nanosilica, it has been shown that the formation of a composite significantly reduces the rate of desorption. Minimal desorption is observed in composites containing hydrodensified nanosilica. The studied composite systems are promising for biomedical researches.

Generation of composite Persea americana (Mill.) (avocado) plants: A proof-of-concept-study.

Science.gov (United States)

Prabhu, S Ashok; Ndlovu, Buyani; Engelbrecht, Juanita; van den Berg, Noëlani

2017-01-01

. PCR and Southern analysis further confirmed the transgenic nature of the roots expressing the screenable marker genes. Transgenic roots showed hyper-branching compared to the wild-type roots but this had no impact on Phytophthora cinnamomi infection. There was no difference in pathogen load 7-days-post inoculation between transformed and control roots. Strategy-2 involving A0.74:ARqua1 combination was the best ex vitro approach in producing composite avocado plants. The approach followed in this proof-of-concept study needs further optimisation involving multiple avocado genotypes and A. rhizogenes strains to achieve enhanced root transformation efficiencies, which would then serve as an effective high-throughput tool in the functional screening of host and pathogen genes to improve our understanding of the avocado-P. cinnamomi interaction.

Essential oil composition of some plants of family zygophyllaceae and euphorbiaceae

International Nuclear Information System (INIS)

Dastagir, G.

2014-01-01

Our objectives were to find out the chemical constituents of some selected plants of family Zygophyllaceae and Euphorbiaceae collected from Peshawar and Attock Hills during 2009, by GC/MS. The oil obtained from three analysed plants of family Zygophyllaceae showed that oxygenated monoterpenes were the highest (90.99%) in Tribulus terrestris, followed by Fagonia cretica (89.94%) and the lowest (36.01%) found in Peganum harmala. Peganum harmala had maximum esters (11.58%) followed by Tribulus terrestris (5.8%) and Fagonia cretica (5.5%). Monoterpenes hydrocarbons were the highest (1.22%) in Fagonia cretica followed by Peganum harmala and absent in Tribulus terrestris. Sesquiterpenes hydrocarbons were maximum (11.01%) in Peganum harmala and absent in Tribulus terrestris. The analysis of essential oils revealed that Fagonia cretica oils had 17 compounds that constituted 100% of the oil composition. Oxygenated monoterpenes (89.94%), were a major group of compounds. Peganum harmala oil had 18 compounds. There were 10 compounds in Tribulus terrestris oil that consisted 100% of the total oil composition. Eight compounds were identified in Chrozophora tinctoria oils giving complete oil composition. It had oxygenated monoterpenes (86.93%), constituting 2(4H) - Benzofuranone, 5, 6, 7, 7a tetrahydro-4, 4, 7a-trimethy (50.718%). Ricinus communis . oil had 8 compounds with 100% of the oil composition. The present study exhibited that phytochemical attributes and chemical composition of the studied plants have potential uses for food, pharmaceutical and cosmetic industry in future. Detailed research work on the antioxidant principles and biological activities of the studied plants is further recommended. (author)

Validation and implementation of model based control strategies at an industrial wastewater treatment plant.

Science.gov (United States)

Demey, D; Vanderhaegen, B; Vanhooren, H; Liessens, J; Van Eyck, L; Hopkins, L; Vanrolleghem, P A

2001-01-01

In this paper, the practical implementation and validation of advanced control strategies, designed using model based techniques, at an industrial wastewater treatment plant is demonstrated. The plant under study is treating the wastewater of a large pharmaceutical production facility. The process characteristics of the wastewater treatment were quantified by means of tracer tests, intensive measurement campaigns and the use of on-line sensors. In parallel, a dynamical model of the complete wastewater plant was developed according to the specific kinetic characteristics of the sludge and the highly varying composition of the industrial wastewater. Based on real-time data and dynamic models, control strategies for the equalisation system, the polymer dosing and phosphorus addition were established. The control strategies are being integrated in the existing SCADA system combining traditional PLC technology with robust PC based control calculations. The use of intelligent control in wastewater treatment offers a wide spectrum of possibilities to upgrade existing plants, to increase the capacity of the plant and to eliminate peaks. This can result in a more stable and secure overall performance and, finally, in cost savings. The use of on-line sensors has a potential not only for monitoring concentrations, but also for manipulating flows and concentrations. This way the performance of the plant can be secured.

Control of a post-combustion CO2 capture plant during process start-up and load variations

DEFF Research Database (Denmark)

Gaspar, Jozsef; Jørgensen, John Bagterp; Fosbøl, Philip Loldrup

2015-01-01

Dynamic and flexible operation of a carbon capture plant is important as thermal power plants must be operated very flexibly to accommodate large shares of intermittent energy sources such as wind and solar energy. To facilitate such operation, dynamic models for simulation, optimization...... and control system design are crucial. In this paper, we present a dynamic mathematical model for the absorption and desorption columns in a carbon capture plant. Moreover, we implement a decentralized proportional-integral (PI) based control scheme and we evaluate the performance of the control structure...... for various operational procedures, e.g. start-up, load changes, noise on the flue gas flow rate and composition. Note that the carbon capture plant is based on the solvent storage configuration. To the authors knowledge, this is the first paper addressing the issue of start-up operation and control of carbon...

Effect of Gamma Rays and Salinity on Growth and Chemical Composition of Ambrosia maritima L. Plant

International Nuclear Information System (INIS)

Moemen, A.M.E.

2012-01-01

This work achieved to study the effects of, mixture of salt 2:2:1 (Na Cl-CaCl 2 and Mg SO 4 ), concentration of (0, 2000, 4000 and 6000 ppm). on growth characters, some chemical components and some active ingredients in shoots of Ambrosia maritima plants, at different stages of growth, during two seasons. Pots 30 cm in diameter were filled of sand-loamy soils in appropriate concentration, all pots were irrigated with tap water. The exposed damsisa seeds to gamma rays, doses (0, 20, 40, and 80 Gy) before sowing together with control non irradiated seeds were sown in saline soils (0, 2000, 4000 and 6000 ppm). Soil salinity treatments caused a decrease in plant height, number of leaves, content of damsin, and an increase in fresh weigh, dry weight, total sugars, total chlorophyll, amino acids and ambrosine content. Also, Gamma rays caused an increase in most of growth parameters and most of chemical composition. It was observed that 40 or 80 Gy was more effective. We investigated the combined effect of levels of salinity and doses of radiation used, this interference improve growth parameters and chemical composition in ambrosia maritima plants and caused ascertain the role of gamma irradiation in plants tolerance to soil salinity and alleviation their harmful effect on plants.

Biological effects of plant residues with constrasting chemical compositions on plant and soil under humid tropical conditions

NARCIS (Netherlands)

Tian, G.

1992-01-01

A study on plant residues with contrasting chemical compositions was conducted under laboratory, growth chamber and humid tropical field conditions to understand the function of the soil fauna in the breakdown of plant residues, the cycling of nutrients, in particular nitrogen, and the

Composite harm to plants by sulfurous acid gas and oxidant

Energy Technology Data Exchange (ETDEWEB)

Matsushima, J

1971-01-01

The composite effects on plants of sulfur dioxide and ozone, SO/sub 2/ and PAN, SO/sub 2/ and nitrogen dioxide, and NO/sub 2/ and ozone were studied. Pinto bean plants were exposed to SO/sub 2/ or O/sub 3/ only, to each gas alternately, and to a mixture of the two. The degree of injury by the gas or gases was indicated in percentage by area of the leaves damaged. In cases where no geometric effect occurred the damage to the plant by the individual gas had been great; damage from the individual gas had been slight in these cases where such an effect was observed. The geometric effect is produced when the density of SO/sub 2/ is rather low, generally 0.05-0.25 ppm. A mixture of SO/sub 2/ and O/sub 3/ was applied to a tabacco plant; it affected fully grown leaves. In experiments on the composite effects of SO/sub 2/ and PAN on bean, tomato and pepper plants, PAN affected mainly young leaves while SO/sub 2/ affected mature ones. These effects were arithmetric rather then geometric. The SO/sub 2/ and NO/sub 2/ were also studied in the same manner. When SO/sub 2/ and NO/sub 2/ were mixed, a geometric effect was conspicuous in damage to vegetables, the symptoms of damage by either of the two appeared about the same, younger leaves being affected less. When treated with the two gases alternately, the damage was greater if the plants were first treated with NO/sub 2/; possible causes for this effect are discussed. No significant composite effect of NO/sub 2/ and O/sub 3/ was observed.

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

Properties of Plant Fiber Yarn Polymer Composites

DEFF Research Database (Denmark)

Madsen, Bo

2004-01-01

. The thesis presents experimental investigations and modelling of the properties of aligned plant fibre composites based on textile hemp yarn and thermoplastic matrices. The textile hemp yarn has been characterised. It is high in cellulose and with fibres well separated from each other; i.e. only few fibres...... are situated in bundles. The twisting angle is low; i.e. about 15 o for the outermost fibres in the yarn. The moisture sorption capacity of the yarn fibres is much lower than that of raw hemp fibres. Stiffness and strength of the fibres as calculated from composite data are in the ranges 50-65 GPa and 530......-650 MPa respectively. These properties show that textile hemp yarn is well suited as composite reinforcement. The relationship between fibre volume fraction and porosity has been studied. A model has been developed that predicts porosity from experimentally determined parameters such as fibre lumen...

Some contributions to the examination of composites from power plant wastes

Directory of Open Access Journals (Sweden)

Trifunović Prvoslav

2015-01-01

Full Text Available This paper describes an investigation into the possibilities of the use of all three types of solid power plant wastes: fly ash (FA, flue gas desulphurization gypsum (FGD gypsum and bottom ash (BA as components of composites for road construction. Two mixtures were made: 1. power plant wastes - Portland cement (PC and 2. power plant wastes - sand (S - Portland cement (PC. The mass ratio of components in these mixtures was: 1. FA - FGD gypsum - BA - PC = 2 : 1.5 : 5 : 1.5 and 2. FA- FGD gypsum-BA - S - PC= 2 : 1.5 : 4 : 1 : 1.5. For both mixtures, the compressive strength, the mineralogical composition, the water absorption and the resistance to freeze-thaw treatment were determined 7 and 28 days after preparation of samples (mixing with water. The obtained results showed that both mixtures could have potential to be used for sub-base layers in road construction and the second mixture (with natural aggregate-sand has advantage over the first mixture in terms of compressive strength, mineralogical composition, and resistance to freeze-thaw treatment.

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

PIXE studies of changes in mineral composition of plants infected with Phytophthora cinnamomi

Science.gov (United States)

Chaudhri, M. Anwar; Papper, C. S.; Weste, G.

1981-03-01

The mineral composition of susceptible and resistant plants from native forests infected with Phytophthora cinnamomi was compared between themselves and with the same species from disease-free areas. Root and shoot samples from different plants were carefully ashed, compressed into pellets and analysed with the thick target PIXE technique. A number of elements, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Sn and Pb, were detected. Many of the elements showed variations, sometimes large, between the composition of susceptible and resistant plants, and between the same species from infected and disease-free forests.

Herbivory of an invasive slug is affected by earthworms and the composition of plant communities.

Science.gov (United States)

Zaller, Johann G; Parth, Myriam; Szunyogh, Ilona; Semmelrock, Ines; Sochurek, Susanne; Pinheiro, Marcia; Frank, Thomas; Drapela, Thomas

2013-05-13

Biodiversity loss and species invasions are among the most important human-induced global changes. Moreover, these two processes are interlinked as ecosystem invasibility is considered to increase with decreasing biodiversity. In temperate grasslands, earthworms serve as important ecosystem engineers making up the majority of soil faunal biomass. Herbivore behaviour has been shown to be affected by earthworms, however it is unclear whether these effects differ with the composition of plant communities. To test this we conducted a mesocosm experiment where we added earthworms (Annelida: Lumbricidae) to planted grassland communities with different plant species composition (3 vs. 12 plant spp.). Plant communities had equal plant densities and ratios of the functional groups grasses, non-leguminous forbs and legumes. Later, Arion vulgaris slugs (formerly known as A. lusitanicus; Gastropoda: Arionidae) were added and allowed to freely choose among the available plant species. This slug species is listed among the 100 worst alien species in Europe. We hypothesized that (i) the food choice of slugs would be altered by earthworms' specific effects on the growth and nutrient content of plant species, (ii) slug herbivory will be less affected by earthworms in plant communities containing more plant species than in those with fewer plant species because of a more readily utilization of plant resources making the impacts of earthworms less pronounced. Slug herbivory was significantly affected by both earthworms and plant species composition. Slugs damaged 60% less leaves when earthworms were present, regardless of the species composition of the plant communities. Percent leaf area consumed by slugs was 40% lower in communities containing 12 plant species; in communities containing only three species earthworms increased slug leaf area consumption. Grasses were generally avoided by slugs. Leaf length and number of tillers was increased in mesocosms containing more plant

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.)

BOREAS TGB-3 Plant Species Composition Data over the NSA Fen

Science.gov (United States)

Bubier, Jill L.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-3) team collected several data sets that contributed to understanding the measured trace gas fluxes over sites in the Northern Study Area (NSA). This data set contains information about the composition of plant species that were within the collars used to measure Net Ecosystem Exchange of CO2 (NEE). The species composition was identified to understand the differences in NEE among the various plant communities in the NSA fen. The data were collected in July of 1994 and 1996. The data are contained in comma-delimited, ASCII files.

Promises in intelligent plant control systems

International Nuclear Information System (INIS)

Otaduy, P.J.

1987-01-01

The control system is the brain of a power plant. The traditional goal of control systems has been productivity. However, in nuclear power plants the potential for disaster requires safety to be the dominant concern, and the worldwide political climate demands trustworthiness for nuclear power plants. To keep nuclear generation as a viable option for power in the future, trust is the essential critical goal which encompasses all others. In most of today's nuclear plants the control system is a hybrid of analog, digital, and human components that focuses on productivity and operates under the protective umbrella of an independent engineered safety system. Operation of the plant is complex, and frequent challenges to the safety system occur which impact on their trustworthiness. Advances in nuclear reactor design, computer sciences, and control theory, and in related technological areas such as electronics and communications as well as in data storage, retrieval, display, and analysis have opened a promise for control systems with more acceptable human brain-like capabilities to pursue the required goals. This paper elaborates on the promise of futuristic nuclear power plants with intelligent control systems and addresses design requirements and implementation approaches

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

PIXE studies of changes in mineral composition of plants infected with Phytophthora cinnamomi

International Nuclear Information System (INIS)

Chaudhri, M.A.; Melbourne Univ., Austin; Weste, G.; Papper, C.S.

1981-01-01

The mineral composition of susceptible and resistant plants from native forests infected with Phytophthora cinnamomi was compared between themselves and with the same species from disease-free areas. Root and shoot samples from different plants were carefully ashed, compressed into pellets and analysed with the thick target PIXE technique. A number of elements, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Sn, and Pb, were detected. Many of the elements showed variations, sometimes large, between the composition of suspectible and resistant plants, and between the same species from infected and disease-free forests. (orig.)

The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

Science.gov (United States)

Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

2015-09-01

Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

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.

Compositions and methods for providing plants with tolerance to abiotic stress conditions

KAUST Repository

Hirt, Heribert; De Zelicourt, Axel; Saad, Maged

2017-01-01

It has been discovered that the desert endophytic bacterium SA187 SA187 can provide resistance or tolerance to abiotic stress conditions to seeds or plants. Compositions containing SA187 can be used to enhance plant development and yield under

Ecosystem development in roadside grasslands: Biotic control, plant-soil interactions, and dispersal limitations

Science.gov (United States)

Garcia-Palacios, P.; Bowker, M.A.; Maestre, F.T.; Soliveres, S.; Valladares, F.; Papadopoulos, J.; Escudero, A.

2011-01-01

Roadside grasslands undergoing secondary succession are abundant, and represent ecologically meaningful examples of novel, human-created ecosystems. Interactions between plant and soil communities (hereafter plant-soil interactions) are of major importance in understanding the role of biotic control in ecosystem functioning, but little is known about these links in the context of ecosystem restoration and succession. The assessment of the key biotic communities and interactions driving ecosystem development will help practitioners to better allocate the limited resources devoted to roadside grassland restoration. We surveyed roadside grasslands from three successional stages (0-2, 7-9, and > 20 years) in two Mediterranean regions of Spain. Structural equation modeling was used to evaluate how interactions between plants, biological soil crusts (BSCs), and soil microbial functional diversity (soil microorganisms) affect indicators of ecosystem development and restoration: plant similarity to the reference ecosystem, erosion control, and soil C storage and N accumulation. Changes in plant community composition along the successional gradient exerted the strongest influence on these indicators. High BSC cover was associated with high soil stability, and high soil microbial functional diversity from late-successional stages was associated with high soil fertility. Contrary to our expectations, the indirect effects of plants, mediated by either BSCs or soil microorganisms, were very weak in both regions, suggesting a minor role for plant-soil interactions upon ecosystem development indicators over long periods. Our results suggest that natural vegetation dynamics effectively improved ecosystem development within a time frame of 20 years in the grasslands evaluated. They also indicate that this time could be shortened if management actions focus on: (1) maintaining wellconserved natural areas close to roadsides to enhance plant compositional changes towards late

Compositions and methods for providing plants with tolerance to abiotic stress conditions

KAUST Repository

Hirt, Heribert

2017-07-27

It has been discovered that the desert endophytic bacterium SA187 SA187 can provide resistance or tolerance to abiotic stress conditions to seeds or plants. Compositions containing SA187 can be used to enhance plant development and yield under environmental stress conditions.

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.)

Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data.

Science.gov (United States)

Estrada, Nubia Luz; Böhlke, J K; Sturchio, Neil C; Gu, Baohua; Harvey, Greg; Burkey, Kent O; Grantz, David A; McGrath, Margaret T; Anderson, Todd A; Rao, Balaji; Sevanthi, Ritesh; Hatzinger, Paul B; Jackson, W Andrew

2017-10-01

Natural perchlorate (ClO 4 - ) in soil and groundwater exhibits a wide range in stable isotopic compositions (δ 37 Cl, δ 18 O, and Δ 17 O), indicating that ClO 4 - may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO 4 - , but little is known about their ability to alter its isotopic composition. We examined the potential for plants to alter the isotopic composition of ClO 4 - in hydroponic and field experiments conducted with snap beans (Phaseolus vulgaris L.). In hydroponic studies, anion ratios indicated that ClO 4 - was transported from solutions into plants similarly to NO 3 - but preferentially to Cl - (4-fold). The ClO 4 - isotopic compositions of initial ClO 4 - reagents, final growth solutions, and aqueous extracts from plant tissues were essentially indistinguishable, indicating no significant isotope effects during ClO 4 - uptake or accumulation. The ClO 4 - isotopic composition of field-grown snap beans was also consistent with that of ClO 4 - in varying proportions from irrigation water and precipitation. NO 3 - uptake had little or no effect on NO 3 - isotopic compositions in hydroponic solutions. However, a large fractionation effect with an apparent ε ( 15 N/ 18 O) ratio of 1.05 was observed between NO 3 - in hydroponic solutions and leaf extracts, consistent with partial NO 3 - reduction during assimilation within plant tissue. We also explored the feasibility of evaluating sources of ClO 4 - in commercial produce, as illustrated by spinach, for which the ClO 4 - isotopic composition was similar to that of indigenous natural ClO 4 - . Our results indicate that some types of plants can accumulate and (presumably) release ClO 4 - to soil and groundwater without altering its isotopic characteristics. Concentrations and isotopic compositions of ClO 4 - and NO 3 - in plants may be useful for determining sources of fertilizers and sources of ClO 4 - in their growth

Unravelling the mechanisms for plant survival on gypsum soils: an analysis of the chemical composition of gypsum plants from Turkey.

Science.gov (United States)

Bolukbasi, A; Kurt, L; Palacio, S

2016-03-01

Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non-exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non-exclusive to gypsum (i.e. gypsovags), which may indicate their similar ecological strategy as stress-tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high- and low-gypsum content soils. Differences were explored with multivariate analyses (RDA) and mixed models (REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high-gypsum than on low-gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress-tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

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

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,…

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)

Fabrication of slag-glass composite with controlled porosity

Directory of Open Access Journals (Sweden)

Ranko Adziski

2008-06-01

Full Text Available The preparation and performance of porous ceramics made from waste materials were investigated. Slag from thermal electrical plant Kakanj (Bosnia and Herzegovina with defined granulations: (0.500÷0.250 mm; (0.250÷0.125 mm; (0.125÷0.063 mm; (0.063÷0.045 mm and 20/10 wt.% of the waste TV screen glass with a granulation <0.063 mm were used for obtaining slag-glass composites with controlled porosity. The one produced from the slag powder fraction (0.125÷0.063 mm and 20 wt.% TV screen glass, sintered at 950°C/2h, was considered as the optimal. This system possesses open porosity of 26.8±1.0%, and interconnected pores with the size of 250–400 μm. The values of E-modulus and bending strength of this composite were 10.6±0.6 GPa and 45.7±0.7 MPa, respectively. The coefficient of thermal expansion was 8.47·10-6/°C. The mass loss in 0.1M HCl solution after 30 days was 1.2 wt.%. The permeability and the form coefficient of the porous composite were K0=0.12 Da and C0=4.53·105 m-1, respectively. The porous composite shows great potential to be used as filters, diffusers for water aeration, dust collectors, acoustic absorbers, etc.

Molecular species composition of plant cardiolipin determined by liquid chromatography mass spectrometry

Science.gov (United States)

Zhou, Yonghong; Peisker, Helga

2016-01-01

Cardiolipin (CL), an anionic phospholipid of the inner mitochondrial membrane, provides essential functions for stabilizing respiratory complexes and is involved in mitochondrial morphogenesis and programmed cell death in animals. The role of CL and its metabolism in plants are less well understood. The measurement of CL in plants, including its molecular species composition, is hampered by the fact that CL is of extremely low abundance, and that plants contain large amounts of interfering compounds including galactolipids, neutral lipids, and pigments. We used solid phase extraction by anion exchange chromatography to purify CL from crude plant lipid extracts. LC/MS was used to determine the content and molecular species composition of CL. Thus, up to 23 different molecular species of CL were detected in different plant species, including Arabidopsis, mung bean, spinach, barley, and tobacco. Similar to animals, plant CL is dominated by highly unsaturated species, mostly containing linoleic and linolenic acid. During phosphate deprivation or exposure to an extended dark period, the amount of CL decreased in Arabidopsis, accompanied with an increased degree in unsaturation. The mechanism of CL remodeling during stress, and the function of highly unsaturated CL molecular species, remains to be defined. PMID:27179363

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.)

Modeling plant composition as community continua in a forest landscape with LiDAR and hyperspectral remote sensing.

Science.gov (United States)

Hakkenberg, C R; Peet, R K; Urban, D L; Song, C

2018-01-01

In light of the need to operationalize the mapping of forest composition at landscape scales, this study uses multi-scale nested vegetation sampling in conjunction with LiDAR-hyperspectral remotely sensed data from the G-LiHT airborne sensor to map vascular plant compositional turnover in a compositionally and structurally complex North Carolina Piedmont forest. Reflecting a shift in emphasis from remotely sensing individual crowns to detecting aggregate optical-structural properties of forest stands, predictive maps reflect the composition of entire vascular plant communities, inclusive of those species smaller than the resolution of the remotely sensed imagery, intertwined with proximate taxa, or otherwise obscured from optical sensors by dense upper canopies. Stand-scale vascular plant composition is modeled as community continua: where discrete community-unit classes at different compositional resolutions provide interpretable context for continuous gradient maps that depict n-dimensional compositional complexity as a single, consistent RGB color combination. In total, derived remotely sensed predictors explain 71%, 54%, and 48% of the variation in the first three components of vascular plant composition, respectively. Among all remotely sensed environmental gradients, topography derived from LiDAR ground returns, forest structure estimated from LiDAR all returns, and morphological-biochemical traits determined from hyperspectral imagery each significantly correspond to the three primary axes of floristic composition in the study site. Results confirm the complementarity of LiDAR and hyperspectral sensors for modeling the environmental gradients constraining landscape turnover in vascular plant composition and hold promise for predictive mapping applications spanning local land management to global ecosystem modeling. © 2017 by the Ecological Society of America.

The influence of canopy-layer composition on understory plant diversity in southern temperate forests

Directory of Open Access Journals (Sweden)

Luciana Mestre

2017-05-01

Full Text Available Background Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning. Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests. The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types (monospecific deciduous Nothofagus pumilio (Np, monospecific evergreen Nothofagus betuloides (Nb, and mixed N. pumilio-N. betuloides (M forests, comparing also between two geographical locations (coast and mountain to estimate differences at landscape level. Results We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots. Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage. Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse. Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate. Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species. Conclusions Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites. Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant

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

Floristic composition and taxonomic distribution of plants in the ...

African Journals Online (AJOL)

Floristic composition and taxonomic distribution of plants in the dryland of Northwestern Nigeria. ... Analysis of abundance and rarity of species reveals that 10% and 90% of the encountered species were abundant and rare respectively in the study area. These finding poses serious ecological concerns in the study area, ...

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.

New pressure control method of mixed gas in a combined cycle power plant of a steel mill

Science.gov (United States)

Xie, Yudong; Wang, Yong

2017-08-01

The enterprise production concept is changing with the development of society. A steel mill requires a combined-cycle power plant, which consists of both a gas turbine and steam turbine. It can recycle energy from the gases that are emitted from coke ovens and blast furnaces during steel production. This plant can decrease the overall energy consumption of the steel mill and reduce pollution to our living environment. To develop a combined-cycle power plant, the pressure in the mixed-gas transmission system must be controlled in the range of 2.30-2.40 MPa. The particularity of the combined-cycle power plant poses a challenge to conventional controllers. In this paper, a composite control method based on the Smith predictor and cascade control was proposed for the pressure control of the mixed gases. This method has a concise structure and can be easily implemented in actual industrial fields. The experiment has been conducted to validate the proposed control method. The experiment illustrates that the proposed method can suppress various disturbances in the gas transmission control system and sustain the pressure of the gas at the desired level, which helps to avoid abnormal shutdowns in the combined-cycle power plant.

Advanced nuclear plant control complex

International Nuclear Information System (INIS)

Scarola, K.; Jamison, S.; Manazir, R.M.; Rescorl, R.L.; Harmon, D.L.

1991-01-01

An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system which is nuclear qualified for rapid response to changes in plant parameters and a component control system which together provide a discrete monitoring and control capability at a panel in the control room. A separate data processing system, which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs and a large, overhead integrated process status overview board. The discrete indicator and alarm system and the data processing system receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accidental conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof. (author)

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)

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)

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

Long-term effects of plant diversity and composition on soil nematode communities in grassland.

NARCIS (Netherlands)

Viketoft, M.; Bengtsson, J.; Sohlenius, B.; Berg, M.P.; Petchey, O.; Palmborg, C.; Huss-Daniel, K.

2009-01-01

An important component of plant-soil feedbacks is how plant species identity and diversity influence soil organism communities. We examine the effects of grassland plant species growing alone and together up to a richness of 12 species on nematode diversity and feeding group composition, eight years

Intelligent Overload Control for Composite Web Services

NARCIS (Netherlands)

Meulenhoff, P.J.; Ostendorf, D.R.; Zivkovic, Miroslav; Meeuwissen, H.B.; Gijsen, B.M.M.

2009-01-01

In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules

Organic, integrated and conventional management in apple orchards: effect on plant species composition, richness and diversity

Directory of Open Access Journals (Sweden)

Zdeňka Lososová

2011-01-01

Full Text Available The study was conducted to assess the effect of conventional, integrated and organic management on differences in plant species composition, richness and diversity. The plants were studied in triads of orchards situated in three regions of the Czech Republic. Data about species occurrences were collected on 15 permanent plots in the tree rows and 15 plots between tree rows in each of the apple orchards during 2009. A total of 201 vascular plant species (127 native species, 65 archaeophytes, and 9 neophytes were found. Management type and also different regional conditions had a significant effect on plant species composition and on diversity parameters of orchard spontaneous vegetation. Species richness and species pool was significantly higher in the organic orchards than in the differently managed orchards. Management type had significant effect on proportions of archaeophytes, and also neophytes in apple orchards. The results showed that a change from conventional to integrated and organic management in apple orchards lead to higher plant species diversity and to changes in plant species composition.

Biological Control of Plant Disease Caused by Bacteria

Directory of Open Access Journals (Sweden)

Triwidodo Arwiyanto

2014-07-01

Full Text Available Bacterial diseases in plants are difficult to control. The emphasis is on preventing the spread of the bacteria rather than curing the diseased plant. Integrated management measures for bacterial plant pathogens should be applied for successfull control. Biological control is one of the control measures viz. through the use of microorganisms to suppress the growth and development of bacterial plant pathogen and ultimately reduce the possibility of disease onset. The study of biological control of bacterial plant pathogen was just began compared with of fungal plant pathogen. The ecological nature of diverse bacterial plant pathogens has led scientists to apply different approach in the investigation of its biological control. The complex process of entrance to its host plant for certain soil-borne bacterial plant pathogens need special techniques and combination of more than one biological control agent. Problem and progress in controlling bacterial plant pathogens biologically will be discussed in more detail in the paper and some commercial products of biological control agents (biopesticides will be introduced.     Penyakit tumbuhan karena bakteri sulit dikendalikan. Penekanan pengendalian adalah pada pencegahan penyebaran bakteri patogen dan bukan pada penyembuhan tanaman yang sudah sakit. Untuk suksesnya pengendalian bakteri patogen tumbuhan diperlukan cara pengelolaan yang terpadu. Pengendalian secara biologi merupakan salah satu cara pengendalian dengan menggunakan mikroorganisme untuk menekan pertumbuhan dan perkembangan bakteri patogen tumbuhan dengan tujuan akhir menurunkan kemungkinan timbulnya penyakit. Sifat ekologi bakteri patogen tumbuhan yang berbeda-beda mengharuskan pendekatan yang berbeda pula dalam pengendaliannya secara biologi. Masalah dan perkembangan dalam pengendalian bakteri patogen tumbuhan secara biologi didiskusikan secara detail dalam makalah ini.

The economics of landscape restoration: Benefits of controlling bush encroachment and invasive plant species in South Africa and Namibia

CSIR Research Space (South Africa)

Stafford, William

2017-01-01

Full Text Available Bush encroachment and alien plant invasions alter the composition and/or balance of species in natural ecosystems and impact biodiversity, land productivity and water availability. Therefore, the appropriate control and management of bush...

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)

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.

Use of ex vitro composite plants to study the interaction of cowpea (Vigna unguiculata L.) with the root parasitic angiosperm Striga gesnerioides

Science.gov (United States)

2012-01-01

Background Cowpea (Vigna unguiculata L.) is an important grain and forage legume grown throughout sub-Saharan Africa primarily by subsistence farmers on poor, drought prone soils. Genetic improvement of the crop is being actively pursued and numerous functional genomics studies are underway aimed at characterizing gene controlling key agronomic characteristics for disease and pest resistances. Unfortunately, similar to other legumes, efficient plant transformation technology is a rate-limiting step in analysis of gene function in cowpea. Results Here we describe an optimized protocol for the rapid generation of transformed hairy roots on ex vitro composite plants of cowpea using Agrobacterium rhizogenes. We further demonstrate the applicability of cowpea composite plants to study gene expression involved in the resistance response of the plant roots to attack by the root parasitic weed, Striga gesnerioides. The utility of the new system and critical parameters of the method are described and discussed herein. Conclusions Cowpea composite plants offer a rapid alternative to methods requiring stable transformation and whole plant regeneration for studying gene expression in resistance or susceptibility responses to parasitic weeds. Their use can likely be readily adapted to look at the effects of both ectopic gene overexpression as well as gene knockdown of root associated defense responses and to the study of a broader range of root associated physiological and aphysiological processes including root growth and differentiation as well as interactions with other root pests, parasites, and symbionts. PMID:22741546

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

A measurement control program for plutonium isotopic gamma-ray systems at the Rocky Flats Plant

International Nuclear Information System (INIS)

Fleissner, J.G.

1986-01-01

A sound measurement control (MC) program should be an integral part of every nondestructive assay measurement system used for the assay of special nuclear materials. This paper describes a measurement control program for plutonium isotopic composition measurements, using high-resolution gamma-ray spectroscopy, that has been implemented in the Analytical Laboratories and the Chemistry Standards Laboratory at the Rocky Flats Plant. This MC program emphasizes the standardization of data collection procedures along with the implementation of internal and external measurement control checks to provide the requisite measurement quality assurance

Legacy effects of no-analogue disturbances alter plant community diversity and composition in semi-arid sagebrush steppe

Science.gov (United States)

Ripplinger, Julie; Franklin, Janet; Edwards, Thomas C.

2015-01-01

Questions(i) What role does the type of managed disturbance play in structuring sagebrush steppe plant communities? (ii) How does the composition of post-disturbance plant communities change with time since disturbance? (iii) Does plant community diversity change over time following managed disturbance?LocationField study within the sagebrush steppe ecosystem. Rich County, Utah, USA.MethodsWe developed a chronosequence spanning up to 50 yrs post-treatment to study sagebrush steppe vegetation dynamics. Direct ordination was used to examine plant community composition by managed disturbance type and time since disturbance, and factorial analysis of covariance was used to examine diversity dynamics following disturbance. Indicator species values were calculated in order to identify characteristic species for each disturbance type.ResultsPlant communities experienced a shift toward distinct community composition for each of the three managed disturbance types, and gave no indication of returning to untreated community composition or diversity. Small post-disturbance increases in the number of non-native grass species were observed in the treatments relative to reference, with native forb species making the largest contribution to altered composition. On fire- and chemically-treated sites the proportional native forb species richness increased over time since disturbance, while the proportional contribution of non-native forbs to total species richness decreased. For all three treatment types, native grasses contributed less on average to total richness than on reference sites, while non-native grasses made up a higher proportion of total richness.ConclusionsCommon shrubland management techniques have legacy effects on the composition and diversity of sagebrush steppe plant communities, and no-analogue disturbances, such as chemical or mechanical treatments, have more pronounced legacy effects than treatments similar to natural disturbance regimes (fire). This study

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

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.

Phylogenetic composition of host plant communities drives plant-herbivore food web structure.

Science.gov (United States)

Volf, Martin; Pyszko, Petr; Abe, Tomokazu; Libra, Martin; Kotásková, Nela; Šigut, Martin; Kumar, Rajesh; Kaman, Ondřej; Butterill, Philip T; Šipoš, Jan; Abe, Haruka; Fukushima, Hiroaki; Drozd, Pavel; Kamata, Naoto; Murakami, Masashi; Novotny, Vojtech

2017-05-01

Insects tend to feed on related hosts. The phylogenetic composition of host plant communities thus plays a prominent role in determining insect specialization, food web structure, and diversity. Previous studies showed a high preference of insect herbivores for congeneric and confamilial hosts suggesting that some levels of host plant relationships may play more prominent role that others. We aim to quantify the effects of host phylogeny on the structure of quantitative plant-herbivore food webs. Further, we identify specific patterns in three insect guilds with different life histories and discuss the role of host plant phylogeny in maintaining their diversity. We studied herbivore assemblages in three temperate forests in Japan and the Czech Republic. Sampling from a canopy crane, a cherry picker and felled trees allowed a complete census of plant-herbivore interactions within three 0·1 ha plots for leaf chewing larvae, miners, and gallers. We analyzed the effects of host phylogeny by comparing the observed food webs with randomized models of host selection. Larval leaf chewers exhibited high generality at all three sites, whereas gallers and miners were almost exclusively monophagous. Leaf chewer generality dropped rapidly when older host lineages (5-80 myr) were collated into a single lineage but only decreased slightly when the most closely related congeneric hosts were collated. This shows that leaf chewer generality has been maintained by feeding on confamilial hosts while only a few herbivores were shared between more distant plant lineages and, surprisingly, between some congeneric hosts. In contrast, miner and galler generality was maintained mainly by the terminal nodes of the host phylogeny and dropped immediately after collating congeneric hosts into single lineages. We show that not all levels of host plant phylogeny are equal in their effect on structuring plant-herbivore food webs. In the case of generalist guilds, it is the phylogeny of deeper

Control of renewable distributed power plants

OpenAIRE

Bullich Massagué, Eduard

2015-01-01

The main objective of this master thesis is to design a power plant controller for a photo- voltaic (PV) power plant. In a first stage, the current situation of the status of the electrical grid is analysed. The electrical network structure is moving from a conventional system (with centralized power generation, unidirectional power ows, easy control) to a smart grid system consisting on distributed generation, renewable energies, smart and complex control architecture and ...

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.

Treatments of non-wood plant fibres used as reinforcement in composite materials

Directory of Open Access Journals (Sweden)

Marie-Ange Arsène

2013-01-01

Full Text Available This paper presents a summary of the knowledge on fibres and pulps of non wood tropical plants used as reinforcement in cementitious composites accumulated during the recent years by Guadeloupean and Brazilian teams participating in collaborative work. Vegetable fibres represent a good alternative as non-conventional materials for the construction of ecological and sustainable buildings. The use of such renewable resources contributes to the development of sustainable technologies. The main objective of the paper is to emphasize the use of agricultural wastes in the production of cement based composites. The botanical, chemical, physical, morphological and mechanical properties of fibres from various plants are described. The effects of different treatments on physical, chemical and mechanical properties of fibres are presented. The most effective treatments in influencing the mechanical and physical properties are pyrolysis and alkaline ones, according to the type of plant. The final choice will have to consider fibre availability, and treatment costs.

The composition and regeneration status of wild food plants in ...

African Journals Online (AJOL)

The composition and regeneration status of wild food plants in Chenene Miombo woodland, Dodoma rural district, Tanzania. VE Tairo. Abstract. No Abstract. Discovery and Innovation Vol. 19 (1&2) 2007: pp. 107-121. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Microbe-mediated plant-soil feedback in pioneer stages of secondary succession causes long-lasting historical contingency effects in plant community composition.

NARCIS (Netherlands)

Kardol, P.; Bezemer, T.M.; Putten, van der W.H.

2006-01-01

Soil microbes and soil fauna have been assumed to play a key role in interspecific plant competition and successional community development. It has been suggested that plants can influence their performance by changing the composition of their associated soil communities. Such feedback effects may

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.)

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

Plant level of automated control system at a NPP with RBMK reactor

International Nuclear Information System (INIS)

Vorob'ev, V.P.; Gorbunov, V.P.; Dmitriev, V.M.; Litvin, A.S.

1987-01-01

The functional structure of plant level automated control system (ACS) at NPP with RBMK-1000 reactors, its binding with the on-line control system of higher and lower levels, as well as engineering requirements to software and recommendations on composition of hardware components, are considered. NPP ACS is an organizational-engineering system consisting of computer facilities and binding aimed at solving management, economical, organizational and physical-engineering problems to control NPP more effectively. The system carries out data acquisition, preliminary processing, analysis, transmission and representation for users to accept solutions for NPP operation by operative and management personnel. The main aim of integrated NPP ACS is the control development and increase of NPP economical efficiency, the increase of electric and heat energy production, the optimization of the production distribution between units, the development of production and economic NPP control

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)

Plant biomass and species composition along an environmental gradient in montane riparian meadows

Science.gov (United States)

Kathleen A. Dwire; J. Boone Kauffman; E. N. Jack Brookshire; John E. Baham

2004-01-01

In riparian meadows, narrow zonation of the dominant vegetation frequently occurs along the elevational gradient from the stream edge to the floodplain terrace. We measured plant species composition and above- and belowground biomass in three riparian plant communities - a priori defined as wet, moist, and dry meadow - along short streamside topographic gradients in...

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

Mineralogical composition changes of postagrogenic soils under different plant communities.

Science.gov (United States)

Churilin, Nikita; Chizhikova, Natalia; Varlamov, Evgheni; Churilina, Alexandra

2017-04-01

Plant communities play the leading role in transformation of soil. The need of studying former arable lands increases due to large number of abandoned lands in Russia. It is necessary to study mineralogical composition of soils involved into natural processes to understand the trends of their development after agricultural activities in the past. The aim of the study is to identify changes in mineralogical composition of soils under the influence of different plant communities. Soils were sampled in the south of Arkhangelsk region, Ustyansky district, near Akichkin Pochinok village. Soils are formed on clay moraine of Moscow glaciation. Soil profiles were dug on interfluve. We selected 4 plant communities on different stages of succession: upland meadow with domination of sod grasses (Phleum pratense, Agrostis tenuis), 16-year-old birch forest where dominants are herbaceous plants such as Poa sp., Chamerion angustiflium, Agrostis tenuis, 16-year-old spruce forest with no herbaceous vegetation and 70-year-old bilberry spruce forest with domination of Vaccinium myrtillus and Vaccinium vitis-idaea. To separate soil fractions mineral content. We noticed a clear differentiation of studied soils both in the content of fraction and composition of minerals. Mineralogical composition and major mineral phases correlation of profiles under 70 years and 16 years of spruce forests are different. Mineralogical content in upper part of profile under the young spruce is more differentiated than in old spruce forest: the amount of quartz and kaolinite increases in upper horizon, although in this case the overall pattern of profile formation of clay material during podzolization remains unchanged. There is more substantial desilting under the birch forest, compared with profile under the spruce of same age within top 50 cm. Under the meadow vegetation we've discovered differentiation in mineral composition. Upper horizons contain smectite phase and differ from the underlying

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...

Methods for nuclear material control used in the basic production of a typical radiochemical plant

International Nuclear Information System (INIS)

Kositsyn, V.F.; Mukhortov, N.F.; Korovin, Yu.I.; Rudenko, V.S.; Petrov, A.M.

1999-01-01

Techniques for destructive and non-destructive assay of the component and isotopic composition of nuclear materials are described, namely gravimetric, titrimetric, coulometric, mass spectrometry, as well as those based on registration of neutron and γ radiations. Their metrologic characteristics are described. The techniques described are suggested to be used for nuclear material (NM) control and accounting purposes at the model radiochemical plant for processing irradiated fuel subassemblies from power reactors. The measurement control program is also described. This program is intended for the measurement quality assurance in the framework of NM control and accountancy system [ru

Variable Isotopic Compositions of Host Plant Populations Preclude Assessment of Aphid Overwintering Sites

Directory of Open Access Journals (Sweden)

Michael S. Crossley

2017-12-01

Full Text Available Soybean aphid (Aphis glycines Matsumura is a pest of soybean in the northern Midwest whose migratory patterns have been difficult to quantify. Improved knowledge of soybean aphid overwintering sites could facilitate the development of control efforts with exponential impacts on aphid densities on a regional scale. In this preliminary study, we explored the utility of variation in stable isotopes of carbon and nitrogen to distinguish soybean aphid overwintering origins. We compared variation in bulk 13C and 15N content in buckthorn (Rhamnus cathartica L. and soybean aphids in Wisconsin, among known overwintering locations in the northern Midwest. Specifically, we looked for associations between buckthorn and environmental variables that could aid in identifying overwintering habitats. We detected significant evidence of correlation between the bulk 13C and 15N signals of soybean aphids and buckthorn, despite high variability in stable isotope composition within and among buckthorn plants. Further, the 15N signal in buckthorn varied predictably with soil composition. However, lack of sufficient differentiation of geographic areas along axes of isotopic and environmental variation appears to preclude the use of carbon and nitrogen isotopic signals as effective predictors of likely aphid overwintering sites. These preliminary data suggest the need for future work that can further account for variability in 13C and 15N within/among buckthorn plants, and that explores the utility of other stable isotopes in assessing likely aphid overwintering sites.

Assessing plant community composition fails to capture impacts of white-tailed deer on native and invasive plant species.

Science.gov (United States)

Nuzzo, Victoria; Dávalos, Andrea; Blossey, Bernd

2017-07-01

Excessive herbivory can have transformative effects on forest understory vegetation, converting diverse communities into depauperate ones, often with increased abundance of non-native plants. White-tailed deer are a problematic herbivore throughout much of eastern North America and alter forest understory community structure. Reducing (by culling) or eliminating (by fencing) deer herbivory is expected to return understory vegetation to a previously diverse condition. We examined this assumption from 1992 to 2006 at Fermilab (Batavia, IL) where a cull reduced white-tailed deer ( Odocoileus virginianus ) abundance in 1998/1999 by 90 % from 24.6 to 2.5/km 2 , and at West Point, NY, where we assessed interactive effects of deer, earthworms, and invasive plants using 30 × 30 m paired fenced and open plots in 12 different forests from 2009 to 2012. We recorded not only plant community responses (species presence and cover) within 1 m 2 quadrats, but also responses of select individual species (growth, reproduction). At Fermilab, introduced Alliaria petiolata abundance initially increased as deer density increased, but then declined after deer reduction. The understory community responded to the deer cull by increased cover, species richness and height, and community composition changed but was dominated by early successional native forbs. At West Point plant community composition was affected by introduced earthworm density but not deer exclusion. Native plant cover increased and non-native plant cover decreased in fenced plots, thus keeping overall plant cover similar. At both sites native forb cover increased in response to deer reduction, but the anticipated response of understory vegetation failed to materialize at the community level. Deer-favoured forbs ( Eurybia divaricata , Maianthemum racemosum , Polygonatum pubescens and Trillium recurvatum ) grew taller and flowering probability increased in the absence of deer. Plant community monitoring fails to capture

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

Base-line data on everglades soil-plant systems: elemental composition, biomass, and soil depth

International Nuclear Information System (INIS)

Volk, B.G.; Schemnitz, S.D.; Gamble, J.F.; Sartain, J.B.

1975-01-01

Plants and soils from plots in the Everglades Wildlife Management Area, Conservation Area 3, were examined. Chemical composition (N, P, K, Ca, Mg, Na, Cu, Fe, Mn, Zn, Co, Sr, Pb, Ni, Cr, Al, and Si) of most plant and soil digests was determined. Cladium jamaicense was the predominant plant species contributing to biomass in all plots except the wet prairie, where Rhynchospora sp. and Panicum hemitomon were most common. The biomass of dead C. jamaicense was greater than that of the living plants in unburned saw-grass plots. The burned saw grass, muck burn, and wet prairie were characterized by a large number of plant species per square meter but smaller average biomass production than the unburned saw-grass locations. Levels of Cu, Mn, Ca, Mg, K, and N in C. jamaicense differed significantly across locations. Highly significant differences in elemental composition existed between plant species. Concentrations of several elements (particularly Zn, Ca, Mg, P, and N) were low in live C. jamaicense compared with other plant species. Cesium-137 levels ranged from 670 to 3100 pCi/kg in sandy and in organic soils, respectively. Polygonum had a 137 Cs level of 11,600 pCi/kg. Dead C. jamaicense indicated a rapid leaching loss of 137 Cs from dead tissue

Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams

Energy Technology Data Exchange (ETDEWEB)

Baattrup-Pedersen, Annette, E-mail: abp@bios.au.dk [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Göthe, Emma [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Riis, Tenna [Department of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1135, Room 217, DK-8000 Aarhus C (Denmark); O' Hare, Matthew T. [Centre for Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom)

2016-02-01

stress. The ability to disentangle several stressors is particularly important in lowland stream environments where several stressors act in concert since the impact of the most important stressor can be targeted first, which is essential to improve the ecological status. - Highlights: • Functional trait composition of aquatic plants can distinguish hydromorphological degradation from eutrophication in streams • A conceptual framework on how eutrophication and hydromorphological degradation interact on functional trait composition • Weed cutting can set aside light as a factor controlling trait-abundance pattern in eutrophic lowland streams.

Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams

International Nuclear Information System (INIS)

Baattrup-Pedersen, Annette; Göthe, Emma; Riis, Tenna; O'Hare, Matthew T.

2016-01-01

stress. The ability to disentangle several stressors is particularly important in lowland stream environments where several stressors act in concert since the impact of the most important stressor can be targeted first, which is essential to improve the ecological status. - Highlights: • Functional trait composition of aquatic plants can distinguish hydromorphological degradation from eutrophication in streams • A conceptual framework on how eutrophication and hydromorphological degradation interact on functional trait composition • Weed cutting can set aside light as a factor controlling trait-abundance pattern in eutrophic lowland streams.

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)

Effects of foliar boron application on seed composition, cell wall boron, and seed δ15N and δ13C isotopes in water-stressed soybean plants

Science.gov (United States)

Bellaloui, Nacer; Hu, Yanbo; Mengistu, Alemu; Kassem, My A.; Abel, Craig A.

2013-01-01

Limited information is available on the effects of foliar boron (B) application on soybean seed composition. The objective of this research was to investigate the effects of foliar B on seed composition (protein, oil, fatty acids, and sugars). Our hypothesis was that since B is involved in nitrogen and carbon metabolism, it may impact seed composition. A repeated greenhouse experiment was conducted where half of the soybean plants was exposed to water stress (WS) and the other half was well-watered. Foliar boron (FB) in the form of boric acid was applied twice at a rate of 1.1 kg ha−1. The first application was during flowering stage, and the second application was during seed-fill stage. Treatments were water stressed plants with no FB (WS–B); water stressed plants with FB (WS+B); watered plants without FB (W–B), and watered plants with FB (W+B). The treatment W–B was used as a control. Comparing with WS–B plants, B concentration was the highest in leaves and seed of W+B plants (84% increase in leaves and 73% in seed). Seeds of W+B plants had higher protein (11% increase), oleic acid (27% increase), sucrose (up to 40% increase), glucose, and fructose comparing with W–B. However, seed stachyose concentrations increased by 43% in WS–B plants seed compared with W–B plants. Cell wall (structural) B concentration in leaves was higher in all plants under water stress, especially in WS–B plants where the percentage of cell wall B reached up to 90%. Water stress changed seed δ15N and δ13C values in both B applied and non-B applied plants, indicating possible effects on nitrogen and carbon metabolism. This research demonstrated that FB increased B accumulation in leaves and seed, and altered seed composition of well-watered and water stressed plants, indicating a possible involvement of B in seed protein, and oleic and linolenic fatty acids. Further research is needed to explain mechanisms of B involvement in seed protein and fatty acids. PMID:23888163

Dynamic Modeling and Plantwide Control of a Hybrid Power and Chemical Plant: An Integrated Gasification Combined Cycle Coupled with a Methanol Plant

Science.gov (United States)

Robinson, Patrick J.

simulators Aspen Plus and Aspen Dynamics. This dissertation first presents a simple approximate method for achieving the objective of having a gasifier model that can be exported into Aspen Dynamics. Limitations in the software dealing with solids make this a necessary task. The basic idea is to use a high molecular weight hydrocarbon that is present in the Aspen library as a pseudo fuel. For many plantwide dynamic studies, a rigorous high-fidelity dynamic model of the gasifier is not needed because its dynamics are very fast and the gasifier gas volume is a relatively small fraction of the total volume of the entire plant. The proposed approximate model captures the essential macro-scale thermal, flow, composition and pressure dynamics. This paper does not attempt to optimize the design or control of gasifiers, but merely presents an idea of how to dynamically simulate coal gasification in an approximate way. This dissertation also presents models of the downstream units of a typical IGCC. Dynamic simulations of the H2S absorption/stripping unit, Water-gas Shift (WGS) reactors, and CO2 absorption/stripping unit are essential for the development of stable and agile plantwide control structures of this hybrid power/chemical plant. Due to the high pressure of the system, hydrogen sulfide is removed by means of physical absorption. SELEXOLRTM (a mixture of the dimethyl ethers of polyethylene glycol) is used to achieve a gas purity of less than 5 ppm H2S. This desulfurized synthesis gas is sent to two water gas shift reactors that convert a total of 99% of carbon monoxide to hydrogen. Physical absorption of carbon dioxide with Selexol produces a hydrogen rich stream (90 mol% H2) to be fed into combustion turbines or to a methanol plant. Steady-state economic designs and plantwide control structures are developed in this dissertation. A steady-state economic design, control structure, and successful turndown of the methanol plant are shown in this dissertation. The Plantwide

Redox Control of Aphid Resistance through Altered Cell Wall Composition and Nutritional Quality.

Science.gov (United States)

Rasool, Brwa; McGowan, Jack; Pastok, Daria; Marcus, Sue E; Morris, Jenny A; Verrall, Susan R; Hedley, Peter E; Hancock, Robert D; Foyer, Christine H

2017-09-01

The mechanisms underpinning plant perception of phloem-feeding insects, particularly aphids, remain poorly characterized. Therefore, the role of apoplastic redox state in controlling aphid infestation was explored using transgenic tobacco ( Nicotiana tabacum ) plants that have either high (PAO) or low (TAO) ascorbate oxidase (AO) activities relative to the wild type. Only a small number of leaf transcripts and metabolites were changed in response to genotype, and cell wall composition was largely unaffected. Aphid fecundity was decreased significantly in TAO plants compared with other lines. Leaf sugar levels were increased and maximum extractable AO activities were decreased in response to aphids in all genotypes. Transcripts encoding the Respiratory Burst Oxidase Homolog F, signaling components involved in ethylene and other hormone-mediated pathways, photosynthetic electron transport components, sugar, amino acid, and cell wall metabolism, were increased significantly in the TAO plants in response to aphid perception relative to other lines. The levels of galactosylated xyloglucan were decreased significantly in response to aphid feeding in all the lines, the effect being the least in the TAO plants. Similarly, all lines exhibited increases in tightly bound (1→4)-β-galactan. Taken together, these findings identify AO-dependent mechanisms that limit aphid infestation. © 2017 American Society of Plant Biologists. All Rights Reserved.

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

Agrobacterium rhizogenes - based transformation of soybean roots to form composite plants

Science.gov (United States)

Composite plants are a powerful tool to rapidly analyze the effects of gene overexpression, gene silencing, and examine test promoter expression in transgenic roots. No sterile tissue culture is needed. This avoids loss of valuable material due to contamination of sterile cultures. This method uses ...

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

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

Induction of stress volatiles and changes in essential oil content and composition upon microwave exposure in the aromatic plant Ocimum basilicum

Energy Technology Data Exchange (ETDEWEB)

Lung, Ildikó [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Soran, Maria-Loredana, E-mail: loredana.soran@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Opriş, Ocsana; Truşcă, Mihail Radu Cătălin [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Niinemets, Ülo [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 1 Kreutzwaldi Street, Tartu 51014 (Estonia); Copolovici, Lucian [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 1 Kreutzwaldi Street, Tartu 51014 (Estonia); Institute of Technical and Natural Sciences Research-Development of “Aurel Vlaicu” University, 2 Elena Drăgoi Street, Arad 310330 (Romania)

2016-11-01

Exposure to sustained low intensity microwaves can constitute a stress for the plants, but its effects on plant secondary chemistry are poorly known. We studied the influence of GSM and WLAN-frequency microwaves on emissions of volatile organic compounds and content of essential oil in the aromatic plant Ocimum basilicum L. hypothesizing that microwave exposure leads to enhanced emissions of stress volatiles and overall greater investment in secondary compounds. Compared to the control plants, microwave irradiation led to decreased emissions of β-pinene, α-phellandrene, bornyl acetate, β-myrcene, α-caryophyllene and benzaldehyde, but increased emissions of eucalyptol, estragole, caryophyllene oxide, and α-bergamotene. The highest increase in emission, 21 times greater compared to control, was observed for caryophyllene oxide. The irradiation resulted in increases in the essential oil content, except for the content of phytol which decreased by 41% in the case of GSM-frequency, and 82% in the case of WLAN-frequency microwave irradiation. The strongest increase in response to WLAN irradiation, > 17 times greater, was observed for hexadecane and octane contents. Comparisons of volatile compositions by multivariate analyses demonstrated a clear separation of different irradiance treatments, and according to the changes in the volatile emissions, the WLAN-frequency irradiation represented a more severe stress than the GSM-frequency irradiation. Overall, these results demonstrating important modifications in the emission rates, essential oil content and composition indicate that microwave irradiation influences the quality of herbage of this economically important spice plant. - Highlights: • Microwave irradiation represents a stress for the plants. • Microwave exposure leads to enhanced emissions of stress volatiles. • O. basilicum irradiation with microwaves increases the essential oil content. • Microwave pollution can constitute a threat to the

Induction of stress volatiles and changes in essential oil content and composition upon microwave exposure in the aromatic plant Ocimum basilicum

International Nuclear Information System (INIS)

Lung, Ildikó; Soran, Maria-Loredana; Opriş, Ocsana; Truşcă, Mihail Radu Cătălin; Niinemets, Ülo; Copolovici, Lucian

2016-01-01

Exposure to sustained low intensity microwaves can constitute a stress for the plants, but its effects on plant secondary chemistry are poorly known. We studied the influence of GSM and WLAN-frequency microwaves on emissions of volatile organic compounds and content of essential oil in the aromatic plant Ocimum basilicum L. hypothesizing that microwave exposure leads to enhanced emissions of stress volatiles and overall greater investment in secondary compounds. Compared to the control plants, microwave irradiation led to decreased emissions of β-pinene, α-phellandrene, bornyl acetate, β-myrcene, α-caryophyllene and benzaldehyde, but increased emissions of eucalyptol, estragole, caryophyllene oxide, and α-bergamotene. The highest increase in emission, 21 times greater compared to control, was observed for caryophyllene oxide. The irradiation resulted in increases in the essential oil content, except for the content of phytol which decreased by 41% in the case of GSM-frequency, and 82% in the case of WLAN-frequency microwave irradiation. The strongest increase in response to WLAN irradiation, > 17 times greater, was observed for hexadecane and octane contents. Comparisons of volatile compositions by multivariate analyses demonstrated a clear separation of different irradiance treatments, and according to the changes in the volatile emissions, the WLAN-frequency irradiation represented a more severe stress than the GSM-frequency irradiation. Overall, these results demonstrating important modifications in the emission rates, essential oil content and composition indicate that microwave irradiation influences the quality of herbage of this economically important spice plant. - Highlights: • Microwave irradiation represents a stress for the plants. • Microwave exposure leads to enhanced emissions of stress volatiles. • O. basilicum irradiation with microwaves increases the essential oil content. • Microwave pollution can constitute a threat to the

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...

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.

Responses of plant community composition and biomass production to warming and nitrogen deposition in a temperate meadow ecosystem.

Science.gov (United States)

Zhang, Tao; Guo, Rui; Gao, Song; Guo, Jixun; Sun, Wei

2015-01-01

Climate change has profound influences on plant community composition and ecosystem functions. However, its effects on plant community composition and biomass production are not well understood. A four-year field experiment was conducted to examine the effects of warming, nitrogen (N) addition, and their interactions on plant community composition and biomass production in a temperate meadow ecosystem in northeast China. Experimental warming had no significant effect on plant species richness, evenness, and diversity, while N addition highly reduced the species richness and diversity. Warming tended to reduce the importance value of graminoid species but increased the value of forbs, while N addition had the opposite effect. Warming tended to increase the belowground biomass, but had an opposite tendency to decrease the aboveground biomass. The influences of warming on aboveground production were dependent upon precipitation. Experimental warming had little effect on aboveground biomass in the years with higher precipitation, but significantly suppressed aboveground biomass in dry years. Our results suggest that warming had indirect effects on plant production via its effect on the water availability. Nitrogen addition significantly increased above- and below-ground production, suggesting that N is one of the most important limiting factors determining plant productivity in the studied meadow steppe. Significant interactive effects of warming plus N addition on belowground biomass were also detected. Our observations revealed that environmental changes (warming and N deposition) play significant roles in regulating plant community composition and biomass production in temperate meadow steppe ecosystem in northeast China.

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.

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...

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.

Biomimetic photo-actuation: sensing, control and actuation in sun-tracking plants

International Nuclear Information System (INIS)

Dicker, M P M; Bond, I P; Weaver, P M; Rossiter, J M

2014-01-01

Although the actuation mechanisms that drive plant movement have been investigated from a biomimetic perspective, few studies have looked at the wider sensing and control systems that regulate this motion. This paper examines photo-actuation—actuation induced by, and controlled with light—through a review of the sun-tracking functions of the Cornish Mallow. The sun-tracking movement of the Cornish Mallow leaf results from an extraordinarily complex—yet extremely elegant—process of signal perception, generation, filtering and control. Inspired by this process, a concept for a simplified biomimetic analogue of this leaf is proposed: a multifunctional structure employing chemical sensing, signal transmission, and control of composite hydrogel actuators. We present this multifunctional structure, and show that the success of the concept will require improved selection of materials and structural design. This device has application in the solar-tracking of photovoltaic panels for increased energy yield. More broadly it is envisaged that the concept of chemical sensing and control can be expanded beyond photo-actuation to many other stimuli, resulting in new classes of robust solid-state devices. (paper)

Intensifying drying process with creation of functional plant compositions

Directory of Open Access Journals (Sweden)

Zh. Petrova

2015-05-01

Full Text Available Introduction. The process of drying agricultural raw products is associated with loss of bioactive substances by the products exposed to heat, light, oxygen, or рН medium. It is reasonable to enhance the table beet processing technology in order to achieve maximum betanin conservation at lower energy consumption. Materials and methods. Table beets, rhubarbs, lemons, and tomatoes were dried at temperature of 50 to 100 ºС, air speed of 1.5 to 3.5 m/s, heat carrier water content of 7 to 15 g/kg, and layer thickness of 2 to 20 mm. The betanіn content was determined via absorption spectra, using the optical density value at 540 nm wavelength. A differential microcalorimeter was used for measuring evaporation heat consumption. Results and discussion.The effect of raw product pre-drying preparation was studied. With no preliminary preparation, the loss of betanin after drying reaches 66 %. The preliminary preparation technology we have developed includes boiling whole root crops with optimal selection of acid medium and allows us to reduce the betanin loss down to 6 %. Regretfully, the process requires large energy consumption. Low energy consumption pre-drying preparation method was developed for antioxidant raw products with thermal processing replaced by blending. The betanin loss, in this case, does not exceed 5 %. Optimal drying temperature of betanin-containing raw stock, after its preliminary processing, is 60 °С. It allows to keep up to 95 % of betanіn. Specific heat consumption for water evaporation out of the developed table beet based antioxidant plant compositions, with addition of rhubarb and lemon, is less by 4 to 5 % as compared to the initial components. Conclusions. Dependence of betanin loss in plant raw stock on the material temperature and composition components, in the course of their pre-drying preparation, was found. It was also found that water evaporation heat, for some antioxidant plant compositions developed, is less

The Effects of Disturbance History on Ground-Layer Plant Community Composition in British Columbia

Directory of Open Access Journals (Sweden)

Michael Ton

2016-05-01

Full Text Available Plant communities are sensitive to perturbations and may display alternative recovery pathways depending on disturbance history. In sub-boreal lodgepole pine forests of central interior British Columbia, Canada, fire and logging are two widespread landscape disturbances that overlap in many regions. We asked whether cumulative, short-interval disturbance from logging and fire resulted in different ground-layer plant communities than resulted from fire alone. Using field-collected data, we compared the taxonomic composition and functional traits of 3-year old plant communities that were either harvested 6-to-13 years prior, or not harvested prior to being burned in a large stand-replacing fire. The taxonomic composition diverged between the two treatments, driven primarily by differences in a few key indicator species such as Petasites frigidus and Vaccinium membranaceum. Analysis of individual species’ morphological traits indicated that only a few species vary in size in relation to disturbance history. Our data suggest that a history of forest harvest leaves a subtle footprint on post-fire ground-layer plant communities at early stages of succession.

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

Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

Directory of Open Access Journals (Sweden)

Maik Hadorn

Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.

Science.gov (United States)

Hao, Yi; Ma, Chuanxin; Zhang, Zetian; Song, Youhong; Cao, Weidong; Guo, Jing; Zhou, Guopeng; Rui, Yukui; Liu, Liming; Xing, Baoshan

2018-01-01

The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C 60 ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C 60 , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of a control and data acquisition system for radiation protection monitors of spent fuel reprocessing plant

International Nuclear Information System (INIS)

Liu Boxue

1997-01-01

For the radiation protection monitoring of spent nuclear fuel reprocessing plant, the paper analyzes the composition and requirements of a control and data acquisition system. With the concepts of typical distributing and opening models, the hardware consists of IPC, communication of RS-485 bus lines and data multiplexer. The software consists of real-time multi-services operation system and modelling program. It can sample monitoring data, control monitor's operation, and process data and other information. It has good expansive and compatible features

Hydraulic concrete composition and properties control system

OpenAIRE

PSHINKO O.M.; KRASNYUK A.V.; HROMOVA O.V.

2015-01-01

Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings) based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canon...

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

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

Conservation law of plants' energy value dependence of plants ...

African Journals Online (AJOL)

The plants differences in biochemical composition are analyzed, and the conservation law of energy value in plants is obtained. The link between the need for the nutrients and the plants biochemical composition is examined, Liebig's law is specified. Keywords: plant's biochemical composition, biochemistry, energy value in ...

Intraspecific variation in essential oil composition of the medicinal plant Lippia integrifolia (Verbenaceae). Evidence for five chemotypes.

Science.gov (United States)

Marcial, Guillermo; de Lampasona, Marina P; Vega, Marta I; Lizarraga, Emilio; Viturro, Carmen I; Slanis, Alberto; Juárez, Miguel A; Elechosa, Miguel A; Catalán, César A N

2016-02-01

The aerial parts of Lippia integrifolia (incayuyo) are widely used in northwestern and central Argentina for their medicinal and aromatic properties. The essential oil composition of thirty-one wild populations of L. integrifolia covering most of its natural range was analyzed by GC and GC-MS. A total of one hundred and fifty two terpenoids were identified in the essential oils. Sesquiterpenoids were the dominant components in all but one of the collections analyzed, the only exception being a sample collected in San Juan province where monoterpenoids amounted to 51%. Five clearly defined chemotypes were observed. One possessed an exquisite and delicate sweet aroma with trans-davanone as dominant component (usually above 80%). Another with an exotic floral odour was rich in oxygenated sesquiterpenoids based on the rare lippifoliane and africanane skeletons. The trans-davanone chemotype is the first report of an essential oil containing that sesquiterpene ketone as the main constituent. The absolute configuration of trans-davanone from L. integrifolia was established as 6S, 7S, 10S, the enantiomer of trans-davanone from 'davana oil' (Artemisia pallens). Wild plants belonging to trans-davanone and lippifolienone chemotypes were propagated and cultivated in the same parcel of land in Santa Maria, Catamarca. The essential oil compositions of the cultivated plants were essentially identical to the original plants in the wild, indicating that the essential oil composition is largely under genetic control. Specimens collected near the Bolivian border that initially were identified as L. boliviana Rusby yielded an essential oil practically identical to the trans-davanone chemotype of L. integrifolia supporting the recent view that L. integrifolia (Gris.) Hieron. and L. boliviana Rusby are synonymous. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of Clonostachys rosea for Control of Plant-Parasitic Nematodes in Soil and in Roots of Carrot and Wheat.

Science.gov (United States)

Iqbal, Mudassir; Dubey, Mukesh; McEwan, Kerstin; Menzel, Uwe; Franko, Mikael Andersson; Viketoft, Maria; Jensen, Dan Funck; Karlsson, Magnus

2018-01-01

Biological control is a promising approach to reduce plant diseases caused by nematodes. We tested the effect of the fungus Clonostachys rosea strain IK726 inoculation on nematode community composition in a naturally nematode infested soil in a pot experiment, and the effect of C. rosea on plant health. The numbers of plant-parasitic nematode genera extracted from soil and plant roots decreased by 40 to 73% when C. rosea was applied, while genera of nonparasitic nematodes were not affected. Soil inoculation of C. rosea increased fresh shoot weight and shoot length of wheat plants by 20 and 24%, respectively, while only shoot dry weight increased by 48% in carrots. Light microscopy of in vitro C. rosea-nematode interactions did not reveal evidence of direct parasitism. However, culture filtrates of C. rosea growing in potato dextrose broth, malt extract broth and synthetic nutrient broth exhibited toxicity toward nematodes and immobilized 57, 62, and 100% of the nematodes, respectively, within 48 h. This study demonstrates that C. rosea can control plant-parasitic nematodes and thereby improve plant growth. The most likely mechanism responsible for the antagonism is antibiosis through production of nematicidal compounds, rather than direct parasitism.

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.

Integrated control centre concepts for CANDU power plants

International Nuclear Information System (INIS)

Lupton, L.R.; Davey, E.C.; Lapointe, P.A.; Shah, R.R.

1990-01-01

The size and complexity of nuclear power plants has increased significantly in the last 20 years. There is general agreement that plant safety and power production can be enhanced if more operational support systems that are significantly different from the ones based on the more conventional technologies used in plant control rooms. In particular, artificial intelligence and related technologies will play a major role in the development of innovative methods for information processing and presentation. These technologies must be integrated into the overall management and control philosophy of the plant and not be treated as vehicles to implement point solutions. The underlying philosophy behind our approach is discussed in this paper. Operator support systems will integrate into the overall control philosophy by complementing the operator. Four support systems are described; each is a prototype of a system being considered for the CANDU 3 control centre

Integrated control centre concepts for CANDU power plants

Energy Technology Data Exchange (ETDEWEB)

Lupton, L. R.; Davey, E. C.; Lapointe, P. A.; Shah, R. R.

1990-01-15

The size and complexity of nuclear power plants has increased significantly in the last 20 years. There is general agreement that plant safety and power production can be enhanced if more operational support systems that are significantly different from the ones based on the more conventional technologies used in plant control rooms. In particular, artificial intelligence and related technologies will play a major role in the development of innovative methods for information processing and presentation. These technologies must be integrated into the overall management and control philosophy of the plant and not be treated as vehicles to implement point solutions. The underlying philosophy behind our approach is discussed in this paper. Operator support systems will integrate into the overall control philosophy by complementing the operator. Four support systems are described; each is a prototype of a system being considered for the CANDU 3 control centre.

On the genetic control of planar growth during tissue morphogenesis in plants.

Science.gov (United States)

Enugutti, Balaji; Kirchhelle, Charlotte; Schneitz, Kay

2013-06-01

Tissue morphogenesis requires extensive intercellular communication. Plant organs are composites of distinct radial cell layers. A typical layer, such as the epidermis, is propagated by stereotypic anticlinal cell divisions. It is presently unclear what mechanisms coordinate cell divisions relative to the plane of a layer, resulting in planar growth and maintenance of the layer structure. Failure in the regulation of coordinated growth across a tissue may result in spatially restricted abnormal growth and the formation of a tumor-like protrusion. Therefore, one way to approach planar growth control is to look for genetic mutants that exhibit localized tumor-like outgrowths. Interestingly, plants appear to have evolved quite robust genetic mechanisms that govern these aspects of tissue morphogenesis. Here we provide a short summary of the current knowledge about the genetics of tumor formation in plants and relate it to the known control of coordinated cell behavior within a tissue layer. We further portray the integuments of Arabidopsis thaliana as an excellent model system to study the regulation of planar growth. The value of examining this process in integuments was established by the recent identification of the Arabidopsis AGC VIII kinase UNICORN as a novel growth suppressor involved in the regulation of planar growth and the inhibition of localized ectopic growth in integuments and other floral organs. An emerging insight is that misregulation of central determinants of adaxial-abaxial tissue polarity can lead to the formation of spatially restricted multicellular outgrowths in several tissues. Thus, there may exist a link between the mechanisms regulating adaxial-abaxial tissue polarity and planar growth in plants.

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

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.

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

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

Factors controlling peat chemistry and vegetation composition in Sudbury peatlands after 30 years of pollution emission reductions

International Nuclear Information System (INIS)

Barrett, Sophie E.; Watmough, Shaun A.

2015-01-01

The objective of this research was to assess factors controlling peat and plant chemistry, and vegetation composition in 18 peatlands surrounding Sudbury after more than 30 years of large (>95%) pollution emission reductions. Sites closer to the main Copper Cliff smelter had more humified peat and the surface horizons were greatly enriched in copper (Cu) and nickel (Ni). Copper and Ni concentrations in peat were significantly correlated with that in the plant tissue of Chamaedaphne calyculata. The pH of peat was the strongest determining factor for species richness, diversity, and community composition, although percent vascular plant cover was strongly negatively correlated with surface Cu and Ni concentrations in peat. Sphagnum frequency was also negatively related to peat Cu and Ni concentrations indicating sites close to Copper Cliff smelter remain adversely impacted by industrial activities. - Highlights: • Surface peat in wetlands in Sudbury is contaminated with Cu and Ni. • The pH of peat is positively related to species richness and diversity. • Metal levels in peat is negatively related to vascular vegetation and Sphagnum cover. • Loss of Sphagnum at contaminated peatlands may impede recovery. - Sudbury peatlands remain impacted by industrial activities as indicated by elevated copper and nickel concentrations and diminished vascular plant cover and Sphagnum frequency.

The role of supplemental ultraviolet-B radiation in altering the metabolite profile, essential oil content and composition, and free radical scavenging activities of Coleus forskohlii, an indigenous medicinal plant.

Science.gov (United States)

Takshak, Swabha; Agrawal, S B

2016-04-01

The effects of supplemental ultraviolet-B (s-UV-B; 3.6 kJ m(-2) day(-1) above ambient) radiation were investigated on plant metabolite profile, essential oil content and composition, and free radical scavenging capacities of methanolic extracts of Coleus forskohlii (an indigenous medicinal plant) grown under field conditions. Essential oil was isolated using hydrodistillation technique while alterations in metabolite profile and oil composition were determined via gas chromatography-mass spectroscopy (GC-MS). Leaf and root methanolic extracts were investigated via various in vitro assays for their DPPH radical-, superoxide radical-, hydrogen peroxide-, hydroxyl radical-, and nitric oxide radical scavenging activities, ferrous ion chelating activity, and reducing power. Phytochemical analysis revealed the presence of alkaloids, anthocyanins, coumarins, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids. Oil content was found to be reduced (by ∼7 %) in supplemental UV-B (s-UV-B) treated plants; the composition of the plant extracts as well as essential oil was also considerably altered. Methanolic extracts from treated plant organs showed more potency as free radical scavengers (their EC50 values being lower than their respective controls). Anomalies were observed in Fe(2+) chelating activity for both leaves and roots. The present study concludes that s-UV-B adversely affects oil content in C. forskohlii and also alters the composition and contents of metabolites in both plant extracts and oil. The results also denote that s-UV-B treated plant organs might be more effective in safeguarding against oxidative stress, though further studies are required to authenticate these findings.

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)

Internal and external factors affecting photosynthetic pigment composition in plants: a meta-analytical approach.

Science.gov (United States)

Esteban, Raquel; Barrutia, Oihana; Artetxe, Unai; Fernández-Marín, Beatriz; Hernández, Antonio; García-Plazaola, José Ignacio

2015-04-01

Photosynthetic pigment composition has been a major study target in plant ecophysiology during the last three decades. Although more than 2000 papers have been published, a comprehensive evaluation of the responses of photosynthetic pigment composition to environmental conditions is not yet available. After an extensive survey, we compiled data from 525 papers including 809 species (subkingdom Viridiplantae) in which pigment composition was described. A meta-analysis was then conducted to assess the ranges of photosynthetic pigment content. Calculated frequency distributions of pigments were compared with those expected from the theoretical pigment composition. Responses to environmental factors were also analysed. The results revealed that lutein and xanthophyll cycle pigments (VAZ) were highly responsive to the environment, emphasizing the high phenotypic plasticity of VAZ, whereas neoxanthin was very stable. The present meta-analysis supports the existence of relatively narrow limits for pigment ratios and also supports the presence of a pool of free 'unbound' VAZ. Results from this study provide highly reliable ranges of photosynthetic pigment contents as a framework for future research on plant pigments. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

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

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 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.

Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants

Science.gov (United States)

Pringle, Elizabeth G; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L

2014-01-01

In plant–ant–hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field. PMID:25505534

Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

Science.gov (United States)

Li, Yongfu; Chen, Na; Harmon, Mark E.; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A.; Mao, Jingdong

2015-10-01

A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species.

Influence of plant root morphology and tissue composition on phenanthrene uptake: Stepwise multiple linear regression analysis

International Nuclear Information System (INIS)

Zhan, Xinhua; Liang, Xiao; Xu, Guohua; Zhou, Lixiang

2013-01-01

Polycyclic aromatic hydrocarbons (PAHs) are contaminants that reside mainly in surface soils. Dietary intake of plant-based foods can make a major contribution to total PAH exposure. Little information is available on the relationship between root morphology and plant uptake of PAHs. An understanding of plant root morphologic and compositional factors that affect root uptake of contaminants is important and can inform both agricultural (chemical contamination of crops) and engineering (phytoremediation) applications. Five crop plant species are grown hydroponically in solutions containing the PAH phenanthrene. Measurements are taken for 1) phenanthrene uptake, 2) root morphology – specific surface area, volume, surface area, tip number and total root length and 3) root tissue composition – water, lipid, protein and carbohydrate content. These factors are compared through Pearson's correlation and multiple linear regression analysis. The major factors which promote phenanthrene uptake are specific surface area and lipid content. -- Highlights: •There is no correlation between phenanthrene uptake and total root length, and water. •Specific surface area and lipid are the most crucial factors for phenanthrene uptake. •The contribution of specific surface area is greater than that of lipid. -- The contribution of specific surface area is greater than that of lipid in the two most important root morphological and compositional factors affecting phenanthrene uptake

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

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.

Using physical properties of molten glass to estimate glass composition

International Nuclear Information System (INIS)

Choi, Kwan Sik; Yang, Kyoung Hwa; Park, Jong Kil

1997-01-01

A vitrification process is under development in KEPRI for the treatment of low-and medium-level radioactive waste. Although the project is for developing and building Vitrification Pilot Plant in Korea, one of KEPRI's concerns is the quality control of the vitrified glass. This paper discusses a methodology for the estimation of glass composition by on-line measurement of molten glass properties, which could be applied to the plant for real-time quality control of the glass product. By remotely measuring viscosity and density of the molten glass, the glass characteristics such as composition can be estimated and eventually controlled. For this purpose, using the database of glass composition vs. physical properties in isothermal three-component system of SiO 2 -Na 2 O-B 2 O 3 , a software TERNARY has been developed which determines the glass composition by using two known physical properties (e.g. density and viscosity)

Fracture mechanisms and fracture control in composite structures

Science.gov (United States)

Kim, Wone-Chul

Four basic failure modes--delamination, delamination buckling of composite sandwich panels, first-ply failure in cross-ply laminates, and compression failure--are analyzed using linear elastic fracture mechanics (LEFM) and the J-integral method. Structural failures, including those at the micromechanical level, are investigated with the aid of the models developed, and the critical strains for crack propagation for each mode are obtained. In the structural fracture analyses area, the fracture control schemes for delamination in a composite rib stiffener and delamination buckling in composite sandwich panels subjected to in-plane compression are determined. The critical fracture strains were predicted with the aid of LEFM for delamination and the J-integral method for delamination buckling. The use of toughened matrix systems has been recommended for improved damage tolerant design for delamination crack propagation. An experimental study was conducted to determine the onset of delamination buckling in composite sandwich panel containing flaws. The critical fracture loads computed using the proposed theoretical model and a numerical computational scheme closely followed the experimental measurements made on sandwich panel specimens of graphite/epoxy faceskins and aluminum honeycomb core with varying faceskin thicknesses and core sizes. Micromechanical models of fracture in composites are explored to predict transverse cracking of cross-ply laminates and compression fracture of unidirectional composites. A modified shear lag model which takes into account the important role of interlaminar shear zones between the 0 degree and 90 degree piles in cross-ply laminate is proposed and criteria for transverse cracking have been developed. For compressive failure of unidirectional composites, pre-existing defects play an important role. Using anisotropic elasticity, the stress state around a defect under a remotely applied compressive load is obtained. The experimentally

Pyridine-type alkaloid composition affects bacterial community composition of floral nectar.

Science.gov (United States)

Aizenberg-Gershtein, Yana; Izhaki, Ido; Santhanam, Rakesh; Kumar, Pavan; Baldwin, Ian T; Halpern, Malka

2015-06-30

Pyridine-type alkaloids are most common in Nicotiana species. To study the effect of alkaloid composition on bacterial community composition in floral nectar, we compared the nicotine-rich wild type (WT) N. attenuata, the nicotine biosynthesis-silenced N. attenuata that was rich in anatabine and the anabasine-rich WT N. glauca plants. We found that the composition of these secondary metabolites in the floral nectar drastically affected the bacterial community richness, diversity and composition. Significant differences were found between the bacterial community compositions in the nectar of the three plants with a much greater species richness and diversity in the nectar from the transgenic plant. The highest community composition similarity index was detected between the two wild type plants. The different microbiome composition and diversity, caused by the different pyridine-type alkaloid composition, could modify the nutritional content of the nectar and consequently, may contribute to the change in the nectar consumption and visitation. These may indirectly have an effect on plant fitness.

Chemical composition of anthropogenic particles on needles collected close to the Estonian oil-shale power plants

International Nuclear Information System (INIS)

Meinander, O.

1995-01-01

Within the countries surrounding the Baltic Sea, north-eastern Estonia is among the most polluted areas. Emissions from the oil-shale power plants produce air pollution problems both locally and on a larger scale. In the atmosphere, pollutants mix and convert. Consequently, the particles deposited due to the use of oil-shale can have various chemical compositions. From the point of view of air chemistry, ecological effects and air pollution modelling, knowledge of the chemical composition of the deposited particles can be of great value. The aim of this work was to study the chemical composition of single anthropogenic particles occurring on needle surfaces in north-eastern Estonia and Southern Finland close to the Estonian oil-shale power plants. For the purpose, scanning electron microscopical microanalysis was used

Instrumentation and process control for fossil demonstration plants. Quarterly technical progress report, April--June 1977

Energy Technology Data Exchange (ETDEWEB)

LeSage, L.G.

1977-07-01

Work has been performed on updating the study of the state-of-the-art of instrumentation for Fossil Demonstration Plants (FDP), development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. A Solids/Gas Flow Test Facility (S/GFTF) under construction for instrument development, testing, evaluation, and calibration is described. The development work for several mass-flow and other on-line instruments is described: acoustic flowmeter, capacitive density flowmeter, neutron activation flowmeter and composition analysis system, gamma ray correlation flowmeter, optical flowmeter, and capacitive liquid interface level meter.

Plutonium Finishing Plant (PFP) Waste Composition and High Efficiency Particulate Air Filter Loading

Energy Technology Data Exchange (ETDEWEB)

ZIMMERMAN, B.D.

2000-12-11

This analysis evaluates the effect of the Plutonium Finishing Plant (PFP) waste isotopic composition on Tank Farms Final Safety Analysis Report (FSAR) accidents involving high-efficiency particulate air (HEPA) filter failure in Double-Contained Receiver Tanks (DCRTs). The HEPA Filter Failure--Exposure to High Temperature or Pressure, and Steam Intrusion From Interfacing Systems accidents are considered. The analysis concludes that dose consequences based on the PFP waste isotopic composition are bounded by previous FSAR analyses. This supports USQD TF-00-0768.

Changes in growth, physiological parameters and the hormonal status of Myrtus communis L. plants irrigated with water with different chemical compositions.

Science.gov (United States)

Acosta-Motos, José Ramón; Ortuño, María Fernanda; Álvarez, Sara; López-Climent, María Fernanda; Gómez-Cadenas, Aurelio; Sánchez-Blanco, María Jesús

2016-02-01

Myrtus communis, an important Mediterranean ornamental shrub, was used to study the effect of irrigation water with different chemical compositions in the plant response. A treatment with NaCl was used to establish the plant resistance to high salinity at long term. Plants were subjected to four irrigation treatments with drainage for three months: Control (0.8 dS m(-1)); two treatments using reclaimed water (RWs): RW1 (2.0 dS m(-1)) and RW2 (5.0 dS m(-1)); and NaCl (10.0 dS m(-1)). High levels of electric conductivity of RWs not affected plant growth, while NaCl decreased leaf dry weight. Coinciding with the accumulation of Na(+) and Cl(-) in the roots, soil water potential decreased, which hinders the mobilization of water to the leaves, decreasing leaf water potential. The osmotic adjustment in the NaCl treatment was due to Na(+) and Cl(-) ions, although the proline could contribute as an Osmo compatible solute, increasing the turgor plants. Also changes in cell walls rigidity minimize the negative effects on the water balance; however, a higher lipid peroxidation was observed in these plants. Stomatal closure was associated with a decrease in K(+) and an increase in abscisic acid. NaCl produced an increase in salicylic acid and did not affect jasmonic acid contents at the end of the experiment. Similar behavior in soil and leaf water potentials, although less pronounced than in NaCl, was shown in RW2 plants. The abscisic acid increased in the RW2 with respect to the control and a decrease in stomatal conductance was observed at the end of the experiment. Plants irrigated with RW1 behaved similarly to the control. Copyright © 2015. Published by Elsevier GmbH.

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

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.

Composition of plants and sediments in the Yssyk-Kyl region

International Nuclear Information System (INIS)

Tynybekov, A.K.; Otte, M.L.

2003-01-01

Full text: Wetlands are perhaps the only type of habitat can be found in every climate zone, over a wide range of altitudes, and on every continent around the world. As a group they comprise a highly variable type of habitat, but all have in common the presence of water at or near the substrate surface during at least part of the year determining the type of soil (hydric soils) and vegetation (halophytes). They are most often found as transition habitats (ecotones) between truly aquatic ecosystems (with permanently submerged substrates, such as lakes and seas) and dry land ecosystems. Where wetlands are located such that water passes through undirectionally, for example when fringing rivers, sediments and solutes may be retained through biological, biogeochemical and physical processes. As a result wetlands act as filters and water quality usually improves after passage through them. While substances are removed from the water, they accumulate in the substrates and biota. The chemical composition of substrates and plants of estuarine and reverin wetlands thus reflects the integrated quality over time of the watershed from which the river drains. By analyzing the substrates and vegetation of such wetlands, an impression of the quality and composition of the whole Watershed can be formed. This was the concept underlying the research Project presented here. This research was part of a multi-disciplinary project Ecology of Water Bodies and the State of Health of the Population in the Region of the South-Eastern Part of Yssyk-Kul Lake. Its main aim was to investigate the relationship between human and environmental health along the southern shore of Lake Yssyk-Kul. Sediments and plants of reverin wetlands of several watersheds feeding into Yssyk-Kul Lake were collected during the summer of 1999 and analyzed for 30+ elements. Based on correlations, two distinct groups of elements were identified, probably related to differences in geology of the areas sampled. Plant

Size, age and composition: characteristics of plant taxa as diversity predictors of gall-midges (Diptera: Cecidomyiidae

Directory of Open Access Journals (Sweden)

Walter S Araújo

2011-12-01

Full Text Available Many hypotheses have been proposed to explain the diversity of gall-midge insects (Diptera: Cecidomyiidae, some of them taking into account plant diversity. This study aims to test the importance of size, age and composition of host plant taxa in the diversity of Cecidomyiidae. For this we used inventories data on the diversity of galling and host plants in Brazil. We found that Asterales, Myrtales and Malpighiales, were the most important orders, with 34, 33 and 25, gall morphotypes, respectively. The most representative host families were Asteraceae (34 morphotypes, Myrtaceae (23 and Fabaceae (22. In general, the order size and the plant family were good predictors of the galling diversity, but not the taxon age. The most diverse host genera for gall-midges were Mikania, Eugenia and Styrax, with 15, 13 and nine galler species, respectively. The size of plant genera showed no significant relationship with the richness of Cecidomyiidae, contrary to the prediction of the plant taxon size hypothesis. The plant genera with the greatest diversity of galling insects are not necessarily those with the greatest number of species. These results indicate that some plant taxa have a high intrinsic richness of galling insects, suggesting that the plant species composition may be equally or more important for the diversity of gall-midges than the size or age of the host taxon. Rev. Biol. Trop. 59 (4: 1599- 1607. Epub 2011 December 01.

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.

Methods and compositions for altering lignin composition in plants

Science.gov (United States)

Srivastava, Avinash C.; Tang, Yuhong; Blancaflor, Elison

2018-03-06

The invention provides methods for decreasing lignin content in plants by reducing expression of a folylpolyglutamate synthetase 1 (FPGS1) coding sequence in the plant. Also provided are methods for reducing lignin content in a plant by down-regulation of FPGS1 expression in the plant. Nucleic acid molecules for modulation of FPGS1 expression and transgenic plants the same are also provided. Plants described herein may be used, for example, as improved biofuel feedstock and as highly digestible forage crops. Methods for processing plant tissue and for producing biofuels by utilizing such plants are also provided.

Steady-state optimization of ore-dressing plants

International Nuclear Information System (INIS)

Niemi, A.J.

1989-01-01

The ore-dressing plant consists of the steps of grinding and flotation. Its optimization is based on steady state simulation of the mass balances with a plant model. The model data are obtained by tracer tests and analysis. An evaluation of performance of the plant has to observe the recovery of the valuable mineral, the throughput of the system and the grade of the concentrate which are outputs of the flotation plant. Simulation with the flotation plant model yields that combination of values of controllable inputs to flotation which corresponds to an optimal operation of the conditioning an flotation system, for a specified feed and its fractional composition. Simulations for other feeds and compositions advise how they should be chosen, for a better overall performance. (author)

The development and use of plant models to assist with both the commissioning and performance optimisation of plant control systems

International Nuclear Information System (INIS)

Conner, A.S.; Region, S.E.

1984-01-01

Successful engagement of cascade control systems used to control complex nuclear plant often present control engineers with difficulties when trying to obtain early automatic operation of these systems. These difficulties often arise because prior to the start of live plant operation, control equipment performance can only be assessed using open loop techniques. By simulating simple models of plant on a computer and linking it to the site control equipment, the performance of the system can be examined and optimised prior to live plant operation. This significantly reduces the plant down time required to correct control equipment performance faults during live plant operation

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

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

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

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.)

How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

Science.gov (United States)

Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W; Schumacher, Jens; Hildebrandt, Anke

2014-01-01

Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

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

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

Treatment of banana and potato plants with a new antifungal composition (European patent specification)

NARCIS (Netherlands)

Stark, J.; Rijn, van F.T.J.; Krieken, van der W.M.; Stevens, L.H.

2010-01-01

International publication number: WO 2009/077613 (25.06.2009 Gazette 2009/26) The present invention relates to the treatment of banana and potato plants with a composition containing natamycin and at least one phosphite containing compound

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.)

EKF composition estimation and GMC control of a reactive distillation column

Science.gov (United States)

Tintavon, Sirivimon; Kittisupakorn, Paisan

2017-08-01

This research work proposes an extended Kalman filter (EKF) estimator to give estimates of product composition and a generic model controller (GMC) to control the temperature of a reactive distillation column (RDC). One of major difficulties to control the RDC is large time delays of product composition measurement. Therefore, the estimates of the product composition are needed and determined based on available and reliable measured tray temperature via the extended Kalman Filter (EKF). With these estimates, the GMC controller is applied to control the RDC's temperature. The performance of the EKF estimator under the GMC control is evaluated in various disturbances and set point change.

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....

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

Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

Science.gov (United States)

Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

2016-01-01

Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions. No claim to US Government works. New Phytologist © 2015 New Phytologist Trust.

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

Plant-wide control of coupled distillation columns with partial condensers

International Nuclear Information System (INIS)

Ebrahimzadeh, Edris; Baxter, Larry L.

2016-01-01

Highlights: • Extractive distillation system for CO_2–ethane azeotrope separation. • Control of distillation column systems that have interconnected partial condenser and total condenser columns. • Single-end temperature control of distillation columns. • Aspen Dynamics tools applied for rigorous steady-state and dynamic simulations. - Abstract: Conventional distillation control processes use vapor distillate flowrate to control column pressure and condenser heat removal to control the reflux drum level. These intuitive control systems work well for isolated columns or columns with total condensers. However, these controls are not effective when columns with partial condensers occur in series. The pressure and reflux drum level interact in such systems in ways that defeat conventional control systems, rendering them unable to maintain product purities in the presence of large feed flowrate and composition disturbances. This investigation documents a plant-wide control structure that can address this issue by controlling pressure through reflux heat removal rate and reflux drum level by reflux flow rate. This control system demonstrates its capability to handle large disturbances in throughput and feed composition through a series of Aspen simulations. This alternative system is no more complicated than the conventional system and should work on distillation columns of nearly all designs, not just the coupled partial condenser designs for which it is essential. Common natural gas processing provides a specific example of this alternative control system. Natural gas commonly includes high concentrations of CO_2 that must be removed prior to pipeline or LNG distribution. The existence of a minimum-boiling temperature azeotrope between ethane, virtually always present in natural gas, and carbon dioxide complicates the separation of CO_2 from the hydrocarbons. This separation commonly employs extractive distillation with high-molecular-weight hydrocarbons. Our

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.

Composition-controlled optical properties of colloidal CdSe quantum dots

Energy Technology Data Exchange (ETDEWEB)

Ayele, Delele Worku [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Department of Chemistry, Bahir Dar University, Bahir Dar (Ethiopia); Su, Wei-Nien, E-mail: wsu@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Chou, Hung-Lung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Pan, Chun-Jern [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Hwang, Bing-Joe, E-mail: bjh@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China)

2014-12-15

Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties.

Composition-controlled optical properties of colloidal CdSe quantum dots

International Nuclear Information System (INIS)

Ayele, Delele Worku; Su, Wei-Nien; Chou, Hung-Lung; Pan, Chun-Jern; Hwang, Bing-Joe

2014-01-01

Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties

Adaptive neuro-fuzzy control of ionic polymer metal composite actuators

International Nuclear Information System (INIS)

Thinh, Nguyen Truong; Yang, Young-Soo; Oh, Il-Kwon

2009-01-01

An adaptive neuro-fuzzy controller was newly designed to overcome the degradation of the actuation performance of ionic polymer metal composite actuators that show highly nonlinear responses such as a straightening-back problem under a step excitation. An adaptive control algorithm with the merits of fuzzy logic and neural networks was applied for controlling the tip displacement of the ionic polymer metal composite actuators. The reference and actual displacements and the change of the error with the electrical inputs were recorded to generate the training data. These data were used for training the adaptive neuro-fuzzy controller to find the membership functions in the fuzzy control algorithm. Software simulation and real-time experiments were conducted by using the Simulink and dSPACE environments. Present results show that the current adaptive neuro-fuzzy controller can be successfully applied to the reliable control of the ionic polymer metal composite actuator for which the performance degrades under long-time actuation

The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant.

Science.gov (United States)

Zhang, Li; Lilley, Catherine J; Imren, Mustafa; Knox, J Paul; Urwin, Peter E

2017-01-01

Plant-parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida , Heterodera glycines , Heterodera avenae and Heterodera filipjevi , in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines . Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium function.

Potential Use of Plant Fibres and their Composites for Biomedical Applications

Directory of Open Access Journals (Sweden)

Farideh Namvar

2014-05-01

Full Text Available Plant-based fibers such as flax, jute, sisal, hemp, and kenaf have been frequently used in the manufacturing of biocomposites. Natural fibres possess a high strength to weight ratio, non-corrosive nature, high fracture toughness, renewability, and sustainability, which give them unique advantages over other materials. The development of biocomposites by reinforcing natural fibres has attracted attention of scientists and researchers due to environmental benefits and improved mechanical performance. Manufacturing of biocomposites from renewable sources is a challenging task, involving metals, polymers, and ceramics. Biocomposites are already utilized in biomedical applications such as drug/gene delivery, tissue engineering, orthopedics, and cosmetic orthodontics. The first essential requirement of materials to be used as biomaterial is its acceptability by the human body. A biomaterial should obtain some important common properties in order to be applied in the human body either for use alone or in combination. Biocomposites have potential to replace or serve as a framework allowing the regeneration of traumatized or degenerated tissues or organs, thus improving the patients’ quality of life. This review paper addresses the utilization of plant fibres and its composites in biomedical applications and considers potential future research directed at environment-friendly biodegradable composites for biomedical applications.

Distributed Low-Complexity Controller for Wind Power Plant in Derated Operation

DEFF Research Database (Denmark)

Biegel, Benjamin; Madjidian, Daria; Spudic, Vedrana

2013-01-01

We consider a wind power plant of megawatt wind turbines operating in derated mode. When operating in this mode, the wind power plant controller is free to distribute power set-points to the individual turbines, as long as the total power demand is met. In this work, we design a controller...... that exploits this freedom to reduce the fatigue on the turbines in the wind power plant. We show that the controller can be designed in a decentralized manner, such that each wind turbine is equipped with a local low-complexity controller relying only on few measurements and little communication. As a basis...... for the controller design, a linear wind turbine model is constructed and verified in an operational wind power plant of megawatt turbines. Due to limitations of the wind power plant available for tests, it is not possible to implement the developed controller; instead the final distributed controller is evaluated...

Large grazers modify effects of aboveground-belowground interactions on small-scale plant community composition

NARCIS (Netherlands)

Veen, G. F. (Ciska); Geuverink, Elzemiek; Olff, Han; Schmid, Bernhard

Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

Large grazers modify effects of aboveground–belowground interactions on small-scale plant community composition

NARCIS (Netherlands)

Veen, G.F.; Geuverink, E.; Olff, H.

2012-01-01

Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

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)

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

Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide

Science.gov (United States)

Prober, Suzanne M.; Leff, Jonathan W.; Bates, Scott T.; Borer, Elizabeth T.; Firn, Jennifer; Harpole, W. Stanley; Lind, Eric M.; Seabloom, Eric W.; Adler, Peter B.; Bakker, Jonathan D.; Cleland, Elsa E.; DeCrappeo, Nicole; DeLorenze, Elizabeth; Hagenah, Nicole; Hautier, Yann; Hofmockel, Kirsten S.; Kirkman, Kevin P.; Knops, Johannes M. H.; La Pierre, Kimberly J.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Risch, Anita C.; Schuetz, Martin; Stevens, Carly J.; Williams, Ryan J.; Fierer, Noah

2015-01-01

Aboveground–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

Crambe tataria sebeók seeds and plants grown in vitro and in vivo fatty acid composition comparison

Directory of Open Access Journals (Sweden)

Nadia Oleksandrivna Pushkarova

2016-10-01

Full Text Available Methods of in vitro conservation offer a number of advantages for endangered species preservation. Crambe tataria Sebeók biochemistry study (fatty acid (FA composition, antioxidant activity (AOA, polyfructan and total soluble protein content is fairly importaint and could show the potential value of this species in agriculture, Food and Chemical Industry or pharmacology including its use as a source of valuble genetic material and could lead to new promising sources of biofuel discovery. Also, comparison of in vitro and in vivo cultured plants could point out to the effect of in vitro culture methods on plants biochemical composition Fatty acid (FA content was determined using Gas chromatography-mass spectrophotometry (GC/MS of fatty acid ethers. Antioxidant activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl radical scavenging method. Total soluble protein content was measured using Bradford method and polyfructan content determination was based upon ketosugars ability to color in the acidic environment with resorcinol. Plants that were grown under in vitro and in vivo conditions and seeds were used in this research. Obtained data showed that C. tataria plants had high AOA and total soluble protein content along with high total FA content along with high content of α-Linolenic acid and absence of erucic acid. Difference in biochemical composition between plants grown in aseptic and not aseptic conditions was shown. 

Designing a New Nano-Plant Composite of Cucurbita pepo for Wound Repair of Skin in Male Albino Mice: A New Nano Approach for Skin Repair

Directory of Open Access Journals (Sweden)

Nooshin Naghsh

2013-06-01

Full Text Available Background & Objective : The Cucurbita pepo is one of plants that are functional in traditional therapy. This plant has antioxidant and skin damage repair properties. This study investigated the effect of Cucurbita pepo nano silver as a new nano-plant composition in wound repair skin in male mice.   Materials & Methods: In this investigation, male albino mice were places in 8 groups, each containing 8 animals. Group I – VIII were treated with nano silver (500, 250, and 125 ppm concentrations and different concentrations of extracts [70%, 50%, and 25%] and the control group received a mixture of 25% Cucurbita pepo extract (125 ppm nano silver. The eighth group, as control, was treated with sterile deionizer water after the induction of wound skin. The average diameter of the wounds was measured 28 days after treatment in the control and treatment groups. These data were analyzed using the t-test and ANOVA statistical method.   Results: The results of this study showed that ethanol extraction (80% has its highest repair effect 28 days post treatment. The average diameter of the wounds in the control group was 1.16 ±. 0.46 cm, which was decreased to 0 cm and 0.12 ±. 0.23 cm in the ethanol extract (70% of the Cucurbita pepo and component groups, respectively (p value ≤ 0.01.   Conclusion: In this project, nano silver-Cucurbita pepo ethanol extraction for wound repair in albino male mice was more effective than single materials. These findings show that the repair synergic effects are between alcoholic extract and nano silver in this nano composite.

Implementing Controlled Composition to Improve Vocabulary Mastery of EFL Students

Science.gov (United States)

Juriah

2015-01-01

The purposes of this study was to know how (1) Controlled composition teaching techniques implemented by the English teacher at SDN 027 Samarinda to improve vocabulary mastery, and (2) Controlled composition teaching techniques improves vocabulary mastery of the sixth grade students of SDN 027 Samarinda. This research used a Classroom Action…

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

How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

Directory of Open Access Journals (Sweden)

Christine Fischer

Full Text Available BACKGROUND: Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. METHODOLOGY/PRINCIPAL FINDINGS: We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs. In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i direct, probably by modifying the pore spectrum and (ii indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. CONCLUSIONS/SIGNIFICANCE: Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

Control of feedwater composition of BWR power plant

International Nuclear Information System (INIS)

Sturla, P.; D'Anna, A.; Borgese, D.

1983-01-01

Corrosion behaviour of fuel element cladding, cycle structural materials and dose rate increase are relevant to physico-chemical characteristics of process coolants and to adopted operational conditions. A careful control of cycle chemistry, during loading and shutdown periods, is necessary to verify material choices, the polishing system and chemistry specifications. For this purpose ENEL carried out some preliminary experimental tests employing continuous control system and samples for specific analytical determinations. The cycle points checked during about two months were: main condensate; condensate after polishing system; outlet of low pressure heathers; final feedwater; inlet and outlet of clean-up system; drains to condenser. The physico-chemical analysis were related to corrosion product levels (Cu, Fe, Ni, Co) and water chemistry (pH, conductivity, dissolved oxygen etc.). The preliminary results allow to express some considerations about sampling procedures, detection limits and reliability of analytical employed methods. The acquisition data time and some morphological oxide pictures are also showed. (author)

Composite potato plants with transgenic roots on non-transgenic shoots: a model system for studying gene silencing in roots.

Science.gov (United States)

Horn, Patricia; Santala, Johanna; Nielsen, Steen Lykke; Hühns, Maja; Broer, Inge; Valkonen, Jari P T

2014-12-01

Composite potato plants offer an extremely fast, effective and reliable system for studies on gene functions in roots using antisense or inverted-repeat but not sense constructs for gene inactivation. Composite plants, with transgenic roots on a non-transgenic shoot, can be obtained by shoot explant transformation with Agrobacterium rhizogenes. The aim of this study was to generate composite potato plants (Solanum tuberosum) to be used as a model system in future studies on root-pathogen interactions and gene silencing in the roots. The proportion of transgenic roots among the roots induced was high (80-100%) in the four potato cultivars tested (Albatros, Desirée, Sabina and Saturna). No wild-type adventitious roots were formed at mock inoculation site. All strains of A. rhizogenes tested induced phenotypically normal roots which, however, showed a reduced response to cytokinin as compared with non-transgenic roots. Nevertheless, both types of roots were infected to a similar high rate with the zoospores of Spongospora subterranea, a soilborne potato pathogen. The transgenic roots of composite potato plants expressed significantly higher amounts of β-glucuronidase (GUS) than the roots of a GUS-transgenic potato line event. Silencing of the uidA transgene (GUS) was tested by inducing roots on the GUS-transgenic cv. Albatros event with strains of A. rhizogenes over-expressing either the uidA sense or antisense transcripts, or inverted-repeat or hairpin uidA RNA. The three last mentioned constructs caused 2.5-4.0 fold reduction in the uidA mRNA expression. In contrast, over-expression of uidA resulted in over 3-fold increase in the uidA mRNA and GUS expression, indicating that sense-mediated silencing (co-suppression) was not functional in roots. The results suggest that composite plants offer a useful experimental system for potato research, which has gained little previous attention.

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

PIXE studies of changes in host mineral compositions of plants due to Phytophthora Cinnamomi

International Nuclear Information System (INIS)

Papper, C.S.; Chaudhri, M.A.

1978-01-01

In order to study the effect of the disease due to Phytophthora Cinnamomi on the vegetation in Wilson's Promontory, the mineral compositions of tolerant and susceptible plants in both healthy and diseased areas have been compared, using proton-induced x-ray emission analysis

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...

Plant extraction process

DEFF Research Database (Denmark)

2006-01-01

A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme.......A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme....

Usage and control of solid-state lighting for plant growth

Energy Technology Data Exchange (ETDEWEB)

Pinho, P.

2008-07-01

plant growth offers an unprecedented possibility to optimise the morphogenesis, the photosynthesis and the nutritional quality of crops. This can be done by controlling the quantity and the spectral composition of the radiation provided, areas where LED-based luminaires excel. These possibilities can contribute to respond to the increasing demand for high-quality horticultural products by the consumers and to the conservation of global natural environment and resources. (orig.)

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)

Computerization of nuclear material accounting and control at storage facilities of RT-1 plant, PA Mayak

International Nuclear Information System (INIS)

Krakhmal'nik, V.I.; Menshchikov, Yu.L.; Mozhaev, D.A.

1999-01-01

Computerized system for nuclear material (NM) accounting and control at RT-1 plant is being created on the basis of advanced engineering and programming tools, which give a possibility to ensure prompt access to the information required, to unify the accounting and report documentation, make statistical processing of the data, and trace the NM transfers in the chain of its storage at facilities of RT-1 plant. Currently, the accounting is performed in parallel, both by the old methods and with computerized system. The following functions are performed by the system at the current stage: input of data on the end product's (plutonium dioxide) quantitative and qualitative composition; data input on the localization of containers with finished products at storage facilities of the plant and the product's temporary characteristics; selective verification of the data on containers and batches, according to the criteria prespecified by the user; data protection against unauthorized access; data archiving; report documents formation and providing [ru

Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters

Science.gov (United States)

2009-12-01

ER D C TR -0 9- 10 Strategic Environmental Research and Development Program Phytoremediation of Composition-B Derived TNT and RDX in...Program ERDC TR-09-10 December 2009 Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters Elly P. H...for U.S. Army Corps of Engineers Washington, DC 20314-1000 ERDC TR-09-10 ii Abstract: This report describes a study in which phytoremediation of

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.

Aspects regarding computer control of 15 N separation plant

International Nuclear Information System (INIS)

Kaucsar, M.; Cosma, V.; Axente, D.; Baldea, A.; Bendea, H.; Bunea, V

2001-01-01

In order to improve the efficiency of a separation plant the whole process must be automatically controlled. The plant has a single output - the isotopic product. This output is characterized by a complex function, which involves qualitative or/and quantitative properties of the product. There are two important inputs into the system, namely: the amount of the substances and compounds which supply the plant and the electric power consumption. Our first aim is to reduce the input/output ratio of the separation plant. On the other hand, by applying this automatic control system we can reduce the operating personnel also. The isotopic product is sampled and analyzed using a dedicated mass spectrometer. An overall closed loop through the separation plant including this mass spectrometer could be very efficient, but the theoretical analysis is too complex and it is very difficult to realize it in practice. Therefore, multiple local control loops are preferred to apply for each product correlated parameter. Between these parameters there are complex interdependencies, governed by differential equations. The computer is equipped with standard input/output hardware, but in order to use it in the complex feedback loops, extra input/output hardware must be added, namely, dedicated input/output module cards. Depending on the operating principle of the detectors and actuators the signals involved in the whole system are analog and digital. The majority of the sensors and transducers generates analog signals and only a few of them have digital output. The last case is typical for transducers specialized mainly for detecting the level of a parameter. Actuators also need analog or digital control signals, corresponding to their operating principles. The computer control of isotopic plant has a great advantage of being very flexible in implementing adequate control software with operator friendly interfacing routines. (authors)

Environmental and community controls on plant canopy chemistry in a Mediterranean-type ecosystem.

Science.gov (United States)

Dahlin, Kyla M; Asner, Gregory P; Field, Christopher B

2013-04-23

Understanding how and why plant communities vary across space has long been a goal of ecology, yet parsing the relative importance of different influences has remained a challenge. Species-specific models are not generalizable, whereas broad plant functional type models lack important detail. Here we consider plant trait patterns at the local scale and ask whether plant chemical traits are more closely linked to environmental gradients or to changes in species composition. We used the visible-to-shortwave infrared (VSWIR) spectrometer of the Carnegie Airborne Observatory to develop maps of four plant chemical traits--leaf nitrogen per mass, leaf carbon per mass, leaf water concentration, and canopy water content--across a diverse Mediterranean-type ecosystem (Jasper Ridge Biological Preserve, CA). For all four traits, plant community alone was the strongest predictor of trait variation (explaining 46-61% of the heterogeneity), whereas environmental gradients accounted for just one fourth of the variation in the traits. This result emphasizes the critical role that species composition plays in mediating nutrient and carbon cycling within and among different communities. Environmental filtering and limits to similarity can act strongly, simultaneously, in a spatially heterogeneous environment, but the local-scale environmental gradients alone cannot account for the variation across this landscape.

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.)

Phyllosphere Microbiota Composition and Microbial Community Transplantation on Lettuce Plants Grown Indoors

Science.gov (United States)

Williams, Thomas R.

2014-01-01

ABSTRACT The aerial surfaces of plants, or phyllosphere, are microbial habitats important to plant and human health. In order to accurately investigate microbial interactions in the phyllosphere under laboratory conditions, the composition of the phyllosphere microbiota should be representative of the diversity of microorganisms residing on plants in nature. We found that Romaine lettuce grown in the laboratory contained 10- to 100-fold lower numbers of bacteria than age-matched, field-grown lettuce. The bacterial diversity on laboratory-grown plants was also significantly lower and contained relatively higher proportions of Betaproteobacteria as opposed to the Gammaproteobacteria-enriched communities on field lettuce. Incubation of field-grown Romaine lettuce plants in environmental growth chambers for 2 weeks resulted in bacterial cell densities and taxa similar to those on plants in the field but with less diverse bacterial populations overall. In comparison, the inoculation of laboratory-grown Romaine lettuce plants with either freshly collected or cryopreserved microorganisms recovered from field lettuce resulted in the development of a field-like microbiota on the lettuce within 2 days of application. The survival of an inoculated strain of Escherichia coli O157:H7 was unchanged by microbial community transfer; however, the inoculation of E. coli O157:H7 onto those plants resulted in significant shifts in the abundance of certain taxa. This finding was strictly dependent on the presence of a field-associated as opposed to a laboratory-associated microbiota on the plants. Phyllosphere microbiota transplantation in the laboratory will be useful for elucidating microbial interactions on plants that are important to agriculture and microbial food safety. PMID:25118240

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)

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)

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.

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

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.

A PtdIns(4)P-driven electrostatic field controls cell membrane identity and signalling in plants.

Science.gov (United States)

Simon, Mathilde Laetitia Audrey; Platre, Matthieu Pierre; Marquès-Bueno, Maria Mar; Armengot, Laia; Stanislas, Thomas; Bayle, Vincent; Caillaud, Marie-Cécile; Jaillais, Yvon

2016-06-20

Many signalling proteins permanently or transiently localize to specific organelles. It is well established that certain lipids act as biochemical landmarks to specify compartment identity. However, they also influence membrane biophysical properties, which emerge as important features in specifying cellular territories. Such parameters include the membrane inner surface potential, which varies according to the lipid composition of each organelle. Here, we found that the plant plasma membrane (PM) and the cell plate of dividing cells have a unique electrostatic signature controlled by phosphatidylinositol-4-phosphate (PtdIns(4)P). Our results further reveal that, contrarily to other eukaryotes, PtdIns(4)P massively accumulates at the PM, establishing it as a critical hallmark of this membrane in plants. Membrane surface charges control the PM localization and function of the polar auxin transport regulator PINOID as well as proteins from the BRI1 KINASE INHIBITOR1 (BKI1)/MEMBRANE ASSOCIATED KINASE REGULATOR (MAKR) family, which are involved in brassinosteroid and receptor-like kinase signalling. We anticipate that this PtdIns(4)P-driven physical membrane property will control the localization and function of many proteins involved in development, reproduction, immunity and nutrition.

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...

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.)

Nuclear-physical methods of investigation of an element composition in samples of soils and plants

International Nuclear Information System (INIS)

Hushmurodov, Sh.; Botaev, N.

2002-01-01

Soil (ground) and vegetative covers of the Earth are one of the most responsive and specific parts of the biosphere with respect to pollution. A proper control after them is of fundamental importance in creating and protecting optical surrounding. Analysis of soils and plants is a necessary and important stage in the process of investigation of microelements' migration in biogeochemical cycles. For this purpose we studied some reserved terrains of Uzbekistan to reveal a level of their contamination by heavy metals, as well as to find out typical and territorial singularities in accumulation of a number of elements by soils and plants. In order to decrease an influence of systematic errors, and to obtain more precise and reliable data, we carried out the element analysis of the samples by different methods, such as gamma-activation analysis, neutron-activation analysis, X-ray spectral analysis, and X-ray fluorescent analysis. As a result of our investigations we have obtained rather great information, which can be used in future to estimate the conditions of the surrounding nature. The investigations allowed us to determine the content of about 40 elements, as well as to show that the data, obtained by different nuclear-physical methods, are in rather good agreement. A reproducibility of the results of the methods, determined in control measurements, depends on the concentration of the analyzed elements, and is equal to 10-35 %. A comparison of the obtained data allowed us to reveal some singularities in element composition of the investigated samples depending on their type and territorial factor. It has been revealed that the data, obtained by different methods, are in rather good agreement. Our investigations allowed us to find out a series of regularities and singularities in accumulation of elements in plants, as well as to show the possibility of using nuclear-physical methods in such investigations

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)

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...

Composite Gauss-Legendre Quadrature with Error Control

Science.gov (United States)

Prentice, J. S. C.

2011-01-01

We describe composite Gauss-Legendre quadrature for determining definite integrals, including a means of controlling the approximation error. We compare the form and performance of the algorithm with standard Newton-Cotes quadrature. (Contains 1 table.)

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...

Lipid Oxidation Inhibitory Effects and Phenolic Composition of Aqueous Extracts from Medicinal Plants of Colombian Amazonia

Directory of Open Access Journals (Sweden)

José Ignacio Ruiz-Sanz

2012-05-01

Full Text Available Diverse plants of ethnobotanic interest in Amazonia are commonly used in traditional medicine. We determined the antioxidant potential against lipid peroxidation, the antimicrobial activity, and the polyphenol composition of several Amazonian plants (Brownea rosademonte, Piper glandulosissimum, Piper krukoffii, Piper putumayoense, Solanum grandiflorum, and Vismia baccifera. Extracts from the plant leaf, bark, and stem were prepared as aqueous infusions, as used in folk medicine, and added to rat liver microsomes exposed to iron. The polyphenolic composition was detected by reverse-phase HPLC coupled to diode-array detector and MS/MS analysis. The antimicrobial activity was tested by the spot-on-a-lawn method against several indicator microorganisms. All the extracts inhibited lipid oxidation, except the P. glandulosissimum stem. The plant extracts exhibiting high antioxidant potential (V. baccifera and B. rosademonte contained high levels of flavanols (particularly, catechin and epicatechin. By contrast, S. grandiflorum leaf, which exhibited very low antioxidant activity, was rich in hydroxycinnamic acids. None of the extracts showed antimicrobial activity. This study demonstrates for the first time the presence of bioactive polyphenolic compounds in several Amazonian plants, and highlights the importance of flavanols as major phenolic contributors to antioxidant activity.

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.

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

The use of ligneous plants for controlling the radioactive contamination of a soil; Utilisation des vegetaux ligneux au controle de la pollution radioactive d'un sol

Energy Technology Data Exchange (ETDEWEB)

Gagnaire, J; Heuze, C; Aubert, M T [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires

1961-07-01

A method for checking on the possible radioactive pollution of CEN-G. soil, by taking samples of tissue of ligneous plants cultivated on the land in question, is proposed and investigated during the vegetation period. A preliminary study on the retention capacity of the CEN-G. soil for solutions containing {sup 32}P and chemical composition is given. (author) [French] Une methode de controle de la pollution radioactive eventuelle du sol du CEN-G., a l'aide de prelevements de tissus de vegetaux ligneux, cultives sur ce terrain est proposee et etudiee pendant la periode vegetative. Une etude preliminaire du pouvoir de retention du sol du CEN-G, vis-a-vis de solutions contenant du {sup 32}P et de composition chimique, est exposee. (auteur)

The influence of CO2 proceding from plant residue decomposition in the soil on isotopic ratio 13C/12c and plant development

International Nuclear Information System (INIS)

Martins, D.

1987-01-01

To determine the effect of plant incorporated in the soil on the microclimate of plant growth, an experiment was carried out in greenhouse and then under field conditions. Plant residue of C-3 crops δ 13 C = - 27.6 0 /00, was incorporated in the soil. This altered the isotopic composition of the CO 2 in soil air and in atmospheric air of soil layers adjacent to the surface. The soil air CO 2 isotopic composition showed that approximately 79% carbon was from the incorporated organic matter and 50% to 3% in O to 30 cm layers, respectively, in the atmospheric air adjacent to the surface. The isotopic ratio 13 C/ 12 C of plants cultivated in soil with incorporated organic matter was determined and it was noted that the envolved CO 2 was photosynthetically absorved by the plants during growth. CO 2 contribution from organic matter to the isotopic composition of C-4 plants varied from 33% to 13% during growth. Plants cultivated in soil with organic matter had a better development than those cultivated in natural soil. Productivity was on average 50% greater than the control plants. (author) [pt

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

A numerical analysis of a composition-adjustable Kalina cycle power plant for power generation from low-temperature geothermal sources

International Nuclear Information System (INIS)

Wang, Enhua; Yu, Zhibin

2016-01-01

Highlights: • A composition-adjustable Kalina cycle is analysed and presented. • An air-cooled condenser is used and thermodynamic performance is analysed. • Composition adjustment can improve system performance significantly. - Abstract: The Kalina cycle is believed to be one of the most promising technologies for power generation from low temperature heat sources such as geothermal energy. So far, most Kalina cycle power plants are designed with a working fluid mixture having a fixed composition, and thus normally operate at a fixed condensing temperature. However, the ambient temperature (i.e., heat sink) varies over a large range as the season changes over a year, particularly in continental climates. Recently, a new concept, i.e., composition-adjustable Kalina cycle, was proposed to develop power plants that can match their condensing temperature with the changing ambient conditions, aiming at improving the cycle’s overall thermal efficiency. However, no detailed analysis of its implementation and the potential benefits under various climate conditions has been reported. For this reason, this paper carried out a comprehensive numerical research on its implementation and performance analysis under several different climate conditions. A mathematical model is firstly established to simulate the working principle of a composition-adjustable Kalina cycle, based on which a numerical program is then developed to analyse the cycle’s performance under various climate conditions. The developed numerical model is verified with some published data. The dynamic composition adjustment in response to the changing ambient temperature is simulated to evaluate its effect on the plant’s performance over a year. The results show that a composition-adjustable Kalina cycle could achieve higher annual-average thermal efficiency than a conventional one with a fixed mixture composition. However, such an improvement of thermal efficiency strongly depends on the heat source

Implementing Controlled Composition to Improve Vocabulary Mastery of EFL Students

Directory of Open Access Journals (Sweden)

Juriah Juriah

2015-06-01

Full Text Available The purposes of this study was to know how (1 Controlled composition teaching techniques implemented by the English teacher at SDN 027 Samarinda to improve vocabulary mastery, and (2 Controlled composition teaching techniques improves vocabulary mastery of the sixth grade students of SDN 027 Samarinda. This research used a Classroom Action Research (CAR as the research design. The subject of the research is the sixth grade students in the 2013/2014 academic year that consists of 43 students. The instruments employed in this study were observation checklist, field note, and vocabulary test. The result of the research showed that in cycle 1 the students’ achievement did not fulfill the minimal criteria of success. However the result of the cycle 1 was better than the preliminary study. The criteria of success did not fulfill in cycle one, some enhancement of the implementation of Controlled Composition were made in cycle two in the form of: Instruct the students bring dictionary, give more examples English sentences, guide the students find the mining of words in the dictionary and write a paragraph, more motivate the students and preparing a media/ picture .Meanwhile the students ’achievement in cycle two showed that fulfilled the criteria of success. Based on the findings and discussion, the conclusions : Firstly, Controlled composition was implemented well by the teacher of SDN 027 Samarinda. Controlled composition was implemented and gave impacts in: (a increasing the students’ vocabulary mastery significantly, (b making the students able to spell the vocabularies, (c making the students understand the meaning English words, and (d making the students able to pronounce English words quite good. Secondly, Controlled composition improved the students’ vocabulary mastery; it was only 20.9% of the students who achieved the English passing grade in the preliminary study, but then 81.39% of the students achieved the English passing grade in

Compositional control of continuously graded anode functional layer

Science.gov (United States)

McCoppin, J.; Barney, I.; Mukhopadhyay, S.; Miller, R.; Reitz, T.; Young, D.

2012-10-01

In this work, solid oxide fuel cells (SOFC's) are fabricated with linear-compositionally graded anode functional layers (CGAFL) using a computer-controlled compound aerosol deposition (CCAD) system. Cells with different CGAFL thicknesses (30 um and 50 um) are prepared with a continuous compositionally graded interface deposited between the electrolyte and anode support current collecting regions. The compositional profile was characterized using energy dispersive X-ray spectroscopic mapping. An analytical model of the compound aerosol deposition was developed. The model predicted compositional profiles for both samples that closely matched the measured profiles, suggesting that aerosol-based deposition methods are capable of creating functional gradation on length scales suitable for solid oxide fuel cell structures. The electrochemical performances of the two cells are analyzed using electrochemical impedance spectroscopy (EIS).

Design and Simulation to Composite PI Controller on the Stratospheric Airship

OpenAIRE

Kangwen Sun; Ming Zhu; Bojin Qi; Xiaoming Chen

2014-01-01

In view of the stratospheric airship application requirements on energy storage and management system, based on the topology of DC/DC converter main circuit, the composite PI controller is designed to realize respective control with the Boost mode and Buck mode. Furthermore, limit stop integration method is proposed to achieve a buck-boost complex DC/DC converter boost with effective switching buck. Then, with the MATLAB Control System Toolbox design model, the composite PI controller design ...

Control of nitrogen oxides at thermal power plants

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Hall, R.E.

1991-01-01

Reviews reports presented at the International symposium on reduction of NO{sub x} emissions from stationary pollutant sources, held in San Francisco (USA) in March 1989. Topics concentrated on the latest trends in power engineering in the USA and Europe. Reports were dedicated to test results of pilot plant equipment employing the increasingly popular LNB, OFA, Reburn, SNCR, and SCR technologies. The following conclusions are drawn on the basis of the symposium proceedings: The nitric oxide problem may be considered exaggerated in regard to thermal power plants because of errors made during flue gas composition analysis. The combination of new combustion chambers and staged air input with simultaneous redesigning of equipment is most widely employed in the USA (achieving a 50% NO{sub x} reduction with minimum effect on power plant operation and maintenance costs). Economic sense demands that primary methods of NO{sub x} removal be used prior to SCR implementation. The SCR technology reducing NO{sub x} emission by 60-80% with ammonia to less than 5 ppm is the most popular flue gas denitrification method. 15 refs.

Element composition of solid airborne particles deposited in snow in the vicinity of gas-fired heating plant

OpenAIRE

Talovskaya, Anna Valerievna; Yazikov, Yegor (Egor) Grigoryevich; Filimonenko, Ekaterina Anatolievna; Samokhina, Nataljya Pavlovna; Shakhova, Tatiana Sergeevna; Parygina, Irina Alekseevna

2016-01-01

Local heating plants are the main pollution source of rural areas. Currently, there are few studies on the composition of local heating plants emissions. The article deals with the research results of air pollution level with solid airborne particles in the vicinity of local gas-fired heating plants of some districts of Tomsk region. The snow sampling was conducted for the purpose of solid airborne particles extraction from snow cover. The content of 28 chemical elements (heavy metals, rare e...

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)

Microstructure, quantification and control of dislocations in bast-type plant fibres

DEFF Research Database (Denmark)

Madsen, Bo; Lester, Catherine L.; Mortensen, Ulrich Andreas

2016-01-01

Bast-type plant fibres are increasingly being used for structural composite applications where high quality fibres with good mechanical properties are required. A central aspect for this application is the existence of dislocations in the cell wall of plant fibres, i.e. regions of misaligned...... cellulose microfibrils, which are believed to form weak points leading to reduced mechanical properties. In the present study, microstructural observations of dislocations are made using high-magnification scanning electron microscopy. An experimental protocol using polarized optical microscopy and image...... that this leads to a reduction in the content of dislocations. This is indicating that dislocations in the cell wall of plant fibres are changeable structures. Preliminary work is presented where plant fibres are exposed to physical treatments involving moisture and mechanical straining in order to change...

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...

Composite Transport Model and Water and Solute Transport across Plant Roots: An Update.

Science.gov (United States)

Kim, Yangmin X; Ranathunge, Kosala; Lee, Seulbi; Lee, Yejin; Lee, Deogbae; Sung, Jwakyung

2018-01-01

The present review examines recent experimental findings in root transport phenomena in terms of the composite transport model (CTM). It has been a well-accepted conceptual model to explain the complex water and solute flows across the root that has been related to the composite anatomical structure. There are three parallel pathways involved in the transport of water and solutes in roots - apoplast, symplast, and transcellular paths. The role of aquaporins (AQPs), which facilitate water flows through the transcellular path, and root apoplast is examined in terms of the CTM. The contribution of the plasma membrane bound AQPs for the overall water transport in the whole plant level was varying depending on the plant species, age of roots with varying developmental stages of apoplastic barriers, and driving forces (hydrostatic vs. osmotic). Many studies have demonstrated that the apoplastic barriers, such as Casparian bands in the primary anticlinal walls and suberin lamellae in the secondary cell walls, in the endo- and exodermis are not perfect barriers and unable to completely block the transport of water and some solute transport into the stele. Recent research on water and solute transport of roots with and without exodermis triggered the importance of the extension of conventional CTM adding resistances that arrange in series (epidermis, exodermis, mid-cortex, endodermis, and pericycle). The extension of the model may answer current questions about the applicability of CTM for composite water and solute transport of roots that contain complex anatomical structures with heterogeneous cell layers.

Factors controlling shell carbon isotopic composition of land snail Acusta despecta sieboldiana estimated from lab culturing experiment

Science.gov (United States)

Zhang, N.; Yamada, K.; Suzuki, N.; Yoshida, N.

2014-05-01

The carbon isotopic composition (δ13C) of land snail shell carbonate derives from three potential sources: diet, atmospheric CO2, and ingested carbonate (limestone). However, their relative contributions remain unclear. Under various environmental conditions, we cultured one land snail species, Acusta despecta sieboldiana collected from Yokohama, Japan, and confirmed that all of these sources affect shell carbonate δ13C values. Herein, we consider the influences of metabolic rates and temperature on the carbon isotopic composition of the shell carbonate. Based on previous works and on results obtained in this study, a simple but credible framework is presented for discussion of how each source and environmental parameter can affect shell carbonate δ13C values. According to this framework and some reasonable assumptions, we have estimated the contributions of different carbon sources for each snail individual: for cabbage (C3 plant) fed groups, the contributions of diet, atmospheric CO2 and ingested limestone respectively vary as 66-80%, 16-24%, and 0-13%. For corn (C4 plant) fed groups, because of the possible food stress (lower consumption ability of C4 plant), the values vary respectively as 56-64%, 18-20%, and 16-26%. Moreover, we present new evidence that snails have discrimination to choose C3 and C4 plants as food. Therefore, we suggest that food preferences must be considered adequately when applying δ13C in paleo-environment studies. Finally, we inferred that, during egg laying and hatching of our cultured snails, carbon isotope fractionation is controlled only by the isotopic exchange of the calcite-HCO3--aragonite equilibrium.

Factors controlling shell carbon isotopic composition of land snail Acusta despecta sieboldiana estimated from laboratory culturing experiment

Science.gov (United States)

Zhang, N.; Yamada, K.; Suzuki, N.; Yoshida, N.

2014-10-01

The carbon isotopic composition (δ13C) of land snail shell carbonate derives from three potential sources: diet, atmospheric CO2, and ingested carbonate (limestone). However, their relative contributions remain unclear. Under various environmental conditions, we cultured one land snail subspecies, Acusta despecta sieboldiana, collected from Yokohama, Japan, and confirmed that all of these sources affect shell carbonate δ13C values. Herein, we consider the influences of metabolic rates and temperature on the carbon isotopic composition of the shell carbonate. Based on results obtained from previous works and this study, a simple but credible framework is presented to illustrate how each source and environmental parameter affects shell carbonate δ13C values. According to this framework and some reasonable assumptions, we estimated the contributions of different carbon sources for each snail individual: for cabbage-fed (C3 plant) groups, the contributions of diet, atmospheric CO2, and ingested limestone vary in the ranges of 66-80, 16-24, and 0-13%, respectively. For corn-fed (C4 plant) groups, because of the possible food stress (less ability to consume C4 plants), the values vary in the ranges of 56-64, 18-20, and 16-26%, respectively. Moreover, according to the literature and our observations, the subspecies we cultured in this study show preferences towards different plant species for food. Therefore, we suggest that the potential food preference should be considered adequately for some species in paleoenvironment studies. Finally, we inferred that only the isotopic exchange of the calcite-HCO3--aragonite equilibrium during egg laying and hatching of our cultured snails controls carbon isotope fractionation.

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.

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.

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)

design of a decoupler controller for forced circulation evaporator used in a radioactive treatment plant

International Nuclear Information System (INIS)

Abdel-Halim, H.A.

2005-01-01

evaporation is a proven method for a treatment of liquid radioactive wastes providing both good decontamination and high concentration . in a radioactive waste treatment plant, an evaporator is used to reduce the volume of medium radioactive liquid waste arising from different applications of nuclear industries. the control system objective is to limit the composition of the liquid waste at a prescribed value. for the safe operation, without damaging the installed equipment, a good control for the evaporator operating pressure and the level of liquid waste inside the separator part has been required. evaporator equipment is a complex process, which is a multivariable, nonlinear and has many disturbances. therefore, design a control strategy for the evaporator is bit difficult. the solution method is based on system decoupling eliminating the parasite interactions between input-output pairing variables and converting multi-inputs multi-outputs (MIMO) system to several single-inputs single-outputs (SISO) systems

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.

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

Autonomous Control of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Basher, H.

2003-10-20

A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in emergency situations, fault detection and diagnosis, nuclear reactor alarm processing and diagnosis, and reactor load-following operations, to name a few. With the advancement of new technologies and computing power, it is feasible to automate most of the nuclear reactor control and operation, which will result in increased safety and economical benefits. This study surveys current status, practices, and recent advances made towards developing autonomous control systems for nuclear reactors.

Autonomous Control of Nuclear Power Plants

International Nuclear Information System (INIS)

Basher, H.

2003-01-01

A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in emergency situations, fault detection and diagnosis, nuclear reactor alarm processing and diagnosis, and reactor load-following operations, to name a few. With the advancement of new technologies and computing power, it is feasible to automate most of the nuclear reactor control and operation, which will result in increased safety and economical benefits. This study surveys current status, practices, and recent advances made towards developing autonomous control systems for nuclear reactors

HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

O. M. Pshinko

2015-08-01

Full Text Available Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canonical equations consists of the equations for concrete strength, absolute volume, concrete mix consistency as well as the equation for optimal concrete saturation with aggregates while minimizing cement content. The joint solution of these four equations related to composition allows determining for the materials the concrete composition of required strength, concrete workability with minimum cement content. The procedure for calculation of hydraulic concrete composition according to the physico-analytical method consists of two parts: 1 physical, which is laboratory testing of concrete mix components in different concrete compositions; 2 analytical, which represents the calculation algorithm for concrete compositions equivalent in concrete strength and workability that comply with the specific conditions of concrete placing. Findings. To solve the problem of designing the concrete composition with the desired properties for railway structures and buildings it was proposed to use the information technology in the form of a developed computer program whose algorithm includes the physico-analytical method for hydraulic concrete composition determination. Originality. The developed concrete composition design method takes into account the basic properties of raw materials, concrete mix and concrete, which are pre-determined. The distinctive feature of physico-analytical method is obtaining of a set of equivalent compositions with a certain concrete mix

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...

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests

Science.gov (United States)

McIntosh, Anne C. S.; Macdonald, S. Ellen; Quideau, Sylvie A.

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

Directory of Open Access Journals (Sweden)

Anne C S McIntosh

Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

Science.gov (United States)

McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

NOVEL COMPOSITE MEMBRANES FOR HYDROGEN SEPARATION IN GASIFICATION PROCESSES IN VISION 21 ENERGY PLANTS

Energy Technology Data Exchange (ETDEWEB)

Michael Schwartz

2004-12-01

This report describes the work performed, accomplishments and conclusion obtained from the project entitled ''Novel Composite Membranes for Hydrogen Separation in Gasification Processes in Vision 21 Energy Plants'' under the United States Department of Energy Contract DE-FC26-01NT40973. ITN Energy Systems was the prime contractor. Team members included: the Idaho National Engineering and Environmental Laboratory; Nexant Consulting; Argonne National Laboratory and Praxair. The objective of the program was to develop a novel composite membrane structure for hydrogen separation as a key technology module within the future ''Vision 21'' fossil fuel plants. The separation technology module is targeted for use within the gasification module of the ''Vision 21'' fossil fuel plant. The high performance and low-cost manufacturing of the proposed technology will benefit the deployment of ''Vision 21'' fossil fuel plant processes by improving the energy efficiency, flexibility and environmental performance of these plants. Of particular importance is that this technology will also produce a stream of pure carbon dioxide. This allows facile sequestration or other use of this greenhouse gas. These features will benefit the U.S. in allowing for the continued use of domestic fossil fuels in a more energy efficient and environmentally acceptable manner. The program developed and evaluated composite membranes and catalysts for hydrogen separation. Components of the monolithic modules were fabricated by plasma spray processing. The engineering and economic characteristics of the proposed Ion Conducting Ceramic Membrane (ICCM) approach, including system integration issues, were also assessed. This resulted in a comprehensive evaluation of the technical and economic feasibility of integration schemes of ICCM hydrogen separation technology within Vision 21 fossil fuel plants. Several results and conclusion

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.

Hot rolled composite billet for nuclear control rods

International Nuclear Information System (INIS)

Miller, G.E.

1976-01-01

This invention relates to a composite plate shaped billet, useful in the fabrication of nuclear control rods, which comprises a core of stainless steel containing about 2 percent boron 10, a thin coating of zirconia on the surfaces of said core, and said zirconia coating being completely encased in a jacket of mild steel, said composite having been hot rolled between about 1075 0 and about 1165 0 C. 1 claim, 8 figures

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

Sol-gel Derived Warfarin - Silica Composites for Controlled Drug Release.

Science.gov (United States)

Dolinina, Ekaterina S; Parfenyuk, Elena V

2017-01-01

Warfarin, commonly used anticoagulant in clinic, has serious shortcomings due to its unsatisfactory pharmacodynamics. One of the efficient ways for the improvement of pharmacological and consumer properties of drugs is the development of optimal drug delivery systems. The aim of this work is to synthesize novel warfarin - silica composites and to study in vitro the drug release kinetics to obtain the composites with controlled release. The composites of warfarin with unmodified (UMS) and mercaptopropyl modified silica (MPMS) were synthesized by sol-gel method. The composite formation was confirmed by FTIR spectra. The concentrations of warfarin released to media with pH 1.6, 6.8 and 7.4 were measured using UV spectroscopy. The drug release profiles from the solid composites were described by a series of kinetic models which includes zero order kinetics, first order kinetics, the modified Korsmeyer-Peppas model and Hixson-Crowell model. The synthesized sol-gel composites have different kinetic behavior in the studied media. In contrast to the warfarin composite with unmodified silica, the drug release from the composite with mercaptopropyl modified silica follows zero order kinetics for 24 h irrespective to the release medium pH due to mixed mechanism (duffusion + degradation and/or disintegration of silica matrix). The obtained results showed that warfarin - silica sol-gel composites have a potential application for the development of novel oral formulation of the drug with controlled delivery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change.

Science.gov (United States)

Gavazov, Konstantin; Albrecht, Remy; Buttler, Alexandre; Dorrepaal, Ellen; Garnett, Mark H; Gogo, Sebastien; Hagedorn, Frank; Mills, Robert T E; Robroek, Bjorn J M; Bragazza, Luca

2018-03-23

Climate change can alter peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular plant-removal experiment in two Sphagnum-dominated peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO 2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO 2 radiocarbon (bomb- 14 C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in peatlands, especially when assessing the future carbon sink function of peatlands undergoing a shift in vegetation community composition in association with climate change. © 2018 John Wiley & Sons Ltd.

Essential oil composition and nutrient analysis of selected medicinal plants in Sultanate of Oman

Directory of Open Access Journals (Sweden)

Javid Hussain

2013-12-01

Full Text Available Objective: To evaluate the nutrients and essential oils of five medicinal plants, Juniperus excelsa (J. excelsa, Dodonaea viscosa, Euryops pinifolius, Teucrium polium (T. polium, and Helianthemum lippii that were collected from Jabal Al Akhdar, Oman. Methods: Proximate parameters (moisture, dry matter, ash, crude fats, proteins, fibers, nitrogen, carbohydrates, and energy values and nutrient analysis (K, Na, Ca, Fe, P, Mg etc. were evaluated in the five medicinal plants using standard techniques. On the basis of these analysis, T. polium and J. excels were selected for essential oil analysis using a rapid solvent-free microwave extraction method and GC-MS. Results: The results showed that leaves of J. excelsa had highest proportion of crude fats, fibers and energy value while ash was highest in T. polium. J. excelsa was also rich in essential minerals such as calcium, magnesium, potassium and iron while the trace elements and heavy metals composition was marginal. A rapid solvent-free microwave extraction method to extract oil from medicinal plants species showed that only T. polium and J. excelsa yielded oil. The chemical composition of essential oils showed higher proportion of delta-3-carene, limonene, β-eudesmol, ledeneoxide (II, α-trans-bergamatene, linalyl acetate and germacrene. Conclusions: J. excelsa and T. polium are a good source of proximate, minerals and essential oils, which can be considered for healthy life besides their medicinal values.

The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant

Directory of Open Access Journals (Sweden)

Li Zhang

2017-06-01

Full Text Available Plant–parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida, Heterodera glycines, Heterodera avenae and Heterodera filipjevi, in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines. Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium 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

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.

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.

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)

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.

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.

Rapid plant evolution in the presence of an introduced species alters community composition.

Science.gov (United States)

Smith, David Solance; Lau, Matthew K; Jacobs, Ryan; Monroy, Jenna A; Shuster, Stephen M; Whitham, Thomas G

2015-10-01

Because introduced species may strongly interact with native species and thus affect their fitness, it is important to examine how these interactions can cascade to have ecological and evolutionary consequences for whole communities. Here, we examine the interactions among introduced Rocky Mountain elk, Cervus canadensis nelsoni, a common native plant, Solidago velutina, and the diverse plant-associated community of arthropods. While introduced species are recognized as one of the biggest threats to native ecosystems, relatively few studies have investigated an evolutionary mechanism by which introduced species alter native communities. Here, we use a common garden design that addresses and supports two hypotheses. First, native S. velutina has rapidly evolved in the presence of introduced elk. We found that plants originating from sites with introduced elk flowered nearly 3 weeks before plants originating from sites without elk. Second, evolution of S. velutina results in a change to the plant-associated arthropod community. We found that plants originating from sites with introduced elk supported an arthropod community that had ~35 % fewer total individuals and a different species composition. Our results show that the impacts of introduced species can have both ecological and evolutionary consequences for strongly interacting species that subsequently cascade to affect a much larger community. Such evolutionary consequences are likely to be long-term and difficult to remediate.

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)

Seed bank and big sagebrush plant community composition in a range margin for big sagebrush

Science.gov (United States)

Martyn, Trace E.; Bradford, John B.; Schlaepfer, Daniel R.; Burke, Ingrid C.; Laurenroth, William K.

2016-01-01

The potential influence of seed bank composition on range shifts of species due to climate change is unclear. Seed banks can provide a means of both species persistence in an area and local range expansion in the case of increasing habitat suitability, as may occur under future climate change. However, a mismatch between the seed bank and the established plant community may represent an obstacle to persistence and expansion. In big sagebrush (Artemisia tridentata) plant communities in Montana, USA, we compared the seed bank to the established plant community. There was less than a 20% similarity in the relative abundance of species between the established plant community and the seed bank. This difference was primarily driven by an overrepresentation of native annual forbs and an underrepresentation of big sagebrush in the seed bank compared to the established plant community. Even though we expect an increase in habitat suitability for big sagebrush under future climate conditions at our sites, the current mismatch between the plant community and the seed bank could impede big sagebrush range expansion into increasingly suitable habitat in the future.

Wood-plastic composites as promising green-composites for automotive industries!

Science.gov (United States)

Ashori, Alireza

2008-07-01

Wood-plastic composite (WPC) is a very promising and sustainable green material to achieve durability without using toxic chemicals. The term WPCs refers to any composites that contain plant fiber and thermosets or thermoplastics. In comparison to other fibrous materials, plant fibers are in general suitable to reinforce plastics due to relative high strength and stiffness, low cost, low density, low CO2 emission, biodegradability and annually renewable. Plant fibers as fillers and reinforcements for polymers are currently the fastest-growing type of polymer additives. Since automakers are aiming to make every part either recyclable or biodegradable, there still seems to be some scope for green-composites based on biodegradable polymers and plant fibers. From a technical point of view, these bio-based composites will enhance mechanical strength and acoustic performance, reduce material weight and fuel consumption, lower production cost, improve passenger safety and shatterproof performance under extreme temperature changes, and improve biodegradability for the auto interior parts.

Evaluation of the Impact of Weed Control Methods on Quantitative and Qualitative Characteristics of Moldavian Balm; A Medicinal Plant

Directory of Open Access Journals (Sweden)

Janmohammadi Mohsen

2016-12-01

Full Text Available Moldavian balm is an annual herbaceous plant and its lemon-scented leaves contain essential oil. However, weeds adversely affect its growth by release of allelochemicals, and/or direct competition for nutrient, moisture, light and space. Current experiment was conducted to evaluate the different weed control methods including preventive approach (soil pasteurization, mechanical methods (one hand weeding, two hand weeding, and successive hand weeding for weed free condition, and chemical control by synthetic herbicides (haloxyfop-R-methyl and trifluralin. Results revealed that stem diameter, quantity of secondary branches, flower-bearing branches and leaves were significantly affected by weed control treatments; the highest lateral growth was obtained by successive mechanical weed control and two hand weeding method, respectively. This trend was also observed in canopy spread and chlorophyll content. Pre-emergence control by trifluralin considerably accelerated the initiation of flowering in Moldavian balm. However, observation of qualitative traits showed that the highest essential oil content and oil yield was obtained when the plants grew in weed free soil which was pasteurized. Considering the recognized essential oils, the most responsive composition was including Geranial, Geranyl acetate, Neral and Geraniol. The lowest amount of Neral was recorded in postemergence control performed by means of haloxyfop-R-methyl herbicide.

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....

Elemental composition of Chesapeake Bay oyster Crassostrea virginica in the vicinity of Calvert Cliffs Nuclear Power Plant

International Nuclear Information System (INIS)

Gavrilas, M.; Munno, F.J.

1984-01-01

The stable element composition of the American oyster Crassostrea virginica collected between June 1978 and August 1983 in the Chesapeake Bay in the vicinity of Calvert Cliffs Nuclear Power Plant was analyzed by neutron activation. The minimum, maximum and the mean values of the elemental concentrations are given. The seasonal effect and the linear correlation between elements entering the oyster composition are shown. 7 references, 1 figure, 4 tables

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

Composite Transport Model and Water and Solute Transport across Plant Roots: An Update

Directory of Open Access Journals (Sweden)

Yangmin X. Kim

2018-02-01

Full Text Available The present review examines recent experimental findings in root transport phenomena in terms of the composite transport model (CTM. It has been a well-accepted conceptual model to explain the complex water and solute flows across the root that has been related to the composite anatomical structure. There are three parallel pathways involved in the transport of water and solutes in roots – apoplast, symplast, and transcellular paths. The role of aquaporins (AQPs, which facilitate water flows through the transcellular path, and root apoplast is examined in terms of the CTM. The contribution of the plasma membrane bound AQPs for the overall water transport in the whole plant level was varying depending on the plant species, age of roots with varying developmental stages of apoplastic barriers, and driving forces (hydrostatic vs. osmotic. Many studies have demonstrated that the apoplastic barriers, such as Casparian bands in the primary anticlinal walls and suberin lamellae in the secondary cell walls, in the endo- and exodermis are not perfect barriers and unable to completely block the transport of water and some solute transport into the stele. Recent research on water and solute transport of roots with and without exodermis triggered the importance of the extension of conventional CTM adding resistances that arrange in series (epidermis, exodermis, mid-cortex, endodermis, and pericycle. The extension of the model may answer current questions about the applicability of CTM for composite water and solute transport of roots that contain complex anatomical structures with heterogeneous cell layers.

Agricultural Plant Pest Control. Manual 93.

Science.gov (United States)

Missouri Univ., Columbia. Agricultural Experiment Station.

This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides for the agricultural plant pest control category. The text discusses the insect pests including caterpillars, beetles, and soil inhabiting insects; diseases and nematodes; and weeds. Consideration is given…

Probabilistic safety assessment- a tool for configuration control of nuclear power plants

International Nuclear Information System (INIS)

Vijaya, A.K.; Guptan, Rajee; Mohan, Nalini; Ghadge, S.G.; Bajaj, S.S.

2006-01-01

A comprehensive configuration control programme implies a sophisticated set of risk related measures to manage and control concurrent unavailabilities of components, the possibility of functional alternative components, the outage times of the unavailable components and the frequency of critical configurations. These measures are implemented through operational and maintenance activities such as maintenance and test scheduling and scheduling of operational realignments. An appropriate risk based configuration control programme would enable plant personnel to maintain the risk level of the nuclear power plant within an acceptable range during all the operational regimes. Use of plant specific PSA to support configuration control makes it risk based. The PSA can help to identify the measures needed according to the situation to reduce risk to acceptable level. The main benefit of establishing a risk based configuration control programme is the reduction of risk peaks and the control of cumulative or average risk. It helps to ensure that as far as possible, the plant does not enter the critical, high risk situations and other risk significant configurations are avoided A plant specific PSA along with a 'Risk Monitor' can be used as an efficient tool for Configuration Control. (author)

The Effect of Host-Plant Phylogenetic Isolation on Species Richness, Composition and Specialization of Insect Herbivores: A Comparison between Native and Exotic Hosts.

Directory of Open Access Journals (Sweden)

Julio Miguel Grandez-Rios

Full Text Available Understanding the drivers of plant-insect interactions is still a key issue in terrestrial ecology. Here, we used 30 well-defined plant-herbivore assemblages to assess the effects of host plant phylogenetic isolation and origin (native vs. exotic on the species richness, composition and specialization of the insect herbivore fauna on co-occurring plant species. We also tested for differences in such effects between assemblages composed exclusively of exophagous and endophagous herbivores. We found a consistent negative effect of the phylogenetic isolation of host plants on the richness, similarity and specialization of their insect herbivore faunas. Notably, except for Jaccard dissimilarity, the effect of phylogenetic isolation on the insect herbivore faunas did not vary between native and exotic plants. Our findings show that the phylogenetic isolation of host plants is a key factor that influences the richness, composition and specialization of their local herbivore faunas, regardless of the host plant origin.

Calcium constrains plant control over forest ecosystem nitrogen cycling.

Science.gov (United States)

Groffman, Peter M; Fisk, Melany C

2011-11-01

Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

Contribution to the studies on the mineral content of plant material through radioactivation analysis; Contribution a l'etude de la composition minerale des matieres vegetales au moyen de l'analyse par radioactivation

Energy Technology Data Exchange (ETDEWEB)

Fourcy, A [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-03-15

Radioactivation analysis is by its great sensibility or its rapidity quite helpful in plant biology and agronomy. Specific composition of plants and results to obtain in biological experimentation have needed a practical research on analytical methods for plant materials, using for radioactivation swimming-pool reactor neutrons and 14 MeV neutrons from a generator. Dosage process for 25 elements is exposed, taking account of the interest of the analysis for each element, the average amount occurring in plants and the result obtained. Many applications are developed, concerning nutrition physiology, genetics, parasitology, toxicology, control of manufactured agricultural and pharmaceutical products industrial and pesticides residues, ecology, radioecology and biochemistry. (author) [French] L'analyse par radioactivation, par sa grande sensibilite ou sa rapidite, est susceptible de rendre de nombreux services en biologie vegetale et en agronomie. La composition particuliere des plantes et les buts recherches dans l'experimentation ont exige une etude concrete des methodes d'analyse propres a la matiere vegetale en utilisant, pour la radioactivation, soit un reacteur de type piscine a eau legere, soit un accelerateur generateur de neutrons de 14 MeV. Le mode de dosage de 25 elements est expose en tenant compte de l'interet de l'analyse de chaque element, des teneurs moyennes rencontrees dans les plantes, et du resultat atteint. De nombreuses applications sont developpees qui touchent a la physiologie de la nutrition, la genetique, la parasitologie, la toxicologie, le controle des fabrications, les pollutions industrielles, l'ecologie, la radioecologie et la biochimie. (auteur)

Partitioning the relative contributions of inorganic plant composition and soil characteristics to the quality of Helichrysum italicum subsp. italicum (Roth) G. Don fil. essential oil.

Science.gov (United States)

Bianchini, Ange; Santoni, François; Paolini, Julien; Bernardini, Antoine-François; Mouillot, David; Costa, Jean

2009-07-01

Composition of Helichrysum italicum subsp. italicum essential oil showed chemical variability according to vegetation cycle, environment, and geographic origins. In the present work, 48 individuals of this plant at different development stages and the corresponding root soils were sampled: i) 28 volatile components were identified and measured in essential oil by using GC and GC/MS; ii) ten elements from plants and soils have been estimated using colorimetry in continuous flux, flame atomic absorption spectrometry, or emission spectrometry (FAAS/FAES); iii) texture and acidity (real and potential) of soil samples were also reported. Relationships between the essential-oil composition, the inorganic plant composition, and the soil characteristics (inorganic composition, texture, and acidity) have been established using multivariate analysis such as Principal Component Analysis (PCA) and partial Redundancy Analysis (RDA). This study demonstrates a high level of intraspecific differences in oil composition due to environmental factors and, more particularly, soil characteristics.

Optimizing the roles of man and computer in nuclear power plant control

International Nuclear Information System (INIS)

Colley, R.W.; Seeman, S.E.

1983-10-01

We are presently participating in a program to optimize the functional man-machine interface for Liquid Metal-Cooled Fast Breeder Reactors. The overall objective of this program is to enhance operational safety; that is, to accommodate plant incidents through optimal integration of man and machine in performing the functions required to safely control a plant during both normal and off-normal conditions. Purpose of this talk is to describe an approach to determine the optimal roles of man and computer in the control of nuclear power plants. Purpose of this session was to get together people that are working in the areas of understanding of how operators control plants, and working on developing new aids for these operators. We were asked to explain how our modeling and approach we're taking will lead us to an optimization of the roles of the man and the computer in the control of nuclear power plants. Our emphasis was to be on the functions required for plant control, and how the attributes of the human operator and the attributes of the computer can be optimally used to enhance operational safety in performing these functions

THE BIODEGRADABILITY AND MECHANICAL STRENGTH OF NUTRITIVE POTS FOR VEGETABLE PLANTING BASED ON LIGNOCELLULOSE COMPOSITE MATERIALS

Directory of Open Access Journals (Sweden)

Petronela Nechita

2010-04-01

Full Text Available Considering the mild degradation strength and the fact that it may be an organic matter reserve for the soil, in the past years lignocellulosic materials have been used as fibrous raw materials in the manufacture of biodegradable nutritive pots for the seedling in vegetable containerized production. This paper analyses the behavior of the nutritive pots made from biodegradable composites for the vegetable seedling production process, focusing on their mechanical strength properties and biodegradability. It was found that the biodegradability of composite materials obtained from a mixture of secondary cellulosic fibers, peat, and additives, is strongly influenced by the presence or absence of the rhizosphere effect and the synergistic relations set in the culture substrate between the plant roots and microorganisms, which develop permanently the recycling and solubilization of mineral nutrients. The results showed that the presence in the substrate of some complex populations made by heterotrophic bacteria favors full degradation of the pulp and lignin contained in the substrate and pots composition. Therefore, unlike the reference sample (plant-free, cultivated versions exhibited an intense biodegradation on the account of rhizosphere effect.

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

Changes in control room at Swedish nuclear power plants

International Nuclear Information System (INIS)

Kecklund, Lena

2005-09-01

The Swedish nuclear power plants were commissioned during a period between 1972 and 1985 and the instrumentation and control equipment are basically from that period. For several years there have been plans made for changes in all the nuclear power plants and to a certain extent the changes in control equipment and monitoring rooms have also been implemented. The object of this project was to make a comprehensive review of the changes in control room design implemented in the Swedish nuclear power plants and to describe how the MTO- (Man-Technology-Organisation) and (Man-Machine-Interface) -issues have been integrated in the process. The survey is intended to give an overall picture of the changes in control room design and man-machine-interface made in the Swedish control rooms, in order to get a deeper knowledge of the change management process and its results as well as of the management of MTO-issues in these projects. The units included in this survey are: Oskarhamn reactor 2 and 3; Ringhals reactor 2, 3 and 4; Forsmark reactor 1, 2 and 3. The Oskarshamn 1 unit has not been included in this report as it has recently undergone an extensive modernisation program as well as a detailed inspection by the SKI (Swedish Nuclear Power Inspectorate). At Ringhals 2 the modernisation work is carried out at present and the unit is also subjected to extensive inspection activities carried out by SKI and is therefore not part of this survey. This report also includes a short description of relevant standards and requirements. Then follows a presentation of the results of the plant survey, presented as case studies for three companies OKG, Ringhals and FKA. Control room changes are summarized as well as the results on specific MTO issues which has been surveyed. In all the power companies there is a joint way of working with projects concerning plant modifications. This process is described for each company separately. In the concluding of the report the strengths and

A metamorphic controller for plant control system design

Directory of Open Access Journals (Sweden)

Tomasz Klopot

2016-07-01

Full Text Available One of the major problems in the design of industrial control systems is the selection and parameterization of the control algorithm. In practice, the most common solution is the PI (proportional-integral controller, which is simple to implement, but is not always the best control strategy. The use of more advanced controllers may result in a better efficiency of the control system. However, the implementation of advanced control algorithms is more time-consuming and requires specialized knowledge from control engineers. To overcome these problems and to support control engineers at the controller design stage, the paper describes a tool, i.e., a metamorphic controller with extended functionality, for selection and implementation of the most suitable control algorithm. In comparison to existing solutions, the main advantage of the metamorphic controller is its possibility of changing the control algorithm. In turn, the candidate algorithms can be tested through simulations and the total time needed to perform all simulations can be less than a few minutes, which is less than or comparable to the design time in the concurrent design approach. Moreover, the use of well-known tuning procedures, makes the system easy to understand and operate even by inexperienced control engineers. The application was implemented in the real industrial programmable logic controller (PLC and tested with linear and nonlinear virtual plants. The obtained simulation results confirm that the change of the control algorithm allows the control objectives to be achieved at lower costs and in less time.

Medicinal plants used to control internal and external parasites in goats

Directory of Open Access Journals (Sweden)

Marcia Sanhokwe

2016-04-01

Full Text Available The use of medicinal plants plays a major role in the primary health care of animals in South Africa. A survey was conducted to document medicinal plants used to control parasites in goats in Kwezi and Ntambethemba villages in the Eastern Cape Province, South Africa. Information from 50 farmers and 3 herbalists was obtained through the use of a structured questionnaire, and a snowball sampling technique was used to identify key informants. The obtained data were analysed using PROC FREQ of SAS (2003, and fidelity level values were determined to estimate the healing potential of the mentioned plants. The survey revealed nine plant species belonging to eight families that were used to control parasites in goats. Asphodelaceae (22.22% was the most frequently used plant family. Leaves were the most used plant parts, constituting 60.38%. They were prepared either as infusions or decoctions of single plants or in mixtures. Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest fidelity level for their use to control parasites, each scoring 100%, followed by Albuca setosa (83.33%. The study revealed low knowledge about ethnoveterinary medicine in the study area. It also revealed that information on ethno-veterinary medicine in this area is mostly confined to older people and there is danger that this knowledge can be lost before being passed on to other generations. Therefore, there is an urgent need to document information on these plant species so that the future generation can benefit. Further investigation should be carried out to validate the efficacy and safety of the above-mentioned plants so as to provide cheap alternative ways of controlling parasites. Keywords: ailments; ethno-veterinary practices; small ruminant; traditional medicine

Plant neighbour identity matters to belowground interactions under controlled conditions.

Science.gov (United States)

Armas, Cristina; Pugnaire, Francisco Ignacio

2011-01-01

Root competition is an almost ubiquitous feature of plant communities with profound effects on their structure and composition. Far beyond the traditional view that plants interact mainly through resource depletion (exploitation competition), roots are known to be able to interact with their environment using a large variety of mechanisms that may inhibit or enhance access of other roots to the resource or affect plant growth (contest interactions). However, an extensive analysis on how these contest root interactions may affect species interaction abilities is almost lacking. In a common garden experiment with ten perennial plant species we forced pairs of plants of the same or different species to overlap their roots and analyzed how belowground contest interactions affected plant performance, biomass allocation patterns, and competitive abilities under abundant resource supply. Our results showed that net interaction outcome ranged from negative to positive, affecting total plant mass and allocation patterns. A species could be a strong competitor against one species, weaker against another one, and even facilitator to a third species. This leads to sets of species where competitive hierarchies may be clear but also to groups where such rankings are not, suggesting that intransitive root interactions may be crucial for species coexistence. The outcome of belowground contest interactions is strongly dependent on neighbours' identity. In natural plant communities this conditional outcome may hypothetically help species to interact in non-hierarchical and intransitive networks, which in turn might promote coexistence.

Tritium control in reprocessing plants

International Nuclear Information System (INIS)

Goumondy, J.P.; Miquel, P.

1977-01-01

There is a danger that the T which is formed in water reactors will prove detrimental to the environment over the next few years, and studies have been undertaken to develop techniques to contain and process it where possible. In order to retain T, which is present largely in the fuel and on the possible to adapt for use in the conventional design of reprocessing plant. In this process T is maintained in the form of an aqueous solution in the high-active area of the plant. Control is achieved by restricting as far as possible the ingress of non-tritiated water into this area, and by setting up a tritiated water barrier at the first U and Pu extraction stage, stripping the tritium-containing solvent at that point with ordinary water. In this way the T can be extracted in a small volume of water with a view to intermediate storage, disposal at sea additional processing to remove the T from the water. Experiments carried out so far have demonstrated the effectiveness of the T barrier and have shown what equipment would be required for the application of the process in new reprocessing plants. (orig.) [de

Design of control rooms and ergonomics in power plants

International Nuclear Information System (INIS)

Herbst, L.; Hinz, W.

1981-01-01

Modern power plant control rooms are characterized by automation of protection and control functions, subdivision according to functions, computer-aided information processing, and ergonomic design. Automation relieves the personnel of stress. Subdivision according to functions permits optimized procedures. Computer-aided information processing results in variable information output tailored to the actual needs. Ergonomic design assures qualified man-machine interaction. Of course, these characteristics will vary between power plants in dependence of unit power, mode of operation, and safety and availability requirements. (orig.) [de

Study of the influence of central nuclear power plants at Valdaliga (Civitavecchia) on the chemical composition of local rain

International Nuclear Information System (INIS)

Bargagli, A.; Morabito, R.; Basili, N.; Tidei, F.

1989-05-01

Data from a wet deposition sampling over the area collocated nearby Civitavecchia power plants are here presented and discussed. In order to establish the possible influence of the power plants emission on the chemical composition of the rain collected, the experimental data have been correlated with synoptic and local meteorological conditions. (author)

Reliable control system for nuclear power plant

International Nuclear Information System (INIS)

Okamoto, Tetsuo; Miyazaki, Shiro

1980-01-01

The System 1100 for nuclear power plants is the measuring and control system which utilizes the features of the System 1100 for electric power market in addition to the results of nuclear instrumentation with EBS-ZN series, and it has the following features. The maintenance and inspection in operation are easy. The construction of control loops is made flexibly by the combination of modules. The construction of multi-variable control system using mainly feed forward control is easy. Such functions as the automatic switching of control modes can be included. The switching of manual and automatic operations is easy, and if some trouble occurred in a module, the manual operation can be made. The aseismatic ability is improved by rigid structure cubicles. Nonflammable materials are used for wires, multi-core cables, paints and printed boards. The anti-noise characteristics are improved, and the reliability is high. The policy of developing the System 1100 for nuclear power plants, the type approval tests on modules and units and the type approval test on the system are described. The items of the system type approval test were standard performance test, earthquake test, noise isolation test, temperature and humidity test, and drift test. The aseismatic cubicle showed good endurance in its vibration test. (Kako, I.)

Tangible interfaces for virtual nuclear power plant control desk

Energy Technology Data Exchange (ETDEWEB)

Aghina, Mauricio Alves C.; Mol, Antonio Carlos A.; Jorge, Carlos Alexandre F.; Lapa, Celso M.F. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Nomiya, Diogo [Engenharia Eletrica (UFRJ), Universidade Federal do Rio de Janeiro, RJ (Brazil); Cunha, Gerson G.; Landau, Luiz [Programa de Engenharia Civil (PEC/COPPE/UFRJ), Universidade Federal do Rio de Janeiro, RJ (Brazil)

2011-07-01

Due to the high safety requirements for nuclear power plant operation, control desks must be designed in such a way operators can take all the procedures safely, with a good overview of all variable indicators and easy access to actuator controls. Also, operators must see alarms indication in a way they can easily identify any abnormal conditions and bring the NPP back to normal operation. The ergonomics and human factors fields have helped evaluations to improve the design of nuclear power plant control systems. Lately, the use of virtual control desks have helped even more such evaluations, by integrating in one platform both nuclear power plant dynamics simulator with a high visual fidelity control desk proto typing. Operators can interact with these virtual control desks in a similar way as with real ones. Such a virtual control desk has been under development at Instituto de Engenharia Nuclear, IEN/CNEN. This paper reports the latest improvements, with the use of more interaction modes, to turn operation a friendlier task. An automatic speech recognition interface has been implemented as a self-contained system, by accessing directly MS Windows Application Interface, and with online neural network training for spoken commend recognition. Thus, operators can switch among different desk views. Besides this, head tracking interfaces have been integrated with the virtual control desk, to move within desk views according to users head movements. Both marker and markerless-based head tracking interfaces have been implemented. Results are shown and commented. (author)

Tangible interfaces for virtual nuclear power plant control desk

International Nuclear Information System (INIS)

Aghina, Mauricio Alves C.; Mol, Antonio Carlos A.; Jorge, Carlos Alexandre F.; Lapa, Celso M.F.; Nomiya, Diogo; Cunha, Gerson G.; Landau, Luiz

2011-01-01

Due to the high safety requirements for nuclear power plant operation, control desks must be designed in such a way operators can take all the procedures safely, with a good overview of all variable indicators and easy access to actuator controls. Also, operators must see alarms indication in a way they can easily identify any abnormal conditions and bring the NPP back to normal operation. The ergonomics and human factors fields have helped evaluations to improve the design of nuclear power plant control systems. Lately, the use of virtual control desks have helped even more such evaluations, by integrating in one platform both nuclear power plant dynamics simulator with a high visual fidelity control desk proto typing. Operators can interact with these virtual control desks in a similar way as with real ones. Such a virtual control desk has been under development at Instituto de Engenharia Nuclear, IEN/CNEN. This paper reports the latest improvements, with the use of more interaction modes, to turn operation a friendlier task. An automatic speech recognition interface has been implemented as a self-contained system, by accessing directly MS Windows Application Interface, and with online neural network training for spoken commend recognition. Thus, operators can switch among different desk views. Besides this, head tracking interfaces have been integrated with the virtual control desk, to move within desk views according to users head movements. Both marker and markerless-based head tracking interfaces have been implemented. Results are shown and commented. (author)

Implementing plant design changes economically

International Nuclear Information System (INIS)

Seamans, L.D.

1994-01-01

Consumers Power Company, as is the case with most utilities, is challenged by the necessity to control non-modification design changes. At the Consumers' Palisades Nuclear Plant, the challenge was met by the establishment of a project team that developed an innovative comprehensive design control process called Functional Equivalent Substitution (FES). This paper describes: (1) the project team composition; (2) the process development methodology; and (3) the implementation results

Trace elements and essential oil composition in chemotypes of the aromatic plant Origanum vulgare

International Nuclear Information System (INIS)

Kanias, G.D.

1998-01-01

Trace elements, essential oil yield and its percentage composition were determined by neutron activation analysis, hydrodistillation and gas chromatography in two chemotypes of Origanum vulgare L. cultivated in the same field. Statistical tests such as analysis of variance, correlation coefficient, t-test, and multiple correlation were applied. The results showed that the samples contain the highest recorded oil yield for aromatic plants. Also, there is a statistically significant difference between the chemotypes of the plant not only in the predominant compound but in a number of other components. Iron, chromium and scandium showed a negative significant correlation with carvacrol and a positive one with thymol. Europium shows characteristic correlations with chromium, cobalt, iron and scandium within each chemotype of the plant. These correlations could make probable a role of this element in the biosynthesis of the predominant compounds. (author)

Identifying Plant Part Composition of Forest Logging Residue Using Infrared Spectral Data and Linear Discriminant Analysis

Directory of Open Access Journals (Sweden)

Gifty E. Acquah

2016-08-01

Full Text Available As new markets, technologies and economies evolve in the low carbon bioeconomy, forest logging residue, a largely untapped renewable resource will play a vital role. The feedstock can however be variable depending on plant species and plant part component. This heterogeneity can influence the physical, chemical and thermochemical properties of the material, and thus the final yield and quality of products. Although it is challenging to control compositional variability of a batch of feedstock, it is feasible to monitor this heterogeneity and make the necessary changes in process parameters. Such a system will be a first step towards optimization, quality assurance and cost-effectiveness of processes in the emerging biofuel/chemical industry. The objective of this study was therefore to qualitatively classify forest logging residue made up of different plant parts using both near infrared spectroscopy (NIRS and Fourier transform infrared spectroscopy (FTIRS together with linear discriminant analysis (LDA. Forest logging residue harvested from several Pinus taeda (loblolly pine plantations in Alabama, USA, were classified into three plant part components: clean wood, wood and bark and slash (i.e., limbs and foliage. Five-fold cross-validated linear discriminant functions had classification accuracies of over 96% for both NIRS and FTIRS based models. An extra factor/principal component (PC was however needed to achieve this in FTIRS modeling. Analysis of factor loadings of both NIR and FTIR spectra showed that, the statistically different amount of cellulose in the three plant part components of logging residue contributed to their initial separation. This study demonstrated that NIR or FTIR spectroscopy coupled with PCA and LDA has the potential to be used as a high throughput tool in classifying the plant part makeup of a batch of forest logging residue feedstock. Thus, NIR/FTIR could be employed as a tool to rapidly probe/monitor the variability

Reversible Compositional Control of Oxide Surfaces by Electrochemical Potentials

KAUST Repository

Mutoro, Eva

2012-01-05

Perovskite oxides can exhibit a wide range of interesting characteristics such as being catalytically active and electronically/ionically conducting, and thus, they have been used in a number of solid-state devices such as solid oxide fuel cells (SOFCs) and sensors. As the surface compositions of perovskites can greatly influence the catalytic properties, knowing and controlling their surface compositions is crucial to enhance device performance. In this study, we demonstrate that the surface strontium (Sr) and cobalt (Co) concentrations of perovskite-based thin films can be controlled reversibly at elevated temperatures by applying small electrical potential biases. The surface compositional changes of La 0.8Sr 0.2CoO 3-δ (LSC 113), (La 0.5Sr 0.5) 2CoO 4±δ (LSC 214), and LSC 214-decorated LSC 113 films (LSC 113/214) were investigated in situ by utilizing synchrotron-based X-ray photoelectron spectroscopy (XPS), where the largest changes of surface Sr were found for the LSC 113/214 surface. These findings offer the potential of reversibly controlling the surface functionality of perovskites. © 2011 American Chemical Society.

The advanced main control console for next japanese PWR plants

International Nuclear Information System (INIS)

Tsuchiya, A.; Ito, K.; Yokoyama, M.

2001-01-01

The purpose of the improvement of main control room designing in a nuclear power plant is to reduce operators' workload and potential human errors by offering a better working environment where operators can maximize their abilities. In order to satisfy such requirements, the design of main control board applied to Japanese Pressurized Water Reactor (PWR) type nuclear power plant has been continuously modified and improved. the Japanese Pressurized Water Reactor (PWR) Utilities (Electric Power Companies) and Mitsubishi Group have developed an advanced main control board (console) reflecting on the study of human factors, as well as using a state of the art electronics technology. In this report, we would like to introduce the configuration and features of the Advanced Main Control Console for the practical application to the next generation PWR type nuclear power plants including TOMARI No.3 Unit of Hokkaido Electric Power Co., Inc. (author)

Comparison of DUPIC fuel composition heterogeneity control methods

Energy Technology Data Exchange (ETDEWEB)

Choi, Hang Bok; Ko, Won Il [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-08-01

A method to reduce the fuel composition heterogeneity effect on the core performance parameters has been studied for the DUPIC fuel which is made of spent pressurized water reactor (PWR) fuels by a dry refabrication process. This study focuses on the reactivity control method which uses either slightly enriched, depleted, or natural uranium to minimize the cost rise effect on the manufacturing of DUPIC fuel, when adjusting the excess reactivity of the spent PWR fuel. In order to reduce the variation of isotopic composition of the DUPIC fuel, the inter-assembly mixing operation was taken three times. Then, three options have been considered: reactivity control by slightly enriched and depleted uranium, reactivity control by natural uranium for high reactivity spent PWR fuels, and reactivity control by natural uranium for linear reactivity spent PWR fuels. The results of this study have shown that the reactivity of DUPIC fuel can be tightly controlled with the minimum amount of fresh uranium feed. For the reactivity control by slightly enriched and depleted uranium, all the spent PWR fuels can be utilized as the DUPIC fuel and the fraction of fresh uranium feed is 3.4% on an average. For the reactivity control by natural uranium, about 88% of spent PWR fuel can be utilized as the DUPIC fuel when the linear reactivity spent PWR fuels are used, and the amount of natural uranium feed needed to control the DUPIC fuel reactivity is negligible. 13 refs., 6 figs., 16 tabs. (Author)

Endogenous allergens and compositional analysis in the allergenicity assessment of genetically modified plants.

Science.gov (United States)

Fernandez, A; Mills, E N C; Lovik, M; Spoek, A; Germini, A; Mikalsen, A; Wal, J M

2013-12-01

Allergenicity assessment of genetically modified (GM) plants is one of the key pillars in the safety assessment process of these products. As part of this evaluation, one of the concerns is to assess that unintended effects (e.g. over-expression of endogenous allergens) relevant for the food safety have not occurred due to the genetic modification. Novel technologies are now available and could be used as complementary and/or alternative methods to those based on human sera for the assessment of endogenous allergenicity. In view of these developments and as a step forward in the allergenicity assessment of GM plants, it is recommended that known endogenous allergens are included in the compositional analysis as additional parameters to be measured. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quality control during construction of power plants

International Nuclear Information System (INIS)

Hartstern, R.F.

1982-01-01

This paper traces the background and examines the necessity for a program to control quality during the construction phase of a power plant. It also attempts to point out considerations for making these programs cost effective

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.)

Functional diversity of microbial decomposers facilitates plant coexistence in a plant-microbe-soil feedback model.

Science.gov (United States)

Miki, Takeshi; Ushio, Masayuki; Fukui, Shin; Kondoh, Michio

2010-08-10

Theory and empirical evidence suggest that plant-soil feedback (PSF) determines the structure of a plant community and nutrient cycling in terrestrial ecosystems. The plant community alters the nutrient pool size in soil by affecting litter decomposition processes, which in turn shapes the plant community, forming a PSF system. However, the role of microbial decomposers in PSF function is often overlooked, and it remains unclear whether decomposers reinforce or weaken litter-mediated plant control over nutrient cycling. Here, we present a theoretical model incorporating the functional diversity of both plants and microbial decomposers. Two fundamental microbial processes are included that control nutrient mineralization from plant litter: (i) assimilation of mineralized nutrient into the microbial biomass (microbial immobilization), and (ii) release of the microbial nutrients into the inorganic nutrient pool (net mineralization). With this model, we show that microbial diversity may act as a buffer that weakens plant control over the soil nutrient pool, reversing the sign of PSF from positive to negative and facilitating plant coexistence. This is explained by the decoupling of litter decomposability and nutrient pool size arising from a flexible change in the microbial community composition and decomposition processes in response to variations in plant litter decomposability. Our results suggest that the microbial community plays a central role in PSF function and the plant community structure. Furthermore, the results strongly imply that the plant-centered view of nutrient cycling should be changed to a plant-microbe-soil feedback system, by incorporating the community ecology of microbial decomposers and their functional diversity.

Methods of saccharification of polysaccharides in plants

Science.gov (United States)

Howard, John; Fake, Gina

2014-04-29

Saccharification of polysaccharides of plants is provided, where release of fermentable sugars from cellulose is obtained by adding plant tissue composition. Production of glucose is obtained without the need to add additional .beta.-glucosidase. Adding plant tissue composition to a process using a cellulose degrading composition to degrade cellulose results in an increase in the production of fermentable sugars compared to a process in which plant tissue composition is not added. Using plant tissue composition in a process using a cellulose degrading enzyme composition to degrade cellulose results in decrease in the amount of cellulose degrading enzyme composition or exogenously applied cellulase required to produce fermentable sugars.

CHAP: a composite nuclear plant simulation program applied to the 3000 MW(t) HTGR

International Nuclear Information System (INIS)

Secker, P.A.; Bailey, P.G.; Gilbert, J.S.; Willcutt, G.J.E. Jr.; Vigil, J.C.

1977-01-01

The Composite HTGR Analysis Program (CHAP) is a general systems analysis program which has been developed at LASL. The program is being used for simulating large HTGR nuclear power plant operation and accident transients. The general features and analytical methods of the CHAP program are discussed. Features of the large HTGR model and results of model transients are also presented

Aromatic Medicinal Plants of the Lamiaceae Family from Uzbekistan: Ethnopharmacology, Essential Oils Composition, and Biological Activities

Directory of Open Access Journals (Sweden)

Nilufar Z. Mamadalieva

2017-02-01

Full Text Available Plants of the Lamiaceae family are important ornamental, medicinal, and aromatic plants, many of which produce essential oils that are used in traditional and modern medicine, and in the food, cosmetics, and pharmaceutical industry. Various species of the genera Hyssopus, Leonurus, Mentha, Nepeta, Origanum, Perovskia, Phlomis, Salvia, Scutellaria, and Ziziphora are widespread throughout the world, are the most popular plants in Uzbek traditional remedies, and are often used for the treatment of wounds, gastritis, infections, dermatitis, bronchitis, and inflammation. Extensive studies of the chemical components of these plants have led to the identification of many compounds, as well as essentials oils, with medicinal and other commercial values. The purpose of this review is to provide a critical overview of the literature surrounding the traditional uses, ethnopharmacology, biological activities, and essential oils composition of aromatic plants of the family Lamiaceae, from the Uzbek flora.

A Business Case for Nuclear Plant Control Room Modernization

International Nuclear Information System (INIS)

Thomas, Ken; Lawrie, Sean; Niedermuller, Josef M.

2016-01-01

This paper presents a generic business case for implementation of technology that supports Control Room Modernization (CRM). The analysis presented in two forms; 1) a standalone technology upgrade, and 2) a technology upgrade that is built upon and incremental to a prior business case created for Mobile Work Packages (MWP). The business case contends that advanced communication and networking and analytical technologies will allow NPP to conduct control room operations with improved focus by reducing human factors and redundant manpower, and therefore operate with fewer errors. While some labor savings can be harvested in terms of overtime, the majority of savings are demonstrated as reduced time to take the plant off line and bring back on line in support of outages. The benefits are quantified to a rough order of magnitude that provides directional guidance to NPPs that are interested in developing a similar business case. This business case focuses on modernization of the operator control room and does not consider a complete overhaul and modernization of a plants instrument and control systems. While operators may be considering such an investment at their plants, the sizable capital investment required is not likely supported by a cost/benefit analysis alone. More likely, it is driven by obsolescence and reliability issues, and requires consideration of mechanical condition of plant systems, capital depreciation, financing, relicensing and overall viability of the plant asset over a 20-year horizon in a competitive market. Prior studies [REF] have indicated that such a modernization of plant I&C systems, alone or as part of a larger modernization effort, can yield very significant reductions in O&M costs. However, the depth of research and analysis required to develop a meaningful business case for a plant modernization effort is well beyond the scope of this study. While CRM as considered in this study can be easily integrated as part of grander plant

A Business Case for Nuclear Plant Control Room Modernization

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ken [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lawrie, Sean [Idaho National Lab. (INL), Idaho Falls, ID (United States); Niedermuller, Josef M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-06-01

This paper presents a generic business case for implementation of technology that supports Control Room Modernization (CRM). The analysis presented in two forms; 1) a standalone technology upgrade, and 2) a technology upgrade that is built upon and incremental to a prior business case created for Mobile Work Packages (MWP). The business case contends that advanced communication and networking and analytical technologies will allow NPP to conduct control room operations with improved focus by reducing human factors and redundant manpower, and therefore operate with fewer errors. While some labor savings can be harvested in terms of overtime, the majority of savings are demonstrated as reduced time to take the plant off line and bring back on line in support of outages. The benefits are quantified to a rough order of magnitude that provides directional guidance to NPPs that are interested in developing a similar business case. This business case focuses on modernization of the operator control room and does not consider a complete overhaul and modernization of a plants instrument and control systems. While operators may be considering such an investment at their plants, the sizable capital investment required is not likely supported by a cost/benefit analysis alone. More likely, it is driven by obsolescence and reliability issues, and requires consideration of mechanical condition of plant systems, capital depreciation, financing, relicensing and overall viability of the plant asset over a 20-year horizon in a competitive market. Prior studies [REF] have indicated that such a modernization of plant I&C systems, alone or as part of a larger modernization effort, can yield very significant reductions in O&M costs. However, the depth of research and analysis required to develop a meaningful business case for a plant modernization effort is well beyond the scope of this study. While CRM as considered in this study can be easily integrated as part of grander plant

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.

Plant community composition and species richness in the High Arctic tundra: from the present to the future

DEFF Research Database (Denmark)

Nabe-Nielsen, Jacob; Normand, Signe; Hui, Francis K.C.

2017-01-01

of these conditions is limited due to the scarcity of studies, especially in the High Arctic. 2. We investigated variations in vascular plant community composition and species richness based on 288 plots distributed on three sites along a coast-inland gradient in Northeast Greenland using a stratified random design......1. Arctic plant communities are altered by climate changes. The magnitude of these alterations depends on whether species distributions are determined by macroclimatic conditions, by factors related to local topography, or by biotic interactions. Our current understanding of the relative importance....... We used an information theoretic approach to determine whether variations in species richness were best explained by macroclimate, by factors related to local topography (including soil water) or by plant-plant interactions. Latent variable models were used to explain patterns in plant community...

Choosing Actuators for Automatic Control Systems of Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Gorbunov, A. I., E-mail: gor@tornado.nsk.ru [JSC “Tornado Modular Systems” (Russian Federation); Serdyukov, O. V. [Siberian Branch of the Russian Academy of Sciences, Institute of Automation and Electrometry (Russian Federation)

2015-03-15

Two types of actuators for automatic control systems of thermal power plants are analyzed: (i) pulse-controlled actuator and (ii) analog-controlled actuator with positioning function. The actuators are compared in terms of control circuit, control accuracy, reliability, and cost.