Supplemental site inspection for Air Force Plant 59, Johnson City, New York, Volume 3: Appendices F-Q

Energy Technology Data Exchange (ETDEWEB)

Nashold, B.; Rosenblatt, D.; Hau, J. [and others

1995-08-01

This summary describes a Supplemental Site Inspection (SSI) conducted by Argonne National Laboratory (ANL) at Air Force Plant 59 (AFP 59) in Johnson City, New York. All required data pertaining to this project were entered by ANL into the Air Force-wide Installation Restoration Program Information System (IRPIMS) computer format and submitted to an appropriate authority. The work was sponsored by the United States Air Force as part of its Installation Restoration Program (IRP). Previous studies had revealed the presence of contaminants at the site and identified several potential contaminant sources. Argonne`s study was conducted to answer questions raised by earlier investigations. This volume consists of appendices F-Q, which contain the analytical data from the site characterization.

Cellular Force Microscopy for in Vivo Measurements of Plant Tissue Mechanics1[W][OA

Science.gov (United States)

Routier-Kierzkowska, Anne-Lise; Weber, Alain; Kochova, Petra; Felekis, Dimitris; Nelson, Bradley J.; Kuhlemeier, Cris; Smith, Richard S.

2012-01-01

Although growth and morphogenesis are controlled by genetics, physical shape change in plant tissue results from a balance between cell wall loosening and intracellular pressure. Despite recent work demonstrating a role for mechanical signals in morphogenesis, precise measurement of mechanical properties at the individual cell level remains a technical challenge. To address this challenge, we have developed cellular force microscopy (CFM), which combines the versatility of classical microindentation techniques with the high automation and resolution approaching that of atomic force microscopy. CFM’s large range of forces provides the possibility to map the apparent stiffness of both plasmolyzed and turgid tissue as well as to perform micropuncture of cells using very high stresses. CFM experiments reveal that, within a tissue, local stiffness measurements can vary with the level of turgor pressure in an unexpected way. Altogether, our results highlight the importance of detailed physically based simulations for the interpretation of microindentation results. CFM’s ability to be used both to assess and manipulate tissue mechanics makes it a method of choice to unravel the feedbacks between mechanics, genetics, and morphogenesis. PMID:22353572

Geohydrologic units and water-level conditions in the Terrace alluvial aquifer and Paluxy Aquifer, May 1993 and February 1994, near Air Force Plant 4, Fort Worth area, Texas

Science.gov (United States)

Rivers, Glen A.; Baker, Ernest T.; Coplin, L.S.

1996-01-01

The terrace alluvial aquifer underlying Air Force Plant 4 and the adjacent Naval Air Station (formerly Carswell Air Force Base) in the Fort Worth area, Texas, is contaminated locally with organic and metal compounds. Residents south and west of Air Force Plant 4 and the Naval Air Station are concerned that contaminants might enter the underlying Paluxy aquifer, which provides water to the city of White Settlement, south of Air Force Plant 4, and to residents west of Air Force Plant 4. The U.S. Environmental Protection Agency has qualified Air Force Plant 4 for Superfund cleanup. The pertinent geologic units include -A~rom oldest to youngest the Glen Rose, Paluxy, and Walnut Formations, Goodland Limestone, and terrace alluvial deposits. Except for the Glen Rose Formation, all units crop out at or near Air Force Plant 4 and the Naval Air Station. The terrace alluvial deposits, which nearly everywhere form the land surface, range from 0 to about 60 feet thick. These deposits comprise a mostly unconsolidated mixture of gravel, sand, silt, and clay. Mudstone and sandstone of the Paluxy Formation crop out north, west, and southwest of Lake Worth and total between about 130 and about 175 feet thick. The terrace alluvial deposits and the Paluxy Formation comprise the terrace alluvial aquifer and the Paluxy aquifer, respectively. These aquifers are separated by the Goodland-Walnut confining unit, composed of the Goodland Limestone and (or) Walnut Formation. Below the Paluxy aquifer, the Glen Rose Formation forms the Glen Rose confining unit. Water-level measurements during May 1993 and February 1994 from wells in the terrace alluvial aquifer indicate that, regionally, ground water flows toward the east-southeast beneath Air Force Plant 4 and the Naval Air Station. Locally, water appears to flow outward from ground-water mounds maintained by the localized infiltration of precipitation and reportedly by leaking water pipes and sanitary and (or) storm sewer lines beneath the

Calculation of dynamic hydraulic forces in nuclear plant piping systems

International Nuclear Information System (INIS)

Choi, D.K.

1982-01-01

A computer code was developed as one of the tools needed for analysis of piping dynamic loading on nuclear power plant high energy piping systems, including reactor safety and relief value upstream and discharge piping systems. The code calculates the transient hydraulic data and dynamic forces within the one-dimensional system, caused by a pipe rupture or sudden value motion, using a fixed space and varying time grid-method of characteristics. Subcooled, superheated, homogeneous two-phase and transition flow regimes are considered. A non-equilibrium effect is also considered in computing the fluid specific volume and fluid local sonic velocity in the two-phase mixture. Various hydraulic components such as a spring loaded or power operated value, enlarger, orifice, pressurized tank, multiple pipe junction (tee), etc. are considered as boundary conditions. Comparisons of calculated results with available experimental data shows a good agreement. (Author)

Operations and Maintenance Manual for Full-Scale Bioventing System at FSA-1, Air Force Plant 4, Fort Worth, Texas

National Research Council Canada - National Science Library

1996-01-01

This Operations and Maintenance (O&M) Manual has been created as a guide for monitoring and maintaining the performance of the full-scale bioventing blower system and vent well plumbing at FSA-1 at Air Force Plant 4 (AFP4), Texas...

Force-feedback tele operation of industrial robots a cost effective solution for decontamination of nuclear plants

International Nuclear Information System (INIS)

Desbats, P.; Andriot, C.; Gicquel, P.; Viallesoubranne, J.P.; Souche, C.

1998-01-01

Decontamination and maintenance in hot cells are some new emerging applications of industrial robots in the nuclear fuel cycle plants. Industrial robots are low cost, accurate and reliable manipulator arms which are used in manufacturing industries usually. Thanks to the recent evolution of robotics technologies, some industrial robots may be adapted to nuclear environment. These robots are transportable, sealed and can be decontaminated, and they may be 'hardened' up to a level of irradiation dose sufficient for operation in low and medium irradiating/contaminating environments. Although industrial robots are usually programmed to perform specific and repetitive tasks, they may be remotely tele-operated by human operators as well. This allows industrial robots to perform usual tele-manipulation tasks encountered in the nuclear plants and more. The paper presents the computer based tele-operation control system TAO2000 TM , developed by the Tele-operation and Robotics Service of CEA, which has been applied to the RX90 TM industrial robot from ST-UBLI company. This robot has been selected in order to perform various maintenance and decontamination tasks in COGEMA plants. TAO2000 provides the overall tele-robotic and robotic functions necessary to perform any remote tele-operation application in hostile environment: force-feedback master-slave control; computer- assisted tele-operation of mechanical processes; trajectory programming as well as various robotics functions; graphical modelling of working environment and simulation; automatic path planning with obstacle avoidance; man-machine interface for tasks programming and mission execution. Experimental results reported in the paper demonstrate the feasibility of force-feedback master-slave control of standard industrial robots. Finally, the design of new, cost effective. tele-operation systems based on industrial robots may be intended for nuclear plants maintenance. (author)

Interactions between fluvial forces and vegetation size, density and morphology influence plant mortality during experimental floods

Science.gov (United States)

Stella, J. C.; Kui, L.; Manners, R.; Wilcox, A. C.; Lightbody, A.; Sklar, L. S.

2015-12-01

Introduction and methods Fluvial disturbance is a key driver of riparian vegetation dynamics in river corridors. Despite an increasing understanding of ecohydraulic interactions between plants and fluvial forces, the interactive influences of plant morphology and sediment supply on plant mortality, a key demographic factor, are largely unknown. To better understand these processes, we designed and conducted a series of flume experiments to: (1) quantify effects of plant traits that interact with flow and sediment transport on plant loss to scour during floods; and (2) predict plant dislodgement for different species across a range of plant sizes, patch densities, and sediment condition (equilibrium transport versus sediment deficit). We ran ten experimental floods in a 28 m long × 0.6 m wide × 0.71 m tall flume, using live, 1-3 year-old tamarisk and cottonwood seedlings with contrasting morphologies with varied combinations of size and density. Results and discussion Both sediment supply and plant traits (morphology and composition) have significant impacts on plant vulnerability during floods. Sediment deficit resulted in bed degradation and a 35% greater risk of plant loss compared to equilibrium sediment conditions. The probability of plant dislodgement in sparse patches was 4.5 times greater than in dense patches. Tamarisk plants and patches had greater frontal area, basal diameter and longer roots compared to cottonwood across all seedling heights. These traits, as well as its lower crown position reduced tamarisk's vulnerability to scour by 75%. Compared with cottonwood, tamarisk exhibits better resistance to floods, due to its greater root biomass and longer roots that stabilize soil, and its greater frontal area and lower crown that effectively trap sediment. These traits likely contribute to riverscape-scale changes in channel morphology that are evident where tamarisk has invaded native riparian communities, and explain the persistence of tamarisk

An Open Source Low-Cost Wireless Control System for a Forced Circulation Solar Plant.

Science.gov (United States)

Salamone, Francesco; Belussi, Lorenzo; Danza, Ludovico; Ghellere, Matteo; Meroni, Italo

2015-11-05

The article describes the design phase, development and practical application of a low-cost control system for a forced circulation solar plant in an outdoor test cell located near Milan. Such a system provides for the use of an electric pump for the circulation of heat transfer fluid connecting the solar thermal panel to the storage tank. The running plant temperatures are the fundamental parameter to evaluate the system performance such as proper operation, and the control and management system has to consider these parameters. A solar energy-powered wireless-based smart object was developed, able to monitor the running temperatures of a solar thermal system and aimed at moving beyond standard monitoring approaches to achieve a low-cost and customizable device, even in terms of installation in different environmental conditions. To this end, two types of communications were used: the first is a low-cost communication based on the ZigBee protocol used for control purposes, so that it can be customized according to specific needs, while the second is based on a Bluetooth protocol used for data display.

An Open Source Low-Cost Wireless Control System for a Forced Circulation Solar Plant

Directory of Open Access Journals (Sweden)

Francesco Salamone

2015-11-01

Full Text Available The article describes the design phase, development and practical application of a low-cost control system for a forced circulation solar plant in an outdoor test cell located near Milan. Such a system provides for the use of an electric pump for the circulation of heat transfer fluid connecting the solar thermal panel to the storage tank. The running plant temperatures are the fundamental parameter to evaluate the system performance such as proper operation, and the control and management system has to consider these parameters. A solar energy-powered wireless-based smart object was developed, able to monitor the running temperatures of a solar thermal system and aimed at moving beyond standard monitoring approaches to achieve a low-cost and customizable device, even in terms of installation in different environmental conditions. To this end, two types of communications were used: the first is a low-cost communication based on the ZigBee protocol used for control purposes, so that it can be customized according to specific needs, while the second is based on a Bluetooth protocol used for data display.

The effect of flurprimidol on Allium rosenbachianum Reg. forced in pots

Directory of Open Access Journals (Sweden)

Halina Laskowska

2013-04-01

Full Text Available The effect of flurprimidol on Allium rosenbachianum (Reg. flowering and forcing period was studied. Bulbs of 18-20 cm circumference were used in the experiment. Two methods of retardant application were used: bulbs soaking before planting and triple spraying of plants during the vegetation period (in the stage of leaf rosette, open leaves and in the phase of green, ‘sitting’ bud. Flurprimidol was used in the following doses: 15 mg ∙dm -3 , 30 mg ∙dm -3 , 45 mg ∙dm -3 and control (plants treated with distilled water. Bulbs were planted into pots on the 20 th of October and ‘wet cooled’ for 14 weeks in the temperature of 9°C. During forcing in a greenhouse, morphological features of plants were observed. It was noted that flurprimidol may be effectively used for suppressing A. rosenbachianum forced in a greenhouse as a pot plant. Flurprimidol used in concentration of 45 mg ∙dm -3 significantly inhibited growth of shoots and length of flower pedicels and leaves and increased number of flowers in inflorescences at the same time. Soaking bulbs of A. rosenbachianumin flurprimidol solution before planting shortened forcing period by 4 days.

Analysis of scrams and forced outages at boiling water reactors

International Nuclear Information System (INIS)

Earle, R.T.; Sullivan, W.P.; Miller, K.R.; Schwegman, W.J.

1980-07-01

This report documents the results of a study of scrams and forced outages at General Electric Boiling Water Reactors (BWRs) operating in the United States. This study was conducted for Sandia Laboratories under a Light Water Reactor Safety Program which it manages for the United States Department of Energy. Operating plant data were used to identify the causes of scrams and forced outages. Causes of scrams and forced outages have been summarized as a function of operating plant and plant age and also ranked according to the number of events per year, outage time per year, and outage time per event. From this ranking, identified potential improvement opportunities were evaluated to determine the associated benefits and impact on plant availability

The mechanisms underlying corrosion product formation and deposition in nuclear power plant circuits through the action of galvanic and thermal electromotive forces

International Nuclear Information System (INIS)

Brusakov, V.P.; Sedov, V.M.; Khitrov, Yu.A.; Brusov, K.N.; Razmashkin, N.V.; Versin, V.V.; Rybalchenko, I.L.

1983-01-01

From a theoretical standpoint, the processes of formation of corrosion products in nuclear power plant circuits, deposition of corrosion products on the circuit surfaces, formation of an equilibrium concentration of corrosion products in the coolant, and distribution of radionuclides resulting from corrosion in different parts of the circuit are considered. It is shown that the main driving forces for the mass-transfer processes in the circuits are the thermal and galvanic electromotive forces (EMF) of the microcouples. On the basis of the theoretical concepts developed the authors have obtained analytical dependences for calculating the individual stages of the process of corrosion product transfer in the circuits. The mechanisms underlying the processes which occur as a result of thermal and galvanic EMFs are considered, together with the factors influencing these processes. The results of verification of the dependences by computational methods are given and they are compared with operational data from nuclear and conventional thermal power plants and with experimental data. (author)

TMI-2 Lessons Learned Task Force status report and short-term recommendations

International Nuclear Information System (INIS)

1979-07-01

Review of the Three Mile Island accident by the TMI-2 Lessons Learned Task Force has disclosed a number of actions in the areas of design and analysis and plant operations that the Task Force recommends be required in the short term to provide substantial additional protection which is required for the public health and safety. All nuclear power plants in operation or in various stages of construction or licensing action are affected to varying degrees by the specific recommendations. The Task Force is continuing work in areas of general safety criteria, systems design requirements, nuclear power plant operations, and nuclear power plant licensing

Optimized reinforcement of nuclear power plant structures for aircraft impact forces

International Nuclear Information System (INIS)

Zerna, W.; Schnellenbach, G.; Stangenberg, F.

1976-01-01

Reactor buildings of nuclear power plants and, to some extent also other buildings of the plant, according to the present safety requirements, have to be able to withstand aircraft impact forces. The building has to withstand this loading only once since afterwards it will be out of use. Accordingly, other criteria for design and the necessary safety measures are valid than in the case of service loads. Large deformations and the development of large cracks due to such loadings are insignificant from a construction point of view for reinforced concrete structures i.e. the stresses can build up to the ultimate load carrying capacity. From the nuclear safety point of view, however, some restrictions are possible in this regard e.g. to obstruct the penetration of fuel through the cracks. Basically all mild steels, with large ducility and without brittle fracture under sudden load increase, are suitable for this purpose. High stresses in the structure would, however, require uneconomical concentrations of mild steel. It is for this reason that the use of high strength steels e.g. St 110/135, has been introduced in Germany for this kind of loading. Through the use of wire strands or cables of high strength steel it is possible to reach a condition of cracks and large deformations due to ultimate loads in zone of point loading. The reinforcement takes on a distinctly curved shape and is able to carry the normal loads and shears through a suspension-structure action. The deformability of the structure for the analysed limit load state can be further increased through a bond-free net. This measure allows a more uniform sketching of the cables or strands over a larger zone. (Auth.)

Analyses of Current And Wave Forces on Velocity Caps

DEFF Research Database (Denmark)

Christensen, Erik Damgaard; Buhrkall, Jeppe; Eskesen, Mark C. D.

2015-01-01

Velocity caps are often used in connection with for instance offshore intake sea water for the use of for cooling water for power plants or as a source for desalinization plants. The intakes can also be used for river intakes. The velocity cap is placed on top of a vertical pipe. The vertical pipe......) this paper investigates the current and wave forces on the velocity cap and the vertical cylinder. The Morison’s force model was used in the analyses of the extracted force time series in from the CFD model. Further the distribution of the inlet velocities around the velocity cap was also analyzed in detail...

Do centrioles generate a polar ejection force?

Science.gov (United States)

Wells, Jonathan

2005-01-01

A microtubule-dependent polar ejection force that pushes chromosomes away from spindle poles during prometaphase is observed in animal cells but not in the cells of higher plants. Elongating microtubules and kinesin-like motor molecules have been proposed as possible causes, but neither accounts for all the data. In the hypothesis proposed here a polar ejection force is generated by centrioles, which are found in animals but not in higher plants. Centrioles consist of nine microtubule triplets arranged like the blades of a tiny turbine. Instead of viewing centrioles through the spectacles of molecular reductionism and neo-Darwinism, this hypothesis assumes that they are holistically designed to be turbines. Orthogonally oriented centriolar turbines could generate oscillations in spindle microtubules that resemble the motion produced by a laboratory vortexer. The result would be a microtubule-mediated ejection force tending to move chromosomes away from the spindle axis and the poles. A rise in intracellular calcium at the onset of anaphase could regulate the polar ejection force by shutting down the centriolar turbines, but defective regulation could result in an excessive force that contributes to the chromosomal instability characteristic of most cancer cells.

Hydraulic Limits on Maximum Plant Transpiration

Science.gov (United States)

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

2011-12-01

Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

Systematic Parameterization of Lignin for the CHARMM Force Field

Energy Technology Data Exchange (ETDEWEB)

Vermaas, Joshua; Petridis, Loukas; Beckham, Gregg; Crowley, Michael

2017-07-06

Plant cell walls have three primary components, cellulose, hemicellulose, and lignin, the latter of which is a recalcitrant, aromatic heteropolymer that provides structure to plants, water and nutrient transport through plant tissues, and a highly effective defense against pathogens. Overcoming the recalcitrance of lignin is key to effective biomass deconstruction, which would in turn enable the use of biomass as a feedstock for industrial processes. Our understanding of lignin structure in the plant cell wall is hampered by the limitations of the available lignin forcefields, which currently only account for a single linkage between lignins and lack explicit parameterization for emerging lignin structures both from natural variants and engineered lignin structures. Since polymerization of lignin occurs via radical intermediates, multiple C-O and C-C linkages have been isolated , and the current force field only represents a small subset of lignin the diverse lignin structures found in plants. In order to take into account the wide range of lignin polymerization chemistries, monomers and dimer combinations of C-, H-, G-, and S-lignins as well as with hydroxycinnamic acid linkages were subjected to extensive quantum mechanical calculations to establish target data from which to build a complete molecular mechanics force field tuned specifically for diverse lignins. This was carried out in a GPU-accelerated global optimization process, whereby all molecules were parameterized simultaneously using the same internal parameter set. By parameterizing lignin specifically, we are able to more accurately represent the interactions and conformations of lignin monomers and dimers relative to a general force field. This new force field will enables computational researchers to study the effects of different linkages on the structure of lignin, as well as construct more accurate plant cell wall models based on observed statistical distributions of lignin that differ between

Future changes in South American biomass distributions, biome distributions and plant trait spectra is dependent on applied atmospheric forcings.

Science.gov (United States)

Langan, Liam; Scheiter, Simon; Higgins, Steven

2017-04-01

It remains poorly understood why the position of the forest-savanna biome boundary, in a domain defined by precipitation and temperature, differs in South America, Africa and Australia. Process based Dynamic Global Vegetation Models (DGVMs) are a valuable tool to investigate the determinants of vegetation distributions, however, many DGVMs fail to predict the spatial distribution or indeed presence of the South American savanna biome. Evidence suggests fire plays a significant role in mediating forest-savanna biome boundaries, however, fire alone appear to be insufficient to predict these boundaries in South America. We hypothesize that interactions between precipitation, constraints on tree rooting depth and fire, affect the probability of savanna occurrence and the position of the savanna-forest boundary. We tested our hypotheses at tropical forest and savanna sites in Brazil and Venezuela using a novel DGVM, aDGVM2, which allows plant trait spectra, constrained by trade-offs between traits, to evolve in response to abiotic and biotic conditions. Plant hydraulics is represented by the cohesion-tension theory, this allowed us to explore how soil and plant hydraulics control biome distributions and plant traits. The resulting community trait distributions are emergent properties of model dynamics. We showed that across much of South America the biome state is not determined by climate alone. Interactions between tree rooting depth, fire and precipitation affected the probability of observing a given biome state and the emergent traits of plant communities. Simulations where plant rooting depth varied in space provided the best match to satellite derived biomass estimates and generated biome distributions that reproduced contemporary biome maps well. Future projections showed that biomass distributions, biome distributions and plant trait spectra will change, however, the magnitude of these changes are highly dependent on the applied atmospheric forcings.

Entomopathogenic and plant pathogenic nematodes as opposing forces in agriculture.

Science.gov (United States)

Kenney, Eric; Eleftherianos, Ioannis

2016-01-01

Plant-parasitic nematodes are responsible for substantial damages within the agriculture industry every year, which is a challenge that has thus far gone largely unimpeded. Chemical nematicides have been employed with varying degrees of success, but their implementation can be cumbersome, and furthermore they could potentially be neutralising an otherwise positive effect from the entomopathogenic nematodes that coexist with plant-parasitic nematodes in soil environments and provide protection for plants against insect pests. Recent research has explored the potential of employing entomopathogenic nematodes to protect plants from plant-parasitic nematodes, while providing their standard degree of protection against insects. The interactions involved are highly complex, due to both the three-organism system and the assortment of variables present in a soil environment, but a strong collection of evidence has accumulated regarding the suppressive capacity of certain entomopathogenic nematodes and their mutualistic bacteria, in the context of limiting the infectivity of plant-parasitic nematodes. Specific factors produced by certain entomopathogenic nematode complexes during the process of insect infection appear to have a selectively nematicidal, or at least repellant, effect on plant-parasitic nematodes. Using this information, an opportunity has formed to adapt this relationship to large-scale, field conditions and potentially relieve the agricultural industry of one of its most substantial burdens. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Human factors engineering in Clinch River Breeder plant design

International Nuclear Information System (INIS)

Planchon, H.P. Jr.; Kaushal, N.N.; Snider, J.

1982-01-01

The Clinch River Breeder Reactor Plant (CRBRP) Project formed a Control Room Task Force to ensure that lessons learned from the Three Mile Island accident are incorporated into the design. The charter for the Control Room Task Force was to review plant operations from the control room. The focus was on the man-machine interface to ensure that the systems' designs and operator actions meshed to properly support plant operation during normal and off-normal conditions. Specific items included for review are described. This paper describes the methodology utilized to accomplish the Task Forces' objectives and the results of the review

Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO

NARCIS (Netherlands)

Loon, Van Marloes P.; Rietkerk, Max; Dekker, Stefan C.; Hikosaka, Kouki; Ueda, Miki U.; Anten, Niels P.R.

2016-01-01

Background and Aims The rising atmospheric CO₂ concentration ([CO₂]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated

EDF guide book for decontamination at power plant

International Nuclear Information System (INIS)

Glorennec, C.; Bemer, J.P.

1988-01-01

Nuclear Power Plant components or equipment often need to be more or less decontaminated before undergoing maintenance. In order to coordinate the activities of the different maintenance specialists belonging to the corporate or site organizations, the management of EDF/Nuclear and Fossil Division has created a decontamination task force. One of the objectives of this task force was to elaborate the present Guide Book for Decontamination at Power Plants. This paper provides assistance to nuclear plants operators in the very specific field of decontamination

AECL's plant Information Technologies

International Nuclear Information System (INIS)

DeVerno, M.; Lupton, L.; Didsbury, R.; Judd, R.

1998-01-01

The competitiveness of the world-wide energy market is a continual driving force for improvements to CANDU performance and lower operating, maintenance, and administration costs. As in other industries, advanced Information Technologies (IT) are changing the way we work and conduct business. The nuclear industry is no different and there exists strong incentives to improve work processes and provide faster and more flexible access to the information needed to effectively manage and maintain nuclear plant assets. AECL has responded to these forces through the development of a vision of integrated IT systems addressing all phases of nuclear plant development and operations. This includes the initial engineering, design, and construction processes as well as support to the long-term operations and maintenance. Integral to the AECL vision is the need for cost-effective engineering and operational configuration management systems, proactive maintenance processes and systems, and advanced plant surveillance and diagnostics. This paper presents the vision and describes the integrated information systems needed to manage both the design basis and operating plant data systems to ensure the cost-effective, long-term viability of CANDU plants. (author)

TMI-2 Lessons Learned Task Force. Final report

International Nuclear Information System (INIS)

1979-10-01

In its final report reviewing the Three Mile Island accident, the TMI-2 Lessons Learned Task Force has suggested change in several fundamental aspects of basic safety policy for nuclear power plants. Changes in nuclear power plant design and operations and in the regulatory process are discussed in terms of general goals. The appendix sets forth specific recommendations for reaching these goals

Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2 : an experiment with plant populations from naturally high CO2 areas

NARCIS (Netherlands)

van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

2016-01-01

Background and Aims The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant–plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may

Less power plants

International Nuclear Information System (INIS)

TASR

2003-01-01

In the Slovak Republic the number of company power plants decreased as against 2001 by two sources. In present time only 35 companies have their own power plants. The companies Slovnaft, Kappa Sturovo, Slovensky hodvab Senica, Matador Puchov, Maytex Liptovsky MikuIas, Kovohuty Krompachy, Chemko Strazske and some Slovak sugar factories belong to the largest company power plants in force of distributing companies. Installed output of present 35 company sources is 531 MW. The largest of separate power plants as Paroplynovy cyklus Bratislava (218 MW) and VD Zilina (72 MW) belong to independent sources. Total installed output of Slovak sources was 8306 MW in the end of last year

DIMO, a plant dispersal model

NARCIS (Netherlands)

Wamelink, G.W.W.; Jochem, R.; Greft, van der J.G.M.; Franke, J.; Malinowska, A.H.; Geertsema, W.; Prins, A.H.; Ozinga, W.A.; Hoek, van der D.C.J.; Grashof-Bokdam, C.J.

2014-01-01

Due to human activities many natural habitats have become isolated. As a result the dispersal of many plant species is hampered. Isolated populations may become extinct and have a lower probability to become reestablished in a natural way. Moreover, plant species may be forced to migrate to new

Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species.

Science.gov (United States)

Harrington, Constance A; Gould, Peter J

2015-01-01

Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each species in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2-5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other species all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant species; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier.

Gravity: one of the driving forces for evolution.

Science.gov (United States)

Volkmann, D; Baluska, F

2006-12-01

Mechanical load is 10(3) larger for land-living than for water-living organisms. As a consequence, antigravitational material in form of compound materials like lignified cell walls in plants and mineralised bones in animals occurs in land-living organisms preferentially. Besides cellulose, pectic substances of plant cell walls seem to function as antigravitational material in early phases of plant evolution and development. A testable hypothesis including vesicular recycling processes into the tensegrity concept is proposed for both sensing of gravitational force and responding by production of antigravitational material at the cellular level.

Automobile impact forces on concrete wall panels. Technical report

International Nuclear Information System (INIS)

Chiapetta, R.L.; Pang, E.C.

1982-06-01

The objective of this study was to develop force-time impact signature data for use in the design or evaluation of nuclear power plant structures subject to tornado-borne automotive vehicle impact. The approach was based on the use of analytical vehicle models to calculate imact forces. To assess the significance of vehicle/structure interaction for head-on impact force-histories, a lumped-mass model of a reinforced concrete wall panel was coupled to a one-dimensional vehicle model for numerous panel design configurations within the range of practical interest. Vehicle-structure interaction was found to have relatively little effect on the force histories

Geodatabase of environmental information for Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas, 1990-2004

Science.gov (United States)

Shah, Sachin D.; Quigley, Sean M.

2005-01-01

Air Force Plant 4 (AFP4) and adjacent Naval Air Station-Joint Reserve Base (NAS-JRB) at Fort Worth, Tex., constitute a government-owned, contractor-operated (GOCO) facility that has been in operation since 1942. Contaminants from the facility, primarily volatile organic compounds (VOCs) and metals, have entered the groundwater-flow system through leakage from waste-disposal sites (landfills and pits) and from manufacturing processes (U.S. Air Force, Aeronautical Systems Center, 1995). The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force (USAF), Aeronautical Systems Center, Environmental Management Directorate (ASC/ENVR), developed a comprehensive database (or geodatabase) of temporal and spatial environmental information associated with the geology, hydrology, and water quality at AFP4 and NAS-JRB. The database of this report provides information about the AFP4 and NAS-JRB study area including sample location names, identification numbers, locations, historical dates, and various measured hydrologic data. This database does not include every sample location at the site, but is limited to an aggregation of selected digital and hardcopy data of the USAF, USGS, and various consultants who have previously or are currently working at the site.

Measuring the Mechanical Properties of Plant Cell Walls

Directory of Open Access Journals (Sweden)

Hannes Vogler

2015-03-01

Full Text Available The size, shape and stability of a plant depend on the flexibility and integrity of its cell walls, which, at the same time, need to allow cell expansion for growth, while maintaining mechanical stability. Biomechanical studies largely vanished from the focus of plant science with the rapid progress of genetics and molecular biology since the mid-twentieth century. However, the development of more sensitive measurement tools renewed the interest in plant biomechanics in recent years, not only to understand the fundamental concepts of growth and morphogenesis, but also with regard to economically important areas in agriculture, forestry and the paper industry. Recent advances have clearly demonstrated that mechanical forces play a crucial role in cell and organ morphogenesis, which ultimately define plant morphology. In this article, we will briefly review the available methods to determine the mechanical properties of cell walls, such as atomic force microscopy (AFM and microindentation assays, and discuss their advantages and disadvantages. But we will focus on a novel methodological approach, called cellular force microscopy (CFM, and its automated successor, real-time CFM (RT-CFM.

Steam power plant

International Nuclear Information System (INIS)

Campbell, J.W.E.

1981-01-01

This invention relates to power plant forced flow boilers operating with water letdown. The letdown water is arranged to deliver heat to partly expanded steam passing through a steam reheater connected between two stages of the prime mover. (U.K.)

Guide for decontamination in P.W.R. power plants

International Nuclear Information System (INIS)

Herisson, J.; Glorennec, C.

1992-01-01

Nuclear power plant components or equipment often need to be more ore less decontaminated before maintenance. In order to coordinate the activities of the various maintenance specialists belonging to the corporate or Site Organizations, the Management of EDF/Nuclear and Fossil Division has created a 'Decontamination Task Force'. The first objective of this Task Force was to prepare this 'Decontamination Guide for Nuclear Power Plants'. This document is the result of a close collaboration, within a specific working group, between representatives of Nuclear Fossil Division (from Nuclear Power Plants and Corporate Departments) and EDF Project and Construction Group. It will provide assistance to Nuclear Plants Operators in the very specific field of decontamination. (author)

Actin based processes that could determine the cytoplasmic architecture of plant cells

NARCIS (Netherlands)

Honing, van der H.S.; Emons, A.M.C.; Ketelaar, M.J.

2007-01-01

Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells

Design and implementation of remote robotic control system for nuclear power plant application achieved through kinesthetic force feedback model

International Nuclear Information System (INIS)

Roy, D.

1995-01-01

The technology of telerobotic control through a universal and transparent Man-Machine Interface is a growing field of robotics research in today's industrial scenario because of its promising application in hazardous and unstructured environments. The joystick, a sophisticated information receiver-translator-transmitter device, serves as a Man-Machine Interface for telerobots. The present paper describes the development paradigms of a remote control system for a planar four degrees-of-freedom joystick following position feed-forward force/torque feedback strategy in a bi-lateral mode. This joystick based control technology is designed to actuate an industrial robot working in nuclear power plant. The remote control system has been illustrated with model, algorithm, electronic hardware and software routines along with experimental results in order to have effective telemanipulation

Forced draft wet cooling systems

International Nuclear Information System (INIS)

Daubert, A.; Caudron, L.; Viollet, P.L.

1975-01-01

The disposal of the heat released from a 1000MW power plant needs a natural draft tower of about 130m of diameter at the base, and 170m height, or a cooling system with a draft forced by about forty vans, a hundred meters in diameter, and thirty meters height. The plumes from atmospheric cooling systems form, in terms of fluid mechanics, hot jets in a cross current. They consist in complex flows that must be finely investigated with experimental and computer means. The study, currently being performed at the National Hydraulics Laboratory, shows that as far as the length and height of visible plumes are concerned, the comparison is favorable to some types of forced draft cooling system, for low and medium velocities, (below 5 or 6m/s at 10m height. Beyond these velocities, the forced draft sends the plume up to smaller heights, but the plume is generally more dilute [fr

Overturning behaviour of nuclear power plant structures during earthquakes

International Nuclear Information System (INIS)

Dalal, J.S.; Perumalswami, P.R.

1977-01-01

Nuclear power plant structures are designed to withstand severe postulated seismic forces. Structures subjected to such forces may be found to ''overturn'', if the factor of safety is computed in the traditional way, treating these forces as static. This study considers the transient nature of the problem and draws distinction between rocking, tipping and overturning. Responses of typical nuclear power plant structures to earthquake motions are used to assess their overturning potential more realistically. Structures founded on both rock and soil are considered. It is demonstrated that the traditional factor of safety, when smaller than unity, indicates only minimal base rotations and not necessarily overturning. (auth.)

Brown algal morphogenesis: Atomic Force Microscopy as a tool to study the role of mechanical forces

Directory of Open Access Journals (Sweden)

Benoit eTesson

2014-09-01

Full Text Available Over the last few years, a growing interest has been directed toward the use of macroalgae as a source of energy, food and molecules for the cosmetic and pharmaceutical industries. Besides this, macroalgal development remains poorly understood compared to other multicellular organisms. Brown algae (Phaeophyceae form a monophyletic lineage of usually large multicellular algae which evolved independently from land plants. In their environment, they are subjected to strong mechanical forces (current, waves and tide, in response to which they modify rapidly and reversibly their morphology. Because of their specific cellular features (cell wall composition, cytoskeleton organization, deciphering how they cope with these forces might help discover new control mechanisms of cell wall softening and cellulose synthesis. Despite the current scarcity in knowledge on brown algal cell wall dynamics and protein composition, we will illustrate, in the light of methods adapted to Ectocarpus siliculosus, to what extent atomic force microscopy can contribute to advance this field of investigation.

Power plant cycle chemistry - a currently neglected power plant chemistry discipline

International Nuclear Information System (INIS)

Bursik, A.

2005-01-01

Power plant cycle chemistry seems to be a stepchild at both utilities and universities and research organizations. It is felt that other power plant chemistry disciplines are more important. The last International Power Cycle Chemistry Conference in Prague may be cited as an example. A critical review of the papers presented at this conference seems to confirm the above-mentioned statements. This situation is very unsatisfactory and has led to an increasing number of component failures and instances of damage to major cycle components. Optimization of cycle chemistry in fossil power plants undoubtedly results in clear benefits and savings with respect to operating costs. It should be kept in mind that many seemingly important chemistry-related issues lose their importance during forced outages of units practicing faulty plant cycle chemistry. (orig.)

Plants status monitor: Modelling techniques and inherent benefits

International Nuclear Information System (INIS)

Breeding, R.J.; Lainoff, S.M.; Rees, D.C.; Prather, W.A.; Fickiessen, K.O.E.

1987-01-01

The Plant Status Monitor (PSM) is designed to provide plant personnel with information on the operational status of the plant and compliance with the plant technical specifications. The PSM software evaluates system models using a 'distributed processing' technique in which detailed models of individual systems are processed rather than by evaluating a single, plant-level model. In addition, development of the system models for PSM provides inherent benefits to the plant by forcing detailed reviews of the technical specifications, system design and operating procedures, and plant documentation. (orig.)

Forests planted for ecosystem restoration or conservation.

Science.gov (United States)

Constance A. Harrington

1999-01-01

Although the phrase, "planting for ecosystem restoration," is of recent origin, many of the earliest large-scale tree plantings were made for what we now refer to as "'restoration" or "conservation" goals. Forest restoration activities may be needed when ecosystems are disturbed by either natural or anthropogenic forces. Disturbances...

Model tests on overall forces on the SSG pilot plant

DEFF Research Database (Denmark)

Margheritini, Lucia; Morris, Alex

. The tests have been realized at the Department of civil Engineering, AAU, in the 3D deep water tank with a scale model 1:60 to prototype and a reproduced bathymetry of the selected location at the time of the experiments. Overall forces and moments have been measured during the tests. The results are given...

Improving nuclear utility generation capacity, understanding the sources of forced outage and learning how to prevent them

International Nuclear Information System (INIS)

Brodeur, D.L.; Todreas, N.E.; Angus, V.T.

1998-01-01

MIT and PECO Energy have completed a detailed examination of the sources of forced outages at the Limerick Generating Station (LGS) Boiling Water Reactor Class IV (BWR IV) site over a five year period and contrasted that information to similar BWR IV utilities in the United States over the same period. Each forced outage was attributed to one system and assigned causal codes of equipment versus human factors and failure attributes such as weak design, poor craftsmanship, and worn parts. It was found that fifty four percent of the lost power at LGS was the result of Balance of Plant failures. Industry wide data identifies fifty nine percent of the lost power as attributed to Balance of Plant failures. Balance of Plant systems are those systems not included in the primary and safety related system category. Considering failure causal factors, forty six percent of the lost power at the utility under study was the result of equipment factors such as weak design or worn parts. Significantly, the study showed a high variance between those systems which caused significant forced outage at the two sister LGS units. This demonstrated the infrequent nature of plant forced outages within a given system. This was supported by the observation that dominant systems attributing to forced outage at LGS were not equally represented in industry data. It is suggested that for individual utilities to dramatically improve unit capability factors with regard to Balance of Plant systems, they must learn from industry wide experiences and develop cooperative means of exchanging lessons learned among similarly designed plants and systems. With the broad knowledge base of system failures, current designs must be frequently assessed and altered until each system poses an acceptable level of risk to generation capacity. (author)

Entry into force of the Convention on Supplementary Compensation for Nuclear Damage: Opening the umbrella

International Nuclear Information System (INIS)

McRae, Ben

2015-01-01

There are 431 commercial nuclear power plants around the world. On 14 April 2015, 193 of these power plants were covered by a nuclear liability instrument (118 power plants by the Paris Convention and 75 by the Vienna Convention). With the entry into force of the Convention on Supplementary Compensation for Nuclear Damage (CSC)4 on 15 April 2015, the number of power plants covered by a nuclear liability instrument increased to 340. Thus, the entry into force of the CSC marked a major milestone towards the establishment of a global nuclear liability regime. This article discusses several events that have promoted progress towards a global nuclear liability regime and then addresses several questions that may arise as countries consider actions necessary to achieve such a regime. (author)

Plant-phytopathogen interactions: bacterial responses to environmental and plant stimuli.

Science.gov (United States)

Leonard, Simon; Hommais, Florence; Nasser, William; Reverchon, Sylvie

2017-05-01

Plant pathogenic bacteria attack numerous agricultural crops, causing devastating effects on plant productivity and yield. They survive in diverse environments, both in plants, as pathogens, and also outside their hosts as saprophytes. Hence, they are confronted with numerous changing environmental parameters. During infection, plant pathogens have to deal with stressful conditions, such as acidic, oxidative and osmotic stresses; anaerobiosis; plant defenses; and contact with antimicrobial compounds. These adverse conditions can reduce bacterial survival and compromise disease initiation and propagation. Successful bacterial plant pathogens must detect potential hosts and also coordinate their possibly conflicting programs for survival and virulence. Consequently, these bacteria have a strong and finely tuned capacity for sensing and responding to environmental and plant stimuli. This review summarizes our current knowledge of the signals and genetic circuits that affect survival and virulence factor expression in three important and well-studied plant pathogenic bacteria with wide host ranges and the capacity for long-term environmental survival. These are: Ralstonia solanacerarum, a vascular pathogen that causes wilt disease; Agrobacterium tumefaciens, a biotrophic tumorigenic pathogen responsible for crown gall disease and Dickeya, a brute force apoplastic pathogen responsible for soft-rot disease. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Proceedings of the meeting of a task force on problems of rare events in the reliability analysis of nuclear power plants

International Nuclear Information System (INIS)

1976-01-01

In safety problems of nuclear plants interest centres on various types of rare events. These may extend from rare modes of failures in the component parts of the system and plant, the simultaneous occurrence of a very low resistance of a structural member and an extremely high load, to rare catastrophic failures which affect whole plant and system complexes. The obvious need is therefore to understand the patterns of behaviour of these events in space and time domains and be able to make some adequate estimate of their probability of occurrence. In 1975, a Task Force of Experts on the Statistical Analysis of Rare Events in Nuclear Installations was set up, its main objective being to explore methods for handling the problems of reliability analysis involving rare events. The main topic area of the Ispra meeting concerns the statistical analysis of structures such as containment and pressure vessels, automatic protection systems, and allied items, with a view to giving a quantified probabilistic statement on particular reliability characteristics. The particular subjects covered by the invited experts who would normally be working in specialized fields, includes, specifically, statistical modelling of rare events, decision theory applied to rare events, small sampling theory in the case of rare events. Man-made phenomena as well as natural phenomena are also considered, as they involve different approaches to modelling. 22 papers are presented, with reports on group discussions

Comments on the seismic safety of nuclear power plants in Eastern Europe

Energy Technology Data Exchange (ETDEWEB)

Tarics, A G [29 Winward Road, Belvedere, CA 94920 (United States); Kelly, J M [Earthquake Engineering Research Center, University of California, Berkeley, CA (United States); Csorba, E M [Technical University Vienna, Vienna (Austria)

2001-03-01

After the break-up of the Soviet Union, ten countries in Eastern Europe inherited Soviet-designed nuclear power plants which were constructed without adequate provisions to resist earthquake-generated lateral forces. An earthquake at their locations could seriously damage these plants and could result in Chernobyl-like consequences on the environment. There is an ongoing program to reinforce these plants using conventional piecemeal methods. A newly developed seismic protection strategy called 'base isolation' or 'seismic isolation', widely used in the United States to retrofit existing buildings, is recommended as an economical, technically superior, and more effective solution - where applicable - to make these nuclear power plants capable of resisting seismic forces. (author)

Comments on the seismic safety of nuclear power plants in Eastern Europe

International Nuclear Information System (INIS)

Tarics, A.G.; Kelly, J.M.; Csorba, E.M.

2001-01-01

After the break-up of the Soviet Union, ten countries in Eastern Europe inherited Soviet-designed nuclear power plants which were constructed without adequate provisions to resist earthquake-generated lateral forces. An earthquake at their locations could seriously damage these plants and could result in Chernobyl-like consequences on the environment. There is an ongoing program to reinforce these plants using conventional piecemeal methods. A newly developed seismic protection strategy called 'base isolation' or 'seismic isolation', widely used in the United States to retrofit existing buildings, is recommended as an economical, technically superior, and more effective solution - where applicable - to make these nuclear power plants capable of resisting seismic forces. (author)

Forced vibration tests on the reactor building of a nuclear power station, 1

International Nuclear Information System (INIS)

Takeda, Toshikazu; Tsunoda, Tomohiko; Wakamatsu, Kunio; Kaneko, Masataka; Nakamura, Mitsuru; Kunoh, Toshio; Murahashi, Hisahiro

1988-01-01

Tsuruga Unit No.2 Nuclear Power Station of the Japan Atomic Power Company is the first PWR-type 4-loop plant constructed in Japan with a prestressed concrete containment vessel (PCCV). This report describes forced vibration tests carried out on the reactor building of this plant. The following were obtained as results: (1) The results of the forced vibration tests corresponded well on the whole with design values. (2) The vibration characteristics of the PCCV observed in the tests after prestressing are no different from the ones before prestressing. This shows that the vibration properties of the PCCV are practically independent of prestressing loads. (3) A seismic response analysis of the design basis earthquake was made on the design model reflecting the test results. The seismic safety of the plant was confirmed by this analysis. (author)

Approaches to translational plant science

DEFF Research Database (Denmark)

Dresbøll, Dorte Bodin; Christensen, Brian; Thorup-Kristensen, Kristian

2015-01-01

is lessened. In our opinion, implementation of translational plant science is a necessity in order to solve the agricultural challenges of producing food and materials in the future. We suggest an approach to translational plant science forcing scientists to think beyond their own area and to consider higher......Translational science deals with the dilemma between basic research and the practical application of scientific results. In translational plant science, focus is on the relationship between agricultural crop production and basic science in various research fields, but primarily in the basic plant...... science. Scientific and technological developments have allowed great progress in our understanding of plant genetics and molecular physiology, with potentials for improving agricultural production. However, this development has led to a separation of the laboratory-based research from the crop production...

How light competition between plants affects trait optimization and vegetation-atmosphere feedbacks

NARCIS (Netherlands)

van Loon, M.P.

2016-01-01

How plants respond to climate change is of major concern, as plants will strongly impact future ecosystem functioning, food production and climate. Competition between plants for resources is an important selective force. As a result competition through natural selection determines vegetation

Catalysts of plant cell wall loosening [version 1; referees: 2 approved

OpenAIRE

Daniel J. Cosgrove

2016-01-01

The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyl...

Ant-plant symbioses: Stalking the chuyachaqui.

Science.gov (United States)

Davidson, D W; McKey, D

1993-09-01

According to Quechua-speaking peoples, orchard-like stands ('Supay Chacras') of two Amazonian ant-plant species are cultivated by the devil, or 'Chuyachaqui'. These "devil gardens" offer extreme examples of specializations that have evolved repeatedly in ant-plant associations. Numerous investigations are beginning to disclose the identity of the Chuyachaqui - the forces behind evolutionary specialization in ant-plant symbioses. These developments have important implications for our understanding of modes of coevolution in symbiotic mutualism, remarkable convergent similarities in the form of ant-plant symbioses on different continents, and pronounced intercontinental differences in the diversity and taxonomic composition of associates. Copyright © 1993. Published by Elsevier Ltd.

Applications of optical manipulation in plant biology

Science.gov (United States)

Buer, Charles S.

Measuring small forces in biology is important for determining basic physiological parameters of a cell. The plant cell wall provides a primary defense and presents a barrier to research. Magnitudes of small forces are impossible to measure with mechanical transducers, glass needles, atomic force microscopy, or micropipet-based force transduction due to the cell wall. Therefore, a noninvasive method of breaching the plant cell wall to access the symplastic region of the cell is required. Laser light provides sub-micrometer positioning, particle manipulation without mechanical contact, and piconewton force determination. Consequently, the extension of laser microsurgery to expand an experimental tool for plant biology encompassed the overall objective. A protocol was developed for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. Ginkgo biloba and Agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques. Better than 95% survival was achieved after plasmolyzing G. biloba cells, ablating a 2-4 μm hole through the cell wall using a pulsed UV laser beam, trapping and manipulating bacteria into the periplasmic region, and deplasmolyzing the cells. Optical trapping experiments implied a difference existed between the bacteria models. Determining the optical trapping efficiency of Agrobacterium rhizogenes and A. tumefaciens strains indicated the A. rhizogenes strain, ATCC 11325, was significantly less efficiently trapped than strains A4 and ATCC 15834 and the A. tumefaciens strain LBA4404. Differences were also found in capsule generation, growth media viscosity, and transmission electron microscopy negative staining implying that a difference in surface structure exists. Calcofluor fluorescence suggests the difference involves an exopolysaccharide. Callus cell plasmolysis revealed Hechtian strands interconnecting the plasma membrane and the cell wall

Myoelectric hand prosthesis force control through servo motor current feedback.

Science.gov (United States)

Sono, Tálita Saemi Payossim; Menegaldo, Luciano Luporini

2009-10-01

This paper presents the prehension force closed-loop control design of a mechanical finger commanded by electromyographic signal (EMG) from a patient's arm. The control scheme was implemented and tested in a mechanical finger prototype with three degrees of freedom and one actuator, driven by arm muscles EMG of normal volunteers. Real-time indirect estimation of prehension force was assessed by measuring the DC servo motor actuator current. A model of the plant comprising finger, motor, and grasped object was proposed. Model parameters were identified experimentally and a classical feedback phase-lead compensator was designed. The controlled mechanical finger was able to provide a more accurate prehension force modulation of a compliant object when compared to open-loop control.

A study on the force balance of an unbalanced globe valve

International Nuclear Information System (INIS)

Yang, Sang Min; Cho, Taik Dong; Ko, Sung Ho; Lee, Ho Young

2007-01-01

A pneumatic control valve is a piping element that controls the volumetric flow rate and pressure of a fluid: it is necessary to analyze the characteristics of the forces with respect to the opening of the valve in order to evaluate its operating performance. The forces occurring during operation are: resisting force and actuator force, where the load resistance is mostly affected by the fluid pressure difference of the valve. In this study, a force balance equation derived from the equilibrium relationship between the resisting force and the actuator force of an unbalanced globe valve is proposed, and the force balance equations are used to model the dynamic equations of a pneumatic unbalanced globe valve installed in nuclear power plants. A CFD analysis is also carried out to evaluate the pressure distribution and forces acting on the top and bottom planes of the valve plug. The results of this analysis have been verified through experimentation. This study has shown that the fluid pressure difference between the inlet and outlet of the valve, measured from the force balance equation of an unbalanced valve, should actually be examined with the fluid-pressure difference between the top and bottom side of the valve plug

Weed biocontrol insects reduce native plant recruitment through second-order apparent competition

Science.gov (United States)

Dean E. Pearson; Ragan M. Callaway

2008-01-01

Small-mammal seed predation is an important force structuring native-plant communities that may also influence exotic-plant invasions. In the intermountain West, deer mice (Peromyscus maniculatus) are prominent predators of native-plant seeds, but they avoid consuming seeds of certain widespread invasives like spotted knapweed (Centaurea...

Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2

NARCIS (Netherlands)

Boer, H.J. de; Lammertsma, E.I.; Wagner-Cremer, F.; Dilcher, D.L.; Wassen, M.J.; Dekker, S.C.

2011-01-01

Plant physiological adaptation to the global rise in atmospheric CO 2 concentration (CO2) is identified as a crucial climatic forcing. To optimize functioning under rising CO2, plants reduce the diffusive stomatal conductance of their leaves (gs) dynamically by closing stomata and structurally by

Prospects for power plant technology

International Nuclear Information System (INIS)

Schilling, H.D.

1993-01-01

Careful conservation of resources in the enlarged context of the rational utilization of energy, the environment and capital will determine future power plant technology. The mainstays will be the further development of power plant concepts based on fossil (predominantly coal) and nuclear fuels; world-wide, also regenerative and CO 2 -free hydro-electric power will play a role. Rapid conversion of the available potential requires clear, long-term stable and reliable political framework conditions for the release of the necessary entrepreneurial forces. (orig.) [de

Role of the plant cell wall in gravity resistance.

Science.gov (United States)

Hoson, Takayuki; Wakabayashi, Kazuyuki

2015-04-01

Gravity resistance, mechanical resistance to the gravitational force, is a principal graviresponse in plants, comparable to gravitropism. The cell wall is responsible for the final step of gravity resistance. The gravity signal increases the rigidity of the cell wall via the accumulation of its constituents, polymerization of certain matrix polysaccharides due to the suppression of breakdown, stimulation of cross-link formation, and modifications to the wall environment, in a wide range of situations from microgravity in space to hypergravity. Plants thus develop a tough body to resist the gravitational force via an increase in cell wall rigidity and the modification of growth anisotropy. The development of gravity resistance mechanisms has played an important role in the acquisition of responses to various mechanical stresses and the evolution of land plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methylome evolution in plants.

Science.gov (United States)

Vidalis, Amaryllis; Živković, Daniel; Wardenaar, René; Roquis, David; Tellier, Aurélien; Johannes, Frank

2016-12-20

Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over long timescales is largely a byproduct of genomic changes. By contrast, methylome evolution over short timescales appears to be driven mainly by spontaneous epimutational events. We argue that novel methods based on analyses of the methylation site frequency spectrum (mSFS) of natural populations can provide deeper insights into the evolutionary forces that act at each timescale.

The Net Climate Impact of Coal-Fired Power Plant Emissions

Science.gov (United States)

Shindell, D.; Faluvegi, G.

2010-01-01

Coal-fired power plants influence climate via both the emission of long-lived carbon dioxide (CO2) and short-lived ozone and aerosol precursors. Using a climate model, we perform the first study of the spatial and temporal pattern of radiative forcing specifically for coal plant emissions. Without substantial pollution controls, we find that near-term net global mean climate forcing is negative due to the well-known aerosol masking of the effects of CO2. Imposition of pollution controls on sulfur dioxide and nitrogen oxides leads to a rapid realization of the full positive forcing from CO2, however. Long-term global mean forcing from stable (constant) emissions is positive regardless of pollution controls. Emissions from coal-fired power plants until 1970, including roughly 1/3 of total anthropogenic CO2 emissions, likely contributed little net global mean climate forcing during that period though they may have induce weak Northern Hemisphere mid-latitude (NHml) cooling. After that time many areas imposed pollution controls or switched to low sulfur coal. Hence forcing due to emissions from 1970 to 2000 and CO2 emitted previously was strongly positive and contributed to rapid global and especially NHml warming. Most recently, new construction in China and India has increased rapidly with minimal application of pollution controls. Continuation of this trend would add negative near-term global mean climate forcing but severely degrade air quality. Conversely, following the Western and Japanese pattern of imposing air quality pollution controls at a later time could accelerate future warming rates, especially at NHmls. More broadly, our results indicate that due to spatial and temporal inhomogeneities in forcing, climate impacts of multi-pollutant emissions can vary strongly from region to region and can include substantial effects on maximum rate-of-change, neither of which are captured by commonly used global metrics. The method we introduce here to estimate

Traits of estuarine marsh plants affect wave dissipation

Science.gov (United States)

Schulte Ostermann, Tilla; Heuner, Maike; Bouma, Tjeerd

2017-04-01

Estuarine vegetation can attenuate hydrodynamic forces such as waves or flow velocities and therefore has an important role in natural tidal bank protection. This function depends on the degree of hydrodynamic forces, bank morphology and on plant traits of the dominant species. The traits vary between the species but also between different marsh sites. Biomass, stem density and biomechanical properties are crucial factors that influence the rate of wave dissipation. These properties illustrate the trade-offs a species is facing in such a dynamic habitat and highlight the ability of dominant species such as Bolboschoenus maritimus and Schoenoplectus tabernaemontani to protect the tidal bank. Along the Elbe estuary, traits of dominant marsh plant species were measured on different sites. The sites vary e.g. in their elevation, salt levels and inundation periods. To analyse the role that plant traits can play in wave dissipation, the structure of the vegetation as well as the composition was recorded. Biomechanical tests helped to understand the species traits regarding stem flexibility and to determine the effects of plant traits on wave dynamics and vice versa. On the conference, we will present how plant traits affect the wave dissipation on tidal marshes and why they vary.

Improved attribution of climate forcing to emissions by pollutant and sector

Science.gov (United States)

Shindell, D. T.

2009-12-01

Evaluating multi-component climate change mitigation strategies requires knowledge of the diverse direct and indirect effects of emissions. Methane, ozone and aerosols are linked through atmospheric chemistry so that emissions of a single pollutant can affect several species. I will show new calculations of atmospheric composition changes, radiative forcing, and the global warming potential (GWP) for increased emissions of tropospheric ozone and aerosol precursors in a coupled composition-climate model. The results demonstrate that gas-aerosol interactions substantially alter the relative importance of the various emissions, suggesting revisions to the GWPs used in international carbon trading. Additionally, I will present results showing how the net climate impact of particular activities depends strongly upon non-CO2 forcing agents for some sectors. These results will be highlighted by discussing the interplay between air quality emissions controls and climate for the case of emissions from coal-fired power plants. The changing balance between CO2 and air quality pollutants from coal plants may have contributed to the 20th century spatial and temporal patterns of climate change, and is likely to continue to do so as more and more plants are constructed in Asia.

Effects on Water Management and Quality Characteristics of Ozone Application in Chicory Forcing Process: A Pilot System

Directory of Open Access Journals (Sweden)

Carlo Nicoletto

2017-04-01

Full Text Available Agriculture is the largest user of world water resources, accounting for 70% of all consumption. Reducing water consumption and increasing water use efficiency in agriculture are two of the main challenges that need to be faced in the coming decades. Radicchio Rosso di Treviso Tardivo (RTT is a vegetable that requires a water forcing process prior to final commercialization which presents a significant environmental impact due to the high water volumes used and then dispersed into the environment. The experiment was aimed at reducing the water use in the forcing process of RTT, by developing a pilot system with recycled water in a closed loop through ozone treatment. Concerning water quality, the redox potential value was higher in the ozonized system, whereas turbidity, pH and electrical conductivity of the ozonized system did not change significantly from the control. Yield and quality of plants obtained in the ozonized system did not significantly differ from the control plants except for the antioxidant activity that was higher in plants forced using the water treated with ozone. Our initial results suggest that the ozone treatment could be applied in the forcing process and is suitable for growers, saving up to 95% of water volumes normally used for this cultivation practice.

French regulations for countering external violent forces affecting nuclear power stations

International Nuclear Information System (INIS)

Dupraz, B.

1986-01-01

This article describes the general principles underlying nuclear safety regulations to counter external violent forces to which plants can be exposed. It then examines the statutory directives concerning external violences connected with human activities or originating from natural phenomena. 3 refs [fr

Hypothetical requirements on number of personnel in Czechoslovak nuclear power plants

International Nuclear Information System (INIS)

Halik, J.

1990-01-01

The structural changes of Czechoslovak power prevent prediction of labor force development by extrapolating the existing development trends. Nuclear power demands a different qualification and occupation structure of the labor force than conventional power generation. The prediction of the number of personnel is based on data on the expected installed capacity and on its commissioning. The following organizational structures are envisaged for a nuclear power plant: the divisions of the Director, of production, maintenance, radiation safety and quality control, technology and investment, economics and personnel. A total of 15,654 personnel are envisaged for nuclear power plants in 2005. A brief comparison is submitted of labor demands in nuclear power plants in Czechoslovakia and in the world. (M.D.). 1 fig., 4 tabs., 3 refs

Competence and regulatory interactions during regeneration in plants

Directory of Open Access Journals (Sweden)

Ajai Joseph Pulianmackal

2014-04-01

Full Text Available The ability to regenerate is widely exploited by multitudes of organisms ranging from unicellular bacteria to multicellular plants for their propagation and repair. But the levels of competence for regeneration vary from species to species. While variety of living cells of a plant display regeneration ability, only a few set of cells maintain their stemness in mammals. This highly pliable nature of plant cells in-terms of regeneration can be attributed to their high developmental plasticity. De novo organ initiation can be relatively easily achieved in plants by proper hormonal regulations. Elevated levels of plant hormone auxin induces the formation of proliferating mass of pluripotent cells called callus, which predominantly express lateral root meristem markers and hence is having an identity similar to lateral root primordia. Organ formation can be induced from the callus by modulating the ratio of hormones. An alternative for de novo organogenesis is by the forced expression of plant specific transcription factors. The mechanisms by which plant cells attain competence for regeneration on hormonal treatment or forced expression remain largely elusive. Recent studies have provided some insight into how the epigenetic modifications in plants affect this competence. In this review we discuss the present understanding of regenerative biology in plants and scrutinize the future prospectives of this topic. While discussing about the regeneration in the sporophyte of angiosperms which is well studied, here we outline the regenerative biology of the gametophytic phase and discuss about various strategies of regeneration that have evolved in the domain of life so that a common consensus on the entire process of regeneration can be made.

Science and Technology: The Making of the Air Force Research Laboratory

Science.gov (United States)

2000-01-01

realize the long- term consequences of this dramatic event. Air Force leaders had unwit t ingly planted seeds that would grow into a s ingle Air...Nevertheless, Paul’s contribution was extremely s ignif icant because he had planted the seed and made the recommendation for a single lab...was cordia l and a l l bus i- ness as the smal l bu t in f luen t ia l group took their seats. Mr. Money and General Muellner were pre- sent

Springfield Processing Plant (SPP) Facility Information

Energy Technology Data Exchange (ETDEWEB)

Leach, Janice; Torres, Teresa M.

2012-10-01

The Springfield Processing Plant is a hypothetical facility. It has been constructed for use in training workshops. Information is provided about the facility and its surroundings, particularly security-related aspects such as target identification, threat data, entry control, and response force data.

Corrected direct force balance method for atomic force microscopy lateral force calibration

International Nuclear Information System (INIS)

Asay, David B.; Hsiao, Erik; Kim, Seong H.

2009-01-01

This paper reports corrections and improvements of the previously reported direct force balance method (DFBM) developed for lateral calibration of atomic force microscopy. The DFBM method employs the lateral force signal obtained during a force-distance measurement on a sloped surface and relates this signal to the applied load and the slope of the surface to determine the lateral calibration factor. In the original publication [Rev. Sci. Instrum. 77, 043903 (2006)], the tip-substrate contact was assumed to be pinned at the point of contact, i.e., no slip along the slope. In control experiments, the tip was found to slide along the slope during force-distance curve measurement. This paper presents the correct force balance for lateral force calibration.

Framatome ANP GmbH concept of Plant Life Management (PLIM)

International Nuclear Information System (INIS)

Daeuwel, W.; Biemann, W.; Danisch, R.; Kastner, B.; Meyer, W.; Nopper, H.; Waas, U.; Warnken, L.

2002-01-01

The deregulation of the power generation industry has resulted in increased competitive pressure and is forcing operators to improve plant operating economy while maintaining high levels of plant safety. A key factor to meeting this challenge is to apply a comprehensive plant life management (PLIM) approach which addresses all relevant ageing and degradation mechanisms regarding the safety concept, plant component structures and documentation, plant personnel, consumables, operations management system and administrative controls. For this reason, Framatome ANP GmbH has developed an integrated PLIM concept applicable for both new and operating plants and focusing on the safety concept, plant component structures and documentation. (orig.)

Acceptance criteria for determining armed response force size at nuclear power plants

International Nuclear Information System (INIS)

1983-02-01

This guidance document contains acceptance criteria to be used in the NRC license review process. It consists of a scored worksheet and guidelines for interpreting the worksheet score that can be used in determining the adequacy of the armed response force size at a nuclear power reactor facility

Safeguards and security modeling for electrochemical plants

International Nuclear Information System (INIS)

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

2013-01-01

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

Safeguards and security modeling for electrochemical plants

Energy Technology Data Exchange (ETDEWEB)

Cipiti, B.B.; Duran, F.A.; Mendoza, L.A.; Parks, M.J.; Dominguez, D.; Le, T.D. [Sandia National Laboratories, PO Box 5800 MS 0747, Albuquerque, NM 87185 (United States)

2013-07-01

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

Microorganism and filamentous fungi drive evolution of plant synapses.

Science.gov (United States)

Baluška, František; Mancuso, Stefano

2013-01-01

In the course of plant evolution, there is an obvious trend toward an increased complexity of plant bodies, as well as an increased sophistication of plant behavior and communication. Phenotypic plasticity of plants is based on the polar auxin transport machinery that is directly linked with plant sensory systems impinging on plant behavior and adaptive responses. Similar to the emergence and evolution of eukaryotic cells, evolution of land plants was also shaped and driven by infective and symbiotic microorganisms. These microorganisms are the driving force behind the evolution of plant synapses and other neuronal aspects of higher plants; this is especially pronounced in the root apices. Plant synapses allow synaptic cell-cell communication and coordination in plants, as well as sensory-motor integration in root apices searching for water and mineral nutrition. These neuronal aspects of higher plants are closely linked with their unique ability to adapt to environmental changes.

Plant community variability on a small area in southeastern Montana

Science.gov (United States)

James G. MacCracken; Daniel W. Uresk; Richard M. Hansen

1984-01-01

Plant communities are inherently variable due to a number of environmental and biological forces. Canopy cover and aboveground biomass were determined for understory vegetation in plant communities of a prairie grassland-forest ecotone in southeastern Montana. Vegetation units were described using polar ordination and stepwise discriminant analysis. Nine of a total of...

Framatome ANP worldwide experience in ageing and plant life management

International Nuclear Information System (INIS)

Daeuwel, W.; Kastner, B.; Nopper, H.

2004-01-01

The deregulation of the power generation industry has resulted in increased competitive pressure and is forcing operators to improve plant operating economy while maintaining high levels of plant safety. A key factor to meet this challenge is to apply a comprehensive plant life management (PLIM) approach which addresses all relevant ageing and degradation mechanisms regarding the safety concept, plant components and documentation, plant personnel, consumables, operations management system and administrative controls. For this reason, Framatome ANP has developed an integrated PLIM concept focussing on the safety concept, plant components and documentation. Representative examples for plant wide analyses are described in the following. The results of the analyses support the plant owner for taking the strategic decisions, involved in plant life extension (PLEX). (orig.)

Seismic effects on nuclear power plants

International Nuclear Information System (INIS)

Borea, A.L.; Meek, J.L.

1973-01-01

This paper sets out to discuss the problems related to the design of the nuclear power plant structure for transient loads that may be experienced from ground motions. It recognizes that ground motion may be experienced from several sources such as nearby explosion, forced vibration, from machinery or from an earthquake. In the first instance of an explosion, there is a need to study the basic wave propagation problem and to obtain expressions for ground motion and acceleration at a distance from the disturbing force. In this the importance of foundation material is stressed. The natural phenomena of the earthquake is also considered. Features associated with attempts to define a suitable basic earthquake - its magnitude, its probability of occurrence, etc. are discussed. Speculation is made as to the probability of earthquake in Australia. The end product of all such investigation is the study of the power plant structures themselves, under the influence of the dynamic forces. This may be undertaken on the crude basis of spectral analysis or by more refined finite element models using a specified earthquake as input. Here emphasis is placed on necessity to include the interaction between foundation and structure as well as accurate modelling of the structure itself. (author)

The Development of a Scientific Evaluation System of Force-on-Force (FOF) Exercise for Performance-based Regulation in Nuclear Security

Energy Technology Data Exchange (ETDEWEB)

Koh, Moonsung; Jung, Myungtak [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2015-05-15

A terrorist attack or sabotage at a nuclear facility could lead result in a great amount of loss of life and social chaos, in addition to serious radiological damage. As threats have been evolved more intelligent, divergent, advanced, the international societies including IAEA encourage for all member states to establish the performance-based regulation using Forceon- Force (FOF) exercise, computer simulation. Consequently, the performance evaluation for physical protection at nuclear facilities should focus on properly reacting to threat scenarios. Physical protection should also include detecting, blocking, delaying, interrupting including the human and technical factors the adversary having malicious intention of the realistic main threat element before he accomplishes the goal based on Design Basis Threat (DBT). After the completion of the FOF evaluation system, KINAC will evaluate, and later strengthen its overall security program in response to changes in the threat environment, technological advancements, and lessons learned. As a result, substantial improvements to a nuclear facility security can be predicted. These improvements will focus on a plant security force, physical barriers, intrusion detection systems, surveillance systems, and access controls. Through the building a Force-on-Force scientific evaluation system, KINAC will establish an efficient physical protection implementation system for nuclear energy facilities.

The Development of a Scientific Evaluation System of Force-on-Force (FOF) Exercise for Performance-based Regulation in Nuclear Security

International Nuclear Information System (INIS)

Koh, Moonsung; Jung, Myungtak

2015-01-01

A terrorist attack or sabotage at a nuclear facility could lead result in a great amount of loss of life and social chaos, in addition to serious radiological damage. As threats have been evolved more intelligent, divergent, advanced, the international societies including IAEA encourage for all member states to establish the performance-based regulation using Forceon- Force (FOF) exercise, computer simulation. Consequently, the performance evaluation for physical protection at nuclear facilities should focus on properly reacting to threat scenarios. Physical protection should also include detecting, blocking, delaying, interrupting including the human and technical factors the adversary having malicious intention of the realistic main threat element before he accomplishes the goal based on Design Basis Threat (DBT). After the completion of the FOF evaluation system, KINAC will evaluate, and later strengthen its overall security program in response to changes in the threat environment, technological advancements, and lessons learned. As a result, substantial improvements to a nuclear facility security can be predicted. These improvements will focus on a plant security force, physical barriers, intrusion detection systems, surveillance systems, and access controls. Through the building a Force-on-Force scientific evaluation system, KINAC will establish an efficient physical protection implementation system for nuclear energy facilities

Investigation of Calibrating Force Transducer Using Sinusoidal Force

International Nuclear Information System (INIS)

Zhang Li; Wang Yu; Zhang Lizhe

2010-01-01

Sinusoidal force calibration method was studied several years before at Physikalisch-Technische Bundesanstalt (PTB). A similar dynamic force calibration system is developed at Changcheng Institute of Metrology and Measurement (CIMM). It uses electro-dynamic shakers to generate dynamic force in the range from 1 N to 20 kN, and heterodyne laser interferometers are used for acceleration measurement. The force transducer to be calibrated is mounted on the shaker, and a mass block is screwed on the top of force transducer, the sinusoidal forces realized by accelerated load masses are traceable to acceleration and mass according to the force definition. The methods of determining Spatial-dependent acceleration on mass block and measuring the end mass of force transducer in dynamic force calibration are discussed in this paper.

Assessment of Effective Prestressed Force of Nuclear Containment Building using SI Technique

Energy Technology Data Exchange (ETDEWEB)

Lee, H. P.; Jang, J. B.; Hwang, K. M.; Song, Y. C. [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2010-10-15

Bonded tendons have been used in reactor buildings of heavy water reactors and the light water reactors of some nuclear power plants operating in Korea. The assessment of prestressed forces on those bonded tendons is becoming an important issue in assuring their continuous operation beyond their design life. In order to assess the effective prestressed force on the bonded tendon, indirect assessment techniques have been applying to the test beams which were manufactured on construction time. Therefore, this research mainly forced to establish the assessment methodology to measure directly the effective prestressed force on the bonded tendon of containment buildings using System Identification (SI) technique. To accomplish this purpose, simple SI method was proposed and adapted three dimensional finite element analysis of the 1:4 scale prestressed concrete containment vessel (PCCV) tested by Sandia National Laboratory in 2000

Comparison of Cellulose Iβ Simulations with Three Carbohydrate Force Fields.

Science.gov (United States)

Matthews, James F; Beckham, Gregg T; Bergenstråhle-Wohlert, Malin; Brady, John W; Himmel, Michael E; Crowley, Michael F

2012-02-14

Molecular dynamics simulations of cellulose have recently become more prevalent due to increased interest in renewable energy applications, and many atomistic and coarse-grained force fields exist that can be applied to cellulose. However, to date no systematic comparison between carbohydrate force fields has been conducted for this important system. To that end, we present a molecular dynamics simulation study of hydrated, 36-chain cellulose Iβ microfibrils at room temperature with three carbohydrate force fields (CHARMM35, GLYCAM06, and Gromos 45a4) up to the near-microsecond time scale. Our results indicate that each of these simulated microfibrils diverge from the cellulose Iβ crystal structure to varying degrees under the conditions tested. The CHARMM35 and GLYCAM06 force fields eventually result in structures similar to those observed at 500 K with the same force fields, which are consistent with the experimentally observed high-temperature behavior of cellulose I. The third force field, Gromos 45a4, produces behavior significantly different from experiment, from the other two force fields, and from previously reported simulations with this force field using shorter simulation times and constrained periodic boundary conditions. For the GLYCAM06 force field, initial hydrogen-bond conformations and choice of electrostatic scaling factors significantly affect the rate of structural divergence. Our results suggest dramatically different time scales for convergence of properties of interest, which is important in the design of computational studies and comparisons to experimental data. This study highlights that further experimental and theoretical work is required to understand the structure of small diameter cellulose microfibrils typical of plant cellulose.

Why we shouldn't underestimate the impact of plant functional diversity

Science.gov (United States)

Groner, V.; Raddatz, T.; Reick, C. H.; Claussen, M.

2017-12-01

We present a series of coupled land-atmosphere simulations with different combinations of plant functional types (PFTs) from mid-Holocene to preindustrial to show how plant functional diversity affects simulated climate-vegetation interaction under changing environmental conditions in subtropical Africa. Scientists nowadays agree that the establishment of the ``green'' Sahara was triggered by external changes in the Earth's orbit and amplified by internal feedback mechanisms. The timing and abruptness of the transition to the ``desert'' state are in turn still under debate. While some previous studies indicated an abrupt collapse of vegetation implying a strong climate-vegetation feedback, others suggested a gradual vegetation decline thereby questioning the existence of a strong climate-vegetation feedback. However, none of these studies explicitly accounted for the role of plant diversity. We show that the introduction or removal of a single PFT can bring about significant impacts on the simulated climate-vegetation system response to changing orbital forcing. While simulations with the standard set of PFTs show a gradual decrease of precipitation and vegetation cover over time, the reduction of plant functional diversity can cause either an abrupt decline of both variables or an even slower response to the external forcing. PFT composition seems to be the decisive factor for the system response to external forcing, and an increase in plant functional diversity does not necessarily increase the stability of the climate-vegetation system. From this we conclude that accounting for plant functional diversity in future studies - not only on palaeo climates - could significantly improve the understanding of climate-vegetation interaction in semi-arid regions, the predictability of the vegetation response to changing climate, and respectively, of the resulting feedback on precipitation.

Phytoremediation of Groundwater at Air Force Plant 4, Carswell, Texas

Science.gov (United States)

2003-09-01

willows, one hackberry, one mesquite, one pecan , one American elm, one unidentified elm, and one unidentified species. Cores were collected from a height...ability of trees to act as pumps was noted in the late 19th century when Eucalyptus trees were planted in Italy and Algeria to dry up marshes. The...Netherlands, Finland, Denmark, Sweden, Italy , Australia, and the United Kingdom. B-2 If shallow ground water contaminated with low level

Staffing decision processes and issues: Case studies of seven US Nuclear Power Plants

International Nuclear Information System (INIS)

Melber, B.; Roussel, A.; Baker, K.; Durbin, N.; Hunt, P.; Hauth, J.; Forslund, C.; Terrill, E.; Gore, B.

1994-03-01

The objective of this report is to identify how decisions are made regarding staffing levels and positions for a sample of U.S. nuclear power plants. In this report, a framework is provided for understanding the major forces driving staffing and the implications of staffing decisions for plant safety. The focus of this report is on driving forces that have led to changes in staffing levels and to the establishment of new positions between the mid-1980s and the early 1990s. Processes used at utilities and nuclear power plants to make and implement these staffing decisions are also discussed in the report. While general trends affecting the plant as a whole are presented, the major emphasis of this report is on staffing changes and practices in the operations department, including the operations shift crew. The findings in this report are based on interviews conducted at seven nuclear power plants and their parent utilities. A discussion of the key findings is followed by a summary of the implications of staffing issues for plant safety

Valves maintenance management in nuclear power plants

International Nuclear Information System (INIS)

Trost, J.

2001-01-01

The deregulation of Europe's power market will force nuclear power plant operators to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing expenditure on maintenance. Framatome ANP GmbH, in cooperation with plant operators is currently developing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. (Author)

Acute changes in lung function associated with proximity to a steel plant: a randomized study.

Science.gov (United States)

Dales, Robert; Kauri, Lisa Marie; Cakmak, Sabit; Mahmud, Mamun; Weichenthal, Scott A; Van Ryswyk, Keith; Kumarathasan, Premkumari; Thomson, Errol; Vincent, Renaud; Broad, Gayle; Liu, Ling

2013-05-01

Steel production is a major industry worldwide yet there is relatively little information on the pulmonary effects of air quality near steel manufacturing plants. The aim of this study was to examine how lung function changes acutely when healthy subjects are situated near a steel plant which is adjacent to a residential area. Sixty-one subjects were randomly assigned to spend 5 consecutive, 8-hour days in a residential neighborhood approximately 0.9km from a steel plant, or approximately 4.5km away at a college campus. Subjects crossed-over between sites after a nine-day washout period. Lung function was measured daily at both sites along with air pollutants including SO2, NO2, O3, PM2.5, and ultrafine particles. Diffusion capacity and pulse oximetry were also examined. Compared with the college site, the forced expiratory volume in 1-second/forced vital capacity, forced expiratory flow between 25% and 75% of the FVC, total lung capacity, functional residual capacity, and residual volume were lower near the steel plant by 0.67% (95% CI: 0.28, 1.06),1.62% (95% CI: 0.50, 2.75), 1.54% (95% CI: 0.68, 2.39), 3.54% (95% CI: 1.95, 5.13) and 11.3% (95% CI: 4.92, 17.75), respectively. Diffusion capacity, forced expiratory volume in 1s, and pulse oximetry were also lower near the plant but these effects were not statistically significant. Sulfur dioxide, ultrafine particulates, and oxides of nitrogen were greater near the steel plant site compared to the college site. Spending short periods of time near a steel plant is associated with a decrease in lung function. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Design of the vitrification plant for HLLW generated from the Tokai Reprocessing Plant

International Nuclear Information System (INIS)

Vematsu, K.

1986-01-01

Power Reactor and Nuclear Fuel Development Corporation (PNC) is now designing a vitrification plant. This plant is for the solidification of high-level liquid waste (HLLW) which is generated from the Tokai Reprocessing Plant, and for the demonstration of the vitrification technology. The detailed design of the plant which started in 1982 was completed in 1984. At present the design improvement is being made for the reduction of construction cost and for the licensing which is going to be applied in 1986. The construction will be started in autumn 1987. The plant has a large shielded cell with low flow ventilation, and employs rack-mounted module system and high performance two-armed servomanipulator system to accomplish the fully remote operations and maintenance. The vitrification of HLLW is based on the liquid-fed Joule-heated ceramic melter process. The processing capacity is equivalent to the reprocessing of 0.7 ton of heavy metals per day. The glass production rate is about 9 kg/h, and about 300 kg of glass is poured periodically from the bottom of the melter into a canister. Produced glass is stored under the forced air cooling condition

A new ion sensing deep atomic force microscope

Energy Technology Data Exchange (ETDEWEB)

Drake, Barney; Randall, Connor; Bridges, Daniel; Hansma, Paul K. [Department of Physics, University of California, Santa Barbara, California 93106 (United States)

2014-08-15

Here we describe a new deep atomic force microscope (AFM) capable of ion sensing. A novel probe assembly incorporates a micropipette that can be used both for sensing ion currents and as the tip for AFM imaging. The key advance of this instrument over previous ion sensing AFMs is that it uses conventional micropipettes in a novel suspension system. This paper focuses on sensing the ion current passively while using force feedback for the operation of the AFM in contact mode. Two images are obtained simultaneously: (1) an AFM topography image and (2) an ion current image. As an example, two images of a MEMS device with a microchannel show peaks in the ion current as the pipette tip goes over the edges of the channel. This ion sensing AFM can also be used in other modes including tapping mode with force feedback as well as in non-contact mode by utilizing the ion current for feedback, as in scanning ion conductance microscopy. The instrument is gentle enough to be used on some biological samples such as plant leaves.

A novel adaptive force control method for IPMC manipulation

International Nuclear Information System (INIS)

Hao, Lina; Sun, Zhiyong; Su, Yunquan; Gao, Jianchao; Li, Zhi

2012-01-01

IPMC is a type of electro-active polymer material, also called artificial muscle, which can generate a relatively large deformation under a relatively low input voltage (generally speaking, less than 5 V), and can be implemented in a water environment. Due to these advantages, IPMC can be used in many fields such as biomimetics, service robots, bio-manipulation, etc. Until now, most existing methods for IPMC manipulation are displacement control not directly force control, however, under most conditions, the success rate of manipulations for tiny fragile objects is limited by the contact force, such as using an IPMC gripper to fix cells. Like most EAPs, a creep phenomenon exists in IPMC, of which the generated force will change with time and the creep model will be influenced by the change of the water content or other environmental factors, so a proper force control method is urgently needed. This paper presents a novel adaptive force control method (AIPOF control—adaptive integral periodic output feedback control), based on employing a creep model of which parameters are obtained by using the FRLS on-line identification method. The AIPOF control method can achieve an arbitrary pole configuration as long as the plant is controllable and observable. This paper also designs the POF and IPOF controller to compare their test results. Simulation and experiments of micro-force-tracking tests are carried out, with results confirming that the proposed control method is viable. (paper)

Spectroscopy and atomic force microscopy of biomass.

Science.gov (United States)

Tetard, L; Passian, A; Farahi, R H; Kalluri, U C; Davison, B H; Thundat, T

2010-05-01

Scanning probe microscopy has emerged as a powerful approach to a broader understanding of the molecular architecture of cell walls, which may shed light on the challenge of efficient cellulosic ethanol production. We have obtained preliminary images of both Populus and switchgrass samples using atomic force microscopy (AFM). The results show distinctive features that are shared by switchgrass and Populus. These features may be attributable to the lignocellulosic cell wall composition, as the collected images exhibit the characteristic macromolecular globule structures attributable to the lignocellulosic systems. Using both AFM and a single case of mode synthesizing atomic force microscopy (MSAFM) to characterize Populus, we obtained images that clearly show the cell wall structure. The results are of importance in providing a better understanding of the characteristic features of both mature cells as well as developing plant cells. In addition, we present spectroscopic investigation of the same samples.

Climate impacts on bird and plant communities from altered animal-plant interactions

Science.gov (United States)

Martin, Thomas E.; Maron, John L.

2012-01-01

The contribution of climate change to declining populations of organisms remains a question of outstanding concern. Much attention to declining populations has focused on how changing climate drives phenological mismatches between animals and their food. Effects of climate on plant communities may provide an alternative, but particularly powerful, influence on animal populations because plants provide their habitats. Here, we show that abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona, USA. We experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk (Cervus canadensis). We excluded elk from one of two paired snowmelt drainages (10 ha per drainage), and replicated this paired experiment across three distant canyons. Over six years, we reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Moreover, predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment. Thus, our results suggest that climate impacts on plant–animal interactions can have forceful ramifying effects on plants, birds, and ecological interactions.

Another Lesson from Plants: The Forward Osmosis-Based Actuator

Science.gov (United States)

Sinibaldi, Edoardo; Argiolas, Alfredo; Puleo, Gian Luigi; Mazzolai, Barbara

2014-01-01

Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2–5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW). Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency) in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems. PMID:25020043

Another lesson from plants: the forward osmosis-based actuator.

Science.gov (United States)

Sinibaldi, Edoardo; Argiolas, Alfredo; Puleo, Gian Luigi; Mazzolai, Barbara

2014-01-01

Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2-5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW). Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency) in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems.

Another lesson from plants: the forward osmosis-based actuator.

Directory of Open Access Journals (Sweden)

Edoardo Sinibaldi

Full Text Available Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2-5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW. Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems.

Lift force fluctuations of magnetically levitated vehicles with an integrated synchronous linear motor and their significance for the technical security

Energy Technology Data Exchange (ETDEWEB)

Mnich, P; Huebner, K D

1980-07-15

In this paper the influence of the motor current on the magnetic force is investigated by an analytical method. With the integrated synchronous linear motor the reactions of the current sheet on the excitation field are depending on the pole angle and the amplitude of the current sheet. For an undisturbed operation - current sheet and induction wave in phase - the influence of the motor current on the magnetic force can be neglected. In case of a disturbed performance, i.e. when the pole angle is changing periodically, fluctuations of the magnetic force will be found. This effect has to be compensated by a reserve magnetic force in the levitation control. With the technical data for the new magnetic levitation pilots plants (International Traffic Fair 1979 at Hamburg and Transrapid - Pilot Plant Emsland) the stated relations are evaluated. Approximated relations for the levitation force are derived. For comparison, a finite-difference computer programme from the 'Institut fuer elektrische Maschinen, Antriebe und Bahnen, Technische Universitaet Braunschweig' is applied. The approximated relations developed in this paper are verified - with a sufficient precision - by the numerical calculations.

Relative importance of plant-mediated bottom-up and top-down forces on herbivore abundance on Brassica oleracea

NARCIS (Netherlands)

Kos, M.; Broekgaarden, C.; Kabouw, P.; Oude Lenferink, K.; Poelman, E.H.; Vet, L.E.M.; Dicke, M.; Loon, van J.J.A.

2011-01-01

1. Arthropod communities are structured by complex interactions between bottom-up (resource-based) and top-down (natural enemy-based) forces. Their relative importance in shaping arthropod communities, however, continues to be under debate. Bottom-up and top-down forces can be affected by

An updated model for nitrate uptake modelling in plants. I. Functional component: cross-combination of flow–force interpretation of nitrate uptake isotherms, and environmental and in planta regulation of nitrate influx

Science.gov (United States)

Le Deunff, Erwan; Malagoli, Philippe

2014-01-01

Background and Aims In spite of major breakthroughs in the last three decades in the identification of root nitrate uptake transporters in plants and the associated regulation of nitrate transport activities, a simplified and operational modelling approach for nitrate uptake is still lacking. This is due mainly to the difficulty in linking the various regulations of nitrate transport that act at different levels of time and on different spatial scales. Methods A cross-combination of a Flow–Force approach applied to nitrate influx isotherms and experimentally determined environmental and in planta regulation is used to model nitrate in oilseed rape, Brassica napus. In contrast to ‘Enzyme–Substrate’ interpretations, a Flow–Force modelling approach considers the root as a single catalytic structure and does not infer hypothetical cellular processes among nitrate transporter activities across cellular layers in the mature roots. In addition, this approach accounts for the driving force on ion transport based on the gradient of electrochemical potential, which is more appropriate from a thermodynamic viewpoint. Key Results and Conclusions Use of a Flow–Force formalism on nitrate influx isotherms leads to the development of a new conceptual mechanistic basis to model more accurately N uptake by a winter oilseed rape crop under field conditions during the whole growth cycle. This forms the functional component of a proposed new structure–function mechanistic model of N uptake. PMID:24638820

Mechatronization of rotating machines in plant; Plant ni okeru kaiten kikai no mechatronics ka

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, H. [Chiyoda Corp., Tokyo (Japan)

1993-10-01

This paper introduces mechatronization of rotating machines in a plant, with application examples of electronic governors as the main subject. For centrifugal compressors, design and fabrication of anti surging control system have become possible by using a programmable logic controller (PLC) and a distributed control system (DCS) with fine scanning time. An electronic governor for turbine control has been added with a function to control amount of power generated by a motive force recovery device in a flowing catalytic cracking equipment by means of an expander inlet valve. This has made possible to operate the motive force recovery device automatically even under a low load operation. With an electronic governor to control supply and receipt amount of steam to and from an existing plant, the governor valve opening angles were so controlled that actual steam header pressure matches the setting, whereas the steam has become possible to be utilized without waste under normal operation. Operation of a comprehensive compressor/turbine monitoring system on DCS, operation of centrifugal compressors of two casings by using electromagnetic bearings, and motor speed control with use of an inverter heve also become possible. 8 figs., 2 tabs.

Safety/security interface assessments at commercial nuclear power plants

International Nuclear Information System (INIS)

Byers, K.R.; Brown, P.J.; Norderhaug, L.R.

1985-01-01

The findings of the Haynes Task Force Committee (NUREG-0992) are used as the basis for defining safety/security assessment team activities at commercial nuclear power plants in NRC Region V. A safety/security interface assessment outline and the approach used for making the assessments are presented along with the composition of team members. As a result of observing simulated plant emergency conditions during scheduled emergency preparedness exercises, examining security and operational response procedures, and interviewing plant personnel, the team has identified instances where safety/security conflicts can occur

Safety/security interface assessments at commercial nuclear power plants

International Nuclear Information System (INIS)

Byers, K.R.; Brown, P.J.; Norderhaug, L.R.

1985-07-01

The findings of the Haynes Task Force Committee (NUREG-0992) are used as the basis for defining safety/security assessment team activities at commercial nuclear power plants in NRC Region V. A safety/security interface assessment outline and the approach used for making the assessments are presented along with the composition of team members. As a result of observing simulated plant emergency conditions during scheduled emergency preparedness exercises, examining security and operational response procedures, and interviewing plant personnel, the team has identified instances where safety/security conflicts can occur. 2 refs

The Y-12 Plant - a model for environmental excellence

Energy Technology Data Exchange (ETDEWEB)

1994-11-01

The Department of Energy`s Y-12 Plant, located in Oak Ridge, Tennessee, occupies more than 800 acres and has a work force of over 4,000 employees. The Y-12 Plant is managed by Martin Marietta Energy Systems, Inc., a subsidiary of Martin Marietta Corporation. Although mission emphases at the Y-12 Plant have evolved and changed with the easing of international tensions, the Plant continues to serve as a key manufacturing unit and technology demonstration center for the Department of Energy and the nation. The Y-12 Plant has undergone many changes in the last 14 years. One of the most dramatic changes has occurred in the environmental programs with measurable improvements in environmental quality, the development of an award-winning pollution prevention program, and the institution of an environmentally-conscious work ethic among the work force. Because the plant is committed to achieving excellence, not just compliance with laws and regulations, a highly structured, multimedia environmental management program is in place. This program, combined with a commitment to protect the environment while striving for continued improvement, has placed Y-12 in the position to reach excellence. As a result of the Y-12 Plant`s changing mission, they are now working closely with American industry through technology transfer to share their experiences and {open_quotes}lessons learned{close_quotes}--including environmental and pollution prevention technology. To facilitate this effort, the Oak Ridge Centers for Manufacturing Technology has been established at the Y-12 Plant. Through the Centers, the Oak Ridge staff applies skills, capabilities, and facilities developed over a 50-year history of the Oak Ridge Complex to a variety of peacetime missions. The services found at the Centers are a key to helping America`s businesses--both small and large--compete in the global marketplace while protecting the nations environment and conserving its resources.

Structural biomacromolecules in plants : what can be learnt from the fossil record?

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Bergen, P.F. van; Blokker, P.; Collinson, M.E.

2003-01-01

The invasion of the land by plants may have forced the evolution of specific physiological adaptation to survive this hostile new environment. Two of the main problems plants had to overcome included an increase in the levels of UV radiation and water loss or desiccation. Studying the resistant

Subatomic forces

International Nuclear Information System (INIS)

Sutton, C.

1989-01-01

Inside the atom, particles interact through two forces which are never felt in the everyday world. But they may hold the key to the Universe. These ideas on subatomic forces are discussed with respect to the strong force, the electromagnetic force and the electroweak force. (author)

NGL supply from Alberta straddle plants

International Nuclear Information System (INIS)

McAdam, B.

1999-01-01

An overview of the current and future North American supply and demand and trends for natural gas liquids (NGLs) is presented. The current Alberta straddle plant configuration, the NGL pipeline system and product flow, and the profitability of straddle plants are described. The driving forces to increase Alberta's straddle plant capacity are also reviewed. These include: (1) increased gas production, (2) increased demand for ethane, (3) control of produced NGLs, and (4) the desire to maintain a competitive position. Highlights of the Centurion Project designed to meet the needs of Dow Chemicals and the producers by providing long-term ethane supply and physical access to a more liquid NGL market, the project's current status and 'next steps' were also summarized. tabs., figs

Influence of nonuniform magnetic fields on orientation of plant seedlings in microgravity conditions

Science.gov (United States)

Nechitailo, G. S.; Mashinsky, A. L.; Kuznetsov, A. A.; Chikov, V. M.; Kuznetsov, O. A.

2001-01-01

Experiments on the spatial behavior of the flax ( Linum usitatissimum, L.) seedlings in a nonuniform magnetic field were conducted on the orbital space stations «Salutå and «Mirå. This field can displace sensory organelles (statoliths) inside receptor cells and such displacement should cause a physiological reaction of the plant - tropistic curvature. Experiments were conducted in the custom-built «Magnetogravistatå facility, where seeds were germinated and grown for 3-4 days in a magnetic field with the dynamic factor grad(H 2/2)≈ 10 7 Oe 2/cm, then fixed on orbit and returned to Earth for analysis. It was found, that 93% of the seedlings were oriented in the field consistently with curvature in response to displacement of statoliths along the field gradient by ponderomotive magnetic forces, while control seedlings grew in the direction of the initial orientation of the seed. This suggests, that gravity receptors of plants recognized magnetic forces on statoliths as gravity, and that gravity stimulus can be substituted for plants by a force of a different physical nature.

Aircraft impact on nuclear power plants concrete structures

International Nuclear Information System (INIS)

Coombs, R.F.; Barbosa, L.C.B.; Santos, S.H.C.

1980-01-01

A summary about the procedures for the analysis of aircraft on concrete structures, aiming to emphasize the aspects related to the nuclear power plants safety, is presented. The impact force is determined by the Riera model. The effect of this impact force on the concrete structures is presented, showing the advantages to use nonlinear behaviour in the concrete submitted to short loads. The simplifications used are shown through a verification example of the nuclear reactor concrete shielding. (E.G.) [pt

Centripetal and centrifugal forces in the moral circle: Competing constraints on moral learning.

Science.gov (United States)

Graham, Jesse; Waytz, Adam; Meindl, Peter; Iyer, Ravi; Young, Liane

2017-10-01

The idea of the moral circle pictures the self in the center, surrounded by concentric circles encompassing increasingly distant possible targets of moral concern, including family, local community, nation, all humans, all mammals, all living things including plants, and all things including inanimate objects. The authors develop the idea of two opposing forces in people's moral circles, with centripetal forces pulling inward, urging greater concern for close others than for distant others, and centrifugal forces pushing outward, resisting "drawing the line" anywhere as a form of prejudice and urging egalitarian concern for all regardless of social distance. Review of the developmental literature shows very early emergence of both moral forces, suggesting at least partly intuitive bases for each. Moral education approaches favoring one force over the other are compared, to show how these forces can provide constraints on moral learning. Finally, the centripetal/centrifugal forces view is applied to current moral debates about empathy and about politics. The authors argue that this view helps us see how intercultural and interpersonal disagreements about morality are based in intrapersonal conflicts shared by all people. Copyright © 2016. Published by Elsevier B.V.

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1990-03-01

In the Quarterly Reports on the operation of the Finnish nuclear power plants such incidents and observations are described relating to nuclear and radiation safety which the regulatory body, the Finnish Centre for Radiation and Nuclear Safety, considers safety-related. During the third quarter of 1989 the Finnish nuclear power plant units Loviisa 1 and 2 and TVO I and II were in commercial operation for most of the time. Nuclear electricity accounted for 39.0% of the total Finnish electricity production in this quarter. The load factor average of the nuclear power plant units was 78.9%. At Loviisa 1, two holes were found in the feedwater distributor of one steam generator. Corresponding wall thinning corrosion was also detected in the walls of two other distributors. The holes were found on the feedwater distributor upper surface in the joint of the secondary circuit feedwater pipe. One hole was about 20 mm x 50 mm in size and the other was a pit hole ca 5 mm in diameter. Metal power had entered the primary circuit at TVO I. This was observed during a post-scram plant start-up. Several control rod drive units had become jammed so tight that control rod withdrawal failed. Metal powder did not hamper reactor scram under the prevailing circumstances because the drive units are prone to jamming only after a control rod is almost fully inserted and because the forces which insert a control rod by various means (electrical, hydraulic) are 6-8 fold compared with the withdrawing force

Forces acting on particles in a Pelton bucket and similarity considerations for erosion

Science.gov (United States)

Rai, A. K.; Kumar, A.; Staubli, T.

2016-11-01

High sediment transport rates cause severe erosion issues in hydropower plants leading to interruptions in power generation, decrease in efficiency and shutdown for repair and maintenance. For Pelton turbines operating at high head, the issue of erosion is severe, especially in components like buckets, nozzle rings and needles. Goal of the study is to develop erosion focussed guidelines for both designing as well as operating hydropower plants with Pelton runners. In this study, the flow of sediment inside a Pelton bucket with respect to forces acting on solid particles is analysed with an analytical approach by considering different dynamic forces originating from the rotation of the turbine, the curvature of the buckets, and the Coriolis effect. Further, the path of sediment particles and its effect on erosion phenomena are analysed based on the process of separation of different sized sediment particles from streamlines. The data relating to head, power, discharge, number of jet and efficiency of 250 hydropower plants installed all over the world were analysed in this study to find the major factors related to erosion in Pelton turbine bucket. From analysis of different force ratios, it is found that an increase of D/B, i.e. the ratio of pitch circle diameter and bucket width, and/or decrease of specific speed (nq) enhances erosion. As the erosion process depends significantly on nondimensional parameters D/B and nq, these are considered as similarity measures for scaling of the erosion process in the Pelton buckets of various sizes.

Quadriceps force and anterior tibial force occur obviously later than vertical ground reaction force: a simulation study

OpenAIRE

Ueno, Ryo; Ishida, Tomoya; Yamanaka, Masanori; Taniguchi, Shohei; Ikuta, Ryohei; Samukawa, Mina; Saito, Hiroshi; Tohyama, Harukazu

2017-01-01

Background: Although it is well known that quadriceps force generates anterior tibial force, it has been unclear whether quadriceps force causes great anterior tibial force during the early phase of a landing task. The purpose of the present study was to examine whether the quadriceps force induced great anterior tibial force during the early phase of a landing task. Methods: Fourteen young, healthy, female subjects performed a single-leg landing task. Muscle force and anterior tibial force w...

Licensing operators for commercial nuclear power plants

International Nuclear Information System (INIS)

Hannon, J.N.

1988-01-01

The human element in the operation of commercial nuclear power plants is of utmost importance. Not only must the operators be technically competent in the execution of numerous complicated tasks, they must be capable of working together as a team to diagnose dynamic plant conditions to ensure that their plants are operated safely. The significance of human interaction skills and crew communications has been demonstrated most vividly in TMI and Chernobyl. It follows that the NRC must retain its high standards for licensing operators. This paper discusses activities and initiatives being employed by the NRC to enhance the reliability of its licensing examinations, and to build a highly qualified examiner work force

Seismic instrumentation for nuclear power plants

International Nuclear Information System (INIS)

Senne Junior, M.

1983-01-01

A seismic instrumentation system used in Nuclear Power Plants to monitor the design parameters of systems, structures and components, needed to provide safety to those Plants, against the action of earthquakes is described. The instrumentation described is based on the nuclear standards in force. The minimum amount of sensors and other components used, as well as their general localization, is indicated. The operation of the instrumentation system as a whole and the handling of the recovered data are dealt with accordingly. The various devices used are not covered in detail, except for the accelerometer, which is the seismic instrumentation basic component. (Author) [pt

Seismic analysis of nuclear power plants

International Nuclear Information System (INIS)

Halbritter, A.L.

1984-01-01

Nuclear Power Plants require exceptional safety guarantees which are reflected in a rigorous control of the employed materials, advanced construction technology, sophisticated methods of analysis and consideration of non conventional load cases such as the earthquake loading. In this paper, the current procedures used in the seismic analysis of Nuclear Power Plants are presented. The seismic analysis of the structures has two objectives: the determination of forces in the structure in order to design it against earthquakes and the generation of floor response spectra to be used in the design of mechanical and electrical components and piping systems. (Author) [pt

Probabilistic production simulation including CHP plants

Energy Technology Data Exchange (ETDEWEB)

Larsen, H.V.; Palsson, H.; Ravn, H.F.

1997-04-01

A probabilistic production simulation method is presented for an energy system containing combined heat and power plants. The method permits incorporation of stochastic failures (forced outages) of the plants and is well suited for analysis of the dimensioning of the system, that is, for finding the appropriate types and capacities of production plants in relation to expansion planning. The method is in the tradition of similar approaches for the analysis of power systems, based on the load duration curve. The present method extends on this by considering a two-dimensional load duration curve where the two dimensions represent heat and power. The method permits the analysis of a combined heat and power system which includes all the basic relevant types of plants, viz., condensing plants, back pressure plants, extraction plants and heat plants. The focus of the method is on the situation where the heat side has priority. This implies that on the power side there may be imbalances between demand and production. The method permits quantification of the expected power overflow, the expected unserviced power demand, and the expected unserviced heat demand. It is shown that a discretization method as well as double Fourier series may be applied in algorithms based on the method. (au) 1 tab., 28 ills., 21 refs.

Trait plasticity, not values, best corresponds with woodland plant success in novel and manipulated habitats

Science.gov (United States)

Robert J. Warren; Jeffrey K. Lake

2012-01-01

Aims: The clustering of plants with similar leaf traits along environmental gradients may arise from adaptation as well as acclimation to heterogeneous habitat conditions. Determining the forces that shape plant leaf traits requires both linking variation in trait morphology with abiotic gradients and linking that trait variation with plant performance under varying...

Guide for prioritizing power plant productivity improvement projects: handbook of availability improvement methodology

International Nuclear Information System (INIS)

1981-01-01

As part of its program to help improve electrical power plant productivity, the Department of Energy (DOE) has developed a methodology for evaluating productivity improvement projects. This handbook presents a simplified version of this methodology called the Availability Improvement Methodology (AIM), which provides a systematic approach for prioritizing plant improvement projects. Also included in this handbook is a description of data taking requirements necessary to support the AIM methodology, benefit/cost analysis, and root cause analysis for tracing persistent power plant problems. In applying the AIM methodology, utility engineers should be mindful that replacement power costs are frequently greater for forced outages than for planned outages. Equivalent availability includes both. A cost-effective ranking of alternative plant improvement projects must discern between those projects which will reduce forced outages and those which might reduce planned outages. As is the case with any analytical procedure, engineering judgement must be exercised with respect to results of purely mathematical calculations

Effectiveness of growth regulators, based on the heterylcarbon acid, on forcing of Tulips (Tulips HD

Directory of Open Access Journals (Sweden)

Derevianko Natalia

2016-03-01

Full Text Available The main factor in growing flowers for forcing is their rate of growth, on account of the fact that in short period of time it is necessary to grow quickly a large number of flowers and to cut them simultaneously. The influence of growth regulators (GR based on heterylcarbon acid on the forcing of tulips in greenhouse conditions (winter period was studied. It was determined that the application of GR1 of the basic within tulip’s forcing period reduces in average to 5 days (from all period of forcing. In case of application GR2 the tulip’s forcing period also reduces to 3 days (from all period of forcing compared with a control group of tulips. The ability of the plant growth regulators under research to accelerate growing properties of flowers is associated with the presence of heterylcarbon acid and potassium ions in their structure of substances. These growth regulators relate to non-toxic compounds and possess antioxidant properties.

Impact of power plant reliability on the choice of operating parameter values

International Nuclear Information System (INIS)

Kramer, R.A.

1985-01-01

In this thesis, the basic structure for the development of a methodology to evaluate the effect of operating parameters on plant availability and generating system economic dispatch optimization is described. Plant availability is determined by a fault free model. In this model historic, time dependent, component induced forced outage data is utilized as the basis for the calculation of projected plant forced outage rates. The influence of a particular fuel-cycle length at a specific generating station on the operational planning of a multi unit generating system is considered. The basis of the dispatch of units in this analysis is optimal economic operation, i.e., the minimization of the cost of reliability supplying electricity to the system's customers. As a result of the utilization of this technique, a simplified example that considers the choice between a 12- and 18-month fuel cycle length is evaluated in terms of its impact on plant availability, fuel cycle economics and overall optimal generating system economic dispatch. The reliability portion of this methodology is applied to a simplified representation of the recirculation system of a pressurized water reactor nuclear power plant to illustrate the analytic techniques

The influence of cricket fast bowlers' front leg technique on peak ground reaction forces.

Science.gov (United States)

Worthington, Peter; King, Mark; Ranson, Craig

2013-01-01

High ground reaction forces during the front foot contact phase of the bowling action are believed to be a major contributor to the high prevalence of lumbar stress fractures in fast bowlers. This study aimed to investigate the influence of front leg technique on peak ground reaction forces during the delivery stride. Three-dimensional kinematic data and ground reaction forces during the front foot contact phase were captured for 20 elite male fast bowlers. Eight kinematic parameters were determined for each performance, describing run-up speed and front leg technique, in addition to peak force and time to peak force in the vertical and horizontal directions. There were substantial variations between bowlers in both peak forces (vertical 6.7 ± 1.4 body weights; horizontal (braking) 4.5 ± 0.8 body weights) and times to peak force (vertical 0.03 ± 0.01 s; horizontal 0.03 ± 0.01 s). These differences were found to be linked to the orientation of the front leg at the instant of front foot contact. In particular, a larger plant angle and a heel strike technique were associated with lower peak forces and longer times to peak force during the front foot contact phase, which may help reduce the likelihood of lower back injuries.

Adding Value to Force Diagrams: Representing Relative Force Magnitudes

Science.gov (United States)

Wendel, Paul

2011-05-01

Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area.1-4 Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams,4-6 and over recent years a rich variety of approaches has been proposed to add value to force diagrams. Suggestions include strategies for identifying candidate forces,6,7 emphasizing the distinction between "contact" and "noncontact" forces,5,8 and the use of computer-based tutorials.9,10 Instructors have suggested a variety of conventions for constructing force diagrams, including approaches to arrow placement and orientation2,11-13 and proposed notations for locating forces or marking action-reaction force pairs.8,11,14,15

Technology and costs for decommissioning of Swedish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-06-01

The decommissioning study for the Swedish nuclear power plants has been carried out during 1992 to 1994 and the work has been led by a steering group consisting of people from the nuclear utilities and SKB. The study has been focused on two reference plants, Oskarshamn 3 and Ringhals 2. Oskarshamn 3 is a boiling water reactor (BWR) and Ringhals 2 is a pressurized water reactor (PWR). Subsequently, the result from these plants have been translated to the other Swedish plants. The study gives an account of the procedures, costs, waste quantities and occupational doses associated with decommissioning of the Swedish nuclear power plants. Dismantling is assumed to start immediately after removal of the spent fuel. No attempts at optimization, in terms of technology or costs, have been made. The nuclear power plant site is restored after decommissioning so that it can be released for use without restriction for other industrial activities. The study shows that a reactor can be dismantled in about five years, with an average labour force of about 150 persons. The maximum labour force required for Oskarshamn 3 has been estimated to about 300 persons. This peak load occurred the first years but is reduced to about 50 persons during the demolishing of the buildings. The cost of decommissioning Oskarshamn 3 has been estimated to be about MSEK 940 in January 1994 prices. The decommissioning of Ringhals 2 has been estimated to be MSEK 640. The costs for the other Swedish nuclear power plants lie in the range MSEK 590-960. 17 refs, 21 figs, 15 tabs.

Technology and costs for decommissioning of Swedish nuclear power plants

International Nuclear Information System (INIS)

1994-06-01

The decommissioning study for the Swedish nuclear power plants has been carried out during 1992 to 1994 and the work has been led by a steering group consisting of people from the nuclear utilities and SKB. The study has been focused on two reference plants, Oskarshamn 3 and Ringhals 2. Oskarshamn 3 is a boiling water reactor (BWR) and Ringhals 2 is a pressurized water reactor (PWR). Subsequently, the result from these plants have been translated to the other Swedish plants. The study gives an account of the procedures, costs, waste quantities and occupational doses associated with decommissioning of the Swedish nuclear power plants. Dismantling is assumed to start immediately after removal of the spent fuel. No attempts at optimization, in terms of technology or costs, have been made. The nuclear power plant site is restored after decommissioning so that it can be released for use without restriction for other industrial activities. The study shows that a reactor can be dismantled in about five years, with an average labour force of about 150 persons. The maximum labour force required for Oskarshamn 3 has been estimated to about 300 persons. This peak load occurred the first years but is reduced to about 50 persons during the demolishing of the buildings. The cost of decommissioning Oskarshamn 3 has been estimated to be about MSEK 940 in January 1994 prices. The decommissioning of Ringhals 2 has been estimated to be MSEK 640. The costs for the other Swedish nuclear power plants lie in the range MSEK 590-960. 17 refs, 21 figs, 15 tabs

Hydraulic limits on maximum plant transpiration and the emergence of the safety-efficiency trade-off.

Science.gov (United States)

Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Jackson, Robert B; Porporato, Amilcare

2013-04-01

Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, thus defining the maximum transpiration rate the xylem can sustain (denoted as E(max)). The presence of this maximum raises the question as to whether plants regulate transpiration through stomata to function near E(max). To address this question, we calculated E(max) across plant functional types and climates using a hydraulic model and a global database of plant hydraulic traits. The predicted E(max) compared well with measured peak transpiration across plant sizes and growth conditions (R = 0.86, P efficiency trade-off in plant xylem. Stomatal conductance allows maximum transpiration rates despite partial cavitation in the xylem thereby suggesting coordination between stomatal regulation and xylem hydraulic characteristics. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Changes in plant water use efficiency over the recent past reconstructed using palaeo plant records from the boreal forest

Science.gov (United States)

Gagen, M.; Finsinger, W.; McCarroll, D.; Wagner, F.

2009-04-01

The Boreal forests contains 33% of the earth's forest cover and are located at the latitude where most of the estimated global warming is predicted to occur. Warming as a consequence of rising carbon dioxide will affect evapotranspiration within the biome, with significant consequences given that water vapour is an important greenhouse gas. However, there is also a physiological forcing associated with the effects of rising carbon dioxide on plants. Higher atmospheric carbon dioxide will reduce evapotraspiration because tree stomata tend to close under elevated carbon dioxide. The warming associated with reduced evapotranspiration is known as carbon dioxide physiological forcing and it is not well constrained. Here we suggest that future predictions of evapotranspiration flux within the Boreal forest zone might be more accurately gauged by taking account of palaeo evidence of changing plant water use efficiency and stomatal density in the two most important Boreal plant species: Pinus sylvestris and Betula nana. Stable carbon isotope ratios in tree ring cellulose and stomatal density measurements, from preserved leaves falling on the forest floor, hold a record of the plant physiological changes associated with adjustment to rising carbon dioxide. We present evidence that, rather than plants simply closing their stomatal apertures under recent elevated carbon dioxide, over the last 150 years reduced evapotranspiration in the northern Boreal forest has been associated with a powerful plastic response including reductions in stomatal conductance via changes in stomatal density and pore length. Furthermore we present evidence that trees may be reaching the limits of their ability to respond plastically to rising carbon dioxide by increasing their water use efficiency.

Power plant perspectives for sugarcane mills

International Nuclear Information System (INIS)

Bocci, E.; Di Carlo, A.; Marcelo, D.

2009-01-01

Biomass, integral to life, is one of the main energy sources that modern technologies could widely develop, overcoming inefficient and pollutant uses. The sugarcane bagasse is one of the more abundant biomass. Moreover, the fluctuating sugar and energy prices force the sugarcane companies to implement improved power plants. Thanks to a multiyear collaboration between University of Rome and University of Piura and Chiclayo, this paper investigates, starting from the real data of an old sugarcane plant, the energy efficiency of the plant. Furthermore, it explores possible improvements as higher temperature and pressure Rankine cycles and innovative configurations based on gasifier plus hot gas conditioning and gas turbine or molten carbonate fuel cells. Even if the process of sugar extraction from sugarcane and the relative Rankine cycles power plants are well documented in literature, this paper shows that innovative power plant configurations can increase the bagasse-based cogeneration potential. Sugarcane companies can become electricity producers, having convenience in the use of sugarcane leaves and trash (when it is feasible). The worldwide implementation of advanced power plants, answering to a market competition, will improve significantly the renewable electricity produced, reducing CO 2 emissions, and increasing economic and social benefits.

THE USE OF CHEMICALS AS PLANT REGULATORS. AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 8.

Science.gov (United States)

Ohio State Univ., Columbus. Center for Vocational and Technical Education.

ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS, THIS MODULE IS SPECIFICALLY CONCERNED WITH CHEMICALS AS PLANT REGULATORS. IT WAS DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF DATA FROM STATE STUDIES. SECTIONS INCLUDE -- (1) CHEMICALS AS MODIFIERS OF PLANT GROWTH, (2)…

Force and Directional Force Modulation Effects on Accuracy and Variability in Low-Level Pinch Force Tracking.

Science.gov (United States)

Park, Sangsoo; Spirduso, Waneen; Eakin, Tim; Abraham, Lawrence

2018-01-01

The authors investigated how varying the required low-level forces and the direction of force change affect accuracy and variability of force production in a cyclic isometric pinch force tracking task. Eighteen healthy right-handed adult volunteers performed the tracking task over 3 different force ranges. Root mean square error and coefficient of variation were higher at lower force levels and during minimum reversals compared with maximum reversals. Overall, the thumb showed greater root mean square error and coefficient of variation scores than did the index finger during maximum reversals, but not during minimum reversals. The observed impaired performance during minimum reversals might originate from history-dependent mechanisms of force production and highly coupled 2-digit performance.

Plant mediated detoxification of mercury and lead

Directory of Open Access Journals (Sweden)

Brajesh Kumar

2017-05-01

Full Text Available In recent years, the development of efficient green chemistry methods for detoxification of metal poisoning has become a major focus of researchers. They have investigated in order to find an eco-friendly and recyclable technique for the removal of heavy metal (Pb2+, Hg2+ contamination from the natural resources. One of the most considered methods is the removal of Pb2+, Hg2+ metal using green plants and their wastes. Among these plant wastes seem to be the best candidates and they are suitable for detoxification of heavy metals. Biosorption by plants involve complex mechanisms, mainly ion exchange, chelation, adsorption by physical forces and ion entrapment in inter and intra fibrillar capillaries and spaces of the structural polysaccharide cell wall network. The advantages of using green plants and their wastes for detoxification of heavy metal have interested researchers to investigate mechanisms of metal ion uptake, and to understand the possible utilization. In this review, we discuss the role of plants and their wastes for minimizing mercury and lead pollution with their toxic effect on both human beings and plants.

Plant-plant interactions in the restoration of Mediterranean drylands

Science.gov (United States)

Valdecantos, Alejandro; Fuentes, David; Smanis, Athanasios

2014-05-01

Plant-plant interactions are complex and dependent of both local abiotic features of the ecosystem and biotic relationships with other plants and animals. The net result of these interactions may be positive, negative or neutral resulting in facilitation, competition or neutralism, respectively (role of phylogeny). It has been proposed that competition is stronger between those individuals that share functional traits than between unrelated ones. The relative interaction effect of one plant on a neighbour may change in relation to resource availability - especially water in drylands. In addition, plants develop above and belowground biomass with time increasing the level and, eventually, changing the intensity and/or the direction of the interaction. In the framework of the restoration of degraded drylands, many studies have focused on the positive (nurse) effects of adult trees, shrubs and even grasses on artificially planted seedlings by improving the microclimate or providing protection against herbivores, but little is known about the interactions between seedlings of different life traits planted together under natural field conditions. In 2010 we established planting plots in two contrasted sites under semiarid Mediterranean climate and introduced one year old seedlings in different combinations of three species, two shrubs (Olea europaea and Pistacia lentiscus) and one grass (Stipa tenacissima). Half of the planting holes in each site were implemented with low-cost ecotechnological inputs to increase water availability by forcing runoff production and promoting deep infiltration (small plastic fabric + dry well). This resulted in four levels of abiotic stress. Biotic interactions were assessed by monitoring seedling survival and growth for three years after planting. The Relative Interaction Index (RII) of S. tenacissima on O. europaea was almost flat and close to 0 along the stress gradient since the beginning of the study suggesting limited interaction

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)

Energy Technology Data Exchange (ETDEWEB)

Taia, Wafaa K; Kotbi, Abeer M [Alexandria Univ., Faculty of Science, Botany Dept., Alexandria (Egypt); AlZahrani, Hassan S [Faculty of Science, King AbdulAziz Univ., Biology Dept., Jeddah (Saudi Arabia)

2007-07-01

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but it is affected by magnetism wherever its direction or force. But all the photosynthetic pigments contents (Chlorophyll A, B and Carotenes) decreased significantly than the control in the three magnetic regimes., but without any effect according to differences in the magnetic force in the aerial and burried regimes of magnetism. It was concluded that magnetism affects both water absorption and retention , the most influenced regime was the aerial magnets followed by the surface and buried ones. This result can be interpreted by the ionization of water which makes water ions respond to magnetic forces. Photosynthetic pigments have been decreased significantly by the exposure to magnetic fields, irrespective to its direction or force and this may be due to the effect of magnetic fields on the reduction in plastids inside the cells. (author)

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)

International Nuclear Information System (INIS)

Taia, Wafaa K; Kotbi, Abeer M; AlZahrani, Hassan S

2007-01-01

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but it is affected by magnetism wherever its direction or force. But all the photosynthetic pigments contents (Chlorophyll A, B and Carotenes) decreased significantly than the control in the three magnetic regimes., but without any effect according to differences in the magnetic force in the aerial and burried regimes of magnetism. It was concluded that magnetism affects both water absorption and retention , the most influenced regime was the aerial magnets followed by the surface and buried ones. This result can be interpreted by the ionization of water which makes water ions respond to magnetic forces. Photosynthetic pigments have been decreased significantly by the exposure to magnetic fields, irrespective to its direction or force and this may be due to the effect of magnetic fields on the reduction in plastids inside the cells. (author)

Direct measurements of intermolecular forces by chemical force microscopy

Science.gov (United States)

Vezenov, Dmitri Vitalievich

1999-12-01

Detailed description of intermolecular forces is key to understanding a wide range of phenomena from molecular recognition to materials failure. The unique features of atomic force microscopy (AFM) to make point contact force measurements with ultra high sensitivity and to generate spatial maps of surface topography and forces have been extended to include measurements between well-defined organic molecular groups. Chemical modification of AFM probes with self-assembled monolayers (SAMs) was used to make them sensitive to specific molecular interactions. This novel chemical force microscopy (CFM) technique was used to probe forces between different molecular groups in a range of environments (vacuum, organic liquids and aqueous solutions); measure surface energetics on a nanometer scale; determine pK values of the surface acid and base groups; measure forces to stretch and unbind a short synthetic DNA duplex and map the spatial distribution of specific functional groups and their ionization state. Studies of adhesion forces demonstrated the important contribution of hydrogen bonding to interactions between simple organic functionalities. The chemical identity of the tip and substrate surfaces as well as the medium had a dramatic effect on adhesion between model monolayers. A direct correlation between surface free energy and adhesion forces was established. The adhesion between epoxy polymer and model mixed SAMs varied with the amount of hydrogen bonding component in the monolayers. A consistent interpretation of CFM measurements in polar solvents was provided by contact mechanics models and intermolecular force components theory. Forces between tips and surfaces functionalized with SAMs terminating in acid or base groups depended on their ionization state. A novel method of force titration was introduced for highly local characterization of the pK's of surface functional groups. The pH-dependent changes in friction forces were exploited to map spatially the

New Law on Nuclear Energy into force on March 1, 1988

International Nuclear Information System (INIS)

Santaholma, J.

1988-01-01

In Finland new Law on Nuclear Energy enters into force on March 1, 1988 after ten years' preparation work. The Parliament approved the new law, compensating the old law on atomic energy on 1957, unanimously in November 1987. The new law provides the decisions on new nuclear power plants to be made by the Government and finally ratified by the Parliament

Scrambled eggs: mechanical forces as ecological factors in early development.

Science.gov (United States)

Moore, Steven W

2003-01-01

Many ecological interactions involve, at some level, mechanical forces and the movements or structural deformations they produce. Although the most familiar examples involve the functional morphology of adult structures, all life history stages (not just the adults) are subject to the laws of physics. Moreover, the success of every lineage depends on the success of every life history stage (again, not just the adults). Therefore, insights gained by using mechanical engineering principles and techniques to study ecological interactions between gametes, embryos, larvae, and their environment are essential to a well-rounded understanding of development, ecology, and evolution. Here I draw on examples from the literature and my own research to illustrate ways in which mechanical forces in the environment shape development. These include mechanical forces acting as selective factors (e.g., when coral gamete size and shape interact with turbulent water flow to determine fertilization success) and as developmental cues (e.g., when plant growth responds to gravity or bone growth responds to mechanical loading). I also examine the opposite cause-and-effect relationship by considering examples in which the development of organisms impacts ecologically relevant mechanical forces. Finally, I discuss the potential for ecological pattern formation as a result of feedback loops created by such bidirectional interactions between developmental processes and mechanical forces in the environment.

Improvements in or relating to chemical plant

International Nuclear Information System (INIS)

Mills, A.L.; Williams, J.A.

1980-01-01

In a plant in which irradiated nuclear fuels are reprocessed or in which plutonium-containing fuels are fabricated, the atmosphere is circulated by the driving force obtained from the condensation of at least part of the atmosphere in a heat exchanger and the evaporation of condensate from another heat exchanger. (U.K.)

Emergency preparedness post-9/11 enhancements at US nuclear plants

International Nuclear Information System (INIS)

Sullivan, R.L.

2005-01-01

Full text: In the wake of the terrorist attacks of 9-11, the US Nuclear Regulatory Commission (NRC) took several actions to improve the security profile and emergency response of its licensees. In early 2002 the commission issued orders to its nuclear power plant licensees which included changes to emergency plans, the performance of staffing adequacy reviews, changes to augmentation practices and the establishment of alternative facilities. Since that time NRC has implemented a force-on-force exercise program that includes emergency response. This program has helped licensees improve their response by testing procedures under simulated attack conditions. More recently, licensees have begun a program to enhance drills and exercises through the use of security event based scenarios. These drills will enhance previous practice and focus on two emerging issues: improving the interface between emergency response, security response and operations during security events and recovery from the loss of plant equipment due to terrorist acts. Additional areas of enhancement such as protective actions for plant personnel will also be discussed and the status of actions to date will be provided. (author)

StringForce

DEFF Research Database (Denmark)

Barendregt, Wolmet; Börjesson, Peter; Eriksson, Eva

2017-01-01

In this paper, we present the forced collaborative interaction game StringForce. StringForce is developed for a special education context to support training of collaboration skills, using readily available technologies and avoiding the creation of a "mobile bubble". In order to play String......Force two or four physically collocated tablets are required. These tablets are connected to form one large shared game area. The game can only be played by collaborating. StringForce extends previous work, both technologically and regarding social-emotional training. We believe String......Force to be an interesting demo for the IDC community, as it intertwines several relevant research fields, such as mobile interaction and collaborative gaming in the special education context....

Construction plant requirements for nuclear sites

International Nuclear Information System (INIS)

Tatum, C.B.; Harris, J.A.

1981-01-01

Planning and developing the temporary construction plant facilities for a nuclear project is equivalent to providing utility services for a small city. Provision of adequate facilities is an important factor in the productivity of both the manual and non-manual work force. This paper summarizes construction facility requirements for a two unit (1300 MWe each) nuclear project. Civil, mechanical and electrical facilities are described, including design, installation and operation. Assignment of responsibility for specific work tasks regarding the construction plant is also discussed. In presenting this data, the authors seek to transfer experience and assist in the provision of adequate facilities on future projects

Presentation to the Atomic Energy Commission and the Air Force, June 14, 1962

Energy Technology Data Exchange (ETDEWEB)

none

1962-10-01

This volume contains the charts and backup material presented to the Atomic Energy Commission and Air Force on June 14, 1962 concerning General Electric's Nuclear Materials and Propulsion Operation (formerly the Aircraft Nuclear Propulsion Department), during its work on the development of a nuclear power plant for manned aircraft.

Report on results of R and D of coal liquefaction technology under Sunshine Project in fiscal 1981 (development of motive force recovery system by hydrohoist); 1981 nendo sekitan ekika gijutsu no kenkyu kaihatsu, chokusetsu suiten ekika plant no kaihatsu seika hokokusho. Hydrohoist ni yoru doryoku kaishu system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-03-01

This paper explains the results of development of a hydrohoist system in a direct hydro-liquefaction plant under the Sunshine Project in fiscal 1981. Coal liquefaction deals with three phases of gas, liquid and solid at high pressures of 100-300 kg/cm{sup 2}. Slurry consisting of coal, catalyst and solvent is once fed into a supply chamber by a low pressure slurry pump. A high pressure slurry formed in a liquefaction reactor, after the separation of gaseous object, is boosted by a booster pump and force-fitted into the supply chamber from the above, discharging the slurry in the chamber to the high pressure reactor side. Since the high pressure product is used as the driving liquid, a force-feeding motive force can be greatly curtailed. It is a motive force recovery type hydrohoist. The product slurry in the supply chamber is discharged from a valve in the upper part; with the inner pressure going down quickly, the discharge valve wears very little. The basic experimental equipment was manufactured in fiscal 1980, with a test research conducted using the improved main equipment in fiscal 1981, and with the conceptual design of the hydrohoist also implemented on the assumption that it was applied to a pilot plant. (NEDO)

Position control of a floating nuclear power plant

International Nuclear Information System (INIS)

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

1993-01-01

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

Dispersion Forces

CERN Document Server

Buhmann, Stefan Yoshi

2012-01-01

In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

Final Environmental Assessment for the First Air Force Air Operations Center, First Air Force Headquarters/Air Force Forces Center, and Highway 98 Overpass at Tyndall Air Force Base, Florida

Science.gov (United States)

2004-01-01

no comments regarding the Draft Environmental Assessment for the First Air Force Operations Center, First Air Force Headquarters/Air Force Forces...COUNCIL ] No Comment BAY - BAY COUNTY No Final Comments Received ENVIRONMENTAL POLICY UNIT - OFFICE OF POLICY AND BUDGET, ENVIRONMENTAL POLICY UNIT NO ...CONSERVATION COMMISSION [ NO COMMENT BY BRIAN BARNETT ON 4/12/04. [STATE - FLORIDA DEPARTMENT OF STATE [ No Comment [TRANSPORTATION - FLORIDA DEPARTMENT

Remark on the role of the driving force in BWR instability

International Nuclear Information System (INIS)

Dykin, V.; Pazsit, I.

2009-01-01

Simple models of BWR instability, used e.g. in understanding the role of the various oscillation modes in the overall stability of the plant, assume that each oscillation mode can be described by a second order system (a damped harmonic oscillator) driven by a white noise driving force. Change of the decay ratio (DR) of the observed signal is, as a rule, associated with the changing of the parameters of the damped oscillator, mainly its damping coefficient, and is interpreted in terms of the change of the stability of the system. However, conceptually, one cannot exclude cases when the change of the response of a driven damped oscillator is due to the change of the properties of the driving force. In this work we investigate the effect of a non-white driving force on the behaviour of the system. A question of interest is how changes of the spectrum of the driving force influence the observed autocorrelation function (ACF) of the resulting signal. Hence we calculate the response of a damped harmonic oscillator driven by a non-white driving force, corresponding to the reactivity effect of propagating density fluctuations in two-phase flow. It is shown how in some special cases such a driving force, when interpreting the neutron noise as if induced by a white noise driving source, can lead to an erroneous conclusion regarding the stability of the system. It is also concluded that in the practically interesting cases the effect of the coloured driving force, arising from propagating density fluctuations, is negligible.

Energy audit: thermal power, combined cycle, and cogeneration plants

Energy Technology Data Exchange (ETDEWEB)

Abbi, Yash Pal

2012-07-01

The availability of fossil fuels required for power plants is reducing and their costs increasing rapidly. This gives rise to increase in the cost of generation of electricity. But electricity regulators have to control the price of electricity so that consumers are not stressed with high costs. In addition, environmental considerations are forcing power plants to reduce CO2 emissions. Under these circumstances, power plants are constantly under pressure to improve the efficiency of operating plants, and to reduce fuel consumption. In order to progress in this direction, it is important that power plants regularly audit their energy use in terms of the operating plant heat rate and auxiliary power consumption. The author attempts to refresh the fundamentals of the science and engineering of thermal power plants, establish its link with the real power plant performance data through case studies, and further develop techno-economics of the energy efficiency improvement measures. This book will rekindle interest in energy audits and analysis of the data for designing and implementation of energy conservation measures on a continuous basis.

The development of base-isolated APWR plants

International Nuclear Information System (INIS)

Tanaka, T.; Nitta, T.

2001-01-01

The full text follows: The seismic design of nuclear power stations plays a critical role in the assurance of plant safety in Japan, and standardization of design is difficult to achieve because every site is subject to different seismic conditions. However, the introduction of seismic -isolation devices is one way to rationally achieve safety assurance and promote design standardization. Base-isolated APWR (advanced pressurized water reactor) plants were developed by applying seismic -isolation devices to APWR plants. The introduction of seismic -isolation devices, which are installed between the ground and buildings, largely decreases the effect of seismic force on buildings. Therefore, the limitation of building shape and eccentricity, which are undertaken in order to prevent the floating of buildings, could be eliminated. This permits the flexibility of building layouts, which result in a reduction of building volume. At the same time, the thickness of the buildings walls that are specific to nuclear power stations, can also be decreased except radiation shield. As for the base-isolated APWR equipment design, the rational design of support structures for equipment and pipings is possible, because the floor response acceleration is greatly reduced. For the cost reduction, it has been confirmed that the base-isolated APWR plants are more economical than traditional APWR plants even after the additionally required expenses for seismic-isolation devices are taken into account. This is primarily because of the rational design of the buildings and equipment which is possible as described above. Another advantage is that building standardization can be promoted because the seismic-isolation devices are able to control the seismic force transmitted to the buildings. This is accomplished by arranging the characteristics of the isolation devices according to the seismic conditions of each site. The introduction of these devices to nuclear power stations is nearly ready

Value added services to CANDU plants

International Nuclear Information System (INIS)

Kakaria, B.K.

2003-01-01

Over the last decade or so, nuclear power plants, just like other types of electricity generating plants, have been facing a number of challenges. Depending on the operating environment of the utility, these challenges are forcing plant owners to examine all facets of the operating costs. Privatization, deregulation and economics of alternative electricity generation methods are exerting enormous pressure on nuclear power plants to streamline costs and improve their operational performance. CANDU reactors are no exception to these forces and face similar pressures. In particular, operating plants that are contemplating plant life extensions are being required to clearly demonstrate the economics of continued operation over other forms of power generation available to the utility. Improvement of capacity factors has the effect of increasing the revenues from the plant and as these revenues increase, the fixed portion of the plant costs including OM and A costs become a smaller percentage of the total revenues. Similar results can be achieved by aiming to reduce the plant OM and A costs. In reality, most well-planned intervention schemes directed at reducing OM and A costs tend to also increase the plant availability. Following plant turnover after commissioning, AECL has been supporting the CANDU owners and utilities with an assortment of products and services dealing with plant operations and outage management issues. AECL has taken the lead in arranging specialized resources, products and services by teaming with other complementary organizations to provide a complete suite of services. Recent examples of such support to operating CANDU plants will be described in the paper. AECL is responding to this changing business environment in two important ways. First, AECL is changing from simply providing a service to its clients towards providing value, something much more important. To this end, AECL is looking to other organizations to form alliances, partnerships and

Methodology for modular nuclear plant design and construction

International Nuclear Information System (INIS)

Lapp, C.W.; Golay, M.

1992-01-01

During the past decade, the rising cost of nuclear power plant construction has caused the cancellation of many projects and has forced some utilities into bankruptcy. Many factors have contributed to capital cost increases, including regulatory changes, the absence of standard designs, and low worker productivity. Low worker productivity can be attributed to the conventional building process, which is not conductive to productive labor. This study presents innovative ways to reduce the capital cost of nuclear plants through more efficient construction processes designed to increase worker productivity. A major portion of the plant capital cost is the interest paid during construction on borrowed capital. Modular fabrication could potentially reduce interest payments by compressing the construction schedule of nuclear facilities. Additional cost savings expected from modular designs arise from improved quality, productivity, and schedule control in fabrication of plant elements within a factory environment

Can Sweden be forced to manage nuclear waste from other countries?

International Nuclear Information System (INIS)

Bergstroem, Ulf; Lindgren, Jonas; Nordfors, Lennart; Hallerby, Christer

2005-06-01

This report tries to answer two questions: Can Sweden, through supranational decisions, be forced to dispose of other nations nuclear waste within its own borders? and How can a Swedish stakeholder follow and influence EU-agendas, in particular concerning nuclear waste? Sometimes it has been argued that, through the EU-membership, Sweden could be forced to accept foreign radioactive waste for disposal in Sweden. However, the Swedish Nuclear Technology Act clearly states that license for final disposal spent nuclear fuels can not be given for fuel from another country than Sweden. At the Swedish EU entry it was found that the national legislation were compatible with the EU regulations, and as a consequence waste from foreign nuclear plants can not be disposed of in Sweden, even if the plant is owned by a Swedish company. Other conclusions in the report are: The system for decision making in EU is complex and slow and must be supported by supranational and international organs. The process is complex, but offers many opportunities for following-up and influencing. The risk for anything happening 'over-night' in the radioactive waste question is minimal. The issue of regulating radioactive waste management in a supranational way, i.e. by forcing a country to accept wastes from another country is not on the agenda. The Euratom treaty is interpreted in the way that such decision can not be made. The international discussions about regional repositories build upon voluntary agreements. Scenarios leading to coersive legislation are judged to be politically unrealistic - and needing important changes to be realised

Influences of Plant Species, Season and Location on Leaf Endophytic Bacterial Communities of Non-Cultivated Plants.

Science.gov (United States)

Ding, Tao; Melcher, Ulrich

2016-01-01

Bacteria are known to be associated endophytically with plants. Research on endophytic bacteria has identified their importance in food safety, agricultural production and phytoremediation. However, the diversity of endophytic bacterial communities and the forces that shape their compositions in non-cultivated plants are largely uncharacterized. In this study, we explored the diversity, community structure, and dynamics of endophytic bacteria in different plant species in the Tallgrass Prairie Preserve of northern Oklahoma, USA. High throughput sequencing of amplified segments of bacterial rDNA from 81 samples collected at four sampling times from five plant species at four locations identified 335 distinct OTUs at 97% sequence similarity, representing 16 phyla. Proteobacteria was the dominant phylum in the communities, followed by the phyla Bacteriodetes and Actinobacteria. Bacteria from four classes of Proteobacteria were detected with Alphaproteobacteria as the dominant class. Analysis of molecular variance revealed that host plant species and collecting date had significant influences on the compositions of the leaf endophytic bacterial communities. The proportion of Alphaproteobacteria was much higher in the communities from Asclepias viridis than from other plant species and differed from month to month. The most dominant bacterial groups identified in LDA Effect Size analysis showed host-specific patterns, indicating mutual selection between host plants and endophytic bacteria and that leaf endophytic bacterial compositions were dynamic, varying with the host plant's growing season in three distinct patterns. In summary, next generation sequencing has revealed variations in the taxonomic compositions of leaf endophytic bacterial communities dependent primarily on the nature of the plant host species.

Influences of Plant Species, Season and Location on Leaf Endophytic Bacterial Communities of Non-Cultivated Plants.

Directory of Open Access Journals (Sweden)

Tao Ding

Full Text Available Bacteria are known to be associated endophytically with plants. Research on endophytic bacteria has identified their importance in food safety, agricultural production and phytoremediation. However, the diversity of endophytic bacterial communities and the forces that shape their compositions in non-cultivated plants are largely uncharacterized. In this study, we explored the diversity, community structure, and dynamics of endophytic bacteria in different plant species in the Tallgrass Prairie Preserve of northern Oklahoma, USA. High throughput sequencing of amplified segments of bacterial rDNA from 81 samples collected at four sampling times from five plant species at four locations identified 335 distinct OTUs at 97% sequence similarity, representing 16 phyla. Proteobacteria was the dominant phylum in the communities, followed by the phyla Bacteriodetes and Actinobacteria. Bacteria from four classes of Proteobacteria were detected with Alphaproteobacteria as the dominant class. Analysis of molecular variance revealed that host plant species and collecting date had significant influences on the compositions of the leaf endophytic bacterial communities. The proportion of Alphaproteobacteria was much higher in the communities from Asclepias viridis than from other plant species and differed from month to month. The most dominant bacterial groups identified in LDA Effect Size analysis showed host-specific patterns, indicating mutual selection between host plants and endophytic bacteria and that leaf endophytic bacterial compositions were dynamic, varying with the host plant's growing season in three distinct patterns. In summary, next generation sequencing has revealed variations in the taxonomic compositions of leaf endophytic bacterial communities dependent primarily on the nature of the plant host species.

Rigid two-axis MEMS force plate for measuring cellular traction force

International Nuclear Information System (INIS)

Takahashi, Hidetoshi; Jung, Uijin G; Shimoyama, Isao; Kan, Tetsuo; Tsukagoshi, Takuya; Matsumoto, Kiyoshi

2016-01-01

Cellular traction force is one of the important factors for understanding cell behaviors, such as spreading, migration and differentiation. Cells are known to change their behavior according to the mechanical stiffness of the environment. However, the measurement of cell traction forces on a rigid environment has remained difficult. This paper reports a micro-electromechanical systems (MEMS) force plate that provides a cellular traction force measurement on a rigid substrate. Both the high force sensitivity and high stiffness of the substrate were obtained using piezoresistive sensing elements. The proposed force plate consists of a 70 µ m  ×  15 µ m  ×  5 µ m base as the substrate for cultivating a bovine aortic smooth muscle cell, and the supporting beams with piezoresistors on the sidewall and the surface were used to measure the forces in both the horizontal and vertical directions. The spring constant and force resolution of the fabricated force plate in the horizontal direction were 0.2 N m −1 and less than 0.05 µ N, respectively. The cell traction force was measured, and the traction force increased by approximately 1 µ N over 30 min. These results demonstrate that the proposed force plate is applicable as an effective traction force measurement. (paper)

AECL's support to operating plants world wide

International Nuclear Information System (INIS)

Azeez, S.; Kakaria, B.K.; Hinchley, E.M.

1998-01-01

Through their operating records, CANDU reactors have established themselves as a successful and cost-effective source of electricity in Canada and abroad. They have proven to be safe, reliable and economical. A variety of factors have contributed to the enviable CANDU record, such as a sound design based on proven principles supported by effective development programs, along with dedicated plant owners committed to excellence in safely maintaining and operating their plants. Atomic Energy of Canada Limited (AECL), the CANDU designer, has continuously maintained a close relationship with owners/operators of the plants in Canada, Argentina, Romania and South Korea. AECL and the plant operators have all benefited from this strengthening relationship by sharing experience and information. CANDU plant operators have been required to respond decisively to the economic realities of downward cost pressures and deregulation. Operating, Maintenance and Administration (OM and A) costs are being given a new focus as plant owners review each cost element to improve the economic returns from their investments. Amongst the three main OM and A constituents, plant maintenance costs are the most variable and have the largest influence on effective plant operations. The correlation between effective plant maintenance and high capacity factors shows clearly the importance of proactive maintenance planning to reduce the frequency and duration of forced plant outages and their negative impacts on plant economics. This paper describes the management processes and organizational structures m AECL that support plant operations and maintenance in operating CANDU plants with cost effective products and services. (author)

Radiation exposures in reprocessing facilities at the Savannah River Plant

International Nuclear Information System (INIS)

Hayes, G.; Caldwell, R.D.; Hall, R.M.

1979-01-01

Two large reprocessing facilities have been operating at the Savannah River Plant since 1955. The plant, which is near Aiken, South Carolina, is operated for the U.S. Department of Energy by the Du Pont Company. The reprocessing facilities have a work force of approximately 1,800. The major processes in the facilities are chemical separations of irradiated material, plutonium finishing, and waste management. This paper presents the annual radiation exposure for the reprocessing work force, particularly during the period 1965 through 1978. It also presents the collective and average individual annual exposures for various occupations including operators, mechanics, electricians, control laboratory technicians, and health physicists. Periodic and repetitive work activities that result in the highest radiation exposures are also described. The assimilation of radionuclides, particularly plutonium, by the work force is reviewed. Methods that have been developed to minimize the exposure of reprocessing personnel are described. The success of these methods is illustrated by experience - there has been no individual worker exposure of greater than 3.1 rems per year and only one plutonium assimilation greater than the maximum permissible body burden during the 24 years of operation of the facilities

Radiation exposures in reprocessing facilities at the Savannah River Plant

International Nuclear Information System (INIS)

Hayes, G.; Caldwell, R.D.; Hall, R.M.

1979-06-01

Two large reprocessing facilities have been operating at the Savannah River Plant since 1955. The plant, which is near Aiken, South Carolina, is operated for the US Department of Energy by the Du Pont Company. The reprocessing facilities have a work force of approximately 1,800. The major processes in the facilities are chemical separations of irradiated material, plutonium finishing, and waste management. This paper presents the annual radiation exposure for the reprocessing work force, particularly during the period 1965 through 1978. It also presents the collective and average individual annual exposures for various occupations including operators, mechanics, electricians, control laboratory technicians, and health physicists. Periodic and repetitive work activities that result in the highest radiation exposures are also described. The assimilation of radionuclides, particularly plutonium, by the work force is reviewed. Methods that have been developed to minimize the exposure of reprocessing personnel are described. The success of these methods is illustrated by experience - there has been no individual worker exposure of greater than 3.1 rems per year and only one plutonium assimilation greater than the maximum permissible body burden during the 24 years of operation of the facilities

Performance of Generating Plant: New Metrics for Industry in Transition

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-09-15

This report is the result of the work of the Performance of Generating Plant task force of the World Energy Council. The report examines the challenges of measuring and improving performance and considers some of the issues related to this field.

Automated force controller for amplitude modulation atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Miyagi, Atsushi, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr; Scheuring, Simon, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr [U1006 INSERM, Université Aix-Marseille, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille (France)

2016-05-15

Atomic Force Microscopy (AFM) is widely used in physics, chemistry, and biology to analyze the topography of a sample at nanometer resolution. Controlling precisely the force applied by the AFM tip to the sample is a prerequisite for faithful and reproducible imaging. In amplitude modulation (oscillating) mode AFM, the applied force depends on the free and the setpoint amplitudes of the cantilever oscillation. Therefore, for keeping the applied force constant, not only the setpoint amplitude but also the free amplitude must be kept constant. While the AFM user defines the setpoint amplitude, the free amplitude is typically subject to uncontrollable drift, and hence, unfortunately, the real applied force is permanently drifting during an experiment. This is particularly harmful in biological sciences where increased force destroys the soft biological matter. Here, we have developed a strategy and an electronic circuit that analyzes permanently the free amplitude of oscillation and readjusts the excitation to maintain the free amplitude constant. As a consequence, the real applied force is permanently and automatically controlled with picoNewton precision. With this circuit associated to a high-speed AFM, we illustrate the power of the development through imaging over long-duration and at various forces. The development is applicable for all AFMs and will widen the applicability of AFM to a larger range of samples and to a larger range of (non-specialist) users. Furthermore, from controlled force imaging experiments, the interaction strength between biomolecules can be analyzed.

Imaging stability in force-feedback high-speed atomic force microscopy

International Nuclear Information System (INIS)

Kim, Byung I.; Boehm, Ryan D.

2013-01-01

We studied the stability of force-feedback high-speed atomic force microscopy (HSAFM) by imaging soft, hard, and biological sample surfaces at various applied forces. The HSAFM images showed sudden topographic variations of streaky fringes with a negative applied force when collected on a soft hydrocarbon film grown on a grating sample, whereas they showed stable topographic features with positive applied forces. The instability of HSAFM images with the negative applied force was explained by the transition between contact and noncontact regimes in the force–distance curve. When the grating surface was cleaned, and thus hydrophilic by removing the hydrocarbon film, enhanced imaging stability was observed at both positive and negative applied forces. The higher adhesive interaction between the tip and the surface explains the improved imaging stability. The effects of imaging rate on the imaging stability were tested on an even softer adhesive Escherichia coli biofilm deposited onto the grating structure. The biofilm and planktonic cell structures in HSAFM images were reproducible within the force deviation less than ∼0.5 nN at the imaging rate up to 0.2 s per frame, suggesting that the force-feedback HSAFM was stable for various imaging speeds in imaging softer adhesive biological samples. - Highlights: ► We investigated the imaging stability of force-feedback HSAFM. ► Stable–unstable imaging transitions rely on applied force and sample hydrophilicity. ► The stable–unstable transitions are found to be independent of imaging rate

Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass.

Science.gov (United States)

Quiroga, R Emiliano; Golluscio, Rodolfo A; Blanco, Lisandro J; Fernández, Roberto J

2010-10-01

It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/ subhumid x heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot: root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure

What about improving the productivity of electric power plants

International Nuclear Information System (INIS)

Lawroski, H.; Knecht, P.D.; Prideaux, D.L.; Zahner, R.R.

1976-01-01

The FEA in April of 1974 established an Interagency Task Group on Power Plant Reliability, which was charged with the broad objective of improving the productivity of existing and planned large fossil-fueled and nuclear power plants. It took approximately 11 months for the task force to publish a report, ''Report on Improving the Productivity of Electrical Power Plants'' (FEA-263-G), a detailed analysis and comparison of successful and below-average-performance power plants. The Nuclear Service Corp. portion of this study examined four large central-station power plants: two fossil (coal) and two nuclear plants. Only plants with electrical generation capacities greater than 400 MWe were considered. The study included the following: staff technical skill, engineering support, QA program, plant/corporate coordination, operation philosophy, maintenance programs, federal/state regulations, network control, and equipment problems. Personnel were interviewed, and checklists providing input from some 21 or more plant and corporate personnel of each utility were utilized. Reports and other documentation were also reviewed. It was recognized early that productivity is closely allied to technical skills and positive motivation. For this reason, considerable attention was given to people in this study

Plant availability design aspects of Korean next generation reactor

International Nuclear Information System (INIS)

Woo Sang Lim; Ha Chung Beak

1998-01-01

The purpose of this paper is to describe the KNGR design concepts adopted for reducing forced outages and refueling outages, and current design changes, to assess their availability impacts compared to existing domestic nuclear power plants, and then to identify design directions for next design stage. (author)

The Need for Strategic Planning for Nuclear Power Plant I and C Upgrades

International Nuclear Information System (INIS)

Hill, J. Douglas; Moore, Paul

2002-01-01

Nuclear power plants rely on Instrumentation and Control (I and C) systems for control, monitoring and protection of the plant. The original, analog designs used in most nuclear plants have become or soon will be obsolete, forcing plants to turn to digital technology. Many factors affect the design of replacement equipment, including long-term and short-term economics, regulatory issues, and the way the plant operates on a day-to-day basis. The first step to all modernization projects should involve strategic planning, to ensure that the overall long and short-term goals of the plant are met. Strategic planning starts with a thorough evaluation of the existing plant control systems, the available options, and the benefits and consequences of these options. (authors)

Principles and applications of force spectroscopy using atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Kyu; Kim, Woong; Park, Joon Won [Dept. of Chemistry, Pohang University of Science and Technology, Pohang (Korea, Republic of)

2016-12-15

Single-molecule force spectroscopy is a powerful technique for addressing single molecules. Unseen structures and dynamics of molecules have been elucidated using force spectroscopy. Atomic force microscope (AFM)-based force spectroscopy studies have provided picoNewton force resolution, subnanometer spatial resolution, stiffness of substrates, elasticity of polymers, and thermodynamics and kinetics of single-molecular interactions. In addition, AFM has enabled mapping the distribution of individual molecules in situ, and the quantification of single molecules has been made possible without modification or labeling. In this review, we describe the basic principles, sample preparation, data analysis, and applications of AFM-based force spectroscopy and its future.

Westinghouse AP600 advanced nuclear plant design

International Nuclear Information System (INIS)

Gangloff, W.

1999-01-01

As part of the cooperative US Department of Energy (DOE) Advanced Light Water Reactor (ALWR) Program and the Electric Power Research Institute (EPRI), the Westinghouse AP600 team has developed a simplified, safe, and economic 600-megawatt plant to enter into a new era of nuclear power generation. Designed to satisfy the standards set by DOE and defined in the ALWR Utility Requirements Document (URD), the Westinghouse AP600 is an elegant combination of innovative safety systems that rely on dependable natural forces and proven technologies. The Westinghouse AP600 design simplifies plant systems and significant operation, inspections, maintenance, and quality assurance requirements by greatly reducing the amount of valves, pumps, piping, HVAC ducting, and other complex components. The AP600 safety systems are predominantly passive, depending on the reliable natural forces of gravity, circulation, convection, evaporation, and condensation, instead of AC power supplies and motor-driven components. The AP600 provides a high degree of public safety and licensing certainty. It draws upon 40 years of experience in light water reactor components and technology, so no demonstration plant is required. During the AP600 design program, a comprehensive test program was carried out to verify plant components, passive safety systems components, and containment behavior. When the test program was completed at the end of 1994, the AP600 became the most thoroughly tested advanced reactor design ever reviewed by the US Nuclear Regulatory Commission (NRC). The test results confirmed the exceptional behavior of the passive systems and have been instrumental in facilitating code validations. Westinghouse received Final Design Approval from the NRC in September 1998. (author)

Design of Robust AMB Controllers for Rotors Subjected to Varying and Uncertain Seal Forces

DEFF Research Database (Denmark)

Lauridsen, Jonas Skjødt; Santos, Ilmar

2017-01-01

This paper demonstrates the design and simulation results of model based controllers for AMB systems, subjectedto uncertain and changing dynamic seal forces. Specifically, a turbocharger with a hole-pattern seal mounted acrossthe balance piston is considered. The dynamic forces of the seal, which...... are dependent on the operational conditions,have a significant effect on the overall system dynamics. Furthermore, these forces are considered uncertain.The nominal and the uncertainty representation of the seal model are established using results from conventionalmodelling approaches, i.e. CFD and Bulkflow......, and experimental results. Three controllers are synthesized: I) AnH∞ controller based on nominal plant representation, II) A µ controller, designed to be robust against uncertaintiesin the dynamic seal model and III) a Linear Parameter Varying (LPV) controller, designed to provide a unifiedperformance over a large...

Three-nucleon forces

International Nuclear Information System (INIS)

Sauer, P.U.

2014-01-01

In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

Dynamics of shearing force and its correlations with chemical compositions and dry matter digestibility of stylo ( stem

Directory of Open Access Journals (Sweden)

Xuejuan Zi

2017-12-01

Full Text Available Objective The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD of stylo. Methods The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

Directory of Open Access Journals (Sweden)

Adam Sweetman

2014-04-01

Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

The effects of dorso-lumbar motion restriction on the ground reaction force components during running.

Science.gov (United States)

Morley, Joseph J; Traum, Edward

2016-04-01

The effects of restricting dorso-lumbar spine mobility on ground reaction forces in runners was measured and assessed. A semi-rigid cast was used to restrict spinal motion during running. Subjects ran across a force platform at 3.6 m/s, planting the right foot on the platform. Data was collected from ten running trials with the cast and ten without the cast and analysed. Casted running showed that the initial vertical heel strike maximum was increased (p running (p running results in measurable and repeatable alterations in ground reaction force components. Alterations in load transfer due to decreased spinal motion may be a factor contributing to selected injuries in runners. Copyright © 2015 Elsevier Ltd. All rights reserved.

Force modulation for improved conductive-mode atomic force microscopy

NARCIS (Netherlands)

Koelmans, W.W.; Sebastian, Abu; Despont, Michel; Pozidis, Haris

We present an improved conductive-mode atomic force microscopy (C-AFM) method by modulating the applied loading force on the tip. Unreliable electrical contact and tip wear are the primary challenges for electrical characterization at the nanometer scale. The experiments show that force modulation

Quantum fictitious forces

DEFF Research Database (Denmark)

Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder

2002-01-01

We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii......) a singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number...... of atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

Upgrading of fire safety in Indian nuclear power plants

International Nuclear Information System (INIS)

Agarwal, N.K.

1998-01-01

Indian nuclear power programme started with the installation of 2 nos. of Boiling Water Reactor (BWR) at Tarapur (TAPS I and II) of 210 MWe each commissioned in the year 1996. The Pressurized Heavy Water Reactor (PHWR) programme in the country started with the installation of 2x220 MWe stations at Rawatbhatta near Kota (RAPS I and II) in the State of Rajasthan in the sixties. At the present moment, the country has 10 stations in operation. Construction is going on for 4 more units of 220 MWe where as work on two more 500 MWe units is going to start soon. Fire safety systems for the earlier units were engineered as per the state-of-art knowledge available then. The need for review of fire protection systems in the Indian nuclear power plants has also been felt since long almost after Brown's Ferry fire in 1975 itself. Task forces consisting of fire experts, systems design engineers, O and M personnel as well as the Fire Protection engineers at the plant were constituted for each plant to review the existing fire safety provisions in details and highlight the upgradation needed for meeting the latest requirements as per the national as well as international practices. The recommendations made by three such task forces for the three plants are proposed to be reviewed in this paper. The paper also highlights the recommendations to be implemented immediately as well as on long-term basis over a period of time

Magnetic field exposure stiffens regenerating plant protoplast cell walls.

Science.gov (United States)

Haneda, Toshihiko; Fujimura, Yuu; Iino, Masaaki

2006-02-01

Single suspension-cultured plant cells (Catharanthus roseus) and their protoplasts were anchored to a glass plate and exposed to a magnetic field of 302 +/- 8 mT for several hours. Compression forces required to produce constant cell deformation were measured parallel to the magnetic field by means of a cantilever-type force sensor. Exposure of intact cells to the magnetic field did not result in any changes within experimental error, while exposure of regenerating protoplasts significantly increased the measured forces and stiffened regenerating protoplasts. The diameters of intact cells or regenerating protoplasts were not changed after exposure to the magnetic field. Measured forces for regenerating protoplasts with and without exposure to the magnetic field increased linearly with incubation time, with these forces being divided into components based on the elasticity of synthesized cell walls and cytoplasm. Cell wall synthesis was also measured using a cell wall-specific fluorescent dye, and no changes were noted after exposure to the magnetic field. Analysis suggested that exposure to the magnetic field roughly tripled the Young's modulus of the newly synthesized cell wall without any lag.

A novel AFM based method for force measurements between individual hair strands

International Nuclear Information System (INIS)

Max, Eva; Haefner, Wolfgang; Wilco Bartels, Frank; Sugiharto, Albert; Wood, Claudia; Fery, Andreas

2010-01-01

Interactions between hairs and other natural fibers are of broad interest for both applications and fundamental understanding of biological interfaces. We present a novel method, that allows force measurements between individual hair strands. Hair fragments can be laser-cut without altering their surface chemistry. Subsequently, they are glued onto Atomic force microscopy (AFM) cantilevers. This allows carrying out measurements between the hair fragment and surface immobilized hair in a well-defined crossed-cylinder geometry. Both force-distance and friction measurements are feasible. Measurements in air with controlled humidity and in aqueous environment show clear differences which can be explained by the dominating role of capillary interactions in air. Friction is found to be anisotropic, reflecting the fine structure of hair cuticula. While the investigations are focused on the particular example of human hair, we expect that the approach can be extended to other animal/plant fibers and thus offers perspectives for broad spectrum systems.

Drag forces of common plant species in temperate streams: consequences of morphology, velocity and biomass

DEFF Research Database (Denmark)

Jensen, Kaj Sand

2008-01-01

Swift flow in streams may physically influence the morphology and distribution of plants. I quantified drag as a function of velocity, biomass and their interaction on the trailing canopy of seven European stream species in an experimental flume and evaluated its importance for species distributi...... than an uneven distribution with the same biomass confined to dense patches surrounded by open flow channels. Thus, management strategies to ensure a patchy plants distribution should be suitable for combining agricultural drainage and ecological stream quality....

Wind Power Plants Fundamentals, Design, Construction and Operation

CERN Document Server

Twele, Jochen

2012-01-01

Wind power plants teaches the physical foundations of usage of Wind Power. It includes the areas like Construction of Wind Power Plants, Design, Development of Production Series, Control, and discusses the dynamic forces acting on the systems as well as the power conversion and its connection to the distribution system. The book is written for graduate students, practitioners and inquisitive readers of any kind. It is based on lectures held at several universities. Its German version it already is the standard text book for courses on Wind Energy Engineering but serves also as reference for practising engineers.

Biotechnological aspects of cytoskeletal regulation in plants.

Science.gov (United States)

Komis, George; Luptovciak, Ivan; Doskocilova, Anna; Samaj, Jozef

2015-11-01

The cytoskeleton is a protein-based intracellular superstructure that evolved early after the appearance of bacterial prokaryotes. Eventually cytoskeletal proteins and their macromolecular assemblies were established in eukaryotes and assumed critical roles in cell movements, intracellular organization, cell division and cell differentiation. In biomedicine the small-molecules targeting cytoskeletal elements are in the frontline of anticancer research with plant-derived cytoskeletal drugs such as Vinca alkaloids and toxoids, being routinely used in the clinical practice. Moreover, plants are also major material, food and energy resources for human activities ranging from agriculture, textile industry, carpentry, energy production and new material development to name some few. Most of these inheritable traits are associated with cell wall synthesis and chemical modification during primary and secondary plant growth and inevitably are associated with the dynamics, organization and interactions of the plant cytoskeleton. Taking into account the vast intracellular spread of microtubules and actin microfilaments the cytoskeleton collectively assumed central roles in plant growth and development, in determining the physical stance of plants against the forces of nature and becoming a battleground between pathogenic invaders and the defense mechanisms of plant cells. This review aims to address the role of the plant cytoskeleton in manageable features of plants including cellulose biosynthesis with implications in wood and fiber properties, in biofuel production and the contribution of plant cytoskeletal elements in plant defense responses against pathogens or detrimental environmental conditions. Ultimately the present work surveys the potential of cytoskeletal proteins as platforms of plant genetic engineering, nominating certain cytoskeletal proteins as vectors of favorable traits in crops and other economically important plants. Copyright © 2015 Elsevier Inc. All

The propagation of pressure pulsations in the primary circuit of power plant A1

International Nuclear Information System (INIS)

Pecinka, L.

1976-01-01

A classification is made of the exciting forces of pressure pulsations in the primary coolant circuit with forced coolant circulation. A mathematical model is constructed of the propagation of pressure pulsations in the system and examples of measurements are given. The measurement methods used and the methods for the generalization of obtained data are assessed. The methods and results of the measurements of hydrodynamic pressure pulsations in a closed primary circuit with forced coolant circulation of the A-1 nuclear power plant are given. (F.M.)

Performance Improvement of a Radioactive Forced Circulation Evaporator System

International Nuclear Information System (INIS)

Zaki, A.A.; Hala, A.A.; Othman, E.A.

2016-01-01

Evaporation is a proven method for treatment of liquid radioactive wastes providing both good decontamination and high concentration. In a radioactive waste treatment plant a forced circulation evaporator is used to reduce the volume of radioactive liquid wastes arising from different applications of nuclear industries. The safe operation, limiting the composition of the liquid radioactive waste at a prescribed value, with high performance efficiency, requires good control for the evaporator operating pressure and the level of liquid waste inside the separator part of the evaporator. The aim of this work was to improve the safety and performance of a forced-circulation evaporator used in a liquid radioactive wastes treatment plant. In this respect, a level controller system for this type of evaporator was designed, where proportional (P), proportional Integral (PI) and deadbeat response controllers for the separator level system were suggested. More over, an ideal 2×2(2 inputs and 2 outputs )de coupler controller for controlling the operating pressure and the product composition was developed. Computer results demonstrated that the deadbeat response has been success fully obtained from the developed separator control system. The maximum over shoot in the unit-step response curve was reduce d to 25 % and the settling time also was reduced to more than the half; about 26 minutes using Ziegler-Nichols tuning technique.The designed de coupling controller has been found effective in achieving a good trade-off between stability and performance

A Plant's Response to Gravity as a Wave Guide Phenomenon

Science.gov (United States)

Wagner, Orvin

1997-11-01

Plant experimental data provides a unifying wave theory (W-wave theory) for the growth and development of plants. A plant's response to gravity is an important aspect of this theory. It appears that a plant part is tuned to the angle with which it initially grew with respect to the gravitational field and changes produce correction responses. This is true because the velocity of W-waves (whose standing waves determine plant structure) within plant tissue is found to be different in different directions (angle a) with respect to the gravitational field. I found that there are preferred values of a, namely integral multiples of near 5 degrees for some plants. Conifers apparently are more sensitive to the gravitational field than deciduous trees, in the cases studied, so their structure is determined in more detail by the gravitational field. A plant's response to gravity appears to be a fundamental phenomenon and may provide a new model for gravity that can be experimentally verified in the laboratory. Along these same lines accelerometers placed in plant tissue indicate that plants produce gravity related forces that facilitate sap flow. See the

Interfacial force measurements using atomic force microscopy

NARCIS (Netherlands)

Chu, L.

2018-01-01

Atomic Force Microscopy (AFM) can not only image the topography of surfaces at atomic resolution, but can also measure accurately the different interaction forces, like repulsive, adhesive and lateral existing between an AFM tip and the sample surface. Based on AFM, various extended techniques have

Investigation of pile foundations of nuclear power plants with help of non linear analyses

International Nuclear Information System (INIS)

Diaz, B.E.; Schulz, M.; Costa, E.; Vaz, L.E.

1984-01-01

A few important 1300 MW PWR nuclear power plants have been built over pile foundations. The design requirements of Nuclear Power Plants prescribe accurate investigation of the as built conditions of the foundation. This study must take into account the actual concrete strength existent among and along the pile shafts of the foundation. In order to simulate the structural response of the foundation up to the failure, a non linear analysis must be performed. In this paper the required computer analysis procedures will be described. It can be verified that the redistribution of the internal forces in this highly hyperstatic soil-structure system can be of two types. The total applied forces over the foundation are redistributed among the piles and for each pile itself a local redistribution of forces takes place along the pile shaft. This type of analysis allows an accurate investigation of the actual safety margin existent in the pile foundation, based on the actual as built conditions of the construction. (Author) [pt

Diagnostic systems in nuclear power plants. Proceedings of a technical committee meeting. Working material

International Nuclear Information System (INIS)

1998-01-01

Nuclear power industry has a quite long tradition in on-line diagnostic of mechanical components and a considerable effort was put in developing diagnostic systems which are able to detect arising mechanical problems at an early stage. Computers are increasingly exploited to provide higher level information on process behaviour such as: early indication of the process deviation from normal conditions; rapid identification of the cause of any disturbance; prediction of the evolution of a disturbance; operator aid through computerized help. Following the recommendation of Several Member States to strengthen the activity in this field two divisions of IAEA established in 1995 the International Task Force on Nuclear Power Plant Diagnostics. The scope of the task force cover both technological developments and safety/licensing aspects of diagnostics. This report contains papers presented at the last in the series of Technical Committee Meetings on the Diagnostic Systems in Nuclear Power Plants organized in the framework of International Task Force

Diagnostic systems in nuclear power plants. Proceedings of a technical committee meeting. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-31

Nuclear power industry has a quite long tradition in on-line diagnostic of mechanical components and a considerable effort was put in developing diagnostic systems which are able to detect arising mechanical problems at an early stage. Computers are increasingly exploited to provide higher level information on process behaviour such as: early indication of the process deviation from normal conditions; rapid identification of the cause of any disturbance; prediction of the evolution of a disturbance; operator aid through computerized help. Following the recommendation of Several Member States to strengthen the activity in this field two divisions of IAEA established in 1995 the International Task Force on Nuclear Power Plant Diagnostics. The scope of the task force cover both technological developments and safety/licensing aspects of diagnostics. This report contains papers presented at the last in the series of Technical Committee Meetings on the Diagnostic Systems in Nuclear Power Plants organized in the framework of International Task Force Refs, figs, tabs

Trade-off between drag reduction and light interception of macrophytes: comparing five aquatic plants with contrasting morphology

NARCIS (Netherlands)

Bal, K.D.; Bouma, T.J.; Buis, K.; Struyf, E.; Jonas, S.; Backx, H.; Meire, P.

2011-01-01

1. Macrophytes in running waters experience an often dynamic and harsh environment. To avoid breakage, plants have to reduce the experienced drag force. However, by reducing leaf area, photosynthetic production is less. Aquatic plants therefore have to find a balance between reducing drag and

Report of Task Force for review of nuclear waste management. Draft

International Nuclear Information System (INIS)

1978-02-01

Some of the findings of the Task Force are: a majority of independent technical experts have concluded that high-level waste can be safely disposed in geological media, but validation of the specific technical choices will be an important element of the licensing process. Reprocessing is not required for the safe disposal of commercial spent fuel. Consideration should be given to an early demonstration of the geologic disposal of a limited number of spent fuel assemblies in the waste Isolation Pilot Plant. The Spent Fuel Policy announced by President Carter in October 1977 must be integrated with the Waste Management Policy. The Task Force report highlights the importance of away from reactor storage that occurs between on-site storage of spent fuel at utilities and ultimate disposal. The target for initial operation in 1985 os a National Waste Repository for the permanent disposal of commercial high-level waste as spent fuel may not be met; this does not affect the early 1980s schedule for the Waste Isolation Pilot Plant. The responsibility for the ultimate disposal for all forms of nuclear waste should be with the Federal Government and long-term waste disposal facilities should be subject to NRC licensing. The NEPA process is an essential part of the nuclear waste management program and Department of Energy efforts in this regard must be strengthened. Policy and program management responsibility for Waste Management should be raised to a higher level in the Department of Energy. There are substantial budgetary impacts of the Task Force recommendations and legislation would be required to carry out many of the suggested changes

Gravity resistance, another graviresponse in plants - role of microtubule-membrane-cell wall continuum

Science.gov (United States)

Hoson, T.; Saito, Y.; Usui, S.; Soga, K.; Wakabayashi, K.

Resistance to the gravitational force has been a serious problem for plants to survive on land, after they first went ashore more than 400 million years ago. Thus, gravity resistance is the principal graviresponse in plants comparable to gravitropism. Nevertheless, only limited information has been obtained for this second gravity response. We have examined the mechanism of gravity resistance using hypergravity conditions produced by centrifugation. The results led a hypothesis on the mechanism of plant resistance to the gravitational force that the plant constructs a tough body by increasing the cell wall rigidity, which are brought about by modification of the cell wall metabolism and cell wall environment, especially pH. The hypothesis was further supported by space experiments during the Space Shuttle STS-95 mission. On the other hand, we have shown that gravity signal may be perceived by mechanoreceptors (mechanosensitive ion channels) on the plasma membrane and amyloplast sedimentation in statocytes is not involved in gravity resistance. Moreover, hypergravity treatment increased the expression levels of genes encoding alpha-tubulin, a component of microtubules and 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of terpenoids such as membrane sterols. The expression of HMGR and alpha- and beta-tubulin genes increased within several hours after hypergravity treatment, depending on the magnitude of gravity. The determination of levels of gene products as well as the analysis with knockout mutants of these genes by T-DNA insertions in Arabidopsis supports the involvement of both membrane sterols and microtubules in gravity resistance. These results suggest that structural or physiological continuum of microtubule-cell membrane-cell wall is responsible for plant resistance to the gravitational force.

Force Measurement with a Piezoelectric Cantilever in a Scanning Force Microscope

OpenAIRE

Tansock, J.; Williams, C. C.

1992-01-01

Detection of surface forces between a tip and sample has been demonstrated with a piezoelectric cantilever in a scanning force microscope (SFM). The use of piezoelectric force sensing is particularly advantageous in semiconductor applications where stray light from conventional optical force-sensing methods can significantly modify the local carrier density. Additionally, the piezoelectric sensors are simple, provide good sensitivity to force, and can be batch fabricated. Our piezoelectric fo...

Force reconstruction from tapping mode force microscopy experiments

International Nuclear Information System (INIS)

Payam, Amir F; Martin-Jimenez, Daniel; Garcia, Ricardo

2015-01-01

Fast, accurate, and robust nanomechanical measurements are intensely studied in materials science, applied physics, and molecular biology. Amplitude modulation force microscopy (tapping mode) is the most established nanoscale characterization technique of surfaces for air and liquid environments. However, its quantitative capabilities lag behind its high spatial resolution and robustness. We develop a general method to transform the observables into quantitative force measurements. The force reconstruction algorithm has been deduced on the assumption that the observables (amplitude and phase shift) are slowly varying functions of the tip–surface separation. The accuracy and applicability of the method is validated by numerical simulations and experiments. The method is valid for liquid and air environments, small and large free amplitudes, compliant and rigid materials, and conservative and non-conservative forces. (paper)

Labor Force

Science.gov (United States)

Occupational Outlook Quarterly, 2012

2012-01-01

The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

The significance of human actions for plant safety

International Nuclear Information System (INIS)

Holloway, N.J.

1988-01-01

The occurrence of the Chernobyl accident and before it the accidents at Three Mile Island, Flixborough and Bhopal, together with lesser process plant accidents, has emphasised the potential danger of human errors in major hazard plant operations. The perception of human error, held by the majority of the public and containing a fair amount of truth for a simple perception, is of an unpredictable and uncontrollable force let loose within the safest of system designs, and able, by virtue of these properties, to override the best laid plans. In this paper, we review the nature of the human errors which most concern us in process plant operation, and consider some of the conceptual approaches which might bring these errors under the same type of control as has been achieved for random hardware failures. (author)

Plant improvements through the use of benchmarking analysis

International Nuclear Information System (INIS)

Messmer, J.R.

1993-01-01

As utilities approach the turn of the century, customer and shareholder satisfaction is threatened by rising costs. Environmental compliance expenditures, coupled with low load growth and aging plant assets are forcing utilities to operate existing resources in a more efficient and productive manner. PSI Energy set out in the spring of 1992 on a benchmarking mission to compare four major coal fired plants against others of similar size and makeup, with the goal of finding the best operations in the country. Following extensive analysis of the 'Best in Class' operation, detailed goals and objectives were established for each plant in seven critical areas. Three critical processes requiring rework were identified and required an integrated effort from all plants. The Plant Improvement process has already resulted in higher operation productivity, increased emphasis on planning, and lower costs due to effective material management. While every company seeks improvement, goals are often set in an ambiguous manner. Benchmarking aids in setting realistic goals based on others' actual accomplishments. This paper describes how the utility's short term goals will move them toward being a lower cost producer

Inferring Interaction Force from Visual Information without Using Physical Force Sensors.

Science.gov (United States)

Hwang, Wonjun; Lim, Soo-Chul

2017-10-26

In this paper, we present an interaction force estimation method that uses visual information rather than that of a force sensor. Specifically, we propose a novel deep learning-based method utilizing only sequential images for estimating the interaction force against a target object, where the shape of the object is changed by an external force. The force applied to the target can be estimated by means of the visual shape changes. However, the shape differences in the images are not very clear. To address this problem, we formulate a recurrent neural network-based deep model with fully-connected layers, which models complex temporal dynamics from the visual representations. Extensive evaluations show that the proposed learning models successfully estimate the interaction forces using only the corresponding sequential images, in particular in the case of three objects made of different materials, a sponge, a PET bottle, a human arm, and a tube. The forces predicted by the proposed method are very similar to those measured by force sensors.

An experimental technique for the modelling of air flow movements in nuclear plant

International Nuclear Information System (INIS)

Ainsworth, R.W.; Hallas, N.J.

1986-01-01

This paper describes an experimental technique developed at Harwell to model ventilation flows in plant at 1/5th scale. The technique achieves dynamic similarity not only for forced convection imposed by the plant ventilation system, but also for the interaction between natural convection (from heated objects) and forced convection. The use of a scale model to study flow of fluids is a well established technique, relying upon various criteria, expressed in terms of dimensionless numbers, to achieve dynamic similarity. For forced convective flows, simulation of Reynolds number is sufficient, but to model natural convection and its interaction with forced convection, the Rayleigh, Grashof and Prandtl numbers must be simulated at the same time. This paper describes such a technique, used in experiments on a hypothetical glove box cell to study the interaction between forced and natural convection. The model contained features typically present in a cell, such as a man, motor, stairs, glove box, etc. The aim of the experiment was to study the overall flow patterns, especially around the model man 'working' at the glove box. The cell ventilation was theoretically designed to produce a downward flow over the face of the man working at the glove box. However, the results have shown that the flow velocities produced an upwards flow over the face of the man. The work has indicated the viability of modelling simultaneously the forced and natural convection processes in a cell. It has also demonstrated that simplistic assumptions cannot be made about ventilation flow patterns. (author)

Digital force-feedback for protein unfolding experiments using atomic force microscopy

Science.gov (United States)

Bippes, Christian A.; Janovjak, Harald; Kedrov, Alexej; Muller, Daniel J.

2007-01-01

Since its invention in the 1990s single-molecule force spectroscopy has been increasingly applied to study protein (un-)folding, cell adhesion, and ligand-receptor interactions. In most force spectroscopy studies, the cantilever of an atomic force microscope (AFM) is separated from a surface at a constant velocity, thus applying an increasing force to folded bio-molecules or bio-molecular bonds. Recently, Fernandez and co-workers introduced the so-called force-clamp technique. Single proteins were subjected to a defined constant force allowing their life times and life time distributions to be directly measured. Up to now, the force-clamping was performed by analogue PID controllers, which require complex additional hardware and might make it difficult to combine the force-feedback with other modes such as constant velocity. These points may be limiting the applicability and versatility of this technique. Here we present a simple, fast, and all-digital (software-based) PID controller that yields response times of a few milliseconds in combination with a commercial AFM. We demonstrate the performance of our feedback loop by force-clamp unfolding of single Ig27 domains of titin and the membrane proteins bacteriorhodopsin (BR) and the sodium/proton antiporter NhaA.

Digital force-feedback for protein unfolding experiments using atomic force microscopy

International Nuclear Information System (INIS)

Bippes, Christian A; Janovjak, Harald; Kedrov, Alexej; Muller, Daniel J

2007-01-01

Since its invention in the 1990s single-molecule force spectroscopy has been increasingly applied to study protein (un-)folding, cell adhesion, and ligand-receptor interactions. In most force spectroscopy studies, the cantilever of an atomic force microscope (AFM) is separated from a surface at a constant velocity, thus applying an increasing force to folded bio-molecules or bio-molecular bonds. Recently, Fernandez and co-workers introduced the so-called force-clamp technique. Single proteins were subjected to a defined constant force allowing their life times and life time distributions to be directly measured. Up to now, the force-clamping was performed by analogue PID controllers, which require complex additional hardware and might make it difficult to combine the force-feedback with other modes such as constant velocity. These points may be limiting the applicability and versatility of this technique. Here we present a simple, fast, and all-digital (software-based) PID controller that yields response times of a few milliseconds in combination with a commercial AFM. We demonstrate the performance of our feedback loop by force-clamp unfolding of single Ig27 domains of titin and the membrane proteins bacteriorhodopsin (BR) and the sodium/proton antiporter NhaA

Nuclear Power Plant Outage Optimization Strategy. 2016 Edition

International Nuclear Information System (INIS)

2016-10-01

This publication is an update of IAEA-TECDOC-1315, Nuclear Power Plant Outage Optimisation Strategy, which was published in 2002, and aims to communicate good outage management practices in a manner that can be used by operators and utilities in Member States. Nuclear power plant outage management is a key factor for safe and economic nuclear power plant performance. This publication discusses plant outage strategy and how this strategy is actually implemented. The main areas that are important for outage optimization that were identified by the utilities and government organizations participating in this report are: 1) organization and management; 2) outage planning and preparation; 3) outage execution; 4) safety outage review; and 5) counter measures to avoid the extension of outages and to facilitate the work in forced outages. Good outage management practices cover many different areas of work and this publication aims to communicate these good practices in a way that they can be used effectively by operators and utilities

Quantum anticentrifugal force

International Nuclear Information System (INIS)

Cirone, M.A.; Schleich, W.P.; Straub, F.; Rzazewski, K.; Wheeler, J.A.

2002-01-01

In a two-dimensional world, a free quantum particle of vanishing angular momentum experiences an attractive force. This force originates from a modification of the classical centrifugal force due to the wave nature of the particle. For positive energies the quantum anticentrifugal force manifests itself in a bunching of the nodes of the energy wave functions towards the origin. For negative energies this force is sufficient to create a bound state in a two-dimensional δ-function potential. In a counterintuitive way, the attractive force pushes the particle away from the location of the δ-function potential. As a consequence, the particle is localized in a band-shaped domain around the origin

The effect of force feedback delay on stiffness perception and grip force modulation during tool-mediated interaction with elastic force fields.

Science.gov (United States)

Leib, Raz; Karniel, Amir; Nisky, Ilana

2015-05-01

During interaction with objects, we form an internal representation of their mechanical properties. This representation is used for perception and for guiding actions, such as in precision grip, where grip force is modulated with the predicted load forces. In this study, we explored the relationship between grip force adjustment and perception of stiffness during interaction with linear elastic force fields. In a forced-choice paradigm, participants probed pairs of virtual force fields while grasping a force sensor that was attached to a haptic device. For each pair, they were asked which field had higher level of stiffness. In half of the pairs, the force feedback of one of the fields was delayed. Participants underestimated the stiffness of the delayed field relatively to the nondelayed, but their grip force characteristics were similar in both conditions. We analyzed the magnitude of the grip force and the lag between the grip force and the load force in the exploratory probing movements within each trial. Right before answering which force field had higher level of stiffness, both magnitude and lag were similar between delayed and nondelayed force fields. These results suggest that an accurate internal representation of environment stiffness and time delay was used for adjusting the grip force. However, this representation did not help in eliminating the bias in stiffness perception. We argue that during performance of a perceptual task that is based on proprioceptive feedback, separate neural mechanisms are responsible for perception and action-related computations in the brain. Copyright © 2015 the American Physiological Society.

DelPhiForce web server: electrostatic forces and energy calculations and visualization.

Science.gov (United States)

Li, Lin; Jia, Zhe; Peng, Yunhui; Chakravorty, Arghya; Sun, Lexuan; Alexov, Emil

2017-11-15

Electrostatic force is an essential component of the total force acting between atoms and macromolecules. Therefore, accurate calculations of electrostatic forces are crucial for revealing the mechanisms of many biological processes. We developed a DelPhiForce web server to calculate and visualize the electrostatic forces at molecular level. DelPhiForce web server enables modeling of electrostatic forces on individual atoms, residues, domains and molecules, and generates an output that can be visualized by VMD software. Here we demonstrate the usage of the server for various biological problems including protein-cofactor, domain-domain, protein-protein, protein-DNA and protein-RNA interactions. The DelPhiForce web server is available at: http://compbio.clemson.edu/delphi-force. delphi@clemson.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Restoring directional growth sense to plants in space

Science.gov (United States)

Gorgolewski, S.

Introduction of new plant classification: electrotropic (Et) and non-electrotropic (nEt) plants gives us a criterion which plants need electric field to grow "normally" in space. The electric field: E is measured in V/m (volt per meter). Do not confuse "electrotropism" understood by some as the response to current flow transversely through the plant's root. This effect was previously described in biological textbooks. I suggest to call it as (Ct) (here C stands for current and t for tropism). In the laboratory we have in the plant growth chamber two transparent to light (wire mesh) conducting sheets separated by m(meters) and V volts potential difference. It has been shown in laboratory that Et is a very important factor in electrotropic plant development. Space experiments with plants grown in orbit from seed to seed have been fully successful only (in my very best knowledge) with nEt plants. The most common nEt plants are grasses (more than 50% of all plants). The nEt plants in space use phototropism as their sensor of direction. In space (and most greenhouses) we have to provide the electric field at least for the Et plants. It has been shown that the electric field is also beneficial to nEt plants which also acquire the sense of direction imposed by stronger than the normal 130V/m E field (vector). The stronger horizontal E field of 1.6kV/m (slightly more than 12 times stronger than 130V/m) does not influence the rate of growth of maize (which is nEt) in 130V/m vertical field or even in the Faraday cage 0V/m. Yet when the maize gets its leaves, they all lean in the horizontal field (1.6kV/m) towards the anode. The direction of the E vector is defined by the E field lines running from the positive to the negative charges. Because the electric forces are a factor of 1038 times stronger than the gravitational forces, it is not important for the E field whether it acts on ions in the gravity or in weightlessness. We have to recall that on the Earth and in space Et

Nuclear plant life - A business decision

International Nuclear Information System (INIS)

Joosten, J.K.

1995-01-01

Regarding the future of the nuclear power option, many scenarios have been put forth over the years. The most commonly accepted projections for installed nuclear capacity show it growing at a rate of about 2% per year throughout the next few decades. These projections appear modes on the surface. However, underlying the projections are critical assumptions and sometimes misconceptions about the lifetimes of existing reactors and how they are determined. The notion of a 40 year plant life is very common. Consequently, many projections start either with the assumption that no plants will be retired in the near terms or with the assumption that each retired plant will be replaced by another nuclear plant after 40 years. Effectively, these assumptions yield future projections for installed capacity that might be characterized as low growth, medium growth and high growth scenarios - or grow, grow, grow. The question remains as to whether or not these assumptions accurately model the driving forces and constraints to nuclear development. After all, there is no scientific basis for believing that all plants, PWRs BWRs, RBMKs, etc., should have the same 40 year life. Most power plant owners purchase the plant for the main reason of supplying electrical power to their consumer. For these owners, electricity production is a day to day commercial activity with various alternatives on how to achieve the prime objective. The decision of which electricity generation alternative to select (gas, coal, nuclear or renewable energy) and how long to operate the plant before replacing it with a new one is essentially a business decision. The paper discusses ageing, the nuclear plant life decision process, the factors which influence the decision and their ramifications regarding the near term growth of nuclear power capacity. The modelling of nuclear plant lifetimes is also discussed. (author). 5 refs, 10 figs, 1 tab

78 FR 2996 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-01-15

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

77 FR 56845 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2012-09-14

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

78 FR 27969 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-05-13

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...

Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas.

Science.gov (United States)

van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

2016-06-01

The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant's lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant-plant interactions was analysed. Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant-plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly driven by plastic and not by genotypic responses to changes in

Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

Energy Technology Data Exchange (ETDEWEB)

Cosgrove, Daniel J.

2015-11-25

The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the ‘Young's modulus’ of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

The contribution of the electrostatic proximity force to atomic force microscopy with insulators

International Nuclear Information System (INIS)

Stanley Czarnecki, W.; Schein, L.B.

2005-01-01

Measurements, using atomic force microscopy, of the force and force derivative on a charged insulating micron sized sphere as a function of gap between the sphere and a conductive plane have revealed attractive forces at finite gaps that are larger than predicted by either van der Waals or conventional electrostatic forces. We suggest that these observations may be due to an electrostatic force that we have identified theoretically and call the proximity force. This proximity force is due to the discrete charges on the surface of the sphere in close proximity to the plane

The contribution of the electrostatic proximity force to atomic force microscopy with insulators

Energy Technology Data Exchange (ETDEWEB)

Stanley Czarnecki, W. [Aetas Technology Corporation, P.O. Box 53398, Irvine, CA 92619-3398 (United States); IBM Corporation, 5600 Cottle Rd., Building 13, San Jose, CA 95193 (United States); Schein, L.B. [Aetas Technology Corporation, P.O. Box 53398, Irvine, CA 92619-3398 (United States)]. E-mail: schein@prodigy.net

2005-05-16

Measurements, using atomic force microscopy, of the force and force derivative on a charged insulating micron sized sphere as a function of gap between the sphere and a conductive plane have revealed attractive forces at finite gaps that are larger than predicted by either van der Waals or conventional electrostatic forces. We suggest that these observations may be due to an electrostatic force that we have identified theoretically and call the proximity force. This proximity force is due to the discrete charges on the surface of the sphere in close proximity to the plane.

Minimizing tip-sample forces in jumping mode atomic force microscopy in liquid

Energy Technology Data Exchange (ETDEWEB)

Ortega-Esteban, A. [Departamento de Fisica de la Materia Condensada, C-3, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Horcas, I. [Nanotec Electronica S.L., Centro Empresarial Euronova 3, Ronda de Poniente 12, 28760 Tres Cantos, Madrid (Spain); Hernando-Perez, M. [Departamento de Fisica de la Materia Condensada, C-3, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Ares, P. [Nanotec Electronica S.L., Centro Empresarial Euronova 3, Ronda de Poniente 12, 28760 Tres Cantos, Madrid (Spain); Perez-Berna, A.J.; San Martin, C.; Carrascosa, J.L. [Centro Nacional de Biotecnologia (CNB-CSIC), Darwin 3, 28049 Madrid (Spain); Pablo, P.J. de [Departamento de Fisica de la Materia Condensada, C-3, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Gomez-Herrero, J., E-mail: julio.gomez@uam.es [Departamento de Fisica de la Materia Condensada, C-3, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

2012-03-15

Control and minimization of tip-sample interaction forces are imperative tasks to maximize the performance of atomic force microscopy. In particular, when imaging soft biological matter in liquids, the cantilever dragging force prevents identification of the tip-sample mechanical contact, resulting in deleterious interaction with the specimen. In this work we present an improved jumping mode procedure that allows detecting the tip-sample contact with high accuracy, thus minimizing the scanning forces ({approx}100 pN) during the approach cycles. To illustrate this method we report images of human adenovirus and T7 bacteriophage particles which are prone to uncontrolled modifications when using conventional jumping mode. -- Highlights: Black-Right-Pointing-Pointer Improvement in atomic force microscopy in buffer solution. Black-Right-Pointing-Pointer Peak force detection. Black-Right-Pointing-Pointer Subtracting the cantilever dragging force. Black-Right-Pointing-Pointer Forces in the 100 pN range. Black-Right-Pointing-Pointer Imaging of delicate viruses with atomic force microscopy.

Force-activatable biosensor enables single platelet force mapping directly by fluorescence imaging.

Science.gov (United States)

Wang, Yongliang; LeVine, Dana N; Gannon, Margaret; Zhao, Yuanchang; Sarkar, Anwesha; Hoch, Bailey; Wang, Xuefeng

2018-02-15

Integrin-transmitted cellular forces are critical for platelet adhesion, activation, aggregation and contraction during hemostasis and thrombosis. Measuring and mapping single platelet forces are desired in both research and clinical applications. Conventional force-to-strain based cell traction force microscopies have low resolution which is not ideal for cellular force mapping in small platelets. To enable platelet force mapping with submicron resolution, we developed a force-activatable biosensor named integrative tension sensor (ITS) which directly converts molecular tensions to fluorescent signals, therefore enabling cellular force mapping directly by fluorescence imaging. With ITS, we mapped cellular forces in single platelets at 0.4µm resolution. We found that platelet force distribution has strong polarization which is sensitive to treatment with the anti-platelet drug tirofiban, suggesting that the ITS force map can report anti-platelet drug efficacy. The ITS also calibrated integrin molecular tensions in platelets and revealed two distinct tension levels: 12-54 piconewton (nominal values) tensions generated during platelet adhesion and tensions above 54 piconewton generated during platelet contraction. Overall, the ITS is a powerful biosensor for the study of platelet mechanobiology, and holds great potential in antithrombotic drug development and assessing platelet activity in health and disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Fundamental assessment of tasks of the shift leader in nuclear power plants

International Nuclear Information System (INIS)

Mansfeld, G.; Birkhofer, A.

1981-01-01

Since the revised version of the regulation governing the qualification of nuclear power plant personnel has been in force - now for two and a half year - the study on hand attempts to give an objective evaluation of the requirements to be made on the level of training and skill of shift supervisors, and to evaluate arguments often brought forward in discussions on shift supervisor qualifications. Since, as the characteristics of training and work differ with every plant operator, the points made in the study cannot be related directly to the individual nuclear power plants. (orig./HSCH) [de

Concurrent Validity of a Portable Force Plate Using Vertical Jump Force-Time Characteristics.

Science.gov (United States)

Lake, Jason; Mundy, Peter; Comfort, Paul; McMahon, John J; Suchomel, Timothy J; Carden, Patrick

2018-05-29

This study examined concurrent validity of countermovement vertical jump (CMJ) reactive strength index modified and force-time characteristics recorded using a one dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral CMJs on two portable force plates placed on top of two in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to take-off, jump height, reactive strength index modified, braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r≥.99). There were small (dbraking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (psystem (95% CL: .9% to 2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement belonged to jump height (2.1%), time to take-off (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force-time variables, from unloaded CMJ and practitioners can use both force plates interchangeably.

Radiative forcing associated with particulate carbon emissions resulting from the use of mercury control technology.

Science.gov (United States)

Lin, Guangxing; Penner, Joyce E; Clack, Herek L

2014-09-02

Injection of powdered activated carbon (PAC) adsorbents into the flue gas of coal fired power plants with electrostatic precipitators (ESPs) is the most mature technology to control mercury emissions for coal combustion. However, the PAC itself can penetrate ESPs to emit into the atmosphere. These emitted PACs have similar size and optical properties to submicron black carbon (BC) and thus could increase BC radiative forcing unintentionally. The present paper estimates, for the first time, the potential emission of PAC together with their climate forcing. The global average maximum potential emissions of PAC is 98.4 Gg/yr for the year 2030, arising from the assumed adoption of the maximum potential PAC injection technology, the minimum collection efficiency, and the maximum PAC injection rate. These emissions cause a global warming of 2.10 mW m(-2) at the top of atmosphere and a cooling of -2.96 mW m(-2) at the surface. This warming represents about 2% of the warming that is caused by BC from direct fossil fuel burning and 0.86% of the warming associated with CO2 emissions from coal burning in power plants. Its warming is 8 times more efficient than the emitted CO2 as measured by the 20-year-integrated radiative forcing per unit of carbon input (the 20-year Global Warming Potential).

Nuclear Power Plant 1996

International Nuclear Information System (INIS)

1997-01-01

Again this year, our magazine presents the details of the conference on Spanish nuclear power plant operation held in February and that was devoted to 1996 operating results. The Protocol for Establishment of a New Electrical Sector Regulation that was signed last December will undoubtedly represent a new challenge for the nuclear industry. By clearing stating that current standards of quality and safety should be maintained or even increased if possible, the Protocol will force the Sector to improve its productivity, which is already high as demonstrated by the results of the last few years described during this conference and by recent sectorial economic studies. Generation of a nuclear kWh that can compete with other types of power plants is the new challenge for the Sector's professionals, who do not fear the new liberalization policies and approaching competition. Lower inflation and the resulting lower interest rates, apart from being representative indices of our economy's marked improvement, will be very helpful in facing this challenge. (Author)

Recommendations to the NRC on human engineering guidelines for nuclear power plant maintainability

Energy Technology Data Exchange (ETDEWEB)

Badalamente, R.V.; Fecht, B.A.; Blahnik, D.E.; Eklund, J.D.; Hartley, C.S.

1986-03-01

This document contains human engineering guidelines which can enhance the maintainability of nuclear power plants. The guidelines have been derived from general human engineering design principles, criteria, and data. The guidelines may be applied to existing plants as well as to plants under construction. They apply to nuclear power plant systems, equipment and facilities, as well as to maintenance tools and equipment. The guidelines are grouped into seven categories: accessibility and workspace, physical environment, loads and forces, maintenance facilities, maintenance tools and equipment, operating equipment design, and information needs. Each chapter of the document details specific maintainability problems encountered at nuclear power plants, the safety impact of these problems, and the specific maintainability design guidelines whose application can serve to avoid these problems in new or existing plants.

Recommendations to the NRC on human engineering guidelines for nuclear power plant maintainability

International Nuclear Information System (INIS)

Badalamente, R.V.; Fecht, B.A.; Blahnik, D.E.; Eklund, J.D.; Hartley, C.S.

1986-03-01

This document contains human engineering guidelines which can enhance the maintainability of nuclear power plants. The guidelines have been derived from general human engineering design principles, criteria, and data. The guidelines may be applied to existing plants as well as to plants under construction. They apply to nuclear power plant systems, equipment and facilities, as well as to maintenance tools and equipment. The guidelines are grouped into seven categories: accessibility and workspace, physical environment, loads and forces, maintenance facilities, maintenance tools and equipment, operating equipment design, and information needs. Each chapter of the document details specific maintainability problems encountered at nuclear power plants, the safety impact of these problems, and the specific maintainability design guidelines whose application can serve to avoid these problems in new or existing plants

Plant uprooting by flow as a fatigue mechanical process

Science.gov (United States)

Perona, Paolo; Edmaier, Katharina; Crouzy, Benoît

2015-04-01

In river corridors, plant uprooting by flow mostly occurs as a delayed process where flow erosion first causes root exposure until residual anchoring balances hydrodynamic forces on the part of the plant that is exposed to the stream. Because a given plant exposure time to the action of the stream is needed before uprooting occurs (time-to-uprooting), this uprooting mechanism has been denominated Type II, in contrast to Type I, which mostly affect early stage seedlings and is rather instantaneous. In this work, we propose a stochastic framework that describes a (deterministic) mechanical fatigue process perturbed by a (stochastic) process noise, where collapse occurs after a given exposure time. We test the model using the experimental data of Edmaier (2014) and Edmaier et al. (submitted), who investigated vegetation uprooting by flow in the limit of low plant stem-to-sediment size ratio by inducing parallel riverbed erosion within an experimental flume. We first identify the proper timescale and lengthscale for rescaling the model. Then, we show that it describes well all the empirical cumulative distribution functions (cdf) of time-to-uprooting obtained under constant riverbed erosion rate and assuming additive gaussian process noise. By this mean, we explore the level of determinism and stochasticity affecting the time-to-uprooting for Avena sativa in relation to root anchoring and flow drag forces. We eventually ascribe the overall dynamics of the Type II uprooting mechanism to the memory of the plant-soil system that is stored by root anchoring, and discuss related implications thereof. References Edmaier, K., Uprooting mechansims of juvenile vegetation by flow erosion, Ph.D. thesis, EPFL, 2014. Edmaier, K., Crouzy, B. and P. Perona. Experimental characterization of vegetation uprooting by flow. J. of Geophys. Res. - Biogeosci., submitted

Assessment of PASS Effectiveness under Severe Accidents in Nuclear Power Plants

International Nuclear Information System (INIS)

Choi, Yu Jung; Lee, Sung Bok; Kim, Hyeong Taek; Lee, Jin Yong

2008-01-01

Following the accident at Three Mile Island Unit 2 (TMI-2) on March 28, 1979, the USNRC formed a lessons-learned Task Force to identify and evaluate safety concerns originating with the TMI-2 accident. NUREG-0578 documented the results of the task force effort. One of the recommendations of the task force was for licensees to upgrade the capability to obtain samples from the reactor coolant system and containment atmosphere under high radioactivity conditions and to provide the capability for chemical and spectral analyses of high-level samples on site. NUREG-0737 contained the details of the TMI recommendations that were to be implemented by the licensees. Additional criteria for post accident sampling system(PASS) were issued by Regulatory Guide 1.97. As the results, PASS has been installed on nuclear power plants(NPPs) in Korea as well as United States. However, significant improvements have been achieved since the TMI-2 accident in the areas of understanding risks associated with nuclear plant operations and developing better strategies for managing the response to potential severe accidents at NPPs. Thus, the requirements for PASS have been re-evaluated in some reports. According to the reports, the samples and measurements from PASS do not contribute significantly to emergency management response to severe accidents due to the long analyzing time, 3 hours. Hence, this paper focused on the development of the quantitative analysis methodology to analyze the sequence of the severe accident in Yonggwang nuclear power plants (YGN) and presented the results of the analysis according to the developed methodology

Up in smoke: regulatory immortality for 'grandfathered' power plants under the NSR rule changes

Energy Technology Data Exchange (ETDEWEB)

Conrad G. Schneider [Clean Air Task Force (USA)

2004-01-01

The US New Source Review (NSR) program requires power plant owners to install modern pollution control whenever they upgrade their plants in a way that will cause more pollution. The Clean Air Task Force and other environmental organizations and dozens of states and municipalities have challenged changes to the NSR rule change exempting grandfathered power plants under certain conditions. The author discussed this legislation and whether the Clear Skies Act will be effective. 9 refs.

Origin and diversification of leucine-rich repeat receptor-like protein kinase (LRR-RLK) genes in plants

OpenAIRE

Liu, Ping-Li; Du, Liang; Huang, Yuan; Gao, Shu-Min; Yu, Meng

2017-01-01

Background Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) are the largest group of receptor-like kinases in plants and play crucial roles in development and stress responses. The evolutionary relationships among LRR-RLK genes have been investigated in flowering plants; however, no comprehensive studies have been performed for these genes in more ancestral groups. The subfamily classification of LRR-RLK genes in plants, the evolutionary history and driving force for the evolution...

Guideline on radiation protection requirements for ionizing radiation shielding in nuclear power plants

International Nuclear Information System (INIS)

1988-01-01

The guideline which entered into force on 1 May 1988 stipulates the radiation protection requirements for shielding against ionizing radiation to be met in the design, construction, commissioning, operation, and decommissioning of nuclear power plants

Forces in general relativity

International Nuclear Information System (INIS)

Ridgely, Charles T

2010-01-01

Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.

Nuclear power plant outage optimisation strategy

International Nuclear Information System (INIS)

2002-10-01

Competitive environment for electricity generation has significant implications for nuclear power plant operations, including among others the need of efficient use of resources, effective management of plant activities such as on-line maintenance and outages. Nuclear power plant outage management is a key factor for good, safe and economic nuclear power plant performance which involves many aspects: plant policy, co-ordination of available resources, nuclear safety, regulatory and technical requirements and, all activities and work hazards, before and during the outage. This technical publication aims to communicate these practices in a way they can be used by operators and utilities in the Member States of the IAEA. It intends to give guidance to outage managers, operating staff and to the local industry on planning aspects, as well as examples and strategies experienced from current plants in operation on the optimization of outage period. This report discusses the plant outage strategy and how this strategy is actually implemented. The main areas identified as most important for outage optimization by the utilities and government organizations participating in this report are: organization and management; outage planning and preparation, outage execution, safety outage review, and counter measures to avoid extension of outages and to easier the work in forced outages. This report was based on discussions and findings by the authors of the annexes and the participants of an Advisory Group Meeting on Determinant Causes for Reducing Outage Duration held in June 1999 in Vienna. The report presents the consensus of these experts regarding best common or individual good practices that can be used at nuclear power plants with the aim to optimize

Operating procedure automation to enhance safety of nuclear power plants

International Nuclear Information System (INIS)

Husseiny, A.A.; Sabri, Z.A.; Adams, S.K.; Rodriguez, R.J.; Packer, D.; Holmes, J.W.

1989-01-01

Use of logic statements and computer assist are explored as means for automation and improvement on design of operating procedures including those employed in abnormal and emergency situations. Operating procedures for downpower and loss of forced circulation are used for demonstration. Human-factors analysis is performed on generic emergency operating procedures for three strategies of control; manual, semi-automatic and automatic, using standard emergency operating procedures. Such preliminary analysis shows that automation of procedures is feasible provided that fault-tolerant software and hardware become available for design of the controllers. Recommendations are provided for tests to substantiate the promise of enhancement of plant safety. Adequate design of operating procedures through automation may alleviate several major operational problems of nuclear power plants. Also, automation of procedures is necessary for partial or overall automatic control of plants. Fully automatic operations are needed for space applications while supervised automation of land-based and offshore plants may become the thrust of new generation of nulcear power plants. (orig.)

78 FR 59939 - Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-09-30

... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... September 17, 2013, announcing the next meeting of the Community Preventive Services Task Force (Task Force... the Task Force to consider the findings of systematic reviews and issue findings and recommendations...

Finding of No Significant Impact (FONSI) for Construction of a Base Civil Engineer Complex at Travis Air Force Base, California

Science.gov (United States)

2002-01-26

2 Ellis Drive Dix o n A v e Rags dale Stree t Bioremedial Site Base Civil Engineering ComplexEnvironmental AssessmentTravis Air Force Base...CNPS List 1B species. This species is an annual herb in the sunflower tribe (Heliantheae) of the sunflower family (Asteraceae). Individual plants...range from approximately 10 to 40 centimeters (cm) tall. Being in the sunflower family (Asteraceae), the characteristic yellow flower of this plant

A portable Halbach magnet that can be opened and closed without force: the NMR-CUFF.

Science.gov (United States)

Windt, Carel W; Soltner, Helmut; van Dusschoten, Dagmar; Blümler, Peter

2011-01-01

Portable equipment for nuclear magnetic resonance (NMR) is becoming increasingly attractive for use in a variety of applications. One of the main scientific challenges in making NMR portable is the design of light-weight magnets that possess a strong and homogeneous field. Existing NMR magnets can provide such magnetic fields, but only for small samples or in small regions, or are rather heavy. Here we show a simple yet elegant concept for a Halbach-type permanent magnet ring, which can be opened and closed with minimal mechanical force. An analytical solution for an ideal Halbach magnet shows that the magnetic forces cancel if the structure is opened at an angle of 35.3° relative to its poles. A first prototype weighed only 3.1 kg, and provided a flux density of 0.57 T with a homogeneity better than 200 ppm over a spherical volume of 5mm in diameter without shimming. The force needed to close it was found to be about 20 N. As a demonstration, intact plants were imaged and water (xylem) flow measured. Magnets of this type (NMR-CUFF = Cut-open, Uniform, Force Free) are ideal for portable use and are eminently suited to investigate small or slender objects that are part of a larger or immobile whole, such as branches on a tree, growing fruit on a plant, or non-metallic tubing in industrial installations. This new concept in permanent-magnet design enables the construction of openable, yet strong and homogeneous magnets, which aside from use in NMR or MRI could also be of interest for applications in accelerators, motors, or magnetic bearings. Copyright © 2010 Elsevier Inc. All rights reserved.

Final Environmental Assessment for the California Space Center at Vandenberg Air Force Base, California

Science.gov (United States)

2010-06-02

rooted , mesophylic plant species that Chapter 3. Affected Environment Final Environmental Assessment - California Space Center, Vandenberg Air...Chapter 3. Affected Environment 3-12 Final Environmental Assessment - California Space Center, Vandenberg Air Force Base the root and debris zone of the...protruding objects, slippery soils or mud, and biological hazards including vegetation (i.e. poison oak and stinging nettle ), animals (i.e. insects

Acoustic force spectroscopy

NARCIS (Netherlands)

Sitters, G.; Kamsma, D.; Thalhammer, G.; Ritsch-Marte, M.; Peterman, E.J.G.; Wuite, G.J.L.

2015-01-01

Force spectroscopy has become an indispensable tool to unravel the structural and mechanochemical properties of biomolecules. Here we extend the force spectroscopy toolbox with an acoustic manipulation device that can exert forces from subpiconewtons to hundreds of piconewtons on thousands of

Handbook of force transducers

CERN Document Server

Stefanescu, Dan Mihai

2011-01-01

Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

12th Air Force > Home

Science.gov (United States)

Force AOR Travel Info News prevnext Slide show 76,410 pounds of food delivered to Haiti 12th Air Force the French Air Force, Colombian Air Force, Pakistan Air Force, Belgian Air Force, Brazilian Air Force

Modern plant management in the competitive market

Energy Technology Data Exchange (ETDEWEB)

Fischer, B.; Franke, U.; Freitag, J.U. [E.ON Kraftwerke GmbH, Hannover (Germany)

2002-07-01

Forced by the deregulation of the energy market and the big drop of electricity prices E.ON Kraftwerke was completely reorganised. Small, flexible units that are focussed on their key tasks were formed. Costs for electricity generation in our plants were reduced. Power plants that are currently not economically efficient are temporarily shut down. Power plants that are permanently not economically efficient are totally shut down. We have now reached a point at which energy prices slowly start to rise again. With our new plant management organization we have a lasting effect on further successfully operating power plants and a positive development of our company. Looking into the future does not create fear about what to do but positive believe that we will soon start new projects. This is the fundament for a stable, successful power plant company. (orig.) [German] Unter dem erheblichen Kostendruck, dem alle Energieversorger derzeit ausgesetzt sind, wurde die Aufbauorganisation von E.ON Energie grundlegend veraendert. Bei E.ON Kraftwerke wurden durch die Schaffung kleiner, flexibler Einheiten und eine klare Konzentration auf das Kerngeschaeft die Kosten fuer die Stromerzeugung in den eigenen Anlagen deutlich gesenkt. Die Auslastung vorhandener wirtschaftlicher Bloecke ist durch die Konservierung von derzeit nicht wirtschaftlichen bzw. durch die Stillegung langfristig nicht wirtschaftlicher Anlagen erheblich verbessert worden. Nachhaltig wurde damit eine Betriebsfuehrungsstrategie entwickelt, die den Bestand und eine positive Entwicklung der Kraftwerksgesellschaft sichert. (orig.)

Development of a commercially viable piezoelectric force sensor system for static force measurement

Science.gov (United States)

Liu, Jun; Luo, Xinwei; Liu, Jingcheng; Li, Min; Qin, Lan

2017-09-01

A compensation method for measuring static force with a commercial piezoelectric force sensor is proposed to disprove the theory that piezoelectric sensors and generators can only operate under dynamic force. After studying the model of the piezoelectric force sensor measurement system, the principle of static force measurement using a piezoelectric material or piezoelectric force sensor is analyzed. Then, the distribution law of the decay time constant of the measurement system and the variation law of the measurement system’s output are studied, and a compensation method based on the time interval threshold Δ t and attenuation threshold Δ {{u}th} is proposed. By calibrating the system and considering the influences of the environment and the hardware, a suitable Δ {{u}th} value is determined, and the system’s output attenuation is compensated based on the Δ {{u}th} value to realize the measurement. Finally, a static force measurement system with a piezoelectric force sensor is developed based on the compensation method. The experimental results confirm the successful development of a simple compensation method for static force measurement with a commercial piezoelectric force sensor. In addition, it is established that, contrary to the current perception, a piezoelectric force sensor system can be used to measure static force through further calibration.

SRT project: tele-robotics maintenance of nuclear power plants

International Nuclear Information System (INIS)

Gomez-Santamaria, J.; Calleja, J.M.; Carmena, P.; Avello, A.; Rubio, Y.A.

2001-01-01

The main aim of the SRT project was to develop a family of robots to help in the operation of nuclear power plants. Four robotic systems were developed and this paper focuses on three of them: ANAES -a steam leak detector through noise analysis-, MALIBA -a master-slave tele-operation system with force feedback- and ROBICEN -a compact pneumatic wall climbing robot-. ANAES (the Spanish acronym of spectrum analysis) consists of a set of sensor heads attached to a computer. Each head has two microphones and a video camera installed on it, and a DC motor that rotates the head. The heads are shielded with lead and boron steel, especially near the video camera. The noise generated by the plant is recorded every day at the same time and the software compares the recorded noise with the mean values of past records. The system can discern whether the noise has remarkably changed and, through phase analysis of the sound recorded by both microphones, identifies the direction of arrival (DOA) of the new noise, probably a steam leak. Using several heads, the new noise source can be identified. The video camera can be used to ease the location of the steam leaks. The stationariness of the measured noise has been tested in C.N. Cofrentes -a Spanish BWR-6 reactor-. A finished system with six heads has recently been installed in the MSR (moisture separator reheater) of the same plant. MALIBA is a master-slave tele-operated system with force feedback. It consists of two robots: a Stewart platform used as master robot and an open chain robot used as slave. The slave robot follows faithfully the movements of the master, and the master robot can reflect a force proportional to the force exerted by the slave on the environment. Three tools have been developed for the slave robot: a robot hand that includes a small video camera, a pneumatic drill and a rectifier. The results obtained have shown its effectiveness for the designed operations. ROBICEN is a lightweight pneumatic robot

SRT project: tele-robotics maintenance of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Gomez-Santamaria, J. [Iberdrola SA, Madrid (Spain); Calleja, J.M.; Carmena, P. [Endesa, Madrid (Spain); Avello, A.; Rubio, Y.A. [CEIT-Centro de Estudias e Investigaciones Tecnicas de Guipuzcoa, San Sebastian (Spain)

2001-07-01

The main aim of the SRT project was to develop a family of robots to help in the operation of nuclear power plants. Four robotic systems were developed and this paper focuses on three of them: ANAES -a steam leak detector through noise analysis-, MALIBA -a master-slave tele-operation system with force feedback- and ROBICEN -a compact pneumatic wall climbing robot-. ANAES (the Spanish acronym of spectrum analysis) consists of a set of sensor heads attached to a computer. Each head has two microphones and a video camera installed on it, and a DC motor that rotates the head. The heads are shielded with lead and boron steel, especially near the video camera. The noise generated by the plant is recorded every day at the same time and the software compares the recorded noise with the mean values of past records. The system can discern whether the noise has remarkably changed and, through phase analysis of the sound recorded by both microphones, identifies the direction of arrival (DOA) of the new noise, probably a steam leak. Using several heads, the new noise source can be identified. The video camera can be used to ease the location of the steam leaks. The stationariness of the measured noise has been tested in C.N. Cofrentes -a Spanish BWR-6 reactor-. A finished system with six heads has recently been installed in the MSR (moisture separator reheater) of the same plant. MALIBA is a master-slave tele-operated system with force feedback. It consists of two robots: a Stewart platform used as master robot and an open chain robot used as slave. The slave robot follows faithfully the movements of the master, and the master robot can reflect a force proportional to the force exerted by the slave on the environment. Three tools have been developed for the slave robot: a robot hand that includes a small video camera, a pneumatic drill and a rectifier. The results obtained have shown its effectiveness for the designed operations. ROBICEN is a lightweight pneumatic robot

Minimizing pulling geometry errors in atomic force microscope single molecule force spectroscopy.

Science.gov (United States)

Rivera, Monica; Lee, Whasil; Ke, Changhong; Marszalek, Piotr E; Cole, Daniel G; Clark, Robert L

2008-10-01

In atomic force microscopy-based single molecule force spectroscopy (AFM-SMFS), it is assumed that the pulling angle is negligible and that the force applied to the molecule is equivalent to the force measured by the instrument. Recent studies, however, have indicated that the pulling geometry errors can drastically alter the measured force-extension relationship of molecules. Here we describe a software-based alignment method that repositions the cantilever such that it is located directly above the molecule's substrate attachment site. By aligning the applied force with the measurement axis, the molecule is no longer undergoing combined loading, and the full force can be measured by the cantilever. Simulations and experimental results verify the ability of the alignment program to minimize pulling geometry errors in AFM-SMFS studies.

On-line testing of nuclear plant temperature and pressure instrumentation and other critical plant equipment. IAEA regional workshop. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-31

Under European regional TC project RER/4/011, IAEA and VUJE Training centre organized a workshop on On-line Testing of Nuclear Power Plant Temperature and Pressure Instrumentation and Other Critical Plant Equipment in Trnava, Slovak Republic, from 25 to 29 May 1998. The objective of the workshop was to review the state-of-the-art in NPP instrumentation, cover typical instrumentation problems and solutions, describe technical and regulatory requirements for verifying the performance of nuclear power plant instrumentation, describe new methods developed and applied in NPPs for on-line verification and performance of instrumentation and present new techniques using existing instrumentation to identify the on-set problems in the plant electrical, mechanical and thermal hydraulic systems. Particular emphasis was placed on temperature measurements by Resistance Temperature Detectors (RTDs) and thermocouples and pressure measurements using motion-balanced and forced-balanced pressure transmitters. This proceedings includes papers presented by the invited speakers and the participants each with an abstract as wells as a summary of the Round-Table discussions Refs, figs, tabs

On-line testing of nuclear plant temperature and pressure instrumentation and other critical plant equipment. IAEA regional workshop. Working material

International Nuclear Information System (INIS)

1998-01-01

Under European regional TC project RER/4/011, IAEA and VUJE Training centre organized a workshop on On-line Testing of Nuclear Power Plant Temperature and Pressure Instrumentation and Other Critical Plant Equipment in Trnava, Slovak Republic, from 25 to 29 May 1998. The objective of the workshop was to review the state-of-the-art in NPP instrumentation, cover typical instrumentation problems and solutions, describe technical and regulatory requirements for verifying the performance of nuclear power plant instrumentation, describe new methods developed and applied in NPPs for on-line verification and performance of instrumentation and present new techniques using existing instrumentation to identify the on-set problems in the plant electrical, mechanical and thermal hydraulic systems. Particular emphasis was placed on temperature measurements by Resistance Temperature Detectors (RTDs) and thermocouples and pressure measurements using motion-balanced and forced-balanced pressure transmitters. This proceedings includes papers presented by the invited speakers and the participants each with an abstract as wells as a summary of the Round-Table discussions

Quality of deli-style turkey enriched with plant sterols.

Science.gov (United States)

Grasso, S; Brunton, N P; Lyng, J G; Harrison, S M; Monahan, F J

2016-12-01

Low-fat meat products could be excellent carriers for plant sterols, known for their cholesterol-lowering properties. In this study, we developed a protocol for the manufacture of a deli-style turkey enriched with plant sterols (S) at a level sufficient to deliver the maximum plant sterols amount recommended for cholesterol reduction by the European Food Safety Authority (3 g of plant sterols per day) in a 70 g portion. We investigated the stability of the plant sterols and the effects of their addition on the product quality. Plant sterols remained stable during the seven-day storage period. The addition of plant sterols significantly affected some texture parameters, shear force, lipid oxidation, L values and water-holding capacity compared with control (C). Sensory analysis was carried out by an untrained panel (32) using the difference-from-control test between C and S samples to evaluate first the extent of the overall sensory difference and then the extent of sensory difference on colour, texture and flavour. Results indicated that panellists considered the intensity of the difference between C and S samples to be 'small'. Plant sterols could be used as a potential health-promoting meat ingredient with no effect on plant sterol stability but with some effects on texture and sensory characteristics. © The Author(s) 2016.

Force sharing and other collaborative strategies in a dyadic force perception task.

Science.gov (United States)

Tatti, Fabio; Baud-Bovy, Gabriel

2018-01-01

When several persons perform a physical task jointly, such as transporting an object together, the interaction force that each person experiences is the sum of the forces applied by all other persons on the same object. Therefore, there is a fundamental ambiguity about the origin of the force that each person experiences. This study investigated the ability of a dyad (two persons) to identify the direction of a small force produced by a haptic device and applied to a jointly held object. In this particular task, the dyad might split the force produced by the haptic device (the external force) in an infinite number of ways, depending on how the two partners interacted physically. A major objective of this study was to understand how the two partners coordinated their action to perceive the direction of the third force that was applied to the jointly held object. This study included a condition where each participant responded independently and another one where the two participants had to agree upon a single negotiated response. The results showed a broad range of behaviors. In general, the external force was not split in a way that would maximize the joint performance. In fact, the external force was often split very unequally, leaving one person without information about the external force. However, the performance was better than expected in this case, which led to the discovery of an unanticipated strategy whereby the person who took all the force transmitted this information to the partner by moving the jointly held object. When the dyad could negotiate the response, we found that the participant with less force information tended to switch his or her response more often.

[Mobile genetic elements in plant sex evolution].

Science.gov (United States)

Gerashchenkov, G A; Rozhnova, N A

2010-11-01

The most significant theories of the appearance and maintenance of sex are presented. However, in the overwhelming majority of existing theories, the problem of sex, which is the central problem of evolutionary biology, is considered primarily through the prism of reproductive features of living organisms, whereas the issue of molecular driving forces of sexual reproduction id restricted to the possible role of mobile genetic elements (MGEs) in the appearance of sexual reproduction. The structural and functional significance of MGEs in the genomic organization of plants is illustrated. It is shown that MGEs could act as important molecular drivers of sex evolution in plants. The involvement of MGEs in the formation of sex chromosomes and possible participation in seeds-without-sex reproduction (apomixis) is discussed. Thus, the hypothesis on the active MGE participation in sex evolution is in good agreement with the modern views on pathways and directions of sex evolution in plants.

Stable dynamics in forced systems with sufficiently high/low forcing frequency.

Science.gov (United States)

Bartuccelli, M; Gentile, G; Wright, J A

2016-08-01

We consider parametrically forced Hamiltonian systems with one-and-a-half degrees of freedom and study the stability of the dynamics when the frequency of the forcing is relatively high or low. We show that, provided the frequency is sufficiently high, Kolmogorov-Arnold-Moser (KAM) theorem may be applied even when the forcing amplitude is far away from the perturbation regime. A similar result is obtained for sufficiently low frequency, but in that case we need the amplitude of the forcing to be not too large; however, we are still able to consider amplitudes which are outside of the perturbation regime. In addition, we find numerically that the dynamics may be stable even when the forcing amplitude is very large, well beyond the range of validity of the analytical results, provided the frequency of the forcing is taken correspondingly low.

High Cable Forces Deteriorate Pinch Force Control in Voluntary-Closing Body-Powered Prostheses.

Directory of Open Access Journals (Sweden)

Mona Hichert

Full Text Available It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Body-powered prostheses (BPPs provide the user with direct proprioceptive feedback. Currently available BPPs often require high cable operation forces, which complicates control of the forces at the terminal device. The aim of this study is to quantify the influence of high cable forces on object manipulation with voluntary-closing prostheses.Able-bodied male subjects were fitted with a bypass-prosthesis with low and high cable force settings for the prehensor. Subjects were requested to grasp and transfer a collapsible object as fast as they could without dropping or breaking it. The object had a low and a high breaking force setting.Subjects conducted significantly more successful manipulations with the low cable force setting, both for the low (33% more and high (50% object's breaking force. The time to complete the task was not different between settings during successful manipulation trials.High cable forces lead to reduced pinch force control during object manipulation. This implies that low cable operation forces should be a key design requirement for voluntary-closing BPPs.

Malaysia and forced migration

Directory of Open Access Journals (Sweden)

Arzura Idris

2012-06-01

Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

Vegetation studies on Vandenberg Air Force Base, California

Science.gov (United States)

Schmalzer, Paul A.; Hickson, Diana E.; Hinkle, C. Ross

1988-01-01

Vandenburg Air Force Base, located in coastal central California with an area of 98,400 ac, contains resources of considerable biological significance. Available information on the vegetation and flora of Vandenburg is summarized and new data collected in this project are presented. A bibliography of 621 references dealing with vegetation and related topics related to Vanderburg was compiled from computer and manual literature searches and a review of past studies of the base. A preliminary floristic list of 642 taxa representing 311 genera and 80 families was compiled from past studies and plants identified in the vegetation sampling conducted in this project. Fifty-two special interest plant species are known to occur or were suggested to occur. Vegetation was sampled using permanent plots and transects in all major plant communities including chaparral, Bishop pine forest, tanbark oak forest, annual grassland, oak woodland, coastal sage scrub, purple sage scrub, coastal dune scrub, coastal dunes, box elder riparian woodland, will riparian woodland, freshwater marsh, salt marsh, and seasonal wetlands. Comparison of the new vegetation data to the compostie San Diego State University data does not indicate major changes in most communities since the original study. Recommendations are made for additional studies needed to maintain and extend the environmental data base and for management actions to improve resource protection.

The Effect of Designated Pollutants on Plant Species

Science.gov (United States)

1981-01-01

L.) Burm. J. Roughlemon seedling 12 Citrus C. limo, Lisbon lemon graft 80 Citrus C. sinensis (L.) Osbeck Valencia orange graft 80 Dudleya Dudleya...CALIFORNIA UNIVERSITY OF CALIFORNIA, IR VINE IR VINE, ORANGE COUNTY, CALIFORNIA 92664 JANUARY 1981 S Approved for public release; distribution...California poppy, indigenous to the Vandenberg Air Force Base area, blooms in the spring. Since flowering of individual plants could not be closely

Single-molecule force spectroscopy: optical tweezers, magnetic tweezers and atomic force microscopy

Science.gov (United States)

Neuman, Keir C.; Nagy, Attila

2012-01-01

Single-molecule force spectroscopy has emerged as a powerful tool to investigate the forces and motions associated with biological molecules and enzymatic activity. The most common force spectroscopy techniques are optical tweezers, magnetic tweezers and atomic force microscopy. These techniques are described and illustrated with examples highlighting current capabilities and limitations. PMID:18511917

Real-time tracking control of electro-hydraulic force servo systems using offline feedback control and adaptive control.

Science.gov (United States)

Shen, Gang; Zhu, Zhencai; Zhao, Jinsong; Zhu, Weidong; Tang, Yu; Li, Xiang

2017-03-01

This paper focuses on an application of an electro-hydraulic force tracking controller combined with an offline designed feedback controller (ODFC) and an online adaptive compensator in order to improve force tracking performance of an electro-hydraulic force servo system (EHFS). A proportional-integral controller has been employed and a parameter-based force closed-loop transfer function of the EHFS is identified by a continuous system identification algorithm. By taking the identified system model as a nominal plant model, an H ∞ offline design method is employed to establish an optimized feedback controller with consideration of the performance, control efforts, and robustness of the EHFS. In order to overcome the disadvantage of the offline designed controller and cope with the varying dynamics of the EHFS, an online adaptive compensator with a normalized least-mean-square algorithm is cascaded to the force closed-loop system of the EHFS compensated by the ODFC. Some comparative experiments are carried out on a real-time EHFS using an xPC rapid prototype technology, and the proposed controller yields a better force tracking performance improvement. Copyright © 2016. Published by Elsevier Ltd.

Force sharing and other collaborative strategies in a dyadic force perception task

Science.gov (United States)

Tatti, Fabio

2018-01-01

When several persons perform a physical task jointly, such as transporting an object together, the interaction force that each person experiences is the sum of the forces applied by all other persons on the same object. Therefore, there is a fundamental ambiguity about the origin of the force that each person experiences. This study investigated the ability of a dyad (two persons) to identify the direction of a small force produced by a haptic device and applied to a jointly held object. In this particular task, the dyad might split the force produced by the haptic device (the external force) in an infinite number of ways, depending on how the two partners interacted physically. A major objective of this study was to understand how the two partners coordinated their action to perceive the direction of the third force that was applied to the jointly held object. This study included a condition where each participant responded independently and another one where the two participants had to agree upon a single negotiated response. The results showed a broad range of behaviors. In general, the external force was not split in a way that would maximize the joint performance. In fact, the external force was often split very unequally, leaving one person without information about the external force. However, the performance was better than expected in this case, which led to the discovery of an unanticipated strategy whereby the person who took all the force transmitted this information to the partner by moving the jointly held object. When the dyad could negotiate the response, we found that the participant with less force information tended to switch his or her response more often. PMID:29474433

Directional Selection from Host Plants Is a Major Force Driving Host Specificity in Magnaporthe Species.

Science.gov (United States)

Zhong, Zhenhui; Norvienyeku, Justice; Chen, Meilian; Bao, Jiandong; Lin, Lianyu; Chen, Liqiong; Lin, Yahong; Wu, Xiaoxian; Cai, Zena; Zhang, Qi; Lin, Xiaoye; Hong, Yonghe; Huang, Jun; Xu, Linghong; Zhang, Honghong; Chen, Long; Tang, Wei; Zheng, Huakun; Chen, Xiaofeng; Wang, Yanli; Lian, Bi; Zhang, Liangsheng; Tang, Haibao; Lu, Guodong; Ebbole, Daniel J; Wang, Baohua; Wang, Zonghua

2016-05-06

One major threat to global food security that requires immediate attention, is the increasing incidence of host shift and host expansion in growing number of pathogenic fungi and emergence of new pathogens. The threat is more alarming because, yield quality and quantity improvement efforts are encouraging the cultivation of uniform plants with low genetic diversity that are increasingly susceptible to emerging pathogens. However, the influence of host genome differentiation on pathogen genome differentiation and its contribution to emergence and adaptability is still obscure. Here, we compared genome sequence of 6 isolates of Magnaporthe species obtained from three different host plants. We demonstrated the evolutionary relationship between Magnaporthe species and the influence of host differentiation on pathogens. Phylogenetic analysis showed that evolution of pathogen directly corresponds with host divergence, suggesting that host-pathogen interaction has led to co-evolution. Furthermore, we identified an asymmetric selection pressure on Magnaporthe species. Oryza sativa-infecting isolates showed higher directional selection from host and subsequently tends to lower the genetic diversity in its genome. We concluded that, frequent gene loss or gain, new transposon acquisition and sequence divergence are host adaptability mechanisms for Magnaporthe species, and this coevolution processes is greatly driven by directional selection from host plants.

Reliability of nuclear power plants and equipment

International Nuclear Information System (INIS)

1985-01-01

The standard sets the general principles, a list of reliability indexes and demands on their selection. Reliability indexes of nuclear power plants include the simple indexes of fail-safe operation, life and maintainability, and of storage capability. All terms and notions are explained and methods of evaluating the indexes briefly listed - statistical, and calculation experimental. The dates when the standard comes in force in the individual CMEA countries are given. (M.D.)

Feather retention force in broiler carcasses slaughtered and held up to 8 hours postmortem prior to scalding

Science.gov (United States)

One factor that could impact the feasibility of commercial on-farm slaughter of broilers is the time delay from on-farm slaughter to scalding and defeathering in the commercial plant that could be 4 h or more. This experiment evaluated feather retention force (FRF) in broilers that were slaughtered ...

TAO2000 V2 computer-assisted force feedback tele-manipulators used as maintenance and production tools at the AREVA NC-La Hague fuel recycling plant

International Nuclear Information System (INIS)

Geffard, Franck; Garrec, Philippe; Piolain, Gerard; Brudieu, Marie-Anne; Thro, Jean-Francois; Coudray, Alain; Lelann, Eric

2012-01-01

During a 15-year joint research program, French Atomic Energy Agency Interactive Robotics Laboratory (CEA LIST) and AREVA have developed several remote operation devices, also called tele-robots. Some of them are now commonly used for maintenance operations at the AREVA NC (Nuclear Cycle) La Hague reprocessing plant. Since the first maintenance operation in 2005, several other successful interventions have been realized using the industrial MA23/RX170 tele-manipulation system. Moreover, since 2010, the through-the-wall tele-robot named MT200 TAO based on the slave arm of the MSM MT200 (La Calhene TM ), has been evaluated in an active production cell at the AREVA NC La Hague fuel recycling plant. Although these evaluations are ongoing, the positive results obtained have led to an update and industrialization program. All these developments are based on the same generic control platform, called TAO2000 V2. TAO2000 V2 is the second release of the CEA LIST core software platform dedicated to computer aided force-feedback tele-operation (TAO is the French acronym for computer aided tele-operation). This paper presents all these developments resulting from the joint research program CEA LIST/AREVA. The TAO2000 V2 controller is first detailed, and then two maintenance operations using the industrial robot RX170 are presented: the removal of the nuclear fuel dissolver wheel rollers and the cleanup of the dissolver wheel inter-bucket spaces. Finally, the new MT200 TAO system and its evaluations at the AREVA NC La Hague facilities are discussed. (authors)

Plant biotechnology patents: applications in agriculture and medicine.

Science.gov (United States)

Hefferon, Kathleen

2010-06-01

Recent advances in agricultural biotechnology have enabled the field of plant biology to move forward in great leaps and bounds. In particular, recent breakthroughs in molecular biology, plant genomics and crop science have brought about a paradigm shift of thought regarding the manner by which plants can be utilized both in agriculture and in medicine. Besides the more well known improvements in agronomic traits of crops such as disease resistance and drought tolerance, plants can now be associated with topics as diverse as biofuel production, phytoremediation, the improvement of nutritional qualities in edible plants, the identification of compounds for medicinal purposes in plants and the use of plants as therapeutic protein production platforms. This diversification of plant science has been accompanied by the great abundance of new patents issued in these fields and, as many of these inventions approach commercial realization, the subsequent increase in agriculturally-based industries. While this review chapter is written primarily for plant scientists who have great interest in the new directions being taken with respect to applications in agricultural biotechnology, those in other disciplines, such as medical researchers, environmental scientists and engineers, may find significant value in reading this article as well. The review attempts to provide an overview of the most recent patents issued for plant biotechnology with respect to both agriculture and medicine. The chapter concludes with the proposal that the combined driving forces of climate change, as well as the ever increasing needs for clean energy and food security will play a pivotal role in leading the direction for applied plant biotechnology research in the future.

Hydrostatic force sensor

International Nuclear Information System (INIS)

Evans, M.S.; Stoughton, R.S.; Kazerooni, H.

1994-08-01

This paper presents a theoretical and experimental investigation of a new kind of force sensor which detects forces by measuring an induced pressure change in a material of large Poisson's ratio. In this investigation we develop mathematical expressions for the sensor's sensitivity and bandwidth, and show that its sensitivity can be much larger and its bandwidth is usually smaller than those of existing strain-gage-type sensors. This force sensor is well-suited for measuring large but slowly varying forces. It can be installed in a space smaller than that required by existing sensors

Availability analysis of United States BWR IV electrical generation plants

International Nuclear Information System (INIS)

Renick, D.H.; Li, F.; Todreas, N.E.

1998-01-01

Availability, as quantified by power output levels, from all active U.S. BWR IV plants were analyzed over a seven and a half year period to determine the operational characteristics of these plants throughout an operating cycle. The operational data were examined for infant mortality, end of cycle decreased availability, and seasonal availability variations. Scheduled outages were also examined to determine the industry's current approach to planning maintenance outages. The results of this study show that nuclear power plants do suffer significant infant mortality following a refueling outage. And while they do not suffer an end of cycle decrease in availability, a mid-cycle period of decreased availability is evident. This period of decreased availability is due to a combination of increased forced unavailability and seasonally scheduled maintenance and refueling outages. These findings form the start of a rational approach to increasing plant availability. (author)

Risk-informed profitability-based analysis support of nuclear power station balance-of-plant change management

Energy Technology Data Exchange (ETDEWEB)

Liming, J.K. [EQE International, Inc., An ABS Group Company, Irvine, CA (United States); Kee, E.J.; Grantom, C.R.; Richards, A.M. [STP Nuclear Operating Company, Wadsworth, TX (United States)

2001-07-01

In this paper, a three-phased method is proposed for the STP Nuclear Operating Company (STPNOC) Risk and Reliability Analysis Section (RRA) to perform analyses and decision-making support for the STPNOC Balance-of-Plant (BOP)Task Force in managing change to simultaneously optimize plant safety and maximize long-term return-on-asset (or profitability) for the South Texas Project Electric Generating Station (STPEGS). (authors)

Risk-informed profitability-based analysis support of nuclear power station balance-of-plant change management

International Nuclear Information System (INIS)

Liming, J.K.; Kee, E.J.; Grantom, C.R.; Richards, A.M.

2001-01-01

In this paper, a three-phased method is proposed for the STP Nuclear Operating Company (STPNOC) Risk and Reliability Analysis Section (RRA) to perform analyses and decision-making support for the STPNOC Balance-of-Plant (BOP)Task Force in managing change to simultaneously optimize plant safety and maximize long-term return-on-asset (or profitability) for the South Texas Project Electric Generating Station (STPEGS). (authors)

Technology and costs for decommissioning the Swedish nuclear power plants

International Nuclear Information System (INIS)

1986-05-01

The study shows that, from the viewpoint of radiological safety, a nuclear power plant can be dismantled immediately after it has been shut down and the fuel has been removed, which is estimated to take about one year. Most of the equipment that will be used in decommissioning is already available and is used routinely in maintenance and rebuilding work at the nuclear power plants. Special equipment need only be developed for dismantlement of the reactor vessel and for demolishing of heavy concrete structures. The dismantling of a nuclear power plant can be accomplished in about five years, with an average labour force of about 200 men. The maximum labour force required for Ringhals 1 has been estimated at about 500 men during the first years, when active systems are being dismantled in a number of fronts in the plant. During the last years when the buildings are being demolished, approximately 50 men are required. In order to limit the labour requirement and the dose burden to the personnel, the material is taken out in as large pieces as possible. The cost of decommissioning a boiling water reactor (BWR) of the size of Ringhals 1 has been estimated to be about MSEK 540 in January 1986 prices, and for a pressurized water reactor (PWR, Ringhals 2) about MSEK 460. The cost for the other Swedish nuclear power plants lie in the range of MSEK 410-760. These are the direct cost for the decommissioning work, to which must be added the costs of transportation and disposal of the decommissioning waste, about 100 000 m/sup3/. These costs have been estimated to be about MSEK 600 for the 12 Swedish reactors. (author)

Crossflow force transducer

International Nuclear Information System (INIS)

Mulcahy, T.M.

1982-05-01

A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

Different forces

CERN Multimedia

1982-01-01

The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies or phenomena in which they have a dominant role.

Simulation of a force on force exercise

International Nuclear Information System (INIS)

Terhune, R.; Van Slyke, D.; Sheppard, T.; Brandrup, M.

1988-01-01

The Security Exercise Evaluation System (SEES) is under development for use in planning Force on Force exercises and as an aid in post-exercise evaluation. This study is part of the development cycle where the simulation results are compared to field data to provide guidance for further development of the model. SEES is an event-driven stochastic computer program simulating individual movement and combat within an urban terrain environment. The simulator models the physics of movement, line of sight, and weapon effects. It relies on the controllers to provide all knowledge of security tactics, which are entered by the controllers during the simulation using interactive color graphic workstations. They are able to develop, modify and implement plans promptly as the simulator maintains real time. This paper reports on how SEES will be used to develop an intrusion plan, test the security response tactics and develop observer logistics. A Force on Force field exercise will then be executed to follow the plan with observations recorded. An analysis is made by first comparing the plan and events of the simulation with the field exercise, modifying the simulation plan to match the actual field exercise, and then running the simulation to develop a distribution of possible outcomes

Influence of post-stroke spasticity on EMG-force coupling and force steadiness in biceps brachii.

Science.gov (United States)

Carlyle, Jennilee K; Mochizuki, George

2018-02-01

Individuals with spasticity after stroke experience a decrease in force steadiness which can impact function. Alterations in the strength of EMG-force coupling may contribute to the reduction in force steadiness observed in spasticity. The aim was to determine the extent to which force steadiness and EMG-force coupling is affected by post-stroke spasticity. This cross-sectional study involved individuals with upper limb spasticity after stroke. Participants were required to generate and maintain isometric contractions of the elbow flexors at varying force levels. Coefficient of variation of force, absolute force, EMG-force cross-correlation function peak and peak latency was measured from both limbs with surface electromyography and isometric dynamometry. Statistically significant differences were observed between the affected and less affected limbs for all outcome measures. Significant main effects of force level were also observed. Force steadiness was not statistically significantly correlated with EMG-force coupling; however, both force steadiness and absolute force were associated with the level of impairment as measured by the Chedoke McMaster Stroke Assessment Scale. Spasticity after stroke uncouples the relationship between EMG and force and is associated with reduced force steadiness during isometric contractions; however, these features of control are not associated in individuals with spasticity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Force Reproduction Error Depends on Force Level, whereas the Position Reproduction Error Does Not

NARCIS (Netherlands)

Onneweer, B.; Mugge, W.; Schouten, Alfred Christiaan

2016-01-01

When reproducing a previously perceived force or position humans make systematic errors. This study determined the effect of force level on force and position reproduction, when both target and reproduction force are self-generated with the same hand. Subjects performed force reproduction tasks at

The original Ampere force and Biot-Savart and Lorentz forces

International Nuclear Information System (INIS)

Pappas, P.T.

1983-01-01

The purpose of this paper is to present the results of a very simple experiment, which favours the original Ampere force and unambiguously disproves the Biot-Savart force of relativity, or its approximation in a covariant relativistic form, namely the Lorentz force. This experiment with its extra degree of freedom has the advantage over the many other similar ones, including Ampere's original experiment, which have been performed in the past and recently by Graneau, of giving results which are both qualitative and quantitative, as well as unambiguous. Due to the strong association of the Biot-Savart and Lorentz force to relativistic theories, the experiment can be also considered as limiting the generality of these theories

Bi-Force

DEFF Research Database (Denmark)

Sun, Peng; Speicher, Nora K; Röttger, Richard

2014-01-01

of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... comparative analysis of biclustering algorithms for gene expressiondata. Brief. Bioinform., 14:279-292.) and compared Bi-Force against eight existing tools: FABIA, QUBIC, Cheng and Church, Plaid, BiMax, Spectral, xMOTIFs and ISA. To this end, a suite of synthetic datasets as well as nine large gene expression...

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.

Drafting force majeure clauses in natural gas purchase/sale contracts -- the practicalities

International Nuclear Information System (INIS)

Reschke, D. N.; Campbell, L. M.

1999-01-01

The place of 'force majeure' provisions, in gas purchase/sale contracts is discussed. This issue, not normally considered to be significant in gas purchase/sale contracts, became a matter of intense interest in the aftermath of the Atcor Ltd v. Continental Energy Marketing case when the trial court, as well as the Alberta Court of Appeals, strongly criticized the wording of the force majeure clause in the contract as containing a 'choice of words that assured litigation'. Force majeure, simply stated, refers to acts of God, (lightning, earthquakes, storms, floods, etc) and acts of war. It is inserted in contracts to limit the liability of parties to the contract in the event of inability to perform due to any of the above acts of God, or acts of war. In this particular case, the force majeure cause included, in addition to the above, a long list of other causes such as strikes, lockouts or other industrial disturbances, insurrections, riots, epidemics, landslides, fires, washouts, explosions of or accidents to plant, machinery or lines of pipe, well blowouts, and pipeline repairs and reconditioning. The trial court found the drafting of the clause archaic, circumventing clarity, and drearily lengthy. In view of the court's decision it is clear that more thought has to go into drafting force majeure decisions in the future. Accordingly, this paper attempts to discuss practical issues of drafting force majeure clauses that clearly reflect the parties' intentions and expectations so that costly litigations might be avoided, or if litigation is unavoidable, to at least have the outcome of such litigation be more predictable. The focus of the discussion is on legal interpretation issues, forms of gas contract force majeure provisions- events and consequences, and standardization of force majeure provisions. It is recommended that the drafter of such clauses should always keep in mind the potential impact that the strict construction and commercial reasonability concepts

78 FR 63208 - UPDATE-Meeting of the Community Preventive Services Task Force (Task Force)

Science.gov (United States)

2013-10-23

... of the Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and... Community Preventive Services Task Force (Task Force). The in-person Task Force meeting is being replaced by... CDC's ability to complete the necessary scientific and logistical support for the meeting. The Task...

Interrelation between striction forces in dielectrics and optically induced forces in transparent media

International Nuclear Information System (INIS)

Torchigin, V P; Torchigin, A V

2012-01-01

Optically induced forces applied to a transparent optical medium, which is inserted in a closed plane optical resonator, are calculated by means of an analysis of the changes in the eigenfrequency and energy stored in the resonator at various positions of the medium. These forces are compared with striction forces applied to the medium considered as a dielectric placed in an alternate electrical field within the resonator. It is shown that the optically induced forces are equal to the striction forces. The results of using the classical formula for striction forces in electrostatics are considered. (paper)

Green Synthesis of Silver Nanoparticles from several NTFP Plants

Directory of Open Access Journals (Sweden)

Somnath BHOWMIK

2016-03-01

Full Text Available The biological synthesis of nanoparticles using plant extracts plays an important role in the field of nanotechnology. In this study, rapid, simple approach was applied for synthesis of silver nanoparticles using , Clerodendrum infortunatum, Mucuna interrupta, Phlogancanthus thyrsiflorus and Sansevieria trifasciata aqueous leaf extract. The plant extract acts both as reducing agent as well as capping agent. To identify the compounds responsible for reduction of silver ions, the functional groups present in plant extract were investigated by FTIR. Various techniques used to characterize synthesized nanoparticles are Scanning Electron Microscopy (SEM, Atomic Force Microscopy (AFM and UV–Visible spectrophotometer. Results confirmed that this protocol was simple, rapid, one step, eco-friendly, non-toxic and might be an alternative conventional physical/chemical methods. Conversion of silver nanoparticles takes place at room temperature without the involvement of any hazardous chemicals.

The Past, Present, and Future of the Air Force's Future Total Force

National Research Council Canada - National Science Library

Duffy, Dennis P

2004-01-01

This project examines the history of the Total Force policy since its inception in 1970 through its implementation today in an effort to determine a future direction for the Air Force's Future Total Force initiative...

Standard model for safety analysis report of fuel fabrication plants

International Nuclear Information System (INIS)

1980-09-01

A standard model for a safety analysis report of fuel fabrication plants is established. This model shows the presentation format, the origin, and the details of the minimal information required by CNEN (Comissao Nacional de Energia Nuclear) aiming to evaluate the requests of construction permits and operation licenses made according to the legislation in force. (E.G.) [pt

Standard model for safety analysis report of fuel reprocessing plants

International Nuclear Information System (INIS)

1979-12-01

A standard model for a safety analysis report of fuel reprocessing plants is established. This model shows the presentation format, the origin, and the details of the minimal information required by CNEN (Comissao Nacional de Energia Nuclear) aiming to evaluate the requests of construction permits and operation licenses made according to the legislation in force. (E.G.) [pt

Analyses and estimates of hydraulic conductivity from slug tests in alluvial aquifer underlying Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas

Science.gov (United States)

Houston, Natalie A.; Braun, Christopher L.

2004-01-01

This report describes the collection, analyses, and distribution of hydraulic-conductivity data obtained from slug tests completed in the alluvial aquifer underlying Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas, during October 2002 and August 2003 and summarizes previously available hydraulic-conductivity data. The U.S. Geological Survey, in cooperation with the U.S. Air Force, completed 30 slug tests in October 2002 and August 2003 to obtain estimates of horizontal hydraulic conductivity to use as initial values in a ground-water-flow model for the site. The tests were done by placing a polyvinyl-chloride slug of known volume beneath the water level in selected wells, removing the slug, and measuring the resulting water-level recovery over time. The water levels were measured with a pressure transducer and recorded with a data logger. Hydraulic-conductivity values were estimated from an analytical relation between the instantaneous displacement of water in a well bore and the resulting rate of head change. Although nearly two-thirds of the tested wells recovered 90 percent of their slug-induced head change in less than 2 minutes, 90-percent recovery times ranged from 3 seconds to 35 minutes. The estimates of hydraulic conductivity range from 0.2 to 200 feet per day. Eighty-three percent of the estimates are between 1 and 100 feet per day.

Adaptation of thermal power plants: The (ir)relevance of climate (change) information

International Nuclear Information System (INIS)

Bogmans, Christian W.J.; Dijkema, Gerard P.J.; Vliet, Michelle T.H. van

2017-01-01

When does climate change information lead to adaptation? We analyze thermal power plant adaptation by means of investing in water-saving (cooling) technology to prevent a decrease in plant efficiency and load reduction. A comprehensive power plant investment model, forced with downscaled climate and hydrological projections, is then numerically solved to analyze the adaptation decisions of a selection of real power plants. We find that operators that base their decisions on current climatic conditions are likely to make identical choices and perform just as well as operators that are fully ‘informed’ about climate change. Where electricity supply is mainly generated by thermal power plants, heat waves, droughts and low river flow may impact electricity supply for decades to come. - Highlights: • We analyze adaptation to climate change by thermal power plants. • A numerical investment model is applied to a coal plant and a nuclear power plant. • The numerical analysis is based on climate and hydrological projections. • Climate change information has a relatively small effect on a power plant's NPV. • Uncertainty and no-regret benefits lower the value of climate change information.

Thermal expansion measurement of turbine and main steam piping by using strain gages in power plants

International Nuclear Information System (INIS)

Na, Sang Soo; Chung, Jae Won; Bong, Suk Kun; Jun, Dong Ki; Kim, Yun Suk

2000-01-01

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shaft alignment problem which sometimes is changed by thermal expansion and external force, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants

Role of attractive forces in tapping tip force microscopy

DEFF Research Database (Denmark)

Kyhle, Anders; Sørensen, Alexis Hammer; Bohr, Jakob

1997-01-01

We present experimental and numerical results demonstrating the drastic influence of attractive forces on the behaviour of the atomic force microscope when operated in the resonant tapping tip mode in an ambient environment. It is often assumed that tapping is related to repulsive interaction...

Surface forces studied with colloidal probe atomic force microscopy

NARCIS (Netherlands)

Giesbers, M.

2001-01-01

Forces between surfaces are a determining factor for the performance of natural as well as synthetic colloidal systems, and play a crucial role in industrial production processes. Measuring these forces is a scientific and experimental challenge and over the years several techniques have

A force-sensing surgical tool with a proximally located force/torque sensor.

Science.gov (United States)

Schwalb, W; Shirinzadeh, B; Smith, J

2017-03-01

Robotic surgery has seen a rapid increase in popularity in the last few decades because advantages such as increased accuracy and dexterity can be realized. These systems still lack force-feedback, where such a capability is believed to be beneficial to the surgeon and can improve safety. In this paper a force-feedback enabled surgical robotic system is described in which the developed force-sensing surgical tool is discussed in detail. The developed surgical tool makes use of a proximally located force/torque sensor, which, in contrast to a distally located sensor, requires no miniaturization or sterilizability. Experimental results are presented, and indicate high force sensing accuracies with errors <0.09 N. It is shown that developing a force-sensing surgical tool utilizing a proximally located force/torque sensor is feasible, where a tool outer diameter of 12 mm can be achieved. For future work it is desired to decrease the current tool outer diameter to 10 mm. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Dynamics of shearing force and its correlations with chemical compositions and in vitro dry matter digestibility of stylo (Stylosanthes guianensis) stem.

Science.gov (United States)

Zi, Xuejuan; Li, Mao; Zhou, Hanlin; Tang, Jun; Cai, Yimin

2017-12-01

The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Widespread mechanosensing controls the structure behind the architecture in plants.

Science.gov (United States)

Hamant, Olivier

2013-10-01

Mechanical forces play an instructing role for many aspects of animal cell biology, such as division, polarity and fate. Although the associated mechanoperception pathways still remain largely elusive in plants, physical cues have long been thought to guide development in parallel to biochemical factors. With the development of new imaging techniques, micromechanics tools and modeling approaches, the role of mechanical signals in plant development is now re-examined and fully integrated with modern cell biology. Using recent examples from the literature, I propose to use a multiscale perspective, from the whole plant down to the cell wall, to fully appreciate the diversity of developmental processes that depend on mechanical signals. Incidentally, this also illustrates how conceptually rich this field is. Copyright © 2013 Elsevier Ltd. All rights reserved.

Increasing flexibility of coal power plant by control system modifications

Directory of Open Access Journals (Sweden)

Marušić Ante

2016-01-01

Full Text Available Expanding implementation of intermittent renewable energy sources has already started to change the role of thermal power plants in energy systems across Europe. Traditionally base load plants are now forced to operate as peaking plants. A familiar transition in upcoming years is expected in Croatia and coal power plant operators are preparing accordingly. To evaluate cycling capabilities and control system operation for flexible operation of selected 210 MW coal plant, series of tests with different load gradients were performed and results were thoroughly analyzed. Two possible “bottlenecks” are identified, thermal stress in superheater header, and achievable ramping rate considering operational limitations of coal feeders, firing system and evaporator dynamics. Several unexpected readings were observed, usually caused by malfunctioning sensors and equipment, resulting in unexpected oscillations of superheated steam temperature. Based on superheater geometry and experimental data, maximal steam temperature gradient during ramping was evaluated. Since thermal stress was well inside the safety margins, the simulation model of the whole boiler was used to evaluate achievable ramping on electric side.

A standing pressure wave hypothesis of oscillating forces generated during a steam line break

International Nuclear Information System (INIS)

Tinoco, H.

2001-01-01

A rapid glance at the figure depicting the net forces acting on the reactor vessel and internals, as obtained through a CFD simulation of a BWR steam line break, reveals an amazing oscillating regularity of these forces which is in glaring contrast to the chaotic behaviour of the steam pressure field in the steam annulus. Assuming that the decompression process excites and maintains standing pressure waves in the annular cylindrical region constituted by the steam annulus, it is possible to reconstruct the net forces acting on the reactor vessel and internals through the contribution of almost only the first dispersive mode. If a Neumann boundary condition is assumed at the section connecting the steam annulus to the steam dome, the frequency predicted is approximately % 5.9 higher than that of the CFD simulations. However, this connecting section allows wave transmission, and a more appropriate boundary condition should be one of the Robin type. Therefore, this section is modelled as an absorbing wall, and the corresponding normal impedance is calculated using the CFD simulations. Week non-linear effects can also be observed in the calculated forces through the presence of the first subharmonic. By the methodology described above, an estimate of the forces acting on the reactor vessel and internals of unit 3 of Forsmark Nuclear Power Plant has been obtained. (author)

Method for lateral force calibration in atomic force microscope using MEMS microforce sensor.

Science.gov (United States)

Dziekoński, Cezary; Dera, Wojciech; Jarząbek, Dariusz M

2017-11-01

In this paper we present a simple and direct method for the lateral force calibration constant determination. Our procedure does not require any knowledge about material or geometrical parameters of an investigated cantilever. We apply a commercially available microforce sensor with advanced electronics for direct measurement of the friction force applied by the cantilever's tip to a flat surface of the microforce sensor measuring beam. Due to the third law of dynamics, the friction force of the equal value tilts the AFM cantilever. Therefore, torsional (lateral force) signal is compared with the signal from the microforce sensor and the lateral force calibration constant is determined. The method is easy to perform and could be widely used for the lateral force calibration constant determination in many types of atomic force microscopes. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of nondestructive evaluation methods to improve power plant availability

International Nuclear Information System (INIS)

Weber, R.M.

1985-01-01

On an ever-increasing basis, utilities are relying on nondestructive evaluation (NDE) as a management and planning tool. In addition to the conventional ASME Code and Technical Specification-required examinations, progressive utilities are utilizing NDE sampling programs to monitor existing conditions and search for potential situations affecting plant safety and reliability. Improved NDE detection and sizing procedures give management personnel the accurate information needed to make the ''go/no go'' decisions on repair programs which can significantly affect plant availability. As the burden of regulatory-imposed inspection requirements increases, plant personnel are increasingly cognizant that NDE is a significant factor in their plant's outage schedule. Whether an outage is scheduled or forced, NDE becomes part of each plant's program to assure the safety and reliability of its critical components. Knowledge and planning of NDE application is important because of the time expended in examination performance and subsequent data evaluation. Managers who are knowledgeable in NDE application can effectively improve plant availability by scheduling NDE as an integral part of their maintenance programs. Examination results can then be used in making decisions directly affecting availability

Project management in fossil plant construction: A perspective for the Nineties

International Nuclear Information System (INIS)

Bhatia, N.K.

1991-01-01

The continuing growth in demand for electric power, and the reluctance of electric utility management to commit to new capacity additions has created a potential for somewhat hectic activity in the fossil power plant construction market. With the changing matrix of power plant types and ownerships, the project manager is called upon to deliver a complex product with exacting contract requirements: lump sum contracts, competitive pricing, short schedules, and performance guarantees. A shortage of experienced professionals in the ranks of the owners, engineers, contractors, and suppliers magnifies the challenge. Plant replication, automation, creative management of vendors and contractors, and participative management of the work force will be key elements of successful projects. Partnering between the clients and the engineers-constructors will be an interesting new relationship model

Short-range fundamental forces

International Nuclear Information System (INIS)

Antoniadis, I.; Baessler, S.; Buchner, M.; Fedorov, V.V.; Hoedl, S.; Nesvizhevsky, V.V.; Pignol, G.; Protasov, K.V.; Lambrecht, A.; Reynaud, S.; Sobolev, Y.

2010-01-01

We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces; 2) spin-dependent axion-like forces. Different experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experiments. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments

The force pyramid: a spatial analysis of force application during virtual reality brain tumor resection.

Science.gov (United States)

Azarnoush, Hamed; Siar, Samaneh; Sawaya, Robin; Zhrani, Gmaan Al; Winkler-Schwartz, Alexander; Alotaibi, Fahad Eid; Bugdadi, Abdulgadir; Bajunaid, Khalid; Marwa, Ibrahim; Sabbagh, Abdulrahman Jafar; Del Maestro, Rolando F

2017-07-01

OBJECTIVE Virtual reality simulators allow development of novel methods to analyze neurosurgical performance. The concept of a force pyramid is introduced as a Tier 3 metric with the ability to provide visual and spatial analysis of 3D force application by any instrument used during simulated tumor resection. This study was designed to answer 3 questions: 1) Do study groups have distinct force pyramids? 2) Do handedness and ergonomics influence force pyramid structure? 3) Are force pyramids dependent on the visual and haptic characteristics of simulated tumors? METHODS Using a virtual reality simulator, NeuroVR (formerly NeuroTouch), ultrasonic aspirator force application was continually assessed during resection of simulated brain tumors by neurosurgeons, residents, and medical students. The participants performed simulated resections of 18 simulated brain tumors with different visual and haptic characteristics. The raw data, namely, coordinates of the instrument tip as well as contact force values, were collected by the simulator. To provide a visual and qualitative spatial analysis of forces, the authors created a graph, called a force pyramid, representing force sum along the z-coordinate for different xy coordinates of the tool tip. RESULTS Sixteen neurosurgeons, 15 residents, and 84 medical students participated in the study. Neurosurgeon, resident and medical student groups displayed easily distinguishable 3D "force pyramid fingerprints." Neurosurgeons had the lowest force pyramids, indicating application of the lowest forces, followed by resident and medical student groups. Handedness, ergonomics, and visual and haptic tumor characteristics resulted in distinct well-defined 3D force pyramid patterns. CONCLUSIONS Force pyramid fingerprints provide 3D spatial assessment displays of instrument force application during simulated tumor resection. Neurosurgeon force utilization and ergonomic data form a basis for understanding and modulating resident force

What a nuclear power plant means for the local authority

International Nuclear Information System (INIS)

Christersson, B.

1977-01-01

The anthor, a senior public official in the local anthority district in which the Oskarshamn nuclear power plant is situated, gives a survey of the effects which the plant has had on the community. The background for its establiskment there, and the licensing procedures followed are presented. While no social problems have occurred, the large temporary labour force necessitated action by the local authority in the field of housing. The politically induced delays in starting on the third reactor have led to a surplus of housing. The plant has required special considerations due to safely to be made in the development plan for the aren. Environmental factors, mainly thermal effects of effluents in the coastal waters, have presented no problems, but investigations are continuling. The only negative effect is the heavy traffic on the local roads when major construction work is in progress. The plant has had positive effect on the employment and local financial situation. (JIW)

What a nuclear power plant means for the local authority

Energy Technology Data Exchange (ETDEWEB)

Christersson, B [Oskershamn Kommune (Sweden)

1977-11-29

The anthor, a senior public official in the local anthority district in which the Oskarshamn nuclear power plant is situated, gives a survey of the effects which the plant has had on the community. The background for its establishment there, and the licensing procedures followed are presented. While no social problems have occurred, the large temporary labour force necessitated action by the local authority in the field of housing. The politically induced delays in starting on the third reactor have led to a surplus of housing. The plant has required special considerations due to safely to be made in the development plan for the area. Environmental factors, mainly thermal effects of effluents in the coastal waters, have presented no problems, but investigations are continuing. The only negative effect is the heavy traffic on the local roads when major construction work is in progress. The plant has had positive effect on the employment and local financial situation.

Nuclear Plant Analyzer development at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Laats, E.T.

1986-10-01

The Nuclear Plant Analyzer (NPA) is a state-of-the-art safety analysis and engineering tool being used to address key nuclear power plant safety issues. Under the sponsorship of the US Nuclear Regulatory Commission (NRC), the NPA has been developed to integrate the NRC's computerized reactor behavior simulation codes such as RELAP5, TRAC-BWR and TRAC-PWR, with well-developed computer color graphics programs and large repositories of reactor design and experimental data. An important feature of the NPA is the capability to allow an analyst to redirect a RELAP5 or TRAC calculation as it progresses through its simulated scenario. The analyst can have the same power plant control capabilities as the operator of an actual plant. The NPA resides on the dual Control Data Corporation Cyber 176 mainframe computers at the Idaho National Engineering Laboratory and Cray-1S computers at the Los Alamos National Laboratory (LANL) and Kirtland Air Force Weapons Laboratory (KAFWL)

Force-Induced Rupture of a DNA Duplex: From Fundamentals to Force Sensors.

Science.gov (United States)

Mosayebi, Majid; Louis, Ard A; Doye, Jonathan P K; Ouldridge, Thomas E

2015-12-22

The rupture of double-stranded DNA under stress is a key process in biophysics and nanotechnology. In this article, we consider the shear-induced rupture of short DNA duplexes, a system that has been given new importance by recently designed force sensors and nanotechnological devices. We argue that rupture must be understood as an activated process, where the duplex state is metastable and the strands will separate in a finite time that depends on the duplex length and the force applied. Thus, the critical shearing force required to rupture a duplex depends strongly on the time scale of observation. We use simple models of DNA to show that this approach naturally captures the observed dependence of the force required to rupture a duplex within a given time on duplex length. In particular, this critical force is zero for the shortest duplexes, before rising sharply and then plateauing in the long length limit. The prevailing approach, based on identifying when the presence of each additional base pair within the duplex is thermodynamically unfavorable rather than allowing for metastability, does not predict a time-scale-dependent critical force and does not naturally incorporate a critical force of zero for the shortest duplexes. We demonstrate that our findings have important consequences for the behavior of a new force-sensing nanodevice, which operates in a mixed mode that interpolates between shearing and unzipping. At a fixed time scale and duplex length, the critical force exhibits a sigmoidal dependence on the fraction of the duplex that is subject to shearing.

Students’ understanding of forces: Force diagrams on horizontal and inclined plane

Science.gov (United States)

Sirait, J.; Hamdani; Mursyid, S.

2018-03-01

This study aims to analyse students’ difficulties in understanding force diagrams on horizontal surfaces and inclined planes. Physics education students (pre-service physics teachers) of Tanjungpura University, who had completed a Basic Physics course, took a Force concept test which has six questions covering three concepts: an object at rest, an object moving at constant speed, and an object moving at constant acceleration both on a horizontal surface and on an inclined plane. The test is in a multiple-choice format. It examines the ability of students to select appropriate force diagrams depending on the context. The results show that 44% of students have difficulties in solving the test (these students only could solve one or two items out of six items). About 50% of students faced difficulties finding the correct diagram of an object when it has constant speed and acceleration in both contexts. In general, students could only correctly identify 48% of the force diagrams on the test. The most difficult task for the students in terms was identifying the force diagram representing forces exerted on an object on in an inclined plane.

Variability of stratification according to operation of the tidal power plant in Lake Sihwa, South Korea.

Science.gov (United States)

Woo, S. B.; Song, J. I.; Jang, T. H.; Park, C. J.; Kwon, H. K.

2017-12-01

Artificial forcing according to operation of the tidal power plant (TPP) affects the physical environmental changes near the power plant. Strong turbulence by generation is expected to change the stratification structure of the Lake Sihwa inside. In order to examine the stratification changes by the power plant operation, ship bottom mounted observation were performed for 13 hours using an acoustic Doppler current profiler (ADCP) and Conductivity-Temperature-Depth (CTD) in Lake Sihwa at near TPP. The strong stratification in Sihwa Lake is maintained before TPP operation. The absence of external forces and freshwater inflow from the land forms the stratification in the Lake. Strong winds in a stratification statement lead to two-layer circulation. After wind event, multi-layer velocity structure is formed which lasted for approximately 4 h. After TPP operation, the jet flow was observed in entire water column at the beginning of the power generation. Vortex is formed by strong jet flow and maintained throughout during power generation period. Strong turbulence flow is generated by the turbine blades, enhancing vertical mixing. External forces, which dominantly affect Lake Sihwa, have changed from the wind to the turbulent flow. The stratification was extinguished by strong turbulent flow and becomes fully-mixed state. Changes in stratification structure are expected to affect material transport and ecological environment change continuously.

Socioeconomic effects of the DOE Gas Centrifuge Enrichment Plant. Volume 1: methodology and analysis

International Nuclear Information System (INIS)

1979-01-01

The socioeconomic effects of the Gas Centrifuge Enrichment Plant being built in Portsmouth, Ohio were studied. Chapters are devoted to labor force, housing, population changes, economic impact, method for analysis of services, analysis of service impacts, schools, and local government finance

Large photovoltages generated by plant photosystem I crystals

Energy Technology Data Exchange (ETDEWEB)

Toporik, Hila; Carmeli, Chanoch; Nelson, Nathan [Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Carmeli, Itai [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Volotsenko, Irina; Molotskii, Michel; Rosenwaks, Yossi [Department of Physical Electronics, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

2012-06-12

Micrometer-thick plant photosystem I crystals made of up to 1000 layers of serially arranged protein complexes generate unprecedented high photovoltages when placed on a conducting solid surface and measured using Kelvin probe force microscopy. The successive layers form serially photoinduced dipoles in the crystal that give rise to electric fields as large as 100 kV cm{sup -1}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A hydroponic system for microgravity plant experiments

Science.gov (United States)

Wright, B. D.; Bausch, W. C.; Knott, W. M.

1988-01-01

The construction of a permanently manned space station will provide the opportunity to grow plants for weeks or months in orbit for experiments or food production. With this opportunity comes the need for a method to provide plants with a continuous supply of water and nutrients in microgravity. The Capillary Effect Root Environment System (CERES) uses capillary forces to maintain control of circulating plant nutrient solution in the weightless environment of an orbiting spacecraft. The nutrient solution is maintained at a pressure slightly less than the ambient air pressure while it flows on one side of a porous membrane. The root, on the other side of the membrane, is surrounded by a thin film of nutrient solution where it contacts the moist surface of the membrane. The root is provided with water, nutrients and air simultaneously. Air bubbles in the nutrient solution are removed using a hydrophobic/hydrophilic membrane system. A model scaled to the size necessary for flight hardware to test CERES in the space shuttle was constructed.

Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

Energy Technology Data Exchange (ETDEWEB)

Teresa W.-M. Fan; Richard M. Higashi; David Crowley; Andrew N. Lane: Teresa A. Cassel; Peter G. Green

2004-12-31

For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.

New evidence for electrotropism in some plant species

Science.gov (United States)

Gorgolewski, S.; Rozej, B.

The ever-present global Atmospheric Electrical F ield (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity to electrotropic effect in different electric field intensities and directions. It was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions in plant tissues. We use a "reference field" (130 V/m) and stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed field polarity. In conclusion electrotropic pl nts deprived of the electrical field do not develop asa expected, as can be seen in BIOSPHERE 2. It was a sad example of what happens when one forgets to provide the plants with this vital natural environmental factor. Electrical fields of different intensity and direction are cheap and easy to generate. More plants were investigated in order to verify their response to electrical fields. Effect of several kV/m horizontal fields, was compared with the vertical 130 V/m field (ued as a reference) and it was shown that electrotropic sensitivity can be found easily. Surprisingly even the nonelectrotropic plants, whose initial growth rate does not depend on the field strength, when they develop leaves begin to lean towards the positive electrode, and become elect rotropic. Ground based fitotron experiments enable us to select cheaply plants which shall be suitable

Natural enemies drive geographic variation in plant defenses

DEFF Research Database (Denmark)

Zuest, Tobias; Heichinger, Christian; Grossniklaus, Ueli

2012-01-01

Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources...... of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two...... aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces....

Force-Time Entropy of Isometric Impulse.

Science.gov (United States)

Hsieh, Tsung-Yu; Newell, Karl M

2016-01-01

The relation between force and temporal variability in discrete impulse production has been viewed as independent (R. A. Schmidt, H. Zelaznik, B. Hawkins, J. S. Frank, & J. T. Quinn, 1979 ) or dependent on the rate of force (L. G. Carlton & K. M. Newell, 1993 ). Two experiments in an isometric single finger force task investigated the joint force-time entropy with (a) fixed time to peak force and different percentages of force level and (b) fixed percentage of force level and different times to peak force. The results showed that the peak force variability increased either with the increment of force level or through a shorter time to peak force that also reduced timing error variability. The peak force entropy and entropy of time to peak force increased on the respective dimension as the parameter conditions approached either maximum force or a minimum rate of force production. The findings show that force error and timing error are dependent but complementary when considered in the same framework with the joint force-time entropy at a minimum in the middle parameter range of discrete impulse.

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

Nuclear power plant functions: overview, maintenance, design practices, training

International Nuclear Information System (INIS)

Gray, J.

1984-01-01

The author gives a history of the nuclear industry in the US beginning with the Atoms for Peace Proposal in 1954 and summarizes the nuclear industry's importance in the realm of electric power production today. The primary problems facing the domestic nuclear industry are identified as the lengthening schedules for plant licensing and construction, and the associated uncertainty in plant costs and difficulty in financing, and the erosion of public confidence. Views on technological approaches to the future of nuclear power and the role regulation will play in the future as a fundamental force are discusses in the paper. Also discussed are the importance of standardization of advanced reactor designs and quality assurance

Labor Force

Science.gov (United States)

Occupational Outlook Quarterly, 2010

2010-01-01

The labor force is the number of people aged 16 or older who are either working or looking for work. It does not include active-duty military personnel or institutionalized people, such as prison inmates. Quantifying this total supply of labor is a way of determining how big the economy can get. Labor force participation rates vary significantly…

Chin force in violin playing.

Science.gov (United States)

Obata, Satoshi; Kinoshita, Hiroshi

2012-06-01

Force generated between the left mandible of violinists and the chinrest of the violin was examined using a force-sensing chinrest developed in this study. A strain-gauge force sensor was built, and it was fixed between the violin's top plate and a chin cup. Fifteen professional/amateur violinists held the violin statically, played musical scales with different sound properties and sounding techniques, as well as an excerpt from a Max Bruch concerto. Peak and mean forces were evaluated for each task. In a separate experiment, lateral movement of the lower teeth due to different levels of voluntary chin force exertion was measured. Static holding forces observed were 15 and 22 N with and without the help of the left hand, respectively. Peak force increased from 16 N at soft dynamics to 20 N at strong dynamics during scales. The force further increased to 29 N with the use of vibrato technique and 35 N during shifts. Tempo and hand position did not affect the force. Playing a Bruch concerto induced a mean peak force of 52 N, ranging from 31 to 82 N among the violinists. The developed force-sensing chinrest could accurately record the generated chin force. Typical chin force to stabilize the violin during ordinary musical performance was less than 30 N, but it could momentarily exceed 50 N when technically demanding musical pieces were performed. The lateral shift of the mandible was fairly small (<0.4 mm) even with high chin-force exertion, possibly due to clenching of the molars.

Contact force structure and force chains in 3D sheared granular systems

Science.gov (United States)

Mair, Karen; Jettestuen, Espen; Abe, Steffen

2010-05-01

Faults often exhibit accumulations of granular debris, ground up to create a layer of rock flour or fault gouge separating the rigid fault walls. Numerical simulations and laboratory experiments of sheared granular materials, suggest that applied loads are preferentially transmitted across such systems by transient force networks that carry enhanced forces. The characterisation of such features is important since their nature and persistence almost certainly influence the macroscopic mechanical stability of these systems and potentially that of natural faults. 3D numerical simulations of granular shear are a valuable investigation tool since they allow us to track individual particle motions, contact forces and their evolution during applied shear, that are difficult to view directly in laboratory experiments or natural fault zones. In characterising contact force distributions, it is important to use global structure measures that allow meaningful comparisons of granular systems having e.g. different grain size distributions, as may be expected at different stages of a fault's evolution. We therefore use a series of simple measures to characterise the structure, such as distributions and correlations of contact forces that can be mapped onto a force network percolation problem as recently proposed by Ostojic and coworkers for 2D granular systems. This allows the use of measures from percolation theory to both define and characterise the force networks. We demonstrate the application of this method to 3D simulations of a sheared granular material. Importantly, we then compare our measure of the contact force structure with macroscopic frictional behaviour measured at the boundaries of our model to determine the influence of the force networks on macroscopic mechanical stability.

Source-sink relationships in radish plant

Directory of Open Access Journals (Sweden)

Z. Starck

2015-01-01

Full Text Available The problem of source-sink relationships in di- and tetraploidal radish plants grown in. hydroponic cultures was investigated in two stages of their development: with intensively growing swollen hypocotyl and in the period of actively accumulating nutrients in the storage organ. It was found, that the proportion, between the mass of organs, their RGR and NAR was very similar in di- and tetraploidal populations, probably owing to a similar rate of photosynthesis and pattern of assimilates distribution. The high variability of swollen hypocotyls size is slightly correlated with the size of the whole aerial part and is not correlated with the rate of photosynthesis in leaves. Partial defoliation of radish plants did not affect the rate of photosynthesis of the remaining leaves. Only in the cotyledones the oldest donors of 14C-assimilates, a slight compensation of photosynthesis was reported. It may suggest, that the rate of photosynthesis in radish plants is not under the control of sink activity. The size of the storage organ have determined in some extent its attractive force and influenced the amount of 14C-assimilates exported from their donors. Translocation of photosynthates from the young, still growing leaves was conditioned mainly by their retention power. Therefore, in young radish plants cotyledons were the main donor of 14C-assimilates.

Pretension construction of safety shell in Chashma nuclear power plant

International Nuclear Information System (INIS)

Gong Zhenbin; Li Yinong; Ni Shaowen

1999-01-01

19T16 post-tension grouped anchor system is applied to the safety shell pretension in Chashma Nuclear Power Plant. The stretching force of each bundle is about 3800 kN and the prestressed reinforcement is stretched in five stages. The double-control measurement of stress controlling and extension checking is applied in strict accordance with the principle of symmetrical construction

Force induced DNA melting

International Nuclear Information System (INIS)

Santosh, Mogurampelly; Maiti, Prabal K

2009-01-01

When pulled along the axis, double-strand DNA undergoes a large conformational change and elongates by roughly twice its initial contour length at a pulling force of about 70 pN. The transition to this highly overstretched form of DNA is very cooperative. Applying a force perpendicular to the DNA axis (unzipping), double-strand DNA can also be separated into two single-stranded DNA, this being a fundamental process in DNA replication. We study the DNA overstretching and unzipping transition using fully atomistic molecular dynamics (MD) simulations and argue that the conformational changes of double-strand DNA associated with either of the above mentioned processes can be viewed as force induced DNA melting. As the force at one end of the DNA is increased the DNA starts melting abruptly/smoothly above a critical force depending on the pulling direction. The critical force f m , at which DNA melts completely decreases as the temperature of the system is increased. The melting force in the case of unzipping is smaller compared to the melting force when the DNA is pulled along the helical axis. In the case of melting through unzipping, the double-strand separation has jumps which correspond to the different energy minima arising due to sequence of different base pairs. The fraction of Watson-Crick base pair hydrogen bond breaking as a function of force does not show smooth and continuous behavior and consists of plateaus followed by sharp jumps.

Are Synonymous Substitutions in Flowering Plant Mitochondria Neutral?

Science.gov (United States)

Wynn, Emily L; Christensen, Alan C

2015-10-01

Angiosperm mitochondrial genes appear to have very low mutation rates, while non-gene regions expand, diverge, and rearrange quickly. One possible explanation for this disparity is that synonymous substitutions in plant mitochondrial genes are not truly neutral and selection keeps their occurrence low. If this were true, the explanation for the disparity in mutation rates in genes and non-genes needs to consider selection as well as mechanisms of DNA repair. Rps14 is co-transcribed with cob and rpl5 in most plant mitochondrial genomes, but in some genomes, rps14 has been duplicated to the nucleus leaving a pseudogene in the mitochondria. This provides an opportunity to compare neutral substitution rates in pseudogenes with synonymous substitution rates in the orthologs. Genes and pseudogenes of rps14 have been aligned among different species and the mutation rates have been calculated. Neutral substitution rates in pseudogenes and synonymous substitution rates in genes are significantly different, providing evidence that synonymous substitutions in plant mitochondrial genes are not completely neutral. The non-neutrality is not sufficient to completely explain the exceptionally low mutation rates in land plant mitochondrial genomes, but selective forces appear to play a small role.

Attainment and retention of force moderation following laparoscopic resection training with visual force feedback.

Science.gov (United States)

Hernandez, Rafael; Onar-Thomas, Arzu; Travascio, Francesco; Asfour, Shihab

2017-11-01

Laparoscopic training with visual force feedback can lead to immediate improvements in force moderation. However, the long-term retention of this kind of learning and its potential decay are yet unclear. A laparoscopic resection task and force sensing apparatus were designed to assess the benefits of visual force feedback training. Twenty-two male university students with no previous experience in laparoscopy underwent relevant FLS proficiency training. Participants were randomly assigned to either a control or treatment group. Both groups trained on the task for 2 weeks as follows: initial baseline, sixteen training trials, and post-test immediately after. The treatment group had visual force feedback during training, whereas the control group did not. Participants then performed four weekly test trials to assess long-term retention of training. Outcomes recorded were maximum pulling and pushing forces, completion time, and rated task difficulty. Extreme maximum pulling force values were tapered throughout both the training and retention periods. Average maximum pushing forces were significantly lowered towards the end of training and during retention period. No significant decay of applied force learning was found during the 4-week retention period. Completion time and rated task difficulty were higher during training, but results indicate that the difference eventually fades during the retention period. Significant differences in aptitude across participants were found. Visual force feedback training improves on certain aspects of force moderation in a laparoscopic resection task. Results suggest that with enough training there is no significant decay of learning within the first month of the retention period. It is essential to account for differences in aptitude between individuals in this type of longitudinal research. This study shows how an inexpensive force measuring system can be used with an FLS Trainer System after some retrofitting. Surgical

System 80+ integrated design of a complete plant

International Nuclear Information System (INIS)

Turk, R.S.; Stamm, S.L.; Fox, W.A.

1992-01-01

In 1985, ABB-Combustion Engineering Nuclear Power (ABB-CENP) and elements of Duke Power Company [now Duke Engineering ampersand Services (DE ampersand S)] joined forces under the aegis of the Electric Power Research Institute (EPRI) Advanced Light Water Reactor (ALWR) Program to develop, with the sponsoring utilities, the design requirements for the next generation of nuclear power plants. With support from the US Department of Energy, ABB-CENP and DE ampersand S again teamed up the following year to initiate a project to design and license the System 80+ standard plant design, an advanced pressurized water reactor that meets these utility requirements. A distinguishing feature of the System 80+ standard design is that it is an essentially complete plant, predesigned and prelicensed to ensure rapid and economical construction. This is in stark contrast to typical prior conduct, where the reactor vendor offered only the nuclear steam supply system and the plant was built on a design-as-you-go basis with constant pressure to release individual elements of the plant design for construction or procurement as soon as possible. Now, however, the design process can be integrated over the total plant, ensuring that the goals set for ALWRs can be met. This integrated design process is manifested in several ways: (1) broad-based participation during the design process by involving designers, analysts, suppliers, constructors, and operators; (2) use of probabilistic risk assessment (PRA) as a design tool to aid in evaluating design features on a total-plant basis; (3) application of human factors engineering methods to a total plant distributed control system to improve the human-machine interface in the design; and (4) use of computer-aided design to enhance assessment of interactions and impacts of all aspects of the total plant. Each of these aspects of integrated plant design is discussed in this paper

Solvent driving force ensures fast formation of a persistent and well-separated radical pair in plant cryptochrome

DEFF Research Database (Denmark)

Lüdemann, Gesa; Solov'yov, Ilia; Kubar, Tomás

2015-01-01

upon the electron transfer. This approach allows us to follow the time evolution of the electron transfer in an unbiased fashion and to reveal the molecular driving force which ensures fast electron transfer in cryptochrome guaranteeing formation of a persistent radical pair suitable...

Capillary force between wetted nanometric contacts and its application to atomic force microscopy.

Science.gov (United States)

Crassous, Jérôme; Ciccotti, Matteo; Charlaix, Elisabeth

2011-04-05

We extend to the case of perfect wetting the exact calculation of Orr et al. (J. Fluid. Mech. 1975, 67, 723) for a pendular ring connecting two dry surfaces. We derive an approximate analytical expression for the capillary force between two highly curved surfaces covered by a wetting liquid film. The domain of validity of this expression is assessed and extended by a custom-made numerical simulation based on the full exact mathematical description. In the case of attractive liquid-solid van der Waals interactions, the capillary force increases monotonically with decreasing vapor pressure up to several times its saturation value. This accurate description of the capillary force makes it possible to estimate the adhesion force between wet nanoparticles; it can also be used to quantitatively interpret pull-off forces measured by atomic force microscopy.

Systems approach used in the Gas Centrifuge Enrichment Plant

International Nuclear Information System (INIS)

Rooks, W.A. Jr.

1982-01-01

A requirement exists for effective and efficient transfer of technical knowledge from the design engineering team to the production work force. Performance-Based Training (PBT) is a systematic approach to the design, development, and implementation of technical training. This approach has been successfully used by the US Armed Forces, industry, and other organizations. The advantages of the PBT approach are: cost-effectiveness (lowest life-cycle training cost), learning effectiveness, reduced implementation time, and ease of administration. The PBT process comprises five distinctive and rigorous phases: Analysis of Job Performance, Design of Instructional Strategy, Development of Training Materials and Instructional Media, Validation of Materials and Media, and Implementation of the Instructional Program. Examples from the Gas Centrifuge Enrichment Plant (GCEP) are used to illustrate the application of PBT

Systems approach used in the Gas Centrifuge Enrichment Plant

Energy Technology Data Exchange (ETDEWEB)

Rooks, W.A. Jr.

1982-01-01

A requirement exists for effective and efficient transfer of technical knowledge from the design engineering team to the production work force. Performance-Based Training (PBT) is a systematic approach to the design, development, and implementation of technical training. This approach has been successfully used by the US Armed Forces, industry, and other organizations. The advantages of the PBT approach are: cost-effectiveness (lowest life-cycle training cost), learning effectiveness, reduced implementation time, and ease of administration. The PBT process comprises five distinctive and rigorous phases: Analysis of Job Performance, Design of Instructional Strategy, Development of Training Materials and Instructional Media, Validation of Materials and Media, and Implementation of the Instructional Program. Examples from the Gas Centrifuge Enrichment Plant (GCEP) are used to illustrate the application of PBT.

Plant functional diversity affects climate-vegetation interaction

Science.gov (United States)

Groner, Vivienne P.; Raddatz, Thomas; Reick, Christian H.; Claussen, Martin

2018-04-01

We present how variations in plant functional diversity affect climate-vegetation interaction towards the end of the African Humid Period (AHP) in coupled land-atmosphere simulations using the Max Planck Institute Earth system model (MPI-ESM). In experiments with AHP boundary conditions, the extent of the green Sahara varies considerably with changes in plant functional diversity. Differences in vegetation cover extent and plant functional type (PFT) composition translate into significantly different land surface parameters, water cycling, and surface energy budgets. These changes have not only regional consequences but considerably alter large-scale atmospheric circulation patterns and the position of the tropical rain belt. Towards the end of the AHP, simulations with the standard PFT set in MPI-ESM depict a gradual decrease of precipitation and vegetation cover over time, while simulations with modified PFT composition show either a sharp decline of both variables or an even slower retreat. Thus, not the quantitative but the qualitative PFT composition determines climate-vegetation interaction and the climate-vegetation system response to external forcing. The sensitivity of simulated system states to changes in PFT composition raises the question how realistically Earth system models can actually represent climate-vegetation interaction, considering the poor representation of plant diversity in the current generation of land surface models.

Discrete Lattice effect of various forcing methods of body force on immersed Boundary-Lattice Boltzmann method

Energy Technology Data Exchange (ETDEWEB)

Son, Sung Wan; Ha, Man Yeong; Yoon, Hyun Sik [Pusan National University, Busan (Korea, Republic of); Jeong, Hae Kwon [POSCO, Pohang (Korea, Republic of); Balachandar, S. [University of Florida, Florida (United States)

2013-02-15

We investigate the discrete lattice effect of various forcing methods in the lattice Boltzmann method (LBM) to include the body force obtained from the immersed boundary method (IBM). In the immersed boundary lattice Boltzmann method (IB-LBM), the LBM needs a forcing method to involve the body force on a forcing point near the immersed boundary that is calculated by IBM. The proper forcing method in LBM is derived to include the body force, which appears to resolve problems such as multiphase flow, non-ideal gas behavior, etc. Many researchers have adopted different forcing methods in LBM to involve the body force from IBM, even when they solved similar problems. However, it is necessary to evaluate the discrete lattice effect, which originates from different forcing methods in LBM, to include the effect of the body force from IBM on the results. Consequently, in this study, a rigorous analysis of the discrete lattice effect for different forcing methods in IB-LBM is performed by solving various problems.

Discrete Lattice effect of various forcing methods of body force on immersed Boundary-Lattice Boltzmann method

International Nuclear Information System (INIS)

Son, Sung Wan; Ha, Man Yeong; Yoon, Hyun Sik; Jeong, Hae Kwon; Balachandar, S.

2013-01-01

We investigate the discrete lattice effect of various forcing methods in the lattice Boltzmann method (LBM) to include the body force obtained from the immersed boundary method (IBM). In the immersed boundary lattice Boltzmann method (IB-LBM), the LBM needs a forcing method to involve the body force on a forcing point near the immersed boundary that is calculated by IBM. The proper forcing method in LBM is derived to include the body force, which appears to resolve problems such as multiphase flow, non-ideal gas behavior, etc. Many researchers have adopted different forcing methods in LBM to involve the body force from IBM, even when they solved similar problems. However, it is necessary to evaluate the discrete lattice effect, which originates from different forcing methods in LBM, to include the effect of the body force from IBM on the results. Consequently, in this study, a rigorous analysis of the discrete lattice effect for different forcing methods in IB-LBM is performed by solving various problems.

High-speed force mapping on living cells with a small cantilever atomic force microscope

International Nuclear Information System (INIS)

Braunsmann, Christoph; Seifert, Jan; Rheinlaender, Johannes; Schäffer, Tilman E.

2014-01-01

The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ≈10−100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed

High-speed force mapping on living cells with a small cantilever atomic force microscope

Energy Technology Data Exchange (ETDEWEB)

Braunsmann, Christoph; Seifert, Jan; Rheinlaender, Johannes; Schäffer, Tilman E., E-mail: Tilman.Schaeffer@uni-tuebingen [Institute of Applied Physics and LISA, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen (Germany)

2014-07-15

The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ≈10−100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed.

Active seismic response control systems for nuclear power plant equipment facilities

International Nuclear Information System (INIS)

Kobori, Takuji; Kanayama, Hiroo; Kamagata, Shuichi

1989-01-01

To sustain severe earthquake ground motion, a new type of anti-seismic structure is proposed, called a Dynamic Intelligent Building (DIB) system, which is positioned as an active seismic response controlled the structure. The structural concept starts from a new recognition of earthquake ground motion, and the structural natural frequency is actively adjusted to avoid resonant vibration, and similarly the external counter-force cancels the resonant force which comes from the dynamic structural motion energy. These concepts are verified using an analytical simulator program. The advanced application of the DIB system, is the Active Supporting system and the Active Stabilizer system for nuclear power plant equipment facilities. (orig.)

Nuclear forces

International Nuclear Information System (INIS)

Holinde, K.

1990-01-01

In this paper the present status of the meson theory of nuclear forces is reviewed. After some introductory remarks about the relevance of the meson exchange concept in the era of QCD and the empirical features of the NN interaction, the exciting history of nuclear forces is briefly outlined. In the main part, the author gives the basic physical ideas and sketch the derivation of the one-boson-exchange model of the nuclear force, in the Feynman approach. Secondly we describe, in a qualitative way, various necessary extensions, leading to the Bonn model of the N interaction. Finally, points to some interesting pen questions connected with the extended quark structure of the hadrons, which are topics of current research activity

East-Asia nuclear/fossil power plant competitiveness

International Nuclear Information System (INIS)

Braun, Ch.

1996-01-01

The competitiveness of a new nuclear plant vs. a new oil or gas fired combined cycle plant or a coal fired plant in East-Asia, is reviewed in the paper. Both the nuclear and the fossil fired plants are evaluated as either utility financed or independent power producer (IPP) financed. Two types of advanced light water reactors (ALWRs) are considered in this paper, namely evolutionary ALWRs (1200 MWe size) and passive ALWRs (600 MWe class). A range of capital and total generation costs for each plant type is reported here. The comparison centers on three elements of overall competitiveness: generation costs, hard currency requirements, and employment requirements. Each of these aspects is considered perspective. Year-by-Year generation cost history over the plant lifetime is shown in some cases. It is found here that a utility financed evolutionary and passive ALWRs are broadly competitive with an IPP financed gas fired combined cycle plant and are more economic than oil fired combined cycle or a coal fired plant. A single unit evolutionary ALWR may have a 12 - 15 % capital cost advantage over a single passive ALWR then adjusted on a per KWe basis. Front-end hard currency requirements of a passive ALWR are 2.5 times higher than for a combined plant and evolutionary ALWRs requires 3.6 times higher up-front cost. However, on a lifetime basis, passive ALWR net hard currency requirements are two times lower than for a combined cycle plant. Evolutionary ALWR net hard currency requirements are three times over than those of a combined cycle plant. The effects of domestic vs. world price of fossil fuels on relative nuclear competitiveness are reviewed in this nuclear competitiveness paper. Employment requirements in an ALWR during both the construction period and lifetime operation, exceed the requirements for oil or gas fired plants by a factor of five. While contributing to overall plant cost, employment requirements can also be viewed as opportunity to increase national

Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

International Nuclear Information System (INIS)

Zou, Zhichao; Wang, Fujun; Yao, Zhifeng; Tao, Ran; Xiao, Ruofu; Li, Huaicheng

2016-01-01

Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t_0) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t_0, the radial force is small (approaching zero). At 0.4–1.4t_0, the radial force increases rapidly. After 1.4t_0, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research provides a scientific

Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

Energy Technology Data Exchange (ETDEWEB)

Zou, Zhichao [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Wang, Fujun, E-mail: wangfj@cau.edu.cn [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Yao, Zhifeng [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Tao, Ran [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Xiao, Ruofu [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Li, Huaicheng [Shanghai Liancheng (Group) Co., Ltd., Shanghai 201812 (China)

2016-12-15

Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t{sub 0}) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t{sub 0}, the radial force is small (approaching zero). At 0.4–1.4t{sub 0}, the radial force increases rapidly. After 1.4t{sub 0}, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research

Forced harmonic oscillations of the Euler-Bernoulli beam with resistance forces

Directory of Open Access Journals (Sweden)

Yuriy S. Krutiy

2015-12-01

Full Text Available The important issue in the oscillation theory is the study of resistance impact on oscillatory processes. Unlike the calculations of free oscillations, that reside in determination of natural frequencies and waveshapes and unlike the calculations of forced oscillations far away from resonance, that are performing without reference to friction, the oscillations researches in vicinity of resonance need accounting of friction forces. Special attention is paid to forced transverse fluctuations in beams as an important technical problem for engineering and building. Aim: The aim of the work is constructing of analytical solution of the problem of forced transverse vibrations of a straight rod with constant cross-section, which is under the influence of the harmonic load taking into account external and internal resistances. Materials and Methods: The internal resistance is taken into account using the corrected hypothesis of Kelvin-Voigt which reflects the empirically proven fact about the frequency-independent internal friction in the material. The external friction is also considered as frequency-independent. Results: An analytical solution is built for the differential equation of forced transverse oscillations of a straight rod with constant cross-section which is under the influence of the harmonic load taking into account external and internal resistances. As a result, analytically derived formulae are presented which describe the forced dynamic oscillations and the dynamic internal forces due to the harmonic load applied to the rod thus reducing the problem with any possible fixed ends to the search of unknown integration constants represented in a form of initial parameters.

Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)

Energy Technology Data Exchange (ETDEWEB)

Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

2014-06-01

Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

Report of the Siting Policy Task Force

International Nuclear Information System (INIS)

1979-08-01

In August 1978, the Nuclear Regulatory Commission directed the staff to develop a general policy statement on nuclear power reactor siting. A Task Force was formed for that purpose and has prepared a statement of current NRC policy and practice and has recommended a number of changes to current policy. Recommendations were made to accomplish the following goals: (1) To strengthen siting as a factor in defense in depth by establishing requirements for site approval that are independent of plant design consideration. The present policy of permitting plant design features to compensate for unfavorable site characteristics has resulted in improved designs but has tended to deemphasize site isolation. (2) To take into consideration in siting the risk associated with accidents beyond the design basis (Class 9) by establishing population density and distribution criteria. Plant design improvements have reduced the probability and consequences of design basis accidents, but there remains the residual risk from accidents not considered in the design basis. Although this risk cannot be completely reduced to zero, it can be significantly reduced by selective siting. (3) To require that sites selected will minimize the risk from energy generation. The selected sites should be among the best available in the region where new generating capacity is needed. Siting requirements should be stringent enough to limit the residual risk of reactor operation but not so stringent as to eliminate the nuclear option from large regions of the country. This is because energy generation from any source has its associated risk, with risks from some energy sources being greater than that of the nuclear option

Design of 90-mgd wastewater reclamation plant

International Nuclear Information System (INIS)

Cain, C.B.; Kluesener, J.W.; Lazarus, E.

1981-01-01

Ninety MGD of municipal secondary effluent is to be reclaimed for use as cooling water in the Palo Verde Nuclear Generating Station in Arizona. The water reclamation plant design criteria are presented for nitrification, lime-soda softening, filtration, and sludge processing. In-pipe storage is used for flow equalization. Forced air down-draft trickling filters with computer-controlled recycle are used for nitrification. Effluent recirculation is used to maintain constant sludge blanket dept in the upflow solids contact clarifier softening units. An influent flow-splitting, gravity-backwash, dual-media filter is used for final suspended solids removal. Rheological data was used in the hydraulic design of sludge piping. Computerized automatic flushing also aids in preventing sludge pumping problems. Reclamation plant design and construction are integrated in one Engineering-Procurement-Construction project conducted by a single company. 5 refs

Heat and mass transfer and hydrodynamics in two-phase flows in nuclear power plants

International Nuclear Information System (INIS)

Styrikovich, M.A.; Polonskii, V.S.; Tsiklauri, G.V.

1986-01-01

This book examines nuclear power plant equipment from the point of view of heat and mass transfer and the behavior of impurities contained in water and in steam, with reference to real water regimes of nuclear power plants. The transfer processes of equipment are considered. Heat and mass transfer are analyzed in the pre-crisis regions of steam-generating passages with non-permeable surfaces, and in capillary-porous structures. Attention is given to forced convection boiling crises and top post-DNB heat transfer. Data on two-phase hydrodynamics in straight and curved channels are correlated and safety aspects of nuclear power plants are discussed

CRISPR-Cas9: tool for qualitative and quantitative plant genome editing

Directory of Open Access Journals (Sweden)

Ali Noman

2016-11-01

Full Text Available Genome editing advancements have made many unachievable ideas practical. Increased adoption of genome editing has been geared by swiftly developing CRISPR-Cas9 technology. This technique is appearing as driving force for innovative utilization in diverse branches of plant biology. CRISPR mediated genome editing is being used for rapid, easy and efficient alteration of indigenous genes among diverse plant species. With approximate completion of conceptual work about CRISPR/Cas9, plant scientists are applying this genome editing tool for crop attributes enhancement. The capability of CRISPR-Cas9 systems for performing targeted and efficient modifications in genome sequence as well as gene expression will certainly spur novel developments not only in model plants but also in crop plants. Additionally, due to non-involvement of foreign DNA, this technique may help alleviating regulatory issues associated with GM Plants. We expect that prevailing challenges in plant science like genomic region manipulation, crop specific vectors etc. will be addressed along with sustained growth of this genome editing tool. In this review, recent progress of CRISPR/Cas9 technology in plants has been summarized and discussed. We review potential of CRISPR/Cas9 for different aspects of plant life. It also covers strengths of this technique in comparison with other genome editing techniques e.g. ZFNs and TALENs and potential challenges in coming decades have been described.

Classical description of dynamical many-body systems with central forces, spin-orbit forces and spin-spin forces

International Nuclear Information System (INIS)

Goepfert, A.

1994-01-01

This thesis develops a new model, and related numerical methods, to describe classical time-dependent many-body systems interacting through central forces, spin-orbit forces and spin-spin forces. The model is based on two-particle interactions. The two-body forces consist of attractive and repulsive parts. In this model the investigated multi-particle systems are self-bound. Also the total potential of the whole ensemble is derived from the two-particle potential and is not imposed 'from outside'. Each particle has the three degrees of freedom of its centre-of-mass motion and the spin degree of freedom. The model allows for the particles to be either charged or uncharged. Furthermore, each particle has an angular momentum, an intrinsic spin, and a magnetic dipole moment. Through the electromagnetic forces between these charges and moments there arise dynamical couplings between them. The internal interactions between the charges and moments are well described by electromagnetic coupling mechanisms. In fact, compared to conventional classical molecular dynamics calculations in van der Waals clusters, which have no spin degrees of freedom, or for Heisenberg spin Systems, which have no orbital degrees of freedom, the model presented here contains both types of degrees of freedom with a highly non-trivial coupling. The model allows to study the fundamental effects resulting from the dynamical coupling of the spin and the orbital-motion sub-systems. In particular, the dynamics of the particle mass points show a behaviour basically different from the one of particles in a potential with only central forces. Furthermore, a special type of quenching procedure was invented, which tends to drive the multi-particle Systems into states with highly periodic, non-ergodic behaviour. Application of the model to cluster simulations has provided evidence that the model can also be used to investigate items like solid-to-liquid phase transitions (melting), isomerism and specific heat

Evaluation of the effectiveness and feasibility of the Waste Isolation Pilot Plant engineered alternatives: Final report of the Engineered Alternatives Task Force

International Nuclear Information System (INIS)

1991-07-01

The Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, is an underground repository designed for the geologic disposal of radioactive wastes resulting from the defense activities and programs of the United States Department of Energy (DOE). The performance of nuclear waste repositories is governed by US Environmental Protection Agency (EPA). The study conducted to demonstrate compliance with this regulation is called performance assessment. The EPA standard requires that DOE provide a reasonable assurance, based on performance assessment, that cumulative releases of radioactivity to the accessible environment will not exceed the standard's criteria. Preliminary performance assessment performed by SNL has indicated that the current design of the WIPP repository, together with the waste forms at the DOE storage and generating sites, may not demonstrate compliance with the EPA Standard. In view of this concern, and prompted by recommendations from external review groups, the DOE established the Engineered Alternatives Task Force (EATF) in September, 1989. The objective of the EATF is to identify potential engineering modifications (referred to as engineered alternatives) to the existing WIPP design and/or to the transuranic (TRU) waste forms, an to evaluate their effectiveness and feasibility in facilitating compliance with the EPA Standard. These alternatives would be designed to completely eliminate or reduce any problems which might cause non-compliance with the EPA Standard. 139 refs., 39 figs., 124 tabs

Mechanisms explaining Coulomb's electric force & Lorentz's magnetic force from a classical perspective

Science.gov (United States)

Correnti, Dan S.

2018-06-01

The underlying mechanisms of the fundamental electric and magnetic forces are not clear in current models; they are mainly mathematical constructs. This study examines the underlying physics from a classical viewpoint to explain Coulomb's electric force and Lorentz's magnetic force. This is accomplished by building upon already established physics. Although no new physics is introduced, extension of existing models is made by close examination. We all know that an electron carries a bound cylindrical B-field (CBF) as it translates. Here, we show how the electron CBF plays an intrinsic role in the generation of the electric and magnetic forces.

Athermalization in atomic force microscope based force spectroscopy using matched microstructure coupling.

Science.gov (United States)

Torun, H; Finkler, O; Degertekin, F L

2009-07-01

The authors describe a method for athermalization in atomic force microscope (AFM) based force spectroscopy applications using microstructures that thermomechanically match the AFM probes. The method uses a setup where the AFM probe is coupled with the matched structure and the displacements of both structures are read out simultaneously. The matched structure displaces with the AFM probe as temperature changes, thus the force applied to the sample can be kept constant without the need for a separate feedback loop for thermal drift compensation, and the differential signal can be used to cancel the shift in zero-force level of the AFM.

Fault tree model of human error based on error-forcing contexts

International Nuclear Information System (INIS)

Kang, Hyun Gook; Jang, Seung Cheol; Ha, Jae Joo

2004-01-01

In the safety-critical systems such as nuclear power plants, the safety-feature actuation is fully automated. In emergency case, the human operator could also play the role of a backup for automated systems. That is, the failure of safety-feature-actuation signal generation implies the concurrent failure of automated systems and that of manual actuation. The human operator's manual actuation failure is largely affected by error-forcing contexts (EFC). The failures of sensors and automated systems are most important ones. The sensors, the automated actuation system and the human operators are correlated in a complex manner and hard to develop a proper model. In this paper, we will explain the condition-based human reliability assessment (CBHRA) method in order to treat these complicated conditions in a practical way. In this study, we apply the CBHRA method to the manual actuation of safety features such as reactor trip and safety injection in Korean Standard Nuclear Power Plants

Uranium mining and milling work force characteristics in the western US

International Nuclear Information System (INIS)

Rapp, D.A.

1980-12-01

This report presents the results of a survey of the socioeconomic characteristics associated with 11 uranium mine and mill operations in 5 Western States. Comparisons are made with the socioeconomic characteristics of construction and operating crews for coal mines and utility plants in eight Western States. Worker productivity also is compared with that in similar types of coal and uranium mining operations. We found that there existed no significant differences between the socioeconomic characteristics of construction and operating crews and the secondary employment impacts associated with uranium mines and mills when compared with those associated with coal mines and utility plants requiring similar skills at comparable locations. In addition, our survey includes a comparison of several characteristics associated with the households of basic and nonbasic work forces and concludes that significant changes have occurred in the last 5 yr. Accordingly, we recommend additional monitoring and updating of data used in several economic forecasting models to avoid unwarranted delays in achieving national energy goals

Regulation on governmental quality control during erection and reconstruction of nuclear power plants in the GDR dated 20 July 1988

International Nuclear Information System (INIS)

1988-01-01

The Regulation enters into force on 1 October 1988 and provides for governmental quality control of products, plants and services intended for the erection and reconstruction of nuclear power plant systems. It covers the following provisions: quality control; licensing of enterprises; approval of the use of products manufactured in the GDR; acceptance of products manufactured in the GDR; clearance of plants and services; clearance of imported products; labelling; consulting of experts; penalties, and interim provisions

Grip Force and 3D Push-Pull Force Estimation Based on sEMG and GRNN

Directory of Open Access Journals (Sweden)

Changcheng Wu

2017-06-01

Full Text Available The estimation of the grip force and the 3D push-pull force (push and pull force in the three dimension space from the electromyogram (EMG signal is of great importance in the dexterous control of the EMG prosthetic hand. In this paper, an action force estimation method which is based on the eight channels of the surface EMG (sEMG and the Generalized Regression Neural Network (GRNN is proposed to meet the requirements of the force control of the intelligent EMG prosthetic hand. Firstly, the experimental platform, the acquisition of the sEMG, the feature extraction of the sEMG and the construction of GRNN are described. Then, the multi-channels of the sEMG when the hand is moving are captured by the EMG sensors attached on eight different positions of the arm skin surface. Meanwhile, a grip force sensor and a three dimension force sensor are adopted to measure the output force of the human's hand. The characteristic matrix of the sEMG and the force signals are used to construct the GRNN. The mean absolute value and the root mean square of the estimation errors, the correlation coefficients between the actual force and the estimated force are employed to assess the accuracy of the estimation. Analysis of variance (ANOVA is also employed to test the difference of the force estimation. The experiments are implemented to verify the effectiveness of the proposed estimation method and the results show that the output force of the human's hand can be correctly estimated by using sEMG and GRNN method.

Overview--Development of a geodatabase and conceptual model of the hydrogeologic units beneath Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas

Science.gov (United States)

Shah, Sachin D.

2004-01-01

Air Force Plant 4 (AFP4) and adjacent Naval Air Station-Joint Reserve Base Carswell Field (NAS–JRB) at Fort Worth, Tex., constitute a contractor-owned, government-operated facility that has been in operation since 1942. Contaminants from the 3,600-acre facility, primarily volatile organic compounds (VOCs) and metals, have entered the ground-water-flow system through leakage from waste-disposal sites and from manufacturing processes. Environmental data collected at AFP4 and NAS–JRB during 1993–2002 created the need for consolidation of the data into a comprehensive temporal and spatial geodatabase. The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force Aeronautical Systems Center Environmental Management Directorate, developed a comprehensive geodatabase of temporal and spatial environmental data associated with the hydrogeologic units beneath the facility. A three-dimensional conceptual model of the hydrogeologic units integrally linked to the geodatabase was designed concurrently. Three hydrogeologic units—from land surface downward, the alluvial aquifer, the GoodlandWalnut confining unit, and the Paluxy aquifer—compose the subsurface of interest at AFP4 and NAS–JRB. The alluvial aquifer consists primarily of clay and silt with sand and gravel channel deposits that might be interconnected or interfingered. The Goodland-Walnut confining unit directly underlies the alluvial aquifer and consists of limestone, marl, shale, and clay. The Paluxy aquifer is composed of dense mudstone and fine- to coarse-grained sandstone

Mechanical design and force calibration of dual-axis micromechanical probe for friction force microscopy

International Nuclear Information System (INIS)

Fukuzawa, Kenji; Terada, Satoshi; Shikida, Mitsuhiro; Amakawa, Hiroaki; Zhang, Hedong; Mitsuya, Yasunaga

2007-01-01

A dual-axis micromechanical probe that combines a double cantilever and torsion beams is presented. This probe can reduce the mechanical cross-talk between the lateral and vertical force detections. In addition, dual-axis forces can be detected by measuring the dual-axis displacement of the probe end using the optical lever-based method used in conventional friction force microscopes (FFMs). In this paper, the mechanical design of the probe, the details of the fabrication method, FFM performance, and calibration of the friction force are discussed. The mechanical design and the microfabrication method for probes that can provide a force resolution of the order of 1 nN without mechanical cross-talk are presented. Calibration of the lateral force signal is possible by using the relationship between the lateral force and the piezodisplacement at the onset of the probe scanning. The micromechanical probe enables simultaneous and independent detection of atomic and friction forces. This leads to accurate investigation of nanotribological phenomena and visualization of the distribution of the friction properties, which helps the identification of the material properties

Force Structure. DOD Needs to Integrate Data into Its Force Identification Process and Examine Options to Meet Requirements for High-Demand Support Forces

National Research Council Canada - National Science Library

2006-01-01

...) will continue to meet its requirements using an all-volunteer force. The Army, in particular, has faced continuing demand for large numbers of forces, especially for forces with support skills...

Options for shortening nuclear power plant refueling outages

International Nuclear Information System (INIS)

Kastl, H.

2001-01-01

Deregulation of the European electricity market on 01.01.1999 forced a large number of electric utilities- especially nuclear power plant operators - to find ways of drastically cutting down their costs in order to be able to compete successfully within the new market environment. Nuclear power plants currently in operation mainly have three potential ways of reducing their power generating costs: by increasing plant availability, reducing fuel costs and cutting down operating costs. The optimization of plant refueling outages offers considerable potential for enhancing plant availability, but also helps bring down operating costs by reducing expenditure on maintenance. In order to optimize an outage in terms of its duration and costs, a variety of approaches are possible - all of which, however, involve certain key factors such as good organization, planning, logistics and control, improvement of equipment and tools, as well as motivation of personnel. Another aspect is the introduction of innovative technologies. In the last few years, such technologies have frequently enabled maintenance effort to be reduced, thus saving considerable time, and have also resulted in a need for fewer personnel to carry out the work, thus reducing radiation exposure. In many instances they have also improved the quality of work and outage performance as a whole. The paper uses recent examples to show how innovative technologies can contribute to-wards reducing nuclear plant maintenance costs and shorten the duration of refueling out-ages. (author)

Measuring Forces between Oxide Surfaces Using the Atomic Force Microscope

DEFF Research Database (Denmark)

Pedersen, Henrik Guldberg; Høj, Jakob Weiland

1996-01-01

The interactions between colloidal particles play a major role in processing of ceramics, especially in casting processes. With the Atomic Force Microscope (AFM) it is possible to measure the inter-action force between a small oxide particle (a few micron) and a surface as function of surface...

Force Dynamics of Verb Complementation

Directory of Open Access Journals (Sweden)

Jacek Woźny

2015-12-01

Full Text Available Force Dynamics of Verb Complementation The concepts of motion and force are both extensively discussed in cognitive linguistics literature. But they are discussed separately. The first usually in the context of ‘motion situations’ (Talmy, Slobin, Zlatev, the other as part of the Force Dynamics framework, which was developed by Talmy. The aim of this paper is twofold: first, to argue that the concepts of force and motion should not be isolated but considered as two inseparable parts of force-motion events. The second goal is to prove that the modified Force Dynamics (force-motion framework can be used for precise characterization of the verb complementation patterns. To this end, a random sample of 50 sentences containing the verb ‘went’ is analyzed, demonstrating the differences between the categories of intensive and intransitive complementation with respect to the linguistically coded parameters of force and motion.

Feasibility of novel four degrees of freedom capacitive force sensor for skin interface force

Directory of Open Access Journals (Sweden)

Murakami Chisato

2012-11-01

Full Text Available Abstract Background The objective of our study was to develop a novel capacitive force sensor that enables simultaneous measurements of yaw torque around the pressure axis and normal force and shear forces at a single point for the purpose of elucidating pressure ulcer pathogenesis and establishing criteria for selection of cushions and mattresses. Methods Two newly developed sensors (approximately 10 mm×10 mm×5 mm (10 and 20 mm×20 mm×5 mm (20 were constructed from silicone gel and four upper and lower electrodes. The upper and lower electrodes had sixteen combinations that had the function as capacitors of parallel plate type. The full scale (FS ranges of force/torque were defined as 0–1.5 N, –0.5-0.5 N and −1.5-1.5 N mm (10 and 0–8.7 N, –2.9-2.9 N and −16.8-16.8 N mm (20 in normal force, shear forces and yaw torque, respectively. The capacitances of sixteen capacitors were measured by an LCR meter (AC1V, 100 kHz when displacements corresponding to four degrees of freedom (DOF forces within FS ranges were applied to the sensor. The measurement was repeated three times in each displacement condition (10 only. Force/torque were calculated by corrected capacitance and were evaluated by comparison to theoretical values and standard normal force measured by an universal tester. Results In measurements of capacitance, the coefficient of variation was 3.23% (10. The Maximum FS errors of estimated force/torque were less than or equal to 10.1 (10 and 16.4% (20, respectively. The standard normal forces were approximately 1.5 (10 and 9.4 N (20 when pressure displacements were 3 (10 and 2 mm (20, respectively. The estimated normal forces were approximately 1.5 (10 and 8.6 N (10 in the same condition. Conclusions In this study, we developed a new four DOF force sensor for measurement of force/torque that occur between the skin and a mattress. In measurement of capacitance, the repeatability was good and it was confirmed that the sensor had

Forced magnetic reconnection

Science.gov (United States)

Vekstein, G.

2017-10-01

This is a tutorial-style selective review explaining basic concepts of forced magnetic reconnection. It is based on a celebrated model of forced reconnection suggested by J. B. Taylor. The standard magnetohydrodynamic (MHD) theory of this process has been pioneered by Hahm & Kulsrud (Phys. Fluids, vol. 28, 1985, p. 2412). Here we also discuss several more recent developments related to this problem. These include energetics of forced reconnection, its Hall-mediated regime, and nonlinear effects with the associated onset of the secondary tearing (plasmoid) instability.

An Optimization-Based Impedance Approach for Robot Force Regulation with Prescribed Force Limits

Directory of Open Access Journals (Sweden)

R. de J. Portillo-Vélez

2015-01-01

Full Text Available An optimization based approach for the regulation of excessive or insufficient forces at the end-effector level is introduced. The objective is to minimize the interaction force error at the robot end effector, while constraining undesired interaction forces. To that end, a dynamic optimization problem (DOP is formulated considering a dynamic robot impedance model. Penalty functions are considered in the DOP to handle the constraints on the interaction force. The optimization problem is online solved through the gradient flow approach. Convergence properties are presented and the stability is drawn when the force limits are considered in the analysis. The effectiveness of our proposal is validated via experimental results for a robotic grasping task.

Ponderomotive Forces in Cosmos

Science.gov (United States)

Lundin, R.; Guglielmi, A.

2006-12-01

This review is devoted to ponderomotive forces and their importance for the acceleration of charged particles by electromagnetic waves in space plasmas. Ponderomotive forces constitute time-averaged nonlinear forces acting on a media in the presence of oscillating electromagnetic fields. Ponderomotive forces represent a useful analytical tool to describe plasma acceleration. Oscillating electromagnetic fields are also related with dissipative processes, such as heating of particles. Dissipative processes are, however, left outside these discussions. The focus will be entirely on the (conservative) ponderomotive forces acting in space plasmas. The review consists of seven sections. In Section 1, we explain the rational for using the auxiliary ponderomotive forces instead of the fundamental Lorentz force for the study of particle motions in oscillating fields. In Section 2, we present the Abraham, Miller, Lundin-Hultqvist and Barlow ponderomotive forces, and the Bolotovsky-Serov ponderomotive drift. The hydrodynamic, quasi-hydrodynamic, and ‘`test-particle’' approaches are used for the study of ponderomotive wave-particle interaction. The problems of self-consistency and regularization are discussed in Section 3. The model of static balance of forces (Section 4) exemplifies the interplay between thermal, gravitational and ponderomotive forces, but it also introduces a set of useful definitions, dimensionless parameters, etc. We analyze the Alfvén and ion cyclotron waves in static limit with emphasis on the specific distinction between traveling and standing waves. Particular attention has been given to the impact of traveling Alfvén waves on the steady state anabatic wind that blows over the polar regions (Section~5). We demonstrate the existence of a wave-induced cold anabatic wind. We also show that, at a critical point, the ponderomotive acceleration of the wind is a factor of 3 greater than the thermal acceleration. Section 6 demonstrates various

Installation Restoration Program. Phase 1. Records Search, Air Force Plant Number 83, Albuquerque, New Mexico

Science.gov (United States)

1983-12-01

site. The sawples should be collected south of the "green tank" and " swiming pool" tanks along the facility fence line. Samples of soil and asphalt...METALS, Metallic elements, including the transition series, which include many lements required for plant and animal nutrition in trace

Air Force Senior Leaders

Science.gov (United States)

Force TV Radio Week in Photos About Us Air Force Senior Leaders SECAF CSAF CMSAF Biographies Adjunct Professors Senior Mentor Biographies Fact Sheets Commander's Call Topics CCT Archive CSAF Reading List 2017 Media Sites Site Registration Contact Us Search AF.mil: Home > About Us > Air Force Senior Leaders

Quantitative 3D-KPFM imaging with simultaneous electrostatic force and force gradient detection

International Nuclear Information System (INIS)

Collins, L; Rodriguez, B J; Okatan, M B; Li, Q; Kravenchenko, I I; Lavrik, N V; Kalinin, S V; Jesse, S

2015-01-01

Kelvin probe force microscopy (KPFM) is a powerful characterization technique for imaging local electrochemical and electrostatic potential distributions and has been applied across a broad range of materials and devices. Proper interpretation of the local KPFM data can be complicated, however, by convolution of the true surface potential under the tip with additional contributions due to long range capacitive coupling between the probe (e.g. cantilever, cone, tip apex) and the sample under test. In this work, band excitation (BE)-KPFM is used to negate such effects. In contrast to traditional single frequency KPFM, multifrequency BE-KPFM is shown to afford dual sensitivity to both the electrostatic force and the force gradient detection, analogous to simultaneous amplitude modulated and frequency modulated KPFM imaging. BE-KPFM is demonstrated on a Pt/Au/SiO x test structure and electrostatic force gradient detection is found to lead to an improved lateral resolution compared to electrostatic force detection. Finally, a 3D-KPFM imaging technique is developed. Force volume (FV) BE-KPFM allows the tip–sample distance dependence of the electrostatic interactions (force and force gradient) to be recorded at each point across the sample surface. As such, FVBE-KPFM provides a much needed pathway towards complete tip–sample capacitive de-convolution in KPFM measurements and will enable quantitative surface potential measurements with nanoscale resolution. (paper)

Experience of research, design, capacity, and operation with forced flow steam generators

International Nuclear Information System (INIS)

Bertolotti, G.; McDonald, B.N.; Pocock, F.J.

1975-01-01

The forced flow steam generators in operation in six American nuclear power plants show an excellent operational behaviour. The concept for this type of steam generator has been developed in the USA, and it has been successfully tested over several years regarding its suitability for PWRs of a larger size. The results concerning construction, materials and water chemistry for this steam generator, which will be used for the first time in the FRG in the nuclear power station Muelheim-Kaerlich, have confirmed the high reliability of this high-efficiency component. (orig./LN) [de

Force transmission in epithelial tissues.

Science.gov (United States)

Vasquez, Claudia G; Martin, Adam C

2016-03-01

In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells' decisions to divide, die, or differentiate. Forces are transmitted across epithelia because cells are mechanically linked through junctional complexes, and forces can propagate through the cell cytoplasm. Here, we review some of the molecular mechanisms responsible for force generation, with a specific focus on the actomyosin cortex and adherens junctions. We then discuss evidence for how these mechanisms promote cell shape changes and force transmission in tissues. © 2016 Wiley Periodicals, Inc.

Could plants help tame the greenhouse?

International Nuclear Information System (INIS)

Baskin, Y.

1993-01-01

It's easy to see how climate change might affect the globe's vegetation, driving hardwood forests into regions now covered with evergreens and causing deserts to shift. It's less easy to picture the other side of the coin: biology's impact on the atmosphere. So mathematician Berrien Moore III of the University of New Hampshire, who heads the International Geosphere-Biosphere Program task force on global analysis, interpretation, and modeling, staged a simple demonstration. He modeled the effects of a biosphere fertilized by increased CO 2 - and found that it could first help, then hinder, human efforts to slow the buildup of greenhouse gases. To simulate such a biotic carbon sink, Moore combined a simple model of CO 2 uptake by the ocean with an equally simple model of its uptake by photosynthesis on land and its release by deforestation and plant decay. He then forced this simple ocean-atmosphere-vegetation model with fossil fuel CO 2 emissions from 1860 to the present. As expected, his model ended up with too much carbon in the atmosphere. So he turned up photosynthesis, fertilizing plant growth in his model, until the rate of CO 2 buildup just matched the observed increase. Moore then explored how this terrestrial carbon sink would respond if the CO 2 buildup slowed. The result: If you were to cap the rate of CO 2 emissions from fossil fuel burning, [this terrestrial] sink would reduce the atmospheric lifetime of CO 2 by a factor of four or five. This cleansing effect would operate on timescales of years or decades, compared with centuries for the ocean, says Moore - fast enough to aid human efforts to slow the CO 2 buildup. However, it doesn't do it forever. If at some point emissions cuts and the terrestrial sink succeeded in reducing atmospheric CO 2 , plant growth would drop and CO 2 levels would bounce back up as all the extra biomass rotted away

Forces in General Relativity

Science.gov (United States)

Ridgely, Charles T.

2010-01-01

Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

Models test on dynamic structure-structure interaction of nuclear power plant buildings

International Nuclear Information System (INIS)

Kitada, Y.; Hirotani, T.

1999-01-01

A reactor building of an NPP (nuclear power plant) is generally constructed closely adjacent to a turbine building and other buildings such as the auxiliary building, and in increasing numbers of NPPs, multiple plants are being planned and constructed closely on a single site. In these situations, adjacent buildings are considered to influence each other through the soil during earthquakes and to exhibit dynamic behaviour different from that of separate buildings, because those buildings in NPP are generally heavy and massive. The dynamic interaction between buildings during earthquake through the soil is termed here as 'dynamic cross interaction (DCI)'. In order to comprehend DCI appropriately, forced vibration tests and earthquake observation are needed using closely constructed building models. Standing on this background, Nuclear Power Engineering Corporation (NUPEC) had planned the project to investigate the DCI effect in 1993 after the preceding SSI (soil-structure interaction) investigation project, 'model tests on embedment effect of reactor building'. The project consists of field and laboratory tests. The field test is being carried out using three different building construction conditions, e.g. a single reactor building to be used for the comparison purposes as for a reference, two same reactor buildings used to evaluate pure DCI effects, and two different buildings, reactor and turbine building models to evaluate DCI effects under the actual plant conditions. Forced vibration tests and earthquake observations are planned in the field test. The laboratory test is planned to evaluate basic characteristics of the DCI effects using simple soil model made of silicon rubber and structure models made of aluminum. In this test, forced vibration tests and shaking table tests are planned. The project was started in April 1994 and will be completed in March 2002. This paper describes an outline and the summary of the current status of this project. (orig.)

Force 2025 and Beyond Strategic Force Design Analytic Model

Science.gov (United States)

2017-01-12

focused thinking , functional hierarchy, task capability matching 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT U 18. NUMBER OF...describe and evaluate current organizational designs in terms of Force Employment and Force Design using the model to offer recommendations and analysis...developed to illuminate the current organizational design structure to better understand how the network of BCTs and enablers function in today’s steady

Analysis of the tractive force pattern on a knot by force measurement during laparoscopic knot tying.

Science.gov (United States)

Takayasu, Kenta; Yoshida, Kenji; Kinoshita, Hidefumi; Yoshimoto, Syunsuke; Oshiro, Osamu; Matsuda, Tadashi

2017-07-19

Quantifying surgical skills assists novice surgeons when learning operative techniques. We measured the interaction force at a ligation point and clarified the features of the force pattern among surgeons with different skill levels during laparoscopic knot tying. Forty-four surgeons were divided into three groups based on experience: 13 novice (0-5 years), 16 intermediate (6-15 years), and 15 expert (16-30 years). To assess the tractive force direction and volume during knot tying, we used a sensor that measures six force-torque values (x-axis: Fx, y-axis: Fy, z-axis: Fz, and xy-axis: Fxy) attached to a slit Penrose drain. All participants completed one double knot and five single knot sequences. We recorded completion time, force volume (FV), maximum force (MF), time over 1.5 N, duration of non-zero force, and percentage time when vertical force exceeded horizontal force (PTz). There was a significant difference between groups for completion time (p = 0.007); FV (total: p = 0.002; Fx: p = 0.004, Fy: p = 0.007, Fxy: p = 0.004, Fz: p force (p = 0.029); and PTz (p force pattern at the ligation point during suturing by surgeons with three levels of experience using a force measurement system. We revealed that both force volume and force direction differed depending on surgeons' skill level during knot tying. Copyright © 2017. Published by Elsevier Inc.

Intermolecular and surface forces

CERN Document Server

Israelachvili, Jacob N

2011-01-01

This reference describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This third edition is expanded into three sections and contains five new chapters over the previous edition.· starts fr

Penium margaritaceum as a model organism for cell wall analysis of expanding plant cells

DEFF Research Database (Denmark)

Rydahl, Maja Gro; Fangel, Jonatan Ulrik; Mikkelsen, Maria Dalgaard

2015-01-01

organization of the polymeric networks of the cell wall around the protoplast also contributes to the direction of growth, the shape of the cell, and the proper positioning of the cell in a tissue. In essence, plant cell expansion represents the foundation of development. Most studies of plant cell expansion...... have focused primarily upon late divergent multicellular land plants and specialized cell types (e.g., pollen tubes, root hairs). Here, we describe a unicellular green alga, Penium margaritaceum (Penium), which can serve as a valuable model organism for understanding cell expansion and the underlying......The growth of a plant cell encompasses a complex set of subcellular components interacting in a highly coordinated fashion. Ultimately, these activities create specific cell wall structural domains that regulate the prime force of expansion, internally generated turgor pressure. The precise...

Plant neighbour identity matters to belowground interactions under controlled conditions.

Science.gov (United States)

Armas, Cristina; Pugnaire, Francisco Ignacio

2011-01-01

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

Projective absoluteness for Sacks forcing

NARCIS (Netherlands)

Ikegami, D.

2009-01-01

We show that Sigma(1)(3)-absoluteness for Sacks forcing is equivalent to the nonexistence of a Delta(1)(2) Bernstein set. We also show that Sacks forcing is the weakest forcing notion among all of the preorders that add a new real with respect to Sigma(1)(3) forcing absoluteness.

OOTW Force Design Tools

Energy Technology Data Exchange (ETDEWEB)

Bell, R.E.; Hartley, D.S.III; Packard, S.L.

1999-05-01

This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

Thermodynamic assessment of amine based CO2 capture technologies in power plants based on European Benchmarking Task Force methodology

NARCIS (Netherlands)

Sanchez Fernandez, E.; Goetheer, E.L.V.; Manzolini, G.; Macchi, E.; Rezvani, S.; Vlugt, T.J.H.

2014-01-01

Post combustion CO2 capture (PCC) with amine solvents is seen as one of the possible technologies which can be implemented in the near term to significantly reduce CO2 emissions from fossil fuel power plants. One of the major concerns for its implementation at large scale in power plants is the high

A proposal of nuclear fusion power plant equipped with SMES

International Nuclear Information System (INIS)

Natsukawa, Tatsuya; Makamura, Hirokazu; Molinas, Marta; Nomura, Shinichi; Tsuji-Iio, Shunji; Shimada, Ryuichi

2000-01-01

When we intend to operate the nuclear fusion power plant (NFPP) under the economically efficient conditions as an independent power plant, it is desirable that the generated electric power should be sent to network according to the power demand. With such strategy being expanded, some energy storage system is available. In this paper, NFPP equipped with the superconducting magnetic energy storage system (SMES) as electric power storage device is proposed. The advantages of NFPP equipped with SMES are discussed and a case study of 500 MW NFPP equipped with 6 GWh SMES is done with estimating its operational value. For SMES coil, the concept of Force Balanced Coil (FBC) is applied and 6 GWh class FBC is briefly designed

Structure design of water discharge surge tank of nuclear power plant

International Nuclear Information System (INIS)

Wang Fang; Hou Shuqiang

2015-01-01

Drainage is an important function of water discharge surge tank in nuclear power plant. There is little wall and beam inside the water discharge surge tank due to the requirement of major work, which is different from the general structure. Taking water discharge surge tank of nuclear power plant for example, concerned problems are expatiated in the structure scheme of water discharge surge tank, and important structural components are analyzed. Structural analysis model is established by ANSYS finite element analysis. A comprehensive and numerical analysis is performed for different combinations of structural model, and the internal force of structure is extracted. Finally, suggestions for design of similar structure are proposed. (authors)

Adhesion force imaging in air and liquid by adhesion mode atomic force microscopy

NARCIS (Netherlands)

van der Werf, Kees; Putman, C.A.J.; Putman, Constant A.; de Grooth, B.G.; Greve, Jan

1994-01-01

A new imaging mode for the atomic force microscope(AFM), yielding images mapping the adhesion force between tip and sample, is introduced. The adhesion mode AFM takes a force curve at each pixel by ramping a piezoactuator, moving the silicon‐nitride tip up and down towards the sample. During the

Beyond-proximity-force-approximation Casimir force between two spheres at finite temperature

Science.gov (United States)

Bimonte, Giuseppe

2018-04-01

A recent experiment [J. L. Garrett, D. A. T. Somers, and J. N. Munday, Phys. Rev. Lett. 120, 040401 (2018), 10.1103/PhysRevLett.120.040401] measured for the first time the gradient of the Casimir force between two gold spheres at room temperature. The theoretical analysis of the data was carried out using the standard proximity force approximation (PFA). A fit of the data, using a parametrization of the force valid for the sphere-plate geometry, was used by the authors to place a bound on deviations from PFA. Motivated by this work, we compute the Casimir force between two gold spheres at finite temperature. The semianalytic formula for the Casimir force that we construct is valid for all separations, and can be easily used to interpret future experiments in both the sphere-plate and sphere-sphere configurations. We describe the correct parametrization of the corrections to PFA for two spheres that should be used in data analysis.

Penium margaritaceum as a model organism for cell wall analysis of expanding plant cells.

Science.gov (United States)

Rydahl, Maja G; Fangel, Jonatan U; Mikkelsen, Maria Dalgaard; Johansen, I Elisabeth; Andreas, Amanda; Harholt, Jesper; Ulvskov, Peter; Jørgensen, Bodil; Domozych, David S; Willats, William G T

2015-01-01

The growth of a plant cell encompasses a complex set of subcellular components interacting in a highly coordinated fashion. Ultimately, these activities create specific cell wall structural domains that regulate the prime force of expansion, internally generated turgor pressure. The precise organization of the polymeric networks of the cell wall around the protoplast also contributes to the direction of growth, the shape of the cell, and the proper positioning of the cell in a tissue. In essence, plant cell expansion represents the foundation of development. Most studies of plant cell expansion have focused primarily upon late divergent multicellular land plants and specialized cell types (e.g., pollen tubes, root hairs). Here, we describe a unicellular green alga, Penium margaritaceum (Penium), which can serve as a valuable model organism for understanding cell expansion and the underlying mechanics of the cell wall in a single plant cell.

Effect of fatigue on force production and force application technique during repeated sprints.

Science.gov (United States)

Morin, Jean-Benoit; Samozino, Pierre; Edouard, Pascal; Tomazin, Katja

2011-10-13

We investigated the changes in the technical ability of force application/orientation against the ground vs. the physical capability of total force production after a multiple-set repeated sprints series. Twelve male physical education students familiar with sprint running performed four sets of five 6-s sprints (24s of passive rest between sprints, 3min between sets). Sprints were performed from a standing start on an instrumented treadmill, allowing the computation of vertical (F(V)), net horizontal (F(H)) and total (F(Tot)) ground reaction forces for each step. Furthermore, the ratio of forces was calculated as RF=F(H)F(Tot)(-1), and the index of force application technique (D(RF)) representing the decrement in RF with increase in speed was computed as the slope of the linear RF-speed relationship. Changes between pre- (first two sprints) and post-fatigue (last two sprints) were tested using paired t-tests. Performance decreased significantly (e.g. top speed decreased by 15.7±5.4%; Pmultiple-set repeated sprint series, both the total force production capability and the technical ability to apply force effectively against the ground are altered, the latter to a larger extent than the former. Copyright © 2011 Elsevier Ltd. All rights reserved.

Annual training manual for security training: Protective force

Energy Technology Data Exchange (ETDEWEB)

1990-10-01

Westinghouse is committed to high quality training relevant to the need of the Protective Forces at the Waste Isolation Pilot Plant (WIPP). The training programs at WIPP are designed to qualify Security personnel to perform WIPP security missions in a professional and responsible manner. The program consists of basic as well as sustainment training, as further described in this plan. This plan documents the WIPP Security training program for security personnel for calendar year 1990. The programs detailed in this plan are designed to adequately train persons to ensure the uninterrupted continuity of Department of Energy (DOE)/Westinghouse operations. The Security Training Program consists of four basic elements. These elements are (1) basic level training; (2) on-the-job training; (3) refresher training; and (4) in-service training.

Burst protected nuclear reactor plant with PWR

International Nuclear Information System (INIS)

Harand, E.; Michel, E.

1978-01-01

In the PWR, several integrated components from the steam raising unit and the main coolant pump are grouped around the reactor pressure vessel in a multiloop circuit and in a vertical arrangement. For safety reasons all primary circuit components and pipelines are situated in burst protection covers. To reduce the area of the plant straight tube steam raising units with forced circulation are used as steam raising units. The boiler pumps are connected to the vertical tubes and to the pressure vessel via double pipelines made as twin chamber pipes. (DG) [de

Main pumps lost incident in the nuclear power plant Atucha I. Modelling with RELAP5/MOD3.2

International Nuclear Information System (INIS)

Ventura, M.A.; Rosso, R.D.

1998-01-01

Time evolution of natural circulation in the nuclear power plant Atucha I (CNA-I), in a main pumps lost incident because of the lost of external power feed, is analyzed. It leads to a strong stop transient, without an important blow down, from a forced nominal flow to a natural circulation one. The results are obtained from RELAP5/MOD3.2 code's modeling. The study is based on the refrigeration conditions analysis, during the first minutes of the reactor out of service. Previously to the transient, work had been done to obtain the plant steady state, with design parameters in operation conditions at 100 % of power. The object is that the actual plant state would be represented. In this way, each plant part (steam generators, reactor, pressurizer, pumps) had been modeled in separated form with the appropriate boundary conditions, to be used in the whole circuit simulation. The developed model, had been validated making use of the comparison between the values obtained to the principal thermodynamic parameters with the plant recorded values, in the same incident. The results are satisfactory in a way. On the other hand, it has suggested some modeling changes. The RELAP5/MOD3.2 capability to model the thermodynamic phenomena in a PHWR plant has been verified when, according to the mentioned incident, the flow pass from a nominal forced flow, to one which is governed by natural circulation, still with the CNA-I untypical design conditions. (author) [es

Papaver Rhoeas L. Hydroalcoholic Extract Exacerbates Forced Swimming Test-Induced Depression in Mice

OpenAIRE

Naser Osanloo; Akram Najafi-Abedi; Fatemeh Jafari; Farshid Javid; Mohsen Pirpiran; Mohammad-Reza Memar-Jafari; Seyed Ali Mousavi-Khosravi; Mohammad Rahimzadeh-Behzadi; Mina Ranjbaran; Hedayat Sahraei

2016-01-01

Introduction: Depression is one of the most frequent psychiatric disorders in the world with occurs with higher incidence in women. In the present study, the effect of water-alcoholic extract of Papaver rhoeas L. on forced swimming test (FST) in Swiss-Webster mice were examined. Methods: We used Swiss-Webster mice (20-25 g) to execute FST on them. The plant extract (1, 10, 30, and 100 mg/kg) was injected to the animals 30 minutes before each session. Fluoxetine (20 mg/k...

Method of Calibrating a Force Balance

Science.gov (United States)

Parker, Peter A. (Inventor); Rhew, Ray D. (Inventor); Johnson, Thomas H. (Inventor); Landman, Drew (Inventor)

2015-01-01

A calibration system and method utilizes acceleration of a mass to generate a force on the mass. An expected value of the force is calculated based on the magnitude and acceleration of the mass. A fixture is utilized to mount the mass to a force balance, and the force balance is calibrated to provide a reading consistent with the expected force determined for a given acceleration. The acceleration can be varied to provide different expected forces, and the force balance can be calibrated for different applied forces. The acceleration may result from linear acceleration of the mass or rotational movement of the mass.

Scratch direction and threshold force in nanoscale scratching using atomic force microscopes

Energy Technology Data Exchange (ETDEWEB)

Tseng, Ampere A., E-mail: ampere.tseng@asu.edu [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Kuo, Chung-Feng Jeffrey; Jou, Shyankay [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Nishimura, Shinya; Shirakashi, Jun-ichi [Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588 (Japan)

2011-09-01

The nanoscaled tip in an AFM (atomic force microscope) has become an effective scratching tool for material removing in nanofabrication. In this article, the characteristics of using a diamond-coated pyramidal tip to scratch Ni-Fe thin film surfaces was experimentally investigated with the focus on the evaluation of the influence of the scratch or scan direction on the final shape of the scratched geometry as well as the applied scratch force. Results indicated that both the scratched profile and the scratch force were greatly affected by the scratch direction. It has been found that, to minimize the formation of protuberances along the groove sides and to have a better control of the scratched geometry, the tip face should be perpendicular to the scratching direction, which is also known as orthogonal cutting condition. To demonstrate the present findings, three groove patterns have been scratched with the tip face perpendicular to the scratching direction and very little amount of protuberances was observed. The threshold scratch force was also predicted based on the Hertz contact theory. Without considering the surface friction and adhesive forces between the tip and substrate, the threshold force predicted was twice smaller than the measurement value. Finally, recommendations for technical improvement and research focuses are provided.

Scratch direction and threshold force in nanoscale scratching using atomic force microscopes

International Nuclear Information System (INIS)

Tseng, Ampere A.; Kuo, Chung-Feng Jeffrey; Jou, Shyankay; Nishimura, Shinya; Shirakashi, Jun-ichi

2011-01-01

The nanoscaled tip in an AFM (atomic force microscope) has become an effective scratching tool for material removing in nanofabrication. In this article, the characteristics of using a diamond-coated pyramidal tip to scratch Ni-Fe thin film surfaces was experimentally investigated with the focus on the evaluation of the influence of the scratch or scan direction on the final shape of the scratched geometry as well as the applied scratch force. Results indicated that both the scratched profile and the scratch force were greatly affected by the scratch direction. It has been found that, to minimize the formation of protuberances along the groove sides and to have a better control of the scratched geometry, the tip face should be perpendicular to the scratching direction, which is also known as orthogonal cutting condition. To demonstrate the present findings, three groove patterns have been scratched with the tip face perpendicular to the scratching direction and very little amount of protuberances was observed. The threshold scratch force was also predicted based on the Hertz contact theory. Without considering the surface friction and adhesive forces between the tip and substrate, the threshold force predicted was twice smaller than the measurement value. Finally, recommendations for technical improvement and research focuses are provided.

Acoustic valve leak detection in nuclear plants

International Nuclear Information System (INIS)

Dimmick, J.G.; Dickey, J.W.

1983-01-01

Internal valve leakage is a hidden energy loss and can cause or prolong a forced outage. Recent advances in acoustic detection of internal valve leakage have reduced piping system maintenance costs, unnecessary downtime, and energy waste. Extremely short payback periods have been reported by plants applying this technology to preventive maintenance, troubleshooting, energy conservation and outage planning. Sensors temporarily attached to the outside of valves and connected to the instruments detect ultrasonic acoustic emissions which are characteristic of internal valve leakage. Since the sensors are attached to the outside of the valves, the time and expense of dismantling the valves or removing them from the systems are eliminated. This paper describes the instrumentation and specific applications to nuclear plant valves, including independent verification of initial findings. Guidelines for potential users, including instrumentation selection, training requirements, application planning, and the choice of in-house versus contract services are discussed

Plant host finding by parasitic plants: a new perspective on plant to plant communication.

Science.gov (United States)

Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

2006-11-01

Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much debated. To date, nearly all studies of volatile-mediated interactions among plant species have focused on the reception of herbivore-induced volatiles by neighboring plants. We recently documented volatile effects in another system, demonstrating that the parasitic plant Cuscuta pentagona uses volatile cues to locate its hosts. This finding may broaden the discussion regarding plant-to-plant communication, and suggests that new classes of volatile-meditated interactions among plant species await discovery.

Force transmissibility versus displacement transmissibility

Science.gov (United States)

Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

2014-10-01

It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

Beyond theories of plant invasions: Lessons from natural landscapes

Science.gov (United States)

Stohlgren, Thomas J.

2002-01-01

There are a growing number of contrasting theories about plant invasions, but most are only weakly supported by small-scale field experiments, observational studies, and mathematical models. Among the most contentious theories is that species-rich habitats should be less vulnerable to plant invasion than species-poor sites, stemming from earlier theories that competition is a major force in structuring plant communities. Early ecologists such as Charles Darwin (1859) and Charles Elton (1958) suggested that a lack of intense interspecific competition on islands made these low-diversity habitats vulnerable to invasion. Small-scale field experiments have supported and contradicted this theory, as have various mathematical models. In contrast, many large-scale observational studies and detailed vegetation surveys in continental areas often report that species-rich areas are more heavily invaded than species-poor areas, but there are exceptions here as well. In this article, I show how these seemingly contrasting patterns converge once appropriate spatial and temporal scales are considered in complex natural environments. I suggest ways in which small-scale experiments, mathematical models, and large- scale observational studies can be improved and better integrated to advance a theoretically based understanding of plant invasions.

Force generation by titin folding.

Science.gov (United States)

Mártonfalvi, Zsolt; Bianco, Pasquale; Naftz, Katalin; Ferenczy, György G; Kellermayer, Miklós

2017-07-01

Titin is a giant protein that provides elasticity to muscle. As the sarcomere is stretched, titin extends hierarchically according to the mechanics of its segments. Whether titin's globular domains unfold during this process and how such unfolded domains might contribute to muscle contractility are strongly debated. To explore the force-dependent folding mechanisms, here we manipulated skeletal-muscle titin molecules with high-resolution optical tweezers. In force-clamp mode, after quenching the force (force trace contained rapid fluctuations and a gradual increase of average force, indicating that titin can develop force via dynamic transitions between its structural states en route to the native conformation. In 4 M urea, which destabilizes H-bonds hence the consolidated native domain structure, the net force increase disappeared but the fluctuations persisted. Thus, whereas net force generation is caused by the ensemble folding of the elastically-coupled domains, force fluctuations arise due to a dynamic equilibrium between unfolded and molten-globule states. Monte-Carlo simulations incorporating a compact molten-globule intermediate in the folding landscape recovered all features of our nanomechanics results. The ensemble molten-globule dynamics delivers significant added contractility that may assist sarcomere mechanics, and it may reduce the dissipative energy loss associated with titin unfolding/refolding during muscle contraction/relaxation cycles. © 2017 The Protein Society.

Cantilever contribution to the total electrostatic force measured with the atomic force microscope

International Nuclear Information System (INIS)

Guriyanova, Svetlana; Golovko, Dmytro S; Bonaccurso, Elmar

2010-01-01

The atomic force microscope (AFM) is a powerful tool for surface imaging at the nanometer scale and surface force measurements in the piconewton range. Among long-range surface forces, the electrostatic forces play a predominant role. They originate if the electric potentials of the substrate and of the tip of the AFM cantilever are different. A quantitative interpretation of the AFM signal is often difficult because it depends in a complicated fashion on the cantilever–tip–surface geometry. Since the electrostatic interaction is a long-range interaction, the cantilever, which is many microns from the surface, contributes to the total electrostatic force along with the tip. Here we present results of the electrostatic interaction between a conducting flat surface and horizontal or tilted cantilevers, with and without tips, at various distances from the surface. As addressed in a previous work, we show that the contribution of the cantilever to the overall force cannot be neglected. Based on a predictive model and on 3D confocal measurements, we discuss the influence of the tilting angle of the cantilever

Basing the US Air Force Special Operations Forces.

Science.gov (United States)

1986-12-01

Headquarters Military Airlift Command (Hq MAC/XONP), Scott AFB, IL, July 8, 1986. 2. Daskin , Mark S. " A Maximum Expected Covering Location Model: Formulation...7942 m~ I SAIR F ORME S ECI L PE DO S CHOOL’ 1 OF EMNIEERINO A E KCRAUS DEC 66 RFIT/OOLOS/MN-6 IUCLRS SIFIE F.’G1F/OI L Ehhmhmmhhhhhhl smomhmhmhhum...Ap a . %Ř ~ ,~, ~~%9~ q%%~ * % . i %%~ . ~* - out; ’-ILE Copy / AFIT/GOR/OS/86D-6 II BASING THE US AIR FORCE SPECIAL OPERATIONS FORCES THESIS Mark E

Interactive forces between lignin and cellulase as determined by atomic force microscopy

OpenAIRE

Qin, Chengrong; Clarke, Kimberley; Li, Kecheng

2014-01-01

Background Lignin is a complex polymer which inhibits the enzymatic conversion of cellulose to glucose in lignocellulose biomass for biofuel production. Cellulase enzymes irreversibly bind to lignin, deactivating the enzyme and lowering the overall activity of the hydrolyzing reaction solution. Within this study, atomic force microscopy (AFM) is used to compare the adhesion forces between cellulase and lignin with the forces between cellulase and cellulose, and to study the moiety groups invo...

Safety prediction technique for nuclear power plants

International Nuclear Information System (INIS)

Henry, C.D. III; Anderson, R.T.

1985-01-01

This paper presents a safety prediction technique (SPT) developed by Reliability Technology Associates (RTA) for nuclear power plants. It is based on a technique applied by RTA to assess the flight safety of US Air Force aircraft. The purpose of SPT is to provide a computerized technique for objective measurement of the effect on nuclear plant safety of component failure or procedural, software, or human error. A quantification is determined, called criticality, which is proportional to the probability that a given component or procedural-human action will cause the plant to operate in a hazardous mode. A hazardous mode is characterized by the fact that there has been a failure/error and the plant, its operating crew, and the public are exposed to danger. Whether the event results in an accident, an incident, or merely the exposure to danger is dependent on the skill and reaction of the operating crew as well as external influences. There are three major uses of SPT: (a) to predict unsafe situations so that corrective action can be taken before accidents occur, (b) to quantify the impact of equipment malfunction or procedural, software, or human error on safety and thereby establish priorities for proposed modifications, and (c) to provide a means of evaluating proposed changes for their impact on safety prior to implementation and to provide a method of tracking implemented changes

Relativistic Linear Restoring Force

Science.gov (United States)

Clark, D.; Franklin, J.; Mann, N.

2012-01-01

We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

In-Situ atomic force microscopic observation of ion beam bombarded plant cell envelopes

International Nuclear Information System (INIS)

Sangyuenyongpipat, S.; Yu, L.D.; Brown, I.G.; Seprom, C.; Vilaithong, T.

2007-01-01

A program in ion beam bioengineering has been established at Chiang Mai University (CMU), Thailand, and ion beam induced transfer of plasmid DNA molecules into bacterial cells (Escherichia coli) has been demonstrated. However, a good understanding of the fundamental physical processes involved is lacking. In parallel work, onion skin cells have been bombarded with Ar + ions at energy 25 keV and fluence1-2 x 10 15 ions/cm 2 , revealing the formation of microcrater-like structures on the cell wall that could serve as channels for the transfer of large macromolecules into the cell interior. An in-situ atomic force microscope (AFM) system has been designed and installed in the CMU bio-implantation facility as a tool for the observation of these microcraters during ion beam bombardment. Here we describe some of the features of the in-situ AFM and outline some of the related work

Emergency Cooling of Nuclear Power Plant Reactors With Heat Removal By a Forced-Draft Cooling Tower

Energy Technology Data Exchange (ETDEWEB)

Murav’ev, V. P., E-mail: murval1@mail.ru

2016-07-15

The feasibility of heat removal during emergency cooling of a reactor by a forced-draft cooling tower with accumulation of the peak heat release in a volume of precooled water is evaluated. The advantages of a cooling tower over a spray cooling pond are demonstrated: it requires less space, consumes less material, employs shorter lines in the heat removal system, and provides considerably better protection of the environment from wetting by entrained moisture.

DCS upgrades for nuclear power plants: Saving money and reducing risk through virtual-stimulation control system checkout

International Nuclear Information System (INIS)

McKim, G.; Yeager, M.; Weirich, C.

2006-01-01

Nuclear power plant control systems of 1970's vintage have reached the end of their life: reliability is poor and spare parts are hard to come by. At First Energy Perry station, two costly feedwater system trips caused by an ailing analog control system led to the decision to replace it with a modern Foxboro I/A-series Distributed Control System. The simulator was also upgraded using the Virtual-Stim simulation of I/A, called FSIM. Virtual-Stim simulation allows the configuration and graphics from the plant to be downloaded onto the simulator as-is, using the same tools and operator interface as the plant, without imprecise translations, conversions, or other emulation. Advances in simulation technology and market forces have led to an open architecture design, allowing FSIM to be 'bridged' to Perry's existing Opensim simulator process model. This appears to be an industry-wide trend as more control system vendors offer Virtual Stimulation solutions for connection to third-party simulation products. Taking a cue from First Energy's Sammis Station FSIM simulator projects, the Perry simulator was used for dedicated control verification and tuning. Preventing forced outages caused by control configuration errors can result in enormous savings, and the simulator is now required to precede any plant modifications rather than just a training tool that lags the plant. This testing revealed several surprising results for a relatively straightforward control strategy, showing that simulator-based testing will be even more crucial in the future as the remain-der of the balance of plant is migrated to digital control. (author)

Differential magnetic force microscope imaging.

Science.gov (United States)

Wang, Ying; Wang, Zuobin; Liu, Jinyun; Hou, Liwei

2015-01-01

This paper presents a method for differential magnetic force microscope imaging based on a two-pass scanning procedure to extract differential magnetic forces and eliminate or significantly reduce background forces with reversed tip magnetization. In the work, the difference of two scanned images with reversed tip magnetization was used to express the local magnetic forces. The magnetic sample was first scanned with a low lift distance between the MFM tip and the sample surface, and the magnetization direction of the probe was then changed after the first scan to perform the second scan. The differential magnetic force image was obtained through the subtraction of the two images from the two scans. The theoretical and experimental results have shown that the proposed method for differential magnetic force microscope imaging is able to reduce the effect of background or environment interference forces, and offers an improved image contrast and signal to noise ratio (SNR). © Wiley Periodicals, Inc.

Determining prestressing forces for inspection of prestressed concrete containments

International Nuclear Information System (INIS)

1990-07-01

General Design Criterion 53, ''Provisions for Containment Testing and Inspection,'' of Appendix A, ''General Design Criteria for Nuclear Power Plants,'' to 10 CFR Part 50, ''Domestic Licensing of Production and Utilization Facilities,'' requires, in part, that the reactor containment be designed to permit (1) periodic inspection of all important areas and (2) an appropriate surveillance program. Regulatory Guide 1.35, ''Inservice Inspection of Ungrouted Tendons in Prestressed Concrete Containment Structures,'' describes a basis acceptable to the NRC staff for developing an appropriate inservice inspection and surveillance program for ungrouted tendons in prestressed concrete containment structures of light-water-cooled reactors. This guide expands and clarifies the NRC staff position on determining prestressing forces to be used for inservice inspections of prestressed concrete containment structures

Capillary force on a tilted cylinder: Atomic Force Microscope (AFM) measurements.

Science.gov (United States)

Kosgodagan Acharige, Sébastien; Laurent, Justine; Steinberger, Audrey

2017-11-01

The capillary force in situations where the liquid meniscus is asymmetric, such as the one around a tilted object, has been hitherto barely investigated even though these situations are very common in practice. In particular, the capillary force exerted on a tilted object may depend on the dipping angle i. We investigate experimentally the capillary force that applies on a tilted cylinder as a function of its dipping angle i, using a home-built tilting Atomic Force Microscope (AFM) with custom made probes. A micrometric-size rod is glued at the end of an AFM cantilever of known stiffness, whose deflection is measured when the cylindrical probe is dipped in and retracted from reference liquids. We show that a torque correction is necessary to understand the measured deflection. We give the explicit expression of this correction as a function of the probes' geometrical parameters, so that its magnitude can be readily evaluated. The results are compatible with a vertical capillary force varying as 1/cosi, in agreement with a recent theoretical prediction. Finally, we discuss the accuracy of the method for measuring the surface tension times the cosine of the contact angle of the liquid on the probe. Copyright © 2017 Elsevier Inc. All rights reserved.

Macroscopic QED in linearly responding media and a Lorentz-Force approach to dispersion forces

Energy Technology Data Exchange (ETDEWEB)

Raabe, Christian

2008-07-08

In this thesis, a very general quantization scheme for the macroscopic electromagnetic field in arbitrary linearly responding media is presented. It offers a unified approach to QED in such media. Applying the quantization scheme, a theory of the dispersion forces on the basis of the Lorentz force is developed. By regarding the dispersion force as the (ground-state or thermal-state) expectation value of the Lorentz force that acts on appropriately defined charge and current densities, Casimir, Casimir-Polder, and van der Waals forces are united in a very natural way that makes transparent their common physical basis. Application of the theory to planar structures yields generalizations of well-known Lifschitz and Casimir-type formulas. (orig.)

Macroscopic QED in linearly responding media and a Lorentz-Force approach to dispersion forces

International Nuclear Information System (INIS)

Raabe, Christian

2008-01-01

In this thesis, a very general quantization scheme for the macroscopic electromagnetic field in arbitrary linearly responding media is presented. It offers a unified approach to QED in such media. Applying the quantization scheme, a theory of the dispersion forces on the basis of the Lorentz force is developed. By regarding the dispersion force as the (ground-state or thermal-state) expectation value of the Lorentz force that acts on appropriately defined charge and current densities, Casimir, Casimir-Polder, and van der Waals forces are united in a very natural way that makes transparent their common physical basis. Application of the theory to planar structures yields generalizations of well-known Lifschitz and Casimir-type formulas. (orig.)

Strength and deformation characteristics of reinforced concrete shell elements subjected to in-plane forces

International Nuclear Information System (INIS)

Aoyagi, Yukio; Yamada, Kazuie.

1983-01-01

Reactor containment vessels have been made of steel so far, but since it was decided to adopt a prestressed concrete vessel in the Tsuruga No. 2 plant of Japan Atomic Power Co., the construction of the containment vessels made of prestressed concrete and reinforced concrete has been studied by various electric power companies. However in Japan, there is no standard for the design and construction of concrete structures of this kind. In the standard of foreign countries used for reference, the basis of the stipulation concerning the aseismatic design of concrete containment vessels is not distinct. In this study, the clarification of the strength and deformation when RC vessels are subjected to seismic force only or to internal pressure and seismic force was aimed at, and the result of the loading test by one or two-direction in-plane forces on RC shell elements was examined. Based on this, the method of estimating the strength and deformation of RC shell elements was proposed. The orthogonal reinforcement was adopted, and the strength of shell elements was determined by the yielding of reinforcing bars. (Kako, I.)

Ionic signaling in plant responses to gravity and touch

Science.gov (United States)

Fasano, Jeremiah M.; Massa, Gioia D.; Gilroy, Simon

2002-01-01

Touch and gravity are two of the many stimuli that plants must integrate to generate an appropriate growth response. Due to the mechanical nature of both of these signals, shared signal transduction elements could well form the basis of the cross-talk between these two sensory systems. However, touch stimulation must elicit signaling events across the plasma membrane whereas gravity sensing is thought to represent transformation of an internal force, amyloplast sedimentation, to signal transduction events. In addition, factors such as turgor pressure and presence of the cell wall may also place unique constraints on these plant mechanosensory systems. Even so, the candidate signal transduction elements in both plant touch and gravity sensing, changes in Ca2+, pH and membrane potential, do mirror the known ionic basis of signaling in animal mechanosensory cells. Distinct spatial and temporal signatures of Ca2+ ions may encode information about the different mechanosignaling stimuli. Signals such as Ca2+ waves or action potentials may also rapidly transfer information perceived in one cell throughout a tissue or organ leading to the systemic reactions characteristic of plant touch and gravity responses. Longer-term growth responses are likely sustained via changes in gene expression and asymmetries in compounds such as inositol-1,4,5-triphosphate (IP3) and calmodulin. Thus, it seems likely that plant mechanoperception involves both spatial and temporal encoding of information at all levels, from the cell to the whole plant. Defining this patterning will be a critical step towards understanding how plants integrate information from multiple mechanical stimuli to an appropriate growth response.

Waste from decommissioning of nuclear power plants

International Nuclear Information System (INIS)

Nielsen, P.O.

1992-05-01

This report is based on the assumption that all twelve nuclear power plants will be shut down no later than A.D. 2010, as was decided by the parliament after the referendum on the future of nuclear power in Sweden. The recent 'Party agreement on the energy policy' of January 15, 1991 does, indeed, leave the door open for an extension of the operational period for the nuclear reactors. This will, however, not change the recommendations and conclusions drawn in this report. The report consists of two parts. Part 1 discusses classification of waste from decommissioning and makes comparisons with the waste arising from reactor operation. Part 2 discusses the documentation required for decommissioning waste. Also this part of the report draws parallels with the documentation required by the authorities for the radioactive waste arising from operation of the nuclear power plants. To some extent these subjects depend on the future use of the nuclear power plant sites after decommissioning of the plants. The options for future site use are briefly discussed in an appendix to the report. There are many similarities between the waste from reactor operations and the waste arising from dismantling and removal of decommissioned nuclear power plants. Hence it seems natural to apply the same criteria and recommendations to decommissioning waste as those presently applicable to reactor waste. This is certainly true also with respect to documentation, and it is strongly recommended that the documentation requirements on decommissioning waste are made identical, or at least similar, to the documentation requirements for reactor waste in force today. (au)

Tube failures due to cooling process problem and foreign materials in power plants

Energy Technology Data Exchange (ETDEWEB)

Ahmad, J. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia); Purbolaksono, J., E-mail: judha@uniten.edu.m [Department of Mechanical Engineering, Universiti Tenaga Nasional, Km 7 Jalan Kajang-Puchong, Kajang 43009, Selangor (Malaysia); Beng, L.C. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia)

2010-07-15

Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

Tube failures due to cooling process problem and foreign materials in power plants

International Nuclear Information System (INIS)

Ahmad, J.; Purbolaksono, J.; Beng, L.C.

2010-01-01

Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

Force balancing in mammographic compression

International Nuclear Information System (INIS)

Branderhorst, W.; Groot, J. E. de; Lier, M. G. J. T. B. van; Grimbergen, C. A.; Neeter, L. M. F. H.; Heeten, G. J. den; Neeleman, C.

2016-01-01

Purpose: In mammography, the height of the image receptor is adjusted to the patient before compressing the breast. An inadequate height setting can result in an imbalance between the forces applied by the image receptor and the paddle, causing the clamped breast to be pushed up or down relative to the body during compression. This leads to unnecessary stretching of the skin and other tissues around the breast, which can make the imaging procedure more painful for the patient. The goal of this study was to implement a method to measure and minimize the force imbalance, and to assess its feasibility as an objective and reproducible method of setting the image receptor height. Methods: A trial was conducted consisting of 13 craniocaudal mammographic compressions on a silicone breast phantom, each with the image receptor positioned at a different height. The image receptor height was varied over a range of 12 cm. In each compression, the force exerted by the compression paddle was increased up to 140 N in steps of 10 N. In addition to the paddle force, the authors measured the force exerted by the image receptor and the reaction force exerted on the patient body by the ground. The trial was repeated 8 times, with the phantom remounted at a slightly different orientation and position between the trials. Results: For a given paddle force, the obtained results showed that there is always exactly one image receptor height that leads to a balance of the forces on the breast. For the breast phantom, deviating from this specific height increased the force imbalance by 9.4 ± 1.9 N/cm (6.7%) for 140 N paddle force, and by 7.1 ± 1.6 N/cm (17.8%) for 40 N paddle force. The results also show that in situations where the force exerted by the image receptor is not measured, the craniocaudal force imbalance can still be determined by positioning the patient on a weighing scale and observing the changes in displayed weight during the procedure. Conclusions: In mammographic breast

Human equation in operating a nuclear-power plant

International Nuclear Information System (INIS)

Barrett, R.S.

1982-01-01

The accident at Three Mile Island has forced the nuclear industry to acknowledge a badly neglected aspect of nuclear-power-plant safety - the human equation. The industry now appears to recognize the importance of operator selection, training, motivation, and licensing, and the need to design a system from the point of view of communication, information retrieval, record keeping, and human factors psychology. As a result, the relatively small initiatives that were begun a few years ago by the EPRI are now being greatly expanded

Plant cell wall sugars: sweeteners for a bio-based economy.

Science.gov (United States)

Van de Wouwer, Dorien; Boerjan, Wout; Vanholme, Bartel

2018-02-12

Global warming and the consequent climate change is one of the major environmental challenges we are facing today. The driving force behind the rise in temperature is our fossil-based economy, which releases massive amounts of the greenhouse gas carbon dioxide into the atmosphere. In order to reduce greenhouse gas emission, we need to scale down our dependency on fossil resources, implying that we need other sources for energy and chemicals to feed our economy. Here, plants have an important role to play; by means of photosynthesis, plants capture solar energy to split water and fix carbon derived from atmospheric carbon dioxide. A significant fraction of the fixed carbon ends up as polysaccharides in the plant cell wall. Fermentable sugars derived from cell wall polysaccharides form an ideal carbon source for the production of bio-platform molecules. However, a major limiting factor in the use of plant biomass as feedstock for the bio-based economy is the complexity of the plant cell wall and its recalcitrance towards deconstruction. To facilitate the release of fermentable sugars during downstream biomass processing, the composition and structure of the cell wall can be engineered. Different strategies to reduce cell wall recalcitrance will be described in this review. The ultimate goal is to obtain a tailor-made biomass, derived from plants with a cell wall optimized for particular industrial or agricultural applications, without affecting plant growth and development. This article is protected by copyright. All rights reserved.

Plant Host Finding by Parasitic Plants: A New Perspective on Plant to Plant Communication

OpenAIRE

Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

2006-01-01

Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much d...

Multistage Force Amplification of Piezoelectric Stacks

Science.gov (United States)

Xu, Tian-Bing (Inventor); Siochi, Emilie J. (Inventor); Zuo, Lei (Inventor); Jiang, Xiaoning (Inventor); Kang, Jin Ho (Inventor)

2015-01-01

Embodiments of the disclosure include an apparatus and methods for using a piezoelectric device, that includes an outer flextensional casing, a first cell and a last cell serially coupled to each other and coupled to the outer flextensional casing such that each cell having a flextensional cell structure and each cell receives an input force and provides an output force that is amplified based on the input force. The apparatus further includes a piezoelectric stack coupled to each cell such that the piezoelectric stack of each cell provides piezoelectric energy based on the output force for each cell. Further, the last cell receives an input force that is the output force from the first cell and the last cell provides an output apparatus force In addition, the piezoelectric energy harvested is based on the output apparatus force. Moreover, the apparatus provides displacement based on the output apparatus force.

Unified force and its relation with global warming crave for hydrogen energy and promote fuel cell technology

International Nuclear Information System (INIS)

Krishnan, K.J.; Kalam, A.

2011-01-01

Global warming is presently a tremendous public interest and has become a threat to every individual. Huge quantities of CO/sub 2/ are emitted to the atmosphere by burning of fossil fuels to produce electricity in power plants and burning of gasoline in aeroplanes and vehicles. Enormous amount of greenhouse gasses are sent into the air when garbage is burnt in landfills. Cutting down of trees and other plants which collect CO/sub 2/ a greenhouse gas which is inhaled and which gives back oxygen which is exhaled makes global warming worse. 'Self-Compressive Surrounding Pressure Force' which is also known as Unified Force is also related with global warming which is proportional to increase of H/sub 2/O level in sea and causes floods, storms, droughts and severe impacts to the environment and society. In order to better understand global warming and its relation with Unified Force, this paper discusses the cause and effect system on the amount of greenhouse gases emitted to the atmosphere from the burning of fossil fuels and also the other green house gases like CH/sub 4/, water vapour, NOx etc. and emphasis its importance to focus on crave for Hydrogen Energy and to promote Fuel Cell technology to keep the earth green and safer from the impacts of global warming. The benefit of switching from fossil fuels to Hydrogen Energy and Fuel Cell technology reduces the impact of global warming, elimination of pollution caused by fossil fuels and greenhouse gases, economic dependence and distributed production. (author)

Herbivores and nutrients control grassland plant diversity via light limitation