Optimal Multi-scale Demand-side Management for Continuous Power-Intensive Processes

Science.gov (United States)

Mitra, Sumit

With the advent of deregulation in electricity markets and an increasing share of intermittent power generation sources, the profitability of industrial consumers that operate power-intensive processes has become directly linked to the variability in energy prices. Thus, for industrial consumers that are able to adjust to the fluctuations, time-sensitive electricity prices (as part of so-called Demand-Side Management (DSM) in the smart grid) offer potential economical incentives. In this thesis, we introduce optimization models and decomposition strategies for the multi-scale Demand-Side Management of continuous power-intensive processes. On an operational level, we derive a mode formulation for scheduling under time-sensitive electricity prices. The formulation is applied to air separation plants and cement plants to minimize the operating cost. We also describe how a mode formulation can be used for industrial combined heat and power plants that are co-located at integrated chemical sites to increase operating profit by adjusting their steam and electricity production according to their inherent flexibility. Furthermore, a robust optimization formulation is developed to address the uncertainty in electricity prices by accounting for correlations and multiple ranges in the realization of the random variables. On a strategic level, we introduce a multi-scale model that provides an understanding of the value of flexibility of the current plant configuration and the value of additional flexibility in terms of retrofits for Demand-Side Management under product demand uncertainty. The integration of multiple time scales leads to large-scale two-stage stochastic programming problems, for which we need to apply decomposition strategies in order to obtain a good solution within a reasonable amount of time. Hence, we describe two decomposition schemes that can be applied to solve two-stage stochastic programming problems: First, a hybrid bi-level decomposition scheme with

Large scale PV plants - also in Denmark. Project report

Energy Technology Data Exchange (ETDEWEB)

Ahm, P [PA Energy, Malling (Denmark); Vedde, J [SiCon. Silicon and PV consulting, Birkeroed (Denmark)

2011-04-15

Large scale PV (LPV) plants, plants with a capacity of more than 200 kW, has since 2007 constituted an increasing share of the global PV installations. In 2009 large scale PV plants with cumulative power more that 1,3 GWp were connected to the grid. The necessary design data for LPV plants in Denmark are available or can be found, although irradiance data could be improved. There seems to be very few institutional barriers for LPV projects, but as so far no real LPV projects have been processed, these findings have to be regarded as preliminary. The fast growing number of very large scale solar thermal plants for district heating applications supports these findings. It has further been investigated, how to optimize the lay-out of LPV plants. Under the Danish irradiance conditions with several winter months with very low solar height PV installations on flat surfaces will have to balance the requirements of physical space - and cost, and the loss of electricity production due to shadowing effects. The potential for LPV plants in Denmark are found in three main categories: PV installations on flat roof of large commercial buildings, PV installations on other large scale infrastructure such as noise barriers and ground mounted PV installations. The technical potential for all three categories is found to be significant and in the range of 50 - 250 km2. In terms of energy harvest PV plants will under Danish conditions exhibit an overall efficiency of about 10 % in conversion of the energy content of the light compared to about 0,3 % for biomass. The theoretical ground area needed to produce the present annual electricity consumption of Denmark at 33-35 TWh is about 300 km2 The Danish grid codes and the electricity safety regulations mention very little about PV and nothing about LPV plants. It is expected that LPV plants will be treated similarly to big wind turbines. A number of LPV plant scenarios have been investigated in detail based on real commercial offers and

Safeguarding of large scale reprocessing and MOX plants

International Nuclear Information System (INIS)

Howsley, R.; Burrows, B.; Longevialle, H. de; Kuroi, H.; Izumi, A.

1997-01-01

In May 97, the IAEA Board of Governors approved the final measures of the ''93+2'' safeguards strengthening programme, thus improving the international non-proliferation regime by enhancing the effectiveness and efficiency of safeguards verification. These enhancements are not however, a revolution in current practices, but rather an important step in the continuous evolution of the safeguards system. The principles embodied in 93+2, for broader access to information and increased physical access already apply, in a pragmatic way, to large scale reprocessing and MOX fabrication plants. In these plants, qualitative measures and process monitoring play an important role in addition to accountancy and material balance evaluations in attaining the safeguard's goals. This paper will reflect on the safeguards approaches adopted for these large bulk handling facilities and draw analogies, conclusions and lessons for the forthcoming implementation of the 93+2 Programme. (author)

Real-Time Monitoring System for a Utility-Scale Photovoltaic Power Plant.

Science.gov (United States)

Moreno-Garcia, Isabel M; Palacios-Garcia, Emilio J; Pallares-Lopez, Victor; Santiago, Isabel; Gonzalez-Redondo, Miguel J; Varo-Martinez, Marta; Real-Calvo, Rafael J

2016-05-26

There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant's components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid.

Real-Time Monitoring System for a Utility-Scale Photovoltaic Power Plant

Science.gov (United States)

Moreno-Garcia, Isabel M.; Palacios-Garcia, Emilio J.; Pallares-Lopez, Victor; Santiago, Isabel; Gonzalez-Redondo, Miguel J.; Varo-Martinez, Marta; Real-Calvo, Rafael J.

2016-01-01

There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant’s components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid. PMID:27240365

Real-Time Monitoring System for a Utility-Scale Photovoltaic Power Plant

Directory of Open Access Journals (Sweden)

Isabel M. Moreno-Garcia

2016-05-01

Full Text Available There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant’s components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid.

A model for continuous improvement at a South African minerals benefication plant

Directory of Open Access Journals (Sweden)

Ras, Eugene Ras

2015-05-01

Full Text Available South Africa has a variety of mineral resources, and several minerals beneficiation plants are currently in operation. These plants must be operated effectively to ensure that the end-users of its products remain internationally competitive. To achieve this objective, plants need a sustainable continuous improvement programme. Several frameworks for continuous improvement are used, with variable success rates, in beneficiation plants around the world. However, none of these models specifically addresses continuous improvement from a minerals-processing point of view. The objective of this research study was to determine which factors are important for a continuous improvement model at a minerals beneficiation plant, and to propose a new model using lean manufacturing, six sigma, and the theory of constraints. A survey indicated that managers in the industry prefer a model that combines various continuous improvement models.

Continuous recycling of enzymes during production of lignocellulosic bioethanol in demonstration scale

International Nuclear Information System (INIS)

Haven, Mai Østergaard; Lindedam, Jane; Jeppesen, Martin Dan; Elleskov, Michael; Rodrigues, Ana Cristina; Gama, Miguel; Jørgensen, Henning; Felby, Claus

2015-01-01

Highlights: • Results from continuous experiments in demonstration scale for a total of 16 days. • Reuse of enzymes is possible through recycling fermentation broth. • Recycling fermentation broth can increase ethanol concentration with lower dry matter. - Abstract: Recycling of enzymes in production of lignocellulosic bioethanol has been tried for more than 30 years. So far, the successes have been few and the experiments have been carried out at conditions far from those in an industrially feasible process. Here we have tested continuous enzyme recycling at demonstration scale using industrial process conditions (high dry matter content and low enzyme dosage) for a period of eight days. The experiment was performed at the Inbicon demonstration plant (Kalundborg, Denmark) capable of converting four tonnes of wheat straw per hour. 20% of the fermentation broth was recycled to the hydrolysis reactor while enzyme dosage was reduced by 5%. The results demonstrate that recycling enzymes by this method can reduce overall enzyme consumption and may also increase the ethanol concentrations in the fermentation broth. Our results further show that recycling fermentation broth also opens up the possibility of lowering the dry matter content in hydrolysis and fermentation while still maintaining high ethanol concentrations.

NONLINEAR PLANT PIECEWISE-CONTINUOUS MODEL MATRIX PARAMETERS ESTIMATION

Directory of Open Access Journals (Sweden)

Roman L. Leibov

2017-09-01

Full Text Available This paper presents a nonlinear plant piecewise-continuous model matrix parameters estimation technique using nonlinear model time responses and random search method. One of piecewise-continuous model application areas is defined. The results of proposed approach application for aircraft turbofan engine piecewisecontinuous model formation are presented

Responses and damages during long-term continuous irradiation in plants

International Nuclear Information System (INIS)

Watanabe, Yoshito

2011-01-01

Effects of long-term continuous irradiation are relevant to studies in radiation ecotoxicology. To investigate plants biological responses to continuous irradiation, we performed metabolome and transcriptome analysis in a model plant, arabidopsis. Comprehensive analysis of primary metabolites using capillary electrophoresis mass spectrometry revealed extensive metabolic changes at early onset of growth inhibition in plants exposed to gamma rays at the dose rate of 20 Gy/day. The changes included elevated levels of B vitamins and second metabolites, commonly responsive to many abiotic and biotic stresses. Responses at early onset of growth inhibition were also observed in the transcriptome analysis using microarray, which showed up-regulation of 55 genes in plants exposed to gamma rays at 20 Gy/day. Although about a half of the up-regulated genes were also responsive just after acute irradiation, the other half was responsive only during long-term continuous irradiation. Database analyses showed that the specifically up-regulated genes to long-term continuous irradiation included genes relating to general stress responses and protein metabolism. The results of these analyses appear to reflect plants responses to progressive radiation damages, from radiation-specific responses, which repair primary DNA damage, to more general stress responses, which maintain homoeostasis against secondary damages. (author)

An Automated and Continuous Plant Weight Measurement System for Plant Factory.

Science.gov (United States)

Chen, Wei-Tai; Yeh, Yu-Hui F; Liu, Ting-Yu; Lin, Ta-Te

2016-01-01

In plant factories, plants are usually cultivated in nutrient solution under a controllable environment. Plant quality and growth are closely monitored and precisely controlled. For plant growth evaluation, plant weight is an important and commonly used indicator. Traditional plant weight measurements are destructive and laborious. In order to measure and record the plant weight during plant growth, an automated measurement system was designed and developed herein. The weight measurement system comprises a weight measurement device and an imaging system. The weight measurement device consists of a top disk, a bottom disk, a plant holder and a load cell. The load cell with a resolution of 0.1 g converts the plant weight on the plant holder disk to an analog electrical signal for a precise measurement. The top disk and bottom disk are designed to be durable for different plant sizes, so plant weight can be measured continuously throughout the whole growth period, without hindering plant growth. The results show that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system; hence, plant weight can be measured by either method. The weight growth of selected vegetables growing in the National Taiwan University plant factory were monitored and measured using our automated plant growth weight measurement system. The experimental results demonstrate the functionality, stability and durability of this system. The information gathered by this weight system can be valuable and beneficial for hydroponic plants monitoring research and agricultural research applications.

An Automated and Continuous Plant Weight Measurement System for Plant Factory

Directory of Open Access Journals (Sweden)

Wei-Tai eChen

2016-03-01

Full Text Available In plant factories, plants are usually cultivated in nutrient solution under a controllable environment. Plant quality and growth are closely monitored and precisely controlled. For plant growth evaluation, plant weight is an important and commonly used indicator. Traditional plant weight measurements are destructive and laborious. In order to measure and record the plant weight during plant growth, an automated measurement system was designed and developed herein. The weight measurement system comprises a weight measurement device and an imaging system. The weight measurement device consists of a top disk, a bottom disk, a plant holder and a load cell. The load cell with a resolution of 0.1 g converts the plant weight on the plant holder disk to an analogue electrical signal for a precise measurement. The top disk and bottom disk are designed to be durable for different plant sizes, so plant weight can be measured continuously throughout the whole growth period, without hindering plant growth. The results show that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system; hence, plant weight can be measured by either method. The weight growth of selected vegetables growing in the National Taiwan University plant factory were monitored and measured using our automated plant growth weight measurement system. The experimental results demonstrate the functionality, stability and durability of this system. The information gathered by this weight system can be valuable and beneficial for hydroponic plants monitoring research and agricultural research applications.

On the random cascading model study of anomalous scaling in multiparticle production with continuously diminishing scale

International Nuclear Information System (INIS)

Liu Lianshou; Zhang Yang; Wu Yuanfang

1996-01-01

The anomalous scaling of factorial moments with continuously diminishing scale is studied using a random cascading model. It is shown that the model currently used have the property of anomalous scaling only for descrete values of elementary cell size. A revised model is proposed which can give good scaling property also for continuously varying scale. It turns out that the strip integral has good scaling property provided the integral regions are chosen correctly, and that this property is insensitive to the concrete way of self-similar subdivision of phase space in the models. (orig.)

Continuous emission monitoring systems for power plants. The state-of-the-art

International Nuclear Information System (INIS)

Bamberger, J.A.

1988-01-01

Continuous monitoring of power plant emissions is performed to improve combustion and control equipment efficiency, and in response to various government agency requirements. This paper focuses upon recent developments in Continuous Emission Monitoring (CEM) and Systems (CEMS) for power plants. Topics presented include the perspective of the U.S. Environmental Protection Agency and the states: Continuous Monitoring of Power Plant Emissions - An EPA Perspective; Pennsylvania's Proposed Continuous Emission Monitoring System Data Telemetry Requirements for Municipal, Hospital and Infectious Waste Incinerators; the importance of quality assurance; Continuous Emission Monitoring and Quality Assurance Requirements for New Power Plants; Highlights of Pennsylvania's Continuous Emission Monitoring System Quality Assurance Program; improved system specifications and data acquisition methods; Improved Specifications for Continuous Emission Monitoring; A Microcomputer-Based Data Acquisition System for CEMS; CEMS applications; Expanded Use of CEMS in Acid Rain Control Programs: Opinions of Users, Control Agencies and Vendors; and an innovative measurement technique to assess electrostatic precipitator performance; The Assessment of Pulverized Coal Fly Ash Collection in Electrostatic Precipitators Using an Instrumental Assessment Technique

[Modeling continuous scaling of NDVI based on fractal theory].

Science.gov (United States)

Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

2013-07-01

Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.

Scaling of Calcium Carbonate at Heated Surfaces in a Continuous System

OpenAIRE

Nergaard, Margrethe

2011-01-01

Scaling is the precipitation of a mineral layer on a surface. Sparingly soluble salts with inverse solubility, which calcium carbonate exhibits, will prefer precipitation at heated surfaces, making heat exchangers a target for scale formation. A continuous setup was used to study scale formation, the nature of the scale formed and scaling rate. An internally heated U-shaped tube was inserted into a continuously stirred tank, giving the same conditions for all scaling points. The experimental ...

French industrial plant AVM for continuous vitrification of high level radioactive wastes

International Nuclear Information System (INIS)

Bonniaud, Roger; Sombret, Claude; Barbe, Alain

1975-01-01

The A.V.M. plant is a continuous process plant now under construction at Marcoule and intended for vitrifying the whole of fission product solutions from the C.E.A. (Commissariat a l'Energie Atomique) - Marcoule reprocessing plant. The outset of the construction took place in the second 1974 half year; the first radioactive run is scheduled in July 1977. The two steps of the process are shown: first a continuous calcination then a continuous glass making from the calcined product and suitable additives. The plant consists in two parts: vitrification and storage facilities. Some wastes will be continuously produced day after day due to gas clean up and worn out materials. Characteristics of the solutions processed, calcined products, glass composition, and expected liquid wastes are given in tables [fr

9 CFR 590.24 - Egg products plants requiring continuous inspection.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Egg products plants requiring..., DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Scope of Inspection § 590.24 Egg products plants requiring continuous inspection. No plant in...

Profitability and sustainability of small - medium scale palm biodiesel plant

Science.gov (United States)

Solikhah, Maharani Dewi; Kismanto, Agus; Raksodewanto, Agus; Peryoga, Yoga

2017-06-01

The mandatory of biodiesel application at 20% blending (B20) has been started since January 2016. It creates huge market for biodiesel industry. To build large-scale biodiesel plant (> 100,000 tons/year) is most favorable for biodiesel producers since it can give lower production cost. This cost becomes a challenge for small - medium scale biodiesel plants. However, current biodiesel plants in Indonesia are located mainly in Java and Sumatra, which then distribute biodiesel around Indonesia so that there is an additional cost for transportation from area to area. This factor becomes an opportunity for the small - medium scale biodiesel plants to compete with the large one. This paper discusses the profitability of small - medium scale biodiesel plants conducted on a capacity of 50 tons/day using CPO and its derivatives. The study was conducted by performing economic analysis between scenarios of biodiesel plant that using raw material of stearin, PFAD, and multi feedstock. Comparison on the feasibility of scenarios was also conducted on the effect of transportation cost and selling price. The economic assessment shows that profitability is highly affected by raw material price so that it is important to secure the source of raw materials and consider a multi-feedstock type for small - medium scale biodiesel plants to become a sustainable plant. It was concluded that the small - medium scale biodiesel plants will be profitable and sustainable if they are connected to palm oil mill, have a captive market, and are located minimally 200 km from other biodiesel plants. The use of multi feedstock could increase IRR from 18.68 % to 56.52 %.

Advanced techniques for energy-efficient industrial-scale continuous chromatography

Energy Technology Data Exchange (ETDEWEB)

DeCarli, J.P. II (Dow Chemical Co., Midland, MI (USA)); Carta, G. (Virginia Univ., Charlottesville, VA (USA). Dept. of Chemical Engineering); Byers, C.H. (Oak Ridge National Lab., TN (USA))

1989-11-01

Continuous annular chromatography (CAC) is a developing technology that allows truly continuous chromatographic separations. Previous work has demonstrated the utility of this technology for the separation of various materials by isocratic elution on a bench scale. Novel applications and improved operation of the process were studied in this work, demonstrating that CAC is a versatile apparatus which is capable of separations at high throughput. Three specific separation systems were investigated. Pilot-scale separations at high loadings were performed using an industrial sugar mixture as an example of scale-up for isocratic separations. Bench-scale experiments of a low concentration metal ion mixture were performed to demonstrate stepwise elution, a chromatographic technique which decreases dilution and increases sorbent capacity. Finally, the separation of mixtures of amino acids by ion exchange was investigated to demonstrate the use of displacement development on the CAC. This technique, which perhaps has the most potential, when applied to the CAC allowed simultaneous separation and concentration of multicomponent mixtures on a continuous basis. Mathematical models were developed to describe the CAC performance and optimize the operating conditions. For all the systems investigated, the continuous separation performance of the CAC was found to be very nearly the same as the batchwise performance of conventional chromatography. the technology appears, thus, to be very promising for industrial applications. 43 figs., 9 tabs.

Acceptability analysis of technical-scale plants for electricity generation; Ansatz zur Akzeptabilitaetsanalyse grosstechnischer Anlagen zur Stromerzeugung

Energy Technology Data Exchange (ETDEWEB)

Schubert, Katharina; Koch, Marco K. [Bochum Univ. (Germany). AG Reaktorsimulation und -sicherheit

2013-03-15

Public acceptance of technical-scale plants for electricity generation is an indispensable prerequisite for the long-term continuity of supply of electricity. Even though nuclear power in Germany continues to meet with particularly grave objections, this is no longer an exception. Problems associated with the rapidly declining willingness of the public to accept specific disadvantages connected with electricity generation are confronting not only nuclear, but also large fossil-fired and renewable-resource power plants. To investigate to what extent these objections based on subjective heuristics are justified, a model is developed for analyzing the objective acceptability of electricity-producing large power plants, which allows the assessment of their acceptability to be measured on the basis of quantitative analysis of the discrepancies between acceptability and acceptance and may serve as a tool for promoting public acceptance. (orig.)

Tracing disinfection byproducts in full-scale desalination plants

KAUST Repository

Le Roux, Julien; Nada, Nabil A.; Khan, Muhammad; Croue, Jean-Philippe

2015-01-01

-scale desalination plants. One thermal multi-stage flash distillation (MSF) plant and two reverse osmosis (RO) plants located on the Red Sea coast of Saudi Arabia. DBPs formed during the prechlorination step were efficiently removed along the treatment processes (MSF

On generalized scaling laws with continuously varying exponents

International Nuclear Information System (INIS)

Sittler, Lionel; Hinrichsen, Haye

2002-01-01

Many physical systems share the property of scale invariance. Most of them show ordinary power-law scaling, where quantities can be expressed as a leading power law times a scaling function which depends on scaling-invariant ratios of the parameters. However, some systems do not obey power-law scaling, instead there is numerical evidence for a logarithmic scaling form, in which the scaling function depends on ratios of the logarithms of the parameters. Based on previous ideas by Tang we propose that this type of logarithmic scaling can be explained by a concept of local scaling invariance with continuously varying exponents. The functional dependence of the exponents is constrained by a homomorphism which can be expressed as a set of partial differential equations. Solving these equations we obtain logarithmic scaling as a special case. The other solutions lead to scaling forms where logarithmic and power-law scaling are mixed

Biomethanol production from gasification of non-woody plant in South Africa: Optimum scale and economic performance

International Nuclear Information System (INIS)

Amigun, Bamikole; Gorgens, Johann; Knoetze, Hansie

2010-01-01

Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW th . The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW th to about 6.44 R/l for a 60 MW th and 3.95 R/l for a 400 MW th methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW th , but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW th plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons.

Biomethanol production from gasification of non-woody plant in South Africa: Optimum scale and economic performance

Energy Technology Data Exchange (ETDEWEB)

Amigun, Bamikole, E-mail: bamigun@csir.co.z [Sustainable Energy Futures, Natural Resources and the Environment, Council for Scientific and Industrial Research (CSIR), Pretoria (South Africa); Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa); Gorgens, Johann; Knoetze, Hansie [Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa)

2010-01-15

Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW{sub th}. The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW{sub th} to about 6.44 R/l for a 60 MW{sub th} and 3.95 R/l for a 400 MW{sub th} methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW{sub th}, but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW{sub th} plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons.

Biomethanol production from gasification of non-woody plant in South Africa. Optimum scale and economic performance

Energy Technology Data Exchange (ETDEWEB)

Amigun, Bamikole [Sustainable Energy Futures, Natural Resources and the Environment, Council for Scientific and Industrial Research (CSIR), Pretoria (South Africa); Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa); Gorgens, Johann; Knoetze, Hansie [Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa)

2010-01-15

Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW{sub th}. The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW{sub th} to about 6.44 R/l for a 60 MW{sub th} and 3.95 R/l for a 400 MW{sub th} methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW{sub th}, but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW{sub th} plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons. (author)

Distributed continuous energy scheduling for dynamic virtual power plants

International Nuclear Information System (INIS)

Niesse, Astrid

2015-01-01

This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

New scale-down methodology from commercial to lab scale to optimize plant-derived soft gel capsule formulations on a commercial scale.

Science.gov (United States)

Oishi, Sana; Kimura, Shin-Ichiro; Noguchi, Shuji; Kondo, Mio; Kondo, Yosuke; Shimokawa, Yoshiyuki; Iwao, Yasunori; Itai, Shigeru

2018-01-15

A new scale-down methodology from commercial rotary die scale to laboratory scale was developed to optimize a plant-derived soft gel capsule formulation and eventually manufacture superior soft gel capsules on a commercial scale, in order to reduce the time and cost for formulation development. Animal-derived and plant-derived soft gel film sheets were prepared using an applicator on a laboratory scale and their physicochemical properties, such as tensile strength, Young's modulus, and adhesive strength, were evaluated. The tensile strength of the animal-derived and plant-derived soft gel film sheets was 11.7 MPa and 4.41 MPa, respectively. The Young's modulus of the animal-derived and plant-derived soft gel film sheets was 169 MPa and 17.8 MPa, respectively, and both sheets showed a similar adhesion strength of approximately 4.5-10 MPa. Using a D-optimal mixture design, plant-derived soft gel film sheets were prepared and optimized by varying their composition, including variations in the mass of κ-carrageenan, ι-carrageenan, oxidized starch and heat-treated starch. The physicochemical properties of the sheets were evaluated to determine the optimal formulation. Finally, plant-derived soft gel capsules were manufactured using the rotary die method and the prepared soft gel capsules showed equivalent or superior physical properties compared with pre-existing soft gel capsules. Therefore, we successfully developed a new scale-down methodology to optimize the formulation of plant-derived soft gel capsules on a commercial scale. Copyright © 2017 Elsevier B.V. All rights reserved.

Scaling laws and technology development strategies for biorefineries and bioenergy plants.

Science.gov (United States)

Jack, Michael W

2009-12-01

The economies of scale of larger biorefineries or bioenergy plants compete with the diseconomies of scale of transporting geographically distributed biomass to a central location. This results in an optimum plant size that depends on the scaling parameters of the two contributions. This is a fundamental aspect of biorefineries and bioenergy plants and has important consequences for technology development as "bigger is better" is not necessarily true. In this paper we explore the consequences of these scaling effects via a simplified model of biomass transportation and plant costs. Analysis of this model suggests that there is a need for much more sophisticated technology development strategies to exploit the consequences of these scaling effects. We suggest three potential strategies in terms of the scaling parameters of the system.

Digital simulation of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant

International Nuclear Information System (INIS)

Ray, A.; Bowman, H.F.

1978-01-01

A nonlinear dynamic model of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant was derived in state-space form from fundamental principles. The plant model is 40th order, time-invariant, deterministic and continuous-time. Numerical results were obtained by digital simulation. Steady-state performance of the nonlinear model was verified with plant heat balance data at 100, 75 and 50 percent load levels. Local stability, controllability and observability were examined in this range using standard linear algorithms. Transfer function matrices for the linearized models were also obtained. Transient response characteristics of 6 system variables for independent step distrubances in 2 different input variables are presented as typical results

Mapping multi-scale vascular plant richness in a forest landscape with integrated LiDAR and hyperspectral remote-sensing.

Science.gov (United States)

Hakkenberg, C R; Zhu, K; Peet, R K; Song, C

2018-02-01

The central role of floristic diversity in maintaining habitat integrity and ecosystem function has propelled efforts to map and monitor its distribution across forest landscapes. While biodiversity studies have traditionally relied largely on ground-based observations, the immensity of the task of generating accurate, repeatable, and spatially-continuous data on biodiversity patterns at large scales has stimulated the development of remote-sensing methods for scaling up from field plot measurements. One such approach is through integrated LiDAR and hyperspectral remote-sensing. However, despite their efficiencies in cost and effort, LiDAR-hyperspectral sensors are still highly constrained in structurally- and taxonomically-heterogeneous forests - especially when species' cover is smaller than the image resolution, intertwined with neighboring taxa, or otherwise obscured by overlapping canopy strata. In light of these challenges, this study goes beyond the remote characterization of upper canopy diversity to instead model total vascular plant species richness in a continuous-cover North Carolina Piedmont forest landscape. We focus on two related, but parallel, tasks. First, we demonstrate an application of predictive biodiversity mapping, using nonparametric models trained with spatially-nested field plots and aerial LiDAR-hyperspectral data, to predict spatially-explicit landscape patterns in floristic diversity across seven spatial scales between 0.01-900 m 2 . Second, we employ bivariate parametric models to test the significance of individual, remotely-sensed predictors of plant richness to determine how parameter estimates vary with scale. Cross-validated results indicate that predictive models were able to account for 15-70% of variance in plant richness, with LiDAR-derived estimates of topography and forest structural complexity, as well as spectral variance in hyperspectral imagery explaining the largest portion of variance in diversity levels. Importantly

Continuous thermal degradation of pyrolytic oil in a bench scale CSTR reaction system

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyong Hwan; Nam, Ki Yun [Climate Change Technology Research Division, Korea Institute of Energy Research, 102 Gajeong-ro, Yuseong-gu, Daejeon 305-343 (Korea)

2010-05-15

Continuous thermal degradation of two pyrolytic oils with low (LPO) and high boiling point distribution (HPO) was conducted in a constant stirrer tank reactor (CSTR) with bench scale. Raw pyrolytic oil as a reactant was obtained from the commercial rotary kiln pyrolysis plant for municipal plastic waste. The degradation experiment was conducted by temperature programming with 10 C/min of heating rate up to 450 C and then maintained with long lapse time at 450 C. Liquid product was sampled at initial reaction time with different degradation temperatures up to 450 C and then constant interval lapse time at 450 C. The product characteristics over two pyrolytic oils were compared by using a continuous reaction system. As a reactant, heavy pyrolytic oil (HPO) showed higher boiling point distribution than that of diesel and also light pyrolytic oil (LPO) was mainly consisting of a mixture of gasoline and kerosene range components. In the continuous reaction, LPO showed higher yield of liquid product and lower residue than those of HPO. The characteristics of liquid products were influenced by the type of raw pyrolytic oil. Also, the result obtained under degradation temperature programming was described. (author)

Large-scale separation of amino acids by continuous displacement chromatography

Energy Technology Data Exchange (ETDEWEB)

DeCarli, J.P. II; Carta, G.; Byers, C.H.

1989-10-01

Continuous annular chromatography (CAC) is a developing technology that allows truly continuous chromatographic separations. Previous work has demonstrated the utility of this technology for the separation of various materials by isocratic elution on a bench scale. Novel applications and improved operation of the process were studied in this work, demonstrating that CAC is a versatile apparatus which is capable of separations at high throughput. Three specific separation systems were investigated. Pilot-scale separations at high loadings were performed using an industrial sugar mixture as an example of scale-up for isocratic separations. Bench-scale experiments of a low concentration metal ion mixture were performed to demonstrate stepwise elution, a chromatographic technique which decreases dilution and increases sorbent capacity. Finally, the separation of mixtures of amino acids by ion exchange was investigated to demonstrate the use of displacement development on the CAC. This technique, which perhaps has the most potential, when applied to the CAC allowed simultaneous separation and concentration of multicomponent mixtures on a continuous basis. Mathematical models were developed to describe the CAC performance and optimize the operating conditions. For all the systems investigated, the continuous separation performance of the CAC was found to be very nearly the same as the batchwise performance of conventional chromatography. The technology appears, thus, to be very promising for industrial applications.

Emissions from waste combustion. An application of statistical experimental design in a laboratory-scale boiler and an investigation from large-scale incineration plants

Energy Technology Data Exchange (ETDEWEB)

Xiaojing, Zhang

1997-05-01

The aim of this thesis is a study of the emissions from the combustion of household refuse. The experiments were both on a laboratory-scale boiler and on full-scale incineration plants. In the laboratory, an artificial household refuse with known composition was fed into a pilot boiler with a stationary grate. Combustion was under non-optimum conditions. Direct sampling with a Tenax adsorbent was used to measure a range of VOCs. Measurements were also made of incompletely burnt hydrocarbons, carbon monoxide, carbon dioxide, oxygen and flue gas temperature. Combustion and emission parameters were recorded continuously by a multi-point data logger. VOCs were analysed by gas chromatography and mass spectrometry (GC/MS). The full-scale tests were on seven Swedish incineration plants. The data were used to evaluate the emissions from large-scale incineration plants with various type of fuels and incinerators, and were also compared with the laboratory results. The response surface model developed from the laboratory experiments was also validated. This thesis also includes studies on the gasification of household refuse pellets, estimations of particulate and soot emissions, and a thermodynamic analysis of PAHs from combustion flue gas. For pellet gasification, experiments were performed on single, well characterised refuse pellets under carefully controlled conditions. The aim was to see if the effects of pellets were different from those of untreated household refuse. The results from both laboratory and full-scale tests showed that the main contributions to emissions from household refuse are plastics and moisture. 142 refs, 82 figs, 51 tabs

Saltstone studies using the scaled continuous processing facility

Energy Technology Data Exchange (ETDEWEB)

Fowley, M. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-08-01

The Savannah River National Laboratory (SRNL) has supported the Saltstone Facility since its conception with bench-scale laboratory experiments, mid-scale testing at vendor facilities, and consultations and testing at the Saltstone Facility. There have been minimal opportunities for the measurement of rheological properties of the grout slurry at the Saltstone Production Facility (SPF); thus, the Scaled Continuous Processing Facility (SCPF), constructed to provide processing data related to mixing, transfer, and other operations conducted in the SPF, is the most representative process data for determining the expected rheological properties in the SPF. These results can be used to verify the laboratory scale experiments that support the SPF using conventional mixing processes that appropriately represent the shear imparted to the slurry in the SPF.

Chemical sensing of plant stress at the ecosystem scale

Directory of Open Access Journals (Sweden)

T. Karl

2008-09-01

Full Text Available Significant ecosystem-scale emissions of methylsalicylate (MeSA, a semivolatile plant hormone thought to act as the mobile signal for systemic acquired resistance (SAR, were observed in an agroforest. Our measurements show that plant internal defence mechanisms can be activated in response to temperature stress and are modulated by water availability on large scales. Highest MeSA fluxes (up to 0.25 mg/m²/h were observed after plants experienced ambient night-time temperatures of ~7.5°C followed by a large daytime temperature increase (e.g. up to 22°C. Under these conditions estimated night-time leaf temperatures were as low as ~4.6°C, likely inducing a response to prevent chilling injury. Our observations imply that plant hormones can be a significant component of ecosystem scale volatile organic compound (VOC fluxes (e.g. as high as the total monoterpene (MT flux and therefore contribute to the missing VOC budget. If generalized to other ecosystems and different types of stresses these findings suggest that semivolatile plant hormones have been overlooked by investigations of the impact of biogenic VOCs on aerosol formation events in forested regions. Our observations show that the presence of MeSA in canopy air serves as an early chemical warning signal indicating ecosystem-scale stresses before visible damage becomes apparent. As a chemical metric, ecosystem emission measurements of MeSA in ambient air could therefore support field studies investigating factors that adversely affect plant growth.

Describing a multitrophic plant-herbivore-parasitoid system at four spatial scales

Science.gov (United States)

Cuautle, M.; Parra-Tabla, V.

2014-02-01

Herbivore-parasitoid interactions must be studied using a multitrophic and multispecies approach. The strength and direction of multiple effects through trophic levels may change across spatial scales. In this work, we use the herbaceous plant Ruellia nudiflora, its moth herbivore Tripudia quadrifera, and several parasitoid morphospecies that feed on the herbivore to answer the following questions: Do herbivore and parasitoid attack levels vary depending on the spatial scale considered? With which plant characteristics are the parasitoid and the herbivore associated? Do parasitoid morphospecies vary in the magnitude of their positive indirect effect on plant reproduction? We evaluated three approximations of herbivore and parasitoid abundance (raw numbers, ratios, and attack rates) at four spatial scales: regional (three different regions which differ in terms of abiotic and biotic characteristics); population (i.e. four populations within each region); patch (four 1 m2 plots in each population); and plant level (using a number of plant characteristics). Finally, we determined whether parasitoids have a positive indirect effect on plant reproductive success (seed number). Herbivore and parasitoid numbers differed at three of the spatial scales considered. However, herbivore/fruit ratio and attack rates did not differ at the population level. Parasitoid/host ratio and attack rates did not differ at any scale, although there was a tendency of a higher attack in one region. At the plant level, herbivore and parasitoid abundances were related to different plant traits, varying the importance and the direction (positive or negative) of those traits. In addition, only one parasitoid species (Bracon sp.) had a positive effect on plant fitness saving up to 20% of the seeds in a fruit. These results underline the importance of knowing the scales that are relevant to organisms at different trophic levels and distinguish between the specific effects of species.

Orodispersible films: Product transfer from lab-scale to continuous manufacturing.

Science.gov (United States)

Thabet, Yasmin; Breitkreutz, Joerg

2018-01-15

Orodispersible films have been described as new beneficial dosage forms for special patient populations. Due to various production settings, different requirements on film formulations are required for non- continuous and continuous manufacturing. In this study, a continuous coating machine was qualified in regards of the process conditions for film compositions and their effects on the formed films. To investigate differences between both manufacturing processes, various film formulations of hydrochlorothiazide and hydroxypropylcellulose (HPC) or hydroxypropylmethycellulose (HPMC) as film formers were produced and the resulting films were characterized. The qualification of the continuously operating coating machine reveals no uniform heat distribution during drying. Coating solutions for continuous manufacturing should provide at least a dynamic viscosity of 1 Pa*s (wet film thickness of 500 μm, velocity of 15.9 cm/min). HPC films contain higher residuals of ethanol or acetone in bench-scale than in continuous production mode. Continuous production lead to lower drug content of the films. All continuously produced films disintegrate within less than 30 s. There are observed significant effects of the production process on the film characteristics. When transferring film manufacturing from lab-scale to continuous mode, film compositions, processing conditions and suitable characterization methods have to be carefully selected and adopted. Copyright © 2017 Elsevier B.V. All rights reserved.

A study of residence time distribution using radiotracer technique in the large scale plant facility

Science.gov (United States)

Wetchagarun, S.; Tippayakul, C.; Petchrak, A.; Sukrod, K.; Khoonkamjorn, P.

2017-06-01

As the demand for troubleshooting of large industrial plants increases, radiotracer techniques, which have capability to provide fast, online and effective detections to plant problems, have been continually developed. One of the good potential applications of the radiotracer for troubleshooting in a process plant is the analysis of Residence Time Distribution (RTD). In this paper, the study of RTD in a large scale plant facility using radiotracer technique was presented. The objective of this work is to gain experience on the RTD analysis using radiotracer technique in a “larger than laboratory” scale plant setup which can be comparable to the real industrial application. The experiment was carried out at the sedimentation tank in the water treatment facility of Thailand Institute of Nuclear Technology (Public Organization). Br-82 was selected to use in this work due to its chemical property, its suitable half-life and its on-site availability. NH4Br in the form of aqueous solution was injected into the system as the radiotracer. Six NaI detectors were placed along the pipelines and at the tank in order to determine the RTD of the system. The RTD and the Mean Residence Time (MRT) of the tank was analysed and calculated from the measured data. The experience and knowledge attained from this study is important for extending this technique to be applied to industrial facilities in the future.

Pilot plant for flue gas treatment - continuous operation tests

International Nuclear Information System (INIS)

Chmielewski, A.G.; Tyminski, B.; Iller, E.; Zimek, Z.; Licki, J.; Radzio, B.

1995-01-01

Tests of continuous operation have been performed on pilot plant at EPS Kaweczyn in the wide range of SO 2 concentration (500-3000 ppm). The bag filter has been applied for aerosol separation. The high efficiencies of SO 2 and NO x removal, approximately 90% were obtained and influenced by such process parameters as: dose, gas temperature and ammonia stoichiometry. The main apparatus of the pilot plant (e.g. both accelerators) have proved their reliability in hard industrial conditions. (Author)

Gamma Ray Tomographic Scan Method for Large Scale Industrial Plants

International Nuclear Information System (INIS)

Moon, Jin Ho; Jung, Sung Hee; Kim, Jong Bum; Park, Jang Geun

2011-01-01

The gamma ray tomography systems have been used to investigate a chemical process for last decade. There have been many cases of gamma ray tomography for laboratory scale work but not many cases for industrial scale work. Non-tomographic equipment with gamma-ray sources is often used in process diagnosis. Gamma radiography, gamma column scanning and the radioisotope tracer technique are examples of gamma ray application in industries. In spite of many outdoor non-gamma ray tomographic equipment, the most of gamma ray tomographic systems still remained as indoor equipment. But, as the gamma tomography has developed, the demand on gamma tomography for real scale plants also increased. To develop the industrial scale system, we introduced the gamma-ray tomographic system with fixed detectors and rotating source. The general system configuration is similar to 4 th generation geometry. But the main effort has been made to actualize the instant installation of the system for real scale industrial plant. This work would be a first attempt to apply the 4th generation industrial gamma tomographic scanning by experimental method. The individual 0.5-inch NaI detector was used for gamma ray detection by configuring circular shape around industrial plant. This tomographic scan method can reduce mechanical complexity and require a much smaller space than a conventional CT. Those properties make it easy to get measurement data for a real scale plant

Large-scale methanol plants. [Based on Japanese-developed process

Energy Technology Data Exchange (ETDEWEB)

Tado, Y

1978-02-01

A study was made on how to produce methanol economically which is expected as a growth item for use as a material for pollution-free energy or for chemical use, centering on the following subjects: (1) Improvement of thermal economy, (2) Improvement of process, and (3) Problems of hardware attending the expansion of scale. The results of this study were already adopted in actual plants, obtaining good results, and large-scale methanol plants are going to be realized.

State-of-the-art of large scale biogas plants

International Nuclear Information System (INIS)

Prisum, J.M.; Noergaard, P.

1992-01-01

A survey of the technological state of large scale biogas plants in Europe treating manure is given. 83 plants are in operation at present. Of these, 16 are centralised digestion plants. Transport costs at centralised digestion plants amounts to between 25 and 40 percent of the total operational costs. Various transport equipment is used. Most large scale digesters are CSTRs, but serial, contact, 2-step, and plug-flow digesters are also found. Construction materials are mostly steel and concrete. Mesophilic digestion is most common (56%), thermophilic digestion is used in 17% of the plants, combined mesophilic and thermophilic digestion is used in 28% of the centralised plants. Mixing of digester content is performed with gas injection, propellers, and gas-liquid displacement. Heating is carried out using external or internal heat exchangers. Heat recovery is only used in Denmark. Gas purification equipment is commonplace, but not often needed. Several plants use separation of the digested manure, often as part of a post-treatment/-purification process or for the production of 'compost'. Screens, sieve belt separaters, centrifuges and filter presses are employed. The use of biogas varies considerably. In some cases, combined heat and power stations are supplying the grid and district heating systems. Other plants use only either the electricity or heat. (au)

Economy of scale: third partner strengthens a keystone ant-plant mutualism.

Science.gov (United States)

Prior, Kirsten M; Palmer, Todd M

2018-02-01

While foundation species can stabilize ecosystems at landscape scales, their ability to persist is often underlain by keystone interactions occurring at smaller scales. Acacia drepanolobium is a foundation tree, comprising >95% of woody cover in East African black-cotton savanna ecosystems. Its dominance is underlain by a keystone mutualistic interaction with several symbiotic ant species in which it provides housing (swollen thorns) and carbohydrate-rich nectar from extra-floral nectaries (EFN). In return, it gains protection from catastrophic damage from mega-herbivores. Crematogaster mimosae is the ecologically dominant symbiotic ant in this system, also providing the highest protection services. In addition to tending EFN, C. mimosae tend scale insects for carbohydrate-rich honeydew. We investigated the role of scale insects in this specialized ant-plant interaction. Specifically, does this putatively redundant third partner strengthen the ant-plant mutualism by making the ant a better protector of the tree? Or does it weaken the mutualism by being costly to the tree while providing no additional benefit to the ant-plant mutualism? We coupled observational surveys with two scale-manipulation experiments and found evidence that this third partner strengthens the ant-plant mutualism. Trees with scale insects experimentally removed experienced a 2.5X increase in elephant damage compared to trees with scale insects present over 10 months. Reduced protection was driven by scale removal causing a decrease in ant colony size and per capita baseline activity and defensive behavior. We also found that ants increased scale-tending and the density of scale insects on trees when EFN were experimentally reduced. Thus, in this system, scale insects and EFN are likely complementary, rather than redundant, resources with scale insects benefitting ants when EFN production is low (such as during annual dry periods in this semi-arid ecosystem). This study reveals that a third

The Plant Phenology Ontology: A New Informatics Resource for Large-Scale Integration of Plant Phenology Data.

Science.gov (United States)

Stucky, Brian J; Guralnick, Rob; Deck, John; Denny, Ellen G; Bolmgren, Kjell; Walls, Ramona

2018-01-01

Plant phenology - the timing of plant life-cycle events, such as flowering or leafing out - plays a fundamental role in the functioning of terrestrial ecosystems, including human agricultural systems. Because plant phenology is often linked with climatic variables, there is widespread interest in developing a deeper understanding of global plant phenology patterns and trends. Although phenology data from around the world are currently available, truly global analyses of plant phenology have so far been difficult because the organizations producing large-scale phenology data are using non-standardized terminologies and metrics during data collection and data processing. To address this problem, we have developed the Plant Phenology Ontology (PPO). The PPO provides the standardized vocabulary and semantic framework that is needed for large-scale integration of heterogeneous plant phenology data. Here, we describe the PPO, and we also report preliminary results of using the PPO and a new data processing pipeline to build a large dataset of phenology information from North America and Europe.

Considerations of scale in the analysis of spatial pattern of plant disease epidemics.

Science.gov (United States)

Turechek, William W; McRoberts, Neil

2013-01-01

Scale is an important but somewhat neglected subject in plant pathology. Scale serves as an abstract concept, providing a framework for organizing observations and theoretical models, and plays a functional role in the organization of ecological communities and physical processes. Rich methodological resources are available to plant pathologists interested in considering either or both aspects of scale in their research. We summarize important concepts in both areas of the literature, particularly as they apply to the spatial pattern of plant disease, and highlight some new results that emphasize the importance of scaling on the emergence of different types of probability distribution in empirical observation. We also highlight the important links between heterogeneity and scale, which are of central importance in plant disease epidemiology and the analysis of spatial pattern. We consider statistical approaches that are available, where actual physical scale is known, and for more conceptual research on hierarchies, where scale plays a more abstract role, particularly for field-based research. For the latter, we highlight methods that plant pathologists could consider to account for the effect of scale in the design of field studies.

Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant

Energy Technology Data Exchange (ETDEWEB)

Cho, Young; Fridman, Alexander

2012-06-30

The overall objective of the present work was to develop a new scale-prevention technology by continuously precipitating and removing dissolved mineral ions (such as calcium and magnesium) in cooling water while the COC could be doubled from the present standard value of 3.5. The hypothesis of the present study was that if we could successfully precipitate and remove the excess calcium ions in cooling water, we could prevent condenser-tube fouling and at the same time double the COC. The approach in the study was to utilize pulse spark discharges directly in water to precipitate dissolved mineral ions in recirculating cooling water into relatively large suspended particles, which could be removed by a self-cleaning filter. The present study began with a basic scientific research to better understand the mechanism of pulse spark discharges in water and conducted a series of validation experiments using hard water in a laboratory cooling tower. Task 1 of the present work was to demonstrate if the spark discharge could precipitate the mineral ions in water. Task 2 was to demonstrate if the selfcleaning filter could continuously remove these precipitated calcium particles such that the blowdown could be eliminated or significantly reduced. Task 3 was to demonstrate if the scale could be prevented or minimized at condenser tubes with a COC of 8 or (almost) zero blowdown. In Task 1, we successfully completed the validation study that confirmed the precipitation of dissolved calcium ions in cooling water with the supporting data of calcium hardness over time as measured by a calcium ion probe. In Task 2, we confirmed through experimental tests that the self-cleaning filter could continuously remove precipitated calcium particles in a simulated laboratory cooling tower such that the blowdown could be eliminated or significantly reduced. In addition, chemical water analysis data were obtained which were used to confirm the COC calculation. In Task 3, we conducted a series

Ecosystem-scale plant hydraulic strategies inferred from remotely-sensed soil moisture

Science.gov (United States)

Bassiouni, M.; Good, S. P.; Higgins, C. W.

2017-12-01

Characterizing plant hydraulic strategies at the ecosystem scale is important to improve estimates of evapotranspiration and to understand ecosystem productivity and resilience. However, quantifying plant hydraulic traits beyond the species level is a challenge. The probability density function of soil moisture observations provides key information about the soil moisture states at which evapotranspiration is reduced by water stress. Here, an inverse Bayesian approach is applied to a standard bucket model of soil column hydrology forced with stochastic precipitation inputs. Through this approach, we are able to determine the soil moisture thresholds at which stomata are open or closed that are most consistent with observed soil moisture probability density functions. This research utilizes remotely-sensed soil moisture data to explore global patterns of ecosystem-scale plant hydraulic strategies. Results are complementary to literature values of measured hydraulic traits of various species in different climates and previous estimates of ecosystem-scale plant isohydricity. The presented approach provides a novel relation between plant physiological behavior and soil-water dynamics.

Commercial-scale biotherapeutics manufacturing facility for plant-made pharmaceuticals.

Science.gov (United States)

Holtz, Barry R; Berquist, Brian R; Bennett, Lindsay D; Kommineni, Vally J M; Munigunti, Ranjith K; White, Earl L; Wilkerson, Don C; Wong, Kah-Yat I; Ly, Lan H; Marcel, Sylvain

2015-10-01

Rapid, large-scale manufacture of medical countermeasures can be uniquely met by the plant-made-pharmaceutical platform technology. As a participant in the Defense Advanced Research Projects Agency (DARPA) Blue Angel project, the Caliber Biotherapeutics facility was designed, constructed, commissioned and released a therapeutic target (H1N1 influenza subunit vaccine) in manufacturing facilities, with the capacity to process over 3500 kg of plant biomass per week in an automated multilevel growing environment using proprietary LED lighting. The facility can commission additional plant grow rooms that are already built to double this capacity. In addition to the commercial-scale manufacturing facility, a pilot production facility was designed based on the large-scale manufacturing specifications as a way to integrate product development and technology transfer. The primary research, development and manufacturing system employs vacuum-infiltrated Nicotiana benthamiana plants grown in a fully contained, hydroponic system for transient expression of recombinant proteins. This expression platform has been linked to a downstream process system, analytical characterization, and assessment of biological activity. This integrated approach has demonstrated rapid, high-quality production of therapeutic monoclonal antibody targets, including a panel of rituximab biosimilar/biobetter molecules and antiviral antibodies against influenza and dengue fever. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

The continuous improvement system of nuclear power plant of Laguna Verde

International Nuclear Information System (INIS)

Rivera C, A.

2009-10-01

This paper describes the continuous improvement system of nuclear power plant of Laguna Verde and the achievements in implementing the same and additionally two study cases are presents. In February 2009 is noteworthy because the World Association of Nuclear Operators we identified as a learning organization, qualification which shows that the continuous improvement system has matured, and this system will expose as I get to learn to capitalize on our own experiences and external experiences diffused by the nuclear industry. In 2007 the management of nuclear power plants integrates its improvement systems and calls it continuous improvement system and is presented in the same extensive report that won the National Quality Award. This system is made up of 5 subsystems operating individually and are also related 1) human performance; 2) referential comparison or benchmarking; 3) self-assessment; 4) corrective action and 5) external operating experience. Five subsystems that plan, generate, capture, manage, communicate and protect the knowledge generated during the processes execution of nuclear power plant of Laguna Verde, as well as from external sources. The target set in 2007 was to increase the intellectual capital to always give response to meeting the security requirements, but creating a higher value to quality, customer, environment protection and society. In brief each of them, highlighting the objective, expectations management, implementation and some benefits. At the end they will describe two study cases selected to illustrate these cases as the organization learns by their continuous improvement system. (Author)

Continuous recycling of enzymes during production of lignocellulosic bioethanol in demonstration scale

DEFF Research Database (Denmark)

Haven, Mai Østergaard; Lindedam, Jane; Jeppesen, Martin D.

2015-01-01

Recycling of enzymes in production of lignocellulosic bioethanol has been tried for more than 30 years. So far, the successes have been few and the experiments have been carried out at conditions far from those in an industrially feasible process. Here we have tested continuous enzyme recycling a...... broth also opens up the possibility of lowering the dry matter content in hydrolysis and fermentation while still maintaining high ethanol concentrations....... at demonstration scale using industrial process conditions (high dry matter content and low enzyme dosage) for a period of eight days. The experiment was performed at the Inbicon demonstration plant (Kalundborg, Denmark) capable of converting four tonnes of wheat straw per hour. 20% of the fermentation broth...... was recycled to the hydrolysis reactor while enzyme dosage was reduced by 5%. The results demonstrate that recycling enzymes by this method can reduce overall enzyme consumption and may also increase the ethanol concentrations in the fermentation broth. Our results further show that recycling fermentation...

The Continued Need for Modeling and Scaled Testing to Advance the Hanford Tank Waste Mission

Energy Technology Data Exchange (ETDEWEB)

Peurrung, Loni M.; Fort, James A.; Rector, David R.

2013-09-03

Hanford tank wastes are chemically complex slurries of liquids and solids that can exhibit changes in rheological behavior during retrieval and processing. The Hanford Waste Treatment and Immobilization Plant (WTP) recently abandoned its planned approach to use computational fluid dynamics (CFD) supported by testing at less than full scale to verify the design of vessels that process these wastes within the plant. The commercial CFD tool selected was deemed too difficult to validate to the degree necessary for use in the design of a nuclear facility. Alternative, but somewhat immature, CFD tools are available that can simulate multiphase flow of non-Newtonian fluids. Yet both CFD and scaled testing can play an important role in advancing the Hanford tank waste mission—in supporting the new verification approach, which is to conduct testing in actual plant vessels; in supporting waste feed delivery, where scaled testing is ongoing; as a fallback approach to design verification if the Full Scale Vessel Testing Program is deemed too costly and time-consuming; to troubleshoot problems during commissioning and operation of the plant; and to evaluate the effects of any proposed changes in operating conditions in the future to optimize plant performance.

Response of pest control by generalist predators to local-scale plant diversity: a meta-analysis.

Science.gov (United States)

Dassou, Anicet Gbèblonoudo; Tixier, Philippe

2016-02-01

Disentangling the effects of plant diversity on the control of herbivores is important for understanding agricultural sustainability. Recent studies have investigated the relationships between plant diversity and arthropod communities at the landscape scale, but few have done so at the local scale. We conducted a meta-analysis of 32 papers containing 175 independent measures of the relationship between plant diversity and arthropod communities. We found that generalist predators had a strong positive response to plant diversity, that is, their abundance increased as plant diversity increased. Herbivores, in contrast, had an overall weak and negative response to plant diversity. However, specialist and generalist herbivores differed in their response to plant diversity, that is, the response was negative for specialists and not significant for generalists. While the effects of scale remain unclear, the response to plant diversity tended to increase for specialist herbivores, but decrease for generalist herbivores as the scale increased. There was no clear effect of scale on the response of generalist predators to plant diversity. Our results suggest that the response of herbivores to plant diversity at the local scale is a balance between habitat and trophic effects that vary according to arthropod specialization and habitat type. Synthesis and applications. Positive effects of plant diversity on generalist predators confirm that, at the local scale, plant diversification of agroecosystems is a credible and promising option for increasing pest regulation. Results from our meta-analysis suggest that natural control in plant-diversified systems is more likely to occur for specialist than for generalist herbivores. In terms of pest management, our results indicate that small-scale plant diversification (via the planting of cover crops or intercrops and reduced weed management) is likely to increase the control of specialist herbivores by generalist predators.

Explosives Removal from Groundwater of the Iowa Army Ammunition Plant in Continuous-Flow Laboratory Systems Planted with Aquatic and Wetland Plants

National Research Council Canada - National Science Library

Best, Elly

1998-01-01

A 49-day, continuous-flow, laboratory study was performed to evaluate the ability of two submersed and one emergent plant species to phytoremediate explosives-contaminated groundwater from the Iowa...

Voltage stability issues in a distribution grid with large scale PV plant

Energy Technology Data Exchange (ETDEWEB)

Perez, Alvaro Ruiz; Marinopoulos, Antonios; Reza, Muhamad; Srivastava, Kailash [ABB AB, Vaesteraas (Sweden). Corporate Research Center; Hertem, Dirk van [Katholieke Univ. Leuven, Heverlee (Belgium). ESAT-ELECTA

2011-07-01

Solar photovoltaics (PV) has become a competitive renewable energy source. The production of solar PV cells and panels has increased significantly, while the cost is reduced due to economics of scale and technological achievements in the field. At the same time, the increase in efficiency of PV power systems and high energy prices are expected to lead PV systems to grid parity in the coming decade. This is expected to boost even more the large scale implementation of PV power plants (utility scale PV) and therefore the impact of such large scale PV plants to power system needs to be studies. This paper investigates the voltage stability issues arising from the connection of a large PV power plant to the power grid. For this purpose, a 15 MW PV power plant was implemented into a distribution grid, modeled and simulated using DIgSILENT Power Factory. Two scenarios were developed: in the first scenario, active power injected into the grid by the PV power plants was varied and the resulted U-Q curve was analyzed. In the second scenario, the impact of connecting PV power plants to different points in the grid - resulting in different strength of the connection - was investigated. (orig.)

Continuous production of fullerenes and other carbon nanomaterials on a semi-industrial scale using plasma technology

International Nuclear Information System (INIS)

Gruenberger, T.M.; Gonzalez-Aguilar, J.; Fulcheri, L.; Fabry, F.; Grivei, E.; Probst, N.; Flamant, G.; Charlier, J.-C.

2002-01-01

A new production method is presented allowing the production of bulk quantities of fullerenes and other carbon nanomaterials using a 3-phase thermal plasma (260 kW). The main characteristics of this method lie in the independent control of the carbon throughput by injection of a solid carbon feedstock, and the immediate extraction of the synthesised product from the reactor, allowing production on a continuous basis. The currently investigated plasma facility is of an intermediate scale between lab-size and an industrial pilot plant, ready for further up scaling to an industrial size. The influence of a large number of different carbon precursors, plasma gases and operating conditions on the fullerene yield has been studied. At this state, quantities of up to 1 kg of carbon can be processed per hour with further scope for increase, leading to production rates for this type of materials not achievable with any other technology at present

Investigation of factors influencing biogas production in a large-scale thermophilic municipal biogas plant

Energy Technology Data Exchange (ETDEWEB)

Weiss, Agnes; Jerome, Valerie; Freitag, Ruth [Bayreuth Univ. (Germany). Chair for Process Biotechnology; Burghardt, Diana; Likke, Likke; Peiffer, Stefan [Bayreuth Univ. (Germany). Dept. of Hydrology; Hofstetter, Eugen M. [RVT Process Equipment GmbH, Steinwiesen (Germany); Gabler, Ralf [BKW Biokraftwerke Fuerstenwalde GmbH, Fuerstenwalde (Germany)

2009-10-15

A continuously operated, thermophilic, municipal biogas plant was observed over 26 months (sampling twice per month) in regard to a number of physicochemical parameters and the biogas production. Biogas yields were put in correlation to parameters such as the volatile fatty acid concentration, the pH and the ammonium concentration. When the residing microbiota was classified via analysis of the 16S rRNA genes, most bacterial sequences matched with unidentified or uncultured bacteria from similar habitats. Of the archaeal sequences, 78.4% were identified as belonging to the genus Methanoculleus, which has not previously been reported for biogas plants, but is known to efficiently use H{sub 2} and CO{sub 2} produced by the degradation of fatty acids by syntrophic microorganisms. In order to further investigate the influence of varied amounts of ammonia (2-8 g/L) and volatile fatty acids on biogas production and composition (methane/CO{sub 2}), laboratory scale satellite experiments were performed in parallel to the technical plant. Finally, ammonia stripping of the process water of the technical plant was accomplished, a measure through which the ammonia entering the biogas reactor via the mash could be nearly halved, which increased the energy output of the biogas plant by almost 20%. (orig.)

Villacidro solar demo plant: Integration of small-scale CSP and biogas power plants in an industrial microgrid

Science.gov (United States)

Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Demontis, V.; Melis, T.; Musio, M.

2016-05-01

The integration of small scale concentrating solar power (CSP) in an industrial district, in order to develop a microgrid fully supplied by renewable energy sources, is presented in this paper. The plant aims to assess in real operating conditions, the performance, the effectiveness and the reliability of small-scale concentrating solar power technologies in the field of distributed generation. In particular, the potentiality of small scale CSP with thermal storage to supply dispatchable electricity to an industrial microgrid will be investigated. The microgrid will be realized in the municipal waste treatment plant of the Industrial Consortium of Villacidro, in southern Sardinia (Italy), which already includes a biogas power plant. In order to achieve the microgrid instantaneous energy balance, the analysis of the time evolution of the waste treatment plant demand and of the generation in the existing power systems has been carried out. This has allowed the design of a suitable CSP plant with thermal storage and an electrochemical storage system for supporting the proposed microgrid. At the aim of obtaining the expected energy autonomy, a specific Energy Management Strategy, which takes into account the different dynamic performances and characteristics of the demand and the generation, has been designed. In this paper, the configuration of the proposed small scale concentrating solar power (CSP) and of its thermal energy storage, based on thermocline principle, is initially described. Finally, a simulation study of the entire power system, imposing scheduled profiles based on weather forecasts, is presented.

Near-infrared spectroscopy for process and substrate supervision of a full-scale biogas plant

Energy Technology Data Exchange (ETDEWEB)

Jacobi, Hans Fabian

2012-07-01

Aim of this study was to investigate the possible use of near-infrared spectroscopy in the supervision of the biogas production process or parts thereof. It was examined, whether the surveillance of (a) the process and (b) substrate was feasible. The following tasks were accomplished to this end: 1. Development, construction and assembly of suitable NIRS-metrology, development of proper control-software as well as of strategies for data acquisition and data handling, 2. calculation and validation of regression models on the basis of acquired spectra and reference data for (a) suitable parameters of the biogas process, (b) composition and biogas potential of the substrate, 3. calculation of continuous time series of all parameters in order to prove the possibility of continuous surveillance, 4. integrated processing of continuously calculated biogas potentials together with plant data for the prediction of the biogas production behavior of the biogas plant. A near-infrared spectrometer was installed and equipped with NIR-measuring heads of own design and construction on a full-scale agricultural biogas plant. For 500 days spectra were continuously logged at (a) a pipe flowed through by fermenter slurry and (b) the feeding station, where silage passed. Based on regularly withdrawn reference samples and the corresponding spectra regression models were calibrated for the several constituents. Continuously logged spectra were used to calculate time series with the aid of the regression models for each constituent. Models and time series were established for the following parameters: (a) process parameters: volatile fatty acids, acetic acid, propionic acid, dry matter, volatile solids; (b) substrate parameters: dry matter, volatile solids, crude fiber, crude fat, crude protein, nitrogen-free extracts, experimentally assessed biogas potential, theoretically assessed biogas potential. Despite the partially low quality of the models it was possible to follow the course of

Amplification of Marzagao small scale hydroelectric power plant; Ampliacao da PCH de Marzagao

Energy Technology Data Exchange (ETDEWEB)

Zeller, A.R.; Porto, D.S.; Pinto, F.S. [Leme Engenharia, MG (Brazil); Melo, A.U.; Almeida, A.M.; Pereira, D.R. [Fertiligas Industria e Comercio Ltda., MG (Brazil)

1991-12-31

This work presents the modernization and power augmentation of Marzagao small scale hydroelectric power plant. In order that the costs of the project be compatible to the total of investments in the project, it was necessary the adoption of methodologies and time scales different from those used for large and medium scale hydroelectric power plants 5 figs.

Continuously distributed magnetization profile for millimeter-scale elastomeric undulatory swimming

Science.gov (United States)

Diller, Eric; Zhuang, Jiang; Zhan Lum, Guo; Edwards, Matthew R.; Sitti, Metin

2014-04-01

We have developed a millimeter-scale magnetically driven swimming robot for untethered motion at mid to low Reynolds numbers. The robot is propelled by continuous undulatory deformation, which is enabled by the distributed magnetization profile of a flexible sheet. We demonstrate control of a prototype device and measure deformation and speed as a function of magnetic field strength and frequency. Experimental results are compared with simple magnetoelastic and fluid propulsion models. The presented mechanism provides an efficient remote actuation method at the millimeter scale that may be suitable for further scaling down in size for micro-robotics applications in biotechnology and healthcare.

Herbivore-induced plant volatiles and tritrophic interactions across spatial scales

NARCIS (Netherlands)

Aartsma, Y.S.Y.; Bianchi, F.J.J.A.; Werf, van der W.; Poelman, E.H.; Dicke, M.

2017-01-01

Herbivore-induced plant volatiles (HIPVs) are an important cue used in herbivore location by carnivorous arthropods such as parasitoids. The effects of plant volatiles on parasitoids have been well characterised at small spatial scales, but little research has been done on their effects at larger

Report of the LASCAR forum: Large scale reprocessing plant safeguards

International Nuclear Information System (INIS)

1992-01-01

This report has been prepared to provide information on the studies which were carried out from 1988 to 1992 under the auspices of the multinational forum known as Large Scale Reprocessing Plant Safeguards (LASCAR) on safeguards for four large scale reprocessing plants operated or planned to be operated in the 1990s. The report summarizes all of the essential results of these studies. The participants in LASCAR were from France, Germany, Japan, the United Kingdom, the United States of America, the Commission of the European Communities - Euratom, and the International Atomic Energy Agency

ORC-mall scale power plant

Energy Technology Data Exchange (ETDEWEB)

Jokinen, T. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Electromechanics

1998-12-31

In the conversion of low temperature heat into electricity, the greatest efficiency is obtained by using a Rankine cycle. The Organic Rankine cycle (ORC) is a Rankine cycle where an organic fluid is used instead of water as the working fluid. In the conventional ORC-solution, an axial turbine drives a standard generator through a high-speed gearbox. The system includes a separate feed pump, vacuum pump, lubrication system and requires several saft seals. The seals of the turbine have a limited working life in particular due to the high speed required. Thus, the entire present conventional ORC-plant is rather complicated and requires maintenance. To avoid these problems, a project was initiated at the Lappeenranta University of Technology to develop a high-speed, process fluid lubricated turbogenerator-feed pump as the prime mover of the ORC. The project has been continued in co-operation with the Helsinki University of Technology under the NEMO 2 program, the main goal being to build a demonstration power plant and to commercialise the project. The goals of the project were: (1) to model the ORC process, turbogenerator, and inverter, (2) to simulate the power plant in different normal and abnormal states, (3) to assess the advantages and disadvantages of various control systems, (4) to study network disturbances such as voltage and current harmonics and to research ways of reducing these disturbances, (5) to optimise heat exchanging surfaces and process parameters, and (6) to participate in the design of the demonstration power plant

Large-scale derived flood frequency analysis based on continuous simulation

Science.gov (United States)

Dung Nguyen, Viet; Hundecha, Yeshewatesfa; Guse, Björn; Vorogushyn, Sergiy; Merz, Bruno

2016-04-01

There is an increasing need for spatially consistent flood risk assessments at the regional scale (several 100.000 km2), in particular in the insurance industry and for national risk reduction strategies. However, most large-scale flood risk assessments are composed of smaller-scale assessments and show spatial inconsistencies. To overcome this deficit, a large-scale flood model composed of a weather generator and catchments models was developed reflecting the spatially inherent heterogeneity. The weather generator is a multisite and multivariate stochastic model capable of generating synthetic meteorological fields (precipitation, temperature, etc.) at daily resolution for the regional scale. These fields respect the observed autocorrelation, spatial correlation and co-variance between the variables. They are used as input into catchment models. A long-term simulation of this combined system enables to derive very long discharge series at many catchment locations serving as a basic for spatially consistent flood risk estimates at the regional scale. This combined model was set up and validated for major river catchments in Germany. The weather generator was trained by 53-year observation data at 528 stations covering not only the complete Germany but also parts of France, Switzerland, Czech Republic and Australia with the aggregated spatial scale of 443,931 km2. 10.000 years of daily meteorological fields for the study area were generated. Likewise, rainfall-runoff simulations with SWIM were performed for the entire Elbe, Rhine, Weser, Donau and Ems catchments. The validation results illustrate a good performance of the combined system, as the simulated flood magnitudes and frequencies agree well with the observed flood data. Based on continuous simulation this model chain is then used to estimate flood quantiles for the whole Germany including upstream headwater catchments in neighbouring countries. This continuous large scale approach overcomes the several

Influence of biofilm formation on corrosion and scaling in geothermal plants

Science.gov (United States)

Kleyböcker, Anne; Lerm, Stephanie; Monika, Kasina; Tobias, Lienen; Florian, Eichinger; Andrea, Seibt; Markus, Wolfgramm; Hilke, Würdemann

2017-04-01

Process failures may occur due to corrosion and scaling processes in open loop geothermal systems. Especially after heat extraction, sulfate reducing bacteria (SRB) contribute to corrosion processes due to a more favorable temperature for their growth. In biofilms containing FeS scales, corrosion processes are enhanced. Furthermore, scales can lead to reduced pipe profiles, to a diminished heat transfer and a decrease in the wellbore injectivity. Inhibitors are frequently applied to minimize scaling in technical systems. A prerequisite for the application of inhibitors in geothermal plants located in the Molasse basin is their degradability under reservoir conditions, e. g. in a reduced environment. In order to determine the effects of scale-inhibitors on the subsurface and microbial processes, laboratory experiments were performed focusing on the microbial inhibitor degradation. First results indicate that the inhibitor degradation under anaerobic conditions is possible. Besides the inhibitor application also other techniques are investigated to economically reduce corrosion and scaling in geothermal plants. In a mobile bypass system, the influence of biofilm formation on corrosion and scaling was investigated. The bypass system was tested at a geothermal heat store in the North German Basin. The plant is operated with highly saline fluid (salinity 130 g/L) and known to be affected by SRB. The SRB contributed to corrosion damages especially at the pump in the well on the cold side. Heat shocks were successfully used in the bypass system to reduce biofilm formation as well as corrosion and scaling processes.

Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique

International Nuclear Information System (INIS)

Pant, H.J.; Sharma, V.K.; Shenoy, K.T.; Sreenivas, T.

2015-01-01

An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40–60 MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. - Highlights: • Radiotracer technique was applied for evaluation of design of a pilot-scale continuous leaching reactor. • Mean residence time and dead volume were estimated. Dead volume was found to be ranging from 4% to 15% at different operating conditions. • Tank-in-series model was used to simulate the measured RTD data and was found suitable to describe the flow in the reactor. • No flow abnormality was found and the reactor behaved as a well-mixed system. The design of the reactor was validated

Multi-scale Modeling of Power Plant Plume Emissions and Comparisons with Observations

Science.gov (United States)

Costigan, K. R.; Lee, S.; Reisner, J.; Dubey, M. K.; Love, S. P.; Henderson, B. G.; Chylek, P.

2011-12-01

The Remote Sensing Verification Project (RSVP) test-bed located in the Four Corners region of Arizona, Utah, Colorado, and New Mexico offers a unique opportunity to develop new approaches for estimating emissions of CO2. Two major power plants located in this area produce very large signals of co-emitted CO2 and NO2 in this rural region. In addition to the Environmental Protection Agency (EPA) maintaining Continuous Emissions Monitoring Systems (CEMS) on each of the power plant stacks, the RSVP program has deployed an array of in-situ and remote sensing instruments, which provide both point and integrated measurements. To aid in the synthesis and interpretation of the measurements, a multi-scale atmospheric modeling approach is implemented, using two atmospheric numerical models: the Weather Research and Forecasting Model with chemistry (WRF-Chem; Grell et al., 2005) and the HIGRAD model (Reisner et al., 2003). The high fidelity HIGRAD model incorporates a multi-phase Lagrangian particle based approach to track individual chemical species of stack plumes at ultra-high resolution, using an adaptive mesh. It is particularly suited to model buoyancy effects and entrainment processes at the edges of the power plant plumes. WRF-Chem is a community model that has been applied to a number of air quality problems and offers several physical and chemical schemes that can be used to model the transport and chemical transformation of the anthropogenic plumes out of the local region. Multiple nested grids employed in this study allow the model to incorporate atmospheric variability ranging from synoptic scales to micro-scales (~200 m), while including locally developed flows influenced by the nearby complex terrain of the San Juan Mountains. The simulated local atmospheric dynamics are provided to force the HIGRAD model, which links mesoscale atmospheric variability to the small-scale simulation of the power plant plumes. We will discuss how these two models are applied and

Herbivore-induced plant volatiles and tritrophic interactions across spatial scales.

Science.gov (United States)

Aartsma, Yavanna; Bianchi, Felix J J A; van der Werf, Wopke; Poelman, Erik H; Dicke, Marcel

2017-12-01

Herbivore-induced plant volatiles (HIPVs) are an important cue used in herbivore location by carnivorous arthropods such as parasitoids. The effects of plant volatiles on parasitoids have been well characterised at small spatial scales, but little research has been done on their effects at larger spatial scales. The spatial matrix of volatiles ('volatile mosaic') within which parasitoids locate their hosts is dynamic and heterogeneous. It is shaped by the spatial pattern of HIPV-emitting plants, the concentration, chemical composition and breakdown of the emitted HIPV blends, and by environmental factors such as wind, turbulence and vegetation that affect transport and mixing of odour plumes. The volatile mosaic may be exploited differentially by different parasitoid species, in relation to species traits such as sensory ability to perceive volatiles and the physical ability to move towards the source. Understanding how HIPVs influence parasitoids at larger spatial scales is crucial for our understanding of tritrophic interactions and sustainable pest management in agriculture. However, there is a large gap in our knowledge on how volatiles influence the process of host location by parasitoids at the landscape scale. Future studies should bridge the gap between the chemical and behavioural ecology of tritrophic interactions and landscape ecology. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Theory and evidence for using the economy-of-scale law in power plant economics

International Nuclear Information System (INIS)

Phung, D.L.

1987-05-01

This report compiles theory and evidence for the use of the economy-of-scale law in energy economics, particularly in the estimation of capital costs for coal-fired and nuclear power plants. The economy-of-scale law is widely used in its simplest form: cost is directly proportional to capacity raised to an exponent. An additive constant is an important component that is not generally taken into account. Also, the economy of scale is perforce valid only over a limited size range. The majority of engineering studies have estimated an economy of scale exponent of 0.7 to 0.9 for coal-fired plants and an exponent of 0.4 to 0.6 for nuclear plants in the capacity ranges of 400 to 1000 MWe. However, the majority of econometric analyses found little or no economy of scale for coal-fired plants and only a slight economy of scale for nuclear plants. This disparity is explained by the fact that economists have included regulatory and time-related costs in addition to the direct and indirect costs used by the engineers. Regulatory and time-related costs have become an increasingly larger portion of total costs during the last decade. In addition, these costs appeared to have either a very small economy of scale or to be increasing as the size of the power plant increased. We conclude that gains in economy of scale can only be made by reducing regulatory and time-related costs through design standardization and regulatory stability, in combination with more favorable economic conditions. 59 refs

Possibility of continuous monitoring of environment around the nuclear plant using satellite remote sensing

International Nuclear Information System (INIS)

Sasaki, Takanori; Tanabu, Yoshimine; Fujita, Shigetaka; Zhao Wenhui

2008-01-01

Interest in nuclear power generation is increasing by rising of power demand and environmental concern. It is important more and more to confirm and show the safety operation of nuclear plants, which is useful to remove anxiety of residents. Satellite remote sensing is one of the way of it. Large observation width and long and continuous observation period are advantage of satellite remote sensing. In addition, it is very important to be able to monitor without visitation on the site. We have continued local area environmental analysis using various satellites. MODIS on Terra and Aqua which are NASA satellites received by Hachinohe Institute of Technology is mainly used. According to these results, we have shown that combined analysis of various information parameters such as land surface temperature, geographical changes, vegetation, etc. is very effective to monitor environmental changes. In these analyses, error detection is very important. Therefore, enough storage data with continuously monitoring in usual state is necessary. Moreover, it is thought that the confirmation of stable operation of plants by means of continuous monitoring can contribute to reduce residents' anxiety of nuclear power plant. Additionally, in the case that the change of influence on surroundings is detected, it is possible to grasp the situation and take measure in early stage by error detection. In this paper, as an possible example of continuous monitoring using satellite remote sensing, we introduce the result of analysis and investigation of which changes of sea surface temperature and chlorophyll concentration on the sea around power plant. (author)

Demonstration of the waste tire pyrolysis process on pilot scale in a continuous auger reactor

International Nuclear Information System (INIS)

Martínez, Juan Daniel; Murillo, Ramón; García, Tomás; Veses, Alberto

2013-01-01

Highlights: • The continuous pyrolysis of waste tire has been demonstrated at pilot scale in an auger reactor. • More than 500 kg of waste tires were processed in 100 operational hours. • The yields and characteristics of the pyrolysis products remained constant. • Mass and energy balances for an industrial scale plant are provided. • The reaction enthalpy necessary to perform the waste tire pyrolysis was determined. -- Abstract: This work shows the technical feasibility for valorizing waste tires by pyrolysis using a pilot scale facility with a nominal capacity of 150 kW th . A continuous auger reactor was operated to perform thirteen independent experiments that conducted to the processing of more than 500 kg of shredded waste tires in 100 h of operation. The reaction temperature was 550 °C and the pressure was 1 bar in all the runs. Under these conditions, yields to solid, liquid and gas were 40.5 ± 0.3, 42.6 ± 0.1 and 16.9 ± 0.3 wt.% respectively. Ultimate and proximate analyses as well as heating value analysis were conducted for both the solid and liquid fraction. pH, water content, total acid number (TAN), viscosity and density were also assessed for the liquid and compared to the specifications of marine fuels (standard ISO 8217). Gas chromatography was used to calculate the composition of the gaseous fraction. It was observed that all these properties remained practically invariable along the experiments without any significant technical problem. In addition, the reaction enthalpy necessary to perform the waste tire pyrolysis process (907.1 ± 40.0 kJ/kg) was determined from the combustion and formation enthalpies of waste tire and conversion products. Finally, a mass balance closure was performed showing an excellent reliability of the data obtained from the experimental campaign

Demonstration of the waste tire pyrolysis process on pilot scale in a continuous auger reactor

Energy Technology Data Exchange (ETDEWEB)

Martínez, Juan Daniel, E-mail: juand.martinez@upb.edu.co [Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza (Spain); Grupo de Investigaciones Ambientales, Instituto de Energía, Materiales y Medio Ambiente, Universidad Pontificia Bolivariana, Circular 1 N°70-01, Bloque 11, piso 2, Medellín (Colombia); Murillo, Ramón; García, Tomás; Veses, Alberto [Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018, Zaragoza (Spain)

2013-10-15

Highlights: • The continuous pyrolysis of waste tire has been demonstrated at pilot scale in an auger reactor. • More than 500 kg of waste tires were processed in 100 operational hours. • The yields and characteristics of the pyrolysis products remained constant. • Mass and energy balances for an industrial scale plant are provided. • The reaction enthalpy necessary to perform the waste tire pyrolysis was determined. -- Abstract: This work shows the technical feasibility for valorizing waste tires by pyrolysis using a pilot scale facility with a nominal capacity of 150 kW{sub th}. A continuous auger reactor was operated to perform thirteen independent experiments that conducted to the processing of more than 500 kg of shredded waste tires in 100 h of operation. The reaction temperature was 550 °C and the pressure was 1 bar in all the runs. Under these conditions, yields to solid, liquid and gas were 40.5 ± 0.3, 42.6 ± 0.1 and 16.9 ± 0.3 wt.% respectively. Ultimate and proximate analyses as well as heating value analysis were conducted for both the solid and liquid fraction. pH, water content, total acid number (TAN), viscosity and density were also assessed for the liquid and compared to the specifications of marine fuels (standard ISO 8217). Gas chromatography was used to calculate the composition of the gaseous fraction. It was observed that all these properties remained practically invariable along the experiments without any significant technical problem. In addition, the reaction enthalpy necessary to perform the waste tire pyrolysis process (907.1 ± 40.0 kJ/kg) was determined from the combustion and formation enthalpies of waste tire and conversion products. Finally, a mass balance closure was performed showing an excellent reliability of the data obtained from the experimental campaign.

Consideration of early closure or continued operation of a nuclear power plant

International Nuclear Information System (INIS)

2006-07-01

This publication provides information to management and executives of electrical utilities responsible for the operation of nuclear power plants who are tasked with decision making related to early closures or continued operation. This information is based on the experiences of a number of countries in addressing a spectrum of issues broader than only the economics of the operation of the plant itself. Any major decision involving changes in direction for a major investment such as a nuclear power plant has the potential to incur considerable additional costs for stakeholders. Major economic risks can be unexpectedly encountered when decisions based on a simplified economic understanding of energy options are successfully challenged on the grounds that choices and decisions have been made without accounting for some environmental, social or economic issues which are considered of prime significance to important stakeholders. Such risks include not only changes in project scope and delays in project implementation due to re-evaluations necessitated by such challenges, but risks related to the effectiveness, efficiency and safety of ongoing operations or shutdown maintenance of the nuclear power plant. Additional risks encountered at this stage are the adequacy of the decommissioning fund and the need to establish a process whereby the availability of adequate funds will be assured at the time of the final plant shutdown. This publication provides information on several of these additional issues important to key stakeholders, and on methods that allow for their assessment and consideration when developing recommendations related to early closures or continued operations of a NPP. This publication consists of two parts: Part I: Includes a discussion of the main issues for consideration, with emphasis on issues important to stakeholders in addition to plant owners. Part II: Provides an example of a basic analytical approach to the assessment of plant life cycle

Plant interactions alter the predictions of metabolic scaling theory

DEFF Research Database (Denmark)

Lin, Yue; Berger, Uta; Grimm, Volker

2013-01-01

Metabolic scaling theory (MST) is an attempt to link physiological processes of individual organisms with macroecology. It predicts a power law relationship with an exponent of 24/3 between mean individual biomass and density during densitydependent mortality (self-thinning). Empirical tests have...... processes can scale up to the population level. MST, like thermodynamics or biomechanics, sets limits within which organisms can live and function, but there may be stronger limits determined by ecological interactions. In such cases MST will not be predictive....... of plant stand development that includes three elements: a model of individual plant growth based on MST, different modes of local competition (size-symmetric vs. -asymmetric), and different resource levels. Our model is consistent with the observed variation in the slopes of self-thinning trajectories...

Continuous thermal hydrolysis and energy integration in sludge anaerobic digestion plants.

Science.gov (United States)

Fdz-Polanco, F; Velazquez, R; Perez-Elvira, S I; Casas, C; del Barrio, D; Cantero, F J; Fdz-Polanco, M; Rodriguez, P; Panizo, L; Serrat, J; Rouge, P

2008-01-01

A thermal hydrolysis pilot plant with direct steam injection heating was designed and constructed. In a first period the equipment was operated in batch to verify the effect of sludge type, pressure and temperature, residence time and solids concentration. Optimal operation conditions were reached for secondary sludge at 170 degrees C, 7 bar and 30 minutes residence time, obtaining a disintegration factor higher than 10, methane production increase by 50% and easy centrifugation In a second period the pilot plant was operated working with continuous feed, testing the efficiency by using two continuous anaerobic digester operating in the mesophilic and thermophilic range. Working at 12 days residence time, biogas production increases by 40-50%. Integrating the energy transfer it is possible to design a self-sufficient system that takes advantage of this methane increase to produce 40% more electric energy. (c) IWA Publishing 2008.

Ecosystem Responses To Plant Phenology Across Scales And Trophic Levels

Science.gov (United States)

Stoner, D.; Sexton, J. O.; Nagol, J. R.; Ironside, K.; Choate, D.; Longshore, K.; Edwards, T., Jr.

2015-12-01

Plant phenology in arid and semi-arid ecoregions is constrained by water availability and governs the life history characteristics of primary and secondary consumers. We related the behavior, demography, and distribution of mammalian herbivores and their principal predator to remotely sensed vegetation and climatological indices across the western United States for the period 2000-2014. Across scales, terrain and topographic position moderates the effects of climatological drought on primary productivity, resulting in differential susceptibility among plant functional types to water stress. At broad scales, herbivores tie parturition to moist sites during the period of maximum increase in local forage production. Consequently, juvenile mortality is highest in regions of extreme phenological variability. Although decoupled from primary production by one or more trophic levels, carnivore home range size and density is negatively correlated to plant productivity and growing season length. At the finest scales, predation influences the behavior of herbivore prey through compromised habitat selection, in which maternal females trade nutritional benefits of high plant biomass for reduced mortality risk associated with increased visibility. Climate projections for the western United States predict warming combined with shifts in the timing and form of precipitation. Our analyses suggest that these changes will propagate through trophic levels as increased phenological variability and shifts in plant distributions, larger consumer home ranges, altered migration behavior, and generally higher volatility in wildlife populations. Combined with expansion and intensification of human land use across the region, these changes will likely have economic implications stemming from increased human-wildlife conflict (e.g., crop damage, vehicle collisions) and changes in wildlife-related tourism.

Reprocessing plants safety

International Nuclear Information System (INIS)

Davies, A.G.; Leighton, C.; Millington, D.

1989-01-01

The reprocessing of irradiated nuclear fuel at British Nuclear Fuels (BNFL) Sellafield site consists of a number of relatively self-contained activities carried out in separate plants across the site. The physical conditions and time scales applied in reprocessing and storage make it relatively benign. The potential for minor releases of radioactivity under fault conditioning is minimised by plant design definition of control procedures, training and supervision. The risks to both the general public and workforce are shown to be low with all the safety criteria being met. Normal operating conditions also have the potential for some occupational radiation exposure and the plant and workers are monitored continuously. Exposure levels have been reduced steadily and will continue to fall with plant improvements. (U.K.)

Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique.

Science.gov (United States)

Pant, H J; Sharma, V K; Shenoy, K T; Sreenivas, T

2015-03-01

An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40-60MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Continuing the service of safety-related concrete structures in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Oland, C.B.; Ellingwood, B.R.; Mori, Y.; Arndt, E.G.

1993-01-01

The Structural Aging (SAG) Program is addressing the aging management of safety-related concrete structures in nuclear power plants (NPPs) for the purpose of providing improved technical bases for their continued service. The program consists of three technical tasks: materials property data base, structural component assessment/repair technologies, and quantitative methodologies for continued service determinations. Recent accomplishments under each of these tasks are summarized

Modeling of water treatment plant using timed continuous Petri nets

Science.gov (United States)

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

2017-08-01

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

Model-based plant-wide optimization of large-scale lignocellulosic bioethanol plants

DEFF Research Database (Denmark)

Prunescu, Remus Mihail; Blanke, Mogens; Jakobsen, Jon Geest

2017-01-01

Second generation biorefineries transform lignocellulosic biomass into chemicals with higher added value following a conversion mechanism that consists of: pretreatment, enzymatic hydrolysis, fermentation and purification. The objective of this study is to identify the optimal operational point...... with respect to maximum economic profit of a large scale biorefinery plant using a systematic model-based plantwide optimization methodology. The following key process parameters are identified as decision variables: pretreatment temperature, enzyme dosage in enzymatic hydrolysis, and yeast loading per batch...... in fermentation. The plant is treated in an integrated manner taking into account the interactions and trade-offs between the conversion steps. A sensitivity and uncertainty analysis follows at the optimal solution considering both model and feed parameters. It is found that the optimal point is more sensitive...

Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance.

Directory of Open Access Journals (Sweden)

Ilja Sonnemann

Full Text Available Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae larvae (43% in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive- and vegetative plant height, and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio. Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of

TRUE Block Scale Continuation Project. Final Report

Energy Technology Data Exchange (ETDEWEB)

Andersson, Peter; Byegaard, Johan [Geosigma AB (Sweden); Billaux, Daniel [Itasca Consultants SA (France); Cvetkovic, Vladimir [Royal Inst. of Technology, Stockholm (Sweden); Dershowitz, William; Doe, Thomas [Golder Associates Inc. (United States); Hermanson, Jan [Golder Associates AB (Sweden); Poteri, Antti [VTT (Finland); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders [Conterra AB (SE)] (ed.)

2007-03-15

The TRUE Block Scale project was carried out during 1996-2002. This project focused on site characterisation and building of hydrostructural and microstructural models, sorbing tracer experiments in single structures and networks of structures over distances ranging between 1 and 100 m and also involved a unified application of various model approaches for modelling the in situ experiments. In 2002, ANDRA, Posiva, JNC and SKB decided to pursue some remaining issues in the so-called TRUE Block Scale Continuation project (TRUE BS2). The specific objectives of BS2 can be summarised as: 'Improve understanding of transport pathways at the block scale, including assessment of effects of geology and geometry, macrostructure and microstructure'. In order to cater to addressing the stated objective a series of hypotheses were formulated which explored the importance of geological information for predicting transport and retention and the possible differences between transport and retention between transport paths dominated by faults and those dominated by non-fault fractures (background fractures). In the process, prospects for carrying out experiments in fracture networks over longer distances (c 20-100 m) were explored. It was identified that experiments with sorbing tracers over these distances were prohibitive because of the time frames involved and the projected low mass recoveries. Instead the experimental locus was shifted to a geological structure previously not investigated by tracer tests in the TRUE Block Scale experiments. The lower immobile zone retention material properties assigned to background fractures compared to those assigned to the fault-type Structure 19 have been verified by means of back-calculations. The evaluated Type 1 flow path (Structure 19, Flow path I) retention material properties, as expressed by {kappa} parameter, are one order of magnitude higher than for the background fracture flow path. This finding is consistent with the

Hierarchical Learning of Tree Classifiers for Large-Scale Plant Species Identification.

Science.gov (United States)

Fan, Jianping; Zhou, Ning; Peng, Jinye; Gao, Ling

2015-11-01

In this paper, a hierarchical multi-task structural learning algorithm is developed to support large-scale plant species identification, where a visual tree is constructed for organizing large numbers of plant species in a coarse-to-fine fashion and determining the inter-related learning tasks automatically. For a given parent node on the visual tree, it contains a set of sibling coarse-grained categories of plant species or sibling fine-grained plant species, and a multi-task structural learning algorithm is developed to train their inter-related classifiers jointly for enhancing their discrimination power. The inter-level relationship constraint, e.g., a plant image must first be assigned to a parent node (high-level non-leaf node) correctly if it can further be assigned to the most relevant child node (low-level non-leaf node or leaf node) on the visual tree, is formally defined and leveraged to learn more discriminative tree classifiers over the visual tree. Our experimental results have demonstrated the effectiveness of our hierarchical multi-task structural learning algorithm on training more discriminative tree classifiers for large-scale plant species identification.

Analysis of supply chain, scale factor, and optimum plant capacity for the production of ethanol from corn stover

International Nuclear Information System (INIS)

Leboreiro, Jose; Hilaly, Ahmad K.

2013-01-01

A detailed model is used to perform a thorough analysis on ethanol production from corn stover via the dilute acid process. The biomass supply chain cost model accounts for all steps needed to source corn stover including collection, transportation, and storage. The manufacturing cost model is based on work done at NREL; attainable conversions of key process parameters are used to calculate production cost. The choice of capital investment scaling function and scaling parameter has a significant impact on the optimum plant capacity. For the widely used exponential function, the scaling factors are functions of plant capacity. The pre-exponential factor decreases with increasing plant capacity while the exponential factor increases as the plant capacity increases. The use of scaling parameters calculated for small plant capacities leads to falsely large optimum plants; data from a wide range of plant capacities is required to produce accurate results. A mathematical expression to scale capital investment for fermentation-based biorefineries is proposed which accounts for the linear scaling behavior of bio-reactors (such as saccharification vessels and fermentors) as well as the exponential nature of all other plant equipment. Ignoring the linear scaling behavior of bio-reactors leads to artificially large optimum plant capacities. The minimum production cost is found to be in the range of 789–830 $ m −3 which is significantly higher than previously reported. Optimum plant capacities are in the range of 5750–9850 Mg d −1 . The optimum plant capacity and production cost are highly sensitive to farmer participation in biomass harvest for low participation rates. -- Highlights: •A detailed model is used to perform a technoeconomic analysis for the production of ethanol from corn stover. •The capital investment scaling factors were found to be a function of plant capacity. •Bio-reactors (such as saccharification vessels and fermentors) in large size

Development of internalizing problems from adolescence to emerging adulthood: Accounting for heterotypic continuity with vertical scaling.

Science.gov (United States)

Petersen, Isaac T; Lindhiem, Oliver; LeBeau, Brandon; Bates, John E; Pettit, Gregory S; Lansford, Jennifer E; Dodge, Kenneth A

2018-03-01

Manifestations of internalizing problems, such as specific symptoms of anxiety and depression, can change across development, even if individuals show strong continuity in rank-order levels of internalizing problems. This illustrates the concept of heterotypic continuity, and raises the question of whether common measures might be construct-valid for one age but not another. This study examines mean-level changes in internalizing problems across a long span of development at the same time as accounting for heterotypic continuity by using age-appropriate, changing measures. Internalizing problems from age 14-24 were studied longitudinally in a community sample (N = 585), using Achenbach's Youth Self-Report (YSR) and Young Adult Self-Report (YASR). Heterotypic continuity was evaluated with an item response theory (IRT) approach to vertical scaling, linking different measures over time to be on the same scale, as well as with a Thurstone scaling approach. With vertical scaling, internalizing problems peaked in mid-to-late adolescence and showed a group-level decrease from adolescence to early adulthood, a change that would not have been seen with the approach of using only age-common items. Individuals' trajectories were sometimes different than would have been seen with the common-items approach. Findings support the importance of considering heterotypic continuity when examining development and vertical scaling to account for heterotypic continuity with changing measures. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

MANUFACTURING AND CONTINUOUS IMPROVEMENT PERFORMANCE LEVEL IN PLANTS OF MEXICO; A COMPARATIVE ANALYSIS AMONG LARGE AND MEDIUM SIZE PLANTS

OpenAIRE

Carlos Monge; Jesús Cruz

2015-01-01

A random and statistically significant sample of 40 medium (12) and large (28) manufacturing plants of Apodaca, Mexico were surveyed using a structured and validated questionnaire to investigate the level of implementation of lean manufacturing, sustainable manufacturing, continuous improvement and operational efficiency and environmental responsibility in them, it is important to mention it was found that performance in the mentioned philosophies, on the two categories of plants is low, howe...

Plant interactions alter the predictions of metabolic scaling theory.

Directory of Open Access Journals (Sweden)

Yue Lin

Full Text Available Metabolic scaling theory (MST is an attempt to link physiological processes of individual organisms with macroecology. It predicts a power law relationship with an exponent of -4/3 between mean individual biomass and density during density-dependent mortality (self-thinning. Empirical tests have produced variable results, and the validity of MST is intensely debated. MST focuses on organisms' internal physiological mechanisms but we hypothesize that ecological interactions can be more important in determining plant mass-density relationships induced by density. We employ an individual-based model of plant stand development that includes three elements: a model of individual plant growth based on MST, different modes of local competition (size-symmetric vs. -asymmetric, and different resource levels. Our model is consistent with the observed variation in the slopes of self-thinning trajectories. Slopes were significantly shallower than -4/3 if competition was size-symmetric. We conclude that when the size of survivors is influenced by strong ecological interactions, these can override predictions of MST, whereas when surviving plants are less affected by interactions, individual-level metabolic processes can scale up to the population level. MST, like thermodynamics or biomechanics, sets limits within which organisms can live and function, but there may be stronger limits determined by ecological interactions. In such cases MST will not be predictive.

Continuous precipitation of uranium peroxide in process pilot plant

International Nuclear Information System (INIS)

Quinelato, A.L.

1990-01-01

An experimental study on uranium peroxide precipitation has been carried out with the objective to evaluate the influence of the main process parameters with a technological approach. The uraniferous solution used was obtained from the hydrometallurgical processing of an ore from Itataia - CE. Studies were developed in two distinct experimental stages. In the first stage, the precipitation was investigated by means of laboratory batch tests and, in the second stage, by means of continuous operation in a process pilot plant. (author)

Extension plant pathology: strengthening resources to continue serving the public interest.

Science.gov (United States)

Everts, K L; Osborne, L; Gevens, A J; Vasquez, S J; Gugino, B K; Ivors, K; Harmon, C

2012-07-01

Extension plant pathologists deliver science-based information that protects the economic value of agricultural and horticultural crops in the United States by educating growers and the general public about plant diseases. Extension plant pathologists diagnose plant diseases and disorders, provide advice, and conduct applied research on local and regional plant disease problems. During the last century, extension plant pathology programs have adjusted to demographic shifts in the U.S. population and to changes in program funding. Extension programs are now more collaborative and more specialized in response to a highly educated clientele. Changes in federal and state budgets and policies have also reduced funding and shifted the source of funding of extension plant pathologists from formula funds towards specialized competitive grants. These competitive grants often favor national over local and regional plant disease issues and typically require a long lead time to secure funding. These changes coupled with a reduction in personnel pose a threat to extension plant pathology programs. Increasing demand for high-quality, unbiased information and the continued reduction in local, state, and federal funds is unsustainable and, if not abated, will lead to a delay in response to emerging diseases, reduce crop yields, increase economic losses, and place U.S. agriculture at a global competitive disadvantage. In this letter, we outline four recommendations to strengthen the role and resources of extension plant pathologists as they guide our nation's food, feed, fuel, fiber, and ornamental producers into an era of increasing technological complexity and global competitiveness.

Investigation of small scale sphere-pac fuel fabrication plant with external gelation process

International Nuclear Information System (INIS)

Maekawa, Kazuhiko; Yoshimura, Tadahiro; Kikuchi, Toshiaki; Hoshino, Yasushi; Munekata, Hideki; Shimizu, Makoto

2005-02-01

In feasibility studies on commercialized FBR cycle system, comprehensive system investigation and properties evaluation for candidate FBR cycle systems have been implemented through view point of safety, economics, environmental burden reduction, non-proliferation resistivity, etc. As part of these studies, an investigation of small scale sphere-pac fuel fabrication plant with external gelation process was conducted. Until last fiscal year, equipment layout in cells and overall layout design of the 200t-HM/y scale fuel fabrication plant were conducted as well as schematical design studies on main equipments in gelation and reagent recovery processes of the plant. System property data concerning economics and environmental burden reduction of fuel fabrication plant was also acquired. In this fiscal year, the processes from vibropacking to fuel assemblies storage were added to the investigation range, and a conceptual design of whole fuel fabrication plant was studied as well as deepening the design study on main equipments. The conceptual design study was mainly conducted for small 50t-HM/y scale plant and a revising investigation was done for 200t-HM/y scale plant. Taking the planed comparative evaluation with pellet fuel fabrication system into account, design of equipments which should be equivalent with pellet system, especially in post-vibropacking processes, were standardized in each system. Based on these design studies, system properties data concerning economics and environmental burden reduction of the plant was also acquired. In comparison with existing design, the cell height was lowered on condition that plug type pneumatic system was adopted and fuel fabrication building was downsized by applying rationalized layout design of pellet system to post-vibropacking processes. Reduction of reagent usage at gelation process and rationalization of sintering and O/M controlling processes etc., are foremost tasks. (author)

SIMULTANEOUS SCHEDULING AND OPERATIONAL OPTIMIZATION OF MULTIPRODUCT, CYCLIC CONTINUOUS PLANTS

Directory of Open Access Journals (Sweden)

A. Alle

2002-03-01

Full Text Available The problems of scheduling and optimization of operational conditions in multistage, multiproduct continuous plants with intermediate storage are simultaneously addressed. An MINLP model, called TSPFLOW, which is based on the TSP formulation for product sequencing, is proposed to schedule the operation of such plants. TSPFLOW yields a one-order-of-magnitude CPU time reduction as well as the solution of instances larger than those formerly reported (Pinto and Grossmann, 1994. Secondly, processing rates and yields are introduced as additional optimization variables in order to state the simultaneous problem of scheduling with operational optimization. Results show that trade-offs are very complex and that the development of a straightforward (rule of thumb method to optimally schedule the operation is less effective than the proposed approach.

SIMULTANEOUS SCHEDULING AND OPERATIONAL OPTIMIZATION OF MULTIPRODUCT, CYCLIC CONTINUOUS PLANTS

Directory of Open Access Journals (Sweden)

Alle A.

2002-01-01

Full Text Available The problems of scheduling and optimization of operational conditions in multistage, multiproduct continuous plants with intermediate storage are simultaneously addressed. An MINLP model, called TSPFLOW, which is based on the TSP formulation for product sequencing, is proposed to schedule the operation of such plants. TSPFLOW yields a one-order-of-magnitude CPU time reduction as well as the solution of instances larger than those formerly reported (Pinto and Grossmann, 1994. Secondly, processing rates and yields are introduced as additional optimization variables in order to state the simultaneous problem of scheduling with operational optimization. Results show that trade-offs are very complex and that the development of a straightforward (rule of thumb method to optimally schedule the operation is less effective than the proposed approach.

A separation theorem for the stochastic sampled-data LQG problem. [control of continuous linear plant disturbed by white noise

Science.gov (United States)

Halyo, N.; Caglayan, A. K.

1976-01-01

This paper considers the control of a continuous linear plant disturbed by white plant noise when the control is constrained to be a piecewise constant function of time; i.e. a stochastic sampled-data system. The cost function is the integral of quadratic error terms in the state and control, thus penalizing errors at every instant of time while the plant noise disturbs the system continuously. The problem is solved by reducing the constrained continuous problem to an unconstrained discrete one. It is shown that the separation principle for estimation and control still holds for this problem when the plant disturbance and measurement noise are Gaussian.

On the need for new continues measurement techniques at combustion plants; Anlaeggningars behov av ny kontinuerlig maetteknik

Energy Technology Data Exchange (ETDEWEB)

Eskilsson, David; Samuelsson, Jessica [Swedish National Testing and Research Inst., Boraas (Sweden)

2006-11-15

The purpose of this study is to make an inventory regarding the need for new continuous measurement techniques at combustion plants in Sweden. In total 15 interviews at 15 different combustion plants were made. The interviewed plants are of different sizes and use different combustion techniques, fuels, and cleaning equipments. They thereby well reflect the combustion plants present in Sweden today. Among many interesting interview results, we chose to highlight: Continuous measurement of the moisture content of the fuel, which can be used to decide the value of a fuel delivery, or for monitoring or to controlling the combustion (e.g. the speed of the grate); Continuous measurement of the heating value of the fuel, which can be used to decide the value of a fuel delivery, or for monitoring or to controlling the combustion. There is a need for temperature sensors which better withstand the environment in the furnace. Moreover, there is also a need for 3-dimensional measurements of the temperature in the furnace, especially for fluidized beds. This information can be used to control the combustion in different ways, e.g. preventing the bed from sintering. At some plants there was a need to measure the rate of corrosion and the growth of deposits. The measurements can be used to control the fuel mix at an early stage and to thereby avoid problems caused by corrosion and deposits. The measurement results can also be used to control the soot cleaning equipment, fuel mixture and adding of additive. At some of the interviewed plants there was a need to continuously measure the amount of unburned fuel in the ash. The continuous measurement results can be used for automatic control or monitoring of the combustion process. Several plants had problems with their dust instruments. Suitable topics for future work include investigating how the measurement techniques mentioned above may be developed/improved and implemented at the plants.

Consequential environmental life cycle assessment of a farm-scale biogas plant.

Science.gov (United States)

Van Stappen, Florence; Mathot, Michaël; Decruyenaere, Virginie; Loriers, Astrid; Delcour, Alice; Planchon, Viviane; Goffart, Jean-Pierre; Stilmant, Didier

2016-06-15

Producing biogas via anaerobic digestion is a promising technology for meeting European and regional goals on energy production from renewable sources. It offers interesting opportunities for the agricultural sector, allowing waste and by-products to be converted into bioenergy and bio-based materials. A consequential life cycle assessment (cLCA) was conducted to examine the consequences of the installation of a farm-scale biogas plant, taking account of assumptions about processes displaced by biogas plant co-products (power, heat and digestate) and the uses of the biogas plant feedstock prior to plant installation. Inventory data were collected on an existing farm-scale biogas plant. The plant inputs are maize cultivated for energy, solid cattle manure and various by-products from surrounding agro-food industries. Based on hypotheses about displaced electricity production (oil or gas) and the initial uses of the plant feedstock (animal feed, compost or incineration), six scenarios were analyzed and compared. Digested feedstock previously used in animal feed was replaced with other feed ingredients in equivalent feed diets, designed to take account of various nutritional parameters for bovine feeding. The displaced production of mineral fertilizers and field emissions due to the use of digestate as organic fertilizer was balanced against the avoided use of manure and compost. For all of the envisaged scenarios, the installation of the biogas plant led to reduced impacts on water depletion and aquatic ecotoxicity (thanks mainly to the displaced mineral fertilizer production). However, with the additional animal feed ingredients required to replace digested feedstock in the bovine diets, extra agricultural land was needed in all scenarios. Field emissions from the digestate used as organic fertilizer also had a significant impact on acidification and eutrophication. The choice of displaced marginal technologies has a huge influence on the results, as have the

A new proposed approach for future large-scale de-carbonization coal-fired power plants

International Nuclear Information System (INIS)

Xu, Gang; Liang, Feifei; Wu, Ying; Yang, Yongping; Zhang, Kai; Liu, Wenyi

2015-01-01

The post-combustion CO 2 capture technology provides a feasible and promising method for large-scale CO 2 capture in coal-fired power plants. However, the large-scale CO 2 capture in conventionally designed coal-fired power plants is confronted with various problems, such as the selection of the steam extraction point and steam parameter mismatch. To resolve these problems, an improved design idea for the future coal-fired power plant with large-scale de-carbonization is proposed. A main characteristic of the proposed design is the adoption of a back-pressure steam turbine, which extracts the suitable steam for CO 2 capture and ensures the stability of the integrated system. A new let-down steam turbine generator is introduced to retrieve the surplus energy from the exhaust steam of the back-pressure steam turbine when CO 2 capture is cut off. Results show that the net plant efficiency of the improved design is 2.56% points higher than that of the conventional one when CO 2 capture ratio reaches 80%. Meanwhile, the net plant efficiency of the improved design maintains the same level to that of the conventional design when CO 2 capture is cut off. Finally, the match between the extracted steam and the heat demand of the reboiler is significantly increased, which solves the steam parameter mismatch problem. The techno-economic analysis indicates that the proposed design is a cost-effective approach for the large-scale CO 2 capture in coal-fired power plants. - Highlights: • Problems caused by CO 2 capture in the power plant are deeply analyzed. • An improved design idea for coal-fired power plants with CO 2 capture is proposed. • Thermodynamic, exergy and techno-economic analyses are quantitatively conducted. • Energy-saving effects are found in the proposed coal-fired power plant design idea

Scaling root processes based on plant functional traits (Invited)

Science.gov (United States)

Eissenstat, D. M.; McCormack, M. L.; Gaines, K.; Adams, T.

2013-12-01

There are great challenges to scaling root processes as variation across species and variation of a particular species over different spatial and temporal scales is poorly understood. We have examined tree species variation using multispecies plantings, often referred to by ecologists as 'common gardens'. Choosing species with wide variation in growth rate, root morphology (diameter, branching intensity) and root chemistry (root N and Ca concentration), we found that variation in root lifespan was well correlated with plant functional traits across 12 species. There was also evidence that localized liquid N addition could increase root lifespan and localized water addition diminished root lifespan over untreated controls, with effects strongest in the species of finest root diameter. In an adjacent forest, we have also seen tree species variation in apparent depth of rooting using water isotopes. In particular species of wood anatomy that was ring porous (e.g. oaks) typically had the deepest rooting depth, whereas those that had either diffuse-porous sapwood (maples) or tracheid sapwood (pines) were shallower rooted. These differences in rooting depth were related to sap flux of trees during and immediately after periods of drought. The extent that the patterns observed in central Pennsylvania are modulated by environment or indicative of other plant species will be discussed.

Large Pilot Scale Testing of Linde/BASF Post-Combustion CO₂ Capture Technology at the Abbott Coal-Fired Power Plant

Energy Technology Data Exchange (ETDEWEB)

O' Brien, Kevin C. [University of Illinois, Champaign, IL (United States)

2017-08-18

The work summarized in this report is the first step towards a project that will re-train and create jobs for personnel in the coal industry and continue regional economic development to benefit regions impacted by previous downturns. The larger project is aimed at capturing ~300 tons/day (272 metric tonnes/day) CO₂ at a 90% capture rate from existing coal- fired boilers at the Abbott Power Plant on the campus of University of Illinois (UI). It will employ the Linde-BASF novel amine-based advanced CO₂ capture technology, which has already shown the potential to be cost-effective, energy efficient and compact at the 0.5-1.5 MWe pilot scales. The overall objective of the project is to design and install a scaled-up system of nominal 15 MWe size, integrate it with the Abbott Power Plant flue gas, steam and other utility systems, and demonstrate the viability of continuous operation under realistic conditions with high efficiency and capacity. The project will also begin to build a workforce that understands how to operate and maintain the capture plants by including students from regional community colleges and universities in the operation and evaluation of the capture system. This project will also lay the groundwork for follow-on projects that pilot utilization of the captured CO₂ from coal-fired power plants. The net impact will be to demonstrate a replicable means to (1) use a standardized procedure to evaluate power plants for their ability to be retrofitted with a pilot capture unit; (2) design and construct reliable capture systems based on the Linde-BASF technology; (3) operate and maintain these systems; (4) implement training programs with local community colleges and universities to establish a workforce to operate and maintain the systems; and (5) prepare to evaluate at the large pilot scale level various methods to utilize the resulting captured CO₂. Towards the larger project goal, the UI-led team, together

Design report small-scale fuel alcohol plant. Volume 2: Detailed construction information

Science.gov (United States)

1980-12-01

The objectives are to provide potential alcohol producers with a reference design and provide a complete, demonstrated design of a small scale fuel alcohol plant. The plant has the capability for feedstock preparation, cooking, saccharification, fermentation, distillation, by-product dewatering, and process steam generation. An interesting feature is an instrumentation and control system designed to allow the plant to run 24 hours per day with only four hours of operator attention.

Operational experience in chemical control of scale in boilers at the Ostrava-Karvina power plants

Energy Technology Data Exchange (ETDEWEB)

Sikora, E; Srovnal, O

1988-03-01

Discusses methods for buildup removal from coal-fired boilers in power plants. Buildup types are analyzed. Standardized methods for buildup removal tested on a commercial scale in the power plants are comparatively evaluated. Scaling in the boiler heat exchange system is investigated. Using hydrofluoric acid for scale removal is discussed. Concentration of hydrofluoric acid ranges from 1.5% to 2.0%. Ryphalgan and Kaptax are used as corrosion inhibitors. Syntron B is also used for scale removal during boiler operation (at a pressure to 6.4% and temperature below 270 C). Efficiency of scale removal using various reagents is discussed. 4 refs.

Monitoring of full-scale hydrodynamic cavitation pretreatment in agricultural biogas plant.

Science.gov (United States)

Garuti, Mirco; Langone, Michela; Fabbri, Claudio; Piccinini, Sergio

2018-01-01

The implementation of hydrodynamic cavitation (HC) pretreatment for enhancing the methane potential from agricultural biomasses was evaluated in a full scale agricultural biogas plant, with molasses and corn meal as a supplementary energy source. HC batch tests were run to investigate the influence on methane production, particle size and viscosity of specific energy input. 470kJ/kgTS was chosen for the full-scale implementation. Nearly 6-months of operational data showed that the HC pretreatment maximized the specific methane production of about 10%, allowing the biogas plant to get out of the fluctuating markets of supplementary energy sources and to reduce the methane emissions. HC influenced viscosity and particle size of digestate, contributing to reduce the energy demand for mixing, heating and pumping. In the light of the obtained results the HC process appears to be an attractive and energetically promising alternative to other pretreatments for the degradation of biomasses in biogas plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

INFLUENCE OF NANOFILTRATION PRETREATMENT ON SCALE DEPOSITION IN MULTI-STAGE FLASH THERMAL DESALINATION PLANTS

Directory of Open Access Journals (Sweden)

Aiman E Al-Rawajfeh

2011-01-01

Full Text Available Scale formation represents a major operational problem encountered in thermal desalination plants. In current installed plants, and to allow for a reasonable safety margin, sulfate scale deposition limits the top brine temperature (TBT in multi-stage flash (MSF distillers up to 110-112oC. This has significant effect on the unit capital, operational and water production cost. In this work, the influence of nanofiltration (NF pretreatment on the scale deposition potential and increasing TBT in MSF thermal desalination plants is modeled on the basis of mass transfer with chemical reaction of solutes in the brine. Full and partial NF-pretreatment of the feed water were investigated. TBT can be increased in MSF by increasing the percentage of NF-treated feed. Full NF pretreatment of the make-up allows TBT in the MSF plant to be raised up to 175oC in the case of di hybrid NF-MSF and up to 165oC in the case of tri hybrid NF-RO-MSF. The significant scale reduction is associated with increasing flashing range, unit recovery, unit performance, and will lead to reduction in heat transfer surface area, pumping power and therefore, water production cost.

Continuous operation of a pilot plant for the production of beryllium oxide

International Nuclear Information System (INIS)

Costa, T.C.; Amaral, S.; Silveira, C.M.S.; Oliveira, A.P. de

1975-01-01

A method of obtaining beryllium oxide with a purity of 99,2% was developed in a pilot plant with a capacity of 7 tons per month destined to operate continuously. The operation market prospects and control of production with the objective of obtaining internacional technical grade beryllium oxide are discussed [pt

Continuous operation of a pilot plant for the production of beryllium oxide

Energy Technology Data Exchange (ETDEWEB)

Costa, T C; Amaral, S; Silveira, C M.S.; de Oliveira, A P [Instituto de Tecnologia, Governador Valadares (Brazil)

1975-12-01

A method of obtaining beryllium oxide with a purity of 99,2% was developed in a pilot plant with a capacity of 7 tons per month destined to operate continuously. The operation market prospects and control of production with the objective of obtaining internacional technical grade beryllium oxide are discussed.

Flow Chemistry on Multigram Scale: Continuous Synthesis of Boronic Acids within 1 s.

Science.gov (United States)

Hafner, Andreas; Meisenbach, Mark; Sedelmeier, Joerg

2016-08-05

The benefits and limitations of a simple continuous flow setup for handling and performing of organolithium chemistry on the multigram scale is described. The developed metalation platform embodies a valuable complement to existing methodologies, as it combines the benefits of Flash Chemistry (chemical synthesis on a time scale of <1 s) with remarkable throughput (g/min) while mitigating the risk of blockages.

Pilot plant study for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Kim, J S [Korea Inst. of Science and Technology, Seoul (Korea, Republic of)

1996-02-01

Most of domestic alcohol fermentation factory adopt batch process of which productivity is lower than continuous fermentation process. They have made great effort to increase productivity by means of partial unit process automatization and process improvement with their accumulated experience but there is technical limitation in productivity of batch fermentation process. To produce and supply fuel alcohol, economic aspects must be considered first of all. Therefore, development of continuous fermentation process, of which productivity is high, is prerequisite to produce and use fuel alcohol but only a few foreign company possess continuous fermentation technic and use it in practical industrial scale fermentation. We constructed pilot plant (5 Stage CSTR 1 kl 99.5 v/v% ethanol/Day scale) to study some aspects stated below and our ultimate aims are production of industrial scale fuel alcohol and construction of the plant by ourselves. Some study concerned with energy saving separation and contamination control technic were entrusted to KAIST, A-ju university and KIST respectively. (author) 67 refs., 100 figs., 58 tabs.

Influence of plant productivity over variability of soil respiration: a multi-scale approach

Science.gov (United States)

Curiel Yuste, J.

2009-04-01

To investigate the role of plant photosynthetic activity on the variations in soil respiration (SR), SR data obtained from manual sampling and automatic soil respiration chambers placed on eddy flux towers sites were used. Plant photosynthetic activity was represented as Gross Primary Production (GPP), calculated from the half hourly continuous measurements of Net Ecosystem Exchange (NEE). The role of plant photosynthetic activity over the variation in SR was investigated at different time-scales: data averaged hourly, daily and weekly were used to study the photosynthetic effect on SR dial variations (Hourly data), 15 days variations (Daily averages), monthly variations (daily and weekly averages) and seasonal variations (weekly data). Our results confirm the important role of plant photosynthetic activity on the variations of SR at each of the mentioned time-scales. The effect of photosynthetic activity on SR was high on hourly time-scale (dial variations of SR). At half of the studied ecosystems GPP was the best single predictor of dial variations of SR. However at most of the studied sites the combination of soil temperature and GPP was the best predictor of dial variations in SR. The effect of aboveground productivity over dial variations of SR lagged on the range of 5 to 15 hours, depending on the ecosystem. At daily to monthly time scale variations of SR were in general better explained with the combination of temperature and moisture variations. However, ‘jumps' in average weekly SR during the growing season yielded anomaly high values of Q10, in some cases above 1000, which probably reflects synoptic changes in photosynthates translocation from plant activity. Finally, although seasonal changes of SR were in general very well explained by temperature and soil moisture, seasonality of SR was better correlated to seasonality of GPP than to seasonality of soil temperature and/or soil moisture. Therefore the magnitude of the seasonal variation in SR was in

Correlated continuous-time random walks—scaling limits and Langevin picture

International Nuclear Information System (INIS)

Magdziarz, Marcin; Metzler, Ralf; Szczotka, Wladyslaw; Zebrowski, Piotr

2012-01-01

In this paper we analyze correlated continuous-time random walks introduced recently by Tejedor and Metzler (2010 J. Phys. A: Math. Theor. 43 082002). We obtain the Langevin equations associated with this process and the corresponding scaling limits of their solutions. We prove that the limit processes are self-similar and display anomalous dynamics. Moreover, we extend the model to include external forces. Our results are confirmed by Monte Carlo simulations

Continuous monitoring of plutonium solution in a conversion plant

International Nuclear Information System (INIS)

Hassan, B.; Piana, M.; Mousalli, G.; Saukkonen, H.; Hosima, T.; Kawa, T.

2000-01-01

This paper describes the implementation of a safeguards Tank Monitoring System (TAMS) in a Plutonium Conversion Plant (PCP). TAMS main objective is to provide the International Atomic Energy Agency (IAEA) (the Agency) with continuous data for safeguards evaluation and review of inventories and flows of plutonium solutions. It has been designed to monitor, in unattended mode, the inventory of each tank and transactions of solutions between tanks, as well as to confirm the absence of borrowing plutonium solutions from and to a neighboring reprocessing plant. The instrumentation consists of one electronic scanner that collects pressure data from electromanometers connected to the tank dip tubes, one uninterruptable power supply and one personal computer operating in a Windows-NT environment. The pressure data transmitted to the acquisition system is saved and converted to volume and density values, coupled with a graph capability to display events in each tank at intervals of 15 seconds. The system operation has not only strengthened the safeguards measures in PCP but also reduced inspection effort while minimizing intrusion to normal plant activities and radiation exposure to personnel. TAMS is a powerful, reliable tool that has significantly improved the effectiveness of safeguards implementation at PCP. The future combined use of TAMS with remote monitoring (RM) will further enhance efficiency of the safeguards measures at PCP. (author)

Evaluating continuous application of treated sludge on soil and plant productivity

Directory of Open Access Journals (Sweden)

Ahmed Al-Busaidi

2018-01-01

Full Text Available Kala Compost is a mixture of treated sewage bio-solids and green wastes. It can improve soil fertility and plant growth. However, long-term application of treated sewage bio-solids could result in heavy metals accumulation and some health problems. e objective of this study was to evaluate the e ect of a long run application of Kala compost mixed with chemical fertilizer on soil and plant productivity. Soil and plant (mainly cucumber samples were taken from 12 greenhouses that received Kala compost continuously for the last ve years. No symptoms of physical or chemical problems were observed in the greenhouses and measured soil samples. Moreover, the soil had su cient values of di erent nutrients for plant growth and all measured micronutrients (heavy metals were within the safe limit and below the range of the international standards. An excellent growth was observed in all grown plants and no symptoms of elements de ciency were found. Chemical analysis of fruit samples did not show any accumulation of heavy metals and all measured elements were within the safe limit and did not exceed the international standards. It can be concluded that Kala compost was a good media for plant growth that can enrich the soil with di erent elements needed for higher yield. However, more monitoring is needed with treated bio-solid application but good management could be the key to avoid any adverse e ect of any contaminant.

Temporal and spatial scaling of the genetic structure of a vector-borne plant pathogen.

Science.gov (United States)

Coletta-Filho, Helvécio D; Francisco, Carolina S; Almeida, Rodrigo P P

2014-02-01

The ecology of plant pathogens of perennial crops is affected by the long-lived nature of their immobile hosts. In addition, changes to the genetic structure of pathogen populations may affect disease epidemiology and management practices; examples include local adaptation of more fit genotypes or introduction of novel genotypes from geographically distant areas via human movement of infected plant material or insect vectors. We studied the genetic structure of Xylella fastidiosa populations causing disease in sweet orange plants in Brazil at multiple scales using fast-evolving molecular markers (simple-sequence DNA repeats). Results show that populations of X. fastidiosa were regionally isolated, and that isolation was maintained for populations analyzed a decade apart from each other. However, despite such geographic isolation, local populations present in year 2000 were largely replaced by novel genotypes in 2009 but not as a result of migration. At a smaller spatial scale (individual trees), results suggest that isolates within plants originated from a shared common ancestor. In summary, new insights on the ecology of this economically important plant pathogen were obtained by sampling populations at different spatial scales and two different time points.

A feasible approach to implement a commercial scale CANDU fuel manufacturing plant in Egypt

International Nuclear Information System (INIS)

El-Shehawy, I.; El-Sharaky, M.; Yasso, K.; Selim, I.; Graham, N.; Newington, D.

1995-01-01

Many planning scenarios have been examined to assess and evaluate the economic estimates for implementing a commercial scale CANDU fuel manufacturing plant in Egypt. The cost estimates indicated strong influence of the annual capital costs on total fuel manufacturing cost; this is particularly evident in a small initial plant where the proposed design output is only sufficient to supply reload fuel for a single CANDU-6 reactor. A modular approach is investigated as a possible way, to reduce the capital costs for a small initial fuel plant. In this approach the plant would do fuel assembly operations only and the remainder of a plant would be constructed and equipped in the stages when high production volumes can justify the capital expenses. Such approach seems economically feasible for implementing a small scale CANDU fuel manufacturing plant in developing countries such as Egypt and further improvement could be achieved over the years of operation. (author)

Introducing close-range photogrammetry for characterizing forest understory plant diversity and surface fuel structure at fine scales

Science.gov (United States)

Benjamin C. Bright; E. Louise Loudermilk; Scott M. Pokswinski; Andrew T. Hudak; Joseph J. O' Brien

2016-01-01

Methods characterizing fine-scale fuels and plant diversity can advance understanding of plant-fire interactions across scales and help in efforts to monitor important ecosystems such as longleaf pine (Pinus palustris Mill.) forests of the southeastern United States. Here, we evaluate the utility of close-range photogrammetry for measuring fuels and plant...

Reduced-scale experimental investigation on ventilation performance of a local exhaust hood in an industrial plant

DEFF Research Database (Denmark)

Huang, Yanqiu; Wang, Yi; Liu, Li

2015-01-01

stratification in the working areas of industrial plants. Investigated factors were confined airflow boundaries, flow rates of the exhaust hoods, source strengths, airflow obstacles and distances between sources and exhaust hoods. Reduced-scale experiments were conducted with a geometric scale of 1...... efficiency. Hood performance was also evaluated by thermal stratification heights in the plants. This study could help improve the capture efficiency of local ventilation systems used in industrial plants. Safe operation heights are recommended in the upper space of industrial plants based on the thermal...

Evaluation of aged concrete structures for continued service in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

1988-01-01

Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability

Treatability and scale-up protocols for polynuclear aromatic hydrocarbon bioremediation of manufactured-gas-plant soils. Final report, September 1987-July 1991

International Nuclear Information System (INIS)

Blackburn, J.W.; DiGrazia, P.M.; Sanseverino, J.

1991-07-01

The report describes activities to develop a framework to reliably scale-up and apply challenging bioremediation processes to polynuclear aromatic hydrocarbons in Manufactured Gas Plant (MGP) soils. It includes: a discussion of the accuracy needed for competitive application of bioremediation; a framework and examples for treatability and scale-up protocols for selection, design and application of these processes; both batch and continuous testing protocols for developing predictive rate data; and special predictive relationships that may be used in process selection/scale-up. The work, coupled with subsequent work (as recommended) to develop an MGP soil desorption/diffusion protocol and new scale-up methods, and with subsequent scale-up testing should lead to the capability for improved selection of MGP sites for bioremediation and improved performance, success, and reliability of field applications. With this greater predictive reliability, bioremediation will be used more often in the field on the most favorable applications and its cost advantages over other remediation options will be realized

Corrections to scaling in random resistor networks and diluted continuous spin models near the percolation threshold.

Science.gov (United States)

Janssen, Hans-Karl; Stenull, Olaf

2004-02-01

We investigate corrections to scaling induced by irrelevant operators in randomly diluted systems near the percolation threshold. The specific systems that we consider are the random resistor network and a class of continuous spin systems, such as the x-y model. We focus on a family of least irrelevant operators and determine the corrections to scaling that originate from this family. Our field theoretic analysis carefully takes into account that irrelevant operators mix under renormalization. It turns out that long standing results on corrections to scaling are respectively incorrect (random resistor networks) or incomplete (continuous spin systems).

Continuous monitoring of odours from a composting plant using electronic noses.

Science.gov (United States)

Sironi, Selena; Capelli, Laura; Céntola, Paolo; Del Rosso, Renato; Il Grande, Massimiliano

2007-01-01

The odour impact of a composting plant situated in an urbanized area was evaluated by continuously monitoring the ambient air close to the plant during a period of about 4 days using two electronic noses. One electronic nose was installed in a nearby house, and the other one inside the perimeter of the composting plant in order to compare the response of both instruments. The results of the monitoring are represented by tables that report the olfactory class and the odour concentration value attributed to the analyzed air for each of the 370 measurements carried out during the monitoring period. The electronic nose installed at the house detected the presence of odours coming from the composting plant for about 7.8% of the monitoring total duration. Of the odour detections, 86% (25 of 29 measurements) were classified as belonging to the olfactory class corresponding to the open air storage of the waste screening overflows heaps, which was therefore identified to be the major odour source of the monitored composting plant. In correspondence of the measurements during which the electronic nose inside the house detected the presence of odours from the composting plant, the olfactory classes recognized by both instruments coincide. Moreover, the electronic nose at the house detected the presence of odours from the composting plant at issue in correspondence of each odour perception of the house occupants. The results of the study show the possibility of using an electronic nose for environmental odours monitoring, which enables the classification of the quality of the air and to quantify the olfactory nuisance from an industrial source in terms of duration and odour concentration.

Small-scale biomass CHP using gasa turbines: a scoping study

International Nuclear Information System (INIS)

James, D.W.; Landen, R.

1996-01-01

Various options for small-scale (up to 250 KWe) Combined Heat and Power (CHP) plants evaluated in this scoping study. Plants using small gas turbines, and able to use biomass fuels when available are included. Three detailed case studies of small-scale biomass CHP plants are compared to match specific technical options with customer requirements. The commercial development of such biomass-fired CHP units, using gas turbines, is shown to be economically viable depending on fuel costs and the continuation of existing financial incentives. (UK)

A new framework to increase the efficiency of large-scale solar power plants.

Science.gov (United States)

Alimohammadi, Shahrouz; Kleissl, Jan P.

2015-11-01

A new framework to estimate the spatio-temporal behavior of solar power is introduced, which predicts the statistical behavior of power output at utility scale Photo-Voltaic (PV) power plants. The framework is based on spatio-temporal Gaussian Processes Regression (Kriging) models, which incorporates satellite data with the UCSD version of the Weather and Research Forecasting model. This framework is designed to improve the efficiency of the large-scale solar power plants. The results are also validated from measurements of the local pyranometer sensors, and some improvements in different scenarios are observed. Solar energy.

Large scale 2D spectral compressed sensing in continuous domain

KAUST Repository

Cai, Jian-Feng

2017-06-20

We consider the problem of spectral compressed sensing in continuous domain, which aims to recover a 2-dimensional spectrally sparse signal from partially observed time samples. The signal is assumed to be a superposition of s complex sinusoids. We propose a semidefinite program for the 2D signal recovery problem. Our model is able to handle large scale 2D signals of size 500 × 500, whereas traditional approaches only handle signals of size around 20 × 20.

Large scale 2D spectral compressed sensing in continuous domain

KAUST Repository

Cai, Jian-Feng; Xu, Weiyu; Yang, Yang

2017-01-01

We consider the problem of spectral compressed sensing in continuous domain, which aims to recover a 2-dimensional spectrally sparse signal from partially observed time samples. The signal is assumed to be a superposition of s complex sinusoids. We propose a semidefinite program for the 2D signal recovery problem. Our model is able to handle large scale 2D signals of size 500 × 500, whereas traditional approaches only handle signals of size around 20 × 20.

Insight into economies of scale for waste packaging sorting plants

DEFF Research Database (Denmark)

Cimpan, Ciprian; Wenzel, Henrik; Maul, Anja

2015-01-01

of economies of scale and discussed complementary relations occurring between capacity size, technology level and operational practice. Processing costs (capital and operational expenditure) per unit waste input were found to decrease from above 100 € for small plants with a basic technology level to 60......This contribution presents the results of a techno-economic analysis performed for German Materials Recovery Facilities (MRFs) which sort commingled lightweight packaging waste (consisting of plastics, metals, beverage cartons and other composite packaging). The study addressed the importance......-70 € for large plants employing advanced process flows. Typical operational practice, often riddled with inadequate process parameters was compared with planned or designed operation. The former was found to significantly influence plant efficiency and therefore possible revenue streams from the sale of output...

The design of a continuous ion-exchange pilot plant for the recovery of uranium from partially clarified solutions

International Nuclear Information System (INIS)

Cloete, F.L.D.

1980-01-01

A preliminary design is given for a pilot plant to recover uranium from partially clarified slime pulp by continuous ion exchange. Process and plant-design methods are indicated briefly, and an outline is given of experimental work that should be undertaken before the start-up of the pilot plant

Research and development of safeguards measures for the large scale reprocessing plant

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Masahiro; Sato, Yuji; Yokota, Yasuhiro; Masuda, Shoichiro; Kobayashi, Isao; Uchikoshi, Seiji; Tsutaki, Yasuhiro; Nidaira, Kazuo [Nuclear Material Control Center, Tokyo (Japan)

1994-12-31

The Government of Japan agreed on the safeguards concepts of commercial size reprocessing plant under the bilateral agreement for cooperation between the Japan and the United States. In addition, the LASCAR, that is the forum of large scale reprocessing plant safeguards, could obtain the fruitful results in the spring of 1992. The research and development of safeguards measures for the Rokkasho Reprocessing Plant should be progressed with every regard to the concepts described in both documents. Basically, the material accountancy and monitoring system should be established, based on the NRTA and other measures in order to obtain the timeliness goal for plutonium, and the un-attended mode inspection approach based on the integrated containment/surveillance system coupled with radiation monitoring in order to reduce the inspection efforts. NMCC has been studying on the following measures for a large scale reprocessing plant safeguards (1) A radiation gate monitor and integrated surveillance system (2) A near real time Shipper and Receiver Difference monitoring (3) A near real time material accountancy system operated for the bulk handling area (4) A volume measurement technique in a large scale input accountancy vessel (5) An in-process inventory estimation technique applied to the process equipment such as the pulse column and evaporator (6) Solution transfer monitoring approach applied to buffer tanks in the chemical process (7) A timely analysis technique such as a hybrid K edge densitometer operated in the on-site laboratory (J.P.N.).

Physical time scale in kinetic Monte Carlo simulations of continuous-time Markov chains.

Science.gov (United States)

Serebrinsky, Santiago A

2011-03-01

We rigorously establish a physical time scale for a general class of kinetic Monte Carlo algorithms for the simulation of continuous-time Markov chains. This class of algorithms encompasses rejection-free (or BKL) and rejection (or "standard") algorithms. For rejection algorithms, it was formerly considered that the availability of a physical time scale (instead of Monte Carlo steps) was empirical, at best. Use of Monte Carlo steps as a time unit now becomes completely unnecessary.

Kinetic model for torrefaction of wood chips in a pilot-scale continuous reactor

DEFF Research Database (Denmark)

Shang, Lei; Ahrenfeldt, Jesper; Holm, Jens Kai

2014-01-01

accordance with the model data. In an additional step a continuous, pilot scale reactor was built to produce torrefied wood chips in large quantities. The "two-step reaction in series" model was applied to predict the mass yield of the torrefaction reaction. Parameters used for the calculation were...... at different torrefaction temperatures, it was possible to predict the HHV of torrefied wood chips from the pilot reactor. The results from this study and the presented modeling approach can be used to predict the product quality from pilot scale torrefaction reactors based on small scale experiments and could...

Large-scale Lurgi plant would be uneconomic: study group

Energy Technology Data Exchange (ETDEWEB)

1964-03-21

Gas Council and National Coal Board agreed that building of large scale Lurgi plant on the basis of study is not at present acceptable on economic grounds. The committee considered that new processes based on naphtha offered more economic sources of base and peak load production. Tables listing data provided in contractors' design studies and summary of contractors' process designs are included.

Evaluation of aged concrete structures for continued service in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

1988-01-01

Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability. 19 refs., 5 figs., 3 tabs

Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses

Science.gov (United States)

Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

2013-12-01

In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these

Ecosystem engineers on plants: indirect facilitation of arthropod communities by leaf-rollers at different scales.

Science.gov (United States)

Vieira, Camila; Romero, Gustavo Q

2013-07-01

Ecosystem engineering is a process by which organisms change the distribution of resources and create new habitats for other species via non-trophic interactions. Leaf-rolling caterpillars can act as ecosystem engineers because they provide shelter to secondary users. In this study, we report the influence of leaf-rolling caterpillars on speciose tropical arthropod communities along both spatial scales (leaf-level and plant-level effects) and temporal scales (dry and rainy seasons). We predict that rolled leaves can amplify arthropod diversity at both the leaf and plant levels and that this effect is stronger in dry seasons, when arthropods are prone to desiccation. Our results show that the abundance, richness, and biomass of arthropods within several guilds increased up to 22-fold in naturally and artificially created leaf shelters relative to unaltered leaves. These effects were observed at similar magnitudes at both the leaf and plant scales. Variation in the shelter architecture (funnel, cylinders) did not influence arthropod parameters, as diversity, abundance, orbiomass, but rolled leaves had distinct species composition if compared with unaltered leaves. As expected, these arthropod parameters on the plants with rolled leaves were on average approximately twofold higher in the dry season. Empty leaf rolls and whole plants were rapidly recolonized by arthropods over time, implying a fast replacement of individuals; within 15-day intervals the rolls and plants reached a species saturation. This study is the first to examine the extended effects of engineering caterpillars as diversity amplifiers at different temporal and spatial scales. Because shelter-building caterpillars are ubiquitous organisms in tropical and temperate forests, they can be considered key structuring elements for arthropod communities on plants.

Quantification and scaling of multipartite entanglement in continuous variable systems.

Science.gov (United States)

Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

2004-11-26

We present a theoretical method to determine the multipartite entanglement between different partitions of multimode, fully or partially symmetric Gaussian states of continuous variable systems. For such states, we determine the exact expression of the logarithmic negativity and show that it coincides with that of equivalent two-mode Gaussian states. Exploiting this reduction, we demonstrate the scaling of the multipartite entanglement with the number of modes and its reliable experimental estimate by direct measurements of the global and local purities.

Developing the biofacility of the future based on continuous processing and single-use technology.

Science.gov (United States)

Klutz, Stephan; Magnus, Jorgen; Lobedann, Martin; Schwan, Peter; Maiser, Benjamin; Niklas, Jens; Temming, Maike; Schembecker, Gerhard

2015-11-10

To maintain or strengthen their market position, biopharmaceutical producers have to adapt their production facilities to a drastically changed market environment. Contrary to currently used large scale batch-wise operated production facilities, where stainless steel equipment is widely applied, small scale and flexible production processes are desired. Consequently, the concept of the "biofacility of the future" has been developed, which combines the attributes fast, flexible, small, inexpensive and sustainable. Four design principles build the facility's basis and are presented within this work: continuous processing, 100% single-use equipment, closed processing and adopting the ballroom concept. However, no publication presents a completely continuously operated platform process for the production of monoclonal antibodies up to now. Therefore, this work establishes the proof of concept regarding continuous antibody manufacturing. A pilot plant for the production of monoclonal antibodies has been built 100% in single-use equipment. It was operated fully continuous and automated in the upstream and the downstream part. The concepts that allow continuously operating the pilot plant are presented within this work, i.e., continuously operated filtration, continuously operated viral inactivation, continuously operated chromatography and a continuously operated formulation. Analytics showed that the produced product was within specification limits of industrial bulk drug substances. Copyright © 2015 Elsevier B.V. All rights reserved.

Reduced risk insecticides to control scale insects and protect natural enemies in the production and maintenance of urban landscape plants.

Science.gov (United States)

Frank, Steven D

2012-04-01

Armored scale insects are among the most difficult to manage and economically important arthropod pests in the production and maintenance of urban landscape plants. This is because of morphological traits that protect them from contact insecticides. I compared initial and season-long control of euonymus scale, Unaspis euonymi Comstock (Hemiptera: Diaspidae), by reduced-risk insecticides (insect growth regulators [IGRs], neonicotinoids, spirotetramat) to determine if they controlled scale as well as more toxic insecticides such as the organophosphate, acephate, and pyrethroid, bifenthrin. I also evaluated how these insecticides affected natural enemy abundance on experimental plants and survival when exposed to insecticide residue. All insecticides tested reduced first generation euonymus scale abundance. In 2009, reinfestation by second generation euonymus scale was highest on plants treated with acetamiprid and granular dinotefuran. In 2010, systemic neonicotinoids and spirotetramat prevented cottony cushion scale infestation 133 d after treatment whereas scale readily infested plants treated with bifenthrin and horticultural oil. Encarsia spp. and Cybocephalus spp. abundance was related to scale abundance. These natural enemies were generally less abundant than predicted by scale abundance on granular dinotefuran treated plants and more abundant on granular thiamethoxam treated plants. Bifenthrin residue killed 90-100% of O. insidiosus and E. citrina within 24 h. My results indicate that reduced risk insecticides can provide season-long scale control with less impact on natural enemies than conventional insecticides. This could have economic and environmental benefits by reducing the number of applications necessary to protect nursery and landscape plants from scale.

Assessment of plant species diversity based on hyperspectral indices at a fine scale.

Science.gov (United States)

Peng, Yu; Fan, Min; Song, Jingyi; Cui, Tiantian; Li, Rui

2018-03-19

Fast and nondestructive approaches of measuring plant species diversity have been a subject of excessive scientific curiosity and disquiet to environmentalists and field ecologists worldwide. In this study, we measured the hyperspectral reflectances and plant species diversity indices at a fine scale (0.8 meter) in central Hunshandak Sandland of Inner Mongolia, China. The first-order derivative value (FD) at each waveband and 37 hyperspectral indices were used to assess plant species diversity. Results demonstrated that the stepwise linear regression of FD can accurately estimate the Simpson (R 2  = 0.83), Pielou (R 2  = 0.87) and Shannon-Wiener index (R 2  = 0.88). Stepwise linear regression of FD (R 2  = 0.81, R 2  = 0.82) and spectral vegetation indices (R 2  = 0.51, R 2  = 0.58) significantly predicted the Margalef and Gleason index. It was proposed that the Simpson, Pielou and Shannon-Wiener indices, which are widely used as plant species diversity indicators, can be precisely estimated through hyperspectral indices at a fine scale. This research promotes the development of methods for assessment of plant diversity using hyperspectral data.

Advanced Grid-Friendly Controls Demonstration Project for Utility-Scale PV Power Plants

Energy Technology Data Exchange (ETDEWEB)

Gevorgian, Vahan; O' Neill, Barbara

2016-01-21

A typical photovoltaic (PV) power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. The availability and dissemination of actual test data showing the viability of advanced utility-scale PV controls among all industry stakeholders can leverage PV's value from being simply an energy resource to providing additional ancillary services that range from variability smoothing and frequency regulation to power quality. Strategically partnering with a selected utility and/or PV power plant operator is a key condition for a successful demonstration project. The U.S. Department of Energy's (DOE's) Solar Energy Technologies Office selected the National Renewable Energy Laboratory (NREL) to be a principal investigator in a two-year project with goals to (1) identify a potential partner(s), (2) develop a detailed scope of work and test plan for a field project to demonstrate the gird-friendly capabilities of utility-scale PV power plants, (3) facilitate conducting actual demonstration tests, and (4) disseminate test results among industry stakeholders via a joint NREL/DOE publication and participation in relevant technical conferences. The project implementation took place in FY 2014 and FY 2015. In FY14, NREL established collaborations with AES and First Solar Electric, LLC, to conduct demonstration testing on their utility-scale PV power plants in Puerto Rico and Texas, respectively, and developed test plans for each partner. Both Puerto Rico Electric Power Authority and the Electric Reliability Council of Texas expressed interest in this project because of the importance of such advanced controls for the reliable operation of their power systems under high penetration levels of variable renewable generation. During FY15, testing was completed on both plants, and a large amount of test data was produced and analyzed that demonstrates the ability of

Overcoming Ex-Post Development Stagnation: Interventions with Continuity and Scaling in Mind

Directory of Open Access Journals (Sweden)

Bradley T. Hiller

2016-02-01

Full Text Available Project interventions are important vehicles for development globally. However, while there is often allocation of resources for new and innovative (pilot projects—with varying levels of success—there is seemingly less focus on consolidating and/or scaling the positive impacts of successful larger interventions. Assuming an overarching development goal to have long lasting impact at scale, this approach seems somewhat contradictory. Scaling is often not integrated into project planning, design and implementation and rarely pursued genuinely in the ex-post. However, where demand for further development remains outstanding beyond project completion, opportunities may exist to build upon project platforms and extend benefits in a cost effective manner. This paper examines existing scaling typologies, before introducing “scaling-within” as a concept to promote greater continuity of development to a wider range of stakeholders. Scaling-within offers the opportunity to “in-fill” intervention principles and practices to both project and non-project communities within a broader strategic framework to address disparities and to promote sustainable development. The authors draw on research from case studies of large-scale integrated watershed rehabilitation projects and assess scaling-within against a contemporary scaling framework drawn from the literature. While the concept is tested with watersheds as the administrative unit, the authors anticipate applications for other project management units.

Water use, productivity and interactions among desert plants

Energy Technology Data Exchange (ETDEWEB)

Ehleringer, J.R.

1992-11-17

Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

Continuous solvent extraction feed adjustment for HTGR fuel reprocessing. Interim development report

International Nuclear Information System (INIS)

Olguin, L.J.

1978-06-01

The two-cycle Acid-Thorex solvent extraction process requires that the feed stream to each thorium cycle be processed to reduce its nitric acid concentration (feed adjustment). This interim development report presents the results of bench-scale and pilot-plant-scale feed adjustment experiments using a continuous mode of operation. An examination of formic acid denitration and fluoride ion volatilization is also included

Exploiting large-scale correlations to detect continuous gravitational waves.

Science.gov (United States)

Pletsch, Holger J; Allen, Bruce

2009-10-30

Fully coherent searches (over realistic ranges of parameter space and year-long observation times) for unknown sources of continuous gravitational waves are computationally prohibitive. Less expensive hierarchical searches divide the data into shorter segments which are analyzed coherently, then detection statistics from different segments are combined incoherently. The novel method presented here solves the long-standing problem of how best to do the incoherent combination. The optimal solution exploits large-scale parameter-space correlations in the coherent detection statistic. Application to simulated data shows dramatic sensitivity improvements compared with previously available (ad hoc) methods, increasing the spatial volume probed by more than 2 orders of magnitude at lower computational cost.

Implications of environmental regulation and coal plant retirements in systems with large scale penetration of wind power

International Nuclear Information System (INIS)

Rahmani, Mohsen; Jaramillo, Paulina; Hug, Gabriela

2016-01-01

Over the last decade there have been a growing number of federal and state regulations aimed at controlling air emissions at power plants and/or increasing the penetration of renewable resources in the grid. Environmental Protection Agency regulations will likely lead to the retrofit, retirement, or replacement of coal-fired power plants while the state Renewable Portfolio Standards will continue to drive large-scale deployment of renewable energy sources, primarily wind. Combined, these changes in the generation fleet could have profound implications for the operations of the power system. In this paper, we aim to better understand the interaction between coal plant retirements and increased levels of wind power. We extensively analyze the operations of the PJM electricity system under a broad set of scenarios that include varying levels of wind penetration and coal plant retirements. Not surprisingly, we find that without transmission upgrades, retirement of coal-fired power plants will likely result in considerable transmission congestion and higher energy prices. Increased wind penetration, with high geographic diversity, could mitigate some of the negative effects of coal plant retirement and lead to a significant reduction in air emissions, but wind forecast error might impose operational constraints on the system at times of peak load. - Highlights: •Retirement of coal plants may increase transmission congestion and LMP prices. •EPA rules might lead to significant reductions in emission of air pollutants. •Wind geographical diversity may reduce transmission constraints and air emissions. •At times of high peak load, wind may not reduce system stress caused by retirement. •RPS policies can support and mitigate negative impacts of EPA regulations.

Validation of a plant-wide phosphorus modelling approach with minerals precipitation in a full-scale WWTP

DEFF Research Database (Denmark)

Mbamba, Christian Kazadi; Flores Alsina, Xavier; Batstone, Damien John

2016-01-01

approach describing ion speciation and ion pairing with kinetic multiple minerals precipitation. Model performance is evaluated against data sets from a full-scale wastewater treatment plant, assessing capability to describe water and sludge lines across the treatment process under steady-state operation...... plant. Dynamic influent profiles were generated using a calibrated influent generator and were used to study the effect of long-term influent dynamics on plant performance. Model-based analysis shows that minerals precipitation strongly influences composition in the anaerobic digesters, but also impacts......The focus of modelling in wastewater treatment is shifting from single unit to plant-wide scale. Plant wide modelling approaches provide opportunities to study the dynamics and interactions of different transformations in water and sludge streams. Towards developing more general and robust...

Full-scale treatment of wastewater from a biodiesel fuel production plant with alkali-catalyzed transesterification.

Science.gov (United States)

De Gisi, Sabino; Galasso, Maurizio; De Feo, Giovanni

2013-01-01

The treatment of wastewater derived from a biodiesel fuel (BDF) production plant with alkali-catalyzed transesterification was studied at full scale. The investigated wastewater treatment plant consisted of the following phases: primary adsorption/coagulation/flocculation/sedimentation processes, biological treatment with the combination of trickling filter and activated sludge systems, secondary flocculation/sedimentation processes, and reverse osmosis (RO) system with spiral membranes. All the processes were developed in a continuous mode, while the RO experiment was performed with batch tests. Two types of BDF wastewater were considered: the first wastewater (WW1) had an average total chemical oxygen demand (COD), pH and feed flow rate of 10,850.8 mg/L, 5.9 and 2946.7 L/h, respectively, while the second wastewater (WW2) had an average total COD, pH and feed flow rate of 43,898.9 mg/L, 3.3 and 2884.6 L/h, respectively. The obtained results from the continuous tests showed a COD removal percentage of more than 90% for the two types of wastewater considered. The removal of biorefractory COD and salts was obtained with a membrane technology in order to reuse the RO permeate in the factory production cycle. The rejections percentage of soluble COD, chlorides and sulphates were 92.8%, 95.0% and 99.5%, respectively. Because the spiral membranes required a high number of washing cycles, the use of plane membranes was preferable. Finally, the RO reject material should be evaporated using the large amount of inexpensive heat present in this type of industry.

Micro-scaled high-throughput digestion of plant tissue samples for multi-elemental analysis

Directory of Open Access Journals (Sweden)

Husted Søren

2009-09-01

Full Text Available Abstract Background Quantitative multi-elemental analysis by inductively coupled plasma (ICP spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data. Results We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight. A commercially available 64-position rotor with 5 ml disposable glass vials, originally designed for microwave-based parallel organic synthesis, was used as a platform for the digestion. The novel micro-scaled method was successfully validated by the use of various certified reference materials (CRM with matrices rich in starch, lipid or protein. When the micro-scaled digestion procedure was applied on single rice grains or small batches of Arabidopsis seeds (1 mg, corresponding to approximately 50 seeds, the obtained elemental profiles closely matched those obtained by conventional analysis using digestion in large volume vessels. Accumulated elemental contents derived from separate analyses of rice grain fractions (aleurone, embryo and endosperm closely matched the total content obtained by analysis of the whole rice grain. Conclusion A high-throughput micro-scaled method has been developed which enables digestion of small quantities of plant samples for subsequent elemental profiling by ICP-spectrometry. The method constitutes a valuable tool for screening of mutants and transformants. In addition, the method facilitates studies of the distribution of essential trace elements between and within plant organs which is relevant for, e.g., breeding programmes aiming at

Continuous micron-scaled rope engineering using a rotating multi-nozzle electrospinning emitter

Science.gov (United States)

Zhang, Chunchen; Gao, Chengcheng; Chang, Ming-Wei; Ahmad, Zeeshan; Li, Jing-Song

2016-10-01

Electrospinning (ES) enables simple production of fibers for broad applications (e.g., biomedical engineering, energy storage, and electronics). However, resulting structures are predominantly random; displaying significant disordered fiber entanglement, which inevitably gives rise to structural variations and reproducibility on the micron scale. Surface and structural features on this scale are critical for biomaterials, tissue engineering, and pharmaceutical sciences. In this letter, a modified ES technique using a rotating multi-nozzle emitter is developed and utilized to fabricate continuous micron-scaled polycaprolactone (PCL) ropes, providing control on fiber intercalation (twist) and structural order. Micron-scaled ropes comprising 312 twists per millimeter are generated, and rope diameter and pitch length are regulated using polymer concentration and process parameters. Electric field simulations confirm vector and distribution mechanisms, which influence fiber orientation and deposition during the process. The modified fabrication system provides much needed control on reproducibility and fiber entanglement which is crucial for electrospun biomedical materials.

Targeted enrichment strategies for next-generation plant biology

Science.gov (United States)

Richard Cronn; Brian J. Knaus; Aaron Liston; Peter J. Maughan; Matthew Parks; John V. Syring; Joshua. Udall

2012-01-01

The dramatic advances offered by modem DNA sequencers continue to redefine the limits of what can be accomplished in comparative plant biology. Even with recent achievements, however, plant genomes present obstacles that can make it difficult to execute large-scale population and phylogenetic studies on next-generation sequencing platforms. Factors like large genome...

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)

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

Variations of adventitious bud plants initiated from cutting scales of irradiated lily

International Nuclear Information System (INIS)

Zhang Kezhong; Zhao Xiangyun; Huang Shanwu; Lu Changxun; Zhang Qixiang

2003-01-01

Adventitious bud plants were initiated from cutting scales of irradiated lilies. During adventitious bud plants growth and development, variation was observed on their petals, stamens, pistils and leaves. Stamens gave birth to the highest mutation rate and the most diverse variation, such as no pollen male sterility type, pollen abortion male sterility type, stamen collapse male sterility type and partial male sterility type, etc. Different male sterility types were found among the three lilies. Considering mutation rate of adventitious bud plants, 1-2 Gy was suitable dose for 'Pollyana' and 1-3 Gy was proper to Lilium regale and 'Romano'

Development of a process for continuous, radiation-chemically initiated, catalytic hydrocarboxylation

International Nuclear Information System (INIS)

Laege, J.

1980-01-01

In the general part are treated technical preparation of aliphatic carboxylic acids and their economical importance, the hydrocarboxylation reaction and general aspects of radiation chemistry. The chapter on results of discontinuous experiments contains experiments of radiochemically initiated catalytical hydroesterification of oct-1-ene and buteneoxide. The chapter on development and arrangement of the continuously working hydrocarboxylation plant deals with the disposition of process flow sheet, single elements of and description of the plant. The chapter on results of continuous experiments describes residence time behaviour of the tube reactor, investigations on the mixing behaviour of educts, influence of residence time and reaction pressure on continuous thermal and thermal-radiochemical hydrocarboxylation. The next chapter proposes a procedure of continuous hydrobarboxylation and esterification at high pressure on an industrial scale. The experimental part presents starting materials, preparation on catalysts and reference substances, performance of discontinuous autoclave experiments, work up and investigation of reaction products, performance of continuous high pressure experiments, Co-60-source, Fricke-dosimetry and analytics. (SPI)

On the network protocol performance evaluation for large scale communication system of nuclear plant

International Nuclear Information System (INIS)

Song, K. S.; Lee, T. H.; Kim, H. R.; Kim, D. H.; Ku, I. S.

1998-01-01

Computer technology has been dramatically advanced and it is now natural to apply digital network technology into nuclear plants. Communication architecture for nuclear plant defines the coordination of safety reactor control, balance of plant, subsystem utilities, and plant monitoring functions, and how they are connected and their user interface to guarantee plant performance and guarantee safety requirements. Therefore, to implement a digital network for control and monitoring systems of advanced nuclear plant needs systematic design and evaluation procedures because of responsive and hard real-time process characteristics of nuclear plant. In this paper, we evaluate several digital network protocols in terms of network delay, link failure effects to hard real-time requirements with full scale traffic

Application of wavelet scaling function expansion continuous-energy resonance calculation method to MOX fuel problem

International Nuclear Information System (INIS)

Yang, W.; Wu, H.; Cao, L.

2012-01-01

More and more MOX fuels are used in all over the world in the past several decades. Compared with UO 2 fuel, it contains some new features. For example, the neutron spectrum is harder and more resonance interference effects within the resonance energy range are introduced because of more resonant nuclides contained in the MOX fuel. In this paper, the wavelets scaling function expansion method is applied to study the resonance behavior of plutonium isotopes within MOX fuel. Wavelets scaling function expansion continuous-energy self-shielding method is developed recently. It has been validated and verified by comparison to Monte Carlo calculations. In this method, the continuous-energy cross-sections are utilized within resonance energy, which means that it's capable to solve problems with serious resonance interference effects without iteration calculations. Therefore, this method adapts to treat the MOX fuel resonance calculation problem natively. Furthermore, plutonium isotopes have fierce oscillations of total cross-section within thermal energy range, especially for 240 Pu and 242 Pu. To take thermal resonance effect of plutonium isotopes into consideration the wavelet scaling function expansion continuous-energy resonance calculation code WAVERESON is enhanced by applying the free gas scattering kernel to obtain the continuous-energy scattering source within thermal energy range (2.1 eV to 4.0 eV) contrasting against the resonance energy range in which the elastic scattering kernel is utilized. Finally, all of the calculation results of WAVERESON are compared with MCNP calculation. (authors)

Assessment of the degradation efficiency of full-scale biogas plants: A comparative study of degradation indicators.

Science.gov (United States)

Li, Chao; Nges, Ivo Achu; Lu, Wenjing; Wang, Haoyu

2017-11-01

Increasing popularity and applications of the anaerobic digestion (AD) process has necessitated the development and identification of tools for obtaining reliable indicators of organic matter degradation rate and hence evaluate the process efficiency especially in full-scale, commercial biogas plants. In this study, four biogas plants (A1, A2, B and C) based on different feedstock, process configuration, scale and operational performance were selected and investigated. Results showed that the biochemical methane potential (BMP) based degradation rate could be use in incisively gauging process efficiency in lieu of the traditional degradation rate indicators. The BMP degradation rates ranged from 70 to 90% wherein plants A2 and C showed the highest throughput. This study, therefore, corroborates the feasibility of using the BMP degradation rate as a practical tool for evaluating process performance in full-scale biogas processes and spots light on the microbial diversity in full-scale biogas processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toward a continuous 405-kyr-calibrated Astronomical Time Scale for the Mesozoic Era

Science.gov (United States)

Hinnov, Linda; Ogg, James; Huang, Chunju

2010-05-01

Mesozoic cyclostratigraphy is being assembled into a continuous Astronomical Time Scale (ATS) tied to the Earth's cyclic orbital parameters. Recognition of a nearly ubiquitous, dominant ~400-kyr cycling in formations throughout the era has been particularly striking. Composite formations spanning contiguous intervals up to 50 myr clearly express these long-eccentricity cycles, and in some cases, this cycling is defined by third- or fourth-order sea-level sequences. This frequency is associated with the 405-kyr orbital eccentricity cycle, which provides a basic metronome and enables the extension of the well-defined Cenozoic ATS to scale the majority of the Mesozoic Era. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, but with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS provide solutions to long-standing geologic problems of tectonics, eustasy, paleoclimate change, and rates of seafloor spreading.

Pilot-scale Biogas Plant for the Research and Development of New Technologies

Directory of Open Access Journals (Sweden)

Ivan Simeonov

2012-09-01

Full Text Available Тhe paper describes a new pilot-scale biogas plant of the Institute of Microbiology - Bulgarian Academy of Sciences. The equipment includes: a 100 L pilot bioreactor, a 200 L metal gasholder, sensors, actuators, a two-level automatic process monitoring and control system, a fire and explosion protection system and two web cameras. The monitoring and control system is composed on the lower level of a controller Beckhoff, and on the higher level - of a PC with specialized software (under development. The pilot biogas plant is designed to work out and scale up various anaerobic digestion (AD technologies based on different types of feedstock. All the data will be stored on the PC for quick reference and possibly data mining, parameter identification and verification of different AD mathematical models.

Building a Laboratory-Scale Biogas Plant and Verifying its Functionality

Science.gov (United States)

Boleman, Tomáš; Fiala, Jozef; Blinová, Lenka; Gerulová, Kristína

2011-01-01

The paper deals with the process of building a laboratory-scale biogas plant and verifying its functionality. The laboratory-scale prototype was constructed in the Department of Safety and Environmental Engineering at the Faculty of Materials Science and Technology in Trnava, of the Slovak University of Technology. The Department has already built a solar laboratory to promote and utilise solar energy, and designed SETUR hydro engine. The laboratory is the next step in the Department's activities in the field of renewable energy sources and biomass. The Department is also involved in the European Union project, where the goal is to upgrade all existed renewable energy sources used in the Department.

Comparing centralised and decentralised anaerobic digestion of stillage from a large-scale bioethanol plant to animal feed production.

Science.gov (United States)

Drosg, B; Wirthensohn, T; Konrad, G; Hornbachner, D; Resch, C; Wäger, F; Loderer, C; Waltenberger, R; Kirchmayr, R; Braun, R

2008-01-01

A comparison of stillage treatment options for large-scale bioethanol plants was based on the data of an existing plant producing approximately 200,000 t/yr of bioethanol and 1,400,000 t/yr of stillage. Animal feed production--the state-of-the-art technology at the plant--was compared to anaerobic digestion. The latter was simulated in two different scenarios: digestion in small-scale biogas plants in the surrounding area versus digestion in a large-scale biogas plant at the bioethanol production site. Emphasis was placed on a holistic simulation balancing chemical parameters and calculating logistic algorithms to compare the efficiency of the stillage treatment solutions. For central anaerobic digestion different digestate handling solutions were considered because of the large amount of digestate. For land application a minimum of 36,000 ha of available agricultural area would be needed and 600,000 m(3) of storage volume. Secondly membrane purification of the digestate was investigated consisting of decanter, microfiltration, and reverse osmosis. As a third option aerobic wastewater treatment of the digestate was discussed. The final outcome was an economic evaluation of the three mentioned stillage treatment options, as a guide to stillage management for operators of large-scale bioethanol plants. Copyright IWA Publishing 2008.

Operational experinece with large scale biogas production at the promest manure processing plant in Helmond, the Netherlands

International Nuclear Information System (INIS)

Schomaker, A.H.H.M.

1992-01-01

In The Netherlands a surplus of 15 million tons of liquid pig manure is produced yearly on intensive pig breeding farms. The dutch government has set a three-way policy to reduce this excess of manure: 1. conversion of animal fodder into a product with less and better ingestible nutrients; 2. distribution of the surplus to regions with a shortage of animal manure; 3. processing of the remainder of the surplus in large scale processing plants. The first large scale plant for the processing of liquid pig manure was put in operation in 1988 as a demonstration plant at Promest in Helmond. The design capacity of this plant is 100,000 tons of pig manure per year. The plant was initiated by the Manure Steering Committee of the province Noord-Brabant in order to prove at short notice whether large scale manure processing might contribute to the solution of the problem of the manure surplus in The Netherlands. This steering committee is a corporation of the national and provincial government and the agricultural industrial life. (au)

Environmental determinants of woody plant diversity at a regional scale in China.

Directory of Open Access Journals (Sweden)

Hong Qian

Full Text Available Understanding what drives the geographic variation of species richness across the globe is a fundamental goal of ecology and biogeography. Environmental variables have been considered as drivers of global diversity patterns but there is no consensus among ecologists on what environmental variables are primary drivers of the geographic variation of species richness. Here, I examine the relationship of woody plant species richness at a regional scale in China with sixteen environmental variables representing energy availability, water availability, energy-water balance, seasonality, and habitat heterogeneity. I found that temperature seasonality is the best predictor of woody species richness in China. Other important environmental variables include annual precipitation, mean temperature of the coldest month, and potential evapotranspiration. The best model explains 85% of the variation in woody plant species richness at the regional scale in China.

Development, modelling and evaluation of a small-scale gas liquefaction plant

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Markussen, Wiebke Brix

2017-01-01

A small-scale gas liquefaction plant was developed and analysed based on process simulation tools and pilot tests. It will be installed in harbours, easing the penetration of liquefied natural gas (LNG) as a maritime fuel, in a sector facing more stringent environmental regulations. The proposed...... plant uses a multi-component refrigerant together with a propane precooling cycle and plate heat exchangers, to achieve a higher performance. This LNG production concept was modelled based on the Danish natural gas composition. Firstly, the total power consumption and heat transfer conductance were...... minimised by optimising the operating conditions and the refrigerant composition. The effects of varying feed and refrigerant compositions were analysed. Secondly, the system layouts were evaluated by conducting an exergetic assessment. Finally, the most promising layouts were validated by pilot plant...

A farm-scale pilot plant for biohydrogen and biomethane production by two-stage fermentation

Directory of Open Access Journals (Sweden)

R. Oberti

2013-09-01

Full Text Available Hydrogen is considered one of the possible main energy carriers for the future, thanks to its unique environmental properties. Indeed, its energy content (120 MJ/kg can be exploited virtually without emitting any exhaust in the atmosphere except for water. Renewable production of hydrogen can be obtained through common biological processes on which relies anaerobic digestion, a well-established technology in use at farm-scale for treating different biomass and residues. Despite two-stage hydrogen and methane producing fermentation is a simple variant of the traditional anaerobic digestion, it is a relatively new approach mainly studied at laboratory scale. It is based on biomass fermentation in two separate, seuqential stages, each maintaining conditions optimized to promote specific bacterial consortia: in the first acidophilic reactorhydrogen is produced production, while volatile fatty acids-rich effluent is sent to the second reactor where traditional methane rich biogas production is accomplished. A two-stage pilot-scale plant was designed, manufactured and installed at the experimental farm of the University of Milano and operated using a biomass mixture of livestock effluents mixed with sugar/starch-rich residues (rotten fruits and potatoes and expired fruit juices, afeedstock mixture based on waste biomasses directly available in the rural area where plant is installed. The hydrogenic and the methanogenic reactors, both CSTR type, had a total volume of 0.7m3 and 3.8 m3 respectively, and were operated in thermophilic conditions (55 2 °C without any external pH control, and were fully automated. After a brief description of the requirements of the system, this contribution gives a detailed description of its components and of engineering solutions to the problems encountered during the plant realization and start-up. The paper also discusses the results obtained in a first experimental run which lead to production in the range of previous

Characterizing steady states of genome-scale metabolic networks in continuous cell cultures.

Directory of Open Access Journals (Sweden)

Jorge Fernandez-de-Cossio-Diaz

2017-11-01

Full Text Available In the continuous mode of cell culture, a constant flow carrying fresh media replaces culture fluid, cells, nutrients and secreted metabolites. Here we present a model for continuous cell culture coupling intra-cellular metabolism to extracellular variables describing the state of the bioreactor, taking into account the growth capacity of the cell and the impact of toxic byproduct accumulation. We provide a method to determine the steady states of this system that is tractable for metabolic networks of arbitrary complexity. We demonstrate our approach in a toy model first, and then in a genome-scale metabolic network of the Chinese hamster ovary cell line, obtaining results that are in qualitative agreement with experimental observations. We derive a number of consequences from the model that are independent of parameter values. The ratio between cell density and dilution rate is an ideal control parameter to fix a steady state with desired metabolic properties. This conclusion is robust even in the presence of multi-stability, which is explained in our model by a negative feedback loop due to toxic byproduct accumulation. A complex landscape of steady states emerges from our simulations, including multiple metabolic switches, which also explain why cell-line and media benchmarks carried out in batch culture cannot be extrapolated to perfusion. On the other hand, we predict invariance laws between continuous cell cultures with different parameters. A practical consequence is that the chemostat is an ideal experimental model for large-scale high-density perfusion cultures, where the complex landscape of metabolic transitions is faithfully reproduced.

Water use, productivity and interactions among desert plants. Final report

Energy Technology Data Exchange (ETDEWEB)

Ehleringer, J.R.

1992-11-17

Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. This project assumes that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to the interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process.

Scale-Dependent Assessment of Relative Disease Resistance to Plant Pathogens

Directory of Open Access Journals (Sweden)

Peter Skelsey

2014-03-01

Full Text Available Phenotyping trials may not take into account sufficient spatial context to infer quantitative disease resistance of recommended varieties in commercial production settings. Recent ecological theory—the dispersal scaling hypothesis—provides evidence that host heterogeneity and scale of host heterogeneity interact in a predictable and straightforward manner to produce a unimodal (“humpbacked” distribution of epidemic outcomes. This suggests that the intrinsic artificiality (scale and design of experimental set-ups may lead to spurious conclusions regarding the resistance of selected elite cultivars, due to the failure of experimental efforts to accurately represent disease pressure in real agricultural situations. In this model-based study we investigate the interaction of host heterogeneity and scale as a confounding factor in the inference from ex-situ assessment of quantitative disease resistance to commercial production settings. We use standard modelling approaches in plant disease epidemiology and a number of different agronomic scenarios. Model results revealed that the interaction of heterogeneity and scale is a determinant of relative varietal performance under epidemic conditions. This is a previously unreported phenomenon that could provide a new basis for informing the design of future phenotyping platforms, and optimising the scale at which quantitative disease resistance is assessed.

Towards continuous enzyme-catalysed processes for the production of biodiesel

DEFF Research Database (Denmark)

Nordblad, Mathias; Pedersen, Anders Kristian; Meyland, Lene Have

The application of lipases in the production of biodiesel can find several roles: in pretreating high FFA oils via esterification, transesterification for converting oil to biodiesel and polishing via esterification to ensure the product is within specification. In all these cases the potential...... size of the process plants, suggest that continuous operation would be highly beneficial due to the economies of scale. To investigate this, we have examined both oil pretreatment via esterification and biodiesel production via transesterification in batch stirred tank reactors (BSTRs), continuous...

Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

NARCIS (Netherlands)

Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

2002-01-01

We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

Septic tank combined with anaerobic filter and conventional UASB: results from full scale plants

Directory of Open Access Journals (Sweden)

F. J. A. da Silva

2013-03-01

Full Text Available Anaerobic digestion is an important alternative for domestic wastewater treatment, especially in warm climate regions. Two full-scale anaerobic schemes were investigated: septic tank combined with anaerobic filter (S T A NF and conventional UASB reactors. Treated effluents from these systems were subjected to disinfection by chlorination. The operational performance of 56 full-scale plants (36 S T A NF and 20 UASB provided a realistic view. Findings showed that the plants operated with low OLR (< 2.0 kg COD/m³.day. Despite this, the removal of organic material was below values suggested by the literature (around 60% for COD. A removal of 4.0 Log10 units of total coliform and E. coli can be reached with residual chlorine (R CL of at least 2.0 Cl-Cl2/l. Although UASB plants have performed better, improvement of maintenance is needed in both treatment configurations.

Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

International Nuclear Information System (INIS)

Savola, Tuula; Fogelholm, Carl-Johan

2006-01-01

In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

Global analysis of seagrass restoration: the importance of large-scale planting

KAUST Repository

van Katwijk, Marieke M.; Thorhaug, Anitra; Marbà , Nú ria; Orth, Robert J.; Duarte, Carlos M.; Kendrick, Gary A.; Althuizen, Inge H. J.; Balestri, Elena; Bernard, Guillaume; Cambridge, Marion L.; Cunha, Alexandra; Durance, Cynthia; Giesen, Wim; Han, Qiuying; Hosokawa, Shinya; Kiswara, Wawan; Komatsu, Teruhisa; Lardicci, Claudio; Lee, Kun-Seop; Meinesz, Alexandre; Nakaoka, Masahiro; O'Brien, Katherine R.; Paling, Erik I.; Pickerell, Chris; Ransijn, Aryan M. A.; Verduin, Jennifer J.

2015-01-01

In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta-analysis shows that both trial survival and seagrass population growth rate in trials that survived are positively affected by the number of plants or seeds initially transplanted. This relationship between restoration scale and restoration success was not related to trial characteristics of the initial restoration. The majority of the seagrass restoration trials have been very small, which may explain the low overall trial survival rate (i.e. estimated 37%). Successful regrowth of the foundation seagrass species appears to require crossing a minimum threshold of reintroduced individuals. Our study provides the first global field evidence for the requirement of a critical mass for recovery, which may also hold for other foundation species showing strong positive feedback to a dynamic environment. Synthesis and applications. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting

Global analysis of seagrass restoration: the importance of large-scale planting

KAUST Repository

van Katwijk, Marieke M.

2015-10-28

In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta-analysis shows that both trial survival and seagrass population growth rate in trials that survived are positively affected by the number of plants or seeds initially transplanted. This relationship between restoration scale and restoration success was not related to trial characteristics of the initial restoration. The majority of the seagrass restoration trials have been very small, which may explain the low overall trial survival rate (i.e. estimated 37%). Successful regrowth of the foundation seagrass species appears to require crossing a minimum threshold of reintroduced individuals. Our study provides the first global field evidence for the requirement of a critical mass for recovery, which may also hold for other foundation species showing strong positive feedback to a dynamic environment. Synthesis and applications. For effective restoration of seagrass foundation species in its typically dynamic, stressful environment, introduction of large numbers is seen to be beneficial and probably serves two purposes. First, a large-scale planting

Continuous monitoring of variations in the 235U enrichment of uranium in the header pipework of a centrifuge enrichment plant

International Nuclear Information System (INIS)

Packer, T.W.

1991-01-01

Non-destructive assay equipment, based on gamma-ray spectrometry and x-ray fluorescence analysis has previously been developed for confirming the presence of low enriched uranium in the header pipework of UF 6 gas centrifuge enrichment plants. However inspections can only be carried out occasionally on a limited number of pipes. With the development of centrifuge enrichment technology it has been suggested that more frequent, or ideally, continuous measurements should be made in order to improve safeguards assurance between inspections. For this purpose we have developed non-destructive assay equipment based on continuous gamma-ray spectrometry and x-ray transmission measurements. This equipment is suitable for detecting significant changes in the 235 U enrichment of uranium in the header pipework of new centrifuge enrichment plants. Results are given in this paper of continuous measurements made in the laboratory and also on header pipework of a centrifuge enrichment plant at Capenhurst

Full-Scale Continuous Mini-Reactor Setup for Heterogeneous Grignard Alkylation of a Pharmaceutical Intermediate

DEFF Research Database (Denmark)

Pedersen, Michael Jønch; Holm, Thomas; Rahbek, Jesper P.

2013-01-01

A reactor setup consisting of two reactors in series has been implemented for a full-scale, heterogeneous Grignard alkylation. Solutions pass from a small filter reactor into a static mixer reactor with multiple side entries, thus combining continuous stirred tank reactor (CSTR) and plug flow...

Scale-up of counter-current chromatography: demonstration of predictable isocratic and quasi-continuous operating modes from the test tube to pilot/process scale.

Science.gov (United States)

Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

2009-12-11

Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18 L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction.

Large-scale membrane transfer process: its application to single-crystal-silicon continuous membrane deformable mirror

International Nuclear Information System (INIS)

Wu, Tong; Sasaki, Takashi; Hane, Kazuhiro; Akiyama, Masayuki

2013-01-01

This paper describes a large-scale membrane transfer process developed for the construction of large-scale membrane devices via the transfer of continuous single-crystal-silicon membranes from one substrate to another. This technique is applied for fabricating a large stroke deformable mirror. A bimorph spring array is used to generate a large air gap between the mirror membrane and the electrode. A 1.9 mm × 1.9 mm × 2 µm single-crystal-silicon membrane is successfully transferred to the electrode substrate by Au–Si eutectic bonding and the subsequent all-dry release process. This process provides an effective approach for transferring a free-standing large continuous single-crystal-silicon to a flexible suspension spring array with a large air gap. (paper)

Scale-up of the Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization Using Continuous Flow Processing

Directory of Open Access Journals (Sweden)

Nenad Micic

2014-01-01

Full Text Available A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

Separation of packaging plastics by froth flotation in a continuous pilot plant

International Nuclear Information System (INIS)

Carvalho, Teresa; Durao, Fernando; Ferreira, Celia

2010-01-01

The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit.

Anaerobic digestion foaming in full-scale biogas plants: A survey on causes and solutions

DEFF Research Database (Denmark)

Kougias, Panagiotis; Boe, Kanokwan; O-Thong, Sompong

2014-01-01

Anaerobic digestion foaming is a common operation problem in biogas plants with negative impacts on the biogas plants economy and environment. A survey of 16 Danish full-scale biogas plants on foaming problems revealed that most of them had experienced foaming in their processes up to three times...... of foaming in this case. Moreover, no difference in bacterial communities between the foaming and non-foaming reactors was observed, showing that filamentous bacteria were not the main reason for foaming in this case. © IWA Publishing 2014....

Continuous process of powder production for MOX fuel fabrication according to ''granat'' technology

International Nuclear Information System (INIS)

Morkovnikov, V.E.; Raginskiy, L.S.; Pavlinov, A.P.; Chernov, V.A.; Revyakin, V.V.; Varykhanov, V.S.; Revnov, V.N.

2000-01-01

During last years the problem of commercial MOX fuel fabrication for nuclear reactors in Russia was solved in a number of directions. The paper deals with the solution of the problem of creating a continuous pilot plant for the production of MOX fuel powders on the basis of the home technology 'Granat', that was tested before on a small-scale pilot-commercial batch-operated plant of the same name and confirmed good results. (authors)

Strategy of plant concept development in Hitachi

International Nuclear Information System (INIS)

Kumiaki, Moriya

2007-01-01

Hitachi contributes to the society in various fields of nuclear power such as the Light Water Reactor field, the Fast Breeder Reactor, the fuel cycle, and the medical treatment. Since the beginning of a first commercial operation of a BWR in Japan, Hitachi has constructed 20 units of BWR. Hitachi continues its efforts in achieving high reliability and large-scale output, and in 1996, it completed Advanced Boiling Water Reactor (ABWR) in cooperation with various BWR utilities, General Electric Company, and Toshiba Corporation. Hitachi has enhanced the ABWR technology further based on the above enough experience. The latest technologies were reflected in Hamaoka unit 5 and Shika unit 2 as the latest ABWR plants. The further upgrade technologies would been reflected in Shimane-3, Ohma-1 and Higashidori-1 as ABWR plants under planning. Hitachi obtains the chance to construct the nuclear power plant continuously. For the next generation, Hitachi is working on developing nuclear power plants that take diversified needs and global characteristics into account. As one of the approaches, the output series formation of BWR is extended as the following. ABWR-II and ESBWR (Economic and Simplified BWR) as a large-scale centralized power supply emphasizing cost efficiency, Medium size ABWR and natural circulation type BWR as medium and small-scale distributed power supply that features flexibility to various market needs, such as minimized capital risks, timely return on a capital investment, etc. As another approach, Hitachi tries to extend the Light Water Reactor technology. RBWR (Resource-Renewable BWR ) that achieves a high conversion ratio over 1.0 based on the BWR technology will make the fuel cycle flexible. Hitachi will continue the challenge for the next ABWR and the future with the enough experience of BWR construction. (author)

Evaluating complementary networks of restoration plantings for landscape-scale occurrence of temporally dynamic species.

Science.gov (United States)

Ikin, Karen; Tulloch, Ayesha; Gibbons, Philip; Ansell, Dean; Seddon, Julian; Lindenmayer, David

2016-10-01

Multibillion dollar investments in land restoration make it critical that conservation goals are achieved cost-effectively. Approaches developed for systematic conservation planning offer opportunities to evaluate landscape-scale, temporally dynamic biodiversity outcomes from restoration and improve on traditional approaches that focus on the most species-rich plantings. We investigated whether it is possible to apply a complementarity-based approach to evaluate the extent to which an existing network of restoration plantings meets representation targets. Using a case study of woodland birds of conservation concern in southeastern Australia, we compared complementarity-based selections of plantings based on temporally dynamic species occurrences with selections based on static species occurrences and selections based on ranking plantings by species richness. The dynamic complementarity approach, which incorporated species occurrences over 5 years, resulted in higher species occurrences and proportion of targets met compared with the static complementarity approach, in which species occurrences were taken at a single point in time. For equivalent cost, the dynamic complementarity approach also always resulted in higher average minimum percent occurrence of species maintained through time and a higher proportion of the bird community meeting representation targets compared with the species-richness approach. Plantings selected under the complementarity approaches represented the full range of planting attributes, whereas those selected under the species-richness approach were larger in size. Our results suggest that future restoration policy should not attempt to achieve all conservation goals within individual plantings, but should instead capitalize on restoration opportunities as they arise to achieve collective value of multiple plantings across the landscape. Networks of restoration plantings with complementary attributes of age, size, vegetation structure, and

Radiation protection service for a nucleonic control system of continuous casting plant after events of accident

International Nuclear Information System (INIS)

Chakrabarti, Santanu; Massand, O.P.

1998-01-01

Extensive use of nucleonic control systems like level controllers was observed during radiation protection surveys in industries such as refineries, steel plants etc., located in the eastern region of India. There were two accidents at continuous casting plant in 1995 which affected the nucleonic control system installed in 1992. The authorities contacted Bhabha Atomic Research Centre (BARC) for radiation protection surveys for the involved nucleonic gauges. The present paper describes the radiation protection services rendered by BARC during such accidents. (author)

Interactive economic analysis of small-scale heating plant

Energy Technology Data Exchange (ETDEWEB)

Landen, R.A.; Sanders, D.L.; Douglas, B.H.

1998-11-01

This report contains the work that has been undertaken by LRZ Limited in pursuance of this agreement. The potential for small-scale biomass heating systems is identified, and surrounding issues relating to acceptance are discussed. Such systems are described, and the origins of capital and running costs examined. A full review of the calculation methods for boiler plant size and fuel consumption is made, and subsequently expounded in four varying case studies. The results of this work are discussed, and the final development of the computer models is reviewed, incorporating further refinements to the method. Finally, data not contained in the text is incorporated in comprehensive appendices. (author)

Urban land use decouples plant-herbivore-parasitoid interactions at multiple spatial scales.

Directory of Open Access Journals (Sweden)

Amanda E Nelson

Full Text Available Intense urban and agricultural development alters habitats, increases fragmentation, and may decouple trophic interactions if plants or animals cannot disperse to needed resources. Specialist insects represent a substantial proportion of global biodiversity and their fidelity to discrete microhabitats provides a powerful framework for investigating organismal responses to human land use. We sampled site occupancy and densities for two plant-herbivore-parasitoid systems from 250 sites across a 360 km2 urban/agricultural landscape to ask whether and how human development decouples interactions between trophic levels. We compared patterns of site occupancy, host plant density, herbivory and parasitism rates of insects at two trophic levels with respect to landcover at multiple spatial scales. Geospatial analyses were used to identify landcover characters predictive of insect distributions. We found that herbivorous insect densities were decoupled from host tree densities in urban landcover types at several spatial scales. This effect was amplified for the third trophic level in one of the two insect systems: despite being abundant regionally, a parasitoid species was absent from all urban/suburban landcover even where its herbivore host was common. Our results indicate that human land use patterns limit distributions of specialist insects. Dispersal constraints associated with urban built development are specifically implicated as a limiting factor.

Development of a continuous dissolution process for the new reprocessing plants at La Hague

International Nuclear Information System (INIS)

Auchapt, P.; Patarin, L.; Tarnero, M.

1984-01-01

The French Commissariat a l'Energie Atomique has designed a continuous rotary dissolver for LWR fuel reprocessing. An industrial prototype has been tested since 1979 at the Service des Prototypes Industriels, at Marcoule. This type of dissolver will be installed at the COGEMA's Reprocessing Plants at La Hague. The advantages of a continuous process are listed, compared to batch dissolutions (chemistry, operation, capacity). The industrial prototype, featuring safe geometry, is described. The R and D program is indicated, and the main results of inactive tests already performed on the industrial prototype are given, including heating, mechanical, and chemical tests (UO 2 dissolutions at 4tU per day)

Development of a continuous dissolution process for the new reprocessing plants at La Hague

International Nuclear Information System (INIS)

Auchapt, P.; Patarin, L.; Tarnero, M.

1984-08-01

The French Commissariat a l'Energie Atomique has designed a continuous rotary dissolver for LWR fuel reprocessing. An industrial prototype has been tested since 1979 at the Service des Prototypes Industriels, at Marcoule. This type of dissolver will be installed at the COGEMA's Reprocessing Plants at La Hague. The advantages of a continuous process are listed, compared to batch dissolutions (chemistry, operation, capacity). The industrial prototype, featuring safe geometry, is described. The R and D program is indicated, and the main results of inactive tests already performed on the industrial prototype are given, including heating, mechanical, and chemical tests (UO 2 dissolutions at 4tU per day)

Final environmental impact statement for the continued operation of the Pantex Plant and associated storage of nuclear weapon components. Volume 3 -- Comment response

International Nuclear Information System (INIS)

1996-11-01

The Draft Environmental Impact Statement (EIS) for the continued operation of Pantex Plant was published in March 1996. The document assessed the alternatives of no action, relocation of the storage of plutonium components resulting from nuclear weapon disassemble activities at Pantex Plant to another site, and the proposed action (preferred alternative) of continuing operations and increasing the quantity of pits in interim storage at Pantex Plant. This report contains the comments and responses received on the Draft EIS

Species turnover drives β-diversity patterns across multiple spatial scales of plant-galling interactions in mountaintop grasslands.

Science.gov (United States)

Coelho, Marcel Serra; Carneiro, Marco Antônio Alves; Branco, Cristina Alves; Borges, Rafael Augusto Xavier; Fernandes, Geraldo Wilson

2018-01-01

This study describes differences in species richness and composition of the assemblages of galling insects and their host plants at different spatial scales. Sampling was conducted along altitudinal gradients composed of campos rupestres and campos de altitude of two mountain complexes in southeastern Brazil: Espinhaço Range and Mantiqueira Range. The following hypotheses were tested: i) local and regional richness of host plants and galling insects are positively correlated; ii) beta diversity is the most important component of regional diversity of host plants and galling insects; and iii) Turnover is the main mechanism driving beta diversity of both host plants and galling insects. Local richness of galling insects and host plants increased with increasing regional richness of species, suggesting a pattern of unsaturated communities. The additive partition of regional richness (γ) into local and beta components shows that local richnesses (α) of species of galling insects and host plants are low relative to regional richness; the beta (β) component incorporates most of the regional richness. The multi-scale analysis of additive partitioning showed similar patterns for galling insects and host plants with the local component (α) incorporated a small part of regional richness. Beta diversity of galling insects and host plants were mainly the result of turnover, with little contribution from nesting. Although the species composition of galling insects and host plant species varied among sample sites, mountains and even mountain ranges, local richness remained relatively low. In this way, the addition of local habitats with different landscapes substantially affects regional richness. Each mountain contributes fundamentally to the composition of regional diversity of galling insects and host plants, and so the design of future conservation strategies should incorporate multiple scales.

Effect of operating conditions and reactor configuration on efficiency of full-scale biogas plants

DEFF Research Database (Denmark)

Angelidaki, Irini; Boe, Kanokwan; Ellegaard, L.

2005-01-01

A study on 18 full-scale centralized biogas plants was carried out in order to find significant operational factors influencing productivity and stability of the plants. It was found that the most plants were operating relatively stable with volatile fatty acids (VFA) concentration below 1.5 g....../l. VFA concentration increase was observed in occasions with dramatic overloading or other disturbances such as operational temperature changes. Ammonia was found to be a significant factor for stability. A correlation between increased residual biogas production and high ammonia was found. When ammonia...

Fault Transient Analysis and Protection Performance Evaluation within a Large-scale PV Power Plant

Directory of Open Access Journals (Sweden)

Wen Jinghua

2016-01-01

Full Text Available In this paper, a short-circuit test within a large-scale PV power plant with a total capacity of 850MWp is discussed. The fault currents supplied by the PV generation units are presented and analysed. According to the fault behaviour, the existing protection coordination principles with the plant are considered and their performances are evaluated. Moreover, these protections are examined in simulation platform under different operating situations. A simple measure with communication system is proposed to deal with the foreseeable problem about the current protection scheme in the PV power plant.

Bacterial community structure and variation in a full-scale seawater desalination plant for drinking water production

NARCIS (Netherlands)

Belila, A.; El-Chakhtoura, J.; Otaibi, N.; Muyzer, G.; Gonzalez-Gil, G.; Saikaly, P.E.; van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

2016-01-01

Microbial processes inevitably play a role in membrane-based desalination plants, mainly recognized as membrane biofouling. We assessed the bacterial community structure and diversity during different treatment steps in a full-scale seawater desalination plant producing 40,000 m3/d of drinking

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1991-12-01

The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO 1 and II were in operation for almost the whole second quarter of 1991. The load factor average was 87.4 %. In consequence of a fire, which broke out in the switchgear building, connections to both external grids were lost and TVO II relied on power supplied by four back-up diesels for 7.5 hrs. The event is classified as Level 2 on the International Nuclear Event Scale. The process of examining the non-leaking fuel bundles removed from the Loviisa nuclear reactors has continued. The examinations have revealed, so far, that the uppermost spacing lattices of the bundles exhibit deformations similar to those detected in the leaking fuel bundles removed from the reactors. This event is classified as Level 1 on the International Nuclear Event Scale. Other events in this quarter which are classified according to the International Nuclear Event Scale are Level Zero (Below Scale) on the Scale. The Finnish Centre for Radiation and Nuclear Safety has assessed the safety of the Loviisa and Olkiluoto nuclear power plants based on the new regulations issued on 14.2.1991 by the Council of State. The safety regulations are much more stringent than those in force when the Loviisa and Olkiluoto nuclear power plants were built. The assessment indicated that the TVO nuclear power plant meets these safety regulations. The Loviisa nuclear power plant meets the requirements with the exception of certain requirements related to the ensuring of safety functions and provision for accidents. At the Loviisa nuclear power plant there are several projects under consideration to enhance safety

Continuing 137 Cs release to the sea from the Fukushima Dai-ichi Nuclear Power Plant through 2012

Directory of Open Access Journals (Sweden)

J. Kanda

2013-09-01

Full Text Available The rate of cesium-137 (137Cs release to the sea from the Fukushima Dai-ichi Nuclear Power Plant for the period until September 2012 was estimated. Publicly released data on 137Cs radioactivity in seawater near the power plant by Tokyo Electric Power Company strongly suggest a continuing release of radionuclides to the sea. The plant has an artificial harbour facility, and the exchange rate of harbour water with surrounding seawater was estimated by the decrease in radioactivity immediately after an intense radioactive water release. The estimated exchange rate of water in the harbour was 0.44 d−1 during the period from 6 to 19 April. The 137Cs radioactivity in the harbour water was substantially higher than that of seawater outside and remained relatively stable after June 2011. A quasi-steady state was assumed with continuous water exchange, and the average release rate of 137Cs was estimated to be 93 GBq d−1 in summer 2011 and 8.1 GBq d−1 in summer 2012.

Integrated Graduate and Continuing Education in Protein Chromatography for Bioprocess Development and Scale-Up

Science.gov (United States)

Carta, Jungbauer

2011-01-01

We describe an intensive course that integrates graduate and continuing education focused on the development and scale-up of chromatography processes used for the recovery and purification of proteins with special emphasis on biotherapeutics. The course includes lectures, laboratories, teamwork, and a design exercise and offers a complete view of…

Design of a DCS Based Model for Continuous Leakage Monitoring System of Rotary Air Preheater of a Thermal Power Plant

Directory of Open Access Journals (Sweden)

Madan BHOWMICK

2011-01-01

Full Text Available The leakage in rotary air preheater makes a considerable contribution to the reduced overall efficiency of fossil-fuel-fired thermal power plants and increase the effect on environment. Since it is normal phenomenon, continuous monitoring of leakage is generally omitted in most power plants. But for accurate analysis of the operation of the thermal power plant, this leakage monitoring plays a vital role. In the present paper, design of a DCS based model for continuous leakages monitoring of rotary air preheater has been described. In the proposed model, the existing DCS based instrumentation system has been modified and online leakage monitoring system has been developed. This model has been installed in a captive power plant with high capacity boilers and very much satisfactory operation of this system has been observed. The observed online data along with their analysis results are presented in this paper.

SCALE Continuous-Energy Monte Carlo Depletion with Parallel KENO in TRITON

International Nuclear Information System (INIS)

Goluoglu, Sedat; Bekar, Kursat B.; Wiarda, Dorothea

2012-01-01

The TRITON sequence of the SCALE code system is a powerful and robust tool for performing multigroup (MG) reactor physics analysis using either the 2-D deterministic solver NEWT or the 3-D Monte Carlo transport code KENO. However, as with all MG codes, the accuracy of the results depends on the accuracy of the MG cross sections that are generated and/or used. While SCALE resonance self-shielding modules provide rigorous resonance self-shielding, they are based on 1-D models and therefore 2-D or 3-D effects such as heterogeneity of the lattice structures may render final MG cross sections inaccurate. Another potential drawback to MG Monte Carlo depletion is the need to perform resonance self-shielding calculations at each depletion step for each fuel segment that is being depleted. The CPU time and memory required for self-shielding calculations can often eclipse the resources needed for the Monte Carlo transport. This summary presents the results of the new continuous-energy (CE) calculation mode in TRITON. With the new capability, accurate reactor physics analyses can be performed for all types of systems using the SCALE Monte Carlo code KENO as the CE transport solver. In addition, transport calculations can be performed in parallel mode on multiple processors.

Broad-Scale Comparison of Photosynthesis in Terrestrial and Aquatic Plant Communities

DEFF Research Database (Denmark)

Sand-Jensen, Kaj; Krause-Jensen, D.

1997-01-01

Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... communities probably due to more efficient light utilization and gas exchange in the terrestrial habitats. By contrast only small differences were found within different aquatic plant communities or within different terrestrial plant communities....... of forests, grasslands and crops and 319 aquatic studies of phytoplankton, macrophyte and attached microalgal communities to test if specific differences existed between the communities. Maximum gross photosynthesis and photosynthetic efficiency were systematically higher in terrestrial than in aquatic...

Discriminant WSRC for Large-Scale Plant Species Recognition

Directory of Open Access Journals (Sweden)

Shanwen Zhang

2017-01-01

Full Text Available In sparse representation based classification (SRC and weighted SRC (WSRC, it is time-consuming to solve the global sparse representation problem. A discriminant WSRC (DWSRC is proposed for large-scale plant species recognition, including two stages. Firstly, several subdictionaries are constructed by dividing the dataset into several similar classes, and a subdictionary is chosen by the maximum similarity between the test sample and the typical sample of each similar class. Secondly, the weighted sparse representation of the test image is calculated with respect to the chosen subdictionary, and then the leaf category is assigned through the minimum reconstruction error. Different from the traditional SRC and its improved approaches, we sparsely represent the test sample on a subdictionary whose base elements are the training samples of the selected similar class, instead of using the generic overcomplete dictionary on the entire training samples. Thus, the complexity to solving the sparse representation problem is reduced. Moreover, DWSRC is adapted to newly added leaf species without rebuilding the dictionary. Experimental results on the ICL plant leaf database show that the method has low computational complexity and high recognition rate and can be clearly interpreted.

LEGO® bricks as building blocks for centimeter-scale biological environments: the case of plants.

Science.gov (United States)

Lind, Kara R; Sizmur, Tom; Benomar, Saida; Miller, Anthony; Cademartiri, Ludovico

2014-01-01

LEGO bricks are commercially available interlocking pieces of plastic that are conventionally used as toys. We describe their use to build engineered environments for cm-scale biological systems, in particular plant roots. Specifically, we take advantage of the unique modularity of these building blocks to create inexpensive, transparent, reconfigurable, and highly scalable environments for plant growth in which structural obstacles and chemical gradients can be precisely engineered to mimic soil.

The impact of continuous integration on other software development practices: a large-scale empirical study

NARCIS (Netherlands)

Zhao, Y.; Serebrenik, A.; Zhou, Y.; Filkov, V.; Vasilescu, B.N.

2017-01-01

Continuous Integration (CI) has become a disruptive innovation in software development: with proper tool support and adoption, positive effects have been demonstrated for pull request throughput and scaling up of project sizes. As any other innovation, adopting CI implies adapting existing practices

Study on large scale knowledge base with real time operation for autonomous nuclear power plant. 1. Basic concept and expecting performance

International Nuclear Information System (INIS)

Ozaki, Yoshihiko; Suda, Kazunori; Yoshikawa, Shinji; Ozawa, Kenji

1996-04-01

Since it is desired to enhance availability and safety of nuclear power plants operation and maintenance by removing human factor, there are many researches and developments for intelligent operation or diagnosis using artificial intelligence (AI) technique. We have been developing an autonomous operation and maintenance system for nuclear power plants by substituting AI's and intelligent robots. It is indispensable to use various and large scale knowledge relative to plant design, operation, and maintenance, that is, whole life cycle data of the plant for the autonomous nuclear power plant. These knowledge must be given to AI system or intelligent robots adequately and opportunely. Moreover, it is necessary to insure real time operation using the large scale knowledge base for plant control and diagnosis performance. We have been studying on the large scale and real time knowledge base system for autonomous plant. In the report, we would like to present the basic concept and expecting performance of the knowledge base for autonomous plant, especially, autonomous control and diagnosis system. (author)

Full scale dynamic testing of Paks nuclear power plant structures

International Nuclear Information System (INIS)

Da Rin, E.M.

1995-01-01

This report refers to the full-scale dynamic structural testing activities that have been performed in December 1994 at the Paks (H) Nuclear Power Plant, within the framework of: the IAEA Coordinated research Programme 'Benchmark Study for the Seismic Analysis and Testing of WWER-type Nuclear Power Plants, and the nuclear research activities of ENEL-WR/YDN, the Italian National Electricity Board in Rome. The specific objective of the conducted investigation was to obtain valid data on the dynamic behaviour of the plant's major constructions, under normal operating conditions, for enabling an assessment of their actual seismic safety to be made. As described in more detail hereafter, the Paks NPP site has been subjected to low level earthquake like ground shaking, through appropriately devised underground explosions, and the dynamic response of the plant's 1 st reactor unit important structures was appropriately measured and digitally recorded. In-situ free field response was measured concurrently and, moreover, site-specific geophysical and seismological data were simultaneously acquired too. The above-said experimental data is to provide basic information on the geophysical and seismological characteristics of the Paks NPP site, together with useful reference information on the true dynamic characteristics of its main structures and give some indications on the actual dynamic soil-structure interaction effects for the case of low level excitation

Improving the action requirements of technical specifications: A risk-comparison of continued operation and plant shutdown

International Nuclear Information System (INIS)

Kim, I.S.; Samanta, P.K.

1994-01-01

When the systems needed to remove decay heat are inoperable or degraded, the risk of shutting down the plant may be comparable to, or even higher than, that of continuing power operation with the equipment inoperable while giving priority to repairs. This concern arises because the plant may not have sufficient capability for removing decay heat during the shutdown. However, Technical Specifications (TSs) often require ''immediate'' shutdown of the plant. In this paper, the authors present risk-based analyses of the various operational policy alternatives available in such situations, with an example application to the standby service water (SSW) system of a BWR. These analyses can be used to define risk-effective requirements for those standby safety systems under discussion

Improving the action requirements of technical specifications: A risk-comparison of continued operation and plant shutdown

Energy Technology Data Exchange (ETDEWEB)

Kim, I.S.; Samanta, P.K. [Brookhaven National Lab., Upton, NY (United States); Mankamo, T.

1995-04-01

When the systems needed to remove decay heat are inoperable or degraded, the risk of shutting down the plant may be comparable to, or even higher than, that of continuing power operation with the equipment inoperable while giving priority to repairs. This concern arises because the plant may not have sufficient capability for removing decay heat during the shutdown. However, Technical Specifications (TSs) often require {open_quotes}immediate{close_quotes} shutdown of the plant. In this paper, we present risk-based analyses of the various operational policy alternatives available in such situations, with an example application to the standby service water (SSW) system of a BWR. These analyses can be used to define risk-effective requirements for those standby safety systems under discussion.

Plant scale studies to enhance the recoveries of Cu, Ni and Mo at By-product Recovery Plant of UCIL, Jaduguda

International Nuclear Information System (INIS)

Rao, G.V.; Sastri, S.R.S.

1998-01-01

Plant scale studies, at 41 tonnes per hour rate, were carried out at Uranium Corporation of India Ltd., Jaduguda with cresylic acid, sodium iso butyl xanthate and potassium amyl xanthate as collectors to evaluate their effectiveness in augmenting the recoveries of copper, nickel and molybdenum present in the uranium bearing ore. Samples collected from each of the three banks with these collectors revealed interesting results. Cresylic acid and light diesel oil combination, with which the plant is operating currently, was found to be selective since the grades of Cu, Ni and Mo obtained are 12.94% Cu, 9.73% Ni, and 4.88% Mo with 61%, 23% and 55.7% recoveries respectively in the first bank itself. The flotation response of nickel minerals is considerably poor with the cresylic acid. Whereas by using xanthates especially the potassium amyl xanthate in combination with pine oil, concentrate containing 5.94% Cu, 8.33% Ni and 2.44% Mo with 93%, 74.3% and 90.8% recoveries respectively could be obtained in the first bank itself. The studies reveal that the current dilution in the grade and low recoveries at the operating plant are probably due to the recirculation of the tailings from the plain cleaning, silicate cleaning and also the scavenger concentrate. The plant scale flotation response of Cu, Ni and Mo with the three collectors at each bank was compared and discussed by comparing the same with the laboratory bulk flotation data. (author)

HOW ECOLOGICAL ENGINEERING HELPED TO CONTINUE BUILDING AND UPGRADE OF THE OPOLE POWER PLANT

Directory of Open Access Journals (Sweden)

Jan Siuta

2016-09-01

Full Text Available Principles of ecological engineering were applied for upgrading the Opole Power Plant under construction, complete with modern installation to protect the environment. The modernized project was a subject of „Integrated environmental impact assessment of the Opole Power Plant” developed by the Institute of Environmental Protection in 1981. The main issues covered by the impact assessment were presented and discussed at the national scientific conference attended, among others, by the representatives of local community from Opole. The conference was organized by the Polish Society of Ecological Engineering on June 5 and 6, 1992. The main aim of the conference was to identify and deliver as broad as possible analysis of environmental conditions for designing, building and operating coal fired power plants. A secondary goal, though of main concern for the Opole agglomeration, was to evaluate many-sided environmental risks resulting from the construction and operation of the Power Plant. The feasibility of continuing the construction of a power generating facility that meets the requirements of the 21st century was demonstrated by the fact that the Opole Power Plant S.A. was awarded the ISO 14001 - Environmental Management System certificate by the British Standards Institution. Advanced construction of the two consecutive blocks of a combined power of 1800 MW in the Opole Power Plant substantiates the validity and effectiveness of the conference organized in 1992.

Slipstream pilot-scale demonstration of a novel amine-based post-combustion technology for carbon dioxide capture from coal-fired power plant flue gas

Energy Technology Data Exchange (ETDEWEB)

Krishnamurthy, Krish R. [Linde LLC, Murray Hill, NJ (United States)

2017-02-03

Post-combustion CO₂ capture (PCC) technology offers flexibility to treat the flue gas from both existing and new coal-fired power plants and can be applied to treat all or a portion of the flue gas. Solvent-based technologies are today the leading option for PCC from commercial coal-fired power plants as they have been applied in large-scale in other applications. Linde and BASF have been working together to develop and further improve a PCC process incorporating BASF’s novel aqueous amine-based solvent technology. This technology offers significant benefits compared to other solvent-based processes as it aims to reduce the regeneration energy requirements using novel solvents that are very stable under the coal-fired power plant feed gas conditions. BASF has developed the desired solvent based on the evaluation of a large number of candidates. In addition, long-term small pilot-scale testing of the BASF solvent has been performed on a lignite-fired flue gas. In coordination with BASF, Linde has evaluated a number of options for capital cost reduction in large engineered systems for solvent-based PCC technology. This report provides a summary of the work performed and results from a project supported by the US DOE (DE-FE0007453) for the pilot-scale demonstration of a Linde-BASF PCC technology using coal-fired power plant flue gas at a 1-1.5 MWe scale in Wilsonville, AL at the National Carbon Capture Center (NCCC). Following a project kick-off meeting in November 2011 and the conclusion of pilot plant design and engineering in February 2013, mechanical completion of the pilot plant was achieved in July 2014, and final commissioning activities were completed to enable start-up of operations in January 2015. Parametric tests were performed from January to December 2015 to determine optimal test conditions and evaluate process performance over a variety of operation parameters. A long-duration 1500-hour continuous test campaign was performed from May to

Continuity and change in medicinal plant use: the example of monasteries on Cyprus and historical iatrosophia texts.

Science.gov (United States)

Lardos, Andreas; Heinrich, Michael

2013-10-28

How medicinal plant knowledge changes over time is a question of central importance in modern ethnopharmacological research. However, only few studies are available which undertook a comprehensive exploration of the evolution of plant use in human cultures. In order to understand this dynamic process, we conduct a systematic diachronic investigation to explore continuity and change in two knowledge systems which are closely related but separated in time-historical iatrosophia texts and today's Greek Orthodox monasteries on Cyprus. An ethnobotanical study was conducted in 21 of the island's monasteries involving various types of interview as well as a written questionnaire survey. Data about medicinal plant use collected in the monasteries was analysed and quantitatively compared to historical iatrosophia texts using data from our pre-existing dataset. We found a core group of plant taxa for which a high consensus exists among the monasteries regarding their medicinal usefulness. Various means and routes of knowledge transmission appear to be involved in the development of this knowledge. The systematic comparison between the monasteries and the iatrosophia shows similarities and differences on various levels. While the plants used by the nuns and monks have by the majority a relationship to the iatrosophia and show a remarkable historical consistency in terms of their use for defined groups of ailments, the importance of many of these plants and the use of herbal medicines in general have changed. This is one of the first studies from the Mediterranean region which is based on a systematic ethnopharmacological analysis involving comprehensive datasets of historical and modern ethnographic data. The example illustrates continuity and change in 'traditional' knowledge as well as the adoption of new knowledge and provides the opportunity to look beyond the dichotomy between traditional and modern concepts of plant usage. Overall, the study suggests that a systematic

Laboratory and pilot plant scale study on the electrochemical oxidation of landfill leachate

International Nuclear Information System (INIS)

Anglada, Angela; Urtiaga, Ana M.; Ortiz, Inmaculada

2010-01-01

Kinetic data regarding COD oxidation were measured in a laboratory scale cell and used to scale-up an electro-oxidation process for landfill leachate treatment by means of boron-doped diamond anodes. A pilot-scale reactor with a total BDD anode area of 1.05 m 2 was designed. Different electrode gaps in the laboratory and pilot plant cells resulted in dissimilar reactor hydrodynamics. Consequently, generalised dimensionless correlations concerning mass transfer were developed in order to define the mass transfer conditions in both electrochemical systems. These correlations were then used in the design equations to validate the scale-up procedure. A series of experiments with biologically pre-treated landfill leachate were done to accomplish this goal. The evolution of ammonia and COD concentration could be well predicted.

Micro-scale energy valorization of grape marcs in winery production plants

International Nuclear Information System (INIS)

Fabbri, Andrea; Bonifazi, Giuseppe; Serranti, Silvia

2015-01-01

Highlights: • BioMethane Potential of grape marcs was investigated. • Grape marcs were characterized to realize a micro-scale energy recovery. • Comparative BMP batch-tests utilizing lab-scale reactors were performed. • Biogas valorization by grape marcs anaerobic digestion at small scale is evaluated. - Abstract: The BiochemicalMethanePotential (BMP) of winery organic waste, with reference to two Italian red and white grapes (i.e. Nero Buono and Greco) by-products was investigated. The study was carried out to verify the possibility to reduce the production impact in a green-waste-management-chain-perspective. The possibility to efficiently utilize wine-related-by-products for energy production at a micro-scale (i.e. small-medium scale winery production plant) was also verified. Results showed as a good correlation can be established between the percentage of COD removal and the biogas production, as the winery can produce, from its waste methanization, about 7800 kW h year −1 electrical and 8900 kW h year −1 thermal. A critical evaluation was performed about the possibility to utilize the proposed approach to realize an optimal biomass waste management and an energetic valorization in a local-energy-production-perspective

LEGO® bricks as building blocks for centimeter-scale biological environments: the case of plants.

Directory of Open Access Journals (Sweden)

Kara R Lind

Full Text Available LEGO bricks are commercially available interlocking pieces of plastic that are conventionally used as toys. We describe their use to build engineered environments for cm-scale biological systems, in particular plant roots. Specifically, we take advantage of the unique modularity of these building blocks to create inexpensive, transparent, reconfigurable, and highly scalable environments for plant growth in which structural obstacles and chemical gradients can be precisely engineered to mimic soil.

Experimental and modelling studies on continuous synthesis and refining of biodiesel in a dedicated bench scale unit using centrifugal contactor separator technology

NARCIS (Netherlands)

Abduh, Muhammad Yusuf; Martinez, Alberto Fernandez; Kloekhorst, Arjan; Manurung, Robert; Heeres, Hero J.

Continuous synthesis and refining of biodiesel (FAME) using a laboratory scale bench scale unit was explored. The unit consists of three major parts: (i) a continuous centrifugal contactor separator (CCCS) to perform the reaction between sunflower oil and methanol; (ii) a washing unit for the crude

Plant-scale anodic dissolution of unirradiated N-Reactor fuel

International Nuclear Information System (INIS)

Gay, E.C.; Miller, W.E.; Laidler, J.J.

1995-01-01

Anodic dissolution tests were made with unirradiated N-Reactor fuel to determine the fuel segment length, diameter, and shape required for high throughput electrorefiner treatment for ultimate disposal in a geologic repository. Based on these tests, a conceptual design was produced of an electrorefiner for a full-scale plant to process N-Reactor spent fuel. In this design, the diameter of an electrode assembly is about 0.6 m (25 in.). Eight of these assemblies in an electrorefiner would accommodate a 1.333-metric-ton batch of N-Reactor fuel. Electrorefining would proceed at a rate of 40 kg uranium per hour

Large-scale sulfolane-impacted soil remediation at a gas plant

Energy Technology Data Exchange (ETDEWEB)

Lavoie, G.; Rockwell, K. [Biogenie Inc., Calgary, AB (Canada)

2006-07-01

A large-scale sulfolane-impacted soil remediation project at a gas plant in central Alberta was discussed. The plant was operational from the 1960s to present and the former operation involved the Sulfinol process which resulted in groundwater contamination. In 2005, the client wanted to address the sources area. The Sulfinol process has been used since the 1960s to remove hydrogen sulfide and other corrosive gases from natural gas streams. Sulfinol uses sulfolane and diisopropanolamine. Sulfolane is toxic, non-volatile, and water soluble. The presentation also addressed the remediation objectives and an additional site assessment that was conducted to better delineate the sulfolane and sulphur plume, as well as metals. The findings of the ESA and site specific challenges were presented. These challenges included: plant operation concerns; numerous overhead, surface, and underground structures; large volume of impacted material, limited space available on site; several types of contaminants; and time required to perform the overall work. Next, the sulfolane remediation strategy was discussed including advantages and results of the investigation. Last, the results of the project were presented. It was found that there were no recordable safety incidents and that all remedial objectives were achieved. tabs., figs.

Continued validation of the Multidimensional Perfectionism Scale.

Science.gov (United States)

Clavin, S L; Clavin, R H; Gayton, W F; Broida, J

1996-06-01

Scores on the Multidimensional Perfectionism Scale have been correlated with measures of obsessive-compulsive tendencies for women, so the validity of scores on this scale for 41 men was examined. Scores on the Perfectionism Scale were significantly correlated (.47-.03) with scores on the Maudsley Obsessive-Compulsive Inventory.

Colour bio-factories: Towards scale-up production of anthocyanins in plant cell cultures.

Science.gov (United States)

Appelhagen, Ingo; Wulff-Vester, Anders Keim; Wendell, Micael; Hvoslef-Eide, Anne-Kathrine; Russell, Julia; Oertel, Anne; Martens, Stefan; Mock, Hans-Peter; Martin, Cathie; Matros, Andrea

2018-06-08

Anthocyanins are widely distributed, glycosylated, water-soluble plant pigments, which give many fruits and flowers their red, purple or blue colouration. Their beneficial effects in a dietary context have encouraged increasing use of anthocyanins as natural colourants in the food and cosmetic industries. However, the limited availability and diversity of anthocyanins commercially have initiated searches for alternative sources of these natural colourants. In plants, high-level production of secondary metabolites, such as anthocyanins, can be achieved by engineering of regulatory genes as well as genes encoding biosynthetic enzymes. We have used tobacco lines which constitutively produce high levels of cyanidin 3-O-rutinoside, delphinidin 3-O-rutinoside or a novel anthocyanin, acylated cyanidin 3-O-(coumaroyl) rutinoside to generate cell suspension cultures. The cell lines are stable in their production rates and superior to conventional plant cell cultures. Scale-up of anthocyanin production in small scale fermenters has been demonstrated. The cell cultures have also proven to be a suitable system for production of 13 C-labelled anthocyanins. Our method for anthocyanin production is transferable to other plant species, such as Arabidopsis thaliana, demonstrating the potential of this approach for making a wide range of highly-decorated anthocyanins. The tobacco cell cultures represent a customisable and sustainable alternative to conventional anthocyanin production platforms and have considerable potential for use in industrial and medical applications of anthocyanins. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Considerations in the evaluation of concrete structures for continued service in aged Nuclear Power Plants (NPPs)

International Nuclear Information System (INIS)

Naus, D.; Marchbanks, M.; Oland, B.; Arndt, G.; Brown, T.

1989-01-01

Currently, there are /approximately/119 commercial nuclear power plants (NPPs) in the US either under construction, operating at low-to-full power, or awaiting an operating license. Together, these units have a net generating capacity of /approximately/110 GW(e). Assuming no life extension of present facilities, the operating licenses for these plants will start to expire in the middle of the next decade with Yankee Rowe being the first plant to attain this status. Where it is noted that with no life extension of facilities, a potential loss of electrical generating capacity in excess of 75 GW(e) could occur during the time period 2006 to 2020 when the operating licenses of 80 to 90 NPPs are scheduled to expire. A potential timely and cost-effective solution to meeting future electricity demand, which has worked well for non-nuclear generating plants, is to extend the service life (operating licenses) of existing NPPs. Since the concrete components in these plants provide a vital safety function, any continued service considerations must include an in-depth assessment of the safety-related concrete structures. 7 refs

Solidification of Savannah River Plant high-level waste

International Nuclear Information System (INIS)

Maher, R.; Shafranek, L.F.; Stevens, W.R. III.

1983-01-01

The Department of Energy, in accord with recommendations from the Du Pont Company, has started construction of a Defense Waste Processing Facility (DWPF) at the Savannah River Plant. The facility should be completed by the end of 1988, and full-scale operation should begin in 1990. This facility will immobilize in borosilicate glass the large quantity of high-level radioactive waste now stored at the plant plus the waste to be generated from continued chemical reprocessing operations. The existing wastes at the Savannah River Plant will be completely converted by about 2010. 21 figures

Phenological growth stages of saffron plant (Crocus sativus L.) according to the BBCH Scale

Energy Technology Data Exchange (ETDEWEB)

Lopez-Corcoles, H.; Brasa-Ramos, A.; Montero-Garcia, F.; Romero-Valverde, M.; Montero-Riquelme, F.

2015-07-01

Phenological studies are important for understanding the influence of climate dynamics on vegetative growth, flowering and fruiting on plants and can be used in many scientific subjects, such as Agronomy, Botany and Plant Biology, but also Climatology as a result of the current global interest in climate change monitoring. The purpose of the detailed specific culture descriptions of the principal growth stages in plants is to provide an instrument for standardization of data recording. To date, there was no coding method to describe developmental stages on saffron plant (Crocus sativus L.). Because of the increasing world-wide interest on this crop, a novel growth development code based on the BBCH extended scale is proposed in this paper. Six principal growth stages were set up, starting from sprouting, cataphylls and flowers appearance, plant appearance and development, replacement corms development, plant senescence and corm dormancy. Each principal growth stage is subdivided into secondary growth stages. Descriptive keys with illustrations are included to make effective use of the system. (Author)

Structural Aging Program to evaluate continued performance of safety-related concrete structures in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

1994-01-01

This report discusses the Structural Aging (SAG) Program which is being conducted at the Oak Ridge National Laboratory (ORNL) for the United States Nuclear Regulatory commission (USNRC). The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. The program is organized into three technical tasks: Materials Property Data Base, Structural Component Assessment/Repair Technologies, and Quantitative Methodology for continued Service Determinations. Objectives and a summary of recent accomplishments under each of these tasks are presented

Experiments to investigate direct containment heating phenomena with scaled models of the Calvert Cliffs Nuclear Power Plant

International Nuclear Information System (INIS)

Blanchat, T.K.; Pilch, M.M.; Allen, M.D.

1997-02-01

The Surtsey Test Facility is used to perform scaled experiments simulating High Pressure Melt Ejection accidents in a nuclear power plant (NPP). The experiments investigate the effects of direct containment heating (DCH) on the containment load. The results from Zion and Surry experiments can be extrapolated to other Westinghouse plants, but predicted containment loads cannot be generalized to all Combustion Engineering (CE) plants. Five CE plants have melt dispersal flow paths which circumvent the main mitigation of containment compartmentalization in most Westinghouse PWRs. Calvert Cliff-like plant geometries and the impact of codispersed water were addressed as part of the DCH issue resolution. Integral effects tests were performed with a scale model of the Calvert Cliffs NPP inside the Surtsey test vessel. The experiments investigated the effects of codispersal of water, steam, and molten core stimulant materials on DCH loads under prototypic accident conditions and plant configurations. The results indicated that large amounts of coejected water reduced the DCH load by a small amount. Large amounts of debris were dispersed from the cavity to the upper dome (via the annular gap). 22 refs., 84 figs., 30 tabs

Small-scale semi-continuous reactor for the conversion of wood to fuel oil

Energy Technology Data Exchange (ETDEWEB)

Eager, R L; Pepper, J M; Mathews, J F

1983-04-01

The design and operation of a small-scale semi-continuous reactor to convert aspen wood meal into an oil product is described. Modifications that reduce erosion/corrosion are also presented. Short residence times and relatively low operating pressures have been achieved for the reaction of aspen with CO and H2O in the presence of Na2CO3. Conversions, char formation, and the effect of sodium carbonate concentration on oil product are reported.

Continuing {sup 137}Cs release to the sea from the Fukushima Dai-ichi nuclear power plant through 2012

Energy Technology Data Exchange (ETDEWEB)

Kanda, J. [Tokyo Univ. of Marine Science and Technology (Japan). Dept. of Ocean Sciences

2013-07-01

The rate of cesium-137 ({sup 137}Cs) release to the sea from the Fukushima Dai-ichi Nuclear Power Plant for the period until September 2012 was estimated. Publicly released data on {sup 137}Cs radioactivity in seawater near the power plant by Tokyo Electric Power Company strongly suggest a continuing release of radionuclides to the sea. The plant has an artificial harbour facility, and the exchange rate of harbour water with surrounding seawater was estimated by the decrease in radioactivity immediately after an intense radioactive water release. The estimated exchange rate of water in the harbour was 0.44 d{sup -1} during the period from 6 to 19 April. The {sup 137}Cs radioactivity in the harbour water was substantially higher than that of seawater outside and remained relatively stable after June 2011. A quasi-steady state was assumed with continuous water exchange, and the average release rate of {sup 137}Cs was estimated to be 93 GBq d{sup -1} in summer 2011 and 8.1 GBq d{sup -1} in summer 2012.

Generic Containment: Detailed comparison of containment simulations performed on plant scale

International Nuclear Information System (INIS)

Kelm, St.; Klauck, M.; Beck, S.; Allelein, H.-J.; Preusser, G.; Sangiorgi, M.; Klein-Hessling, W.; Bakalov, I.; Bleyer, A.; Bentaib, A.; Kljenak, I.; Stempniewicz, M.; Kostka, P.; Morandi, S.; Ada del Corno, B.; Bratfisch, C.; Risken, T.; Denk, L.; Parduba, Z.; Paci, S.

2014-01-01

Highlights: • Consequent implementation of the recommendations derived from the OECD/NEA ISP-47. • Phenomenological code-to-code comparison performed on plant scale. • Systematic identification and elimination of the user effect. • Identification of fundamental differences in the model basis. • Application to PAR system analysis. - Abstract: One outcome of the OECD/NEA ISP-47 activity was the recommendation to elaborate a ‘Generic Containment’ in order to allow comparing and rating the results obtained by different lumped-parameter models on plant scale. Within the European SARNET2 project ( (http://www.sar-net.eu)), such a Generic Containment nodalisation, based on a German PWR (1300 MW el ), was defined. This agreement on the nodalisation allows investigating the remaining differences among the results, especially the ‘user-effect’, related to the modelling choices, as well as fundamental differences in the underlying model basis in detail. The methodology applied in order to compare the different code predictions consisted of a series of three benchmark steps with increasing complexity as well as a systematic comparison of characteristic variables and observations. This paper summarises the benchmark series, the lessons learned during specifying the steps, comparing and discussing the results and finally gives an outlook on future steps

Continuous monitoring methods for assessment of structural integrity in nuclear power plants; Jatkuvan monitoroinnin menetelmaet rakenteiden eheyden varmistamiseen ydinvoimaloissa

Energy Technology Data Exchange (ETDEWEB)

Sarkimo, M

1998-01-01

This report is a review of the frequently used continuous monitoring methods that are applied or can possibly be applied in nuclear power plants. The methods covered include condition monitoring and non-destructive testing (NDT) techniques that can be used to detect flaws in components and the malfunction of machinery. The specific techniques for water chemistry monitoring are not covered by this report. The systems based on acoustic emission are considered to be suitable for continuous monitoring applications and these are discussed in greater detail compared to other methods. The loose parts monitoring and leak detection systems based on acoustic emission have practical applications in several nuclear power plants. The real-time monitoring of crack-tip movement using the ultrasonic method is also discussed. Some results are also referred to from the research and development work to monitor crack initiation and growth on the surface of high-speed rotating components using the electromagnetic method. Vibration measurements and analysis are mentioned as a usual tool for monitoring the condition of rotating machinery but also some special aspects of nuclear power plants are included. Finally the on-line fatigue and integrity monitoring systems are briefly discussed and given some considerations regarding the material property measurements using continuous non-destructive methods. (orig.). 34 refs.

135 tf climbing crane for the construction of large scale plants

International Nuclear Information System (INIS)

1981-01-01

Development of a larger capacity, wider working radius and higher lift climbing crane was in demand since the large block construction method become common in plant construction. At first, scaling up of the conventional climbing crane was planned. But, it turned out that the deflection at the top of the jib would cause the load to drift at takeoff in crane operation. Therefore, the crane was newly designed to solve the problem. Some of its advantage are as follows. (1) This crane can be used as either a climbing or a nonclimbing type depending on installation locations and objective plants. (2) Accurate and easy operation is achieved because of little deflection at the top of the jib. (3) Efficient crane operation is possible through high speed hoisting and slewing motions in frequent auxiliary hoisting operations. (4) The construction time can be shortened by adopting pin joints between the blocks and by reducing the number of assembling parts at the site. A nonclimbing type crane is now in operation at the nuclear power plant in Kashiwazaki and a climbing type will be in operation at the nuclear power plant in Fukushima this year. The report presents an outline of the specifications, structures and advantages. (author)

Plant reproductive allocation predicts herbivore dynamics across spatial and temporal scales.

Science.gov (United States)

Miller, Tom E X; Tyre, Andrew J; Louda, Svata M

2006-11-01

Life-history theory suggests that iteroparous plants should be flexible in their allocation of resources toward growth and reproduction. Such plasticity could have consequences for herbivores that prefer or specialize on vegetative versus reproductive structures. To test this prediction, we studied the response of the cactus bug (Narnia pallidicornis) to meristem allocation by tree cholla cactus (Opuntia imbricata). We evaluated the explanatory power of demographic models that incorporated variation in cactus relative reproductive effort (RRE; the proportion of meristems allocated toward reproduction). Field data provided strong support for a single model that defined herbivore fecundity as a time-varying, increasing function of host RRE. High-RRE plants were predicted to support larger insect populations, and this effect was strongest late in the season. Independent field data provided strong support for these qualitative predictions and suggested that plant allocation effects extend across temporal and spatial scales. Specifically, late-season insect abundance was positively associated with interannual changes in cactus RRE over 3 years. Spatial variation in insect abundance was correlated with variation in RRE among five cactus populations across New Mexico. We conclude that plant allocation can be a critical component of resource quality for insect herbivores and, thus, an important mechanism underlying variation in herbivore abundance across time and space.

Continuity and Innovation. 25 years of simulator training for nuclear power plants in Germany

International Nuclear Information System (INIS)

Lindauer, E.

2002-01-01

The first training simulator for nuclear power plant personnel in Germany was commissioned twenty-five years ago. This date was rather early, both when measured by the development of the German nuclear power program and when compared with the international situation. This farsighted decision demonstrates the importance nuclear power plant operators attach to the sound training of plant personnel. The consistent, and also costly, further development over the past twenty-five years shows that this attitude has not changed. A modern simulator center was built at a total cost of approx. 250 million Euro which can be characterized briefly as follows: - 13 full simulators cover most specific features of existing nuclear power plants. These simulators are backfitted continuously and represent the current state of simulation technology. - Their experience over many years has allowed the staff of approx. 140 to accumulate a high level of know-how in training and simulator operation. Learning from experience is greatly assisted by the fact that all activities are concentrated at one center. - The way in which the center is organized ensures close cooperation with the nuclear power plants responsible for the training of their personnel. - There is a systematic training concept which is being actively developed further. Some of the main developments in recent years include training for emergencies; intensified training in behavioral aspects, such as communication and leadership; the use of simulators for emergency drills; testing of modifications, etc. (orig.) [de

Full-scale impact test data for tornado-missile design of nuclear plants

International Nuclear Information System (INIS)

Stephenson, A.E.; Sliter, G.E.

1977-01-01

It is standard practice to consider the effects of low-probability impacts of tornado-borne debris (''tornado missiles'' such as utility poles and steel pipes) in the structural design of nuclear power plants in the United States. To provide data that can be used directly in the design procedure, a series of full-scale tornado-missile impact tests was performed. This paper is a brief summary of the results and conclusions from these tests. The tests consisted of reinforced concrete panels impacted by poles, pipes, and rods propelled by a rocket sled. The panels were constructed to current minimum standards and had thicknesses typical of auxiliary buildings of nuclear power plants. A specific objective was the determination of the impact velocities below which the panels do not experience backface scabbing. Another objective was to assess the adequacy of (1) conventional design formulae for penetration and scabbing and (2) conventional design methods for overall structural response. Test missiles and velocities represented those in current design standards. Missiles included utility poles, steel pipes, and steel bars. It is important to interpret the data in this paper in recognition that the test conditions represent conservative assumptions regarding maximum wind speeds, injection of the missile into the wind stream, aerodynamic trajectory, and orientation of missile at impact. Even with the severe assumptions made, the full-scale tests described demonstrate the ability of prototypical nuclear plant walls and roofs to provide adequate protection against postulated tornado-missile impact

Economic trends of tokamak power plants independent of physics scaling models

International Nuclear Information System (INIS)

Reid, R.L.; Steiner, D.

1978-01-01

This study examines the effects of plasma radius, field on axis, plasma impurity level, and aspect ratio on power level and unit capital cost, $/kW/sub e/, of tokamak power plants sized independent of plasma physics scaling models. It is noted that tokamaks sized in this manner are thermally unstable based on trapped particle scaling relationships. It is observed that there is an economic advantage for larger power level tokamaks achieved by physics independent sizing; however, the incentive for increased power levels is less than that for fission reactors. It is further observed that the economic advantage of these larger power level tokamaks is decreased when plasma thermal stability measures are incorporated, such as by increasing the plasma impurity concentration. This trend of economy with size obtained by physics independent sizing is opposite to that observed when the tokamak designs are constrained to obey the trapped particle and empirical scaling relationships

Removal of ammonia nitrogen in wastewater by microwave radiation: A pilot-scale study

International Nuclear Information System (INIS)

Lin Li; Chen Jing; Xu Zuqun; Yuan Songhu; Cao Menghua; Liu Huangcheng; Lu Xiaohua

2009-01-01

A large removal of ammonia nitrogen in wastewater has been achieved by microwave (MW) radiation in our previous bench-scale study. This study developed a continuous pilot-scale MW system to remove ammonia nitrogen in real wastewater. A typical high concentration of ammonia nitrogen contaminated wastewater, the coke-plant wastewater from a Coke company, was treated. The output power of the microwave reactor was 4.8 kW and the handling capacity of the reactor was about 5 m 3 per day. The ammonia removal efficiencies under four operating conditions, including ambient temperature, wastewater flow rate, aeration conditions and initial concentration were evaluated in the pilot-scale experiments. The ammonia removal could reach about 80% for the real coke-plant wastewater with ammonia nitrogen concentrations of 2400-11000 mg/L. The running cost of the MW technique was a little lower than the conventional steam-stripping method. The continuous microwave system showed the potential as an effective method for ammonia nitrogen removal in coke-plant water treatment. It is proposed that this process is suitable for the treatment of toxic wastewater containing high concentrations of ammonia nitrogen.

Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

DEFF Research Database (Denmark)

Hu, Weihao; Su, Chi; Fang, Jiakun

2013-01-01

This paper presents a simulation model of a wind power plant based on a MW-level variable speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory. Three different kinds of ancillary frequency control strategies, namely inertia...... control strategies are effective means for providing ancillary frequency control of variable speed wind turbines with full-scale back-to-back power converters....... emulation, primary frequency control and secondary frequency control, are proposed in order to improve the frequency stability of power systems. The modified IEEE 39-bus test system with a large-scale wind power penetration is chosen as the studied power system. Simulation results show that the proposed...

Micro-scale energy valorization of grape marcs in winery production plants

Energy Technology Data Exchange (ETDEWEB)

Fabbri, Andrea; Bonifazi, Giuseppe; Serranti, Silvia, E-mail: silvia.serranti@uniroma1.it

2015-02-15

Highlights: • BioMethane Potential of grape marcs was investigated. • Grape marcs were characterized to realize a micro-scale energy recovery. • Comparative BMP batch-tests utilizing lab-scale reactors were performed. • Biogas valorization by grape marcs anaerobic digestion at small scale is evaluated. - Abstract: The BiochemicalMethanePotential (BMP) of winery organic waste, with reference to two Italian red and white grapes (i.e. Nero Buono and Greco) by-products was investigated. The study was carried out to verify the possibility to reduce the production impact in a green-waste-management-chain-perspective. The possibility to efficiently utilize wine-related-by-products for energy production at a micro-scale (i.e. small-medium scale winery production plant) was also verified. Results showed as a good correlation can be established between the percentage of COD removal and the biogas production, as the winery can produce, from its waste methanization, about 7800 kW h year{sup −1} electrical and 8900 kW h year{sup −1} thermal. A critical evaluation was performed about the possibility to utilize the proposed approach to realize an optimal biomass waste management and an energetic valorization in a local-energy-production-perspective.

Plant-scale anodic dissolution of unirradiated N-Reactor fuel

International Nuclear Information System (INIS)

Gay, E.C.; Miller, W.E.; Laidler, J.J.

1995-01-01

Anodic dissolution tests were made with unirradiated N-Reactor fuel to determine the fuel segment length, diameter, and shape required for high throughput electro-refiner treatment for ultimate disposal in a geologic repository. Based on these tests, a conceptual design was produced of an electro-refiner for a full-scale plant to process N-Reactor spent fuel. In this design, the diameter of an electrode assembly is about 0.6 m (25 in.). Eight of these assemblies in an electro-refiner would accommodate a 1.333-metric-ton batch of N-Reactor fuel. Electrorefining would proceed at a rate of 40 kg uranium per hour. (author)

Empirical likelihood-based confidence intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity.

Science.gov (United States)

Gengsheng Qin; Davis, Angela E; Jing, Bing-Yi

2011-06-01

For a continuous-scale diagnostic test, it is often of interest to find the range of the sensitivity of the test at the cut-off that yields a desired specificity. In this article, we first define a profile empirical likelihood ratio for the sensitivity of a continuous-scale diagnostic test and show that its limiting distribution is a scaled chi-square distribution. We then propose two new empirical likelihood-based confidence intervals for the sensitivity of the test at a fixed level of specificity by using the scaled chi-square distribution. Simulation studies are conducted to compare the finite sample performance of the newly proposed intervals with the existing intervals for the sensitivity in terms of coverage probability. A real example is used to illustrate the application of the recommended methods.

Environmental Impacts From the Installation and Operation of Large-scale Solar Power Plants

Energy Technology Data Exchange (ETDEWEB)

Fthenakis, V.; Turney, Damon

2011-04-23

Large-scale solar power plants are being developed at a rapid rate, and are setting up to use thousands or millions of acres of land globally. The environmental issues related to the installation and operation phases of such facilities have not, so far, been addressed comprehensively in the literature. Here we identify and appraise 32 impacts from these phases, under the themes of land use intensity, human health and well-being, plant and animal life, geohydrological resources, and climate change. Our appraisals assume that electricity generated by new solar power facilities will displace electricity from traditional U.S. generation technologies. Altogether we find 22 of the considered 32 impacts to be beneficial. Of the remaining 10 impacts, 4 are neutral, and 6 require further research before they can be appraised. None of the impacts are negative relative to traditional power generation. We rank the impacts in terms of priority, and find all the high-priority impacts to be beneficial. In quantitative terms, large-scale solar power plants occupy the same or less land per kW h than coal power plant life cycles. Removal of forests to make space for solar power causes CO{sub 2} emissions as high as 36 g CO{sub 2} kW h{sup -1}, which is a significant contribution to the life cycle CO{sub 2} emissions of solar power, but is still low compared to CO{sub 2} emissions from coal-based electricity that are about 1100 g CO{sub 2} kW h{sup -1}.

Karhunen-Loève (PCA) based detection of multiple oscillations in multiple measurement signals from large-scale process plants

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Wickerhauser, M.V.

2007-01-01

 In the perspective of optimizing the control and operation of large scale process plants, it is important to detect and to locate oscillations in the plants. This paper presents a scheme for detecting and localizing multiple oscillations in multiple measurements from such a large-scale power plant....... The scheme is based on a Karhunen-Lo\\`{e}ve analysis of the data from the plant. The proposed scheme is subsequently tested on two sets of data: a set of synthetic data and a set of data from a coal-fired power plant. In both cases the scheme detects the beginning of the oscillation within only a few samples....... In addition the oscillation localization has also shown its potential by localizing the oscillations in both data sets....

Mathematical modeling of nitrous oxide (N2O) emissions from full-scale wastewater treatment plants.

Science.gov (United States)

Ni, Bing-Jie; Ye, Liu; Law, Yingyu; Byers, Craig; Yuan, Zhiguo

2013-07-16

Mathematical modeling of N2O emissions is of great importance toward understanding the whole environmental impact of wastewater treatment systems. However, information on modeling of N2O emissions from full-scale wastewater treatment plants (WWTP) is still sparse. In this work, a mathematical model based on currently known or hypothesized metabolic pathways for N2O productions by heterotrophic denitrifiers and ammonia-oxidizing bacteria (AOB) is developed and calibrated to describe the N2O emissions from full-scale WWTPs. The model described well the dynamic ammonium, nitrite, nitrate, dissolved oxygen (DO) and N2O data collected from both an open oxidation ditch (OD) system with surface aerators and a sequencing batch reactor (SBR) system with bubbling aeration. The obtained kinetic parameters for N2O production are found to be reasonable as the 95% confidence regions of the estimates are all small with mean values approximately at the center. The model is further validated with independent data sets collected from the same two WWTPs. This is the first time that mathematical modeling of N2O emissions is conducted successfully for full-scale WWTPs. While clearly showing that the NH2OH related pathways could well explain N2O production and emission in the two full-scale plants studied, the modeling results do not prove the dominance of the NH2OH pathways in these plants, nor rule out the possibility of AOB denitrification being a potentially dominating pathway in other WWTPs that are designed or operated differently.

Small-scale hydroelectric power plant of Passo do Inferno automation system; Sistema de automatizacao da PCH Passo do Inferno

Energy Technology Data Exchange (ETDEWEB)

Santos, Luiz C. Lisboa; Moralles, Reni; Quadros, Carlos A.D.; Martiny, Raul; Moehlecke, Juarez E.; Costa, Nelson D. da; Cesar, Rogerio L.; Santos, Sergio S.; Basei, Eleu Natal [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)

1993-12-31

This work introduces the automation system brought into the 1,7 MVA small-scale hydroelectric power plant of Passo do Inferno, state of Rio Grande do Sul, Brazil. The following systems are presented: supervision, security and generation control, as well as the program and the controller. In this work, it is focused the generation control system, as a new outfitted system in small-scale hydroelectric power plants 3 figs.

Phenological growth stages of saffron plant (Crocus sativus L. according to the BBCH Scale

Directory of Open Access Journals (Sweden)

Horacio Lopez-Corcoles

2015-09-01

Full Text Available Phenological studies are important for understanding the influence of climate dynamics on vegetative growth, flowering and fruiting on plants and can be used in many scientific subjects, such as Agronomy, Botany and Plant Biology, but also Climatology as a result of the current global interest in climate change monitoring. The purpose of the detailed specific culture descriptions of the principal growth stages in plants is to provide an instrument for standardization of data recording. To date, there was no coding method to describe developmental stages on saffron plant (Crocus sativus L.. Because of the increasing world-wide interest on this crop, a novel growth development code based on the BBCH extended scale is proposed in this paper. Six principal growth stages were set up, starting from sprouting, cataphylls and flowers appearance, plant appearance and development, replacement corms development, plant senescence and corm dormancy. Each principal growth stage is subdivided into secondary growth stages. Descriptive keys with illustrations are included to make effective use of the system.

Particle physics and polyedra proximity calculation for hazard simulations in large-scale industrial plants

Science.gov (United States)

Plebe, Alice; Grasso, Giorgio

2016-12-01

This paper describes a system developed for the simulation of flames inside an open-source 3D computer graphic software, Blender, with the aim of analyzing in virtual reality scenarios of hazards in large-scale industrial plants. The advantages of Blender are of rendering at high resolution the very complex structure of large industrial plants, and of embedding a physical engine based on smoothed particle hydrodynamics. This particle system is used to evolve a simulated fire. The interaction of this fire with the components of the plant is computed using polyhedron separation distance, adopting a Voronoi-based strategy that optimizes the number of feature distance computations. Results on a real oil and gas refining industry are presented.

Zero discharge performance of an industrial pilot-scale plant treating palm oil mill effluent.

Science.gov (United States)

Wang, Jin; Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Chi, Li-Na; Li, Xu-Dong

2015-01-01

Palm oil is one of the most important agroindustries in Malaysia. Huge quantities of palm oil mill effluent (POME) pose a great threat to aqueous environment due to its very high COD. To make full use of discharged wastes, the integrated "zero discharge" pilot-scale industrial plant comprising "pretreatment-anaerobic and aerobic process-membrane separation" was continuously operated for 1 year. After pretreatment in the oil separator tank, 55.6% of waste oil in raw POME could be recovered and sold and anaerobically digested through 2 AnaEG reactors followed by a dissolved air flotation (DAF); average COD reduced to about 3587 mg/L, and biogas production was 27.65 times POME injection which was used to generate electricity. The aerobic effluent was settled for 3 h or/and treated in MBR which could remove BOD3 (30°C) to less than 20 mg/L as required by Department of Environment of Malaysia. After filtration by UF and RO membrane, all organic compounds and most of the salts were removed; RO permeate could be reused as the boiler feed water. RO concentrate combined with anaerobic surplus sludge could be used as biofertilizer.

Decoding Synteny Blocks and Large-Scale Duplications in Mammalian and Plant Genomes

Science.gov (United States)

Peng, Qian; Alekseyev, Max A.; Tesler, Glenn; Pevzner, Pavel A.

The existing synteny block reconstruction algorithms use anchors (e.g., orthologous genes) shared over all genomes to construct the synteny blocks for multiple genomes. This approach, while efficient for a few genomes, cannot be scaled to address the need to construct synteny blocks in many mammalian genomes that are currently being sequenced. The problem is that the number of anchors shared among all genomes quickly decreases with the increase in the number of genomes. Another problem is that many genomes (plant genomes in particular) had extensive duplications, which makes decoding of genomic architecture and rearrangement analysis in plants difficult. The existing synteny block generation algorithms in plants do not address the issue of generating non-overlapping synteny blocks suitable for analyzing rearrangements and evolution history of duplications. We present a new algorithm based on the A-Bruijn graph framework that overcomes these difficulties and provides a unified approach to synteny block reconstruction for multiple genomes, and for genomes with large duplications.

Spatial heterogeneity regulates plant-pollinator networks across multiple landscape scales.

Directory of Open Access Journals (Sweden)

Eduardo Freitas Moreira

Full Text Available Mutualistic plant-pollinator interactions play a key role in biodiversity conservation and ecosystem functioning. In a community, the combination of these interactions can generate emergent properties, e.g., robustness and resilience to disturbances such as fluctuations in populations and extinctions. Given that these systems are hierarchical and complex, environmental changes must have multiple levels of influence. In addition, changes in habitat quality and in the landscape structure are important threats to plants, pollinators and their interactions. However, despite the importance of these phenomena for the understanding of biological systems, as well as for conservation and management strategies, few studies have empirically evaluated these effects at the network level. Therefore, the objective of this study was to investigate the influence of local conditions and landscape structure at multiple scales on the characteristics of plant-pollinator networks. This study was conducted in agri-natural lands in Chapada Diamantina, Bahia, Brazil. Pollinators were collected in 27 sampling units distributed orthogonally along a gradient of proportion of agriculture and landscape diversity. The Akaike information criterion was used to select models that best fit the metrics for network characteristics, comparing four hypotheses represented by a set of a priori candidate models with specific combinations of the proportion of agriculture, the average shape of the landscape elements, the diversity of the landscape and the structure of local vegetation. The results indicate that a reduction of habitat quality and landscape heterogeneity can cause species loss and decrease of networks nestedness. These structural changes can reduce robustness and resilience of plant-pollinator networks what compromises the reproductive success of plants, the maintenance of biodiversity and the pollination service stability. We also discuss the possible explanations for

Spatial heterogeneity regulates plant-pollinator networks across multiple landscape scales.

Science.gov (United States)

Moreira, Eduardo Freitas; Boscolo, Danilo; Viana, Blandina Felipe

2015-01-01

Mutualistic plant-pollinator interactions play a key role in biodiversity conservation and ecosystem functioning. In a community, the combination of these interactions can generate emergent properties, e.g., robustness and resilience to disturbances such as fluctuations in populations and extinctions. Given that these systems are hierarchical and complex, environmental changes must have multiple levels of influence. In addition, changes in habitat quality and in the landscape structure are important threats to plants, pollinators and their interactions. However, despite the importance of these phenomena for the understanding of biological systems, as well as for conservation and management strategies, few studies have empirically evaluated these effects at the network level. Therefore, the objective of this study was to investigate the influence of local conditions and landscape structure at multiple scales on the characteristics of plant-pollinator networks. This study was conducted in agri-natural lands in Chapada Diamantina, Bahia, Brazil. Pollinators were collected in 27 sampling units distributed orthogonally along a gradient of proportion of agriculture and landscape diversity. The Akaike information criterion was used to select models that best fit the metrics for network characteristics, comparing four hypotheses represented by a set of a priori candidate models with specific combinations of the proportion of agriculture, the average shape of the landscape elements, the diversity of the landscape and the structure of local vegetation. The results indicate that a reduction of habitat quality and landscape heterogeneity can cause species loss and decrease of networks nestedness. These structural changes can reduce robustness and resilience of plant-pollinator networks what compromises the reproductive success of plants, the maintenance of biodiversity and the pollination service stability. We also discuss the possible explanations for these relationships and

Importance of ecohydrological modelling approaches in the prediction of plant behaviour and water balance at different scales

Science.gov (United States)

García-Arias, Alicia; Ruiz-Pérez, Guiomar; Francés, Félix

2017-04-01

Vegetation plays a main role in the water balance of most hydrological systems. However, in the past it has been barely considered the effect of the interception and evapotranspiration for hydrological modelling purposes. During the last years many authors have recognised and supported ecohydrological approaches instead of traditional strategies. This contribution is aimed to demonstrate the pivotal role of the vegetation in ecohydrological models and that a better understanding of the hydrological systems can be achieved by considering the appropriate processes related to plants. The study is performed in two scales: the plot scale and the reach scale. At plot scale, only zonal vegetation was considered while at reach scale both zonal and riparian were taken into account. In order to assure the main role of the water on the vegetation development, semiarid environments have been selected for the case studies. Results show an increase of the capabilities to predict plant behaviour and water balance when interception and evapotranspiration are taken into account in the soil water balance

Large-scale enzymatic production of natural flavour esters in organic solvent with continuous water removal.

Science.gov (United States)

Gubicza, L; Kabiri-Badr, A; Keoves, E; Belafi-Bako, K

2001-11-30

A new, large-scale process was developed for the enzymatic production of low molecular weight flavour esters in organic solvent. Solutions for the elimination of substrate and product inhibitions are presented. The excess water produced during the process was continuously removed by hetero-azeotropic distillation and esters were produced at yields of over 90%.

Single-tube hydroponics as a novel idea for small-scale production of crop seed in a plant incubator.

Science.gov (United States)

Kuroda, Masaharu; Ikenaga, Sachiko

2015-01-01

We present a novel protocol for small-scale production of crop seed in a plant incubator termed "Single-tube hydroponics." Our protocol minimizes the materials and methods for cultivation whereby a large number of independent plants can be cultured in a limited space. This study may aid in the improvement of crop seed components, especially in the cultivation of transgenic plants.

Predicting habitat suitability for rare plants at local spatial scales using a species distribution model.

Science.gov (United States)

Gogol-Prokurat, Melanie

2011-01-01

If species distribution models (SDMs) can rank habitat suitability at a local scale, they may be a valuable conservation planning tool for rare, patchily distributed species. This study assessed the ability of Maxent, an SDM reported to be appropriate for modeling rare species, to rank habitat suitability at a local scale for four edaphic endemic rare plants of gabbroic soils in El Dorado County, California, and examined the effects of grain size, spatial extent, and fine-grain environmental predictors on local-scale model accuracy. Models were developed using species occurrence data mapped on public lands and were evaluated using an independent data set of presence and absence locations on surrounding lands, mimicking a typical conservation-planning scenario that prioritizes potential habitat on unsurveyed lands surrounding known occurrences. Maxent produced models that were successful at discriminating between suitable and unsuitable habitat at the local scale for all four species, and predicted habitat suitability values were proportional to likelihood of occurrence or population abundance for three of four species. Unfortunately, models with the best discrimination (i.e., AUC) were not always the most useful for ranking habitat suitability. The use of independent test data showed metrics that were valuable for evaluating which variables and model choices (e.g., grain, extent) to use in guiding habitat prioritization for conservation of these species. A goodness-of-fit test was used to determine whether habitat suitability values ranked habitat suitability on a continuous scale. If they did not, a minimum acceptable error predicted area criterion was used to determine the threshold for classifying habitat as suitable or unsuitable. I found a trade-off between model extent and the use of fine-grain environmental variables: goodness of fit was improved at larger extents, and fine-grain environmental variables improved local-scale accuracy, but fine-grain variables

Large-scale integration of off-shore wind power and regulation strategies of cogeneration plants in the Danish electricity system

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply......The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply...

Use of ABB ADVANT Power for large scale instrumentation and controls replacements in nuclear power plants

International Nuclear Information System (INIS)

Pucak, J.L.; Brown, E.M.

1999-01-01

One of the major issues facing plants planning for life extension is the viability and feasibility of modernization of a plant's existing I and C systems including the safety systems and the control room. This paper discusses the ABB approach to the implementation of large scale Instrumentation and Controls (I and C) modernization. ABB applies a segmented architecture approach using the ADVANT Power control system to meet the numerous constraints of a major I and C upgrade program. The segmented architecture and how it supports implementation of a complete I and C upgrade either in one outage or in a series of outages is presented. ADVANT Power contains standardized industrial control equipment that is designed to support 1E applications as well as turbine and non-1E process control. This equipment forms the basis for the architecture proposed for future new nuclear plant sales as well as large scale retrofits. (author)

Integration of torrefaction with steam power plant

Energy Technology Data Exchange (ETDEWEB)

Zakri, B.; Saari, J.; Sermyagina, E.; Vakkilainen, E.

2013-09-01

Torrefaction is one of the pretreatment technologies to enhance the fuel characteristics of biomass. The efficient and continuous operation of a torrefaction reactor, in the commercial scale, demands a secure biomass supply, in addition to adequate source of heat. Biorefinery plants or biomass-fuelled steam power plants have the potential to integrate with the torrefaction reactor to exchange heat and mass, using available infrastructure and energy sources. The technical feasibility of this integration is examined in this study. A new model for the torrefaction process is introduced and verified by the available experimental data. The torrefaction model is then integrated in different steam power plants to simulate possible mass and energy exchange between the reactor and the plants. The performance of the integrated plant is investigated for different configurations and the results are compared. (orig.)

Determination and modeling of the influence of the fluid-dynamics in hydro-treating bench scale plants

Energy Technology Data Exchange (ETDEWEB)

Burkhardt, T.

1999-09-16

At an industrial scale, the hydro-treating of oil fractions is carried out in multiphase fixed bed reactors. The oil and hydrogen cross the catalyst bed, usually in co-current downflow. Since the product specifications are steadily becoming more severe, the testing of new catalysts and of modified operating conditions in pilot plants becomes increasingly important. Although these pilot plants are frequently by a factor of 100 000 smaller than the industrial units, they still have to allow the up-scaling to industrial units. In the literature relatively low conversion degrees in pilot plants are frequently reported, especially in downflow. The significantly lower fluid velocities in pilot plants seem to be responsible for such differences, as the influence of fluid-dynamic non-idealities and of the extra-particle mass transfer phenomena increases with a decrease of the fluid velocities. In the present work, the influence of important fluid-dynamic non-idealities on the hydro-treating of gas oil fractions in pilot plants was examined. This was done on the one hand in experiments with different pilot plants and on the other hand by simulations with an especially developed multiphase model. The phenomena were considered as well in an isolated manner. In order to examine any interactions with the chemical reactions, they were also studied in a reactive system. This methodology was applied to the phenomena, 'axial dispersion'and 'gas-liquid mass transfer'. (author)

The hot bench scale plant Ester for the vitrification of high level wastes

International Nuclear Information System (INIS)

Nannicini, R.; Strazzer, A.; Cantale, C; Donato, A.; Grossi, G.

1985-01-01

In this paper the hot bench-scale plant ESTER for the vitrification of the high-level radioactive wastes is described, and the main results of the first radioactive campaign are reported. The ESTER plant, which is placed in the ADECO-ESSOR hot cells of the C.C.R.-EURATOM-ISPRA, has been built and is operated by the ENEA, Departement of Fuel Cycle. It began operating with real radioactive wastes about 1 year ago, solidifying a total of 12 Ci of fission products into 2,02 Kg of borosilicate glass, corresponding to 757 ml of glass. During the vitrification many samples of liquid and gaseous streams have been taken and analyzed. A radioactivity balance in the plant has been calculated, as well as a mass balance of nitrates and of the 137 Cs and 106 Ru volatized in the process

Predicting ecosystem functioning from plant traits: Results from a multi-scale ecophsiological modeling approach

NARCIS (Netherlands)

Wijk, van M.T.

2007-01-01

Ecosystem functioning is the result of processes working at a hierarchy of scales. The representation of these processes in a model that is mathematically tractable and ecologically meaningful is a big challenge. In this paper I describe an individual based model (PLACO¿PLAnt COmpetition) that

Final environmental impact statement for the continued operation of the Pantex Plant and associated storage of nuclear weapon components. Volume 1 -- Main report

International Nuclear Information System (INIS)

1996-11-01

This document assesses the potential environmental impacts over approximately 10 years of continued operation of Pantex Plant, including foreseeable projects and activities. For Pantex Plant, this document assesses the alternatives of No Action, Relocation of the storage of plutonium components (pits) resulting from nuclear weapon disassembly activities at Pantex Plant to another site, and the Proposed Action (Preferred Alternative) of continuing operations and increasing the quantity of pits in interim storage at Pantex Plant. For the Pit Storage Relocation Alternative, this document also assesses the potential environmental impacts to three DOE candidate sites and one Department of Defense candidate site that could be selected for the relocation of the nuclear component storage activities from Pantex Plant. Evaluations of site infrastructure, land resources, geology and soils, water resources, air quality, acoustics, biotic resources, cultural resources, socio-economic resources, intrasite transportation, waste management, human health, aircraft accidents, and environmental justice for Pantex Plant and the candidate sites are included in the assessment. The intersite transportation of nuclear and hazardous materials is also assessed

Investigation of the gypsum quality at three full-scale wet flue gas desulphurisation plants

DEFF Research Database (Denmark)

Hansen, Brian Brun; Kiil, Søren; Johnsson, Jan Erik

2011-01-01

In the present study the gypsum (CaSO4·2H2O) quality at three full-scale wet flue gas desulphurisation (FGD) plants and a pilot plant were examined and compared. Gypsum quality can be expressed in terms of moisture content (particle size and morphology dependent) and the concentration of residual......, low moisture content and low impurity content). An episode concerning a sudden deterioration in the gypsum dewatering properties was furthermore investigated, and a change in crystal morphology, as well as an increased impurity content (aluminium, iron and fluoride), was detected....

Design of a Small Scale Pilot Biodiesel Production Plant and Determination of the Fuel Properties of Biodiesel Produced With This Plant

Directory of Open Access Journals (Sweden)

Tanzer Eryılmaz

2014-09-01

Full Text Available A small scale pilot biodiesel production plant that has a volume of 65 liters/day has been designed, constructed and tested. The plant was performed using oil mixture (50% wild mustard seed oil + 50% refined canola oil and methanol with sodium hydroxide (NaOH catalyst. The fuel properties of biodiesel indicated as density at 15oC (889.64 kg/m3, kinematic viscosity at 40oC (6.975 mm2/s, flash point (170oC, copper strip corrosion (1a, water content (499.87 mg/kg, and calorific value (39.555 MJ/kg, respectively.

Reciprocal interactions between fluvial processes and riparian plants at multiple scales: ecogeomorphic feedbacks drive coevolution of floodplain morphology and vegetation communities

Science.gov (United States)

Stella, J. C.; Kui, L.; Diehl, R. M.; Bywater-Reyes, S.; Wilcox, A. C.; Shafroth, P. B.; Lightbody, A.

2017-12-01

Fluvial forces interact with woody riparian plants in complex ways to influence the coevolution of river morphology and floodplain plant communities. Here, we report on an integrated suite of multi-disciplinary studies that contrast the responses of plants with different morphologies, tamarisk (Tamarix spp.) and cottonwood (Populus fremontii) in terms of (1) differences in vulnerability to scour and burial during floods; (2) interactions and feedbacks between plants and river morphodynamics; and (3) long-term coevolution of river floodplains and riparian communities following flow regulation from dams. The focus of these studies is sand-bed rivers in arid-land regions where invasion by tamarisk has strongly influenced riverine plant communities and geomorphic processes. We complemented a suite of field-scale flume experiments using live seedlings to quantify the initial stages of plant-river interactions with an analysis of long-term vegetation and geomorphic changes along the dammed Bill Williams River (AZ, USA) using time-series air photographs. Vegetation-fluvial interactions varied with plant characteristics, river hydraulics and sediment conditions, across the wide range of scales we investigated. In the flume studies, tamarisk's denser crowns and stiffer stems induced greater sedimentation compared to cottonwood. This resulted in tamarisk's greater mortality from burial as small seedlings under sediment equilibrium conditions but higher relative survival in larger floods under sediment deficit scenarios, in which more cottonwoods were lost to root scour. Sediment deficit conditions, as occurs downstream of dams, induced both greater scour and greater plant loss. With larger size and at higher densities, plants' vulnerability diminished due to greater root anchoring and canopy effects on hydraulics. At the corridor scale, we observed a pattern of plant encroachment during five decades of flow regulation, in which channel narrowing and simplification was more

Survey on the technological development issues for large-scale methanol engine power generation plant; Ogata methanol engine hatsuden plant ni kansuru gijutsu kaihatsu kadai chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

Based on the result of `Survey on the feasibility of large-scale methanol engine power generation plant` in fiscal 1992, concrete technological development issues were studied for its practical use, and the technological R & D scheme was prepared for large-scale methanol engine power plant featured by low NOx and high efficiency. Technological development issues of this plant were as follows: improvement of thermal efficiency, reduction of NOx emission, improvement of the reliability and durability of ignition and fuel injection systems, and reduction of vibration. As the economical effect of the technological development, the profitability of NOx control measures was compared between this methanol engine and conventional heavy oil diesel engines or gas engines. As a result, this engine was more economical than conventional engines. It was suggested that development of the equipment will be completed in nearly 4 years through every component study, single-cylinder model experiment and real engine test. 21 refs., 43 figs., 19 tabs.

Towards assuring the continued performance of safety-related concrete structures in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Oland, C.B.; Ellingwood, B.; Mori, Y.; Arndt, E.G.

1993-01-01

The Structural Aging (SAG) Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. Pertinent concrete structures are described in terms of their importance, design considerations, and materials of construction. Degradation factors which can potentially impact the ability of these structures to meet their functional and performance requirements are identified. A review of the performance history of the concrete components in nuclear power plants is provided. Accomplishments of the SLAG Program are summarized, i.e., development of the structural materials information center, development of a structural aging assessment methodology, evaluation of models for predicting the remaining life of in-service concrete, review of in-service inspection methods, and development of a methodology for reliability-based condition assessment and life prediction of concrete structures. On-going activities are also described

Photocatalytic treatment of an industrial effluent using artificial and solar UV radiation: an operational cost study on a pilot plant scale.

Science.gov (United States)

Durán, A; Monteagudo, J M; San Martín, I

2012-05-15

The aim of this work was to study the operation costs of treating a real effluent from an integrated gasification combined cycle (IGCC) power station located in Spain. The study compares different homogeneous photocatalytic processes on a pilot plant scale using different types of radiation (artificial UV or solar UV with a compound parabolic collector). The efficiency of the processes was evaluated by an analysis of the total organic carbon (TOC) removed. The following processes were considered in the study: (i) a photo-Fenton process at an artificial UV pilot plant (with the initial addition of H(2)O(2)), (ii) a modified photo-Fenton process with continuous addition of H(2)O(2) and O(2) to the system and (iii) a ferrioxalate-assisted solar photo-Fenton process at a compound parabolic collector (CPC) pilot plant. The efficiency of these processes in degrading pollutants has been studied previously, and the results obtained in each of those studies have been published elsewhere. The operational costs due to the consumption of electrical energy, reagents and catalysts were calculated from the optimal conditions of each process. The results showed that the solar photo-Fenton system was economically feasible, being able to achieve up to 75% mineralization with a total cost of 6 €/m(3), which can be reduced to 3.6 €/m(3) by subtracting the electrical costs because the IGCC plant is self-sufficient in terms of energy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Overview of Activities in U.S. Related to Continued Service of Nuclear Power Plant Concrete Structures

International Nuclear Information System (INIS)

Naus, Dan J.

2011-01-01

Safety-related nuclear power plant concrete structures are described and commentary on continued service assessments of these structures is provided. In-service inspection and testing requirements in the U.S. are summarized. The license renewal process in the U.S. is outlined and its current status noted. A summary of operating experience related to U.S. nuclear power plant concrete structures is presented. Several candidate areas are identified where additional research would be of benefit to aging management of NPP concrete structures. Finally current ORNL activities related to aging-management of concrete structures are outlined: development of operating experience database, application of structural reliability theory, and compilation of elevated temperature concrete material property data and information.

Circular linkages between soil biodiversity, fertility and plant productivity are limited to topsoil at the continental scale.

Science.gov (United States)

Delgado-Baquerizo, Manuel; Powell, Jeff R; Hamonts, Kelly; Reith, Frank; Mele, Pauline; Brown, Mark V; Dennis, Paul G; Ferrari, Belinda C; Fitzgerald, Anna; Young, Andrew; Singh, Brajesh K; Bissett, Andrew

2017-08-01

The current theoretical framework suggests that tripartite positive feedback relationships between soil biodiversity, fertility and plant productivity are universal. However, empirical evidence for these relationships at the continental scale and across different soil depths is lacking. We investigate the continental-scale relationships between the diversity of microbial and invertebrate-based soil food webs, fertility and above-ground plant productivity at 289 sites and two soil depths, that is 0-10 and 20-30 cm, across Australia. Soil biodiversity, fertility and plant productivity are strongly positively related in surface soils. Conversely, in the deeper soil layer, the relationships between soil biodiversity, fertility and plant productivity weaken considerably, probably as a result of a reduction in biodiversity and fertility with depth. Further modeling suggested that strong positive associations among soil biodiversity-fertility and fertility-plant productivity are limited to the upper soil layer (0-10 cm), after accounting for key factors, such as distance from the equator, altitude, climate and physicochemical soil properties. These findings highlight the importance of surface soil biodiversity for soil fertility, and suggest that any loss of surface soil could potentially break the links between soil biodiversity-fertility and/or fertility-plant productivity, which can negatively impact nutrient cycling and food production, upon which future generations depend. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Continental-scale water fluxes from continuous GPS observations of Earth surface loading

Science.gov (United States)

Borsa, A. A.; Agnew, D. C.; Cayan, D. R.

2015-12-01

After more than a decade of observing annual oscillations of Earth's surface from seasonal snow and water loading, continuous GPS is now being used to model time-varying terrestrial water fluxes on the local and regional scale. Although the largest signal is typically due to the seasonal hydrological cycle, GPS can also measure subtle surface deformation caused by sustained wet and dry periods, and to estimate the spatial distribution of the underlying terrestrial water storage changes. The next frontier is expanding this analysis to the continental scale and paving the way for incorporating GPS models into the National Climate Assessment and into the observational infrastructure for national water resource management. This will require reconciling GPS observations with predictions from hydrological models and with remote sensing observations from a suite of satellite instruments (e.g. GRACE, SMAP, SWOT). The elastic Earth response which transforms surface loads into vertical and horizontal displacements is also responsible for the contamination of loading observations by tectonic and anthropogenic transients, and we discuss these and other challenges to this new application of GPS.

Impacts of invading alien plant species on water flows at stand and catchment scales

Science.gov (United States)

Le Maitre, D. C.; Gush, M. B.; Dzikiti, S.

2015-01-01

There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300–400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200–300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5–2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. PMID:25935861

Impacts of invading alien plant species on water flows at stand and catchment scales.

Science.gov (United States)

Le Maitre, D C; Gush, M B; Dzikiti, S

2015-05-01

There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300-400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200-300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5-2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. Published by Oxford University Press on behalf of the Annals of Botany

A novel design approach for small scale low enthalpy binary geothermal power plants

International Nuclear Information System (INIS)

Gabbrielli, Roberto

2012-01-01

Highlights: ► Off-design analysis of ORC geothermal power plants through the years and the days. ► Thermal degradation of the geothermal source reduces largely the plant performances. ► The plant capacity factor is low if the brine temperature is far from the design value. ► The performances through the life are more important than those at the design point. ► ORC geothermal power plants should be designed with the end-life brine temperature. - Abstract: In this paper a novel design approach for small scale low enthalpy binary geothermal power plants is proposed. After the suction, the hot water (brine) superheats an organic fluid (R134a) in a Rankine cycle and, then, is injected back underground. This fact causes the well-known thermal degradation of the geothermal resource during the years. Hence, the binary geothermal power plants have to operate with conditions that largely vary during their life and, consequently, the most part of their functioning is executed in off-design conditions. So, as the novel approach here proposed, the design temperature of the geothermal resource is selected between its highest and lowest values, that correspond to the beginning and the end of the operative life of the geothermal power plant, respectively. Hence, using a detailed off-design performance model, the optimal design point of the geothermal power plant is evaluated maximizing the total actualized cash flow from the incentives for renewable power generation. Under different renewable energy incentive scenarios, the power plant that is designed using the lowest temperature of the geothermal resource always results the best option.

Metagenomic binning reveals the functional roles of core abundant microorganisms in twelve full-scale biogas plants

DEFF Research Database (Denmark)

Campanaro, Stefano; Treu, Laura; Kougias, Panagiotis

2018-01-01

and environmental factors on MAGs abundance and to investigate the methanogenic performance of the biogas plants. Prediction of the functional properties of MAGs was obtained analyzing their KEGG pathways and their carbohydrate active domains. Network analysis allowed investigation of species-species associations......The aim of this work was to elucidate the microbial ecology in twelve mesophilic and thermophilic full-scale biogas plants using a genome-centric metagenomic approach. In this study both biogas plants treating manure and those treating sludge from waste water treatment plants were considered...... and shed light on syntrophic interactions between members belonging to the anaerobic digestion dark matter (phylum Fermentibacteria). By stratifying and comparing different levels of information, it was predicted that some MAGs have a crucial role in the manure-supplemented thermophilic biogas plants...

System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

Energy Technology Data Exchange (ETDEWEB)

Edwin A. Harvego; James E. O' Brien; Michael G. McKellar

2012-11-01

Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimization of the design using a detailed process flow sheet and realistic operating conditions specified by the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.

Old Yet New--Pharmaceuticals from Plants

Science.gov (United States)

Houghton, Peter J.

2001-02-01

Plants or their crude extracts have been used since prehistory to treat human ailments. Plants are still used in this way in many parts of the world, but Western scientific medicine has tended to isolate active compounds, or make derivatives of them, for use as drugs. Compounds produced by the plant have been important pharmaceuticals since the isolation of morphine almost two hundred years ago and new naturally occurring compounds such as paclitaxel are continually being introduced commercially. Bioactive molecules may also be produced from chemicals found in plants by chemical modification using synthetic chemistry or microorganisms (as in the production of steroids). A third major contribution of plant chemicals to drugs is their utilization as templates for the design of new compounds made by synthesis (e.g. the discovery of aspirin and related compounds from substances in willow bark). New pharmaceuticals from plants are being discovered by examining traditional medicines and by large-scale bioassay screening processes. In addition, the chemical survival systems of plants that exist in hostile environments are receiving increasing attention as leads to discover active compounds. The knowledge of botanical relationships helps find new sources of known compounds of interest and novel compounds with similar structures from related species. Future prospects for the discovery of new compounds from plants are broadened by the new technologies of gene manipulation, tissue culture, and combinatorial chemistry, so it is very likely that natural products from plants will continue to play an important role in the fight against disease.

Design considerations for a farm-scale biogas plant based on pilot-scale anaerobic digesters loaded with rice straw and piggery wastewater

International Nuclear Information System (INIS)

Mussoline, Wendy; Esposito, Giovanni; Lens, Piet; Garuti, Gilberto; Giordano, Andrea

2012-01-01

Two pilot-scale (1 m 3 ) digesters filled with untreated rice straw and co-digested with raw pig wastewater were operated to obtain design parameters for a farm-scale biogas plant. Both digesters contained 50 kg of dry straw mixed with diluted pig wastewater to create dry digestion conditions (20% TS) and operated for 189 days with leachate recirculation. Digester A was designed for optimum performance (150 L of pig wastewater and mesophilic temperatures) while Digester B was designed to establish minimum inputs (60 L of pig wastewater at ambient temperatures). The pig wastewater provided sufficient buffering capacity to maintain appropriate pH values (between 7.0 and 8.1) and nutrient balances (TOC to TKN ratios of 20 in Digester A and 32 in Digester B). Total biogas production was 22,859 L in Digester A and 1420 L from Digester B, resulting in specific methane yields of 231 and 12 L CH 4 /kgVS added, respectively. Gas production in Digester A was directly correlated with temperature, but the overall lack of methanogenic activity was caused primarily by the reduced wastewater volume. Two theoretical farm-scale scenarios (considering both untreated and pretreated rice straw) were developed for a 100-ha rice farm. Either scenario can produce 100,000 m 3 CH 4 per year, yielding 328 MWh. Major differences including heat input, space requirements, loading frequency, digester volume, engine size, wastewater quantities, and additives are quantitatively defined. The appropriate choice for a farm-scale operation is the simplest model using untreated rice straw without additives, although six times more heat and twice as much reactor volume is required. -- Highlights: ► The co-digestion of untreated rice straw and piggery wastewater is investigated. ► Gas production increases with the volume of pig wastewater added and temperature. ► Pig wastewater alone can provide appropriate buffering capacity and nutrient balance. ► Pilot-scale results are used to establish

Interval Continuous Plant Identification from Value Sets

Directory of Open Access Journals (Sweden)

R. Hernández

2012-01-01

Full Text Available This paper shows how to obtain the values of the numerator and denominator Kharitonov polynomials of an interval plant from its value set at a given frequency. Moreover, it is proven that given a value set, all the assigned polynomials of the vertices can be determined if and only if there is a complete edge or a complete arc lying on a quadrant. This algorithm is nonconservative in the sense that if the value-set boundary of an interval plant is exactly known, and particularly its vertices, then the Kharitonov rectangles are exactly those used to obtain these value sets.

Experimental results and thermodynamic analysis of a natural gas small scale cogeneration plant for power and refrigeration purposes

International Nuclear Information System (INIS)

Bazzo, Edson; Nacif de Carvalho, Alvaro; Matelli, José Alexandre

2013-01-01

In this work, experimental results are reported for a small scale cogeneration plant for power and refrigeration purposes. The plant includes a natural gas microturbine and an ammonia/water absorption chiller fired by steam. The system was tested under different turbine loads, steam pressures and chiller outlet temperatures. An evaluation based on the 1st and 2nd Laws of Thermodynamics was also performed. For the ambient temperature around 24 °C and microturbine at full load, the plant is able to provide 19 kW of saturated steam at 5.3 bar (161 °C), corresponding to 9.2 kW of refrigeration at −5 °C (COP = 0.44). From a 2nd law point-of-view, it was found that there is an optimal chiller outlet temperature that maximizes the chiller exergetic efficiency. As expected, the microturbine presented the highest irreversibilities, followed by the absorption chiller and the HRSG. In order to reduce the plant exergy destruction, it is recommended a new design for the HRSG and a new insulation for the exhaust pipe. -- Highlights: • A small scale cogeneration plant for power and refrigeration is proposed and analyzed. • The plant is based on a microturbine and a modified absorption chiller. • The plant is analysed based on 1st and 2nd laws of thermodynamics. • Experimental results are found for different power and refrigeration conditions. • The plant proved to be technically feasible

Continental-scale patterns of Cecropia reproductive phenology: evidence from herbarium specimens.

Science.gov (United States)

Zalamea, Paul-Camilo; Munoz, François; Stevenson, Pablo R; Paine, C E Timothy; Sarmiento, Carolina; Sabatier, Daniel; Heuret, Patrick

2011-08-22

Plant phenology is concerned with the timing of recurring biological events. Though phenology has traditionally been studied using intensive surveys of a local flora, results from such surveys are difficult to generalize to broader spatial scales. In this study, contrastingly, we assembled a continental-scale dataset of herbarium specimens for the emblematic genus of Neotropical pioneer trees, Cecropia, and applied Fourier spectral and cospectral analyses to investigate the reproductive phenology of 35 species. We detected significant annual, sub-annual and continuous patterns, and discuss the variation in patterns within and among climatic regions. Although previous studies have suggested that pioneer species generally produce flowers continually throughout the year, we found that at least one third of Cecropia species are characterized by clear annual flowering behaviour. We further investigated the relationships between phenology and climate seasonality, showing strong associations between phenology and seasonal variations in precipitation and temperature. We also verified our results against field survey data gathered from the literature. Our findings indicate that herbarium material is a reliable resource for use in the investigation of large-scale patterns in plant phenology, offering a promising complement to local intensive field studies.

Properties and Performance of SOFCs Produced on a Pre-Pilot Plant Scale

DEFF Research Database (Denmark)

Hagen, Anke; Menon, Mohan; Barfod, Rasmus

2006-01-01

specific cell resistance at 850 °C was found to be 0.24 Ω cm2 with a standard deviation of 0.05 Ω cm2. The variation in performance between the cells can be largely attributed to variations in the cathode performance. Experimental evidence will be presented on full 4 × 4 cm2 cells, symmetric cells with two......In the present paper, anode supported solid oxide fuel cells (SOFCs), produced on a pre-pilot plant scale in ten batches of ∼100 cells, are characterised with respect to performance. The main purpose was to evaluate the reproducibility of the scaled-up process. Based on 20 tests, the average area...

Construction of scales to measure leadership behavior at nuclear power plants. 2

Energy Technology Data Exchange (ETDEWEB)

Misumi, Jyuji; Yamada, Akira [Institute of Nuclear Safety System Inc., Kyoto (Japan); Shinohara, Shinobu [and others

1994-05-01

We tried to construct the PM leadership behavior measuring scales at nuclear power plants. In our factor analysis of leadership types of shift supervisors, maintenance and repair subsection chiefs and sub contractors` field leaders, three factors respectively were found. In the leadership scales for shift supervisors, the first factor was named the factor of group maintenance, the second factor was named the factor of directive-order for goal achievement and the third factor was named the factor of specialty for goal achievement. For maintenance and repair subsection chiefs, the first factor was named the factor of directive-order for goal achievement, and second factor was named the factor of group maintenance and the third factor was named the factor of rigidity-pressure for goal achievement. For subcontractors` leaders, the first factor was named the factor of directive-specialty for goal achievement, the second factor named the factor of group maintenance and the third factor was named the factor of rigidity-pressure for achievement. We constructed PM leadership measuring scales for each advisory position and verified its validity by using workplace `morale`-(satisfaction, etc.) as a subordinate variable. Also, in regard to the distribution of scales, we verified the validity of distance scales by examining it by Quantification III. (author)

Construction of scales to measure leadership behavior at nuclear power plants. 2

International Nuclear Information System (INIS)

Misumi, Jyuji; Yamada, Akira; Shinohara, Shinobu

1994-01-01

We tried to construct the PM leadership behavior measuring scales at nuclear power plants. In our factor analysis of leadership types of shift supervisors, maintenance and repair subsection chiefs and sub contractors' field leaders, three factors respectively were found. In the leadership scales for shift supervisors, the first factor was named the factor of group maintenance, the second factor was named the factor of directive-order for goal achievement and the third factor was named the factor of specialty for goal achievement. For maintenance and repair subsection chiefs, the first factor was named the factor of directive-order for goal achievement, and second factor was named the factor of group maintenance and the third factor was named the factor of rigidity-pressure for goal achievement. For subcontractors' leaders, the first factor was named the factor of directive-specialty for goal achievement, the second factor named the factor of group maintenance and the third factor was named the factor of rigidity-pressure for achievement. We constructed PM leadership measuring scales for each advisory position and verified its validity by using workplace 'morale'-(satisfaction, etc.) as a subordinate variable. Also, in regard to the distribution of scales, we verified the validity of distance scales by examining it by Quantification III. (author)

Project final report: Energetic planning focusing small scale hydroelectric power plants; Relatorio final. Projeto planejamento energetico com enfase em pequenas centrais hidreletricas

Energy Technology Data Exchange (ETDEWEB)

Costa, Yara dos Santos

1994-12-31

Considering the increasing need for a better utilization of the Brazilian hydric resources, a deeper analysis of small scale hydroelectric power plants has been demanding. This work presents a case study of energetic planning based upon small scale hydroelectric power plants in a district of Amazon state - North Brazil 8 refs., 11 figs., 19 tabs.

Water use, productivity and interactions among desert plants

Energy Technology Data Exchange (ETDEWEB)

Ehleringer, J.R.

1992-11-17

Water plays a central role affecting all aspects of the dynamics in aridland ecosystems. Productivity, stability, and competitive interactions among ecosystem components within aridlands are key processes related directly to water in deserts. The ecological studies in this project revolve around one fundamental premise: that integrated aspects of plant metabolism provide insight into the structure and function of plant communities and ecosystems. While it is difficult to extrapolate from instantaneous physiological observations to higher scales, such as whole plant performance or to interactions between plants as components of ecosystems, several key aspects of plant metabolism are scalable. Analyses of stable isotopic composition in plant tissues at natural abundance levels provide a useful tool that can provide insight into the consequences of physiological processes over temporal and spatial scales. Some plant processes continuously fractionate among light and heavy stable isotopic forms of an element; over time this results in integrated measures of plant metabolism. For example, carbon isotope fractionation during photosynthesis results in leaf carbon isotopic composition that is a measure of the set-point for photosynthetic metabolism and of water-use efficiency. Thus it provides information on the temporal scaling of a key physiological process. In contrast, hydrogen is not fractionated during water uptake through the root. Soil water availability in shallow, deep, and/or groundwater layers vary spatially; therefore hydrogen isotope ratios of xylem sap provide a direct measure of the water source currently used by a plant. The longer-term record of carbon and hydrogen isotope ratios is recorded annually in xylem tissues (tree rings). The research in this project addresses variation in stable isotopic composition of aridland plants and its consequences for plant performance and community-level interactions.

PERFORM 60 - Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

Science.gov (United States)

Leclercq, Sylvain; Lidbury, David; Van Dyck, Steven; Moinereau, Dominique; Alamo, Ana; Mazouzi, Abdou Al

2010-11-01

In nuclear power plants, materials may undergo degradation due to severe irradiation conditions that may limit their operational life. Utilities that operate these reactors need to quantify the ageing and the potential degradations of some essential structures of the power plant to ensure safe and reliable plant operation. So far, the material databases needed to take account of these degradations in the design and safe operation of installations mainly rely on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and continuous progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the effects of irradiation on materials microstructure. A first step towards this goal has been successfully reached through the development of the RPV-2 and Toughness Module numerical tools by the scientific community created around the FP6 PERFECT project. These tools allow to simulate irradiation effects on the constitutive behaviour of the reactor pressure vessel low alloy steel, and also on its failure properties. Relying on the existing PERFECT Roadmap, the 4 years Collaborative Project PERFORM 60 has mainly for objective to develop multi-scale tools aimed at predicting the combined effects of irradiation and corrosion on internals (austenitic stainless steels) and also to improve existing ones on RPV (bainitic steels). PERFORM 60 is based on two technical sub-projects: (i) RPV and (ii) internals. In addition to these technical sub-projects, the Users' Group and Training sub-project shall allow representatives of constructors, utilities, research organizations… from Europe, USA and Japan to receive the information and training to get their own appraisal on limits and potentialities of the developed tools. An important effort will also be made to teach young

PERFORM 60 - Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

Energy Technology Data Exchange (ETDEWEB)

Leclercq, Sylvain, E-mail: sylvain.leclercq@edf.f [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France); Lidbury, David [SERCO Assurance - Walton House, 404 Faraday Street, Birchwood Park, Warrington, Cheshire WA3 6GA (United Kingdom); Van Dyck, Steven [SCK-CEN, Nuclear Material Science, Boeretang 200, BE, 2400 Mol (Belgium); Moinereau, Dominique [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France); Alamo, Ana [CEA Saclay, DEN/DSOE, 91191 Gif-sur-Yvette (France); Mazouzi, Abdou Al [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France)

2010-11-01

In nuclear power plants, materials may undergo degradation due to severe irradiation conditions that may limit their operational life. Utilities that operate these reactors need to quantify the ageing and the potential degradations of some essential structures of the power plant to ensure safe and reliable plant operation. So far, the material databases needed to take account of these degradations in the design and safe operation of installations mainly rely on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and continuous progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the effects of irradiation on materials microstructure. A first step towards this goal has been successfully reached through the development of the RPV-2 and Toughness Module numerical tools by the scientific community created around the FP6 PERFECT project. These tools allow to simulate irradiation effects on the constitutive behaviour of the reactor pressure vessel low alloy steel, and also on its failure properties. Relying on the existing PERFECT Roadmap, the 4 years Collaborative Project PERFORM 60 has mainly for objective to develop multi-scale tools aimed at predicting the combined effects of irradiation and corrosion on internals (austenitic stainless steels) and also to improve existing ones on RPV (bainitic steels). PERFORM 60 is based on two technical sub-projects: (i) RPV and (ii) internals. In addition to these technical sub-projects, the Users' Group and Training sub-project shall allow representatives of constructors, utilities, research organizations... from Europe, USA and Japan to receive the information and training to get their own appraisal on limits and potentialities of the developed tools. An important effort will also be made to teach

Interpreting Carbon Fluxes from a Spatially Heterogeneous Peatland with Thawing Permafrost: Scaling from Plant Community Scale to Ecosystem Scale

Science.gov (United States)

Harder, S. R.; Roulet, N. T.; Strachan, I. B.; Crill, P. M.; Persson, A.; Pelletier, L.; Watt, C.

2014-12-01

Various microforms, created by spatial differential thawing of permafrost, make up the subarctic heterogeneous Stordalen peatland complex (68°22'N, 19°03'E), near Abisko, Sweden. This results in significantly different peatland vegetation communities across short distances, as well as differences in wetness, temperature and peat substrates. We have been measuring the spatially integrated CO2, heat and water vapour fluxes from this peatland complex using eddy covariance and the CO2 exchange from specific plant communities within the EC tower footprint since spring 2008. With this data we are examining if it is possible to derive the spatially integrated ecosystem-wide fluxes from community-level simple light use efficiency (LUE) and ecosystem respiration (ER) models. These models have been developed using several years of continuous autochamber flux measurements for the three major plant functional types (PFTs) as well as knowledge of the spatial variability of the vegetation, water table and active layer depths. LIDAR was used to produce a 1 m resolution digital evaluation model of the complex and the spatial distribution of PFTs was obtained from concurrent high-resolution digital colour air photography trained from vegetation surveys. Continuous water table depths have been measured for four years at over 40 locations in the complex, and peat temperatures and active layer depths are surveyed every 10 days at more than 100 locations. The EC footprint is calculated for every half-hour and the PFT based models are run with the corresponding environmental variables weighted for the PFTs within the EC footprint. Our results show that the Sphagnum, palsa, and sedge PFTs have distinctly different LUE models, and that the tower fluxes are dominated by a blend of the Sphagnum and palsa PFTs. We also see a distinctly different energy partitioning between the fetches containing intact palsa and those with thawed palsa: the evaporative efficiency is higher and the Bowen

Electric Energy Consumption of the Full Scale Research Biogas Plant “Unterer Lindenhof”: Results of Longterm and Full Detail Measurements

Directory of Open Access Journals (Sweden)

Thomas Jungbluth

2012-12-01

Full Text Available This work thoroughly evaluates the electric power consumption of a full scale, 3 × 923 m3 complete stirred tank reactor (CSTR research biogas plant with a production capacity of 186 kW of electric power. The plant was fed with a mixture of livestock manure and renewable energy crops and was operated under mesophilic conditions. This paper will provide an insight into precise electric energy consumption measurements of a full scale biogas plant over a period of two years. The results showed that a percentage of 8.5% (in 2010 and 8.7% (in 2011 of the produced electric energy was consumed by the combined heat and power unit (CHP, which was required to operate the biogas plant. The consumer unit agitators with 4.3% (in 2010 and 4.0% (in 2011 and CHP unit with 2.5% (in 2010 and 2011 accounted for the highest electrical power demand, in relation to the electric energy produced by the CHP unit. Calculations show that 51% (in 2010 and 46% (in 2011 of the total electric energy demand was due to the agitators. The results finally showed the need for permanent measurements to identify and quantify the electric energy saving potentials of full scale biogas plants.

Scale and scaling in agronomy and environmental sciences

Science.gov (United States)

Scale is of paramount importance in environmental studies, engineering, and design. The unique course covers the following topics: scale and scaling, methods and theories, scaling in soils and other porous media, scaling in plants and crops; scaling in landscapes and watersheds, and scaling in agro...

Spatially continuous dataset at local scale of Taita Hills in Kenya and Mount Kilimanjaro in Tanzania

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Sizah Mwalusepo

2016-09-01

Full Text Available Climate change is a global concern, requiring local scale spatially continuous dataset and modeling of meteorological variables. This dataset article provided the interpolated temperature, rainfall and relative humidity dataset at local scale along Taita Hills and Mount Kilimanjaro altitudinal gradients in Kenya and Tanzania, respectively. The temperature and relative humidity were recorded hourly using automatic onset THHOBO data loggers and rainfall was recorded daily using GENERALR wireless rain gauges. Thin plate spline (TPS was used to interpolate, with the degree of data smoothing determined by minimizing the generalized cross validation. The dataset provide information on the status of the current climatic conditions along the two mountainous altitudinal gradients in Kenya and Tanzania. The dataset will, thus, enhance future research. Keywords: Spatial climate data, Climate change, Modeling, Local scale

Continuing the service of aging concrete structures in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Oland, C.B.; Arndt, E.G.

1993-01-01

Concrete structures play a vital role in the safe operation of all light-water reactor plants because they provide foundation, support, shielding and containment functions. History tells us that concrete is a durable material. However, a number of factors can compromise its performance, singly or in combination: (1) faulty design, (2) use of unsuitable materials, (3) improper workmanship, (4) exposure to aggressive environments, and (5) excessive structural loads. Furthermore, aging of nuclear power plant (NPP) concrete structures occurs with the passage of time and has the potential, if its effects are not controlled, to increase the risk to public health and safety. Although limited, incidences of degradation of concrete structures in NPPs indicate that there is a need for improved surveillance, inspection/testing, and maintenance to enhance the technical bases for assurance of continued safe operation of NPPs. Guidelines and criteria for use in evaluating the remaining structural margins (residual life) are required. Potential regulatory applications of this research include: improved predictions of long-term material and structural performance and available safety margins at future times; establishment of limits on exposure to environmental stressors; reduction in total reliance by licensing on inspection and surveillance through development of a methodology which will enable the integrity of structures to be assessed (either pre- or post-accident); and improvements in damage inspection methodology through potential incorporation of results into national standards which could be referenced by standard review plans

Zero Discharge Performance of an Industrial Pilot-Scale Plant Treating Palm Oil Mill Effluent

Directory of Open Access Journals (Sweden)

Jin Wang

2015-01-01

Full Text Available Palm oil is one of the most important agroindustries in Malaysia. Huge quantities of palm oil mill effluent (POME pose a great threat to aqueous environment due to its very high COD. To make full use of discharged wastes, the integrated “zero discharge” pilot-scale industrial plant comprising “pretreatment-anaerobic and aerobic process-membrane separation” was continuously operated for 1 year. After pretreatment in the oil separator tank, 55.6% of waste oil in raw POME could be recovered and sold and anaerobically digested through 2 AnaEG reactors followed by a dissolved air flotation (DAF; average COD reduced to about 3587 mg/L, and biogas production was 27.65 times POME injection which was used to generate electricity. The aerobic effluent was settled for 3 h or/and treated in MBR which could remove BOD3 (30°C to less than 20 mg/L as required by Department of Environment of Malaysia. After filtration by UF and RO membrane, all organic compounds and most of the salts were removed; RO permeate could be reused as the boiler feed water. RO concentrate combined with anaerobic surplus sludge could be used as biofertilizer.

Zero Discharge Performance of an Industrial Pilot-Scale Plant Treating Palm Oil Mill Effluent

Science.gov (United States)

Mahmood, Qaisar; Qiu, Jiang-Ping; Li, Yin-Sheng; Chang, Yoon-Seong; Chi, Li-Na; Li, Xu-Dong

2015-01-01

Palm oil is one of the most important agroindustries in Malaysia. Huge quantities of palm oil mill effluent (POME) pose a great threat to aqueous environment due to its very high COD. To make full use of discharged wastes, the integrated “zero discharge” pilot-scale industrial plant comprising “pretreatment-anaerobic and aerobic process-membrane separation” was continuously operated for 1 year. After pretreatment in the oil separator tank, 55.6% of waste oil in raw POME could be recovered and sold and anaerobically digested through 2 AnaEG reactors followed by a dissolved air flotation (DAF); average COD reduced to about 3587 mg/L, and biogas production was 27.65 times POME injection which was used to generate electricity. The aerobic effluent was settled for 3 h or/and treated in MBR which could remove BOD3 (30°C) to less than 20 mg/L as required by Department of Environment of Malaysia. After filtration by UF and RO membrane, all organic compounds and most of the salts were removed; RO permeate could be reused as the boiler feed water. RO concentrate combined with anaerobic surplus sludge could be used as biofertilizer. PMID:25685798

Large-Scale Combined Heat and Power (CHP) Generation at Loviisa Nuclear Power Plant Unit 3

International Nuclear Information System (INIS)

Bergroth, N.

2010-01-01

Fortum has applied for a Decision in Principle concerning the construction of a new nuclear power plant unit (Loviisa 3) ranging from 2800-4600 MWth at its site located at the southern coast of Finland. An attractive alternative investigated is a co-generation plant designed for large-scale district heat generation for the Helsinki metropolitan area that is located approximately 75 km west of the site. The starting point is that the district heat generation capacity of 3 unit would be around 1 000 MWth.The possibility of generating district heat for the metropolitan area by Loviisa's two existing nuclear power plant units was investigated back in the 1980s, but it proved unpractical at the time. With the growing concern of the climate change and the subsequent requirements on heat and power generation, the idea is much more attractive today, when recognising its potential to decrease Finland's carbon dioxide emissions significantly. Currently the district heat generation in metropolitan area is based on coal and natural gas, producing some five to seven million tonnes of carbon dioxide emissions annually. Large-scale combined heat and power (CHP) generation at the 3 unit could cut this figure by up to four million tonnes. This would decrease carbon dioxide emissions by as much as six percent. In addition, large-scale CHP generation would increase the overall efficiency of the new unit significantly and hence, reduce the environmental impact on the local marine environment by cutting heat discharges into the Gulf of Nuclear energy has been used for district heating in several countries both in dedicated nuclear heating plants and in CHP generation plants. However, the heat generation capacity is usually rather limited, maximum being around 250 MWth per unit. Set against this, the 3 CHP concept is much more ambitious, not only because of the much larger heat generation output envisaged, but also because the district heating water would have to be transported over a

Intensive land use drives small-scale homogenization of plant- and leafhopper communities and promotes generalists.

Science.gov (United States)

Chisté, Melanie N; Mody, Karsten; Kunz, Gernot; Gunczy, Johanna; Blüthgen, Nico

2018-02-01

The current biodiversity decline through anthropogenic land-use not only involves local species losses, but also homogenization of communities, with a few generalist species benefitting most from human activities. Most studies assessed community heterogeneity (β-diversity) on larger scales by comparing different sites, but little is known about impacts on β-diversity within each site, which is relevant for understanding variation in the level of α-diversity, the small-scale distribution of species and associated habitat heterogeneity. To obtain our dataset with 36,899 individuals out of 117 different plant- and leafhopper (Auchenorrhyncha) species, we sampled communities of 140 managed grassland sites across Germany by quantitative vacuum suction of five 1 m 2 plots on each site. Sites differed in land-use intensity as characterized by intensity of fertilization, mowing and grazing. Our results demonstrate a significant within-site homogenization of plant- and leafhopper communities with increasing land-use intensity. Correspondingly, density (- 78%) and γ-diversity (- 35%) declined, particularly with fertilization and mowing intensity. More than 34% of plant- and leafhopper species were significant losers and only 6% were winners of high land-use intensity, with abundant and widespread species being less affected. Increasing land-use intensity adversely affected dietary specialists and promoted generalist species. Our study emphasizes considerable, multifaceted effects of land-use intensification on species loss, with a few dominant generalists winning, and an emerging trend towards more homogenized assemblages. By demonstrating homogenization for the first time within sites, our study highlights that anthropogenic influences on biodiversity even occur on small scales.

Removal of Iron Oxide Scale from Feed-water in Thermal Power Plant by Using Magnetic Separation

Science.gov (United States)

Nakanishi, Motohiro; Shibatani, Saori; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

2017-09-01

One of the factors of deterioration in thermal power generation efficiency is adhesion of the scale to inner wall in feed-water system. Though thermal power plants have employed All Volatile Treatment (AVT) or Oxygen Treatment (OT) to prevent scale formation, these treatments cannot prevent it completely. In order to remove iron oxide scale, we proposed magnetic separation system using solenoidal superconducting magnet. Magnetic separation efficiency is influenced by component and morphology of scale which changes their property depending on the type of water treatment and temperature. In this study, we estimated component and morphology of iron oxide scale at each equipment in the feed-water system by analyzing simulated scale generated in the pressure vessel at 320 K to 550 K. Based on the results, we considered installation sites of the magnetic separation system.

Waste Isolation Pilot Plant Dry Bin-Scale Integrated Systems Checkout Plan

International Nuclear Information System (INIS)

1991-04-01

In order to determine the long-term performance of the Waste Isolation Pilot Plant (WIPP) disposal system, in accordance with the requirements of the US Environmental Protection Agency (EPA) Standard 40 CFR 191, Subpart B, Sections 13 and 15, two performance assessment tests will be conducted. The tests are titled WIPP Bin-Scale Contact Handled (CH) Transuranic (TRU) Waste Tests and WIPP In Situ Alcove CH TRU Waste Tests. These tests are designed to measure the gas generation characteristics of CH TRU waste. Much of the waste will be specially prepared to provide data for a better understanding of the interactions due to differing degradation modes, waste forms, and repository environmental affects. The bin-scale test is designed to emplace nominally 146 bins. The majority of the bins will contain various forms of waste. Eight bins will be used as reference bins and will contain no waste. This checkout plan exercises the systems, operating procedures, and training readiness of personnel to safely carry out those specifically dedicated activities associated with conducting the bin-scale test plan for dry bins only. The plan does not address the entire WIPP facility readiness state. 18 refs., 6 figs., 3 tabs

Long-term N and P additions alter the scaling of plant nitrogen to phosphorus in a Tibetan alpine meadow.

Science.gov (United States)

Zhang, Juanjuan; Yan, Xuebin; Su, Fanglong; Li, Zhen; Wang, Ying; Wei, Yanan; Ji, Yangguang; Yang, Yi; Zhou, Xianhui; Guo, Hui; Hu, Shuijin

2018-06-01

Nitrogen and phosphorus are two important nutrient elements for plants. The current paradigm suggests that the scaling of plant tissue N to P is conserved across environments and plant taxa because these two elements are coupled and coordinately change with each other following a constant allometric trajectory. However, this assumption has not been vigorously examined, particularly in changing N and P environments. We propose that changes in relative availability of N and P in soil alter the N to P relationship in plants. Taking advantage of a 4-yr N and P addition experiment in a Tibetan alpine meadow, we examined changes in plant N and P concentrations of 14 common species. Our results showed that while the scaling of N to P under N additions was similar to the previously reported pattern with a uniform 2/3 slope of the regression between log N and log P, it was significantly different under P additions with a smaller slope. Also, graminoids had different responses from forbs. These results indicate that the relative availability of soil N and P is an important determinant regulating the N and P concentrations in plants. These findings suggest that alterations in the N to P relationships may not only alter plant photosynthate allocation to vegetative or reproductive organs, but also regulate the metabolic and growth rate of plant and promote shifts in plant community composition in a changing nutrient loading environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Macro optical projection tomography for large scale 3D imaging of plant structures and gene activity.

Science.gov (United States)

Lee, Karen J I; Calder, Grant M; Hindle, Christopher R; Newman, Jacob L; Robinson, Simon N; Avondo, Jerome J H Y; Coen, Enrico S

2017-01-01

Optical projection tomography (OPT) is a well-established method for visualising gene activity in plants and animals. However, a limitation of conventional OPT is that the specimen upper size limit precludes its application to larger structures. To address this problem we constructed a macro version called Macro OPT (M-OPT). We apply M-OPT to 3D live imaging of gene activity in growing whole plants and to visualise structural morphology in large optically cleared plant and insect specimens up to 60 mm tall and 45 mm deep. We also show how M-OPT can be used to image gene expression domains in 3D within fixed tissue and to visualise gene activity in 3D in clones of growing young whole Arabidopsis plants. A further application of M-OPT is to visualise plant-insect interactions. Thus M-OPT provides an effective 3D imaging platform that allows the study of gene activity, internal plant structures and plant-insect interactions at a macroscopic scale. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Determination Total Phosphour of Maize Plant Samples by Continuous Flow Analyzer in Comparison with Vanadium Molybdate Yellow Colorimetric Method

OpenAIRE

LIU Yun-xia; WEN Yun-jie; HUANG Jin-li; LI Gui-hua; CHAI Xiao; WANG Hong

2015-01-01

The vanadium molybdate yellow colorimetric method(VMYC method) is regarded as one of conventional methods for determining total phosphorus(P) in plants, but it is time consuming procedure. Continuous flow analyzer(CFA) is a fluid stream segmentation technique with air segments. It is used to measure P concentration based on the molybdate-antimony-ascorbic acid method of Murphy and Riley. Sixty nine of maize plant samples were selected and digested with H2SO4-H2O2. P concentrations in the dige...

Fine-scale spatial genetic structure in predominantly selfing plants with limited seed dispersal: A rule or exception?

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Sergei Volis

2016-04-01

Full Text Available Gene flow at a fine scale is still poorly understood despite its recognized importance for plant population demographic and genetic processes. We tested the hypothesis that intensity of gene flow will be lower and strength of spatial genetic structure (SGS will be higher in more peripheral populations because of lower population density. The study was performed on the predominantly selfing Avena sterilis and included: (1 direct measurement of dispersal in a controlled environment; and (2 analyses of SGS in three natural populations, sampled in linear transects at fixed increasing inter-plant distances. We found that in A. sterilis major seed dispersal is by gravity in close (less than 2 m vicinity of the mother plant, with a minor additional effect of wind. Analysis of SGS with six nuclear SSRs revealed a significant autocorrelation for the distance class of 1 m only in the most peripheral desert population, while in the two core populations with Mediterranean conditions, no genetic structure was found. Our results support the hypothesis that intensity of SGS increases from the species core to periphery as a result of decreased within-population gene flow related to low plant density. Our findings also show that predominant self-pollination and highly localized seed dispersal lead to SGS at a very fine scale, but only if plant density is not too high.

Effect of water purification process in radioactive content: analysis on small scale purification plants

International Nuclear Information System (INIS)

Lopez del Rio, H.; Quiroga S, J. C.; Davila R, J. I.; Mireles G, F.

2009-10-01

Water from small scale purification plants is a low cost alternative for consumers in comparison to the bottled commercial presentations. Because of its low cost per liter, the consumption of this product has increased in recent years, stimulating in turn the installation of purification systems for these small businesses. The purpose of this study was to estimate the efficiency of small scale purification systems located in the cities of Zacatecas and Guadalupe, Zacatecas, to reduce the radioactive content of water. It was measured the total alpha and beta activity in water samples of entry and exit to process, through the liquid scintillation technique. In general it was observed that the process is more efficient in removing alpha that beta activity. The fraction of total alpha activity removed varied between 27 and 100%, while between 0 and 77% of the total beta activity was removed by the analyzed plants. In all cases, the total radioactivity level was lower than the maximum permissible value settled by the official mexican standard for drinking water. (Author)

Allometric convergence in savanna trees and implications for the use of plant scaling models in variable ecosystems.

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Andrew T Tredennick

Full Text Available Theoretical models of allometric scaling provide frameworks for understanding and predicting how and why the morphology and function of organisms vary with scale. It remains unclear, however, if the predictions of 'universal' scaling models for vascular plants hold across diverse species in variable environments. Phenomena such as competition and disturbance may drive allometric scaling relationships away from theoretical predictions based on an optimized tree. Here, we use a hierarchical Bayesian approach to calculate tree-specific, species-specific, and 'global' (i.e. interspecific scaling exponents for several allometric relationships using tree- and branch-level data harvested from three savanna sites across a rainfall gradient in Mali, West Africa. We use these exponents to provide a rigorous test of three plant scaling models (Metabolic Scaling Theory (MST, Geometric Similarity, and Stress Similarity in savanna systems. For the allometric relationships we evaluated (diameter vs. length, aboveground mass, stem mass, and leaf mass the empirically calculated exponents broadly overlapped among species from diverse environments, except for the scaling exponents for length, which increased with tree cover and density. When we compare empirical scaling exponents to the theoretical predictions from the three models we find MST predictions are most consistent with our observed allometries. In those situations where observations are inconsistent with MST we find that departure from theory corresponds with expected tradeoffs related to disturbance and competitive interactions. We hypothesize savanna trees have greater length-scaling exponents than predicted by MST due to an evolutionary tradeoff between fire escape and optimization of mechanical stability and internal resource transport. Future research on the drivers of systematic allometric variation could reconcile the differences between observed scaling relationships in variable ecosystems and

Development and Preliminary Validation of the Scale for Evaluation of Psychiatric Integrative and Continuous Care—Patient’s Version

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Yuriy Ignatyev

2017-08-01

Full Text Available This pilot study aimed to evaluate and examine an instrument that integrates relevant aspects of cross-sectoral (in- and outpatients mental health care, is simply to use and shows satisfactory psychometric properties. The development of the scale comprised literature research, held 14 focus groups and 12 interviews with patients and health care providers, item-pool generation, content validation by a scientific expert panel, and face validation by 90 patients. The preliminary scale was tested on 385 patients across seven German hospitals with cross-sectoral mental health care (CSMHC as part of their treatment program. Psychometric properties of the scale were evaluated using genuine and transformed data scoring. To check reliability and postdictive validity of the scale, Cronbach’s α coefficient and multivariable linear regression were used. This development process led to the development of an 18-item scale called the “Scale for Evaluation of Psychiatric Integrative and Continuous Care (SEPICC” with a two-point and five-point response options. The scale consists of two sections. The first section assesses the presence or absence of patients’ experiences with various CSMHC’ relevant components such as home treatment, flexibility of treatments’ switching, case management, continuity of care, cross-sectoral therapeutic groups, and multidisciplinary teams. The second section evaluates the patients’ opinions about these relevant components. Using raw and transformed scoring resulted into comparable results. However, data distribution using transformed scoring showed a smaller deviation from normality. For the overall scale, the Cronbach’s α coefficient was 0.82. Self-reported experiences with relevant components of the CSMHC were positively associated with the patients approval of these components. In conclusion, the new scale provides a good starting point for further validation. It can be used as a tool to evaluate CSMHC

Continuous acid dew point measurement in coal-fired power plants; Kontinuierliche Saeuretaupunktmessung in Braunkohlekraftwerken

Energy Technology Data Exchange (ETDEWEB)

Foedisch, Holger; Schulz, Joerg; Schengber, Petra; Dietrich, Gabriele [Dr. Foedisch Umweltmesstechnik AG, Markranstaedt (Germany)

2009-07-01

The reduction of flue gas losses is one option to increase power plant efficiency. The target is the optimised low waste gas temperature. When applying lignite and other high-sulphur fuels the temperature of the flue gas is mainly determined by the acid dew point. Temperature of the flue gas system is to amount some 10 to 20 K above the assumed acid dew point. The acid dew point measuring system AMD 08 is able to detect the real acid dew point in a quasi-continuous way. Thus, it is possible to deliberately decrease waste gas temperature. (orig.)

Industrial scale-plant for HLW partitioning in Russia

International Nuclear Information System (INIS)

Dzekun, E.G.; Glagolenko, Y.V.; Drojko, E.G.; Kurochkin, A.I.

1996-01-01

Radiochemical plant of PA > at Ozersk, which was come on line in December 1948 originally for weapon plutonium production and reoriented on the reprocessing of spent fuel, till now keeps on storage HLW of the military program. Application of the vitrification method since 1986 has not essentially reduced HLW volumes. So, as of September 1, 1995 vitrification installations had been processed 9590 m 3 HLW and 235 MCi of radionuclides was included in glass. However only 1100 m 3 and 20.5 MCi is part of waste of the military program. The reason is the fact, that the technology and equipment of vitrification were developed for current waste of Purex-process, for which low contents of corrosion-dangerous impurity to materials of vitrification installation is characteristic of. With reference to HLW, which are growing at PA > in the course of weapon plutonium production, the program of Science-Research Works includes the following main directions of work. Development of technology and equipment of installations for immobilising HLW with high contents of impurity into a solid form at induction melter. Application of High-temperature Adsorption Method for sorption of radionuclides from HLW on silica gel. Application of Partitioning Method of radionuclides from HLW, based on extraction cesium and strontium into cobalt dicarbollyde or crown-ethers, but also on recovery of cesium radionuclides by sorption on inorganic sorbents. In this paper the results of work on creation of first industrial scale-plant for partitioning HLW by the extraction and sorption methods are reported

Commissioning and operating experience of compressed air system of a reprocessing plant (Paper No. 5.10)

International Nuclear Information System (INIS)

Nair, M.K.T.; Bajpai, D.D.; Mishra, A.K.; Kulkarni, H.B.; Raje, R.V.; Rajeshwar, S.

1992-01-01

Compressed air system is one of the most important utility systems, required in the continued operation of a radiochemical plant. Moisture and oil free compressed air is used in large scale for process control and process operations in reprocessing plants. Commissioning and operating experience of this system is described in detail, to indicate the importance of the system in the overall design and operation of such chemical plant. (author). 1 tab

Micro-scale energy valorization of grape marcs in winery production plants.

Science.gov (United States)

Fabbri, Andrea; Bonifazi, Giuseppe; Serranti, Silvia

2015-02-01

The Biochemical Methane Potential (BMP) of winery organic waste, with reference to two Italian red and white grapes (i.e. Nero Buono and Greco) by-products was investigated. The study was carried out to verify the possibility to reduce the production impact in a green-waste-management-chain-perspective. The possibility to efficiently utilize wine-related-by-products for energy production at a micro-scale (i.e. small-medium scale winery production plant) was also verified. Results showed as a good correlation can be established between the percentage of COD removal and the biogas production, as the winery can produce, from its waste methanization, about 7800 kW h year(-1) electrical and 8900 kW h year(-1) thermal. A critical evaluation was performed about the possibility to utilize the proposed approach to realize an optimal biomass waste management and an energetic valorization in a local-energy-production-perspective. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhancement of struvite pellets crystallization in a full-scale plant using an industrial grade magnesium product.

Science.gov (United States)

Crutchik, D; Morales, N; Vázquez-Padín, J R; Garrido, J M

2017-02-01

A full-scale struvite crystallization system was operated for the treatment of the centrate obtained from the sludge anaerobic digester in a municipal wastewater treatment plant. Additionally, the feasibility of an industrial grade Mg(OH) 2 as a cheap magnesium and alkali source was also investigated. The struvite crystallization plant was operated for two different periods: period I, in which an influent with low phosphate concentration (34.0 mg P·L -1 ) was fed to the crystallization plant; and period II, in which an influent with higher phosphate concentration (68.0 mg P·L -1 ) was used. A high efficiency of phosphorus recovery by struvite crystallization was obtained, even when the effluent treated had a high level of alkalinity. Phosphorus recovery percentage was around 77%, with a phosphate concentration in the effluent between 10.0 and 30.0 mg P·L -1 . The experiments gained struvite pellets of 0.5-5.0 mm size. Moreover, the consumption of Mg(OH) 2 was estimated at 1.5 mol Mg added·mol P recovered -1 . Thus, industrial grade Mg(OH) 2 can be an economical alternative as magnesium and alkali sources for struvite crystallization at industrial scale.

Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

Science.gov (United States)

Jolley, Katherine E

2015-01-01

Summary The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72–100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates. PMID:26734089

Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

Directory of Open Access Journals (Sweden)

A. John Blacker

2015-12-01

Full Text Available The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72–100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates.

Synthesis in pilot plant scale and physical properties of sulfonated polystyrene

Directory of Open Access Journals (Sweden)

Martins Cristiane R.

2003-01-01

Full Text Available The homogenous sulfonation of polystyrene was developed in a pilot plant scale producing polymers with different sulfonation degrees (18 to 22 mole % of sulfonated styrene units. The reaction yield depends chiefly on the concentration ratio of acetyl sulfate and polystyrene. The morphological and thermal properties of the sulfonated polystyrene obtained by homogeneous sulfonation were studied by means of scanning electron microscopy, differential scanning calorimetry and thermogravimetry. The glass transition temperature of sulfonated polystyrene increases in relation to pure polystyrene and DCp was evaluated in order to confirm the strong interactions among the ~SO3H groups.

Continuous bench-scale slurry catalyst testing direct coal liquefaction rawhide sub-bituminous coal

Energy Technology Data Exchange (ETDEWEB)

Bauman, R.F.; Coless, L.A.; Davis, S.M. [and others

1995-12-31

In 1992, the Department of Energy (DOE) sponsored research to demonstrate a dispersed catalyst system using a combination of molybdenum and iron precursors for direct coal liquefaction. This dispersed catalyst system was successfully demonstrated using Black Thunder sub-bituminous coal at Wilsonville, Alabama by Southern Electric International, Inc. The DOE sponsored research continues at Exxon Research and Development Laboratories (ERDL). A six month continuous bench-scale program using ERDL`s Recycle Coal Liquefaction Unit (RCLU) is planned, three months in 1994 and three months in 1995. The initial conditions in RCLU reflect experience gained from the Wilsonville facility in their Test Run 263. Rawhide sub-bituminous coal which is similar to the Black Thunder coal tested at Wilsonville was used as the feed coal. A slate of five dispersed catalysts for direct coal liquefaction of Rawhide sub-bituminous coal has been tested. Throughout the experiments, the molybdenum addition rate was held constant at 100 wppm while the iron oxide addition rate was varied from 0.25 to 1.0 weight percent (dry coal basis). This report covers the 1994 operations and accomplishments.

The continuous improvement system of nuclear power plant of Laguna Verde; El sistema de mejora continua de la central nucleoelectrica Laguna Verde

Energy Technology Data Exchange (ETDEWEB)

Rivera C, A. [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Km. 42.5 Cardel-Nautla, Veracruz (Mexico)], e-mail: arr99999@cfe.gob.mx

2009-10-15

This paper describes the continuous improvement system of nuclear power plant of Laguna Verde and the achievements in implementing the same and additionally two study cases are presents. In February 2009 is noteworthy because the World Association of Nuclear Operators we identified as a learning organization, qualification which shows that the continuous improvement system has matured, and this system will expose as I get to learn to capitalize on our own experiences and external experiences diffused by the nuclear industry. In 2007 the management of nuclear power plants integrates its improvement systems and calls it continuous improvement system and is presented in the same extensive report that won the National Quality Award. This system is made up of 5 subsystems operating individually and are also related 1) human performance; 2) referential comparison or benchmarking; 3) self-assessment; 4) corrective action and 5) external operating experience. Five subsystems that plan, generate, capture, manage, communicate and protect the knowledge generated during the processes execution of nuclear power plant of Laguna Verde, as well as from external sources. The target set in 2007 was to increase the intellectual capital to always give response to meeting the security requirements, but creating a higher value to quality, customer, environment protection and society. In brief each of them, highlighting the objective, expectations management, implementation and some benefits. At the end they will describe two study cases selected to illustrate these cases as the organization learns by their continuous improvement system. (Author)

Grid Support in Large Scale PV Power Plants using Active Power Reserves

DEFF Research Database (Denmark)

Craciun, Bogdan-Ionut

to validate the performance of the frequency support functions, a flexible grid model with IEEE 12 bus system characteristics has been developed and implemented in RTDS. A power hardware-in-the-loop (PHIL) system composed by 20 kW plant (2 x 10 kW inverters and PV linear simulator) and grid simulator (RTDS......Photovoltaic (PV) systems are in the 3rd place in the renewable energy market, after hydro and wind power. The increased penetration of PV within the electrical power system has led to stability issues of the entire grid in terms of its reliability, availability and security of the supply....... As a consequence, Large scale PV Power Plants (LPVPPs) operating in Maximum Power Point (MPP) are not supporting the electrical network, since several grid triggering events or the increased number of downward regulation procedures have forced European Network of Transmission System Operators for Electricity...

Evaluation and Characterization of In-Line Annealed Continuous Cast Aluminum Sheet

Energy Technology Data Exchange (ETDEWEB)

Dr Subodh K. Das

2006-01-17

This R&D program will develop optimized, energy-efficient thermo-mechanical processing procedures for in-line annealing of continuously cast hot bands of two 5000 series aluminum alloys (5754 and 5052). The implementation of the R&D will result in the production of sheet with improved formability at high levels of productivity consistency and quality. The proposed R&D involves the following efforts: (1) Design and build continuous in-line annealing equipment for plant-scale trials; (2) Carry out plant-scale trials at Commonwealth Aluminum Corp.'s (CAC) plant in Carson; (3) Optimize the processing variables utilizing a metallurgical model for the kinetics of microstructure and texture evolution during thermo-mechanical processing; (4) Determine the effects of processing variables on the microstructure, texture, mechanical properties, and formability of aluminum sheet; (5) Develop design parameters for commercial implementation; and (6) Conduct techno-economic studies of the recommended process equipment to identify impacts on production costs. The research and development is appropriate for the domestic industry as it will result in improved aluminum processing capabilities and thus lead to greater application of aluminum in various industries including the automotive market. A teaming approach is critical to the success of this effort as no single company alone possesses the breadth of technical and financial resources for successfully carrying out the effort. This program will enable more energy efficient aluminum sheet production technology, produce consistent high quality product, and have The proposal addresses the needs of the aluminum industry as stated in the aluminum industry roadmap by developing new and improved aluminum processes utilizing energy efficient techniques. The effort is primarily related to the subsection on Rolling and Extrusion with the R&D to address energy and environmental efficiencies in aluminum manufacturing and will provide

Life cycle assessment of a small-scale anaerobic digestion plant from cattle waste

International Nuclear Information System (INIS)

Mezzullo, William G.; McManus, Marcelle C.; Hammond, Geoff P.

2013-01-01

Highlights: ► Emissions from plant manufacture contributed little towards the lifecycle impacts. ► The use phase of the AD plant could have significant impacts. ► Production of biogas and fertiliser created significant impacts. ► The consequential displacement of kerosene showed a net-benefit. ► The study concluded that it is essential to cover the digestate storage tank. -- Abstract: This paper outlines the results of a comprehensive life cycle study of the production of energy, in the form of biogas, using a small scale farm based cattle waste fed anaerobic digestion (AD) plant. The life cycle assessment (LCA) shows that in terms of environmental and energy impact the plant manufacture contributes very little to the whole life cycle impacts. The results show that compared with alternative energy supply the production and use of biogas is beneficial in terms of greenhouse gases and fossil fuel use. This is mainly due to the replacement of the alternative, kerosene, and from fertiliser production from the AD process. However, these benefits come at a cost to ecosystem health and the production of respiratory inorganics. These were found to be a result of ammonia emissions during the production phase of the biogas. These damages can be significantly reduced if further emission control measures are undertaken.

Nutrient regulation by continuous feeding removes limitations on cell yield in the large-scale expansion of Mammalian cell spheroids.

Directory of Open Access Journals (Sweden)

Bradley P Weegman

Full Text Available Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, β-TC6 insulinoma cells were aggregated and cultured for 3 weeks as a model of manufacturing a mammalian cell product. Cell expansion rates and medium nutrient levels were compared in static, stirred suspension bioreactors (SSB, and continuously fed (CF SSB. While SSB cultures facilitated increased culture volumes, no increase in cell yields were observed, partly due to limitations in key nutrients, which were consumed by the cultures between feedings, such as glucose. Even when glucose levels were increased to prevent depletion between feedings, dramatic fluctuations in glucose levels were observed. Continuous feeding eliminated fluctuations and improved cell expansion when compared with both static and SSB culture methods. Further improvements in growth rates were observed after adjusting the feed rate based on calculated nutrient depletion, which maintained physiological glucose levels for the duration of the expansion. Adjusting the feed rate in a continuous medium replacement system can maintain the consistent nutrient levels required for the large-scale application of many cell products. Continuously fed bioreactor systems combined with nutrient regulation can be used to improve the yield and reproducibility of mammalian cells for biological products and cellular therapies and will facilitate the translation of cell culture from the research lab to clinical applications.

Nutrient Regulation by Continuous Feeding Removes Limitations on Cell Yield in the Large-Scale Expansion of Mammalian Cell Spheroids

Science.gov (United States)

Weegman, Bradley P.; Nash, Peter; Carlson, Alexandra L.; Voltzke, Kristin J.; Geng, Zhaohui; Jahani, Marjan; Becker, Benjamin B.; Papas, Klearchos K.; Firpo, Meri T.

2013-01-01

Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, β-TC6 insulinoma cells were aggregated and cultured for 3 weeks as a model of manufacturing a mammalian cell product. Cell expansion rates and medium nutrient levels were compared in static, stirred suspension bioreactors (SSB), and continuously fed (CF) SSB. While SSB cultures facilitated increased culture volumes, no increase in cell yields were observed, partly due to limitations in key nutrients, which were consumed by the cultures between feedings, such as glucose. Even when glucose levels were increased to prevent depletion between feedings, dramatic fluctuations in glucose levels were observed. Continuous feeding eliminated fluctuations and improved cell expansion when compared with both static and SSB culture methods. Further improvements in growth rates were observed after adjusting the feed rate based on calculated nutrient depletion, which maintained physiological glucose levels for the duration of the expansion. Adjusting the feed rate in a continuous medium replacement system can maintain the consistent nutrient levels required for the large-scale application of many cell products. Continuously fed bioreactor systems combined with nutrient regulation can be used to improve the yield and reproducibility of mammalian cells for biological products and cellular therapies and will facilitate the translation of cell culture from the research lab to clinical applications. PMID:24204645

Scaling down from species to individuals: a flower-visitation network between individual honeybees and thistle plants

DEFF Research Database (Denmark)

Dupont, Yoko; Nielsen, Kristian T.; Olesen, Jens Mogens

2011-01-01

stems and monitored all floral visits. The constructed bipartite network of individual plants and bees had a high connectance and low nestedness, but it was not significantly modular. Frequency distributions of number of links per species (i.e. linkage level) had their best fit to a truncated power law......, and interactions were asymmetrical. Unipartite networks of either plants or bees had exceedingly short average path length and high clustering. Linkage level of plants increased with their number of flower heads and height of inflorescence (floral display parameters). Overall, the individual network of honeybees...... and thistles was denser linked than what is known from species pollination networks. Characteristics of both plants (e.g. floral display) and animals (e.g. foraging behaviour) are likely to generate this intra–specific, inter–individual link pattern. Such features of individual–individual networks may scale up...

Methane Production of Full-Scale Anaerobic Digestion Plants Calculated from Substrate’s Biomethane Potentials Compares Well with the One Measured On-Site

Energy Technology Data Exchange (ETDEWEB)

Holliger, Christof, E-mail: christof.holliger@epfl.ch [Laboratory for Environmental Biotechnology, School for Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Fruteau de Laclos, Hélène [Methaconsult, Préverenges (Switzerland); Hack, Gabrielle [Laboratory for Environmental Biotechnology, School for Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland)

2017-06-09

Biomethane potential (BMP) tests are used to determine the amount of methane that can be produced from organic materials in order to design different components of full-scale anaerobic digestion (AD) plants such as size of the digesters and units exploiting the produced biogas. However, little is known on how well BMPs compare with biogas production from the same organic materials in full-scale installations. In this study, two AD plants were chosen to carry out such comparisons, a dry AD plant treating green waste from urban areas and food waste from restaurants and supermarkets, and a liquid AD plant treating waste sludge from wastewater treatment and seven additional organic wastes. The BMPs of multiple samples of the individual organic materials collected during a period of 7–9 months were determined. Separate tests of mixtures of organic materials confirmed that the BMP of the mixtures can be calculated by adding the BMPs of the individual materials. The weekly methane production during the investigated periods was calculated from the full-scale installation data on the feeding of the digesters and the BMPs of each substrate fed into the digesters and compared with the weekly methane production measured on-site. The latter was calculated from the most accurately measured entity, either the electricity or the volume of purified biomethane injected into the grid. The weekly methane production rates calculated from BMPs and the one measured on-site were very similar and followed the same pattern. Some exceptions could be explained by, e.g., an overload of the full-scale installation. The measured weekly methane production accounted for 94.0 ± 6.8 and 89.3 ± 5.7% of the calculated weekly methane production for the wet and dry AD plant, respectively. For 26 out of 29 weeks, the calculated weekly methane production overestimated the measured one in the case of the wet AD plant and for 37 out of 39 weeks for the dry AD plant. Based on these results, it is

Methane Production of Full-Scale Anaerobic Digestion Plants Calculated from Substrate’s Biomethane Potentials Compares Well with the One Measured On-Site

International Nuclear Information System (INIS)

Holliger, Christof; Fruteau de Laclos, Hélène; Hack, Gabrielle

2017-01-01

Biomethane potential (BMP) tests are used to determine the amount of methane that can be produced from organic materials in order to design different components of full-scale anaerobic digestion (AD) plants such as size of the digesters and units exploiting the produced biogas. However, little is known on how well BMPs compare with biogas production from the same organic materials in full-scale installations. In this study, two AD plants were chosen to carry out such comparisons, a dry AD plant treating green waste from urban areas and food waste from restaurants and supermarkets, and a liquid AD plant treating waste sludge from wastewater treatment and seven additional organic wastes. The BMPs of multiple samples of the individual organic materials collected during a period of 7–9 months were determined. Separate tests of mixtures of organic materials confirmed that the BMP of the mixtures can be calculated by adding the BMPs of the individual materials. The weekly methane production during the investigated periods was calculated from the full-scale installation data on the feeding of the digesters and the BMPs of each substrate fed into the digesters and compared with the weekly methane production measured on-site. The latter was calculated from the most accurately measured entity, either the electricity or the volume of purified biomethane injected into the grid. The weekly methane production rates calculated from BMPs and the one measured on-site were very similar and followed the same pattern. Some exceptions could be explained by, e.g., an overload of the full-scale installation. The measured weekly methane production accounted for 94.0 ± 6.8 and 89.3 ± 5.7% of the calculated weekly methane production for the wet and dry AD plant, respectively. For 26 out of 29 weeks, the calculated weekly methane production overestimated the measured one in the case of the wet AD plant and for 37 out of 39 weeks for the dry AD plant. Based on these results, it is

Computational Techniques for Model Predictive Control of Large-Scale Systems with Continuous-Valued and Discrete-Valued Inputs

Directory of Open Access Journals (Sweden)

Koichi Kobayashi

2013-01-01

Full Text Available We propose computational techniques for model predictive control of large-scale systems with both continuous-valued control inputs and discrete-valued control inputs, which are a class of hybrid systems. In the proposed method, we introduce the notion of virtual control inputs, which are obtained by relaxing discrete-valued control inputs to continuous variables. In online computation, first, we find continuous-valued control inputs and virtual control inputs minimizing a cost function. Next, using the obtained virtual control inputs, only discrete-valued control inputs at the current time are computed in each subsystem. In addition, we also discuss the effect of quantization errors. Finally, the effectiveness of the proposed method is shown by a numerical example. The proposed method enables us to reduce and decentralize the computation load.

A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

Science.gov (United States)

Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

2015-04-01

A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

Impact of continuing scaling on the device performance of 3D cylindrical junction-less charge trapping memory

International Nuclear Information System (INIS)

Li Xinkai; Huo Zongliang; Jin Lei; Jiang Dandan; Hong Peizhen; Xu Qiang; Tang Zhaoyun; Li Chunlong; Ye Tianchun

2015-01-01

This work presents a comprehensive analysis of 3D cylindrical junction-less charge trapping memory device performance regarding continuous scaling of the structure dimensions. The key device performance, such as program/erase speed, vertical charge loss, and lateral charge migration under high temperature are intensively studied using the Sentaurus 3D device simulator. Although scaling of channel radius is beneficial for operation speed improvement, it leads to a retention challenge due to vertical leakage, especially enhanced charge loss through TPO. Scaling of gate length not only decreases the program/erase speed but also leads to worse lateral charge migration. Scaling of spacer length is critical for the interference of adjacent cells and should be carefully optimized according to specific cell operation conditions. The gate stack shape is also found to be an important factor affecting the lateral charge migration. Our results provide guidance for high density and high reliability 3D CTM integration. (paper)

A Model of Continuous Improvement in High Schools: A Process for Research, Innovation Design, Implementation, and Scale

Science.gov (United States)

Cohen-Vogel, Lora; Cannata, Marisa; Rutledge, Stacey A.; Socol, Allison Rose

2016-01-01

This chapter describes a model for continuous improvement that guides the work of the National Center on Scaling Up Effective Schools, or NCSU. NCSU is a research and development center funded by the Institute for Education Sciences, the research arm of the United States Department of Education. At the core of the Center's work is an innovative…

Biomass conversion to hydrocarbon fuels using the MixAlco™ process at a pilot-plant scale

International Nuclear Information System (INIS)

Taco Vasquez, Sebastian; Dunkleman, John; Chaudhuri, Swades K.; Bond, Austin; Holtzapple, Mark T.

2014-01-01

Texas A and M University has built a MixAlco™ pilot plant that converts biomass to hydrocarbons (i.e., jet fuel, gasoline) using the following steps: fermentation, descumming, dewatering, thermal ketonization, distillation, hydrogenation, and oligomerization. This study describes the pilot plant and reports results from an 11-month production campaign. The focus was to produce sufficient jet fuel to be tested by the U.S. military. Because the scale was relatively small, energy-saving features were not included in the pilot plant. Further, the equipment was operated in a manner to maximize productivity even if yields were low. During the production campaign, a total of 6.015 Mg of shredded paper and 120 kg of chicken manure (dry basis) were fermented to produce 126.5 m 3 of fermentation broth with an average concentration of 12.5 kg m −3 . A total of 1582 kg of carboxylate salts were converted to 587 L of raw ketones, which were distilled and hydrogenated to 470 L of mixed alcohols ranging from C3 to C12. These alcohols, plus 300 L of alcohols made by an industrial partner (Terrabon, Inc.) were shipped to an independent contractor (General Electric) and transformed to jet fuel (∼100 L) and gasoline (∼100 L) byproduct. - Highlights: • We produce hydrocarbons from paper and chicken manure in a pilot-scale production using the MixAlco™ process. • About 100 L of jet fuel were produced for military testing. • High production rates and good product quality were preferred rather than high yields or energy efficiency. • The MixAlco™ process converted successfully lignocellulosic biomass to hydrocarbons and viable for commercial-scale production

Changes in soil bacterial community structure as a result of incorporation of Brassica plants compared with continuous planting eggplant and chemical disinfection in greenhouses.

Science.gov (United States)

Li, Tianzhu; Liu, Tongtong; Zheng, Chengyu; Kang, Chunsheng; Yang, Zichao; Yao, Xiaotong; Song, Fengbin; Zhang, Runzhi; Wang, Xuerong; Xu, Ning; Zhang, Chunyi; Li, Wei; Li, Shumin

2017-01-01

Greenhouse eggplant monocropping in China has contributed to the aggravation of soil-borne diseases, reductions in crop quality and yield, and the degradation of physical and chemical soil properties. Crop rotation is one effective way of alleviating the problems of continuous cropping worldwide; however, few studies have reported changes in soil bacterial community structures and physical and chemical soil properties after Brassica vegetables had been rotated with eggplant in greenhouses. In this experiment, mustard-eggplant (BFN) and oilseed rape-eggplant (BFC) rotations were studied to identify changes in the physicochemical properties and bacterial community structure in soil that was previously subject to monocropping. Samples were taken after two types of Brassica plants incorporated into soil for 15 days to compare with continually planted eggplant (control, CN) and chemical disinfection of soil (CF) in greenhouses. MiSeq pyrosequencing was used to analyze soil bacterial diversity and structure in the four different treatments. A total of 55,129 reads were identified, and rarefaction analysis showed that the soil treatments were equally sampled. The bacterial richness of the BFC treatment and the diversity of the BFN treatment were significantly higher than those of the other treatments. Further comparison showed that the bacterial community structures of BFC and BFN treatments were also different from CN and CF treatments. The relative abundance of several dominant bacterial genera in the BFC and BFN treatments (such as Flavobacteria, Stenotrophomonas, Massilia and Cellvibrio, which played different roles in improving soil fertility and advancing plant growth) was distinctly higher than the CN or CF treatments. Additionally, the total organic matter and Olsen-P content of the BFC and BFN treatments were significantly greater than the CN treatment. We conclude that Brassica vegetables-eggplant crop rotations could provide a more effective means of solving

Real-Time Imaging of Plant Cell Wall Structure at Nanometer Scale, with Respect to Cellulase Accessibility and Degradation Kinetics (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Ding, S. Y.

2012-05-01

Presentation on real-time imaging of plant cell wall structure at nanometer scale. Objectives are to develop tools to measure biomass at the nanometer scale; elucidate the molecular bases of biomass deconstruction; and identify factors that affect the conversion efficiency of biomass-to-biofuels.

Development of a new steady state zero-dimensional simulation model for woody biomass gasification in a full scale plant

International Nuclear Information System (INIS)

Formica, Marco; Frigo, Stefano; Gabbrielli, Roberto

2016-01-01

Highlights: • A simulation model with Aspen Plus is created for a full scale biomass gasification plant. • Test results, equipment data and control logics are considered in the simulation model. • The simulation results are in agreement with the experimental data. • The gasifying air temperature affects largely the energy performance of the gasification plant. • Increasing the equivalent ratio implies a strong reduction of the gasification efficiency. - Abstract: A new steady state zero-dimensional simulation model for a full-scale woody biomass gasification plant with fixed-bed downdraft gasifier has been developed using Aspen Plus®. The model includes the technical characteristics of all the components (gasifier, cyclone, exchangers, piping, etc.) of the plant and works in accordance with its actual main control logics. Simulation results accord with those obtained during an extensive experimental activity. After the model validation, the influence of operating parameters such as the equivalent ratio, the biomass moisture content and the gasifying air temperature on syngas composition have been analyzed in order to assess the operative behavior and the energy performance of the experimental plant. By recovering the sensible heat of the syngas at the outlet of the gasifier, it is possible to obtain higher values of the gasifying air temperature and an improvement of the overall gasification performances.

Optimal installation program for reprocessing plants

International Nuclear Information System (INIS)

Kubokawa, Toshihiko; Kiyose, Ryohei

1976-01-01

Optimization of the program of installation of reprocessing plants is mathematically formulated as problem of mixed integer programming, which is numerically solved by the branch-and-bound method. A new concept of quasi-penalty is used to obviate the difficulties associated with dual degeneracy. The finiteness of the useful life of the plant is also taken into consideration. It is shown that an analogous formulation is possible for the cases in which the demand forecasts and expected plant lives cannot be predicted with certainty. The scale of the problem is found to have kN binary variables, (k+2)N continuous variables, and (k+3)N constraint conditions, where k is the number of intervals used in the piece-wise linear approximation of a nonlinear objective function, and N the overall duration of the period covered by the installation program. Calculations are made for N=24 yr and k=3, with the assumption that the plant life is 15 yr, the plant scale factor 0.5, and the maximum plant capacity 900 (t/yr). The results are calculated and discussed for four different demand forecasts. The difference of net profit between optimal and non-optimal installation programs is found to be in the range of 50 -- 100 M$. The pay-off matrix is calculated, and the optimal choice of action when the demand cannot be forecast with certainty is determined by applying Bayes' theory. The optimal installation program under such conditions of uncertainty is obtained also with a stochastic mixed integer programming model. (auth.)

Very-large-scale production of antibodies in plants: The biologization of manufacturing.

Science.gov (United States)

Buyel, J F; Twyman, R M; Fischer, R

2017-07-01

Gene technology has facilitated the biologization of manufacturing, i.e. the use and production of complex biological molecules and systems at an industrial scale. Monoclonal antibodies (mAbs) are currently the major class of biopharmaceutical products, but they are typically used to treat specific diseases which individually have comparably low incidences. The therapeutic potential of mAbs could also be used for more prevalent diseases, but this would require a massive increase in production capacity that could not be met by traditional fermenter systems. Here we outline the potential of plants to be used for the very-large-scale (VLS) production of biopharmaceutical proteins such as mAbs. We discuss the potential market sizes and their corresponding production capacities. We then consider available process technologies and scale-down models and how these can be used to develop VLS processes. Finally, we discuss which adaptations will likely be required for VLS production, lessons learned from existing cell culture-based processes and the food industry, and practical requirements for the implementation of a VLS process. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Thermal stratification in a scaled-down suppression pool of the Fukushima Daiichi nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Jo, Byeongnam, E-mail: jo@vis.t.u-tokyo.ac.jp [Nuclear Professional School, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan); Erkan, Nejdet [Nuclear Professional School, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan); Takahashi, Shinji [Department of Nuclear Engineering and Management, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Song, Daehun [Nuclear Professional School, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan); Hyundai and Kia Corporate R& D Division, Hyundai Motors, 772-1, Jangduk-dong, Hwaseong-Si, Gyeonggi-Do 445-706 (Korea, Republic of); Sagawa, Wataru; Okamoto, Koji [Nuclear Professional School, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan)

2016-08-15

Highlights: • Thermal stratification was reproduced in a scaled-down suppression pool of the Fukushima Daiichi nuclear power plants. • Horizontal temperature profiles were uniform in the toroidal suppression pool. • Subcooling-steam flow rate map of thermal stratification was obtained. • Steam bubble-induced flow model in suppression pool was suggested. • Bubble frequency strongly depends on the steam flow rate. - Abstract: Thermal stratification in the suppression pool of the Fukushima Daiichi nuclear power plants was experimentally investigated in sub-atmospheric pressure conditions using a 1/20 scale torus shaped setup. The thermal stratification was reproduced in the scaled-down suppression pool and the effect of the steam flow rate on different thermal stratification behaviors was examined for a wide range of steam flow rates. A sparger-type steam injection pipe that emulated Fukushima Daiichi Unit 3 (F1U3) was used. The steam was injected horizontally through 132 holes. The development (formation and disappearance) of thermal stratification was significantly affected by the steam flow rate. Interestingly, the thermal stratification in the suppression pool vanished when subcooling became lower than approximately 5 °C. This occurred because steam bubbles are not well condensed at low subcooling temperatures; therefore, those bubbles generate significant upward momentum, leading to mixing of the water in the suppression pool.

Decomposition of residual oil by large scale HSC plant

Energy Technology Data Exchange (ETDEWEB)

Washimi, Koichi; Ogata, Yoshitaka; Limmer, H.; Schuetter, H. (Toyo Engineering Corp., funabashi, Japan VEB Petrolchemisches Kombinat Schwedt, Schwedt (East Germany))

1989-07-01

Regarding large scale and high decomposition ratio visbreaker HSC, characteristic points and operation conditions of a new plant in East Germany were introduced. As for the characteristics of the process, high decomposition ratio and stable decpmposed oil, availability of high sulfur content oil or even decomposed residuum of visbreaker, stableness of produced light oil with low content of unsaturated components, low investment with low running cost, were indicated. For the realization of high decomposition ratio, designing for suppressing the decomposition in heating furnace and accelaration of it in soaking drum, high space velocity of gas phase for better agitation, were raised. As the main subject of technical development, design of soaking drum was indicated with main dimensions for the designing. Operation conditions of the process in East Germany using residual oil supplied from already working visbreaker for USSR crude oil were introduced. 6 refs., 4 figs., 2 tabs.

The experiences to improve plant performance and reliability of Ko-Ri nuclear power plants

International Nuclear Information System (INIS)

Kang, Ho Weon

1998-01-01

This paper provides a discussion of the lessons learned from operational experience and the future plans to improve performance of the Ko-Ri plant. To operate nuclear power plants safely with good performance is the only way to mitigate the negative image of nuclear power generation to the public and to enhance the economical benefit compared to other electrical generation method. Therefore, in a continuous effort to overcome a negative challenge from outside, we have driven an aggressive 'OCTF' campaign as part of safety. As a result of our efforts, the following remarkable achievements have been accomplished. (1) 3 times of OCTF during recent three years (2) Selected twice as a top notch power plant on the list of NEI magazine in terms of plant capacity factor (3) No scram recorded in 1997 for all 4 units at Ko-Ri site. Ko-Ri is now undergoing the large scale plant betterment projects for retaking-off our operating performance to the level of new challenge target. Such improvement of critical components in the reactor coolant system and turbine system greatly contribute to increase the safety and reliability of the plant and to shortening of the planned outage period as well as to reduction of radiation exposure and radwaste. (Cho, G. S.). 5 tabs., 10 figs

An improved basis for evaluating continued service of Category I concrete structures in nuclear power plants

International Nuclear Information System (INIS)

Naus, D.J.; Oland, C.B.; Ellingwood, B.; Mori, Y.; Arndt, E.G.

1992-01-01

The Structural Aging (SAG) Program has the overall objective of preparing technical bases for regulatory criteria which will provide the NRC with potential structural safety issues and acceptance criteria for use in nuclear power plant evaluations for continued service. In meeting this objective three primary activities are underway: (1) development of a structural materials information center containing data and information on the variation of concrete and concrete-related material properties over time; (2) establishment of procedures to make quantitative evaluations of the presence, magnitude, and significance of environmental stressors or aging factors that can impact critical component performance, as well as techniques which can be used for repair of degraded concrete structures; and (3) formulation of a quantitative methodology for performing current condition assessments and making reliability-based life predictions of critical concrete structures in nuclear power plants. Accomplishments to date under each of these tasks are presented

Seismic tests on a reduced scale mock-up of a reprocessing plant cooling pond

International Nuclear Information System (INIS)

Queval, J.C.; Gantenbein, F.; Lebelle, M.

1995-01-01

In conjunction with COGEMA and SGN, CEA has launched an important research program to validate the reprocessing plant cooling pond calculation mainly for the effect of the racks on the fluid-pond interaction. The paper presents the tests performed on a reduced scale mock-up (scale 1/5). The tests are composed by: -random excitations at very low excitation level to measure the natural frequencies, especially the first sloshing mode frequency; -sinusoidal tests to measure the damping; -seismic tests performed with 3 different time reduction scales (1, 1/5, 1/√5) and 3 different synthetic accelerograms. Two types of simplified model with added masses and finite element model were developed. Comparisons of measured and calculated pressure fields against the panels will be presented. The measured frequencies, obtained during tests, are in good agreement with Housner's results. (authors). 2 refs., 4 figs., 5 tabs

Fatty acid methyl ester (FAME) technology for monitoring biological foaming in activated sludge: full scale plant verification.

Science.gov (United States)

Lee, J W; Cha, D K; Kim, I; Son, A; Ahn, K H

2008-02-01

Fatty acid methyl ester (FAME) technology was evaluated as a monitoring tool for quantification of Gordonia amarae in activated sludge systems. The fatty acid, 19:1 alcohol, which was identified as a unique fatty acid in G. amarae was not only confirmed to be present in foaming plant samples, but the quantity of the signature peak correlated closely with the degree of foaming. Foaming potential experiment provided a range of critical foaming levels that corresponded to G. amarae population. This range of critical Gordonia levels was correlated to the threshold signature FAME amount. Six full-scale wastewater treatment plants were selected based on a survey to participate in our full-scale study to evaluate the potential application of the FAME technique as the Gordonia monitoring tool. Greater amounts of signature FAME were extracted from the mixed liquor samples obtained from treatment plants experiencing Gordonia foaming problems. The amounts of signature FAME correlated well with the conventional filamentous counting technique. These results demonstrated that the relative abundance of the signature FAMEs can be used to quantitatively monitor the abundance of foam-causing microorganism in activated sludge.

Correlated continuous time random walks: combining scale-invariance with long-range memory for spatial and temporal dynamics

International Nuclear Information System (INIS)

Schulz, Johannes H P; Chechkin, Aleksei V; Metzler, Ralf

2013-01-01

Standard continuous time random walk (CTRW) models are renewal processes in the sense that at each jump a new, independent pair of jump length and waiting time are chosen. Globally, anomalous diffusion emerges through scale-free forms of the jump length and/or waiting time distributions by virtue of the generalized central limit theorem. Here we present a modified version of recently proposed correlated CTRW processes, where we incorporate a power-law correlated noise on the level of both jump length and waiting time dynamics. We obtain a very general stochastic model, that encompasses key features of several paradigmatic models of anomalous diffusion: discontinuous, scale-free displacements as in Lévy flights, scale-free waiting times as in subdiffusive CTRWs, and the long-range temporal correlations of fractional Brownian motion (FBM). We derive the exact solutions for the single-time probability density functions and extract the scaling behaviours. Interestingly, we find that different combinations of the model parameters lead to indistinguishable shapes of the emerging probability density functions and identical scaling laws. Our model will be useful for describing recent experimental single particle tracking data that feature a combination of CTRW and FBM properties. (paper)

Spectral measurements at different spatial scales in potato: relating leaf, plant and canopy nitrogen status

Science.gov (United States)

Jongschaap, Raymond E. E.; Booij, Remmie

2004-09-01

Chlorophyll contents in vegetation depend on soil nitrogen availability and on crop nitrogen uptake, which are important management factors in arable farming. Crop nitrogen uptake is important, as nitrogen is needed for chlorophyll formation, which is important for photosynthesis, i.e. the conversion of absorbed radiance into plant biomass. The objective of this study was to estimate leaf and canopy nitrogen contents by near and remote sensing observations and to link observations at leaf, plant and canopy level. A theoretical base is presented for scaling-up leaf optical properties to whole plants and crops, by linking different optical recording techniques at leaf, plant and canopy levels through the integration of vertical nitrogen distribution. Field data come from potato experiments in The Netherlands in 1997 and 1998, comprising two potato varieties: Eersteling and Bintje, receiving similar nitrogen treatments (0, 100, 200 and 300 kg N ha -1) in varying application schemes to create differences in canopy nitrogen status during the growing season. Ten standard destructive field samplings were performed to follow leaf area index and crop dry weight evolution. Samples were analysed for inorganic nitrogen and total nitrogen contents. At sampling dates, spectral measurements were taken both at leaf level and at canopy level. At leaf level, an exponential relation between SPAD-502 readings and leaf organic nitrogen contents with a high correlation factor of 0.91 was found. At canopy level, an exponential relation between canopy organic nitrogen contents and red edge position ( λrep, nm) derived from reflectance measurements was found with a good correlation of 0.82. Spectral measurements (SPAD-502) at leaf level of a few square mm were related to canopy reflectance measurements (CropScan™) of approximately 0.44 m 2. Statistical regression techniques were used to optimise theoretical vertical nitrogen profiles that allowed scaling-up leaf chlorophyll measurements

Continuous Measurements of Canopy-level Solar-Induced Chlorophyll Fluorescence for Inferring Diurnal and Seasonal Dynamics of Photosynthesis in Crop Fields in the Midwestern USA

Science.gov (United States)

Miao, G.; Guan, K.; Yang, X.; Bernacchi, C.; DeLucia, E. H.; Cai, Y.; Masters, M. D.; Peng, B.

2016-12-01

Plants emitted photons of red and far-red light, called chlorophyll fluorescence, after sunlight absorption for photosynthesis. This solar-induced fluorescence (SIF) is generated simultaneously while plants actively photosynthesize. The link between photosynthesis and SIF resulting from the competition for the same excitation energy has long been investigated and applied for inferring the rate of photosynthesis. Recent development of continuous SIF observational technology is furthering the inferring potential as well as our understandings of fluctuations of SIF and photosynthesis with changes in environmental conditions. To better understand this photosynthesis-SIF link at multiple time scales and their relationships with environmental drivers, we deployed two newly developed tower-based SIF systems (FluoSpec) in a corn (Zea mays L., C4 plant) field and a soybean (Glycine max L., C3 plant) field at University of Illinois Energy Farm and conducted continuous near-surface SIF measurements at canopy scale from mid-growing season of 2016. Eddy covariance flux towers were installed in parallel at both sites for canopy-scale gas exchange measurements. Relationship between SIF and flux tower photosynthesis will be analyzed to derive the empirical models for photosynthesis retrieval from SIF signals. Preliminary results indicate that canopy SIF can reflect diurnal and seasonal dynamics of photosynthesis. Mechanistic analysis on SIF fluctuations and responses to environmental variations will be conducted as well for a closer look at mechanism of photosynthetic responses. Corn and soybean SIF and photosynthesis-SIF relationship will be compared to investigate the difference between C4 and C3 plants.

A Numeric Scorecard Assessing the Mental Health Preparedness for Large-Scale Crises at College and University Campuses: A Delphi Study

Science.gov (United States)

Burgin, Rick A.

2012-01-01

Large-scale crises continue to surprise, overwhelm, and shatter college and university campuses. While the devastation to physical plants and persons is often evident and is addressed with crisis management plans, the number of emotional casualties left in the wake of these large-scale crises may not be apparent and are often not addressed with…

Increase of methane formation by ethanol addition during continuous fermentation of biogas sludge.

Science.gov (United States)

Refai, Sarah; Wassmann, Kati; van Helmont, Sebastian; Berger, Stefanie; Deppenmeier, Uwe

2014-12-01

Very recently, it was shown that the addition of acetate or ethanol led to enhanced biogas formation rates during an observation period of 24 h. To determine if increased methane production rates due to ethanol addition can be maintained over longer time periods, continuous reactors filled with biogas sludge were developed which were fed with the same substrates as the full-scale reactor from which the sludge was derived. These reactors are well reflected conditions of a full-scale biogas plant during a period of 14 days. When the fermenters were pulsed with 50-100 mM ethanol, biomethanation increased by 50-150 %, depending on the composition of the biogas sludge. It was also possible to increase methane formation significantly when 10-20 mM pure ethanol or ethanolic solutions (e.g. beer) were added daily. In summary, the experiments revealed that "normal" methane production continued to take place, but ethanol led to production of additional methane.

A theoretical framework for whole-plant carbon assimilation efficiency based on metabolic scaling theory: a test case using Picea seedlings.

Science.gov (United States)

Wang, Zhiqiang; Ji, Mingfei; Deng, Jianming; Milne, Richard I; Ran, Jinzhi; Zhang, Qiang; Fan, Zhexuan; Zhang, Xiaowei; Li, Jiangtao; Huang, Heng; Cheng, Dongliang; Niklas, Karl J

2015-06-01

Simultaneous and accurate measurements of whole-plant instantaneous carbon-use efficiency (ICUE) and annual total carbon-use efficiency (TCUE) are difficult to make, especially for trees. One usually estimates ICUE based on the net photosynthetic rate or the assumed proportional relationship between growth efficiency and ICUE. However, thus far, protocols for easily estimating annual TCUE remain problematic. Here, we present a theoretical framework (based on the metabolic scaling theory) to predict whole-plant annual TCUE by directly measuring instantaneous net photosynthetic and respiratory rates. This framework makes four predictions, which were evaluated empirically using seedlings of nine Picea taxa: (i) the flux rates of CO(2) and energy will scale isometrically as a function of plant size, (ii) whole-plant net and gross photosynthetic rates and the net primary productivity will scale isometrically with respect to total leaf mass, (iii) these scaling relationships will be independent of ambient temperature and humidity fluctuations (as measured within an experimental chamber) regardless of the instantaneous net photosynthetic rate or dark respiratory rate, or overall growth rate and (iv) TCUE will scale isometrically with respect to instantaneous efficiency of carbon use (i.e., the latter can be used to predict the former) across diverse species. These predictions were experimentally verified. We also found that the ranking of the nine taxa based on net photosynthetic rates differed from ranking based on either ICUE or TCUE. In addition, the absolute values of ICUE and TCUE significantly differed among the nine taxa, with both ICUE and temperature-corrected ICUE being highest for Picea abies and lowest for Picea schrenkiana. Nevertheless, the data are consistent with the predictions of our general theoretical framework, which can be used to access annual carbon-use efficiency of different species at the level of an individual plant based on simple, direct

STAGE TECHNOLOGY FOR OBTAINIGN AN ECONOMIC WHITE WINE TO AN INDUSTRIAL SCALE

Directory of Open Access Journals (Sweden)

Juan Esteban Miño Valdés

2015-07-01

Full Text Available The purpose of this work was to develop a sustainable technology to produce economical white wine, industrial scale, not viniferous grapes grown in Misiones. This technological project started at laboratory scale, it continued in a pilot plant and planned to an industrial scale. It was considered as productive unit 12 rural families with 27 hectares of vines each. The 8 stages followed with inductive and deductive methodology were: the development of dry white wine at laboratory scale, the evaluation of the variables of the process in the vilification, the Mathematical modeling of alcoholic fermentation in winemaking conditions, the assessment of the fitness of wines for human consumption, the establishment of a technological process for winemaking in a pilot plant, the evaluation in pilot plant of the technological process established, the calculation and selection of industrial equipment and finally, the costs estimation and profitability of the industrial technological process. A technology for a production capacity of 5,834 L day-1, with dynamic economic indicators was reached whose values were 6,602,666 net present value of U$D, an internal rate of return of 60 % for a period of payback a value net of three years to date.

Scaling Concepts in Describing Continuous Phase Transitions

Indian Academy of Sciences (India)

The behaviour near such a continuous transition point displays many remarkable .... for the free energy, and the remaining statements can be obtained from thermodynamic ... axis are close to zero, leading to a 2D-spin system. Theoretically ...

Safety Effect Analysis of the Large-Scale Design Changes in a Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Chan; Lee, Hyun-Gyo [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2015-05-15

These activities were predominantly focused on replacing obsolete systems with new systems, and these efforts were not only to prolong the plant life, but also to guarantee the safe operation of the units. This review demonstrates the safety effect evaluation using the probabilistic safety assessment (PSA) of the design changes, system improvements, and Fukushima accident action items for Kori unit 1 (K1). For the large scale of system design changes for K1, the safety effects from the PSA perspective were reviewed using the risk quantification results before and after the system improvements. This evaluation considered the seven significant design changes including the replacement of the control building air conditioning system and the performance improvement of the containment sump using a new filtering system as well as above five system design changes. The analysis results demonstrated that the CDF was reduced by 12% overall from 1.62E-5/y to 1.43E-5/y. The CDF reduction was larger in the transient group than in the loss of coolant accident (LOCA) group. In conclusion, the analysis using the K1 PSA model supports that the plant safety has been appropriately maintained after the large-scale design changes in consideration of the changed operation factors and failure modes due to the system improvements.

Qualification of a full plant nodalization for the prediction of the core exit temperature through a scaling methodology

Energy Technology Data Exchange (ETDEWEB)

Freixa, J., E-mail: jordi.freixa-terradas@upc.edu; Martínez-Quiroga, V., E-mail: victor.martinez.quiroga@upc.edu; Reventós, F., E-mail: francesc.reventos@upc.edu

2016-11-15

Highlights: • Core exit temperature is used in PWRs as an indication of core heat up. • Qualification of full scale nuclear reactors by means of a scaling methodology. • Scaling of RELAP5 calculations to full scale power plants. - Abstract: System codes and their necessary power plant nodalizations are an essential step in thermal hydraulic safety analysis. In order to assess the safety of a particular power plant, in addition to the validation and verification of the code, the nodalization of the system needs to be qualified. Since most existing experimental data come from scaled-down facilities, any qualification process must therefore address scale considerations. The Group of Thermal Hydraulic Studies at Technical University of Catalonia has developed a scaling-up methodology (SCUP) for the qualification of full-scale nodalizations through a systematic procedure based on the extrapolation of post-test simulations of Integral Test Facility experiments. In the present work, the SCUP methodology will be employed to qualify the nodalization of the AscóNPP, a Pressurized Water Reactor (PWR), for the reproduction of an important safety phenomenon which is the effectiveness of the Core Exit Temperature (CET) as an Accident Management (AM) indicator. Given the difficulties in placing measurements in the core region, CET measurements are used as a criterion for the initiation of safety operational procedures during accidental conditions in PWR. However, the CET response has some limitation in detecting inadequate core cooling simply because the measurement is not taken in the position where the cladding exposure occurs. In order to apply the SCUP methodology, the OECD/NEA ROSA-2 Test 3, an SBLOCA in the hot leg, has been selected as a starting point. This experiment was conducted at the Large Scale Test Facility (LSTF), a facility operated by the Japanese Atomic Energy Agency (JAEA) and was focused on the assessment of the effectiveness of AM actions triggered by

Pesticide volatilization from soil and plant surfaces: Measurements at different scales versus model predictions

Energy Technology Data Exchange (ETDEWEB)

Wolters, A.

2003-07-01

Simulation of pesticide volatilization from plant and soil surfaces as an integral component of pesticide fate models is of utmost importance, especially as part of the PEC (predicted environmental concentrations) models used in the registration procedures for pesticides. Experimentally determined volatilization rates at different scales were compared to model predictions to improve recent approaches included in European registration models. To assess the influence of crucial factors affecting volatilization under well-defined conditions, a laboratory chamber was set-up and validated. Aerodynamic conditions were adjusted to fulfill the requirements of the German guideline on assessing pesticide volatilization for registration purposes. At the semi-field scale, volatilization rates were determined in a wind-tunnel study after soil surface application of pesticides to gleyic cambisol. The following descending order of cumulative volatilization was observed: chlorpyrifos > parathion-methyl > terbuthylazine > fenpropimorph. Parameterization of the models PEARL (pesticide emission assessment at regional and local scales) and PELMO (pesticide leaching model) was performed to mirror the experimental boundary conditions. (orig.)

Watermill and Small-Scale Hydroelectric Power Plant Landscapes Assessed According to Ecological Aspects

Directory of Open Access Journals (Sweden)

Lilita Lazdāne

2013-10-01

Full Text Available Research of watermill and small-scale hydroelectric power plant (HPP landscapes in Latvia according to ecological aspects is a part of a more complex research. The aim of this research is to examine the existing situation of watermill and small-scale HPP landscapes in Latvia by applying the ecological assessment criteria, and then try to formulate a definition of common tendencies of the landscape character. This paper provides a landscape inventory matrix for research in the field stu­dies of landscape identification at the local planning level. The duration of the research was from 2010 to 2012. The research includes 42 territories starting with the three most densely developed areas in Latvia: in Latgale, Kurzeme and Vidzeme uplands distribution ranges. The research results reflect tendencies of the landscape features assessed according to the previously developed criteria of ecological aspects.

Scale models: A proven cost-effective tool for outage planning

Energy Technology Data Exchange (ETDEWEB)

Lee, R. [Commonwealth Edison Co., Morris, IL (United States); Segroves, R. [Sargent & Lundy, Chicago, IL (United States)

1995-03-01

As generation costs for operating nuclear stations have risen, more nuclear utilities have initiated efforts to improve cost effectiveness. Nuclear plant owners are also being challenged with lower radiation exposure limits and new revised radiation protection related regulations (10 CFR 20), which places further stress on their budgets. As source term reduction activities continue to lower radiation fields, reducing the amount of time spent in radiation fields becomes one of the most cost-effective ways of reducing radiation exposure. An effective approach for minimizing time spent in radiation areas is to use a physical scale model for worker orientation planning and monitoring maintenance, modifications, and outage activities. To meet the challenge of continued reduction in the annual cumulative radiation exposures, new cost-effective tools are required. One field-tested and proven tool is the physical scale model.

An ROC-type measure of diagnostic accuracy when the gold standard is continuous-scale.

Science.gov (United States)

Obuchowski, Nancy A

2006-02-15

ROC curves and summary measures of accuracy derived from them, such as the area under the ROC curve, have become the standard for describing and comparing the accuracy of diagnostic tests. Methods for estimating ROC curves rely on the existence of a gold standard which dichotomizes patients into disease present or absent. There are, however, many examples of diagnostic tests whose gold standards are not binary-scale, but rather continuous-scale. Unnatural dichotomization of these gold standards leads to bias and inconsistency in estimates of diagnostic accuracy. In this paper, we propose a non-parametric estimator of diagnostic test accuracy which does not require dichotomization of the gold standard. This estimator has an interpretation analogous to the area under the ROC curve. We propose a confidence interval for test accuracy and a statistical test for comparing accuracies of tests from paired designs. We compare the performance (i.e. CI coverage, type I error rate, power) of the proposed methods with several alternatives. An example is presented where the accuracies of two quick blood tests for measuring serum iron concentrations are estimated and compared.

Calibration of a complex activated sludge model for the full-scale wastewater treatment plant

OpenAIRE

Liwarska-Bizukojc, Ewa; Olejnik, Dorota; Biernacki, Rafal; Ledakowicz, Stanislaw

2011-01-01

In this study, the results of the calibration of the complex activated sludge model implemented in BioWin software for the full-scale wastewater treatment plant are presented. Within the calibration of the model, sensitivity analysis of its parameters and the fractions of carbonaceous substrate were performed. In the steady-state and dynamic calibrations, a successful agreement between the measured and simulated values of the output variables was achieved. Sensitivity analysis revealed that u...

Landscape object-based analysis of wetland plant functional types: the effects of spatial scale, vegetation classes and classifier methods

Science.gov (United States)

Dronova, I.; Gong, P.; Wang, L.; Clinton, N.; Fu, W.; Qi, S.

2011-12-01

Remote sensing-based vegetation classifications representing plant function such as photosynthesis and productivity are challenging in wetlands with complex cover and difficult field access. Recent advances in object-based image analysis (OBIA) and machine-learning algorithms offer new classification tools; however, few comparisons of different algorithms and spatial scales have been discussed to date. We applied OBIA to delineate wetland plant functional types (PFTs) for Poyang Lake, the largest freshwater lake in China and Ramsar wetland conservation site, from 30-m Landsat TM scene at the peak of spring growing season. We targeted major PFTs (C3 grasses, C3 forbs and different types of C4 grasses and aquatic vegetation) that are both key players in system's biogeochemical cycles and critical providers of waterbird habitat. Classification results were compared among: a) several object segmentation scales (with average object sizes 900-9000 m2); b) several families of statistical classifiers (including Bayesian, Logistic, Neural Network, Decision Trees and Support Vector Machines) and c) two hierarchical levels of vegetation classification, a generalized 3-class set and more detailed 6-class set. We found that classification benefited from object-based approach which allowed including object shape, texture and context descriptors in classification. While a number of classifiers achieved high accuracy at the finest pixel-equivalent segmentation scale, the highest accuracies and best agreement among algorithms occurred at coarser object scales. No single classifier was consistently superior across all scales, although selected algorithms of Neural Network, Logistic and K-Nearest Neighbors families frequently provided the best discrimination of classes at different scales. The choice of vegetation categories also affected classification accuracy. The 6-class set allowed for higher individual class accuracies but lower overall accuracies than the 3-class set because

Engineering microbial cell factories for the production of plant natural products: from design principles to industrial-scale production.

Science.gov (United States)

Liu, Xiaonan; Ding, Wentao; Jiang, Huifeng

2017-07-19

Plant natural products (PNPs) are widely used as pharmaceuticals, nutraceuticals, seasonings, pigments, etc., with a huge commercial value on the global market. However, most of these PNPs are still being extracted from plants. A resource-conserving and environment-friendly synthesis route for PNPs that utilizes microbial cell factories has attracted increasing attention since the 1940s. However, at the present only a handful of PNPs are being produced by microbial cell factories at an industrial scale, and there are still many challenges in their large-scale application. One of the challenges is that most biosynthetic pathways of PNPs are still unknown, which largely limits the number of candidate PNPs for heterologous microbial production. Another challenge is that the metabolic fluxes toward the target products in microbial hosts are often hindered by poor precursor supply, low catalytic activity of enzymes and obstructed product transport. Consequently, despite intensive studies on the metabolic engineering of microbial hosts, the fermentation costs of most heterologously produced PNPs are still too high for industrial-scale production. In this paper, we review several aspects of PNP production in microbial cell factories, including important design principles and recent progress in pathway mining and metabolic engineering. In addition, implemented cases of industrial-scale production of PNPs in microbial cell factories are also highlighted.

From local to central: a network analysis of who manages plant pest and disease outbreaks across scales

Directory of Open Access Journals (Sweden)

Ryan R. J. McAllister

2015-03-01

Full Text Available One of the key determinants of success in managing natural resources is "institutional fit," i.e., how well the suite of required actions collectively match the scale of the environmental problem. The effective management of pest and pathogen threats to plants is a natural resource problem of particular economic, social, and environmental importance. Responses to incursions are managed by a network of decision makers and managers acting at different spatial and temporal scales. We applied novel network theoretical methods to assess the propensity of growers, local industry, local state government, and state and national government head offices to foster either within- or across-scale coordination during the successful 2001 Australian response to the outbreak of the fungal pathogen black sigatoka (Mycosphaerella fijiensis. We also reconstructed the response network to proxy what that network would look like today under the Australian government's revised response system. We illustrate a structural move in the plant biosecurity response system from one that was locally driven to the current top-down system, in which the national government leads coordination of a highly partitioned engagement process. For biological incursions that spread widely across regions, nationally rather than locally managed responses may improve coordination of diverse tasks. However, in dealing with such challenges of institutional fit, local engagement will always be critical in deploying flexible and adaptive local responses based on a national system. The methods we propose detect where and how network structures foster cross-scale interactions, which will contribute to stronger empirical studies of cross-scale environmental governance.

Full scale vibration test on nuclear power plant auxiliary building: Part I

International Nuclear Information System (INIS)

Langer, V.; Tinic, S.; Berger, E.; Zwicky, P.; Prater, E.G.

1987-01-01

In connection with the construction of the reinforced concrete auxiliary building housing the two boric water tanks (so-called BOTA building) of the Beznau Nuclear Power Plant in Switzerland the opportunity was given to carry out full scale vibration tests in November 1985. The overall aim of the tests was to validate computational models and parameters widely used in the seismic analysis of the structures and critical components of nuclear power plants. The scope of the experimental investigation was the determination of the eigenfrequencies and damping values for the fundamental soil-structure interaction (SSI) modes. The excitation level was aimed to be as high as feasibly possible. A working group was formed of representatives of the owner, NOK, the consulting firm Basler and Hofmann and the ETH to supervise the project. The project's main phases were the planning and execution of the tests, the evaluation of recorded data, numerical simulation of the tests using different computer models and finally the comparison and interpretation of measured and computed results

Demonstration of Active Power Controls by Utility-Scale PV Power Plant in an Island Grid: Preprint

Energy Technology Data Exchange (ETDEWEB)

Gevorgian, Vahan; O' Neill, Barbara

2017-02-01

The National Renewable Energy Laboratory (NREL), AES, and the Puerto Rico Electric Power Authority conducted a demonstration project on a utility-scale photovoltaic (PV) plant to test the viability of providing important ancillary services from this facility. As solar generation increases globally, there is a need for innovation and increased operational flexibility. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, it may mitigate the impact of its variability on the grid and contribute to important system requirements more like traditional generators. In 2015, testing was completed on a 20-MW AES plant in Puerto Rico, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to provide various types of new grid-friendly controls. This data showed how active power controls can leverage PV's value from being simply an intermittent energy resource to providing additional ancillary services for an isolated island grid. Specifically, the tests conducted included PV plant participation in automatic generation control, provision of droop response, and fast frequency response.

Power plant economy of scale and cost trends: further analyses and review of empirical studies

International Nuclear Information System (INIS)

Fisher, C.F. Jr.; Paik, S.; Schriver, W.R.

1986-07-01

Multiple regression analyses were performed on capital cost data for nuclear and coal-fired power plants in an extension of an earlier study which indicated that nuclear units completed prior to the accident at Three-Mile Island (TMI) have no economy of scale, and that units completed after that event have a weak economy of scale (scaling exponent of about 0.81). The earlier study also indicated that the scaling exponent for coal-fired units is about 0.92, compared with conceptual models which project scaling exponents in a range from about 0.5 to 0.9. Other empirical studies have indicated poor economy of scale, but a large range of cost-size scaling exponents has been reported. In the present study, the results for nuclear units indicate a scaling exponent of about 0.94 but with no economy of scale for large units, that a first unit costs 17% more than a second unit, that a unit in the South costs 20% less than others, that a unit completed after TMI costs 33% more than one completed before TMI, and that costs are increasing at 9.3% per year. In the present study, the results for coal-fired units indicate a scaling exponent of 0.93 but with better scaling economy in the larger units, that a first unit costs 38.5% more, a unit in the South costs 10% less, flue-gas desulfurization units cost 23% more, and that costs are increasing at 4% per year

Fuzzy logic and its possibility using in automation of small-scale hydroelectric power plants regulation

International Nuclear Information System (INIS)

Puskajler, J.

2004-01-01

The paper explains how can computer understand and process inaccurate (indefinite) information. It is processing of terms like e.g. 'around in the middle of month' or 'not too big'. Fuzzy logic, fuzzy sets, operations with them, fuzzy rules and using of linguistics variables are explained. The possibilities of application of fuzzy systems in automation of regulation of small-scale hydro power plants are discussed. (author)

Continuous wave power scaling in high power broad area quantum cascade lasers

Science.gov (United States)

Suttinger, M.; Leshin, J.; Go, R.; Figueiredo, P.; Shu, H.; Lyakh, A.

2018-02-01

Experimental and model results for high power broad area quantum cascade lasers are presented. Continuous wave power scaling from 1.62 W to 2.34 W has been experimentally demonstrated for 3.15 mm-long, high reflection-coated 5.6 μm quantum cascade lasers with 15 stage active region for active region width increased from 10 μm to 20 μm. A semi-empirical model for broad area devices operating in continuous wave mode is presented. The model uses measured pulsed transparency current, injection efficiency, waveguide losses, and differential gain as input parameters. It also takes into account active region self-heating and sub-linearity of pulsed power vs current laser characteristic. The model predicts that an 11% improvement in maximum CW power and increased wall plug efficiency can be achieved from 3.15 mm x 25 μm devices with 21 stages of the same design but half doping in the active region. For a 16-stage design with a reduced stage thickness of 300Å, pulsed roll-over current density of 6 kA/cm2 , and InGaAs waveguide layers; optical power increase of 41% is projected. Finally, the model projects that power level can be increased to 4.5 W from 3.15 mm × 31 μm devices with the baseline configuration with T0 increased from 140 K for the present design to 250 K.

A study of safeguards approach for the area of plutonium evaporator in a large scale reprocessing plant

International Nuclear Information System (INIS)

Sakai, Hirotada; Ikawa, Koji

1994-01-01

A preliminary study on a safeguards approach for the chemical processing area in a large scale reprocessing plant has been carried out. In this approach, plutonium inventory at the plutonium evaporator will not be taken, but containment and surveillance (C/S) measures will be applied to ensure the integrity of an area specifically defined to include the plutonium evaporator. The plutonium evaporator area consists of the evaporator itself and two accounting points, i.e., one before the plutonium evaporator and the other after the plutonium evaporator. For newly defined accounting points, two alternative measurement methods, i.e., accounting vessels with high accuracy and flow meters, were examined. Conditions to provide the integrity of the plutonium evaporator area were also examined as well as other technical aspects associated with this approach. The results showed that an appropriate combination of NRTA and C/S measures would be essential to realize a cost effective safeguards approach to be applied for a large scale reprocessing plant. (author)

Study on the combustion behavior of radiolytically generated hydrogen explosion in small scale annular vessels at the reprocessing plant

International Nuclear Information System (INIS)

Kudo, Tatsuya; Tamauchi, Yoshikazu; Arai, Nobuyuki; Dai, Wenbin; Sakaihara, Motohiro; Kanehira, Osamu

2017-01-01

Hydrogen is generated by radiolysis of water, etc. in process vessels in reprocessing plant. Usually, the hydrogen is scavenged by compressed air into vessels to prevent hydrogen explosion. When an earthquake beyond design based occurs, for example, the compressed air may stop and the hydrogen starts accumulating in the vessels, and under this condition, an ignition source might set off hydrogen explosion. Therefore, the explosion derived by the radiolytically generated hydrogen is designated as one of severe accidents on Rokkasho Reprocessing Plant in new regulatory requirements. It is important to understand the combustion behavior of hydrogen explosion inside a vessel for consideration of safety measures against the severe accident, because the influences of detonation are not considered in the design basis of vessels. Especially, the investigations about the combustion behavior which considered influence of interior obstacles inside the vessel are not performed yet. In order to investigate the combustion behavior comprehensively, explosion experiment, combustion analysis and structural analysis are carried out using the representative vessels (small scale annular vessel, small scale plate vessel, large scale annular vessel and large scale cylindrical vessel) selected from Rokkasho Reprocessing Plant. In this paper, the results of experiments and analysis of small scale annular vessel (as one of representative vessel, imitated a pulsed column in the reprocessing plant) are reported. As imitated vessels, three vessels are manufactured with different interior obstacle arrangements as follows, A) cylindrical obstacles are faithfully reproduced and are arranged based on the actual vessel, B) cylindrical obstacles are arranged more densely than the actual vessel, and C) there are no obstacles inside the vessel. Experiments of hydrogen explosion are performed under condition of stoichiometric hydrogen-air ratio (premixed hydrogen-air is used). As a result of

Bionomy of the laurel scale Aonidia lauri (Bouche (Hemiptera: Diaspididae in Podgorica, Montenegro

Directory of Open Access Journals (Sweden)

Graora Draga

2016-01-01

Full Text Available Aonidia lauri (Bouche (Hemiptera: Diaspididae is a serious pest of laurel (Laurus nobilis L. in urban parts of the City of Podgorica (Montenegro. Severe infestation causes chlorotic spots and necrotic rings around feeding spots, drying and dieback of leaves and buds. In addition, plants become physiologically weak and lose in aesthetic quality, while continuous infestation in urban areas often leads to partial or complete drying of plants. This study of the biology of A. lauri on L. nobilis was carried out at three locations in Podgorica ('Stara Varoš', 'Centar' and 'Preko Morače', Montenegro, in 2010 and 2011. A. lauri developed three generations annually and overwintered on laurel leaves and branches as the second-instar nymph-larval stage. An extended period of larval development ensures a continuous presence of all development stages on plants, which leads to overlapping of generations. Sporadic predatory ladybirds, Chilocorus bipustulatus (L. (Coleoptera: Coccinellidae, whose larvae and adults feed on scales, were detected inside A. lauri colonies.

The continued operation of nuclear power plants contents of the May 2003 O.P.E.C.S.T. report

International Nuclear Information System (INIS)

Birraux, C.; Bataille, Ch.; Barber, N.

2009-01-01

Their study sought a fair way of handling this matter. They tried to strike a ba-lance between the commercial perspectives of electric companies, consumers' economic interests, technological developments in the nuclear indus-try, and national energy independence, without reducing the high level of nuclear safety requirement. In this document, they advised first, to increase investment for research into materials ageing, second, to orient the ten-year review process towards continuing rather than stopping activity and third, to assert the absolute rule that, for obvious safety reasons, each decision regarding the lifetime of nuclear power plants had to be made on a case-by-case basis. Today they observe that all the necessary improvements have indeed been made On one hand, EDF now benefits from a grant to increase the competitiveness and safety of present-day power plants; on the other hand, the Act of 13. June 2006 organized a more constructive ten-year review process white at the same time it continued to empower the case-by-case rule. This framework fosters the ongoing, progressive replacement of old reactors by the EPR. This is being done with efficient speed and on a non-dramatic basis. (author)

The experiences to improve plant performance and reliability of Ko-Ri nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kang, Ho Weon [Korea Electric Power Corp. Ko-Ri nuclear power division, Ko-Ri (Korea, Republic of)

1998-07-01

This paper provides a discussion of the lessons learned from operational experience and the future plans to improve performance of the Ko-Ri plant. To operate nuclear power plants safely with good performance is the only way to mitigate the negative image of nuclear power generation to the public and to enhance the economical benefit compared to other electrical generation method. Therefore, in a continuous effort to overcome a negative challenge from outside, we have driven an aggressive 'OCTF' campaign as part of safety. As a result of our efforts, the following remarkable achievements have been accomplished. (1) 3 times of OCTF during recent three years (2) Selected twice as a top notch power plant on the list of NEI magazine in terms of plant capacity factor (3) No scram recorded in 1997 for all 4 units at Ko-Ri site. Ko-Ri is now undergoing the large scale plant betterment projects for retaking-off our operating performance to the level of new challenge target. Such improvement of critical components in the reactor coolant system and turbine system greatly contribute to increase the safety and reliability of the plant and to shortening of the planned outage period as well as to reduction of radiation exposure and radwaste. (Cho, G. S.). 5 tabs., 10 figs.

Computational models for residual creep life prediction of power plant components

International Nuclear Information System (INIS)

Grewal, G.S.; Singh, A.K.; Ramamoortry, M.

2006-01-01

All high temperature - high pressure power plant components are prone to irreversible visco-plastic deformation by the phenomenon of creep. The steady state creep response as well as the total creep life of a material is related to the operational component temperature through, respectively, the exponential and inverse exponential relationships. Minor increases in the component temperature can thus have serious consequences as far as the creep life and dimensional stability of a plant component are concerned. In high temperature steam tubing in power plants, one mechanism by which a significant temperature rise can occur is by the growth of a thermally insulating oxide film on its steam side surface. In the present paper, an elegantly simple and computationally efficient technique is presented for predicting the residual creep life of steel components subjected to continual steam side oxide film growth. Similarly, fabrication of high temperature power plant components involves extensive use of welding as the fabrication process of choice. Naturally, issues related to the creep life of weldments have to be seriously addressed for safe and continual operation of the welded plant component. Unfortunately, a typical weldment in an engineering structure is a zone of complex microstructural gradation comprising of a number of distinct sub-zones with distinct meso-scale and micro-scale morphology of the phases and (even) chemistry and its creep life prediction presents considerable challenges. The present paper presents a stochastic algorithm, which can be' used for developing experimental creep-cavitation intensity versus residual life correlations for welded structures. Apart from estimates of the residual life in a mean field sense, the model can be used for predicting the reliability of the plant component in a rigorous probabilistic setting. (author)

Continuous microalgal cultivation in a laboratory-scale photobioreactor under seasonal day-night irradiation: experiments and simulation.

Science.gov (United States)

Bertucco, Alberto; Beraldi, Mariaelena; Sforza, Eleonora

2014-08-01

In this work, the production of Scenedesmus obliquus in a continuous flat-plate laboratory-scale photobioreactor (PBR) under alternated day-night cycles was tested both experimentally and theoretically. Variation of light intensity according to the four seasons of the year were simulated experimentally by a tunable LED lamp, and effects on microalgal growth and productivity were measured to evaluate the conversion efficiency of light energy into biomass during the different seasons. These results were used to validate a mathematical model for algae growth that can be applied to simulate a large-scale production unit, carried out in a flat-plate PBR of similar geometry. The cellular concentration in the PBR was calculated in both steady-state and transient conditions, and the value of the maintenance kinetic term was correlated to experimental profiles. The relevance of this parameter was finally outlined.

Demonstration of a full-scale plant using an UASB followed by a ceramic MBR for the reclamation of industrial wastewater.

Science.gov (United States)

Niwa, Terutake; Hatamoto, Masashi; Yamashita, Takuya; Noguchi, Hiroshi; Takase, Osamu; Kekre, Kiran A; Ang, Wui Seng; Tao, Guihe; Seah, Harry; Yamaguchi, Takashi

2016-10-01

This study comprehensively evaluated the performance of a full-scale plant (4550m(3)d(-1)) using a UASB reactor followed by a ceramic MBR for the reclamation and reuse of mixed industrial wastewater containing many inorganics, chemical, oil and greases. This plant was demonstrated as the first full-scale system to reclaim the mixed industrial wastewater in the world. During 395days of operation, influent chemical oxygen demand (COD) fluctuated widely, but this system achieved COD removal rate of 91% and the ceramic MBR have operated flux of 21-25LMH stably. This means that this system adsorbed the feed water fluctuation and properly treated the water. Energy consumption of this plant was achieved 0.76kWhmm(-3) and this value is same range of domestic sewage MBR system. The combination of an UASB reactor and ceramic MBR is the most economical and feasible solution for water reclamation of mixed industrial wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

The beta-diversity of species interactions: Untangling the drivers of geographic variation in plant-pollinator diversity and function across scales.

Science.gov (United States)

Burkle, Laura A; Myers, Jonathan A; Belote, R Travis

2016-01-01

Geographic patterns of biodiversity have long inspired interest in processes that shape the assembly, diversity, and dynamics of communities at different spatial scales. To study mechanisms of community assembly, ecologists often compare spatial variation in community composition (beta-diversity) across environmental and spatial gradients. These same patterns inspired evolutionary biologists to investigate how micro- and macro-evolutionary processes create gradients in biodiversity. Central to these perspectives are species interactions, which contribute to community assembly and geographic variation in evolutionary processes. However, studies of beta-diversity have predominantly focused on single trophic levels, resulting in gaps in our understanding of variation in species-interaction networks (interaction beta-diversity), especially at scales most relevant to evolutionary studies of geographic variation. We outline two challenges and their consequences in scaling-up studies of interaction beta-diversity from local to biogeographic scales using plant-pollinator interactions as a model system in ecology, evolution, and conservation. First, we highlight how variation in regional species pools may contribute to variation in interaction beta-diversity among biogeographic regions with dissimilar evolutionary history. Second, we highlight how pollinator behavior (host-switching) links ecological networks to geographic patterns of plant-pollinator interactions and evolutionary processes. Third, we outline key unanswered questions regarding the role of geographic variation in plant-pollinator interactions for conservation and ecosystem services (pollination) in changing environments. We conclude that the largest advances in the burgeoning field of interaction beta-diversity will come from studies that integrate frameworks in ecology, evolution, and conservation to understand the causes and consequences of interaction beta-diversity across scales. © 2016 Botanical

UPC Scaling-up methodology for Deterministic Safety Assessment and Support to Plant Operation

Energy Technology Data Exchange (ETDEWEB)

Martínez-Quiroga, V.; Reventós, F.; Batet, Il.

2015-07-01

Best Estimate codes along with necessary nodalizations are widely used tools in nuclear engineering for both Deterministic Safety Assessment (DSA) and Support to Plant Operation and Control. In this framework, the application of quality assurance procedures in both codes and nodalizations becomes an essential step prior any significant study. Along these lines the present paper introduces the UPC SCUP, a systematic methodology based on the extrapolation of the Integral Test Facilities (ITF) post-test simulations by means of scaling analyses. In that sense, SCUP fulfills a gap in current nodalization qualification procedures, the related with the validation of NPP nodalizations for Design Basis Accidents conditions. Three are the pillars that support SCUP: judicial selection of the experimental transients, full confidence in the quality of the ITF simulations, and simplicity in justifying discrepancies that appear between ITF and NPP counterpart transients. The techniques that are presented include the socalled Kv scaled calculations as well as the use of two new approaches, ”Hybrid nodalizations” and ”Scaled-up nodalizations”. These last two methods have revealed themselves to be very helpful in producing the required qualification and in promoting further improvements in nodalization. The study of both LSTF and PKL counterpart tests have allowed to qualify the methodology by the comparison with experimental data. Post-test simulations at different sizes allowed to define which phenomena could be well reproduced by system codes and which not, in this way also establishing the basis for the extrapolation to an NPP scaled calculation. Furthermore, the application of the UPC SCUP methodology demonstrated that selected phenomena can be scaled-up and explained between counterpart simulations by carefully considering the differences in scale and design. (Author)

IMHEX fuel cell repeat component manufacturing continuous improvement accomplishments

Energy Technology Data Exchange (ETDEWEB)

Jakaitis, L.A.; Petraglia, V.J.; Bryson, E.S. [M-C Power Corp., Burr Ridge, IL (United States)] [and others

1996-12-31

M-C Power is taking a power generation technology that has been proven in the laboratory and is making it a commercially competitive product. There are many areas in which this technology required scale up and refinement to reach the market entry goals for the IMHEX{reg_sign} molten carbonate fuel cell power plant. One of the primary areas that needed to be addressed was the manufacturing of the fuel cell stack. Up to this point, the fuel cell stack and associated components were virtually hand made for each system to be tested. M-C Power has now continuously manufactured the repeat components for three 250 kW stacks. M-C Power`s manufacturing strategy integrated both evolutionary and revolutionary improvements into its comprehensive commercialization effort. M-C Power`s objectives were to analyze and continuously improve stack component manufacturing and assembly techniques consistent with established specifications and commercial scale production requirements. Evolutionary improvements are those which naturally occur as the production rates are increased and experience is gained. Examples of evolutionary (learning curve) improvements included reducing scrap rates and decreasing raw material costs by buying in large quantities. Revolutionary improvements result in significant design and process changes to meet cost and performance requirements of the market entry system. Revolutionary changes often involve identifying new methods and developing designs to accommodate the new process. Based upon our accomplishments, M-C Power was able to reduce the cost of continuously manufactured fuel cell repeat components from the first to third 250 kW stack by 63%. This paper documents the continuous improvement accomplishments realized by M-C Power during IMHEX{reg_sign} fuel cell repeat component manufacturing.

Event classification related to overflow of solvent containing uranium according to the INES scale (International Nuclear and Radiological Event Scale)

International Nuclear Information System (INIS)

Dourado, Eneida R.G.; Assis, Juliana T. de; Lage, Ricardo F.; Lopes, Karina B.

2013-01-01

This paper aims to frame the event overflow organic solvent rich in uranium, from a decanter of ore beneficiation plant, caused by the fall in the supply of electricity, according to the criteria established by the International Nuclear Event Scale and radiological (INES), facilitating the understanding of the occurrence and communication with the public regarding the radiation safety aspects involved. With the fall of electricity, routine procedures in situations of installation stop were performed, however, due to operational failure, the valve on the transfer line liquor was not closed. Thus, the mixer continued being fed with liquor, that led the consequent leakage of solvent loaded with uranium. It reached the drainage system, and the box of rainwater harvesting of the plant. However, immediately after the detection of the event, corrective actions were initiated and the overflow was contained. Regulatory agencies followed the removal of the solvent and on the results of the analysis of environmental monitoring, found that the event did not provide exposure to workers or any other impact. Therefore, comparing the characteristics of the event and the guidelines proposed by the INES scale, it is concluded that the classification of the event is below scale/level 0, confirming the absence of risk to the local population, workers and the environment

Revealing the regime of shallow coral reefs at patch scale by continuous spatial modeling

Directory of Open Access Journals (Sweden)

Antoine eCollin

2014-11-01

Full Text Available Reliably translating real-world spatial patterns of ecosystems is critical for understanding processes susceptible to reinforce resilience. However the great majority of studies in spatial ecology use thematic maps to describe habitats and species in a binary scheme. By discretizing the transitional areas and neglecting the gradual replacement across a given space, the thematic approach may suffer from substantial limitations when interpreting patterns created by many continuous variables. Here, local and regional spectral proxies were used to design and spatially map at very fine scale a continuous index dedicated to one of the most complex seascapes, the coral reefscape. Through a groundbreaking merge of bottom-up and top-down approach, we demonstrate that three to seven-habitat continuous indices can be modeled by nine, six, four and three spectral proxies, respectively, at 0.5 m spatial resolution using hand- and spaceborne measurements. We map the seven-habitat continuous index, spanning major Indo-Pacific coral reef habitats through the far red-green normalized difference ratio over the entire lagoon of a low (Tetiaroa atoll and a high volcanic (Moorea island in French Polynesia with 84% and 82% accuracy, respectively. Further examinations of the two resulting spatial models using a customized histoscape (density function of model values distributed on a concentric strip across the reef crest-coastline distance show that Tetiaroa exhibits a greater variety of coral reef habitats than Moorea. By designing such easy-to-implement, transferrable spectral proxies of coral reef regime, this study initiates a framework for spatial ecologists tackling coral reef biodiversity, responses to stresses, perturbations and shifts. We discuss the limitations and contributions of our findings towards the study of worldwide coral reef resilience following stochastic environmental change.

State of the art of aerobic granulation in continuous flow bioreactors.

Science.gov (United States)

Kent, Timothy R; Bott, Charles B; Wang, Zhi-Wu

In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of

Continuous Culture Microbioreactors

DEFF Research Database (Denmark)

Schäpper, Daniel

investigation, which typically means performing cultivations in larger and larger scales. As the size of the reactor increases from shake ask to bench-scale reactors to pilot-plant installations the number of strains decreases until only one strain is left at production scale which hopefully is the ideal strain...... chaotically into the reactor chamber again. Thus, over time, all of the reactor oor will be covered which prevents the formation of dead zones. Temperature is controlled by means of an external (and thus re-usable) heating plate which contains both a temperature sensor and a resistance heating wire...

Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values

Science.gov (United States)

Small-scale continuous flow wetland mesocosms (~0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed ...

Optimal sizing of utility-scale photovoltaic power generation complementarily operating with hydropower: A case study of the world’s largest hydro-photovoltaic plant

International Nuclear Information System (INIS)

Fang, Wei; Huang, Qiang; Huang, Shengzhi; Yang, Jie; Meng, Erhao; Li, Yunyun

2017-01-01

Highlights: • Feasibility of complementary hydro-photovoltaic operation across the world is revealed. • Three scenarios of the novel operation mode are proposed to satisfy different load demand. • A method for optimally sizing a utility-scale photovoltaic plant is developed by maximizing the net revenue during lifetime. • The influence of complementary hydro-photovoltaic operation upon water resources allocation is investigated. - Abstract: The high variability of solar energy makes utility-scale photovoltaic power generation confront huge challenges to penetrate into power system. In this paper, the complementary hydro-photovoltaic operation is explored, aiming at improving the power quality of photovoltaic and promoting the integration of photovoltaic into the system. First, solar-rich and hydro-rich regions across the world are revealed, which are suitable for implementing the complementary hydro-photovoltaic operation. Then, three practical scenarios of the novel operation mode are proposed for better satisfying different types of load demand. Moreover, a method for optimal sizing of a photovoltaic plant integrated into a hydropower plant is developed by maximizing the net revenue during lifetime. Longyangxia complementary hydro-photovoltaic project, the current world’s largest hydro-photovoltaic power plant, is selected as a case study and its optimal photovoltaic capacities of different scenarios are calculated. Results indicate that hydropower installed capacity and annual solar curtailment rate play crucial roles in the size optimization of a photovoltaic plant and complementary hydro-photovoltaic operation exerts little adverse effect upon the water resources allocation of Longyangxia reservoir. The novel operation mode not only improves the penetration of utility-scale photovoltaic power generation but also can provide a valuable reference for the large-scale utilization of other kinds of renewable energy worldwide.

Uses of continuous measuring techniques for optimizing the operation of municipal sewage treatment plants; Einsatzmoeglichkeiten kontinuierlicher Messtechnik zur Betriebsoptimierung kommunaler Klaeranlagen

Energy Technology Data Exchange (ETDEWEB)

Wedi, D [Vermicon AG, Muenchen/Braunschweig (Germany)

1998-12-31

Three different optimization measures are briefly discussed, each of which was carried out with the support of continuous measurements: efforts to enhance the sedimentation performance of a final sedimentation tank, investigations to establish the nitrification performance of an existing plant, and measurements permitting optimized parametrization of the complex control of a new sewage treatement plant. (orig./SR) [Deutsch] Es werden drei verschiedene Optimierungsmassnahmen kurz erlaeutert, die jeweils mit Unterstutzung kontinuierlicher Messungen erfolgten: Arbeiten zur Verbesserung der Sedimentationsleistung eines Nachklaerbeckens, Untersuchungen zur besseren Nachrechnung der Nitrifikationskapazitaet einer bestehenden Anlage und Messungen zur optimierten Parametrierung einer komplexeren Regelung einer neuen Klaeranlage. (orig./SR)

Uses of continuous measuring techniques for optimizing the operation of municipal sewage treatment plants; Einsatzmoeglichkeiten kontinuierlicher Messtechnik zur Betriebsoptimierung kommunaler Klaeranlagen

Energy Technology Data Exchange (ETDEWEB)

Wedi, D. [Vermicon AG, Muenchen/Braunschweig (Germany)

1997-12-31

Three different optimization measures are briefly discussed, each of which was carried out with the support of continuous measurements: efforts to enhance the sedimentation performance of a final sedimentation tank, investigations to establish the nitrification performance of an existing plant, and measurements permitting optimized parametrization of the complex control of a new sewage treatement plant. (orig./SR) [Deutsch] Es werden drei verschiedene Optimierungsmassnahmen kurz erlaeutert, die jeweils mit Unterstutzung kontinuierlicher Messungen erfolgten: Arbeiten zur Verbesserung der Sedimentationsleistung eines Nachklaerbeckens, Untersuchungen zur besseren Nachrechnung der Nitrifikationskapazitaet einer bestehenden Anlage und Messungen zur optimierten Parametrierung einer komplexeren Regelung einer neuen Klaeranlage. (orig./SR)

Enrichment and cultivation of a sulfide-oxidizing bacteria consortium for its deploying in full-scale biogas desulfurization

International Nuclear Information System (INIS)

González Sánchez, Armando; Flores Márquez, Trinidad Eliseo; Revah, Sergio; Morgan Sagastume, Juan Manuel

2014-01-01

Operational experiences and strategies to get suitable chemolithoautotrophic sulfide-oxidizing biomass from activated sludge wastewater treatment plant for its deploying in a full-scale biogas desulfurization plant are described. An economic nutrient source was applied to foster microbial selection and rapid growth. Respirometry was implemented on full-scale installations to monitor the ability of the specialized bacteria consortium to oxidize reduced sulfur i.e. H 2 S. During the deployment in the full-scale desulfurization reactor, intermittent sulfide feed from biogas scrubbing was performed to accelerate the startup the desulfurization process. - Highlights: • A simple method for reaching high amounts of specialized sulfide-oxidizing bacterial consortium from activated sludge was developed. • The full-scale desulfurization process can be continuously monitored by respirometry allowing fast decision making if problems arise. • The dissolved sulfide concentration was estimated with an empirical correlation between measurements of ORP, dissolved oxygen and pH

Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant

International Nuclear Information System (INIS)

Blanchat, T.K.; Allen, M.D.; Pilch, M.M.

1994-01-01

The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories (SNL) are used to perform scaled experiments for the Nuclear Regulatory Commission (NRC) that simulate High Pressure Melt Ejection (HPME) accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic atmospheres, and hydrogen generation and combustion, can be studied

Conceptuation of a continuously working vacuum pump train for fusion power plants

International Nuclear Information System (INIS)

Giegerich, Thomas; Day, Christian

2013-01-01

The Karlsruhe Institute of Technology (KIT) is developing a continuously working and non-cryogenic pumping solution for a demonstration power plant (DEMO). This pumping train shall cover the full operational pressure regime of a fusion reactor and is based on two pump types, namely diffusion pumps and liquid ring pumps. The whole pumping train must fulfill high safety and reliability requirements and it has to be made fully tritium compatible. In this paper, the design of a prototype pumping train and the special requirements for a DEMO machine are presented and discussed. A central feature of this pumping train is the use of a liquid metal as tritium compatible working fluid in both pump types, that leads to a pumping train which is able to cover a pressure range of 12 decades, namely from 10 −9 to 10 3 mbar. Finally, a test facility for pump testing over a wide pressure regime is described. In this facility (THESEUS), experiments with a diffusion pump have been performed and first results are presented

Conceptuation of a continuously working vacuum pump train for fusion power plants

Energy Technology Data Exchange (ETDEWEB)

Giegerich, Thomas, E-mail: thomas.giegerich@kit.edu; Day, Christian

2013-10-15

The Karlsruhe Institute of Technology (KIT) is developing a continuously working and non-cryogenic pumping solution for a demonstration power plant (DEMO). This pumping train shall cover the full operational pressure regime of a fusion reactor and is based on two pump types, namely diffusion pumps and liquid ring pumps. The whole pumping train must fulfill high safety and reliability requirements and it has to be made fully tritium compatible. In this paper, the design of a prototype pumping train and the special requirements for a DEMO machine are presented and discussed. A central feature of this pumping train is the use of a liquid metal as tritium compatible working fluid in both pump types, that leads to a pumping train which is able to cover a pressure range of 12 decades, namely from 10{sup −9} to 10{sup 3} mbar. Finally, a test facility for pump testing over a wide pressure regime is described. In this facility (THESEUS), experiments with a diffusion pump have been performed and first results are presented.

Advanced plant engineering and construction of Japanese ABWRs

International Nuclear Information System (INIS)

Gotoh, N.; Sumikawa, J.; Yoshida, N.; Yoshida, M.

1998-01-01

Remarkable improvement has been made in recent nuclear power plant design and construction in Japan. These many improved engineering technologies has been made a good use in the lately commercial operated two world's first 1,356MWe ABW's (Advanced Boiling Water Reactors), and made a great contribution to the smooth progress and the completion of a highly reliable plant construction. Especially, two engineering technologies, (1), three-dimensional computer aided design system through engineering data-base, and (2), large scale modularising construction method, have been successfully applied as the integrated engineering technologies of the plant construction. And two integrated reviews, 'integrated design review, confirmation of new and changed design and prevention of failure recurrence' in the design stage, and 'constructing plant review' at the site, have been widely and systematically conducted as a link in the chain of steady reliability improvement activities. These advanced and/or continuous and steady technologies are one of most important factors for high reliability through the entire lifetime of a nuclear plant, including planning, design, construction, operation and maintenance stages. (author)

High performance multi-scale and multi-physics computation of nuclear power plant subjected to strong earthquake. An Overview

International Nuclear Information System (INIS)

Yoshimura, Shinobu; Kawai, Hiroshi; Sugimoto, Shin'ichiro; Hori, Muneo; Nakajima, Norihiro; Kobayashi, Kei

2010-01-01

Recently importance of nuclear energy has been recognized again due to serious concerns of global warming and energy security. In parallel, it is one of critical issues to verify safety capability of ageing nuclear power plants (NPPs) subjected to strong earthquake. Since 2007, we have been developing the multi-scale and multi-physics based numerical simulator for quantitatively predicting actual quake-proof capability of ageing NPPs under operation or just after plant trip subjected to strong earthquake. In this paper, we describe an overview of the simulator with some preliminary results. (author)

With Scale in Mind: A Continuous Improvement Model for Implementation

Science.gov (United States)

Redding, Christopher; Cannata, Marisa; Taylor Haynes, Katherine

2017-01-01

The conventional approach to scaling up educational reforms considers the development and testing phases to be distinct from the work of implementing at scale. Decades of research suggest that this approach yields inconsistent and often disappointing improvements for schools most in need. More recent scholarship on scaling school improvement…

Optimization-based methodology for wastewater treatment plant synthesis – a full scale retrofitting case study

DEFF Research Database (Denmark)

Bozkurt, Hande; Gernaey, Krist; Sin, Gürkan

2015-01-01

Existing wastewater treatment plants (WWTP) need retrofitting in order to better handle changes in the wastewater flow and composition, reduce operational costs as well as meet newer and stricter regulatory standards on the effluent discharge limits. In this study, we use an optimization based...... technologies. The superstructure optimization problem is formulated as a Mixed Integer (non)Linear Programming problem and solved for different scenarios - represented by different objective functions and constraint definitions. A full-scale domestic wastewater treatment plant (265,000 PE) is used as a case...... framework to manage the multi-criteria WWTP design/retrofit problem for domestic wastewater treatment. The design space (i.e. alternative treatment technologies) is represented in a superstructure, which is coupled with a database containing data for both performance and economics of the novel alternative...

Performance of a pilot-scale continuous flow microbial electrolysis cell fed winery wastewater.

Science.gov (United States)

Cusick, Roland D; Bryan, Bill; Parker, Denny S; Merrill, Matthew D; Mehanna, Maha; Kiely, Patrick D; Liu, Guangli; Logan, Bruce E

2011-03-01

A pilot-scale (1,000 L) continuous flow microbial electrolysis cell was constructed and tested for current generation and COD removal with winery wastewater. The reactor contained 144 electrode pairs in 24 modules. Enrichment of an exoelectrogenic biofilm required ~60 days, which is longer than typically needed for laboratory reactors. Current generation was enhanced by ensuring adequate organic volatile fatty acid content (VFA/SCOD ≥ 0.5) and by raising the wastewater temperature (31 ± 1°C). Once enriched, SCOD removal (62 ± 20%) was consistent at a hydraulic retention time of 1 day (applied voltage of 0.9 V). Current generation reached a maximum of 7.4 A/m(3) by the planned end of the test (after 100 days). Gas production reached a maximum of 0.19 ± 0.04 L/L/day, although most of the product gas was converted to methane (86 ± 6%). In order to increase hydrogen recovery in future tests, better methods will be needed to isolate hydrogen gas produced at the cathode. These results show that inoculation and enrichment procedures are critical to the initial success of larger-scale systems. Acetate amendments, warmer temperatures, and pH control during startup were found to be critical for proper enrichment of exoelectrogenic biofilms and improved reactor performance.

Food plant diversity as broad-Scale Determinant of Avian Frugivore Richness

DEFF Research Database (Denmark)

Kissling, W. Daniel; Rahbek, Carsten; Böhning-Gaese, Katrin

2007-01-01

from niche assembly mechanisms (e.g. coevolutionary adaptations to fruit size, fruit colour or vertical stratification of fruit presentation) or, alternatively, from stochastic speciation-extinction processes. In any case, the close relationship between species richness of Ficus and avian frugivores......The causes of variation in animal species richness at large spatial scales are intensively debated. Here, we examine whether the diversity of food plants, contemporary climate and energy, or habitat heterogeneity determine species richness patterns of avian frugivores across sub-Saharan Africa....... Path models indicate that species richness of Ficus (their fruits being one of the major food resources for frugivores in the tropics) has the strongest direct effect on richness of avian frugivores, whereas the influences of variables related to water-energy and habitat heterogeneity are mainly...

Optimization of instant powdered chicken feet broth’s drying temperature and time on pilot plant scale production

Science.gov (United States)

Hidayati, N.; Widyaningsih, T. D.

2018-03-01

Chicken feet by-product of chicken industries amounted to approximately 65,894 tons/year commonly used as broths. These by-products are potentially produced into an instant form as an anti-inflammatory functional food on industrial scale. Therefore, it is necessary to optimize the critical parameters of the drying process. The aim of this study was to determine the optimum temperature and time of instant powdered chicken feet broth’s drying on pilot plant scale, to find out product’s comparison of the laboratory and pilot plant scale, and to assess financial feasibility of the business plan. The optimization of pilot plant scale’s research prepared and designed with Response Surface Methodology-Central Composite Design. The optimized factors were powdered broth’s drying temperature (55°C, 60°C, 65°C) and time (10 minutes, 11 minutes, 12 minutes) with the response observed were water and chondroitin sulphate content. The optimum condition obtained was drying process with temperature of 60.85°C for 10,05 minutes resulting in 1.90 ± 0.02% moisture content, 32.48 ± 0.28% protein content, 12.05 ± 0.80% fat content, 28.92 ± 0.09 % ash content, 24.64 ± 0.52% carbohydrate content, 1.26 ± 0.05% glucosamine content, 0.99 ± 0.23% chondroitin sulphate content, 50.87 ± 1.00% solubility, 8.59 ± 0.19% water vapour absorption, 0.37% levels of free fatty acid, 13.66 ± 4.49% peroxide number, lightness of 60.33 ± 1.24, yellowness of 3.83 ± 0.26 and redness of 21.77 ± 0.42. Financial analysis concluded that this business project was feasible to run.

Rain events and their effect on effluent quality studied at a full scale activated sludge treatment plant.

Science.gov (United States)

Wilén, B M; Lumley, D; Mattsson, A; Mino, T

2006-01-01

The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.

Genetic 'fingerprints' to characterise microbial communities during organic overloading and in large-scale biogas plants

Energy Technology Data Exchange (ETDEWEB)

Kleyboecker, A.; Lerm, S.; Vieth, A.; Wuerdemann, H. [GeoForschungsZentrum Potsdam, Bio-Geo-Engineering, Potsdam (Germany); Miethling-Graff, R. [Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany). Inst. fuer Agraroekologie; Wittmaier, M. [Institut fuer Kreislaufwirtschaft, Bremen (Germany)

2007-07-01

Since fermentation is a complex process, biogas reactors are still known as 'black boxes'. Mostly they are not run at their maximum loading rate due to the possible failure in the process by organic overloading. This means that there are still unused capacities to produce more biogas in less time. Investigations of different large-scale biogas plants showed that fermenters are operated containing different amounts of volatile fatty acids. These amounts can vary so much that one of two digestors, both possessing the same VFA concentration, does not produce gas anymore while the other is still at work. A reason for this phenomenon might be found in the composition of the microbial communities or in differences in the operation of the plants. To gain a better understanding of the 'black box', structural changes in microbial communities during controlled organic overloading in a laboratory and biocenosis of large-scale reactors were investigated. A genetic fingerprint based on 16S rDNA (PCR-SSCP) was used to characterise the microbial community. (orig.)

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

Recommendations on the choice of gas analysis equipment for systems of continuous monitoring and accounting of emissions from thermal power plants

Science.gov (United States)

Kondrat'eva, O. E.; Roslyakov, P. V.; Burdyukov, D. A.; Khudolei, O. D.; Loktionov, O. A.

2017-10-01

According to Federal Law no. 219-FZ, dated July 21, 2014, all enterprises that have a significant negative impact on the environment shall continuously monitor and account emissions of harmful substances into the atmospheric air. The choice of measuring equipment that is included in continuous emission monitoring and accounting systems (CEM&ASs) is a complex technical problem; in particular, its solution requires a comparative analysis of gas analysis systems; each of these systems has its advantages and disadvantages. In addition, the choice of gas analysis systems for CEM&ASs should be maximally objective and not depend on preferences of separate experts and specialists. The technique of choosing gas analysis equipment that was developed in previous years at Moscow Power Engineering Institute (MPEI) has been analyzed and the applicability of the mathematical tool of a multiple criteria analysis to choose measuring equipment for the continuous emission monitoring and accounting system have been estimated. New approaches to the optimal choice of gas analysis equipment for systems of the continuous monitoring and accounting of harmful emissions from thermal power plants have been proposed, new criteria of evaluation of gas analysis systems have been introduced, and weight coefficients have been determined for these criteria. The results of this study served as a basis for the Preliminary National Standard of the Russian Federation "Best Available Technologies. Automated Systems of Continuous Monitoring and Accounting of Emissions of Harmful (Polluting) Substances from Thermal Power Plants into the Atmospheric Air. Basic Requirements," which was developed by the Moscow Power Engineering Institute, National Research University, in cooperation with the Council of Power Producers and Strategic Electric Power Investors Association and the All-Russia Research Institute for Materials and Technology Standardization.

On the Analysis and Fault-Diagnosis Tools for Small-Scale Heat and Power Plants