WorldWideScience

Sample records for rotation coppice task

  1. An identification of potential new herbicides for short rotation coppice (Task 4). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report summarises the findings of a project to identify potential new herbicides and their suitability for weed control in commercial short rotation coppice (SRC) crops, and to establish the safety of the crops. The arrangements for the use of 'off-label' pesticides, which are permitted for use on other crops, on SRC are discussed along with the importance of the use of laboratory pot trials and field trials. Several herbicides are proposed for larger scale field trials.

  2. Public perceptions of short rotation coppice

    International Nuclear Information System (INIS)

    Sadler, R.

    1993-01-01

    The ''Wood as a Fuel'' programme - which funded the research covered in this report - is one of the renewable energy development programmes managed by ETSU (the Energy Technology Support Unit) for the Department of Trade and Industry. This national programme is developing the production and use of fuel wood from two main sources - forestry residues and short rotation coppice. Wood fuel from short rotation coppice offers the greater potential - energy equivalent to 10 mtce (million tonnes of coal equivalent) could be produced annually from 1 million hectares of land. This programme is now well established, with ten trial coppice sites in operation, plus some 40 others. A number of successfully willow and poplar clones have been selected for different soil conditions, and machinery for planting and harvesting has been developed. Local consortia of farmers and users are being established to provide long-term markets for the wood fuel produced. (author)

  3. Mechanised harvesting of short-rotation coppices

    OpenAIRE

    Vanbeveren, Stefan P.P.; Spinelli, Raffaele; Eisenbies, Mark; Schweier, Janine; Mola-Yudego, Blas; Magagnotti, Natascia; Acuna, Mauricio; Dimitriou, Ioannis; Ceulemans, Reinhart

    2017-01-01

    Abstract: Short-rotation coppice (SRC) is an important source of woody biomass for bioenergy. Despite the research carried out on several aspects of SRC production, many uncertainties create barriers to farmers establishing SRC plantations. One of the key economic sources of uncertainty is harvesting methods and costs; more specifically, the performance of contemporary machine methods is reviewed. We collected data from 25 literature references, describing 166 field trials. Three harvesting s...

  4. Radiocaesium uptake and cycling in willow short rotation coppice

    International Nuclear Information System (INIS)

    Gommers, A.

    2002-01-01

    The document is an abstract of a PhD thesis. The study investigates the uptake and cycling of radiocaesium in willow short rotation coppice. Different factors influencing the soil-to-wood transfer of radiocaesium were investigated, among others the type of minerals, supply of potassium and soil composition

  5. Some environmental impacts of short rotation willow coppice

    International Nuclear Information System (INIS)

    Slater, F.M.; Hodson, R.W.; Randrson, P.F.; Lynn, S.F.

    1997-01-01

    Short rotation willow coppice is a relatively new crop in upland Britain, and particularly in Environmentally Sensitive Areas the conservation and environmental effect of biomass crops needs to be evaluated. Investigations of sewage-sludge-treated plots in mid-Wales show that, because weed control was inadequate, recovery of the flora to its semi-natural precultivated state was rapid within and between experimental plots. Soil invertebrates responded to temporal stimuli before all else. Foliar-feeding invertebrates were greater in plots which had added fertilizer. Following cultivation voles were generally lost from the ploughed areas but field mice remained. Birds were studied in more extensive areas of short rotation coppice in central England and the assemblage of species was found to be similar to those found in conventional coppice but with a foreshortened successional sequence. The conservation value of short rotation willow coppice lies mainly in the abundant foliar invertebrates that provide a rich source of food for small passerine birds, particularly summer migrants. It also provides good cover for game birds - and their predators. (author)

  6. Nutrient enhanced short rotation coppice for biomass in central Wales

    Energy Technology Data Exchange (ETDEWEB)

    Hodson, R.W.; Slater, F.M.; Lynn, S.F.; Randerson, P.F. [Univ. of Wales (United Kingdom)

    1993-12-31

    Two projects involving short rotation willow coppice are taking place on the eastern side of the Cambrian Mountains in central Wales. One project examines, as an alternative land use, the potential of short rotation willow coppice variously enhanced by combinations of lime, phosphorous and potassium fertilizers and also digested sewage sludge on an acidic upland site at an altitude of 260m. The first year results of this project are described in detail, showing the necessity for limestone additions and also demonstrating that of the four willow varieties established, Salix dasyclados is the only possible, profitable fuel crop. The other project involving willow in a filter bed system is outlined along with an additional project investigating the effect of sewage sludge additions on the Rubus fruticosus production in a birch dominated mixed deciduous woodland.

  7. Storage and handling of willow from short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P. D.; Spinelli, R.

    1997-07-01

    During the project two main storage and drying trials were organised. The first trial in 1996 consisted of 14 piles of 6 different size material (whole shoots, via 200 mm chunk, 100 mm chunk, 50 mm chip, 28 mm chips, 25 mm chips) and six different methods of covering: Open air storage, storage under plastic cover, storage under top-cover, airtight storage, unventilated storage under roof, and intermittent ventilation (cooling) under roof. The drying trial in 1997 which consisted of four piles was established in Horsens in the same building as the ventilated trials the year before. Only Austoft 50 mm chips were used for this trial. The four piles were established in February and removed in May. Based on all the results of the trials the following conclusions can be drawn: Storage of willow from short rotation coppice is very difficult. Fine chips, such as producted by the two main harvesting machines Claas and Austoft are not suitable for storage over prolonged periods of time (more than 2 months); fine chips loose a large amount of dry matter and a lot of their lower heating value; fine chips also have a heavy infestation of micro-organisms which might cause working environment problems; short rotation coppice is best delivered straight into the heating plants during harvest; if short rotation coppice has to be stored, then this should be done as whole shoots or large chunk; if short rotation coppice has to be stored as chips for a longer period of time (more than two months), then these chips should be sealed airtight as silage. (EG) EFP-94; EFP-95; EFP-96. 10 refs.

  8. Short rotation coppice for energy production: hydrological guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.L.

    2003-07-01

    This report provides hydrological guidelines for growers, land and water resource managers, environmental groups and other parties interested in utilising short rotation coppice (SRC) for energy production. The aim of the report is to help interested parties decide if a location is suitable for SRC planting by considering whether potential hydrological impacts will have an adverse effect on crop productivity and yield. The guidelines consider: the water use of SRC compared with other crops; the factors governing water use; the water requirements for a productive crop; and the likely impacts on the availability and quantity of water. The report points out that there are still gaps in our knowledge of the processes controlling the water use and growth of SRC and notes that, in some situations, there will be considerable uncertainty in predictions.

  9. Quality Testing of Short Rotation Coppice Willow Cuttings

    Directory of Open Access Journals (Sweden)

    Katrin Heinsoo

    2018-06-01

    Full Text Available The production and feasibility of Short Rotation Coppice depend on cutting early performance. The shoot and root biomass production of Salix cuttings in hydroponic conditions was studied. The amount of sprouted biomass after four weeks of growth depended on cutting the diameter, but the original position of the cutting along the rod or number of visible buds was not in correlation with biomass produced. Application of mineral fertilizer or soil originating from the willow plantation did not increase the total production. On the contrary, the addition of soil tended to decrease biomass production and we assumed this was a result of a shortage of light. Under the influence of fertilization, plants allocated greater biomass to roots. Comparison of different clones revealed that those with S. dasyclados genes tended to allocate less biomass to roots and the poorest-performing clone in our experiment, also had the lowest wood production in the plantation. The number of visible buds on the cutting was also clone-specific.

  10. An evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2000-07-01

    The objective of the project was to evaluate the safety and efficacy of a range of herbicides and mixtures of herbicides, with both contact and residual activity, for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). This report provides growers and advisers of short rotation coppice with important (but still limited) information on how to achieve improved weed control of problem weeds increasingly prevalent in SRC fields. This may provide guidance towards often-essential emergency treatments when the crop establishment is under considerable pressure and the potential safety, or otherwise, of certain weed-specific herbicides. (author)

  11. Sensitivity of short rotation poplar coppice biomass productivity to the throughfall reduction Estimating future drought impacts

    Czech Academy of Sciences Publication Activity Database

    Orság, Matěj; Fischer, Milan; Tripathi, Abishek; Žalud, Zdeněk; Trnka, Miroslav

    2018-01-01

    Roč. 109 (2018), s. 182-189 ISSN 0961-9534 Institutional support: RVO:86652079 Keywords : water -use * energy * stand * systems * dominance * density * l. * Dominance * Drought * Mortality * Productivity * Short-rotation coppice * Throughfall manipulation Subject RIV: GC - Agronomy OBOR OECD: Agronomy, plant breeding and plant protection Impact factor: 3.219, year: 2016

  12. Short-rotation coppicing in France. Current state of research and prospects for future development

    Energy Technology Data Exchange (ETDEWEB)

    Bonduelle, P. (Association Foret Cellulose, Trelaze (France)); Bouvarel, L. (Institut National de la Recherche Agronomique, Olivet (France). Unite Experimentale Biomasse, Forestiere et Foret Paysanne); Petit, H. (Association pour la Rationalisation et la Mecanisation de l' Exploitation Forestiere, Fontainebleau (France)); Pierson, J. (Cellulose des Ardennes, Montemedy (France)); Savanne, D. (Agence de l' Environnement et de la Maitrise de l' Energie, 75 - Paris (France)); Sourie, J.C. (Institut National de la Recherche Agronomique, Grignon (France). Station d' Economie et de Sociologie Rurales)

    1992-01-01

    This article analyzes the current context and the prospects for crop development as well as offering a number of examples of short rotation coppicing projects. The industrial outlets created through state aid remain the primary driving force behind plantations at this time. (author)

  13. Establishment and monitoring of large scale trials of short rotation coppice for energy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.; Stevens, E.A.; Watters, M.P.

    1998-09-01

    The overall objective of the trials was to obtain information on costs, logistics, productivity and biology of short rotation coppice crops in order to evaluate their potential for producing wood for fuel. More specifically, the objectives of the final and most recent phase of the research work were: the continuing management and monitoring of the coppice trial sites established during phases 1 and 2 of the project; to provide technical and economic data on the management and maintenance of the continuing coppice trail sites; to identify appropriate methods for stool removal and land reclamation and provide technical and economic data on those operations; and to undertake yield assessment at the remaining sites using appropriate methods of yield estimation. (author)

  14. Life-cycle assessment of eucalyptus short-rotation coppices for bioenergy production in Southern France

    OpenAIRE

    Gabrielle , Benoit; Nguyen The , Nicolas; Maupu , Pauline; Vial , Estelle

    2011-01-01

    Short rotation coppices (SRCs) are considered prime candidates for biomass production, yielding good-quality feedstock that is easy to harvest. Besides technical, social and economical aspects, environmental issues are important to take into account when developing SRCs. Here, we evaluated the environmental impacts of delivering 1 GJ of heat from eucalyptus SRC using life cycle assessment (LCA), based on management scenarios involving different rotations lengths, fertilizer input rates, stem ...

  15. The silviculture, nutrition and economics of short rotation willow coppice in the uplands of mid-Wales

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R J; Randerson, P F; Slater, F M

    2000-07-01

    The potential of short rotation coppice as a biomass crop on land over 250m (the uplands) of mid Wales was studied. The results found in this study indicate that growing short rotation coppice willow in the uplands is a viable proposition with regard to establishment success and yields. In the event of a secure wood chip market in Wales, returns to the grower would be comparable to those from sheep production. (author)

  16. Short rotation coppice as a business field of an energy utility

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, T. (RWE Innogy Cogen GmbH, Dortmund (Germany))

    2010-07-01

    Companies that start planting short rotation coppice (SRC), enter a new territory. In fact, this subject is often discussed, but there is - at least in Germany - still comparatively little practical knowledge on that. Since ca. 1 year, RWE Innogy Cogen is doing pioneer work here and starts establishing SRC in Germany and Europe. Therefore, first results and experiences, as well as consequences for practice shall be presented and discussed in this article. (orig.)

  17. Growing short rotation coppice on agricultural land in Germany: A Real Options Approach

    International Nuclear Information System (INIS)

    Musshoff, Oliver

    2012-01-01

    In many cases decision-makers apparently do not adapt as fast as expected to changing economic conditions. This is also the case for the conversion of farm land to short rotation coppice. From an economic point of view, short rotation coppice has become more interesting in the last few years. Nevertheless, farm land still is rarely used to grow this quite unknown crop. Several explanatory approaches (e.g., traditionalistic behavior and risk aversion) are currently discussed in order to explain this behavior. A relatively new explanatory approach is the Real Options Approach. The Real Options Approach uses a comprehensive dynamic-stochastic model that combines the uncertainty of investment returns, the sunk costs, and the temporal flexibility of the investment implementation. The quintessence of the Real Options Approach is that—compared to the Classical Investment Theory—the investment triggers will be shifted upwards if investments involve intertemporal opportunity costs. This paper develops a real options model which allows the determination of triggers on the basis of realistic assumptions. We examined when farmers, who only dispose of sandy soils with little water-storing capacity, should convert set-aside land to short rotation coppice. The results show that farmers should not convert until the present value of the investment returns exceeds the investment costs considerably. Thus, they confirm the empirically observed reluctance in conversion. Furthermore, it turned out that the magnitude of the difference between the Classical Investment Theory and the Real Options Approach depends heavily on the type of stochastic process that underlies the investment returns. -- Highlights: ► Frequently observed reluctance of farmers to convert to short rotation coppice. ► Risk neutral farmers should convert if the investment multiple exceeds 1.57. ► The Real Options Approach is an explanatory approach for this observation. ► Results depend very much on the

  18. A further evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2002-07-01

    This report summarises the findings of a project evaluating the safety and efficiency of eleven herbicides for controlling weeds in newly plated willow short rotation coppices, and provides growers with information on post-emergence herbicide options, control of problem weeds, and emergency treatments. Weed germination, crop safety, and the encouraging results obtained using Reflex T and Impuls are discussed. It is suggested that a Technical Register of herbicide applications with contributions by growers and advisers should be considered by the British Biogen trade industry body.

  19. Short rotation coppice as a fuel: framework for a contractual infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This report summarises the results of a study exploring the contractual interface between growers and suppliers of short rotation coppice fuels and power generators in England and Wales, France and Sweden. Reviews of the main contractual considerations in relation to growers and generators in the UK, and Swedish and UK studies are presented. Proposals for the contractual treatment in the UK of the issues raised by the studies are considered, and recommendations for the treatment of contractual and economic requirements prevailing in France and Sweden are given. Appendices contains model agreements. (UK)

  20. Enhancing the conservation value of short rotation biomass coppice. Phase 1

    International Nuclear Information System (INIS)

    Sage, R.B.; Robertson, P.A.; Poulson, J.G.

    1994-01-01

    The game and conservation value of existing short rotation coppice plantations in Britain and Ireland has been assessed. Four main wild life groups were surveyed during appropriate periods in 1993. These were songbirds, butterflies, pheasants and ground flora. For each group the process of field data collection, analysis and interpretation is described, the results are summarized and briefly discussed. A final overall discussion of the results in terms of their general findings and how typical they may be for future, large-scale production plots is presented. Proposals are made regarding management techniques that could be used with future plantings to benefit the various wildlife groups. (50 figures, 19 tables, 30 references). (UK)

  1. Generalized allometric regression to estimate biomass of Populus in short-rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Ben Brahim, Mohammed; Gavaland, Andre; Cabanettes, Alain [INRA Centre de Toulouse, Castanet-Tolosane Cedex (France). Unite Agroforesterie et Foret Paysanne

    2000-07-01

    Data from four different stands were combined to establish a single generalized allometric equation to estimate above-ground biomass of individual Populus trees grown on short-rotation coppice. The generalized model was performed using diameter at breast height, the mean diameter and the mean height of each site as dependent variables and then compared with the stand-specific regressions using F-test. Results showed that this single regression estimates tree biomass well at each stand and does not introduce bias with increasing diameter.

  2. ARBRE monitoring - ecology of short rotation coppice plantations. Interim report 2000

    Energy Technology Data Exchange (ETDEWEB)

    Rich, T.J.; Sage, R.; Moore, N.; Robertson, P.; Aegerter, J.; Bishop, J.

    2001-07-01

    Short Rotation willow coppice (SRC) is a potential habitat for wildlife in the British countryside according to research reported in the late 1990s, but so far the trials have been on small plantations without reference to the land use it would supersede. This interim report, on a 4-year study which began in January 2000, discusses the commercial availability of SRC plantations and assesses what might be achievable by changing land usage. Work so far, conducted on indicator species (songbirds, ground flora, butterflies, insects), suggests that there are likely to be marked environmental benefits to be gained through SRC.

  3. Sensitivity of short rotation poplar coppice biomass productivity to the throughfall reduction – Estimating future drought impacts

    Czech Academy of Sciences Publication Activity Database

    Orság, Matěj; Fischer, Milan; Tripathi, Abishek; Žalud, Zdeněk; Trnka, Miroslav

    2018-01-01

    Roč. 109 (2018), s. 182-189 ISSN 0961-9534 R&D Projects: GA MŠk(CZ) LO1415; GA MZe(CZ) QJ1610072 Institutional support: RVO:86652079 Keywords : Dominance * Drought * Mortality * Productivity * Short-rotation coppice * Throughfall manipulation Subject RIV: GC - Agronomy Impact factor: 3.219, year: 2016

  4. Results from software based empirical models of and standing biomass for poplar and willow grown as short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, M.E.; Morgan, G.W.; Brewer, A.C. (Forest Research Biometrics, Surveys and Statistics Division, Forest Research, Wrecclesham (United Kingdom))

    2007-07-01

    Statistical analysis was used to create a model for estimating the quantity of biomass produced by crops of poplar and willow grown as short rotation coppice. This model was converted into a software system as described here. The software is currently available for scientific demonstration. (orig.)

  5. Natural flood retention in mountain areas by forests and forest like short rotation coppices

    Science.gov (United States)

    Reinhardt-Imjela, Christian; Schulte, Achim; Hartwich, Jens

    2017-04-01

    Natural water retention is an important element of flood risk management in flood generating headwater areas in the low mountain ranges of Central Europe. In this context forests are of particular interest because of the high infiltration capacities of the soils and to increase water retention reforestation of agricultural land would be worthwhile. However competing claims for land use in intensely cultivated regions in Central Europe impede reforestation plans so the potential for a significant increase of natural water retention in forests is strongly limited. Nevertheless the development of innovative forms of land use and crop types opens new perspectives for a combination of agricultural land use with the water retention potential of forests. Recently the increasing demand for renewable energy resources leads to the cultivation of fast growing poplar and willow hybrids on agricultural land in short rotation coppices (SRC). Harvested in cycles of three to six years the wood from the plantations can be used as wood chips for heat and electricity production in specialized power plants. With short rotation plantations a crop type is established on arable land which is similar to forests so that an improvement of water retention can be expected. To what extend SRC may contribute to flood attenuation in headwater areas is investigated for the Chemnitzbach watershed (48 km2) in the Eastern Ore Mountains (Free State of Saxony, Germany), a low mountain range which is an important source of flood runoff in the Elbe basin. The study is based on a rainfall-runoff model of flood events using the conceptual modelling system NASIM. First results reveal a significant reduction of the flood peaks after the implementation of short rotation coppices. However the effect strongly depends on two factors. The first factor is the availability of areas for the plantations. For a substantial impact on the watershed scale large areas are required and with decreasing percentages of SRC

  6. Improving the water use efficiency of short rotation coppice (SRC) willows

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, W.; Bonneau, L.; Groves, S.; Armstrong, A.; Lindegard, K.

    2003-07-01

    On the premise that biofuels will make a significant contribution to the UK's renewable energy sources by the year 2010, willow short rotation coppicing is being studied. The high water requirement of willow is seen as a potential problem in the drier regions of the UK and increasing the water use efficiency and/or draught resistance would extend the areas where willow coppicing would be profitable. The first part of the project was to investigate the water use of a number of near-market varieties of willow and evaluate techniques for early drought tolerance screening in a breeding program and for this, field studies were conducted. This report gives some very early results from the preliminary study. Since DTI funding ceased before the one-season study of the three-year program was complete, the results should be regarded as tentative only. The next phase of the program will be funded by DEFRA and will include efforts to identify how a range of high-yielding willows respond to water stress.

  7. Background CH4 and N2O fluxes in low-input short rotation coppice

    Science.gov (United States)

    Görres, Carolyn-Monika; Zenone, Terenzio; Ceulemans, Reinhart

    2016-04-01

    Extensively managed short rotation coppice systems are characterized by low fluxes of CH4 and N2O. However due to the large global warming potential of these trace gases (GWP100: CH4: 34, N2O: 298), such background fluxes can still significantly contribute to offsetting the CO2 uptake of short rotation coppice systems. Recent technological advances in fast-response CH4 and N2O analysers have improved our capability to capture these background fluxes, but their quantification still remains a challenge. As an example, we present here CH4 and N2O fluxes from a short-rotation bioenergy plantation in Belgium. Poplars have been planted in a double-row system on a loamy sand in 2010 and coppiced in the beginning of 2012 and 2014 (two-year rotation system). In 2013 (June - November) and 2014 (April - August), the plantation's CH4 and N2O fluxes were measured in parallel with an eddy covariance tower (EC) and an automated chamber system (AC). The EC had a detection limit of 13.68 and 0.76 μmol m-2 h-1 for CH4 and N2O, respectively. The median detection limit of the AC was 0.38 and 0.08 μmol m-2 h-1 for CH4 and N2O, respectively. The EC picked up a few high CH4 emission events with daily averages >100 μmol m-2 h-1, but a large proportion of the measured fluxes were within the EC's detection limit. The same was true for the EC-derived N2O fluxes where the daily average flux was often close to the detection limit. Sporadically, some negative (uptake) fluxes of N2O were observed. On the basis of the EC data, no clear link was found between CH4 and N2O fluxes and environmental variables. The problem with fluxes within the EC detection limit is that a significant amount of the values can show the opposite sign, thus "mirroring" the true flux. Subsequently, environmental controls of background trace gas fluxes might be disguised in the analysis. As a next step, it will be tested if potential environmental drivers of background CH4 and N2O fluxes at the plantation can be

  8. Growth and yield of mixed polyclonal stands of Populus in short-rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Benbrahim, Mohammed; Gavaland, Andre [INRA centre de Toulouse (France). Unite Agroforesterie et foret Paysanne; Gauvin, Jean [INRA centre d' Orleans (France). Unite d' Amelioration des arbres forestiers

    2000-07-01

    Eight clones of poplar were used to compare the growth and productivity of monoclonal and polyclonal mixed plantations in short-rotation coppice. At the end of the eight growing season, the diameter at breast height (DBH) and height of trees were measured and dry weight and yield were estimated. Polyclonal mixtures did not affect mortality. Few differences in growth were observed between clones in monoclonal plots. Polyclonal mixture slightly affected the growth and tree size of the clones compared with monoclonal plots. No increase in stand heterogeneity in relation to clone deployment was observed. A neighbourhood index was calculated for each tree and was significantly affected by polyclonal mixture. However, the relationship between the neighbourhood index and the DBH indicated that this effect did not cause a great change in DBH. Consequently, dry weight and yield productivity were not affected by clone deployment.

  9. Non-energy markets for small roundwood, forest residues and short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Watt, G.

    1995-06-01

    Competition for roundwood is intense at the present time with prices ranging from approximately Pound 20 to Pound 51 per green tonne delivered at mill. The sawmilling industry produces nearly 2 million green tonnes of residues annually from converting British roundwood and about 85% of this is used by the panelboard and paperboard mills. The remaining 15%, comprising mostly bark, and some of the unpeeled chips are used as material for mulching, landscaping and horticultural use, play areas, paths and horse gallops, soil composting and soil conditioning. Wood shavings and sawdust is produced by joinery and milling firms from imported sawn timber and amounts to about 300,000 tonnes/annum. Approximately 70% of this is used for higher priced markets, bedding for horses, chicken and turkeys, cattle and other uses. The remaining 30% is used in the wood processing industry. An increasing volume of solid wood waste which previously went for landfill sites is now being recycled and this trend is expected to continue. Only a very small proportion of the forest residues (tree tops and branches) produced each year is utilised and most of this material is used as mulch for horticultural and landscape uses. Markets for material from traditional short rotation coppice are limited relative to potential production but work is underway to develop new markets. There are no established markets for recently planted non-traditional coppice of willow and poplar with potential for energy production. Trials organised by ETSU and the DTI have indicated the suitability of the material for chipboard production provided the bark percentage is not too high. (author)

  10. Non-energy markets for small roundwood, forest residues and short rotation coppice

    International Nuclear Information System (INIS)

    Watt, G.

    1995-01-01

    Competition for roundwood is intense at the present time with prices ranging from approximately Pound 20 to Pound 51 per green tonne delivered at mill. The sawmilling industry produces nearly 2 million green tonnes of residues annually from converting British roundwood and about 85% of this is used by the panelboard and paperboard mills. The remaining 15%, comprising mostly bark, and some of the unpeeled chips are used as material for mulching, landscaping and horticultural use, play areas, paths and horse gallops, soil composting and soil conditioning. Wood shavings and sawdust is produced by joinery and milling firms from imported sawn timber and amounts to about 300,000 tonnes/annum. Approximately 70% of this is used for higher priced markets, bedding for horses, chicken and turkeys, cattle and other uses. The remaining 30% is used in the wood processing industry. An increasing volume of solid wood waste which previously went for landfill sites is now being recycled and this trend is expected to continue. Only a very small proportion of the forest residues (tree tops and branches) produced each year is utilised and most of this material is used as mulch for horticultural and landscape uses. Markets for material from traditional short rotation coppice are limited relative to potential production but work is underway to develop new markets. There are no established markets for recently planted non-traditional coppice of willow and poplar with potential for energy production. Trials organised by ETSU and the DTI have indicated the suitability of the material for chipboard production provided the bark percentage is not too high. (author)

  11. Development of short-rotation willow coppice systems for environmental purposes in Sweden

    International Nuclear Information System (INIS)

    Mirck, Jaconette; Verwijst, Theo; Isebrands, J.G.; Ledin, Stig

    2005-01-01

    During the last three decades, driving forces behind the development of short-rotation willow coppice (SRWC) in Sweden have been changing from a primary focus on biomass production towards emphasis on environmental applications. In most cases, current commercial SRWC practice is geared towards a combination of biomass production for energy purposes and environmental goals. The latter goals range from decreasing the impact of specific contaminants in the environment to organic waste handling in a recycling system in urban and/or agricultural areas. Where biomass production and pollutant management overlap, the science of phytoremediation has its practical application. Through phytoremediation, waste products that previously have been a burden for society can be used as valuable resources to increase short-rotation willow biomass production. In this paper we will present the terminology and definitions of different types of phytoremediation. We also give an overview of five different cases of phytoremediation activities with a potential for large-scale implementation. Some of the types of activities are already commercially used in Sweden; others seem promising but still need further development. (Author)

  12. Work analysis of the machine Claas Jaguar 880 employed in short rotation coppice harvesting

    Directory of Open Access Journals (Sweden)

    Verani S

    2010-02-01

    Full Text Available Working times observed during different harvesting phases in a poplar short rotation coppice (second rotation were calculated. The main objective of the work was to evaluate the yard productivity and the economic gain in order to furnish good indications to the field operators about the harvesting planning. A comparisons between productivity and economic features was carried out on observed (experimental yard and optimized data (optimized yard, the latter characterized by the absence of the inproductive times due to suboptimal yard organization. The harvested gross time as a function of distance covered by machine was assessed using linear regressions methods. The observed average biomass in plantation was 47.32 t ha-1. The harvesting gross average productivity observed in experimental yard was 34.20 t h-1 and the optimized was 54.16 t h-1. The working ability was 0.76 and 1.18 ha h-1 for experimental and optimized yard, respectively. The final product (chips costs estimated was 9.81 euro t-1 and 444.46 euro ha-1 in the experimental yard. The optimized yard was 22-24% more efficient. This paper demonstrates the feasibilty to estimate harvesting times and costs per hectare using linear regressions with good approximation when the standing biomass in plantation is known.

  13. A further evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2002-07-01

    This report describes a study of the safety and efficacy of a range of herbicides and mixtures of herbicides (with both contact and residual activity) for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). Severe competition from weeds that have not been controlled adequately by pre-emergence herbicide application is one of the commonest causes of SRC crop failure. In the study, the effects of 11 herbicide treatments currently recommendation for weed control with cereals, legumes or potatoes were compared with an untreated control. There was minimal crop death from any treatment, though most of the treatments caused varying degrees of phytotoxicity. Two commercial products, Reflex T and Impuls, gave the best overall crop safety and weed control results. The report provides growers of SRC and their advisors with some information on how to achieve improved weed control in SRC fields, and recommends that British Biogen (the trade industry body) should consider the compilation of a technical register of herbicide applications based on information supplied by growers and advisers, including field treatment details.

  14. Response surface methodology to simplify calculation of wood energy potency from tropical short rotation coppice species

    Science.gov (United States)

    Haqiqi, M. T.; Yuliansyah; Suwinarti, W.; Amirta, R.

    2018-04-01

    Short Rotation Coppice (SRC) system is an option to provide renewable and sustainable feedstock in generating electricity for rural area. Here in this study, we focussed on application of Response Surface Methodology (RSM) to simplify calculation protocols to point out wood chip production and energy potency from some tropical SRC species identified as Bauhinia purpurea, Bridelia tomentosa, Calliandra calothyrsus, Fagraea racemosa, Gliricidia sepium, Melastoma malabathricum, Piper aduncum, Vernonia amygdalina, Vernonia arborea and Vitex pinnata. The result showed that the highest calorific value was obtained from V. pinnata wood (19.97 MJ kg-1) due to its high lignin content (29.84 %, w/w). Our findings also indicated that the use of RSM for estimating energy-electricity of SRC wood had significant term regarding to the quadratic model (R2 = 0.953), whereas the solid-chip ratio prediction was accurate (R2 = 1.000). In the near future, the simple formula will be promising to calculate energy production easily from woody biomass, especially from SRC species.

  15. Greenhouse gas mitigation potential of short-rotation-coppice based generation of electricity in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.; Meyer-Aurich, A.; Kern, J.; Balasus, A.; Prochnow, A. [Leibniz Inst. of Agricultural Engineering, Potsdam (Germany)

    2010-07-01

    The generation of energy from wood biomass may help secure local energy supplies and reduce the greenhouse effect by substituting fossil resources with bio-based ones. In the case of short rotation coppice (SRC), bio-based resources can be generated by extensive agricultural production systems. They produce less carbon dioxide equivalent (CO{sub 2eq}) emissions than fossil resources. This paper reported on a study in which a model system was developed for a regional supply chain producing second generation bioenergy generated from SRC in eastern Germany. The study focuses on the generation of electricity and was compared to a business-as-usual reference system, based on the latest CO{sub 2} mitigation factors for renewable energies in the German power-generation mix. A life cycle assessment based on greenhouse gas (GHG) inventories was also conducted in which other factors were also considered, such as options for nutrient cycling. The key determinants for GHG mitigation with SRC were also discussed with regards to indirect land-use effects resulting from increased demand for land.

  16. The role of short rotation coppice technology in fuelwood supply in Rungwe district, Tanzania

    Directory of Open Access Journals (Sweden)

    G.M. Karwani

    2016-06-01

    Full Text Available The roles of Short Rotation Coppice (SRC Technology in fuelwood supply and offsetting CO2 emissions in the Tanzania and most African countries remain poorly understood. This study was carried in Rungwe District, Mbeya region in Tanzania, to determine trends, extent and drivers of adoption of SRC; identify various sources of household energy and assess the contribution of SRC to the total household fuelwood needs, and trees and shrub species used as sources of fuelwood. Data were collected using reconnaissance, field and social surveys and was analyzed using the Statistical Package for Social Sciences (SPSS. Results revealed that, 97.5% of local community adopted the SRC technology since 1960s. Eucalyptus spp. are mostly planted in woodlots and field boundaries while Persea americana and Leucaena leucocephala are intercropped in farmlands. The survey indicated that out of 176 tons of fuelwood used annually, 73% comes from SRC technology, 25% from non-SRC technology, and only 2% is purchased to supplement household fuelwood shortage. Local communities depend heavily on biomass energy from woodlots and farmlands where tree species like Eucalyptus spp. plays a key role in meeting the energy demand. This study demonstrates that SRC technologies like woodlots, boundary planting, and intercropping in farmland hold high promise to meet the household energy demand. If promoted and backed with strong policies and supportive land tenure, these technologies may reduce the harvesting pressure on native forests for energy demand and contribute to climate change mitigation and adaptation.

  17. Predictive models of biomass for poplar and willow. Short rotation coppice in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, A.C.; Morgan, G.W.; Poole, E.J.; Baldwin, M.E.; Tubby, I. (Biometrics, Surveys and Statistics Division, Forest Research, Farnham (United Kingdom))

    2007-07-01

    A series of forty-nine experimental trials on short rotation coppice (SRC) were conducted throughout the United Kingdom using a selection of varieties of poplar and willow with the aim of evaluating their performance for wood fuel production under a representative range of UK conditions. Observations on the crops and on a range of site and climatic conditions during the growth of the crops were taken over two three-year cutting cycles. These observations were used to develop a suite of empirical models for poplar and willow SRC growth and yield from which systems were constructed to provide a- priori predictions of biomass yield for any site in the UK with known characteristics (predictive yield models), and estimates of biomass yield from a standing crop (standing biomass models). The structure of the series of field trials and the consequent approach and methodology used in the construction of the suite of empirical models are described, and their use in predicting biomass yields of poplar and willow SRC is discussed. (orig.)

  18. Monitoring the progress of NFFO-3 projects: short rotation willow coppice - agronomy and economics

    International Nuclear Information System (INIS)

    Twemlow, R.K.M.

    1997-01-01

    The involvement of Sidney C. Banks p.l.c., and the subsidiary company Banks Agriculture, in fuel supply for biofuelled power stations started some 4 years ago. When identifying possible opportunities and crops it was apparent that, with the third tranche of Non-Fossil Fuel Obligations (NFFO3) coming up, there were companies looking at developing biofuelled power stations, using Short Rotation Coppice (SRC) and for this they needed to link with potential fuel suppliers. Sidney C. Banks p.l.c. linked with South Western Power (SWP) (a subsidiary of South Western Electricity p.l.c. (SWEB)) to act as their sole fuel supplier on projected biofuel wood power stations. Subsequently two wood fuelled power stations were awarded to SWP and Sidney C. Banks p.l.c. in the 3rd Tranche from NFFO, in December 1994. The objectives of this project were to: establish a network of SRC growers to produce fuel for a NFFO project; monitor the success of the enterprise; implement a programme of constant improvement to optimise the fuel supply strategy; and provide valuable information as to the performance of the SRC crop in large scale commercial production. (author)

  19. Harvesting of short rotation coppice. Harvesting trials with a cut and storage system in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schweier, J.; Becker, G.

    2012-11-01

    Short rotation coppice (SRC) harvesting techniques are available in Germany, but broad experience and knowledge about machine performance and the related effective costs of harvesting operations are still missing. This information is crucial, as harvesting costs strongly influence the economic performance of the overall supply chain. Therefore, it was the aim of this study to collect and analyze productivity data of different harvesting systems for SRC. The combined cut and chip system on the one hand and the cut and storage system on the other hand were studied by literature review. Several studies analyze the combined cut and chip systems and the reported machine productivities showed great variations. The average was 30 green tons per scheduled machine hour (gt smh{sup -1}). Few studies are analysing the cut and storage system. They report that machines still are under development and that further research is needed. Therefore, time studies of harvesting operations using the cut and storage system were carried out. Five trials were performed with the harvesting machine 'Stemster MK III' developed by Nordic Biomass. The share of productive working time was 85% and the average productivity was 21 gt smh{sup -1}. These results were compared with values from the literature. Resulting harvesting costs were calculated per oven dry ton (Euro odt{sup -1}). The advantages and disadvantages of both harvesting systems are highlighted. (orig.)

  20. Potential of poplar short rotation coppice cultivation for bioenergy in Southern Portugal

    International Nuclear Information System (INIS)

    Pereira, Sandrina; Costa, Mário; Graça Carvalho, Maria da; Rodrigues, Abel

    2016-01-01

    Highlights: • Evaluation of the potential of poplar coppice cultivation for bioenergy. • Biomass costs from 76.9 to 120.5 Euro/ton and net energy from 34.7 to 75.4 PJ. • Biomass co-firing in power plants reduces CO_2 emissions between 8.2% and 16.5%. • A scenario of CO_2 allowances trading can turn the project financially viable. - Abstract: This manuscript examines the potential of poplar short rotation coppice cultivation for bioenergy in the Alentejo region, Southern Portugal. The biomass is intended to fulfil, at least, 10% (energy basis) of the fuel needs of two Portuguese coal-fired power plants (Sines and Pego), using co-firing technology. The study considers the overall production chain from cradle to power plant gate, cultivated in scrubland areas with duration of 12 years, harvested every three years and with 6667 plants per ha, covering a land area of about 52,250 ha. Three different biomass annual yields are assumed. The results show that the biomass selling prices range from 76.9 to 120.5 Euro ton"−"1, to match the production costs. The net energy of the overall project ranges from 34.7 to 75.4 PJ and the project cost from 619 to 823.9 MEuro. The main environmental impact of the project is the reduction of the CO_2 emissions due to the biomass co-firing, instead of burning coal alone. The power plants can reduce CO_2 emissions over the project lifetime between 8.2% and 16.5% of the current values. The financial analysis demonstrates that the project is not financially feasible without external grants, but a policy scenario of carbon allowances trading may be instrumental on turning it financially feasible, depending on allowances and coal market prices. Finally, with a reduction of 50% in the main costs, the project becomes financially feasible under a CO_2 emissions trading scenario for a biomass yield of 20 dry ton ha"−"1 per year.

  1. Firewood yield and profitability of a traditional Daniellia oliveri short-rotation coppice on fallow lands in Benin

    International Nuclear Information System (INIS)

    Avohou, T. Hermane; Houehounha, Remy; Glele-Kakai, Romain; Assogbadjo, Achille Ephrem; Sinsin, Brice

    2011-01-01

    Sub-Saharan Africa has a great diversity of local coppicing species which are exploited in traditional short coppice systems for firewood. Biomass yield and profitability of these systems as well as their responses to silvicultural improvement are little known. This study evaluated the firewood yield and the profitability of a traditional Daniellia oliveri short-rotation coppice on fallow lands in central Benin. Two weed management options were considered: (1) the weedy option, usually practiced by locals, which experienced grass competition and bushfires, and (2) the weed-free option, which consisted in periodic removal of grasses and other species. Destructive measurements and allometric equations were used to estimate biomass yield in 12 plots over 42 months. A cost-benefit analysis model based on the net present value and the benefit-cost ratio was used to compare the profitability of the two management options. Biomass accumulation rate averaged 1.08 ± 0.20 tonnes of dry matter ha -1 year -1 (t DM ha -1 year -1 ) in weedy conditions. Weed removal improved 3.5 times this rate in weed-free plots (3.83 ± 0.47 t DM ha -1 year -1 ). After 42 months, total biomass reached 3.67 ± 0.65 t DM ha -1 in weedy plots and 11.63 ± 0.76 t DM ha -1 in weed-free plots. Most of the biomass (≥88%) was marketable in local markets. Coppice exploitation was profitable after 24 months for both management options. Weed removal improved the profits three times. A sensitivity analysis showed that both options were still profitable with up to 25% increase of labour and transport costs, 25% decrease of biomass price and 12% increase of the discount rate. (author)

  2. Coppicing evaluation of short rotation coppice in the southeast of the U.S. to determine appropriate harvesting methods.

    Science.gov (United States)

    Rafael Santiago; Tom Gallagher; Matthew Smidt; Dana Mitchell

    2016-01-01

    Renewable fuels are being tested as an alternative for fossil fuels. For the Southeast U.S., the use of woody biomass has proven to be an excellent source of renewable energy in terms of cost benefit and availability. Short rotation woody crops (SRWC) are timber plantations with exclusive characteristics that can meet the intensive demand for wood due to their fast...

  3. Conversion from cropland to short rotation coppice willow and poplar: Accumulation of soil organic carbon

    Science.gov (United States)

    Georgiadis, Petros; Stupak, Inge; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-04-01

    Increased demand for bioenergy has intensified the production of Short Rotation Coppice (SRC) willow and poplar in temperate zones. We used a combined chronosequence and paired plot approach to study the potential of SRC willow and poplar stands to increase the soil carbon stock compared to stocks of the previous arable land-use. The study focused on well-drained soils. We sampled soil from 30 SRC stands in Denmark and southern Sweden including soils from their adjacent arable fields. The 18 willow and 12 poplar stands formed a chronosequence ranging between 4 and 29 years after conversion. The soil was sampled both with soil cores taken by fixed depths of 0-5, 5-10, 10-15, 15-25, and 25-40 cm and by genetic horizons from soil pits to 1m depth. The aim of the study was to estimate the difference and the ratio between soil carbon contents of the SRC and annual crop land and analyze the results as a chronosequence to examine the effect of age after conversion on the difference. Covariates such as soil type, fertilization type and harvest frequency were also taken into account. Preliminary results suggest an overall increase in carbon stocks over time with average accumulation rates ranging from 0.25 to 0.4 Mg ha-1 yr-1 in willow and poplar stands. Poplar stands had higher rates of C gain, probably due to less frequent harvesting. The differences in carbon between the SRC and the paired cropland were initially negative but changed to positive over time, implying loss of carbon after conversion and a later gain in soil carbon with stand age. Pairwise differences ranged from -25 Mg C ha-1 to 37 Mg C ha-1 for the top 40 cm. The carbon stock ratio of the SRC stand to the arable land was estimated to minimize the effect of site-related factors. The results of this analysis suggested that the ratio increased significantly with age after conversion for the top 10 cm of the soil, both for poplar and willow. A slight increase with age was also noticed at the deeper depths, but

  4. Influence of Robinia pseudoacacia short rotation coppice on soil physical properties

    Science.gov (United States)

    Xavier, Morvan; Isabelle, Bertrand; Gwenaelle, Gibaud

    2015-04-01

    Human activities can lead to the degradation of soil physical properties. For instance, machinery traffic across the land can induce the development of compacted areas at the wheel tracks. It leads to a decrease in porosity which results in a decrease of the hydraulic conductivity, and therefore, prevents water infiltration and promotes surface runoff. Land use, soil management and soil cover also have a significant influence on soil physical properties (Kodesova et al., 2011). In the arable land, surface runoff and soil erosion are enhanced by the absence of soil cover for part of the year and by the decrease of aggregate stability due to a decline of soil organic matter. In that context, few studies focused on the effects of a Robinia pseudoacacia short rotation coppice (SRC) on soil physical properties. Therefore, this study aims to determine the effect of the conversion of a grassland in a SRC on soil physical properties. These properties have also been compared to those of arable land and natural forest. For that, in several plots of the experimental farm of Grignon (30 km west of Paris, France), different measurements were performed: i) soil water retention on a pressure plate apparatus for 7 water potential between 0 and 1500 kPa, ii) bulk density using the method for gravelly and rocky soil recommended by the USDA, iii) aggregate stability using the method described in Le Bissonnais (1996), and iv) soil hydraulic conductivity using a Guelph permeameter. All these measurements were performed on the same soil type and on different land uses: arable land (AL), grassland (GL), natural forest (NF) and short rotation coppice (SRC) of Robinia pseudoacacia planted 5 years ago. Soil water retention measurements are still under progress and will be presented in congress. Bulk density measurements of the AL, GL and SRC are not significantly different. They ranged from 1.32 to 1.42. Only the NF measurements are significantly lower than the other (0.97). Aggregate

  5. Biomass energy in organic farming - the potential role of short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Uffe; Dalgaard, Tommy [Danish Inst. of Agricultural Sciences (DIAS), Dept. of Agroecology, Research Centre Foulum, Tjele (Denmark); Kristensen, Erik Steen [Danish Research Centre for Organic Farming (DARCOF), Research Centre Foulum, Tjele (Denmark)

    2005-02-01

    One of the aims of organic farming is to 'reduce the use of non-renewable resources (e.g. fossil fuels) to a minimum'. So far, however, only very little progress has been made to introduce renewable energy in organic farming. This paper presents energy balances of Danish organic farming compared with energy balances of conventional farming. In general, the conversion to organic farming leads to a lower energy use (approximately 10% per unit of product). But the production of energy in organic farming is very low compared with the extensive utilisation of straw from conventional farming in Denmark (energy content of straw used for energy production was equivalent to 18% of total energy input in Danish agriculture in 1996). Biomass is a key energy carrier with a good potential for on-farm development. Apart from utilising farm manure and crop residues for biogas production, the production of nutrient efficient short rotation coppice (SRC) is an option in organic farming. Alder (Alnus spp.) is an interesting crop due to its symbiosis with the actinomycete Frankia, which has the ability to fix up to 185 kg/ha nitrogen (N{sub 2}) from the air. Yields obtained at different European sites are presented and the R and D needed to implement energy cropping in organic farming is discussed. Possible win-win solutions for SRC production in organic farming that may facilitate its implementation are; the protection of ground water quality in intensively farmed areas, utilisation of wastewater for irrigation, or combination with outdoor animal husbandry such as pigs or poultry. (Author)

  6. Water use of a multigenotype poplar short-rotation coppice from tree to stand scale.

    Science.gov (United States)

    Bloemen, Jasper; Fichot, Régis; Horemans, Joanna A; Broeckx, Laura S; Verlinden, Melanie S; Zenone, Terenzio; Ceulemans, Reinhart

    2017-02-01

    Short-rotation coppice (SRC) has great potential for supplying biomass-based heat and energy, but little is known about SRC's ecological footprint, particularly its impact on the water cycle. To this end, we quantified the water use of a commercial scale poplar ( Populus ) SRC plantation in East Flanders (Belgium) at tree and stand level, focusing primarily on the transpiration component. First, we used the AquaCrop model and eddy covariance flux data to analyse the different components of the stand-level water balance for one entire growing season. Transpiration represented 59% of evapotranspiration (ET) at stand scale over the whole year. Measured ET and modelled ET were lower as compared to the ET of reference grassland, suggesting that the SRC only used a limited amount of water. Secondly, we compared leaf area scaled and sapwood area scaled sap flow ( F s ) measurements on individual plants vs. stand scale eddy covariance flux data during a 39-day intensive field campaign in late summer 2011. Daily stem diameter variation (∆ D ) was monitored simultaneously with F s to understand water use strategies for three poplar genotypes. Canopy transpiration based on sapwood area or leaf area scaling was 43.5 and 50.3 mm, respectively, and accounted for 74%, respectively, 86%, of total ecosystem ET measured during the intensive field campaign. Besides differences in growth, the significant intergenotypic differences in daily ∆ D (due to stem shrinkage and swelling) suggested different water use strategies among the three genotypes which were confirmed by the sap flow measurements. Future studies on the prediction of SRC water use, or efforts to enhance the biomass yield of SRC genotypes, should consider intergenotypic differences in transpiration water losses at tree level as well as the SRC water balance at stand level.

  7. Effect of biomass pretreatment on the product distribution and composition resulting from the hydrothermal liquefaction of short rotation coppice willow

    DEFF Research Database (Denmark)

    Grigoras, Ionela; Stroe, Rodica-Elisabeta; Sintamarean, Iulia-Maria

    2017-01-01

    A major challenge for the implementation of hydrothermal liquefaction (HTL) as a continuous process is the formulation of lignocellulosic feedstock, which is prone to phase separation into water and biomass parts when pressurized. One approach to remedy such phase separation is to reduce the dry...... from the HTL of willow and proposes short rotation coppice as an alternative biomass feedstock for biofuels production. Alkaline–thermal pretreatment, besides making high dry matter pumpable feedstock slurries, also led to an increase in the production of the bio-crude product with an oxygen content...

  8. Modelling short-rotation coppice and tree planting for urban carbon management - a citywide analysis.

    Science.gov (United States)

    McHugh, Nicola; Edmondson, Jill L; Gaston, Kevin J; Leake, Jonathan R; O'Sullivan, Odhran S

    2015-10-01

    The capacity of urban areas to deliver provisioning ecosystem services is commonly overlooked and underutilized. Urban populations have globally increased fivefold since 1950, and they disproportionately consume ecosystem services and contribute to carbon emissions, highlighting the need to increase urban sustainability and reduce environmental impacts of urban dwellers. Here, we investigated the potential for increasing carbon sequestration, and biomass fuel production, by planting trees and short-rotation coppice (SRC), respectively, in a mid-sized UK city as a contribution to meeting national commitments to reduce CO 2 emissions.Iterative GIS models were developed using high-resolution spatial data. The models were applied to patches of public and privately owned urban greenspace suitable for planting trees and SRC, across the 73 km 2 area of the city of Leicester. We modelled tree planting with a species mix based on the existing tree populations, and SRC with willow and poplar to calculate biomass production in new trees, and carbon sequestration into harvested biomass over 25 years.An area of 11 km 2 comprising 15% of the city met criteria for tree planting and had the potential over 25 years to sequester 4200 tonnes of carbon above-ground. Of this area, 5·8 km 2 also met criteria for SRC planting and over the same period this could yield 71 800 tonnes of carbon in harvested biomass.The harvested biomass could supply energy to over 1566 domestic homes or 30 municipal buildings, resulting in avoided carbon emissions of 29 236 tonnes of carbon over 25 years when compared to heating by natural gas. Together with the net carbon sequestration into trees, a total reduction of 33 419 tonnes of carbon in the atmosphere could be achieved in 25 years by combined SRC and tree planting across the city. Synthesis and applications . We demonstrate that urban greenspaces in a typical UK city are underutilized for provisioning ecosystem services by trees and

  9. Prospects for arable farm uptake of Short Rotation Coppice willow and miscanthus in England.

    Science.gov (United States)

    Glithero, Neryssa J; Wilson, Paul; Ramsden, Stephen J

    2013-07-01

    Biomass will play a role in the UK meeting EU targets on renewable energy use. Short Rotation Coppice (SRC) and miscanthus are potential biomass feedstocks; however, supply will rely on farmer willingness to grow these crops. Despite attractive crop establishment grants for dedicated energy crops (DECs) in the UK, uptake remains low. Drawing on results from an on-farm survey with 244 English arable farmers, 81.6% (87.7%) of farmers would not consider growing miscanthus (SRC), while respectively, 17.2% (11.9%) would consider growing and 1.2% (0.4%) were currently growing these crops. Farmer age, location, land ownership, farm type, farm size and farmer education level were not significant factors in determining acceptance of DECs. The main reasons cited for not growing DECs were impacts on land quality, lack of appropriate machinery, commitment of land for a long period of time, time to financial return and profitability. Reasons cited for willingness to grow DECs included land quality, ease of crop management, commitment of land for a long period of time, and profitability. Farmers cited a range of 'moral' (e.g. should not be using land for energy crops when there is a shortage of food), land quality, knowledge, profit and current farming practice comments as reasons for not growing DECs, while those willing to grow DECs cited interest in renewable energy, willingness to consider new crops, and low labour needs as rationale for their interest. Farm business objectives indicated that maximising profit and quality of life were most frequently cited as very important objectives. Previous research in the UK indicates that farmers in arable areas are unlikely to convert large areas of land to DECs, even where these farmers have an interest and willingness to grow them. Assuming that those farmers interested in growing DECs converted 9.29% (average percentage of arable land set-aside between 1996 and 2005) of their utilised agricultural area to these crops, 50,700

  10. Dry Matter Losses and Greenhouse Gas Emissions From Outside Storage of Short Rotation Coppice Willow Chip.

    Science.gov (United States)

    Whittaker, Carly; Yates, Nicola E; Powers, Stephen J; Misselbrook, Tom; Shield, Ian

    This study examined the dry matter losses and the greenhouse gas (GHG) concentrations within two short rotation coppice (SRC) willow wood chip storage heaps. One heap was built on a grassland area (East Midlands) and the other (Rothamsted) on a concrete hard standing. A series of 1- and 3-m probes were embedded in the heaps in order to retrieve gas samples for analysis, and pre-weighed net bags were positioned in the core of the heap to detect dry matter losses. The bagged samples showed dry matter losses of 18 and 19 % in the East Midlands and Rothamsted heaps after 210 and 97 days storage, respectively. The Rothamsted heap showed a whole-heap dry matter loss of 21 %. During this time, the wood chips dried from 54 to 39 % moisture content in the East Midlands heap and 50 to 43 % at Rothamsted. The results from analysing the whole Rothamsted heap indicated an overall loss of 1.5 GJ per tonne stored, although measurements from bagged samples in the core suggested that the chips dried sufficiently to have a minimal energy loss from storage. The process of mixing the heap, however, led to incorporation of wet outer layers and hence the average moisture content was higher in an average sample of chip. After establishment of the heaps, the temperature rose rapidly and this correlated with a peak in carbon dioxide (CO 2 ) concentration within the heap. A peak in methane (CH 4 ) concentration was also detected in both heaps, though more noticeably in the East Midlands heap after around 55 days. In both instances, the peak CH 4 concentration occurred as CO 2 concentrations dropped, suggesting that after an active period of aerobic decomposition in the first 2 months of storage, the conditions in the heap became anaerobic. The results from this study suggest that outside wood chip storage is not an efficient method of storing biomass, though this may be location-specific as there are some studies showing lower dry matter losses. It is necessary to explore other

  11. Biomass productivity and water use relation in short rotation poplar coppice (Populus nigra x p. maximowiczii) in the conditions of Czech Moravian Highlands

    Czech Academy of Sciences Publication Activity Database

    Fischer, Milan; Trnka, Miroslav; Kučera, J.; Fajman, M.; Žalud, Zdeněk

    LIX, č. 6 (2011), s. 141-152 ISSN 1211-8516 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : short rotation coppice * biomass increment * water consumption * water use effi ciency Subject RIV: EH - Ecology, Behaviour

  12. Annual and Intra-Annual Water Balance Components of a Short Rotation Poplar Coppice Based on Sap Flow and Micrometeorological and Hydrological Approaches

    Czech Academy of Sciences Publication Activity Database

    Fischer, Milan; Orság, Matěj; Trnka, Miroslav; Pohanková, Eva; Hlavinka, Petr; Tripathi, Abishek; Žalud, Zdeněk

    2013-01-01

    Roč. 991, JUN 04-07 (2013), s. 401-408 ISSN 0567-7572 Institutional support: RVO:67179843 Keywords : short rotation poplar coppice * water balance * sap flow * Bowen ratio and energy balance method * modeling Subject RIV: EH - Ecology, Behaviour

  13. The development of a wood fuel gasification plant utilising short rotation coppice and forestry residues: project ARBRE

    International Nuclear Information System (INIS)

    Pitcher, K.F.; Lundbergt, H.

    1997-01-01

    This paper will discuss the development of ARBRE Energy, a joint venture company that includes Yorkshire Environmental of the United Kingdom and Tenniska Processer AB of Sweden. The project will establish 2000 hectares of short rotation coppices, some of which will be organically fertilized with digested sewage sludges, to provide 80% of the fuel requirements of a biomass integrated gasification combined cycle (BIGCC) electricity generation plant. The remaining 20% of the fuel requirements will come from forestry waste, although in the first 5 years all the fuel will come from the forestry sources until the coppices are mature. The project will construct a gasification plant at Eggborough, North Yorkshire, England, which will provide gas to a gas turbine and steam turbine generation system, producing 10 MW and exporting 8 MW of electricity. It has been included in the 1993 tranche of the UK's Non Fossil Fuel Obligation (NFFO) and has gained financial support from the European Commission's THERMIE programme as a targeted BIGCC project. The project's technical and environmental effects and benefits will be examined in detail, together with the award of its planning permit and agreement on its operating license. (author)

  14. Biomass yield and fuel characteristics of short-rotation coppice (willow, poplar, empress tree)

    Energy Technology Data Exchange (ETDEWEB)

    Maier, J.; Vetter, R. [Institute for Land Management Compatible to Environmental Requirements, Muellheim (Germany)

    2004-07-01

    In two pedo-climatic different regions in the state of Baden-Wuerttemberg three shortrotation coppices willow, poplar and empress tree were tested with regard to their biomass productivity on arable land and to their properties for energetic use. Between 8 and 13 tons of dry matter per hectare and year could be produced under extensive cultivation conditions, over 15 tons with irrigation. Due to their composition, it can be assumed that their use as solid fuel in a biomass combustor is just as unproblematic as with forest timber. (orig.)

  15. Climate impact and energy efficiency from electricity generation through anaerobic digestion or direct combustion of short rotation coppice willow

    International Nuclear Information System (INIS)

    Ericsson, Niclas; Nordberg, Åke; Sundberg, Cecilia; Ahlgren, Serina; Hansson, Per-Anders

    2014-01-01

    Highlights: • Using LCA, CHP from willow use in biogas was compared with direct combustion. • Direct combustion was ninefold more energy-efficient. • Biogas had a much greater cooling effect on global mean surface temperature. • The effects of soil carbon changes on temperature over time differed. • Biogas had long-term temperature effects, direct combustion short-term effects. - Abstract: Short rotation coppice willow is an energy crop used in Sweden to produce electricity and heat in combined heat and power plants. Recent laboratory-scale experiments have shown that SRC willow can also be used for biogas production in anaerobic digestion processes. Here, life cycle assessment is used to compare the climate impact and energy efficiency of electricity and heat generated by these measures. All energy inputs and greenhouse gas emissions, including soil organic carbon fluxes were included in the life cycle assessment. The climate impact was determined using time-dependent life cycle assessment methodology. Both systems showed a positive net energy balance, but the direct combustion system delivered ninefold more energy than the biogas system. Both systems had a cooling effect on the global mean surface temperature change. The cooling impact per hectare from the biogas system was ninefold higher due to the carbon returned to soil with the digestate. Compensating the lower energy production of the biogas system with external energy sources had a large impact on the result, effectively determining whether the biogas scenario had a net warming or cooling contribution to the global mean temperature change per kWh of electricity. In all cases, the contribution to global warming was lowered by the inclusion of willow in the energy system. The use of time-dependent climate impact methodology shows that extended use of short rotation coppice willow can contribute to counteract global warming

  16. Mechanical pre-planting weed control in short rotation coppice using deep forestry ploughing techniques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    This report describes a trial by Border biofuels to investigate the deep forestry plough as a mechanical pre-planting weed control method to reduce weed infestations in willow coppice and thus contribute to improved establishment and eventual yield. The results suggest that there was a considerable increase in biomass productivity from the deep ploughed area compared to the conventionally cultivated area at all three SRC sites tested. This technique also suggests that the deep forestry ploughing provides the benefit of much reduced levels of seed germination of many annual weed species and a reduction in levels of perennial weed infestation. It is not possible at this stage to predict the longer term benefits in terms of harvestable biomass productivity but it may be considered that the improved establishment and lack of weed competition would consistently produce higher yields of biomass than plantations which suffer from persistent and invasive weed competition. (author)

  17. Short rotation coppice with Robinia pseudoacacia L. : a land use option for carbon sequestration on reclaimed mine sites

    Energy Technology Data Exchange (ETDEWEB)

    Quinkenstein, A.; Bohm, C.; Freese, D. [Brandenburg Univ. of Technology, Cottbus (Germany). Soil Protection and Recultivation; Huttl, R.R. [Brandenburg Univ. of Technology, Cottbus (Germany). Soil Protection and Recultivation; GFZ German Research Centre for Geosciences, Potsdam (Germany)

    2010-07-01

    A study in northeast Germany has shown that the establishment of short rotation coppices (SRC) of Robinia pseudoacacia L. may be a viable option for improving farmers income on marginal soils. The plantations produce woody biomass at a fast rate for energy use. Carbon is accumulated in the harvestable biomass, as well as in the stump and the roots. These plant compartments form a long-term carbon storage pool because they can survive a harvest, stay vital at the site and continue to grow as the plant ages. As organic litter decomposes, additional carbon is sequestered under SRC as soil organic carbon. The carbon sequestration in SRC of R. pseudoacacia on mining sites within the Lower Lusatian region in northeast Germany was studied and the results were complemented with findings of current field studies conducted on reclaimed mine sites. The average above ground dry matter productivity of R. pseudoacacia was found to be 3 to 10 Mg per hectare per year, depending on the plantation age and rotation period. It has been estimated that the carbon storage within the soil accounts to a carbon sequestration of up to 6 Mg per hectare per year for a soil depth of 60 cm.

  18. ARBRE monitoring - ecology of short rotation coppice. Four year study involving wildlife monitoring of commercial SCR plantations planted on arable land and arable control plots

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, M.D.; Bishop, J.D.; McKay, H.V.; Sage, R.B.

    2004-07-01

    This report summarises the findings of the UK Department of Trade and Industry (DTI) funded project monitoring wildlife within and around a number of commercially managed Short Rotation Coppice (SRC) plantations aimed at using the information gathered to assess the ecological impact of SRC plantations on the wildlife in the area. The background to the study is traced, and details are given of the monitoring programme examining the distribution of flora and fauna within the plantations, and the monitoring of birds, plants, insects and butterflies. The greater diversity of wildlife and plants in the SRC plots, the higher densities of birds, and the increasing number of butterfly species are discussed along with the increased mean number of invertebrate orders with subsequent growth of willow coppices, and the habitats at the edges of the plots and at headlands designed for access to machinery within the plots.

  19. Management with willow short rotation coppice increase the functional gene diversity and functional activity of a heavy metal polluted soil.

    Science.gov (United States)

    Xue, K; van Nostrand, J D; Vangronsveld, J; Witters, N; Janssen, J O; Kumpiene, J; Siebielec, G; Galazka, R; Giagnoni, L; Arenella, M; Zhou, J-Z; Renella, G

    2015-11-01

    We studied the microbial functional diversity, biochemical activity, heavy metals (HM) availability and soil toxicity of Cd, Pb and Zn contaminated soils, kept under grassland or short rotation coppice (SRC) to attenuate the risks associated with HM contamination and restore the soil ecological functions. Soil microbial functional diversity was analyzed by the GeoChip, a functional gene microarray containing probes for genes involved in nutrient cycling, metal resistance and stress response. Soil under SRC showed a higher abundance of microbial genes involved in C, N, P and S cycles and resistance to various HM, higher microbial biomass, respiration and enzyme activity rates, and lower HM availability than the grassland soil. The linkages between functional genes of soil microbial communities and soil chemical properties, HM availability and biochemical activity were also investigated. Soil toxicity and N, P and Pb availability were important factors in shaping the microbial functional diversity, as determined by CCA. We concluded that in HM contaminated soils the microbial functional diversity was positively influenced by SRC management through the reduction of HM availability and soil toxicity increase of nutrient cycling. The presented results can be important in predicting the long term environmental sustainability of plant-based soil remediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Sewage sludge and wastewater fertilisation of Short Rotation Coppice (SRC) for increased bioenergy production - Biological and economic potential

    International Nuclear Information System (INIS)

    Dimitriou, I.; Rosenqvist, H.

    2011-01-01

    Application of municipal residues, e.g. wastewater or sewage sludge, to Short Rotation Coppice (SRC) is among the most attractive methods for attaining environmental and energy goals set for Europe. At current woodchip prices in Sweden, the gross margin for SRC cultivation is positive only if biomass production is >9 t DM/ha yr. The gross profit margin increases (by 39 and 199 EUR/GJ, respectively) if sewage sludge and wastewater are applied to SRC. Application of residues to SRC has proved to be an acceptable alternative treatment method, and the farmer's profit can be markedly increased if compensation is paid for waste treatment. If all available sludge and wastewater were applied to SRC plantations, they could be grown on large agricultural areas in Europe, and c. 6000 PJ of renewable energy could be produced annually. However, a more economical landuse strategy, e.g. the use of more P-rich residues, appears more rational, and is biologically justifiable. (author)

  1. Sewage sludge and wastewater fertilisation of Short Rotation Coppice (SRC) for increased bioenergy production - Biological and economic potential

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, I. [Department of Crop Production Ecology, Swedish University of Agricultural Sciences, P.O. Box 7043, SE 750 07 Uppsala (Sweden); Rosenqvist, H. [Department of Agriculture-Farming Systems, Technology and Product Quality, Swedish University of Agricultural Sciences, P.O. Box 17, SE-261 21 Billeberga (Sweden)

    2011-02-15

    Application of municipal residues, e.g. wastewater or sewage sludge, to Short Rotation Coppice (SRC) is among the most attractive methods for attaining environmental and energy goals set for Europe. At current woodchip prices in Sweden, the gross margin for SRC cultivation is positive only if biomass production is >9 t DM/ha yr. The gross profit margin increases (by 39 and 199 EUR/GJ, respectively) if sewage sludge and wastewater are applied to SRC. Application of residues to SRC has proved to be an acceptable alternative treatment method, and the farmer's profit can be markedly increased if compensation is paid for waste treatment. If all available sludge and wastewater were applied to SRC plantations, they could be grown on large agricultural areas in Europe, and c. 6000 PJ of renewable energy could be produced annually. However, a more economical landuse strategy, e.g. the use of more P-rich residues, appears more rational, and is biologically justifiable. (author)

  2. Energy plants increasingly important. Scientific results and practical experiences on the production of biogas plants and short rotation coppices. Symposium; Energiepflanzen im Aufwind. Wissenschaftliche Ergebnisse und praktische Erfahrungen zur Produktion von Biogaspflanzen und Feldholz. Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Heiermann, M.; Scholz, V.; Foltan, H. (comps.)

    2007-05-15

    The conference proceedings contain 15 contributions on energy plants: energy plant production in Germany - developments and research activities; potentials and constraints of cultivating energy crops; environmental aspects of production and utilization of energy plants; costs of energy crop supply; crops for the biogas production in the territory of Brandenburg; mixed cropping systems on sandy soils - alternative cropping strategies; impact of ensiling process on biogas production - recent research results; solid state anaerobic digestion of renewable biomass sources - state of research and development; energy crops as feedstock in a biogas plant; proffer and demand of wood fuel in the State of Brandenburg; regulatory framework of growing short rotation coppice; mechanization of SRC production; 20 years of short rotation coppice; willow production and marketing in Denmark; short rotation coppice production in Italy.

  3. Energy coppice

    International Nuclear Information System (INIS)

    Mitchell, C.P.

    1991-01-01

    One form of renewable energy production involves the growing of energy coppice on agricultural land. It is important as it can be grown on those areas of agricultural land which are surplus to agricultural production. Hence it can be seen as an alternative farm crop, and as such, a possible solution to the problem of agricultural surpluses as well as providing a source of energy. Studies have indicated that up to one million hectares of land surplus to agricultural production may be suitable for growing energy coppice. However, its development as an agricultural crop will only happen if it can be produced at costs competitive with alternative fuels and there is a reliable and long term market offering good returns. (author)

  4. Water requirements of short rotation poplar coppice: Experimental and modelling analyses across Europe

    Czech Academy of Sciences Publication Activity Database

    Fischer, Milan; Zenone, T.; Trnka, Miroslav; Orság, Matěj; Montagnani, L.; Ward, E. J.; Tripathi, Abishek; Hlavinka, Petr; Seufert, G.; Žalud, Zdeněk; King, J.; Ceulemans, R.

    2018-01-01

    Roč. 250, MAR (2018), s. 343-360 ISSN 0168-1923 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : energy-balance closure * dual crop coefficient * radiation use efficiency * simulate yield response * below-ground carbon * vs. 2nd rotation * flux data * biomass production * forest model * stand-scale * Bioenergy * Bowen ratio and energy balance * Crop coefficient * Eddy covariance * Evapotranspiration * Water balance Subject RIV: GC - Agronomy OBOR OECD: Agriculture Impact factor: 3.887, year: 2016

  5. Willow coppice systems in short rotation forestry: effects of plant spacing, rotation length and clonal composition on biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Willebrand, E.; Ledin, S.; Verwijst, T. (Swedish University of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research)

    1993-01-01

    Above ground biomass production was determined for ten Salix clones grown in pure and mixed stands at a square spacing of 1 m and seven rotation periods (1 to 6 and 8 years), and of one clone grown at four square spacings (0.5, 0.6, 0.7 and 1 m), with rotation cycles of 1 to 5 years. Most clones reached a maximum mean annual increment (8 to 14 tons dry matter ha[sup -1] yr[sup -1]) under a rotation period of 4 to 5 years. Densely spaced stands exhibited a higher production than wider spacings during the first harvests under the shortest rotation periods. Neither in later harvests of short cycles (1 to 3 years) nor in any harvests of longer cycles (> 3 years) did spacing affect biomass production. Some clones suffered from leaf rust and grazing by roe deer. Clone mixtures showed a higher biomass production in the later stages due to the compensatory effect of the successful clones which, when growing in mixtures, could fill out the gaps left by individuals that suffered from impacts other than competition. We conclude that extremely short rotations (1 to 2 years) are unsuitable for Swedish conditions, and that 4- to 6-year rotations perform best. In such longer rotations, biomass production of stands with 2 x 10[sup 4] plants per hectare equals the production of denser stands. (Author)

  6. Assessing Regional-Scale Impacts of Short Rotation Coppices on Ecosystem Services by Modeling Land-Use Decisions.

    Science.gov (United States)

    Schulze, Jule; Frank, Karin; Priess, Joerg A; Meyer, Markus A

    2016-01-01

    Meeting the world's growing energy demand through bioenergy production involves extensive land-use change which could have severe environmental and social impacts. Second generation bioenergy feedstocks offer a possible solution to this problem. They have the potential to reduce land-use conflicts between food and bioenergy production as they can be grown on low quality land not suitable for food production. However, a comprehensive impact assessment that considers multiple ecosystem services (ESS) and biodiversity is needed to identify the environmentally best feedstock option, as trade-offs are inherent. In this study, we simulate the spatial distribution of short rotation coppices (SRCs) in the landscape of the Mulde watershed in Central Germany by modeling profit-maximizing farmers under different economic and policy-driven scenarios using a spatially explicit economic simulation model. This allows to derive general insights and a mechanistic understanding of regional-scale impacts on multiple ESS in the absence of large-scale implementation. The modeled distribution of SRCs, required to meet the regional demand of combined heat and power (CHP) plants for solid biomass, had little or no effect on the provided ESS. In the policy-driven scenario, placing SRCs on low or high quality soils to provide ecological focus areas, as required within the Common Agricultural Policy in the EU, had little effect on ESS. Only a substantial increase in the SRC production area, beyond the regional demand of CHP plants, had a relevant effect, namely a negative impact on food production as well as a positive impact on biodiversity and regulating ESS. Beneficial impacts occurred for single ESS. However, the number of sites with balanced ESS supply hardly increased due to larger shares of SRCs in the landscape. Regression analyses showed that the occurrence of sites with balanced ESS supply was more strongly driven by biophysical factors than by the SRC share in the landscape. This

  7. An evaluation of harvesting machinery for short rotation coppice willow in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Spinelli, R.

    1997-12-31

    During the harvesting seasons 1994-1995 and 1995-1996 several harvesting trials were carried out within the EU project on harvesting and storage of Short Rotation Crops and within a national project. During this period the following machines were investigated: Diemelstadt poplar harvester, cut and chip; Claas forage harvester with SRF header, cut and chip; Austoft sugarcane harvester, adapted to SRF, cut and chip; Bender II, cut and chip; Hvidsted Energy Allrounder, whole shoot harvester; Dansalix whole shoot harvester. In the 1994-1995 season the intention was to harvest 300 tonnes of whole shoots, chunks and chips for a storage trial. The main conclusions of the 1994-1995 harvesting season must be that harvesting willow with the existing machines in wet winters without frozen ground is very difficult. The machines will have to be developed further and special interest should be given to developing shuttle vehicles with the same flotation as the tracked harvester. Several of the problems encountered with the machines in Denmark were confirmed by the experience in the other trials. Road transportation of chips from SRF plantations is just as expensive as transporting energy chips from the forest at about Dkr 50 per tonne over 48 km. Transporting whole shoots is very expensive due to the low bulk density. Transportation of whole shoots over 48 km costs on the average Dkr 133 per tonne fresh. A very short pilot study into chipping of whole shoots from a three metre high pile indicated that this comminution with a normal forest chipper has a low productivity (8.9 tonnes fresh per work place hour) and is very expensive at Dkr 157 per tonne. This productivity can be improved by equipping the chipper with a special feeding table and better feed rollers for the SRF crop. (EG)

  8. Limitations for phytoextraction management on metal-polluted soils with poplar short rotation coppice-evidence from a 6-year field trial.

    Science.gov (United States)

    Michels, E; Annicaerta, B; De Moor, S; Van Nevel, L; De Fraeye, M; Meiresonne, L; Vangronsveld, J; Tack, F M G; Ok, Y S; Meers, Erik

    2018-01-02

    Poplar clones were studied for their phytoextraction capacity in the second growth cycle (6-year growth) on a site in the Belgian Campine region, which is contaminated with Cd and Zn via historic atmospheric deposition of nearby zinc smelter activities. The field trial revealed regrowth problems for some clones that could not be predicted in the first growth cycle. Four allometric relations were assessed for their capacity to predict biomass yield in the second growth cycle. A power function based on the shoot diameter best estimates the biomass production of poplar with R 2 values between 0.94 and 0.98. The woody biomass yield ranged from 2.1 to 4.8 ton woody Dry Mass (DM) ha -1 y -1 . The primary goal was to reduce soil concentrations of metals caused by phytoextraction. Nevertheless, increased metal concentrations were determined in the topsoil. This increase can partially be explained by the input of metals from deeper soil layers in the top soil through litterfall. The phytoextraction option with poplar short rotation coppice in this setup did not lead to the intended soil remediation in a reasonable time span. Therefore, harvest of the leaf biomass is put forward as a crucial part of the strategy for soil remediation through Cd/Zn phytoextraction.

  9. Allometric Models to Predict Aboveground Woody Biomass of Black Locust (Robinia pseudoacacia L. in Short Rotation Coppice in Previous Mining and Agricultural Areas in Germany

    Directory of Open Access Journals (Sweden)

    Christin Carl

    2017-09-01

    Full Text Available Black locust is a drought-resistant tree species with high biomass productivity during juvenility; it is able to thrive on wastelands, such as former brown coal fields and dry agricultural areas. However, research conducted on this species in such areas is limited. This paper aims to provide a basis for predicting tree woody biomass for black locust based on tree, competition, and site variables at 14 sites in northeast Germany that were previously utilized for mining or agriculture. The study areas, which are located in an area covering 320 km × 280 km, are characterized by a variety of climatic and soil conditions. Influential variables, including tree parameters, competition, and climatic parameters were considered. Allometric biomass models were employed. The findings show that the most important parameters are tree and competition variables. Different former land utilizations, such as mining or agriculture, as well as growth by cores or stumps, significantly influenced aboveground woody biomass production. The new biomass models developed as part of this study can be applied to calculate woody biomass production and carbon sequestration of Robinia pseudoacacia L. in short rotation coppices in previous mining and agricultural areas.

  10. Willow Short Rotation Coppice Trial in a Former Mining Area in Northern Spain: Effects of Clone, Fertilization and Planting Density on Yield after Five Years

    Directory of Open Access Journals (Sweden)

    María Castaño-Díaz

    2018-03-01

    Full Text Available A willow short rotation coppice (SRC trial was conducted on former mining land in northern Spain over a period of five years, with the purpose of evaluating the effects on yield of two planting densities (9876 and 14,815 cuttings ha−1, three treatments (control, two levels of nitrogen, phosphorus and potassium compound fertilizer (NPK plus weed control and three willow clones (Björn, Inger, Olof. The area was subsoiled, ploughed, harrowed and fertilized with NPK before trial establishment. A randomized block design was applied, with three replications of each treatment in a total of 54 plots, each of an area of 400 m2. The effects of the interactions between the various factors on yield and other growth parameters were also studied. The clone factor significantly affected the number of shoots per stool (greatest for the Inger clone and the Olof clone, which showed the lowest mortality rate and produced the largest trees and largest quantity of biomass. The combined application of fertilizer and herbicide also significantly increased the values of all response variables considered, except the mortality rate. The planting density did not significantly affect the response variables. Clone × treatment interactions were significant for the shoots per stool, height, diameter and biomass variables, and the Olof clone displayed the highest height and diameter growth and yield. The results obtained in the first rotation indicate that the Olof clone adapted well to the trial conditions and therefore would be appropriate for producing biomass in abandoned mine land in Asturias. These findings will help in the development of strategies for the establishment and management of SRC on marginal land.

  11. Potential benefits of commercial willow Short Rotation Coppice (SRC) for farm-scale plant and invertebrate communities in the agri-environment

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, Rebecca L.; Hanley, Mick E.; Goulson, Dave; Clarke, Donna J.; Doncaster, C. Patrick; Taylor, Gail [University of Southampton, Faculty of Natural and Environmental Sciences, Life Sciences Building, Southampton, S017 1BJ (United Kingdom)

    2011-01-15

    The cultivation of bioenergy crops (BECs) represents a significant land-use change in agri-environments, but their deployment has raised important issues globally regarding possible impacts on biodiversity. Few studies however, have systematically examined the effect of commercial scale bioenergy plantations on biodiversity in agri-ecosystems. In this study we investigate how the abundance and diversity of two key components of farmland biodiversity (ground flora and winged invertebrates) varied between mature willow Short Rotation Coppice (SRC) and two alternative land-use options (arable crops and set-aside land). Although the abundance of winged invertebrates was similar across all land-uses, taxonomic composition varied markedly. Hymenoptera and large Hemiptera (>5 mm) were more abundant in willow SRC than in arable or set-aside. Similarly although plant species richness was greater in set-aside, our data show that willow SRC supports a different plant community to the other land-uses, being dominated by competitive perennial species such as Elytrigia repens and Urtica dioica. Our results suggest that under current management practices a mixed farming system incorporating willow SRC can benefit native farm-scale biodiversity. In particular the reduced disturbance in willow SRC allows the persistence of perennial plant species, potentially providing a stable refuge and food sources for invertebrates. In addition, increased Hymenoptera abundance in willow SRC could potentially have concomitant effects on ecosystem processes, as many members of this Order are important pollinators of crop plants or otherwise fulfil an important beneficial role as predators or parasites of crop pests. (author)

  12. Long-term yield effects of establishment method and weed control in willow for short rotation coppice (SRC)

    DEFF Research Database (Denmark)

    Larsen, Søren Ugilt; Jørgensen, Uffe; Kjeldsen, Jens Bonderup

    2014-01-01

    matter (DM) yield was measured over 6 harvest rotations corresponding to 16 years. In 1st rotation, yield differed significantly between establishment methods with highest yield for 1.8 m rods (10.4 Mg ha−1 year−1), intermediate yield for cuttings and 0.2 m billets (8.6 and 8.5 Mg ha−1 year−1...... establishment methods; 1) vertical planting of standard 0.2 m cuttings; 2) horizontal planting of 0.1 m billets; 3) horizontal planting of 0.2 m billets; 4) horizontal planting of 1.8 m rods. All establishment methods were combined with mechanical and chemical weed control during the establishment year. Dry......, respectively) and lowest for 0.1 m billets (5.6 Mg ha−1 year−1). No differences were found in 2nd rotation. Over 1st and 2nd rotation, mechanical weed control resulted in significantly lower yield than chemical control when combined with 0.1 m billets. Cuttings and 1.8 m rods were compared over 1st, 2nd, 3rd...

  13. Harvest and logistics for better profitability from small cultivations of Short Rotation Willow Coppice; Skoerdeteknik och logistik foer baettre loensamhet fraan smaa odlingar av Salix

    Energy Technology Data Exchange (ETDEWEB)

    Baky, Andras; Forsberg, Maya; Rosenqvist, Haakan; Jonsson, Nils; Sundberg, Martin

    2010-06-15

    In Sweden, the political desire to increase the amount of short rotation willow coppice (Salix) plantations has been expressed. However, for various reasons interest from farmers has been low. The hypothesis of this study is that the total area of Salix cultivation can be increased by also cultivating fields smaller than those generally considered economic today. In order to lower production costs, machine systems adapted for harvest of smaller fields are required. The possibility of using farmers' existing tractors and more convenient machines, as well as achieving lower machine costs for smaller fields, may increase farmers' interest. The long-term objective is to achieve large-scale deliveries of willow with small-scale solutions at farm level, as an option and complement to today's more large-scale systems for harvesting willow. Costs, energy use and climatic impact (CO{sub 2} emissions) for two harvest and logistical chains suitable for small fields have been calculated from field to energy plant, and methods for minimizing these costs have been analyzed. Comparison is made with the direct chipping system, the most commonly used in Sweden today. The systems studied comprised: 1. Direct bundling harvest system with a tractor-towed harvester, collection of bundles in the field with a trailer-mounted crane, and storage in a pile before delivery. Chipping is performed at the energy plant. 2. Direct billeting with a tractor-towed harvester accompanied simultaneously by a tractor and trailer for collection, and storage in a pile before delivery. 3. Direct chipping with a self-propelled modified forage harvester accompanied simultaneously by a tractor and container for collection, and direct delivery to plant. Both the billet and bundle systems show higher costs than the direct chipping system, irrespective of field size. The analysis of different scenarios and conditions shows possibilities of lowering the costs through certain measures. Furthermore

  14. Standards in chestnut coppice system: cultural heritage or coltural requirement?

    Directory of Open Access Journals (Sweden)

    Manetti MC

    2012-12-01

    Full Text Available Standards in chestnut coppice system: cultural heritage or coltural requirement? This paper aims at evaluating the role of standards in chestnut coppices from a biological and functional perspective. In addition to a detailed analysis of Italian regulations on the issue, the technical definition of the term is analysed: (i as for the functional role of standards; (ii to assess whether the required functions are technically necessary and are being actually performed. In this contex, the results of an experimental trial are reported. The goal of the trial were to assess the shoots’ parameters, the stand productivity, the dynamics of canopy cover in coppices with or without standards. In 2001, at harvesting operations in a coppice aged 30 with standards managed by the local community, two experimental plots 2500 m2 each were established. The two theses being compared were: simple coppice and coppixce with standards (100 standards per hectare. The released standards were qualified immediately after final harvesting. Sprouting ability, growth pattern and stool vitality were surveyed in March 2004 (at age 2, in May 2008 (at age 6 and in April 2010 (at age 8. First results highlighted the evidence of statistically significant differences between the two thesis. The high number of standards effected negatively both vitality and growth pattern of the stools. Simple coppice recorded a lower shoot mortality, a higher diametrical growth and canopy cover degree as well; the heigth growth was, on the opposite, significantly lower. These results, although referred to a limited lifespan (1/3 of the rotation time and to one site only, underline productive, ecological and environmental benefits and as a consequence suggest the widening of the experimental network and the development of new, more relevant and consistent rules, making acceptable the simple coppice as a possible silvicultural choice to be applied to chestnut coppices.

  15. Short-rotation coppices. State of the realizability, organisation and a model for the evaluation of the production and supply of rapidly growing wood from short-rotation coppices als a biofuel for biomass-fuelled heating power stations in Bavaria; Kurzumtriebsplantagen. Stand der Umsetzbarkeit, Organisation und ein Modell zur oekonomischen Bewertung von Produktion und Bereitstellung schnell wachsenden Holzes aus Kurzumtriebsplantagen als biogener Festbrennstoff fuer Biomasse(heiz)kraftwerke in Bayern

    Energy Technology Data Exchange (ETDEWEB)

    Paschlau, Helmut F

    2011-04-07

    The study examines most aspects of Short-rotation Coppice Crops (SRC), mainly from willows (Salix sp.) and poplars (Populus sp.), for energetic use in big biomass powerstations in Bavaria (southern Germany). In addition to the compilation of framework conditions concerning environmental and agrarian politics as well as legal issues, every link in the process chain of SRC will be considered - from planting to harvesting, treatment of the wood chips and Just-in-time delivery to the powerplant - followed by an evaluation of SRC in ecological terms. The basic aim of this study is to evaluate every single link with regard to organisational und economic issues, analysis of relevant markets and to develop a comprehensive calculation model for the amount of annuities of the whole process chain.

  16. Task rotation in an underground coal mine: A pilot study.

    Science.gov (United States)

    Jones, Olivia F; James, Carole L

    2018-01-01

    Task rotation is used to decrease the risk of workplace injuries and improve work satisfaction. To investigate the feasibility, benefits and challenges of implementing a task rotation schedule within an underground coalmine in NSW, Australia. A mixed method case control pilot study with the development and implementation of a task rotation schedule for 6 months with two work crews. A questionnaire including The Nordic Musculoskeletal Questionnaire, The Need for Recovery after Work Scale, and The Australian WHOQOL- BREF Australian Edition was used to survey workers at baseline, 3 and 6 months. A focus group was completed with the intervention crew and management at the completion of the study. In total, twenty-seven participants completed the survey. Significant improvements in the psychological and environmental domains of the WHOQOL-BREF questionnaire were found in the intervention crew. Musculoskeletal pain was highest in the elbow, lower back and knee, and fatigue scores improved, across both groups. The intervention crew felt 'mentally fresher', 'didn't do the same task twice in a row', and 'had more task variety which made the shift go quickly'. Task rotation was positively regarded, with psychological benefits identified. Three rotations during a 9-hour shift were feasible and practical in this environment.

  17. Titrating decision processes in the mental rotation task.

    Science.gov (United States)

    Provost, Alexander; Heathcote, Andrew

    2015-10-01

    Shepard and Metzler's (1971) seminal mental-rotation task-which requires participants to decide if 1 object is a rotated version of another or its mirror image-has played a central role in the study of spatial cognition. We provide the first quantitative model of behavior in this task that is comprehensive in the sense of simultaneously providing an account of both error rates and the full distribution of response times. We used Brown and Heathcote's (2008) model of choice processing to separate out the contributions of mental rotation and decision stages. This model-based titration process was applied to data from a paradigm where converging evidence supported performance being based on rotation rather than other strategies. Stimuli were similar to Shepard and Metzler's block figures except a long major axis made rotation angle well defined for mirror stimuli, enabling comprehensive modeling of both mirror and normal responses. Results supported a mental rotation stage based on Larsen's (2014) model, where rotation takes a variable amount of time with a mean and variance that increase linearly with rotation angle. Differences in response threshold differences were largely responsible for mirror responses being slowed, and for errors increasing with rotation angle for some participants. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  18. Gender differences in brain activation on a mental rotation task.

    Science.gov (United States)

    Semrud-Clikeman, Margaret; Fine, Jodene Goldenring; Bledsoe, Jesse; Zhu, David C

    2012-10-01

    Few neuroimaging studies have explored gender differences on mental rotation tasks. Most studies have utilized samples with both genders, samples mainly consisting of men, or samples with six or fewer females. Graduate students in science fields or liberal arts programs (20 males, 20 females) completed a mental rotation task during functional magnetic resonance imaging (fMRI). When a pair of cube figures was shown, the participant made a keypad response based on whether the pair is the same/similar or different. Regardless of gender, the bilateral middle frontal gyrus, bilateral intraparietal sulcus (IPS), and the left precuneus were activated when a subject tried to solve the mental rotation task. Increased activation in the right inferior frontal gyrus/middle frontal gyrus, the left precuneus/posterior cingulate cortex/cuneus region, and the left middle occipital gyrus was found for men as compared to women. Better accuracy and shorter response times were correlated with an increased activation in the bilateral intraparietal sulcus. No significant brain activity differences related to mental rotation were found between academic majors. These findings suggest that networks involved in visual attention appear to be more strongly activated in the mental rotation tasks in men as compared to women. It also suggests that men use a more automatic process when analyzing complex visual reasoning tasks while women use a more top-down process.

  19. Sex Differences in Mental Rotation Tasks: Not Just in the Mental Rotation Process!

    Science.gov (United States)

    Boone, Alexander P.; Hegarty, Mary

    2017-01-01

    The paper-and-pencil Mental Rotation Test (Vandenberg & Kuse, 1978) consistently produces large sex differences favoring men (Voyer, Voyer, & Bryden, 1995). In this task, participants select 2 of 4 answer choices that are rotations of a probe stimulus. Incorrect choices (i.e., foils) are either mirror reflections of the probe or…

  20. Shoot allometry and biomass productivity in poplar and willow varieties grown as short rotation coppice. Summary of results 1995-2000

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, R.; Henshall, P.; Tubby, I.

    2003-07-01

    This report summarises the results of a 4 year study assessing shoot diameters and lengths using non-destructive measurements in order to establish allometric relationships between biomass and non-destructive measurements and also to provide estimates of increments for the development of a model of short rotation cultivation growth and yield. Details are given of the basic methodology and measurement conventions; the data preparation, quality assurance classification and storage; and shoot diameter and length assessments and allometry analyses.

  1. Stakeholder analysis for coppice forestry in Bulgaria

    Directory of Open Access Journals (Sweden)

    IvayloVelichkov

    2009-11-01

    Full Text Available The study analyzes the state of coppice forestry in Bulgaria during last 18 years. Stakeholders and their interests and preferences in coppice forests are explored and assessed. Forests restitution process in Bulgaria started in 1997 and has not been finished yet. Nevertheless, significant further changes of the current ownershipdistribution are not expected. By the end of 2007, the state was the biggest coppice forest owner/stakeholder in Bulgaria with 71.3% of all coppice forests being state property. The other two important stakeholders are the municipalities (14.0% and private owners (12.0%. Currently, forest owners' number in Bulgaria exceeds 1million, the average holding area being smaller than 1 ha. Only 150 individual plots are larger than 50 ha. The majority of private owners aim at taking maximum and immediate profit from their recently restituted forest properties. In most cases that reflects in clearcuts. Coppice forests management has been one of the problematicissues of Bulgarian forestry for decades. Despite of forest authorities significant efforts, the area of coppice forests in Bulgaria (1.78 million ha in 2007 remained unchanged for a period of 50 years. The official forest policy is still aimed at conversionof coppice forests into seed ones through different silvicultural methods. That policy is applied to almost all coppice forests regardless of their ownership.

  2. Coppicing potential of Eucalyptus nitens : results from a field survey ...

    African Journals Online (AJOL)

    In order to determine factors which could have a positive influence on the coppicing potential of Eucalyptus nitens , a field survey was carried out at Draycott, near Estcourt in the KwaZulu-Natal Midlands. Five measures of the ability to coppice (stump survival, height of coppice, number of dominant shoots, coppicing ...

  3. Development of a coppice planting machine to commercial standards

    Energy Technology Data Exchange (ETDEWEB)

    Turton, J.S.

    2000-07-01

    This report gives details of the development work carried out on the Turton Engineering Coppice Planting machine in order to commercially market it. The background to the machine which plants single rows of cuttings from rods is traced,, and previous development work, design work, production of sub-assemblies and the assembly of modules, inspection and assembly, static trials, and commercial planting are examined. Further machine developments, proving trials, and recommendations for further work are discussed. Appendices address relationships applicable to vertical planting, the Turton short rotation cultivation machine rod format, estimated prices and charges, and a list of main suppliers. (UK)

  4. Comparison of growth response to thinning in oak forests managed as coppice with standards and high forest

    Science.gov (United States)

    Gautam, S.; Hasenauer, H.; Pietsch, S. A.

    2009-04-01

    The BIOME-BGC model integrates the main physical, biological and physiological processes based on current understanding of ecophysiology to assess forest ecosystem dynamics. This study evaluates the application of the model to assess the thinning effects on coppiced oak forests in Austria. We analyze the growth response, i.e. growth efficiency (GE), nitrogen use efficiency (NUE), water use efficiency (WUE) and radiation use efficiency (RUE) of oak forests to thinning. The results of coppice with standards and high forests simulations are analysed for differences in simulated growth response after thinning. The forest field data of the year 2006 and the respective model runs are used to evaluate model application. Strong positive relationship (r2 = 0.90) with unbiased results and statistically insignificant differences between predicted and observed volume allows the use of the model as a diagnostic tool to assess management effects. Results indicate that the coppice with standards exhibits a significantly higher yield by 2.97% (i.e. 10 cubic meters per hectare in one rotation), a higher harvest (49.9%) but a lower growing stock (19.69%) than the high forests. The higher growing stock and the lower extraction in the high forests confirm that the high forest sequestrates significantly more carbon than the coppice with standards. Results show that thinning leads to an increase in the GE, the NUE and the WUE, and to a decrease in the RUE. Although the coppice with standards forest ecosystem exhibits higher values in all studied growth parameters, only the difference in the NUE was statistically significant. This verifies that the difference in the yield between the coppice with standards and the high forests is mainly governed by the NUE difference in stands after thinning. The coppice with standards system produces an equal amount of net primary production while consuming significantly less nitrogen (16%) compared to the high forest system. In the coppice with

  5. The influence of micropropagation on growth and coppicing ability of Eucalyptus polybractea.

    Science.gov (United States)

    Goodger, Jason Q D; Woodrow, Ian E

    2010-02-01

    A micropropagation protocol was recently developed for Eucalyptus polybractea R.T. Baker, a commercially important eucalypt grown in short-rotation coppice cultivation and harvested for its foliar 1,8-cineole oil. Micropropagation of elite E. polybractea trees has resulted in selection gains for foliar oil traits, but decreased above-ground biomass accumulation has been observed in clones compared to related half-sibling families. This study aims to use a greenhouse study to investigate if micropropagation induces somaclonal variation that can account for the reduction in above-ground biomass in E. polybractea clones. Secondly, the study aims to compare the coppicing ability of micropropagated clones with related half-sibling seedlings using de-topped plantation-grown saplings. The results of the greenhouse study suggest that micropropagation of E. polybractea induces somaclonal variation that manifests in more mature leaf morphologies such as increased foliar oil concentrations and lower specific leaf area (SLA), attributable to an isobilateral arrangement of increased palisade mesophyll layers. Lower SLA, rather than differences in root allocation, is likely to be a key contributor to the lower relative growth rates observed in early sapling growth of micropropagated clones. In the field study, all micropropagated and seedling-derived E. polybractea saplings coppiced vigorously in the 12 months after de-topping. The coppice growth was so vigorous in the 12 months after de-topping that total above-ground biomass equalled that of the 27-month-old saplings, irrespective of propagation source. The morphological distinction between leaves of micropropagated and seed-derived plants was no longer evident in the coppice regrowth. The results presented here suggest that the micropropagated leaf morphology and the resultant growth reduction is transient and micropropagated plants coppice just as vigorously as seed-derived plants. Therefore, micropropagation is unlikely to

  6. Mental rotation task in a pilot during and after pregnancy.

    Science.gov (United States)

    Piccardi, Laura; Verde, Paola; Bianchini, Filippo; Morgagni, Fabio; Guariglia, Cecilia; Strollo, Felice

    2013-10-01

    Discordant findings have been reported about the change in pregnant women's cognitive test performance. Visuo-spatial abilities, which are crucial in terrestrial/flight navigation, could be influenced by hormonal variations. A 32-yr-old Italian Air Force pilot underwent a 2-D Mental Rotation Task (MRT) and hormonal assessment in the second trimester of pregnancy and 1 yr after delivery. Her performance was compared with that of two nonpregnant groups of women: one with flying experience and the other without. Estradiol and progesterone were significantly higher in pregnancy compared with postpartum, while testosterone was almost unchanged. During pregnancy, we observed a significant difference in the subject's response time compared with pilots (she was slower) and nonpilots (she was faster). One year after delivery, her performance was still better than the nonpilot group and was almost the same as the pilot group. Our data are consistent with an effect of pregnancy on visuo-spatial ability that can last for some time after delivery, even with the early recovery of the hormonal levels. MRT smoothly changed in our subject, supporting previous findings that women who are experts in flight navigation are less sensitive to hormonal fluctuations. In this case, visuospatial ability requiring effortful processing underwent variations during pregnancy and postpartum. Further studies are needed in order to confirm our observations in a wider population.

  7. Object permanence in dogs: invisible displacement in a rotation task.

    Science.gov (United States)

    Miller, Holly C; Gipson, Cassie D; Vaughan, Aubrey; Rayburn-Reeves, Rebecca; Zentall, Thomas R

    2009-02-01

    Dogs were tested for object permanence using an invisible displacement in which an object was hidden in one of two containers at either end of a beam and the beam was rotated. Consistent with earlier research, when the beam was rotated 180 degrees , the dogs failed to find the object. However, when the beam was rotated only 90 degrees , they were successful. Furthermore, when the dogs were led either 90 degrees or 180 degrees around the apparatus, they were also successful. In a control condition, when the dogs could not see the direction of the 90 degrees rotation, they failed to find the object. The results suggest that the 180 degrees rotation may produce an interfering context that can be reduced by rotating the apparatus only 90 degrees or by changing the dogs' perspective. Once the conflict is eliminated, dogs show evidence of object permanence that includes invisibly displaced objects.

  8. The effects of visual discriminability and rotation angle on 30-month-olds’ search performance in spatial rotation tasks

    Directory of Open Access Journals (Sweden)

    Mirjam Ebersbach

    2016-10-01

    Full Text Available Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds’ success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children (N = 29 performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children.

  9. The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds' Search Performance in Spatial Rotation Tasks.

    Science.gov (United States)

    Ebersbach, Mirjam; Nawroth, Christian

    2016-01-01

    Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds' success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children ( N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children.

  10. The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds’ Search Performance in Spatial Rotation Tasks

    Science.gov (United States)

    Ebersbach, Mirjam; Nawroth, Christian

    2016-01-01

    Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds’ success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children (N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children. PMID:27812346

  11. Energy dissipation of rockfalls by coppice structures

    Directory of Open Access Journals (Sweden)

    G. Ciabocco

    2009-06-01

    Full Text Available The objective of this work is to develop elements to improve understanding of the behaviour of a coppice in relation to the phenomenon of falling boulders. The first section proposes an amendment to the equation for calculating the index which describes the probability of impact between a rock and plants in managed coppice forests. A study was carried out, using models to calculate the kinetic energy of a falling boulder along a slope considering the kinetic energy dissipated during the impact with the structure of forest plants managed by coppice. The output of the simulation models were then compared with the real dynamics of falling boulders in field tests using digital video.

    It emerged from an analysis of the results of this comparison that a modification to the 1989 Gsteiger equation was required, in order to calculate the "Average Distance between Contacts" (ADC. To this purpose, the concept of "Structure of Interception", proposed in this paper, was developed, valid as a first approach for describing the differences in the spatial distribution of stems between coppice and forest. This study also aims to provide suggestions for forestry management, in order to maintain or increase the protective capacity of a coppice managed with conventional techniques for the area studied, modifying the dendrometric characteristics.

  12. Feasibility Study of Haptic Display for Rotation Tasks of Wrist Work

    OpenAIRE

    曽根, 順治; 岩井, 秀樹; 山田, 勝実; 陳, 軍; 徳山, 喜政; 今野, 晃市; Sone, Junji; Iwai, Hideki; Yamada, Katsumi; Chen, Jun; Tokuyama, Yoshimasa; Konno, Kouichi

    2011-01-01

    We have developed a haptic display for rotational tasks that involve functions of the human wrist. We represent the torque using a motor and a brake. Reference torque curves are obtained by the measuring torque required for each actual task using a torque sensor. The brake represents the stop condition. We have confirmed the effectiveness of the display by comparing the actual tasks with the haptic display experiment.

  13. Chemical utilization of coppice: III - furfural

    Energy Technology Data Exchange (ETDEWEB)

    Vidrich, V.; Cecconi, C.A.; Fusi, P.

    1980-01-01

    The numerous applications of furfural in industry are briefly summarized and the mean contents of furfural and of methyl furfural in some Italian coppice species and species of the Mediterranean maquis capable of exploitation for this purpose are reported. (Refs. 14).

  14. Preschool children adapt grasping movements to upcoming object manipulations: Evidence from a dial rotation task.

    Science.gov (United States)

    Herbort, Oliver; Büschelberger, Juliane; Janczyk, Markus

    2018-03-01

    In adults, the motor plans for object-directed grasping movements reflects the anticipated requirements of intended future object manipulations. This prospective mode of planning has been termed second-order planning. Surprisingly, second-order planning is thought to be fully developed only by 10 years of age, when children master seemingly more complex motor skills. In this study, we tested the hypothesis that already 5- and 6-year-old children consistently use second-order planning but that this ability does not become apparent in tasks that are traditionally used to probe it. We asked 5- and 6-year-olds and adults to grasp and rotate a circular dial in a clockwise or counterclockwise direction. Although children's grasp selections were less consistent on an intra- and inter-individual level than adults' grasp selections, all children adjusted their grasps to the upcoming dial rotations. By contrast, in an also administered bar rotation task, only a subset of children adjusted their grasps to different bar rotations, thereby replicating previous results. The results indicate that 5- and 6-year-olds consistently use second-order planning in a dial rotation task, although this ability does not become apparent in bar rotation tasks. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Reliabilities of mental rotation tasks: limits to the assessment of individual differences.

    Science.gov (United States)

    Hirschfeld, Gerrit; Thielsch, Meinald T; Zernikow, Boris

    2013-01-01

    Mental rotation tasks with objects and body parts as targets are widely used in cognitive neuropsychology. Even though these tasks are well established to study between-groups differences, the reliability on an individual level is largely unknown. We present a systematic study on the internal consistency and test-retest reliability of individual differences in mental rotation tasks comparing different target types and orders of presentations. In total n = 99 participants (n = 63 for the retest) completed the mental rotation tasks with hands, feet, faces, and cars as targets. Different target types were presented in either randomly mixed blocks or blocks of homogeneous targets. Across all target types, the consistency (split-half reliability) and stability (test-retest reliabilities) were good or acceptable both for intercepts and slopes. At the level of individual targets, only intercepts showed acceptable reliabilities. Blocked presentations resulted in significantly faster and numerically more consistent and stable responses. Mental rotation tasks-especially in blocked variants-can be used to reliably assess individual differences in global processing speed. However, the assessment of the theoretically important slope parameter for individual targets requires further adaptations to mental rotation tests.

  16. Hemispheric dominance during the mental rotation task in patients with schizophrenia.

    Science.gov (United States)

    Chen, Jiu; Yang, Laiqi; Zhao, Jin; Li, Lanlan; Liu, Guangxiong; Ma, Wentao; Zhang, Yan; Wu, Xingqu; Deng, Zihe; Tuo, Ran

    2012-04-01

    Mental rotation is a spatial representation conversion capability using an imagined object and either object or self-rotation. This capability is impaired in schizophrenia. To provide a more detailed assessment of impaired cognitive functioning in schizophrenia by comparing the electrophysiological profiles of patients with schizophrenia and controls while completing a mental rotation task using both normally-oriented images and mirror images. This electroencephalographic study compared error rates, reaction times and the topographic map of event-related potentials in 32 participants with schizophrenia and 29 healthy controls during mental rotation tasks involving both normal images and mirror images. Among controls the mean error rate and the mean reaction time for normal images and mirror images were not significantly different but in the patient group the mean (sd) error rate was higher for mirror images than for normal images (42% [6%] vs. 32% [9%], t=2.64, p=0.031) and the mean reaction time was longer for mirror images than for normal images (587 [11] ms vs. 571 [18] ms, t=2.83, p=0.028). The amplitude of the P500 component at Pz (parietal area), Cz (central area), P3 (left parietal area) and P4 (right parietal area) were significantly lower in the patient group than in the control group for both normal images and mirror images. In both groups the P500 for both the normal and mirror images was significantly higher in the right parietal area (P4) compared with left parietal area (P3). The mental rotation abilities of patients with schizophrenia for both normally-oriented images and mirror images are impaired. Patients with schizophrenia show a diminished left cerebral contribution to the mental rotation task, a more rapid response time, and a differential response to normal images versus mirror images not seen in healthy controls. Specific topographic characteristics of the EEG during mental rotation tasks are potential biomarkers for schizophrenia.

  17. Detecting Coppice Legacies from Tree Growth

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Jana; Pejcha, Vít; Altman, Jan; Plener, Tomáš; Dörner, Petr; Doležal, Jiří

    2016-01-01

    Roč. 11, č. 1 (2016), s. 1-14 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.20.0267; GA ČR GAP504/12/1952; GA ČR(CZ) GA14-12262S EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : coppicing * history * tree-ring analysis Subject RIV: EH - Ecology, Behaviour Impact factor: 2.806, year: 2016

  18. Task Rotation: Strategies for Differentiating Activities and Assessments by Learning Style. A Strategic Teacher PLC Guide

    Science.gov (United States)

    Silver, Harvey; Moirao, Daniel; Jackson, Joyce

    2011-01-01

    One of the hardest jobs in teaching is to differentiate learning activities and assessments to your students' learning styles. But you and your colleagues can learn how to do this together when each of you has this guide to the Task Rotation strategy from our ultimate guide to teaching strategies, "The Strategic Teacher". Use the guide in your…

  19. Effects of gender, imagery ability, and sports practice on the performance of a mental rotation task.

    Science.gov (United States)

    Habacha, Hamdi; Molinaro, Corinne; Dosseville, Fabrice

    2014-01-01

    Mental rotation is one of the main spatial abilities necessary in the spatial transformation of mental images and the manipulation of spatial parameters. Researchers have shown that mental rotation abilities differ between populations depending on several variables. This study uses a mental rotation task to investigate effects of several factors on the spatial abilities of 277 volunteers. The results demonstrate that high and low imagers performed equally well on this tasks. Athletes outperformed nonathletes regardless of their discipline, and athletes with greater expertise outperformed those with less experience. The results replicate the previously reported finding that men exhibit better spatial abilities than women. However, with high amounts of practice, the women in the current study were able to perform as well as men.

  20. Shoulder Strength Requirements for Upper Limb Functional Tasks: Do Age and Rotator Cuff Tear Status Matter?

    Science.gov (United States)

    Santago, Anthony C; Vidt, Meghan E; Li, Xiaotong; Tuohy, Christopher J; Poehling, Gary G; Freehill, Michael T; Saul, Katherine R

    2017-12-01

    Understanding upper limb strength requirements for daily tasks is imperative for early detection of strength loss that may progress to disability due to age or rotator cuff tear. We quantified shoulder strength requirements for 5 upper limb tasks performed by 3 groups: uninjured young adults and older adults, and older adults with a degenerative supraspinatus tear prior to repair. Musculoskeletal models were developed for each group representing age, sex, and tear-related strength losses. Percentage of available strength used was quantified for the subset of tasks requiring the largest amount of shoulder strength. Significant differences in strength requirements existed across tasks: upward reach 105° required the largest average strength; axilla wash required the largest peak strength. However, there were limited differences across participant groups. Older adults with and without a tear used a larger percentage of their shoulder elevation (p functional tasks to effectively detect early strength loss, which may lead to disability.

  1. Cognitive strategies in the mental rotation task revealed by EEG spectral power.

    Science.gov (United States)

    Gardony, Aaron L; Eddy, Marianna D; Brunyé, Tad T; Taylor, Holly A

    2017-11-01

    The classic mental rotation task (MRT; Shepard & Metzler, 1971) is commonly thought to measure mental rotation, a cognitive process involving covert simulation of motor rotation. Yet much research suggests that the MRT recruits both motor simulation and other analytic cognitive strategies that depend on visuospatial representation and visual working memory (WM). In the present study, we investigated cognitive strategies in the MRT using time-frequency analysis of EEG and independent component analysis. We scrutinized sensorimotor mu (µ) power reduction, associated with motor simulation, parietal alpha (pα) power reduction, associated with visuospatial representation, and frontal midline theta (fmθ) power enhancement, associated with WM maintenance and manipulation. µ power increased concomitant with increasing task difficulty, suggesting reduced use of motor simulation, while pα decreased and fmθ power increased, suggesting heightened use of visuospatial representation processing and WM, respectively. These findings suggest that MRT performance involves flexibly trading off between cognitive strategies, namely a motor simulation-based mental rotation strategy and WM-intensive analytic strategies based on task difficulty. Flexible cognitive strategy use may be a domain-general cognitive principle that underlies aptitude and spatial intelligence in a variety of cognitive domains. We close with discussion of the present study's implications as well as future directions. Published by Elsevier Inc.

  2. Effects of water and nutrient addition on the coppice growth response of cut Terminalia sericea

    Directory of Open Access Journals (Sweden)

    Hloniphani Moyo

    2016-07-01

    Full Text Available The ability of a woody plant to coppice and remain vigorous largely depends on the severity of disturbances, resource availability and the mobilisation of stored reserves. There is limited information about the role played by resource limitation on the recovery of cut trees. This study investigated the effects of water and nutrient supplementation on coppice growth responses of resprouting cut trees in a semi-arid savannah in South Africa. Cut trees were exposed to different levels of water and nutrient (nitrogen and phosphorus supplementation over a period of 2 years in a factorial experimental design. We hypothesised that adding water and nutrients would result in an increased coppice growth response and replenishment of stored structural reserves. Adding water and nutrients significantly increased shoot diameter, shoot length and resprouting ratio for the initial 12 months after cutting but not stored structural reserves. Such a response pattern suggests that the initial growth of resprouting shoots may be strongly resource-limited, while resources are concentrated on supporting fewer resprouting shoots compared to a higher number. Conservation implications: If practicing rotational tree harvesting, trees resprouting in resource-poor locations need a longer resting period to recover stored reserves and to also recover lost height after cutting.

  3. Post-cultural stand dynamics in an abandoned chestnut coppice at its ecological border

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Until the be­ginning of the last century, chestnut has played an important role as staple food and primary wood source. In many cases it was cultivated at the border of its ecological limits where it was planted by man in place of the original and more site-adapted tree species. However, with the abandonment of the rural activities, ma­nagement of chestnut forests was progressively left starting from more marginal areas, usually occupied by coppice stands. After the interruption of the traditional coppice management system (usual rotation periods of 10-25 years, natural intra- and interspecific competition dynamics have become the driving force of the stand evolution. This may lead to dramatic changes in both structure and species composition of the stands. The aim of this study is to analyse the post-cultural evolution of an abandoned chestnut coppice in the Pesio Valley (Piedmont, Italy in order to highlight the competition among different "basic silvi­cultural components" of the forest using a dendroecological approach. The "basic silvicultural components" are intended as the elements defined as groups of trees of the stand that have similar features such as silvi­culturally relevant attributes: species (chestnut, beech, fir, origin (seed, sprout and cultural age and function (standard/reserve, maiden, shoot, regeneration, dead tree. The mean growth curves of the compo­nents show the different fitness of each category. From a general point of view, the beech and fir components show a better competitive potential in comparison with chestnut. Among chestnut components, maidens from seeds reveal a better growth trend compared to coppice shoots and standards.

  4. Reduced plantar sole sensitivity facilitates early adaptation to a visual rotation pointing task when standing upright

    Directory of Open Access Journals (Sweden)

    Maxime Billot

    2016-09-01

    Full Text Available Humans are capable of pointing to a target with accuracy. However, when vision is distorted through a visual rotation or mirror-reversed vision, the performance is initially degraded and thereafter improves with practice. There are suggestions this gradual improvement results from a sensorimotor recalibration involving initial gating of the somatosensory information from the pointing hand. In the present experiment, we examined if this process interfered with balance control by asking participants to point to targets with a visual rotation from a standing posture. This duality in processing sensory information (i.e., gating sensory signals from the hand while processing those arising from the control of balance could generate initial interference leading to a degraded pointing performance. We hypothesized that if this is the case, the attenuation of plantar sole somatosensory information through cooling could reduce the sensorimotor interference, and facilitate the early adaptation (i.e. improvement in the pointing task. Results supported this hypothesis. These observations suggest that processing sensory information for balance control interferes with the sensorimotor recalibration process imposed by a pointing task when vision is rotated.

  5. Treatment of landfill leachate by irrigation of willow coppice - Plant response and treatment efficiency

    International Nuclear Information System (INIS)

    Aronsson, Paer; Dahlin, Torleif; Dimitriou, Ioannis

    2010-01-01

    Landfill leachates usually need to be treated before discharged, and using soil-plant systems for this has gained substantial interest in Sweden and in the UK. A three-year field study was conducted in central Sweden to quantify plant response, treatment efficiency and impact on groundwater quality of landfill leachate irrigation of short-rotation willow coppice (Salix). Two willow varieties were tested and four irrigation regimes in sixteen 400-m 2 plots. The willow plants did not react negatively, despite very high annual loads of nitrogen (≤2160 kg N/ha), chloride (≤8600 kg Cl/ha) and other elements. Mean annual growth was 1.5, 9.8 and 12.6 tonnes DM/ha during years 1-3. For one of two willow varieties tested, relative leaf length accurately predicted growth rate. Irrigation resulted in elevated groundwater concentrations of all elements applied. Treatment efficiency varied considerably for different elements, but was adequate when moderate loads were applied. - Short-rotation willow coppice was successfully used for treating a strong landfill leachate in central Sweden over three years.

  6. Dizzy people perform no worse at a motor imagery task requiring whole body mental rotation; a case-control comparison

    Directory of Open Access Journals (Sweden)

    Sarah B Wallwork

    2013-06-01

    Full Text Available We wanted to find out whether people who suffer from dizziness take longer than people who do not, to perform a motor imagery task that involves implicit whole body rotation. Our prediction was that people in the ‘dizzy’ group would take longer at a left/right neck rotation judgment task but not a left/right hand judgment task, because actually performing the former, but not the latter, would exacerbate their dizziness. Secondly, we predicted that when dizzy participants responded to neck rotation images, responses would be greatest when images were in the upside-down orientation; an orientation with greatest dizzy-provoking potential. To test this idea, we used a case-control comparison design. One hundred and eighteen participants who suffered from dizziness and 118 age, gender, arm pain and neck pain matched controls took part in the study. Participants undertook two motor imagery tasks; a left/right neck rotation judgment task and a left/right hand judgment task. The tasks were completed using the Recognise program; an on-line reaction time task program. Images of neck rotation were shown in four different orientations; 0°, 90°, 180° and 270°. Participants were asked to respond to each ‘neck’ image identifying it as either ‘right neck rotation’ or a ‘left neck rotation’, or for hands, a right or a left hand. Results showed that participants in the ‘dizzy’ group were slower than controls at both tasks (p= 0.015, but this was not related to task (p= 0.498. Similarly, ‘dizzy’ participants were not proportionally worse at images of different orientations (p= 0.878. Our findings suggest impaired performance in dizzy people, an impairment that may be confined to motor imagery or may extend more generally.

  7. Energy budget and greenhouse gas balance evaluation of sustainable coppice systems for electricity production

    International Nuclear Information System (INIS)

    Lettens, Suzanna; Muys, Bart; Ceulemans, Reinhart; Moons, Ellen; Garcia, Juan; Coppin, Pol

    2003-01-01

    The use of bio-energy crops for electricity production is considered an effective means to mitigate the greenhouse effect, mainly due to its ability to substitute fossil fuels. A whole range of crops qualify for bio-energy production and a rational choice is not readily made. This paper evaluates the energy and greenhouse gas balance of a mixed indigenous hardwood coppice as an extensive, low-input bio-energy crop. The impact on fossil energy use and greenhouse gas emission is calculated and discussed by comparing its life cycle (cultivation, processing and conversion into energy) with two conventional bio-energy crops (short rotation systems of willow and Miscanthus). For each life cycle process, the flows of fossil energy and greenhouse gas that are created for the production of one functional unit are calculated. The results show that low-input bio-energy crops use comparatively less fossil fuel and avoid more greenhouse gas emission per unit of produced energy than conventional bio-energy crops during the first 100 yr. Where the mixed coppice system avoids up till 0.13 t CO 2 eq./GJ, Miscanthus does not exceed 0.07 t CO 2 eq./GJ. After 100 yr their performances become comparable, amounting to 0.05 t CO 2 eq./ha/GJ. However, if the land surface itself is chosen as a functional unit, conventional crops perform better with respect to mitigating the greenhouse effect. Miscanthus avoids a maximum of 12.9 t CO 2 eq./ha/yr, while mixed coppice attains 9.5 t CO 2 eq./ha/yr at the most

  8. Interaction in Short rotation coppice willow, Salix viminalis genotype mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Begley, D. [Department of Biological Sciences, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom); McCracken, A.R. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)]|[Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Dawson, W.M. [Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Watson, S. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)

    2009-02-15

    Seven straight Salix viminalis genotypes with different levels of rust (Melampsora epitea) susceptibility were grown as mono-plots as well as being incorporated into a range of mixtures. Two 3-year harvests (2003 and 2006) were taken. Disease progress was followed on each of the individual genotypes throughout each growing season 2001-2006. In 2003 there were small but significant yield increases from the mixtures compared to the yield of individual components grown as mono-plots. These differences were not evident at the second harvest in 2006. No consistent effect of mixtures on reducing rust on the most susceptible genotype, Salix viminalis '77082' were observed. In some years, e.g. 2003, at certain times during the growing season, significant reductions were observed on Salix viminalis '77082' in certain 3-way mixtures compared to mono-plots. These, however, were not repeated consistently in subsequent years. It was concluded that the current commercial practice in many parts of Europe of planting mixtures as a disease control strategy will only be effective if there is sufficient genetic diversity between the Salix genotypes incorporated into the mixture. (author)

  9. The practical use of short rotation coppice in land restoration

    NARCIS (Netherlands)

    Paulson, M.; Bardos, P.; Harmsen, J.; Wilczek, J.; Barton, M.; Edwards, D.

    2003-01-01

    A potential for synergy exists between organic waste recycling, biomass production and long-term risk management for contaminated land, particularly where the immediate economic case for reuse of the land is marginal. The possibility of income generation from waste management activities and biomass

  10. Planning wood extraction in a forest coppice

    Directory of Open Access Journals (Sweden)

    Civitarese V

    2006-01-01

    Full Text Available A series of cartographic models of analysis have been elaborated through the softwares ArcView GIS (ESRI 2002 and Surfer 8 (Golden software 2002 to find optimal work systems for the wood extraction in an oak coppice, located on the Monti della Tolfa, near Rome, Italy. The main factors analyzed were the morphology of the territory and the roads characteristics. The methodological procedure followed was applied on the different classes of slope, the direction of water outflow, the presence of ditches and channels, the principal and secondary roads, the wood cover and the clearings. The possibility to employ tractors with cages, polyethylene chutes, mules and cable cranes has been examined, also identifying the fittest areas to their use. This first analytical phase was followed by a second phase dedicated to the evaluation of the technical feasibility. The proposed method contributes to a rational planning of the work site. The advantage could be the planning of extraction operations on the map, but it will be necessary to verify the method in field studies. Although this method has been developed on limited extensions of territories, it could be applicable to situations of greater complexity, representing the base for the creation of a tool that may be employed in ampler territorial contexts, such as Comunità Montane and hydrographic basins.

  11. Coppice forests, or the changeable aspect of things, a review

    Directory of Open Access Journals (Sweden)

    Gianfranco Fabbio

    2016-11-01

    Full Text Available Coppiced forests were the main source of firewood, brushwood, and charcoal for rural and urban settlements’ basic needs such as cooking food and domestic heating for thousands of years and up to the mid-20th century in many European countries and, specifically, in Mediterranean countries. The global diffusion of fossil fuels reduced this leadership and the coppice system turned, to some extent, to a reminder of the past. Nowadays, the ongoing global changes and the related green-economy issues call for resilient systems and effective bio-energy producers. These issues have caused a second turning point and the coppice has returned fifty years later to play a role. A review of the silvicultural system has been carried out with a special focus on the changes which have occurred in between, taking Italy as a consistent case-study. The analysis is mainly framed upon the long-term research trials established by the CREA-Forestry Research Centre in the late sixties, to find out adaptive management strategies and overcome the system’s crisis. The findings and further knowledge achieved so far on the dynamics and functioning of coppice forests in the outgrown phase, both as natural evolutive patterns and silviculture-driven processes, are highlighted in this paper. They provide useful tools to handle the management shift regarding forthcoming issues, i.e. the current role attributable to the coppice system within the changing environment and the renewable energy demand. The basic features of each management area and their complementarities within the current framework are outlined.

  12. Establishing a New Screening System for Mild Cognitive Impairment and Alzheimer's Disease with Mental Rotation Tasks that Evaluate Visuospatial Function.

    Science.gov (United States)

    Suzuki, Ayuko; Shinozaki, Jun; Yazawa, Shogo; Ueki, Yoshino; Matsukawa, Noriyuki; Shimohama, Shun; Nagamine, Takashi

    2018-01-01

    The mental rotation task is well-known for the assessment of visuospatial function; however, it has not been used for screening of dementia patients. The aim of this study was to create a simple screening test for patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) by focusing on non-amnestic symptoms. Age-matched healthy controls (age 75.3±6.8), patients with MCI (76.5±5.5), and AD (78.2±5.0) participated in this study. They carried out mental rotation tasks targeting geometric graphics or alphabetical characters with three rotating angles (0°, 90°, and 180°) and indicated the correct answer. Response accuracy and reaction time were recorded along with their eye movements using an eye tracker. To quantify their visual processing strategy, the run count ratio (RC ratio) was calculated by dividing the mean number of fixations in incorrect answers by that in correct answers. AD patients showed lower accuracy and longer reaction time than controls. They also showed a significantly greater number of fixation and smaller saccade amplitude than controls, while fixation duration did not differ significantly. The RC ratio was higher for AD, followed by MCI and control groups. By setting the cut-off value to 0.47 in the 180° rotating angle task, we could differentiate MCI patients from controls with a probability of 80.0%. We established a new screening system for dementia patients by evaluating visuospatial function. The RC ratio during a mental rotation task is useful for discriminating MCI patients from controls.

  13. Below-ground biomass production and allometric relationships of eucalyptus coppice plantation in the central highlands of Madagascar

    International Nuclear Information System (INIS)

    Razakamanarivo, Ramarson H.; Razakavololona, Ando; Razafindrakoto, Marie-Antoinette; Vieilledent, Ghislain; Albrecht, Alain

    2012-01-01

    Short rotations of Eucalyptus plantations under coppice regime are extensively managed for wood production in Madagascar. Nevertheless, little is known about their biomass production and partitioning and their potential in terms of carbon sequestration. If above-ground biomass (AGB) can be estimated based on established allometric relations, below-ground (BGB) estimates are much less common. The aim of this work was to develop allometric equations to estimate biomass of these plantations, mainly for the root components. Data from 9 Eucalyptus robusta stands (47–87 years of plantation age, 3–5 years of coppice-shoot age) were collected and analyzed. Biomass of 3 sampled trees per stand was determined destructively. Dry weight of AGB components (leaves, branches and stems) were estimated as a function of basal area of all shoots per stump and dry weight for BGB components (mainly stump, coarse root (CR) and medium root (MR)) were estimated as a function of stump circumference. Biomass was then computed using allometric equations from stand inventory data. Stand biomass ranged from 102 to 130 Mg ha −1 with more than 77% contained in the BGB components. The highest dry weight was allocated in the stump and in the CR (51% and 42% respectively) for BGB parts and in the stem (69%) for AGB part. Allometric relationships developed herein could be applied to other Eucalyptus plantations which present similar stand density and growing conditions; anyhow, more is needed to be investigated in understanding biomass production and partitioning over time for this kind of forest ecosystem. -- Highlights: ► We studied the potential of old eucalyptus coppices in Madagascar to mitigate global warming. ► Biomass measurement, mainly for below-ground BGB (stump, coarse-medium-and fine roots) was provided. ► BGB allometry relationships for short rotation forestry under coppice were established. ► BGB were found to be important with their 102-130MgC ha -1 (<77% of the C in

  14. Coppice Woods and Pollard Trees in the Visual Arts

    Directory of Open Access Journals (Sweden)

    Lacina Jan

    2016-11-01

    Full Text Available The sprouting capacity of some broadleaves has been used for their regeneration since ancient times. Often concurrently with taking advantage of sprouting stools, the trees used to be shaped also by pruning their stems, namely on pasturelands and in grazing forests. The activity of woodcutters and shepherds was obviously rather common in warmer climates with broadleaved stands because coppice and pollard trees appear relatively often in the visual arts from ancient works through the period if the Italian and German Renaissance up to the romantic and realistic landscape painting of the 19th century overlapping into the 20th century. For centuries, most frequently illustrated in European and Czech paintings have been pollard willows (Salix spp.. Other coppice and pollard tree species identified in paintings are oaks (Quercus spp., hornbeam (Carpinus betulus, European beech (Fagus sylvatica, European chestnut (Castanea sativa, and rarely other species, too. Artists apparently often used bizarrely shaped woods to increase the dramatic atmosphere of their landscape sceneries as well as figural compositions, and the coppice and pollard trees had certainly also a symbolic meaning in some of their works.

  15. Is the Male Advantage in Mental-Rotation Performance Task Independent? On the Usability of Chronometric Tests and Paper-and-Pencil Tests in Children

    Science.gov (United States)

    Quaiser-Pohl, Claudia; Neuburger, Sarah; Heil, Martin; Jansen, Petra; Schmelter, Andrea

    2014-01-01

    This article presents a reanalysis of the data of 862 second and fourth graders collected in two previous studies, focusing on the influence of method (psychometric vs. chronometric) and stimulus type on the gender difference in mental-rotation accuracy. The children had to solve mental-rotation tasks with animal pictures, letters, or cube…

  16. Clonal variation in heavy metal accumulation and biomass production in a poplar coppice culture. II. Vertical distribution and phytoextraction potential

    International Nuclear Information System (INIS)

    Laureysens, I.; Temmerman, L. de; Hastir, T.; Gysel, M. van; Ceulemans, R.

    2005-01-01

    Short rotation coppice cultures (SRC) are intensively managed, high-density plantations of multi-shoot trees. In April 1996, an SRC field trial with 17 different poplar clones was established in Boom (Belgium) on a former waste disposal site. In December 1996 and January 2001, all shoots were cut back to a height of 5 cm to create a coppice culture. For six clones, wood and bark were sampled at the bottom, middle and top of a shoot in August and November 2002. No significant height effect of metal concentration was found, but for wood, metal concentrations generally increased toward the top of the shoot in August, and decreased toward the top of the shoot in November. Phytoextraction potential of a clone was primarily determined by metal concentration and by biomass production. Shoot size and number of shoots per stool were less important, as a high biomass production could be achieved by producing a few large shoots or many smaller shoots. Clone Fritzi Pauley accumulated 1.4 kg ha -1 of Al over two years; Wolterson and Balsam Spire showed a relatively high accumulation of Cd and Zn, i.e. averaging, respectively 47 and 57 g ha -1 for Cd and 2.4 and 2.0 kg ha -1 for Zn over two years. - Poplar shows potential for phytoextraction of Al, Cd and Zn on slightly contaminated soils

  17. Clonal variation in heavy metal accumulation and biomass production in a poplar coppice culture. II. Vertical distribution and phytoextraction potential

    Energy Technology Data Exchange (ETDEWEB)

    Laureysens, I. [University of Antwerp, Campus Drie Eiken, Department of Biology, Universiteitsplein 1, B-2610 Wilrijk (Belgium)]. E-mail: ilse.laureysens@ua.ac.be; Temmerman, L. de [Veterinary and Agrochemical Research Centre (VAR), Leuvensesteenweg 17, B-3080 Tervuren (Belgium); Hastir, T. [University of Antwerp, Campus Drie Eiken, Department of Biology, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Gysel, M. van [University of Antwerp, Campus Drie Eiken, Department of Chemistry, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Ceulemans, R. [University of Antwerp, Campus Drie Eiken, Department of Biology, Universiteitsplein 1, B-2610 Wilrijk (Belgium)

    2005-02-01

    Short rotation coppice cultures (SRC) are intensively managed, high-density plantations of multi-shoot trees. In April 1996, an SRC field trial with 17 different poplar clones was established in Boom (Belgium) on a former waste disposal site. In December 1996 and January 2001, all shoots were cut back to a height of 5 cm to create a coppice culture. For six clones, wood and bark were sampled at the bottom, middle and top of a shoot in August and November 2002. No significant height effect of metal concentration was found, but for wood, metal concentrations generally increased toward the top of the shoot in August, and decreased toward the top of the shoot in November. Phytoextraction potential of a clone was primarily determined by metal concentration and by biomass production. Shoot size and number of shoots per stool were less important, as a high biomass production could be achieved by producing a few large shoots or many smaller shoots. Clone Fritzi Pauley accumulated 1.4 kg ha{sup -1} of Al over two years; Wolterson and Balsam Spire showed a relatively high accumulation of Cd and Zn, i.e. averaging, respectively 47 and 57 g ha{sup -1} for Cd and 2.4 and 2.0 kg ha{sup -1} for Zn over two years. - Poplar shows potential for phytoextraction of Al, Cd and Zn on slightly contaminated soils.

  18. Continuous theta burst stimulation (cTBS on left cerebellar hemisphere affects mental rotation tasks during music listening.

    Directory of Open Access Journals (Sweden)

    Silvia Picazio

    Full Text Available Converging evidence suggests an association between spatial and music domains. A cerebellar role in music-related information processing as well as in spatial-temporal tasks has been documented. Here, we investigated the cerebellar role in the association between spatial and musical domains, by testing performances in embodied (EMR or abstract (AMR mental rotation tasks of subjects listening Mozart Sonata K.448, which is reported to improve spatial-temporal reasoning, in the presence or in the absence of continuous theta burst stimulation (cTBS of the left cerebellar hemisphere. In the absence of cerebellar cTBS, music listening did not influence either MR task, thus not revealing a "Mozart Effect". Cerebellar cTBS applied before musical listening made subjects faster (P = 0.005 and less accurate (P = 0.005 in performing the EMR but not the AMR task. Thus, cerebellar inhibition by TBS unmasked the effect of musical listening on motor imagery. These data support a coupling between music listening and sensory-motor integration in cerebellar networks for embodied representations.

  19. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance

    NARCIS (Netherlands)

    Pannebakker, M.M.; van Dam, W.O.; Band, G.P.H.; Ridderinkhof, K.R.; Hommel, B.

    2011-01-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial

  20. A direct comparison of spine rotational stiffness and dynamic spine stability during repetitive lifting tasks.

    Science.gov (United States)

    Graham, Ryan B; Brown, Stephen H M

    2012-06-01

    Stability of the spinal column is critical to bear loads, allow movement, and at the same time avoid injury and pain. However, there has been a debate in recent years as to how best to define and quantify spine stability, with the outcome being that different methods are used without a clear understanding of how they relate to one another. Therefore, the goal of the present study was to directly compare lumbar spine rotational stiffness, calculated with an EMG-driven biomechanical model, to local dynamic spine stability calculated using Lyapunov analyses of kinematic data, during a series of continuous dynamic lifting challenges. Twelve healthy male subjects performed 30 repetitive lifts under three varying load and three varying rate conditions. With an increase in the load lifted (constant rate) there was a significant increase in mean, maximum, and minimum spine rotational stiffness (pstiffness (pstiffness and a non-significant decrease in local dynamic stability (p>0.05). Weak linear relationships were found for the varying rate conditions (r=-0.02 to -0.27). The results suggest that spine rotational stiffness and local dynamic stability are closely related to one another, as they provided similar information when movement rate was controlled. However, based on the results from the changing lifting rate conditions, it is evident that both models provide unique information and that future research is required to completely understand the relationship between the two models. Using both techniques concurrently may provide the best information regarding the true effects of (in) stability under different loading and movement scenarios, and in comparing healthy and clinical populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. The Composite Strain Index (COSI) and Cumulative Strain Index (CUSI): methodologies for quantifying biomechanical stressors for complex tasks and job rotation using the Revised Strain Index.

    Science.gov (United States)

    Garg, Arun; Moore, J Steven; Kapellusch, Jay M

    2017-08-01

    The Composite Strain Index (COSI) quantifies biomechanical stressors for complex tasks consisting of exertions at different force levels and/or with different exertion times. The Cumulative Strain Index (CUSI) further integrates biomechanical stressors from different tasks to quantify exposure for the entire work shift. The paper provides methodologies to compute COSI and CUSI along with examples. Complex task simulation produced 169,214 distinct tasks. Use of average, time-weighted average (TWA) and peak force and COSI classified 66.9, 28.2, 100 and 38.9% of tasks as hazardous, respectively. For job rotation the simulation produced 10,920 distinct jobs. TWA COSI, peak task COSI and CUSI classified 36.5, 78.1 and 66.6% jobs as hazardous, respectively. The results suggest that the TWA approach systematically underestimates the biomechanical stressors and peak approach overestimates biomechanical stressors, both at the task and job level. It is believed that the COSI and CUSI partially address these underestimations and overestimations of biomechanical stressors. Practitioner Summary: COSI quantifies exposure when applied hand force and/or duration of that force changes during a task cycle. CUSI integrates physical exposures from job rotation. These should be valuable tools for designing and analysing tasks and job rotation to determine risk of musculoskeletal injuries.

  2. Growth-related problems of aging and senescence in fast growing trees grown on short rotations

    Energy Technology Data Exchange (ETDEWEB)

    Blake, T J

    1981-06-01

    The paper is aimed at identifying some possible problem areas in the future management of coppice stands on short rotations. The paper considers the possible role of plant hormones, water, cultural and enviromental factors in regulating shoot production, growth and senescence in hardwoods grown on short rotations for biomass production. 77 references.

  3. Tree-rings mirror management legacy: dramatic response of standard oaks to past coppicing in Central Europe.

    Directory of Open Access Journals (Sweden)

    Jan Altman

    Full Text Available BACKGROUND: Coppicing was one of the most important forest management systems in Europe documented in prehistory as well as in the Middle Ages. However, coppicing was gradually abandoned by the mid-20(th century, which has altered the ecosystem structure, diversity and function of coppice woods. METHODOLOGY/PRINCIPAL FINDINGS: Our aim was to disentangle factors shaping the historical growth dynamics of oak standards (i.e. mature trees growing through several coppice cycles in a former coppice-with-standards in Central Europe. Specifically, we tried to detect historical coppicing events from tree-rings of oak standards, to link coppicing events with the recruitment of mature oaks, and to determine the effects of neighbouring trees on the stem increment of oak standards. Large peaks in radial growth found for the periods 1895-1899 and 1935-1939 matched with historical records of coppice harvests. After coppicing, the number of newly recruited oak standards markedly grew in comparison with the preceding or following periods. The last significant recruitment of oak standards was after the 1930s following the last regular coppicing event. The diameter increment of oak standards from 1953 to 2003 was negatively correlated with competition indices, suggesting that neighbouring trees (mainly resprouting coppiced Tilia platyphyllos partly suppressed the growth of oak standards. Our results showed that improved light conditions following historical coppicing events caused significant increase in pulses of radial growth and most probably maintained oak recruitment. CONCLUSIONS/SIGNIFICANCE: Our historical perspective carries important implications for oak management in Central Europe and elsewhere. Relatively intense cutting creating open canopy woodlands, either as in the coppicing system or in the form of selective cutting, is needed to achieve significant radial growth in mature oaks. It is also critical for the successful regeneration and long

  4. The Characteristics of Fibres within Coppiced and Non-Coppiced Rosewood (Pterocarpus erinaceus Poir. and their Aptness for Wood - and Paper - Based Products

    Directory of Open Access Journals (Sweden)

    Frederick ANTHONIO

    2017-06-01

    Full Text Available Rosewood (Pterocarpus erinaceus is highly priced for furniture, flooring and cabinetry for its rich hue and durability. Its coppiced wood augments the timber for regular supply and sustainable utilization. Fibre morphology from macerated slivers within its coppiced and non-coppiced stems and their utilization potential were assessed. Derived ratios for the fibres were also calculated. The axial positions (butt, middle, crown affected the fibre dimensions. Fibre length was greater for coppiced trees [i.e., 1663±11, 1488±5, 1511±10µm (for sapwood and 1498±10, 1486±9, 1394±4µm (for heartwood] than the non-coppiced [i.e., 1240±7, 1013±5, 1137±5µm (sapwood and 1094±8, 1002±2, 1041±9µm (heartwood]. In all, those for sapwoods were greater than heartwoods’. Significant differences (P˂0.05 existed between fibre lengths from the coppiced (1394±4-1663±11µm and non-coppiced trees (1002±2-1240±7µm. Fibre diameters for coppiced sapwood and heartwood were 23±1, 20±1, 22±0.8µm and 21.5±0.3, 20.7±0.5, 21.3±2µm and noncoppiced recorded 21±0.6, 20.7±0.3, 20.6±0.1µm and 21±0, 21±0.4, 21±0.8µm respectively. Their respective double wall thicknesses were 8.4±0.2, 7.2±0.2, 9.4±1µm and 8.2±0.2, 9±0.3, 9.1±0.4µm for coppiced wood, and 9.1±1, 7.8±0.1, 8.1±0.3µm and 8.5±0.3, 8±0.4, 8±1 for non-coppiced. Thus, radial stem position also influenced fibre morphology. The fibre indices [i.e., Runkel Ratio, Slenderness Ratio and Flexibility Coefficient for coppiced wood (0.6±0.06-0.85±0.06, 68±4-77±6, 56±4-64±2 respectively and non-coppiced (0.64±0.12-0.8±0, 49±1-58±4, 57±3-62±2 respectively] indicate the timber’s aptness for pulp and paper. Besides, the Wood Industry could exploit the fibre characteristics of coppiced wood also for engineering of fibre-based products and structural applications.

  5. Growth of teak regenerated by coppice and stump planting in Mae Moh Plantation, Lampang province, Thailand

    Directory of Open Access Journals (Sweden)

    Anatta Auykim

    2017-08-01

    Full Text Available The current annual increment (CAIdbh and the mean annual increment (MAIdbh both for the diameter at breast height (1.3 m were investigated to compare the differences between coppice and stump-planted teak in Mae Moh Plantation. Forty-eight sample cores were collected from a 9 yr-old teak plantation using an increment borer; annual increments were analyzed using dendrochronological techniques. The results indicated that there was no significant (p > 0.05 difference in the average diameter at breast height (DBH between the coppice and stump-planted teak, whereas the total height of stump planting was significantly greater than that of coppice teak. The CAIdbh of coppice teak was in the range 0.316–2.371 cm and continuously decreased throughout the 9 yr period. The CAIdbh of stump planting was in the range 0.162–1.982 cm and continuously increased from the beginning of growth for 5 yr followed by a decline thereafter for 4 yr. The CAIdbh of coppice showed rapid growth in the years 1–4 and was greater than for the stump-planted teak even in years 5–8 after planting; however, the growth of the stump-planted teak in the ninth year was higher than for the coppice. The MAIdbh values of coppice and stump-planted teak were not significantly (p > 0.05 different. The results showed that CAIdbh at age 5 yr can be used as a silvicultural guide to increase the yield of teak coppice.

  6. The Effects of Adding Coordinate Axes To a Mental Rotations Task in Measuring Spatial Visualization Ability in Introductory Undergraduate Technical Graphics Courses.

    Science.gov (United States)

    Branoff, Ted

    1998-01-01

    Reports on a study to determine whether the presence of coordinate axes in a test of spatial-visualization ability affects scores and response times on a mental-rotations task for students enrolled in undergraduate introductory graphic communications classes. Based on Pavios's dual-coding theory. Contains 36 references. (DDR)

  7. A key role for experimental task performance: effects of math talent, gender and performance on the neural correlates of mental rotation.

    Science.gov (United States)

    Hoppe, Christian; Fliessbach, Klaus; Stausberg, Sven; Stojanovic, Jelena; Trautner, Peter; Elger, Christian E; Weber, Bernd

    2012-02-01

    The neurophysiological mechanisms underlying superior cognitive performance are a research area of high interest. The majority of studies on the brain-performance relationship assessed the effects of capability-related group factors (e.g. talent, gender) on task-related brain activations while only few studies examined the effect of the inherent experimental task performance factor. In this functional MRI study, we combined both approaches and simultaneously assessed the effects of three relatively independent factors on the neurofunctional correlates of mental rotation in same-aged adolescents: math talent (gifted/controls: 17/17), gender (male/female: 16/18) and experimental task performance (median split on accuracy; high/low: 17/17). Better experimental task performance of mathematically gifted vs. control subjects and male vs. female subjects validated the selected paradigm. Activation of the inferior parietal lobule (IPL) was identified as a common effect of mathematical giftedness, gender and experimental task performance. However, multiple linear regression analyses (stepwise) indicated experimental task performance as the only predictor of parietal activations. In conclusion, increased activation of the IPL represents a positive neural correlate of mental rotation performance, irrespective of but consistent with the obtained neurocognitive and behavioral effects of math talent and gender. As experimental performance may strongly affect task-related activations this factor needs to be considered in capability-related group comparison studies on the brain-performance relationship. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Effect of coppicing height on the regeneration and productivity of certain firewood shrubs in alkaline soils of north Indian plains

    Energy Technology Data Exchange (ETDEWEB)

    Misra, P.N.; Tewari, S.K.; Singh, Dheer; Katiyar, R.S. [National Botanical Research Inst., Lucknow (India)

    1995-12-31

    Four shrubs, viz. Hibiscus tiliaceus, Leucaena leucocephala, Vitex negundo and Sesbania sesban, were evaluated for their performance as firewood crops in coppiced stands of varying cutting heights (15, 30 and 45 cm) in repeated annual harvests (4) on alkaline soils of the North Indian plains. The dry wood yield of Leucaena and Sesbania ranged between 22.9-42.6 and 9.9-18.0 tonnes ha{sup -1} year{sup -1}, respectively. Leucaena showed progressive increases in yield from coppiced stumps up to the 4th harvest while Sesbania showed a reduction after the third harvest mainly due to the high degeneration (60%) of coppiced stumps. Degeneration was low (< 10%) in Leucaena and Vitex. The coppicing heights generally did not show any significant effect on the growth and productivity. The number of coppice shoots per stump increased with stump height and production of coppice shoots was maximum in Vitex and minimum in Leucaena. The average diameter of coppice shoots tended to decrease with increasing coppicing height of the stumps. (author)

  9. Managing ergonomics in the development of rotation between workstations in the automotive industry. A balance between health and traceability of tasks.

    Science.gov (United States)

    Filus, Rodrigo; Partel, Luciana

    2012-01-01

    Abstract When the subject rotation between workstations (job rotation) is inside the organizations it's seemed that technically there are lots of restrictions to the development of an adequate system of rotation. We went from the need for an advanced ergonomic study and even possible restrictions of versatility and training of employees. The implementation of the ideal system of rotation passes through stages of development and research ergonomic study of the level of employee versatility, awareness and discussion with employees, implementation of the proposed system, feedback and audits for maintenance of the ideal sequence and time of rotation. For the success of the project there is a need for multidisciplinary involvement in the areas of manufacturing engineering, industrial engineering, human resources, medical services and manufacturing. Rotation between the tasks may mean that a worker should conduct two or more different activities in different parts of the day (ie. change between activity A and activity B "between 1 hours and 2 hours interval). An important consideration is to ensure that different activities do not present the same ergonomic risk for the same body part. The tracing of the execution of the activity is an important factor for production processes. Thus it is possible to conduct appropriate levels of training for employees and ensure safe and sustainable processes in terms of workers' health, productivity and quality.

  10. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance.

    Science.gov (United States)

    Pannebakker, Merel M; Jolicœur, Pierre; van Dam, Wessel O; Band, Guido P H; Ridderinkhof, K Richard; Hommel, Bernhard

    2011-09-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. A New Stem Taper Function for Short-rotation poplar

    Energy Technology Data Exchange (ETDEWEB)

    Benbrahim, Mohammed [INRA Centre de Bordeaux, Cestas (France). Unite de Recherches Forestieres; Gavaland, Andre [INRA Centre de Toulouse, Castanet-Tolosane (France). Unite Agroforesterie et Foret Paysanne

    2003-07-01

    A new stem taper function was established for individual trees of two poplar hybrid clones grown on a short-rotation coppice. The model could be easily fitted and required three parameters to be estimated. It can be used to estimate both diameter at a given height and height for a given top diameter. Two of the three parameters controlled the conical and the neiloid parts of the stem. Significant differences in these parameters were observed between the two clones even if no differences were observed for diameter at breast height or total height of the stem. The model could not be integrated to calculate volumes (total volume, merchantable volume), which were estimated by numerical integration. However, use of this new model allows the optimal length of billets to be determined and thus maximizes the merchantable biomass of poplar in short-rotation coppice by minimizing the biomass of residues.

  12. Responses in young Quercus petraea: coppices and standards under favourable and drought conditions

    Czech Academy of Sciences Publication Activity Database

    Stojanović, Marko; Čater, M.; Pokorný, Radek

    2016-01-01

    Roč. 76, jan (2016), s. 127-136 ISSN 1641-1307 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67179843 Keywords : coppice * standards * comparison * photosynthetic response * quantum yield * light conditions * drought response Subject RIV: EF - Botanics Impact factor: 0.776, year: 2016

  13. Coppicing systems as a way of understanding patterns in forest vegetation

    Czech Academy of Sciences Publication Activity Database

    Hédl, Radim; Ewald, J.; Bernhardt-Römermann, M.; Kirkby, K.

    2017-01-01

    Roč. 52, č. 1 (2017), s. 1-3 ISSN 1211-9520 Institutional support: RVO:67985939 Keywords : traditional coppices * vegetation dynamics * ecological restoration Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.017, year: 2016

  14. Intensive game keeping, coppicing and butterflies: The story of Milovicky Wood, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Beneš, Jiří; Čížek, Oldřich; Dovala, J.; Konvička, Martin

    2006-01-01

    Roč. 237, 1-3 (2006), s. 353-365 ISSN 0378-1127 R&D Projects: GA ČR GA526/04/0417 Institutional research plan: CEZ:AV0Z50070508 Keywords : butterfly conservation * Central Europe * coppice management Subject RIV: EH - Ecology, Behaviour Impact factor: 1.839, year: 2006

  15. Evaluating the Impact of Depth Cue Salience in Working Three-Dimensional Mental Rotation Tasks by Means of Psychometric Experiments

    Science.gov (United States)

    Arendasy, Martin; Sommer, Markus; Hergovich, Andreas; Feldhammer, Martina

    2011-01-01

    The gender difference in three-dimensional mental rotation is well documented in the literature. In this article we combined automatic item generation, (quasi-)experimental research designs and item response theory models of change measurement to evaluate the effect of the ability to extract the depth information conveyed in the two-dimensional…

  16. An evaluation of the optimum timing for planting short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.; Jefferies, R.; Parfitt, R.

    2004-07-01

    This report summarises the results of a project to determine the optimum timing for planting, evaluate problems due to late planting in the spring, and to study the planting of willows at different times during the autumn. Details are given of the site installation, previous research on the effect of planting date and storage, and assessment of the establishment and biomass productivity and the viability of cuttings in long-term storage. Charts illustrating biomass productivity are presented, and long-term storage of willow cuttings for autumn planting is discussed.

  17. Modelling supply and demand of bioenergy from short rotation coppice and Miscanthus in the UK.

    Science.gov (United States)

    Bauen, A W; Dunnett, A J; Richter, G M; Dailey, A G; Aylott, M; Casella, E; Taylor, G

    2010-11-01

    Biomass from lignocellulosic energy crops can contribute to primary energy supply in the short term in heat and electricity applications and in the longer term in transport fuel applications. This paper estimates the optimal feedstock allocation of herbaceous and woody lignocellulosic energy crops for England and Wales based on empirical productivity models. Yield maps for Miscanthus, willow and poplar, constrained by climatic, soil and land use factors, are used to estimate the potential resource. An energy crop supply-cost curve is estimated based on the resource distribution and associated production costs. The spatial resource model is then used to inform the supply of biomass to geographically distributed demand centres, with co-firing plants used as an illustration. Finally, the potential contribution of energy crops to UK primary energy and renewable energy targets is discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams

    OpenAIRE

    KUPPENS, Tom; CORNELISSEN, Tom; CARLEER, Robert; YPERMAN, Jan; SCHREURS, Sonja; JANS, Maarten; THEWYS, Theo

    2010-01-01

    The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass an...

  19. Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams.

    Science.gov (United States)

    Kuppens, T; Cornelissen, T; Carleer, R; Yperman, J; Schreurs, S; Jans, M; Thewys, T

    2010-12-01

    The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. The functional role of dorso-lateral premotor cortex during mental rotation: an event-related fMRI study separating cognitive processing steps using a novel task paradigm.

    Science.gov (United States)

    Lamm, Claus; Windischberger, Christian; Moser, Ewald; Bauer, Herbert

    2007-07-15

    Subjects deciding whether two objects presented at angular disparity are identical or mirror versions of each other usually show response times that linearly increase with the angle between objects. This phenomenon has been termed mental rotation. While there is widespread agreement that parietal cortex plays a dominant role in mental rotation, reports concerning the involvement of motor areas are less consistent. From a theoretical point of view, activation in motor areas suggests that mental rotation relies upon visuo-motor rather than visuo-spatial processing alone. However, the type of information that is processed by motor areas during mental rotation remains unclear. In this study we used event-related fMRI to assess whether activation in parietal and dorsolateral premotor areas (dPM) during mental rotation is distinctively related to processing spatial orientation information. Using a newly developed task paradigm we explicitly separated the processing steps (encoding, mental rotation proper and object matching) required by mental rotation tasks and additionally modulated the amount of spatial orientation information that had to be processed. Our results show that activation in dPM during mental rotation is not strongly modulated by the processing of spatial orientation information, and that activation in dPM areas is strongest during mental rotation proper. The latter finding suggests that dPM is involved in more generalized processes such as visuo-spatial attention and movement anticipation. We propose that solving mental rotation tasks is heavily dependent upon visuo-motor processes and evokes neural processing that may be considered as an implicit simulation of actual object rotation.

  1. Economic analysis of replacement regeneration and coppice regeneration in eucalyptus stands under risk conditions

    Directory of Open Access Journals (Sweden)

    Isabel Carolina de Lima Guedes

    2011-09-01

    Full Text Available Projects are by their very nature subject to conditions of uncertainty that obstruct the decision-making process. Uncertainties involving forestry projects are even greater, as they are combined with time of return on capital invested, being medium to long term. For successful forest planning, it is necessary to quantify uncertainties by converting them into risks. The decision on whether to adopt replacement regeneration or coppice regeneration in a forest stand is influenced by several factors, which include land availability for new forest crops, changes in project end use, oscillations in demand and technological advancement. This study analyzed the economic feasibility of replacement regeneration and coppice regeneration of eucalyptus stands, under deterministic and under risk conditions. Information was gathered about costs and revenues for charcoal production in order to structure the cash flow used in the economic analysis, adopting the Net Present Value method (VPL. Risk assessment was based on simulations running the Monte Carlo method. Results led to the following conclusions: replacement regeneration is economically viable, even if the future stand has the same productivity as the original stand; coppice regeneration is an economically viable option even if productivity is a mere 70% of the original stand (high-tree planted stand, the best risk-return ratio option is restocking the stand (replacement regeneration by one that is 20% more productive; the probabilistic analysis running the Monte Carlo method revealed that invariably there is economic viability for the various replacement and coppice regeneration options being studied, minimizing uncertainties and consequently increasing confidence in decision-making.

  2. Habitat requirements of endangered species in a former coppice of high conservation value

    Czech Academy of Sciences Publication Activity Database

    Roleček, Jan; Vild, Ondřej; Sladký, J.; Řepka, R.

    2017-01-01

    Roč. 52, č. 1 (2017), s. 59-69 ISSN 1211-9520 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : abandoned coppice * environmental requirements * red-list species Subject RIV: EH - Ecology, Behaviour OBOR OECD: Plant sciences, botany Impact factor: 1.017, year: 2016

  3. Patterns of functional diversity of two trophic groups after canopy thinning in an abandoned coppice

    Czech Academy of Sciences Publication Activity Database

    Šipoš, Jan; Hédl, Radim; Hula, V.; Chudomelová, Markéta; Košulič, O.; Niedobová, J.; Riedl, Vladan

    2017-01-01

    Roč. 52, č. 1 (2017), s. 45-58 ISSN 1211-9520 R&D Projects: GA AV ČR IAA600050812; GA MŠk(CZ) EE2.3.20.0267 EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : coppice restoration * functional diversity * trophic groups Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.017, year: 2016

  4. Dynamics of herbaceous vegetation during four years of experimental coppice introduction

    Czech Academy of Sciences Publication Activity Database

    Hédl, Radim; Šipoš, Jan; Chudomelová, Markéta; Utinek, D.

    2017-01-01

    Roč. 52, č. 1 (2017), s. 83-99 ISSN 1211-9520 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : biodiversity * ecological restoration * coppice-with-standards Subject RIV: EH - Ecology, Behaviour OBOR OECD: Plant sciences, botany Impact factor: 1.017, year: 2016

  5. Distribution of organic matter and plant nutrients in a sal (shorea robusta) coppice plantation

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, O.N.; Sharma, D.C.; Srivastava, P.B.L.

    The biomass and nutrient content (N, P, K, Ca, Mg) of leaves, twigs, branches, stems and bark were determined for sample trees in a stand in the New Forest, Dehra Dun, coppiced 21 years previously. It was estimated that the removal of stems, branches and bark by harvesting at this age would remove 82-91% of the total nutrients (kg/ha) in the stand.

  6. Forecasting tree growth in coppiced and high forests in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Stojanović, Marko; Sánchez-Salguero, R.; Levanič, T.; Szatniewska, Justyna; Pokorný, Radek; Linares, J. C.

    2017-01-01

    Roč. 405, DEC (2017), s. 56-68 ISSN 0378-1127 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : coppice * high forest * senssile oak * dendroecology * basal area increment * climate change * emission scenarios Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 3.064, year: 2016

  7. Experimental restoration of coppice-with-standards: Response of understorey vegetation from the conservation perspective.

    Science.gov (United States)

    Vild, Ondřej; Roleček, Jan; Hédl, Radim; Kopecký, Martin; Utinek, Dušan

    2013-12-15

    A substantial part of European lowland woodlands was managed as coppices or wood pastures for millennia. However, traditional management forms were almost completely abandoned in Central Europe by the middle of the 20th century. Combined with the effects of nitrogen deposition and herbivore pressure, shifts in management resulted in biodiversity loss affecting particularly light-demanding oligotrophic plant species. Experimental thinning was applied in a former oak coppice-with-standards in an attempt to restore vanishing understorey plant communities. Two levels of thinning intensity and zero management as control were used on 90 plots. Ten years after the treatment, significant changes in species composition and diversity were observed in heavily thinned plots, while moderate thinning had mostly insignificant effects. Light-demanding oligotrophic species significantly increased, indicating positive consequences of restoration. However, heavy thinning also brought about the expansion of native ruderal species. Alien species remained unchanged. We conclude that the restoration of coppice-with-standards can be an efficient tool to support vanishing light-demanding woodland species. Combined with biodiversity benefits, the increasing demand for biofuel may contribute to the renaissance of traditional management forms in forestry.

  8. Conversion trials in mixed coppices of Gargano (Puglia, Italy: first results

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Six plots have been drawn in an mixed aged coppice stand, 40 years after last coppicing; they represent a typical expression of Doronico-Carpinetum phytosociological association and they are characteristic of many woods of Gargano’s territory, composed by Quercus cerris L. (turkey oak, Quercus pubescens Willd. (downy oak, Acer opalus Mill. (italian maple, Carpinus betulus L. (european hornbeam, Ostrya carpinifolia Scop. (hop hornbeam. Compared treatments are: natural evolution of the coppice without thinning versus two thinning regimes with different intensity, both aimed to convert the stands into high forests. 1200 and 1600 stems per hectare were released in the conversion plots. Plots, control and treated in 2001, have been measured before and immediately after thinning and remeasured five years later. At the present time, stands are characterized by a basically monolayered structure, in which turkey oak is prevalent in term of basal area. Moreover in thinned areas, losses on the released shoots number are unimportant both in absolute and in percent terms; in control plot, instead, competition by plants of upper storey on the dominated ones means high values of mortality.

  9. Large sexual-orientation-related differences in performance on mental rotation and judgment of line orientation tasks.

    Science.gov (United States)

    Rahman, Qazi; Wilson, Glenn D

    2003-01-01

    This study examined the performance of heterosexual and homosexual men and women on 2 tests of spatial processing, mental rotation (MR) and Benton Judgment of Line Orientation (JLO). The sample comprised 60 heterosexual men, 60 heterosexual women, 60 homosexual men, and 60 homosexual women. There were significant main effects of gender (men achieving higher scores overall) and Gender x Sexual Orientation interactions. Decomposing these interactions revealed large differences between the male groups in favor of heterosexual men on JLO and MR performance. There was a modest difference between the female groups on MR total correct scores in favor of homosexual women but no differences in MR percentage correct. The evidence suggests possible variations in the parietal cortex between homosexual and heterosexual persons.

  10. Movimentos oculares e padrões de busca visual em tarefas de rotação mental Eye movements and scan patterns in mental rotation tasks

    Directory of Open Access Journals (Sweden)

    Priscila Covre

    2005-06-01

    Full Text Available O objetivo deste estudo é identificar as estratégias utilizadas nas tarefas de rotação mental pela análise dos traçados dos movimentos oculares. Foi analisado o desempenho de 40 participantes na comparação de pares de objetos tridimensionais rotacionados no eixo y, com diferenças de angulação de 0o a 180o. Foi utilizado um sistema computacional de rastreamento dos movimentos oculares (eyetracking durante a visualização de figuras. Os resultados mostram que tempo de julgamento, duração média das fixações do olho, número de fixações nos objetos e número de alternâncias entre os dois objetos aumentam em função da diferença de angulação. Análise dos traçados oculares, com base na inspeção visual, indica o uso de dois tipos de estratégias: rotação mental em torno dos eixos padrões e comparação independente da orientação. O uso dessas estratégias é discutido com relação ao desempenho dos participantes e à memória de trabalho.The purpose of this paper is to identify the strategies used on mental rotation tasks by analyzing ocular movements. The performance of 40 participants on comparison of pairs of three-dimensional objects, rotated on the y-axis, from 0o to 180o was analyzed. An eye-tracking computerized system was used to track eye movements during scene visualization. Results showed that judgment time, fixation duration, number of fixations and number of switches between the objects increased with rotation angle. Analysis by visual inspection indicates the use of two kinds of strategies: Mental rotation around the standard axis and comparison of orientation-free descriptions. The use of the strategies is discussed with regard to performance and working memory.

  11. Environmental influence of willow coppice systems on farm land

    International Nuclear Information System (INIS)

    Ledin, S.

    1997-01-01

    As for all cultivated crops, there are numerous environmental influences when growing willows. These influences are connected with additions to the soil, management measures and changes caused by the developing crop. As a perennial crop with good root penetration into the soil, high water use and efficient nutrient uptake over a long growing season, short rotation forests with willows have an influence on the environment that differs from the influence of annual farm crops. Also the landscape is affected differently by the dense willow stand with a height of seven meters before harvest. There is usually less use of herbicides in the perennial woody crop. Due to larger amounts of litter from the willow plantation and no tillage, there is with time an increase of the humus content in the soil. In relation to this, the soil fauna, using organic material for food, prosper in the short rotation forest. Considerably more cadmium is taken up by the willows than by conventional annual crops. This could be used to clean the soil of cadmium, but more knowledge is needed for the optimisation of this procedure. Willows are usually efficient in taking up nutrients, including nitrogen, but when used as vegetation filters it is important to assess the actual ability of a stand to take up N. This ability varies considerably with the development stage of the plantation and also with site conditions. (au) 30 refs

  12. Carbon Stocks of Fine Woody Debris in Coppice Oak Forests at Different Development Stages

    Directory of Open Access Journals (Sweden)

    Ender Makineci

    2017-06-01

    Full Text Available Dead woody debris is a significant component of the carbon cycle in forest ecosystems. This study was conducted in coppice-originated oak forests to determine carbon stocks of dead woody debris in addition to carbon stocks of different ecosystem compartments from the same area and forests which were formerly elucidated. Weight and carbon stocks of woody debris were determined with recent samplings and compared among development stages (diameter at breast height (DBH, D1.3m, namely small-diameter forests (SDF = 0–8 cm, medium diameter forests (MDF = 8–20 cm, and large-diameter forests (LDF = 20–36 cm. Total woody debris was collected in samplings; as bilateral diameters of all woody debris parts were less than 10 cm, all woody parts were in the “fine woody debris (FWD” class. The carbon concentrations of FWD were about 48% for all stages. Mass (0.78–4.92 Mg·ha−1 and carbon stocks (0.38–2.39 Mg·ha−1 of FWD were significantly (p > 0.05 different among development stages. FWD carbon stocks were observed to have significant correlation with D1.3m, age, basal area, and carbon stocks of aboveground biomass (Spearman rank correlation coefficients; 0.757, 0.735, 0.709, and 0.694, respectively. The most important effects on carbon budgets of fine woody debris were determined to be coppice management and intensive utilization. Also, national forestry management, treatments of traditional former coppice, and conversion to high forest were emphasized as having substantial effects.

  13. Forest operations in coppice: Environmental assessment of two different logging methods.

    Science.gov (United States)

    Laschi, Andrea; Marchi, Enrico; González-García, Sara

    2016-08-15

    Wood is a renewable resource and it actively contributes to enhance energy production under a sustainable perspective. However, harvesting, transport and use of wood imply several consequences and impacts on environment. There are different ways for managing forests dedicated to wood production and a sustainable approach is fundamental to preserve the resource. In this context, Life Cycle Assessment (LCA) is a useful tool for estimating the environmental impacts related to renewable resources. Traditional coppice is a common approach for forest management in several areas, including southern Europe and, specifically, Italy, Spain and the Balkans. Due to different terrain conditions, different types of forest operations are considered for wood extraction from coppices, where the main product is firewood used in domestic heating. The aim of this work was to compare the main common systems for firewood production in two different terrain conditions ('flat/low steep' and 'steep/very steep' terrains), in a representative environment for Mediterranean area, located in central Italy, by means of LCA. Seven different impact categories were evaluated in a cradle-to-gate perspective taking into account all the operations carried out from the trees felling to the firewood storage at factory. Results showed that the extraction phase was the most important in terms of environmental burdens in firewood production and the use of heavy and high-power machines negatively influenced the emissions compared with manual operations. Finally, considering the general low-inputs involved in wood production in coppice, the transport of workers by car to the work site resulted on consistent contributions into environmental burdens. An additional analysis about the modifications of CH4 and N2O exchanges between soil and atmosphere, due to soil compaction in the extraction phase, was made and based on bibliographic information. Results showed a sensible difference between disturbed and

  14. Impact of Canopy Openness on Spider Communities: Implications for Conservation Management of Formerly Coppiced Oak Forests.

    Directory of Open Access Journals (Sweden)

    Ondřej Košulič

    Full Text Available Traditional woodland management created a mosaic of differently aged patches providing favorable conditions for a variety of arthropods. After abandonment of historical ownership patterns and traditional management and the deliberate transformation to high forest after World War II, large forest areas became darker and more homogeneous. This had significant negative consequences for biodiversity. An important question is whether even small-scale habitat structures maintained by different levels of canopy openness in abandoned coppiced forest may constitute conditions suitable for forest as well as open habitat specialists. We investigated the effect of canopy openness in former traditionally coppiced woodlands on the species richness, functional diversity, activity density, conservation value, and degree of rareness of epigeic spiders. In each of the eight studied locations, 60-m-long transect was established consisting of five pitfall traps placed at regular 15 m intervals along the gradient. Spiders were collected from May to July 2012. We recorded 90 spider species, including high proportions of xeric specialists (40% and red-listed threatened species (26%. The peaks of conservation indicators, as well as spider community abundance, were shifted toward more open canopies. On the other hand, functional diversity peaked at more closed canopies followed by a rapid decrease with increasing canopy openness. Species richness was highest in the middle of the canopy openness gradient, suggesting an ecotone effect. Ordinations revealed that species of conservation concern tended to be associated with sparse and partly opened canopy. The results show that the various components of biodiversity peaked at different levels of canopy openness. Therefore, the restoration and suitable forest management of such conditions will retain important diversification of habitats in formerly coppiced oak forest stands. We indicate that permanent presence of small

  15. Physiological aspects of short-rotation culture of the poplar. Fertilization of soils by sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, G

    1988-01-01

    This study, on the poplar (Populus Trichocarpa x Populus deltoides, c.v. Raspalje) concerned two different problems. The first is a physiological study on the tree treated in short rotation; the second deals with a fertilization by sewage sludge and the consequences on the environment. We have carried out in the laboratory two complementary experiments, the one, on the culture of the poplar in hydroponic medium with a pollutant element (Hg), and the other in the potentialities of soil retention. In the first part, we have showed that: - the best period for coppicing is between Mid August and May, as soon as the stumps were four or five years-old, - the coppicing has a stimulating effect on the growth of the coppice shoots, - the mean number of dominant coppice shoots, after several coppicing, is two, - the productivity is about 20 to 30 tonnes of dry matter per hectare and per year. The second part of this study has showed that: - using 3.2 tonnes of dehydrated sewage sludge per hectare and per year to fertilize, has the same effects on productivity of poplars as a classical fertilization (every 5 years) by chemical manure (N, P, K), - there were no differences in the concentration of heavy metals (Cd, Cu, Pb and Hg), in the different parts of the poplars, between the different plots fertilized with sewage sludge, chemical manure and controlled. Moreover, the experiments performed, in the laboratory showed that: - pollutant elements (Cd, Cu) were fixed in the top of the column soil, - using a hydroponic solution containing a mercuric chloride, labelled ({sup 203}Hg), the poplars absorb very little of the pollutant element. Only 10% of the mercury in the solution was to be found in the plant and 99% of this in the root-system, more precisely, at the level epidermic barrier.

  16. Vegetation and flora of short-rotation willow stands from a conservation viewpoint

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, L.

    1986-01-01

    The energy forests were studied using random 0.5 x 0.5 m quadrats in which cover for field- and bottom-layer species was recorded in a percentage scale. The data were analysed using various multivariate methods. The vegetation and flora of twelve coppices in southern Sweden were investigated. Also the succession during the establishment phase on a meadow on the west coast and on a peat bog in the east-central part of the country was studied. Moreover, the impact on fen vegetation downstream of an energy forest on a peat bog was investigated. The flora and vegetation of energy forests is dominated by common ruderal species like Cirsium arvense, Galeopsis tetrahit and Urtica dioica. Uncommon species from woodland and fen habitats are only occasionally found. The field layer of energy forests shows a clear seasonality with maximal cover in July. The species number and the composition of vegetation vary greatly between the coppices and is largely determined by the management system. Intense cultivation including fertilization and the use of herbicides depletes the flora. Long rotation times decrease both species diversity and the field-layer cover. Uncommon species are mostly found in old coppices, which also often have a rich spring flora. A change in flora and vegetation occurs when an energy forest is established. The change is great and the time needed for stabilization of the energy forest flora is long when the original flora is dissimilar to the coppice flora. Willow coppices can increase habitat diversity in regions dominated by coniferous forests or in large-scale agricultural areas. Structural heterogeneity of a stand promotes diversity of the flora. Such heterogeneity can be created if a stand is composed of a variety of willow clones, if it is harvested at intervals, contains gaps, open ditches and is surrounded by edge zones of various types.

  17. Impact of wild ungulates on coppices from the Bisenzio Valley (province of Prato, Italy

    Directory of Open Access Journals (Sweden)

    Bianchi L

    2014-06-01

    Full Text Available Similar to other Apennine areas, a considerable increase of wild ungulate density has been observed in the past decades in the Bisenzio valley (province of Prato, leading to a strong impact on coppice regeneration. In some felling areas, the prolonged browsing on young suckers turned the stumps into low and dense bushes, thus threatening the survival of the forest stand and triggering a loss of environmental stability. The aim of this work was to study the impact of deer on sprout regeneration after cutting in mixed coppices felled in the period 2007-2010 and characterized by the dominance of chestnut, hornbeam, Turkey oak, and beech. Some 36 plots were established in four municipal districts of the Prato province (Cantagallo, Vernio, Montemurlo, Vaiano. Damage and browsing intensity on each stump were evaluated using an index that allowed the comparison among different areas and fores stand types. Regardless of the species, over 90% of the sprouts revealed a very strong damage, whereas only 6% did not exhibit any damage. A significant difference in the sprout height was detected between browsed and non-browsed areas. Despite a high incidence of damage in all the studied areas, chestnut showed a greater resilience against browsing. In summary, overgrazing by wild game may determine severe contraints to the evolutionary dynamics of forest stands, frustrating the effects of silvicultural practices. The possible benefits of the implementation of a large-scale integrated wildlife plan, including hunting and forest-evironmental management are discussed.

  18. Initial spacing of poplars and willows grown as arable coppice

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, A.; Johns, C.

    1997-11-01

    Two clones of poplar and two clones of willow were grown at two sites, on a three year cutting cycle, at six different square spacings, between 0.8 metres and 1.5 metres. The two willow clones 'Bowles hybrid' and 'Dasyclados' were planted at both sites. The poplar clones Populus interamericana 'Beaupre' and Populus trichocarpa 'Columbia River'' were planted at Wishanger in Hampshire. The poplar clones Populus interamericana 'Boelare' and Populus trichocarpa 'Trichobel' were planted at Downham Market in Norfolk. The highest yield of 17.55 oven dry tonnes per hectare (odt/ha/annum) was obtained from 'Bowles hybrid', at the closest spacing, grown on a water meadow adjacent to the River Wey at Wishanger. The highest yield for all clones at both sites was achieved at the closest spacing (in this first rotation). There was a significant linear effect. One of the most interesting observations was that when comparing the gradient of the linear relationship, within species, the gradient was steeper for the higher yielding clone. This was particularly so for the willows. This would suggest that higher yielding clones are more tolerant of crowding, or, that upright Salix viminalis make better use of close space than the more spreading Salix dasyclados. The new Salix x Salix schwerinnii hybrids should therefore also be responsive to closer spacing. The same effect was observed for the poplars at Wishanger only, but the difference was not as dramatic. There was a suggestion from the highest yielding poplar plots that optimum yield may still be obtained at the currently recommended spacing of 1.0 metre x 1.0 metre. (author)

  19. Short rotation Wood Crops Program

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L.L.; Ehrenshaft, A.R.

    1990-08-01

    This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

  20. Examination as to the classification of representative tree species at Satoyama coppice forest using multiwavelength range data observed from aircraft

    International Nuclear Information System (INIS)

    Setojima, M.; Imai, Y.; Funahashi, M.; Kawai, M.; Katsuki, T.

    2006-01-01

    In this study, we examined the possibility of classifying representative tree species at Satoyama coppice forest based on spectral reflectance of the tree species. We used the airborne hyperspectral data observed in exhibition leaf stage at the test forest (about 3.4ha) in Tama Forest Science Garden (Hachioji, Tokyo) , where the forest type similar to that of Satoyama is preserved. The classification accuracy was verified by comparing the results of interpretation of color aerial photographs taken in spring and autumn in chronological order and the field survey. As a result, the 534-556 nm (band 6 and band 7) in the visible range and 739-762 nm (band 15 and band 16), 785nm (band 17) in the near infrared range are effective bands for classification of the species of such trees as Castanopsis sieboldii, Quercus glauca, Zelkova serrata, Quercus serrata, Cryptomeria japonica, and Chamaecyparis obutusa, which are representative trees in Satoyama coppice forest in Tama district

  1. Tree-Rings Mirror Management Legacy: Dramatic Response of Standard Oaks to Past Coppicing in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Altman, Jan; Hédl, Radim; Szabó, Péter; Mazůrek, Petr; Riedl, Vladan; Müllerová, Jana; Kopecký, Martin; Doležal, Jiří

    2013-01-01

    Roč. 8, č. 2 (2013), e55770 E-ISSN 1932-6203 R&D Projects: GA ČR GAP504/12/1952; GA AV ČR IAA600050812; GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67985939 Keywords : tree-rings * coppicing * competition Subject RIV: EH - Ecology, Behaviour Impact factor: 3.534, year: 2013

  2. Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study.

    Science.gov (United States)

    Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P; Crewther, Sheila G

    2016-01-01

    Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial stimuli (3D cube shapes) utilizing a 1-back task while functional magnetic resonance imaging (fMRI) scans were acquired. Sixteen healthy participants (9 women, M = 23.94 years, SD = 2.49) were required to perform the 1-back task with or without mentally rotating the shapes 90° on a vertical axis. When no rotation was required (maintenance-only condition), a right hemispheric lateralization was revealed across fronto-parietal areas. However, when the task involved maintaining and manipulating the same stimuli through 90° rotation, activation was primarily seen in the bilateral parietal lobe and left fusiform gyrus. The findings confirm that the well-established right lateralized fronto-parietal networks are likely to underlie simple maintenance of visuo-spatial stimuli. The results also suggest that the added demand of manipulation of information maintained online appears to require further neural recruitment of functionally related areas. In particular mental rotation of visuospatial stimuli required bilateral parietal areas, and the left fusiform gyrus potentially to maintain a categorical or object representation. It can be concluded that WM is a complex neural process involving the interaction of an increasingly large network.

  3. On Job Rotation

    OpenAIRE

    Metin M. Cosgel; Thomas J. Miceli

    1998-01-01

    A fundamental principle of economics with which Adam Smith begins The Wealth of Nations is the division of labor. Some firms, however, have been pursuing a practice called job rotation, which assigns each worker not to a single and specific task but to a set of several tasks among which he or she rotates with some frequency. We examine the practice of job rotation as a serious alternative to specialization, with three objectives. The first is to consider current and historical examples of job...

  4. Differential effects of voluntary wheel running and toy rotation on the mRNA expression of neurotrophic factors and FKBP5 in a post-traumatic stress disorder rat model with the shuttle-box task.

    Science.gov (United States)

    Tanichi, Masaaki; Toda, Hiroyuki; Shimizu, Kunio; Koga, Minori; Saito, Taku; Enomoto, Shingo; Boku, Shuken; Asai, Fumiho; Mitsui, Yumi; Nagamine, Masanori; Fujita, Masanori; Yoshino, Aihide

    2018-06-18

    Life-threatening experiences can result in the development of post-traumatic stress disorder. We have developed an animal model for post-traumatic stress disorder (PTSD) using a shuttle box in rats. In this paradigm, the rats were exposed to inescapable foot-shock stress (IS) in a shuttle box, and then an avoidance/escape task was performed in the same box 2 weeks after IS. A previous study using this paradigm revealed that environmental enrichment (EE) ameliorated avoidance/numbing-like behaviors, but not hyperarousal-like behaviors, and EE also elevated hippocampal brain-derived neurotrophic factor (BDNF) expression. However, the differential effects of EE components, i.e., running wheel (RW) or toy rotation, on PTSD-like behaviors has remained unclear. In this experiment, we demonstrated that RW, toy rotation, and EE (containing RW and toy rotation) ameliorated avoidance/numbing-like behaviors, induced learning of avoidance responses, and improved depressive-like behaviors in traumatized rats. The RW increased the hippocampal mRNA expression of neurotrophic factors, especially BDNF and glial-cell derived neurotrophic factor. Toy rotation influenced FK506 binding protein 5 mRNA expression, which is believed to be a regulator of the hypothalamic-pituitary-adrenal (HPA)-axis system, in the hippocampus and amygdala. This is the first report to elucidate the differential mechanistic effects of RW and toy rotation. The former appears to exert its effects via neurotrophic factors, while the latter exerts its effects via the HPA axis. Further studies will lead to a better understanding of the influence of environmental factors on PTSD. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Dry matter losses and quality changes during short rotation coppice willow storage in chip or rod form.

    Science.gov (United States)

    Whittaker, Carly; Yates, Nicola E; Powers, Stephen J; Misselbrook, Tom; Shield, Ian

    2018-05-01

    This study compares dry matter losses and quality changes during the storage of SRC willow as chips and as rods. A wood chip stack consisting of approximately 74 tonnes of fresh biomass, or 31 tonnes dry matter (DM) was built after harvesting in the spring. Three weeks later, four smaller stacks of rods with an average weight of 0.8 tonnes, or 0.4 tonnes DM were built. During the course of the experiment temperature recorders placed in the stacks found that the wood chip pile reached 60 °C within 10 days of construction, but the piles of rods remained mostly at ambient temperatures. Dry matter losses were calculated by using pre-weighed independent samples within the stacks and by weighing the whole stack before and after storage. After 6 months the wood chip stack showed a DM loss of between 19.8 and 22.6%, and mean losses of 23.1% were measured from the 17 independent samples. In comparison, the rod stacks showed an average stack DM loss of between 0 and 9%, and between 1.4% and 10.6% loss from the independent samples. Analysis of the stored material suggests that storing willow in small piles of rods produces a higher quality fuel in terms of lower moisture and ash content; however, it has a higher fine content compared to storage in chip form. Therefore, according to the two storage methods tested here, there may be a compromise between maximising the net dry matter yield from SRC willow and the final fine content of the fuel.

  6. Biophysical drivers of the carbon dioxide, water vapor, and energy exchanges of a short-rotation poplar coppice

    Czech Academy of Sciences Publication Activity Database

    Zenone, T.; Fischer, Milan; Arriga, N.; Broeckx, Laura S.; Verlinden, M. S.; Vanbeveren, S.; Zona, D.; Ceulemans, R.

    2015-01-01

    Roč. 209, sep (2015), s. 22-35 ISSN 0168-1923 R&D Projects: GA MŠk LH12037; GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : bioenergy crop * carbon uptake * evapotranspiration * surface conductance * leaf area index * omega factor * decoupling Subject RIV: EH - Ecology, Behaviour Impact factor: 4.461, year: 2015

  7. Willow clones with high biomass yield in short rotation coppice in the southern region of Tohoku district (Japan)

    International Nuclear Information System (INIS)

    Mitsui, Yu; Seto, Shoko; Nishio, Mari; Minato, Kazuya; Ishizawa, Kimiharu; Satoh, Shigeru

    2010-01-01

    The present study was conducted to select willow (Salix spp.) clones with a high potential for use as biomass energy crops in the southern region of Tohoku district in Japan. Cuttings of 8 willow clones were planted on an abandoned farmland near Sendai (av. annual temp., 10.9 o C) in March 2006, grown throughout the year and cut back in late December 2006 to resprout from the remaining stools in March 2007. The biomass yield in December 2007, after the first growing season, was highest in Salix pet-susu clone KKD, followed by Salix pseudolinearis clone FXM and Salix sachalinensis clone SEN. The biomass yield on December 2008, after the second growing season, was again highest in clone KKD followed by clone FXM, S. pet-susu clone HB471 and S. sachalinensis clone SEN; the average annual yield of dry mass after the second growing season being 3.09, 2.58, 2.17 and 1.85 kgDM plant -1 for the clones in this order. Plant growth form differed among the clones. Clones FXM and SEN had several shoots of almost uniform base diameter, whereas clones KKD and HB471 showed plagiotropic growth with one thick and several thin shoots. The calorific values of dried stem segments were similar among clones, ranging from 18.7 to 19.1 kJ g -1 . The dried stem segments contained 78.9-81.2 wt.% hollocellulose, 27.2-32.3 wt.% lignin and 2.1-4.0 wt.% extractives with ethanol-benzene, depending on clones. Based on these results, we could select four clones (KKD, FXM, HB471 and SEN) suitable for biomass production by SRWC in this area.

  8. Annual variations in the solar energy conversion efficiency in a willow coppice stand

    International Nuclear Information System (INIS)

    Noronha-Sannervik, A.; Kowalik, P.

    2003-01-01

    Productivity of an experimental willow coppice forest located at Uppsala, Sweden, was monitored between 1985 and 1994. The 2.7 ha stand was planted in 1984 with a density of 20 000 cuttings per ha and was harvested three times. During the monitored period, the annual stem wood production and the cumulated values of total solar radiation during the growing season, were measured. The conversion of incoming solar radiation into stem biomass was evaluated and the results show that the solar energy conversion efficiency (ECE), for the first and fourth year of the cutting cycle, is, on average, 64% of the ECE for the second and third year of the cutting cycle. It is discussed that the low ECE of 1-year-old shoots is related to a delay in leaf canopy development at the beginning of the growing season and lack of weed control after harvest. For the 4-years-old shoots, the low ECE, is believed to be related to the increased shoot and stool mortality caused by the self-thinning process ongoing in the willow stand. It is recommended that the harvesting interval should be based on the specific development of the stand and more attention should be paid to weed control, especially in the first growing season after harvest

  9. Effect of the silvicultural treatment on canopy properties, litter and seed production in beech coppices under conversion to high forest.

    Directory of Open Access Journals (Sweden)

    Andrea Cutini

    2010-12-01

    Full Text Available European beech (Fagus sylvatica L. is widely distributed in Italy where it covers 1035103 ha, mainly concentrated in the mountainous areas at altitudes above 900 m. The major part is represented by high forest often issued from the conversion of coppice woods, which in the past was the silvicultural system most widely applied mainly to provide fire wood. The social changes occurred in the second half of the last century –fire wood market crisis and the increasing importance of environmental issues- enhanced the conversion into high forest of large areas previously managed as coppice by means of different silvicultural treatments and practices. Nevertheless, the environmental benefits of this choice were not adequately investigated. Results of annual measurements (1992-2009 made in a beech coppice stand aged 65 are here reported. The study area is located on the Alpe di Catenaia, a pre-Apennine outcrop close to Arezzo (Central Italy. Variables strictly related to stand productivity and dynamics such as annual litter and seed production, leaf area index (LAI and transmittance (PAR were measured in the research area of Buca Zamponi to estimate the effects of two theses, natural evolution (TEST and conversion into high forest (DIR. Three thinnings were undertaken in the latter thesis in 1972, 1987 and 2002. Additional theses of natural evolution (CONTR and advance seed cutting (TS were added in 2002 in a nearby study area (Eremo della Casella. Results showed the high productivity of coppice stands, under conversion to high forest, with mean values of annual total litter, leaf litter and leaf area index of 5 Mg ha-1, 3 Mg ha-1 and 6 m2m-2, respectively. These findings confirm both the prompt response of beech to intensive thinning cycles and the reliability of undertaking coppice conversion into high forest. Furthermore, the positive trend observed in the ecological parameters and the high consistency of leaf fraction, highlight the still juvenile

  10. Rotation Invariance Neural Network

    OpenAIRE

    Li, Shiyuan

    2017-01-01

    Rotation invariance and translation invariance have great values in image recognition tasks. In this paper, we bring a new architecture in convolutional neural network (CNN) named cyclic convolutional layer to achieve rotation invariance in 2-D symbol recognition. We can also get the position and orientation of the 2-D symbol by the network to achieve detection purpose for multiple non-overlap target. Last but not least, this architecture can achieve one-shot learning in some cases using thos...

  11. A Key Role for Experimental Task Performance: Effects of Math Talent, Gender and Performance on the Neural Correlates of Mental Rotation

    Science.gov (United States)

    Hoppe, Christian; Fliessbach, Klaus; Stausberg, Sven; Stojanovic, Jelena; Trautner, Peter; Elger, Christian E.; Weber, Bernd

    2012-01-01

    The neurophysiological mechanisms underlying superior cognitive performance are a research area of high interest. The majority of studies on the brain-performance relationship assessed the effects of capability-related group factors (e.g. talent, gender) on task-related brain activations while only few studies examined the effect of the inherent…

  12. Rotated alphanumeric characters do not automatically activate frontoparietal areas subserving mental rotation

    DEFF Research Database (Denmark)

    Weiss, Michael M; Wolbers, Thomas; Peller, Martin

    2008-01-01

    Functional neuroimaging studies have identified a set of areas in the intraparietal sulcus and dorsal precentral cortex which show a linear increase in activity with the angle of rotation across a variety of mental rotation tasks. This linear increase in activity with angular disparity suggests t...... modulated by angular disparity during the stimulus categorization task. These results suggest that at least for alphanumerical characters, areas implicated in mental rotation will only be called into action if the task requires a rotational transformation....

  13. How drought severity constrains GPP and its partitioning among carbon pools in a Quercus ilex coppice?

    Science.gov (United States)

    Rambal, S.; Lempereur, M.; Limousin, J. M.; Martin-StPaul, N. K.; Ourcival, J. M.; Rodríguez-Calcerrada, J.

    2014-06-01

    The partitioning of photosynthates toward biomass compartments has a crucial role in the carbon sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought prone forests. We analyzed the fate of GPP in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Gross and net carbon fluxes between the ecosystem and the atmosphere were measured with an eddy-covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy-covariance fluxes with annual productions we managed to close a C budget and derive values of autotrophic and heterotrophic respirations, NPP and carbon use efficiency (CUE, the ratio between NPP and GPP). Average values of yearly NEP, GPP and Reco were 282, 1259 and 977 g C m-2. The corresponding ANPP components were 142.5, 26.4 and 69.6 g C m-2 for leaves, reproductive effort (flowers and fruits) and stems. Gross and net carbon exchange between the ecosystem and the atmosphere were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected, the stem growth, to the least affected, the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease more slightly in response to drought than GPP and NPP, probably due to drought-acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem and highlight the value of maintaining continuous experimental

  14. Decline in holm oak coppices (Quercus ilex L. subsp. ballota (Desf.) Samp.): biometric and physiological interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Serrada, R.; Gómez-Sanz, V.; Aroca, M.J.; Otero, J.; Bravo-Fernández, J.A.; Roig, S.

    2017-11-01

    Aim of the study: To analyse the decline in aged holm oak coppice forests as regards above-ground and below-ground fractions and physiological features. Area of study: Centre of the Iberian Peninsula (Guadalajara province). Material and methods: 26 pairs of holm oak stools with different vigour but with similar site and structural characteristics within each pair were selected. Morphological (basal area, number of stools, maximum height) and physiological traits (leaf water potential, stomatal conductance) of the standing stools were assessed. Their aerial and underground parts were extracted and different size fractions of both their above and below-ground biomass were quantified. Linear mixed models were built to test the effect of ’Stool vigour’ on the mean behaviour of the measured variables. Additionally, for the aerial part, linear regressions between the weights of the different size fractions and the basal area at breast height were performed using ‘Stool vigour’ as a fixed factor. Main results: For the same site, root depth, and number and diameter of shoots than good vigour stools, poor vigour stools displayed: lower predawn water potential, greater leaf mass per unit of area; lower total leaf area; lower above-ground biomass (in total as well as per fractions); lower fine roots biomass; lower proportion of leaf biomass and a greater proportion of biomass of both all roots and those with diameter 2-7 cm. Research highlights: The above-ground physiological and morphological characteristics of declined stools are interpreted as poorer adaptation to site conditions. Root system architecture was found to be relevant to explain this behaviour.

  15. Decline in holm oak coppices (Quercus ilex L. subsp. ballota (Desf.) Samp.): biometric and physiological interpretations

    International Nuclear Information System (INIS)

    Serrada, R.; Gómez-Sanz, V.; Aroca, M.J.; Otero, J.; Bravo-Fernández, J.A.; Roig, S.

    2017-01-01

    Aim of the study: To analyse the decline in aged holm oak coppice forests as regards above-ground and below-ground fractions and physiological features. Area of study: Centre of the Iberian Peninsula (Guadalajara province). Material and methods: 26 pairs of holm oak stools with different vigour but with similar site and structural characteristics within each pair were selected. Morphological (basal area, number of stools, maximum height) and physiological traits (leaf water potential, stomatal conductance) of the standing stools were assessed. Their aerial and underground parts were extracted and different size fractions of both their above and below-ground biomass were quantified. Linear mixed models were built to test the effect of ’Stool vigour’ on the mean behaviour of the measured variables. Additionally, for the aerial part, linear regressions between the weights of the different size fractions and the basal area at breast height were performed using ‘Stool vigour’ as a fixed factor. Main results: For the same site, root depth, and number and diameter of shoots than good vigour stools, poor vigour stools displayed: lower predawn water potential, greater leaf mass per unit of area; lower total leaf area; lower above-ground biomass (in total as well as per fractions); lower fine roots biomass; lower proportion of leaf biomass and a greater proportion of biomass of both all roots and those with diameter 2-7 cm. Research highlights: The above-ground physiological and morphological characteristics of declined stools are interpreted as poorer adaptation to site conditions. Root system architecture was found to be relevant to explain this behaviour.

  16. Rotating flow

    CERN Document Server

    Childs, Peter R N

    2010-01-01

    Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows. Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries. Traditional fluid and flow dynamics titles offer the essential background but generally include very sparse coverage of rotating flows-which is where this book comes in. Beginning with an accessible introduction to rotating flow, recognized expert Peter Childs takes you through fundamental equations, vorticity and vortices, rotating disc flow, flow around rotating cylinders and flow in rotating cavities, with an introduction to atmospheric and oceanic circul...

  17. Rotational seismology

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    Rotational seismology is an emerging study of all aspects of rotational motions induced by earthquakes, explosions, and ambient vibrations. It is of interest to several disciplines, including seismology, earthquake engineering, geodesy, and earth-based detection of Einstein’s gravitation waves.Rotational effects of seismic waves, together with rotations caused by soil–structure interaction, have been observed for centuries (e.g., rotated chimneys, monuments, and tombstones). Figure 1a shows the rotated monument to George Inglis observed after the 1897 Great Shillong earthquake. This monument had the form of an obelisk rising over 19 metres high from a 4 metre base. During the earthquake, the top part broke off and the remnant of some 6 metres rotated about 15° relative to the base. The study of rotational seismology began only recently when sensitive rotational sensors became available due to advances in aeronautical and astronomical instrumentations.

  18. Silvicultural options in ageing holm oak (Quercus ilex L. coppices in Gargano: results after 14 growing seasons

    Directory of Open Access Journals (Sweden)

    Scopigno D

    2008-12-01

    Full Text Available In the frame of a long-term research program concerning management of ageing holm oak coppices, results available after 14 growing seasons are reported in present paper. Experimental treatments include: A 50 standards per hectare, all of the same age; B 250 standards per hectare, all of the same age; C 140 standards per hectare, with two different ages; D conversion to high forest; E natural evolution (control. A total of 15 permanent plots were established (5 treatments x 3 replicates per treatment and the experimental design used is that of randomised blocks. Based on observations concerning seedlings and shoots development and standards growth and competitive effects, the following preliminary results may be highlighted: i recovering the traditional coppicing system with few standards per hectare represents a valid option from both ecological and shoots growth point of view; the stools, with few standards per hectare, showed a larger number of sprouts, provided with a higher average height and larger diameters; ii uneven-aged standards represent a good alternative form the points of view of both landscape impact immediately after felling operations and stand resistance to climatic damages; iii a good alternative is to apply conversion treatments to high forest, whenever their site quality allows these operations.

  19. Effect of coppicing, thinning and throughfall reduction on soil water content and soil CO2 efflux in a sessile oak forest

    Czech Academy of Sciences Publication Activity Database

    Dařenová, Eva; Crabbe, Richard A.; Knott, R.; Uherková, B.; Kadavý, J.

    2018-01-01

    Roč. 52, č. 2 (2018), č. článku 9927. ISSN 0037-5330 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : coppice * precipitation * Quercus petraea * soil respiration * soil moisture Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 1.495, year: 2016

  20. The impact of cattle and goats grazing on vegetation in oak stands of varying coppicing age

    Science.gov (United States)

    Papachristou, Thomas G.; Platis, Panayiotis D.

    2011-01-01

    The effects of cattle and goats grazing on oak shoot growth and herbaceous vegetation in three oak forest stands with different coppicing age (1, 4 and 7 yrs after the clear cutting) were investigated. In April 1997, an experimental area was chosen with three forest stands, which were clear cut in 1996 (CL1996), 1993 (CL1993), and 1990 (CL1990). All stands were grazed by cattle and goats after they were clear cut. In each forest stand, five 10 m × 10 m paired plots were located, which represented grazed and protected patches. Herbage biomass within protected and grazed plots was measured four times each year (spring: May-June, summer: July-August, autumn: September-October, and winter: November-December). Behavioural observations on grazing animals were conducted in the same periods. In both protected and open plots the height and basal diameter of all oak shoots on 5 preselected stumps were measured at the end of five growing periods from 1997 to 2001. All forest stands carried a similar amount of available herbage (averaged over forest stands and growing season, 2614 kg/ha). Grazing animals removed on average 1057 kg/ha throughout the growing period. Cattle mainly consumed herbage (97% of bites) while goats consumed a mixture of oak browse (41% bites), herbaceous species (34% bites), and other woody species browse (25% bites). The height, diameter and volume of oak shoots were affected by grazing. The three forest stands had similar shoot heights in the protected plots in 2001 after 5 years of grazing protection. The volume of oak shoots of the grazed plots were 146.7 cm3 for CL1996, 232.9 cm3 for CL1993, and 239.1 cm3 for CL1990 in 2001 (i.e. 5, 8, and 11 years grazing after the clear cuttings, respectively). The protected plots carried greater volumes of oak shoots, CL1996: 496.0 cm3 (few months grazing before protection), CL1993: 690.0 cm3 (4 years grazing before protection), and CL1990: 344.0 cm3 (7 years grazing before protection). In conclusion, almost

  1. Global rotation

    International Nuclear Information System (INIS)

    Rosquist, K.

    1980-01-01

    Global rotation in cosmological models is defined on an observational basis. A theorem is proved saying that, for rigid motion, the global rotation is equal to the ordinary local vorticity. The global rotation is calculated in the space-time homogeneous class III models, with Godel's model as a special case. It is shown that, with the exception of Godel's model, the rotation in these models becomes infinite for finite affine parameter values. In some directions the rotation changes sign and becomes infinite in a direction opposite to the local vorticity. The points of infinite rotation are identified as conjugate points along the null geodesics. The physical interpretation of the infinite rotation is discussed, and a comparison with the behaviour of the area distance at conjugate points is given. (author)

  2. Sustainable Energy Solutions Task 2.0: Wind Turbine Reliability and Maintainability Enhancement through System-wide Structure Health Monitoring and Modifications to Rotating Components

    Energy Technology Data Exchange (ETDEWEB)

    Twomey, Janet M. [Wichita State Univ., Wichita, KS (United States)

    2010-04-30

    An evaluation of nondestructive structural health monitoring methods was completed with over 132 documents, 37 specifically about wind turbines, summarized into a technology matrix. This matrix lists the technology, what can be monitored with this technology, and gives a short summary of the key aspects of the technology and its application. Passive and active acoustic emission equipment from Physical Acoustics Corp. and Acellent Technologies have been evaluated and selected for use in experimental state loading and fatigue tests of composite wind turbine blade materials. Acoustic Emission (AE) and Active Ultrasonic Testing (AUT), were applied to composite coupons with both simulated and actual damage. The results found that, while composites are more complicated in nature, compared to metallic structures, an artificial neural network analysis could still be used to determine damage. For the AE system, the failure mode could be determined (i.e. fiber breakage, delamination, etc.). The Acellent system has been evaluated to work well with composite materials. A test-rig for reliability testing of the rotating components was constructed. The research on the types of bearings used in the wind turbines indicated that in most of the designs, the main bearings utilized to support the shaft are cylindrical roller bearings. The accelerated degradation testing of a population of bearings was performed. Vibration and acoustic emission data was collected and analyzed in order to identify a representative degradation signal for each bearing to identify the initiation of the degradation process in the bearings. Afterwards, the RMS of the vibration signal from degradation initiation up to the end of the useful life of the bearing was selected to predict the remaining useful life of the bearing. This step included fitting Autoregressive Moving Average (ARMA) models to the degradation signals and approximating the probability distribution function (PDF) of remaining useful life

  3. Visualizing Compound Rotations with Virtual Reality

    Science.gov (United States)

    Flanders, Megan; Kavanagh, Richard C.

    2013-01-01

    Mental rotations are among the most difficult of all spatial tasks to perform, and even those with high levels of spatial ability can struggle to visualize the result of compound rotations. This pilot study investigates the use of the virtual reality-based Rotation Tool, created using the Virtual Reality Modeling Language (VRML) together with…

  4. Rotating Wavepackets

    Science.gov (United States)

    Lekner, John

    2008-01-01

    Any free-particle wavepacket solution of Schrodinger's equation can be converted by differentiations to wavepackets rotating about the original direction of motion. The angular momentum component along the motion associated with this rotation is an integral multiple of [h-bar]. It is an "intrinsic" angular momentum: independent of origin and…

  5. Rotating dryer

    International Nuclear Information System (INIS)

    Noe, C.

    1984-01-01

    Products to dry are introduced inside a rotating tube placed in an oven, the cross section of the tube is an arc of spiral. During clockwise rotation of the tube products are maintained inside and mixed, during anticlockwise products are removed. Application is made to drying of radioactive wastes [fr

  6. Ability of LANDSAT-8 Oli Derived Texture Metrics in Estimating Aboveground Carbon Stocks of Coppice Oak Forests

    Science.gov (United States)

    Safari, A.; Sohrabi, H.

    2016-06-01

    The role of forests as a reservoir for carbon has prompted the need for timely and reliable estimation of aboveground carbon stocks. Since measurement of aboveground carbon stocks of forests is a destructive, costly and time-consuming activity, aerial and satellite remote sensing techniques have gained many attentions in this field. Despite the fact that using aerial data for predicting aboveground carbon stocks has been proved as a highly accurate method, there are challenges related to high acquisition costs, small area coverage, and limited availability of these data. These challenges are more critical for non-commercial forests located in low-income countries. Landsat program provides repetitive acquisition of high-resolution multispectral data, which are freely available. The aim of this study was to assess the potential of multispectral Landsat 8 Operational Land Imager (OLI) derived texture metrics in quantifying aboveground carbon stocks of coppice Oak forests in Zagros Mountains, Iran. We used four different window sizes (3×3, 5×5, 7×7, and 9×9), and four different offsets ([0,1], [1,1], [1,0], and [1,-1]) to derive nine texture metrics (angular second moment, contrast, correlation, dissimilar, entropy, homogeneity, inverse difference, mean, and variance) from four bands (blue, green, red, and infrared). Totally, 124 sample plots in two different forests were measured and carbon was calculated using species-specific allometric models. Stepwise regression analysis was applied to estimate biomass from derived metrics. Results showed that, in general, larger size of window for deriving texture metrics resulted models with better fitting parameters. In addition, the correlation of the spectral bands for deriving texture metrics in regression models was ranked as b4>b3>b2>b5. The best offset was [1,-1]. Amongst the different metrics, mean and entropy were entered in most of the regression models. Overall, different models based on derived texture metrics

  7. Eucalyptus and Populus short rotation woody crops for phosphate mined lands in Florida USA

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, D L; Carter, D R; Langholtz, M H [The School of Forest Resources and Conservation, University of Florida, Box 110410, Gainesville, FL 32611 0410 (United States); Stricker, J A [Polk County Extension Service, University of Florida, Gainesville, FL 32611 (United States)

    2006-08-15

    Our short-rotation woody crops (SRWC) research in central and southern Florida is (1) developing superior Eucalyptus grandis (EG), E. amplifolia (EA), and cottonwood (Populus deltoides, PD) genotypes, (2) determining appropriate management practices for and associated productivities of these genotypes, and (3) assessing their economics and markets. Reclaimed clay settling areas (CSA) and overburden sites in phosphate mined areas in central Florida are a potential land base of over 80,000ha for SRWC production. On CSAs, PD grows well in the absence of cogongrass (Imperata cylindrica) but is not as productive as the non-invasive EG and EA. SRWC establishment on CSAs requires strict implementation of the following cultural practices: thorough site preparation through herbiciding/disking and bedding, superior trees, watering/packing seedlings, fertilization with ammonium nitrate at planting and annually thereafter as feasible, high planting density possibly including double row planting, and winter harvesting so that coppice regeneration suppresses weeds. PD cultural requirements, that may require post-planting weed control to suppress herbaceous competition, exceed those of the eucalypts. EG SRWCs on CSAs are at risk of blowdown 3-4 years after planting or coppicing; younger PD, EG, and EA SRWCs appear much less susceptible to wind damage. Genetic improvement must continue if EG, EA, and PD are to increase in commercial feasibility. SRWC cost competitiveness will depend on establishment success, yield improvements, harvesting costs, and identifying/using incentives. Strong collaboration among public and private partners is necessary for commercializing SRWCs in Florida. (author)

  8. Rotating preventers

    International Nuclear Information System (INIS)

    Tangedahl, M.J.; Stone, C.R.

    1992-01-01

    This paper reports that recent changes in the oil and gas industry and ongoing developments in horizontal and underbalanced drilling necessitated development of a better rotating head. A new device called the rotating blowout preventer (RBOP) was developed by Seal-Tech. It is designed to replace the conventional rotating control head on top of BOP stacks and allows drilling operations to continue even on live (underbalanced) wells. Its low wear characteristics and high working pressure (1,500 psi) allow drilling rig crews to drill safely in slightly underbalanced conditions or handle severe well control problems during the time required to actuate other BOPs in the stack. Drilling with a RBOP allows wellbores to be completely closed in tat the drill floor rather than open as with conventional BOPs

  9. Earth Rotation

    Science.gov (United States)

    Dickey, Jean O.

    1995-01-01

    The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

  10. Bridging the gap between feedstock growers and users: the study of a coppice poplar-based biorefinery.

    Science.gov (United States)

    Dou, Chang; Gustafson, Rick; Bura, Renata

    2018-01-01

    In the biofuel industry, land productivity is important to feedstock growers and conversion process product yield is important to the biorefinery. The crop productivity, however, may not positively correlate with bioconversion yield. Therefore, it is important to evaluate sugar yield and biomass productivity. In this study, 2-year-old poplar trees harvested in the first coppice cycle, including one low-productivity hybrid and one high-productivity hybrid, were collected from two poplar tree farms. Through steam pretreatment and enzymatic hydrolysis, the bioconversion yields of low- and high-productivity poplar hybrids were compared for both sites. The low-productivity hybrids had 9-19% higher sugar yields than the high-productivity hybrids, although they have the similar chemical composition. Economic calculations show the impact on the plantation and biorefinery of using the two feedstocks. Growing a high-productivity hybrid means the land owner would use 11-26% less land (which could be used for other crops) or collect $2.53-$3.46 MM/year extra revenue from the surplus feedstock. On the other side, the biorefinery would receive 5-10% additional revenue using the low-productivity hybrid. We propose a business model based on the integration of the plantation and the biorefinery. In this model, different feedstocks are assessed using a metric of product tonnage per unit land per year. Use of this new economic metric bridges the gap between feedstock growers and users to maximize the overall production efficiency.

  11. Stand-volume estimation from multi-source data for coppiced and high forest Eucalyptus spp. silvicultural systems in KwaZulu-Natal, South Africa

    Science.gov (United States)

    Dube, Timothy; Sibanda, Mbulisi; Shoko, Cletah; Mutanga, Onisimo

    2017-10-01

    Forest stand volume is one of the crucial stand parameters, which influences the ability of these forests to provide ecosystem goods and services. This study thus aimed at examining the potential of integrating multispectral SPOT 5 image, with ancillary data (forest age and rainfall metrics) in estimating stand volume between coppiced and planted Eucalyptus spp. in KwaZulu-Natal, South Africa. To achieve this objective, Partial Least Squares Regression (PLSR) algorithm was used. The PLSR algorithm was implemented by applying three tier analysis stages: stage I: using ancillary data as an independent dataset, stage II: SPOT 5 spectral bands as an independent dataset and stage III: combined SPOT 5 spectral bands and ancillary data. The results of the study showed that the use of an independent ancillary dataset better explained the volume of Eucalyptus spp. growing from coppices (adjusted R2 (R2Adj) = 0.54, RMSEP = 44.08 m3/ha), when compared with those that were planted (R2Adj = 0.43, RMSEP = 53.29 m3/ha). Similar results were also observed when SPOT 5 spectral bands were applied as an independent dataset, whereas improved volume estimates were produced when using combined dataset. For instance, planted Eucalyptus spp. were better predicted adjusted R2 (R2Adj) = 0.77, adjusted R2Adj = 0.59, RMSEP = 36.02 m3/ha) when compared with those that grow from coppices (R2 = 0.76, R2Adj = 0.46, RMSEP = 40.63 m3/ha). Overall, the findings of this study demonstrated the relevance of multi-source data in ecosystems modelling.

  12. How drought severity constrains gross primary production(GPP) and its partitioning among carbon pools in a Quercus ilex coppice?

    Science.gov (United States)

    Rambal, S.; Lempereur, M.; Limousin, J. M.; Martin-StPaul, N. K.; Ourcival, J. M.; Rodríguez-Calcerrada, J.

    2014-12-01

    The partitioning of photosynthates toward biomass compartments plays a crucial role in the carbon (C) sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought-prone forests. We analyzed the fate of gross primary production (GPP) in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Carbon fluxes between the ecosystem and the atmosphere were measured with an eddy covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns, and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy covariance fluxes with annual net primary productions (NPP), we managed to close a C budget and derive values of autotrophic, heterotrophic respirations and carbon-use efficiency (CUE; the ratio between NPP and GPP). Average values of yearly net ecosystem production (NEP), GPP and Reco were 282, 1259 and 977 g C m-2. The corresponding aboveground net primary production (ANPP) components were 142.5, 26.4 and 69.6 g C m-2 for leaves, reproductive effort (flowers and fruits) and stems, respectively. NEP, GPP and Reco were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected - the stem growth - to the least affected - the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease less drastically in response to drought than GPP and NPP did, probably due to drought acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem, and

  13. Short rotation willow coppice for renewable energy and improved environment. Proceedings of a joint Swedish - Estonian seminar on energy forestry and vegetation filters

    International Nuclear Information System (INIS)

    Perttu, K.; Koppel, A.

    1996-01-01

    The overall aim of the present seminar was to present and discuss results from the joint Swedish - Estonian energy forestry research activities during the period of 1993-1995 and to publish the papers in a technical report. The results is a publication, presenting interesting methods and results, and is meant partly to serve as the final report of the joint efforts during the period mentioned, partly to be used for future planning of new projects and for application of funding for a continued cooperation. Separate abstracts have been prepared for all of the 17 papers in the report

  14. Evaluation of Indirect Measurement Method of Seasonal Patterns of Leaf Area Index in a High-Density Short Rotation Coppice Culture of Poplar

    Czech Academy of Sciences Publication Activity Database

    Tripathi, Abishek; Fischer, Milan; Orság, Matěj; Marek, Michal V.; Žalud, Zdeněk; Trnka, Miroslav

    2016-01-01

    Roč. 64, č. 2 (2016), s. 549-556 ISSN 1211-8516 R&D Projects: GA MŠk(CZ) LD13030; GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : SunScan Plant Canopy Analyzer * litterfall * specific leaf area * poplar clone J-105 Subject RIV: GC - Agronomy

  15. Potential and limitations of local tree ring records in estimating a priori the growth performance of short-rotation coppice plantations

    Czech Academy of Sciences Publication Activity Database

    Trnka, Miroslav; Fischer, Milan; Bartošová, Lenka; Orság, Matěj; Kyncl, T.; Ceulemans, R.; King, J.R.; Büntgen, Ulf

    2016-01-01

    Roč. 92, sep (2016), s. 12-19 ISSN 0961-9534 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LD13030 Institutional support: RVO:67179843 Keywords : dendroecology * plantation site selection * populus nigra * poplar hybrid * weather-growth relationship Subject RIV: EH - Ecology, Behaviour Impact factor: 3.219, year: 2016

  16. Rotator cuff exercises

    Science.gov (United States)

    ... 25560729 . Read More Frozen shoulder Rotator cuff problems Rotator cuff repair Shoulder arthroscopy Shoulder CT scan Shoulder MRI scan Shoulder pain Patient Instructions Rotator cuff - self-care Shoulder surgery - discharge Using your ...

  17. Above-ground biomass production and allometric relations of Eucalyptus globulus Labill. coppice plantations along a chronosequence in the central highlands of Ethiopia

    International Nuclear Information System (INIS)

    Zewdie, Mulugeta; Olsson, Mats; Verwijst, Theo

    2009-01-01

    Eucalyptus plantations are extensively managed for wood production in the central highlands of Ethiopia. Nevertheless, little is known about their biomass (dry matter) production, partitioning and dynamics over time. Data from 10 different Eucalyptus globulus stands, with a plantation age ranging from 11 to 60 years and with a coppice-shoot age ranging from 1 to 9 years were collected and analyzed. Above-ground tree biomass of 7-10 sampled trees per stand was determined destructively. Dry weights of tree components (W c ; leaves, twigs, branches, stembark, and stemwood) and total above-ground biomass (W a ) were estimated as a function of diameter above stump (D), tree height (H) and a combination of these. The best fits were obtained, using combinations of D and H. When only one explanatory variable was used, D performed better than H. Total above-ground biomass was linearly related to coppice-shoot age. In contrast a negative relation was observed between the above-ground biomass production and total plantation age (number of cutting cycles). Total above-ground biomass increased from 11 t ha -1 at a stand age of 1 year to 153 t ha -1 at 9 years. The highest dry weight was allocated to stemwood and decreased in the following order: stemwood > leaves > stembark > twigs > branches. The equations developed in this study to estimate biomass components can be applied to other Eucalyptus plantations under the assumption that the populations being studied are similar with regard to density and tree size to those for which the relationships were developed

  18. Above-ground biomass production and allometric relations of Eucalyptus globulus Labill. coppice plantations along a chronosequence in the central highlands of Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Zewdie, Mulugeta; Olsson, Mats; Verwijst, Theo [Swedish University of Agricultural Sciences, Department of Crop Production Ecology, P.O. Box 7043, 75007 Uppsala (Sweden)

    2009-03-15

    Eucalyptus plantations are extensively managed for wood production in the central highlands of Ethiopia. Nevertheless, little is known about their biomass (dry matter) production, partitioning and dynamics over time. Data from 10 different Eucalyptus globulus stands, with a plantation age ranging from 11 to 60 years and with a coppice-shoot age ranging from 1 to 9 years were collected and analyzed. Above-ground tree biomass of 7-10 sampled trees per stand was determined destructively. Dry weights of tree components (W{sub c}; leaves, twigs, branches, stembark, and stemwood) and total above-ground biomass (W{sub a}) were estimated as a function of diameter above stump (D), tree height (H) and a combination of these. The best fits were obtained, using combinations of D and H. When only one explanatory variable was used, D performed better than H. Total above-ground biomass was linearly related to coppice-shoot age. In contrast a negative relation was observed between the above-ground biomass production and total plantation age (number of cutting cycles). Total above-ground biomass increased from 11 t ha{sup -1} at a stand age of 1 year to 153 t ha{sup -1} at 9 years. The highest dry weight was allocated to stemwood and decreased in the following order: stemwood > leaves > stembark > twigs > branches. The equations developed in this study to estimate biomass components can be applied to other Eucalyptus plantations under the assumption that the populations being studied are similar with regard to density and tree size to those for which the relationships were developed. (author)

  19. Impact of elevated CO2 and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation

    International Nuclear Information System (INIS)

    Marinari, Sara; Calfapietra, Carlo; De Angelis, Paolo; Mugnozza, Giuseppe Scarascia; Grego, Stefano

    2007-01-01

    The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO 2 and fertilization (two CO 2 treatments, elevated CO 2 and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO 2 enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO 2 and N fertilization amplified some element unbalances such as the K/N-ratio. - CO 2 enrichment reduced foliar nitrogen and increased the magnesium concentration in poplar

  20. Soil ecological impacts of the short rotation industry with poplar trees and pastures in Mecklenburg-Western Pomerania; Bodenoekologische Auswirkungen der Kurzumtriebswirtschaft mit Pappeln und Weiden in Mecklenburg-Vorpommern

    Energy Technology Data Exchange (ETDEWEB)

    Kahle, Petra; Moeller, Josefine; Seelig, Andreas; Baum, Christel [Rostock Univ. (Germany). Professur Bodenphysik und Ressourcenschutz

    2013-10-01

    The impact of short rotation coppice (SRC), a former soil rotation coppice (FRC) and a continuously annually tilled arable soil (TS) on different soil properties was investigated. Parameters were chemical soil properties, like the concentration of soil organic matter (SOC) and total nitrogen (Nt), physical soil properties, like the bulk density, porosity and aggregate stability and biological soil properties, like abundance and biomass of earth worms. The return to annual crops involved an intense tillage and aeration of the soil. The study indicated, that the lack of tillage under SRC and the quantity of leaf and root litter can lead to an increased carbon accumulation in the upper soil. Tillage of former SRC leads to a fast redistribution of SOC in the topsoil combined with a loss of porosity, aggregate stability and abundance of earth worms. Subsequent investigations should contribute to select tillage strategies for FRC, which contribute to conserve the accumulated SOC and decrease the impact on the porosity and aggregate stability. (orig.)

  1. Rotational motion in nuclei

    International Nuclear Information System (INIS)

    Bohr, A.

    1977-01-01

    History is surveyed of the development of the theory of rotational states in nuclei. The situation in the 40's when ideas formed of the collective states of a nucleus is evoked. The general rotation theory and the relation between the single-particle and rotational motion are briefly discussed. Future prospects of the rotation theory development are indicated. (I.W.)

  2. Rotational motion in nuclei

    International Nuclear Information System (INIS)

    Bohr, A.

    1976-01-01

    Nuclear structure theories are reviewed concerned with nuclei rotational motion. The development of the deformed nucleus model facilitated a discovery of rotational spectra of nuclei. Comprehensive verification of the rotational scheme and a successful classification of corresponding spectra stimulated investigations of the rotational movement dynamics. Values of nuclear moments of inertia proved to fall between two marginal values corresponding to rotation of a solid and hydrodynamic pattern of an unrotating flow, respectively. The discovery of governing role of the deformation and a degree of a symmetry violence for determining rotational degrees of freedon is pointed out to pave the way for generalization of the rotational spectra

  3. Evaluating the Ergonomic Benefit of a Wrist Brace on Wrist Posture, Muscle Activity, Rotational Stiffness, and Peak Shovel-Ground Impact Force During a Simulated Tree-Planting Task.

    Science.gov (United States)

    Sheahan, Peter J; Cashaback, Joshua G A; Fischer, Steven L

    2017-09-01

    Background Tree planters are at a high risk for wrist injury due to awkward postures and high wrist loads experienced during each planting cycle, specifically at shovel-ground impact. Wrist joint stiffness provides a measure that integrates postural and loading information. Objective The purpose of this study was to evaluate wrist joint stiffness requirements at the instant of shovel-ground impact during tree planting and determine if a wrist brace could alter muscular contributions to wrist joint stiffness. Method Planters simulated tree planting with and without wearing a brace on their planting arm. Surface electromyography (sEMG) from six forearm muscles and wrist kinematics were collected and used to calculate muscular contributions to joint rotational stiffness about the wrist. Results Wrist joint stiffness increased with brace use, an unanticipated and negative consequence of wearing a brace. As a potential benefit, planters achieved a more neutrally oriented wrist angle about the flexion/extension axis, although a less neutral wrist angle about the ulnar/radial axis was observed. Muscle activity did not change between conditions. Conclusion The joint stiffness analysis, combining kinematic and sEMG information in a biologically relevant manner, revealed clear limitations with the interface between the brace grip and shovel handle that jeopardized the prophylactic benefits of the current brace design. This limitation was not as evident when considering kinematics and sEMG data independently. Application A neuromechanical model (joint rotational stiffness) enhanced our ability to evaluate the brace design relative to kinematic and sEMG parameter-based metrics alone.

  4. Is rotating between static and dynamic work beneficial for our fatigue state?

    NARCIS (Netherlands)

    Luger, T.; Bosch, T.; Hoozemans, M.J.M.; Veeger,D.H.E.J.; Looze, M.P. de

    2016-01-01

    Shoulder disorders comprise a large part of work-related musculoskeletal disorders. Risk factors, such as repetitiveness and monotony, may cause muscle fatigue and be attenuated by task rotation. We investigated rotation between a dynamic box-lifting task and a relatively static pick-and-place task

  5. First rotation Eucalyptus macarthurii cut stump control in KwaZulu ...

    African Journals Online (AJOL)

    Many cold tolerant eucalypts, E. macarthurii in particular, coppice vigorously following harvesting, and in contrast to E. grandis are proving difficult to kill by existing cut stump control methods. Based on past research, selected cut stump treatments were tested on single stem E. macarthurii trees, that had not been coppiced, ...

  6. Fertilization of Willow Coppice Over Three Consecutive 2-Year Rotations—Effects on Biomass Production, Soil Nutrients and Water

    DEFF Research Database (Denmark)

    Georgiadis, Petros; Sevel, Lisbeth; Raulund-Rasmussen, Karsten

    2017-01-01

    production was determined at harvest, soil solution samples were collected monthly, water fluxes were modelled using CoupModel and nutrient budgets were calculated. The unfertilized control had a mean biomass production of 8.3, 8.3 and 9.5 odt ha−1 year−1, respectively, in the three rotations. This indicated...

  7. Rotationally invariant correlation filtering

    International Nuclear Information System (INIS)

    Schils, G.F.; Sweeney, D.W.

    1985-01-01

    A method is presented for analyzing and designing optical correlation filters that have tailored rotational invariance properties. The concept of a correlation of an image with a rotation of itself is introduced. A unified theory of rotation-invariant filtering is then formulated. The unified approach describes matched filters (with no rotation invariance) and circular-harmonic filters (with full rotation invariance) as special cases. The continuum of intermediate cases is described in terms of a cyclic convolution operation over angle. The angular filtering approach allows an exact choice for the continuous trade-off between loss of the correlation energy (or specificity regarding the image) and the amount of rotational invariance desired

  8. The role of rotational hand movements and general motor ability in children’s mental rotation performance

    Directory of Open Access Journals (Sweden)

    Petra eJansen

    2015-07-01

    Full Text Available Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular seem to have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N= 83; Age range: 7.0-8.3 and 9.0-10.11 years. In addition, we assessed the role of motor ability in this relationship. Boys in the 7-8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability.

  9. Confidence mediates the sex difference in mental rotation performance.

    Science.gov (United States)

    Estes, Zachary; Felker, Sydney

    2012-06-01

    On tasks that require the mental rotation of 3-dimensional figures, males typically exhibit higher accuracy than females. Using the most common measure of mental rotation (i.e., the Mental Rotations Test), we investigated whether individual variability in confidence mediates this sex difference in mental rotation performance. In each of four experiments, the sex difference was reliably elicited and eliminated by controlling or manipulating participants' confidence. Specifically, confidence predicted performance within and between sexes (Experiment 1), rendering confidence irrelevant to the task reliably eliminated the sex difference in performance (Experiments 2 and 3), and manipulating confidence significantly affected performance (Experiment 4). Thus, confidence mediates the sex difference in mental rotation performance and hence the sex difference appears to be a difference of performance rather than ability. Results are discussed in relation to other potential mediators and mechanisms, such as gender roles, sex stereotypes, spatial experience, rotation strategies, working memory, and spatial attention.

  10. Rotating swings—a theme with variations

    Science.gov (United States)

    Pendrill, Ann-Marie

    2016-01-01

    Rotating swing rides can be found in many amusement parks, in many different versions. The ‘wave swinger’ ride, which introduces a wave motion by tilting the roof, is among the classical amusement rides that are found in many different parks, in different sizes, from a number of different makes and names, and varying thematization. The ‘StarFlyer’ is a more recent version, adding the thrill of lifting the riders 60 m or more over the ground. These rotating swing rides involve beautiful physics, often surprising, but easily observed, when brought to attention. The rides can be used for student worksheet tasks and assignments of different degrees of difficulty, across many math and physics topics. This paper presents a number of variations of student tasks relating to the theme of rotating swing rides.

  11. Parameterization of rotational spectra

    International Nuclear Information System (INIS)

    Zhou Chunmei; Liu Tong

    1992-01-01

    The rotational spectra of the strongly deformed nuclei with low rotational frequencies and weak band mixture are analyzed. The strongly deformed nuclei are commonly encountered in the rare-earth region (e. g., 150 220). A lot of rotational band knowledge are presented

  12. Rotating reactors : a review

    NARCIS (Netherlands)

    Visscher, F.; Schaaf, van der J.; Nijhuis, T.A.; Schouten, J.C.

    2013-01-01

    This review-perspective paper describes the current state-of-the-art in the field of rotating reactors. The paper has a focus on rotating reactor technology with applications at lab scale, pilot scale and industrial scale. Rotating reactors are classified and discussed according to their geometry:

  13. The interference effects of non-rotated versus counter-rotated trials in visuomotor adaptation.

    Science.gov (United States)

    Hinder, Mark R; Walk, Laura; Woolley, Daniel G; Riek, Stephan; Carson, Richard G

    2007-07-01

    An isometric torque-production task was used to investigate interference and retention in adaptation to multiple visuomotor environments. Subjects produced isometric flexion-extension and pronation-supination elbow torques to move a cursor to acquire targets as quickly as possible. Adaptation to a 30 degrees counter-clockwise (CCW) rotation (task A), was followed by a period of rest (control), trials with no rotation (task B0), or trials with a 60 degrees clockwise (CW) rotation (task B60). For all groups, retention of task A was assessed 5 h later. With initial training, all groups reduced the angular deviation of cursor paths early in the movements, indicating feedforward adaptation. For the control group, performance at commencement of the retest was significantly better than that at the beginning of the initial learning. For the B0 group, performance in the retest of task A was not dissimilar to that at the start of the initial learning, while for the B60 group retest performance in task A was markedly worse than initially observed. Our results indicate that close juxtaposition of two visuomotor environments precludes improved retest performance in the initial environment. Data for the B60 group, specifically larger angular errors upon retest compared with initial exposures, are consistent with the presence of anterograde interference. Furthermore, full interference occurred even when the visuomotor environment encountered in the second task was not rotated (B0). This latter novel result differs from those obtained for force field learning, where interference does not occur when task B does not impose perturbing forces, i.e., when B consists of a null field (Brashers-Krug et al., Nature 382:252-255, 1996). The results are consistent with recent proposals suggesting different interference mechanisms for visuomotor (kinematic) compared to force field (dynamic) adaptations, and have implications for the use of washout trials when studying interference between

  14. Rotating Stars in Relativity

    Directory of Open Access Journals (Sweden)

    Stergioulas Nikolaos

    2003-01-01

    Full Text Available Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on the equilibrium properties and on the nonaxisymmetric instabilities in f-modes and r-modes have been updated and several new sections have been added on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity.

  15. The Swedish energy forestry research programme at the Department of Short Rotation Forestry, SUAS, Uppsala. Summary report prepared for the evaluation of the short-rotation forestry research 1993-1996

    Energy Technology Data Exchange (ETDEWEB)

    Ledin, S.; Christersson, L. [eds.

    1996-12-31

    The overall aim of the Department of Short Rotation Forestry is to carry out research for development of basic, theoretical and practical knowledge in the related disciplines of biology, ecology and cultivation techniques in order to reach a high and sustainable production of woody biomass for energy purposes using environmentally acceptable methods. This report gives summaries of nine research programs within the Department, and the reports were prepared for the evaluation of the research during the period 1993-1996. The projects are: 1. Competition in short rotation forests (Theo Verwijst); 2. Carbon allocation as a function of nutrient and water availability (Lars Rytter, Tom Ericsson); 3. States and fluxes of water and carbon dioxide in the soil-plant-atmosphere system (Anders Lindroth); 4. Root dynamics of fast growing deciduous trees (Rose-Marie Rytter); 5. Accumulation and mobilization of root reserves in coppice growth (Lisa Sennerby-Forsse, Lars Bollmark, Yuehua von Fircks); 6. Effects of nutrient supply on frost resistance in fast growing Salix clones (Heinrich von Fircks); 7. Optimizing water and nutrients in poplar and willow plantations for maximum growth (Sune Elowson); 8. Soil biology in relation to energy forestry (Ulf Granhall); and 9. Plant protection in short rotation forestry against fungi and bacteria (Mauritz Ramstedt)

  16. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    1999-01-01

    In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belo...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion......In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

  17. Rotations with Rodrigues' vector

    International Nuclear Information System (INIS)

    Pina, E

    2011-01-01

    The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears to be a fundamental matrix that is used to express the components of the angular velocity, the rotation matrix and the angular momentum vector. The Hamiltonian formalism of rotational dynamics in terms of this vector uses the same matrix. The quantization of the rotational dynamics is performed with simple rules if one uses Rodrigues' vector and similar formal expressions for the quantum operators that mimic the Hamiltonian classical dynamics.

  18. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    2001-01-01

    In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong ...... approximations to the Riemannian metric, and that the subsequent corrections are inherent in the least squares estimation.......In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

  19. Rotational displacement skills in rhesus macaques (Macaca mulatta).

    Science.gov (United States)

    Hughes, Kelly D; Santos, Laurie R

    2012-11-01

    Rotational displacement tasks, in which participants must track an object at a hiding location within an array while the array rotates, exhibit a puzzling developmental pattern in humans. Human children take an unusually long time to master this task and tend to solve rotational problems through the use of nongeometric features or landmarks as opposed to other kinds of spatial cues. We investigated whether these developmental characteristics are unique to humans by testing rotational displacement skills in a monkey species, the rhesus macaque (Macaca mulatta), using a looking-time method. Monkeys first saw food hidden in two differently colored boxes within an array. The array was then rotated 180° and the boxes reopened to reveal the food in an expected or unexpected location. Our first two experiments explored the developmental time-course of performance on this rotational displacement task. We found that adult macaques looked longer at the unexpected event, but such performance was not mirrored in younger-aged macaques. In a third study, we systematically varied featural information and visible access to the array to investigate which strategies adult macaques used in solving rotational displacements. Our results show that adult macaques need both sets of information to solve the task. Taken together, these results suggest both similarities and differences in mechanisms by which human and nonhuman primates develop this spatial skill.

  20. Asteroid rotation rates

    International Nuclear Information System (INIS)

    Binzel, R.P.; Farinella, P.

    1989-01-01

    Within the last decade the data base of asteroid rotation parameters (rotation rates and lightcurve amplitudes) has become sufficiently large to identify some definite rends and properties which can help us to interpret asteroid collisional evolution. Many significant correlations are found between rotation parameters and diameter, with distinct changes occurring near 125 km. The size range, which is also the diameter above which self-gravity may become important, perhaps represents a division between surviving primordial asteroids and collisional fragments. A Maxwellian is able to fit the observed rotation rate distributions of asteroids with D>125 km, implying that their rotation rates may be determined by collisional evolution. Asteroids with D<125 km show an excess of slow rotators and their non-Maxwellian distributions suggests that their rotation rates are more strongly influenced by other processes, such as the distribution resulting from their formation in catastrophic disruption events. Other correlations observed in the data set include different mean rotation rates for C, S and M type asteroids implying that their surface spectra are indicative of bulk properties

  1. The spatial rotator

    DEFF Research Database (Denmark)

    Rasmusson, Allan; Hahn, Ute; Larsen, Jytte Overgaard

    2013-01-01

    This paper presents a new local volume estimator, the spatial rotator, which is based on measurements on a virtual 3D probe, using computer assisted microscopy. The basic design of the probe builds upon the rotator principle which requires only a few manual intersection markings, thus making...

  2. Superconducting rotating machines

    International Nuclear Information System (INIS)

    Smith, J.L. Jr.; Kirtley, J.L. Jr.; Thullen, P.

    1975-01-01

    The opportunities and limitations of the applications of superconductors in rotating electric machines are given. The relevant properties of superconductors and the fundamental requirements for rotating electric machines are discussed. The current state-of-the-art of superconducting machines is reviewed. Key problems, future developments and the long range potential of superconducting machines are assessed

  3. Fundamental Relativistic Rotator

    International Nuclear Information System (INIS)

    Staruszkiewicz, A.

    2008-01-01

    Professor Jan Weyssenhoff was Myron Mathisson's sponsor and collaborator. He introduced a class of objects known in Cracow as '' kreciolki Weyssenhoffa '', '' Weyssenhoff's rotating little beasts ''. The Author describes a particularly simple object from this class. The relativistic rotator described in the paper is such that its both Casimir invariants are parameters rather than constants of motion. (author)

  4. SMAP Faraday Rotation

    Science.gov (United States)

    Le Vine, David

    2016-01-01

    Faraday rotation is a change in the polarization as signal propagates through the ionosphere. At L-band it is necessary to correct for this change and measurements are made on the spacecraft of the rotation angle. These figures show that there is good agreement between the SMAP measurements (blue) and predictions based on models (red).

  5. Units of rotational information

    Science.gov (United States)

    Yang, Yuxiang; Chiribella, Giulio; Hu, Qinheping

    2017-12-01

    Entanglement in angular momentum degrees of freedom is a precious resource for quantum metrology and control. Here we study the conversions of this resource, focusing on Bell pairs of spin-J particles, where one particle is used to probe unknown rotations and the other particle is used as reference. When a large number of pairs are given, we show that every rotated spin-J Bell state can be reversibly converted into an equivalent number of rotated spin one-half Bell states, at a rate determined by the quantum Fisher information. This result provides the foundation for the definition of an elementary unit of information about rotations in space, which we call the Cartesian refbit. In the finite copy scenario, we design machines that approximately break down Bell states of higher spins into Cartesian refbits, as well as machines that approximately implement the inverse process. In addition, we establish a quantitative link between the conversion of Bell states and the simulation of unitary gates, showing that the fidelity of probabilistic state conversion provides upper and lower bounds on the fidelity of deterministic gate simulation. The result holds not only for rotation gates, but also to all sets of gates that form finite-dimensional representations of compact groups. For rotation gates, we show how rotations on a system of given spin can simulate rotations on a system of different spin.

  6. The rotating universe

    International Nuclear Information System (INIS)

    Ruben, G.; Treder, H.J.

    1987-01-01

    For a long time the question whether the universe rotates or not is discussed. Aspects of Huygens, Newton, Mach and other important historical scientists in this field are reported. The investigations of the mathematician Kurt Groedel in order to prove the rotation of the universe are illustrated. Kurt Groedel has shown that Einstein's gravitational equations of general relativity theory and the cosmological postulate of global homogeneity of cosmic matter (that is the Copernical principle) are not contradictionary to a rotating universe. Abberation measurements, position determination by means of radiointerferometry and methods for the determination of the rotation of the universe from the isotropy of the background radiation are presented. From these experiments it can be concluded that the universe seems not to rotate as already Einstein expected

  7. Rotation sensor switch

    International Nuclear Information System (INIS)

    Sevec, J.B.

    1978-01-01

    A protective device to provide a warning if a piece of rotating machinery slows or stops is comprised of a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal

  8. Rotating stars in relativity.

    Science.gov (United States)

    Paschalidis, Vasileios; Stergioulas, Nikolaos

    2017-01-01

    Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on equilibrium properties and on nonaxisymmetric oscillations and instabilities in f -modes and r -modes have been updated. Several new sections have been added on equilibria in modified theories of gravity, approximate universal relationships, the one-arm spiral instability, on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity including both hydrodynamic and magnetohydrodynamic studies of these objects.

  9. Water Quality Changes in a Short-Rotation Woody Crop Riparian Buffer

    Science.gov (United States)

    Rosa, D.; Clausen, J.; Kuzovkina, J.

    2016-12-01

    Converting riparian buffers in agricultural areas from annual row crops to short rotation woody crops (SRWCs) grown for biofuel can provide both water quality benefits and a financial incentive for buffer adoption among agricultural producers. A randomized complete block design was used to determine water quality changes resulting from converting plots previously cultivated in corn to SRWC willow (Salix. spp) adjacent to a stream in Storrs, CT. Both overland flow and ground water samples were analyzed for total nitrogen (TN), nitrate + nitrite (NO2+NO3-N), and total phosphorus (TP). Overland flow was also analyzed for suspended solids concentration (SSC). Lower (p = 0.05) concentrations of TN (56%) and TP (61%) were observed in post-coppice surface runoff from willow plots than from corn plots. Shallow ground water concentrations at the edge of willow plots were lower in TN (56%) and NO3+NO2-N (64%), but 35% higher in TP, than at the edge of corn plots. SSC was also lower (72%) in overland flow associated with willow compared to corn. The treatment had no effect on discharge or mass export. These results suggest conversion from corn to a SRWC in a riparian area can provide water quality benefits similar to those observed in restored and established buffers.

  10. The functional anatomy of forearm rotation

    OpenAIRE

    Lees, Vivien C.

    2009-01-01

    The elbow, forearm and wrist act as a unified structure to provide a stable, strong and highly mobile strut for positioning the hand in space and for conducting load-bearing tasks. An understanding of the relevant anatomy and biomechanics is important for the surgeon assessing and treating disorders of forearm function. This paper is concerned with illuminating the principles and concepts governing forearm rotation and load-bearing functions.

  11. Rotation, Stability and Transport

    Energy Technology Data Exchange (ETDEWEB)

    Connor, J. W.

    2007-07-01

    Tokamak plasmas can frequently exhibit high levels of rotation and rotation shear. This can usually be attributed to various sources: injection of momentum, e.g. through neutral beams, flows driven by plasma gradients or torques resulting from non-ambipolar particle loss; however, the source sometimes remains a mystery, such as the spontaneous rotation observed in Ohmic plasmas. The equilibrium rotation profile is given by the balance of these sources with transport and other losses; the edge boundary conditions can play an important role in determining this profile . Such plasma rotation, particularly sheared rotation, is predicted theoretically to have a significant influence on plasma behaviour. In the first place, sonic flows can significantly affect tokamak equilibria and neoclassical transport losses. However, the influence of rotation on plasma stability and turbulence is more profound. At the macroscopic level it affects the behaviour of the gross MHD modes that influence plasma operational limits. This includes sawteeth, the seeding of neoclassical tearing modes, resistive wall modes and the onset of disruptions through error fields, mode locking and reconnection. At the microscopic level it has a major effect on the stability of ballooning modes, both ideal MHD and drift wave instabilities such as ion temperature gradient (ITG) modes. In the non-linear state, as unstable drift waves evolve into turbulent structures, sheared rotation also tears apart eddies, thereby reducing the resulting transport. There is considerable experimental evidence for these effects on both MHD stability and plasma confinement. In particular, the appearance of improved confinement modes with transport barriers, such as edge H-mode barriers and internal transport barriers (ITBs) appears to correlate well with the presence of sheared plasma rotation. This talk will describe the theory underlying some of these phenomena involving plasma rotation, on both macroscopic and microscopic

  12. Rotator cuff - self-care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000358.htm Rotator cuff - self-care To use the sharing features on ... and shoulder exercises may help ease your symptoms. Rotator Cuff Problems Common rotator cuff problems include: Tendinitis , which ...

  13. Rotating universe models

    International Nuclear Information System (INIS)

    Tozini, A.V.

    1984-01-01

    A review is made of some properties of the rotating Universe models. Godel's model is identified as a generalized filted model. Some properties of new solutions of the Einstein's equations, which are rotating non-stationary Universe models, are presented and analyzed. These models have the Godel's model as a particular case. Non-stationary cosmological models are found which are a generalization of the Godel's metrics in an analogous way in which Friedmann is to the Einstein's model. (L.C.) [pt

  14. Rotating positron tomographs revisited

    International Nuclear Information System (INIS)

    Townsend, D.; Defrise, M.; Geissbuhler, A.

    1994-01-01

    We have compared the performance of a PET scanner comprising two rotating arrays of detectors with that of the more conventional stationary-ring design. The same total number of detectors was used in each, and neither scanner had septa. For brain imaging, we find that the noise-equivalent count rate is greater for the rotating arrays by a factor of two. Rotating arrays have a sensitivity profile that peaks in the centre of the field of view, both axially and transaxially. In the transaxial plane, this effect offsets to a certain extent the decrease in the number of photons detected towards the centre of the brain due to self-absorption. We have also compared the performance of a rotating scanner to that of a full-ring scanner with the same number of rings. We find that a full-ring scanner with an axial extent of 16.2 cm (24 rings) is a factor of 3.5 more sensitive than a rotating scanner with 40% of the detectors and the same axial extent. (Author)

  15. Impaired mental rotation in benign paroxysmal positional vertigo and acute vestibular neuritis.

    Directory of Open Access Journals (Sweden)

    Matteo eCandidi

    2013-11-01

    Full Text Available Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical-cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (Vestibular Neuritis – VN- and Benign Paroxysmal positional Vertigo – BPPV with respect to healthy matched controls (C. We used two mental rotation tasks in which participants were required to: i mentally rotate their own body in space (egocentric rotation thus using vestibular processing to a large extent and ii mentally rotate human figures (allocentric rotation thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations.

  16. Role of strategies and prior exposure in mental rotation.

    Science.gov (United States)

    Cherney, Isabelle D; Neff, Nicole L

    2004-06-01

    The purpose of these two studies was to examine sex differences in strategy use and the effect of prior exposure on the performance on Vandenberg and Kuse's 1978 Mental Rotation Test. A total of 152 participants completed the spatial task and self-reported their strategy use. Consistent with previous studies, men outperformed women. Strategy usage did not account for these differences, although guessing did. Previous exposure to the Mental Rotation Test, American College Test scores and frequent computer or video game play predicted performance on the test. These results suggest that prior exposure to spatial tasks may provide cues to improve participants' performance.

  17. The optical rotator

    DEFF Research Database (Denmark)

    Tandrup, T; Gundersen, Hans Jørgen Gottlieb; Jensen, Eva B. Vedel

    1997-01-01

    further discuss the methods derived from this principle and present two new local volume estimators. The optical rotator benefits from information obtained in all three dimensions in thick sections but avoids over-/ underprojection problems at the extremes of the cell. Using computer-assisted microscopes......The optical rotator is an unbiased, local stereological principle for estimation of cell volume and cell surface area in thick, transparent slabs, The underlying principle was first described in 1993 by Kieu Jensen (T. Microsc. 170, 45-51) who also derived an estimator of length, In this study we...... the extra measurements demand minimal extra effort and make this estimator even more efficient when it comes to estimation of individual cell size than many of the previous local estimators, We demonstrate the principle of the optical rotator in an example (the cells in the dorsal root ganglion of the rat...

  18. Vibrations of rotating machinery

    CERN Document Server

    Matsushita, Osami; Kanki, Hiroshi; Kobayashi, Masao; Keogh, Patrick

    2017-01-01

    This book opens with an explanation of the vibrations of a single degree-of-freedom (dof) system for all beginners. Subsequently, vibration analysis of multi-dof systems is explained by modal analysis. Mode synthesis modeling is then introduced for system reduction, which aids understanding in a simplified manner of how complicated rotors behave. Rotor balancing techniques are offered for rigid and flexible rotors through several examples. Consideration of gyroscopic influences on the rotordynamics is then provided and vibration evaluation of a rotor-bearing system is emphasized in terms of forward and backward whirl rotor motions through eigenvalue (natural frequency and damping ratio) analysis. In addition to these rotordynamics concerning rotating shaft vibration measured in a stationary reference frame, blade vibrations are analyzed with Coriolis forces expressed in a rotating reference frame. Other phenomena that may be assessed in stationary and rotating reference frames include stability characteristic...

  19. Rotating quantum states

    International Nuclear Information System (INIS)

    Ambruş, Victor E.; Winstanley, Elizabeth

    2014-01-01

    We revisit the definition of rotating thermal states for scalar and fermion fields in unbounded Minkowski space–time. For scalar fields such states are ill-defined everywhere, but for fermion fields an appropriate definition of the vacuum gives thermal states regular inside the speed-of-light surface. For a massless fermion field, we derive analytic expressions for the thermal expectation values of the fermion current and stress–energy tensor. These expressions may provide qualitative insights into the behaviour of thermal rotating states on more complex space–time geometries

  20. Rotating bubble membrane radiator

    Science.gov (United States)

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  1. economic assessment of two selected non-timber forest products in ...

    African Journals Online (AJOL)

    Aladex

    forest product commonly used for domestic and industrial energy generation. ... continue to depend on wood because bringing oil, gas and electricity within their .... coppicing and coppice trees are normally harvested in rotational patches ...

  2. Rotations and angular momentum

    International Nuclear Information System (INIS)

    Nyborg, P.; Froyland, J.

    1979-01-01

    This paper is devoted to the analysis of rotational invariance and the properties of angular momentum in quantum mechanics. In particular, the problem of addition of angular momenta is treated in detail, and tables of Clebsch-Gordan coefficients are included

  3. Negative Rotation Cinch Strap.

    Science.gov (United States)

    This project discloses an improved unitary parachute torso harness, having a single fastening means, wherein an auxillary tightening strap is...attached to the groin straps of said harness. Said auxillary straps are used to prevent torso rotation or harness slippage and to prevent harness elongation

  4. A rotating string

    International Nuclear Information System (INIS)

    Jensen, B.

    1993-06-01

    The author presents a global solution of Einstein's equations which represents a rotating cosmic string with a finite coreradius. The importance of pressure for the generation of closed timelike curves outside the coreregion of such strings is clearly displayed in this model due to the simplicity of the source. 10 refs

  5. Rotator Cuff Injuries.

    Science.gov (United States)

    Connors, G. Patrick

    Many baseball players suffer from shoulder injuries related to the rotator cuff muscles. These injuries may be classified as muscular strain, tendonitis or tenosynovitis, and impingement syndrome. Treatment varies from simple rest to surgery, so it is important to be seen by a physician as soon as possible. In order to prevent these injuries, the…

  6. Rotational dynamics with Tracker

    International Nuclear Information System (INIS)

    Eadkhong, T; Danworaphong, S; Rajsadorn, R; Jannual, P

    2012-01-01

    We propose the use of Tracker, freeware for video analysis, to analyse the moment of inertia (I) of a cylindrical plate. Three experiments are performed to validate the proposed method. The first experiment is dedicated to find the linear coefficient of rotational friction (b) for our system. By omitting the effect of such friction, we derive I for a cylindrical plate rotated around its central axis from the other two experiments based on the relation between torque and angular acceleration of rotational motion and conservation of energy. Movies of the rotating plate and hung masses are recorded. As a result, we have the deviation of I from its theoretical value of 0.4% and 3.3%, respectively. Our setup is completely constructed from locally available inexpensive materials and the experimental results indicate that the system is highly reliable. This work should pave the way for those who prefer to build a similar setup from scratch at relatively low cost compared to commercial units. (paper)

  7. The Axial Curve Rotator.

    Science.gov (United States)

    Hunter, Walter M.

    This document contains detailed directions for constructing a device that mechanically produces the three-dimensional shape resulting from the rotation of any algebraic line or curve around either axis on the coordinate plant. The device was developed in response to student difficulty in visualizing, and thus grasping the mathematical principles…

  8. Can planetary nebulae rotate

    International Nuclear Information System (INIS)

    Grinin, V.P.

    1982-01-01

    It is shown that the inclination of spectral lines observed in a number of planetary nebulae when the spectrograph slit is placed along the major axis, which is presently ascribed to nonuniform expansion of the shells, actually may be due to rotation of the nebulae about their minor axes, as Campbell and Moore have suggested in their reports. It is assumed that the rotation of the central star (or, if the core is a binary system, circular motions of gas along quasi-Keplerian orbits) serves as the source of the original rotation of a protoplanetary nebula. The mechanism providing for strengthening of the original rotation in the process of expansion of the shell is the tangential pressure of L/sub α/ radiation due to the anisotropic properties of the medium and radiation field. The dynamic effect produced by them is evidently greatest in the epoch when the optical depth of the nebula in the L/sub c/ continuum becomes on the order of unity in the course of its expansion

  9. Mental object rotation in Parkinson's disease.

    Science.gov (United States)

    Crucian, Gregory P; Barrett, Anna M; Burks, David W; Riestra, Alonso R; Roth, Heidi L; Schwartz, Ronald L; Triggs, William J; Bowers, Dawn; Friedman, William; Greer, Melvin; Heilman, Kenneth M

    2003-11-01

    Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.

  10. A Required Rotation in Clinical Laboratory Management for Pathology Residents

    Science.gov (United States)

    Hoda, Syed T.; Crawford, James M.

    2016-01-01

    Leadership and management training during pathology residency have been identified repeatedly by employers as insufficient. A 1-month rotation in clinical laboratory management (CLM) was created for third-year pathology residents. We report on our experience and assess the value of this rotation. The rotation was one-half observational and one-half active. The observational component involved being a member of department and laboratory service line leadership, both at the departmental and institutional level. Observational participation enabled learning of both the content and principles of leadership and management activities. The active half of the rotation was performance of a project intended to advance the strategic trajectory of the department and laboratory service line. In our program that matriculates 4 residents per year, 20 residents participated from April 2010 through December 2015. Their projects either activated a new priority area or helped propel an existing strategic priority forward. Of the 16 resident graduates who had obtained their first employment or a fellowship position, 9 responded to an assessment survey. The majority of respondents (5/9) felt that the rotation significantly contributed to their ability to compete for a fellowship or their first employment position. The top reported benefits of the rotation included people management; communication with staff, departmental, and institutional leadership; and involvement in department and institutional meetings and task groups. Our 5-year experience demonstrates both the successful principles by which the CLM rotation can be established and the high value of this rotation to residency graduates. PMID:28725766

  11. A Required Rotation in Clinical Laboratory Management for Pathology Residents

    Directory of Open Access Journals (Sweden)

    Arvind Rishi MD

    2016-05-01

    Full Text Available Leadership and management training during pathology residency have been identified repeatedly by employers as insufficient. A 1-month rotation in clinical laboratory management (CLM was created for third-year pathology residents. We report on our experience and assess the value of this rotation. The rotation was one-half observational and one-half active. The observational component involved being a member of department and laboratory service line leadership, both at the departmental and institutional level. Observational participation enabled learning of both the content and principles of leadership and management activities. The active half of the rotation was performance of a project intended to advance the strategic trajectory of the department and laboratory service line. In our program that matriculates 4 residents per year, 20 residents participated from April 2010 through December 2015. Their projects either activated a new priority area or helped propel an existing strategic priority forward. Of the 16 resident graduates who had obtained their first employment or a fellowship position, 9 responded to an assessment survey. The majority of respondents (5/9 felt that the rotation significantly contributed to their ability to compete for a fellowship or their first employment position. The top reported benefits of the rotation included people management; communication with staff, departmental, and institutional leadership; and involvement in department and institutional meetings and task groups. Our 5-year experience demonstrates both the successful principles by which the CLM rotation can be established and the high value of this rotation to residency graduates.

  12. Wave-driven Rotation in Supersonically Rotating Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    A. Fetterman and N.J. Fisch

    2010-02-15

    Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

  13. Wave-driven Rotation in Supersonically Rotating Mirrors

    International Nuclear Information System (INIS)

    Fetterman, A.; Fisch, N.J.

    2010-01-01

    Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

  14. Does the athletes? body shape the athletes? mind? A few ideas on athletes? mental rotation performance. Commentary on Jansen and Lehmann

    OpenAIRE

    Heinen, Thomas

    2013-01-01

    Athletes exhibit differences in perceptual-cognitive abilities when compared to non-athletes. Recent theoretical developments focus on the role of the athletes? body in perceptual-cognitive tasks such as mental rotation tasks. It is assumed that the degree to which stimuli in mental rotation tasks can be embodied facilitates the mental rotation process. The implications of this assumption are discussed and ideas for future research are presented.

  15. Short rotation woody biomass production as option for the restoration of post-mining areas in lower Lusatia, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, C.; Quinkenstein, A.; Freese, D. [Brandenburg Univ. of Technology, Cottbus (Germany). Soil Protection and Recultivation; Huttl, R.R. [Brandenburg Univ. of Technology, Cottbus (Germany). Soil Protection and Recultivation; GFZ German Research Centre for Geosciences, Potsdam (Germany)

    2010-07-01

    Reclaimed mine sites in the Lusatian lignite-mining district in Germany are characterized by low annual precipitation and marginal soils. As such, crop yield is typically low and conventional land use systems fail in terms of reliable and efficient crop production. The production of woody biomass for bioenergy may be a promising alternative to improve soil fertility and also to enhance the economic value of these post-mining areas. Previous studies have shown that black locust (Robinia pseudoacacia L.) may be a suitable tree species for this purpose. This paper evaluated the ecological and economic benefits of producing woody biomass in short rotation coppices (SRC) and alley cropping systems (ACS) with black locust. The results showed that compared to conventional agriculture, such land use is not very profitable due to high establishment and harvesting costs and the comparatively low prices for wood energy. However, because of the improved microclimate, the crop yield in ACS is higher than in conventional agriculture. The cultivation of black locust resulted in a higher humus accumulation and in a lower harvest-related nutrient export than the cultivation of alfalfa as a typical recultivation crop in this region. It was concluded SRC with black locust is more beneficial than conventional agriculture in terms of improving soil fertility in the degraded post-mining areas of Lower Lusatia.

  16. Allometric equations commonly used for estimating shoot biomass in short-rotation wood energy species: a review

    Directory of Open Access Journals (Sweden)

    Julio Cesar Ríos-Saucedo

    2016-01-01

    Full Text Available Los cultivos dendroenergéticos de corta rotación en monte bajo (Short Rotation Coppice -SRC comúnmente están formados por individuos unifustales en el primer ciclo de corta, pero a partir del segundo ciclo, de cada cepa surgen numerosos vástagos o brotes, los cuales presentan desafíos interesantes al momento de estimar su biomasa. El objetivo de este trabajo fue identificar especies, longitud de rotación y tipos de modelos alométricos usados para estimar biomasa en SRC, en revistas científicas de las bases de datos Scopus y Web of Science. Entre los modelos para estimar la biomasa (y de uso más frecuente destaca el exponencial, que tiene como variable predictora el diámetro normal ( D ( y = b 0 D b 1 , diámetro basal de tallo ( Db ( y = b 0 Db b 1 y la combinación de diámetro normal al cuadrado por la altura total ( D 2 H ( y = b 0 + b 1 D 2 H . Los géneros con mayor número de modelos diferentes fueron Populus, Salix y Eucalyptus . Los dos primeros son los más estudiados. La longitud de rotación empleada en los cultivos estudiados varió de uno a 15 años.

  17. Rotator Cuff Injuries - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Rotator Cuff Injuries URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Rotator Cuff Injuries - Multiple Languages To use the sharing features ...

  18. Asteroid rotation. IV

    International Nuclear Information System (INIS)

    Harris, A.W.; Young, J.W.

    1983-01-01

    The results from the year 1979 of an ongoing program of asteroid photometry at Table Mountain Observatory are presented. The results for 53 asteroids are summarized in a table, showing the number, name, opposition date, taxonomic class, diameter, absolute magnitude, mean absolute magnitude at zero phase angle and values of the absolute magnitude and linear phase coefficient derived from it, the rotation period in hours, peak-to-peak amplitude of variation, difference between mean and maximum brightness, and reliability index. Another table presents data on aspect and comparison stars, including brightness and distance data. Reliable rotation periods are reported for 22 asteroids for which no previous values are known. For seven asteroids, periods are reported which are revisions of previously reported values

  19. Rotatable seal assembly

    International Nuclear Information System (INIS)

    Garibaldi, J.L.; Logan, C.M.

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an oring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers

  20. Rotator cuff disease

    International Nuclear Information System (INIS)

    Ziatkin, M.B.; Iannotti, J.P.; Roberts, M.; Dalinka, M.K.; Esterhai, J.L.; Kressel, H.Y.; Lenkinski, R.E.

    1988-01-01

    A dual-surface-coil array in a Helmholtz configuration was used to evaluate th rotator cuff in ten normal volunteers and 44 patients. Studies were performed with a General Electric 1.5-T MR imager. Thirty-two patients underwent surgery, 25 of whom also underwent arthrography. In comparison with surgery, MR imaging was more sensitive than arthrography for rotator cuff tears (91% vs 71%). The specificity and accuracy of MR imaging were 88% and 91%. The accuracy increased with use of an MR grading system. MR findings correlated with surgical findings with regard to the size and site of tears. MR findings of cuff tears were studied with multivariate analysis. Correlation was also found between a clinical score, the MR grade, and the clinical outcome

  1. The Spatiale Rotator

    DEFF Research Database (Denmark)

    Rasmusson, Allan

    2009-01-01

    it is embedded and sectioned. This has the unfortunate side effect that all information about positioning within the object is lost for blocks and sections. For complex tissue, like the mammalian brain, this information is of utmost importance to ensure measurements are performed in the correct region......The inherent demand for unbiasedness for some stereological estimators imposes a demand of not only positional uniform randomness but also isotropic randomness, i.e. directional uniform randomness. In order to comply with isotropy, one must perform a random rotation of the object of interest before...... is obeyed by randomizing the orientation of the virtual probe itself within the thick section. Overall, the benefit is that positional information is kept for any block and section of the specimen. As the Spatial Rotator is a 3D probe, data must be gathered from sections thicker than 25 micro meters to form...

  2. Rotational spectrum of tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, M. Eugenia, E-mail: maria.sanz@kcl.ac.uk; Cabezas, Carlos, E-mail: ccabezas@qf.uva.es; Mata, Santiago, E-mail: santiago.mata@uva.es; Alonso, Josè L., E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, 47011 Valladolid (Spain)

    2014-05-28

    The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

  3. Rotator cuff tendon connections with the rotator cable.

    Science.gov (United States)

    Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

    2017-07-01

    The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

  4. Frictional Torque on a Rotating Disc

    Science.gov (United States)

    2012-01-01

    Tracker Eur. J. Phys. 33 615–22 [2] Alam J, Hassan H, Shamim S , Mahmood W and Anwar M S 2011 Precise measurement of velocity dependent friction in...on a rotating disc 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) US Naval Academy,Physics Department,Annapolis,MD,21402-1363 8. PERFORMING ORGANIZATION

  5. Visuospatial memory computations during whole-body rotations in roll

    NARCIS (Netherlands)

    Pelt, S. van; Gisbergen, J.A.M. van; Medendorp, W.P.

    2005-01-01

    We used a memory-saccade task to test whether the location of a target, briefly presented before a whole-body rotation in roll, is stored in egocentric or in allocentric coordinates. To make this distinction, we exploited the fact that subjects, when tilted sideways in darkness, make systematic

  6. Broadband Rotational Spectroscopy

    Science.gov (United States)

    Pate, Brooks

    2014-06-01

    The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

  7. Cognitive task analysis

    NARCIS (Netherlands)

    Schraagen, J.M.C.

    2000-01-01

    Cognitive task analysis is defined as the extension of traditional task analysis techniques to yield information about the knowledge, thought processes and goal structures that underlie observable task performance. Cognitive task analyses are conducted for a wide variety of purposes, including the

  8. The rotational spectrum of IBr

    International Nuclear Information System (INIS)

    Tiemann, E.; Moeller, T.

    1975-01-01

    The microwave spectrum of IBr was measured in the low rotational transition J = 3 → 2 in order to resolve the hyperfine structure as completely as possible. Rotational constants and quadrupole coupling constants were derived for both nuclei. The observation of the rotational spectrum in different vibrational states yields the vibrational dependence of the rotational constants as well as of the hyperfine parameters. The Dunham potential coefficients α 0 , α 1 , α 2 , α 3 are given. (orig.) [de

  9. Effects of practice variability on unimanual arm rotation.

    Science.gov (United States)

    James, Eric G; Conatser, Phillip

    2014-01-01

    High variability practice has been found to lead to a higher rate of motor learning than low variability practice in sports tasks. The authors compared the effects of low and high levels of practice variability on a simple unimanual arm rotation task. Participants performed rhythmic unimanual internal-external arm rotation as smoothly as possible before and after 2 weeks of low (LV) or high (HV) variability practice and after a 2-week retention interval. Compared to the pretest, the HV group significantly decreased hand, radioulnar, and shoulder rotation jerk on the retention test and shoulder jerk on the posttest. After training the LV group had lower radioulnar and shoulder jerk on the posttest but not the retention test. The results supported the hypothesis that high variability practice would lead to greater learning and reminiscence than low variability practice and the theoretical prediction of a bifurcation in the motor learning dynamics.

  10. Snakes and spin rotators

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1990-01-01

    The generalized snake configuration offers advantages of either shorter total snake length and smaller orbit displacement in the compact configuration or the multi-functions in the split configuration. We found that the compact configuration can save about 10% of the total length of a snake. On other hand, the spilt snake configuration can be used both as a snake and as a spin rotator for the helicity state. Using the orbit compensation dipoles, the spilt snake configuration can be located at any distance on both sides of the interaction point of a collider provided that there is no net dipole rotation between two halves of the snake. The generalized configuration is then applied to the partial snake excitation. Simple formula have been obtained to understand the behavior of the partial snake. Similar principle can also be applied to the spin rotators. We also estimate the possible snake imperfections are due to various construction errors of the dipole magnets. Accuracy of field error of better than 10 -4 will be significant. 2 refs., 5 figs

  11. Cognitive Motor Coordination Training Improves Mental Rotation Performance in Primary School-Aged Children

    Science.gov (United States)

    Pietsch, Stefanie; Böttcher, Caroline; Jansen, Petra

    2017-01-01

    The long-term physical activity in specific sport activities can change the quality of mental rotation performance. This study investigates the influence of "Life Kinetik"--a motion program with tasks of cognition and motor coordination--on mental rotation performance of 44 primary school-aged children. While the experimental group…

  12. CISM Course on Rotating Fluids

    CERN Document Server

    1992-01-01

    The volume presents a comprehensive overview of rotation effects on fluid behavior, emphasizing non-linear processes. The subject is introduced by giving a range of examples of rotating fluids encountered in geophysics and engineering. This is then followed by a discussion of the relevant scales and parameters of rotating flow, and an introduction to geostrophic balance and vorticity concepts. There are few books on rotating fluids and this volume is, therefore, a welcome addition. It is the first volume which contains a unified view of turbulence in rotating fluids, instability and vortex dynamics. Some aspects of wave motions covered here are not found elsewhere.

  13. COMMISSIONING SPIN ROTATORS IN RHIC

    International Nuclear Information System (INIS)

    MACKAY, W.W.; AHRENS, L.; BAI, M.; COURANT, E.D.; FISCHER, W.; HUANG, H.; LUCCIO, A.; MONTAG, C.; PILAT, F.; PTITSYN, V.; ROSER, T.; SATOGATA, T.; TRBOJEVIC, D.; VANZIEJTS, J.

    2003-01-01

    During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other side. This allows independent control for each beam with vertical, longitudinal, or radial polarization at the experiment. In this paper, we present results from the first run using the new spin rotators at PHENIX

  14. Using the Hand Laterality Judgement Task to Assess Motor Imagery: A Study of Practice Effects in Repeated Measurements

    Science.gov (United States)

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    2012-01-01

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control tasks twice at a 3-week interval. Differences in the…

  15. The influence of task variation on manifestation of fatigue is ambiguous : a literature review

    NARCIS (Netherlands)

    Luger, T.; Bosch, T.; Veeger, D.; Looze, M. de

    2014-01-01

    Task variation has been proposed to reduce shoulder fatigue resulting from repetitive hand-arm tasks. This review analyses the effect of task variation, both 'temporal (i.e. change of work-rest ratio)' and 'activity (i.e. job rotation)' variation, on physiological responses, endurance time (ET) and

  16. CONFERENCE: Muon spin rotation

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Erik

    1986-11-15

    An international physics conference centred on muons without a word about leptons, weak interactions, EMC effects, exotic decay modes or any other standard high energy physics jargon. Could such a thing even have been imagined ten years ago? Yet about 120 physicists and chemists from 16 nations gathered at the end of June in Uppsala (Sweden) for their fourth meeting on Muon Spin Rotation, Relaxation and Resonance, without worrying about the muon as an elementary particle. This reflects how the experimental techniques based on the muon spin interactions have reached maturity and are widely recognized by condensed matter physicists and specialized chemists as useful tools.

  17. Autonomous quantum rotator

    DEFF Research Database (Denmark)

    Fogedby, Hans C.; Imparato, Alberto

    2018-01-01

    to a directed rotary motion. At variance with the classical case, the thermal fluctuations in the baths give rise to a non-vanishing average torque contribution; this is a genuine quantum effect akin to the Casimir effect. In the steady state the heat current flowing between the two baths is systematically......, the rotator cannot work either as a heat pump or as a heat engine. We finally use our exact results to extend an ab initio quantum simulation algorithm to the out-of-equilibrium regime. Copyright (C) EPLA, 2018...

  18. Rotating specimen rack repair

    International Nuclear Information System (INIS)

    Miller, G.E.; Rogers, P.J.; Nabor, W.G.; Bair, H.

    1984-01-01

    In 1980, an operator at the UCI TRIGA Reactor noticed difficulties with the rotation of the specimen rack. Investigations showed that the drive bearing in the rack had failed and allowed the bearings to enter the rack. After some time of operation in static mode it was decided that installation of a bearing substitute - a graphite sleeve - would be undertaken. Procedures were written and approved for removal of the rack, fabrication and installation of the sleeve, and re-installation of the rack. This paper describes these procedures in some detail. Detailed drawings of the necessary parts may be obtained from the authors

  19. Rotational anomalies without anyons

    International Nuclear Information System (INIS)

    Hagen, C.R.

    1985-01-01

    A specific field theory is proposed in two spatial dimensions which has anomalous rotational properties. Although this might be expected to lead to a concrete realization of what Wilczek refers to as the anyon, it is shown by utilizing the transformation properties of the system and the statistics of the underlying charge fields that anyonic interpolations between bosons and fermions do not occur. This leads to the suggestion that anyons inferred from semiclassical considerations will not survive the transition to a fully relativistic field theory

  20. Rotating electrical machines

    CERN Document Server

    Le Doeuff, René

    2013-01-01

    In this book a general matrix-based approach to modeling electrical machines is promulgated. The model uses instantaneous quantities for key variables and enables the user to easily take into account associations between rotating machines and static converters (such as in variable speed drives).   General equations of electromechanical energy conversion are established early in the treatment of the topic and then applied to synchronous, induction and DC machines. The primary characteristics of these machines are established for steady state behavior as well as for variable speed scenarios. I

  1. Task demand, task management, and teamwork

    Energy Technology Data Exchange (ETDEWEB)

    Braarud, Per Oeivind; Brendryen, Haavar

    2001-03-15

    The current approach to mental workload assessment in process control was evaluated in 3 previous HAMMLAB studies, by analysing the relationship between workload related measures and performance. The results showed that subjective task complexity rating was related to team's control room performance, that mental effort (NASA-TLX) was weakly related to performance, and that overall activity level was unrelated to performance. The results support the argument that general cognitive measures, i.e., mental workload, are weakly related to performance in the process control domain. This implies that other workload concepts than general mental workload are needed for valid assessment of human reliability and for valid assessment of control room configurations. An assessment of task load in process control suggested that how effort is used to handle task demand is more important then the level of effort invested to solve the task. The report suggests two main workload related concepts with a potential as performance predictors in process control: task requirements, and the work style describing how effort is invested to solve the task. The task requirements are seen as composed of individual task demand and team demand. In a similar way work style are seen as composed of individual task management and teamwork style. A framework for the development of the concepts is suggested based on a literature review and experiences from HAMMLAB research. It is suggested that operational definitions of workload concepts should be based on observable control room behaviour, to assure a potential for developing performance-shaping factors. Finally an explorative analysis of teamwork measures and performance in one study indicated that teamwork concepts are related to performance. This lends support to the suggested development of team demand and teamwork style as elements of a framework for the analysis of workload in process control. (Author)

  2. Using mental rotation to evaluate the benefits of stereoscopic displays

    Science.gov (United States)

    Aitsiselmi, Y.; Holliman, N. S.

    2009-02-01

    Context: The idea behind stereoscopic displays is to create the illusion of depth and this concept could have many practical applications. A common spatial ability test involves mental rotation. Therefore a mental rotation task should be easier if being undertaken on a stereoscopic screen. Aim: The aim of this project is to evaluate stereoscopic displays (3D screen) and to assess whether they are better for performing a certain task than over a 2D display. A secondary aim was to perform a similar study but replicating the conditions of using a stereoscopic mobile phone screen. Method: We devised a spatial ability test involving a mental rotation task that participants were asked to complete on either a 3D or 2D screen. We also design a similar task to simulate the experience on a stereoscopic cell phone. The participants' error rate and response times were recorded. Using statistical analysis, we then compared the error rate and response times of the groups to see if there were any significant differences. Results: We found that the participants got better scores if they were doing the task on a stereoscopic screen as opposed to a 2D screen. However there was no statistically significant difference in the time it took them to complete the task. We also found similar results for 3D cell phone display condition. Conclusions: The results show that the extra depth information given by a stereoscopic display makes it easier to mentally rotate a shape as depth cues are readily available. These results could have many useful implications to certain industries.

  3. Optimal rotation sequences for active perception

    Science.gov (United States)

    Nakath, David; Rachuy, Carsten; Clemens, Joachim; Schill, Kerstin

    2016-05-01

    One major objective of autonomous systems navigating in dynamic environments is gathering information needed for self localization, decision making, and path planning. To account for this, such systems are usually equipped with multiple types of sensors. As these sensors often have a limited field of view and a fixed orientation, the task of active perception breaks down to the problem of calculating alignment sequences which maximize the information gain regarding expected measurements. Action sequences that rotate the system according to the calculated optimal patterns then have to be generated. In this paper we present an approach for calculating these sequences for an autonomous system equipped with multiple sensors. We use a particle filter for multi- sensor fusion and state estimation. The planning task is modeled as a Markov decision process (MDP), where the system decides in each step, what actions to perform next. The optimal control policy, which provides the best action depending on the current estimated state, maximizes the expected cumulative reward. The latter is computed from the expected information gain of all sensors over time using value iteration. The algorithm is applied to a manifold representation of the joint space of rotation and time. We show the performance of the approach in a spacecraft navigation scenario where the information gain is changing over time, caused by the dynamic environment and the continuous movement of the spacecraft

  4. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  5. Laterality-Specific Training Improves Mental Rotation Performance in Young Soccer Players.

    Science.gov (United States)

    Pietsch, Stefanie; Jansen, Petra

    2018-01-01

    This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.

  6. Task assignment and coaching

    OpenAIRE

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching from a manager, the junior employee only has information about his past performance. Based on his past performance, a talented junior who has performed a difficult task sometimes decides to leave the...

  7. Functional Task Test (FTT)

    Science.gov (United States)

    Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.; hide

    2009-01-01

    This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

  8. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching

  9. Mental rotation and working memory in musicians' dystonia.

    Science.gov (United States)

    Erro, Roberto; Hirschbichler, Stephanie T; Ricciardi, Lucia; Ryterska, Agata; Antelmi, Elena; Ganos, Christos; Cordivari, Carla; Tinazzi, Michele; Edwards, Mark J; Bhatia, Kailash P

    2016-11-01

    Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians' dystonia is a type of focal hand dystonia that is grouped together with writer's cramp under the rubric of "occupational dystonia", but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer's cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians' dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. Eight patients with musicians' dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. Patients with musicians' dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Lunar Rotation, Orientation and Science

    Science.gov (United States)

    Williams, J. G.; Ratcliff, J. T.; Boggs, D. H.

    2004-12-01

    The Moon is the most familiar example of the many satellites that exhibit synchronous rotation. For the Moon there is Lunar Laser Ranging measurements of tides and three-dimensional rotation variations plus supporting theoretical understanding of both effects. Compared to uniform rotation and precession the lunar rotational variations are up to 1 km, while tidal variations are about 0.1 m. Analysis of the lunar variations in pole direction and rotation about the pole gives moment of inertia differences, third-degree gravity harmonics, tidal Love number k2, tidal dissipation Q vs. frequency, dissipation at the fluid-core/solid-mantle boundary, and emerging evidence for an oblate boundary. The last two indicate a fluid core, but a solid inner core is not ruled out. Four retroreflectors provide very accurate positions on the Moon. The experience with the Moon is a starting point for exploring the tides, rotation and orientation of the other synchronous bodies of the solar system.

  11. A compact rotating dilution refrigerator

    Science.gov (United States)

    Fear, M. J.; Walmsley, P. M.; Chorlton, D. A.; Zmeev, D. E.; Gillott, S. J.; Sellers, M. C.; Richardson, P. P.; Agrawal, H.; Batey, G.; Golov, A. I.

    2013-10-01

    We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid 4He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 10-3 rad s-1 up to angular velocities in excess of 2.5 rad s-1. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

  12. Keep calm! Gender differences in mental rotation performance are modulated by habitual expressive suppression.

    Science.gov (United States)

    Fladung, Anne-Katharina; Kiefer, Markus

    2016-11-01

    Men have been frequently found to perform more accurately than women in mental rotation tasks. However, men and women also differ with regard to the habitual use of emotion regulation strategies, particularly with regard to expressive suppression, i.e., the suppression of emotional expression in behavior. As emotional suppression is more often used by men, emotion regulation strategies might be a variable modulating gender differences in mental rotation performance. The present study, therefore, examined the influences of gender and emotion regulation strategies on mental rotation performance accuracy and feedback processing. Twenty-eight men and 28 women matched for relevant demographic variables performed mental rotation tasks of varying difficulty over a prolonged time. Emotional feedback was given immediately after each trial. Results showed that women reported to use expressive suppression less frequently than men. Women made more errors in the mental rotation task than men confirming earlier demonstrations of gender differences. Furthermore, women were more impaired by the negative feedback as indicated by the increased likelihood of subsequent errors compared with men. Task performance of women not habitually using expressive suppression was most inferior and most strongly influenced by failure feedback compared with men. Women using expressive suppression more habitually did not significantly differ in mental rotation accuracy and feedback processing from men. Hence, expressive suppression reduces gender differences in mental rotation accuracy by improving cognitive performance following failure feedback.

  13. Wormholes immersed in rotating matter

    Directory of Open Access Journals (Sweden)

    Christian Hoffmann

    2018-03-01

    Full Text Available We demonstrate that rotating matter sets the throat of an Ellis wormhole into rotation, allowing for wormholes which possess full reflection symmetry with respect to the two asymptotically flat spacetime regions. We analyze the properties of this new type of rotating wormholes and show that the wormhole geometry can change from a single throat to a double throat configuration. We further discuss the ergoregions and the lightring structure of these wormholes.

  14. Internal rotation of the Sun

    International Nuclear Information System (INIS)

    Duvall, T.L. Jr.; Goode, P.R.; Gouch, D.O.

    1984-01-01

    The frequency difference between prograde and retrograde sectoral solar oscillations is analysed to determine the rotation rate of the solar interior, assuming no latitudinal dependence. Much of the solar interior rotates slightly less rapidly than the surface, while the innermost part apparently rotates more rapidly. The resulting solar gravitational quadrupole moment is J 2 = (1.7 +- 0.4) x 10 -7 and provides a negligible contribution to current planetary tests of Einstein's theory of general relativity. (author)

  15. Earth's variable rotation

    Science.gov (United States)

    Hide, Raymond; Dickey, Jean O.

    1991-01-01

    Recent improvements in geodetic data and practical meteorology have advanced research on fluctuations in the earth's rotation. The interpretation of these fluctuations is inextricably linked with studies of the dynamics of the earth-moon system and dynamical processes in the liquid metallic core of the earth (where the geomagnetic field originates), other parts of the earth's interior, and the hydrosphere and atmosphere. Fluctuations in the length of the day occurring on decadal time scales have implications for the topographay of the core-mantle boundary and the electrical, magnetic, ande other properties of the core and lower mantle. Investigations of more rapid fluctuations bear on meteorological studies of interannual, seasonal, and intraseasonal variations in the general circulation of the atmosphere and the response of the oceans to such variations.

  16. Sporcularda rotator cuff problemleri

    OpenAIRE

    Guven, Osman; Guven, Zeynep; Gundes, Hakan; Yalcin, Selim

    2004-01-01

    Rotator cuff tendinitinin etyolojisinde genellikle birden çok faktörün kombinasyonu görülür. Yüzme, raket sporları ve fırlatma sporlarının özellikle gelişmiş ülkelerde giderek yaygınlaşması bu konuya olan ilginin artmasına sebep olmuştur. Eski konseptlerde aktif bir sporcuda tedavinin başarısı genellikle eski atletik seviyesine dönmesi ile ölçülürdü. Son zamanlarda atletik tekniklerin analizi, atroskopik evaluasyon gibi yeni bir Iükse sahip olmamız ve Iiteratürün yeniden gözden geçirilmesi il...

  17. Surface dimpling on rotating work piece using rotation cutting tool

    Science.gov (United States)

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  18. The Effect of Fatigued External Rotator Muscles of the Shoulder on the Shoulder Position Sense

    Directory of Open Access Journals (Sweden)

    Naoya Iida

    2011-10-01

    Full Text Available This study aimed to investigate the effect of fatigue in shoulder external rotator muscles on position sense of shoulder abduction, internal rotation, and external rotation. The study included 10 healthy subjects. Shoulder position sense was measured before and after a fatigue task involving shoulder external rotator muscles. The fatigue task was performed using an isokinetic machine. To confirm the muscle fatigue, electromyography (EMG was recorded, and an integrated EMG and median power frequency (MDF during 3 sec performed target torque were calculated. After the fatigue task, the MDF of the infraspinatus muscle significantly decreased. This indicates that the infraspinatus muscle was involved in the fatigue task. In addition, the shoulder position sense of internal and external rotation significantly decreased after the fatigue task. These results suggest that the fatigue reduced the accuracy of sensory input from muscle spindles. However, no significant difference was observed in shoulder position sense of abduction before and after the fatigue task. This may be due to the fact that infraspinatus muscle did not act as prime movers in shoulder abduction. These results suggest that muscle fatigue decreased position sense during movements in which the affected muscles acted as prime movers.

  19. Cognitive profile of patients with rotated drawing at copy or recall: a controlled group study.

    Science.gov (United States)

    Molteni, Federica; Traficante, Debora; Ferri, Francesca; Isella, Valeria

    2014-03-01

    When copying or recalling a figure from memory, some patient with dementia or focal brain lesions may rotate the drawing through ±90° or 180°. We have tried to clarify the nature of this phenomenon by investigating the cognitive profile of 22 patients who rotated the copy of the Rey-Osterrieth Complex Figure and 27 who rotated (only) the recall, and two control groups of cases with the same neuropsychiatric diagnoses, but no misorientation deficit. Brain MRI and FDG-PET images were also analysed. Predictor of rotation at the copy versus rotation at the recall was visuospatial impairment as measured by the copy of the Rey Figure; predictors of rotation at the copy versus no rotation were, again, visuospatial deficits, in addition to an abnormal performance at the task of selective attention. No specific profile of cognitive impairment distinguished patients with and without rotation at the recall. Disproportionate temporo-parieto-occipital atrophy or hypometabolism were evident in cases with misorientation of the copy, while predominant frontal abnormalities were found in cases of rotated recall. Based on these findings, rotated drawing at the copy is interpreted as a dorsal visual stream deficit, whose occurrence is more probable when attentional control is impaired. Rotation at recall seems to have a distinct, more anterior, neural substrate, but its dysexecutive nature has yet to be demonstrated. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Rotation of the planet mercury.

    Science.gov (United States)

    Jefferys, W H

    1966-04-08

    The equations of motion for the rotation of Mercury are solved for the general case by an asymptotic expansion. The findings of Liu and O'Keefe, obtained by numerical integration of a special case, that it is possible for Mercury's rotation to be locked into a 2:3 resonance with its revolution, are confirmed in detail. The general solution has further applications.

  1. Stabilities of MHD rotational discontinuities

    International Nuclear Information System (INIS)

    Wang, S.

    1984-11-01

    In this paper, the stabilities of MHD rotational discontinuities are analyzed. The results show that the rotational discontinuities in an incompressible magnetofluid are not always stable with respect to infinitesimal perturbation. The instability condition in a special case is obtained. (author)

  2. Optical isolation by Faraday rotator

    International Nuclear Information System (INIS)

    Kasai, Takeshi; Matsushima, Isao; Nemoto, Fusashi; Yano, Masaaki

    1984-01-01

    Three Faraday rotators designed as optical isolators in a high power glass laser system are described. The spatial fluctuation of applied magnetic field is less than 1% throughout the Faraday glass rod. The Faraday rotators transmit more than 80% of the forward-going laser light and reject more than 96% of the backward-going light. (author)

  3. Rotational superradiance in fluid laboratories

    CERN Document Server

    Cardoso, Vitor; Richartz, Mauricio; Weinfurtner, Silke

    2016-01-01

    Rotational superradiance has been predicted theoretically decades ago, and is the chief responsible for a number of important effects and phenomenology in black hole physics. However, rotational superradiance has never been observed experimentally. Here, with the aim of probing superradiance in the lab, we investigate the behaviour of sound and surface waves in fluids resting in a circular basin at the center of which a rotating cylinder is placed. We show that with a suitable choice for the material of the cylinder, surface and sound waves are amplified. By confining the superradiant modes near the rotating cylinder, an instability sets in. Our findings are experimentally testable in existing fluid laboratories and hence offer experimental exploration and comparison of dynamical instabilities arising from rapidly rotating boundary layers in astrophysical as well as in fluid dynamical systems.

  4. Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert [Applied Technology Associates, Albuquerque, NM (United States); Laughlin, Darren [Applied Technology Associates, Albuquerque, NM (United States); Brune, Robert [Applied Technology Associates, Albuquerque, NM (United States)

    2016-10-19

    Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is on induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.

  5. Flow past a rotating cylinder

    Science.gov (United States)

    Mittal, Sanjay; Kumar, Bhaskar

    2003-02-01

    Flow past a spinning circular cylinder placed in a uniform stream is investigated via two-dimensional computations. A stabilized finite element method is utilized to solve the incompressible Navier Stokes equations in the primitive variables formulation. The Reynolds number based on the cylinder diameter and free-stream speed of the flow is 200. The non-dimensional rotation rate, [alpha] (ratio of the surface speed and freestream speed), is varied between 0 and 5. The time integration of the flow equations is carried out for very large dimensionless time. Vortex shedding is observed for [alpha] cylinder. The results from the stability analysis for the rotating cylinder are in very good agreement with those from direct numerical simulations. For large rotation rates, very large lift coefficients can be obtained via the Magnus effect. However, the power requirement for rotating the cylinder increases rapidly with rotation rate.

  6. Bidirectional optical rotation of cells

    Directory of Open Access Journals (Sweden)

    Jiyi Wu

    2017-08-01

    Full Text Available Precise and controlled rotation manipulation of cells is extremely important in biological applications and biomedical studies. Particularly, bidirectional rotation manipulation of a single or multiple cells is a challenge for cell tomography and analysis. In this paper, we report an optical method that is capable of bidirectional rotation manipulation of a single or multiple cells. By launching a laser beam at 980 nm into dual-beam tapered fibers, a single or multiple cells in solutions can be trapped and rotated bidirectionally under the action of optical forces. Moreover, the rotational behavior can be controlled by altering the relative distance between the two fibers and the input optical power. Experimental results were interpreted by numerical simulations.

  7. Transport Task Force Leadership, Task 4

    International Nuclear Information System (INIS)

    Callen, J.D.

    1991-07-01

    The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport

  8. Hydrodynamics of rotating superfluids

    International Nuclear Information System (INIS)

    Chandler, E.A.

    1981-01-01

    In this thesis, a coarse grained hydrodynamics is developed from the exact description of Tkachenko. To account for the dynamics of the vortex lattice, the macroscopic vortex displacement field is treated as an independent degree of freedom. The conserved energy is written in terms of the coarse-grained normal fluid, superfluid, and vortex velocities and includes an elastic energy associated with deformations of the vortex lattice. Equations of motion consistent with the conservation of energy, entropy and vorticity and containing mutual friction terms arising from microscopic interactions between normal fluid excitations and the vortex lines are derived. When the vortex velocity is eliminated from the damping terms, this system of equations becomes essentially that of BK with added elastic terms in the momentum stress tensor and energy current. The dispersion relation and damping of the first and second sound modes and the two transverse modes sustained by the system are investigated. It is shown that mutual friction mixes the transverse modes of the normal and superfluid components and damps the transverse mode associated with the relative velocity of these components, making this wave evanescent in the plane perpendicular to the rotation axis. The wave associated with transverse motion of the total mass current is a generalized Tkachenko mode, whose dispersion relation reduces to that derived by Tkachenko wave when the wavevector lies in this plane

  9. Magnetostrophic Rotating Magnetoconvection

    Science.gov (United States)

    King, Eric; Aurnou, Jonathan

    2016-11-01

    Planetary magnetic fields are generated by turbulent convection within their vast interior liquid metal cores. Although direct observation is not possible, this liquid metal circulation is thought to be dominated by the controlling influences of Coriolis and Lorentz forces. Theory famously predicts that local-scale convection naturally settles into the so-called magnetostrophic state, where the Coriolis and Lorentz forces partially cancel, and convection is optimally efficient. To date, no laboratory experiments have reached the magnetostrophic regime in turbulent liquid metal convection. Furthermore, computational dynamo simulations have as yet failed to produce a globally magnetostrophic dynamo, which has led some to question the existence of the magnetostrophic state. Here, we present results from the first turbulent magnetostrophic rotating magnetoconvection experiments using the liquid metal gallium. We find that turbulent convection in the magnetostrophic regime is, in fact, maximally efficient. The experimental results clarify these previously disparate results, suggesting that the fluid dynamics saturate in magnetostrophic balance within turbulent liquid metal, planetary cores. The authors thank the NSF Geophysics Program for financial support.

  10. Rotating quantum Gaussian packets

    International Nuclear Information System (INIS)

    Dodonov, V V

    2015-01-01

    We study two-dimensional quantum Gaussian packets with a fixed value of mean angular momentum. This value is the sum of two independent parts: the ‘external’ momentum related to the motion of the packet center and the ‘internal’ momentum due to quantum fluctuations. The packets minimizing the mean energy of an isotropic oscillator with the fixed mean angular momentum are found. They exist for ‘co-rotating’ external and internal motions, and they have nonzero correlation coefficients between coordinates and momenta, together with some (moderate) amount of quadrature squeezing. Variances of angular momentum and energy are calculated, too. Differences in the behavior of ‘co-rotating’ and ‘anti-rotating’ packets are shown. The time evolution of rotating Gaussian packets is analyzed, including the cases of a charge in a homogeneous magnetic field and a free particle. In the latter case, the effect of initial shrinking of packets with big enough coordinate-momentum correlation coefficients (followed by the well known expansion) is discovered. This happens due to a competition of ‘focusing’ and ‘de-focusing’ in the orthogonal directions. (paper)

  11. Rotator cuff pathology

    International Nuclear Information System (INIS)

    Pigeau, I.; Doursounian, L.; Maigne, J.Y.; Guinet, C.; Meary, E.; Buy, J.N.; Touzard, R.C.; Vadrot, D.; Laval-Jeantet, M.

    1989-01-01

    Fifteen volunteers and 73 patients with suspected rotator cuff lesions were examined at 0.5 T with T2 * -weighted gradient-echo (GE) MR imaging (700/33/30 degrees) (oblique coronal and sagittal 3 mm thick, surface coil). Results were compared with those of arthrography (all cases), T1-weighted GE imaging (400/20/90 degrees) (35 cases), surgery (28 cases), and T2-weighted spin-echo (SE) images (2,000/60-120) (17 cases). GE images demonstrated all tears (complete, 32, partial, 12) and was superior to arthrography in determining site and size and in displaying muscles (critical point in surgical planning). In 20 cases without tears on arthrography, GE imaging demonstrated five cases of tendinitis, five cases of bursitis, and six probable intratendinous or superficial partial tears. T2 * -weighted GE imaging was superior to T2-weighted SE and T1-weighted GE imaging, with higher fluid contrast and a low fat signal. Therefore, it might replace arthrography in the diagnosis and surgical approach to this pathology

  12. "Photographing money" task pricing

    Science.gov (United States)

    Jia, Zhongxiang

    2018-05-01

    "Photographing money" [1]is a self-service model under the mobile Internet. The task pricing is reasonable, related to the success of the commodity inspection. First of all, we analyzed the position of the mission and the membership, and introduced the factor of membership density, considering the influence of the number of members around the mission on the pricing. Multivariate regression of task location and membership density using MATLAB to establish the mathematical model of task pricing. At the same time, we can see from the life experience that membership reputation and the intensity of the task will also affect the pricing, and the data of the task success point is more reliable. Therefore, the successful point of the task is selected, and its reputation, task density, membership density and Multiple regression of task positions, according to which a nhew task pricing program. Finally, an objective evaluation is given of the advantages and disadvantages of the established model and solution method, and the improved method is pointed out.

  13. Board Task Performance

    DEFF Research Database (Denmark)

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

    2012-01-01

    identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings....... The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes...... and board task performance....

  14. Modelling of Rotational Capacity in Reinforced Linear Elements

    DEFF Research Database (Denmark)

    Hestbech, Lars; Hagsten, Lars German; Fisker, Jakob

    2011-01-01

    on the rotational capacity of the plastic hinges. The documentation of ductility can be a difficult task as modelling of rotational capacity in plastic hinges of frames is not fully developed. On the basis of the Theory of Plasticity a model is developed to determine rotational capacity in plastic hinges in linear......The Capacity Design Method forms the basis of several seismic design codes. This design philosophy allows plastic deformations in order to decrease seismic demands in structures. However, these plastic deformations must be localized in certain zones where ductility requirements can be documented...... reinforced concrete elements. The model is taking several important parameters into account. Empirical values is avoided which is considered an advantage compared to previous models. Furthermore, the model includes force variations in the reinforcement due to moment distributions and shear as well...

  15. Sensorless Estimation and Nonlinear Control of a Rotational Energy Harvester

    Science.gov (United States)

    Nunna, Kameswarie; Toh, Tzern T.; Mitcheson, Paul D.; Astolfi, Alessandro

    2013-12-01

    It is important to perform sensorless monitoring of parameters in energy harvesting devices in order to determine the operating states of the system. However, physical measurements of these parameters is often a challenging task due to the unavailability of access points. This paper presents, as an example application, the design of a nonlinear observer and a nonlinear feedback controller for a rotational energy harvester. A dynamic model of a rotational energy harvester with its power electronic interface is derived and validated. This model is then used to design a nonlinear observer and a nonlinear feedback controller which yield a sensorless closed-loop system. The observer estimates the mechancial quantities from the measured electrical quantities while the control law sustains power generation across a range of source rotation speeds. The proposed scheme is assessed through simulations and experiments.

  16. Toroidal rotation studies in KSTAR

    Science.gov (United States)

    Lee, S. G.; Lee, H. H.; Yoo, J. W.; Kim, Y. S.; Ko, W. H.; Terzolo, L.; Bitter, M.; Hill, K.; KSTAR Team

    2014-10-01

    Investigation of the toroidal rotation is one of the most important topics for the magnetically confined fusion plasma researches since it is essential for the stabilization of resistive wall modes and its shear plays an important role to improve plasma confinement by suppressing turbulent transport. The most advantage of KSTAR tokamak for toroidal rotation studies is that it equips two main diagnostics including the high-resolution X-ray imaging crystal spectrometer (XICS) and charge exchange spectroscopy (CES). Simultaneous core toroidal rotation and ion temperature measurements of different impurity species from the XICS and CES have shown in reasonable agreement with various plasma discharges in KSTAR. It has been observed that the toroidal rotation in KSTAR is faster than that of other tokamak devices with similar machine size and momentum input. This may due to an intrinsically low toroidal field ripple and error field of the KSTAR device. A strong braking of the toroidal rotation by the n = 1 non-resonant magnetic perturbations (NRMPs) also indicates these low toroidal field ripple and error field. Recently, it has been found that n = 2 NRMPs can also damp the toroidal rotation in KSTAR. The detail toroidal rotation studies will be presented. Work supported by the Korea Ministry of Science, ICT and Future Planning under the KSTAR project.

  17. Rotational discontinuities in anisotropic plasmas

    International Nuclear Information System (INIS)

    Omidi, N.

    1992-01-01

    The kinetic structure of rotational discontinuities (RDs) in anisotropic plasmas with T perpendicular /T parallel > 1 is investigated by using a one-dimensional electromagnetic hybrid code. To form the RD, a new approach is used where the plasma is injected from one boundary and reflected from the other, resulting in the generation of a traveling fast shock and an RD. Unlike the previously used methods, no a priori assumptions are made regarding the initial structure (i.e. width or sense of rotation) of the rotational discontinuity. The results show that across the RD both the magnetic field strength and direction, as well as the plasma density change. Given that such a change can also be associated with an intermediate shock, the Rankine-Hugoniot relations are used to confirm that the observed structures are indeed RDs. It is found that the thickness of RDs is a few ion inertial lengths and is independent of the rotation angle. Also, the preferred sense of rotation is in the electron sense; however, RDs with a rotation angle larger than 180 degree are found to be unstable, changing their rotation to a stable ion sense

  18. [Rotator cuff tear athropathy prevalence].

    Science.gov (United States)

    Guerra-Soriano, F; Encalada-Díaz, M I; Ruiz-Suárez, M; Valero-González, F S

    2017-01-01

    Glenohumeral arthritis secondary to massive rotator cuff tear presents with a superior displacement and femoralization of the humeral head with coracoacromial arch acetabularization. The purpose of this study was to establish prevalence of rotator cuff tear artropathy (CTA) at our institution. Four hundred electronic records were reviewed from which we identified 136 patients with rotator cuff tears. A second group was composed with patients with massive cuff tears that were analized and staged by the Seebauer cuff tear arthropathy classification. Thirty four patients with massive rotator cuff tears were identified, 8 male and 26 female (age 60.1 ± 10.26 years). Massive rotator cuff tear prevalence was 25%. CTA prevalence found in the rotator cuff group was 19 and 76% in the massive cuff tears group. Patients were staged according to the classification with 32% in stage 1a, 11% 1b, 32% 2a and 0% 2b. CTA prevalence in patients with rotator cuff tears and massive cuff tears is higher than the one reported in American population. We consider that a revision of the Seebauer classification to be appropriate to determine its reliability.

  19. Rotating relativistic neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Weber, F.; Glendenning, N.K.

    1991-07-21

    Models of rotating neutron stars are constructed in the framework of Einstein's theory of general relativity. For this purpose a refined version of Hartle's method is applied. The properties of these objects, e.g. gravitational mass, equatorial and polar radius, eccentricity, red- and blueshift, quadrupole moment, are investigated for Kepler frequencies of 4000 s{sup {minus}1} {le} {Omega}{sub K} {le} 9000 s{sup {minus}1}. Therefore a self-consistency problem inherent in the determination of {Omega}{sub K} must be solved. The investigation is based on neutron star matter equations of state derived from the relativistic Martin-Schwinger hierarch of coupled Green's functions. By means of introducing the Hartree, Hartree-Fock, and ladder ({Lambda}) approximations, models of the equation of state derived. A special feature of the latter approximation scheme is the inclusion of dynamical two-particle correlations. These have been calculated from the relativistic T-matrix applying both the HEA and Bonn meson-exchange potentials of the nucleon-nucleon force. The nuclear forces of the former two treatments are those of the standard scalar-vector-isovector model of quantum hadron dynamics, with parameters adjusted to the nuclear matter data. An important aspect of this work consists in testing the compatibility of different competing models of the nuclear equation of state with data on pulsar periods. By this the fundamental problem of nuclear physics concerning the behavior of the equation of state at supernuclear densities can be treated.

  20. Effect of rotation on convective mass transfer in rotating channels

    International Nuclear Information System (INIS)

    Pharoah, J.G.; Djilali, N.

    2002-01-01

    Laminar flow and mass transfer in rotating channels is investigated in the context of centrifugal membrane separation. The effect of orientation with respect to the rotational axis is examined for rectangular channels of aspect ratio 3 and the Rossby number is varied from 0.3 to 20.9. Both Ro and the channel orientation are found to have a significant effect on the flow. Mass transfer calculations corresponding to reverse osmosis desalination are carried out at various operating pressures and all rotating cases exhibit significant process enhancements at relatively low rotation rates. Finally, while it is common in the membrane literature to correlate mass transfer performance with membrane shear rates this is shown not to be valid in the cases presented herein. (author)

  1. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    , is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...

  2. Task leaders reports

    International Nuclear Information System (INIS)

    Loriaux, E.F.; Jehee, J.N.T.

    1995-01-01

    Report on CRP-OSS Task 4.1.1. ''Survey of existing documentation relevant to this programme's goals'' and report on CRP-OSS Task 4.1.2. ''Survey of existing Operator Support Systems and the experience with them'' are presented. 2 tabs

  3. Energy wood production in short rotation. Opportunities and problems in their implementation. An analysis involving expert interviews; Energieholzproduktion im Kurzumtrieb. Chancen und Probleme bei ihrer Umsetzung. Eine Analyse unter Einbeziehung von Experteninterviews

    Energy Technology Data Exchange (ETDEWEB)

    Wirkner, Ronny

    2010-12-01

    The thesis has to the content the latest stand and the possibilities of further development of wood energy production by short rotation coppice (SRC). After analyzing the development of this relatively new option of the management of fast growing tree species and their possibilities, the associated legal bases are being analyzed. In addition to related agricultural land, other options will be considered to establish land (forest, fallow land). Weaknesses in delimitation and promotion, especially at country level are discussed. There follows a detailed consideration of the economical and ecological contemplation of wood agricultural cultivation, as well as the basics of the management including the raw material supply. The analyzed results serve as a basis for running interviews with experts of the subject fast growing tree species. The results of the interviews show that SRC mainly as an opportunity for long-term wood energy supply and establishment of regional circuits is seen with emphasis on the agricultural sector, but in this context there are lots of deficits on side of the management technology, basic conditions and other establishment barriers that we are confront with. After overcoming the remaining start-up difficulties however the chances are good to expand the energy wood production in short rotation forestry in an economically viable, ecologically profitable and socially acceptable way and therewith contribute to the diversification of agricultural production and relief of multifunctional forest management. (orig.)

  4. Axial gap rotating electrical machine

    Science.gov (United States)

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  5. On the relativity of rotation

    International Nuclear Information System (INIS)

    Gron, O.

    2010-01-01

    The question whether rotational motion is relative according to the general theory of relativity is discussed. Einstein's ambivalence concerning this question is pointed out. In the present article I defend Einstein's way of thinking on this when he presented the theory in 1916. The significance of the phenomenon of perfect inertial dragging in connection with the relativity of rotational motion is discussed. The necessity of introducing an extended model of the Minkowski spacetime, in which a globally empty space is supplied with a cosmic mass shell with radius equal to its own Schwarzschild radius, in order to extend the principle of relativity to accelerated and rotational motion, is made clear.

  6. Using the Hand Laterality Judgement Task to assess motor imagery : a study of practice effects in repeated measurements

    NARCIS (Netherlands)

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control

  7. The Role of Motor Processes in Three-Dimensional Mental Rotation: Shaping Cognitive Processing via Sensorimotor Experience

    Science.gov (United States)

    Moreau, David

    2012-01-01

    An extensive body of literature has explored the involvement of motor processes in mental rotation, yet underlying individual differences are less documented and remain to be fully understood. We propose that sensorimotor experience shapes spatial abilities such as assessed in mental rotation tasks. Elite wrestlers' and non-athletes' mental…

  8. Uncovering the cognitive processes underlying mental rotation: an eye-movement study.

    Science.gov (United States)

    Xue, Jiguo; Li, Chunyong; Quan, Cheng; Lu, Yiming; Yue, Jingwei; Zhang, Chenggang

    2017-08-30

    Mental rotation is an important paradigm for spatial ability. Mental-rotation tasks are assumed to involve five or three sequential cognitive-processing states, though this has not been demonstrated experimentally. Here, we investigated how processing states alternate during mental-rotation tasks. Inference was carried out using an advanced statistical modelling and data-driven approach - a discriminative hidden Markov model (dHMM) trained using eye-movement data obtained from an experiment consisting of two different strategies: (I) mentally rotate the right-side figure to be aligned with the left-side figure and (II) mentally rotate the left-side figure to be aligned with the right-side figure. Eye movements were found to contain the necessary information for determining the processing strategy, and the dHMM that best fit our data segmented the mental-rotation process into three hidden states, which we termed encoding and searching, comparison, and searching on one-side pair. Additionally, we applied three classification methods, logistic regression, support vector model and dHMM, of which dHMM predicted the strategies with the highest accuracy (76.8%). Our study did confirm that there are differences in processing states between these two of mental-rotation strategies, and were consistent with the previous suggestion that mental rotation is discrete process that is accomplished in a piecemeal fashion.

  9. Assessing visuospatial abilities in healthy aging: A novel visuomotor task

    Directory of Open Access Journals (Sweden)

    Natalie eDe Bruin

    2016-02-01

    Full Text Available This study examined the efficacy of a novel reaching-and-grasping task in determining visuospatial abilities across adulthood. The task required male and female young (18-25 years and older adults (60-82 years to replicate a series of complex models by locating and retrieving the appropriate building blocks from an array. The task allows visuospatial complexity to be manipulated independently from the visuomotor demands. Mental rotation and spatial visualisation abilities were assessed. The results showed that the time taken to complete the tasks increased with increased mental rotation complexity. Patterns of hand use were also influenced by the complexity of the models being constructed with right hand use being greater for the less complex models. In addition, although older adults consistently performed the visuomotor tasks slower than the younger adults, their performance was comparable when expressed as the percent change in task demands. This is suggestive that spatial abilities are preserved in older adults. Given the ecologically validity, the described task is an excellent candidate for investigating (1 developmental, (2 sex-based and (3 pathology-based differences in spatial abilities in the visuomotor domain.

  10. On rapid rotation in stellarators

    International Nuclear Information System (INIS)

    Helander, Per

    2008-01-01

    The conditions under which rapid plasma rotation may occur in a three-dimensional magnetic field, such as that of a stellarator, are investigated. Rotation velocities comparable to the ion thermal speed are found to be attainable only in magnetic fields which are approximately isometric. In an isometric magnetic field the dependence of the magnetic field strength B on the arc length l along the field is the same for all field lines on each flux surface ψ. Only in fields where the departure from exact isometry, B=B(ψ,l), is of the order of the ion gyroradius divided by the macroscopic length scale are rotation speeds comparable to the ion thermal speed possible. Moreover, it is shown that the rotation must be in the direction of the vector ∇ψx∇B. (author)

  11. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  12. Differential rotation in magnetic stars

    International Nuclear Information System (INIS)

    Moss, D.

    1981-01-01

    The possibility that large-scale magnetic fields in stars are the product of a contemporary dynamo situated in the convective stellar core, rather than being a fossil from an earlier stage in the history of the star, is investigated. It is demonstrated that then the envelope will almost inevitably be in a state of differential rotation. Some simple models are constructed to illustrate the magnitude of the effects on the structure of the envelope and magnetic field. It is found that, for models which are relatively rapidly rotating, a modest differential rotation at the surface of the core may increase considerably the ratio of internal to surface field, but only give rise to a small surface differential rotation. (author)

  13. Conjunct rotation: Codman's paradox revisited.

    Science.gov (United States)

    Wolf, Sebastian I; Fradet, Laetitia; Rettig, Oliver

    2009-05-01

    This contribution mathematically formalizes Codman's idea of conjunct rotation, a term he used in 1934 to describe a paradoxical phenomenon arising from a closed-loop arm movement. Real (axial) rotation is distinguished from conjunct rotation. For characterizing the latter, the idea of reference vector fields is developed to define the neutral axial position of the humerus for any given orientation of its long axis. This concept largely avoids typical coordinate singularities arising from decomposition of 3D joint motion and therefore can be used for postural (axial) assessment of the shoulder joint both clinically and in sports science in almost the complete accessible range of motion. The concept, even though algebraic rather complex, might help to get an easier and more intuitive understanding of axial rotation of the shoulder in complex movements present in daily life and in sports.

  14. Current status of rotational atherectomy.

    Science.gov (United States)

    Tomey, Matthew I; Kini, Annapoorna S; Sharma, Samin K

    2014-04-01

    Rotational atherectomy facilitates percutaneous coronary intervention for complex de novo lesions with severe calcification. A strategy of routine rotational atherectomy has not, however, conferred reduction in restenosis or major adverse cardiac events. As it is technically demanding, rotational atherectomy is also uncommon. At this 25-year anniversary since the introduction of rotational atherectomy, we sought to review the current state-of-the-art in rotational atherectomy technique, safety, and efficacy data in the modern era of drug-eluting stents, strategies to prevent and manage complications, including slow-flow/no-reflow and burr entrapment, and appropriate use in the context of the broader evolution in the management of stable ischemic heart disease. Fundamental elements of optimal technique include use of a single burr with burr-to-artery ratio of 0.5 to 0.6-rotational speed of 140,000 to 150,000 rpm, gradual burr advancement using a pecking motion, short ablation runs of 15 to 20 s, and avoidance of decelerations >5,000 rpm. Combined with meticulous technique, optimal antiplatelet therapy, vasodilators, flush solution, and provisional use of atropine, temporary pacing, vasopressors, and mechanical support may prevent slow-flow/no-reflow, which in contemporary series is reported in 0.0% to 2.6% of cases. On the basis of the results of recent large clinical trials, a subset of patients with complex coronary artery disease previously assigned to rotational atherectomy may be directed instead to medical therapy alone or bypass surgery. For patients with de novo severely calcified lesions for which rotational atherectomy remains appropriate, referral centers of excellence are required. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Rotating Shadowband Spectroradiometer (RSS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kiedron, P; Schlemmer, J; Klassen, M

    2005-01-01

    The rotating shawdowband spectroradiometer (RSS) implements the same automated shadowbanding technique used by the multifilter rotating shadowband radiometer (MFRSR), and so it too provides spectrally-resolved, direct-normal, diffuse-horizontal, and total-horizontal irradiances, and can be calibrated in situ via Langley regression. The irradiance spectra are measured simultaneously at all spectral elements (pixels) in 360-nm to 1050-nm range.

  16. Faraday rotation measurements at Ootacamund

    Science.gov (United States)

    Sethia, G.; Chandra, H.; Deshpande, M. R.; Rastogi, R. G.

    1978-01-01

    The results of Faraday rotation measurements made at Ootacamund during ATS-6 phase II are presented. For summer and equinoctial months, even though no clear noon bite-out is observed in the variation of Faraday a decrease is observed in the rate of increase of rotation around 0900-1000 hours LT. This is attributed to the 'fountain effect' which is responsible for the noontime bite-out in F2-region peak electron density.

  17. Relaxation processes in rotational motion

    International Nuclear Information System (INIS)

    Broglia, R.A.

    1986-01-01

    At few MeV above the yrast line the normally strong correlations among γ-ray energies in a rotational sequence become weaker. This observation can be interpreted as evidence for the damping of rotational motion in hot nuclei. It seems possible to relate the spreading width of the E2-rotational decay strength to the spread in frequency Δω 0 of rotational bands. The origin of these fluctuations is found in: (1) fluctuations in the occupation of special single-particle orbits which contribute a significant part of the total angular momentum; and (2) fluctuations in the moment of inertia induced by vibrations of the nuclear shape. Estimates of Δω 0 done making use of the hundred-odd known discrete rotational bands in the rare-earth region lead, for moderate spin and excitation energies (I ≅ 30 and U ≅ 3 to 4 MeV), to rotational spreading widths of the order of 60 to 160 keV in overall agreement with the data. 24 refs

  18. The rotation of galaxy clusters

    International Nuclear Information System (INIS)

    Tovmassian, H.M.

    2015-01-01

    The method for detection of the galaxy cluster rotation based on the study of distribution of member galaxies with velocities lower and higher of the cluster mean velocity over the cluster image is proposed. The search for rotation is made for flat clusters with a/b> 1.8 and BMI type clusters which are expected to be rotating. For comparison there were studied also round clusters and clusters of NBMI type, the second by brightness galaxy in which does not differ significantly from the cluster cD galaxy. Seventeen out of studied 65 clusters are found to be rotating. It was found that the detection rate is sufficiently high for flat clusters, over 60 per cent, and clusters of BMI type with dominant cD galaxy, ≈ 35 per cent. The obtained results show that clusters were formed from the huge primordial gas clouds and preserved the rotation of the primordial clouds, unless they did not have mergings with other clusters and groups of galaxies, in the result of which the rotation has been prevented

  19. Generic cognitive adaptations to task interference in task switching

    NARCIS (Netherlands)

    Poljac, E.; Bekkering, H.

    2009-01-01

    The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing

  20. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lighting – Lighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...

  1. Evaluating low-resolution tomography neurofeedback by single dissociation of mental grotation task from stop signal task performance.

    Science.gov (United States)

    Getter, Nir; Kaplan, Zeev; Todder, Doron

    2015-10-01

    Electroencephalography source localization neurofeedback, i.e Standardized low-resolution tomography (sLORETA) neurofeedback are non-invasive method for altering region specific brain activity. This is an improvement over traditional neurofeedback which were based on recordings from a single scalp-electrode. We proposed three criteria clusters as a methodological framework to evaluate electroencephalography source localization neurofeedback and present relevant data. Our objective was to evaluate standardized low resolution EEG tomography neurofeedback by examining how training one neuroanatomical area effects the mental rotation task (which is related to the activity of bilateral Parietal regions) and the stop-signal test (which is related to frontal structures). Twelve healthy participants were enrolled in a single session sLORETA neurofeedback protocol. The participants completed both the mental rotation task and the stop-signal test before and after one sLORETA neurofeedback session. During sLORETA neurofeedback sessions participants watched one sitcom episode while the picture quality co-varied with activity in the superior parietal lobule. Participants were rewarded for increasing activity in this region only. Results showed a significant reaction time decrease and an increase in accuracy after sLORETA neurofeedback on the mental rotation task but not after stop signal task. Together with behavioral changes a significant activity increase was found at the left parietal brain after sLORETA neurofeedback compared with baseline. We concluded that activity increase in the parietal region had a specific effect on the mental rotation task. Tasks unrelated to parietal brain activity were unaffected. Therefore, sLORETA neurofeedback could be used as a research, or clinical tool for cognitive disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Contaminated sediment research task: SHC Task 3.61.3

    Science.gov (United States)

    A poster presentation for the SHC BOSC review will summarize the research efforts under Sustainable and Healthy Communities Research Program (SHC) in the Contaminated Sediment Task within the Contaminated Sites Project. For the Task, Problem Summary & Decision Context; Task O...

  3. Refueling system with small diameter rotatable plugs

    International Nuclear Information System (INIS)

    Ritz, W.C.

    1987-01-01

    This patent describes a liquid-metal fastbreeder nuclear reactor comprising a reactor pressure vessel and closure head therefor, a reactor core barrel disposed within the reactor vessel and enclosing a reactor core having therein a large number of closely spaced fuel assemblies, and the reactor core barrel and the reactor core having an approximately concentric circular cross-sectional configuration with a geometric center in predetermined location within the reactor vessel. The improved refueling system described here comprises: a large controllably rotatable plug means comprising the substantial portion of the closure head, a reactor upper internals structure mounted from the large rotatable plug means. The large rotatable plug means has an approximately circular configuration which approximates the cross-sectional configuration of the reactor core barrel with a center of rotation positioned a first predetermined distance from the geometric center of the reactor core barrel so that the large rotatable plug means rotates eccentrically with respect to the reactor core barrel; a small controllably rotatable plug means affixed to the large rotatable plug means and rotatable with respect thereto. The small rotatable plug means has a center of rotation which is offset a second predetermined distance from the rotational center of the large rotatable plug means so that the small rotatable plug means rotates eccentrically with respect to the large rotatable plug means

  4. Coordinated Control of Three-Dimensional Components of Smooth Pursuit to Rotating and Translating Textures.

    Science.gov (United States)

    Edinger, Janick; Pai, Dinesh K; Spering, Miriam

    2017-01-01

    The neural control of pursuit eye movements to visual textures that simultaneously translate and rotate has largely been neglected. Here we propose that pursuit of such targets-texture pursuit-is a fully three-dimensional task that utilizes all three degrees of freedom of the eye, including torsion. Head-fixed healthy human adults (n = 8) tracked a translating and rotating random dot pattern, shown on a computer monitor, with their eyes. Horizontal, vertical, and torsional eye positions were recorded with a head-mounted eye tracker. The torsional component of pursuit is a function of the rotation of the texture, aligned with its visual properties. We observed distinct behaviors between those trials in which stimulus rotation was in the same direction as that of a rolling ball ("natural") in comparison to those with the opposite rotation ("unnatural"): Natural rotation enhanced and unnatural rotation reversed torsional velocity during pursuit, as compared to torsion triggered by a nonrotating random dot pattern. Natural rotation also triggered pursuit with a higher horizontal velocity gain and fewer and smaller corrective saccades. Furthermore, we show that horizontal corrective saccades are synchronized with torsional corrective saccades, indicating temporal coupling of horizontal and torsional saccade control. Pursuit eye movements have a torsional component that depends on the visual stimulus. Horizontal and torsional eye movements are separated in the motor periphery. Our findings suggest that translational and rotational motion signals might be coordinated in descending pursuit pathways.

  5. Tokamak rotation and charge exchange

    International Nuclear Information System (INIS)

    Hazeltine, R.D.; Rowan, W.L.; Solano, E.R.; Valanju, P.M.

    1991-01-01

    In the absence of momentum input, tokamak toroidal rotation rates are typically small - no larger in particular than poloidal rotation - even when the radial electric field is strong, as near the plasma edge. This circumstance, contradicting conventional neoclassical theory, is commonly attributed to the rotation damping effect of charge exchange, although a detailed comparison between charge-exchange damping theory and experiment is apparently unavailable. Such a comparison is attempted here in the context of recent TEXT experiments, which compare rotation rates, both poloidal and toroidal, in helium and hydrogen discharges. The helium discharges provide useful data because they are nearly free of ion-neutral charge exchange; they have been found to rotate toroidally in reasonable agreement with neoclassical predictions. The hydrogen experiments show much smaller toroidal motion as usual. The theoretical calculation uses the full charge-exchange operator and assumes plateau collisionality, roughly consistent with the experimental conditions. The authors calculate the ion flow as a function of v cx /v c , where v cx is the charge exchange rate and v c the Coulomb collision frequency. The results are in reasonable accord with the observations. 1 ref

  6. The structure of rotational discontinuities

    International Nuclear Information System (INIS)

    Neugebauer, M.

    1989-01-01

    This study examines the structures of a set of rotational discontinuities detected in the solar wind by the ISEE-3 spacecraft. It is found that the complexity of the structure increases as the angle θ between the propagation vector k and the magnetic field decreases. For rotational discontinuities that propagate at a large angle to the field with an ion (left-hand) sense of rotation, the magnetic hodograms tend to be flattened, in agreement with prior numerical simulations. When θ is large, angular overshoots are often observed at one or both ends of the discontinuity. When the propagation is nearly parallel to the field (i.e., when θ is small), many different types of structure are seen, ranging from straight lines, the S-shaped curves, to complex, disorganized shapes

  7. Motions on a rotating planet

    Science.gov (United States)

    Schröer, H.

    In chapter 1 we want to describe the motion of a falling body on a rotating planet. The planet rotates with an arbitrary changable angular velocity and has a translational acceleration. We obtain 3 differential equations. For the general gravitational field an exact solution is possible, when the differential equation system is explicit solvable. Then we consider the case, if the angular velocity and the translational acceleration is constant. With a special transformation we get 3 partial differential equations of first order. Instead of a planet sphere we can choose a general body of rotation. Even general bodies are possible. Chapter 2 contains the motion in a local coordinate system on planet's surface. We have an inhomogeneous linear differential equation of first order. If the angular velocity is constant, we get a system with constant coefficients. There is an english and a german edition.

  8. Absence of sex differences in mental rotation performance in autism spectrum disorder.

    Science.gov (United States)

    Rohde, Melanie S; Georgescu, Alexandra L; Vogeley, Kai; Fimmers, Rolf; Falter-Wagner, Christine M

    2017-08-01

    Mental rotation is one of the most investigated cognitive functions showing consistent sex differences. The 'Extreme Male Brain' hypothesis attributes the cognitive profile of individuals with autism spectrum disorder to an extreme version of the male cognitive profile. Previous investigations focused almost exclusively on males with autism spectrum disorder with only limited implications for affected females. This study is the first testing a sample of 12 female adults with high-functioning autism spectrum disorder compared to 14 males with autism spectrum disorder, 12 typically developing females and 14 typically developing males employing a computerised version of the mental rotation test. Reaction time and accuracy served as dependent variables. Their linear relationship with degree of rotation allows separation of rotational aspects of the task, indicated by slopes of the psychometric function, and non-rotational aspects, indicated by intercepts of the psychometric function. While the typical and expected sex difference for rotational task aspects was corroborated in typically developing individuals, no comparable sex difference was found in autism spectrum disorder individuals. Autism spectrum disorder and typically developing individuals did not differ in mental rotation performance. This finding does not support the extreme male brain hypothesis of autism.

  9. Sequence-dependent rotation axis changes and interaction torque use in overarm throwing.

    Science.gov (United States)

    Hansen, Clint; Rezzoug, Nasser; Gorce, Philippe; Venture, Gentiane; Isableu, Brice

    2016-01-01

    We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal-external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder-centre of mass axis and the shoulder-elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs' rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder-elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release.

  10. Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

    Science.gov (United States)

    Lien, Mei-Ching; Ruthruff, Eric

    2004-01-01

    This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

  11. Rotated balance in humans due to repetitive rotational movement

    Science.gov (United States)

    Zakynthinaki, M. S.; Madera Milla, J.; López Diaz De Durana, A.; Cordente Martínez, C. A.; Rodríguez Romo, G.; Sillero Quintana, M.; Sampedro Molinuevo, J.

    2010-03-01

    We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

  12. Mach's principle and rotating universes

    International Nuclear Information System (INIS)

    King, D.H.

    1990-01-01

    It is shown that the Bianchi 9 model universe satisfies the Mach principle. These closed rotating universes were previously thought to be counter-examples to the principle. The Mach principle is satisfied because the angular momentum of the rotating matter is compensated by the effective angular momentum of gravitational waves. A new formulation of the Mach principle is given that is based on the field theory interpretation of general relativity. Every closed universe with 3-sphere topology is shown to satisfy this formulation of the Mach principle. It is shown that the total angular momentum of the matter and gravitational waves in a closed 3-sphere topology universe is zero

  13. Robot task space analyzer

    International Nuclear Information System (INIS)

    Hamel, W.R.; Osborn, J.

    1997-01-01

    Many nuclear projects such as environmental restoration and waste management challenges involve radiation or other hazards that will necessitate the use of remote operations that protect human workers from dangerous exposures. Remote work is far more costly to execute than what workers could accomplish directly with conventional tools and practices because task operations are slow and tedious due to difficulties of remote manipulation and viewing. Decades of experience within the nuclear remote operations community show that remote tasks may take hundreds of times longer than hands-on work; even with state-of-the-art force- reflecting manipulators and television viewing, remote task performance execution is five to ten times slower than equivalent direct contact work. Thus the requirement to work remotely is a major cost driver in many projects. Modest improvements in the work efficiency of remote systems can have high payoffs by reducing the completion time of projects. Additional benefits will accrue from improved work quality and enhanced safety

  14. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    by shared goals and knowledge as well as mutual respect and frequent, timely, accurate and problem-solving ways of communication with the purpose of dealing with the tasks at hand in an integrated way. We introduce and discuss relational coordination theory through a case-study within public healthcare....... Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  15. NH3 quantum rotators in Hofmann clathrates: intensity and width of rotational transition lines

    International Nuclear Information System (INIS)

    Vorderwisch, Peter; Sobolev, Oleg; Desmedt, Arnaud

    2004-01-01

    Inelastic structure factors for rotational transitions of uniaxial NH 3 quantum rotators, measured in a Hofmann clathrate with biphenyl as guest molecule, agree with those calculated for free rotators. A finite intrinsic line width, found for rotational transitions involving the rotational level j=3 at low temperature, supports a recently suggested model based on resonant rotor-rotor coupling

  16. Mental rotation and the motor system: embodiment head over heels.

    Science.gov (United States)

    Krüger, Markus; Amorim, Michel-Ange; Ebersbach, Mirjam

    2014-01-01

    We examined whether body parts attached to abstract stimuli automatically force embodiment in a mental rotation task. In Experiment 1, standard cube combinations reflecting a human pose were added with (1) body parts on anatomically possible locations, (2) body parts on anatomically impossible locations, (3) colored end cubes, and (4) simple end cubes. Participants (N=30) had to decide whether two simultaneously presented stimuli, rotated in the picture plane, were identical or not. They were fastest and made less errors in the possible-body condition, but were slowest and least accurate in the impossible-body condition. A second experiment (N=32) replicated the results and ruled out that the poor performance in the impossible-body condition was due to the specific stimulus material. The findings of both experiments suggest that body parts automatically trigger embodiment, even when it is counterproductive and dramatically impairs performance, as in the impossible-body condition. It can furthermore be concluded that body parts cannot be used flexibly for spatial orientation in mental rotation tasks, compared to colored end cubes. Thus, embodiment appears to be a strong and inflexible mechanism that may, under certain conditions, even impede performance. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  18. Rotation of White Dwarf Stars

    OpenAIRE

    Kawaler, Steven D.

    2014-01-01

    I discuss and consider the status of observational determinations of the rotation velocities of white dwarf stars via asteroseismology and spectroscopy. While these observations have important implications on our understanding of the angular momentum evolution of stars in their late stages of evolution, more direct methods are sorely needed to disentangle ambiguities.

  19. Rotational damping motion in nuclei

    International Nuclear Information System (INIS)

    Egido, J.L.; Faessler, A.

    1991-01-01

    The recently proposed model to explain the mechanism of the rotational motion damping in nuclei is exactly solved. When compared with the earlier approximative solution, we find significative differences in the low excitation energy limit (i.e. Γ μ 0 ). For the strength functions we find distributions going from the Wigner semicircle through gaussians to Breit-Wigner shapes. (orig.)

  20. Rotation in a gravitational billiard

    Science.gov (United States)

    Peraza-Mues, G. G.; Carvente, Osvaldo; Moukarzel, Cristian F.

    Gravitational billiards composed of a viscoelastic frictional disk bouncing on a vibrating wedge have been studied previously, but only from the point of view of their translational behavior. In this work, the average rotational velocity of the disk is studied under various circumstances. First, an experimental realization is briefly presented, which shows sustained rotation when the wedge is tilted. Next, this phenomenon is scrutinized in close detail using a precise numerical implementation of frictional forces. We show that the bouncing disk acquires a spontaneous rotational velocity whenever the wedge angle is not bisected by the direction of gravity. Our molecular dynamics (MD) results are well reproduced by event-driven (ED) simulations. When the wedge aperture angle θW>π/2, the average tangential velocity Rω¯ of the disk scales with the typical wedge vibration velocity vb, and is in general a nonmonotonic function of the overall tilt angle θT of the wedge. The present work focuses on wedges with θW=2π/3, which are relevant for the problem of spontaneous rotation in vibrated disk packings. This study makes part of the PhD Thesis of G. G. Peraza-Mues.

  1. Visual and Haptic Mental Rotation

    Directory of Open Access Journals (Sweden)

    Satoshi Shioiri

    2011-10-01

    Full Text Available It is well known that visual information can be retained in several types of memory systems. Haptic information can also be retained in a memory because we can repeat a hand movement. There may be a common memory system for vision and action. On the one hand, it may be convenient to have a common system for acting with visual information. On the other hand, different modalities may have their own memory and use retained information without transforming specific to the modality. We compared memory properties of visual and haptic information. There is a phenomenon known as mental rotation, which is possibly unique to visual representation. The mental rotation is a phenomenon where reaction time increases with the angle of visual target (eg,, a letter to identify. The phenomenon is explained by the difference in time to rotate the representation of the target in the visual sytem. In this study, we compared the effect of stimulus angle on visual and haptic shape identification (two-line shapes were used. We found that a typical effect of mental rotation for the visual stimulus. However, no such effect was found for the haptic stimulus. This difference cannot be explained by the modality differences in response because similar difference was found even when haptical response was used for visual representation and visual response was used for haptic representation. These results indicate that there are independent systems for visual and haptic representations.

  2. A rotating arc plasma invertor

    International Nuclear Information System (INIS)

    Reusch, M.F.; Jayaram, K.

    1987-02-01

    A device is described for the inversion of direct current to alternating current. The main feature is the use of a rotating plasma arc in crossed electric and magnetic fields as a switch. This device may provide an economic alternative to other inversion methods in some circumstances

  3. Ultrasonography of the Rotator Cuff

    International Nuclear Information System (INIS)

    Yoon, Yong Cheol

    2006-01-01

    The ultrasonography (US) is an important modality in evaluating shoulder disease. It is accurate in diagnosing the various shoulder diseases including tendinosis, calcific tendinitis, and subacromial bursitis as well as rotator cuff tears. This article presents a pictorial review of US anatomy of the shoulder, the technical aspects of shoulder US, major types of shoulder pathology, and interventional procedure under US guidance

  4. Ultrasonography of the Rotator Cuff

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yong Cheol [Samsung Medica Center, Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

    2006-09-15

    The ultrasonography (US) is an important modality in evaluating shoulder disease. It is accurate in diagnosing the various shoulder diseases including tendinosis, calcific tendinitis, and subacromial bursitis as well as rotator cuff tears. This article presents a pictorial review of US anatomy of the shoulder, the technical aspects of shoulder US, major types of shoulder pathology, and interventional procedure under US guidance

  5. Rotations in a Vertebrate Setting

    Science.gov (United States)

    McCollum, Gin

    2003-05-01

    Rotational movements of the head are often considered to be measured in a single three dimensional coordinate system implemented by the semicircular canals of the vestibular system of the inner ear. However, the vertebrate body -- including the nervous system -- obeys rectangular symmetries alien to rotation groups. At best, nervous systems mimic the physical rotation group in a fragmented way, only partially reintegrating physical movements in whole organism responses. The vestibular canal reference frame is widely used in nervous systems, for example by eye movements. It is used to some extent even in the cerebrum, as evidenced by the remission of hemineglect -- in which half of space is ignored -- when the vestibular system is stimulated. However, reintegration of space by the organism remains incomplete. For example, compensatory eye movements (which in most cases aid visual fixation) may disagree with conscious self-motion perception. In addition, movement-induced nausea, illusions, and cue-free perceptions demonstrate symmetry breaking or incomplete spatial symmetries. As part of a long-term project to investigate rotation groups in nervous systems, we have analyzed the symmetry group of a primary vestibulo-spinal projection.

  6. Synchrotron Radiation and Faraday Rotation

    NARCIS (Netherlands)

    Heald, George

    2015-01-01

    Synchrotron radiation and its degree of linear polarization are powerful tracers of magnetic fields that are illuminated by cosmic ray electrons. Faraday rotation of the linearly polarized radiation is induced by intervening line-of-sight magnetic fields that are embedded in ionized plasmas. For

  7. Black hole vacua and rotation

    International Nuclear Information System (INIS)

    Krishnan, Chethan

    2011-01-01

    Recent developments suggest that the near-region of rotating black holes behaves like a CFT. To understand this better, I propose to study quantum fields in this region. An instructive approach for this might be to put a large black hole in AdS and to think of the entire geometry as a toy model for the 'near-region'. Quantum field theory on rotating black holes in AdS can be well-defined (unlike in flat space), if fields are quantized in the co-rotating-with-the-horizon frame. First, some generalities of constructing Hartle-Hawking Green functions in this approach are discussed. Then as a specific example where the details are easy to handle, I turn to 2+1 dimensions (BTZ), write down the Green functions explicitly starting with the co-rotating frame, and observe some structural similarities they have with the Kerr-CFT scattering amplitudes. Finally, in BTZ, there is also an alternate construction for the Green functions: we can start from the covering AdS 3 space and use the method of images. Using a 19th century integral formula, I show the equality between the boundary correlators arising via the two constructions.

  8. Perturbative treatment of nuclear rotations

    International Nuclear Information System (INIS)

    Civitarese, O.

    1980-01-01

    In this work, it is described the case corresponding to perturbative quantum treatment of a fermion system in free rotation and the divergences which resulted from the 'break' in symmetry, associated by the adoption of a deformed basis as a non pertubed solution. (A.C.A.S.) [pt

  9. Meniscus Stability in Rotating Systems

    Science.gov (United States)

    Reichel, Yvonne; Dreyer, Michael

    2013-11-01

    In this study, the stability of free surfaces of fluid between two rotating coaxial, circular disks is examined. Radially mounted baffles are used to form menisci of equal size. To the center of the upper disk, a tube is connected in which a separate meniscus is formed. Assuming solid-body rotation and ignoring dynamic effects, it is observed that the free surfaces between the disks fail to remain stable once the rotation speed exceeds a critical value. In other words, Rayleigh-Taylor instability ensues when the capillary forces fail to balance centrifugal forces. Dimensionless critical rotation speeds are studied by means of the Surface Evolver via SE-FIT for varied number of baffles, the normalized distance between the disks, and the normalized central tube radius. Drop tower tests are performed to confirm some of the numerical results. The computation also reveals that there are different modes of instability as a function of the relevant parameters. This study was funded by the space agency of the German Aerospace Center with resources of the Federal Ministry of Economics and Technology on the basis of a resolution of the German Bundestag under grant number 50 RL 1320.

  10. Data Center Tasking.

    Science.gov (United States)

    Temares, M. Lewis; Lutheran, Joseph A.

    Operations tasking for data center management is discussed. The original and revised organizational structures of the data center at the University of Miami are also described. The organizational strategy addresses the functions that should be performed by the data center, anticipates the specialized skills required, and addresses personnel…

  11. Biomedical applications engineering tasks

    Science.gov (United States)

    Laenger, C. J., Sr.

    1976-01-01

    The engineering tasks performed in response to needs articulated by clinicians are described. Initial contacts were made with these clinician-technology requestors by the Southwest Research Institute NASA Biomedical Applications Team. The basic purpose of the program was to effectively transfer aerospace technology into functional hardware to solve real biomedical problems.

  12. India's Unfinished Telecom Tasks

    Indian Academy of Sciences (India)

    India's Telecom Story is now well known · Indian Operators become an enviable force · At the same time · India Amongst the Leaders · Unfinished Tasks as Operators · LightGSM ON: Innovation for Rural Area from Midas · Broadband Access Options for India · Broadband driven by DSL: still too slow · Is Wireless the answer?

  13. Aerial Rotation Effects on Vertical Jump Performance Among Highly Skilled Collegiate Soccer Players.

    Science.gov (United States)

    Barker, Leland A; Harry, John R; Dufek, Janet S; Mercer, John A

    2017-04-01

    Barker, LA, Harry, JR, Dufek, JS, and Mercer, JA. Aerial rotation effects on vertical jump performance among highly skilled collegiate soccer players. J Strength Cond Res 31(4): 932-938, 2017-In soccer matches, jumps involving rotations occur when attempting to head the ball for a shot or pass from set pieces, such as corner kicks, goal kicks, and lob passes. However, the 3-dimensional ground reaction forces used to perform rotational jumping tasks are currently unknown. Therefore, the purpose of this study was to compare bilateral, 3-dimensional, and ground reaction forces of a standard countermovement jump (CMJ0) with those of a countermovement jump with a 180° rotation (CMJ180) among Division-1 soccer players. Twenty-four participants from the soccer team of the University of Nevada performed 3 trials of CMJ0 and CMJ180. Dependent variables included jump height, downward and upward phase times, vertical (Fz) peak force and net impulse relative to mass, and medial-lateral and anterior-posterior force couple values. Statistical significance was set a priori at α = 0.05. CMJ180 reduced jump height, increased the anterior-posterior force couple in the downward and upward phases, and increased upward peak Fz (p ≤ 0.05). All other variables were not significantly different between groups (p > 0.05). However, we did recognize that downward peak Fz trended lower in the CMJ0 condition (p = 0.059), and upward net impulse trended higher in the CMJ0 condition (p = 0.071). It was concluded that jump height was reduced during the rotational jumping task, and rotation occurred primarily via AP ground reaction forces through the entire countermovement jump. Coaches and athletes may consider additional rotational jumping in their training programs to mediate performance decrements during rotational jump tasks.

  14. Structure of molecules and internal rotation

    CERN Document Server

    Mizushima, San-Ichiro

    1954-01-01

    Structure of Molecules and Internal Rotation reviews early studies on dihalogenoethanes. This book is organized into two parts encompassing 8 chapters that evaluate the Raman effect in ethane derivatives, the energy difference between rotational isomers, and the infrared absorption of ethane derivatives. Some of the topics covered in the book are the potential barrier to internal rotation; nature of the hindering potential; entropy difference between the rotational isomers; internal rotation in butane, pentane, and hexane; and internal rotation in long chain n-paraffins. Other chapters deal wi

  15. Wave-Driven Rotation In Centrifugal Mirrors

    International Nuclear Information System (INIS)

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2011-01-01

    Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

  16. An electrophysiological study of the mental rotation of polygons.

    Science.gov (United States)

    Pierret, A; Peronnet, F; Thevenet, M

    1994-05-09

    Reaction times and event-related potentials (ERPs) were recorded during a task requiring subjects to decide whether two sequentially presented polygons had the same shape regardless of differences in orientation. Reaction times increased approximately linearly with angular departure from upright orientation, which suggests that mental rotation was involved in the comparison process. The ERPs showed, between 665 and 1055 ms, a late posterior negativity also increasing with angular disparity from upright, which we assumed to reflect mental rotation. Two other activities were exhibited, from 265 to 665 ms, which may be related either to an evaluation of the stimulus or a predetermination of its orientation, and from 1055 to 1600 ms attributed to the decision process.

  17. Magneto-rotational instability in differentially rotating liquid metals

    International Nuclear Information System (INIS)

    Velikhov, E.P.; Ivanov, A.A.; Lakhin, V.P.; Serebrennikov, K.S.

    2006-01-01

    We study the stability of Couette flow between two cylinders in the presence of axial magnetic field in local WKB approximation. We find the analytical expression of the critical angular velocity minimized over the wave number and the imposed magnetic field as a function of the measure of deviation of the rotation law from the Rayleigh line. The result found is in a good agreement with the previously known numerical results based on the global analysis. We perform a minimization of the critical Reynolds number over the wave number at fixed magnetic field both analytically and numerically. We show that a compromise between resistive suppression of magneto-rotational instability at weak magnetic field and the increase of the critical Reynolds number with the increase of magnetic field is possible. It takes place at moderate values of magnetic field of order 3x10 2 gauss giving the critical Reynolds number of order 4x10 4

  18. Microprocessor multi-task monitor

    International Nuclear Information System (INIS)

    Ludemann, C.A.

    1983-01-01

    This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond

  19. Rapidly rotating general relativistic stars. Pt. 2. Differentially rotating polytropes

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Hidemi [Tokyo Univ. (Japan). Faculty of Science; Eriguchi, Yoshiharu [Tokyo Univ. (Japan). Dept. of Astronomy; Hachisu, Izumi [Kyoto Univ. (Japan). Dept. of Aeronautical Engineering

    1989-07-01

    We have applied the numerical method which was developed for Newtonian gravity to general relativistic, differentially rotating bodies including ring-like structures. A number of equilibrium structures are obtained for two different polytropic indices N=1/2 and N=3/2, because the various proposed equations of state for the nuclear density region fall into the range N=1/2 to 3/2 from the viewpoint of its softness. (author).

  20. Task Force report

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The International Task Force on Prevention of Nuclear Terrorism was formed in 1985 under the auspices of the Nuclear Control Institute. This report is a consensus report of the 26 task force members - all members not necessarily agreeing on every point and all wordings, but in each case a substantial majority did agree. First, the report defines the threat, then establishes the priorities. Short-term recommendations are presented on: (1) protecting nuclear weapons; (2) protecting nuclear materials; (3) protecting nuclear facilities; (4) intelligence programs; (5) civil liberties concerns; (6) controlling nuclear transfers; (7) US - Soviet cooperation; (8) arms control initiatives; (9) convention of physical protection of nuclear material; (10) role of emergency management programs; and (11) role of the media. Brief long-term recommendations are included on (1) international measures, and (2) emerging nuclear technologies. An Appendix, Production of Nuclear Materials Usable in Weapons is presented for further consideration (without recommendations)

  1. Rostering and Task Scheduling

    DEFF Research Database (Denmark)

    Dohn, Anders Høeg

    . The rostering process is non-trivial and especially when service is required around the clock, rostering may involve considerable effort from a designated planner. Therefore, in order to minimize costs and overstaffing, to maximize the utilization of available staff, and to ensure a high level of satisfaction...... as possible to the available staff, while respecting various requirements and rules and while including possible transportation time between tasks. This thesis presents a number of industrial applications in rostering and task scheduling. The applications exist within various contexts in health care....... Mathematical and logic-based models are presented for the problems considered. Novel components are added to existing models and the modeling decisions are justified. In one case, the model is solved by a simple, but efficient greedy construction heuristic. In the remaining cases, column generation is applied...

  2. The task force process

    International Nuclear Information System (INIS)

    Applegate, J.S.

    1995-01-01

    This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several open-quotes big pictureclose quotes issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald

  3. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  4. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  5. LHCb computing tasks

    CERN Document Server

    Binko, P

    1998-01-01

    This document describes the computing tasks of the LHCb computing system. It also describes the logistics of the dataflow between the tasks and the detailed requirements for each task, in particular the data sizes and CPU power requirements. All data sizes are calculated assuming that the LHCb experiment will take data about 107 s per year at a frequency of 200 Hz, which gives 2 \\Theta 109 real events per year. The raw event size should not exceed 100 kB (200 TB per year). We will have to generate about 109 MonteCarlo events per year. The current MonteCarlo simulation program based on the GEANT3.21 package requires about 12 s to produce an average event (all CPU times are normalised to a 1000 MIPS processor). The size of an average MonteCarlo event will be about 200 kB (100 TB per year) of simulated data (without the hits). We will start to use the GEANT4 package in 1998. Rejection factors of 8 and 25 are required in the Level-2 and Level-3 triggers respectively, to reduce the frequency of events to 200 Hz. T...

  6. Development of coaxial rotating-plasma gun

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Tanabe, Toshio; Mase, Hiroshi

    1985-01-01

    A rotating-plasma gun has been devised to produce plasma streams with higher rotational velocities. The working mechanism of the gun and the results of a preliminary experiment have been described. (author)

  7. SEG Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert; Laughlin, Darren; Brune, Bob

    2016-10-17

    Significant advancements in the development of sensors to enable rotational seismic measurements have been achieved. Prototypes are available now to support experiments that help validate the utility of rotational seismic measurements.

  8. Learning Rotation for Kernel Correlation Filter

    KAUST Repository

    Hamdi, Abdullah; Ghanem, Bernard

    2017-01-01

    . This paper tries to tackle the problem of rotation by reformulating the optimization problem for learning the correlation filter. This modification (RKCF) includes learning rotation filter that utilizes circulant structure of HOG feature to guesstimate

  9. Aerospike Nozzle for Rotating Detonation Engine Application

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents a graduate MS research thesis on improving the efficiency of rotating detonation engines by using aerospike nozzle technologies. A rotating...

  10. Transformation of Real Spherical Harmonics under Rotations

    Science.gov (United States)

    Romanowski, Z.; Krukowski, St.; Jalbout, A. F.

    2008-08-01

    The algorithm rotating the real spherical harmonics is presented. The convenient and ready to use formulae for l = 0, 1, 2, 3 are listed. The rotation in R3 space is determined by the rotation axis and the rotation angle; the Euler angles are not used. The proposed algorithm consists of three steps. (i) Express the real spherical harmonics as the linear combination of canonical polynomials. (ii) Rotate the canonical polynomials. (iii) Express the rotated canonical polynomials as the linear combination of real spherical harmonics. Since the three step procedure can be treated as a superposition of rotations, the searched rotation matrix for real spherical harmonics is a product of three matrices. The explicit formulae of matrix elements are given for l = 0, 1, 2, 3, what corresponds to s, p, d, f atomic orbitals.

  11. Task analysis and support for problem solving tasks

    International Nuclear Information System (INIS)

    Bainbridge, L.

    1987-01-01

    This paper is concerned with Task Analysis as the basis for ergonomic design to reduce human error rates, rather than for predicting human error rates. Task Analysis techniques usually provide a set of categories for describing sub tasks, and a framework describing the relations between sub-tasks. Both the task type categories and their organisation have implications for optimum interface and training design. In this paper, the framework needed for considering the most complex tasks faced by operators in process industries is discussed such as fault management in unexpected situations, and what is likely to minimise human error in these circumstances. (author)

  12. Rotational effects on impingement cooling

    Science.gov (United States)

    Epstein, A. H.; Kerrebrock, J. L.; Koo, J. J.; Preiser, U. Z.

    1987-01-01

    The present consideration of rotation effects on heat transfer in a radially exhausted, impingement-cooled turbine blade model gives attention to experimental results for Reynolds and Rossby numbers and blade/coolant temperature ratio values that are representative of small gas turbine engines. On the basis of a model that encompasses the effects of Coriolis force and buoyancy on heat transfer, bouyancy is identified as the cause of an average Nusselt number that is 20-30 percent lower than expected from previous nonrotating data. A heuristic model is proposed which predicts that the impingement jets nearest the blade roots should deflect inward, due to a centripetal force generated by their tangential velocity counter to the blade motion. Potentially serious thermal stresses must be anticipated from rotation effects in the course of blade design.

  13. Secular stability of rotating stars

    International Nuclear Information System (INIS)

    Imamura, J.N.; Friedman, J.L.; Durisen, R.H.

    1984-01-01

    In this work, we calculate the secular stability limits of rotating polytropes to nonaxisymmetric perturbations of low m. We consider polytropic indices ranging from 1 to 3 and several angular momentum distributions. Results are most conveniently presented in terms of the t-parameter, defined as the ratio of the rotational kinetic energy to the absolute value of the gravitational energy of the fluid. Previous work on polytropes considered only the m = 2 mode, which is unstable for values of the t-parameter greater than 0.14 +- 0.01 for the n values n = 1.5 and 3 and the angular momentum distributions tested (see Durisen and Imamura 1981). The GRR secular stability limit of the m = 2 mode for the Maclaurin spheroids (n = O) was determined by Chandrasekhar (1970). GRR stability limits of higher m modes for the Maclaurin spheroids were located approximately by Comins (1979a,b) and more precisely by Friedman (1983)

  14. Tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  15. Understand rotating isothermal collapses yet

    International Nuclear Information System (INIS)

    Tohline, J.E.

    1985-01-01

    A scalar virial equation is used to describe the dynamic properties of equilibrium gas clouds, taking into account the relative effects of surface pressure, rotation, self gravity and internal isothermal pressure. Details concerning the internal structure of the clouds are ignored in order to obtain a globalized analytical expression. The obtained solution to the equation is found to agree with the surface-pressure-dominated model of Stahler (1983), and the rotation-dominated model of Hayashi, Narita, and Miyama (1982). On the basis of the analytical expression of virial equilibrium in the clouds, some of the limiting properties of isothermal clouds are described, and a realistic starting model for cloud collapse is proposed. 18 references

  16. MHD equilibrium with toroidal rotation

    International Nuclear Information System (INIS)

    Li, J.

    1987-03-01

    The present work attempts to formulate the equilibrium of axisymmetric plasma with purely toroidal flow within ideal MHD theory. In general, the inertial term Rho(v.Del)v caused by plasma flow is so complicated that the equilibrium equation is completely different from the Grad-Shafranov equation. However, in the case of purely toroidal flow the equilibrium equation can be simplified so that it resembles the Grad-Shafranov equation. Generally one arbitrary two-variable functions and two arbitrary single variable functions, instead of only four single-variable functions, are allowed in the new equilibrium equations. Also, the boundary conditions of the rotating (with purely toroidal fluid flow, static - without any fluid flow) equilibrium are the same as those of the static equilibrium. So numerically one can calculate the rotating equilibrium as a static equilibrium. (author)

  17. Effects of noise and task loading on a communication task loading on a communication task

    Science.gov (United States)

    Orrell, Dean H., II

    Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

  18. Rotation Covariant Image Processing for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Henrik Skibbe

    2013-01-01

    Full Text Available With the advent of novel biomedical 3D image acquisition techniques, the efficient and reliable analysis of volumetric images has become more and more important. The amount of data is enormous and demands an automated processing. The applications are manifold, ranging from image enhancement, image reconstruction, and image description to object/feature detection and high-level contextual feature extraction. In most scenarios, it is expected that geometric transformations alter the output in a mathematically well-defined manner. In this paper we emphasis on 3D translations and rotations. Many algorithms rely on intensity or low-order tensorial-like descriptions to fulfill this demand. This paper proposes a general mathematical framework based on mathematical concepts and theories transferred from mathematical physics and harmonic analysis into the domain of image analysis and pattern recognition. Based on two basic operations, spherical tensor differentiation and spherical tensor multiplication, we show how to design a variety of 3D image processing methods in an efficient way. The framework has already been applied to several biomedical applications ranging from feature and object detection tasks to image enhancement and image restoration techniques. In this paper, the proposed methods are applied on a variety of different 3D data modalities stemming from medical and biological sciences.

  19. Gender Difference Does Not Mean Genetic Difference: Externalizing Improves Performance in Mental Rotation

    Science.gov (United States)

    Moe, Angelica

    2012-01-01

    The fear of underperforming owing to stereotype threat affects women's performance in tasks such as mathematics, chess, and spatial reasoning. The present research considered mental rotation and explored effects on performance and on regulatory focus of instructions pointing to different explanations for gender differences. Two hundred and one…

  20. Muon spin rotation in superconductors

    International Nuclear Information System (INIS)

    Gladisch, M.; Orth, H.; Putlitz, G. zu; Wahl, W.; Wigand, M.; Herlach, D.; Seeger, A.; Metz, H.; Teichler, H.

    1979-01-01

    By means of the muon spin rotation technique (μ + SR), the temperature dependence of the magnetic field inside the normal-conducting domains of high-purity tantalum crystals in the intermediate state has been measured in the temperature range 2.36 K + SR. Possible applications of these findings to the study of long-range diffusion of positive muons at low temperatures are indicated. (Auth.)

  1. Rotation of a Moonless Earth

    Science.gov (United States)

    Lissauer, Jack J.; Barnes, Jason W.; Chambers, John E.

    2013-01-01

    We numerically explore the obliquity (axial tilt) variations of a hypothetical moonless Earth. Previous work has shown that the Earth's Moon stabilizes Earth's obliquity such that it remains within a narrow range, between 22.1 deg and 24.5 deg. Without lunar influence, a frequency-map analysis by Laskar et al. showed that the obliquity could vary between 0 deg. and 85 deg. This has left an impression in the astrobiology community that a large moon is necessary to maintain a habitable climate on an Earth-like planet. Using a modified version of the orbital integrator mercury, we calculate the obliquity evolution for moonless Earths with various initial conditions for up to 4 Gyr. We find that while obliquity varies significantly more than that of the actual Earth over 100,000 year timescales, the obliquity remains within a constrained range, typically 20-25 deg. in extent, for timescales of hundreds of millions of years. None of our Solar System integrations in which planetary orbits behave in a typical manner show obliquity accessing more than 65% of the full range allowed by frequency-map analysis. The obliquities of moonless Earths that rotate in the retrograde direction are more stable than those of pro-grade rotators. The total obliquity range explored for moonless Earths with rotation periods shorter than 12 h is much less than that for slower-rotating moonless Earths. A large moon thus does not seem to be needed to stabilize the obliquity of an Earth-like planet on timescales relevant to the development of advanced life.

  2. Fluctuation analysis of rotational spectra

    International Nuclear Information System (INIS)

    Doessing, T.; Bracco, A.; Broglia, R.A.; Matsuo, M.

    1996-01-01

    The compound state rotational degree of freedom is ''damped'' in the sense that the electric quadrupole decay of a single quantum state with angular momentum I exhibits a spectrum of final states all having spin I-2. In actual experiments, the cascade of γ-rays associated with each of the members of the ensemble of compound nuclei uses each of the ''discrete'' transitions many more times than the ''continuum'' transitions. Relatively large and small fluctuations in the recorded coincidence spectrum ensue, respectively. The analysis of the fluctuations will be shown to be instrumental to gain insight into the phenomenon of rotational damping. For this purpose, two- and higher-fold coincidence spectra emitted from rotating nuclei are analyzed with respect to the count fluctuations. The coincidences from consecutive γ-rays emitted from discrete rotational bands generate ridges in the E γ1 .E γ2 spectrum, and the fluctuation analysis of the ridges is based upon the ansatz of a random selection of transition energies from band to band. This ansatz is supported by a cranked mean-field calculation for the nucleus 168 Yb, as well as by analyzing resolved bands in 168 Yb and its neighbors. The fluctuation analysis of the central valley (E γ1 =E γ2 ) is based upon the ansatz of fluctuations in the intensity of the transitions of Porter-Thomas type superposed on a smooth spectrum of transition energies. This ansatz is again supported by a mixed-band calculation. The mathematical treatment of count fluctuations is formulated in general (orig.)

  3. Rotational Symmetry Breaking in Baby Skyrme Models

    Science.gov (United States)

    Karliner, Marek; Hen, Itay

    We discuss one of the most interesting phenomena exhibited by baby skyrmions - breaking of rotational symmetry. The topics we will deal with here include the appearance of rotational symmetry breaking in the static solutions of baby Skyrme models, both in flat as well as in curved spaces, the zero-temperature crystalline structure of baby skyrmions, and finally, the appearance of spontaneous breaking of rotational symmetry in rotating baby skyrmions.

  4. Exact solutions for rotating charged dust

    International Nuclear Information System (INIS)

    Islam, J.N.

    1984-01-01

    Earlier work by the author on rotating charged dust is summarized. An incomplete class of exact solutions for differentially rotating charged dust in Newton-Maxwell theory for the equal mass and charge case that was found earlier is completed. A new global exact solution for cylindrically symmetric differentially rotating charged dust in Newton-Maxwell theory is presented. Lastly, a new exact solution for cylindrically symmetric rigidly rotating charged dust in general relativity is given. (author)

  5. Optical illusions induced by rotating medium

    Science.gov (United States)

    Zang, XiaoFei; Huang, PengCheng; Zhu, YiMing

    2018-03-01

    Different from the traditional single-function electromagnetic wave rotators (rotate the electromagnetic wavefronts), we propose that rotating medium can be extended to optical illusions such as breaking the diffraction limit and overlapping illusion. Furthermore, the homogeneous but anisotropic rotating medium is simplified by homogeneous and isotropic positive-index materials according to the effective medium theory, which is helpful for future device fabrication. Finite element simulations for the two-dimensional case are performed to demonstrate these properties.

  6. Rotation, Reflection, and Frame Changes; Orthogonal tensors in computational engineering mechanics

    Science.gov (United States)

    Brannon, R. M.

    2018-04-01

    Whilst vast literature is available for the most common rotation-related tasks such as coordinate changes, most reference books tend to cover one or two methods, and resources for less-common tasks are scarce. Specialized research applications can be found in disparate journal articles, but a self-contained comprehensive review that covers both elementary and advanced concepts in a manner comprehensible to engineers is rare. Rotation, Reflection, and Frame Changes surveys a refreshingly broad range of rotation-related research that is routinely needed in engineering practice. By illustrating key concepts in computer source code, this book stands out as an unusually accessible guide for engineers and scientists in engineering mechanics.

  7. Laterality-Specific Training Improves Mental Rotation Performance in Young Soccer Players

    Directory of Open Access Journals (Sweden)

    Stefanie Pietsch

    2018-02-01

    Full Text Available This study investigates the influence of specific soccer training with the non-dominant leg on mental rotation performance of 20 adolescent soccer players between 10 and 11 years of age. While the experimental group performed soccer specific tasks only with the non-dominant foot once a week for 10 weeks, the control group absolved the same exercises with the dominant foot for the same period of time. Both groups performed a mental rotation task and shot, dribbling and ball control tests before and after the 10 week intervention. The most relevant result was that the experimental group showed a significantly larger increase in mental rotation ability than the control group.

  8. Developing an Asteroid Rotational Theory

    Science.gov (United States)

    Geis, Gena; Williams, Miguel; Linder, Tyler; Pakey, Donald

    2018-01-01

    The goal of this project is to develop a theoretical asteroid rotational theory from first principles. Starting at first principles provides a firm foundation for computer simulations which can be used to analyze multiple variables at once such as size, rotation period, tensile strength, and density. The initial theory will be presented along with early models of applying the theory to the asteroid population. Early results confirm previous work by Pravec et al. (2002) that show the majority of the asteroids larger than 200m have negligible tensile strength and have spin rates close to their critical breakup point. Additionally, results show that an object with zero tensile strength has a maximum rotational rate determined by the object’s density, not size. Therefore, an iron asteroid with a density of 8000 kg/m^3 would have a minimum spin period of 1.16h if the only forces were gravitational and centrifugal. The short-term goal is to include material forces in the simulations to determine what tensile strength will allow the high spin rates of asteroids smaller than 150m.

  9. Towards age/rotation/magnetic activity relation with seismology

    Directory of Open Access Journals (Sweden)

    Mathur Savita

    2015-01-01

    Full Text Available The knowledge of stellar ages directly impacts the characterization of a planetary system as it puts strong constraints on the moment when the system was born. Unfortunately, the determination of precise stellar ages is a very difficult task. Different methods can be used to do so (based on isochrones or chemical element abundances but they usually provide large uncertainties. During its evolution a star goes through processes leading to loss of angular momentum but also changes in its magnetic activity. Building rotation, magnetic, age relations would be an asset to infer stellar ages model independently. Several attempts to build empirical relations between rotation and age (namely gyrochronology were made with a focus on cluster stars where the age determination is easier and for young stars on the main sequence. For field stars, we can now take advantage of high-precision photometric observations where we can perform asteroseismic analyses to improve the accuracy of stellar ages. Furthermore, the variability in the light curves allow us to put strong constraints on the stellar rotation and magnetic activity. By combining these precise measurements, we are on the way of understanding and improving relations between magnetic activity, rotation, and age, in particular at different stages of stellar evolution. I will review the status on gyrochronology relationships based on observations of young cluster stars. Then I will focus on solar-like stars and describe the inferences on stellar ages, rotation, and magnetism that can be provided by high-quality photometric observations such as the ones of the Kepler mission, in particular through asteroseismic analyses.

  10. Mental rotation of anthropoid hands: a chronometric study

    Directory of Open Access Journals (Sweden)

    L.G. Gawryszewski

    2007-03-01

    Full Text Available It has been shown that mental rotation of objects and human body parts is processed differently in the human brain. But what about body parts belonging to other primates? Does our brain process this information like any other object or does it instead maximize the structural similarities with our homologous body parts? We tried to answer this question by measuring the manual reaction time (MRT of human participants discriminating the handedness of drawings representing the hands of four anthropoid primates (orangutan, chimpanzee, gorilla, and human. Twenty-four right-handed volunteers (13 males and 11 females were instructed to judge the handedness of a hand drawing in palm view by pressing a left/right key. The orientation of hand drawings varied from 0º (fingers upwards to 90º lateral (fingers pointing away from the midline, 180º (fingers downwards and 90º medial (finger towards the midline. The results showed an effect of rotation angle (F(3, 69 = 19.57, P < 0.001, but not of hand identity, on MRTs. Moreover, for all hand drawings, a medial rotation elicited shorter MRTs than a lateral rotation (960 and 1169 ms, respectively, P < 0.05. This result has been previously observed for drawings of the human hand and related to biomechanical constraints of movement performance. Our findings indicate that anthropoid hands are essentially equivalent stimuli for handedness recognition. Since the task involves mentally simulating the posture and rotation of the hands, we wondered if "mirror neurons" could be involved in establishing the motor equivalence between the stimuli and the participants' own hands.

  11. Motor Processes in Children's Mental Rotation

    Science.gov (United States)

    Frick, Andrea; Daum, Moritz M.; Walser, Simone; Mast, Fred W.

    2009-01-01

    Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a…

  12. Investigation of antimagnetic rotation in 100Pd

    International Nuclear Information System (INIS)

    Zhu, S.; Garg, U.; Afanasjev, A. V.; Frauendorf, S.; Kharraja, B.; Ghugre, S. S.; Chintalapudi, S. N.; Janssens, R. V. F.; Carpenter, M. P.; Kondev, F. G.

    2001-01-01

    High spin states have been studied in the nucleus 100 Pd with the aim of investigating the novel phenomenon of ''antimagnetic rotation.'' A cascade of four ''rotational-band-like'' transitions is proposed as corresponding to antimagnetic rotation, based on the observed spectroscopic properties and a comparison with calculations in the configuration-dependent cranked Nilsson-Strutinsky formalism

  13. Flow Visualization of a Rotating Detonation Engine

    Science.gov (United States)

    2016-10-05

    SUPPLEMENTARY NOTES 14. ABSTRACT The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing...2014 – 12/4/2015 Summary: The rotating detonation engine ( RDE ) is a propulsion system that obtains thrust using continuously existing detonation...structure. Studies have been conducted on rotating detonation engines ( RDE ) that obtain thrust from the continuously propagating detonation waves in the

  14. Combining Automatic Item Generation and Experimental Designs to Investigate the Contribution of Cognitive Components to the Gender Difference in Mental Rotation

    Science.gov (United States)

    Arendasy, Martin E.; Sommer, Markus; Gittler, Georg

    2010-01-01

    Marked gender differences in three-dimensional mental rotation have been broadly reported in the literature in the last few decades. Various theoretical models and accounts were used to explain the observed differences. Within the framework of linking item design features of mental rotation tasks to cognitive component processes associated with…

  15. The task-to-task communication between computers

    International Nuclear Information System (INIS)

    Lin Shuzi; Zhang Bingyun; Zhao Weiren

    1992-01-01

    The task-to-task communication is used in the Institute of High Energy Physics. The BES (Beijing Spectrometer) uses the communication mode to take some of the BEPC (Beijing Electron Positron Collider) running parameters needed by BES experiments in a periodic time. The authors describe the principle of transparent task-to-task communication and how to use it in BES on-line data acquisition system

  16. Children's Task Engagement during Challenging Puzzle Tasks

    Science.gov (United States)

    Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha

    2017-01-01

    We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…

  17. Does spinal excitability scale to the difficulty of the dual-task?

    Science.gov (United States)

    Day, Devon M; Boivin, Mario T; Adkin, Allan L; Tokuno, Craig D

    2017-08-01

    This study examined whether spinal excitability, as measured by the soleus Hoffmann reflex (H-reflex), is scaled to the difficulty level of the dual-task being performed. Twenty-two participants completed a combination of three balance task and three secondary cognitive (visuo-motor) task difficulty levels for a total of nine dual-task conditions. An additional eight participants were tested while performing the same three balance task difficulty levels on its own (i.e., single-tasking). The balance task required participants to maintain their balance on a fixed or rotating stabilometer while the visuo-motor task required participants to respond to moving targets presented on a monitor. Throughout each single- and dual-task trial, H-reflexes were elicited from the soleus. Although dual-task performance, as quantified by visuo-motor task accuracy as well as the root mean square of the stabilometer position and velocity, decreased by 10-34% with increasing dual-task difficulty (p dual-task conditions (p = 0.483-0.758). This contrasts to when participants performed the balance task as a single-task, where the H-reflex amplitude decreased by ~25% from the easy to the hard balance task difficulty level (p = 0.037). In contrast to the commonly reported finding of a reduced soleus H-reflex amplitude when individuals perform a less posturally stable task by itself, the results indicate that spinal excitability is not modulated as a function of dual-task difficulty. It is possible that when an individual's attentional resource capacity is exceeded during dual-tasking, they become ineffective in regulating spinal excitability for balance control.

  18. Friction, Free Axes of Rotation and Entropy

    Directory of Open Access Journals (Sweden)

    Alexander Kazachkov

    2017-03-01

    Full Text Available Friction forces acting on rotators may promote their alignment and therefore eliminate degrees of freedom in their movement. The alignment of rotators by friction force was shown by experiments performed with different spinners, demonstrating how friction generates negentropy in a system of rotators. A gas of rigid rotators influenced by friction force is considered. The orientational negentropy generated by a friction force was estimated with the Sackur-Tetrode equation. The minimal change in total entropy of a system of rotators, corresponding to their eventual alignment, decreases with temperature. The reported effect may be of primary importance for the phase equilibrium and motion of ubiquitous colloidal and granular systems.

  19. Visual perception of axes of head rotation

    Science.gov (United States)

    Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

    2013-01-01

    Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is

  20. Collective rotation from ab initio theory

    International Nuclear Information System (INIS)

    Caprio, M.A.; Maris, P.; Vary, J.P.; Smith, R.

    2015-01-01

    Through ab initio approaches in nuclear theory, we may now seek to quantitatively understand the wealth of nuclear collective phenomena starting from the underlying internucleon interactions. No-core configuration interaction (NCCI) calculations for p-shell nuclei give rise to rotational bands, as evidenced by rotational patterns for excitation energies, electromagnetic moments and electromagnetic transitions. In this review, NCCI calculations of 7–9 Be are used to illustrate and explore ab initio rotational structure, and the resulting predictions for rotational band properties are compared with experiment. We highlight the robustness of ab initio rotational predictions across different choices for the internucleon interaction. (author)

  1. Visual perception of axes of head rotation

    Directory of Open Access Journals (Sweden)

    David Mattijs Arnoldussen

    2013-02-01

    Full Text Available Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. 1. Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit.We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow’s rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals.2. Do transformed visual self-rotation signals reflect the arrangement of the semicircular canals (SCC? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those BOLD signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes.3. We investigated if subject’s sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is not arranged into

  2. Examining cotton in rotation with rice and cotton in rotation with other crops using natural experiment

    Science.gov (United States)

    Sun, Ling; Zhu, Zesheng

    2017-08-01

    This paper is to show the ability of remote sensing image analysis combined with statistical analysis to characterize the environmental risk assessment of cotton in rotation with rice and cotton in rotation with other crops in two ways: (1) description of rotation period of cotton in rotation with rice and cotton in rotation with other crops by the observational study or natural experiment; (2) analysis of rotation period calculation of cotton in rotation with rice and cotton in rotation with other crops. Natural experimental results show that this new method is very promising for determining crop rotation period for estimating regional averages of environmental risk. When it is applied to determining crop rotation period, two requested remote sensing images of regional crop are required at least.

  3. Rotation and Accretion Powered Pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Kaspi, V M [Department of Physics, McGill University, 3600 University St, Montreal, QC H3A 2T8 (Canada)

    2008-03-07

    Pulsar astrophysics has come a long way in the 40 years since the discovery of the first pulsar by Bell and Hewish. From humble beginnings as bits of 'scruff' on the Cambridge University group's chart recorder paper, the field of pulsars has blossomed into a major area of mainstream astrophysics, with an unparalleled diversity of astrophysical applications. These range from Nobel-celebrated testing of general relativity in the strong-field regime to constraining the equation-of-state of ultradense matter; from probing the winds of massive stars to globular cluster evolution. Previous notable books on the subject of pulsars have tended to focus on some particular topic in the field. The classic text Pulsars by Manchester and Taylor (1977 San Francisco, CA: Freeman) targeted almost exclusively rotation-powered radio pulsars, while the Meszaros book High-Energy Radiation from Magnetized Neutron Stars (1992 Chicago, IL: University of Chicago Press) considered both rotation- and accretion-powered neutron stars, but focused on their radiation at x-ray energies and above. The recent book Neutron Stars 1 by Haensel et al (2007 Berlin: Springer) considers only the equation of state and neutron-star structure. Into this context appears Rotation and Accretion Powered Pulsars, by Pranab Ghosh. In contrast to other books, here the author takes an encyclopedic approach and attempts to synthesize practically all of the major aspects of the two main types of neutron star. This is ambitious. The only comparable undertaking is the useful but more elementary Lyne and Graham-Smith text Pulsar Astronomy (1998 Cambridge: Cambridge University Press), or Compact Stellar X-ray Sources (eds Lewin and van der Klis, 2006 Cambridge: Cambridge University Press), an anthology of technical review articles that also includes black hole topics. Rotation and Accretion Powered Pulsars thus fills a clear void in the field, providing a readable, graduate-level book that covers nearly

  4. Rotation and Accretion Powered Pulsars

    International Nuclear Information System (INIS)

    Kaspi, V M

    2008-01-01

    Pulsar astrophysics has come a long way in the 40 years since the discovery of the first pulsar by Bell and Hewish. From humble beginnings as bits of 'scruff' on the Cambridge University group's chart recorder paper, the field of pulsars has blossomed into a major area of mainstream astrophysics, with an unparalleled diversity of astrophysical applications. These range from Nobel-celebrated testing of general relativity in the strong-field regime to constraining the equation-of-state of ultradense matter; from probing the winds of massive stars to globular cluster evolution. Previous notable books on the subject of pulsars have tended to focus on some particular topic in the field. The classic text Pulsars by Manchester and Taylor (1977 San Francisco, CA: Freeman) targeted almost exclusively rotation-powered radio pulsars, while the Meszaros book High-Energy Radiation from Magnetized Neutron Stars (1992 Chicago, IL: University of Chicago Press) considered both rotation- and accretion-powered neutron stars, but focused on their radiation at x-ray energies and above. The recent book Neutron Stars 1 by Haensel et al (2007 Berlin: Springer) considers only the equation of state and neutron-star structure. Into this context appears Rotation and Accretion Powered Pulsars, by Pranab Ghosh. In contrast to other books, here the author takes an encyclopedic approach and attempts to synthesize practically all of the major aspects of the two main types of neutron star. This is ambitious. The only comparable undertaking is the useful but more elementary Lyne and Graham-Smith text Pulsar Astronomy (1998 Cambridge: Cambridge University Press), or Compact Stellar X-ray Sources (eds Lewin and van der Klis, 2006 Cambridge: Cambridge University Press), an anthology of technical review articles that also includes black hole topics. Rotation and Accretion Powered Pulsars thus fills a clear void in the field, providing a readable, graduate-level book that covers nearly everything you

  5. On the stability of rotational discontinuities

    International Nuclear Information System (INIS)

    Richter, P.; Scholer, M.

    1989-01-01

    The stability of symmetric rotational discontinuities in which the magnetic field rotates by 180 degree is investigated by means of a one-dimensional self-consistent hybrid code. Rotational discontinuities with an angle Θ > 45 degree between the discontinuity normal direction and the upstream magnetic field are found to be relatively stable. The discontinuity normal is in the x direction and the initial magnetic field has finite y component only in the transition region. In the case of the ion (left-handed) sense of rotation of the tangential magnetic field, the transition region does not broaden with time. In the case of the electron (right-handed) sense of rotation, a damped wavetrain builds up in the B y component downstream of the rotational discontinuity and the discontinuity broadens with time. Rotational discontinuities with smaller angles, Θ, are unstable. Examples for a rotational discontinuity with Θ = 30 degree and the electron sense of rotation as well as a rotational discontinuity with Θ = 15 degree and the ion sense of rotation show that these discontinuities into waves. These waves travel approximately with Alfven velocity in the upstream direction and are therefore phase standing in the simulation system. The magnetic hodograms of these disintegrated discontinuities are S-shaped. The upstream portion of the hodogram is always right-handed; the downstream portion is always left-handed

  6. Relativistic rotation and the anholonomic object

    International Nuclear Information System (INIS)

    Corum, J.F.

    1977-01-01

    The purpose of this communication is to call attention to the conceptual economy provided by the object of anholonomity for the theory of relativity. This geometric object expresses certain consequences of relativity theory and provides a single, simple framework for discussing a variety of phenomena. It particularly clarifies the description of relativistic rotation. The relativistic rotational transformation of the four coordinate differentials of flat space--time generates a set of anholonomic, or inexact differentials, whose duals are an orthogonal set of basis vectors. How should a rotating observer interpret physical events referred to such orthogonal, but anholonomic frames The answer to this question rests upon the origin and physical significance of the object of anholonomity. It is demonstrated that not only is the rotational Lorentz transformation an anholonomic transformation, but that the intrinsic anholonomic effects are essential to interpreting rotational phenomena. In particular, the Sagnac effect may be interpreted as the physical manifestation of temporal anholonomity under rotation. The Thomas precession of a reference axis may be interpreted as a consequence of the spatial anholonomity of the rotating frame. Further, the full four-dimensional covariance of Maxwellian electrodynamics, under a relativistic Lorentz rotation, is possible only with the inclusion of anholonomic effects. The anholonomic approach clarifies the distinction between the physically different operations of source rotation and observer rotation in a flat space--time. It is finally concluded that a consistant theory of relativistic rotation, satisfying the principle of general covariance, inherently requires the presence of the object of anholonomity

  7. Blink activity and task difficulty.

    Science.gov (United States)

    Tanaka, Y; Yamaoka, K

    1993-08-01

    This study investigated the relationship between task difficulty and blink activity, which includes blink rate, blink amplitude, and blink duration. Two kinds of tasks established two levels of difficulty. In Exp. 1, a mental arithmetic task was used to examine the relationship. Analysis showed that blink rate for a difficult task was significantly higher than that for an easier one. In Exp. 2, a letter-search task (hiragana Japanese alphabet) was used while the other conditions were the same as those in Exp. 1; however, the results of this experiment were not influenced by the difficulty of the task. As results indicate that blink rate is related to not only difficulty but also the nature of the task, the nature of the task is probably dependent on a mechanism in information processing. The results for blink amplitude and blink duration showed no systematic change during either experiment.

  8. Biology task group

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available

  9. Staff rotation: implications for occupational therapy.

    Science.gov (United States)

    Taylor, A; Andriuk, M L; Langlois, P; Provost, E

    1995-10-01

    Occupational therapy departments of tertiary care hospitals can provide staff with opportunities to gain diverse clinical experience if they rotate through the various services such as surgery, medicine, geriatrics, plastic surgery and orthopaedics. The system of rotation offers both advantages and disadvantages for the staff and the institution. The Royal Victoria Hospital in Montreal, a large university teaching hospital, had traditionally offered staff the opportunity to rotate. Changes in staffing and their needs however, resulted in rotation becoming an important issue within the department. This article presents the pros and the cons of rotation and non-rotation systems as identified by therapists and administrators across Canada. Staff rotation was found to have an effect on job satisfaction and a therapist's career orientation. Given these findings, administrators may want to reconsider the role of the generalist and specialist in their facilities.

  10. Parallel computation of rotating flows

    DEFF Research Database (Denmark)

    Lundin, Lars Kristian; Barker, Vincent A.; Sørensen, Jens Nørkær

    1999-01-01

    This paper deals with the simulation of 3‐D rotating flows based on the velocity‐vorticity formulation of the Navier‐Stokes equations in cylindrical coordinates. The governing equations are discretized by a finite difference method. The solution is advanced to a new time level by a two‐step process....... In the first step, the vorticity at the new time level is computed using the velocity at the previous time level. In the second step, the velocity at the new time level is computed using the new vorticity. We discuss here the second part which is by far the most time‐consuming. The numerical problem...

  11. Nondestructive testing bench without rotation

    International Nuclear Information System (INIS)

    Perdijon, J.

    1976-01-01

    On-line testing by ultrasonics in combination with eddy currents represents a large saving in time and equipment since the tube to be checked only needs to pass once quickly and without rotation. The answer to this problem is to use encircling transducers, which means that the mirror interposed to detect transverse defects must be conical while that used to detect longitudinal defects is helically shaped. A cell combining these two mirrors with an eddy current coil to test thin small-diameter tubes is described. The first trial year shows that defects are detected independently of their position, with a sensitivity at least equal to that of conventional systems [fr

  12. Rotational and translational Brownian motion

    International Nuclear Information System (INIS)

    Coffey, W.T.; Salford Univ.

    1980-01-01

    In this review it is proposed to summarise the work on the theory of the translational and rotational Brownian movement which has been carried on over roughly the past 30 years. The review is intended to take the form of a tutorial paper rather than a list of the results obtained by the various investigators over the period in question. In this vein then it seems appropriate to firstly give a brief account of those parts of the theory of probability which are relevant to the problems under discussion. (orig.)

  13. Rotating detectors and Mach's principle

    International Nuclear Information System (INIS)

    Paola, R.D.M. de; Svaiter, N.F.

    2000-08-01

    In this work we consider a quantum version of Newton s bucket experiment in a fl;at spacetime: we take an Unruh-DeWitt detector in interaction with a real massless scalar field. We calculate the detector's excitation rate when it is uniformly rotating around some fixed point and the field is prepared in the Minkowski vacuum and also when the detector is inertial and the field is in the Trocheries-Takeno vacuum state. These results are compared and the relations with Mach's principle are discussed. (author)

  14. Generalization of stochastic visuomotor rotations.

    Directory of Open Access Journals (Sweden)

    Hugo L Fernandes

    Full Text Available Generalization studies examine the influence of perturbations imposed on one movement onto other movements. The strength of generalization is traditionally interpreted as a reflection of the similarity of the underlying neural representations. Uncertainty fundamentally affects both sensory integration and learning and is at the heart of many theories of neural representation. However, little is known about how uncertainty, resulting from variability in the environment, affects generalization curves. Here we extend standard movement generalization experiments to ask how uncertainty affects the generalization of visuomotor rotations. We find that although uncertainty affects how fast subjects learn, the perturbation generalizes independently of uncertainty.

  15. Qubit rotation and Berry phase

    International Nuclear Information System (INIS)

    Banerjee, D.; Bandyopadhyay, P.

    2005-11-01

    A quantized fermion is represented by a scalar particle encircling a magnetic flux line. It has the spinor structure which can be constructed from quantum gates and qubits. We have studied here the role of Berry phase in removing dynamical phase during one qubit rotation of a quantized fermion. The entanglement of two qubits inserting spin-echo to one of them results the trapped Berry phase to measure entanglement. Some effort is given to study the effect of noise on the Berry phase of spinors and their entangled states. (author)

  16. Design of rotating electrical machines

    CERN Document Server

    Pyrhonen , Juha; Hrabovcova , Valeria

    2013-01-01

    In one complete volume, this essential reference presents an in-depth overview of the theoretical principles and techniques of electrical machine design. This timely new edition offers up-to-date theory and guidelines for the design of electrical machines, taking into account recent advances in permanent magnet machines as well as synchronous reluctance machines. New coverage includes: Brand new material on the ecological impact of the motors, covering the eco-design principles of rotating electrical machinesAn expanded section on the design of permanent magnet synchronous machines, now repo

  17. ROTATIONAL VELOCITIES FOR M DWARFS

    International Nuclear Information System (INIS)

    Jenkins, J. S.; Ramsey, L. W.; Jones, H. R. A.; Pavlenko, Y.; Barnes, J. R.; Pinfield, D. J.; Gallardo, J.

    2009-01-01

    We present spectroscopic rotation velocities (v sin i) for 56 M dwarf stars using high-resolution Hobby-Eberly Telescope High Resolution Spectrograph red spectroscopy. In addition, we have also determined photometric effective temperatures, masses, and metallicities ([Fe/H]) for some stars observed here and in the literature where we could acquire accurate parallax measurements and relevant photometry. We have increased the number of known v sin i values for mid M stars by around 80% and can confirm a weakly increasing rotation velocity with decreasing effective temperature. Our sample of v sin is peak at low velocities (∼3 km s -1 ). We find a change in the rotational velocity distribution between early M and late M stars, which is likely due to the changing field topology between partially and fully convective stars. There is also a possible further change in the rotational distribution toward the late M dwarfs where dust begins to play a role in the stellar atmospheres. We also link v sin i to age and show how it can be used to provide mid-M star age limits. When all literature velocities for M dwarfs are added to our sample, there are 198 with v sin i ≤ 10 km s -1 and 124 in the mid-to-late M star regime (M3.0-M9.5) where measuring precision optical radial velocities is difficult. In addition, we also search the spectra for any significant Hα emission or absorption. Forty three percent were found to exhibit such emission and could represent young, active objects with high levels of radial-velocity noise. We acquired two epochs of spectra for the star GJ1253 spread by almost one month and the Hα profile changed from showing no clear signs of emission, to exhibiting a clear emission peak. Four stars in our sample appear to be low-mass binaries (GJ1080, GJ3129, Gl802, and LHS3080), with both GJ3129 and Gl802 exhibiting double Hα emission features. The tables presented here will aid any future M star planet search target selection to extract stars with low v

  18. The rotation of spiral galaxies.

    Science.gov (United States)

    Rubin, V C

    1983-06-24

    There is accumulating evidence that as much as 90 percent of the mass of the universe is nonluminous and is clumped, halo-like, around individual galaxies. The gravitational force of this dark matter is presumed to be responsible for the high rotational velocities of stars and gas in the disks of spiral galaxie. At present, the form of the dark matter is unknown. Possible candidates span a range in mass of 10(70), from non-zero-mass neutrinos to massive black holes.

  19. Parallel computation of rotating flows

    DEFF Research Database (Denmark)

    Lundin, Lars Kristian; Barker, Vincent A.; Sørensen, Jens Nørkær

    1999-01-01

    This paper deals with the simulation of 3‐D rotating flows based on the velocity‐vorticity formulation of the Navier‐Stokes equations in cylindrical coordinates. The governing equations are discretized by a finite difference method. The solution is advanced to a new time level by a two‐step process...... is that of solving a singular, large, sparse, over‐determined linear system of equations, and the iterative method CGLS is applied for this purpose. We discuss some of the mathematical and numerical aspects of this procedure and report on the performance of our software on a wide range of parallel computers. Darbe...

  20. Qubit rotation and Berry phase

    International Nuclear Information System (INIS)

    Banerjee, Dipti; Bandyopadhyay, Pratul

    2006-01-01

    A quantized fermion is represented by a scalar particle encircling a magnetic flux line. It has a spinor structure which can be constructed from quantum gates and qubits. We have studied here the role of Berry phase in removing dynamical phase during one qubit rotation of a quantized fermion. The entanglement of two qubits inserting spin-echo to one of them allows the trapped Berry phase to measure entanglement. Some effort is given to study the effect of noise on the Berry phase of spinors and their entangled states

  1. Task-dependent output of human parasternal intercostal motor units across spinal levels.

    Science.gov (United States)

    Hudson, Anna L; Gandevia, Simon C; Butler, Jane E

    2017-12-01

    During breathing, there is differential activity in the human parasternal intercostal muscles and the activity is tightly coupled to the known mechanical advantages for inspiration of the same regions of muscles. It is not known whether differential activity is preserved for the non-respiratory task of ipsilateral trunk rotation. In the present study, we compared single motor units during resting breathing and axial rotation of the trunk during apnoea. We not only confirmed non-uniform recruitment of motor units across parasternal intercostal muscles in breathing, but also demonstrated that the same motor units show an altered pattern of recruitment in the non-respiratory task of trunk rotation. The output of parasternal intercostal motoneurones is modulated differently across spinal levels depending on the task and these results help us understand the mechanisms that may govern task-dependent differences in motoneurone output. During inspiration, there is differential activity in the human parasternal intercostal muscles across interspaces. We investigated whether the earlier recruitment of motor units in the rostral interspaces compared to more caudal spaces during inspiration is preserved for the non-respiratory task of ipsilateral trunk rotation. Single motor unit activity (SMU) was recorded from the first, second and fourth parasternal interspaces on the right side in five participants in two tasks: resting breathing and 'isometric' axial rotation of the trunk during apnoea. Recruitment of the same SMUs was compared between tasks (n = 123). During resting breathing, differential activity was indicated by earlier recruitment of SMUs in the first and second interspaces compared to the fourth space in inspiration (P motor units showed an altered pattern of recruitment because SMUs in the first interspace were recruited later and at a higher rotation torque than those in the second and fourth interspaces (P recruitment measures, was good-excellent [intraclass

  2. PGOPHER: A program for simulating rotational, vibrational and electronic spectra

    International Nuclear Information System (INIS)

    Western, Colin M.

    2017-01-01

    The PGOPHER program is a general purpose program for simulating and fitting molecular spectra, particularly the rotational structure. The current version can handle linear molecules, symmetric tops and asymmetric tops and many possible transitions, both allowed and forbidden, including multiphoton and Raman spectra in addition to the common electric dipole absorptions. Many different interactions can be included in the calculation, including those arising from electron and nuclear spin, and external electric and magnetic fields. Multiple states and interactions between them can also be accounted for, limited only by available memory. Fitting of experimental data can be to line positions (in many common formats), intensities or band contours and the parameters determined can be level populations as well as rotational constants. PGOPHER is provided with a powerful and flexible graphical user interface to simplify many of the tasks required in simulating, understanding and fitting molecular spectra, including Fortrat diagrams and energy level plots in addition to overlaying experimental and simulated spectra. The program is open source, and can be compiled with open source tools. This paper provides a formal description of the operation of version 9.1. - Highlights: • Easy-to-use graphical interface for assigning and understanding molecular spectra. • Simulates rotational and vibrational structure of many types of molecular spectra. • Fits molecular properties to line positions or spectral contours. • Handles linear molecules and symmetric and asymmetric tops. • Handles perturbations, nuclear and electron spin, and electric and magnetic fields.

  3. Are Differences Between Men and Women in Rotated Pattern Recognition Due to the Use of Different Cognitive Strategies?

    Directory of Open Access Journals (Sweden)

    Catherine Brandner

    2013-08-01

    Full Text Available A recursive hypothesis suggests that gender differences in spatial abilities, including mental rotation tasks, are the result of differences in the strategies that men and women use to process information. To address this issue, we systematically explored men and women’s performance for rotated patterns by assessing recognition, confidence rating and response time, thought to be fundamental to spatial processing, with classical methods, and with signal detection theory (SDT parameters (d-prime and c-bias. Among our findings, we highlight d-prime as the most robust parameter to assess gender differences and predict group membership. Furthermore, we conclude that better performance by men is due to their strategy of transforming a mental rotation task into a simpler task comparing the alignment of test stimuli to the surrounding experimental environment.

  4. Comparison of methods for separating vibration sources in rotating machinery

    Science.gov (United States)

    Klein, Renata

    2017-12-01

    Vibro-acoustic signatures are widely used for diagnostics of rotating machinery. Vibration based automatic diagnostics systems need to achieve a good separation between signals generated by different sources. The separation task may be challenging, since the effects of the different vibration sources often overlap. In particular, there is a need to separate between signals related to the natural frequencies of the structure and signals resulting from the rotating components (signal whitening), as well as a need to separate between signals generated by asynchronous components like bearings and signals generated by cyclo-stationary components like gears. Several methods were proposed to achieve the above separation tasks. The present study compares between some of these methods. The paper also presents a new method for whitening, Adaptive Clutter Separation, as well as a new efficient algorithm for dephase, which separates between asynchronous and cyclo-stationary signals. For whitening the study compares between liftering of the high quefrencies and adaptive clutter separation. For separating between the asynchronous and the cyclo-stationary signals the study compares between liftering in the quefrency domain and dephase. The methods are compared using both simulated signals and real data.

  5. Selection of maintenance tasks

    Energy Technology Data Exchange (ETDEWEB)

    Dean, B; Rombos, P [Wardrop (W.L.) and Associates Ltd., Winnipeg, MB (Canada)

    1995-10-01

    Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs.

  6. Selection of maintenance tasks

    International Nuclear Information System (INIS)

    Dean, B.; Rombos, P.

    1995-10-01

    Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs

  7. Fragmentation of rotating protostellar clouds

    International Nuclear Information System (INIS)

    Tohline, J.E.

    1980-01-01

    We examine, with a three-dimensional hydrodynamic computer code, the behavior of rotating, isothermal gas clouds as they collapse from Jeans unstable configurations, in order to determine whether they are susceptible to fragmentation during the initial dynamic collapse phase of their evolution. We find that a gas cloud will not fragment unless (a) it begins collapsing from a radius much smaller than the Jeans radius (i.e., the cloud initially encloses many Jeans masses) and (b) irregularities in the cloud's initial structure (specifically, density inhomogeneities) enclose more than one Jeans mass of material. Gas pressure smooths out features that are not initially Jeans unstable while rotation plays no direct role in damping inhomogeneities. Instead of fragmenting, most of our models collapse to a ring configuration (as has been observed by other investigators in two-dimensional, axisymmetric models). The rings appear to be less susceptible to gragmentation from arbitrary perturbations in their structure than has previously been indicated in other work. Because our models, which include the effects of gas pressure, do not readily fragment during a phase of dynamic collapse, we suggest that gas clouds in the galactic disk undergo fragmentation only during quasi-equilibrium phases of their evolution

  8. A nonsingular rotating black hole

    International Nuclear Information System (INIS)

    Ghosh, Sushant G.

    2015-01-01

    The spacetime singularities in classical general relativity are inevitable, as predicated by the celebrated singularity theorems. However, it is a general belief that singularities do not exist in Nature and that they are the limitations of the general relativity. In the absence of a welldefined quantum gravity, models of regular black holes have been studied. We employ a probability distribution inspired mass function m(r) to replace the Kerr black hole mass M to represent a nonsingular rotating black hole that is identified asymptotically (r >> k, k > 0 constant) exactly as the Kerr-Newman black hole, and as the Kerr black hole when k = 0. The radiating counterpart renders a nonsingular generalization of Carmeli's spacetime as well as Vaidya's spacetime, in the appropriate limits. The exponential correction factor changing the geometry of the classical black hole to remove the curvature singularity can also be motivated by quantum arguments. The regular rotating spacetime can also be understood as a black hole of general relativity coupled to nonlinear electrodynamics. (orig.)

  9. Mars geodesy, rotation and gravity

    International Nuclear Information System (INIS)

    Rosenblatt, Pascal; Dehant, Veronique

    2010-01-01

    This review provides explanations of how geodesy, rotation and gravity can be addressed using radioscience data of an orbiter around a planet or of the lander on its surface. The planet Mars is the center of the discussion. The information one can get from orbitography and radioscience in general concerns the global static gravitational field, the time variation of the gravitational field induced by mass exchange between the atmosphere and the ice caps, the time variation of the gravitational field induced by the tides, the secular changes in the spacecraft's orbit induced by the little moons of Mars named Phobos and Deimos, the gravity induced by particular targets, the Martian ephemerides, and Mars' rotation and orientation. The paper addresses as well the determination of the geophysical parameters of Mars and, in particular, the state of Mars' core and its size, which is important for understanding the planet's evolution. Indeed, the state and dimension of the core determined from the moment of inertia and nutation depend in turn on the percentage of light elements in the core as well as on the core temperature, which is related to heat transport in the mantle. For example, the radius of the core has implications for possible mantle convection scenarios and, in particular, for the presence of a perovskite phase transition at the bottom of the mantle. This is also important for our understanding of the large volcanic province Tharsis on the surface of Mars. (invited reviews)

  10. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  11. Reciprocally-Rotating Velocity Obstacles

    KAUST Repository

    Giese, Andrew

    2014-05-01

    © 2014 IEEE. Modern multi-agent systems frequently use highlevel planners to extract basic paths for agents, and then rely on local collision avoidance to ensure that the agents reach their destinations without colliding with one another or dynamic obstacles. One state-of-the-art local collision avoidance technique is Optimal Reciprocal Collision Avoidance (ORCA). Despite being fast and efficient for circular-shaped agents, ORCA may deadlock when polygonal shapes are used. To address this shortcoming, we introduce Reciprocally-Rotating Velocity Obstacles (RRVO). RRVO generalizes ORCA by introducing a notion of rotation for polygonally-shaped agents. This generalization permits more realistic motion than ORCA and does not suffer from as much deadlock. In this paper, we present the theory of RRVO and show empirically that it does not suffer from the deadlock issue ORCA has, permits agents to reach goals faster, and has a comparable collision rate at the cost of performance overhead quadratic in the (typically small) user-defined parameter δ.

  12. Slowly braked, rotating neutron stars

    Science.gov (United States)

    Sato, H.

    1975-01-01

    A slowly braked, rotating neutron star is believed to be a star which rapidly rotates, has no nebula, is nonpulsing, and has a long initial braking time of ten thousand to a million years because of a low magnetic field. Such an object might be observable as an extended weak source of infrared or radio wave radiation due to the scattering of low-frequency strong-wave photons by accelerated electrons. If these objects exist abundantly in the Galaxy, they would act as sources of relatively low-energy cosmic rays. Pulsars (rapidly braked neutron stars) are shown to have difficulties in providing an adequate amount of cosmic-ray matter, making these new sources seem necessary. The possibility that the acceleration mechanism around a slowly braked star may be not a direct acceleration by the strong wave but an acceleration due to plasma turbulence excited by the strong wave is briefly explored. It is shown that white dwarfs may also be slowly braked stars with braking times longer than 3.15 million years.

  13. Secular stability of rotating stars

    International Nuclear Information System (INIS)

    Imamura, J.N.; Friedman, J.L.; Durisen, R.H.

    1984-01-01

    In this work, the authors calculate the secular stability limits of rotating polytropes to nonaxisymmetric perturbations of low m. Polytropic indices ranging from 1 to 3 and several angular momentum distributions are considered. Results are most conveniently presented in terms of the t-parameter, defined as the ratio of the rotational kinetic energy to the absolute value of the gravitational energy of the fluid. Previous work on polytropes considered only the m = 2 mode, which is unstable for values of the t-parameter greater than 0.14 +- 0.01 for the n values n = 1.5 and 3 and the angular momentum distributions tested (see Durisen and Imamura 1981). The GRR secular stability limit of the m - 2 mode for the Maclaurin spheroids (n = 0) was determined by Chandrasekhar (1970). GRR stability limits of higher m modes for the Maclaurin spheroids were located approximately by Comins (1979a,b) and more precisely by Friedman (1983). 16 references, 2 tables

  14. Rotating frames in special relativity

    International Nuclear Information System (INIS)

    Strauss, M.

    1979-01-01

    The transformation theory for rotating frames presented in a previous paper is generalized by replacing the usual condition r = R for ωR < c (invariance of radius) by r = Rg(βsub(R)) so that r is now defined for all values of R, 0 <= R <= infinity. This generalization does not affect the kinematic transformation bracetheta, T → bracethetasup(r), bracesup(r) and the result group structure required by the theoretical constraints previously established, provided the old parameter 'r' (=R) is now identified throughout with either r or R; for physical reasons it must be identified with R. The function g, which cannot be fixed by theoretical constraints, determines the degree of geometrical anisotropy in the rotating plane z = const. More specifically, since g enters the expression for the ratio C/D (circumference/diameter) its choice corresponds to the choice of a congruence definition for lengths in radial and tangential directions. While on this (purely geometrical) level g remains undetermined, it can be uniquely determined experimentally on the kinematic level, e.g. by observing in Σsup(ω) the motion of a free particle. Thus the supremacy of kinematics over geometry is explicated by a further instance. At the same time, special relativity theory (SRT) is shown to belong to the class of theories with theoretically unsolvable problems. (author)

  15. Validation of the Rotation Ratios Method

    International Nuclear Information System (INIS)

    Foss, O.A.; Klaksvik, J.; Benum, P.; Anda, S.

    2007-01-01

    Background: The rotation ratios method describes rotations between pairs of sequential pelvic radiographs. The method seems promising but has not been validated. Purpose: To validate the accuracy of the rotation ratios method. Material and Methods: Known pelvic rotations between 165 radiographs obtained from five skeletal pelvises in an experimental material were compared with the corresponding calculated rotations to describe the accuracy of the method. The results from a clinical material of 262 pelvic radiographs from 46 patients defined the ranges of rotational differences compared. Repeated analyses, both on the experimental and the clinical material, were performed using the selected reference points to describe the robustness and the repeatability of the method. Results: The reference points were easy to identify and barely influenced by pelvic rotations. The mean differences between calculated and real pelvic rotations were 0.0 deg (SD 0.6) for vertical rotations and 0.1 deg (SD 0.7) for transversal rotations in the experimental material. The intra- and interobserver repeatability of the method was good. Conclusion: The accuracy of the method was reasonably high, and the method may prove to be clinically useful

  16. Femoral component rotation in patellofemoral joint replacement.

    Science.gov (United States)

    van Jonbergen, Hans-Peter W; Westerbeek, Robin E

    2018-06-01

    Clinical outcomes in patellofemoral joint replacement may be related to femoral component rotation. Assessment of rotational alignment is however difficult as patients with isolated patellofemoral osteoarthritis often have trochlear dysplasia. The use of the medial malleolus as a landmark to guide rotation has been suggested. The purpose of our study was to evaluate this technique with regard to femoral component rotation, and to correlate rotation with clinical outcomes at one-year follow-up. Forty-one knees in 39 patients had patellofemoral joint replacement using the Zimmer Gender-Solutions patellofemoral prosthesis. Intraoperatively, we determined femoral component rotational alignment using an extramedullary rod aimed at the inferior tip of the medial malleolus. Postoperatively, we measured the angle between the femoral component and the anatomical transepicondylar axis using CT. The amount of rotation was correlated with clinical outcomes at one-year follow-up. Forty knees in 38 patients were available for one-year follow-up. Mean femoral component rotation relative to the anatomical transepicondylar axis was 1.4° external rotation (range, -3.8 to 5.7°). We found no statistically significant correlation between femoral component rotation and change from baseline KOOS subscales at one-year follow-up. Our findings show that when using the medial malleolus as a landmark to guide rotation, the femoral component of the patellofemoral prosthesis was oriented in external rotation relative to the anatomical transepicondylar axis in 80% of knees. Our study did not show a relation between the amount of external rotation and clinical outcomes. Level III. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Velocity-dependent changes of rotational axes in the non-visual control of unconstrained 3D arm motions.

    Science.gov (United States)

    Isableu, B; Rezzoug, N; Mallet, G; Bernardin, D; Gorce, P; Pagano, C C

    2009-12-29

    We examined the roles of inertial (e(3)), shoulder-centre of mass (SH-CM) and shoulder-elbow articular (SH-EL) rotation axes in the non-visual control of unconstrained 3D arm rotations. Subjects rotated the arm in elbow configurations that yielded either a constant or variable separation between these axes. We hypothesized that increasing the motion frequency and the task complexity would result in the limbs' rotational axis to correspond to e(3) in order to minimize rotational resistances. Results showed two velocity-dependent profiles wherein the rotation axis coincided with the SH-EL axis for S and I velocities and then in the F velocity shifted to either a SH-CM/e(3) trade-off axis for one profile, or to no preferential axis for the other. A third profile was velocity-independent, with the SH-CM/e(3) trade-off axis being adopted. Our results are the first to provide evidence that the rotational axis of a multi-articulated limb may change from a geometrical axis of rotation to a mass or inertia based axis as motion frequency increases. These findings are discussed within the framework of the minimum inertia tensor model (MIT), which shows that rotations about e(3) reduce the amount of joint muscle torque that must be produced by employing the interaction torque to assist movement.

  18. Space webs based on rotating tethered formations

    Science.gov (United States)

    Palmerini, Giovanni B.; Sgubini, Silvano; Sabatini, Marco

    2009-07-01

    Several on-going studies indicate the interest for large, light orbiting structures, shaped as fish nets or webs: along the ropes of the web small spacecraft can move like spiders to position and re-locate, at will, pieces of hardware devoted to specific missions. The concept could be considered as an intermediate solution between the large monolithic structure, heavy and expensive to realize, but easy to control, and the formations of satellites, where all system members are completely free and should manoeuvre in order to acquire a desired configuration. Instead, the advantage of having a "hard-but-light" link among the different grids lays in the partition of the tasks among system components and in a possible overall reduction of the control system complexity and cost. Unfortunately, there is no stable configuration for an orbiting, two-dimensional web made by light, flexible tethers which cannot support compression forces. A possible solution is to make use of centrifugal forces to pull the net, with a reduced number of simple thrusters located at the tips of the tethers to initially acquire the required spin. In this paper a dynamic analysis of a simplified rotating web is performed, in order to evaluate the spinning velocity able to satisfy the requirement for the stability of the system. The model adopted overlaps simpler elements, each of them given by a tether (made up of a number of linear finite elements) connecting two extreme bodies accommodating the spinning thrusters. The combination of these "diameter-like" elements provides the web, shaped according to the specific requirements. The net is primarily considered as subjected to Keplerian attraction and J2 and drag perturbations only, but its behaviour under thermal inputs is also investigated.

  19. Physics, Formation and Evolution of Rotating Stars

    CERN Document Server

    Maeder, André

    2009-01-01

    Rotation is ubiquitous at each step of stellar evolution, from star formation to the final stages, and it affects the course of evolution, the timescales and nucleosynthesis. Stellar rotation is also an essential prerequisite for the occurrence of Gamma-Ray Bursts. In this book the author thoroughly examines the basic mechanical and thermal effects of rotation, their influence on mass loss by stellar winds, the effects of differential rotation and its associated instabilities, the relation with magnetic fields and the evolution of the internal and surface rotation. Further, he discusses the numerous observational signatures of rotational effects obtained from spectroscopy and interferometric observations, as well as from chemical abundance determinations, helioseismology and asteroseismology, etc. On an introductory level, this book presents in a didactical way the basic concepts of stellar structure and evolution in "track 1" chapters. The other more specialized chapters form an advanced course on the gradua...

  20. The rotation of P/Halley

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Szegoe, K.; Kondor, A.; Merenyi, E.; Smith, B.A.; Larson, S.; Toth, I.

    1987-11-01

    The nucleus of the comet Halley rotates as a slightly asymmetric top, the orientation of the rotation axis (the orientation of the angular momentum vector) is b=54 deg +-15 deg, l=219 deg +-15 deg in the ecliptic system. In the case of the rotation of an asymmetric top the rotation axis is not fixed rigidly to the body, which means that while the nucleus rotates around the axis with a period of 2.2+-0.05 d, its long axis 'nods' periodically with a period of 7.4+-0.05 d. The amplitude of the 'nodding' is about 15 deg +-3 deg in both directions relative to a plane perpendicular to the rotation axis. (author) 21 refs.; 6 figs.; 2 tabs

  1. Contained Modes In Mirrors With Sheared Rotation

    International Nuclear Information System (INIS)

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2010-01-01

    In mirrors with E x B rotation, a fixed azimuthal perturbation in the lab frame can appear as a wave in the rotating frame. If the rotation frequency varies with radius, the plasma-frame wave frequency will also vary radially due to the Doppler shift. A wave that propagates in the high rotation plasma region might therefore be evanescent at the plasma edge. This can lead to radially localized Alfven eigenmodes with high azimuthal mode numbers. Contained Alfven modes are found both for peaked and non-peaked rotation profiles. These modes might be useful for alpha channeling or ion heating, as the high azimuthal wave number allows the plasma wave frequency in the rotating frame to exceed the ion cyclotron frequency.

  2. From Newton's bucket to rotating polygons

    DEFF Research Database (Denmark)

    Bach, B.; Linnartz, E. C.; Vested, Malene Louise Hovgaard

    2014-01-01

    We present an experimental study of 'polygons' forming on the free surface of a swirling water flow in a partially filled cylindrical container. In our set-up, we rotate the bottom plate and the cylinder wall with separate motors. We thereby vary rotation rate and shear strength independently...... and move from a rigidly rotating 'Newton's bucket' flow to one where bottom and cylinder wall are rotating oppositely and the surface is strongly turbulent but flat on average. Between those two extremes, we find polygonal states for which the rotational symmetry is spontaneously broken. We investigate...... the phase diagram spanned by the two rotational frequencies at a given water filling height and find polygons in a regime, where the two frequencies are sufficiently different and, predominantly, when they have opposite signs. In addition to the extension of the family of polygons found with the stationary...

  3. Polygons on a rotating fluid surface.

    Science.gov (United States)

    Jansson, Thomas R N; Haspang, Martin P; Jensen, Kåre H; Hersen, Pascal; Bohr, Tomas

    2006-05-05

    We report a novel and spectacular instability of a fluid surface in a rotating system. In a flow driven by rotating the bottom plate of a partially filled, stationary cylindrical container, the shape of the free surface can spontaneously break the axial symmetry and assume the form of a polygon rotating rigidly with a speed different from that of the plate. With water, we have observed polygons with up to 6 corners. It has been known for many years that such flows are prone to symmetry breaking, but apparently the polygonal surface shapes have never been observed. The creation of rotating internal waves in a similar setup was observed for much lower rotation rates, where the free surface remains essentially flat [J. M. Lopez, J. Fluid Mech. 502, 99 (2004). We speculate that the instability is caused by the strong azimuthal shear due to the stationary walls and that it is triggered by minute wobbling of the rotating plate.

  4. Contained Modes In Mirrors With Sheared Rotation

    Energy Technology Data Exchange (ETDEWEB)

    Abraham J. Fetterman and Nathaniel J. Fisch

    2010-10-08

    In mirrors with E × B rotation, a fixed azimuthal perturbation in the lab frame can appear as a wave in the rotating frame. If the rotation frequency varies with radius, the plasma-frame wave frequency will also vary radially due to the Doppler shift. A wave that propagates in the high rotation plasma region might therefore be evanescent at the plasma edge. This can lead to radially localized Alfven eigenmodes with high azimuthal mode numbers. Contained Alfven modes are found both for peaked and non-peaked rotation profiles. These modes might be useful for alpha channeling or ion heating, as the high azimuthal wave number allows the plasma wave frequency in the rotating frame to exceed the ion cyclotron frequency. __________________________________________________

  5. Contained modes in mirrors with sheared rotation

    International Nuclear Information System (INIS)

    Fetterman, Abraham J.; Fisch, Nathaniel J.

    2010-01-01

    In mirrors with ExB rotation, a fixed azimuthal perturbation in the laboratory frame can appear as a wave in the rotating frame. If the rotation frequency varies with radius, the plasma-frame wave frequency will also vary radially due to the Doppler shift. A wave that propagates in the high rotation plasma region might therefore be evanescent at the plasma edge. This can lead to radially localized Alfven eigenmodes with high azimuthal mode numbers. Contained Alfven modes are found both for peaked and nonpeaked rotation profiles. These modes might be useful for alpha channeling or ion heating, as the high azimuthal wave number allows the plasma wave frequency in the rotating frame to exceed the ion cyclotron frequency.

  6. Perception of self motion during and after passive rotation of the body around an earth-vertical axis.

    Science.gov (United States)

    Sinha, N; Zaher, N; Shaikh, A G; Lasker, A G; Zee, D S; Tarnutzer, A A

    2008-01-01

    We investigated the perception of self-rotation using constant-velocity chair rotations. Subjects signalled self motion during three independent tasks (1) by pushing a button when rotation was first sensed, when velocity reached a peak, when velocity began to decrease, and when velocity reached zero, (2) by rotating a disc to match the perceived motion of the body, or (3) by changing the static position of the dial such that a bigger change in its position correlated with a larger perceived velocity. All three tasks gave a consistent quantitative measure of perceived angular velocity. We found a delay in the time at which peak velocity of self-rotation was perceived (2-5 s) relative to the beginning or to the end of chair rotation. In addition the decay of the perception of self-rotation was preceded by a sensed constant-velocity interval or plateau (9-14 s). This delay in the rise of self-motion perception, and the plateau for the maximum perceived velocity, contrasts with the rapid rise and the immediate decay of the angular vestibuloocular reflex (aVOR). This difference suggests that the sensory signal from the semicircular canals undergoes additional neural processing, beyond the contribution of the velocity-storage mechanism of the aVOR, to compute the percept of self-motion.

  7. Controlling Sample Rotation in Acoustic Levitation

    Science.gov (United States)

    Barmatz, M. B.; Stoneburner, J. D.

    1985-01-01

    Rotation of acoustically levitated object stopped or controlled according to phase-shift monitoring and control concept. Principle applies to square-cross-section levitation chamber with two perpendicular acoustic drivers operating at same frequency. Phase difference between X and Y acoustic excitation measured at one corner by measuring variation of acoustic amplitude sensed by microphone. Phase of driver adjusted to value that produces no rotation or controlled rotation of levitated object.

  8. Continuously rotating cat scanning apparatus and method

    International Nuclear Information System (INIS)

    Bax, R.F.

    1980-01-01

    A tomographic scanner with a continuously rotating source of radiation is energized by converting inertial mechanical energy to electrical energy. The mechanical-to-electrical conversion apparatus is mounted with the x-ray source to be energized on a rotating flywheel. The inertial mechanical energy stored in the rotating conversion apparatus, flywheel and x-ray source is utilized for generating electrical energy used, in turn, to energize the x-ray source

  9. Plasma rotation in coaxial discharges

    International Nuclear Information System (INIS)

    Masoud, M.M.; Soliman, H.M.; Elkhalafawy, T.A.

    1985-01-01

    Plasma rotation has been observed near the breech of the coaxial electrodes, which propagates inside the coaxial gun and moreover this has been detected in the expansion chamber. Azimuthal component of plasma current has been detected. The measuring of the axial magnetic field distribution in time along the expansion chamber-axis shows a single maximum peak for all position. Azimuthal component of electric field exists along the axis of the expansion chamber and results for two angular positions (0 0 , 180 0 ) at r 2.5 cm has been presented. Thus it is obvious that the whole plasma bulk moves in a screw configuration before and after the focus position. 9 fig

  10. Duality rotations for interacting fields

    International Nuclear Information System (INIS)

    Gaillard, M.K.; Zumino, Bruno

    1981-05-01

    We study the properties of interacting field theories which are invariant under duality rotations which transform a vector field strength into its dual. We consider non-abelian duality groups and find that the largest group for n interacting field strengths is the non-compact Sp(2n,R), which has U(n) as its maximal compact subgroup. We show that invariance of the equations of motion requires that the Lagrangian change in a particular way under duality. We use this property to demonstrate the existence of conserved currents, the invariance of the energy momentum tensor, and also in the general construction of the Lagrangian. Finally we comment on the existence of zero mass spin one bound states in N=8 supergravity, which possesses a non-compact E 7 dual invariance

  11. Rotational structures in 174Ta

    International Nuclear Information System (INIS)

    Hojman, Daniel; Kreiner, A.J.; Davidson, Miguel

    1989-01-01

    The nucleus 174 Ta has been studied for the first time through the fusion-evaporation reaction 169 Tm ( 9 Be,4n) using a 4 mg/cm 2 self-supporting Tm foil in the 40 to 65 MeV bombarding energy range (the 4n channel was found to peak at 50 MeV). The experiments comprised γ and X-ray singles in beam and activity spectra, γ-γ-t coincidences (one of the counters was Compton suppressed) and γ-ray angular distributions. The results obtained allowed the construction of a high-spin level scheme. This scheme, which resembles that of 172 Ta, comprises several rotational bands which correspond to different couplings of the valence nucleons. One of these structures, the doubly decoupled band (DDB), is particularly interesting because it is the first observed case of a DDB based on an I π =3 + state. (Author) [es

  12. Rotation of the Solar Equator

    Science.gov (United States)

    Kotov, V. A.

    2017-06-01

    Regular measurements of the general magnetic field of the Sun, performed over about half a century at the Crimean Astrophysical Observatory, the J. Wilcox Solar Observatory, and five other observatories, are considered in detail for the time 1968 - 2016. They include more than twenty-six thousand daily values of the mean line-of-sight field strength of the visible solar hemisphere. On the basis of these values, the equatorial rotation period of the Sun is found to be 26.926(9) d (synodic). It is shown that its half-value coincides within error limits with both the main period of the magnetic four-sector structure, 13.4577(25) d, and the best-commensurate period of the slow motions of the major solar system bodies, 13.479(22) d (sidereal). The probability that the two periods coincide by chance is estimated to be about 10^{-7}. The true origin of this odd resonance is unknown.

  13. Vibration of imperfect rotating disk

    Directory of Open Access Journals (Sweden)

    Půst L.

    2011-12-01

    Full Text Available This study is concerned with the theoretical and numerical calculations of the flexural vibrations of a bladed disk. The main focus of this study is to elaborate the basic background for diagnostic and identification methods for ascertaining the main properties of the real structure or an experimental model of turbine disks. The reduction of undesirable vibrations of blades is proposed by using damping heads, which on the experimental model of turbine disk are applied only on a limited number of blades. This partial setting of damping heads introduces imperfection in mass, stiffness and damping distribution on the periphery and leads to more complicated dynamic properties than those of a perfect disk. Calculation of FEM model and analytic—numerical solution of disk behaviour in the limited (two modes frequency range shows the splitting of resonance with an increasing speed of disk rotation. The spectrum of resonance is twice denser than that of a perfect disk.

  14. Intrinsic rotation with gyrokinetic models

    International Nuclear Information System (INIS)

    Parra, Felix I.; Barnes, Michael; Catto, Peter J.; Calvo, Iván

    2012-01-01

    The generation of intrinsic rotation by turbulence and neoclassical effects in tokamaks is considered. To obtain the complex dependences observed in experiments, it is necessary to have a model of the radial flux of momentum that redistributes the momentum within the tokamak in the absence of a preexisting velocity. When the lowest order gyrokinetic formulation is used, a symmetry of the model precludes this possibility, making small effects in the gyroradius over scale length expansion necessary. These effects that are usually small become important for momentum transport because the symmetry of the lowest order gyrokinetic formulation leads to the cancellation of the lowest order momentum flux. The accuracy to which the gyrokinetic equation needs to be obtained to retain all the physically relevant effects is discussed.

  15. SPARSE FARADAY ROTATION MEASURE SYNTHESIS

    International Nuclear Information System (INIS)

    Andrecut, M.; Stil, J. M.; Taylor, A. R.

    2012-01-01

    Faraday rotation measure synthesis is a method for analyzing multichannel polarized radio emissions, and it has emerged as an important tool in the study of Galactic and extragalactic magnetic fields. The method requires the recovery of the Faraday dispersion function from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we discuss a recovery method that assumes a sparse approximation of the Faraday dispersion function in an overcomplete dictionary of functions. We discuss the general case when both thin and thick components are included in the model, and we present the implementation of a greedy deconvolution algorithm. We illustrate the method with several numerical simulations that emphasize the effect of the covered range and sampling resolution in the Faraday depth space, and the effect of noise on the observed data.

  16. The solar house that rotates

    International Nuclear Information System (INIS)

    Miloni, R.P.

    2001-01-01

    This article describes an innovative solar building in Weiz, Austria, that uses passive solar technologies, photovoltaics and a ground-coupled heat pump to cover its minimal energy requirements. The house, which follows the sun by rotating around its central axis, is described in detail, including its climatic design and its 'plus-energy' concept. Details are also given on the materials used in the house's construction and the functioning of its thermal insulation. The various operating modes of the house from the systems point of view are described for differing seasons and climatic extremes. Marketing aspects for this standardised house, featuring personal-computer-based on-line definition of facade cladding, fittings, photovoltaic power, furnishings etc. and real-time rendering of the house are also discussed

  17. Development of novel tasks for studying view-invariant object recognition in rodents: Sensitivity to scopolamine.

    Science.gov (United States)

    Mitchnick, Krista A; Wideman, Cassidy E; Huff, Andrew E; Palmer, Daniel; McNaughton, Bruce L; Winters, Boyer D

    2018-05-15

    The capacity to recognize objects from different view-points or angles, referred to as view-invariance, is an essential process that humans engage in daily. Currently, the ability to investigate the neurobiological underpinnings of this phenomenon is limited, as few ethologically valid view-invariant object recognition tasks exist for rodents. Here, we report two complementary, novel view-invariant object recognition tasks in which rodents physically interact with three-dimensional objects. Prior to experimentation, rats and mice were given extensive experience with a set of 'pre-exposure' objects. In a variant of the spontaneous object recognition task, novelty preference for pre-exposed or new objects was assessed at various angles of rotation (45°, 90° or 180°); unlike control rodents, for whom the objects were novel, rats and mice tested with pre-exposed objects did not discriminate between rotated and un-rotated objects in the choice phase, indicating substantial view-invariant object recognition. Secondly, using automated operant touchscreen chambers, rats were tested on pre-exposed or novel objects in a pairwise discrimination task, where the rewarded stimulus (S+) was rotated (180°) once rats had reached acquisition criterion; rats tested with pre-exposed objects re-acquired the pairwise discrimination following S+ rotation more effectively than those tested with new objects. Systemic scopolamine impaired performance on both tasks, suggesting involvement of acetylcholine at muscarinic receptors in view-invariant object processing. These tasks present novel means of studying the behavioral and neural bases of view-invariant object recognition in rodents. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Hall effect in the presence of rotation

    Science.gov (United States)

    Zubkov, M. A.

    2018-02-01

    A rotating relativistic fermion system is considered. The consideration is based on the Dirac equation written in the laboratory (non-rotating) reference frame. Rotation in this approach gives rise to the effective magnetic and electric fields that act in the same way both on positive and negative electric charges. In the presence of external electric field in the given system the electric current appears orthogonal to both the electric field and the axis of rotation. The possible applications to the physics of quark-gluon plasma are discussed.

  19. Forced vibrations of rotating circular cylindrical shells

    International Nuclear Information System (INIS)

    Igawa, Hirotaka; Maruyama, Yoshiyuki; Endo, Mitsuru

    1995-01-01

    Forced vibrations of rotating circular cylindrical shells are investigated. Basic equations, including the effect of initial stress due to rotation, are formulated by the finite-element method. The characteristic relations for finite elements are derived from the energy principle by considering the finite strain. The equations of motion can be separated into quasi-static and dynamic ones, i.e., the equations in the steady rotating state and those in the vibration state. Radial concentrated impulses are considered as the external dynamic force. The transient responses of circular cylindrical shells are numerically calculated under various boundary conditions and rotating speeds. (author)

  20. Relativistic effects in a rotating coordinate system

    International Nuclear Information System (INIS)

    Chugreev, Y.V.

    1989-01-01

    The general approach to calculating various physical effects in a rotating, noninertial reference frame based on the tetrad formalism for observables is discussed. It is shown that the method based on the search for the ''true'' coordinate transformation from an inertial to the rotating frame is ill-founded. Most special relativistic effects in a rotating frame have been calculated without any nonrelativistic restrictions. It is shown how simple physical experiments can be used to determine whether a circle is at rest in the equatorial plane of a Kerr--Newman gravitational source in the relativistic theory of gravity or is rotating about an axis through its center

  1. Rotational spectroscopy with an optical centrifuge.

    Science.gov (United States)

    Korobenko, Aleksey; Milner, Alexander A; Hepburn, John W; Milner, Valery

    2014-03-07

    We demonstrate a new spectroscopic method for studying electronic transitions in molecules with extremely broad range of angular momentum. We employ an optical centrifuge to create narrow rotational wave packets in the ground electronic state of (16)O2. Using the technique of resonance-enhanced multi-photon ionization, we record the spectrum of multiple ro-vibrational transitions between X(3)Σg(-) and C(3)Πg electronic manifolds of oxygen. Direct control of rotational excitation, extending to rotational quantum numbers as high as N ≳ 120, enables us to interpret the complex structure of rotational spectra of C(3)Πg beyond thermally accessible levels.

  2. Learning Rotation for Kernel Correlation Filter

    KAUST Repository

    Hamdi, Abdullah

    2017-08-11

    Kernel Correlation Filters have shown a very promising scheme for visual tracking in terms of speed and accuracy on several benchmarks. However it suffers from problems that affect its performance like occlusion, rotation and scale change. This paper tries to tackle the problem of rotation by reformulating the optimization problem for learning the correlation filter. This modification (RKCF) includes learning rotation filter that utilizes circulant structure of HOG feature to guesstimate rotation from one frame to another and enhance the detection of KCF. Hence it gains boost in overall accuracy in many of OBT50 detest videos with minimal additional computation.

  3. Rotation of vertically oriented objects during earthquakes

    Science.gov (United States)

    Hinzen, Klaus-G.

    2012-10-01

    Vertically oriented objects, such as tombstones, monuments, columns, and stone lanterns, are often observed to shift and rotate during earthquake ground motion. Such observations are usually limited to the mesoseismal zone. Whether near-field rotational ground motion components are necessary in addition to pure translational movements to explain the observed rotations is an open question. We summarize rotation data from seven earthquakes between 1925 and 2009 and perform analog and numeric rotation testing with vertically oriented objects. The free-rocking motion of a marble block on a sliding table is disturbed by a pulse in the direction orthogonal to the rocking motion. When the impulse is sufficiently strong and occurs at the `right' moment, it induces significant rotation of the block. Numeric experiments of a free-rocking block show that the initiation of vertical block rotation by a cycloidal acceleration pulse applied orthogonal to the rocking axis depends on the amplitude of the pulse and its phase relation to the rocking cycle. Rotation occurs when the pulse acceleration exceeds the threshold necessary to provoke rocking of a resting block, and the rocking block approaches its equilibrium position. Experiments with blocks subjected to full 3D strong motion signals measured during the 2009 L'Aquila earthquake confirm the observations from the tests with analytic ground motions. Significant differences in the rotational behavior of a monolithic block and two stacked blocks exist.

  4. Rotation influence on the plasma helical instability

    International Nuclear Information System (INIS)

    Gutkin, T.I.; Tsypin, V.S.; Boleslavskaya, G.I.

    1980-01-01

    The influence of the rotation on helical instability of a plasma with the fixed boundaries (HIFB) is investigated taking into account the compressibility. A case of infinitely long cylinder with distributed current is considered. Cases when a rotating plasma is confined by current magnetic field are analytically considered. It is shown that in the case of the fixed boundary taking into account the compressibility in the HIFB increment increases and the picture of the rotation influence on HIFB considerably changes. Besides, it is shown that in the case of high plasma pressures HIFB can stabilize as a result of the rotation

  5. Injection Therapies for Rotator Cuff Disease.

    Science.gov (United States)

    Lin, Kenneth M; Wang, Dean; Dines, Joshua S

    2018-04-01

    Rotator cuff disease affects a large proportion of the overall population and encompasses a wide spectrum of pathologies, including subacromial impingement, rotator cuff tendinopathy or tear, and calcific tendinitis. Various injection therapies have been used for the treatment of rotator cuff disease, including corticosteroid, prolotherapy, platelet-rich plasma, stem cells, and ultrasound-guided barbotage for calcific tendinitis. However, the existing evidence for these therapies remains controversial or sparse. Ultimately, improved understanding of the underlying structural and compositional deficiencies of the injured rotator cuff tissue is needed to identify the biological needs that can potentially be targeted with injection therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. The effect of rotations on Michelson interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Maraner, Paolo, E-mail: pmaraner@unibz.it

    2014-11-15

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

  7. The effect of rotations on Michelson interferometers

    International Nuclear Information System (INIS)

    Maraner, Paolo

    2014-01-01

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

  8. Polygons on a rotating fluid surface

    DEFF Research Database (Denmark)

    Jansson, Thomas R.N.; Haspang, Martin P.; Jensen, Kåre H.

    2006-01-01

    We report a novel and spectacular instability of a fluid surface in a rotating system. In a flow driven by rotating the bottom plate of a partially filled, stationary cylindrical container, the shape of the free surface can spontaneously break the axial symmetry and assume the form of a polygon...... rotating rigidly with a speed different from that of the plate. With water, we have observed polygons with up to 6 corners. It has been known for many years that such flows are prone to symmetry breaking, but apparently the polygonal surface shapes have never been observed. The creation of rotating...

  9. Neoclassical poloidal and toroidal rotation in tokamaks

    International Nuclear Information System (INIS)

    Kim, Y.B.; Diamond, P.H.; Groebner, R.J.

    1991-01-01

    Explicit expressions for the neoclassical poloidal and toroidal rotation speeds of primary ion and impurity species are derived via the Hirshman and Sigmar moment approach. The rotation speeds of the primary ion can be significantly different from those of impurities in various interesting cases. The rapid increase of impurity poloidal rotation in the edge region of H-mode discharges in tokamaks can be explained by a rapid steepening of the primary ion pressure gradient. Depending on ion collisionality, the poloidal rotation speed of the primary ions at the edge can be quite small and the flow direction may be opposite to that of the impurities. This may cast considerable doubts on current L to H bifurcation models based on primary ion poloidal rotation only. Also, the difference between the toroidal rotation velocities of primary ions and impurities is not negligible in various cases. In Ohmic plasmas, the parallel electric field induces a large impurity toroidal rotation close to the magnetic axis, which seems to agree with experimental observations. In the ion banana and plateau regime, there can be non-negligible disparities between primary ion and impurity toroidal rotation velocities due to the ion density and temperature gradients. Detailed analytic expressions for the primary ion and impurity rotation speeds are presented, and the methodology for generalization to the case of several impurity species is also presented for future numerical evaluation

  10. Increased Upper Trapezius Muscle Stiffness in Overhead Athletes with Rotator Cuff Tendinopathy.

    Directory of Open Access Journals (Sweden)

    Hio Teng Leong

    Full Text Available Although excessive tension of the upper trapezius (UT is thought to contribute to rotator cuff tendinopathy, no study examined UT tension in athletes with and without rotator cuff tendinopathy. Here we used UT shear modulus measured using ultrasound shear wave elastography as an index of muscle stiffness/tension. The aims of this study were twofold: 1 to determine whether the UT muscle shear modulus is altered in athletes with rotator cuff tendinopathy compared to asymptomatic athletes, and 2 to detect optimal cut-off points of UT shear modulus in identifying athletes with rotator cuff tendinopathy. Forty-three male volleyball players (17 asymptomatic and 26 with rotator cuff tendinopathy, mean age = 22.9±3.5 years participated in the study. UT shear modulus was quantified during active arm holding at 30° and 60° of shoulder abduction and passive arm positioning at 0°, 30° and 60° of shoulder abduction. During the active tasks, the UT shear modulus was higher in athletes with rotator cuff tendinopathy than the asymptomatic athletes (p = 0.002, regardless the arm position. During the passive tasks, athletes with rotator cuff tendinopathy exhibited a higher UT shear modulus than asymptomatic athletes only at 0° of shoulder abduction (13.0±2.5 kPa vs 10.2±1.8 kPa, p = 0.001. When considering the active task, an optimal cut-off shear modulus of 12.0 kPa at 30° of shoulder abduction (sensitivity = 0.84, specificity = 0.57, AUC = 0.757, p = 0.008 and 9.5 kPa at 60° of shoulder abduction (sensitivity = 0.88, specificity = 0.67, AUC = 0.816, p = 0.002 was detected. When considering the passive task at 0° of shoulder abduction, a cut-off of 12.2 kPa was found (sensitivity = 0.73, AUC = 0.817, p = 0.001. Findings from the present study show that monitoring passive and active UT muscle shear modulus may provide important information for the prevention/rehabilitation of rotator cuff tendinopathy.

  11. Dissociating object-based from egocentric transformations in mental body rotation: effect of stimuli size.

    Science.gov (United States)

    Habacha, Hamdi; Moreau, David; Jarraya, Mohamed; Lejeune-Poutrain, Laure; Molinaro, Corinne

    2018-01-01

    The effect of stimuli size on the mental rotation of abstract objects has been extensively investigated, yet its effect on the mental rotation of bodily stimuli remains largely unexplored. Depending on the experimental design, mentally rotating bodily stimuli can elicit object-based transformations, relying mainly on visual processes, or egocentric transformations, which typically involve embodied motor processes. The present study included two mental body rotation tasks requiring either a same-different or a laterality judgment, designed to elicit object-based or egocentric transformations, respectively. Our findings revealed shorter response times for large-sized stimuli than for small-sized stimuli only for greater angular disparities, suggesting that the more unfamiliar the orientations of the bodily stimuli, the more stimuli size affected mental processing. Importantly, when comparing size transformation times, results revealed different patterns of size transformation times as a function of angular disparity between object-based and egocentric transformations. This indicates that mental size transformation and mental rotation proceed differently depending on the mental rotation strategy used. These findings are discussed with respect to the different spatial manipulations involved during object-based and egocentric transformations.

  12. Postural Effects on the Mental Rotation of Body-Related Pictures: An fMRI Study

    Directory of Open Access Journals (Sweden)

    Fangbing Qu

    2018-05-01

    Full Text Available This study investigated the embodied effects involved in the mental rotation of pictures of body parts (hands and feet. Blood oxygen level-dependent (BOLD signals were collected from 18 healthy volunteers who performed mental rotation tasks of rotated drawings of hands under different arm postures. Congruent drawings of hands (those congruent with left-hand posture evoked stronger activation in the left supplementary motor area (SMA, left precentral gyrus, and left superior parietal lobule (SPL than did incongruent drawings of hands. Congruent drawings of hands (those congruent with right-hand posture evoked significant activation in the left inferior parietal lobule (IPL, right SMA, bilateral middle frontal gyrus (MFG, left inferior frontal gyrus (IFG, and bilateral superior frontal gyrus (SFG compared to that evoked by the incongruent drawings of hands. Similar methodology was implemented with drawings of feet. However, no significant differences in brain activation were observed between congruent and incongruent drawings of feet. This finding suggests that body posture influences body part-related mental rotation in an effector-specific manner. A direct comparison between the medially and laterally rotated drawings revealed activation in the right IPL, left precentral gyrus, bilateral IFG, and bilateral SFG. These results suggest that biomechanical constraints affect the cognitive process of mental rotation.

  13. Cognitive task load analysis : Allocating tasks and designing support

    NARCIS (Netherlands)

    Neerincx, M.A.

    2003-01-01

    We present a method for Cognitive Task Analysis that guides the early stages of software development, aiming at an optimal cognitive load for operators of process control systems. The method is based on a practical theory of cognitive task load and support. In addition to the classical measure

  14. Imaging with rotating slit apertures and rotating collimators

    International Nuclear Information System (INIS)

    Gindi, G.R.; Arendt, J.; Barrett, H.H.; Chiu, M.Y.; Ervin, A.; Giles, C.L.; Kujoory, M.A.; Miller, E.L.; Simpson, R.G.

    1982-01-01

    The statistical quality of conventional nuclear medical imagery is limited by the small signal collect through low-efficiency conventional apertures. Coded-aperture imaging overcomes this by employing a two-step process in which the object is first efficiently detected as an ''encoded'' form which does not resemble the object, and then filtered (or ''decoded'') to form an image. We present here the imaging properties of a class of time-modulated coded apertures which, unlike most coded apertures, encode projections of the object rather than the object itself. These coded apertures can reconstruct a volume object nontomographically, tomographically (one plane focused), or three-dimensionally. We describe a new decoding algorithm that reconstructs the object from its planar projections. Results of noise calculations are given, and the noise performance of these coded-aperture systems is compared to that of conventional counterparts. A hybrid slit-pinhole system which combines the imaging advantages of a rotating slit and a pinhole is described. A new scintillation detector which accurately measures the position of an event in one dimension only is presented, and its use in our coded-aperture system is outlined. Finally, results of imaging test objects and animals are given

  15. Imaging with rotating slit apertures and rotating collimators

    International Nuclear Information System (INIS)

    Gindi, G.R.; Arendt, J.; Barrett, H.H.; Chiu, M.Y.; Ervin, A.; Giles, C.L.; Kujoory, M.A.; Miller, E.L.; Simpson, R.G.

    1982-01-01

    The statistical quality of conventional nuclear medical imagery is limited by the small signal collected through low-efficiency conventional apertures. Coded-aperture imaging overcomes this by employing a two-step process in which the object is first efficiently detected as an encoded form which does not resemble the object, and then filtered (or decoded) to form an image. We present here the imaging properties of a class of time-modulated coded apertures which, unlike most coded apertures, encode projections of the object rather than the object itself. These coded apertures can reconstruct a volume object nontomographically, tomographically (one plane focused), or three-dimensionally. We describe a new decoding algorithm that reconstructs the object from its planar projections. Results of noise calculations are given, and the noise performance of these coded-aperture systems is compared to that of conventional counterparts. A hybrid slit-pinhole system which combines the imaging advantages of a rotating slit and a pinhole is described. A new scintillation detector which accurately measures the position of an event in one dimension only is presented, and its use in our coded-aperture system is outlined. Finally, results of imaging test objects and animals are given

  16. Solving a mental rotation task in congenital hemiparesis: Motor imagery versus visual imagery

    NARCIS (Netherlands)

    Steenbergen, B.; Nimwegen, M.L. van; Crajé, M.C.

    2007-01-01

    A recent study showed that motor imagery was compromised after right congenital hemiparesis. In that study, posture of the displayed stimuli and the actual posture of the hand making the response were incongruent. Ample evidence exists that such an incongruency may negatively influence laterality

  17. Motor imagery in Asperger syndrome: testing action simulation by the hand laterality task.

    Directory of Open Access Journals (Sweden)

    Massimiliano Conson

    Full Text Available Asperger syndrome (AS is a neurodevelopmental condition within the Autism Spectrum Disorders (ASD characterized by specific difficulties in social interaction, communication and behavioural control. In recent years, it has been suggested that ASD is related to a dysfunction of action simulation processes, but studies employing imitation or action observation tasks provided mixed results. Here, we addressed action simulation processes in adolescents with AS by means of a motor imagery task, the classical hand laterality task (to decide whether a rotated hand image is left or right; mental rotation of letters was also evaluated. As a specific marker of action simulation in hand rotation, we assessed the so-called biomechanical effect, that is the advantage for judging hand pictures showing physically comfortable versus physically awkward positions. We found the biomechanical effect in typically-developing participants but not in participants with AS. Overall performance on both hand laterality and letter rotation tasks, instead, did not differ in the two groups. These findings demonstrated a specific alteration of motor imagery skills in AS. We suggest that impaired mental simulation and imitation of goal-less movements in ASD could be related to shared cognitive mechanisms.

  18. Correlates of academic procrastination: discomfort, task aversiveness, and task capability.

    Science.gov (United States)

    Milgram, N; Marshevsky, S; Sadeh, C

    1995-03-01

    The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating.

  19. Off-Resonance Acoustic Levitation Without Rotation

    Science.gov (United States)

    Barmatz, M. B.; Allen, J. L.

    1984-01-01

    Orthogonal acoustic-levitation modes excited at slightly different frequencies to control rotation. Rotation of object in square cross-section acoustic-levitation chamber stopped by detuning two orthogonal (x and y) excitation drivers in plane of square cross section. Detuning done using fundamental degenerate modes or odd harmonic modes.

  20. Study of rotational band in 111Sn

    International Nuclear Information System (INIS)

    Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Raut, R.; Goswami, A.; Saha Sarkar, M.; Bhattacharya, S.; Mukherjee, A.; Mukherjee, G.; Basu, S.K.; Mukhopadhyay, S.

    2006-01-01

    The motivation of the present work is to study the negative-parity rotational band in 111 Sn. Study of the lifetimes of the states of the rotational band is expected to provide information on their structures as well as the band termination phenomenon