WorldWideScience

Sample records for energy landscape perspectives

  1. Ideal glass transitions in thin films: An energy landscape perspective

    OpenAIRE

    Truskett, Thomas M.; Ganesan, Venkat

    2003-01-01

    We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperatu...

  2. Ideal glass transitions in thin films: An energy landscape perspective

    Science.gov (United States)

    Truskett, Thomas M.; Ganesan, Venkat

    2003-07-01

    We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperature of thin films, suggesting the utility of landscape-based approaches for studying the behavior of confined fluids.

  3. Polyomaviridae Assembly Polymorphism from an Energy Landscape Perspective

    Directory of Open Access Journals (Sweden)

    Karim M. ElSawy

    2008-01-01

    Full Text Available Polyomaviridae assemble in vitro into different aggregates depending on experimental conditions. We use an energy landscape approach using empirical energy calculations to quantify how the formation of these different aggregates depends on pH, the presence of bound calcium ions and disulfide linkages. Computations are carried out for SV40, a member of the Polyomaviridae family and are based on the binding free energy landscape of three distinct trimers of pentamers that correspond to the different bonding configurations between the capsid proteins observed in its crystal structure. Our computational analysis shows that the energetics of one of these environments is pivotal for the polymorphic assembly behaviour of SV40, whilst the binding energy landscapes of the other two environments are broadly funnel-shaped and thus contribute little to the formation of particles other than virus-like particles (VLP. We have quantified how the existence of bound calcium ions in the absence of disulfide linkages enhances the binding free energies of all three environments and hence, favours the assembly of VLPs. Moreover, estimation of the relative binding free energies of the three environments at pH 5 and pH 8 reveals that they are destabilized at pH 5 relative to pH 8. The extent of this destabilization is dependent on the presence of disulfide linkages and bound calcium ions and accounts for the experimentally observed polymorphic behaviour of VP1 proteins at pH 5. Interestingly, concurrent existence of bound calcium ions and disulfide linkages is found to be destabilizing and thus may disrupt the assembly of VLPs at pH 8.

  4. Exploring Energy Landscapes

    Science.gov (United States)

    Wales, David J.

    2018-04-01

    Recent advances in the potential energy landscapes approach are highlighted, including both theoretical and computational contributions. Treating the high dimensionality of molecular and condensed matter systems of contemporary interest is important for understanding how emergent properties are encoded in the landscape and for calculating these properties while faithfully representing barriers between different morphologies. The pathways characterized in full dimensionality, which are used to construct kinetic transition networks, may prove useful in guiding such calculations. The energy landscape perspective has also produced new procedures for structure prediction and analysis of thermodynamic properties. Basin-hopping global optimization, with alternative acceptance criteria and generalizations to multiple metric spaces, has been used to treat systems ranging from biomolecules to nanoalloy clusters and condensed matter. This review also illustrates how all this methodology, developed in the context of chemical physics, can be transferred to landscapes defined by cost functions associated with machine learning.

  5. Monitoring Forest Change in Landscapes Under-Going Rapid Energy Development: Challenges and New Perspectives

    Directory of Open Access Journals (Sweden)

    Paul D. Pickell

    2014-07-01

    Full Text Available The accelerated development of energy resources around the world has substantially increased forest change related to oil and gas activities. In some cases, oil and gas activities are the primary catalyst of land-use change in forested landscapes. We discuss the challenges associated with characterizing ecological change related to energy resource development using North America as an exemplar. We synthesize the major impacts of energy development to forested ecosystems and offer new perspectives on how to detect and monitor anthropogenic disturbance during the Anthropocene. The disturbance of North American forests for energy development has resulted in persistent linear corridors, suppression of historical disturbance regimes, novel ecosystems, and the eradication of ecological memory. Characterizing anthropogenic disturbances using conventional patch-based disturbance measures will tend to underestimate the ecological impacts of energy development. Suitable indicators of anthropogenic impacts in forests should be derived from the integration of multi-scalar Earth observations. Relating these indicators to ecosystem condition will be a capstone in the progress toward monitoring forest change in landscapes undergoing rapid energy development.

  6. Urban Landscape Perspectives

    Directory of Open Access Journals (Sweden)

    Frederick Steiner

    2014-03-01

    Full Text Available Cities present significant opportunities for new landscape perspectives that can help inform conservation and development decisions. Early in the twenty-first century, the majority of the planet’s population became urban as more people lived in city-regions for the first time in our history. As the global population increases, so does this urbanization. The environmental challenges of population and urban growth are profound. Landscapes represent a synthesis of natural and cultural processes. Cities are certainly cultural phenomena. Historically, cities provided refuge from nature. The expanding field of urban ecology, coupled with landscape ecology, can enhance how the dual natural and cultural dimensions of landscapes in cities are understood. Furthermore, concepts such as ecosystem services and green infrastructure are proving useful for urban landscape planning and design. Examples from Dayton, Ohio; Brooklyn, New York; and Austin, Texas are presented.

  7. Research using energy landscape

    International Nuclear Information System (INIS)

    Kim, Hack Jin

    2007-01-01

    Energy landscape is a theoretical tool used for the study of systems where cooperative processes occur such as liquid, glass, clusters, and protein. Theoretical and experimental researches related to energy landscape are introduced in this review

  8. The market of energy storage. Stakes and perspectives by 2020 - Analysis of the competitive landscape

    International Nuclear Information System (INIS)

    2013-01-01

    Within a context of lack of regulatory framework, of existence of technological deadlocks, and of absence of any defined business model, this publication reports a study of the emerging market of energy storage. It examines the role public authorities can play to promote investments in this sector, what are the opportunities for operators, and which are the perspectives on the middle term for the French market. In order to highlight recent and future evolutions of stationary and embarked storage, the authors propose an analysis of the main market growth drivers and brakes, a focus on the impact of regulatory, legal, economic, tax-related, technological, and social-cultural factors on sector stakeholders. They also propose an overview of the market status for the cases of stationary and embarked storage, and of the main challenges for these both segments. A panorama of existing actors is given with an analysis of their position, strengths and weaknesses, and of the main axis of development for 4 categories of actors (industries, battery manufacturers, energy operators, and start ups)

  9. Energy landscape Allgaeu; Energielandschaft Allgaeu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-04-01

    In tandems with questions on the energy policy turnaround, the topics cultural landscape history, morphology, actual land use, tourism, settlement development or infrastructure are summarized in regional concepts and designs to a consistent landscape. Thus, a true integration of renewable energies in the landscape enhances existing or creates completely new landscape qualities. Energy supply shall be understood as a component of the every day life world. The energy supply shall not be hidden any more, but it rather should be communicated as the brand 'Allgaeu'.

  10. Energy landscapes in a crowded world

    NARCIS (Netherlands)

    Pasqualetti, Martin; Stremke, Sven

    2018-01-01

    One of the main drivers of landscape transformation has been our demand for energy. We refer to the results of such transformations as "energy landscapes". This paper examines the definition of energy landscapes within a conceptual framework, proposes a classification of energy landscapes, and

  11. Energy Landscape of Social Balance

    Science.gov (United States)

    Marvel, Seth A.; Strogatz, Steven H.; Kleinberg, Jon M.

    2009-11-01

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social “balance” allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  12. Energy landscape of social balance.

    Science.gov (United States)

    Marvel, Seth A; Strogatz, Steven H; Kleinberg, Jon M

    2009-11-06

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social "balance" allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  13. The changing geopolitical landscape of energy

    International Nuclear Information System (INIS)

    Lesourne, Jacques

    2011-08-01

    The author first discusses the impact of the financial crisis of 2008, and of the large-scale exploitation of shale gases in the USA on energy policies and on the geopolitical landscape of energy. Then, he discusses the influence that events which occurred in 2011 had on these issues: firstly, the Copenhagen and Cancun Conferences, secondly, the Fukushima accident, thirdly, the nuclear phasing-out by Germany and incidentally by Italy, and fourthly, the Arab Spring. In the next parts, he comments the consequences for the European energy policy, and the perspectives for the struggle against climate change

  14. The String Landscape: A Personal Perspective

    Science.gov (United States)

    Dienes, Keith R.

    2015-02-01

    In keeping with the "Perspectives" theme of this volume, this Chapter provides a personal perspective on the string landscape. Along the way, the perspectives of many other physicists are discussed as well. No attempt is made to provide a thorough and balanced review of the field, and indeed there is a slight emphasis on my own contributions to this field, as these contributions have been critical to forming my perspective. This Chapter is adapted from a Colloquium which I have delivered at a number of institutions worldwide, and I have attempted to retain the informal and non-technical spirit and style of this Colloquium presentation as much as possible.

  15. Energy transition: towards landscape devastation?

    International Nuclear Information System (INIS)

    Posokhow, Andre

    2013-09-01

    The author criticizes some aspects of the content of the French policy for energy transition. He states that the objective of reduction of greenhouse emissions is unreachable and moreover useless when China keeps on opening new coal-fired power stations. He states that temperatures do not increase any longer and that it is not sure that CO 2 emissions are responsible for past increases. He outlines that the power of wind turbines is only a quarter of their theoretical one, that replacing nuclear energy by wind energy would require the installation of 33.000 wind turbines. He states that objectives of energy saving are not credible, and that the energy mix predictions are fuzzy. He outlines contradictions about the nuclear power station life duration, states that the installation of 210 wind turbines per district would devastate the French landscape

  16. Energy perspectives

    International Nuclear Information System (INIS)

    Tissot, B.

    2005-01-01

    In France and in Europe, the political vision of energy production has not yet been taken to heart as much as its importance merits, despite a certain awareness of the gravity of the phenomena within the population. It would already be very difficult to halve the consumption of fossil fuels in France in 2050, without a swift and profound change in our energy-consumption choices (in particular in transport) and a considerable research effort. To divide it by four seems unrealistic, since France, unlike other countries, has already benefited from the transition from electricity produced from fossil fuels to nuclear electricity which does not emit CO 2 . A major evolution in energy, in Europe and throughout the World, is inevitable in the course of the century. To prevent this from being too violent and painful, a process of fundamental research and technological development should be launched forthwith, in all fields of energy production, storage and use, with a large effort supported by major research programmes. Some recommendations are given for the main research fields that should be: capture and long term storage of CO 2 , energy savings in transport, energy supply to large cities and nuclear power plant enhancement, hydrogen storage, wind energy and its unavailability problem, use of forest resources, photovoltaic electricity in rural and isolated regions, temporary storage of electricity

  17. Competing Wind Energy Discourses, Contested Landscapes

    Directory of Open Access Journals (Sweden)

    Antje Otto

    2014-10-01

    Full Text Available The impairment of landscapes is a concern constantly raised against wind energy developments in Germany as in other countries. Often, landscapes or landscape types are treated in the literature as essentialist or at least as uncontested categories. We analyse two examples of local controversies about wind energy, in which “landscape” is employed by supporters and opponents alike, from a poststructuralist and discourse theoretical angle. The aim is to identify and compare landscape constructs produced in the micro discourses of wind energy objectors and proponents at local level (a within each case, (b between the two cases and (c with landscape constructs that were previously found in macro discourses. One major finding is that several different landscapes can exist at one and the same place. Furthermore there seems to be a relatively stable set of competing landscape concepts which is reproduced in specific controversies. The paper concludes by highlighting practical consequences and by identifying promising avenues of further research.

  18. Physical mechanism of mind changes and tradeoffs among speed, accuracy, and energy cost in brain decision making: Landscape, flux, and path perspectives

    International Nuclear Information System (INIS)

    Yan Han; Wang Jin; Zhang Kun

    2016-01-01

    Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, have been successfully described by attractor dynamics. For decision making in the brain, a quantitative description of global attractor landscapes has not yet been completely given. Here, we developed a theoretical framework to quantify the landscape associated with the steady state probability distributions and associated steady state curl flux, measuring the degree of non-equilibrium through the degree of detailed balance breaking for decision making. We quantified the decision-making processes with optimal paths from the undecided attractor states to the decided attractor states, which are identified as basins of attractions, on the landscape. Both landscape and flux determine the kinetic paths and speed. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. Our theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results imply that there is an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered the possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key factors in the corresponding neural networks. (paper)

  19. The French market of wind energy and its perspectives. Which evolution for the competition landscape in a disrupting regulatory context?

    International Nuclear Information System (INIS)

    2010-11-01

    This article presents the content of a market study which aimed at providing an overview of the development of wind energy in France after market lift-off, at assessing the influence of Grenelle II on this sector, at assessing the competitiveness of wind energy with respect to other production sources, and at analysing strategies of equipment manufacturers and operators on a market where competitive positions are from being fixed. The report proposes an overview of the French wind energy market (legal context, growth dynamics, market valorisation, cost structure and profitability, support measures), analyses the positions and challenges of wind turbine manufacturers (the front end of the sector) and of wind farm developers and operators (the back end of the sector). Several manufacturers (Areva, Enercon, Gamesa, GE Energy, Nordex, REpower, Siemens and Vestas) and developers and operators (Boralex, EDF Energies Nouvelles, EDP Renovavels, Eolfi, GDF Suez, Iberdrola Renovables, Poweo, Theolia) have been analysed

  20. Sustainable energy landscapes : designing, planning, and development

    NARCIS (Netherlands)

    Stremke, S.; Dobbelsteen, van den A.

    2013-01-01

    In the near future the appearance and spatial organization of urban and rural landscapes will be strongly influenced by the generation of renewable energy. One of the critical tasks will be the re-integration of these sustainable energy landscapes into the existing environment—which people value and

  1. Energy forest cultivation and the landscape

    International Nuclear Information System (INIS)

    Bell, Simon

    1994-01-01

    The place of energy forestry in the landscape is discussed, principally with reference to Britain and Europe. The importance of design as a means of ensuring an attractive appearance, while meeting functional and economic requirements, is stressed. Simple design principles which help energy forests, mainly short rotation arable coppice, to fit into the landscape are suggested. (author)

  2. Perspectives on landscape identity, a conceptual challenge

    NARCIS (Netherlands)

    Stobbelaar, D.J.; Pedroli, B.

    2011-01-01

    The concept of landscape identity is often referred to in landscape policy and planning. A clear definition of the concept is lacking however. This is problematic because the term ‘landscape identity’ can have many different meanings and thus easily lead to confusion. We define landscape identity as

  3. Energy landscapes, landscapes in transition. How to prepare one's territory to the deployment of renewable energies

    International Nuclear Information System (INIS)

    2014-06-01

    This guide first defines the notion of landscape, outlines what is at stake with decentralised renewable energy production, and presents the various important aspects of a deployment of decentralised renewable energy production. It describes how to define a general strategy for the integration of this production: relationship between energy and landscape, project implementation, partnership, tools to anticipate changes, evolution of social demand through dialogue, conciliation of technical and financial constraints and landscape ambitions. An appendix proposes legal and bibliographical information: legal relationships between energy and landscape, possible arrangements for PLU (plan local d'urbanisme, local urban plan) and SCOT (schema de coherence territoriale, territorial planning document)

  4. Why is a landscape perspective important in studies of primates?

    Science.gov (United States)

    Arroyo-Rodríguez, Víctor; Fahrig, Lenore

    2014-10-01

    With accelerated deforestation and fragmentation through the tropics, assessing the impact that landscape spatial changes may have on biodiversity is paramount, as this information is required to design and implement effective management and conservation plans. Primates are expected to be particularly dependent on the landscape context; yet, our understanding on this topic is limited as the majority of primate studies are at the local scale, meaning that landscape-scale inferences are not possible. To encourage primatologists to assess the impact of landscape changes on primates, and help future studies on the topic, we describe the meaning of a "landscape perspective" and evaluate important assumptions of using such a methodological approach. We also summarize a number of important, but unanswered, questions that can be addressed using a landscape-scale study design. For example, it is still unclear if habitat loss has larger consistent negative effects on primates than habitat fragmentation per se. Furthermore, interaction effects between habitat area and other landscape effects (e.g., fragmentation) are unknown for primates. We also do not know if primates are affected by synergistic interactions among factors at the landscape scale (e.g., habitat loss and diseases, habitat loss and climate change, hunting, and land-use change), or whether landscape complexity (or landscape heterogeneity) is important for primate conservation. Testing for patterns in the responses of primates to landscape change will facilitate the development of new guidelines and principles for improving primate conservation. © 2014 Wiley Periodicals, Inc.

  5. Perspectives on Energy Security

    International Nuclear Information System (INIS)

    Carlsson-Kanyama, Annika; Holmgren, Aake J.; Joensson, Thomas; Larsson, Robert L.

    2007-05-01

    A common notion of 'Energy Security' is that it includes access to energy resources without risking the the survival of the state. 'Security of supply' is most often the concept emphasized in the political discourse on energy security and it includes both production as well as secure and safe delivery of energy to the end consumers. Another aspect of energy security is the need for reducing energy consumption by improving energy efficiency. In this report, eight chapters covering these and other perspectives on energy security are presented. Six of the chapters deal with the supply perspective. Included topics cover power politics and geopolitical perspectives regarding large infrastructure projects and the ambitions of the EU in this regard. Further, methods and approaches for conducting risk analyses of electricity supply systems as well as for improving the security of digital control systems are discussed. As climate change will affect the supply and distribution of energy, one chapter presents an overview of this topic. The consumption perspective is discussed against the backdrop of research about household consumption practices and the role of climate change for future consumption levels. Finally, the role of armed forces as a large energy users is touched upon, as well as how so-called 'future studies' have dealt with energy as a topic

  6. Energy landscapes shape animal movement ecology.

    Science.gov (United States)

    Shepard, Emily L C; Wilson, Rory P; Rees, W Gareth; Grundy, Edward; Lambertucci, Sergio A; Vosper, Simon B

    2013-09-01

    The metabolic costs of animal movement have been studied extensively under laboratory conditions, although frequently these are a poor approximation of the costs of operating in the natural, heterogeneous environment. Construction of "energy landscapes," which relate animal locality to the cost of transport, can clarify whether, to what extent, and how movement properties are attributable to environmental heterogeneity. Although behavioral responses to aspects of the energy landscape are well documented in some fields (notably, the selection of tailwinds by aerial migrants) and scales (typically large), the principles of the energy landscape extend across habitat types and spatial scales. We provide a brief synthesis of the mechanisms by which environmentally driven changes in the cost of transport can modulate the behavioral ecology of animal movement in different media, develop example cost functions for movement in heterogeneous environments, present methods for visualizing these energy landscapes, and derive specific predictions of expected outcomes from individual- to population- and species-level processes. Animals modulate a suite of movement parameters (e.g., route, speed, timing of movement, and tortuosity) in relation to the energy landscape, with the nature of their response being related to the energy savings available. Overall, variation in movement costs influences the quality of habitat patches and causes nonrandom movement of individuals between them. This can provide spatial and/or temporal structure to a range of population- and species-level processes, ultimately including gene flow. Advances in animal-attached technology and geographic information systems are opening up new avenues for measuring and mapping energy landscapes that are likely to provide new insight into their influence in animal ecology.

  7. The renewable energies: the landscape

    International Nuclear Information System (INIS)

    Acket, C.; Bacher, P.

    2005-03-01

    If one takes into account the hydroelectric power, the France is the first european country in the renewable energies domain. The position is also honorable concerning the wood energy. Meanwhile, for the solar and wind energy, France is late. To discuss this debate, the authors bring together today data on the renewable energies, offer some proposals for the next 50 years taking into account the reduction of greenhouse gases emission for 2050. (A.L.B.)

  8. Towards an Integrated Energy Landscape

    NARCIS (Netherlands)

    de Boer, Jessica; Zuidema, Christian

    2013-01-01

    In this paper, we show that an area-based approach to fostering the ‘energy transition’ has potential to help spatial planners and policy makers understand how innovative sustainable energy initiatives may contribute to the energy transition. On the basis of a desk study of research reports on

  9. Orientational dynamics and energy landscape features of ...

    Indian Academy of Sciences (India)

    WINTEC

    Energy landscape analysis of inherent structures shows that the ... to be strikingly similar to that of supercooled molecular liquids5 .... where eiα is the α-component (in the space-fixed frame) of the unit orientation vector ei along the principal symmetry axis of the ith ellipsoid of revo- ..... understand pathways of protein folding.

  10. Health Promoting Pocket Parks in a Landscape Architectural Perspective

    DEFF Research Database (Denmark)

    Peschardt, Karin Kragsig

    This thesis presents how the health potential of pocket parks can be improved through design from a landscape architectural perspective. In developed countries, the densification of cities is a wide-spread tendency which often results in a compact city planning structure. People who live in dense...... promoting potential of nine pocket parks in Copenhagen. From a landscape architectural perspective the health potential is investigated based on both qualitative and quantitative methods. The study elucidates use, the restorative potential as well as how physical content within the pocket parks can...

  11. Evaluating the landscape impact of renewable energy plants

    Science.gov (United States)

    Ioannidis, Romanos; Koutsoyiannis, Demetris

    2017-04-01

    Different types of renewable energy have been on an ongoing competition with each other. There has been a lot of research comparing the most common types of renewable energy plants in relation with their efficiency, cost and environmental impact. However, few papers so far have attempted to analyse their impact on landscape and there has never been in depth research on which type of renewable energy causes the least impact on the natural, cultural and aesthetic characteristics of a landscape. This seems to be a significant omission given the vast areas of land already covered with renewable energy plants and the worldwide plans for many more renewable energy projects in the future. Meanwhile, the low aesthetic quality of renewable energy plants has already been an obstacle to their further development, with several relevant examples from countries such as Spain and the Netherlands. There have even been cases where aesthetic degradation is the primary or even the single argument of the opposition to proposed plants. In any case, the aesthetic design and the integration of renewable energy plants into the landscape should really be important design parameters if we plan those projects to truly be sustainable and to be considered complete works of engineering. To initiate dialogue over those aspects of renewable energy, we provide a first comparison on hydro, solar and wind energy. To materialize this comparison, we use data from existing dams, photovoltaic and wind farms. Initially, the average area per MW covered by each type of energy plant is calculated and then evaluated qualitatively from a landscape-impact perspective. Although the area affected is comparable in these three cases, the analysis of the data suggests that dams offer a considerable amount of advantages compared to the other two types of plants. This conclusion arises from the fact that dams, whose basic impact to the landscape is the creation of an artificial lake, contribute much less to the

  12. Exploring the conformational energy landscape of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Nienhaus, G.U. [Univ. of Illinois, Urbana, IL (United States)]|[Universitaet Ulm (Germany); Mueller, J.D.; McMahon, B.H. [Univ. of Illinois, Urbana, IL (United States)] [and others

    1997-04-01

    Proteins possess a complex energy landscape with a large number of local minima called conformational substates that are arranged in a hierarchical fashion. Here we discuss experiments aimed at the elucidation of the energy landscape in carbonmonoxy myoglobin (MbCO). In the highest tier of the hierarchy, a few taxonomic substates exist. Because of their small number, these substates are accessible to detailed structural investigations. Spectroscopic experiments are discussed that elucidate the role of protonations of amino acid side chains in creating the substates. The lower tiers of the hierarchy contain a large number of statistical substates. Substate interconversions are observed in the entire temperature range from below 1 K up to the denaturation temperature, indicating a wide spectrum of energy barriers that separate the substates.

  13. Landscape mapping MAV using single image perspective cues

    CSIR Research Space (South Africa)

    Tekane, YC

    2015-01-01

    Full Text Available in order to do mapping, our method does require a 3D model. Instead, our method first classifies the type of site the MAV is in, and the uses vision algorithms based on perspective cues to estimate the landscape location and the do mapping. We tested our...

  14. Ten perspectives on Nordic energy

    Energy Technology Data Exchange (ETDEWEB)

    Tennbakk, Berit

    2006-10-15

    Summary: Perspective no. 1: Costly early learning from the EU ETS - Unforeseen price levels hit industries hard; Perspective no. 2: Market based support schemes - Do they work as intended? Perspective no. 3: New decade in the Nordic energy markets. Perspective no. 4: Reduced CO{sub 2} emissions and more renewables - Are we getting there or not? Perspective no. 5: Interpretation of financial requirements - An impediment to sound investments? Perspective no. 6: Who should invest in infrastructure - Public or private investors? Perspective no. 7: Re regulation is not the answer - Need for coordination calls for a visible hand? Perspective no. 8: Increased infrastructure investments - Due to EU ETS and support schemes for RES. Perspective no. 9: Energy, welfare and industry - Complex links make policy making difficult. Perspective no. 10 'Fuel' for an energy policy discussion - A Nordic energy policy agenda? (AG)

  15. Energy-landscape Nexus: Advancing a conceptual framework for the design of sustainable energy landscapes

    NARCIS (Netherlands)

    Stremke, S.

    2013-01-01

    For some time now, the concept of “energy landscape” is discussed in academia while more and more practising landscape architects contribute to the siting, designing, and assessment of renewable energy technologies (see Stremke et al. 2012). Yet, there remains some ambiguity what exactly is meant

  16. Future energy perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Halsnaes, K.; Christensen, J.M. [Risoe National Lab., Systems Analysis Dept., Roskilde (Denmark)

    2002-10-01

    Future energy perspectives: 1) The global energy consumption will continue to grow primarily in developing countries, their share of global energy consumption will grow from approx. 35% in 1990 to 60% in 2050. 2) Policy focus will be primarily on environmental concerns in the industrial countries and on energy for development and access to energy for the poor in developing countries. 3) With global climate concerns and the implementation of the Kyoto protocol, global environment issues will have increased prominence in energy sector priorities. 4) Fossil fuel resources are on a global level still abundant and prices are expected to be relatively low in the short to medium term. 5) Energy supply security has for geopolitical reasons become an increasing concern especially in the US and the EU. 6) Significant investments are required to ensure development of new clean energy technologies for introduction in the medium to long term. 7) Market reforms are being implemented in almost all regions of the world changing both the investment and policy regimes. 8) International studies (IPCC and WEC) have analysed several alternative energy scenarios Alternative policies and priorities can lead to a wide range of different energy futures. 9) WEC middle scenario B, from 1990 to 2050; predicts growth in GDP 3.5 times and primary energy consumption 2.2 times and CO{sub 2} 1.5 times. This scenario is expecting supply to be dominated by fossil fuel (80% in 1990 and still 65% in 2050), with high share of natural gas and nuclear with slow growth in renewable energy. 10) A more radical scenario (C1) is expecting renewable energy such as biomass, solar and wind to contribute 27% in 2050; declining oil and coal; increased use of natural gas and a minor contribution from nuclear. A development path like this require significant near-term investments in technology research and development. 11) The large increase in global energy demand in the next century will require large investments

  17. Future energy perspectives

    International Nuclear Information System (INIS)

    Halsnaes, K.; Christensen, J.M.

    2002-01-01

    Future energy perspectives: 1) The global energy consumption will continue to grow primarily in developing countries, their share of global energy consumption will grow from approx. 35% in 1990 to 60% in 2050. 2) Policy focus will be primarily on environmental concerns in the industrial countries and on energy for development and access to energy for the poor in developing countries. 3) With global climate concerns and the implementation of the Kyoto protocol, global environment issues will have increased prominence in energy sector priorities. 4) Fossil fuel resources are on a global level still abundant and prices are expected to be relatively low in the short to medium term. 5) Energy supply security has for geopolitical reasons become an increasing concern especially in the US and the EU. 6) Significant investments are required to ensure development of new clean energy technologies for introduction in the medium to long term. 7) Market reforms are being implemented in almost all regions of the world changing both the investment and policy regimes. 8) International studies (IPCC and WEC) have analysed several alternative energy scenarios Alternative policies and priorities can lead to a wide range of different energy futures. 9) WEC middle scenario B, from 1990 to 2050; predicts growth in GDP 3.5 times and primary energy consumption 2.2 times and CO 2 1.5 times. This scenario is expecting supply to be dominated by fossil fuel (80% in 1990 and still 65% in 2050), with high share of natural gas and nuclear with slow growth in renewable energy. 10) A more radical scenario (C1) is expecting renewable energy such as biomass, solar and wind to contribute 27% in 2050; declining oil and coal; increased use of natural gas and a minor contribution from nuclear. A development path like this require significant near-term investments in technology research and development. 11) The large increase in global energy demand in the next century will require large investments. The

  18. New interaction paths in the energy landscape: the role of local energy initiatives

    OpenAIRE

    de Boer, Jessica; Zuidema, Christian; Gugerell, Katharina

    2018-01-01

    Energy transition is an encompassing process which not only involves the energy system but also the landscape in which the energy system is embedded. Renewable energy is triggering new interactions with local landscapes in physical, socio-economic and institutional senses. We capture these interactions using the energy landscape concept, which expresses the interdependence of the energy system with the landscape. We aim to understand whether and how local energy initiatives facilitate this in...

  19. Potential energy landscapes of elemental and heterogeneous chalcogen clusters

    International Nuclear Information System (INIS)

    Mauro, John C.; Loucks, Roger J.; Balakrishnan, Jitendra; Varshneya, Arun K.

    2006-01-01

    We describe the potential energy landscapes of elemental S 8 , Se 8 , and Te 8 clusters using disconnectivity graphs. Inherent structures include both ring and chain configurations, with rings especially dominant in Se 8 . We also map the potential energy landscapes of heterogeneous Se n (S,Te) 8-n clusters, which offer insights into the structure of heterogeneous chalcogen glasses

  20. Mitigation/Adaptation: landscape architecture meets sustainable energy transition

    NARCIS (Netherlands)

    Stremke, S.

    2009-01-01

    Mitigation of climate change and adaptation to renewable energy sources are among the emerging fields of activity in landscape architecture. If landscape architects recognize the need for sustainable development on the basis of renewable energy sources, then how can we contribute to sustainable and

  1. Free energy landscape and molecular pathways of gas hydrate nucleation

    International Nuclear Information System (INIS)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu

    2016-01-01

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p B histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p B histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  2. Free energy landscape and molecular pathways of gas hydrate nucleation.

    Science.gov (United States)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu

    2016-12-07

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p B histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p B histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  3. Free energy landscape and molecular pathways of gas hydrate nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Yuanfei; Porras, Anna; Li, Tianshu, E-mail: tsli@gwu.edu [Department of Civil and Environmental Engineering, George Washington University, Washington DC 20052 (United States)

    2016-12-07

    Despite the significance of gas hydrates in diverse areas, a quantitative knowledge of hydrate formation at a molecular level is missing. The impediment to acquiring this understanding is primarily attributed to the stochastic nature and ultra-fine scales of nucleation events, posing a great challenge for both experiment and simulation to explore hydrate nucleation. Here we employ advanced molecular simulation methods, including forward flux sampling (FFS), p{sub B} histogram analysis, and backward flux sampling, to overcome the limit of direct molecular simulation for exploring both the free energy landscape and molecular pathways of hydrate nucleation. First we test the half-cage order parameter (H-COP) which we developed for driving FFS, through conducting the p{sub B} histogram analysis. Our results indeed show that H-COP describes well the reaction coordinates of hydrate nucleation. Through the verified order parameter, we then directly compute the free energy landscape for hydrate nucleation by combining both forward and backward flux sampling. The calculated stationary distribution density, which is obtained independently of nucleation theory, is found to fit well against the classical nucleation theory (CNT). Subsequent analysis of the obtained large ensemble of hydrate nucleation trajectories show that although on average, hydrate formation is facilitated by a two-step like mechanism involving a gradual transition from an amorphous to a crystalline structure, there also exist nucleation pathways where hydrate crystallizes directly, without going through the amorphous stage. The CNT-like free energy profile and the structural diversity suggest the existence of multiple active transition pathways for hydrate nucleation, and possibly also imply the near degeneracy in their free energy profiles among different pathways. Our results thus bring a new perspective to the long standing question of how hydrates crystallize.

  4. Perspectives of Fijian Policymakers on the Obesity Prevention Policy Landscape

    Directory of Open Access Journals (Sweden)

    Anna-Marie Hendriks

    2015-01-01

    Full Text Available In Fiji and other Pacific Island countries, obesity has rapidly increased in the past decade. Therefore, several obesity prevention policies have been developed. Studies show that their development has been hampered by factors within Fiji’s policy landscape such as pressure from industry. Since policymakers in the Fijian national government are primarily responsible for the development of obesity policies, it is important to understand their perspectives; we therefore interviewed 15 policymakers from nine Fijian ministries. By applying the “attractor landscape” metaphor from dynamic systems theory, we captured perceived barriers and facilitators in the policy landscape. A poor economic situation, low food self-sufficiency, power inequalities, inappropriate framing of obesity, limited policy evidence, and limited resource sharing hamper obesity policy developments in Fiji. Facilitators include policy entrepreneurs and policy brokers who were active when a window of opportunity opened and who strengthened intersectoral collaboration. Fiji’s policy landscape can become more conducive to obesity policies if power inequalities are reduced. In Fiji and other Pacific Island countries, this may be achievable through increased food self-sufficiency, strengthened intersectoral collaboration, and the establishment of an explicit functional focal unit within government to monitor and forecast the health impact of policy changes in non-health sectors.

  5. Perspectives of Fijian Policymakers on the Obesity Prevention Policy Landscape

    Science.gov (United States)

    Hendriks, Anna-Marie; Delai, Mere Y.; Thow, Anne-Marie; Gubbels, Jessica S.; De Vries, Nanne K.; Kremers, Stef P. J.; Jansen, Maria W. J.

    2015-01-01

    In Fiji and other Pacific Island countries, obesity has rapidly increased in the past decade. Therefore, several obesity prevention policies have been developed. Studies show that their development has been hampered by factors within Fiji's policy landscape such as pressure from industry. Since policymakers in the Fijian national government are primarily responsible for the development of obesity policies, it is important to understand their perspectives; we therefore interviewed 15 policymakers from nine Fijian ministries. By applying the “attractor landscape” metaphor from dynamic systems theory, we captured perceived barriers and facilitators in the policy landscape. A poor economic situation, low food self-sufficiency, power inequalities, inappropriate framing of obesity, limited policy evidence, and limited resource sharing hamper obesity policy developments in Fiji. Facilitators include policy entrepreneurs and policy brokers who were active when a window of opportunity opened and who strengthened intersectoral collaboration. Fiji's policy landscape can become more conducive to obesity policies if power inequalities are reduced. In Fiji and other Pacific Island countries, this may be achievable through increased food self-sufficiency, strengthened intersectoral collaboration, and the establishment of an explicit functional focal unit within government to monitor and forecast the health impact of policy changes in non-health sectors. PMID:26380307

  6. Energy landscapes in proteins and glasses

    Science.gov (United States)

    Singh, Sadanand

    Soft materials are ubiquitous in our day-to-day life. They include liquids, colloids, polymers, foams, gels, granular systems, and a number of biological materials. While these materials exhibit a wide range of textures and morphologies, many of their properties have common physicochemical origins. A better understanding of such origins would lead to rational design and engineering of functional soft materials. A common feature of soft materials is the wide range of time and length scales that characterizes their behavior. Unfortunately, available molecular modeling techniques are often ill-suited for problems that exhibit multiple length and time scales. In this thesis, we introduce and implement new simulation methods that have enabled molecular-level studies of soft materials. Such methods permit calculation of free energy surfaces, and we demonstrate their usefulness in the context of proteins and glasses, both of which exhibit rugged free energy landscapes. A first application is concerned with human amylin, a protein associated with Type II diabetes. Patients with Type II diabetes exhibit fibrillar deposits of human amylin protein in the pancreas. By applying the advanced simulation methods and algorithms developed in this work, we investigate the structure and folding dynamics of human amylin. A detailed mechanism is presented at the atomic-level for the nucleation and aggregation of the peptide. The results presented in this work could help in development of therapeutic strategies for Type II diabetes. The second application is concerned with the study of vapor-deposited ultrastable glasses. These stable glasses have, far below the conventional glass transition temperature, the properties expected from the equilibrium supercooled liquid state. Our results indicate that optimal stability is attained when deposition occurs near the Kauzmann temperature. We also show that the extraordinary stability of model vapor deposited glasses is associated with distinct

  7. World energy perspectives

    International Nuclear Information System (INIS)

    2002-01-01

    Basic facts on energy reserves and main environmental effects of energy production are recalled. Physical constraints associated to the different energy production means are summarized, and present cost estimates are given. (author)

  8. Cuban energy development perspectives

    International Nuclear Information System (INIS)

    Berdellans Escobar, Ilse; Perez Martin, David; Lopez Lopez, Ileana; Ricardo Mora, Henry; Gomez De la Torre, Yoandys

    2005-01-01

    In this paper from energy demand scenario calculated for the country until 2025, energy supply options were assessed. Three energy development scenarios considering economic and social development projections and different energy options were evaluated: a reference scenario which includes the nowadays energy development projections; a second scenario basing the development on intensive use of domestic fossil fuels; and a third scenario, where the development is based on the maximum use of domestic renewable energy potential. The results are analyzed and recommendations are formulated

  9. How animals distribute themselves in space: variable energy landscapes

    OpenAIRE

    Masello, Juan F.; Kato, Akiko; Sommerfeld, Julia; Mattern, Thomas; Quillfeldt, Petra

    2017-01-01

    Background Foraging efficiency determines whether animals will be able to raise healthy broods, maintain their own condition, avoid predators and ultimately increase their fitness. Using accelerometers and GPS loggers, features of the habitat and the way animals deal with variable conditions can be translated into energetic costs of movement, which, in turn, can be translated to energy landscapes.We investigated energy landscapes in Gentoo Penguins Pygoscelis papua from two colonies at New Is...

  10. Broadening Australia's energy perspective

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, N R [ed.

    1984-01-01

    Several papers advocated strategic marketing to give economic strength to the energy system while satisfying domestic demand and improving international sales. Others proposed policies for orderly and optimum development to satisfy national interests. Utilization of resources is discussed in papers on dry brown coal, coal-oil mixtures, uranium, synthetic fuels, and solar energy. The application of energy to processes, such as evaporation, drying and electric transport vehicles is covered. Problems in the transport of energy are also described. Energy efficient Stirling engines for locomotives, solar energy applications and fluidized-bed combustors are among several conversion devices considered. Energy management is covered in other papers. Relevant papers have been abstracted separately.

  11. The effects of landscaping on the residential cooling energy

    Science.gov (United States)

    Misni, A.

    2018-02-01

    This paper examines the effectiveness of landscaping on the air-conditioning energy saving of houses in a tropical environment. This case study involved looking at the construction and landscaping of three single-family houses in three sections of Shah Alam, Selangor, Malaysia. The houses ranged in age from 5 to 30 years old, which provided different examples of construction and maturity levels of the surrounding landscaping. Landscaping affects the thermal performance as well as on the air-conditioning energy of houses, in how it provides shade, channels wind, and evapotranspiration. While the construction of the three houses was similar, they were different in size and design, including their landscape design. These houses were chosen because they are representative of single-family tropical houses and landscaping styles in Malaysia since 30 years ago. Three houses were chosen; the 30-year-old house, the 10-year-old house, and the 5-year-old house. In a tropical country, landscaping is used to reduce the effects of the hot and humid climate. The houses spent 15-45% of the electricity cost on cooling. These results were influenced by human factors and the surrounding landscaping. Every type of vegetation, such as trees, grass, shrubs, groundcover, and turf, contributes to reducing air temperatures near the house and providing evaporative cooling.

  12. Random versus Deterministic Descent in RNA Energy Landscape Analysis

    Directory of Open Access Journals (Sweden)

    Luke Day

    2016-01-01

    Full Text Available Identifying sets of metastable conformations is a major research topic in RNA energy landscape analysis, and recently several methods have been proposed for finding local minima in landscapes spawned by RNA secondary structures. An important and time-critical component of such methods is steepest, or gradient, descent in attraction basins of local minima. We analyse the speed-up achievable by randomised descent in attraction basins in the context of large sample sets where the size has an order of magnitude in the region of ~106. While the gain for each individual sample might be marginal, the overall run-time improvement can be significant. Moreover, for the two nongradient methods we analysed for partial energy landscapes induced by ten different RNA sequences, we obtained that the number of observed local minima is on average larger by 7.3% and 3.5%, respectively. The run-time improvement is approximately 16.6% and 6.8% on average over the ten partial energy landscapes. For the large sample size we selected for descent procedures, the coverage of local minima is very high up to energy values of the region where the samples were randomly selected from the partial energy landscapes; that is, the difference to the total set of local minima is mainly due to the upper area of the energy landscapes.

  13. Potential energy landscape of TIP4P/2005 water

    Science.gov (United States)

    Handle, Philip H.; Sciortino, Francesco

    2018-04-01

    We report a numerical study of the statistical properties of the potential energy landscape of TIP4P/2005, one of the most accurate rigid water models. We show that, in the region where equilibrated configurations can be generated, a Gaussian landscape description is able to properly describe the model properties. We also find that the volume dependence of the landscape properties is consistent with the existence of a locus of density maxima in the phase diagram. The landscape-based equation of state accurately reproduces the TIP4P/2005 pressure-vs-volume curves, providing a sound extrapolation of the free-energy at low T. A positive-pressure liquid-liquid critical point is predicted by the resulting free-energy.

  14. New interaction paths in the energy landscape: the role of local energy initiatives

    NARCIS (Netherlands)

    de Boer, Jessica; Zuidema, Christian; Gugerell, Katharina

    2018-01-01

    Energy transition is an encompassing process which not only involves the energy system but also the landscape in which the energy system is embedded. Renewable energy is triggering new interactions with local landscapes in physical, socio-economic and institutional senses. We capture these

  15. Energy landscapes for a machine learning application to series data

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Andrew J.; Stevenson, Jacob D.; Das, Ritankar; Wales, David J., E-mail: dw34@cam.ac.uk [University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2016-03-28

    Methods developed to explore and characterise potential energy landscapes are applied to the corresponding landscapes obtained from optimisation of a cost function in machine learning. We consider neural network predictions for the outcome of local geometry optimisation in a triatomic cluster, where four distinct local minima exist. The accuracy of the predictions is compared for fits using data from single and multiple points in the series of atomic configurations resulting from local geometry optimisation and for alternative neural networks. The machine learning solution landscapes are visualised using disconnectivity graphs, and signatures in the effective heat capacity are analysed in terms of distributions of local minima and their properties.

  16. Energy landscapes for a machine learning application to series data

    International Nuclear Information System (INIS)

    Ballard, Andrew J.; Stevenson, Jacob D.; Das, Ritankar; Wales, David J.

    2016-01-01

    Methods developed to explore and characterise potential energy landscapes are applied to the corresponding landscapes obtained from optimisation of a cost function in machine learning. We consider neural network predictions for the outcome of local geometry optimisation in a triatomic cluster, where four distinct local minima exist. The accuracy of the predictions is compared for fits using data from single and multiple points in the series of atomic configurations resulting from local geometry optimisation and for alternative neural networks. The machine learning solution landscapes are visualised using disconnectivity graphs, and signatures in the effective heat capacity are analysed in terms of distributions of local minima and their properties.

  17. Inflation in random landscapes with two energy scales

    Science.gov (United States)

    Blanco-Pillado, Jose J.; Vilenkin, Alexander; Yamada, Masaki

    2018-02-01

    We investigate inflation in a multi-dimensional landscape with a hierarchy of energy scales, motivated by the string theory, where the energy scale of Kahler moduli is usually assumed to be much lower than that of complex structure moduli and dilaton field. We argue that in such a landscape, the dynamics of slow-roll inflation is governed by the low-energy potential, while the initial condition for inflation are determined by tunneling through high-energy barriers. We then use the scale factor cutoff measure to calculate the probability distribution for the number of inflationary e-folds and the amplitude of density fluctuations Q, assuming that the low-energy landscape is described by a random Gaussian potential with a correlation length much smaller than M pl. We find that the distribution for Q has a unique shape and a preferred domain, which depends on the parameters of the low-energy landscape. We discuss some observational implications of this distribution and the constraints it imposes on the landscape parameters.

  18. Perspectives for nuclear energy

    International Nuclear Information System (INIS)

    Baugnet, J.-M.; Abderrahim, H.A.; Dekeyser, J.; Meskens, G.

    1998-09-01

    In Belgium, approximately 60 percent of the produced electricity is generated by nuclear power. At present, nuclear power production tends to stagnate in Europe and North America but is still growing in Asia. The document gives an overview of the present status and the future energy demand with emphasis on electric power. Different evaluation criteria including factors hindering and factors promoting the expansion of nuclear power as well as requirements of new nuclear power plants are discussed. The extension of the lifetime of existing facilities as well as fuel supply are taken into consideration. A comparative assesment of nuclear power with other energy sources is made. The report concludes with estimating the contribution and the role of nuclear power in future energy demand as well as with an overview of future reactors and research and development programmes

  19. Energy policy perspectives

    International Nuclear Information System (INIS)

    Stihl, H.P.

    1998-01-01

    More competition is to be achieved in the energy markets of Europe and Germany. New legislation is being adopted to this end, but attempts are also made to block it. DIHT, the Association of German Chambers of Industry and Commerce, examines the influence exerted on competition in the energy sector and on deregulation by the German Act Redefining Hard Coal Subsidies, the German Act Reorganizing Power Economy Law, and the separation of grid operation and power generation and the access to the grid this provides to third parties. In order to be reliable, electricity generation must be based on a broad, balanced mix of energy sources. In the baseload range, neither low-cost lignite - development of the Garzweiler II new open cast mine - nor nuclear power -where the Muelheim-Kaerlich Nuclear Power Station is threatened by permanent shutdown - must be excluded. Especially consumers are to benefit from more competition, while the interests of associations or groupings must rank second. (orig.) [de

  20. Integrated visions (part II): Envisioning Sustainable Energy Landscapes

    NARCIS (Netherlands)

    Stremke, S.; Koh, J.; Neven, C.T.; Boekel, A.

    2012-01-01

    ABSTRACT Climate change and resource depletion are driving the transition to renewable energy sources. Both the supply of renewables and the demand for energy are influenced by the physical environment and therefore concern spatial planning and landscape design. Envisioning the longterm development

  1. Inflation, Dark Matter, and Dark Energy in the String Landscape

    OpenAIRE

    Liddle, Andrew R; Ureña-López, L Arturo

    2006-01-01

    We consider the conditions needed to unify the description of dark matter, dark energy and inflation in the context of the string landscape. We find that incomplete decay of the inflaton field gives the possibility that a single field is responsible for all three phenomena. By contrast, unifying dark matter and dark energy into a single field, separate from the inflaton, appears rather difficult.

  2. Energy Landscape and Pathways for Transitions between Watson-Crick and Hoogsteen Base Pairing in DNA.

    Science.gov (United States)

    Chakraborty, Debayan; Wales, David J

    2018-01-04

    The recent discovery that Hoogsteen (HG) base pairs are widespread in DNA across diverse sequences and positional contexts could have important implications for understanding DNA replication and DNA-protein recognition. While evidence is emerging that the Hoogsteen conformation could be a thermodynamically accessible conformation of the DNA duplex and provide a means to expand its functionality, relatively little is known about the molecular mechanism underlying the Watson-Crick (WC) to HG transition. In this Perspective, we describe pathways and kinetics for this transition at an atomic level of detail, using the energy landscape perspective. We show that competition between the duplex conformations results in a double funnel landscape, which explains some recent experimental observations. The interconversion pathways feature a number of intermediates, with a variable number of WC and HG base pairs. The relatively slow kinetics, with possible deviations from two-state behavior, suggest that this conformational switch is likely to be a challenging target for both simulation and experiment.

  3. Energy Landscapes for the Self-Assembly of Supramolecular Polyhedra

    Science.gov (United States)

    Russell, Emily R.; Menon, Govind

    2016-06-01

    We develop a mathematical model for the energy landscape of polyhedral supramolecular cages recently synthesized by self-assembly (Sun et al. in Science 328:1144-1147, 2010). Our model includes two essential features of the experiment: (1) geometry of the organic ligands and metallic ions; and (2) combinatorics. The molecular geometry is used to introduce an energy that favors square-planar vertices (modeling {Pd}^{2+} ions) and bent edges with one of two preferred opening angles (modeling boomerang-shaped ligands of two types). The combinatorics of the model involve two-colorings of edges of polyhedra with four-valent vertices. The set of such two-colorings, quotiented by the octahedral symmetry group, has a natural graph structure and is called the combinatorial configuration space. The energy landscape of our model is the energy of each state in the combinatorial configuration space. The challenge in the computation of the energy landscape is a combinatorial explosion in the number of two-colorings of edges. We describe sampling methods based on the symmetries of the configurations and connectivity of the configuration graph. When the two preferred opening angles encompass the geometrically ideal angle, the energy landscape exhibits a very low-energy minimum for the most symmetric configuration at equal mixing of the two angles, even when the average opening angle does not match the ideal angle.

  4. Energy forecasts, perspectives and methods

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, J E; Mogren, A

    1984-01-01

    The authors have analyzed different methods for long term energy prognoses, in particular energy consumption forecasts. Energy supply and price prognoses are also treated, but in a less detailed manner. After defining and discussing the various methods/models used in forecasts, a generalized discussion of the influence on the prognoses from the perspectives (background factors, world view, norms, ideology) of the prognosis makers is given. Some basic formal demands that should be asked from any rational forecast are formulated and discussed. The authors conclude that different forecasting methodologies are supplementing each other. There is no best method, forecasts should be accepted as views of the future from differing perspectives. The primary prognostic problem is to show the possible futures, selecting the wanted future is a question of political process.

  5. Learning free energy landscapes using artificial neural networks.

    Science.gov (United States)

    Sidky, Hythem; Whitmer, Jonathan K

    2018-03-14

    Existing adaptive bias techniques, which seek to estimate free energies and physical properties from molecular simulations, are limited by their reliance on fixed kernels or basis sets which hinder their ability to efficiently conform to varied free energy landscapes. Further, user-specified parameters are in general non-intuitive yet significantly affect the convergence rate and accuracy of the free energy estimate. Here we propose a novel method, wherein artificial neural networks (ANNs) are used to develop an adaptive biasing potential which learns free energy landscapes. We demonstrate that this method is capable of rapidly adapting to complex free energy landscapes and is not prone to boundary or oscillation problems. The method is made robust to hyperparameters and overfitting through Bayesian regularization which penalizes network weights and auto-regulates the number of effective parameters in the network. ANN sampling represents a promising innovative approach which can resolve complex free energy landscapes in less time than conventional approaches while requiring minimal user input.

  6. Learning free energy landscapes using artificial neural networks

    Science.gov (United States)

    Sidky, Hythem; Whitmer, Jonathan K.

    2018-03-01

    Existing adaptive bias techniques, which seek to estimate free energies and physical properties from molecular simulations, are limited by their reliance on fixed kernels or basis sets which hinder their ability to efficiently conform to varied free energy landscapes. Further, user-specified parameters are in general non-intuitive yet significantly affect the convergence rate and accuracy of the free energy estimate. Here we propose a novel method, wherein artificial neural networks (ANNs) are used to develop an adaptive biasing potential which learns free energy landscapes. We demonstrate that this method is capable of rapidly adapting to complex free energy landscapes and is not prone to boundary or oscillation problems. The method is made robust to hyperparameters and overfitting through Bayesian regularization which penalizes network weights and auto-regulates the number of effective parameters in the network. ANN sampling represents a promising innovative approach which can resolve complex free energy landscapes in less time than conventional approaches while requiring minimal user input.

  7. The German energy landscape in 2015

    International Nuclear Information System (INIS)

    Lauer, Hartmut

    2016-01-01

    This article proposes a brief overview of the German energy sector: stagnation of primary energy consumption, shares of the different energy sources (renewable, coal, lignite, oil, gas, nuclear), shares of the different electric power production sources and their recent evolution. It evokes issues related to the objectives defined for energy transition, the high level of renewable energy production and the high level of power exports. It outlines that consumption must be reduced to reach the objectives defined for 2020. It notices a stagnation of the energy system de-carbonation, and comments the evolution of electricity prices

  8. Solar energy perspectives in France

    International Nuclear Information System (INIS)

    2008-01-01

    In a context combining climate change, energy supply crisis, an increased interest in solar energy, a strongly increasing market of solar installations, new technologies, a promotion of the development of the use solar energy in France and a fast development of the water heater and photovoltaic generator markets in France, this report proposes a wide overview of the past, present and future development of solar energy. It discusses the evolution of the French national energy policy and of the solar energy within this policy. It presents and discusses the solar energy resources, their strengths and weaknesses, their geographical and time distribution. It describes the various uses and applications of solar energy in buildings, discusses different aspects of this market (actors, economical data, evolutions, public incentives, perspectives). Then, it describes and discusses technical and economical aspects of two important technologies, the photovoltaic solar energy and the thermodynamic conversion of solar energy. Public incentives, laws and regulations, technical and economic aspects of the connection to the distribution network are then discussed. Some recommendations and ideas are formulated concerning research activities, industrial development, quality of equipment and facilities, personnel education, investment needs

  9. Sustainable energy landscapes: The power of imagination

    NARCIS (Netherlands)

    Stremke, S.

    2012-01-01

    Resource depletion and climate change motivate a transition to sustainable energy systems that make effective use of renewable sources. Sustainable energy transition necessitates a transformation of large parts of the existing built environment and presents one of the great challenges of present-day

  10. From universal to local: perspectives on cultural landscape heritage in South Africa

    NARCIS (Netherlands)

    Cocks, M.; Vetter, S.; Wiersum, K.F.

    2018-01-01

    The concept of cultural landscapes relates to the multifaceted links between
    people, place and identity. From a professional perspective, the concept
    refers to a category of designated conservation areas with specific biocultural
    heritage values. From a local perspective, it may refer to

  11. Membranes: A Variety of Energy Landscapes for Many Transfer Opportunities.

    Science.gov (United States)

    Bacchin, Patrice

    2018-02-22

    A membrane can be represented by an energy landscape that solutes or colloids must cross. A model accounting for the momentum and the mass balances in the membrane energy landscape establishes a new way of writing for the Darcy law. The counter-pressure in the Darcy law is no longer written as the result of an osmotic pressure difference but rather as a function of colloid-membrane interactions. The ability of the model to describe the physics of the filtration is discussed in detail. This model is solved in a simplified energy landscape to derive analytical relationships that describe the selectivity and the counter-pressure from ab initio operating conditions. The model shows that the stiffness of the energy landscape has an impact on the process efficiency: a gradual increase in interactions (such as with hourglass pore shape) can reduce the separation energetic cost. It allows the introduction of a new paradigm to increase membrane efficiency: the accumulation that is inherent to the separation must be distributed across the membrane. Asymmetric interactions thus lead to direction-dependent transfer properties and the membrane exhibits diode behavior. These new transfer opportunities are discussed.

  12. Peptide Free Energy Landscapes Calibrated by Molecular Orbital Calculations

    OpenAIRE

    Ono, S.; Kuroda, M.; Higo, J.; Kamiya, N.; Nakajima, N.; Nakamura, H.

    2002-01-01

    Free energy landscapes of peptide conformations werecalibrated by ab initiomolecular orbital calculations, after enhancedconformational sampling using the multicanonical molecular dynamicssimulations. Three different potentials of mean force for an isolateddipeptide were individually obtained using the conventional force fields,AMBER parm94, AMBER parm96, and CHARMm22. Each potential ofmean force was calibrated based on the umbrella sampling algorithm fromthe adiabatic energy map that was cal...

  13. Free-energy landscape of a hyperstable RNA tetraloop.

    Science.gov (United States)

    Miner, Jacob C; Chen, Alan A; García, Angel E

    2016-06-14

    We report the characterization of the energy landscape and the folding/unfolding thermodynamics of a hyperstable RNA tetraloop obtained through high-performance molecular dynamics simulations at microsecond timescales. Sampling of the configurational landscape is conducted using temperature replica exchange molecular dynamics over three isochores at high, ambient, and negative pressures to determine the thermodynamic stability and the free-energy landscape of the tetraloop. The simulations reveal reversible folding/unfolding transitions of the tetraloop into the canonical A-RNA conformation and the presence of two alternative configurations, including a left-handed Z-RNA conformation and a compact purine Triplet. Increasing hydrostatic pressure shows a stabilizing effect on the A-RNA conformation and a destabilization of the left-handed Z-RNA. Our results provide a comprehensive description of the folded free-energy landscape of a hyperstable RNA tetraloop and highlight the significant advances of all-atom molecular dynamics in describing the unbiased folding of a simple RNA secondary structure motif.

  14. Physics landscape-fixed target energies

    International Nuclear Information System (INIS)

    Berger, E.L.

    1989-10-01

    An introductory review is presented of physics issues and opportunities at Fermilab fixed-target energies. Included are discussions of precision electroweak studies; deep inelastic lepton scattering; heavy quark production, spectroscopy, and decays; perturbative QCD; prompt photon production; massive lepton production; and spin dependence. 79 refs., 7 figs

  15. Which energy perspectives for Europe?

    International Nuclear Information System (INIS)

    Delaporte, P.

    2011-01-01

    After having noticed that wood will always be welcome but will remain marginal, coal is too dirty, oil too expensive, nuclear raises acceptability problems in some regions, and renewable energies are much too expensive to produce electricity, the author discusses the only remaining source: natural gas. On a medium term, he outlines and comments the dominant position of the Russian provider, Gazprom, but also France's dependence on few providers (Norway, Russia and Algeria). Then, while considering the targeted threshold (30% of the total consumed energy), he identifies actions to be performed regarding gas supplies. As gas, as a fossil and polluting energy, may not and will not hold this leadership position, other perspective will have to be explored

  16. Energy landscapes of resting-state brain networks

    Directory of Open Access Journals (Sweden)

    Takamitsu eWatanabe

    2014-02-01

    Full Text Available During rest, the human brain performs essential functions such as memory maintenance, which are associated with resting-state brain networks (RSNs including the default-mode network (DMN and frontoparietal network (FPN. Previous studies based on spiking-neuron network models and their reduced models, as well as those based on imaging data, suggest that resting-state network activity can be captured as attractor dynamics, i.e., dynamics of the brain state toward an attractive state and transitions between different attractors. Here, we analyze the energy landscapes of the RSNs by applying the maximum entropy model, or equivalently the Ising spin model, to human RSN data. We use the previously estimated parameter values to define the energy landscape, and the disconnectivity graph method to estimate the number of local energy minima (equivalent to attractors in attractor dynamics, the basin size, and hierarchical relationships among the different local minima. In both of the DMN and FPN, low-energy local minima tended to have large basins. A majority of the network states belonged to a basin of one of a few local minima. Therefore, a small number of local minima constituted the backbone of each RSN. In the DMN, the energy landscape consisted of two groups of low-energy local minima that are separated by a relatively high energy barrier. Within each group, the activity patterns of the local minima were similar, and different minima were connected by relatively low energy barriers. In the FPN, all dominant energy were separated by relatively low energy barriers such that they formed a single coarse-grained global minimum. Our results indicate that multistable attractor dynamics may underlie the DMN, but not the FPN, and assist memory maintenance with different memory states.

  17. Whose landscape? - An anthropological perspective on landscape perception in reindeer tending (In Swedish with Summary in English

    Directory of Open Access Journals (Sweden)

    Anna Järpe

    2005-04-01

    Full Text Available When we talk publicly about landscape and land use, both in legal and in popular contexts, the evaluation of our natural environment is usually based on an industrial concept of land and landscape. "Nature" is seen as a resource to be used or managed in different ways. My research originates in a questioning of this assumption: can we take for granted that the same perceptions and evaluations are shared by all concerned parties? In this article, I will use an ecologic anthropological perspective to consider the livelihood of reindeer tending and suggest an alternative to what can be called a scientific understanding of the world. I maintain that the relations that people have with their environment, and the values that they ascribe to it, are perceptions that are shaped and affected in our interactions with the surrounding world, and that these perceptions vary between different groups of people. Land use, land rights, access to fishing waters, and who gets to hunt what; these are not only questions about how we should manage the landscape, but also about whose landscape we are managing. Arguing that the reindeer tenders' landscape is a shifting mosaic of varying conditions that they must relate to rather than an object to be used and controlled by human interests, I want to show how anthropological research can provide an insight into the different perspectives and modes of understanding that we need to consider in the formulation of future policies and laws. At least if we want to resolve land use conflicts in contested areas fairly and on a sustainable long-term basis.

  18. Solar Energy Perspectives In Egypt

    International Nuclear Information System (INIS)

    Comsan, M.N.H.

    2010-01-01

    Egypt belongs to the global sun-belt. The country is in advantageous position with solar energy. In 1991 solar atlas for Egypt was issued indicating that the country enjoys 2900-3200 hours of sunshine annually with annual direct normal energy density 1970-3200 kWh/m2 and technical solar-thermal electricity generating potential of 73.6 Peta watt hour (PWh). Egypt was among the first countries to utilize solar energy. In 1910, a practical industrial scale solar system engine was built at Maadi south to Cairo using solar thermal parabolic collectors. The engine was used to produce steam which drove a series of large water pumps for irrigation. Nowadays utilization of solar energy includes use of photovoltaic cells, solar water heating and solar thermal power. Use of solar thermal technology may include both electricity generation and water desalination, which is advantageous for Egypt taking in consideration its shortage in water supply. The article discusses perspectives of solar energy in Egypt and developmental trends till 2050

  19. Comparing the Folding and Misfolding Energy Landscapes of Phosphoglycerate Kinase

    OpenAIRE

    Agocs, Gergely; Szabo, Bence T.; Koehler, Gottfried; Osvath, Szabolcs

    2012-01-01

    Partitioning of polypeptides between protein folding and amyloid formation is of outstanding pathophysiological importance. Using yeast phosphoglycerate kinase as model, here we identify the features of the energy landscape that decide the fate of the protein: folding or amyloidogenesis. Structure formation was initiated from the acid-unfolded state, and monitored by fluorescence from 10 ms to 20 days. Solvent conditions were gradually shifted between folding and amyloidogenesis, and the prop...

  20. Accelerated weight histogram method for exploring free energy landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, V.; Lidmar, J.; Hess, B. [Department of Theoretical Physics and Swedish e-Science Research Center, KTH Royal Institute of Technology, 10691 Stockholm (Sweden)

    2014-07-28

    Calculating free energies is an important and notoriously difficult task for molecular simulations. The rapid increase in computational power has made it possible to probe increasingly complex systems, yet extracting accurate free energies from these simulations remains a major challenge. Fully exploring the free energy landscape of, say, a biological macromolecule typically requires sampling large conformational changes and slow transitions. Often, the only feasible way to study such a system is to simulate it using an enhanced sampling method. The accelerated weight histogram (AWH) method is a new, efficient extended ensemble sampling technique which adaptively biases the simulation to promote exploration of the free energy landscape. The AWH method uses a probability weight histogram which allows for efficient free energy updates and results in an easy discretization procedure. A major advantage of the method is its general formulation, making it a powerful platform for developing further extensions and analyzing its relation to already existing methods. Here, we demonstrate its efficiency and general applicability by calculating the potential of mean force along a reaction coordinate for both a single dimension and multiple dimensions. We make use of a non-uniform, free energy dependent target distribution in reaction coordinate space so that computational efforts are not wasted on physically irrelevant regions. We present numerical results for molecular dynamics simulations of lithium acetate in solution and chignolin, a 10-residue long peptide that folds into a β-hairpin. We further present practical guidelines for setting up and running an AWH simulation.

  1. Territorial ordination and fragmentation of the landscape - Perspectives for the ecological integrity

    International Nuclear Information System (INIS)

    Velez Restrepo, Luis Anibal

    2001-01-01

    The field of planning increasingly emphasizes the importance of rooting the strategies of biological diversity on an ecological perspective of landscape linked to the processes and plans of structural reordering of the territory. However, there is still a conceptual and methodological tendency to go back to the old habits in many processes of land planning. This work discusses such disparity. It includes first a general discussion of traditional approaches to conservation and the new perspectives and concepts focused on landscape, second, examining the conventional ecological approach to planning and land use management it shows the fragmentary way in which it determines land uses without any attention to the workings of biodiversity. Finally, this paper looks at the importance and the opportunity of articulating spatial patterns and ecological processes in ways that maintain the integrity of landscape

  2. Characterizing structural transitions using localized free energy landscape analysis.

    Directory of Open Access Journals (Sweden)

    Nilesh K Banavali

    Full Text Available Structural changes in molecules are frequently observed during biological processes like replication, transcription and translation. These structural changes can usually be traced to specific distortions in the backbones of the macromolecules involved. Quantitative energetic characterization of such distortions can greatly advance the atomic-level understanding of the dynamic character of these biological processes.Molecular dynamics simulations combined with a variation of the Weighted Histogram Analysis Method for potential of mean force determination are applied to characterize localized structural changes for the test case of cytosine (underlined base flipping in a GTCAGCGCATGG DNA duplex. Free energy landscapes for backbone torsion and sugar pucker degrees of freedom in the DNA are used to understand their behavior in response to the base flipping perturbation. By simplifying the base flipping structural change into a two-state model, a free energy difference of upto 14 kcal/mol can be attributed to the flipped state relative to the stacked Watson-Crick base paired state. This two-state classification allows precise evaluation of the effect of base flipping on local backbone degrees of freedom.The calculated free energy landscapes of individual backbone and sugar degrees of freedom expectedly show the greatest change in the vicinity of the flipping base itself, but specific delocalized effects can be discerned upto four nucleotide positions away in both 5' and 3' directions. Free energy landscape analysis thus provides a quantitative method to pinpoint the determinants of structural change on the atomic scale and also delineate the extent of propagation of the perturbation along the molecule. In addition to nucleic acids, this methodology is anticipated to be useful for studying conformational changes in all macromolecules, including carbohydrates, lipids, and proteins.

  3. Globalisation, sustainable development and competencies of landscape change in a European perspective

    DEFF Research Database (Denmark)

    Brandt, Jesper

    2005-01-01

    During the last 10 years the collective goals connected with the agenda of sustainable development has been challenged by the globalisation agenda furthering a global liberalised market with the individual producer and consumer in focus. Only in the local planning and management of the concrete...... landscape the two agendas seems to meet. In a European perspective the European landscape convention has been promoted as a common frame for the promotion of landscape aspect of the sustainability agenda. The paper analyses the EU proposal for a European Agricultural Fund for Rural Development (EAFRD) from...... on the ability and strength of local authorities to unite for such goals, and that detailed analyses of the power balance between different geographical competences in the rural community is necessary to evaluate the possibilities for a sustainable landscape development in rural areas under the conditions...

  4. Sustainable Energy Landscape: Implementing Energy Transition in the Physical Realm

    NARCIS (Netherlands)

    Stremke, S.

    2015-01-01

    Since the beginning of the new millennium, the concept of “energy landscape” is being discussed by academia from the environmental design domain while more and more practitioners have been contributing to sustainable energy transition. Yet, there remains some ambiguity as to what exactly is meant

  5. New Energy Landscapes of Pennsylvania: Forests to Farms to Fracking

    Science.gov (United States)

    Johnson, Deborah A.

    This dissertation adds to the literature on energy needed by industry, government, and citizens for decision-making. The pursuit to access or create new energy resources spawns new landscapes of energy in the early 21st century. The combination of hydraulic fracturing and horizontal drilling technologies---popularly called "fracking"---enables entry into previously inaccessible natural gas reserves such as the Marcellus shale much of which lies beneath Pennsylvania. Although this unconventional method offers a promising source of domestic energy and job growth, the potential for negative impacts raises concerns and questions. The questions include: What is the controversy about fracking in Pennsylvania? What are the impacts of fracking? What costs is Pennsylvania paying as it shifts to shale gas extraction? Are there activities taking place or material signs that point to the emerging new landscapes? Are the individuals and organizations that resist shale gas extraction---the so-called "Green Forces"---and others who live within the region of development more or less attuned to these costs? A mixed methods approach consists of landscape and stakeholder analyses including visual examination of GIS-generated maps, satellite images, and photos taken in the field specifically from four counties: Washington, Warren, McKean, and Bradford. Research captures stakeholders' voices across the public, government, and private sectors at different scales. A stakeholder matrix facilitates data organization and analysis. Data include 114 individual statements from an EPA Public Meeting, texts from 40 online-newspaper articles or blogs, and face-to-face interviews or focus group participation of 36 individuals. Further data come from a public health conference, industry convention, and public protest. The new energy landscape covers spaces in Pennsylvania where oil and gas development previously had not been present. It obscures as well as exposes the legacy of past energy

  6. Improved free-energy landscape reconstruction of bacteriorhodopsin highlights local variations in unfolding energy.

    Science.gov (United States)

    Heenan, Patrick R; Yu, Hao; Siewny, Matthew G W; Perkins, Thomas T

    2018-03-28

    Precisely quantifying the energetics that drive the folding of membrane proteins into a lipid bilayer remains challenging. More than 15 years ago, atomic force microscopy (AFM) emerged as a powerful tool to mechanically extract individual membrane proteins from a lipid bilayer. Concurrently, fluctuation theorems, such as the Jarzynski equality, were applied to deduce equilibrium free energies (ΔG 0 ) from non-equilibrium single-molecule force spectroscopy records. The combination of these two advances in single-molecule studies deduced the free-energy of the model membrane protein bacteriorhodopsin in its native lipid bilayer. To elucidate this free-energy landscape at a higher resolution, we applied two recent developments. First, as an input to the reconstruction, we used force-extension curves acquired with a 100-fold higher time resolution and 10-fold higher force precision than traditional AFM studies of membrane proteins. Next, by using an inverse Weierstrass transform and the Jarzynski equality, we removed the free energy associated with the force probe and determined the molecular free-energy landscape of the molecule under study, bacteriorhodopsin. The resulting landscape yielded an average unfolding free energy per amino acid (aa) of 1.0 ± 0.1 kcal/mol, in agreement with past single-molecule studies. Moreover, on a smaller spatial scale, this high-resolution landscape also agreed with an equilibrium measurement of a particular three-aa transition in bacteriorhodopsin that yielded 2.7 kcal/mol/aa, an unexpectedly high value. Hence, while average unfolding ΔG 0 per aa is a useful metric, the derived high-resolution landscape details significant local variation from the mean. More generally, we demonstrated that, as anticipated, the inverse Weierstrass transform is an efficient means to reconstruct free-energy landscapes from AFM data.

  7. Using a social-ecological systems perspective to understand tourism and landscape interactions in coastal areas

    Directory of Open Access Journals (Sweden)

    Jasper Hessel Heslinga

    2017-04-01

    Full Text Available Purpose – The purpose of this paper is to look at the potential synergies between tourism and landscapes and examine the potential contribution of tourism to build social-ecological resilience in the Dutch Wadden. Design/methodology/approach – The authors reveal how a social-ecological systems perspective can be used to conceptualize the Wadden as a coupled and dynamic system. This paper is a conceptual analysis that applies this approach to the Dutch Wadden. The data used for the inquiry primarily comes from a literature review. Findings – The authors argue that the social-ecological systems perspective is a useful approach and could be used to improve the governance of multi-functional socio-ecological systems in coastal areas. Opportunities for synergies between tourism and landscapes have been overlooked. The authors consider that tourism and nature protection are potentially compatible and that the synergies should be identified. Research limitations/implications – This paper is only a conceptual application rather than an empirical case study. Further research to actually apply the methodology is needed. Practical implications – Managers of protected areas should consider applying a social-ecological systems approach. Social implications – The views of a wide variety of stakeholders should be considered in landscape planning. Originality/value – The value of this paper lies in the articulation of the social-ecological systems perspective as a way to identify and understand the complex interactions between tourism and landscape, and the potential synergies between them.

  8. Marine renewable energies: status and development perspectives

    International Nuclear Information System (INIS)

    2011-01-01

    This document proposes an overview of the marine renewable energy (MRE) market, of the development perspectives, of the industrial, academic and institutional actors, of current technologies and technologies under development, and of French and European research and development programs. These energies comprise: tidal energy, the exploitation of sea temperature differences with respect with depth, wave energy, marine current power energy, osmotic and marine biomass energy

  9. Relative Values: Perspectives on a Neuroimaging Technology From Above and Within the Ethical Landscape.

    Science.gov (United States)

    Samuel, Gabrielle; Cribb, Alan; Owens, John; Williams, Clare

    2016-09-01

    In this paper we contribute to "sociology in bioethics" and help clarify the range of ways sociological work can contribute to ethics scholarship. We do this using a case study of an innovative neurotechnology, functional magnetic resonance imaging, and its use to attempt to diagnose and communicate with severely brain-injured patients. We compare empirical data from interviews with relatives of patients who have a severe brain injury with perspectives from mainstream bioethics scholars. We use the notion of an "ethical landscape" as an analogy for the different ethical positions subjects can take-whereby a person's position relative to the landscape makes a difference to the way they experience and interact with it. We show that, in comparison to studying abstract ethics "from above" the ethical landscape, which involves universal generalizations and global judgements, studying ethics empirically "from the ground," within the ethical landscape foregrounds a more plural and differentiated picture. We argue it is important not to treat empirical ethics as secondary to abstract ethics, to treat on-the-ground perspectives as useful only insofar as they can inform ethics from above. Rather, empirical perspectives can illuminate the plural vantage points in ethical judgments, highlight the "lived" nature of ethical reasoning, and point to all ethical vantage points as being significant. This is of epistemic importance to normative ethics, since researchers who pay attention to the various positions in and trajectories through the ethical landscape are unlikely to think about ethics in terms of abstract agency-as can happen with top-down ethics-or to elide agency with the agency of policymakers. Moreover, empirical perspectives may have transformative implications for people on the ground, especially where focus on the potential harms and benefits they face brings their experiences and interests to the forefront of ethical and policy discussion.

  10. Multiscale coarse-graining of the protein energy landscape.

    Directory of Open Access Journals (Sweden)

    Ronald D Hills

    2010-06-01

    Full Text Available A variety of coarse-grained (CG models exists for simulation of proteins. An outstanding problem is the construction of a CG model with physically accurate conformational energetics rivaling all-atom force fields. In the present work, atomistic simulations of peptide folding and aggregation equilibria are force-matched using multiscale coarse-graining to develop and test a CG interaction potential of general utility for the simulation of proteins of arbitrary sequence. The reduced representation relies on multiple interaction sites to maintain the anisotropic packing and polarity of individual sidechains. CG energy landscapes computed from replica exchange simulations of the folding of Trpzip, Trp-cage and adenylate kinase resemble those of other reduced representations; non-native structures are observed with energies similar to those of the native state. The artifactual stabilization of misfolded states implies that non-native interactions play a deciding role in deviations from ideal funnel-like cooperative folding. The role of surface tension, backbone hydrogen bonding and the smooth pairwise CG landscape is discussed. Ab initio folding aside, the improved treatment of sidechain rotamers results in stability of the native state in constant temperature simulations of Trpzip, Trp-cage, and the open to closed conformational transition of adenylate kinase, illustrating the potential value of the CG force field for simulating protein complexes and transitions between well-defined structural states.

  11. Protein energy landscapes determined by five-dimensional crystallography

    International Nuclear Information System (INIS)

    Schmidt, Marius; Srajer, Vukica; Henning, Robert; Ihee, Hyotcherl; Purwar, Namrta; Tenboer, Jason; Tripathi, Shailesh

    2013-01-01

    Barriers of activation within the photocycle of a photoactive protein were extracted from comprehensive time courses of time resolved crystallographic data collected at multiple temperature settings. Free-energy landscapes decisively determine the progress of enzymatically catalyzed reactions [Cornish-Bowden (2012 ▶), Fundamentals of Enzyme Kinetics, 4th ed.]. Time-resolved macromolecular crystallography unifies transient-state kinetics with structure determination [Moffat (2001 ▶), Chem. Rev.101, 1569–1581; Schmidt et al. (2005 ▶), Methods Mol. Biol.305, 115–154; Schmidt (2008 ▶), Ultrashort Laser Pulses in Medicine and Biology] because both can be determined from the same set of X-ray data. Here, it is demonstrated how barriers of activation can be determined solely from five-dimensional crystallography, where in addition to space and time, temperature is a variable as well [Schmidt et al. (2010 ▶), Acta Cryst. A66, 198–206]. Directly linking molecular structures with barriers of activation between them allows insight into the structural nature of the barrier to be gained. Comprehensive time series of crystallographic data at 14 different temperature settings were analyzed and the entropy and enthalpy contributions to the barriers of activation were determined. One hundred years after the discovery of X-ray scattering, these results advance X-ray structure determination to a new frontier: the determination of energy landscapes

  12. Technology assessment in energy landscapes. Agent-based modeling of energy conflicts

    International Nuclear Information System (INIS)

    Scheffran, Juergen; Link, P. Michael; Shaaban, Mostafa; Suesser, Diana

    2017-01-01

    The risks and conflicts of the fossil-nuclear age are in contrast to the effects of renewable energies which appear in a largely positive light. However, the transformation towards a low-carbon energy supply creates new energy landscapes with a high demand for suitable land areas - which may also provoke energy conflicts. Technology assessment can contribute to reducing such energy conflicts and increasing public acceptance by using spatial agent-based models that represent dynamic decisions and interactions of stakeholders regarding energy alternatives and land-use options. Northern Germany serves as a case study region where farmers and communities are local actors of the energy transition.

  13. Alternating access mechanisms of LeuT-fold transporters: trailblazing towards the promised energy landscapes.

    Science.gov (United States)

    Kazmier, Kelli; Claxton, Derek P; Mchaourab, Hassane S

    2017-08-01

    Secondary active transporters couple the uphill translocation of substrates to electrochemical ion gradients. Transporter conformational motion, generically referred to as alternating access, enables a central ligand binding site to change its orientation relative to the membrane. Here we review themes of alternating access and the transduction of ion gradient energy to power this process in the LeuT-fold class of transporters where crystallographic, computational and spectroscopic approaches have converged to yield detailed models of transport cycles. Specifically, we compare findings for the Na + -coupled amino acid transporter LeuT and the Na + -coupled hydantoin transporter Mhp1. Although these studies have illuminated multiple aspects of transporter structures and dynamics, a number of questions remain unresolved that so far hinder understanding transport mechanisms in an energy landscape perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Landscape of Future Accelerators at the Energy and Intensity Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M. J. [Northern Illinois U.; Chattopadhyay, S. [Northern Illinois U.

    2016-11-21

    An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

  15. Hierarchical Protein Free Energy Landscapes from Variationally Enhanced Sampling.

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-12-13

    In recent work, we demonstrated that it is possible to obtain approximate representations of high-dimensional free energy surfaces with variationally enhanced sampling ( Shaffer, P.; Valsson, O.; Parrinello, M. Proc. Natl. Acad. Sci. , 2016 , 113 , 17 ). The high-dimensional spaces considered in that work were the set of backbone dihedral angles of a small peptide, Chignolin, and the high-dimensional free energy surface was approximated as the sum of many two-dimensional terms plus an additional term which represents an initial estimate. In this paper, we build on that work and demonstrate that we can calculate high-dimensional free energy surfaces of very high accuracy by incorporating additional terms. The additional terms apply to a set of collective variables which are more coarse than the base set of collective variables. In this way, it is possible to build hierarchical free energy surfaces, which are composed of terms that act on different length scales. We test the accuracy of these free energy landscapes for the proteins Chignolin and Trp-cage by constructing simple coarse-grained models and comparing results from the coarse-grained model to results from atomistic simulations. The approach described in this paper is ideally suited for problems in which the free energy surface has important features on different length scales or in which there is some natural hierarchy.

  16. Trp-cage: Folding free energy landscape in explicit water

    Science.gov (United States)

    Zhou, Ruhong

    2003-11-01

    Trp-cage is a 20-residue miniprotein, which is believed to be the fastest folder known so far. In this study, the folding free energy landscape of Trp-cage has been explored in explicit solvent by using an OPLSAA force field with periodic boundary condition. A highly parallel replica exchange molecular dynamics method is used for the conformation space sampling, with the help of a recently developed efficient molecular dynamics algorithm P3ME/RESPA (particle-particle particle-mesh Ewald/reference system propagator algorithm). A two-step folding mechanism is proposed that involves an intermediate state where two correctly formed partial hydrophobic cores are separated by an essential salt-bridge between residues Asp-9 and Arg-16 near the center of the peptide. This metastable intermediate state provides an explanation for the superfast folding process. The free energy landscape is found to be rugged at low temperatures, and then becomes smooth and funnel-like above 340 K. The lowest free energy structure at 300 K is only 1.50 Å C-RMSD (C-rms deviation) from the NMR structures. The simulated nuclear Overhauser effect pair distances are in excellent agreement with the raw NMR data. The temperature dependence of the Trp-cage population, however, is found to be significantly different from experiment, with a much higher melting transition temperature above 400 K (experimental 315 K), indicating that the current force fields, parameterized at room temperature, need to be improved to correctly predict the temperature dependence.

  17. Multivariable extrapolation of grand canonical free energy landscapes

    Science.gov (United States)

    Mahynski, Nathan A.; Errington, Jeffrey R.; Shen, Vincent K.

    2017-12-01

    We derive an approach for extrapolating the free energy landscape of multicomponent systems in the grand canonical ensemble, obtained from flat-histogram Monte Carlo simulations, from one set of temperature and chemical potentials to another. This is accomplished by expanding the landscape in a Taylor series at each value of the order parameter which defines its macrostate phase space. The coefficients in each Taylor polynomial are known exactly from fluctuation formulas, which may be computed by measuring the appropriate moments of extensive variables that fluctuate in this ensemble. Here we derive the expressions necessary to define these coefficients up to arbitrary order. In principle, this enables a single flat-histogram simulation to provide complete thermodynamic information over a broad range of temperatures and chemical potentials. Using this, we also show how to combine a small number of simulations, each performed at different conditions, in a thermodynamically consistent fashion to accurately compute properties at arbitrary temperatures and chemical potentials. This method may significantly increase the computational efficiency of biased grand canonical Monte Carlo simulations, especially for multicomponent mixtures. Although approximate, this approach is amenable to high-throughput and data-intensive investigations where it is preferable to have a large quantity of reasonably accurate simulation data, rather than a smaller amount with a higher accuracy.

  18. Approximate scaling properties of RNA free energy landscapes

    Science.gov (United States)

    Baskaran, S.; Stadler, P. F.; Schuster, P.

    1996-01-01

    RNA free energy landscapes are analysed by means of "time-series" that are obtained from random walks restricted to excursion sets. The power spectra, the scaling of the jump size distribution, and the scaling of the curve length measured with different yard stick lengths are used to describe the structure of these "time series". Although they are stationary by construction, we find that their local behavior is consistent with both AR(1) and self-affine processes. Random walks confined to excursion sets (i.e., with the restriction that the fitness value exceeds a certain threshold at each step) exhibit essentially the same statistics as free random walks. We find that an AR(1) time series is in general approximately self-affine on timescales up to approximately the correlation length. We present an empirical relation between the correlation parameter rho of the AR(1) model and the exponents characterizing self-affinity.

  19. Temporal disconnectivity of the energy landscape in glassy systems

    Science.gov (United States)

    Lempesis, Nikolaos; Boulougouris, Georgios C.; Theodorou, Doros N.

    2013-03-01

    An alternative graphical representation of the potential energy landscape (PEL) has been developed and applied to a binary Lennard-Jones glassy system, providing insight into the unique topology of the system's potential energy hypersurface. With the help of this representation one is able to monitor the different explored basins of the PEL, as well as how - and mainly when - subsets of basins communicate with each other via transitions in such a way that details of the prior temporal history have been erased, i.e., local equilibration between the basins in each subset has been achieved. In this way, apart from detailed information about the structure of the PEL, the system's temporal evolution on the PEL is described. In order to gather all necessary information about the identities of two or more basins that are connected with each other, we consider two different approaches. The first one is based on consideration of the time needed for two basins to mutually equilibrate their populations according to the transition rate between them, in the absence of any effect induced by the rest of the landscape. The second approach is based on an analytical solution of the master equation that explicitly takes into account the entire explored landscape. It is shown that both approaches lead to the same result concerning the topology of the PEL and dynamical evolution on it. Moreover, a "temporal disconnectivity graph" is introduced to represent a lumped system stemming from the initial one. The lumped system is obtained via a specially designed algorithm [N. Lempesis, D. G. Tsalikis, G. C. Boulougouris, and D. N. Theodorou, J. Chem. Phys. 135, 204507 (2011), 10.1063/1.3663207]. The temporal disconnectivity graph provides useful information about both the lumped and the initial systems, including the definition of "metabasins" as collections of basins that communicate with each other via transitions that are fast relative to the observation time. Finally, the two examined

  20. Landscape and biodiversity as new resources for agro-ecology? Insights from farmers' perspectives

    Directory of Open Access Journals (Sweden)

    Nicolas Salliou

    2017-06-01

    Full Text Available Pesticide reduction is a key current challenge. Scientific findings in landscape ecology suggest that complex landscapes favor insect pest biological control by conservation of natural enemy habitats. A potential agro-ecological innovation is to conserve or engineer such complex landscapes to reduce pesticide use. However, whereas the relevant resources are often well known in most natural resource management situations, potential resources involved in this innovation (natural enemies and the landscape are not necessarily considered as resources in the eyes of their potential users. From the perspective that resources are socially constructed, our objective was to investigate whether and how these resources are considered by their potential users. To do so, we conducted research in an area specializing in tree-fruit (apple production in southwestern France. This site was selected for its high pest incidence and high use of insecticides on orchards and, consequently, high stakes involved for any alternative. We conducted 30 comprehensive interviews with stakeholders (farmers and crop advisors about their pest control strategies to explore their representation of their landscape and natural enemies. Our results show that natural enemies are considered by local stakeholders as public good resources, especially in the context of interventions by public institutions for their conservation, acclimation, and management. Farmers sometimes consider natural enemies as private goods when they can isolate the crop, enclosing it with nets or some other type of boundary. We also show that the landscape was not considered as a resource for biological pest control by conservation, but rather as a source of pests. We advocate for more research on the effects of landscapes on natural enemies, including participatory research based on dialogue among farmers, crop advisors, and scientists.

  1. Nuclear energy in a sustainable development perspective

    International Nuclear Information System (INIS)

    Bertel, E.; Wilmer, P.

    2001-01-01

    The characteristics of nuclear energy are reviewed and assessed from a sustainable development perspective highlighting key economic, environmental and social issues, challenges and opportunities relevant for energy policy making.. The analysis covers the potential role of nuclear energy in increasing the human and man-made capital assets of the world while preserving its natural and environmental resource assets as well as issues to be addressed in order to enhance the contribution of nuclear energy to sustainable development goals. (author)

  2. Renewable energies - Situation and perspectives

    International Nuclear Information System (INIS)

    Acket, Claude; Vaillant, Jacques

    2011-01-01

    The world has to face increasing energy needs while it is today dependent of fossil fuels at 80%. Getting out of the fossil fuels dependence model requires an important effort to promote the energy saving and the carbon-free energies as well, and in particular the renewable energy sources. Taking all this information into account, the authors evaluate the global share that renewable energies could represent in the energy mix, in France and in the entire world. This share represents today only 10% of the energy consumed, but will it remain marginal or will it become important and eventually prominent? (J.S.)

  3. The multi-level perspective analysis: Indonesia geothermal energy transition study

    Science.gov (United States)

    Wisaksono, A.; Murphy, J.; Sharp, J. H.; Younger, P. L.

    2018-01-01

    The study adopts a multi-level perspective in technology transition to analyse how the transition process in the development of geothermal energy in Indonesia is able to compete against the incumbent fossil-fuelled energy sources. Three levels of multi-level perspective are socio-technical landscape (ST-landscape), socio-technical regime (ST-regime) and niche innovations in Indonesia geothermal development. The identification, mapping and analysis of the dynamic relationship between each level are the important pillars of the multi-level perspective framework. The analysis considers the set of rules, actors and controversies that may arise in the technological transition process. The identified geothermal resource risks are the basis of the emerging geothermal technological innovations in Indonesian geothermal. The analysis of this study reveals the transition pathway, which yields a forecast for the Indonesian geothermal technology transition in the form of scenarios and probable impacts.

  4. Energy situation and perspectives of using solar energy in Crimea

    International Nuclear Information System (INIS)

    Stoyanova, I.I.; Mashkara, O.G.; Vikhorev, Yu.A.; Sokolovskaya, N.I.

    1997-01-01

    The article presents the talk on the energy situation and perspectives of the use of solar energy in Crimea, Ukraine, given at the International Workshop on applied solar energy held in Tashkent(Uzbekistan) in June 1997. The main use of solar energy is solar energy heating systems developed and produced in Crimea. The project of 100 MWt solar power plant is proposed for construction in Crimea and will improve ecological situation in resort area. (A.A.D.)

  5. Discrete kinetic models from funneled energy landscape simulations.

    Directory of Open Access Journals (Sweden)

    Nicholas P Schafer

    Full Text Available A general method for facilitating the interpretation of computer simulations of protein folding with minimally frustrated energy landscapes is detailed and applied to a designed ankyrin repeat protein (4ANK. In the method, groups of residues are assigned to foldons and these foldons are used to map the conformational space of the protein onto a set of discrete macrobasins. The free energies of the individual macrobasins are then calculated, informing practical kinetic analysis. Two simple assumptions about the universality of the rate for downhill transitions between macrobasins and the natural local connectivity between macrobasins lead to a scheme for predicting overall folding and unfolding rates, generating chevron plots under varying thermodynamic conditions, and inferring dominant kinetic folding pathways. To illustrate the approach, free energies of macrobasins were calculated from biased simulations of a non-additive structure-based model using two structurally motivated foldon definitions at the full and half ankyrin repeat resolutions. The calculated chevrons have features consistent with those measured in stopped flow chemical denaturation experiments. The dominant inferred folding pathway has an "inside-out", nucleation-propagation like character.

  6. Energy Technology Perspectives 2012: Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-05

    Energy Technology Perspectives (ETP) is the International Energy Agency's most ambitious publication on new developments in energy technology. It demonstrates how technologies -- from electric vehicles to smart grids -- can make a decisive difference in achieving the objective of limiting the global temperature rise to 2 C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  7. Water resources and human behaviour: an integrated landscape management perspective

    Directory of Open Access Journals (Sweden)

    Luiz Oosterbeek

    2013-09-01

    Full Text Available A two sides balance can be drawn from the last 20 years of active intents to change local, regional and global policies concerning water and global environment issues. On one hand, as a consequence of the “sustainable development” model, there is an increasing awareness of the issues in stake, and environment became a core part of any public policy. International conferences and the investment in scientific research in these areas are an expression of this. Yet, concerns are growing in face of the increasing stress imposed on freshwater resources, climate change and the difficulties to achieve international consensus on specific strategies. This was the focus of discussion in the international conference on climate change organised in Nagoya in December 2010, by ICSS, ICSU and ICPHS. A revision of the conceptual approach to sustainable development, moving beyond a strictly socio-economic understanding of human behaviour and incorporating, as basic strategies, the dimensions of culture, didactics of dilemma and governance, is currently being applied in some scenarios, hopefully with a better result. The paper discusses water resources in the context of climate change from this integrated perspective.

  8. Sustainable Energy Future - Nordic Perspective

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    1998-01-01

    This invited paper first outlines the methodologies applied in analysing the energy savings potentials, as applied to a Nordic and a European case study. Afterwards are shown results for how a high quality of life can be achieved with an energy consumption only a small fraction of the present in ...... in Europe. The energy policy in Denmark since 1973 is outlined, including the activities and the roles of NGOs. Finally are described some of the difficulties of implementing energy saving policies, especially in combination with increasing liberalization of the energy market....

  9. Mexican energy situation and perspectives

    International Nuclear Information System (INIS)

    Pnce, A.

    1978-01-01

    The energy situation of Mexico is analyzed, including a projection to year 2000. An energy trade balance for 1975 is presented, including the energy invested in the imported and exported manufactured goods. Although Mexico is an oil exporting country, it is found that there was a net import of 32 million barrels of oil equivalent. The projection shows that by developing all alternative sources, hydrocarbons will supply 73% of all the primary energy at the end of the century. A 20,000 MW(e) nucleoelectric program would depress hydrocarbons percentage to 63%. It is concluded that there has been a lack of a coherent energy policy which would permit to elaborate adequate energy development programs. Some criteria are recommended for an energy policy: a) the oil export program should be reviewed; b) The country should encourage the generation of its own technology; c) The energy demand growth-rate should be maintained high enough until an acceptable level of per-capita consumption is reached; d) The internal prices of energy should be reviewed to modify the consumption scheme and e) The primary energy sources should be diversified as possible; with special emphasis on nuclear energy which is the only one important alternative at short time. (author)

  10. Free energy landscape of a minimalist salt bridge model.

    Science.gov (United States)

    Li, Xubin; Lv, Chao; Corbett, Karen M; Zheng, Lianqing; Wu, Dongsheng; Yang, Wei

    2016-01-01

    Salt bridges are essential to protein stability and dynamics. Despite the importance, there has been scarce of detailed discussion on how salt bridge partners interact with each other in distinct solvent exposed environments. In this study, employing a recent generalized orthogonal space tempering (gOST) method, we enabled efficient molecular dynamics simulation of repetitive breaking and reforming of salt bridge structures within a minimalist salt-bridge model, the Asp-Arg dipeptide and thereby were able to map its detailed free energy landscape in aqueous solution. Free energy surface analysis shows that although individually-solvated states are more favorable, salt-bridge states still occupy a noticeable portion of the overall population. Notably, the competing forces, e.g. intercharge attractions that drive the formation of salt bridges and solvation forces that pull the charged groups away from each other, are energetically comparable. As the result, the salt bridge stability is highly tunable by local environments; for instance when local water molecules are perturbed to interact more strongly with each other, the population of the salt-bridge states is likely to increase. Our results reveal the critical role of local solvent structures in modulating salt-bridge partner interactions and imply the importance of water fluctuations on conformational dynamics that involves solvent accessible salt bridge formations. © 2015 The Protein Society.

  11. Solar energy - status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Ahm, P. [PA Energy A/S, Malling (Denmark)

    2007-05-15

    Solar energy in terms of thermal Solar Hot Water systems and electricity producing Photovoltaics contribute at present only to the global energy supply at a fraction of 1 %. However, the potential for solar energy is immense: the earth receives in 1 hour from the sun the equivalent of the present annual global energy supply. Solar energy is one of the emerging renewable energy technologies still not competitive, but exhibiting both technical and economic potential to be so inside 10-15 years. There is basically no necessary 'technology jumps' as prerequisites, but such a development will demand a favorable political climate. Growing political awareness, driven partly by environmental concerns partly by concerns about security of energy supply, of the need to promote solar energy and renewables, e.g. on global level spurred on by the recent UN/IPCC report and on an EU level by the EC commitment to reach 20 % renewables in the electricity supply by 2010 and 20 % renewables in the overall energy production by 2020, appears to ensure the necessary future political support for renewables, but not necessarily for solar energy technologies, in particular photovoltaics's, which is still not yet competitive to other renewables although exhibiting a tremendous potential. (au)

  12. Wave energy: a Pacific perspective.

    Science.gov (United States)

    Paasch, Robert; Ruehl, Kelley; Hovland, Justin; Meicke, Stephen

    2012-01-28

    This paper illustrates the status of wave energy development in Pacific rim countries by characterizing the available resource and introducing the region's current and potential future leaders in wave energy converter development. It also describes the existing licensing and permitting process as well as potential environmental concerns. Capabilities of Pacific Ocean testing facilities are described in addition to the region's vision of the future of wave energy.

  13. Perspectives for nuclear energy; Perspectives pour l'energie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Baugnet, J -M; Abderrahim, H A; Dekeyser, J; Meskens, G

    1998-09-01

    In Belgium, approximately 60 percent of the produced electricity is generated by nuclear power. At present, nuclear power production tends to stagnate in Europe and North America but is still growing in Asia. The document gives an overview of the present status and the future energy demand with emphasis on electric power. Different evaluation criteria including factors hindering and factors promoting the expansion of nuclear power as well as requirements of new nuclear power plants are discussed. The extension of the lifetime of existing facilities as well as fuel supply are taken into consideration. A comparative assesment of nuclear power with other energy sources is made. The report concludes with estimating the contribution and the role of nuclear power in future energy demand as well as with an overview of future reactors and research and development programmes.

  14. Continental energy plan. Canadian perspectives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The 'continental energy plan' was first mentioned by US President George Bush during his election campaign, and relates to the adjustment of energy resources development in Canada and Mexico. The US energy policy aims to reduce US dependence on middle east oil supplies, increase US energy production, increase regional integration of energy supplies throughout North America, increase US refining capacity, reduce regulatory barriers, increase use of alternative energies, and to increase support for research and development. Under the Canada/US FTA (Free Trade Agreement) and NAFTA (North American Free Trade Agreement), not less than 50% of Canadian crude oil and natural gas are imported to the US market. As for Mexico, it exempted most portions of its energy sector from the agreement during the NAFTA negotiations. Now that Mexico itself is facing energy shortage, however, it is anticipated that under President Vincente Fox it will adopt a policy like that of Canada and start development by introducing foreign money into the fields of oil, gas, and electricity. (NEDO)

  15. Global energy perspective of Turkey

    International Nuclear Information System (INIS)

    Sen, H. Mete

    2006-01-01

    Global energy demand is growing rapidly at an average rate of 4% per year in parallel with the economy while EU-25 has only 0,8% during the last decade. Total primary energy supply is 87 818 000 toe of which 72% was imported; in comparison the average dependency rate is 49,5% in the EU. Such excessive dependency creates harmful effects on the national economy. Oil and natural gas imports bill was 19,5 billion US $ in 2005. Primary energy demand growth rate is twice as much of the production rate in the period 1980 2004. Fossil fuels accounts for 86% of Turkeys global energy supply in 2004. Population growth rate is one of the major parameters affecting the energy balance. Energy and electricity consumptions per capita are still one third of the EUs average.. Turkeys coal reserves needs to be utilized at higher rate and hydropower, wind power and geothermal energy potentials should be developed in order to decrease the imported energy dependence, soon. Due to the buy or pay bilateral agreements with suppliers, storage capabilities should be realized for excessive natural gas supply. Turkeys average growth rate of electricity production is 8,1% while installed capacity has 8,5% for the last 25 years. The present total installed capacity is 39 020 MW in which renewables has a share of 34%. Total electricity production was 162 TWh in 2005 of which 75,4% was supplied by thermal power plants. Share of natural gas is 44% of the annual electricity production. Considering the present power plants and the ones under construction, electricity supply and demand will be in balance till the year of 2010 (with high demand scenario) or 2015 (with low demand scenario). Nuclear power is being considered for electricity supply security after 2015. But, the general approach for supply security is first to develop the domestic coal reserves, renewable energy resources.

  16. Energy geopolitics, an American perspective

    International Nuclear Information System (INIS)

    Henderson, Simon

    2008-01-01

    Even if geopolitics can be said not to exist for Americans who, like for example in the field of energy, believe that any problem can find a solution with the help of money and of the American ingenuity, and who are in fact only interested in a lower energy price, the author comments how energy issues are addressed by the candidates to the President election of 2008. The author notices that American people may have to realise, at least for a while, that their country is accused to bear a large share of responsibilities in environmental problems

  17. Bayesian energy landscape tilting: towards concordant models of molecular ensembles.

    Science.gov (United States)

    Beauchamp, Kyle A; Pande, Vijay S; Das, Rhiju

    2014-03-18

    Predicting biological structure has remained challenging for systems such as disordered proteins that take on myriad conformations. Hybrid simulation/experiment strategies have been undermined by difficulties in evaluating errors from computational model inaccuracies and data uncertainties. Building on recent proposals from maximum entropy theory and nonequilibrium thermodynamics, we address these issues through a Bayesian energy landscape tilting (BELT) scheme for computing Bayesian hyperensembles over conformational ensembles. BELT uses Markov chain Monte Carlo to directly sample maximum-entropy conformational ensembles consistent with a set of input experimental observables. To test this framework, we apply BELT to model trialanine, starting from disagreeing simulations with the force fields ff96, ff99, ff99sbnmr-ildn, CHARMM27, and OPLS-AA. BELT incorporation of limited chemical shift and (3)J measurements gives convergent values of the peptide's α, β, and PPII conformational populations in all cases. As a test of predictive power, all five BELT hyperensembles recover set-aside measurements not used in the fitting and report accurate errors, even when starting from highly inaccurate simulations. BELT's principled framework thus enables practical predictions for complex biomolecular systems from discordant simulations and sparse data. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  18. Computational design of RNAs with complex energy landscapes.

    Science.gov (United States)

    Höner zu Siederdissen, Christian; Hammer, Stefan; Abfalter, Ingrid; Hofacker, Ivo L; Flamm, Christoph; Stadler, Peter F

    2013-12-01

    RNA has become an integral building material in synthetic biology. Dominated by their secondary structures, which can be computed efficiently, RNA molecules are amenable not only to in vitro and in vivo selection, but also to rational, computation-based design. While the inverse folding problem of constructing an RNA sequence with a prescribed ground-state structure has received considerable attention for nearly two decades, there have been few efforts to design RNAs that can switch between distinct prescribed conformations. We introduce a user-friendly tool for designing RNA sequences that fold into multiple target structures. The underlying algorithm makes use of a combination of graph coloring and heuristic local optimization to find sequences whose energy landscapes are dominated by the prescribed conformations. A flexible interface allows the specification of a wide range of design goals. We demonstrate that bi- and tri-stable "switches" can be designed easily with moderate computational effort for the vast majority of compatible combinations of desired target structures. RNAdesign is freely available under the GPL-v3 license. Copyright © 2013 Wiley Periodicals, Inc.

  19. Relationship between energy landscape and low-temperature dynamics of ±J spin glasses

    International Nuclear Information System (INIS)

    Kobe, S.; Krawczyk, J.

    2004-01-01

    Clusters and valleys in the exact low-energy landscape of finite Edwards-Anderson ±J spin glasses are related to the distribution of spin domains and free spins in the ground states. The time evolution of the spin correlation function reflects a walk through the landscape at a given temperature and shows typical glassy behaviour

  20. World Energy Roadmap - A Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Alharthi, A.A.; Alfehaid, M.A.

    2007-07-01

    The dialogue between energy consumers and producers that has been going on for the past fifteen years has revealed the basic parameters of the complex energy scene. While the consumers are concerned with security of supply, the producers have equal concern with access to markets. A common ground for the two groups is sustainable development because both aim at the continuous flow of oil to ensure continued economic growth. Both have valid concerns and share equal responsibility towards the world at large where competitive advantages available to both groups are employed to achieve global sustainable development. The key to achieving this goal in a world of competing and (to some extent) conflicting priorities is not only a sizable and irreversible investment by both groups, but also the desire to relax unwarranted regulations that have hindered progress in the energy industry. (auth)

  1. Landscape and Energy%景观和能源

    Institute of Scientific and Technical Information of China (English)

    德克·西蒙斯; 李佳怿(译); 吴晓彤(校)

    2016-01-01

    research-through-design projects. The Rotterdam case is produced with local stakeholders for the 2014 ‘Landscape and Energy’ book publication. This land-oriented case is complemented by a project on the seascape of the North Sea as a future energy landscape in the IABR-2016 project 2050: An Energetic Odyssey. Especialy the last case not only justifies the conclusion that landscape architecture can play a role but also that research-by-design is a strong instrument to help in policy making.

  2. Global energy perspectives until 2050

    International Nuclear Information System (INIS)

    Schiffer, H.W.

    2008-01-01

    A sustained energy supply must do equal justice to the goals of economic, environmental and social compatibility. If there is a conflict of goals, the object cannot be to maximize one parameter from this bundle of goals; a balance should rather be sought between the set targets. An analysis of long-term projections for world energy supply shows that a greater convergence between expected developments and those considered necessary for climate policy reasons can only be reached by consistently pursuing all approaches suitable for achieving the targets set - e. g. in climate protection - at a minimum cost. The solution is not one of 'either - or' but of 'both - and'. (orig.)

  3. A perspective on energy exports

    International Nuclear Information System (INIS)

    O'Connor, A.J.

    1983-06-01

    Based on New Brunswick Power's energy export experience over the past two decades, it appears that Canada could have a very special and unique opportunity to input into the US energy market over the coming decades. The CANDU reactor can offer one of these opportunities. Such business opportunities can be of very real benefit to both countries and to the particular regions involved. Like any other form of business, this one must be carefully planned and must be conducted in an environment conducive to the achievement of the objectives of the business

  4. A high energy physics perspective

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1997-01-01

    The status of the Standard model and role of symmetry in its development are reviewed. Some outstanding problems are surveyed and possible solutions in the form of additional open-quotes Hidden Symmetries close quotes are discussed. Experimental approaches to uncover open-quotes New Physicsclose quotes associated with those symmetries are described with emphasis on high energy colliders. An outlook for the future is given

  5. Conference on landscape impacts of wind energy and local acceptance: France-Germany crossed views

    International Nuclear Information System (INIS)

    Bouscatel, Jerome; Olagne, Regis; Derkenne, Chantal; Galiano, Mila; Mayer, Joerg; Ratzbor, Guenter; Laborgne, Pia; Nadai, Alain; Ratouis, Marie-Odile; Schoebel-Rutschmann, Soeren; Petit, Jean-Francois; Guennewig, Dieter; Portales, David

    2008-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on the landscape impacts of wind energy. In the framework of this French-German exchange of experience, more than 100 participants exchanged views on the environmental impact of wind farms and the opinion of residents. This document brings together the available presentations (slides) made during this event: 1 - French people and wind energy (Mila Galiano); 2 - Wind energy acceptance in Germany: an essential factor for the wind industry development (Joerg Mayer); 3 - Taking into account landscapes and residents in the development of wind farms: a France-Germany comparison (Pia Laborgne, Alain Nadai); 3 - Wind energy development supervision thanks to territorial planning in Germany (Guenter Ratzbor); 4 - Landscape challenges in wind energy development: point of view and role of a state decentralised department (Marie-Odile Ratouis); 5 - Park or landscape - Wind turbines as elements of the cultural landscape (Soeren Schoebel-Rutschmann); 6 - How should a developer approach the 'landscape' aspect when foreseeing a wind energy project installation (Jean-Francois Petit); 7 - More consensual wind energy projects along highways, railways and overhead power lines? (Dieter Guennewig); 8 - The 'wings top': un example of participatory and citizen's project (David Portales)

  6. Nuclear energy - a spiritual perspective

    International Nuclear Information System (INIS)

    Jones, M.

    1983-01-01

    The subject is covered in chapters entitled: the search for energy (historical); from uranium to the bomb (radioactivity); the principle of fission (atomic structure; isotopes); fear of nuclear reactors (types of reactor; antinuclear groups; economic argument; socio-political argument; psychological argument); Capra and the dance of life; elements and ethers (life ethers and subtle elements); origins of matter (etheric forces; the primal matrix); the balance of gold and silver (etheric forces, which can only be directly perceived in the spirit); Lucifer, Ahriman and nuclear accident; Christ's resurrection and the essence of matter; the opening of the abyss; the divine mother. (U.K.)

  7. The free energy landscape of small molecule unbinding.

    Directory of Open Access Journals (Sweden)

    Danzhi Huang

    2011-02-01

    Full Text Available The spontaneous dissociation of six small ligands from the active site of FKBP (the FK506 binding protein is investigated by explicit water molecular dynamics simulations and network analysis. The ligands have between four (dimethylsulphoxide and eleven (5-diethylamino-2-pentanone non-hydrogen atoms, and an affinity for FKBP ranging from 20 to 0.2 mM. The conformations of the FKBP/ligand complex saved along multiple trajectories (50 runs at 310 K for each ligand are grouped according to a set of intermolecular distances into nodes of a network, and the direct transitions between them are the links. The network analysis reveals that the bound state consists of several subbasins, i.e., binding modes characterized by distinct intermolecular hydrogen bonds and hydrophobic contacts. The dissociation kinetics show a simple (i.e., single-exponential time dependence because the unbinding barrier is much higher than the barriers between subbasins in the bound state. The unbinding transition state is made up of heterogeneous positions and orientations of the ligand in the FKBP active site, which correspond to multiple pathways of dissociation. For the six small ligands of FKBP, the weaker the binding affinity the closer to the bound state (along the intermolecular distance are the transition state structures, which is a new manifestation of Hammond behavior. Experimental approaches to the study of fragment binding to proteins have limitations in temporal and spatial resolution. Our network analysis of the unbinding simulations of small inhibitors from an enzyme paints a clear picture of the free energy landscape (both thermodynamics and kinetics of ligand unbinding.

  8. Mediterranean Energy Perspectives, Egypt - Executive summary

    International Nuclear Information System (INIS)

    2011-01-01

    Egypt is a significant oil producer and a rapidly growing natural gas producer. Its strategic location makes it an important transit corridor for world energy markets. Mediterranean Energy Perspectives - Egypt provides insights into the country's energy situation today and over the next two decades. It presents detailed data and analysis of interest to those who have a stake in both the supply and demand side of the energy equation. It is the first in-depth country review in OME's Mediterranean Energy Perspectives (MEP) series. The publication draws upon the extensive expertise of the Observatoire Mediterraneen de l'Energie (OME) and its members. MEP-Egypt is a unique and comprehensive analysis of the energy sector in Egypt. It contains data from the early days of its energy industry up to today as well as a view on its evolution to 2030 based on the supply and demand model developed by OME (Mediterranean Energy Model). Current efforts related to renewable energy sources are carefully considered as they are key issues for the Egyptian energy sector and for the whole economic and environment future of the country. MEP-Egypt presents: - Historical and forecast data on the supply and demand balance for each segment of the Egyptian energy sector. - Past, present and future of oil and gas exploration and discoveries. - Oil and gas fields: production and development. - Oil and gas production profiles and prospects to 2030. - Detailed information on refineries, pipelines, LNG terminals and storage facilities. - Evolution of electricity generation and installed capacity. - Developments of innovative and renewable energy sources. - Prospects for CO 2 emissions and sustainable development. - Fiscal regime of the energy industry. - Alternative energy scenarios: a Conservative scenario, a Proactive scenario and two High Economic Growth variants. MEP-Egypt has been prepared by a joint-team of Egyptian industry experts and OME staff, supported by related companies, institutions

  9. Dynamic energy landscapes of riboswitches help interpret conformational rearrangements and function.

    Directory of Open Access Journals (Sweden)

    Giulio Quarta

    Full Text Available Riboswitches are RNAs that modulate gene expression by ligand-induced conformational changes. However, the way in which sequence dictates alternative folding pathways of gene regulation remains unclear. In this study, we compute energy landscapes, which describe the accessible secondary structures for a range of sequence lengths, to analyze the transcriptional process as a given sequence elongates to full length. In line with experimental evidence, we find that most riboswitch landscapes can be characterized by three broad classes as a function of sequence length in terms of the distribution and barrier type of the conformational clusters: low-barrier landscape with an ensemble of different conformations in equilibrium before encountering a substrate; barrier-free landscape in which a direct, dominant "downhill" pathway to the minimum free energy structure is apparent; and a barrier-dominated landscape with two isolated conformational states, each associated with a different biological function. Sharing concepts with the "new view" of protein folding energy landscapes, we term the three sequence ranges above as the sensing, downhill folding, and functional windows, respectively. We find that these energy landscape patterns are conserved in various riboswitch classes, though the order of the windows may vary. In fact, the order of the three windows suggests either kinetic or thermodynamic control of ligand binding. These findings help understand riboswitch structure/function relationships and open new avenues to riboswitch design.

  10. Numerical evaluation of the statistical properties of a potential energy landscape

    International Nuclear Information System (INIS)

    Nave, E La; Sciortino, F; Tartaglia, P; Michele, C De; Mossa, S

    2003-01-01

    The techniques which allow the numerical evaluation of the statistical properties of the potential energy landscape for models of simple liquids are reviewed and critically discussed. Expressions for the liquid free energy and its vibrational and configurational components are reported. Finally, a possible model for the statistical properties of the landscape, which appears to describe correctly fragile liquids in the region where equilibrium simulations are feasible, is discussed

  11. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  12. Landscape architecture between politics and science : an integrative perspective on landscape planning and design in the network society

    NARCIS (Netherlands)

    Jonge, de J.M.

    2009-01-01

    This thesis examines the typical nature of design thinking, which is compared and contrasted with scientific and political thinking. A theretical framework is formulated and applied to landscape planning and design. During the 20th century the established operational orientation in landscape

  13. Energy Transition: Missed Opportunities and Emerging Challenges for Landscape Planning and Designing

    Directory of Open Access Journals (Sweden)

    Renée M. de Waal

    2014-07-01

    Full Text Available Making the shift from fossil fuels to renewable energy seems inevitable. Because energy transition poses new challenges and opportunities to the discipline of landscape architecture, the questions addressed in this paper are: (1 what landscape architects can learn from successful energy transitions in Güssing, Jühnde and Samsø; and (2 to what extent landscape architecture (or other spatial disciplines contributed to energy transition in the aforementioned cases. An exploratory, comparative case study was conducted to identify differences and similarities among the cases, to answer the research questions, and to formulate recommendations for further research and practice. The comparison indicated that the realized renewable energy systems are context-dependent and, therefore, specifically designed to meet the respective energy demand, making use of the available potentials for renewable energy generation and efficiency. Further success factors seemed to be the presence of (local frontrunners and a certain degree of citizen participation. The relatively smooth implementation of renewable energy technologies in Jühnde and on Samsø may indicate the importance of careful and (partly institutionalized consideration of landscape impact, siting and design. Comparing the cases against the literature demonstrated that landscape architects were not as involved as they, theoretically, could have been. However, particularly when the aim is sustainable development, rather than “merely” renewable energy provision, the integrative concept of “sustainable energy landscapes” can be the arena where landscape architecture and other disciplines meet to pursue global sustainability goals, while empowering local communities and safeguarding landscape quality.

  14. Nuclear energy in a sustainable development perspective

    International Nuclear Information System (INIS)

    2000-01-01

    The concept of sustainable development, which emerged from the report of the 1987 World Commission on Environment and Development (the Brundtland report), is of increasing interest to policy makers and the public. In the energy sector, sustainable development policies need to rely on a comparative assessment of alternative options, taking into account their economic, health, environmental and social aspects, at local, regional and global levels. This publication by the OECD Nuclear Energy Agency investigates nuclear energy from a sustainable development perspective, and highlights the opportunities and challenges that lie ahead in this respect. It provides data and analyses that may help in making trades-off and choices in the energy and electricity sectors at the national level, taking into account country-specific circumstances and priorities. It will be of special interest to policy makers in the nuclear and energy fields

  15. Perspectives of U.S. energy problems

    International Nuclear Information System (INIS)

    Kimel, W.R.

    In 1973 U.S. energy problems were brought dramatically into focus by the Arab oil embargo. A variety of bills passed by the Congress since that time and others that are under consideration do not adequately address our energy situation. To correct this situation the author believes free enterprise should be allowed to operate with as little regulation as possible to increase energy production using coal and nuclear as well as other 'soft' technologies. Conservation will also play an important role if economic factors are allowed to control logical implementation and application of energy saving techniques. Specifically, nuclear power must play a significant role because it has been proven economical, safe, dependable and the best energy source we know from an environmental perspective. (L.L.)

  16. Reliable protein folding on non-funneled energy landscapes: the free energy reaction path

    OpenAIRE

    Lois, Gregg; Blawzdziewicz, Jerzy; O'Hern, Corey S.

    2008-01-01

    A theoretical framework is developed to study the dynamics of protein folding. The key insight is that the search for the native protein conformation is influenced by the rate r at which external parameters, such as temperature, chemical denaturant or pH, are adjusted to induce folding. A theory based on this insight predicts that (1) proteins with non-funneled energy landscapes can fold reliably to their native state, (2) reliable folding can occur as an equilibrium or out-of-equilibrium pro...

  17. Households' ICT use in an energy perspective

    DEFF Research Database (Denmark)

    Røpke, Inge; Gram-Hanssen, Kirsten; Jensen, Jesper Ole

    2008-01-01

    The starting point for this paper is the lack of linkage between two of the prominent social agendas of the time – the development of the information society and the question of how to prevent man-made climate change. The paper is intended as a contribution to integrate the two agendas by conside......The starting point for this paper is the lack of linkage between two of the prominent social agendas of the time – the development of the information society and the question of how to prevent man-made climate change. The paper is intended as a contribution to integrate the two agendas...... by considering ICT in an energy perspective. In particular, the paper focuses on the integration of ICT in households and the energy impacts related to changing everyday practices. As this has not received much attention in previous research, the paper has an explorative character. Firstly, the paper reviews...... some of the previous studies on ICT and energy and the consumption perspective is introduced. Secondly, the integration of ICT in everyday practices and the dynamics behind the changes are outlined, inspired by a historical perspective. Thirdly, a figure of the relationships between changing everyday...

  18. Chemical Denaturants Smoothen Ruggedness on the Free Energy Landscape of Protein Folding.

    Science.gov (United States)

    Malhotra, Pooja; Jethva, Prashant N; Udgaonkar, Jayant B

    2017-08-08

    To characterize experimentally the ruggedness of the free energy landscape of protein folding is challenging, because the distributed small free energy barriers are usually dominated by one, or a few, large activation free energy barriers. This study delineates changes in the roughness of the free energy landscape by making use of the observation that a decrease in ruggedness is accompanied invariably by an increase in folding cooperativity. Hydrogen exchange (HX) coupled to mass spectrometry was used to detect transient sampling of local energy minima and the global unfolded state on the free energy landscape of the small protein single-chain monellin. Under native conditions, local noncooperative openings result in interconversions between Boltzmann-distributed intermediate states, populated on an extremely rugged "uphill" energy landscape. The cooperativity of these interconversions was increased by selectively destabilizing the native state via mutations, and further by the addition of a chemical denaturant. The perturbation of stability alone resulted in seven backbone amide sites exchanging cooperatively. The size of the cooperatively exchanging and/or unfolding unit did not depend on the extent of protein destabilization. Only upon the addition of a denaturant to a destabilized mutant variant did seven additional backbone amide sites exchange cooperatively. Segmentwise analysis of the HX kinetics of the mutant variants further confirmed that the observed increase in cooperativity was due to the smoothing of the ruggedness of the free energy landscape of folding of the protein by the chemical denaturant.

  19. Incorporating Renewable Energy Science in Regional Landscape Design: Results from a Competition in The Netherlands

    Directory of Open Access Journals (Sweden)

    Renée M. de Waal

    2015-04-01

    Full Text Available Energy transition is expected to make an important contribution to sustainable development. Although it is argued that landscape design could foster energy transition, there is scant empirical research on how practitioners approach this new challenge. The research question central to this study is: To what extent and how is renewable energy science incorporated in regional landscape design? To address this knowledge gap, a case study of a regional landscape design competition in the Netherlands, held from 2010–2012, is presented. Its focus was on integral, strategic landscape transformation with energy transition as a major theme. Content analysis of the 36 competition entries was supplemented and triangulated with a survey among the entrants, observation of the process and a study of the competition documents and website. Results indicated insufficient use of key-strategies elaborated by renewable energy science. If landscape design wants to adopt a supportive role towards energy transition, a well-informed and evidence-based approach is highly recommended. Nevertheless, promising strategies for addressing the complex process of ensuring sustainable energy transition also emerged. They include the careful cultivation of public support by developing inclusive and bottom-up processes, and balancing energy-conscious interventions with other land uses and interests.

  20. Mediterranean Energy Perspectives 2011 - Executive summary

    International Nuclear Information System (INIS)

    2011-01-01

    Mediterranean Energy Perspectives 2011 provides insights into the energy situation today and over the next two decades in the Mediterranean region. Its detailed data and analyses are of interest to stakeholders on both the supply and demand sides of the energy equation. This is the third edition in the MEP series, which highlights the extensive work of OME (Observatoire Mediterraneen de l'Energie). This outlook draws upon the expertise of OME and its members. MEP 2011 provides a unique and comprehensive analysis of the energy sector in the Mediterranean. It presents data ranging from the early days of the region's energy industry to the situation today and an outlook to 2030, based on OME's supply and demand model, the Mediterranean Energy Model. Current efforts related to renewable energy sources and energy efficiency are carefully considered as they are key issues for the Mediterranean energy sector and for the whole economic and environment future of the region. MEP 2011 presents: - A description of the Mediterranean countries in a global context. - Historical and forecast data on the supply and demand balance for each segment of the Mediterranean energy sector. - Energy demand to 2030, including two cases: the Conservative and Proactive Scenarios. - Trends in past, present and future oil and natural gas production and development. - Existing and planned oil and gas infrastructure. - Evolution of electricity generation and installed capacity. - Developments in innovative and renewable energy sources. - In-depth analysis of energy efficiency measures and policies. - Prospects for CO 2 emissions and sustainable development. MEP 2011 has been prepared by a joint-team of OME experts supported by related companies and independent expertise. Bringing this expertise together provides an important reference for industry analysts and investors who wish to get a complete picture of the energy industry and markets in the Mediterranean, the way they operate and their long

  1. Risks of energy generation in perspective

    International Nuclear Information System (INIS)

    Cohen, B.L.

    Life expectancy reduction (LER) figures due to various risks are given. The example, air pollution from coal burning gives an LER of 12 days, and nuclear power, by government estimates, gives an LER of 0.04 days. The 25-day LER from all our use of energy is placed in perspective by comparing equivalent risks from everday hazards. The logical assumsption that reducing energy consumption reduces the LER figure is shown to be false because lower energy consumption lowers per capita income, which in turn greatly reduces life expectancy of the population. Energy shortage also ultimately leads to greater unemployment which increases the rate of suicide and murder and so, again, decreases life expectancy. (J.T.A.)

  2. Swiss Energy Perspectives 2035 - Management summary

    International Nuclear Information System (INIS)

    2007-01-01

    This management summary issued by the Swiss Federal Office of Energy (SFOE) summarises the Swiss Energy Perspectives 2035 - a five-part synthesis report published in 2007. The report presents no prognoses but provides an 'if-then' overview of a set of four scenarios that examined ways in which Swiss energy demands could be met by the year 2035. National and international boundary conditions taken into account are reviewed and the four scenarios are introduced and briefly described. These include the reference scenario 'Business as Usual', 'Increased Co-operation' between politics and business, 'New Priorities' with goals set to reduce energy consumption and CO 2 emissions and 'On the Way to a 2000-Watt Society'. Risks posed and chances provided are discussed, as are the options for taking action

  3. Island biogeography and landscape structure: Integrating ecological concepts in a landscape perspective of anthropogenic impacts in temporary wetlands

    International Nuclear Information System (INIS)

    Angeler, David G.; Alvarez-Cobelas, Miguel

    2005-01-01

    Although our understanding of environmental risk assessment in temporary wetlands has been improved by the use of multi-species toxicity testing, we still know little of how landscape variables mediate the strength of, and recovery from, anthropogenic stress in such ecosystems. To bridge this research gap, we provide a theoretical framework of the response of temporary wetlands to anthropogenic disturbance along a habitat-isolation continuum based on island biogeography theory, landscape ecology and dispersal and colonization strategies of temporary wetland organisms. - Environmental risk assessment in temporary wetlands may benefit from consideration of island biogeography theory and landscape structure

  4. An interdisciplinary perspective on industrial energy efficiency

    International Nuclear Information System (INIS)

    Palm, Jenny; Thollander, Patrik

    2010-01-01

    This paper combines engineering and social science approaches to enhance our understanding of industrial energy efficiency and broaden our perspective on policy making in Europe. Sustainable development demands new strategies, solutions, and policy-making approaches. Numerous studies of energy efficiency potential state that cost-effective energy efficiency technologies in industry are not always implemented for various reasons, such as lack of information, procedural impediments, and routines not favoring energy efficiency. Another reason for the efficiency gap is the existence of particular values, unsupportive of energy efficiency, in the dominant networks of a branch of trade. Analysis indicates that different sectors of rather closed communities have established their own tacit knowledge, perceived truths, and routines concerning energy efficiency measures. Actors in different industrial sectors highlight different barriers to energy efficiency and why cost-effective energy efficiency measures are not being implemented. The identified barriers can be problematized in relation to the social context to understand their existence and how to resolve them.

  5. Heritage Conservation and Urban Landscaping of Ancient Pan Pool Neighborhood, Qufu: a Historical and Indigenous Perspective

    Directory of Open Access Journals (Sweden)

    Yingchun Zhang

    2014-12-01

    Full Text Available Gu Pan Pool neighborhood got its name because of Gu Pan Chi, (古泮池,the ancient Pan Pool, located in the southeastern part of Confucius’ birthplace, Qufu, the birth place of Confucius with a history of 3000 year. Gu Pan Pool has been recently under preservation with the joint efforts of World Bank cultural heritage conservation project and the local municipal government. With disparate interests in mind, the three stakeholders of heritage, the world bank, Qufu municipal government and local residents are contradictory with each other in the regeneration process, in which the local voices are often ignored. The purpose of this paper is to rethink heritage making from a historical and indigenous perspective in the contemporary Chinese urban historic landscape planning process. The author contends that the cultural value and pluralism embedded in the ritual way of thinking in Chinese Classics inherited and transmitted for thousands of years could be an alternative way of thinking for the landscape planning practices in the homogenizing culture of global capitalism. This research aims to reinterpret and re-activate Confucianism as cultural heritage to enrich the understanding and hence the sustainability related to human action in urban spaces with emphasis on planning processes in contemporary China.

  6. Clean energy technologies : perspectives and recent progress

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, G. [Natural Resources Canada, Ottawa, ON (Canada). Office of Energy Research and Development

    2006-07-01

    There is a need to move toward a bio-based economy that offers new ways of thinking and new approaches to energy consumption and use. Bioenergy technologies can complement highly efficient fossil fuels with renewable and sustainable alternatives to achieve improved health and air quality, while reducing greenhouse gases. Perspectives on the bio-based economy and recent progress in bioenergy technologies were addressed in this presentation. The purpose was to explore the opportunities and challenges of using biomass for energy systems in industrial settings. The presentation provided information on current research being undertaken in bioenergy in the agricultural and forest fibre industries. Information on the Canadian Biomass Innovation Network (CBIN), which consists of federal researchers, program managers, policy makers and expert advisors and on its thermochemical energy systems were discussed in detail. CBIN's mission, vision, priorities, outputs, and funding were identified. Thermochemical conversion research under CBIN relates to combustion, gasification, and pyrolysis. tabs., figs.

  7. Specificity and affinity quantification of flexible recognition from underlying energy landscape topography.

    Directory of Open Access Journals (Sweden)

    Xiakun Chu

    2014-08-01

    Full Text Available Flexibility in biomolecular recognition is essential and critical for many cellular activities. Flexible recognition often leads to moderate affinity but high specificity, in contradiction with the conventional wisdom that high affinity and high specificity are coupled. Furthermore, quantitative understanding of the role of flexibility in biomolecular recognition is still challenging. Here, we meet the challenge by quantifying the intrinsic biomolecular recognition energy landscapes with and without flexibility through the underlying density of states. We quantified the thermodynamic intrinsic specificity by the topography of the intrinsic binding energy landscape and the kinetic specificity by association rate. We found that the thermodynamic and kinetic specificity are strongly correlated. Furthermore, we found that flexibility decreases binding affinity on one hand, but increases binding specificity on the other hand, and the decreasing or increasing proportion of affinity and specificity are strongly correlated with the degree of flexibility. This shows more (less flexibility leads to weaker (stronger coupling between affinity and specificity. Our work provides a theoretical foundation and quantitative explanation of the previous qualitative studies on the relationship among flexibility, affinity and specificity. In addition, we found that the folding energy landscapes are more funneled with binding, indicating that binding helps folding during the recognition. Finally, we demonstrated that the whole binding-folding energy landscapes can be integrated by the rigid binding and isolated folding energy landscapes under weak flexibility. Our results provide a novel way to quantify the affinity and specificity in flexible biomolecular recognition.

  8. Impacts of renewable energy on landscape. Alternative of offshore wind in marine areas

    Directory of Open Access Journals (Sweden)

    Francesca Moraci

    2014-01-01

    Full Text Available The effects determined in the landscape by plants powered by renewable sources represent some unresolved issues in terms of visual and landscape impact mitigation in general. These aspects relate to the landscape are recognized in all types of impact with due attention to the various components and dynamics involved identifiable in the landscape of reference.The wind power plants, in particular, while making unquestionable environmental benefits thanks to the production of energy from renewable sources, but imposes a significant cost to the landscape with the installation of wind turbines in contexts necessarily favorable to impact,  interrupting the skyline, creating territorial discontinuities, "subtracting" and altering the landscape in the absence of effective mitigation works.The environmental compatibility of the proposed solutions depends primarily on the location of wind farms.Is necessary indicate  an overall strategy, a shared model of planning and land management, as in other European countries such as Denmark, Germany, France and the United Kingdom where the choice of locating wind farms has resulted in a new draft territory, construction and redesign of the landscape.

  9. Is the fenamate group a polymorphophore?: contrasting the crystal energy landscapes of fenamic and tolfenamic acids

    NARCIS (Netherlands)

    Uzoh, O.G.; Cruz-Cabeza, A.J.; Price, S. L.

    2012-01-01

    The concept of a polymorphophore was investigated by contrasting the crystal energy landscapes of monomorphic fenamic acid (2-(phenylamino)-benzoic acid, FA) and one of its highly polymorphic derivatives, tolfenamic acid (2-[(3-chloro-2-methylphenyl)amino]-benzoic acid, TA). The crystal energy

  10. Linking habitat selection to fitness-related traits in herbivores: the role of the energy landscape

    Science.gov (United States)

    Ryan A. Long; R. T. Bowyer; Warren P. Porter; Paul Mathewson; Kevin L. Monteith; Scott L. Findholt; Brian L. Dick; John G. Kie

    2016-01-01

    Animals may partially overcome environmental constraints on fitness by behaviorally adjusting their exposure to costs and supplies of energy. Few studies, however, have linked spatiotemporal variation in the energy landscape to behaviorally mediated measures of performance that ostensibly influence individual fitness. We hypothesized that strength of selection by North...

  11. The inverted free energy landscape of an intrinsically disordered peptide by simulations and experiments.

    Science.gov (United States)

    Granata, Daniele; Baftizadeh, Fahimeh; Habchi, Johnny; Galvagnion, Celine; De Simone, Alfonso; Camilloni, Carlo; Laio, Alessandro; Vendruscolo, Michele

    2015-10-26

    The free energy landscape theory has been very successful in rationalizing the folding behaviour of globular proteins, as this representation provides intuitive information on the number of states involved in the folding process, their populations and pathways of interconversion. We extend here this formalism to the case of the Aβ40 peptide, a 40-residue intrinsically disordered protein fragment associated with Alzheimer's disease. By using an advanced sampling technique that enables free energy calculations to reach convergence also in the case of highly disordered states of proteins, we provide a precise structural characterization of the free energy landscape of this peptide. We find that such landscape has inverted features with respect to those typical of folded proteins. While the global free energy minimum consists of highly disordered structures, higher free energy regions correspond to a large variety of transiently structured conformations with secondary structure elements arranged in several different manners, and are not separated from each other by sizeable free energy barriers. From this peculiar structure of the free energy landscape we predict that this peptide should become more structured and not only more compact, with increasing temperatures, and we show that this is the case through a series of biophysical measurements.

  12. Control of the Effective Free-Energy Landscape in a Frustrated Magnet by a Field Pulse

    Science.gov (United States)

    Wan, Yuan; Moessner, Roderich

    2017-10-01

    Thermal fluctuations can lift the degeneracy of a ground state manifold, producing a free-energy landscape without accidentally degenerate minima. In a process known as order by disorder, a subset of states incorporating symmetry breaking may be selected. Here, we show that such a free-energy landscape can be controlled in a nonequilibrium setting as the slow motion within the ground state manifold is governed by the fast modes out of it. For the paradigmatic case of the classical pyrochlore X Y antiferromagnet, we show that a uniform magnetic field pulse can excite these fast modes to generate a tunable effective free-energy landscape with minima at thermodynamically unstable portions of the ground state manifold.

  13. Global perspectives on future nuclear energy utilisation

    International Nuclear Information System (INIS)

    Watts, G.L.

    1998-01-01

    This paper is presented as an overview of the nuclear sector from a global perspective. The aim is to show that nuclear power does have a future but that this will only be fully realised when the industry is able to demonstrate that it is part of the solution to the world's energy and environmental difficulties rather than part of the problem. The paper looks at the projected world energy demand as the population increases and countries develop, showing that nuclear power is required to meet this demand. In presenting nuclear power as a solution, the paper addresses the challenges facing us such as public confidence, environmental opposition, political issues and finance. It addresses the debate over reprocessing and direct disposal of irradiated nuclear fuel and looks at the competition from other fuels. The paper suggests how the industry might approach these issues such that nuclear power is indeed regarded globally as a solution to some of the worlds most pressing problems. (author)

  14. Radiation versus radiation: nuclear energy in perspective

    International Nuclear Information System (INIS)

    Gonzalez, A.J.; Anderer, J.

    1989-01-01

    This paper seeks to provide a proper perspective on radiation exposures from nuclear energy. Instead of comparing these exposures with other pollutants, natural and man-made, it assesses the radiation doses that result from the human environment and from the entire fuel cycle associated with nuclear generated electricity. It explores radiation versus radiation, not only in terms of absolute levels but, more importantly, of the enormous variability characterizing many radiation sources. The quantitative findings and their implications are meant to contribute to a balanced understanding of the radiological impact of nuclear energy, and so to help to bridge the information gap that is perceived to exist on this issue. The 1988 Unscear report and its seven scientific annexes provide an authoritative and dispassionate factual basis for examining radiation levels from all sources, natural and man-made. It is the main source for this paper. (author)

  15. Quantifying the topography of the intrinsic energy landscape of flexible biomolecular recognition

    Science.gov (United States)

    Chu, Xiakun; Gan, Linfeng; Wang, Erkang; Wang, Jin

    2013-01-01

    Biomolecular functions are determined by their interactions with other molecules. Biomolecular recognition is often flexible and associated with large conformational changes involving both binding and folding. However, the global and physical understanding for the process is still challenging. Here, we quantified the intrinsic energy landscapes of flexible biomolecular recognition in terms of binding–folding dynamics for 15 homodimers by exploring the underlying density of states, using a structure-based model both with and without considering energetic roughness. By quantifying three individual effective intrinsic energy landscapes (one for interfacial binding, two for monomeric folding), the association mechanisms for flexible recognition of 15 homodimers can be classified into two-state cooperative “coupled binding–folding” and three-state noncooperative “folding prior to binding” scenarios. We found that the association mechanism of flexible biomolecular recognition relies on the interplay between the underlying effective intrinsic binding and folding energy landscapes. By quantifying the whole global intrinsic binding–folding energy landscapes, we found strong correlations between the landscape topography measure Λ (dimensionless ratio of energy gap versus roughness modulated by the configurational entropy) and the ratio of the thermodynamic stable temperature versus trapping temperature, as well as between Λ and binding kinetics. Therefore, the global energy landscape topography determines the binding–folding thermodynamics and kinetics, crucial for the feasibility and efficiency of realizing biomolecular function. We also found “U-shape” temperature-dependent kinetic behavior and a dynamical cross-over temperature for dividing exponential and nonexponential kinetics for two-state homodimers. Our study provides a unique way to bridge the gap between theory and experiments. PMID:23754431

  16. Evidence and opportunities for integrating landscape ecology into natural resource planning across multiple-use landscapes

    Science.gov (United States)

    Trammel, E. Jamie; Carter, Sarah; Haby, Travis S.; Taylor, Jason J.

    2018-01-01

    Enhancing natural resource management has been a focus of landscape ecology since its inception, but numerous authors argue that landscape ecology has not yet been effective in achieving the underlying goal of planning and designing sustainable landscapes. We developed nine questions reflecting the application of fundamental research topics in landscape ecology to the landscape planning process and reviewed two recent landscape-scale plans in western North America for evidence of these concepts in plan decisions. Both plans considered multiple resources, uses, and values, including energy development, recreation, conservation, and protection of cultural and historic resources. We found that land use change and multiscale perspectives of resource uses and values were very often apparent in planning decisions. Pattern-process relationships, connectivity and fragmentation, ecosystem services, landscape history, and climate change were reflected less frequently. Landscape sustainability was considered only once in the 295 decisions reviewed, and outputs of landscape models were not referenced. We suggest six actionable opportunities for further integrating landscape ecology concepts into landscape planning efforts: 1) use landscape sustainability as an overarching goal, 2) adopt a broad ecosystem services framework, 3) explore the role of landscape history more comprehensively, 4) regularly consider and accommodate potential effects of climate change, 5) use landscape models to support plan decisions, and 6) promote a greater presence of landscape ecologists within agencies that manage large land bases and encourage active involvement in agency planning efforts. Together these actions may improve the defensibility, durability, and sustainability of landscape plan decisions.

  17. Connecting the kinetics and energy landscape of tRNA translocation on the ribosome.

    Directory of Open Access Journals (Sweden)

    Paul C Whitford

    Full Text Available Functional rearrangements in biomolecular assemblies result from diffusion across an underlying energy landscape. While bulk kinetic measurements rely on discrete state-like approximations to the energy landscape, single-molecule methods can project the free energy onto specific coordinates. With measures of the diffusion, one may establish a quantitative bridge between state-like kinetic measurements and the continuous energy landscape. We used an all-atom molecular dynamics simulation of the 70S ribosome (2.1 million atoms; 1.3 microseconds to provide this bridge for specific conformational events associated with the process of tRNA translocation. Starting from a pre-translocation configuration, we identified sets of residues that collectively undergo rotary rearrangements implicated in ribosome function. Estimates of the diffusion coefficients along these collective coordinates for translocation were then used to interconvert between experimental rates and measures of the energy landscape. This analysis, in conjunction with previously reported experimental rates of translocation, provides an upper-bound estimate of the free-energy barriers associated with translocation. While this analysis was performed for a particular kinetic scheme of translocation, the quantitative framework is general and may be applied to energetic and kinetic descriptions that include any number of intermediates and transition states.

  18. Another possible energy landscape; Un autre paysage energetique possible

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-06-01

    This analysis presents the national energy balances from the national energy accounting. The first part presents the accounting analysis on the electric power consumption and production in France. The second part deals with the global energy accounting, for the energy sources and utilization, together. From these analysis the authors show how the global energy efficiency of production and utilization is possible. Solutions allowing the reduction of the non renewable energies consumption and solution for the nuclear power phaseout are also proposed. (A.L.B.)

  19. Exploring the free energy landscape: from dynamics to networks and back.

    Directory of Open Access Journals (Sweden)

    Diego Prada-Gracia

    2009-06-01

    Full Text Available Knowledge of the Free Energy Landscape topology is the essential key to understanding many biochemical processes. The determination of the conformers of a protein and their basins of attraction takes a central role for studying molecular isomerization reactions. In this work, we present a novel framework to unveil the features of a Free Energy Landscape answering questions such as how many meta-stable conformers there are, what the hierarchical relationship among them is, or what the structure and kinetics of the transition paths are. Exploring the landscape by molecular dynamics simulations, the microscopic data of the trajectory are encoded into a Conformational Markov Network. The structure of this graph reveals the regions of the conformational space corresponding to the basins of attraction. In addition, handling the Conformational Markov Network, relevant kinetic magnitudes as dwell times and rate constants, or hierarchical relationships among basins, completes the global picture of the landscape. We show the power of the analysis studying a toy model of a funnel-like potential and computing efficiently the conformers of a short peptide, dialanine, paving the way to a systematic study of the Free Energy Landscape in large peptides.

  20. Deciphering hierarchical features in the energy landscape of adenylate kinase folding/unfolding

    Science.gov (United States)

    Taylor, J. Nicholas; Pirchi, Menahem; Haran, Gilad; Komatsuzaki, Tamiki

    2018-03-01

    Hierarchical features of the energy landscape of the folding/unfolding behavior of adenylate kinase, including its dependence on denaturant concentration, are elucidated in terms of single-molecule fluorescence resonance energy transfer (smFRET) measurements in which the proteins are encapsulated in a lipid vesicle. The core in constructing the energy landscape from single-molecule time-series across different denaturant concentrations is the application of rate-distortion theory (RDT), which naturally considers the effects of measurement noise and sampling error, in combination with change-point detection and the quantification of the FRET efficiency-dependent photobleaching behavior. Energy landscapes are constructed as a function of observation time scale, revealing multiple partially folded conformations at small time scales that are situated in a superbasin. As the time scale increases, these denatured states merge into a single basin, demonstrating the coarse-graining of the energy landscape as observation time increases. Because the photobleaching time scale is dependent on the conformational state of the protein, possible nonequilibrium features are discussed, and a statistical test for violation of the detailed balance condition is developed based on the state sequences arising from the RDT framework.

  1. An Exploration Perspective of Beamed Energy Propulsion

    International Nuclear Information System (INIS)

    Cole, John

    2008-01-01

    The Vision for Exploration is currently focused on flying the Space Shuttle safely to complete our Space Station obligations, retiring the Shuttle in 2010, then returning humans to the Moon and learning how to proceed to Mars and beyond. The NASA budget still includes funds for science and aeronautics but the primary focus is on human exploration. Fiscal constraints have led to pursuing exploration vehicles that use heritage hardware, particularly existing boosters and engines, with the minimum modifications necessary to satisfy mission requirements. So, pursuit of immature technologies is not currently affordable by NASA. Beamed energy is one example of an immature technology, from a human exploration perspective, that may eventually provide significant benefits for human exploration of space, but likely not in the near future. Looking to the more distant future, this paper will examine some of the criteria that must be achieved by beamed energy propulsion to eventually contribute to human exploration of the solar system. The analysis focuses on some of the implications of increasing the payload fraction of a launch vehicle, with a quick look at trans-lunar injection. As one would expect, there is potential for benefit, and there are concerns. The analysis concludes with an assessment of the Technology Readiness Level (TRL) for some beamed energy propulsion components, indicating that TRL 2 is close to being completed

  2. LANDSCAPE MODELING OF CHARACTERISTIC HABITAT SCALES, DISPERSAL, AND CONNECTIVITY FROM THE PERSPECTIVE OF THE ORGANISM

    Science.gov (United States)

    A modeling framework was developed to investigate the interactive effects of life history characteristics and landscape heterogeneity on dispersal success. An individual-based model was used to examine how dispersal between resource patches is affected by four landscape characte...

  3. Direct design of an energy landscape with bistable DNA origami mechanisms.

    Science.gov (United States)

    Zhou, Lifeng; Marras, Alexander E; Su, Hai-Jun; Castro, Carlos E

    2015-03-11

    Structural DNA nanotechnology provides a feasible technique for the design and fabrication of complex geometries even exhibiting controllable dynamic behavior. Recently we have demonstrated the possibility of implementing macroscopic engineering design approaches to construct DNA origami mechanisms (DOM) with programmable motion and tunable flexibility. Here, we implement the design of compliant DNA origami mechanisms to extend from prescribing motion to prescribing an energy landscape. Compliant mechanisms facilitate motion via deformation of components with tunable stiffness resulting in well-defined mechanical energy stored in the structure. We design, fabricate, and characterize a DNA origami nanostructure with an energy landscape defined by two stable states (local energy minima) separated by a designed energy barrier. This nanostructure is a four-bar bistable mechanism with two undeformed states. Traversing between those states requires deformation, and hence mechanical energy storage, in a compliant arm of the linkage. The energy barrier for switching between two states was obtained from the conformational distribution based on a Boltzmann probability function and closely follows a predictive mechanical model. Furthermore, we demonstrated the ability to actuate the mechanism into one stable state via additional DNA inputs and then release the actuation via DNA strand displacement. This controllable multistate system establishes a foundation for direct design of energy landscapes that regulate conformational dynamics similar to biomolecular complexes.

  4. Contested Cottage Landscapes: Host perspective to the increase of foreign second home ownership in Finland 1990-2008

    Directory of Open Access Journals (Sweden)

    Kati Pitkänen

    2011-01-01

    Full Text Available Cross-border and international second home ownership is a worldwide phenomenon and growing in popularity as people seek for desirable environments further away than before. As the desired landscapes are also likely to possess a considerable local and national value, research is needed to find out how host societies perceive and receive the newcomers. This paper explores the Finnish public debate on foreign second home ownership from 1990 to 2008, a period that has witnessed a considerable growth in foreign property ownership. The paper uses the concept of cottage landscape to analyse how second homes are positioned nationally and how foreign second home ownership is debated in relation to the national definitions and valuations. Based on changing emphases and fears related to the phenomenon, three periods of public debate are distinguished. The results demonstrate the iconic image of cottage landscape in the Finnish society by showing how foreign second home ownership is perceived as a threat to the Finnish way of life, landownership rights and national identity. From the perspective of the host society, foreign second home ownership is a complicated and emotional matter with potential to arise opposition and even conflicts when the foreign demand focuses on locally or nationally valued landscapes. Therefore research on the internationalisation of second home ownership can no longer ignore the perspective of the host society.

  5. Free-energy landscape of protein oligomerization from atomistic simulations

    Science.gov (United States)

    Barducci, Alessandro; Bonomi, Massimiliano; Prakash, Meher K.; Parrinello, Michele

    2013-01-01

    In the realm of protein–protein interactions, the assembly process of homooligomers plays a fundamental role because the majority of proteins fall into this category. A comprehensive understanding of this multistep process requires the characterization of the driving molecular interactions and the transient intermediate species. The latter are often short-lived and thus remain elusive to most experimental investigations. Molecular simulations provide a unique tool to shed light onto these complex processes complementing experimental data. Here we combine advanced sampling techniques, such as metadynamics and parallel tempering, to characterize the oligomerization landscape of fibritin foldon domain. This system is an evolutionarily optimized trimerization motif that represents an ideal model for experimental and computational mechanistic studies. Our results are fully consistent with previous experimental nuclear magnetic resonance and kinetic data, but they provide a unique insight into fibritin foldon assembly. In particular, our simulations unveil the role of nonspecific interactions and suggest that an interplay between thermodynamic bias toward native structure and residual conformational disorder may provide a kinetic advantage. PMID:24248370

  6. Designing sustainable energy landscapes : concepts, principles and procedures

    NARCIS (Netherlands)

    Stremke, S.

    2010-01-01

    The depletion of fossil fuels, in combination with climate change, necessitates a transition to sustainable energy systems. Such systems are characterized by a decreased energy demand and an increase in the use of renewables. The objective of this dissertation is to advance the planning and design

  7. Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation.

    Science.gov (United States)

    Iida, Shinji; Nakamura, Haruki; Higo, Junichi

    2016-06-15

    We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein-protein or protein-ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. © 2016 The Author(s).

  8. Relaxation height in energy landscapes : an application to multiple metastable states

    NARCIS (Netherlands)

    Cirillo, E.N.M.; Nardi, F.R.

    2012-01-01

    The study of systems with multiple (not necessarily degenerate) metastable states presents subtle difficulties from the mathematical point of view related to the variational problem that has to be solved in these cases. We introduce the notion of relaxation height in a general energy landscape and

  9. Probing the Free Energy Landscape of the FBP28 WW Domain Using Multiple Techniques

    NARCIS (Netherlands)

    Periole, Xavier; Allen, Lucy R.; Tamiola, Kamil; Mark, Alan E.; Paci, Emanuele

    The free-energy landscape of a small protein, the FBP 28 WW domain, has been explored using molecular dynamics (MD) simulations with alternative descriptions of the molecule. The molecular models used range from coarse-grained to all-atom with either an implicit or explicit treatment of the solvent.

  10. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  11. The emergence of green infrastructure as promoting the centralisation of a landscape perspective in spatial planning - the case of Ireland

    OpenAIRE

    Lennon, Mick; Scott, Mark J.; Collier, Marcus; Foley, Karen

    2016-01-01

    The 'landscape' approach to planning and design has long since advanced a social ecological perspective that conceives ecosystems health and human well-being as mutually constitutive. However, conventional public sector organisational arrangements segregate and discretely administer development issues, thereby militating against the holistic viewpoint necessary to redress the entwined nature of complex planning issues. The emergence and continuing evolution of green infrastructure (GI) thinki...

  12. Remote sensing in landscape ecology: experiences and perspectives in a European context

    NARCIS (Netherlands)

    Groom, G.; Mücher, C.A.; Ihse, M.; Wrbka, T.

    2006-01-01

    That the relationship between remote sensing and landscape ecology is significant is due in large part to the strong spatial component within landscape ecology. However it is nevertheless necessary to have frequent overview of the interface between remote sensing and landscape ecology, particularly

  13. Improving energy efficiency in industrial energy systems an interdisciplinary perspective on barriers, energy audits, energy management, policies, and programs

    CERN Document Server

    Thollander, Patrik

    2012-01-01

    Industrial energy efficiency is one of the most important means of reducing the threat of increased global warming. Research however states that despite the existence of numerous technical energy efficiency measures, its deployment is hindered by the existence of various barriers to energy efficiency. The complexity of increasing energy efficiency in manufacturing industry calls for an interdisciplinary approach to the issue. Improving energy efficiency in industrial energy systems applies an interdisciplinary perspective in examining energy efficiency in industrial energy systems, and discuss

  14. From Target to Implementation: Perspectives for the International Governance of Forest Landscape Restoration

    Directory of Open Access Journals (Sweden)

    Till Pistorius

    2014-03-01

    Full Text Available Continuing depletion of forest resources, particularly in tropical developing countries, has turned vast areas of intact ecosystems into urbanized and agricultural lands. The degree of degradation varies, but in most cases, the ecosystem functions and the ability to provide a variety of ecosystem services are severely impaired. In addition to many other challenges, successful forest restoration of these lands requires considerable resources and funding, but the ecological, economic and social benefits have the potential to outweigh the investment. As a consequence, at the international policy level, restoration is seen as a field of land use activities that provides significant contributions to simultaneously achieving different environmental and social policy objectives. Accordingly, different policy processes at the international policy level have made ecological landscape restoration a global priority, in particular the Convention on Biological Diversity with the Aichi Target 15 agreed upon in 2010, which aims at restoring 15% of all degraded land areas by 2020. While such ambitious policy targets are important for recognizing and agreeing upon solutions for environmental problems, they are unlikely to be further substantiated or governed. The objective of this paper is thus to develop a complementary governance approach to the top-down implementation of the Aichi target. Drawing on collaborative and network governance theories, we discuss the potential of a collaborative networked governance approach and perspectives for overcoming the inherent challenges facing a rapid large-scale restoration of degraded lands.

  15. Conjugate gradient filtering of instantaneous normal modes, saddles on the energy landscape, and diffusion in liquids.

    Science.gov (United States)

    Chowdhary, J; Keyes, T

    2002-02-01

    Instantaneous normal modes (INM's) are calculated during a conjugate-gradient (CG) descent of the potential energy landscape, starting from an equilibrium configuration of a liquid or crystal. A small number (approximately equal to 4) of CG steps removes all the Im-omega modes in the crystal and leaves the liquid with diffusive Im-omega which accurately represent the self-diffusion constant D. Conjugate gradient filtering appears to be a promising method, applicable to any system, of obtaining diffusive modes and facilitating INM theory of D. The relation of the CG-step dependent INM quantities to the landscape and its saddles is discussed.

  16. The relative importance of physical and biological energy in landscape evolution

    Science.gov (United States)

    Turowski, J. M.; Schwanghart, W.

    2017-12-01

    Landscapes are formed by the interplay of uplift and geomorphic processes, including interacting and competing physical and biological processes. For example, roots re-inforce soil and thereby stabilize hillslopes and the canopy cover of the forest may mediate the impact of precipitation. Furthermore, plants and animals act as geomorphic agents, directly altering landscape response and dynamics by their actions: tree roots may crack rocks, thus changing subsurface water flows and exposing fresh material for denudation; fungi excrete acids that accelerate rates of chemical weathering, and burrowing animals displace soil and rocks while digging holes for shelter or in search of food. Energetically, landscapes can be viewed as open systems in which topography stores potential energy above a base level. Tectonic processes add energy to the system by uplift and mechanically altering rock properties. Especially in unvegetated regions, erosion and transport by wind can be an important geomorphic process. Advection of atmospheric moisture in high altitudes provides potential energy that is converted by water fluxes through catchments. At the same time, the conversion of solar energy through atmospheric and biological processes drives primary production of living organisms. If we accept that biota influence geomorphic processes, then what is their energetic contribution to landscape evolution relative to physical processes? Using two case studies, we demonstrate that all components of energy input are negligible apart from biological production, quantified by net primary productivity (NPP) and potential energy conversion by water that is placed high up in the landscape as rainfall and leaves it as runoff. Assuming that the former is representative for biological energy and the latter for physical energy, we propose that the ratio of these two values can be used as a proxy for the relative importance of biological and physical processes in landscape evolution. All necessary

  17. The Landscape of Renewable Energies in Europe in 2030

    International Nuclear Information System (INIS)

    Cruciani, Michel

    2017-06-01

    The study analyses the European rules designed to promote renewable energy, highlighting their innovations and the difficulties they will raise. The study highlights the consequences of some of the measures envisaged and pays particular attention to the electricity market. On 30 November 2016, the European Commission issued a new set of proposals, the 'Clean Energy Package', covering a wide spectrum of activities. This study analyses the provisions of this package which aim at improving energy efficiency by 30% and giving renewable energy a share of 27% of consumption by 2030. In 2014, Member States had called for these objectives to be assessed for the entire European Union. Nevertheless the Commission wishes to obtain a mandate to check that each State makes an honest contribution to the collective effort. The study stresses that the 30% target for energy efficiency weakens the role of the CO_2 market. The simulations reveal that this weakness will benefit coal, which keeps in 2030 a higher share than it would have occupied with a target of 27%, whereas natural gas is penalized by a low CO_2 price. It also appears that by remaining too low, the price of CO_2 will discourage certain investments in favour of renewable energies that would have naturally emerged with a high price. Therefore it will be necessary to roll out costly public policies to trigger these investments, so that the share of these energies totals 27% by 2030. The simulations also show that the renewable energy target will be largely achieved through very rapid growth of wind and solar power. The proposals of 30 November 2016 hence are drafted to encourage the development of these two sectors by reforming the electricity market so that it establishes a price that is remunerative and reduces the need for public aid, while clearly reflecting the burdens generated by the different actors. It seems unlikely that the Member States will accept such a profound market reform as the Commission envisages

  18. Global optimization of proteins using a dynamical lattice model: Ground states and energy landscapes

    OpenAIRE

    Dressel, F.; Kobe, S.

    2004-01-01

    A simple approach is proposed to investigate the protein structure. Using a low complexity model, a simple pairwise interaction and the concept of global optimization, we are able to calculate ground states of proteins, which are in agreement with experimental data. All possible model structures of small proteins are available below a certain energy threshold. The exact lowenergy landscapes for the trp cage protein (1L2Y) is presented showing the connectivity of all states and energy barriers.

  19. How Could Companies Engage in Sustainable Landscape Management? An Exploratory Perspective

    Directory of Open Access Journals (Sweden)

    Paul Opdam

    2018-01-01

    Full Text Available Current concepts that aim to align economic development with sustainability, such as the circular and green economy, often consider natural systems as externalities. We extend the green economy concept by including the landscape as the provider of social, economic and environmental values. Our aim is to explore how companies could engage in creating landscape-inclusive solutions for sustainable landscapes. We propose a conceptual model of the relationship between companies and landscape services based on a demand for landscape benefits by companies, implications for wider society. We present a short overview of how scientists addressed the role of companies in landscape-inclusive solutions. We also give some examples taken from the World Wide Web to illustrate the variety of ways in which companies already invest in landscape services. Our findings suggest that the relationship between companies and landscapes is not yet strongly recognized in sustainability science. However, examples from practice show that some companies do recognize the added values of landscape services, to the extent that they invest in landscape management. We conclude that future research should provide information on the added value of landscape-inclusive solutions to companies, and increase their capacity to engage in regional social–ecological networks.

  20. Energy Landscape of Pentapeptides in a Higher-Order (ϕ,ψ Conformational Subspace

    Directory of Open Access Journals (Sweden)

    Karim M. ElSawy

    2016-01-01

    Full Text Available The potential energy landscape of pentapeptides was mapped in a collective coordinate principal conformational subspace derived from principal component analysis of a nonredundant representative set of protein structures from the PDB. Three pentapeptide sequences that are known to be distinct in terms of their secondary structure characteristics, (Ala5, (Gly5, and Val.Asn.Thr.Phe.Val, were considered. Partitioning the landscapes into different energy valleys allowed for calculation of the relative propensities of the peptide secondary structures in a statistical mechanical framework. The distribution of the observed conformations of pentapeptide data showed good correspondence to the topology of the energy landscape of the (Ala5 sequence where, in accord with reported trends, the α-helix showed a predominant propensity at 298 K. The topography of the landscapes indicates that the stabilization of the α-helix in the (Ala5 sequence is enthalpic in nature while entropic factors are important for stabilization of the β-sheet in the Val.Asn.Thr.Phe.Val sequence. The results indicate that local interactions within small pentapeptide segments can lead to conformational preference of one secondary structure over the other where account of conformational entropy is important in order to reveal such preference. The method, therefore, can provide critical structural information for ab initio protein folding methods.

  1. Calculation of the Local Free Energy Landscape in the Restricted Region by the Modified Tomographic Method.

    Science.gov (United States)

    Chen, Changjun

    2016-03-31

    The free energy landscape is the most important information in the study of the reaction mechanisms of the molecules. However, it is difficult to calculate. In a large collective variable space, a molecule must take a long time to obtain the sufficient sampling during the simulation. To save the calculation quantity, decreasing the sampling region and constructing the local free energy landscape is required in practice. However, the restricted region in the collective variable space may have an irregular shape. Simply restricting one or more collective variables of the molecule cannot satisfy the requirement. In this paper, we propose a modified tomographic method to perform the simulation. First, it divides the restricted region by some hyperplanes and connects the centers of hyperplanes together by a curve. Second, it forces the molecule to sample on the curve and the hyperplanes in the simulation and calculates the free energy data on them. Finally, all the free energy data are combined together to form the local free energy landscape. Without consideration of the area outside the restricted region, this free energy calculation can be more efficient. By this method, one can further optimize the path quickly in the collective variable space.

  2. Low Energy Supersymmetry from the Heterotic String Landscape

    CERN Document Server

    Lebedev, O; Raby, S; Ramos-Sanchez, S; Ratz, M; Vaudrevange, P K S; Wingerter, A; Lebedev, Oleg; Nilles, Hans-Peter; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K. S.; Wingerter, Akin

    2007-01-01

    We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favoured. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

  3. Landscape management for sustainable supplies of bio energy feedstock and enhanced soil quality

    International Nuclear Information System (INIS)

    Douglas, K.; Muth, D.

    2013-01-01

    Agriculture can simultaneously address global food, feed, fiber, and energy challenges provided our soil, water, and air resources are not compromised in doing so. Our objective is to present a landscape management concept as an approach for integrating multiple bio energy feedstock sources into current crop production systems. This is done to show how multiple, increasing global challenges can be met in a sustainable manner. We discuss how collaborative research among Usda-Agricultural Research Service (ARS), US Department of Energy (DOE) Idaho National Laboratory (INL), several university extension and research partners, and industry representatives [known as the Renewable Energy Assessment Project (Reap) team] has led to the development of computer-based decision aids for guiding sustainable bio energy feedstock production. The decision aids, known initially as the Corn Stover Tool and more recently as the Landscape Environmental Assessment Framework (Leaf) are tools designed to recognize the importance of nature s diversity and can therefore be used to guide sustainable feedstock production without having negative impacts on critical ecosystem services. Using a 57 ha farm site in central Iowa, USA, we show how producer decisions regarding corn (Zea mays L.) stover harvest within the US Corn Belt can be made in a more sustainable manner. This example also supports Reap team conclusions that stover should not be harvested if average grain yields are less than 11 Mg ha-1 unless more balanced landscape management practices are implemented. The tools also illustrate the importance of sub-field management and site-specific stover harvest strategies

  4. Energy landscape reveals that the budding yeast cell cycle is a robust and adaptive multi-stage process.

    Directory of Open Access Journals (Sweden)

    Cheng Lv

    2015-03-01

    Full Text Available Quantitatively understanding the robustness, adaptivity and efficiency of cell cycle dynamics under the influence of noise is a fundamental but difficult question to answer for most eukaryotic organisms. Using a simplified budding yeast cell cycle model perturbed by intrinsic noise, we systematically explore these issues from an energy landscape point of view by constructing an energy landscape for the considered system based on large deviation theory. Analysis shows that the cell cycle trajectory is sharply confined by the ambient energy barrier, and the landscape along this trajectory exhibits a generally flat shape. We explain the evolution of the system on this flat path by incorporating its non-gradient nature. Furthermore, we illustrate how this global landscape changes in response to external signals, observing a nice transformation of the landscapes as the excitable system approaches a limit cycle system when nutrients are sufficient, as well as the formation of additional energy wells when the DNA replication checkpoint is activated. By taking into account the finite volume effect, we find additional pits along the flat cycle path in the landscape associated with the checkpoint mechanism of the cell cycle. The difference between the landscapes induced by intrinsic and extrinsic noise is also discussed. In our opinion, this meticulous structure of the energy landscape for our simplified model is of general interest to other cell cycle dynamics, and the proposed methods can be applied to study similar biological systems.

  5. Modeling energy fluxes in heterogeneous landscapes employing a mosaic approach

    Science.gov (United States)

    Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2015-04-01

    Recent studies show that uncertainties in regional and global climate and weather simulations are partly due to inadequate descriptions of the energy flux exchanges between the land surface and the atmosphere. One major shortcoming is the limitation of the grid-cell resolution, which is recommended to be about at least 3x3 km² in most models due to limitations in the model physics. To represent each individual grid cell most models select one dominant soil type and one dominant land use type. This resolution, however, is often too coarse in regions where the spatial diversity of soil and land use types are high, e.g. in Central Europe. An elegant method to avoid the shortcoming of grid cell resolution is the so called mosaic approach. This approach is part of the recently developed ecosystem model framework Expert-N 5.0. The aim of this study was to analyze the impact of the characteristics of two managed fields, planted with winter wheat and potato, on the near surface soil moistures and on the near surface energy flux exchanges of the soil-plant-atmosphere interface. The simulated energy fluxes were compared with eddy flux tower measurements between the respective fields at the research farm Scheyern, North-West of Munich, Germany. To perform these simulations, we coupled the ecosystem model Expert-N 5.0 to an analytical footprint model. The coupled model system has the ability to calculate the mixing ratio of the surface energy fluxes at a given point within one grid cell (in this case at the flux tower between the two fields). This approach accounts for the differences of the two soil types, of land use managements, and of canopy properties due to footprint size dynamics. Our preliminary simulation results show that a mosaic approach can improve modeling and analyzing energy fluxes when the land surface is heterogeneous. In this case our applied method is a promising approach to extend weather and climate models on the regional and on the global scale.

  6. Participatory mapping of landscape values in a Pan-European perspective

    DEFF Research Database (Denmark)

    García-Martín, María; Fagerholm, Nora; Bieling, Claudia

    2017-01-01

    Context: Human–nature interactions are reflected in the values people assign to landscapes. These values shape our understanding and actions as landscape co-creators, and need to be taken into account to achieve an integrated management of the landscape that involves civil society. Objectives......: The aim of this research was to increase the current knowledge on the most and least common landscape values perceived by local stakeholders, the patterns in the spatial distribution of values, and their connection to different socio-economic backgrounds and landscape characteristics across Europe....... Methods: The research consisted of a cross-site comparison study on how landscape values are perceived in six areas of Europe using Public Participation GIS surveys. Answers were analysed combining contingency tables, spatial autocorrelation and bivariate correlation methods, kernel densities, land cover...

  7. Non-equilibrium physics of neural networks for leaning, memory and decision making: landscape and flux perspectives

    Science.gov (United States)

    Wang, Jin

    Cognitive behaviors are determined by underlying neural networks. Many brain functions, such as learning and memory, can be described by attractor dynamics. We developed a theoretical framework for global dynamics by quantifying the landscape associated with the steady state probability distributions and steady state curl flux, measuring the degree of non-equilibrium through detailed balance breaking. We found the dynamics and oscillations in human brains responsible for cognitive processes and physiological rhythm regulations are determined not only by the landscape gradient but also by the flux. We found that the flux is closely related to the degrees of the asymmetric connections in neural networks and is the origin of the neural oscillations. The neural oscillation landscape shows a closed-ring attractor topology. The landscape gradient attracts the network down to the ring. The flux is responsible for coherent oscillations on the ring. We suggest the flux may provide the driving force for associations among memories. Both landscape and flux determine the kinetic paths and speed of decision making. The kinetics and global stability of decision making are explored by quantifying the landscape topography through the barrier heights and the mean first passage time. The theoretical predictions are in agreement with experimental observations: more errors occur under time pressure. We quantitatively explored two mechanisms of the speed-accuracy tradeoff with speed emphasis and further uncovered the tradeoffs among speed, accuracy, and energy cost. Our results show an optimal balance among speed, accuracy, and the energy cost in decision making. We uncovered possible mechanisms of changes of mind and how mind changes improve performance in decision processes. Our landscape approach can help facilitate an understanding of the underlying physical mechanisms of cognitive processes and identify the key elements in neural networks.

  8. Perspectives of Nuclear Energy for Human Development

    International Nuclear Information System (INIS)

    Rouyer, Jean-Loup

    2002-01-01

    In this period of expectation and short term viewing, everyone has difficulties to draw long term perspectives. A positive global world vision of sustainable development gives confidence in the preparation of energy future in a moving international context. This presentation proposes to share such a long term vision inside which energy scenarios for nuclear development take their right place. It is founded on a specific analysis of an index of countries global development which is representative of a country efficiency. Human Development Index (HDI) is a composite international index recommended and calculated every year since 1990 by the United Nations Development Program (UNDP). This index is still very dependent of GNP, which ignores the disparities of revenues inside the country. That is why a Country Efficiency Index (CEI) has been defined to better represent the capacity of a country to utilize its resources for welfare of its inhabitants. CEI is a ratio of health and education levels to the capacity of the country to satisfy this welfare. CEI has been calculated for the 70 more populated countries of the world for the year 1997. CEI calculation has been also performed for European Countries, the United States, China and India on the period from 1965 to 1997. It is observed a growth of CEI. for France from 0.6 to 0.78, and from 0.7 to 0.85 for USA. In 1997, CEI of China was 0.46, and 0.38 for India. This index is a good tool to measure the progression of development of the countries and the related energy needs. Comparison of the evolutions of CEI of these different countries shows a similar positive trend with some delay between OECD countries and China or India. A positive scenario for the future is based on a similar curve for these developing countries with learning effect which produces development with less energy consumption. This simulation results however in energy needs that exceed fossil fuel today available resources in 2070. Ultimate fossil

  9. Energy landscape of defects in body-centered cubic metals

    International Nuclear Information System (INIS)

    Alexander, Rebecca

    2016-01-01

    The structural materials in nuclear reactors are subjected to severe irradiation conditions, leading to changes in their mechanical properties. The aging of these materials raises important issues such as those related to the safety of existing plants and future reactors. In many cases, materials with body-centered cubic bcc crystal structure are used with iron, tungsten, vanadium and tantalum as base metal. Collisions between irradiating particles and atoms constituting materials generate point defects whose migration leads to the formation of clusters responsible for aging. In this thesis, we studied the energetic properties of point defects in the bcc metals mentioned above at the atomic scale. Modeling point defects at the atomic scale can be achieved with different methods that differ only in the quality of the description of the interaction between atoms. Studies using accurate atomic interactions such ab initio calculations are computationally costly making it impossible to directly study clusters of large sizes. The modeling of atomic interactions using semi-empirical potentials reduces the reliability of predictive calculations but allow calculations for large-sized clusters. In this thesis we have developed a unique energy model for dislocation loops as well as for three-dimensional interstitial cluster of type C15. The resulting model has no size limit and can be set entirely by ab initio calculations. To test its robustness for large sizes of clusters we also set this model with semi-empirical potentials calculations and compared the predictions of the model to atomic simulations. With our development we have determined: (i) The relative stability of interstitial dislocation loops according to their Burgers vectors. (ii) The stability of the clusters C15 compared to the type of cluster loop. We showed that the C15 type clusters are more stable when they involve less than 41 interstitials in iron. (iii) In Ta we were able to show the same stability till

  10. Renewable energy policy and landscape management in Andalusia, Spain: The facts

    International Nuclear Information System (INIS)

    Prados, Maria-Jose

    2010-01-01

    Renewable energy has developed spectacularly in Spain since the European Union started a process of energy policy reform. A review of Spanish State legislation on renewable energies confirms that the success in installing renewable energy is attributable to public aid. Andalusia is one of the autonomous communities, which has simultaneously developed the legal framework and very successfully implemented the introduction of renewable power. When implementing the central government's policy, the Andalusian regional government prioritised increases in both surface cover by wind and solar plants (thermal and photovoltaic energy) and in the number of companies involved. However, this development of renewable energies took place without any proper integration into regional spatial and landscape planning. This paper explores renewable power implementation in Andalusia through regulatory measures put in place over the last decade to develop renewable energy systems and the way they can be managed alongside planning issues. The location of large-scale renewable plants has had consequences for territory in the socio-political context of renewable energy promotion. The main findings focus on renewable energy plant sprawl throughout rural areas in Andalusia with no clear effect on landscape management and no firm backing from the local population.

  11. How Human Niche Construction is tied to the landscape perspective of domesticated landscapes and how this may help the discussion about the offset of the Anthropocene

    Science.gov (United States)

    Kluiving, Sjoerd; Hamel, Arthur

    2016-04-01

    This research is based on a review of published examples of geoarchaeological and landscape archaeological research throughout Europe. Through environmental reconstruction we relatively date the starting points where humans a) are altering their own selective environment as an inceptive change, b) respond to a (deteriorated) selective environment in a counteractive change. It is stated that geoarchaeology and landscape archaeology make a valuable contribution to NCT studies in considering landscape gradients as focal lines. NCT phase transitions from inceptive to counteractive changes are proposed as useful alternative in the debate about the onset of the Anthropocene. While searching for a relevant approach to define this period where humans are driving the Earth, we discuss the pitfalls of the dialectic Nature/Culture and social/environmental divides and finally we prefer to approach the issue from the complex system perspective which does not opposes 'humans' with 'the rest'. In complex systems, such as Earth system, linear cause consequence relations do not exist. Therefore the response of the system is not always related in time, space or proportions with the causes. On this basis, we present an alternative definition of the Anthropocene based on the causes of the changes instead of their effects. These causes are to be found in the change in human behaviour. The Niche Construction Theory conciliates the causes and the complex system approach previous remarks: that the effects are not easily correlated with the causes of changes. This is the point of view adopted by Zeder and Smith (2013) who argue that the onset of the Anthropocene is the start of Neolithic revolution, matching the lower boundary of the Holocene. Zeder M. A. and Smith B.D. (2013). The onset of the Anthropocene. Anthropocene, 4:8-13.

  12. Free Energy Landscapes of Alanine Oligopeptides in Rigid-Body and Hybrid Water Models.

    Science.gov (United States)

    Nayar, Divya; Chakravarty, Charusita

    2015-08-27

    Replica exchange molecular dynamics is used to study the effect of different rigid-body (mTIP3P, TIP4P, SPC/E) and hybrid (H1.56, H3.00) water models on the conformational free energy landscape of the alanine oligopeptides (acAnme and acA5nme), in conjunction with the CHARMM22 force field. The free energy landscape is mapped out as a function of the Ramachandran angles. In addition, various secondary structure metrics, solvation shell properties, and the number of peptide-solvent hydrogen bonds are monitored. Alanine dipeptide is found to have similar free energy landscapes in different solvent models, an insensitivity which may be due to the absence of possibilities for forming i-(i + 4) or i-(i + 3) intrapeptide hydrogen bonds. The pentapeptide, acA5nme, where there are three intrapeptide backbone hydrogen bonds, shows a conformational free energy landscape with a much greater degree of sensitivity to the choice of solvent model, though the three rigid-body water models differ only quantitatively. The pentapeptide prefers nonhelical, non-native PPII and β-sheet populations as the solvent is changed from SPC/E to the less tetrahedral liquid (H1.56) to an LJ-like liquid (H3.00). The pentapeptide conformational order metrics indicate a preference for open, solvent-exposed, non-native structures in hybrid solvent models at all temperatures of study. The possible correlations between the properties of solvent models and secondary structure preferences of alanine oligopeptides are discussed, and the competition between intrapeptide, peptide-solvent, and solvent-solvent hydrogen bonding is shown to be crucial in the relative free energies of different conformers.

  13. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films.

    Science.gov (United States)

    Kim, Tae Heon; Yoon, Jong-Gul; Baek, Seung Hyub; Park, Woong-kyu; Yang, Sang Mo; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Noh, Tae Won

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  14. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films

    Science.gov (United States)

    Heon Kim, Tae; Yoon, Jong-Gul; Hyub Baek, Seung; Park, Woong-Kyu; Mo Yang, Sang; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Won Noh, Tae

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  15. Relationship between energy systems and landscapes. Guidelines and tools for design and management

    Directory of Open Access Journals (Sweden)

    Elisabetta Ginelli

    2014-10-01

    Full Text Available Landscapes undergoing conservation, valorisation, management and reconstruction policies, become a fundamental factor for the local/global development of natural, cultural, human and social potentials of territories. With the contribution of technological design culture, the research, having a strong multidisciplinary character, focuses on managing the relationship between energy systems and landscapes with the general aim of subverting and transforming apparent conflicts in synergies, in order to overcome a sectorial and segmented approach barely based on energy performances. Through the introduction of a complex multidimensional methodology of analysis and evaluation the goal of this work, is to develop standards of acceptability, meta-design criteria and guidelines for design, intro- ducing a methodology for multidimen- sional complex analysis and evaluation, to support Public Authorities.

  16. The mechanisms for filling carbon nanotubes with molten salts: carbon nanotubes as energy landscape filters

    International Nuclear Information System (INIS)

    Bishop, Clare L; Wilson, Mark

    2009-01-01

    The mechanisms for filling carbon nanotubes with molten salts are investigated using molecular dynamics computer simulation. Inorganic nanotubular structures, whose morphologies can be rationalized in terms of the folding, or the removal of sections from, planes of square nets are found to form. The formation mechanisms are found to follow a 'chain-by-chain' motif in which the structures build systematically from charge neutral M-X-M-Xc chains. The formation mechanisms are rationalized in terms of the ion-ion interactions (intra-chain and inter-chain terms). In addition, the mechanisms of filling are discussed in terms of a 'hopping' between basins on the underlying energy landscape. The role of the carbon nanotube as an energy landscape filter is discussed.

  17. Frustration in the energy landscapes of multidomain protein misfolding.

    Science.gov (United States)

    Zheng, Weihua; Schafer, Nicholas P; Wolynes, Peter G

    2013-01-29

    Frustration from strong interdomain interactions can make misfolding a more severe problem in multidomain proteins than in single-domain proteins. On the basis of bioinformatic surveys, it has been suggested that lowering the sequence identity between neighboring domains is one of nature's solutions to the multidomain misfolding problem. We investigate folding of multidomain proteins using the associative-memory, water-mediated, structure and energy model (AWSEM), a predictive coarse-grained protein force field. We find that reducing sequence identity not only decreases the formation of domain-swapped contacts but also decreases the formation of strong self-recognition contacts between β-strands with high hydrophobic content. The ensembles of misfolded structures that result from forming these amyloid-like interactions are energetically disfavored compared with the native state, but entropically favored. Therefore, these ensembles are more stable than the native ensemble under denaturing conditions, such as high temperature. Domain-swapped contacts compete with self-recognition contacts in forming various trapped states, and point mutations can shift the balance between the two types of interaction. We predict that multidomain proteins that lack these specific strong interdomain interactions should fold reliably.

  18. Landscapes of Central Italy through Science, Poetry and Music. A perspective for educating to the planet sustainability

    Science.gov (United States)

    Nesci, Olivia; Valentini, Laura

    2016-04-01

    Born from a desire to promote the Italian landscape by integrating its physical aesthetic with its cultural and artistic heritage, we develop a story about the landscape told in popular science, and supported by visual stimulations, poetry and ancient music. Our work proceeds through two different routes. The first route analyzes the landscape from the scientific point of view trying to understand how it evolves and responds in response to changes in independent variables. The second path examines the landscape from a perspective more closely related to the visual and emotional impact that a place evokes, its history, its cultural significance, and perception of its fragility. The latter is perhaps a more complex path, more intimate, which develop fully only through the intersection of different forms of language, linked to specific arts. Three different disciplines focused on the same site, the combination of which results in an emotional experience where the encounter between different languages becomes an expression of the place. Among the many amazing landscapes of Italy, we focus on three known sites from the hystorical region of Montefeltro, in central Italy: "The flatiron of Petrano Mount", "The Stones of Montefeltro", "The sea-cliff of San Bartolo". Since a few years we have created a team of five researchers-artists, called "TerreRare" (Rare Earth Elements), whose mission is the desire to promote the gorgeous Italian landscape. Olivia Nesci, geomorphologist, begins this story analyzing the processes and the "forces" that have created and modified the landscape over time. Laura Valentini, a geologist and a musician, through the musical language, try to reproduce the emotional impact of the site, by searching for a piece of ancient music, composed for harpsichord. The choice of the musical instrument and the historical period is not accidental: the harpsichord has a punchy and gritty tone that clearly expresses the "strength" of the landscape; early music

  19. Autonomously folding protein fragments reveal differences in the energy landscapes of homologous RNases H.

    Directory of Open Access Journals (Sweden)

    Laura E Rosen

    Full Text Available An important approach to understanding how a protein sequence encodes its energy landscape is to compare proteins with different sequences that fold to the same general native structure. In this work, we compare E. coli and T. thermophilus homologs of the protein RNase H. Using protein fragments, we create equilibrium mimics of two different potential partially-folded intermediates (I(core and I(core+1 hypothesized to be present on the energy landscapes of these two proteins. We observe that both T. thermophilus RNase H (ttRNH fragments are folded and have distinct stabilities, indicating that both regions are capable of autonomous folding and that both intermediates are present as local minima on the ttRNH energy landscape. In contrast, the two E. coli RNase H (ecRNH fragments have very similar stabilities, suggesting that the presence of additional residues in the I(core+1 fragment does not affect the folding or structure as compared to I(core. NMR experiments provide additional evidence that only the I(core intermediate is populated by ecRNH. This is one of the biggest differences that has been observed between the energy landscapes of these two proteins. Additionally, we used a FRET experiment in the background of full-length ttRNH to specifically monitor the formation of the I(core+1 intermediate. We determine that the ttRNH I(core+1 intermediate is likely the intermediate populated prior to the rate-limiting barrier to global folding, in contrast to E. coli RNase H for which I(core is the folding intermediate. This result provides new insight into the nature of the rate-limiting barrier for the folding of RNase H.

  20. Multifunctional energy landscape for a DNA G-quadruplex: An evolved molecular switch

    Science.gov (United States)

    Cragnolini, Tristan; Chakraborty, Debayan; Šponer, Jiří; Derreumaux, Philippe; Pasquali, Samuela; Wales, David J.

    2017-10-01

    We explore the energy landscape for a four-fold telomere repeat, obtaining interconversion pathways between six experimentally characterised G-quadruplex topologies. The results reveal a multi-funnel system, with a variety of intermediate configurations and misfolded states. This organisation is identified with the intrinsically multi-functional nature of the system, suggesting a new paradigm for the classification of such biomolecules and clarifying issues regarding apparently conflicting experimental results.

  1. Keynote address: Modern agricultural landscapes – a perspective on their past, present and future

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard

    of landscape patterns in affected territories, leading to the creation of a new type of landscape. A distinctly modern agricultural landscape, characterized by rectilinear spatial forms, functionally segregated, specialized land use patterns, individualized decision making practices and an agricultural economy...... embedded within regional, globalizing networks of economic, technological and cultural exchange. In such landscapes, patterns of land use have since converged to an increasing extent, forming flows of correlated practices and associated ecological impairments observable across extensive arrays of otherwise...... of a capitalist modern origin. In this context, the purpose of this keynote address is to explore how the relationship between institutional and physical legacies of land use modernization affects decision making in contemporary agricultural landscapes. On the basis of a selection of European and postcolonial...

  2. A new approach to quantify semiochemical effects on insects based on energy landscapes.

    Directory of Open Access Journals (Sweden)

    Rory P Wilson

    Full Text Available Our ability to document insect preference for semiochemicals is pivotal in pest control as these agents can improve monitoring and be deployed within integrated pest management programmes for more efficacious control of pest species. However, methods used to date have drawbacks that limit their utility. We present and test a new concept for determining insect motivation to move towards, or away from, semiochemicals by noting direction and speed of movement as animals work against a defined energy landscape (environmentally dependent variation in the cost of transport requiring different powers to negotiate. We conducted trials with the pine weevils Hylobius abietis and peach-potato aphids Myzus persicae exposed to various attractants and repellents and placed so that they either moved up defined slopes against gravity or had to travel over variously rough surfaces.Linear Mixed Models demonstrated clear reductions in travel speed by insects moving along increasingly energetically taxing energy landscapes but also that responses varied according to different semiochemicals, thus highlighting the value of energy landscapes as a new concept to help measure insect motivation to access or avoid different attractants or repellents across individuals.New sensitive, detailed indicators of insect motivation derived from this approach should prove important in pest control across the world.

  3. Energy perspectives 2035 - Volume 4, side-notes

    International Nuclear Information System (INIS)

    2007-01-01

    This comprehensive report published by the Swiss Federal Office of Energy (SFOE) presents a number of side-notes pertaining to the first three volumes of the Energy Perspectives series of reports. Various topics are discussed by the authors of the first three volumes of the perspectives in the meetings held by the Energy Perspectives Working Group. The sixteen side-notes presented here cover the following topics: General conditions, fossil resources, the influence of climate warming, CO 2 emissions trading (Joint Implementation JI and Clean Development Mechanism CDM), definition of potentials, air traffic, imported renewable electricity, hydro power, electricity cost calculation, sensitivity analysis of centralised power production facilities, heat-pumps and their power consumption, cold spells and heat-waves, risk and its perception, the 2000-Watt society and international and national energy perspectives

  4. Energy landscape of all-atom protein-protein interactions revealed by multiscale enhanced sampling.

    Directory of Open Access Journals (Sweden)

    Kei Moritsugu

    2014-10-01

    Full Text Available Protein-protein interactions are regulated by a subtle balance of complicated atomic interactions and solvation at the interface. To understand such an elusive phenomenon, it is necessary to thoroughly survey the large configurational space from the stable complex structure to the dissociated states using the all-atom model in explicit solvent and to delineate the energy landscape of protein-protein interactions. In this study, we carried out a multiscale enhanced sampling (MSES simulation of the formation of a barnase-barstar complex, which is a protein complex characterized by an extraordinary tight and fast binding, to determine the energy landscape of atomistic protein-protein interactions. The MSES adopts a multicopy and multiscale scheme to enable for the enhanced sampling of the all-atom model of large proteins including explicit solvent. During the 100-ns MSES simulation of the barnase-barstar system, we observed the association-dissociation processes of the atomistic protein complex in solution several times, which contained not only the native complex structure but also fully non-native configurations. The sampled distributions suggest that a large variety of non-native states went downhill to the stable complex structure, like a fast folding on a funnel-like potential. This funnel landscape is attributed to dominant configurations in the early stage of the association process characterized by near-native orientations, which will accelerate the native inter-molecular interactions. These configurations are guided mostly by the shape complementarity between barnase and barstar, and lead to the fast formation of the final complex structure along the downhill energy landscape.

  5. Landscape epidemiology: An emerging perspective in the mapping and modelling of disease and disease risk factors

    Directory of Open Access Journals (Sweden)

    Nnadi Nnaemeka Emmanuel

    2011-09-01

    Full Text Available Landscape epidemiology describes how the temporal dynamics of host, vector, and pathogen populations interact spatially within a permissive environment to enable transmission. It also aims at understanding the vegetation and geologic conditions that are necessary for the maintenance and transmission of a particular pathogen. The current review describes the evolution of landscape epidemiology. As a science, it also highlights the various methods of mapping and modeling diseases and disease risk factors. The key tool to characterize landscape is satellite remote sensing and these data are used as inputs to drive spatial models of transmission risk.

  6. The potential energy landscape in the Lennard-Jones binary mixture model

    International Nuclear Information System (INIS)

    Sampoli, M; Benassi, P; Eramo, R; Angelani, L; Ruocco, G

    2003-01-01

    The potential energy landscape in the Kob-Andersen Lennard-Jones binary mixture model has been studied carefully from the liquid down to the supercooled regime, from T = 2 down to 0.46. One thousand independent configurations along the time evolution locus have been examined at each temperature investigated. From the starting configuration, we searched for the nearest saddle (or quasi-saddle) and minimum of the potential energy. The vibrational densities of states for the starting and the two derived configurations have been evaluated. Besides the number of negative eigenvalues of the saddles other quantities show some signature of the approach of the dynamical arrest temperature

  7. A Dutch Perspective on Coastal Louisiana Flood Risk Reduction and Landscape Stabilization

    National Research Council Canada - National Science Library

    Dijkman, Jos

    2007-01-01

    .... The project was aimed at identifying options for the long-term reduction of flood risks and landscape stabilization in Planning Areas I and 2 in Louisiana, in the framework of the Louisiana Coastal...

  8. Rural identity and landscape aesthetics in exurbia: Some issues to resolve from a Central European perspective

    Directory of Open Access Journals (Sweden)

    Janečková Molnárová Kristina

    2017-03-01

    Full Text Available Although perceptions of landscape aesthetics are currently attracting great research interest, some aspects of the topic have remained almost unexamined. This review highlights some less studied areas that are of particular importance for landscape management, with special focus on rapidly growing exurban areas. While the visual quality of the environment is undoubtedly one of the drivers that has been spurring the exurban development of rural settlements, much remains unknown about the perception of the visual quality of these settlements. Another pressing issue is the need to determine general principles of consensus formation concerning visual landscape preferences. This study concludes that in order to preserve the rural character of exurban landscapes, there is an urgent need to identify the aesthetic values that define the character of rural settlements and their importance to the stakeholder groups.

  9. Opportunities and challenges for mainstreaming ecosystem services in development planning: perspectives from a landscape level

    CSIR Research Space (South Africa)

    Sitas, Nadia E

    2014-10-01

    Full Text Available Despite much progress in ecosystem services research, a gap still appears to exist between this research and the implementation of landscape management and development activities on the ground, especially within a developing country context...

  10. Simple solvable energy-landscape model that shows a thermodynamic phase transition and a glass transition.

    Science.gov (United States)

    Naumis, Gerardo G

    2012-06-01

    When a liquid melt is cooled, a glass or phase transition can be obtained depending on the cooling rate. Yet, this behavior has not been clearly captured in energy-landscape models. Here, a model is provided in which two key ingredients are considered in the landscape, metastable states and their multiplicity. Metastable states are considered as in two level system models. However, their multiplicity and topology allows a phase transition in the thermodynamic limit for slow cooling, while a transition to the glass is obtained for fast cooling. By solving the corresponding master equation, the minimal speed of cooling required to produce the glass is obtained as a function of the distribution of metastable states.

  11. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Dahle, Håkon; Økland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-07-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent field (SMVF) and the Loki's Castle Vent Field (LCVF). Chemical energy landscapes were evaluated through modelling of the Gibbs energy from selected redox reactions under different mixing ratios between seawater and hydrothermal fluids. Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF. The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes. We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

  12. STATE OF THE ART OF THE LANDSCAPE ARCHITECTURE SPATIAL DATA MODEL FROM A GEOSPATIAL PERSPECTIVE

    OpenAIRE

    Kastuari, A.; Suwardhi, D.; Hanan, H.; Wikantika, K.

    2016-01-01

    Spatial data and information had been used for some time in planning or landscape design. For a long time, architects were using spatial data in the form of topographic map for their designs. This method is not efficient, and it is also not more accurate than using spatial analysis by utilizing GIS. Architects are sometimes also only accentuating the aesthetical aspect for their design, but not taking landscape process into account which could cause the design could be not suitable for its us...

  13. Experiences from a winter school on landscape agronomy : stakes, difficulties, perspectives

    OpenAIRE

    Rapey, Hélène; Lardon, Sylvie; Galli, Mariassunta; Moonen, Camilla; Benoit, Marc; Thenail, Claudine; Barberi, Paolo; Caron, Patrick; Marraccini, Elisa; Rizzo, Davide; Bonari, Enrico

    2008-01-01

    In the latest fifteen years, agronomic reserach has shown a growing interst for studies which link farm or field scale to landscape scale. Thus, agronomy is called to renew its research questions and methodologies, and as well its educational programmes. In this context, some French and Italian researchers interested in these topics, coming from different scientific fields but sharing interests on landscape scale issues in research and higher education, decided to join their efforts eround a ...

  14. The Conservation of the Landscape in the Perspective of a Public Open Spaces System in Recife

    OpenAIRE

    Carneiro, Ana Rita Sá; Duarte, Mirela; Marques, Eliábi A.

    2009-01-01

    This paper presents the relationship between the study of public open spaces and the urban landscape in Recife, according a systemic vision. This relationship is defined with the historical analysis of the natural ecosystems in the site landscape such as rivers, coast vegetation and mangrove, and the atlantic forest, which was occupied by the time. This method was chosen to understand the morphology of open spaces, its typology and which is preserved as natural and cultural heritage. Nowadays...

  15. An energy landscape based approach for studying supercooled liquid and glassy thin films

    Science.gov (United States)

    Shah, Pooja; Mittal, Jeetain; Truskett, Thomas M.

    2004-03-01

    Materials in confined spaces are important in science and technology. Examples include biological fluids in membranes, liquids trapped in porous rocks, and thin-film materials used in high-resolution patterning technologies. However, few reliable rules exist to predict how the properties of materials will be affected by thin-film confinement. We have recently shown that the potential energy landscape formalism can be used to study, by both theory [1] and simulation [2], how the behavior of thin-film materials depends on sample dimensions and film-substrate interactions. Our landscape-based mean-field theory [1] can be used to study both the thermodynamic properties and the ideal glass transition of thin films. It predicts that, in the case of neutral or repulsive walls, the ideal glass transition temperature is lowered by decreasing film thickness. This is in qualitative agreement with experimental trends for the kinetic glass transition in confined fluids. Landscape-based approaches are also valuable for understanding the structural and mechanical properties of thin-film glasses. We demonstrate how the concept of an "equation of state of the energy landscape" [3] can be generalized to thin films [1, 2], where it gives insights into potential molecular mechanisms of tensile strength. [1] T. M. Truskett and V. Ganesan, J. Chem. Phys. 119, 1897-1900(2003); J. Mittal, P. Shah and T. M. Truskett, to be submitted to Langmuir. [2] P. Shah and T. M. Truskett, to be submitted to J. Phys. Chem. B. [3] S. Sastry, P. G. Debenedetti and F. H. Stillinger, Phys. Rev. E 56, 5533 (1997)

  16. Free energy landscapes of electron transfer system in dipolar environment below and above the rotational freezing temperature

    International Nuclear Information System (INIS)

    Suzuki, Yohichi; Tanimura, Yoshitaka

    2007-01-01

    Electron transfer reaction in a polar solvent is modeled by a solute dipole surrounded by dipolar molecules with simple rotational dynamics posted on the three-dimensional distorted lattice sites. The interaction energy between the solute and solvent dipoles as a reaction coordinate is adopted and free energy landscapes are calculated by generating all possible states for a 26 dipolar system and by employing Wang-Landau sampling algorithm for a 92 dipolar system. For temperatures higher than the energy scale of dipole-dipole interactions, the free energy landscapes for the small reaction coordinate region have quadratic shape as predicted by Marcus [Rev. Mod. Phys. 65, 599 (1993)] whereas for the large reaction coordinate region, the landscapes exhibit a nonquadratic shape. When the temperature drops, small notched structures appear on the free energy profiles because of the frustrated interactions among dipoles. The formation of notched structure is analyzed with statistical approach and it is shown that the amplitude of notched structure depend upon the segment size of the reaction coordinate and is characterized by the interaction energy among the dipoles. Using simulated free energy landscapes, the authors calculate the reaction rates as a function of the energy gap for various temperatures. At high temperature, the reactions rates follow a bell shaped (inverted parabolic) energy gap law in the small energy gap regions, while it becomes steeper than the parabolic shape in a large energy gap regions due to the nonquadratic shape of the free energy landscape. The peak position of parabola also changes as the function of temperature. At low temperature, the profile of the reaction rates is no longer smooth because of the many local minima of the free energy landscape

  17. Potential energy landscape and robustness of a gene regulatory network: toggle switch.

    Directory of Open Access Journals (Sweden)

    Keun-Young Kim

    2007-03-01

    Full Text Available Finding a multidimensional potential landscape is the key for addressing important global issues, such as the robustness of cellular networks. We have uncovered the underlying potential energy landscape of a simple gene regulatory network: a toggle switch. This was realized by explicitly constructing the steady state probability of the gene switch in the protein concentration space in the presence of the intrinsic statistical fluctuations due to the small number of proteins in the cell. We explored the global phase space for the system. We found that the protein synthesis rate and the unbinding rate of proteins to the gene were small relative to the protein degradation rate; the gene switch is monostable with only one stable basin of attraction. When both the protein synthesis rate and the unbinding rate of proteins to the gene are large compared with the protein degradation rate, two global basins of attraction emerge for a toggle switch. These basins correspond to the biologically stable functional states. The potential energy barrier between the two basins determines the time scale of conversion from one to the other. We found as the protein synthesis rate and protein unbinding rate to the gene relative to the protein degradation rate became larger, the potential energy barrier became larger. This also corresponded to systems with less noise or the fluctuations on the protein numbers. It leads to the robustness of the biological basins of the gene switches. The technique used here is general and can be applied to explore the potential energy landscape of the gene networks.

  18. STATE OF THE ART OF THE LANDSCAPE ARCHITECTURE SPATIAL DATA MODEL FROM A GEOSPATIAL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    A. Kastuari

    2016-10-01

    Full Text Available Spatial data and information had been used for some time in planning or landscape design. For a long time, architects were using spatial data in the form of topographic map for their designs. This method is not efficient, and it is also not more accurate than using spatial analysis by utilizing GIS. Architects are sometimes also only accentuating the aesthetical aspect for their design, but not taking landscape process into account which could cause the design could be not suitable for its use and its purpose. Nowadays, GIS role in landscape architecture has been formalized by the emergence of Geodesign terminology that starts in Representation Model and ends in Decision Model. The development of GIS could be seen in several fields of science that now have the urgency to use 3 dimensional GIS, such as in: 3D urban planning, flood modeling, or landscape planning. In this fields, 3 dimensional GIS is able to support the steps in modeling, analysis, management, and integration from related data, that describe the human activities and geophysics phenomena in more realistic way. Also, by applying 3D GIS and geodesign in landscape design, geomorphology information can be better presented and assessed. In some research, it is mentioned that the development of 3D GIS is not established yet, either in its 3D data structure, or in its spatial analysis function. This study literature will able to accommodate those problems by providing information on existing development of 3D GIS for landscape architecture, data modeling, the data accuracy, representation of data that is needed by landscape architecture purpose, specifically in the river area.

  19. State of the Art of the Landscape Architecture Spatial Data Model from a Geospatial Perspective

    Science.gov (United States)

    Kastuari, A.; Suwardhi, D.; Hanan, H.; Wikantika, K.

    2016-10-01

    Spatial data and information had been used for some time in planning or landscape design. For a long time, architects were using spatial data in the form of topographic map for their designs. This method is not efficient, and it is also not more accurate than using spatial analysis by utilizing GIS. Architects are sometimes also only accentuating the aesthetical aspect for their design, but not taking landscape process into account which could cause the design could be not suitable for its use and its purpose. Nowadays, GIS role in landscape architecture has been formalized by the emergence of Geodesign terminology that starts in Representation Model and ends in Decision Model. The development of GIS could be seen in several fields of science that now have the urgency to use 3 dimensional GIS, such as in: 3D urban planning, flood modeling, or landscape planning. In this fields, 3 dimensional GIS is able to support the steps in modeling, analysis, management, and integration from related data, that describe the human activities and geophysics phenomena in more realistic way. Also, by applying 3D GIS and geodesign in landscape design, geomorphology information can be better presented and assessed. In some research, it is mentioned that the development of 3D GIS is not established yet, either in its 3D data structure, or in its spatial analysis function. This study literature will able to accommodate those problems by providing information on existing development of 3D GIS for landscape architecture, data modeling, the data accuracy, representation of data that is needed by landscape architecture purpose, specifically in the river area.

  20. Perspectives of energy supply in unified Germany

    International Nuclear Information System (INIS)

    Gieske, F.

    1991-01-01

    This article deals with the role of the various energy carriers within a future energy concept. The energy supply industry aims at a well-balanced energy mixture which is to include nuclear energy as well as domestic and imported coal. The supply industry will not turn a deaf ear to opening up the competitive scene, the author thinks, however, there well have to be special economic and technical preconditions. (orig.) [de

  1. The environmental benefits of cellulosic energy crops at a landscape scale

    International Nuclear Information System (INIS)

    Graham, R.L.; Liu, W.; English, B.C.

    1995-01-01

    The objective of this paper is to present a broad overview of the potential environmental impacts of biomass energy from energy crops--particularly the cellulosic energy crops current under development. For this discussion, the term energy crop refers to a crop grown primarily to create feedstock for either making biofuels such as ethanol or burning in a heat or electricity generation facility. Cellulosic energy crops are designed to be used in cellulose-based ethanol conversion processes (as opposed to starch or sugar-based ethanol conversion processes). As more cellulose can be produced per hectare of land than can sugar or starch, the cellulose-based ethanol conversion process is a more efficient sue of land for ethanol production. Assessing the environmental impacts of biomass energy from energy crops is complex because the environmental impact of using biomass for energy must be considered in the context of alternative energy options while the environmental impact of producing biomass from energy crops must be considered in the context of alternative land-uses. Using biomass-derived energy can reduce greenhouse gas emissions or increase them; growing biomass energy crops can enhance soil fertility or degrade it. Without knowing the context of the biomass energy, one can say little about its specific environmental impacts. The primary focus of this paper is an evaluation of the environmental impacts of growing cellulosic energy crops especially at the landscape or regional scale. However, to set the stage for this discussion, the authors begin by comparing the environmental advantages and disadvantages of biomass-derived energy relative to other energy alternatives such as coal, hydropower, nuclear power, oil/gasoline, natural gas and photovoltaics

  2. Marine renewable energy in China: Current status and perspectives

    Directory of Open Access Journals (Sweden)

    Yong-liang Zhang

    2014-07-01

    Full Text Available Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China's coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeting China's future energy needs. Additionally, considering the uneven distribution of China's marine renewable energy and the influences of its exploitation on the environment, we have suggested several sites with great potential for each kind of marine energy. Furthermore, perspectives on and challenges related with marine renewable energy in China are addressed.

  3. Power from Perspective: Potential future United States energy portfolios

    International Nuclear Information System (INIS)

    Tonn, Bruce; Healy, K.C.; Gibson, Amy; Ashish, Ashutosh; Cody, Preston; Beres, Drew; Lulla, Sam; Mazur, Jim; Ritter, A.J.

    2009-01-01

    This paper presents United States energy portfolios for the year 2030, developed from seven different Perspectives. The Perspectives are characterized by different weights placed on fourteen defining values (e.g., cost, social acceptance). The portfolios were constructed to achieve three primary goals, energy independence, energy security, and greenhouse gas reductions. The portfolios are also evaluated over a comprehensive set of secondary criteria (e.g., economic growth, technical feasibility). It is found that very different portfolios based on very different defining values can achieve the three primary goals. Commonalities among the portfolios include reliance upon cellulosic ethanol, nuclear power, and energy efficiency to meet year 2030 energy demands. It is concluded that the US energy portfolio must be diverse and to achieve national energy goals will require an explicit statement of goals, a strong role for government, and coordinated action across society

  4. Role of Electrostatics in Protein-RNA Binding: The Global vs the Local Energy Landscape.

    Science.gov (United States)

    Ghaemi, Zhaleh; Guzman, Irisbel; Gnutt, David; Luthey-Schulten, Zaida; Gruebele, Martin

    2017-09-14

    U1A protein-stem loop 2 RNA association is a basic step in the assembly of the spliceosomal U1 small nuclear ribonucleoprotein. Long-range electrostatic interactions due to the positive charge of U1A are thought to provide high binding affinity for the negatively charged RNA. Short range interactions, such as hydrogen bonds and contacts between RNA bases and protein side chains, favor a specific binding site. Here, we propose that electrostatic interactions are as important as local contacts in biasing the protein-RNA energy landscape toward a specific binding site. We show by using molecular dynamics simulations that deletion of two long-range electrostatic interactions (K22Q and K50Q) leads to mutant-specific alternative RNA bound states. One of these states preserves short-range interactions with aromatic residues in the original binding site, while the other one does not. We test the computational prediction with experimental temperature-jump kinetics using a tryptophan probe in the U1A-RNA binding site. The two mutants show the distinct predicted kinetic behaviors. Thus, the stem loop 2 RNA has multiple binding sites on a rough RNA-protein binding landscape. We speculate that the rough protein-RNA binding landscape, when biased to different local minima by electrostatics, could be one way that protein-RNA interactions evolve toward new binding sites and novel function.

  5. Energy and the economy: an interrelated perspective

    Energy Technology Data Exchange (ETDEWEB)

    Krenz, J H

    1977-06-01

    Energy consumption and economic activity for the United States has been closely related. Using input-output accounts, the variations between sectors which provide most of the consumer final demand are shown to be not as large as often assumed. The energy intensiveness of continental Western European nations, being only one half that of the United States, suggests that continued U.S. economic growth is possible without a corresponding increase in energy consumption. A reduction in energy intensiveness can be achieved through energy-related capital investments and social changes. Estimates for both the monetary value of the required capital investments and the corresponding energy required for the investments are obtained.

  6. Electrostatics, structure prediction, and the energy landscapes for protein folding and binding.

    Science.gov (United States)

    Tsai, Min-Yeh; Zheng, Weihua; Balamurugan, D; Schafer, Nicholas P; Kim, Bobby L; Cheung, Margaret S; Wolynes, Peter G

    2016-01-01

    While being long in range and therefore weakly specific, electrostatic interactions are able to modulate the stability and folding landscapes of some proteins. The relevance of electrostatic forces for steering the docking of proteins to each other is widely acknowledged, however, the role of electrostatics in establishing specifically funneled landscapes and their relevance for protein structure prediction are still not clear. By introducing Debye-Hückel potentials that mimic long-range electrostatic forces into the Associative memory, Water mediated, Structure, and Energy Model (AWSEM), a transferable protein model capable of predicting tertiary structures, we assess the effects of electrostatics on the landscapes of thirteen monomeric proteins and four dimers. For the monomers, we find that adding electrostatic interactions does not improve structure prediction. Simulations of ribosomal protein S6 show, however, that folding stability depends monotonically on electrostatic strength. The trend in predicted melting temperatures of the S6 variants agrees with experimental observations. Electrostatic effects can play a range of roles in binding. The binding of the protein complex KIX-pKID is largely assisted by electrostatic interactions, which provide direct charge-charge stabilization of the native state and contribute to the funneling of the binding landscape. In contrast, for several other proteins, including the DNA-binding protein FIS, electrostatics causes frustration in the DNA-binding region, which favors its binding with DNA but not with its protein partner. This study highlights the importance of long-range electrostatics in functional responses to problems where proteins interact with their charged partners, such as DNA, RNA, as well as membranes. © 2015 The Protein Society.

  7. Time Series Analysis of Energy Production and Associated Landscape Fragmentation in the Eagle Ford Shale Play

    Science.gov (United States)

    Pierre, Jon Paul; Young, Michael H.; Wolaver, Brad D.; Andrews, John R.; Breton, Caroline L.

    2017-11-01

    Spatio-temporal trends in infrastructure footprints, energy production, and landscape alteration were assessed for the Eagle Ford Shale of Texas. The period of analysis was over four 2-year periods (2006-2014). Analyses used high-resolution imagery, as well as pipeline data to map EF infrastructure. Landscape conditions from 2006 were used as baseline. Results indicate that infrastructure footprints varied from 94.5 km2 in 2008 to 225.0 km2 in 2014. By 2014, decreased land-use intensities (ratio of land alteration to energy production) were noted play-wide. Core-area alteration by period was highest (3331.6 km2) in 2008 at the onset of play development, and increased from 582.3 to 3913.9 km2 by 2014, though substantial revegetation of localized core areas was observed throughout the study (i.e., alteration improved in some areas and worsened in others). Land-use intensity in the eastern portion of the play was consistently lower than that in the western portion, while core alteration remained relatively constant east to west. Land alteration from pipeline construction was 65 km2 for all time periods, except in 2010 when alteration was recorded at 47 km2. Percent of total alteration from well-pad construction increased from 27.3% in 2008 to 71.5% in 2014. The average number of wells per pad across all 27 counties increased from 1.15 to 1.7. This study presents a framework for mapping landscape alteration from oil and gas infrastructure development. However, the framework could be applied to other energy development programs, such as wind or solar fields, or any other regional infrastructure development program.

  8. Energy Technology Perspectives 2012: Executive Summary [Spanish version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Energy Technology Perspectives (ETP) is the International Energy Agency’s most ambitious publication on new developments in energy technology. It demonstrates how technologies – from electric vehicles to smart grids – can make a decisive difference in achieving the objective of limiting the global temperature rise to 2°C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  9. Energy Technology Perspectives 2012: Executive Summary [Arabic version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Energy Technology Perspectives (ETP) is the International Energy Agency’s most ambitious publication on new developments in energy technology. It demonstrates how technologies – from electric vehicles to smart grids – can make a decisive difference in achieving the objective of limiting the global temperature rise to 2°C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  10. Energy Technology Perspectives 2012: Executive Summary [Italian version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Energy Technology Perspectives (ETP) is the International Energy Agency’s most ambitious publication on new developments in energy technology. It demonstrates how technologies – from electric vehicles to smart grids – can make a decisive difference in achieving the objective of limiting the global temperature rise to 2°C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  11. Energy Technology Perspectives 2012: Executive Summary [French version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Energy Technology Perspectives (ETP) is the International Energy Agency’s most ambitious publication on new developments in energy technology. It demonstrates how technologies – from electric vehicles to smart grids – can make a decisive difference in achieving the objective of limiting the global temperature rise to 2°C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  12. Energy Technology Perspectives 2012: Executive Summary [Portuguese version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Energy Technology Perspectives (ETP) is the International Energy Agency’s most ambitious publication on new developments in energy technology. It demonstrates how technologies – from electric vehicles to smart grids – can make a decisive difference in achieving the objective of limiting the global temperature rise to 2°C and enhancing energy security. ETP 2012 presents scenarios and strategies to 2050, with the aim of guiding decision makers on energy trends and what needs to be done to build a clean, secure and competitive energy future.

  13. Perspectives of development of the nuclear energy in China

    International Nuclear Information System (INIS)

    2002-04-01

    The coal is the main primary energy source in China. In spite of the economic development, the coal consumption decreases regularly since the last years. It is the consequences of the energy policy of China which closed little coal mines of poor productivity. The today energy balance of China lays on two supplying sources: 70 % coal and 24 % hydro energy. To face the increasing economic development China will need a complementary electric power production source. In this context, this document presents the today nuclear energy situation in the chinese energy policy, the perspectives for the french nuclear industry and the possible chinese-french collaboration. (A.L.B.)

  14. Nuclear energy risks and benefits in perspective

    International Nuclear Information System (INIS)

    Gordelier, S.

    2007-01-01

    Energy demand, rising prices, security of supply, climate change... these are major issues facing today's energy policy makers. In response, the NEA has recently published a study on Risks and Benefits of Nuclear Energy in order to provide these policy makers with authoritative information in support of their decision making. The study has also provided much of the basis for this article. (author)

  15. Free energy landscape and cooperatively rearranging region in a hard sphere glass

    Science.gov (United States)

    Yoshidome, Takashi; Yoshimori, Akira; Odagaki, Takashi

    2007-08-01

    Exploiting the density functional theory, we calculate the free energy landscape (FEL) of the hard sphere glass in three dimensions. From the FEL, we estimate the number of the particles in the cooperatively rearranging region (CRR). We find that the density dependence of the number of the particles in the CRR is expressed as a power law function of the density. Analyzing the relaxation process in the CRR, we also find that the string motion is the elementary process for the structural relaxation, which leads to the natural definition of the simultaneously rearranging region as the particles displaced in the string motion.

  16. Exploring the energy landscape of the charge transport levels in organic semiconductors at the molecular scale.

    Science.gov (United States)

    Cornil, J; Verlaak, S; Martinelli, N; Mityashin, A; Olivier, Y; Van Regemorter, T; D'Avino, G; Muccioli, L; Zannoni, C; Castet, F; Beljonne, D; Heremans, P

    2013-02-19

    strongly interacting electron-hole pairs can potentially escape from their Coulomb well, a process that is at the heart of photoconversion or molecular doping. Yet they do, with near-quantitative yield in some cases. Limited screening by the low dielectric medium in organic materials leads to subtle static and dynamic electronic polarization effects that strongly impact the energy landscape for charges, which offers a rationale for this apparent inconsistency. In this Account, we use different theoretical approaches to predict the energy landscape of charge carriers at the molecular level and review a few case studies highlighting the role of electrostatic interactions in conjugated organic molecules. We describe the pros and cons of different theoretical approaches that provide access to the energy landscape defining the motion of charge carriers. We illustrate the applications of these approaches through selected examples involving OFETs, OLEDs, and solar cells. The three selected examples collectively show that energetic disorder governs device performances and highlights the relevance of theoretical tools to probe energy landscapes in molecular assemblies.

  17. Energy use in Denmark: An international perspective

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, L.; Howarth, R.; Andersson, B.; Price, L.

    1992-08-01

    This report analyzes the evolution use in Denmark since the early 1970s in order to shed light on the future path of energy use in Denmark, with particular emphasis on the role of energy efficiency. The authors found that improvements in end-use energy efficiency reduced primary energy requirements in Denmark by 22% between 1972 and 1988. Focusing on developments in six individual sectors of the Danish economy (residential, manufacturing, other industry, service, travel, and freight), they found that the residential, manufacturing, and service sectors have led the improvements in efficiency. Travel showed few significant improvements and the efficiency of freight transportation worsened. The international comparisons showed that the structure of energy use in Denmark is less energy-intensive than that of most high-income OECD countries, with the exception of Japan. Overall, they concluded that most of the energy savings achieved in Denmark were brought about through improvements in technology. They also found that an important stimulus for improved efficiency was higher energy prices, led in no small part by significant taxes imposed on small consumers of heating oil, electricity, and motor fuels. Energy-efficiency programs accelerated energy savings in homes and commercial buildings. The rate of improvement of energy efficiency in Denmark has slowed down significantly since 1984, consistent with trends observed in other major countries. While many of the energy-efficiency goals stated or implied in Denmark`s Energi 2000 are achievable over a very long period, present trends do not point towards achievement of these goals by 2010 or even 2020. Strong measures will have to be developed by both public and private authorities if energy efficiency is to make a key contributions to reducing environmental problems associated with energy use in Denmark.

  18. Energy landscape for martensitic phase transformation in shape memory NiTi

    International Nuclear Information System (INIS)

    Kibey, S.; Sehitoglu, H.; Johnson, D.D.

    2009-01-01

    First-principles calculations are presented for parent B2 phase and martensitic B19 and B19' phases in NiTi. The results indicate that both B19 and B19' are energetically more stable than the parent B2 phase. By means of ab initio density functional theory, the complete distortion-shuffle energy landscape associated with B2 → B19 transformation in NiTi is then determined. In addition to accounting for the Bain-type deformation through the Cauchy-Born rule, the study explicitly accounts for the shuffle displacements experienced by the internal ions in NiTi. The energy landscape allows the energy barrier associated with the B2 → B19 transformation pathway to be identified. The results indicate that a barrier of 0.48 mRyd atom -1 (relative to the B2 phase) must be overcome to transform the parent B2 NiTi to orthorhombic B19 martensite

  19. Quantitative analysis of the publishing landscape in high-energy physics

    International Nuclear Information System (INIS)

    Mele, Salvatore; Dallman, David; Vigen, Jens; Yeomans, Joanne

    2006-01-01

    World-wide collaboration in high-energy physics (HEP) is a tradition which dates back several decades, with scientific publications mostly coauthored by scientists from different countries. This coauthorship phenomenon makes it difficult to identify precisely the 'share' of each country in HEP scientific production. One year's worth of HEP scientific articles published in peer-reviewed journals is analysed and their authors are uniquely assigned to countries. This method allows the first correct estimation on a pro rata basis of the share of HEP scientific publishing among several countries and institutions. The results provide an interesting insight into the geographical collaborative patterns of the HEP community. The HEP publishing landscape is further analysed to provide information on the journals favoured by the HEP community and on the geographical variation of their author bases. These results provide quantitative input to the ongoing debate on the possible transition of HEP publishing to an Open Access model. Foreword. This paper reports the results of a recent detailed study of the publishing landscape in high energy physics. We thought that because of its direct relevance to the high energy physics community, this important quantitative input to the debate on the transition to Open Access naturally finds its place in our journal. Marc Henneaux, JHEP Scientific Director

  20. Primavera Ring. Management perspectives on La Primavera forest buffer zone, from the cultural landscapes approach

    Directory of Open Access Journals (Sweden)

    Pedro Alcocer Santos

    2016-06-01

    Full Text Available The current article intends to high light the need to implement a buffer zone for La Primavera Forest,  Biosphere reserve MaB UNESCO in Guadalajara, Jalisco. The criteria to develop this transition zone is based on understanding this territory as a Cultural Landscape. Seeking common ground between Biosphere Reserves and Cultural Landscapes criteria to organize the management and development of the buffer zone. To understand the opponents of city development and forest preservation as complementary elements, a paradigm shift is needed. This is an applied research from the ITESO, and it is structured as a Think Tank that involves society, government and academy.

  1. Government in energy affairs - perspectives and alternatives

    International Nuclear Information System (INIS)

    Neethling, D.C.

    1986-01-01

    The present role of the South African Government in energy policy formulation and implementation is assessed in the light of its possible future evolvement, particularly with reference to the tabling of a White Paper on Energy policy during 1986. The brief of the Ministry of Mineral and Energy Affairs is firstly assessed with particular reference to the energy-related functions of the Department itself and those of the various parastatal and statutory organisations and institutions. The various executive and regulatory functions which circumscribe the involvement of government in energy procurement, production and distribution, are critically reviewed in the light of possible further deregulation and the establishment of a more market-orientated energy economy in South Africa. Secondly, the administrative and consultative mechanisms are identified which are believed to be appropriate for the successful co-ordination of the energy-related interests of government and the private sector. It is argued that history has shown that energy policy decisions in South Africa have essentially been guided by non-energy priorities, in particular geopolitical and strategic considerations. It is foreseen that although this situation will prevail to a greater or lesser degree depending on the measure of energy self-sufficiency which will be achieved, particularly insofar as import-dependency of crude oil is concerned, that the emphasis would, indeed should, shift to national energy priorities and considerations. 12 refs., 2 figs

  2. Industrial energy efficiency: A policy perspective

    International Nuclear Information System (INIS)

    Chandler, W.U.

    1990-01-01

    Policies that promote energy efficiency can work; but potential energy savings are unlikely to be realized without effective policy leadership. This article discusses the opportunities in several countries for increasing energy efficiency. Both ''open'' and centrally planned economies could be much more energy efficient. In the United States, for example, the government needs to stimulate energy efficiency. This could be done by sponsoring research to develop new processes, creating favourable financial conditions for investment in efficiency, and making the advantages of energy efficiency technologies better known. International collaboration in sponsoring research and transfer technologies could be of the greatest importance in improving energy efficiency in countries with centrally planned economies, including the Soviet Union, as well as in developing countries. Favourable conditions for achieving both economic development and environmental protection can be created through cooperation on the international level. (author). 24 refs, 4 tabs

  3. Obsolete or resurgent? The International Energy Agency in a changing global landscape

    International Nuclear Information System (INIS)

    Van de Graaf, Thijs

    2012-01-01

    Founded in response to the 1973 oil shock, the International Energy Agency (IEA) is arguably still the most important multilateral organization for energy-importing countries. Yet, the global geopolitical landscape has changed considerably since the IEA's creation. The rise of new energy consumers, new energy-related challenges and new international energy forums prompt a rethink of the agency's current role and institutional design. This article seeks to contribute to the recent debate on the future role of the IEA by examining specific drivers, avenues and constraints for institutional reform. The method used is SWOT analysis, which allows to summarize the key factors emanating from an assessment of an organization's internal characteristics (strengths and weaknesses) and its external environment (opportunities and threats). Building on this SWOT analysis, the article formulates a strategy for the IEA to remain the focal point in global energy governance. Key elements of this strategy include: stronger engagement with new consumers, rapprochement with OPEC, becoming a leading voice in the energy transition, and changing the agency's internal governance practices. - Highlights: ► The IEA is challenged by the rise of new consumers, threats and organizations. ► Assessment of the agency’s internal characteristics and external environment. ► The IEA needs to step up its outreach policy and fully embrace sustainable energy.

  4. A deterministic method for estimating free energy genetic network landscapes with applications to cell commitment and reprogramming paths.

    Science.gov (United States)

    Olariu, Victor; Manesso, Erica; Peterson, Carsten

    2017-06-01

    Depicting developmental processes as movements in free energy genetic landscapes is an illustrative tool. However, exploring such landscapes to obtain quantitative or even qualitative predictions is hampered by the lack of free energy functions corresponding to the biochemical Michaelis-Menten or Hill rate equations for the dynamics. Being armed with energy landscapes defined by a network and its interactions would open up the possibility of swiftly identifying cell states and computing optimal paths, including those of cell reprogramming, thereby avoiding exhaustive trial-and-error simulations with rate equations for different parameter sets. It turns out that sigmoidal rate equations do have approximate free energy associations. With this replacement of rate equations, we develop a deterministic method for estimating the free energy surfaces of systems of interacting genes at different noise levels or temperatures. Once such free energy landscape estimates have been established, we adapt a shortest path algorithm to determine optimal routes in the landscapes. We explore the method on three circuits for haematopoiesis and embryonic stem cell development for commitment and reprogramming scenarios and illustrate how the method can be used to determine sequential steps for onsets of external factors, essential for efficient reprogramming.

  5. Comparison of Recent Oil and Gas, Wind Energy, and Other Anthropogenic Landscape Alteration Factors in Texas Through 2014.

    Science.gov (United States)

    Pierre, Jon Paul; Wolaver, Brad D; Labay, Benjamin J; LaDuc, Travis J; Duran, Charles M; Ryberg, Wade A; Hibbitts, Toby J; Andrews, John R

    2018-05-01

    Recent research assessed how hydrocarbon and wind energy expansion has altered the North American landscape. Less understood, however, is how this energy development compares to other anthropogenic land use changes. Texas leads U.S. hydrocarbon production and wind power generation and has a rapidly expanding population. Thus, for ~47% of Texas (~324,000 km 2 ), we mapped the 2014 footprint of energy activities (~665,000 oil and gas wells, ~5700 wind turbines, ~237,000 km oil and gas pipelines, and ~2000 km electrical transmission lines). We compared the footprint of energy development to non-energy-related activities (agriculture, roads, urbanization) and found direct landscape alteration from all factors affects ~23% of the study area (~76,000 km 2 ), led by agriculture (~16%; ~52,882 km 2 ). Oil and gas activities altered turbine pads and ~10 km 2 from power transmission lines. We found that edge effects of widely-distributed energy infrastructure caused more indirect landscape alteration than larger, more concentrated urbanization and agriculture. This study presents a novel technique to quantify and compare anthropogenic activities causing both direct and indirect landscape alteration. We illustrate this landscape-mapping framework in Texas for the Spot-tailed Earless Lizard (Holbrookia lacerata); however, the approach can be applied to a range of species in developing regions globally.

  6. Perspectives for a global energy supply

    International Nuclear Information System (INIS)

    Krafft, P.

    1987-01-01

    The economic development of the industrial world and the population explosion in the Third World will lead to a further increase in world energy consumption. Up to the year 2020 a doubling of today's consumption must be reckoned with. Further increases may be necessary in order to raise the per capita consumption of the population in the Third World. In order to meet this increasing demand it is necessary to consider all available energy sources. The nonrenewable energy sources oil, coal, gas and uranium will have to carry a greater proportion than the current 80 %. The resources suffice for that. However many obstacles must be surmounted in order to secure an essentially increasing energy production. Shortage symptoms with oil are to be expected within a foreseeable space of time. Only coal and nuclear energy can close the gap. In order to avert adverse effects on the climate, CO 2 emissions must be controlled. This can best be achieved by promoting water power, solar energy and nuclear energy as the principal sources. The postulates of the Swiss energy policy 'saving', 'substitution', 'research' and 'provision' seek to guarantee the energy supply. The promotion of hydro, solar and nuclear power must be added. The postulate of a withdrawal from nuclear energy is untenable considering its worldwide development. It would retard Switzerland in its pursuit of supply security and a better environment. 6 figs

  7. PEI's perspective on renewable energy development

    International Nuclear Information System (INIS)

    Brown, B.

    2005-01-01

    Approximately 7 per cent of Prince Edward Island's (PEI) energy supply is from renewable sources, acquired mainly from biomass. Wind power accounts for 0.5 per cent of electricity production. This paper discussed issues concerning renewable energy developments in PEI, with particular reference to the PEI Renewable Energy Act as well as the PEI energy framework and renewable energy strategy, which was the result of public consultation sessions held in 2003. The results of these sessions indicated that greater development of indigenous renewable energy resources was desired, particularly in wind power. It was also stated that the government should help to advance renewable energy development in the province. Several development opportunities were highlighted, including: wind; biodiesel; ethanol; biomass; bio-gas; and small-scale hydro. The advantages of wind power were reviewed and wind data was presented. The economic and community benefits of renewable energy include local price stability, development opportunities, diversity of fuel type and security of supply. It was noted that renewable energy fully complemented the energy goals of the PEI government. Several strategies were discussed towards the development of renewable energy, including feasibility studies in biogas and biomass generation. The PEI government's commitment towards developing a regulatory framework acknowledging environmental sustainability was re-stated. Objectives include the promotion of renewable energy sources through the establishment of a Renewable Portfolio Standard for electricity; improvements in the economics of small-scale electricity production from renewable resources through the introduction of net metering; decreases in peak demand; enablement of green credits; the designation of areas for large-scale wind developments; and provision of guaranteed prices paid to producers for medium and large-scale renewable energy generators through feed-in tariffs. tabs, figs

  8. Mediterranean energy perspectives - Turkey. Executive summary

    International Nuclear Information System (INIS)

    2014-09-01

    This in-depth study provides insight into Turkey's energy profile from the early 1960's to the present and an outlook to 2030. MEP-Turkey presents detailed analysis and data on the supply and demand balance for the major components of the energy sector with particular emphasis on sectoral analysis. It is based on OME's proprietary Mediterranean Energy Econometric Model for Turkey developed for this publication. The outlook to 2030 presents two possible pathways for energy demand based on different assumptions. The conservative scenario considers past trends, policies in force and on-going projects, but takes a cautious approach regarding the implementation and timing of policy measures and planned projects. The proactive scenario assumes effective achievements to lessen dependence on imported fuels by giving emphasis to production of domestic resources, stronger efficiency programmes and a more diversified energy supply mix including more renewable energy. To achieve ambitious energy efficiency levels and implement as much renewable energy sources as foreseen in the Proactive Scenario will require unwavering political will, strong policies and measures, as well as sizeable investments, especially by the private sector. Both scenarios, built from the same assumption for population, economic growth, and international fossil-fuel prices, are based on the premise that energy demand will be met. Turkey's future, stimulated by a booming economy and population, an export-oriented industry and a blossoming domestic market, looks bright. The energy needed to fuel this growth will depend greatly on the paths chosen. In this context, the country finds itself at a historical crossroads in its development, as the energy policy choices it makes today will shape Turkey's energy future and its ability to attract the considerable investments required in the energy industry

  9. Energy demand seen as an open perspective

    International Nuclear Information System (INIS)

    Scholz, L.

    1990-01-01

    In the course assessments of the potentials of conserving energy it has become clear that the major problems in such attempts do not come from the field of science or technology, but rather from the economy and the society. The chapter on prognostic assessment of energy demand therefore discusses the procedures in the Federal Republic of Germany and prognoses of energy demand and supply in their context, which is made up of ecological, economic, political and sociological factors. (DG) [de

  10. The Landscape of the Czech Middle Ages in the Perspective of Modern Science

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Robert

    2012-01-01

    Roč. 38, č. 1 (2012), s. 35-62 ISSN 0323-0988 R&D Projects: GA ČR(CZ) GBP410/12/G113 Institutional support: RVO:67985963 Keywords : historical landscape * Middle Ages * local names Subject RIV: AB - History

  11. Using a social-ecological systems perspective to understand tourism and landscape interactions in coastal areas

    NARCIS (Netherlands)

    Heslinga, Jasper; Groote, Peter D.; Vanclay, Francis

    2017-01-01

    Purpose The purpose of this paper is to look at the potential synergies between tourism and landscapes and examine the potential contribution of tourism to build social-ecological resilience in the Dutch Wadden. Design/methodology/approach The authors reveal how a social-ecological systems

  12. Can we manage tropical landscapes? – an answer from the Caribbean perspective.

    Science.gov (United States)

    Ariel E. Lugo

    2002-01-01

    Humans have used Caribbean island landscapes for millennia. The conversion of wild lands to built-up lands or to agricultural lands in these tropical countries follows predictable patterns. Conversion of moist forest life zones and fertile flatlands is faster than conversion of wet and rain forest life zones and low fertility steep lands. In Puerto Rico, these trends...

  13. Changes in canopy fuels and fire behavior after ponderosa pine restoration treatments: A landscape perspective

    Science.gov (United States)

    J. P. Roccaforte; P. Z. Fule

    2008-01-01

    (Please note, this is an abstract only) We modeled crown fire behavior and assessed changes in canopy fuels before and after the implementation of restoration treatments in a ponderosa pine landscape at Mt. Trumbull, Arizona. We measured 117 permanent plots before (1996/1997) and after (2003) thinning and burning treatments. The plots are evenly distributed across the...

  14. A Tale of Two Regions: Landscape Ecological Planning for Shale Gas Energy Futures

    Science.gov (United States)

    Murtha, T., Jr.; Schroth, O.; Orland, B.; Goldberg, L.; Mazurczyk, T.

    2015-12-01

    As we increasingly embrace deep shale gas deposits to meet global energy demands new and dispersed local and regional policy and planning challenges emerge. Even in regions with long histories of energy extraction, such as coal, shale gas and the infrastructure needed to produce the gas and transport it to market offers uniquely complex transformations in land use and landcover not previously experienced. These transformations are fast paced, dispersed and can overwhelm local and regional planning and regulatory processes. Coupled to these transformations is a structural confounding factor. While extraction and testing are carried out locally, regulation and decision-making is multilayered, often influenced by national and international factors. Using a geodesign framework, this paper applies a set of geospatial landscape ecological planning tools in two shale gas settings. First, we describe and detail a series of ongoing studies and tools that we have developed for communities in the Marcellus Shale region of the eastern United States, specifically the northern tier of Pennsylvania. Second, we apply a subset of these tools to potential gas development areas of the Fylde region in Lancashire, United Kingdom. For the past five years we have tested, applied and refined a set of place based and data driven geospatial models for forecasting, envisioning, analyzing and evaluating shale gas activities in northern Pennsylvania. These models are continuously compared to important landscape ecological planning challenges and priorities in the region, e.g. visual and cultural resource preservation. Adapting and applying these tools to a different landscape allow us to not only isolate and define important regulatory and policy exigencies in each specific setting, but also to develop and refine these models for broader application. As we continue to explore increasingly complex energy solutions globally, we need an equally complex comparative set of landscape ecological

  15. Energy Perspectives of Montenegro up to 2030

    International Nuclear Information System (INIS)

    Vujosevic, I.

    2008-01-01

    In this paper some key indicators of the actual state in the energy sector, as well as some results of the Strategy of Energy Development in Montenegro up to 2025 year with emphasis on the electricity sector, are presented. An approximate energy balance forecast in Montenegro up to 2030 is given. With an insight in the proper resource basis, the option of transfer part of Tara River's waters in Moraca River (HPP Kostanica) is especially tackled, which was, unfortunately, due to reasons of opportunism, left out from the adopted Energy Strategy.(author)

  16. Perspectives of nuclear energy peaceful uses. International conference

    International Nuclear Information System (INIS)

    Mahmud, K.; Adil, G.; Dinara, A.

    2010-11-01

    Full text : The scientists from following countries (Usa, Pakistan, Russia, Azerbaijan, Spain, Uzbekistan, Iran) took part at the International Conference devoted to Perspectives of Nuclear Energy Peaceful Uses. The activity was conducted in five sections : Section 1 was devoted to perspectives and statuses on nuclear energy; Section 2 was devoted to radiation impact on the environment : radioecology situation, radiation security, existing problems and their solutions; Section 3 was devoted to radiation materiology (radiation chemistry, radiation physics, radiation effects in solid states). Section 4 was devoted to existing problems of nuclear and radiation security in our Azerbaijan Republic. Section 5 was devoted to radioecology situation, its problems and the ways on their.

  17. Perspectives of nuclear energy peaceful uses. International conference

    International Nuclear Information System (INIS)

    Kerimov, Mahmud; Garibov, Adil

    2010-11-01

    Full text: The scientists from following countries (Usa, Pakistan, Russia, Azerbaijan, Spain, Uzbekistan, Iran) took part at the International Conference devoted to Perspectives of Nuclear Energy Peaceful Uses. The activity was conducted in five sections : Section 1 was devoted to perspectives and statuses on nuclear energy; Section 2 was devoted to radiation impact on the environment : radioecology situation, radiation security, existing problems and their solutions; Section 3 was devoted to radiation materiology (radiation chemistry, radiation physics, radiation effects in solid states). Section 4 was devoted to existing problems of nuclear and radiation security in our Azerbaijan Republic. Section 5 was devoted to radioecology situation, its problems and the ways of their solutions.

  18. Energy use in Norway: An international perspective

    Energy Technology Data Exchange (ETDEWEB)

    Unander, F.F.; Alm, L.K.; Schipper, L.

    1997-06-01

    The report examines the evolution of the structure and intensity of energy use in the main sectors of the Norwegian economy such as manufacturing, residential sector, services, and transport. The development in Norway is contrasted and compared to that in nine other countries such as Denmark, Sweden, Finland, Germany, U.K., France, Italy, United States, and Japan. The results show that Norway per capita energy use (excluding energy use in petroleum production) in 1992, after USA and Finland, was the highest of the 10 OECD countries being studied. Together with Finland, Norway showed the strongest growth in energy use per capita from 1973 to 1992. Some of the increased energy use in Norway can be attributed to more energy intensive structure and higher activity levels in the Norwegian economy. If the effect from changes in these two factors is excluded by holding the activity and structure in each sector constant at its 1973-level and only vary sub-sectorial energy intensities, Norway is still the country with the least reduction in energy intensities over the period from 1973 to 1992. Important underlying reasons in the same period are caused by increased indoor comfort level and the availability of both low-cost hydro power and biomass resources partly sheltering Norway from the impact of higher oil prices. 12 refs., 47 figs., 3 tabs.

  19. Bulgarian geothermal energy resources - state and perspective

    Energy Technology Data Exchange (ETDEWEB)

    Gramatikov, P S [Faculty of Natural Sciences and Mathematics, Dept. of Physical Engineering, South West Univ. ` Neofit Rilsky` , Blagoevgrad (Bulgaria)

    1997-12-01

    As special attention is paid to geothermal energy because the geothermal sources are distributed all over the territory of Bulgaria. Governmental incentives for initiating national action programs for energy efficiency, new renewable sources and the environment as well as educational activities are particularly important. The energy sector, as any other sector of the national economy, is currently undergoing considerable changes on its way to market relations, primarily connected to determining the role of the state as well as the form of ownership. The state energy policy is based on a long - term energy strategy complying with the natural conditions of the country, the expected macro - economic development, the geopolitical situation and regional development of energy cooperation with neighboring and closely situated countries. Limited reserves of fossil fuels, increased local and global environmental risks and recent technological achievements have straightened the global importance of renewable sources of thermal and electric energy. This is even more relevant for Bulgaria with small fossil fuel reserves (lignite) to be nearly exhausted and the environment notably polluted. Concerning local renewable sources of thermal energy and electricity, it is necessary to re-estimate their strategic role, to complete the input data for the resources, also to establish national programs supported by research and educational activities and international cooperation. (orig./AKF)

  20. Global warming from an energy perspective

    International Nuclear Information System (INIS)

    Edwards, A.G.

    1991-01-01

    Global climate change and energy are integrally related. The majority of greenhouse gas emissions are the result of energy production and use; at the same time, warming will affect energy patterns in California through physical increases in energy demand, physical changes in energy supply, and changes in both energy end-use patterns and supplies resulting from climate-change policies. There seems to be a growing political consensus that the world (as well as the state) needs to act soon to minimize further commitment to future warming. While California is not likely to experience the physical changes resulting from a warmer climate for years or perhaps decades, policy responses to the warming issue may cause more immediate impacts. This chapter will discuss how policy response to potential warming may be the most significant early impact of the issue on California's energy system. Makers of energy policy face the dilemma of deciding how to respond to the climate warming issue in the face of scientific uncertainties about its timing and seriousness. The chapter will conclude by presenting a conceptual framework for dealing with this dilemma, along with general recommendations for action

  1. Perspectives of China's wind energy development

    Institute of Scientific and Technical Information of China (English)

    He Dexin; Wang Zhongying

    2009-01-01

    Wind energy is a kind of clean renewable energy, which is also relatively mature in technology, with large-scale development conditions and prospect for the commercialization. The development of wind energy is a systematic project, involving policy, law, technology, economy, society, environment, education and other aspects. The relation-ship among all the aspects should be well treated and coordinated. This paper has discussed the following relationships which should be well coordinated: relationship between wind resources and wind energy development, relationship be-tween the wind turbine generator system and the components, relationship between wind energy technology and wind en-ergy industry, relationship between off-grid wind power and grid-connected wind power, relationship between wind farm and the power grid, relationship between onshore wind power and offshore wind power, relationship between wind energy and other energies, relationship between technology introduction and self-innovation, relationship among foreign-funded, joint ventured and domestic-funded enterprises and relationship between the government guidance and the market regula-tion, as well as giving out some suggestions.

  2. Restructuring the energy industry: A financial perspective

    International Nuclear Information System (INIS)

    Abrams, W.A.

    1995-01-01

    This paper present eight tables summarizing financial aspects of energy industry restructuring. Historical, current, and future business characteristics of energy industries are outlined. Projections of industry characteristics are listed for the next five years and for the 21st century. Future independent power procedures related to financial aspects are also outlined. 8 tabs

  3. Protein Folding Free Energy Landscape along the Committor - the Optimal Folding Coordinate.

    Science.gov (United States)

    Krivov, Sergei V

    2018-06-06

    Recent advances in simulation and experiment have led to dramatic increases in the quantity and complexity of produced data, which makes the development of automated analysis tools very important. A powerful approach to analyze dynamics contained in such data sets is to describe/approximate it by diffusion on a free energy landscape - free energy as a function of reaction coordinates (RC). For the description to be quantitatively accurate, RCs should be chosen in an optimal way. Recent theoretical results show that such an optimal RC exists; however, determining it for practical systems is a very difficult unsolved problem. Here we describe a solution to this problem. We describe an adaptive nonparametric approach to accurately determine the optimal RC (the committor) for an equilibrium trajectory of a realistic system. In contrast to alternative approaches, which require a functional form with many parameters to approximate an RC and thus extensive expertise with the system, the suggested approach is nonparametric and can approximate any RC with high accuracy without system specific information. To avoid overfitting for a realistically sampled system, the approach performs RC optimization in an adaptive manner by focusing optimization on less optimized spatiotemporal regions of the RC. The power of the approach is illustrated on a long equilibrium atomistic folding simulation of HP35 protein. We have determined the optimal folding RC - the committor, which was confirmed by passing a stringent committor validation test. It allowed us to determine a first quantitatively accurate protein folding free energy landscape. We have confirmed the recent theoretical results that diffusion on such a free energy profile can be used to compute exactly the equilibrium flux, the mean first passage times, and the mean transition path times between any two points on the profile. We have shown that the mean squared displacement along the optimal RC grows linear with time as for

  4. The US textile industry: An energy perspective

    Energy Technology Data Exchange (ETDEWEB)

    Badin, J. S.; Lowitt, H. E.

    1988-01-01

    This report investigates the state of the US textile industry in terms of energy consumption and conservation. Specific objectives were: To update and verify energy and materials consumption data at the various process levels in 1984; to determine the potential energy savings attainable with current (1984), state-of-the-art, and future production practices and technologies (2010); and to identify new areas of research and development opportunity that will enable these potential future savings to be achieved. Results of this study concluded that in the year 2010, there is a potential to save between 34% and 53% of the energy used in current production practices, dependent on the projected technology mix. RandD needs and opportunities were identified for the industry in three categories: process modification, basic research, and improved housekeeping practices that reduce energy consumption. Potential RandD candidates for DOE involvement with the private sector were assessed and selected from the identified list.

  5. Illustrating perspectives of energy and mobility

    Energy Technology Data Exchange (ETDEWEB)

    Guel, T.; Turton, H.

    2009-06-15

    This report issued by the Energy Economics Group and the Laboratory for Energy Systems Analysis at the Paul Scherrer Institute (PSI) analyses current and future trends in the area of energy and mobility on a global, European level as well as with respect to the German-speaking countries Austria, Germany and Switzerland. In a first step, developments with regard to how mobility is achieved and the energy consumption involved are examined and the impact of business-as-usual trends on global carbon dioxide (CO{sub 2}) emissions and future fuel consumption is discussed. In a second step, the paper outlines potential alternative futures in terms of energy and mobility. Finally, the paper derives and presents recommendations for policy-makers.

  6. Illustrating perspectives of energy and mobility

    International Nuclear Information System (INIS)

    Guel, T.; Turton, H.

    2009-06-01

    This report issued by the Energy Economics Group and the Laboratory for Energy Systems Analysis at the Paul Scherrer Institute (PSI) analyses current and future trends in the area of energy and mobility on a global, European level as well as with respect to the German-speaking countries Austria, Germany and Switzerland. In a first step, developments with regard to how mobility is achieved and the energy consumption involved are examined and the impact of business-as-usual trends on global carbon dioxide (CO 2 ) emissions and future fuel consumption is discussed. In a second step, the paper outlines potential alternative futures in terms of energy and mobility. Finally, the paper derives and presents recommendations for policy-makers.

  7. A cavitation transition in the energy landscape of simple cohesive liquids and glasses

    International Nuclear Information System (INIS)

    Altabet, Y. Elia; Debenedetti, Pablo G.; Stillinger, Frank H.

    2016-01-01

    In particle systems with cohesive interactions, the pressure-density relationship of the mechanically stable inherent structures sampled along a liquid isotherm (i.e., the equation of state of an energy landscape) will display a minimum at the Sastry density ρ S . The tensile limit at ρ S is due to cavitation that occurs upon energy minimization, and previous characterizations of this behavior suggested that ρ S is a spinodal-like limit that separates all homogeneous and fractured inherent structures. Here, we revisit the phenomenology of Sastry behavior and find that it is subject to considerable finite-size effects, and the development of the inherent structure equation of state with system size is consistent with the finite-size rounding of an athermal phase transition. What appears to be a continuous spinodal-like point at finite system sizes becomes discontinuous in the thermodynamic limit, indicating behavior akin to a phase transition. We also study cavitation in glassy packings subjected to athermal expansion. Many individual expansion trajectories averaged together produce a smooth equation of state, which we find also exhibits features of finite-size rounding, and the examples studied in this work give rise to a larger limiting tension than for the corresponding landscape equation of state.

  8. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    Science.gov (United States)

    Nguyen, Duc; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Girolami, Gregory S.; Lyding, Joseph; Gruebele, Martin

    2014-11-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB2 glass surface, two-state hopping of 1-2 nm diameter cooperatively rearranging regions or "clusters" occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how "mixed" features can show up in surface dynamics of glasses.

  9. Energy perspectives 2035 - Volume 1, synthesis

    International Nuclear Information System (INIS)

    2007-01-01

    This comprehensive report published by the Swiss Federal Office of Energy (SFOE) presents a synthesis of the results of a study that examined four scenarios concerning future developments in Swiss energy supply policy. The four scenarios include the variants entitled 'business as usual', 'increased co-operation', 'new priorities' and 'on the way to a 2000-Watt society'. The four scenarios are presented in detail in a separate paper. Here, for each scenario, policy options, energy demand, electricity offerings and CO 2 emissions are noted. The scenarios are compared with each other and evaluated with respect to energy efficiency and energy demand. Examples are quoted and developments in demand are examined. Their sensitivities with respect to Gross Domestic Product (GDP), climate change and their costs are discussed. Renewable sources of energy for power, heating and motor fuels are discussed and non-renewable sources of energy such as nuclear power, gas-fired power stations, combined heat and power installations and district heating systems are examined. Electricity supply and possible shortages are discussed, as are environmental pollution and nuclear wastes. Finally, a dynamic balance model and effects on consumption, trade, employment and welfare are discussed and challenges placed concerning security of supply, environmental protection, the economy, society, politics and legislation are examined

  10. Perspectives in energy requirements of mankind

    International Nuclear Information System (INIS)

    Symonds, J.L.

    1975-08-01

    The growth of energy demand from the nineteenth century to the present and its likely future development are described, for the interested layman, in the context of the changing pattern of resource use. The availability and distribution of the renewable and non-renewable resources of energy, which will provide for the future, show that developed and developing countries will incur supply problems in the decades ahead unless the potential of all energy reserves is tapped. Factors such as the market penetration of new resources and the depletion of resources are outlined. It is pointed out that coal may be used increasingly for some time but that nuclear energy is the only other energy form which is immediately available and which can be utilised commercially. Nuclear energy will be needed even if countries are prepared to cut back to low growth rates in energy use. It is suggested that lower growth rates may well be necessary in the next twenty to thirty years, since it takes this time to bring new alternative technologies into commercial use, and a further similar period will be required to achieve significant resource substitution. (author)

  11. Ten Perspectives on Nordic Energy. Final report for the first phase of the Nordic Energy Perspectives project

    International Nuclear Information System (INIS)

    Ryden, Bo

    2006-09-01

    Nordic Energy Perspectives is an interdisciplinary energy research project which, from a holistic perspective, analyses and creates new insights into the consequences for energy markets and energy systems of the goals and instruments of energy policy in the light of new conditions. The project's aim is to provide better bases for decisions on energy and environmental policy at both national and international levels. It is intended to contribute to constructive dialogue between researchers, politicians, authorities and actors on the energy markets. A first phase of the project has been carried out during Apr 2005 - Sep 2006. This report summarises the most important results. Around fifteen current research issues have been analysed. Some of these issues have been analysed in detail, while others have been studied more generally. This means that we can present a comprehensive flora of results in a number of areas, whereas in regard to other questions the analysis is less deep and the conclusions are not as firmly grounded. We have nonetheless chosen to present the entire range of results in this final report. An objective of Nordic Energy Perspectives has been to create a forum for fact-based discussion and dialogue between decision-makers and other energy actors from different disciplines and different countries. Today this forum is fully active. We are very eager that the forum should survive and that the discussion should continue concerning the themes treated by Nordic Energy Perspectives. Hence, for each of the chapters 1-17 below, we identify the researchers whom the reader can contact for further dialogue. The ten perspectives, which are based on contributions from the whole research group, have the following headlines: Costly early learnings from the first year of EU ETS: Unforeseen price levels hit industries hard; Market based support schemes - do they really work as intended; New decade in the Nordic energy markets; Reduced CO 2 emissions and more

  12. Co-designing energy landscapes: Application of participatory mapping and geographic information systems in the exploration of low carbon futures

    NARCIS (Netherlands)

    Stremke, S.; Picchi, Paolo

    2017-01-01

    The chapter begins with a literature review of energy potential mapping, ecosystem services (ES) assessment and participatory mapping (PM). PM is a key technique to conduct tradeoff analysis while co-designing sustainable energy landscapes (SEL) with local communities. Stakeholders, among others,

  13. Communication: Theoretical prediction of free-energy landscapes for complex self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, William M.; Reinhardt, Aleks; Frenkel, Daan [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2015-01-14

    We present a technique for calculating free-energy profiles for the nucleation of multicomponent structures that contain as many species as building blocks. We find that a key factor is the topology of the graph describing the connectivity of the target assembly. By considering the designed interactions separately from weaker, incidental interactions, our approach yields predictions for the equilibrium yield and nucleation barriers. These predictions are in good agreement with corresponding Monte Carlo simulations. We show that a few fundamental properties of the connectivity graph determine the most prominent features of the assembly thermodynamics. Surprisingly, we find that polydispersity in the strengths of the designed interactions stabilizes intermediate structures and can be used to sculpt the free-energy landscape for self-assembly. Finally, we demonstrate that weak incidental interactions can preclude assembly at equilibrium due to the combinatorial possibilities for incorrect association.

  14. The European Energy Policy: Building New Perspectives

    International Nuclear Information System (INIS)

    Maisonneuve, Cecile

    2014-04-01

    The origins of Europe's severe energy policy problems lie in a failed economic approach, which itself can be partly explained by political and ideological causes. This study seeks to address these political issues. Energy is not an exclusively economic issue, far from it. Since taxation and diplomacy are key aspects, energy is necessarily a political issue that policy-makers must handle. From this point of view, 2014 has to be seen as a political opportunity: it needs to be a year for re-founding a common policy fundamentally, based on two principles. First is the principle of realism, which implies re-situating energy policy in its international environment and putting the issue of costs back into the heart of political decision-making. The second principle is solidarity, in other words the clear restatement that there is a European general interest... which is not the sum of 28 national interests, but also that energy should be viewed as a system, and not as a collection of local policies and interests. Europe's common energy policy must retain its long term goal of ensuring the energy transition, but it must review the path to achieving this. This transition cannot be a technical, economic and geopolitical bet, which is presently the case. It has to be a controlled undertaking, implying governance and instruments. More generally, the transition requires a very different state of mind (Section III), compared to today's technocratic and non-cooperative approach (Section II), which has led to the prevailing state of energy chaos in Europe (Section I)

  15. China's energy consumption: A perspective from Divisia aggregation approach

    International Nuclear Information System (INIS)

    Liao, Hua; Wei, Yi-Ming

    2010-01-01

    China's total energy consumption, according to the official data, decreased impressively during 1997-1998 and increased sharply during 2003-2007, which in turn resulted in energy intensity fluctuation. Many literatures explained this ''unusual phenomenon'' from the perspectives of technical change, economic structure shifting and statistical data quality. They measured aggregate energy in thermal units by using linear summation approaches. In this paper, from the perspectives of heterogeneity and imperfect substitutability among diverse energy types, we further examine China's aggregate energy consumption by using Divisia (Sato-Vartia) approach. The results show that China's aggregate energy consumption and intensity fluctuated slightly less than values calculated by using conventional linear approaches, and the ''unusual phenomenon'' is partly explained. It also implies that China's energy intensity changes in 2006-2007 are slightly more optimistic than those officially reported, and the official communique of provincial energy intensity reduction achievements are partly bias. Some provincial achievement are underestimated or overestimated on some provinces. Our empirical results are also helpful to further research, such as energy-economic modeling, energy price elasticity, and elasticity of substitution among capital-labor-energy-material (KLEM). The difficulties or defects when using Divisia approach are also discussed in this paper. (author)

  16. Energy Efficiency Perspectives of PMR Networks

    Directory of Open Access Journals (Sweden)

    Marco Dolfi

    2016-12-01

    Full Text Available Recently, the concern about energy efficiency in wireless communications has been growing rapidly. Manufacturers and researchers have developed innovative solutions, highlighting the benefits in reducing operational expenditures (OPEX and carbon footprint. Professional Mobile Radio (PMR systems, like Terrestrial Trunked Radio (TETRA, have been designed to provide voice and data services to professional users. The energy consumption is one of the critical aspects of PMR broadband solutions and a major constraint for PMR services. The future convergence of PMR to the LTE system introduces a new topic in the research discussion about the energy efficiency of wireless systems. This paper focuses on the feasibility of energy efficient solutions for current and potentially future PMR networks, by providing a mathematical formulation of power consumption in TETRA base stations and assessing possible business models and energy saving solutions for enhanced mission-critical operations. The energy efficiency evaluation has been performed by taking into account the traffic load of a deployed TETRA regional network: in the considered network scenario with 150 base stations, significant OPEX savings up to 70 thousand Euros per year of operation are achieved. Moreover, the proposed solutions allow for saving more than 1 ton of CO 2 per year.

  17. Socio-economic perspectives on shifting cultivation landscapes in Northern Laos

    DEFF Research Database (Denmark)

    Heinimann, Andreas; Hett, Cornelia; Hurni, Kaspar

    2013-01-01

    Despite the rapid agricultural transition that has occurred in the past decade, shifting cultivation remains a widespread agricultural practice in the northern uplands of Lao PDR. Little information is available on the basic socio-economic situation and respective possible patterns in shifting cu...... minorities, pointing to multi-dimensional marginality of these areas. We discuss whether economic growth and increased market accessibility are sufficient to lift these landscapes out of poverty....

  18. Students Perceptions of Excellence in Landscape Architecture Studio Projects: A UNSW Perspective

    Directory of Open Access Journals (Sweden)

    Linda Corkery

    2004-06-01

    Full Text Available This paper describes an action-research project undertaken to explore teaching and learning in the design studio in the Faculty of the Built Environment (FBE, University of New South Wales, Sydney. The research project involved three undergraduate design programmes (architecture, interior architecture and landscape architecture within the FBE, however this paper will focus only on the findings related to the Bachelor of Landscape Architecture (BLArch programme. The studio is at the core of the design-based curriculum for the landscape architecture degree. This setting nurtures and encourages students to demonstrate a range of capabilities and attributes expected in professional practice. Design projects are complex, integrated assessment tasks. While design teachers use criteria to assess knowledge and skills, students often feel the judgement of overall design project excellence is based on subjective interpretation. There is also concern about the effectiveness of design teaching across the studios. Specifically, the study identified students' perceptions of what constitutes the mark of High Distinction (HD and characteristics of the ideal design teacher. This paper does not present a discourse analysis of the theoretical framework and concepts of the research project. That material is presented in previous and subsequent publications (Corkery et al, 2003.

  19. Energy technology perspectives - scenarios and strategies to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-03

    At their 2005 summit in Gleneagles, G8 leaders confronted questions of energy security and supply and lowering of CO{sub 2} emissions and decided to act with resolve and urgency. They called upon the International Energy Agency to provide advice on scenarios and strategies for a clean and secure energy future. Energy Technology Perspectives is a response to the G8 request. This work demonstrates how energy technologies can make a difference in a series of global scenarios to 2050. It reviews in detail the status and prospects of key energy technologies in electricity generation, buildings, industry and transport. It assesses ways the world can enhance energy security and contain growth in CO{sub 2} emissions by using a portfolio of current and emerging technologies. Major strategic elements of a successful portfolio are energy efficiency, CO{sub 2} capture and storage, renewables and nuclear power. 110 figs., 4 annexes.

  20. Energy technology perspectives: scenarios and strategies to 2050 [Russian version

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    At their 2005 summit in Gleneagles, G8 leaders confronted questions of energy security and supply and lowering of CO{sub 2} emissions and decided to act with resolve and urgency. They called upon the International Energy Agency to provide advice on scenarios and strategies for a clean and secure energy future. Energy Technology Perspectives is a response to the G8 request. This work demonstrates how energy technologies can make a difference in a series of global scenarios to 2050. It reviews in detail the status and prospects of key energy technologies in electricity generation, buildings, industry and transport. It assesses ways the world can enhance energy security and contain growth in CO{sub 2} emissions by using a portfolio of current and emerging technologies. Major strategic elements of a successful portfolio are energy efficiency, CO{sub 2} capture and storage, renewables and nuclear power. 110 figs., 4 annexes.

  1. Energy [R]evolution 2008-a sustainable world energy perspective

    International Nuclear Information System (INIS)

    Krewitt, Wolfram; Teske, Sven; Simon, Sonja; Pregger, Thomas; Graus, Wina; Blomen, Eliane; Schmid, Stephan; Schaefer, Oliver

    2009-01-01

    The Energy [R]evolution 2008 scenario is an update of the Energy [R]evolution scenario published in 2007. It takes up recent trends in global socio-economic developments, and analyses to which extent they affect chances for achieving global climate protection targets. The main target is to reduce global CO 2 emissions to 10 Gt per year in 2050, thus limiting global average temperature increase to 2 deg. C and preventing dangerous anthropogenic interference with the climate system. A review of sector and region specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding energy supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The Energy [R]evolution scenario shows that renewable energy can provide more than half of the world's energy needs by 2050. Developing countries can virtually stabilise their CO 2 emissions, whilst at the same time increasing energy consumption through economic growth. OECD countries will be able to reduce their emissions by up to 80%.

  2. China's energy security: The perspective of energy users

    International Nuclear Information System (INIS)

    Bambawale, Malavika Jain; Sovacool, Benjamin K.

    2011-01-01

    The article explores the energy security concerns faced by China from the point of view of energy users working in government, university, civil society and business sectors. The authors first derive a set of seven hypotheses related to Chinese energy security drawn from a review of the recent academic literature. We then explain each of these seven hypotheses, relating to (1) security of energy supply, (2) geopolitics, (3) climate change, (4) decentralization, (5) energy efficiency, (6) research and innovation of new energy technologies, and (7) self sufficiency and trade. Lastly, the article tests these hypotheses through a survey distributed in English and Mandarin completed by 312 Chinese participants. The conclusion presents insights for policymakers and energy scholars.

  3. Renewable Energy Systems: Technology Overview and Perspectives

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ionel, Dan M.; Yang, Yongheng

    2017-01-01

    In this chapter, essential statistics demonstrating the increasing role of renewable energy generation are first discussed. A state-of-the-art review section covers the fundamentals of wind turbine and photovoltaic (PV) systems. Schematic diagrams illustrating the main components and system topol......, including PV and concentrating solar power; wave energy; fuel cells; and storage with batteries and hydrogen, respectively. Recommended further readings on topics of electric power engineering for renewable energy are included in the final section.......In this chapter, essential statistics demonstrating the increasing role of renewable energy generation are first discussed. A state-of-the-art review section covers the fundamentals of wind turbine and photovoltaic (PV) systems. Schematic diagrams illustrating the main components and system...... topologies are included. Also, the increasing role of power electronics is explained as an enabler for renewable energy integration and for future power systems and smart grids. Recent examples of research and development, including new devices and system installations for utility power plants...

  4. Nuclear energy outlook: a GE perspective

    International Nuclear Information System (INIS)

    Fuller, J.

    2006-01-01

    Full text: Full text: As one of the world's leading suppliers of power generation and energy delivery technologies, GE Energy provides comprehensive solutions for coal, oil, natural gas and nuclear energy; renewable resources such as wind, solar and biogas, along with other alternative fuels. With the ever increasing demand for energy and pressures to decrease greenhouse gas emissions, global trends indicate a move towards building more base line nuclear generation capacity. As a reliable, cost-competitive option for commercial power generation, nuclear energy also addresses many of the issues the world faces when it comes to the environment. Since developing nuclear reactor technology in the 1950s, GE's Boiling Water Reactor (BWR) technology accounts for more than 90 operating plants in the world today. Building on that success, GE's ABWR design is now the first and only Generation 111 nuclear reactor in operation today. This advanced reactor technology, coupled with current construction experience and a qualified global supply chain, make ESBWR, GE's Generation III+ reactor design, an attractive option for owners considering adding nuclear generation capacity. In pursuit of new technologies, GE has teamed with Silex to develop, commercialize and license third generation laser enrichment technology. By acquiring the exclusive rights to develop and commercialize this technology, GE is positioned to support the anticipated global demands for enriched uranium. At GE, we are continuing to develop imaginative ideas and investing in products that are cost effective, increase productivity, limit greenhouse gas emissions, and improve safety and security for our customers

  5. Perspectives on renewable energy and Village Power

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, A.R.

    1997-12-01

    The author provides a brief overview of the role the Department of Energy has been playing in the area of renewable energy sources and their applications at a village level. Energy demand is rising sharply, and shortages are becoming more acute. Developing countries will present a large demand, and market opportunity over the next 40 years. Environmental concerns are a factor in the choice for what sources to promote and develop. The author touches on the features of renewable sources which makes them attractive to DOE for some applications, and what the goals of the department are in supporting this technology. Examples of applications at the level of village power are presented for both the US and abroad.

  6. Rural energy - ODA`s perspective

    Energy Technology Data Exchange (ETDEWEB)

    Woolnough, D.

    1997-12-01

    The Overseas Development Administration has as a goal `to improve the quality of life of people in poorer countries by contributing to sustainable development and reducing poverty and suffering.` Rural energy fits into this goal as a means to an end. The emphasis is firmly on the service provided, with the aim being provision of basic needs as a part of rural development. ODA plays a role in this task on a number of fronts: research and development; support for NGO`s; aid in a bilateral or multilateral form. The view of ODA is that even rural energy projects must emphasize the service provided and must be economically sustainable. Within its sphere of influence, there is a clearly growing position for the employment of rural energy programs.

  7. Fusion--fission energy systems, some utility perspectives

    International Nuclear Information System (INIS)

    Huse, R.A.; Burger, J.M.; Lotker, M.

    1974-01-01

    Some of the issues that are important in assessing fusion-- fission energy systems from a utility perspective are discussed. A number of qualitative systems-oriented observations are given along with some economic quantification of the benefits from fusion--fission hybrids and their allowed capital cost. (U.S.)

  8. State of art and perspectives of using renewable energy sources

    International Nuclear Information System (INIS)

    Berkovskij, B.M.; Mikhalevich, A.A.

    1996-01-01

    State of art of renewable energy sources for the beginning of the nineties and perspectives up to 2020 are considered by the forecast of the European Commission. The program of the World Sun Summit up to 1996-2005 is presented

  9. Investigation of the Structures and Energy Landscapes of Thiocyanate-Water Clusters

    Directory of Open Access Journals (Sweden)

    Lewis C. Smeeton

    2017-03-01

    Full Text Available The Basin Hopping search method is used to find the global minima (GM and map the energy landscapes of thiocyanate-water clusters, (SCN−(H2On with 3–50 water molecules, with empirical potentials describing the ion-water and water-water interactions. (It should be noted that beyond n = 23, the lowest energy structures were only found in 1 out of 8 searches so they are unlikely to be the true GM but are indicative low energy structures. As for pure water clusters, the low energy isomers of thiocyanate-water clusters show a preponderance of fused water cubes and pentagonal prisms, with the weakly solvated thiocyanate ion lying on the surface, replacing two water molecules along an edge of a water polyhedron and with the sulfur atom in lower coordinated sites than nitrogen. However, by comparison with Density Functional Theory (DFT calculations, the empirical potential is found to overestimate the strength of the thiocyanate-water interaction, especially O–H⋯S, with low energy DFT structures having lower coordinate N and (especially S atoms than for the empirical potential. In the case of these finite ion-water clusters, the chaotropic (“disorder-making” thiocyanate ion weakens the water cluster structure but the water molecule arrangement is not significantly changed.

  10. Waste to energy the carbon perspective

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders; Astrup, Thomas Fruergaard

    2015-01-01

    Waste to energy plants are key treatment facilities for municipal solid waste in Europe. The technology provides efficient volume reduction, mass reduction and hygienisation of the waste. However, the technology is highly disputed in some countries. It is crucial to understand the role of waste...

  11. Primary energy: present status and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Thielheim, K O

    1982-01-01

    A survey of the base-load energy sources available to humans is presented, starting from the point of view that all energy used is ultimately derived from nuclear processes within the sun. Specific note is made of European energy options, noting the large dependence on imported oil. Detailed exploration of available nuclear fuel resources is carried out, with attention given to fission, fusion, and breeder reactor plants and to the state-of-the-art and technology for each. The problems of nuclear waste disposal are discussed, and long term burial in salt domes is outlined as a satisfactory method of containing the materials for acceptable periods of time. The CO/sub 2/ greenhouse effect hazards caused by increased usage of coal-derived fuels are considered and precautions to be taken on a global scale to ameliorate the warming effects are recommended. The limitations to hydropower are examined, as are those of tidal power. Solar cells are projected to be produced in GW quantities by the year 2000, while wind-derived electricity is predicted to provide a minimum of 5% of the world energy needs in the future.

  12. Perspective in high energy physics instrumentation

    International Nuclear Information System (INIS)

    Rossi, L.

    1995-10-01

    The discovery potential of the next generation of particle accelerators, and in particular of the large hadron collider (LHC), can only be fully exploited by very sophisticated particle detectors. The basics of detectors for momentum and energy measurement is here presented together with a recollection of recent developments which are relevant for use at high luminosity accelerators

  13. Directed Magnetic Particle Transport above Artificial Magnetic Domains Due to Dynamic Magnetic Potential Energy Landscape Transformation.

    Science.gov (United States)

    Holzinger, Dennis; Koch, Iris; Burgard, Stefan; Ehresmann, Arno

    2015-07-28

    An approach for a remotely controllable transport of magnetic micro- and/or nanoparticles above a topographically flat exchange-bias (EB) thin film system, magnetically patterned into parallel stripe domains, is presented where the particle manipulation is achieved by sub-mT external magnetic field pulses. Superparamagnetic core-shell particles are moved stepwise by the dynamic transformation of the particles' magnetic potential energy landscape due to the external magnetic field pulses without affecting the magnetic state of the thin film system. The magnetic particle velocity is adjustable in the range of 1-100 μm/s by the design of the substrate's magnetic field landscape (MFL), the particle-substrate distance, and the magnitude of the applied external magnetic field pulses. The agglomeration of magnetic particles is avoided by the intrinsic magnetostatic repulsion of particles due to the parallel alignment of the particles' magnetic moments perpendicular to the transport direction and parallel to the surface normal of the substrate during the particle motion. The transport mechanism is modeled by a quantitative theory based on the precise knowledge of the sample's MFL and the particle-substrate distance.

  14. Impacts on the environment and landscape of new energy productions on farm parcels and buildings, Final report

    International Nuclear Information System (INIS)

    Pointereau, Ph.; Bochu, J.L.; Couturier, Ch.; Coulon, F.; Arnal, A.; Giorgis, S.

    2009-01-01

    This study aims at identifying positive and negative impacts of new energy productions implemented in farms on the environment (water, soil, biodiversity, space occupancy) and on landscapes, and at proposing techniques and regulations to strengthen positive consequences and to limit possible problems created by these energy productions. The considered productions are: trees apart from forest (hedges and copses), new farm energetic crops (Miscanthus for example), solar equipment (photovoltaic mounted on buildings or on ground, solar hot water and solar dryers), biogas production equipment, hydraulic micro-plants. The authors addressed the following environmental impacts: water (in quantity and quality), soils (quality, erosion risks), biodiversity, space occupancy (with respect to other activities), and landscape

  15. An environmental perspective on Lithuania's energy options

    International Nuclear Information System (INIS)

    Banks, A.; Todd, J.

    1995-01-01

    The views of experts on Lithuania's energy options are reviewed. On the one hand, nuclear energy is seen as an island of stability in the power industry in the conditions of economic crisis, and some decision-makers believe that Lithuania cannot survive without nuclear. On the other hand, the Ignalina NPP is the largest Chernobyl-type RBMK plant within the former Soviet Union, posing a dangerous environmental hazard to the Baltic Sea region, and no upgrading seems to be capable of bringing the reactors up to the safety standards of today's Western reactors. Many experts believe that the only solution is to shut the reactors down as soon as possible. (P.A.) 33 refs

  16. A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity

    DEFF Research Database (Denmark)

    Stoy, Paul C.; Mauder, Matthias; Foken, Thomas

    2013-01-01

    approached 1. These results suggest that landscape-level heterogeneity in vegetation and topography cannot be ignored as a contributor to incomplete energy balance closure at the flux network level, although net radiation measurements, biological energy assimilation, unmeasured storage terms......The energy balance at most surface-atmosphere flux research sites remains unclosed. The mechanisms underlying the discrepancy between measured energy inputs and outputs across the global FLUXNET tower network are still under debate. Recent reviews have identified exchange processes and turbulent...... motions at large spatial and temporal scales in heterogeneous landscapes as the primary cause of the lack of energy balance closure at some intensively-researched sites, while unmeasured storage terms cannot be ruled out as a dominant contributor to the lack of energy balance closure at many other sites...

  17. Ocean thermal energy conversion: Perspective and status

    Science.gov (United States)

    Thomas, Anthony; Hillis, David L.

    The use of the thermal gradient between the warm surface waters and the deep cold waters of tropical oceans was first proposed by J. A. d'Arsonval in 1881 and tried unsuccessfully by George Claude in 1930. Interest in Ocean Thermal Energy Conversion (OTEC) and other renewable energy sources revived in the 1970s as a result of oil embargoes. At that time, the emphasis was on large floating plants miles from shore producing 250 to 400 MW for maintained grids. When the problems of such plants became better understood and the price of oil reversed its upward trend, the emphasis shifted to smaller (10 MW) shore based plants on tropical islands. Such plants would be especially attractive if they produce fresh water as a by-product. During the past 15 years, major progress has been made in converting OTEC unknowns into knowns. Mini-OTEC proved the closed cycle concept. Cost effective heat exchanger concepts were identified. An effective biofouling control technique was discovered. Aluminum was determined to be promising for OTEC heat exchangers. Heat transfer augmentation techniques were identified, which promised a reduction on heat exchanger size and cost. Fresh water was produced by an OTEC open cycle flash evaporator, using the heat energy in the seawater itself. The current R and D emphasis is on the design and construction of a test facility to demonstrate the technical feasibility of the open cycle process. The 10 MW shore-based, closed cycle plant can be built with today's technology; with the incorporation of a flash evaporator, it will produce fresh water as well as electrical power; both valuable commodities on many tropical islands. The open cycle process has unknowns that require solution before the technical feasibility can be demonstrated. The economic viability of either cycle depends on reducing the capital costs of OTEC plants and on future trends in the costs of conventional energy sources.

  18. Perspectives in high energy nuclear collisions

    International Nuclear Information System (INIS)

    Rafelski, J.

    1983-08-01

    This report gives an overview of some aspects of hadronic physics relevant for the conception of a research facility devoted to the study of high energy nuclear collisions. Several concepts to be studied in nuclear collisions are selected, with emphasis placed on the properties and nature of the quark-gluon plasma, the formation of the plasma state in the central region and its anticipated lifetime, and the observability, through strangeness content of this new form of nuclear matter. (orig.)

  19. Energy and environment: an intergovernmental perspective

    Energy Technology Data Exchange (ETDEWEB)

    Keenan, B.R. (ed.)

    1978-01-01

    The Ohio River Valley Assembly was convened for round table discussions of the development of the energy resources of the valley and the environmental impacts. The participation was limited to government officials and participants included representatives from local, state, and federal governments and from several regional organizations with particular responsibilities in the Ohio River Valley. The background papers, comments by legislators, speeches, and the final report of the Assembly are compiled. (JSR)

  20. Perspectives on future high energy physics

    International Nuclear Information System (INIS)

    Samios, N.P.

    1996-01-01

    The author states two general ways in which one must proceed in an attempt to forecast the future of high energy physics. The first is to utilize the state of knowledge in the field and thereby provide theoretical and experimental guidance on future directions. The second approach is technical, namely, how well can one do in going to higher energies with present techniques or new accelerator principles. He concludes that the future strategy is straightforward. The present accelerator facilities must be upgraded and run to produce exciting and forefront research. At the same time, the theoretical tools should be sharpened both extrapolating from lower energies (100 GeV) to high (multi TeV) and vice versa. The US should be involved in the LHC, both in the accelerator and experimental areas. There should be an extensive R and D program on accelerators for a multi-TeV capability, emphasizing e + e - and μ + μ - colliders. Finally, the international cooperative activities should be strengthened and maintained

  1. Perspectives on future high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Samios, N.P.

    1996-12-31

    The author states two general ways in which one must proceed in an attempt to forecast the future of high energy physics. The first is to utilize the state of knowledge in the field and thereby provide theoretical and experimental guidance on future directions. The second approach is technical, namely, how well can one do in going to higher energies with present techniques or new accelerator principles. He concludes that the future strategy is straightforward. The present accelerator facilities must be upgraded and run to produce exciting and forefront research. At the same time, the theoretical tools should be sharpened both extrapolating from lower energies (100 GeV) to high (multi TeV) and vice versa. The US should be involved in the LHC, both in the accelerator and experimental areas. There should be an extensive R and D program on accelerators for a multi-TeV capability, emphasizing e{sup +}e{sup {minus}} and {mu}{sup +}{mu}{sup {minus}} colliders. Finally, the international cooperative activities should be strengthened and maintained.

  2. Experimental perspectives in low energy lepton physics

    International Nuclear Information System (INIS)

    Fiorini, E.

    1986-01-01

    Low energy nuclear physics has been and is going to be an essential tool for the study of weak interaction and neutrino physics. The use of the atomic nucleus as a ''microlaboratory'' with well defined quantum numbers is undoubtedly going to yield important and sometimes perhaps unexpected results on the symmetry laws governing the subnuclear world. These searches are however very hard experimentally and the bottleneck on obtaining more stringent results only rarely depends on the need of large and expensive apparatuses as those used in high energy physics: more limiting are technical difficulties. The author believes therefore that a real break-through to overcome the present experimental limitations can only be obtained with totally new and sometime ''non canonical'' technical approaches. This paper is an admittedly incomplete discussion of some of them. The author considers separately searches for rare decays, detection of low energy neutrinos and measurements of the neutrino mass, even if some of these new techniques are common to more than one of these subjects

  3. A Community Landscape Model of Pro-Environmental Behavior: The Effects of Landscape and Community Interaction on Residential Energy Behaviors in Two Pennsylvania Towns

    Science.gov (United States)

    Mainzer, Stephen P.

    We are using more energy every year. Between 2001 and 2011, Pennsylvania residential electricity sales increased by two and a half times the number of new customers, accounting for almost one third of the state's total electricity consumption. Our ability to meet demand by acquiring new energy sources faces several challenges. Confusion surrounds the physical and economic accessibility of remaining fossil fuel sources. Immense land use requirements and subsequent environmental impacts challenge a total shift to renewable energy sources. The laws of thermodynamics limit the potential for new technology to efficiently convert raw energy to consumable sources. As a result, any rational strategy to meet future energy demands must involve conservation. Conservation is a pro-environmental behavior, an act intended to benefit the environment surrounding a person. I posit that a transdisciplinary model, the community landscape model of the pro-environmental behavior, unifies the conceptually analogous - yet disparate - fields of landscape, community, and behavior towards explaining residential energy conservation actions. Specifically, the study attempted to describe links between the physical environment, social environment, and conservation behaviors through a mixed-method framework. Two Pennsylvania townships - Spring and East Buffalo townships - were selected from an analysis of housing, electricity consumption, and land cover trends. Key informants from both townships informed the design of a survey instrument that captured the utility consumption, residential conservation actions, energy and environmental values, types and levels of community engagement, perceived barriers, and socio-demographic information from 107 randomly selected households. A mixed-method analysis produced evidence that place-based values and intention to participate in the community were significantly linked to lower utility consumption in households. People who cared deeply about their town

  4. Control over Structure and Function of Peptide Amphiphile Supramolecular Assemblies through Molecular Design and Energy Landscapes

    Science.gov (United States)

    Tantakitti, Faifan

    Supramolecular chemistry is a powerful tool to create a material of a defined structure with tunable properties. This strategy has led to catalytically active, bioactive, and environment-responsive materials, among others, that are valuable in applications ranging from sensor technology to energy and medicine. Supramolecular polymers formed by peptide amphiphiles (PAs) have been especially relevant in tissue regeneration due to their ability to form biocompatible structures and mimic many important signaling molecules in biology. These supramolecular polymers can form nanofibers that create networks which mimic natural extracellular matrices. PA materials have been shown to induce growth of blood vessels, bone, cartilage, and nervous tissue, among others. The work described in this thesis not only studied the relationship between molecular structure and functions of PA assemblies, but also uncovered a powerful link between the energy landscape of their supramolecular self-assembly and the ability of PA materials to interact with cells. In chapter 2, it is argued that fabricating fibrous nanostructures with defined mechanical properties and decoration with bioactive molecules is not sufficient to create a material that can effectively communicate with cells. By systemically placing the fibronectin-derived RGDS epitope at increasing distances from the surface of PA nanofibers through a linker of one to five glycine residues, integrin-mediated RGDS signaling was enhanced. The results suggested that the spatial presentation of an epitope on PA nanofibers strongly influences the bioactivity of the PA substrates. In further improving functionality of a PA-based scaffold to effectively direct cell growth and differentiation, chapter 3 explored the use of a cell microcarrier to compartmentalize and simultaneously tune insoluble and soluble signals in a single matrix. PA nanofibers were incorporated at the surface of the microcarrier in order to promote cell adhesion, while

  5. Honey Bee Survival and Pathogen Prevalence: From the Perspective of Landscape and Exposure to Pesticides

    Directory of Open Access Journals (Sweden)

    Mohamed Alburaki

    2018-06-01

    Full Text Available In order to study the in situ effects of the agricultural landscape and exposure to pesticides on honey bee health, sixteen honey bee colonies were placed in four different agricultural landscapes. Those landscapes were three agricultural areas with varying levels of agricultural intensity (AG areas and one non-agricultural area (NAG area. Colonies were monitored for different pathogen prevalence and pesticide residues over a period of one year. RT-qPCR was used to study the prevalence of seven different honey bee viruses as well as Nosema sp. in colonies located in different agricultural systems with various intensities of soybean, corn, sorghum, and cotton production. Populations of the parasitic mite Varroa destructor were also extensively monitored. Comprehensive MS-LC pesticide residue analyses were performed on samples of wax, honey, foragers, winter bees, dead bees, and crop flowers for each apiary and location. A significantly higher level of varroa loads were recorded in colonies of the AG areas, but this at least partly correlated with increased colony size and did not necessarily result from exposure to pesticides. Infections of two viruses (deformed wing virus genotype a (DWVa and acute bee paralysis virus (ABPV and Nosema sp. varied among the four studied locations. The urban location significantly elevated colony pathogen loads, while AG locations significantly benefited and increased the colony weight gain. Cotton and sorghum flowers contained high concentrations of insecticide including neonicotinoids, while soybean and corn had less pesticide residues. Several events of pesticide toxicity were recorded in the AG areas, and high concentrations of neonicotinoid insecticides were detected in dead bees.

  6. The Landscape of Cervante´s Don Quixote: Orteguians Perspectives

    Directory of Open Access Journals (Sweden)

    Ángel Pérez Martínez

    2013-12-01

    Full Text Available Perspectival theory, related to Don Quixote by the many references in the corpus of Ortega, enables further research about the importance of the landscape and the physical description in order to understand the work of Cervantes. Similarly, it should be mentioned its relation with the development of literary theory. Such investigations give an interesting point of view under the framework called travel genre and its tangential contact with Quijote. On the other hand, and because of the publication of Obras Completas by Ortega, we find ourselves with a new order of the writings from the philosopher and an appropriate index for research.

  7. Energy transition in transport sector from energy substitution perspective

    Science.gov (United States)

    Sun, Wangmin; Yang, Xiaoguang; Han, Song; Sun, Xiaoyang

    2017-10-01

    Power and heating generation sector and transport sector contribute a highest GHG emissions and even air pollutions. This paper seeks to investigate life cycle costs and emissions in both the power sector and transport sector, and evaluate the cost-emission efficient (costs for one unit GHG emissions) of the substitution between new energy vehicles and conventional gasoline based vehicles under two electricity mix scenarios. In power sector, wind power and PV power will be cost comparative in 2030 forecasted with learning curve method. With high subsidies, new energy cars could be comparative now, but it still has high costs to lower GHG emissions. When the government subsidy policy is reversible, the emission reduction cost for new energy vehicle consumer will be 900/ton. According to the sensitive analysis, the paper suggests that the government implement policies that allocate the cost to the whole life cycle of energy production and consumption related to transport sector energy transition and policies that are in favor of new energy vehicle consumers but not the new energy car producers.

  8. Golf-course and funnel energy landscapes: Protein folding concepts in martensites

    Science.gov (United States)

    Shankaraiah, N.

    2017-06-01

    We use protein folding energy landscape concepts such as golf course and funnel to study re-equilibration in athermal martensites under systematic temperature quench Monte Carlo simulations. On quenching below a transition temperature, the seeded high-symmetry parent-phase austenite that converts to the low-symmetry product-phase martensite, through autocatalytic twinning or elastic photocopying, has both rapid conversions and incubation delays in the temperature-time-transformation phase diagram. We find the rapid (incubation delays) conversions at low (high) temperatures arises from the presence of large (small) size of golf-course edge that has the funnel inside for negative energy states. In the incubating state, the strain structure factor enters into the Brillouin-zone golf course through searches for finite transitional pathways which close off at the transition temperature with Vogel-Fulcher divergences that are insensitive to Hamiltonian energy scales and log-normal distributions, as signatures of dominant entropy barriers. The crossing of the entropy barrier is identified through energy occupancy distributions, Monte Carlo acceptance fractions, heat emission, and internal work.

  9. Perspectives on High-Energy-Density Physics

    Science.gov (United States)

    Drake, R. Paul

    2008-11-01

    Much of 21st century plasma physics will involve work to produce, understand, control, and exploit very non-traditional plasmas. High-energy density (HED) plasmas are often examples, variously involving strong Coulomb interactions and few particles per Debeye sphere, dominant radiation effects, strongly relativistic effects, or strongly quantum-mechanical behavior. Indeed, these and other modern plasma systems often fall outside the early standard theoretical definitions of ``plasma''. This presentation will focus on two types of HED plasmas that exhibit non-traditional behavior. Our first example will be the plasmas produced by extremely strong shock waves. Shock waves are present across the entire realm of plasma densities, often in space or astrophysical contexts. HED shock waves (at pressures > 1 Mbar) enable studies in many areas, from equations of state to hydrodynamics to radiation hydrodynamics. We will specifically consider strongly radiative shocks, in which the radiative energy fluxes are comparable to the mechanical energy fluxes that drive the shocks. Modern HED facilities can produce such shocks, which are also present in dense, energetic, astrophysical systems such as supernovae. These shocks are also excellent targets for advanced simulations due to their range of spatial scales and complex radiation transport. Our second example will be relativistic plasmas. In general, these vary from plasmas containing relativistic particle beams, produced for some decades in the laboratory, to the relativistic thermal plasmas present for example in pulsar winds. Laboratory HED relativistic plasmas to date have been those produced by laser beams of irradiance ˜ 10^18 to 10^22 W/cm^2 or by accelerator-produced HED electron beams. These have applications ranging from generation of intense x-rays to production of proton beams for radiation therapy to acceleration of electrons. Here we will focus on electron acceleration, a spectacular recent success and a rare

  10. Development perspectives of nuclear energy in Morocco

    International Nuclear Information System (INIS)

    Mekki-Berrada, A.

    1987-01-01

    Morocco is on the way to developing and gaining access to advanced technologies which will allow it to take good advantage of its natural resources. Most of the fuels necessary for electricity production have to be imported. Nuclear energy appears a better alternative to imported oil or coal, mainly due to kWh price competitivness, great potential of uranium in phosphates and to the limitations placed on the coal option by harbour and transport infrastructure. The first nuclear power plant is planned to go into operation in the year 2000

  11. PELE:  Protein Energy Landscape Exploration. A Novel Monte Carlo Based Technique.

    Science.gov (United States)

    Borrelli, Kenneth W; Vitalis, Andreas; Alcantara, Raul; Guallar, Victor

    2005-11-01

    Combining protein structure prediction algorithms and Metropolis Monte Carlo techniques, we provide a novel method to explore all-atom energy landscapes. The core of the technique is based on a steered localized perturbation followed by side-chain sampling as well as minimization cycles. The algorithm and its application to ligand diffusion are presented here. Ligand exit pathways are successfully modeled for different systems containing ligands of various sizes:  carbon monoxide in myoglobin, camphor in cytochrome P450cam, and palmitic acid in the intestinal fatty-acid-binding protein. These initial applications reveal the potential of this new technique in mapping millisecond-time-scale processes. The computational cost associated with the exploration is significantly less than that of conventional MD simulations.

  12. Quantitative analysis of the publishing landscape in High-Energy Physics

    CERN Document Server

    Mele, S; Vigen, Jens; Yeomans, Joanne

    2006-01-01

    World-wide collaboration in high-energy physics (HEP) is a tradition which dates back several decades, with scientific publications mostly coauthored by scientists from different countries. This coauthorship phenomenon makes it difficult to identify precisely the "share" of each country in HEP scientific production. One year's worth of HEP scientific articles published in peer-reviewed journals is analysed and their authors are uniquely assigned to countries. This method allows the first correct estimation on a pro rata basis of the share of HEP scientific publishing among several countries and institutions. The results provide an interesting insight into the geographical collaborative patterns of the HEP community. The HEP publishing landscape is further analysed to provide information on the journals favoured by the HEP community and on the geographical variation of their author bases. These results provide quantitative input to the ongoing debate on the possible transition of HEP publishing to an Open Acce...

  13. Free Energy Landscape of the Dissolution of Gibbsite at High pH

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhizhang; Kerisit, Sebastien N.; Stack, Andrew G.; Rosso, Kevin M.

    2018-03-26

    The individual elementary reactions involved in the dissolution of a solid into solution remain mostly speculative due to a lack of suitable, direct experimental probes. In this regard, we have applied atomistic simulations to map the free energy landscape of the dissolution of gibbsite from a step edge, as a model of metal hydroxide dissolution. The overall reaction combines kink site formation and kink site propagation. Two individual reactions were found to be rate-limiting for kink site formation, that is, the displacement of Al from a step site to a ledge adatom site and its detachment from ledge/terrace adatom sites into the solution. As a result, a pool of mobile and labile Al adsorbed species, or adatoms, exists before the release of Al into solution. Because of the quasi-hexagonal symmetry of gibbsite, kink site propagation can occur in multiple directions. Overall, the simulation results will enable the development of microscopic mechanistic models of metal oxide dissolution.

  14. Perspective of nuclear energy and advanced reactors

    International Nuclear Information System (INIS)

    Lopez Jimenez, J.; Cobian, J.

    2007-01-01

    Future nuclear energy growth will be the result of the contributions of every single plant being constructed or projected at present as it is connected to the grid. As per IAEA, there exists presently 34 nuclear power plants under construction 81 with the necessary permits and funding and 223 proposed, which are plants seriously pursuing permits and financing. This means that in a few decades the number of nuclear power plants in operation will have doubled. This growth rate is characterised by the incorporation of new countries to the nuclear club and the gradually increasing importance of Asian countries. During this expansive phase, generation III and III+designs are or will be used. These designs incorporate the experience from operating plants, and introduce innovations on rationalization design efficiency and safety, with emphasis on passive safety features. In a posterior phase, generation IV designs, presently under development, will be employed. Generation IV consists of several types of reactors (fast reactors, very high temperature reactors, etc), which will improve further sustain ability, economy, safety and reliability concepts. The described situation seems to lead to a renaissance of the nuclear energy to levels hardly thinkable several years ago. (Author)

  15. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    International Nuclear Information System (INIS)

    Nguyen, Duc; Girolami, Gregory S.; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Lyding, Joseph; Gruebele, Martin

    2014-01-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB 2 glass surface, two-state hopping of 1–2 nm diameter cooperatively rearranging regions or “clusters” occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (<0.5 nm) imaging, scanning tunneling spectroscopy and voltage modulation, ruling out individual atoms, diffusing adsorbates, or pinned charges as the origin of the observed two-state hopping. Smaller clusters are more likely to hop, larger ones are more likely to be immobile. HfB 2 has a very high bulk glass transition temperature T g , and we observe no three-state hopping or sequential two-state hopping previously seen on lower T g glass surfaces. The electronic density of states of clusters does not change when they hop up or down, allowing us to calibrate an accurate relative z-axis scale. By directly measuring and histogramming single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how “mixed” features can show up in surface dynamics of glasses

  16. Energy policy in Italy and perspectives for 2010

    International Nuclear Information System (INIS)

    Janot-Giorgetti, M.; Lamquet, O.

    2000-08-01

    In Europe the energy sector is moving to a community policy oriented on the competition opening of the market (Internal Energy Market Program), by national initiatives of liberalization and privatization of the energy production and distribution and also the environmental policy. In this context the italian Government is moving towards a survey and regulation organism and aims today to implement measures allowing a correct and quality operating of the market. This document presents a state of the art of the italian market and the perspectives for 2010. It enhances also the innovative projects according the environmental policy. (A.L.B.)

  17. A survey of the neuroscience resource landscape: perspectives from the neuroscience information framework.

    Science.gov (United States)

    Cachat, Jonathan; Bandrowski, Anita; Grethe, Jeffery S; Gupta, Amarnath; Astakhov, Vadim; Imam, Fahim; Larson, Stephen D; Martone, Maryann E

    2012-01-01

    The number of available neuroscience resources (databases, tools, materials, and networks) available via the Web continues to expand, particularly in light of newly implemented data sharing policies required by funding agencies and journals. However, the nature of dense, multifaceted neuroscience data and the design of classic search engine systems make efficient, reliable, and relevant discovery of such resources a significant challenge. This challenge is especially pertinent for online databases, whose dynamic content is largely opaque to contemporary search engines. The Neuroscience Information Framework was initiated to address this problem of finding and utilizing neuroscience-relevant resources. Since its first production release in 2008, NIF has been surveying the resource landscape for the neurosciences, identifying relevant resources and working to make them easily discoverable by the neuroscience community. In this chapter, we provide a survey of the resource landscape for neuroscience: what types of resources are available, how many there are, what they contain, and most importantly, ways in which these resources can be utilized by the research community to advance neuroscience research. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Perspectives of nuclear energy in Lithuania

    International Nuclear Information System (INIS)

    Bieliauskas, V.; Marchenas, V.

    1998-01-01

    Description of present status of nuclear power in Lithuania and prospects for future are presented. Lithuania operate two reactors of RBMK-1500 type. Since regaining of independence in 1990 Lithuania made a great efforts in developing legal framework for nuclear power regulation and improving safety of both reactors at Ignalina NPP. The main ideas of the draft of a new energy strategy are summarized. As regards nuclear power development in Lithuania there are two scenarios in the draft strategy: operation of the plant till the end of its design lifetime and operation of the plant till the gap closure between fuel channel and graphite and non re channeling of the reactors. Comparison of the cost and implications to the country's economy of both scenarios is discussed

  19. Is Nuclear Energy Sustainable - A Comparative Perspective

    International Nuclear Information System (INIS)

    Hirschberg, S.

    2002-01-01

    The electric utility sector is of central importance for economic growth and social development. While numerous societal and economic benefits arise from electricity production, it can also have impacts which may not be fully and unanimously reconciled with the concept of sustainability. Moving the electricity sector towards sustainable development calls for the integration of environmental, social and economic aspects in the decision-making process. As an input to such a process, one needs to assess how the different options perform with respect to specific sustainability criteria. As a part of the ''Comprehensive Assessment of Energy Systems'', carried out by the Paul Scherrer Institute (PSI), the electricity and heat supply systems are examined in view of sustainability criteria and the associated indicators, thus allowing operationalization of the sustainability concept

  20. Renewable energies, development, and environment: discourses, realities, and perspectives

    International Nuclear Information System (INIS)

    2007-01-01

    After two contributions describing the context of renewable energies and their different objectives and roles in the North and in the South, a set of contributions discusses some controversies and generally accepted ideas about renewable energies: fossil energy appraisal and the greenhouse effect of presently used fuels, the issue of irregularity and climate hazards, photovoltaic energy as a development key for South countries, vulnerability of energy systems, renewable energies and energy market privatisation. The next set of contributions deals with different examples: renewable energies in Africa, electricity and high dams, small hydro developments in China, wind energy in Morocco, solar water-heaters in Tunisia, bio-energies and food security, second generation bio-fuels, biomass energy in Cambodia. Sheets are then proposed with a brief historical overview, a description of the state of the art, an indication of the installed power, of market shares, and a brief discussion of perspectives for the different renewable energy sources: large and small hydro, photovoltaic, thermodynamic solar, wind, geothermal, thermal solar, bio-fuels, biomass, and biogas

  1. Crossover to potential energy landscape dominated dynamics in a model glass-forming liquid

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Sastry, S.; Dyre, Jeppe

    2000-01-01

    An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence for the ......An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence...... for the long held view that below a crossover temperature, Tx, the liquid's dynamics can be separated into (i) vibrations around inherent structures and (ii) transitions between inherent structures [M. Goldstein, J. Chem. Phys. 51, 3728 (1969)], i.e., the dynamics become "dominated" by the potential energy...... landscape. In agreement with previous proposals, we find that Tx is within the vicinity of the mode-coupling critical temperature Tc. We further find that near Tx, transitions between inherent structures occur via cooperative, stringlike rearrangements of groups of particles moving distances substantially...

  2. Landscapes for Energy and Wildlife: Conservation Prioritization for Golden Eagles across Large Spatial Scales.

    Directory of Open Access Journals (Sweden)

    Jason D Tack

    Full Text Available Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development.

  3. Wind energy. Energy technologies in national, European and global perspective

    International Nuclear Information System (INIS)

    Hauge Madsen, P.; Bjerregaard, E.T.D.

    2002-01-01

    According to a recent study, global wind generating capacity increased by some 6800 MW in 2001, an annual growth of just over half the corresponding figure for 2000. 2001 was the third consecutive year in which new wind power capacity exceeded new nuclear power capacity, showing the maturity of wind power technology. Total installed wind power worldwide by the end of 2001 was close to 25.000 MW. Germany, Spain and Denmark are the main players, accounting for 56% of the world's capacity increase in 2001 and a total cumulative installed capacity of 14.750 MW, or 59% of the global total. The USA and India are also significant users of wind power; in 2001 the USA added 1700 MW of new installed capacity to become the world's second-largest market for wind power. The report Wind Force 10 outlines a scenario in which wind power provides 10% of the world's electricity by 2020, corresponding to a total installed capacity of 1200 GW. Risoe's System Analysis Department has looked at the possible future costs of electricity produced by wind turbines compared to conventional power. A learning curve analysis of historical data results in a progress ratio of 0,85. This means that for every doubling of the installed capacity, the cost of wind-generated electricity is reduced by 15%. Until recently the main driver for wind power has been a concern for greenhouse gases. Security of energy supply has now become an important issue, however, especially in Europe and the USA. Wind power plants can be erected at short notice and in a modular fashion that allows capacity to be added as required. The European Commission has supported wind power by sponsoring international research co-operation between institutes, universities and equipment manufacturers. The IEA supports worldwide co-operation, and has recently issued a report on the longterm R and D needs of wind energy. Denmark has, mainly financed by the Danish Energy Agency, taken part in the IEA's R and D Wind international co

  4. Wind energy. Energy technologies in national, European and global perspective

    Energy Technology Data Exchange (ETDEWEB)

    Hauge Madsen, P.; Bjerregaard, E.T.D. [Risoe National Lab., Wind Energy Dept., Roskilde (Denmark)

    2002-10-01

    According to a recent study, global wind generating capacity increased by some 6800 MW in 2001, an annual growth of just over half the corresponding figure for 2000. 2001 was the third consecutive year in which new wind power capacity exceeded new nuclear power capacity, showing the maturity of wind power technology. Total installed wind power worldwide by the end of 2001 was close to 25.000 MW. Germany, Spain and Denmark are the main players, accounting for 56% of the world's capacity increase in 2001 and a total cumulative installed capacity of 14.750 MW, or 59% of the global total. The USA and India are also significant users of wind power; in 2001 the USA added 1700 MW of new installed capacity to become the world's second-largest market for wind power. The report Wind Force 10 outlines a scenario in which wind power provides 10% of the world's electricity by 2020, corresponding to a total installed capacity of 1200 GW. Risoe's System Analysis Department has looked at the possible future costs of electricity produced by wind turbines compared to conventional power. A learning curve analysis of historical data results in a progress ratio of 0,85. This means that for every doubling of the installed capacity, the cost of wind-generated electricity is reduced by 15%. Until recently the main driver for wind power has been a concern for greenhouse gases. Security of energy supply has now become an important issue, however, especially in Europe and the USA. Wind power plants can be erected at short notice and in a modular fashion that allows capacity to be added as required. The European Commission has supported wind power by sponsoring international research co-operation between institutes, universities and equipment manufacturers. The IEA supports worldwide co-operation, and has recently issued a report on the longterm R and D needs of wind energy. Denmark has, mainly financed by the Danish Energy Agency, taken part in the IEA's R and D Wind

  5. Free-Energy Calculations. A Mathematical Perspective

    Science.gov (United States)

    Pohorille, Andrzej

    2015-01-01

    conductance, defined as the ratio of ionic current through the channel to applied voltage, can be calculated in MD simulations by way of applying an external electric field to the system and counting the number of ions that traverse the channel per unit time. If the current is small, a voltage significantly higher than the experimental one needs to be applied to collect sufficient statistics of ion crossing events. Then, the calculated conductance has to be extrapolated to the experimental voltage using procedures of unknown accuracy. Instead, we propose an alternative approach that applies if ion transport through channels can be described with sufficient accuracy by the one-dimensional diffusion equation in the potential given by the free energy profile and applied voltage. Then, it is possible to test the assumptions of the equation, recover the full voltage/current dependence, determine the reliability of the calculated conductance and reconstruct the underlying (equilibrium) free energy profile, all from MD simulations at a single voltage. We will present the underlying theory, model calculations that test this theory and simulations on ion conductance through a channel that has been extensively studied experimentally. To our knowledge this is the first case in which the complete, experimentally measured dependence of the current on applied voltage has been reconstructed from MD simulations.

  6. Nuclear energy and proliferation: A longer perspective

    International Nuclear Information System (INIS)

    Weinberg, A.M.

    1985-01-01

    Nuclear power has expanded slowly; and it is largely based on reactors that require no recycle. The original basis for concern about proliferation - that nuclear power would be used very widely and that it would be based on systems that required reprocessing - has been shaken. The present world nuclear energy system, which is small and based on no-recycle reactors, is relatively resistant to proliferation via diversion from power reactors. Though worry about proliferation can never be eliminated, the perceived connection between power and bombs can be slowly reduced. The proposal to link fuel take-back with waste disposal poses a dilemma for the ''nuclear environmental'' activists. This group objects to nuclear power because, in their view, reactor wastes threaten the environment, and because bombs and reactors are connected. Both objections are held, often passionately; it would be difficult to assess which takes primacy. This proposal further breaks the ''Nuclear Connection,'' but at the expense of adding a little to the volume of wastes the United States would have to dispose of. We are in effect saying that the loosening of the nuclear connection through the take-back scheme should take precedence over the tiny environmental burden incurred by the addition of a few percent to the total wastes the U.S. already must dispose of. It is hoped that the nuclear environmental community will recognize this trade-off, and will help create the atmosphere of public understanding necessary if fuel take-back is to be accepted in the United States

  7. Rapid landscape change in 6th century northern Jordan: interdisciplinary geoarchaeological perspectives

    Science.gov (United States)

    Lucke, Bernhard

    2016-04-01

    Landscapes of the ancient fertile crescent are considered affected by soil degradation as result of long-term farming since the Neolithic, and impressive ruins of antiquity led to assumptions that their abandonment must have been conntected with reduced agricultural productivity. In this context, a valley fill near the site of Abila of the Decapolis in northern Jordan was apparently deposited largely during the 6th century AD, and provides evidence for a rapid and intense landscape change during the Late Byzantine period. However, an interdisciplinary case study of land use, soil development, and sediments found that the valley fill cannot be connected with large-scale soil erosion in the vicinity of the site. On the one hand, this is indicated by the distribution of soil development and archaeological material as marker of past land use activity in the past, which suggests that the best soils were and still are used intensively. On the other hand, the sediments seem to point to the occurrence of climatic extremes such as heavy floods, the occurrence of soil creep after water saturation, but also a significant shift to aridity which may have triggered socio-economic changes of subsistence strategies from agriculture to pastoralism. The dates of sediments which are available so far indicate that the climatic change seemingly occurred rapidly within approximately 100 years during the late 6th and early 7th century AD, possibly connected with the "year without sun" or 'Mystery Veil' which the Byzantine historian Procopius described in the year 536 AD. Modern analogies of the Pinatubo eruption in 1991 let it seem possible that a volcanic event, perhaps the outbreak of the Ilopango volcano, was connected with these environmental turbulences. Such events cannot be understood by isolated studies: without a broad interdisciplinary framework, single archives are prone to misinterpretation, and our understanding of the environmental history of Abila is still very limited.

  8. Understanding energy technology developments from an innovation system perspective

    Energy Technology Data Exchange (ETDEWEB)

    Borup, M.; Nygaard Madsen, A. [Risoe National Lab., DTU, Systems Analysis Dept., Roskilde (Denmark); Gregersen, Birgitte [Aalborg Univ., Department of Business Studies (Denmark)

    2007-05-15

    With the increased market-orientation and privatisation of the energy area, the perspective of innovation is becoming more and more relevant for understanding the dynamics of change and technology development in the area. A better understanding of the systemic and complex processes of innovation is needed. This paper presents an innovation systems analysis of new and emerging energy technologies in Denmark. The study focuses on five technology areas: bio fuels, hydrogen technology, wind energy, solar cells and energy-efficient end-use technologies. The main result of the analysis is that the technology areas are quite diverse in a number of innovation-relevant issues like actor set-up, institutional structure, maturity, and connections between market and non-market aspects. The paper constitutes background for discussing the framework conditions for transition to sustainable energy technologies and strengths and weaknesses of the innovation systems. (au)

  9. Energy Development and Environmental NGOs: The Asian Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Lin

    1998-12-01

    This report compares and analyses the energy-sector activities of non-governmental organizations (NGOs) in Asia. The main focus is on energy development with an environmental orientation such as large hydroelectric power development, energy efficiency improvements, and new and renewable energy development. Specifically, it (1) analyses the motivations, aims, characteristics and means of operation of the NGOs in their involvement in projects related to energy and environment, (2) studies the process of NGOs involvement in decision-making and the extent to which processes are affected by the nature of operation and why, (3) reviews the relationships and means of interaction of NGOs with governmental agencies, international aid organizations and the private sector, (4) examines the influence of international NGOs on local and regional NGOs and the differences in their values and modes of operation, and finally (5) describes the implications of NGO contributions to the emergence of global civil society from an Asian perspective. 28 refs., 1 fig., 1 tab.

  10. Anomalous dimensionality dependence of diffusion in a rugged energy landscape: How pathological is one dimension?

    Science.gov (United States)

    Seki, Kazuhiko; Bagchi, Kaushik; Bagchi, Biman

    2016-05-01

    Diffusion in one dimensional rugged energy landscape (REL) is predicted to be pathologically different (from any higher dimension) with a much larger chance of encountering broken ergodicity [D. L. Stein and C. M. Newman, AIP Conf. Proc. 1479, 620 (2012)]. However, no quantitative study of this difference has been reported, despite the prevalence of multidimensional physical models in the literature (like a high dimensional funnel guiding protein folding/unfolding). Paradoxically, some theoretical studies of these phenomena still employ a one dimensional diffusion description for analytical tractability. We explore the dimensionality dependent diffusion on REL by carrying out an effective medium approximation based analytical calculations and compare them with the available computer simulation results. We find that at an intermediate level of ruggedness (assumed to have a Gaussian distribution), where diffusion is well-defined, the value of the effective diffusion coefficient depends on dimensionality and changes (increases) by several factors (˜5-10) in going from 1d to 2d. In contrast, the changes in subsequent transitions (like 2d to 3d and 3d to 4d and so on) are far more modest, of the order of 10-20% only. When ruggedness is given by random traps with an exponential distribution of barrier heights, the mean square displacement (MSD) is sub-diffusive (a well-known result), but the growth of MSD is described by different exponents in one and higher dimensions. The reason for such strong ruggedness induced retardation in the case of one dimensional REL is discussed. We also discuss the special limiting case of infinite dimension (d = ∞) where the effective medium approximation becomes exact and where theoretical results become simple. We discuss, for the first time, the role of spatial correlation in the landscape on diffusion of a random walker.

  11. The captains of energy systems dynamics from an energy perspective

    CERN Document Server

    Prantil, Vincent C

    2015-01-01

    In teaching an introduction to transport or systems dynamics modeling at the undergraduate level, it is possible to lose pedagogical traction in a sea of abstract mathematics. What the mathematical modeling of time-dependent system behavior offers is a venue in which students can be taught that physical analogies exist between what they likely perceive as distinct areas of study in the physical sciences. We introduce a storyline whose characters are superheroes that store and dissipate energy in dynamic systems. Introducing students to the overarching conservation laws helps develop the analog

  12. Tuning Surface Energy Landscapes in Metallic Quantum Films using Alkali Adsorbates

    Science.gov (United States)

    Khajetoorians, Alexander; Qin, Shengyong; Zhu, Wenguang; Eisele, Holger; Zhang, Zhenyu; Shih, Chih-Kang

    2008-03-01

    Quantum confinement shows a strong interplay with growth and kinetics in thin metal systems where the Fermi wavelength has a special relationship to the surface normal lattice constant. In the case of Pb/Si(111) systems, this relationship reveals an interesting thickness-dependent bilayer oscillation in the density of states and surface energy up to a phase. In this paper, we report on a novel effect: tuning of the energy landscape of a flat-top quantum Pb mesa using Cs adsorbates. Using STM/STS, we show that depositing Cs adsorbates on a thin Pb mesa promotes quantum stable Pb nanoislands on preferentially unstable thicknesses. Thickness-dependent nanoisland densities show a strong bilayer oscillation correlating with quantum stability. By modifying the Cs coverage on the mesa surface, we can tune the lateral size distribution of the nanoislands and the overall amplitude of the island density oscillation. Nanoisland formation is linked to a step decoration of Cs adatoms along the step edge of the nanoisland.

  13. Hybrid organic–inorganic inks flatten the energy landscape in colloidal quantum dot solids

    KAUST Repository

    Liu, Mengxia

    2016-11-14

    Bandtail states in disordered semiconductor materials result in losses in open-circuit voltage (Voc) and inhibit carrier transport in photovoltaics. For colloidal quantum dot (CQD) films that promise low-cost, large-area, air-stable photovoltaics, bandtails are determined by CQD synthetic polydispersity and inhomogeneous aggregation during the ligand-exchange process. Here we introduce a new method for the synthesis of solution-phase ligand-exchanged CQD inks that enable a flat energy landscape and an advantageously high packing density. In the solid state, these materials exhibit a sharper bandtail and reduced energy funnelling compared with the previous best CQD thin films for photovoltaics. Consequently, we demonstrate solar cells with higher Voc and more efficient charge injection into the electron acceptor, allowing the use of a closer-to-optimum bandgap to absorb more light. These enable the fabrication of CQD solar cells made via a solution-phase ligand exchange, with a certified power conversion efficiency of 11.28%. The devices are stable when stored in air, unencapsulated, for over 1,000 h.

  14. Strategies for the exploration of free energy landscapes: Unity in diversity and challenges ahead

    Directory of Open Access Journals (Sweden)

    Fabio Pietrucci

    2017-11-01

    Full Text Available Computer simulations play an important role in the study of transformation processes of condensed matter, including phase transitions, chemical reactions, and conformational changes of biomolecules. In principle, atomic trajectories, such as those generated using the molecular dynamics approach, contain detailed structural, thermodynamic, and kinetic information about activated processes. In practice, due to free energy barriers, there is often a wide gap between the time scale of the transformation and the time scale accessible with simulations. This review offers a practical guide to the ingenious methods aimed to accelerate the exploration and reconstruction of free energy landscapes of complex systems. The focus is on basic unifying concepts, successful strategies, and pitfalls, illustrated with examples of application to scientific problems from different disciplines. The current challenges in the field consist mainly in the cumbersome identification of optimal reaction coordinates and in the extensive recourse to expert human supervision and fine tuning of the algorithms. The full achievement of wide-spectrum formulations and easy reproducibility of results would constitute the breakthrough necessary to enter the era of routine use of enhanced sampling simulations.

  15. Hybrid organic–inorganic inks flatten the energy landscape in colloidal quantum dot solids

    KAUST Repository

    Liu, Mengxia; Voznyy, Oleksandr; Sabatini, Randy; Arquer, F.  Pelayo Garcí a de; Munir, Rahim; Balawi, Ahmed  Hesham; Lan, Xinzheng; Fan, Fengjia; Walters, Grant; Kirmani, Ahmad R.; Hoogland, Sjoerd; Laquai, Fré dé ric; Amassian, Aram; Sargent, Edward  H.

    2016-01-01

    Bandtail states in disordered semiconductor materials result in losses in open-circuit voltage (Voc) and inhibit carrier transport in photovoltaics. For colloidal quantum dot (CQD) films that promise low-cost, large-area, air-stable photovoltaics, bandtails are determined by CQD synthetic polydispersity and inhomogeneous aggregation during the ligand-exchange process. Here we introduce a new method for the synthesis of solution-phase ligand-exchanged CQD inks that enable a flat energy landscape and an advantageously high packing density. In the solid state, these materials exhibit a sharper bandtail and reduced energy funnelling compared with the previous best CQD thin films for photovoltaics. Consequently, we demonstrate solar cells with higher Voc and more efficient charge injection into the electron acceptor, allowing the use of a closer-to-optimum bandgap to absorb more light. These enable the fabrication of CQD solar cells made via a solution-phase ligand exchange, with a certified power conversion efficiency of 11.28%. The devices are stable when stored in air, unencapsulated, for over 1,000 h.

  16. A worldwide perspective on energy, environment and sustainable development

    International Nuclear Information System (INIS)

    Dincer, Ibrahim; Rosen, Marc A.

    1998-01-01

    from both current and future perspectives. Finally, several conclusions and recommendations are drawn which may be useful to energy scientists and engineers and policy makers. (Author)

  17. Can Slovakia to survive without nuclear energy? State and perspectives of nuclear energetics. Attitudes of public to nuclear energy

    International Nuclear Information System (INIS)

    Suchomel, J.; Murinova, S.

    2004-01-01

    In this presentation authors deals with the review of the state of nuclear energetics in the Slovak Republic. Perspectives of nuclear energy and renewable sources of energy as well as attitudes of public to nuclear energy are discussed

  18. Marine Renewable Energy in the Mediterranean Sea: Status and Perspectives

    Directory of Open Access Journals (Sweden)

    Takvor H. Soukissian

    2017-09-01

    Full Text Available In this work, an extended overview of the marine renewable energy in the Mediterranean Sea is provided as regards current status, potential problems, challenges, and perspectives of development. An integrated and holistic approach is necessary for the economic viability and sustainability of marine renewable energy projects; this approach comprises three different frameworks, not always aligned, i.e., geotechnical/engineering, socio-economic, and environmental/ecological frameworks. In this context, the geomorphological, climatological, socio-economic, and environmental/ecological particularities of the Mediterranean basin are discussed, as they constitute key issues of the spatial context in which marine renewable energy projects are to be implemented. General guidelines for the sustainable development of marine renewable energy in the Mediterranean are also provided.

  19. A Framework for Implementing and Valuing Biodiversity Offsets in Colombia: A Landscape Scale Perspective

    Directory of Open Access Journals (Sweden)

    Shirley Saenz

    2013-11-01

    Full Text Available Biodiversity offsets provide a mechanism for maintaining or enhancing environmental values in situations where development is sought, despite negative environmental impacts. They seek to ensure that unavoidable deleterious environmental impacts of development are balanced by environmental gains. When onsite impacts warrant the use of offsets there is often little attention paid to make sure that the location of offset sites provides the greatest conservation benefit, ensuring they are consistent with landscape level conservation goals. In most offset frameworks it is difficult for developers to proactively know the offset requirements they will need to implement. Here we propose a framework to address these needs. We propose a series of rules for selecting offset sites that meet the conservation needs of potentially impacted biological targets. We then discuss an accounting approach that seeks to support offset ratio determinations based on a structured and transparent approach. To demonstrate the approach, we present a framework developed in partnership with the Colombian Ministry of Environment and Sustainable Development to reform existing mitigation regulatory processes.

  20. From Food Producer to Landscape Preserver: A Swiss Perspective on the Future of the Balinese Subak

    Directory of Open Access Journals (Sweden)

    Rachel P. Lorenzen

    2013-10-01

    Full Text Available Abstract The future of Bali’s agriculture is at a cross-roads. Tourismand urbanisation are slowly but steadily dismemberingone of the cornerstones of Balinese culture, the subak andits distinct ways of sharing water, cultivating rice andbeautifying the landscape. A combined effort is requiredof farmers, the government and society to rethink andreappraise the value of agriculture for the Balinese peopleand the economy. Such a change of perception needs toconsider the question of adequate compensation for thework farmers do in the fields, grooming 1000 year oldrice terraces, and planting, irrigating, and celebrating rice.To place Bali in a global context, I examine Switzerland’sprotective agricultural policies, rural developmentplanning and community-led initiatives which may offersome unconventional but pragmatic solutions to turn thetables for Bali’s rice sector protecting the subak institution.At last, I envisage a future for the subak and its members, anactive and proud farming community, not only famous riceproducers and fair water sharers but also recognised andappraised for their services to society as cultural landscapepreservers.

  1. Early reproductive success of western bluebirds and ash-throated flycatchers: a landscape-contaminant perspective.

    Science.gov (United States)

    Fair, Jeanne M; Myers, Orrin B

    2002-01-01

    Eggshell quality, clutch size, sex ratio, and hatching success of western bluebirds (Sialia mexicana) and ash-throated flycatchers (Myiarchus cinerascens) were studied on a landscape-soil contaminant gradient at Los Alamos National Laboratory (LANL) in New Mexico from 1997 to 1999. A variety of contaminants (heavy metals, chemicals, insecticides, polychlorinated biphenyls (PCBs), organochlorines, and radioactive isotopes) range across different spatial scales and concentrations on LANL land. This study is an example of a monitoring program over a large area with varying degree of contamination that is used to highlight locations of concern for future research. There were two locations where the flycatcher had a lower hatching success. The bluebirds at Sandia wetland, a location of concern for PCBs. had a thinner eggshell thickness index (RATCLIFFE) and the eggs were smaller than at other locations. The flycatcher had thinner eggshells than bluebirds, which could add to sensitivity to exposure to contaminants. There was no variation in clutch size or sex ratio between locations or areas closer to contaminant release sites for both species. Percent females in the clutch ranged from 0 to 100% in the WEBL and from 33 to 67% for ATFL.

  2. The epigenetic landscape of age-related diseases: the geroscience perspective.

    Science.gov (United States)

    Gensous, Noémie; Bacalini, Maria Giulia; Pirazzini, Chiara; Marasco, Elena; Giuliani, Cristina; Ravaioli, Francesco; Mengozzi, Giacomo; Bertarelli, Claudia; Palmas, Maria Giustina; Franceschi, Claudio; Garagnani, Paolo

    2017-08-01

    In this review, we summarize current knowledge regarding the epigenetics of age-related diseases, focusing on those studies that have described DNA methylation landscape in cardio-vascular diseases, musculoskeletal function and frailty. We stress the importance of adopting the conceptual framework of "geroscience", which starts from the observation that advanced age is the major risk factor for several of these pathologies and aims at identifying the mechanistic links between aging and age-related diseases. DNA methylation undergoes a profound remodeling during aging, which includes global hypomethylation of the genome, hypermethylation at specific loci and an increase in inter-individual variation and in stochastic changes of DNA methylation values. These epigenetic modifications can be an important contributor to the development of age-related diseases, but our understanding on the complex relationship between the epigenetic signatures of aging and age-related disease is still poor. The most relevant results in this field come from the use of the so called "epigenetics clocks" in cohorts of subjects affected by age-related diseases. We report these studies in final section of this review.

  3. Shaping the professional landscape through research, advocacy and education - an Australian perspective.

    Science.gov (United States)

    Siemensma, Gemma; Ritchie, Ann; Lewis, Suzanne

    2017-06-01

    This article is the first in a new series in this regular feature. The intention of the series is to look at important global developments in health science libraries. Librarians will be invited to share with HILJ readers key initiatives in their country or region. These articles should serve as a road map, describing the key changes in the field and exploring factors driving these changes. We initiate this series with an article by three Australian librarians who use research findings to depict the evolving professional landscape in their country. The starting point of their analysis is a report completed in 2011 which looked into likely future workforce and education requirements for health library professionals. The authors trace the achievements since then, most notably in the areas of research, advocacy and education. Clearly, a great deal has been achieved leading to a greater return on investment. The authors maintain that the key to shaping the profession and enhancing the status of librarians is ongoing professional development. To this end, Australia is promoting a systematic, competency based health specialist certification. Finally, they identify trends impacting on health librarianship, such as the growing importance of research data management and consumer health literacy. JM. © 2017 Health Libraries Group.

  4. Probing the energy landscape of alanine dipeptide and decalanine using temperature as a tunable parameter in molecular dynamics

    International Nuclear Information System (INIS)

    Chatterjee, A; Bhattacharya, S

    2016-01-01

    We perform several molecular dynamics (MD) calculations of solvated alanine dipeptide and decalanine in vacuum with temperature as a tunable parameter and in the process, generate Markov state models (MSMs) at each temperature. An interesting observation that the kinetic rates appear to obey the Arrhenius rate law allows us to predict the dynamics of alanine dipeptide at 300 K at the microsecond timescales using the nanoseconds long high temperature calculations without actually performing MD simulations at 300 K. We conclude that the energy landscape of alanine dipeptide contains superbasins deeper than k B T and determine the energy barriers associated with the moves from the Arrhenius rate expression. Similar insights regarding the energy landscape associated with folding/unfolding pathways of a deca-alanine molecule are obtained using kinetic rates calculated at different temperatures. (paper)

  5. Natural resources and energy systems: a strategic perspective

    International Nuclear Information System (INIS)

    Lee, T.H.; Schmidt, E.; Anderer, J.

    1986-06-01

    Oil prices falls to below ten dollar a barrel. US synfuel program cancelled after billions of dollars are invested. Tennessee Valley Authority tries to sell unfinished nuclear plants to China. Completed nuclear plant stands idle in Austria. Canadians seek uses for excess power from Candu plants. A glut of cheap oil, a general excess of operating nuclear capacity, an ever growing number of mothballed or not quite completed non-operating nuclear plants. Today the formidable challenge is to use abundant energy sources in ways that support social and economic development and protect the environment. In this paper we seek to provide a strategic perspective on how to meet this challenge. Toward this end, we explore the misconceptions of the past that led to costly errors in energy planning. The issue here is to dispel the myth of resource depletion as the driving force for the shift from one energy source to another. To gain insight into the actual basis for energy substitution, we turn our attention to energy patterns, viewing these in retrospect and prospect. This review of energy development provides an opportunity to consider some of the environmental implications of the expanded use of energy resources. These findings are then drawn together in an attempt to highlight certain R and D options that we believe offer a sound basis for strategic energy management. (Author, shortened by G.Q.)

  6. Living and ageing in the technological landscapes of homes and public places - an international perspective

    DEFF Research Database (Denmark)

    Helle, Tina; Kottorp, Anders; Gudetti, Susanne

    upon the use of new, innovative assessments and intervention strategies to address ET use and public places, and understand how these can support evidence-based intervention planning in practice. Methods: The teaching methods will be interactive sessions based upon open-space methodology, using: (1...... and participation in public places for people with functional impairments, while little is still known of the cognitive aspects of accessibility. In order to access and use homes and public spaces (including health care services, crucial challenges are associated with technology, both everyday technology (e.g. cell...... places for the target group of his/her practice, (2) Reflect upon challenges in access/use of public places and ET from a multicultural perspective , (3) Know about current international research in occupational therapy in this area, and how this can be implemented into his/her practice, and (4) Reflect...

  7. Free energy landscape and multiple folding pathways of an H-type RNA pseudoknot.

    Directory of Open Access Journals (Sweden)

    Yunqiang Bian

    Full Text Available How RNA sequences fold to specific tertiary structures is one of the key problems for understanding their dynamics and functions. Here, we study the folding process of an H-type RNA pseudoknot by performing a large-scale all-atom MD simulation and bias-exchange metadynamics. The folding free energy landscapes are obtained and several folding intermediates are identified. It is suggested that the folding occurs via multiple mechanisms, including a step-wise mechanism starting either from the first helix or the second, and a cooperative mechanism with both helices forming simultaneously. Despite of the multiple mechanism nature, the ensemble folding kinetics estimated from a Markov state model is single-exponential. It is also found that the correlation between folding and binding of metal ions is significant, and the bound ions mediate long-range interactions in the intermediate structures. Non-native interactions are found to be dominant in the unfolded state and also present in some intermediates, possibly hinder the folding process of the RNA.

  8. Local embeddedness in community energy projects. A social entrepreneurship perspective

    Directory of Open Access Journals (Sweden)

    Mihaela Vancea

    2017-12-01

    Full Text Available An increasing number of community energy projects have emerged recently, reflecting diverse sociotechnical configurations in the energy sector. This article is based on an empirical study examining different types of community energy projects such as energy cooperatives, public service utilities and other entrepreneurially oriented initiatives across the European Union. Based on an in-depth analysis of three case studies, the article aims to introduce a social entrepreneurship perspective when discussing the relationship between local embeddedness and different forms of organisation and ownership in community energy. The results indicate that community energy projects can expand beyond the local scale without losing their collective and democratic form of functioning and ownership. Moreover, social movements can act as catalysts for this expansion beyond the local, in a quest for wider social transformation. Social entrepreneurship may provide a suitable analytical lens to avoid the ‘local trap’ when examining different forms of organisation and ownership in renewable energy, and further explore the question of scaling.

  9. Unique Perspectives on a Transforming Energy Economy: 2014 Annual Report (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    Gossett, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-03-01

    What makes JISEA unique? Unique perspectives. This brochure highlights the unique perspectives provided by the Joint Institute for Strategic Energy Analysis through JISEA's recent accomplishments and the people behind them.

  10. Energy in Italy: Problems and perspectives (1990-2020)

    International Nuclear Information System (INIS)

    Bassani, G.F.; Bianucci, M.; Carra, S.; Cifarelli, L.

    2009-01-01

    Given the importance and up-to-dateness of the subject, the Italian Physical Society-SIF has decided to reprint its White Book, Energy in Italy: problems and perspectives (1990-2020), as a special issue of Il Nuovo Cimento B. This issue is in honour of the late SIF President Giuseppe Franco Bassani, to recall his leading role in establishing a very active and authoritative Sif Energy Commission, bringing together a number of distinguished experts in the various fields. The Sif Energy Commission was able to produce this White Book, as a comprehensive study on the subject, in just one year time. It was successfully presented at the international meeting on Energy perspectives in Europe, jointly organized by the European Physical Society (Eps) and Sif. The meeting was held in Varenna, Italy, on 7-8 April 2008: it was the second of a series that eventually led to the creation in 2010 of a dedicated Eps Energy Group, budded from the existing Eps Technology Group. First printed in Italian, the White Book was than translated into English and widely circulated within the Eps. It can be downloaded in open access from the SIF web site (http://www.sif.it). In its present updated version, it is made available to the readers of Il Nuovo Cimento B. Last but not least, the White Book has inspired the so-called Energy at School set of booklets targeting Italian high-school teachers and pupils, that will shortly appear as addenda to the Sif journal Giornale di Fisica and will be freely distributed both in paper and electronic versions.

  11. Machine learning for the structure-energy-property landscapes of molecular crystals.

    Science.gov (United States)

    Musil, Félix; De, Sandip; Yang, Jack; Campbell, Joshua E; Day, Graeme M; Ceriotti, Michele

    2018-02-07

    Molecular crystals play an important role in several fields of science and technology. They frequently crystallize in different polymorphs with substantially different physical properties. To help guide the synthesis of candidate materials, atomic-scale modelling can be used to enumerate the stable polymorphs and to predict their properties, as well as to propose heuristic rules to rationalize the correlations between crystal structure and materials properties. Here we show how a recently-developed machine-learning (ML) framework can be used to achieve inexpensive and accurate predictions of the stability and properties of polymorphs, and a data-driven classification that is less biased and more flexible than typical heuristic rules. We discuss, as examples, the lattice energy and property landscapes of pentacene and two azapentacene isomers that are of interest as organic semiconductor materials. We show that we can estimate force field or DFT lattice energies with sub-kJ mol -1 accuracy, using only a few hundred reference configurations, and reduce by a factor of ten the computational effort needed to predict charge mobility in the crystal structures. The automatic structural classification of the polymorphs reveals a more detailed picture of molecular packing than that provided by conventional heuristics, and helps disentangle the role of hydrogen bonded and π-stacking interactions in determining molecular self-assembly. This observation demonstrates that ML is not just a black-box scheme to interpolate between reference calculations, but can also be used as a tool to gain intuitive insights into structure-property relations in molecular crystal engineering.

  12. Strong field-matching effects in superconducting YBa2Cu3O7-δ films with vortex energy landscapes engineered via masked ion irradiation

    Science.gov (United States)

    Swiecicki, I.; Ulysse, C.; Wolf, T.; Bernard, R.; Bergeal, N.; Briatico, J.; Faini, G.; Lesueur, J.; Villegas, Javier E.

    2012-06-01

    We have developed a masked ion irradiation technique to engineer the energy landscape for vortices in oxide superconductors. This approach associates the possibility to design the landscape geometry at the nanoscale with the unique capability to adjust the depth of the energy wells for vortices. This enabled us to unveil the key role of vortex channeling in modulating the amplitude of the field matching effects with the artificial energy landscape, and to make the latter govern flux dynamics over an unusually wide range of temperatures and applied fields for high-temperature superconducting films.

  13. Our Common Landscapes For The Future

    DEFF Research Database (Denmark)

    Brandt, Jesper

    2017-01-01

    Foreword for Marc Antrop and Veerle van Eetvelde: Landscape Perspectives – The Holistic Nature of Landscapes Our common landscapes for the future by Jesper Brandt The solution of the ecological crisis through a transformation towards sustainable development is the most urgent challenge in our time....... It is not just a question of CO2 and conversion toward renewable energy. The reestablishment and conscious development of our common landscapes at all spatial scales for the combined benefits of biodiversity, our cultural heritage and the preservation and development of ecosystem services will probably...... be the most comprehensive and necessary social task in the future, if a conversion towards a sustainable development shall succeed in due time. This is so because it will be necessary to ensure that the potential material wealth of modern society will be transformed into a good, fruitful and healthy life...

  14. Efficient Determination of Free Energy Landscapes in Multiple Dimensions from Biased Umbrella Sampling Simulations Using Linear Regression.

    Science.gov (United States)

    Meng, Yilin; Roux, Benoît

    2015-08-11

    The weighted histogram analysis method (WHAM) is a standard protocol for postprocessing the information from biased umbrella sampling simulations to construct the potential of mean force with respect to a set of order parameters. By virtue of the WHAM equations, the unbiased density of state is determined by satisfying a self-consistent condition through an iterative procedure. While the method works very effectively when the number of order parameters is small, its computational cost grows rapidly in higher dimension. Here, we present a simple and efficient alternative strategy, which avoids solving the self-consistent WHAM equations iteratively. An efficient multivariate linear regression framework is utilized to link the biased probability densities of individual umbrella windows and yield an unbiased global free energy landscape in the space of order parameters. It is demonstrated with practical examples that free energy landscapes that are comparable in accuracy to WHAM can be generated at a small fraction of the cost.

  15. Enhanced, targeted sampling of high-dimensional free-energy landscapes using variationally enhanced sampling, with an application to chignolin.

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-02-02

    The capabilities of molecular simulations have been greatly extended by a number of widely used enhanced sampling methods that facilitate escaping from metastable states and crossing large barriers. Despite these developments there are still many problems which remain out of reach for these methods which has led to a vigorous effort in this area. One of the most important problems that remains unsolved is sampling high-dimensional free-energy landscapes and systems that are not easily described by a small number of collective variables. In this work we demonstrate a new way to compute free-energy landscapes of high dimensionality based on the previously introduced variationally enhanced sampling, and we apply it to the miniprotein chignolin.

  16. Enhanced, targeted sampling of high-dimensional free-energy landscapes using variationally enhanced sampling, with an application to chignolin

    Science.gov (United States)

    Shaffer, Patrick; Valsson, Omar; Parrinello, Michele

    2016-01-01

    The capabilities of molecular simulations have been greatly extended by a number of widely used enhanced sampling methods that facilitate escaping from metastable states and crossing large barriers. Despite these developments there are still many problems which remain out of reach for these methods which has led to a vigorous effort in this area. One of the most important problems that remains unsolved is sampling high-dimensional free-energy landscapes and systems that are not easily described by a small number of collective variables. In this work we demonstrate a new way to compute free-energy landscapes of high dimensionality based on the previously introduced variationally enhanced sampling, and we apply it to the miniprotein chignolin. PMID:26787868

  17. Gentlest ascent dynamics for calculating first excited state and exploring energy landscape of Kohn-Sham density functionals.

    Science.gov (United States)

    Li, Chen; Lu, Jianfeng; Yang, Weitao

    2015-12-14

    We develop the gentlest ascent dynamics for Kohn-Sham density functional theory to search for the index-1 saddle points on the energy landscape of the Kohn-Sham density functionals. These stationary solutions correspond to excited states in the ground state functionals. As shown by various examples, the first excited states of many chemical systems are given by these index-1 saddle points. Our novel approach provides an alternative, more robust way to obtain these excited states, compared with the widely used ΔSCF approach. The method can be easily generalized to target higher index saddle points. Our results also reveal the physical interest and relevance of studying the Kohn-Sham energy landscape.

  18. The European market of the wind energy and its perspectives

    International Nuclear Information System (INIS)

    Heddebaud, D.

    2005-01-01

    This study presents a whole panorama of the wind energy market and its perspectives. It proposes an analysis of the strategical place of the main manufacturers and operators and presents the activities, the key data and the development strategies of 14 wind power market operators. It aims to answer the following questions: What are the new possibilities for the mature markets? What will be the impact of the offshore wind power? What is the future of the independent manufacturers and of the industrialists? (A.L.B.)

  19. Energy landscape, structure and rate effects on strength properties of alpha-helical proteins

    International Nuclear Information System (INIS)

    Bertaud, Jeremie; Hester, Joshua; Jimenez, Daniel D; Buehler, Markus J

    2010-01-01

    The strength of protein domains is crucial to identify the mechanical role of protein domains in biological processes such as mechanotransduction, tissue mechanics and tissue remodeling. Whereas the concept of strength has been widely investigated for engineered materials, the strength of fundamental protein material building blocks and how it depends on structural parameters such as the chemical bonding, the protein filament length and the timescale of observation or deformation velocity remains poorly understood. Here we report a systematic analysis of the influence of key parameters that define the energy landscape of the strength properties of alpha-helical protein domains, including energy barriers, unfolding and refolding distances, the locations of folded and unfolded states, as well as variations of the length and pulling velocity of alpha-helical protein filaments. The analysis is facilitated by the development of a double-well mesoscale potential formulation, utilized here to carry out a systematic numerical analysis of the behavior of alpha-helices. We compare the results against widely used protein strength models based on the Bell model, one of the simplest models used to characterize the strength of protein filaments. We find that, whereas Bell-type models are a reasonable approximation to describe the rupture of alpha-helical protein domains for a certain range of pulling speeds and values of energy barriers, the model ceases to hold for very large energy barriers and for very small pulling speeds, in agreement with earlier findings. We conclude with an application of our mesoscale model to investigate the effect of the length of alpha-helices on their mechanical strength. We find a weakening effect as the length of alpha-helical proteins increases, followed by an asymptotic regime in which the strength remains constant. We compare strand lengths found in biological proteins with the scaling law of strength versus alpha-helix filament length. The

  20. Present status and perspective of Japanese atomic energy industry

    International Nuclear Information System (INIS)

    Miura, Kenzo

    1990-01-01

    Already 35 years are going to elapse since atomic energy industry was founded in Japan, and the positive development has been carried out in the nuclear power generation mainly with light water reactors as the base energy, as the result, now both the result of electric power generation and the technology have reached the highest level in the world. These are due to the accumulation of efforts, the preponderant assignment of able men and the positive investment for the research and development of the atomic energy industry. However, since 1985, the slowdown of power reactor development, the practical use of new type power reactors such as fast breeder reactors and the establishment of nuclear fuel cycle such as uranium enrichment and fuel reprocessing have been the new situation to be dealt with. In order to properly and flexibly cope with such change of situation, the healthy development of the atomic energy industry so as to secure the market on a certain scale and develop the business with responsibility is indispensable. The outlay of electric power industry related to atomic energy, the development of atomic energy market and the sales of mining and manufacturing industries, the trend of research and development and personnel, and the perspective and subjects of hereafter are reported. (K.I.)

  1. Principles of landscape architecture

    NARCIS (Netherlands)

    Nijhuis, S.

    2013-01-01

    The Department of Urbanism at the Faculty of Architecture and Built Environment, TU Delft considers urbanism as a planning and design oriented activity towards urban and rural landscapes. It aims to enhance, restore or create landscapes from a perspective of sustainable development, so as to guide,

  2. Perspectives for nuclear energy; Perspectives pour l'energie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Baugnet, J.-M.; Abderrahim, H.A.; Dekeyser, J.; Meskens, G

    1998-09-01

    In Belgium, approximately 60 percent of the produced electricity is generated by nuclear power. At present, nuclear power production tends to stagnate in Europe and North America but is still growing in Asia. The document gives an overview of the present status and the future energy demand with emphasis on electric power. Different evaluation criteria including factors hindering and factors promoting the expansion of nuclear power as well as requirements of new nuclear power plants are discussed. The extension of the lifetime of existing facilities as well as fuel supply are taken into consideration. A comparative assesment of nuclear power with other energy sources is made. The report concludes with estimating the contribution and the role of nuclear power in future energy demand as well as with an overview of future reactors and research and development programmes.

  3. Statistical topography of fitness landscapes

    OpenAIRE

    Franke, Jasper

    2011-01-01

    Fitness landscapes are generalized energy landscapes that play an important conceptual role in evolutionary biology. These landscapes provide a relation between the genetic configuration of an organism and that organism’s adaptive properties. In this work, global topographical features of these fitness landscapes are investigated using theoretical models. The resulting predictions are compared to empirical landscapes. It is shown that these landscapes allow, at least with respe...

  4. Flexible and Stretchable Energy Storage: Recent Advances and Future Perspectives.

    Science.gov (United States)

    Liu, Wei; Song, Min-Sang; Kong, Biao; Cui, Yi

    2017-01-01

    Energy-storage technologies such as lithium-ion batteries and supercapacitors have become fundamental building blocks in modern society. Recently, the emerging direction toward the ever-growing market of flexible and wearable electronics has nourished progress in building multifunctional energy-storage systems that can be bent, folded, crumpled, and stretched while maintaining their electrochemical functions under deformation. Here, recent progress and well-developed strategies in research designed to accomplish flexible and stretchable lithium-ion batteries and supercapacitors are reviewed. The challenges of developing novel materials and configurations with tailored features, and in designing simple and large-scaled manufacturing methods that can be widely utilized are considered. Furthermore, the perspectives and opportunities for this emerging field of materials science and engineering are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Choices for A Brighter Future: Perspectives on Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    NREL

    1999-09-30

    The report discusses the perspectives on the evolving U.S. electricity future, the renewable electric technology portfolio, the regional outlook, and the opportunities to move forward. Renewables are at a critical juncture as the domestic electricity marketplace moves toward an era of increased choice and greater diversity. The cost and performance of these technologies have improved dramatically over the past decade, yet their market penetration has stalled as the power industry grapples with the implications of the emerging competitive marketplace. Renewable energy technologies already contribute to the global energy mix and are ready to make an even greater contribution in the future. However, the renewables industry faces critical market uncertainties, both domestically and internationally, as policy commitments to renewables at both the federal and state levels are being reshaped to match the emerging competitive marketplace. The energy decisions that we make, or fail to make, today will have long-lasting implications. We can act now to ensure that renewable energy will play a major role in meeting the challenges of the evolving energy future. We have the power to choose.

  6. Food, energy and the environment from a Swedish perspective

    International Nuclear Information System (INIS)

    Engstroem, Rebecka

    2006-10-01

    National sector responsibility legislation places specific obligations on Swedish sector authorities to handle environmental issues within their sector. Because of this responsibility, there is a need to map environmental impacts from sectors and to identify key problems and strategies to reduce impacts in each sector. Agriculture and energy are two sectors causing severe environmental impacts, and these are therefore interesting as case studies. Employing a systems perspective when exploring impacts and options for their reduction ensures that problems are not simply shifted in time or space or between problems, but are considered in a holistic manner. Using this perspective, indirect effects such as changes upstream or downstream of the production chain, as well as among consumers, can be considered when seeking strategies to reduce environmental impacts in a sector. A method to investigate environmental impacts from a sector was developed and tested in the cases of agriculture and energy (Papers I and II). The method was based on environmentally extended Input-Output Analysis (IOA) and Life Cycle Assessment (LCA). IOA-data from Swedish Environmental Accounts were used as the starting point for the inventory. Such data provide information on direct and indirect impacts from the sector. To capture those aspects not included in the Environmental Accounts, the Swedish Environmental Quality Objectives were subsequently used as a checklist, and information on the missing aspects was obtained from literature. For further processing of the data, characterisation and weighting methods from LCA methodology were used to identify hotspots, i.e. the most important problems. The results showed that biodiversity, greenhouse effect, eutrophication, use of non-renewable resources and toxicity were potential hotspots in the agriculture sector. In the energy sector, the hotspots were air quality, greenhouse effect, use of non-renewable resources and toxicity. Analysis of sector

  7. Perspective of long term demand and supply of energy and general inspection of energy policy

    International Nuclear Information System (INIS)

    1983-01-01

    Since the oil crisis, Japanese energy policy was promoted to get rid of the excess dependence on petroleum and to attain energy security, but energy situation largely changed during the past ten years, and it has become necessary to make general inspection on the long term demand and supply of energy and the energy policy. After the second oil crisis, the worldwide demand of petroleum decreased drastically due to the rapid price rise, and the base price of crude oil was lowered for the first time. It is necessary to positively endeavor to reduce energy cost with new idea. The points of the general inspection are the correspondence of the energy policy to the large structural change of energy, the most desirable system for attaining the optimum structure of energy demand and supply and the utilization of market mechanism as far as possible. This report is the results of discussion held eight times since April, 1983. The change of energy situation in Japan and abroad and the perspective, the new problems in energy countermeasures and the trend of response, the preferential and effective promotion of general energy countermeasures and so on are reported. This report shows the fundamental direction of energy countermeasures hereafter, and the concrete and special examination must be made on many remaining problems. (Kako, I.)

  8. The effect of tensile stress on the conformational free energy landscape of disulfide bonds.

    Directory of Open Access Journals (Sweden)

    Padmesh Anjukandi

    Full Text Available Disulfide bridges are no longer considered to merely stabilize protein structure, but are increasingly recognized to play a functional role in many regulatory biomolecular processes. Recent studies have uncovered that the redox activity of native disulfides depends on their C-C-S-S dihedrals, χ2 and χ'2. Moreover, the interplay of chemical reactivity and mechanical stress of disulfide switches has been recently elucidated using force-clamp spectroscopy and computer simulation. The χ2 and χ'2 angles have been found to change from conformations that are open to nucleophilic attack to sterically hindered, so-called closed states upon exerting tensile stress. In view of the growing evidence of the importance of C-C-S-S dihedrals in tuning the reactivity of disulfides, here we present a systematic study of the conformational diversity of disulfides as a function of tensile stress. With the help of force-clamp metadynamics simulations, we show that tensile stress brings about a large stabilization of the closed conformers, thereby giving rise to drastic changes in the conformational free energy landscape of disulfides. Statistical analysis shows that native TDi, DO and interchain Ig protein disulfides prefer open conformations, whereas the intrachain disulfide bridges in Ig proteins favor closed conformations. Correlating mechanical stress with the distance between the two a-carbons of the disulfide moiety reveals that the strain of intrachain Ig protein disulfides corresponds to a mechanical activation of about 100 pN. Such mechanical activation leads to a severalfold increase of the rate of the elementary redox S(N2 reaction step. All these findings constitute a step forward towards achieving a full understanding of functional disulfides.

  9. Landscape of Dolní Kounice from the perspective of the authors of the Franciscan (“Stabile”) Cadastre

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Petr

    2010-01-01

    Roč. 11, č. 2 (2010), s. 3-17 ISSN 0300-5402 Institutional research plan: CEZ:AV0Z30860518 Keywords : landscape * Franciscan Cadastre * land use changes Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://web.natur.cuni.cz/ksgrrsek/acta/2010/AUC_2010_45_Dvorak_Landscape_of_Dolni.pdf

  10. Perspectives on implementing energy efficiency in existing Swedish detached houses

    Energy Technology Data Exchange (ETDEWEB)

    Joelsson, Anna; Gustavsson, Leif [Ecotechnology, Department of Engineering, Physics and Mathematics, Mid Sweden University, SE-831 25 Oestersund (Sweden)

    2008-01-15

    In this study, we first analyse energy-efficiency measures in existing electrically heated houses in Sweden from a societal economic perspective. Measures to a house envelopes and to energy supply chains are evaluated through a system analysis approach and we include the external costs of climate change and the effect of different Swedish climatic zones. We find that in a typical house from the 1970s, conversion from electric heating is highly motivated since the mitigation cost of conversion is lower than the estimated external costs of emitted CO{sub 2}. Both conversions and house envelope measures are more motivated in the northern part of the country, where there is a higher heat demand. A successful implementation of changes requires them to be attractive for consumers to adopt. We therefore secondly analyse the economic conditions for Swedish house owners to implement societal economic cost-efficient measures. We include the economic influence of an investment subsidy for heating system conversion, an income tax deduction for changing windows, customer electricity tax, real estate tax and of the cost of purchased energy from different energy suppliers. Apart from the economics, several other factors affect a house owner's decision to change heating systems. We therefore thirdly analyse house owners' perceptions of different heating supply alternatives based on the results of two comprehensive questionnaires. These different perspectives are combined in a discussion whether the studied policy instruments encourage house owners to implement changes in accordance with the energy-efficiency goals of decision makers. We find that the investment subsidy could be useful to break the lock-in effect of resistance heaters, which house owners seemed to experience. The electricity tax makes heating systems in line with national goals more competitive and efficiency measures to the house envelope more profitable. The reduction of the electricity tax in the northern part

  11. Perspectives on implementing energy efficiency in existing Swedish detached houses

    International Nuclear Information System (INIS)

    Joelsson, Anna; Gustavsson, Leif

    2008-01-01

    In this study, we first analyse energy-efficiency measures in existing electrically heated houses in Sweden from a societal economic perspective. Measures to a house envelopes and to energy supply chains are evaluated through a system analysis approach and we include the external costs of climate change and the effect of different Swedish climatic zones. We find that in a typical house from the 1970s, conversion from electric heating is highly motivated since the mitigation cost of conversion is lower than the estimated external costs of emitted CO 2 . Both conversions and house envelope measures are more motivated in the northern part of the country, where there is a higher heat demand. A successful implementation of changes requires them to be attractive for consumers to adopt. We therefore secondly analyse the economic conditions for Swedish house owners to implement societal economic cost-efficient measures. We include the economic influence of an investment subsidy for heating system conversion, an income tax deduction for changing windows, customer electricity tax, real estate tax and of the cost of purchased energy from different energy suppliers. Apart from the economics, several other factors affect a house owner's decision to change heating systems. We therefore thirdly analyse house owners' perceptions of different heating supply alternatives based on the results of two comprehensive questionnaires. These different perspectives are combined in a discussion whether the studied policy instruments encourage house owners to implement changes in accordance with the energy-efficiency goals of decision makers. We find that the investment subsidy could be useful to break the lock-in effect of resistance heaters, which house owners seemed to experience. The electricity tax makes heating systems in line with national goals more competitive and efficiency measures to the house envelope more profitable. The reduction of the electricity tax in the northern part of

  12. Wind energy in China. Current scenario and future perspectives

    International Nuclear Information System (INIS)

    Changliang, Xia; Zhanfeng, Song

    2009-01-01

    Wind power in China registered a record level of expansion recently, and has doubled its total capacity every year since 2004. Many experts believe that China will be central to the future of the global wind energy market. Consequently, the growth pattern of wind power in China may be crucial to the further development of the global wind market. This paper firstly presented an overview of wind energy potential in China and reviewed the national wind power development course in detail. Based on the installed wind capacity in China over the past 18 years and the technical potential of wind energy resources, the growth pattern was modeled in this study for the purpose of prospect analysis, in order to obtain projections concerning the development potential. The future perspectives of wind energy development in China are predicted and analyzed. This study provides a comprehensive overview of the current status of wind power in China and some insights into the prospects of China's wind power market, which is emerging as a new superpower in the global wind industry. (author)

  13. From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction.

    Science.gov (United States)

    Akhter, Nasrin; Shehu, Amarda

    2018-01-19

    Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

  14. From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction

    Directory of Open Access Journals (Sweden)

    Nasrin Akhter

    2018-01-01

    Full Text Available Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

  15. Modeling long-term changes in forested landscapes and their relation to the Earth's energy balance

    Science.gov (United States)

    Shugart, H. H.; Emanuel, W. R.; Solomon, A. M.

    1984-01-01

    The dynamics of the forested parts of the Earth's surface on time scales from decades to centuries are discussed. A set of computer models developed at Oak Ridge National Laboratory and elsewhere are applied as tools. These models simulate a landscape by duplicating the dynamics of growth, death and birth of each tree living on a 0.10 ha element of the landscape. This spatial unit is generally referred to as a gap in the case of the forest models. The models were tested against and applied to a diverse array of forests and appear to provide a reasonable representation for investigating forest-cover dynamics. Because of the climate linkage, one important test is the reconstruction of paleo-landscapes. Detailed reconstructions of changes in vegetation in response to changes in climate are crucial to understanding the association of the Earth's vegetation and climate and the response of the vegetation to climate change.

  16. Nuclear energy, fissile and renewable energies: which energy transition for tomorrow's France? History, assessment and perspectives

    International Nuclear Information System (INIS)

    Procaccia, Henri

    2014-01-01

    As the depletion of energy resources, their unequal use by a rich world on the one hand and developing countries on the other hand will be the key issues for a necessary energy transition, and as these issues come along the problem of climate change, the author more particularly discusses the French situation and perspectives. He discusses and compares the benefits, risks and drawbacks of nuclear energy (a rather clean energy in terms of greenhouse gas emission) with that of other energy sources. He also discusses and compares the possible scenarios of energy transition for France on a medium and on a long term. After some generalities on the military and civil use of nuclear energy (risks associated with nuclear energy, cost of nuclear energy), he proposes an overview of geopolitical aspects related to energy (relationship between demography and energy, actual and estimated energy sources). He describes the main elements of nuclear physics (atom structure, neutron reactions, thermonuclear fusion, radioactivity, exposure sources and regulation), and presents the various nuclear technologies (historical evolution, operation principles of nuclear power plants, nuclear technologies, PWR design and return on experience, EPR, the experimental ITER reactor). He recalls and comments the main nuclear accidents and their consequences (Three Mile Island, Chernobyl, Fukushima), addresses the issue of nuclear wastes (origin, processing and storage, packaging and management for the different types of wastes). Then, he addresses the climate issue and more particularly the greenhouse effect and its impact on climate. The next chapter proposes an overview of the world electricity production and consumption and of the production of renewable energies. The author compares the costs of the different technologies of electricity production, and then discusses the perspectives in terms of energy price, energy and electricity demand by different sectors

  17. Cuban Landscapes

    DEFF Research Database (Denmark)

    Scarpaci, Joseph L.; Portela, Armando

    This accessible book offers a vivid geographic portrait of Cuba, exploring the island’s streetscapes, sugar cane fields, beaches, and rural settlements; its billboards, government buildings, and national landmarks. The authors illuminate how natural and built landscapes have shaped Cuban identity...... (cubanidad), and vice versa. They provide a unique perspective on Cuba’s distinct historical periods and political economies, from the colonial period through republicanism and today’s socialist era. Compelling topics include the legacies of slavery and the sugar industry, the past and future of urban...

  18. Economics of nuclear energy in a sustainable development perspective

    International Nuclear Information System (INIS)

    Bertel, E.

    2006-01-01

    The paper is based on a recent OECD study on projected costs of generating electricity and other NEA studies on external costs including carbon emissions and global climate change risks. The overall objective of the analysis is to provide key elements for assessing nuclear energy in a sustainable development perspective, taking into account social and environmental aspects. Levelised lifetime costs of generating electricity are presented and compared for nuclear power plants and alternative generation technologies including gas-fired, coal-fired and wind power plants. The data presented refer to state-of-the-art power plants that could be commissioned by 2015 or earlier. Cost drivers and their variability from country to country and technology to technology are analysed. The paper also addresses external costs and benefits of nuclear energy as compared with those of alternative options. In particular, it provides insights regarding the impact of policy measures to reduce greenhouse gas emissions on the relative competitiveness of fossil-fuelled power plants and nearly carbon-free technologies (e.g., nuclear or wind). Other external costs such as social concerns, environmental impacts of residual emissions and contribution to security of energy supply are discussed

  19. Ocean thermal energy: concept and resources, history and perspectives

    International Nuclear Information System (INIS)

    Nihous, Gerard

    2015-10-01

    Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

  20. Energy perspectives 2035 - Volume 2, scenarios I to IV

    International Nuclear Information System (INIS)

    Kirchner, A.

    2007-01-01

    This comprehensive report published by the Swiss Federal Office of Energy (SFOE) takes a look at the four scenarios concerning future developments in Swiss energy supply policy. The four complex scenarios include variants entitled 'business as usual', 'increased co-operation', 'new priorities' and 'on the way to a 2000-Watt society'. These scenarios deal with the development of energy demand and electricity offerings in Switzerland for the period 1990 to 2035. They are reviewed in the light of various sensitivity factors. These sensitivity factors include a high GDP, oil prices of 50 US-dollars per barrel and a warmer climate. The report presents the results of the model calculations made. First of all, the report takes a look at the motivation and aims behind the work and discusses the modelling methods, system limits and conventions used and the possibilities offered by the perspectives as well as the limits encountered. The four scenarios are then presented and discussed in detail. Implementation variants in the private, services, industrial and traffic sectors are discussed and various electricity supply variants are presented, as are the associated environmental issues involved. The scenarios are compared with each other and pricing and security of supply issues are discussed. Finally, a short synopsis of the scenarios is presented and decision criteria are discussed as are implementation instruments. Ethical dilemmas and the risks involved are noted

  1. Securing the energy industry : perspectives in security risk management

    Energy Technology Data Exchange (ETDEWEB)

    Hurd, G.L. [Anadarko Canada Corp., Calgary, AB (Canada)

    2003-07-01

    This presentation offered some perspectives in security risk management as it relates to the energy sector. Since the events of September 11, 2001 much attention has been given to terrorism and the business is reviewing protection strategies. The paper made reference to each of the following vulnerabilities in the energy sector: information technology, globalization, business restructuring, interdependencies, political/regulatory change, and physical/human factors. The vulnerability of information technology is that it can be subject to cyber and virus attacks. Dangers of globalization lie in privacy and information security, forced nationalization, organized crime, and anti-globalization efforts. It was noted that the Y2K phenomenon provided valuable lessons regarding interdependencies and the effects of power outages, water availability, transportation disruption, common utility corridor accidents, and compounding incidents. The paper also noted the conflict between the government's desire to have a resilient infrastructure that can withstand and recover from attacks versus a company's ability to afford this capability. The physical/human factors that need to be considered in risk management include crime, domestic terrorism, and disasters such as natural disasters, industrial disasters and crisis. The energy industry has geographically dispersed vulnerable systems. It has done a fair job of physical security and has good emergency management practices, but it was noted that the industry cannot protect against all threats. A strategy of vigilance and awareness is needed to deal with threats. Other strategies include contingency planning, physical security, employee communication, and emergency response plans. tabs., figs.

  2. The inherent dynamics of a molecular liquid: Geodesic pathways through the potential energy landscape of a liquid of linear molecules

    Science.gov (United States)

    Jacobson, Daniel; Stratt, Richard M.

    2014-05-01

    Because the geodesic pathways that a liquid follows through its potential energy landscape govern its slow, diffusive motion, we suggest that these pathways are logical candidates for the title of a liquid's "inherent dynamics." Like their namesake "inherent structures," these objects are simply features of the system's potential energy surface and thus provide views of the system's structural evolution unobstructed by thermal kinetic energy. This paper shows how these geodesic pathways can be computed for a liquid of linear molecules, allowing us to see precisely how such molecular liquids mix rotational and translational degrees of freedom into their dynamics. The ratio of translational to rotational components of the geodesic path lengths, for example, is significantly larger than would be expected on equipartition grounds, with a value that scales with the molecular aspect ratio. These and other features of the geodesics are consistent with a picture in which molecular reorientation adiabatically follows translation—molecules largely thread their way through narrow channels available in the potential energy landscape.

  3. Colloids exposed to random potential energy landscapes: From particle number density to particle-potential and particle-particle interactions

    International Nuclear Information System (INIS)

    Bewerunge, Jörg; Capellmann, Ronja F.; Platten, Florian; Egelhaaf, Stefan U.; Sengupta, Ankush; Sengupta, Surajit

    2016-01-01

    Colloidal particles were exposed to a random potential energy landscape that has been created optically via a speckle pattern. The mean particle density as well as the potential roughness, i.e., the disorder strength, were varied. The local probability density of the particles as well as its main characteristics were determined. For the first time, the disorder-averaged pair density correlation function g (1) (r) and an analogue of the Edwards-Anderson order parameter g (2) (r), which quantifies the correlation of the mean local density among disorder realisations, were measured experimentally and shown to be consistent with replica liquid state theory results.

  4. Oil and Gas Development in Southwestern Wyoming - Energy Data and Services for the Wyoming Landscape Conservation Initiative (WLCI)

    Science.gov (United States)

    Biewick, Laura

    2009-01-01

    The purpose of this report is to explore current oil and gas energy development in the area encompassing the Wyoming Landscape Conservation Initiative. The Wyoming Landscape Conservation Initiative is a long-term science-based effort to ensure southwestern Wyoming's wildlife and habitat remain viable in areas facing development pressure. Wyoming encompasses some of the highest quality wildlife habitats in the Intermountain West. At the same time, this region is an important source of natural gas. Using Geographic Information System technology, energy data pertinent to the conservation decision-making process have been assembled to show historical oil and gas exploration and production in southwestern Wyoming. In addition to historical data, estimates of undiscovered oil and gas are included from the 2002 U.S. Geological Survey National Assessment of Oil and Gas in the Southwestern Wyoming Province. This report is meant to facilitate the integration of existing data with new knowledge and technologies to analyze energy resources development and to assist in habitat conservation planning. The well and assessment data can be accessed and shared among many different clients including, but not limited to, an online web-service for scientists and resource managers engaged in the Initiative.

  5. Energy Profile and Perspectives on Northeast Asian Energy Co-operation of North Korea

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    Energy policy of North Korea is basically based on the 'Principle of Self-reliance'. Throughout the active development of domestic energy sources, North Korea try to maximize the energy self-reliance as well as to minimize the outflow of currency for the import of energy. But, the 'Principle of Self-reliance' of energy sector brought about the excess dependency on coal and hydro, and eventually causes the contraction of oil and natural gas consumption. This kind of adverse reaction of the 'Principle of Self-reliance' is the major reason of overall weakness of national-wide economic system. It is not known actually what kinds of perspectives North Korea has on the Northeast Asian energy cooperation. But, it can be said that Northeast Asian energy cooperation can be the best chance for North Korea to solve current energy crisis and to transfer the economic system to capitalism for the recovery of national economy. 19 refs., 4 figs., 9 tabs.

  6. Exploring the energy landscape of biopolymers using single molecule force spectroscopy and molecular simulations

    OpenAIRE

    Hyeon, Changbong

    2010-01-01

    In recent years, single molecule force techniques have opened a new avenue to decipher the folding landscapes of biopolymers by allowing us to watch and manipulate the dynamics of individual proteins and nucleic acids. In single molecule force experiments, quantitative analyses of measurements employing sound theoretical models and molecular simulations play central role more than any other field. With a brief description of basic theories for force mechanics and molecular simulation techniqu...

  7. Analyzing high resolution topography for advancing the understanding of mass and energy transfer through landscapes: A review

    Science.gov (United States)

    Passaiacquaa, Paola; Belmont, Patrick; Staley, Dennis M.; Simley, Jeffery; Arrowsmith, J. Ramon; Bode, Collin A.; Crosby, Christopher; DeLong, Stephen; Glenn, Nancy; Kelly, Sara; Lague, Dimitri; Sangireddy, Harish; Schaffrath, Keelin; Tarboton, David; Wasklewicz, Thad; Wheaton, Joseph

    2015-01-01

    The study of mass and energy transfer across landscapes has recently evolved to comprehensive considerations acknowledging the role of biota and humans as geomorphic agents, as well as the importance of small-scale landscape features. A contributing and supporting factor to this evolution is the emergence over the last two decades of technologies able to acquire high resolution topography (HRT) (meter and sub-meter resolution) data. Landscape features can now be captured at an appropriately fine spatial resolution at which surface processes operate; this has revolutionized the way we study Earth-surface processes. The wealth of information contained in HRT also presents considerable challenges. For example, selection of the most appropriate type of HRT data for a given application is not trivial. No definitive approach exists for identifying and filtering erroneous or unwanted data, yet inappropriate filtering can create artifacts or eliminate/distort critical features. Estimates of errors and uncertainty are often poorly defined and typically fail to represent the spatial heterogeneity of the dataset, which may introduce bias or error for many analyses. For ease of use, gridded products are typically preferred rather than the more information-rich point cloud representations. Thus many users take advantage of only a fraction of the available data, which has furthermore been subjected to a series of operations often not known or investigated by the user. Lastly, standard HRT analysis work-flows are yet to be established for many popular HRT operations, which has contributed to the limited use of point cloud data.In this review, we identify key research questions relevant to the Earth-surface processes community within the theme of mass and energy transfer across landscapes and offer guidance on how to identify the most appropriate topographic data type for the analysis of interest. We describe the operations commonly performed from raw data to raster products and

  8. Fugitive methane emissions from natural, urban, agricultural, and energy-production landscapes of eastern Australia

    Science.gov (United States)

    Kelly, Bryce F. J.; Iverach, Charlotte P.; Lowry, Dave; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.

    2015-04-01

    Modern cavity ringdown spectroscopy systems (CRDS) enable the continuous measurement of methane concentration. This allows for improved quantification of greenhouse gas emissions associated with various natural and human landscapes. We present a subset of over 4000 km of continuous methane surveying along the east coast of Australia, made using a Picarro G2301 CRDS, deployed in a utility vehicle with an air inlet above the roof at 2.2 mAGL. Measurements were made every 5 seconds to a precision of cut coal mines, unconventional gas developments (coal seam gas; CSG), and leaks detected in cities and country towns. In areas of dryland crops the median methane concentration was 1.78 ppm, while in the irrigation districts located on vertisol soils the concentration was as low as 1.76 ppm, which may indicate that these soils are a sink for methane. In the Hunter Valley, New South Wales, open-cut coal mining district we mapped a continuous 50 km interval where the concentration of methane exceeded 1.80 ppm. The median concentration in this interval was 2.02 ppm. Peak readings were beyond the range of the reliable measurement (in excess of 3.00 ppm). This extended plume is an amalgamation of plumes from 17 major pits 1 to 10 km in length. Adjacent to CSG developments in the Surat Basin, southeast Queensland, only small anomalies were detected near the well-heads. Throughout the vast majority of the gas fields the concentration of methane was below 1.80 ppm. The largest source of fugitive methane associated with CSG was off-gassing methane from the co-produced water holding ponds. At one location the down wind plume had a cross section of approximately 1 km where the concentration of methane was above 1.80 ppm. The median concentration within this section was 1.82 ppm, with a peak reading of 2.11 ppm. The ambient air methane concentration was always higher in urban environments compared to the surrounding countryside. Along one major road in Sydney we mapped an interval

  9. The energy landscapes of repeat-containing proteins: topology, cooperativity, and the folding funnels of one-dimensional architectures.

    Directory of Open Access Journals (Sweden)

    Diego U Ferreiro

    2008-05-01

    Full Text Available Repeat-proteins are made up of near repetitions of 20- to 40-amino acid stretches. These polypeptides usually fold up into non-globular, elongated architectures that are stabilized by the interactions within each repeat and those between adjacent repeats, but that lack contacts between residues distant in sequence. The inherent symmetries both in primary sequence and three-dimensional structure are reflected in a folding landscape that may be analyzed as a quasi-one-dimensional problem. We present a general description of repeat-protein energy landscapes based on a formal Ising-like treatment of the elementary interaction energetics in and between foldons, whose collective ensemble are treated as spin variables. The overall folding properties of a complete "domain" (the stability and cooperativity of the repeating array can be derived from this microscopic description. The one-dimensional nature of the model implies there are simple relations for the experimental observables: folding free-energy (DeltaG(water and the cooperativity of denaturation (m-value, which do not ordinarily apply for globular proteins. We show how the parameters for the "coarse-grained" description in terms of foldon spin variables can be extracted from more detailed folding simulations on perfectly funneled landscapes. To illustrate the ideas, we present a case-study of a family of tetratricopeptide (TPR repeat proteins and quantitatively relate the results to the experimentally observed folding transitions. Based on the dramatic effect that single point mutations exert on the experimentally observed folding behavior, we speculate that natural repeat proteins are "poised" at particular ratios of inter- and intra-element interaction energetics that allow them to readily undergo structural transitions in physiologically relevant conditions, which may be intrinsically related to their biological functions.

  10. The greenGain project - Biomass from landscape conservation and maintenance work for renewable energy production in the EU

    Science.gov (United States)

    Clalüna, Aline; Baumgarten, Wibke; García Galindo, Daniel; Lenz, Klaus; Doležal, Jan; De Filippi, Federico; Lorenzo, Joaquín; Montagnoli, Louis

    2017-04-01

    The project greenGain is looking for solutions to increase the energy production with regional and local biomass from landscape conservation and maintenance work, which is performed in the public interest. The relevant resources analysed in the greenGain model regions are, among others, biomass residues from clearing invasive vegetation in marginal agricultural lands in Spain, and residues from abandoned vineyards and olive groves in landscape protected areas in Italy. The main target groups are regional and local players who are responsible for maintenance and conservation work and for the biomass residue management in their regions. Moreover, the focus will be on service providers - including farmers and forest owners, their associations, NGOs, energy providers and consumers. Local companies, municipalities and public authorities are collaborating to identify the still underutilised non-food biomass resources and to discuss the way to integrate them into the local and regional biomass markets. Since the start of the three year project in January 2015, the partners from Italy, Spain, Czech Republic and Germany analysed, among other, the biomass feedstock potential coming from landscape maintenance work, and assessed various technological options to utilise this type of biomass. Further, political, legal and environmental aspects as well as awareness raising and public acceptance actions regarding the energetic use of biomass from public areas were assessed. greenGain also facilitates the exchange between model regions and other similar relevant players in the EU and shares examples of good practice. General guidelines will be prepared to guarantee a wide dissemination to other regions in the EU. Thus, the project shows how to build-up reliable knowledge on local availability of this feedstock and provides know-how concerning planning, harvesting, pre-treatment, storage and sustainable conversion pathways to a wide range of stakeholders in the EU.

  11. Structure prediction of nanoclusters; a direct or a pre-screened search on the DFT energy landscape?

    Science.gov (United States)

    Farrow, M R; Chow, Y; Woodley, S M

    2014-10-21

    The atomic structure of inorganic nanoclusters obtained via a search for low lying minima on energy landscapes, or hypersurfaces, is reported for inorganic binary compounds: zinc oxide (ZnO)n, magnesium oxide (MgO)n, cadmium selenide (CdSe)n, and potassium fluoride (KF)n, where n = 1-12 formula units. The computational cost of each search is dominated by the effort to evaluate each sample point on the energy landscape and the number of required sample points. The effect of changing the balance between these two factors on the success of the search is investigated. The choice of sample points will also affect the number of required data points and therefore the efficiency of the search. Monte Carlo based global optimisation routines (evolutionary and stochastic quenching algorithms) within a new software package, viz. Knowledge Led Master Code (KLMC), are employed to search both directly and after pre-screening on the DFT energy landscape. Pre-screening includes structural relaxation to minimise a cheaper energy function - based on interatomic potentials - and is found to improve significantly the search efficiency, and typically reduces the number of DFT calculations required to locate the local minima by more than an order of magnitude. Although the choice of functional form is important, the approach is robust to small changes to the interatomic potential parameters. The computational cost of initial DFT calculations of each structure is reduced by employing Gaussian smearing to the electronic energy levels. Larger (KF)n nanoclusters are predicted to form cuboid cuts from the rock-salt phase, but also share many structural motifs with (MgO)n for smaller clusters. The transition from 2D rings to 3D (bubble, or fullerene-like) structures occur at a larger cluster size for (ZnO)n and (CdSe)n. Differences between the HOMO and LUMO energies, for all the compounds apart from KF, are in the visible region of the optical spectrum (2-3 eV); KF lies deep in the UV region

  12. Renewable energy development scheme of the Ardennes district. January 2010, Assessment 2010 and perspectives 2011, Assessment 2011 and perspectives 2012, Assessment 2012 and perspectives 2013, Assessment 2013 and perspectives 2014, Assessment 2014 and perspectives 2015, Key figures 2015, Key figures 2016

    International Nuclear Information System (INIS)

    Perissat, Frederic; N'Gahane, Pierre; Savy, Jean-Francois

    2010-01-01

    After a recall of France's commitments in the struggle against climate change and in the reduction of greenhouse gas emissions, this report first proposes a diagnosis of the Ardennes district territory in terms of potential development of renewable energies with respect to objectives defined on the short, medium and long terms. Thus, for each renewable energy (wind, hydroelectricity, solar, geothermal, biogas, solid biomass, energies used in transports), it proposes an analysis of the present potential while discussing technical constraints, environmental benefits and drawbacks (impacts on landscapes, on the natural environment, on heritage), economic benefits and drawbacks, and governance issues. Sheets are then proposed which give a synthetic presentation (action type, situation, objectives, actions to be undertaken, partners, time frame, result indicators) of actions and projects related to these different renewable energies. Appendices contain a methodological note, a presentation of the organisational approach. A synthetic version of the first part is proposed with a set of two-page documents, one document for each energy. Another set of documents gather annual publications which contain assessments and discussions of development perspectives for each renewable energy in the district

  13. A landscape ecological perspective on the regulation of N, P and organic matter in the Danish agri-environment

    DEFF Research Database (Denmark)

    Andersen, Erling; Vejre, Henrik; Dalgaard, Tommy

    ecological models. The study includes analyses of policy documents, action plans, legislation, guidelines and other implementation papers. We identify spatially targeted measures and underlying assumptions regarding the landscape and assess the landscape component of models used for policy design...... of the Danish approach to (non)targeting. Today there is a broad consensus among stakeholders and farmers on the need for spatially differentiation and the next generation of measures are likely to reflect this. This will target the mitigation efforts towards high load areas affecting vulnerable ecosystems...... regulation in Denmark. In the early plans of the 1980s focus was on simple measures such as improving manure storage facilities and handling with no or few links to landscapes. This changed with the introduction of fertilization plans (1987) and norm based fertilizer rules (1991). However, the measures were...

  14. 储能技术研究景观辨识及演化探析%Identifying the Landscape and Its Evolution in Energy Storage Research

    Institute of Scientific and Technical Information of China (English)

    刘娜; 孙静林; 毛荐其

    2017-01-01

    This study seeks to integrate statistics, text mining, burst detecting and co-occurrence network visualiza-tion to identify the landscape and its evolution of energy storage research from a holistic perspective based on ar-ticles on physical, chemical, electromagnetic and phase change energy storage extracted from SCI-E and SSCI data-base between 1991 and 2015. A stability coefficient and an innovation coefficient are also defined to measure the stability evolution and innovation evolution of keywords co-occurrence networks in energy storage respectively. Our results indicate that the research in energy storage is highly-concentrated in key issues, hot topics are fly-wheel, lithium ion batteries, supercapacitors and phase change materials, and frontier topics are compressed air energy storage, energy storage, lithium ion batteries, thermal conductivity and thermal energy storage. We also find keywords co-occurrence networks expand significantly, knowledge structures evolve constantly and energy storage research is still in its innovation phase.%基于SCI-E及SSCI数据库,检索并提取1991—2015年间物理储能、化学储能、电磁储能和相变储能4大技术领域的论文数据,试图整合统计分析、文本挖掘、突现检测算法和共现网络可视化方法,旨在从整体视角实现对4大储能技术领域科学研究景观的辨识及演化探析.此外,还定义了稳定系数和创新系数,以测度储能关键词共现网络的稳定性演化和创新性演化.研究发现:储能领域的研究问题是高度集中的,"飞轮"、"锂离子电池"、"超级电容器"和"相变材料"是研究热点,"压缩空气储能"、"能源存储"、"锂离子电池"、"导热性"和"热发电"是研究前沿;储能关键词共现网络扩张明显,知识结构也不断演化,储能研究仍处于创新热络期.

  15. Free energy landscape and transition pathways from Watson–Crick to Hoogsteen base pairing in free duplex DNA

    Science.gov (United States)

    Yang, Changwon; Kim, Eunae; Pak, Youngshang

    2015-01-01

    Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson–Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine–thymine (A–T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events. PMID:26250116

  16. Free energy landscape and transition pathways from Watson-Crick to Hoogsteen base pairing in free duplex DNA.

    Science.gov (United States)

    Yang, Changwon; Kim, Eunae; Pak, Youngshang

    2015-09-18

    Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson-Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine-thymine (A-T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. New and renewable energies. Stakes, driving forces and perspectives of the renewable energies market

    International Nuclear Information System (INIS)

    2000-09-01

    New and renewable energies (hydro-power, wind-power, solar, biomass, biogas, geothermal and fuel cells) are progressively entering the industrialization phase (except for hydro-power which is already largely developed). Thus they are no more considered as solutions for utopian ecologists but have reached the status of alternative technologies. This study takes stock of the following questions: what are the applications of renewable energies, what is their stage of development and their potential with respect to fossil fuels, what are their perspectives of development, and what are the strategies developed by the actors of the sector? The main stakes of the renewable energy sector are: fulfilling the increasing power needs (in particular with the wind and solar power in isolated areas), improving the competitiveness (reduction of the investment costs), developing financial incentives (tax relief, financial helps, eco-taxes..), participating to the reduction of pollutant emissions. The renewable energy sector is progressively structuring and profits by the increasing implication of major energy actors, such as the oil companies. The behaviour and strategy of 14 major actors of the renewable energy sector is also analyzed. (J.S.)

  18. The significance of the amorphous potential energy landscape for dictating glassy dynamics and driving solid-state crystallisation

    DEFF Research Database (Denmark)

    Ruggiero, Michael T; Krynski, Marcin; Kissi, Eric Ofosu

    2017-01-01

    clear experimental and computational evidence in support of a theory that proposes that the shape and structure of the potential-energy surface (PES) is the fundamental factor underlying the glass-transition processes, regardless of the frequency that experimental methods probe. Whilst this has been....... Combined, these findings provide compelling evidence that the PES landscape, and the corresponding energy barriers, are the ultimate controlling feature behind the atomic and molecular dynamics of disordered solids, regardless of the frequency at which they occur....... proposed previously, we demonstrate, using ab initio molecular-dynamics (AIMD) simulations, that it is of critical importance to carefully consider the complete PES - both the intra-molecular and inter-molecular features - in order to fully understand the entire range of atomic-dynamical processes...

  19. Health risks in perspective: Judging health risks of energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, M.D.

    1992-09-18

    Almost daily, Americans receive reports from the mass news media about some new and frightening risk to health and welfare. Most such reports emphasize the newsworthiness of the risks -- the possibility of a crisis, disagreements among experts, how things happened, who is responsible for fixing them, how much will it cost, conflict among parties involved, etc. As a rule, the magnitudes of the risks, or the difficulty of estimating those magnitudes, have limited newsworthiness, and so they are not mentioned. Because of this emphasis in the news media, most people outside the risk assessment community must judge the relative significance of the various risks to which we all are exposed with only that information deemed newsworthy by reporters. This information is biased and shows risks in isolation. There is no basis for understanding and comparing the relative importance of risks among themselves, or for comparing one risk, perhaps a new or newly-discovered one, in the field of all risks. The purpose of this report is to provide perspective on the various risks to which we are routinely exposed. It serves as a basis for understanding the meaning of quantitative risk estimates and for comparing new or newly-discovered risks with other, better-understood risks. Specific emphasis is placed on health risks of energy technologies.

  20. The Swiss Energy Sector. Innovation landscape and chances for the Netherlands; De Zwitserse energiesector. Innovatielandschap en kansen voor Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Van Ewijk, S. [Innovatie Attache Netwerk, Ambassad Berlijn, Berlin (Netherlands)

    2012-08-15

    An overview is given of innovation in the Swiss energy sector and the following research question will be answered: what are the characteristics of the Swiss innovation landscape in the energy sector and what opportunities are there for the Dutch energy sector? The emphasis is on themes that occur in the Dutch top sector policy, such as natural gas and energy conservation. The aim is to encourage cooperation between the Netherlands and Switzerland in the field of energy and provide inspiration for investment, policy solutions and markets in the field of energy. Each chapter contains references to Swiss authorities for more information and further steps [Dutch] Een overzicht wordt gegeven van innovatie in de Zwitserse energiesector en probeert de volgende onderzoeksvraag te beantwoorden: wat zijn de kenmerken van het Zwitserse innovatielandschap in de energiesector en welke kansen zijn er voor de Nederlandse energiesector? De nadruk ligt daarbij op thema's die ook in het Nederlandse topsectorbeleid voorkomen, zoals aardgas en energiebesparing. Het doel is om de samenwerking tussen Nederland en Zwitserland op energiegebied te stimuleren en informatie te bieden als inspiratie voor investeringen, beleidsoplossingen en afzetmarkten op energiegebied. Ieder hoofdstuk bevat verwijzingen naar Zwitserse instanties voor meer informatie en verdere stappen.

  1. French people, energy transition, and energy savings. IFOP for Energie Perspective

    International Nuclear Information System (INIS)

    Fourquet, Jerome; Chasles-Parot, Marion

    2014-10-01

    After a presentation of the adopted methodology, this report presents under the form of tables, and comments the results of a survey performed on the perception and relationship French people have on and with energy transition and energy savings. Different aspects have been addressed and assessed by this survey: confidence in local authorities, recognition of energy transition, sensitivity of the issue of energy transition, an example of a local authority communication about energy issues, notoriety of subsidies and primes awarded by the local authority for energy-related works, assessment of well-being in housing, housing occupation status, intention to perform energy-related renovation works in the housing, choice between a large national group or a local company to perform these works

  2. The importance of on-site evaluation for placing renewable energy in the landscape: A case study of the Búrfell wind farm (Iceland

    Directory of Open Access Journals (Sweden)

    Frantál Bohumil

    2017-12-01

    Full Text Available Using a case study of the Búrfell wind farm project, a large wind farm proposed in the Central Highlands of Iceland, the authors attempt to provide new insights into the factors shaping subjective landscape perceptions and attitudes to renewable energy developments, and into alternative methods that may be used for their assessment. The research was based on an on-site visit and actual experience of the place, investigated using a combination of mental mapping, the technique of the semantic differential and a questionnaire survey. The results show that participants visiting a landscape and using all sensory organs in combination with mental mapping, can reveal more important information than using only ‘laboratory’ methods with static photographs. The results suggest that the perception of landscape is highly subjective. Those perceiving the landscape as more open, homogenous, industrial, unfamiliar and resilient also consider it more compatible with wind turbines. The perception of the landscape’s compatibility with wind turbines proved to be a dominant factor shaping attitudes towards the project. The acceptance of wind turbines is not, however, inconsistent with the perception of landscape as beautiful, wild and unique. Participants from more densely populated countries and countries with a developed wind energy industry were more tolerant of wind turbines in the Icelandic landscape.

  3. Transformation of rural-urban cultural landscapes in Europe: Integrating approaches from ecological, socio-economic and planning perspectives

    Directory of Open Access Journals (Sweden)

    S. Pauleit

    2010-10-01

    Full Text Available This paper presents a review of the presentations and synthesis of the discussion during a Symposium on ‘Transformation of rural-urban cultural landscapes in Europe: Integrating approaches from ecological, socio-economic and planning perspectives’ held at the European IALE conference 2009 in Salzburg, Austria. The symposium addressed an extended and much debated subject of the landscape dynamics in Europe. The papers presented during the symposium showcased a broad spectrum of cutting edge research questions and challenges faced by the cultural landscapes of Europe. During six sessions, 18 presentations (besides 20 posters were made by 36 scientists (including co-authors from 14 countries, representing 25 institutions of Europe. A glance at the presentations revealed that the state-of-the-art focuses on driving forces and selected aspects of transformation processes, methods of its analysis and planning support as dimensions of research in this field. However, inter- and transdisciplinary research and integrative approaches to the development of rural-urban cultural landscapes are needed. The extended discussion session at the latter part of the symposium highlighted some critical and unaddressed research questions which remained a pending agenda for future research.

  4. Determinants of plant community assembly in a mosaic of landscape units in central Amazonia: ecological and phylogenetic perspectives.

    Directory of Open Access Journals (Sweden)

    María Natalia Umaña

    Full Text Available The Amazon harbours one of the richest ecosystems on Earth. Such diversity is likely to be promoted by plant specialization, associated with the occurrence of a mosaic of landscape units. Here, we integrate ecological and phylogenetic data at different spatial scales to assess the importance of habitat specialization in driving compositional and phylogenetic variation across the Amazonian forest. To do so, we evaluated patterns of floristic dissimilarity and phylogenetic turnover, habitat association and phylogenetic structure in three different landscape units occurring in terra firme (Hilly and Terrace and flooded forests (Igapó. We established two 1-ha tree plots in each of these landscape units at the Caparú Biological Station, SW Colombia, and measured edaphic, topographic and light variables. At large spatial scales, terra firme forests exhibited higher levels of species diversity and phylodiversity than flooded forests. These two types of forests showed conspicuous differences in species and phylogenetic composition, suggesting that environmental sorting due to flood is important, and can go beyond the species level. At a local level, landscape units showed floristic divergence, driven both by geographical distance and by edaphic specialization. In terms of phylogenetic structure, Igapó forests showed phylogenetic clustering, whereas Hilly and Terrace forests showed phylogenetic evenness. Within plots, however, local communities did not show any particular trend. Overall, our findings suggest that flooded forests, characterized by stressful environments, impose limits to species occurrence, whereas terra firme forests, more environmentally heterogeneous, are likely to provide a wider range of ecological conditions and therefore to bear higher diversity. Thus, Amazonia should be considered as a mosaic of landscape units, where the strength of habitat association depends upon their environmental properties.

  5. Determinants of Plant Community Assembly in a Mosaic of Landscape Units in Central Amazonia: Ecological and Phylogenetic Perspectives

    Science.gov (United States)

    Umaña, María Natalia; Norden, Natalia; Cano, Ángela; Stevenson, Pablo R.

    2012-01-01

    The Amazon harbours one of the richest ecosystems on Earth. Such diversity is likely to be promoted by plant specialization, associated with the occurrence of a mosaic of landscape units. Here, we integrate ecological and phylogenetic data at different spatial scales to assess the importance of habitat specialization in driving compositional and phylogenetic variation across the Amazonian forest. To do so, we evaluated patterns of floristic dissimilarity and phylogenetic turnover, habitat association and phylogenetic structure in three different landscape units occurring in terra firme (Hilly and Terrace) and flooded forests (Igapó). We established two 1-ha tree plots in each of these landscape units at the Caparú Biological Station, SW Colombia, and measured edaphic, topographic and light variables. At large spatial scales, terra firme forests exhibited higher levels of species diversity and phylodiversity than flooded forests. These two types of forests showed conspicuous differences in species and phylogenetic composition, suggesting that environmental sorting due to flood is important, and can go beyond the species level. At a local level, landscape units showed floristic divergence, driven both by geographical distance and by edaphic specialization. In terms of phylogenetic structure, Igapó forests showed phylogenetic clustering, whereas Hilly and Terrace forests showed phylogenetic evenness. Within plots, however, local communities did not show any particular trend. Overall, our findings suggest that flooded forests, characterized by stressful environments, impose limits to species occurrence, whereas terra firme forests, more environmentally heterogeneous, are likely to provide a wider range of ecological conditions and therefore to bear higher diversity. Thus, Amazonia should be considered as a mosaic of landscape units, where the strength of habitat association depends upon their environmental properties. PMID:23028844

  6. Deregulation and sustainable energy supply: perspectives of nuclear power and renewable energies

    International Nuclear Information System (INIS)

    Voss, A.

    2001-01-01

    In the concept expressed by the Brundtland Commission and in the Rio Declaration, sustainability incorporates the need - contradictory at first sight - to make sparing use of the environment and promote economic and social development at the same time. Future generations must not be stripped of their possibilities to live and develop. In this comprehensive interpretation, some quantitative orientation for various energy options can be obtained by means of lifetime analyses. The parameters available for evaluation are resource, environmental and economic aspects. Introducing competition and deregulation in the power industry is legitimate not only for reasons of economic theory. Experience has shown that efficient growth and careful management of scarce resources are achieved not by government planning and regulation, but by the allocation efficiency of the markets. This makes competition a key factor of sustainable development. Against this background, perspectives of nuclear power and of renewable energy sources are evaluated. (orig.) [de

  7. Which energies for tomorrow? The perspectives of development of nuclear energy

    International Nuclear Information System (INIS)

    Sicard, Bruno; Regaldo, Jacques; Salvatores, Stephano; Bigot, Bernard; Billot, Philippe; Kert, Christian; Blisson, Yves; Beslu, Pierre

    2016-03-01

    This document first proposes a brief synthesis of opening speeches and of contributions, and then Power Point presentations of these contributions. These interventions proposed an overview of development perspectives and safety challenges for nuclear energy in the world (current evolution of the world nuclear fleet, international cooperation, role and mission of the World Association of Nuclear Operators or WANO, new tools, a first assessment 5 years after the Fukushima accident), an overview of perspectives on the medium and long terms for EDF nuclear fleet in view of a fourth decennial inspection of 900 MWe reactors (continuous improvement of safety in the operated fleet, orientations proposed for the fourth decennial inspections in terms of conformity control and of peculiarities for this safety re-assessment with respect to different accidents and threats), an overview according the CEA of what is at stake for research as far as tomorrow's energies are concerned (CEA global strategy, CEA missions in the field of civil nuclear, R and D on reactors of second and third generation, industrial challenges of R and D, R and D as a support to reactor lifetime extension, presentation of various research platforms and projects)

  8. Hierarchical structure of the energy landscape of proteins revisited by time series analysis. II. Investigation of explicit solvent effects

    Science.gov (United States)

    Alakent, Burak; Camurdan, Mehmet C.; Doruker, Pemra

    2005-10-01

    Time series analysis tools are employed on the principal modes obtained from the Cα trajectories from two independent molecular-dynamics simulations of α-amylase inhibitor (tendamistat). Fluctuations inside an energy minimum (intraminimum motions), transitions between minima (interminimum motions), and relaxations in different hierarchical energy levels are investigated and compared with those encountered in vacuum by using different sampling window sizes and intervals. The low-frequency low-indexed mode relationship, established in vacuum, is also encountered in water, which shows the reliability of the important dynamics information offered by principal components analysis in water. It has been shown that examining a short data collection period (100ps) may result in a high population of overdamped modes, while some of the low-frequency oscillations (memory: future conformations are less dependent on previous conformations due to the lowering of energy barriers in hierarchical levels of the energy landscape. In short-time dynamics (sight contradicts. However, this comes about because water enhances the transitions between minima and forces the protein to reduce its already inherent inability to maintain oscillations observed in vacuum. Some of the frequencies lower than 10cm-1 are found to be overdamped, while those higher than 20cm-1 are slightly increased. As for the long-time dynamics in water, it is found that random-walk motion is maintained for approximately 200ps (about five times of that in vacuum) in the low-indexed modes, showing the lowering of energy barriers between the higher-level minima.

  9. Landscape Studio

    DEFF Research Database (Denmark)

    Hansen, Peter Lundsgaard

    2017-01-01

    Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices.......Landscape studio documents is the biography of the method 'design conversation' and contributes to the way we work with landscapes. The blog communicates renewed landscape didactics and leads to the innovation of design practices....

  10. Energy efficiency from business management perspective; Prosessi-integraatin energiatehokkuuden liikejohtaminen - PI-ENERGIALIITO

    Energy Technology Data Exchange (ETDEWEB)

    Ahtila, P.; Tuomaala, M. (Helsinki Univ. of Technology, Center for Energy Technology, Espoo (Finland)); Malmi, T.; Virtanen, T. (Helsinki School of Economics, Helsinki (Finland))

    2008-07-01

    The purpose of the research is to enhance the ways to manage energy efficiency as part of business management. The work includes a study of the differences between technical energy efficiency metrics and a company's business management metrics. The work also includes a study of the differences between energy efficiency management at a unit process scale and energy efficiency management at a total site scale. In addition, the ways to evaluate energy efficiency investments are studied. The research tries to propose ways to support existing practices in order to promote energy efficiency investment activity. The research is supported by case studies where a change in process energy efficiency is carried out. The case studies are evaluated from two perspectives: from engineering perspective and from business management perspective. (orig.)

  11. Lessons from the polder. Energy tax design in The Netherlands from a climate change perspective

    International Nuclear Information System (INIS)

    Vollebergh, Herman R.J.

    2008-01-01

    This paper evaluates energy tax reform in The Netherlands between 1988 and 2002 from a climate change perspective. In particular, the introduction of two (indirect) taxes on energy products is now responsible for a considerable amount of tax revenue from a green tax base. The paper discusses the energy tax base and rate structure from a modern Pigovian tax perspective and illustrates the practical difficulties involved in the indirect and non-uniform taxation of emissions. Also further improvements of the energy tax structure are discussed, such as a better targeting of the energy tax base and tax rate to fuel characteristics. (author)

  12. Channel Classification across Arid West Landscapes in Support of OHW Delineation

    Science.gov (United States)

    2013-01-01

    perspective at Agua Fria River, AZ ...................................................................... 24 Figure 12. Landscape perspective at...27 Figure 16. Active channel at Agua Fria River, AZ...33 Figure 24. Landscape perspective at Agua Fria River, AZ

  13. The Energy Footprint on the Landscape and What this Means for Plants, Animals, and Ecosystems

    OpenAIRE

    Belnap, Jayne

    2012-01-01

    Dryland regions of the western U.S. contain abundant energy resources, whether they are traditional oil/gas or alternative sources such as solar or wind. With energy exploration and development comes surface disturbance and other impacts. The impact of energy exploration, such as running seismic lines, is associated with soil surface disruption that can be quite severe at a local level. Energy development brings a host of other concerns that need to be considered and likely mitigated. All ene...

  14. Addressing the trade-climate change-energy nexus: China's explorations in a global governance landscape

    OpenAIRE

    Monkelbaan, Joachim

    2014-01-01

    We have arrived at a critical juncture when it comes to understanding the numerous ways in which trade interacts with climate change and energy (trade-climate-energy nexus). Trade remains crucial for the sustainable development of the world's greatest trading nation: China. After clarifying the linkages within the trade, climate change and energy nexus, this article delves into China's specific needs and interests related to trade, climate change and energy. Then it explores the ways in which...

  15. Free energy landscape of dissociative adsorption of methane on ideal and defected graphene from ab initio simulations

    Science.gov (United States)

    Wlazło, M.; Majewski, J. A.

    2018-03-01

    We study the dissociative adsorption of methane at the surface of graphene. Free energy profiles, which include activation energies for different steps of the reaction, are computed from constrained ab initio molecular dynamics. At 300 K, the reaction barriers are much lower than experimental bond dissociation energies of gaseous methane, strongly indicating that the graphene surface acts as a catalyst of methane decomposition. On the other hand, the barriers are still much higher than on the nickel surface. Methane dissociation therefore occurs at a higher rate on nickel than on graphene. This reaction is a prerequisite for graphene growth from a precursor gas. Thus, the growth of the first monolayer should be a fast and efficient process while subsequent layers grow at a diminished rate and in a more controllable manner. Defects may also influence reaction energetics. This is evident from our results, in which simple defects (Stone-Wales defect and nitrogen substitution) lead to different free energy landscapes at both dissociation and adsorption steps of the process.

  16. How Landscape Ecology Can Promote the Development of Sustainable Landscapes in Europe

    DEFF Research Database (Denmark)

    Brandt, Jesper; Antrop, Marc; Ramos, Isabel Loupa

    2013-01-01

    related concepts. International cooperation demands a certain harmonization of these concepts for better mutual understanding. The 2000 European Landscape Convention provided an important momentum to rethink research, policy and management of landscapes from the perspective of sustainable development...

  17. Marine renewable energy in China: Current status and perspectives

    OpenAIRE

    Yong-liang Zhang; Zheng Lin; Qiu-lin Liu

    2014-01-01

    Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China's coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeti...

  18. Optimal dimensionality reduction of complex dynamics: the chess game as diffusion on a free-energy landscape.

    Science.gov (United States)

    Krivov, Sergei V

    2011-07-01

    Dimensionality reduction is ubiquitous in the analysis of complex dynamics. The conventional dimensionality reduction techniques, however, focus on reproducing the underlying configuration space, rather than the dynamics itself. The constructed low-dimensional space does not provide a complete and accurate description of the dynamics. Here I describe how to perform dimensionality reduction while preserving the essential properties of the dynamics. The approach is illustrated by analyzing the chess game--the archetype of complex dynamics. A variable that provides complete and accurate description of chess dynamics is constructed. The winning probability is predicted by describing the game as a random walk on the free-energy landscape associated with the variable. The approach suggests a possible way of obtaining a simple yet accurate description of many important complex phenomena. The analysis of the chess game shows that the approach can quantitatively describe the dynamics of processes where human decision-making plays a central role, e.g., financial and social dynamics.

  19. Clean energy storage technology in the making: An innovation systems perspective on flywheel energy storage.

    Science.gov (United States)

    Wicki, Samuel; Hansen, Erik G

    2017-09-20

    The emergence and diffusion of green and sustainable technologies is full of obstacles and has therefore become an important area of research. We are interested in further understanding the dynamics between entrepreneurial experimentation, market formation, and institutional contexts, together playing a decisive role for successful diffusion of such technologies. Accordingly, we study these processes by adopting a technological innovation system perspective focusing on actors, networks, and institutions as well as the functions provided by them. Using a qualitative case study research design, we focus on the high-speed flywheel energy storage technology. As flywheels are based on a rotating mass allowing short-term storage of energy in kinetic form, they represent an environmentally-friendly alternative to electrochemical batteries and therefore can play an important role in sustainable energy transitions. Our contribution is threefold: First , regarding the flywheel energy storage technology, our findings reveal two subsystems and related markets in which development took different courses. In the automotive sector, flywheels are developing well as a braking energy recovery technology under the influence of two motors of innovation. In the electricity sector, they are stagnating at the stage of demonstration projects because of two important system weaknesses that counteract demand for storage. Second , we contribute to the theory of technological innovation systems by better understanding the internal dynamics between different functions of an innovation system as well as between the innovation system and its (external) contextual structures. Our third contribution is methodological. According to our best knowledge, we are the first to use system dynamics to (qualitatively) analyze and visualize dynamics between the diverse functions of innovation systems with the aim of enabling a better understanding of complex and iterative system processes. The paper also

  20. Free energy landscape of siRNA-polycation complexation: Elucidating the effect of molecular geometry, polymer flexibility, and charge neutralization.

    Directory of Open Access Journals (Sweden)

    Gianvito Grasso

    Full Text Available The success of medical threatments with DNA and silencing interference RNA is strongly related to the design of efficient delivery technologies. Cationic polymers represent an attractive strategy to serve as nucleic-acid carriers with the envisioned advantages of efficient complexation, low cost, ease of production, well-defined size, and low polydispersity index. However, the balance between efficacy and toxicity (safety of these polymers is a challenge and in need of improvement. With the aim of designing more effective polycationic-based gene carriers, many parameters such as carrier morphology, size, molecular weight, surface chemistry, and flexibility/rigidity ratio need to be taken into consideration. In the present work, the binding mechanism of three cationic polymers (polyarginine, polylysine and polyethyleneimine to a model siRNA target is computationally investigated at the atomistic level. In order to better understand the polycationic carrier-siRNA interactions, replica exchange molecular dynamic simulations were carried out to provide an exhaustive exploration of all the possible binding sites, taking fully into account the siRNA flexibility together with the presence of explicit solvent and ions. Moreover, well-tempered metadynamics simulations were employed to elucidate how molecular geometry, polycation flexibility, and charge neutralization affect the siRNA-polycations free energy landscape in term of low-energy binding modes and unbinding free energy barriers. Significant differences among polymer binding modes have been detected, revealing the advantageous binding properties of polyarginine and polylysine compared to polyethyleneimine.

  1. Efficient sampling over rough energy landscapes with high barriers: A combination of metadynamics with integrated tempering sampling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. Isaac [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Zhang, Jun; Che, Xing; Yang, Lijiang; Gao, Yi Qin, E-mail: gaoyq@pku.edu.cn [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Biodynamic Optical Imaging Center, Peking University, Beijing 100871 (China)

    2016-03-07

    In order to efficiently overcome high free energy barriers embedded in a complex energy landscape and calculate overall thermodynamics properties using molecular dynamics simulations, we developed and implemented a sampling strategy by combining the metadynamics with (selective) integrated tempering sampling (ITS/SITS) method. The dominant local minima on the potential energy surface (PES) are partially exalted by accumulating history-dependent potentials as in metadynamics, and the sampling over the entire PES is further enhanced by ITS/SITS. With this hybrid method, the simulated system can be rapidly driven across the dominant barrier along selected collective coordinates. Then, ITS/SITS ensures a fast convergence of the sampling over the entire PES and an efficient calculation of the overall thermodynamic properties of the simulation system. To test the accuracy and efficiency of this method, we first benchmarked this method in the calculation of ϕ − ψ distribution of alanine dipeptide in explicit solvent. We further applied it to examine the design of template molecules for aromatic meta-C—H activation in solutions and investigate solution conformations of the nonapeptide Bradykinin involving slow cis-trans isomerizations of three proline residues.

  2. Cellular network entropy as the energy potential in Waddington's differentiation landscape

    Science.gov (United States)

    Banerji, Christopher R. S.; Miranda-Saavedra, Diego; Severini, Simone; Widschwendter, Martin; Enver, Tariq; Zhou, Joseph X.; Teschendorff, Andrew E.

    2013-01-01

    Differentiation is a key cellular process in normal tissue development that is significantly altered in cancer. Although molecular signatures characterising pluripotency and multipotency exist, there is, as yet, no single quantitative mark of a cellular sample's position in the global differentiation hierarchy. Here we adopt a systems view and consider the sample's network entropy, a measure of signaling pathway promiscuity, computable from a sample's genome-wide expression profile. We demonstrate that network entropy provides a quantitative, in-silico, readout of the average undifferentiated state of the profiled cells, recapitulating the known hierarchy of pluripotent, multipotent and differentiated cell types. Network entropy further exhibits dynamic changes in time course differentiation data, and in line with a sample's differentiation stage. In disease, network entropy predicts a higher level of cellular plasticity in cancer stem cell populations compared to ordinary cancer cells. Importantly, network entropy also allows identification of key differentiation pathways. Our results are consistent with the view that pluripotency is a statistical property defined at the cellular population level, correlating with intra-sample heterogeneity, and driven by the degree of signaling promiscuity in cells. In summary, network entropy provides a quantitative measure of a cell's undifferentiated state, defining its elevation in Waddington's landscape. PMID:24154593

  3. Integration of ecological and thermodynamic concepts in the design of sustainable energy landscapes

    NARCIS (Netherlands)

    Stremke, S.; Koh, J.

    2011-01-01

    Resource depletion and climate change motivate a transition to sustainable energy systems that make effective use of renewable sources. Whereas nature presents strategies to sustain on the basis of renewables, the Laws of Thermodynamics can help to increase efficiency in energy use. In previous

  4. Jointly optimizing selection of fuel treatments and siting of forest biomass-based energy production facilities for landscape-scale fire hazard reduction.

    Science.gov (United States)

    Peter J. Daugherty; Jeremy S. Fried

    2007-01-01

    Landscape-scale fuel treatments for forest fire hazard reduction potentially produce large quantities of material suitable for biomass energy production. The analytic framework FIA BioSum addresses this situation by developing detailed data on forest conditions and production under alternative fuel treatment prescriptions, and computes haul costs to alternative sites...

  5. Identifying Greater Sage-Grouse source and sink habitats for conservation planning in an energy development landscape.

    Science.gov (United States)

    Kirol, Christopher P; Beck, Jeffrey L; Huzurbazar, Snehalata V; Holloran, Matthew J; Miller, Scott N

    2015-06-01

    Conserving a declining species that is facing many threats, including overlap of its habitats with energy extraction activities, depends upon identifying and prioritizing the value of the habitats that remain. In addition, habitat quality is often compromised when source habitats are lost or fragmented due to anthropogenic development. Our objective was to build an ecological model to classify and map habitat quality in terms of source or sink dynamics for Greater Sage-Grouse (Centrocercus urophasianus) in the Atlantic Rim Project Area (ARPA), a developing coalbed natural gas field in south-central Wyoming, USA. We used occurrence and survival modeling to evaluate relationships between environmental and anthropogenic variables at multiple spatial scales and for all female summer life stages, including nesting, brood-rearing, and non-brooding females. For each life stage, we created resource selection functions (RSFs). We weighted the RSFs and combined them to form a female summer occurrence map. We modeled survival also as a function of spatial variables for nest, brood, and adult female summer survival. Our survival-models were mapped as survival probability functions individually and then combined with fixed vital rates in a fitness metric model that, when mapped, predicted habitat productivity (productivity map). Our results demonstrate a suite of environmental and anthropogenic variables at multiple scales that were predictive of occurrence and survival. We created a source-sink map by overlaying our female summer occurrence map and productivity map to predict habitats contributing to population surpluses (source habitats) or deficits (sink habitat) and low-occurrence habitats on the landscape. The source-sink map predicted that of the Sage-Grouse habitat within the ARPA, 30% was primary source, 29% was secondary source, 4% was primary sink, 6% was secondary sink, and 31% was low occurrence. Our results provide evidence that energy development and avoidance of

  6. Energy perspectives of the France by 2020-2050. The learning of the past

    International Nuclear Information System (INIS)

    2007-09-01

    This report brings together the works of the Energy Commission implemented by the strategical analysis center. The first part presents the perspectives and the realities concerning the energy production and consumption. The second part deals with the techniques evolution, the prices and the costs of the energies. The third and fourth parts are respectively devoted to the evolution of the attitudes and opinions and the public policies in matter of the energies. (A.L.B.)

  7. Industrial energy efficiency: Interdisciplinary perspectives on the thermodynamic, technical and economic constraints

    OpenAIRE

    McKenna, Russell

    2009-01-01

    Overreliance on energy from fossil fuels is unsustainable because of their regional depletion and associated environmental impacts. The British industrial sector accounts for around one fifth of final energy demand and one third of carbon emissions nationally. This thesis attempts to quantify the potential for industrial energy efficiency from the current baseline, by adopting thermodynamic and economic perspectives. The methodology involves a top-down analysis of energy trends within the man...

  8. Energy landscapes of nucleophilic substitution reactions: a comparison of density functional theory and coupled cluster methods

    NARCIS (Netherlands)

    Swart, M.; Sola, M.; Bickelhaupt, F.M.

    2007-01-01

    We have carried out a detailed evaluation of the performance of all classes of density functional theory (DFT) for describing the potential energy surface (PES) of a wide range of nucleophilic substitution (S

  9. Structural and kinetic mapping of side-chain exposure onto the protein energy landscape.

    Science.gov (United States)

    Bernstein, Rachel; Schmidt, Kierstin L; Harbury, Pehr B; Marqusee, Susan

    2011-06-28

    Identification and characterization of structural fluctuations that occur under native conditions is crucial for understanding protein folding and function, but such fluctuations are often rare and transient, making them difficult to study. Native-state hydrogen exchange (NSHX) has been a powerful tool for identifying such rarely populated conformations, but it generally reveals no information about the placement of these species along the folding reaction coordinate or the barriers separating them from the folded state and provides little insight into side-chain packing. To complement such studies, we have performed native-state alkyl-proton exchange, a method analogous to NSHX that monitors cysteine modification rather than backbone amide exchange, to examine the folding landscape of Escherichia coli ribonuclease H, a protein well characterized by hydrogen exchange. We have chosen experimental conditions such that the rate-limiting barrier acts as a kinetic partition: residues that become exposed only upon crossing the unfolding barrier are modified in the EX1 regime (alkylation rates report on the rate of unfolding), while those exposed on the native side of the barrier are modified predominantly in the EX2 regime (alkylation rates report on equilibrium populations). This kinetic partitioning allows for identification and placement of partially unfolded forms along the reaction coordinate. Using this approach we detect previously unidentified, rarely populated conformations residing on the native side of the barrier and identify side chains that are modified only upon crossing the unfolding barrier. Thus, in a single experiment under native conditions, both sides of the rate-limiting barrier are investigated.

  10. Competitive landscape of the EU’s insulation materials industry for energy-efficient buildings

    OpenAIRE

    PAVEL CLAUDIU; BLAGOEVA DARINA

    2017-01-01

    Insulation materials could contribute significantly to improving the overall energy efficiency and sustainability of the buildings, especially by reducing the energy losses through the building envelope (walls, roofs, floors, etc.). The global demand for thermal insulation materials in building applications is projected to increase at a CAGR of 4.5 % between 2016 and 2027. In the EU the demand for thermal insulation materials is estimated at 3.48 % (2015-2027). Wool minerals (glass and stone ...

  11. Condensed landscape experience

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    demands, quality of space, mixture of functions, urban complexity, public life and cultural heritage. In order to launch such an approach, an understanding of the spatial, social and environmental significance of a radical re-thinking of relationships between architecture and landscape is necessary...... is becoming a standard in contemporary architecture. Merging architecture and landscape has turned into a principle for an ecological / sustainable architecture. Yet, my aspiration is to achieve a wider interaction involving an application of a wider range of perspectives, such as: urban identity, social......‘Re-thinking interaction between landscape and urban buildings’ participates in an interdisciplinary discourse about the theoretical and practical advantages of openly juxtaposing landscape and architecture without having one more advanced in importance. Recently, the greenification of buildings...

  12. Energy security from the Russian perspective. Think pipes not rockets

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, Waclaw

    2008-07-01

    The presentation reviews the understanding of energy security, the Russian role in the energy source market and discusses how to increase the energy security. Environmental aspects such as climate change, CO2 reduction and the environmental costs of fossil fuel consumption with respect to the energy security are emphasized (tk)

  13. Energy conservation-problems and perspectives for developing nations

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. R. [National Productivity Council, New Delhi, India; Padrmanabhan, S.

    1980-03-15

    While studies of the past indicated a tight coupling of energy consumption and GNP, longer range indications are that they can be mutually decoupled. Developing nations can move forward towards achieving significant energy savings in their economics without fear of economic stagnation. Conservation policies at the national level are difficult to enunciate and the implementation mechanisms have to be strengthened. Macro-level economics may not be easily apparent as unit level economics. If energy conservation is not practiced, we would require the development of additional energy supply capacity with all of its economic implications. The role of science and technology inputs in industrial processes for minimizing energy consumption is significant. Sufficient funds should be allocated for pursuance of R and D activities in energy conservation and in developing alternative energy resources to supplement and later replace the existing costly transient fuels. A climate to promote conservation of energy should formulate policies which lays emphasis on energy conservation strategies rather than soley on energy growth issues. The effort should be directed towards energy programs that are a judicious mix up of energy and energy conservation strategies for achieving economic growth and a reasonable standard of living commensurate with the aspirations of the people. In capital-scarce economies, an account of the fact that energy conservation requires far less investment than energy capital supplies, conservation policies must play a central role in the overall framework of developing nation's national energy policies.

  14. Energy transition within an alter-globalization perspective

    International Nuclear Information System (INIS)

    Combes, Maxime; Azam, Genevieve; Balvet, Jacqueline; Planche, Jeanne; Sabatier, Gilles

    2013-05-01

    This publication proposes a discussion of the present and general energy transition according to seven principles: 1) to stop the current energy transition is an imperious necessity; 2) energy sobriety to meet climatic requirements; 3) to avoid the technical-scientific trap in order to re-politicise energy transition; 4) to disconnect finance and energy in order to take back the control of it; 5) to de-merchandise energy to build up equality; 6) to build up the resilience of territories and of people; 7) energy as a common good, beyond State and market

  15. Ratchet Effects and Domain Wall Energy Landscapes in Amorphous Magnetic Films with 2D Arrays of Asymmetric Holes

    Science.gov (United States)

    Martin, J. I.; Alija, A.; Sobrado, I.; Perez-Junquera, A.; Rodriguez-Rodriguez, G.; Velez, M.; Alameda, J. M.; Marconi, V. I.; Kolton, A. B.; Parrondo, J. M. R.

    2009-03-01

    The driven motion of domain walls in extended magnetic films patterned with 2D arrays of asymmetric holes has been found to be subject to two different crossed ratchet effects [1] which results in an inversion of the sign of domain wall motion rectification as a function of the applied magnetic field. This effect can be understood in terms of the competition between drive, elasticity and asymmetric pinning as revealed by a simple 4̂-model. In order to optimize the asymmetric hole design, the relevant energy landscapes for domain wall motion across the array of asymmetric holes have been calculated by micromagnetic simulations as a function of array geometrical characteristics. The effects of a transverse magnetic field on these two crossed ratchet effects will also be discussed in terms of the decrease in domain wall energy per unit area and of the modifications in the magnetostatic barriers for domain wall pinning at the asymmetric inclusions. Work supported by Spanish MICINN.[1] A. Perez-Junquera et al, Phys. Rev. Lett. 100 (2008) 037203

  16. Urban Planning for a Renewable Energy Future: Methodological Challenges and Opportunities from a Design Perspective

    NARCIS (Netherlands)

    Vandevijvere, H.; Stremke, S.

    2012-01-01

    Urban planning for a renewable energy future requires the collaboration of different disciplines both in research and practice. In the present article, the planning of a renewable energy future is approached from a designer’s perspective. A framework for analysis of the planning questions at hand is

  17. Problems and perspectives in energy law and environmental law. Documentation; Probleme und Perspektiven im Energieumweltrecht. Dokumentation

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, Wolfram; Pielow, Johann-Christian (eds.)

    2009-07-01

    This book contains the contributions and discussion of the 13th annual meeting of the Institute of Mining Law and Energy Law of the Ruhr University Bochum. The meeting washed on 6 March 2009 under the title ''Problems and Perspectives in Energy Law and Environmental Law''. (orig.)

  18. A new perspective on anisotropy and multiple energy gaps in superconductors

    International Nuclear Information System (INIS)

    Milkove, K.R.; Bostock, J.; MacVicar, M.L.A.

    1976-01-01

    New perspective on superconducting anisotropy and multiple energy gaps: direct experimental evidence shows that widely accepted anisotropy and multiple energy gap interpretations of tunneling data are consistent with a voltage divider model and may not relate to intrinsic superconducting properties. The model also accounts for other common data anomalies. (author)

  19. Sub-seasonal thaw slump mass wasting is not consistently energy limited at the landscape scale

    Directory of Open Access Journals (Sweden)

    S. Zwieback

    2018-02-01

    Full Text Available Predicting future thaw slump activity requires a sound understanding of the atmospheric drivers and geomorphic controls on mass wasting across a range of timescales. On sub-seasonal timescales, sparse measurements indicate that mass wasting at active slumps is often limited by the energy available for melting ground ice, but other factors such as rainfall or the formation of an insulating veneer may also be relevant. To study the sub-seasonal drivers, we derive topographic changes from single-pass radar interferometric data acquired by the TanDEM-X satellites. The estimated elevation changes at 12 m resolution complement the commonly observed planimetric retreat rates by providing information on volume losses. Their high vertical precision (around 30 cm, frequent observations (11 days and large coverage (5000 km2 allow us to track mass wasting as drivers such as the available energy change during the summer of 2015 in two study regions. We find that thaw slumps in the Tuktoyaktuk coastlands, Canada, are not energy limited in June, as they undergo limited mass wasting (height loss of around 0 cm day−1 despite the ample available energy, suggesting the widespread presence of early season insulating snow or debris veneer. Later in summer, height losses generally increase (around 3 cm day−1, but they do so in distinct ways. For many slumps, mass wasting tracks the available energy, a temporal pattern that is also observed at coastal yedoma cliffs on the Bykovsky Peninsula, Russia. However, the other two common temporal trajectories are asynchronous with the available energy, as they track strong precipitation events or show a sudden speed-up in late August respectively. The observed temporal patterns are poorly related to slump characteristics like the headwall height. The contrasting temporal behaviour of nearby thaw slumps highlights the importance of complex local and temporally varying controls on mass wasting.

  20. Evapotranspiration and surface energy balance across an agricultural-urban landscape gradient in Southern California, USA.

    Science.gov (United States)

    Shiflett, S. A.; Anderson, R. G.; Jenerette, D.

    2014-12-01

    Urbanization substantially affects energy, surface and air temperature, and hydrology due to extensive modifications in land surface properties such as vegetation, albedo, thermal capacity and soil moisture. The magnitude and direction of these alterations depends heavily on the type of urbanization that occurs. We investigated energy balance variation in a local network of agricultural and urban ecosystems using the eddy covariance method to better understand how vegetation fraction and degree of urbanization affects energy exchanges between the land surface and the atmosphere. We deployed eddy flux systems within a well-irrigated, agricultural citrus orchard, a moderately developed urban zone with a substantial amount of local vegetative cover, and an intensely developed urban zone with minimal vegetative cover and increased impervious surfaces relative to the other two sites. Latent energy (LE) fluxes in the agricultural area ranged from 7.9 ± 1.4 W m-2 (nighttime) to 168.7 ± 6.2 W m-2 (daytime) compared to 10.2 ± 3.5 W m-2 and 40.6 ± 4.1 W m-2, respectively, for the moderately developed urban area. Sensible energy (H) fluxes ranged from -9.1 ± 1.0 W m-2 (nighttime) to 119 ± 7.0 W m-2 (daytime) in the agricultural area compared to 9.6 ± 2.6 W m-2 and 134 ± 6.0 W m-2, respectively, for the moderately developed urban zone. Daytime LE is reduced with increasing urbanization; however, daily cycles of LE are less recognizable in urban areas compared to distinct daily cycles obtained above a mature citrus crop. In contrast, both daytime and nighttime H increases with increasing degree of urbanization. Reduction in vegetation and increases in impervious surfaces along an urbanization gradient leads to alterations in energy balance, which are associated with microclimate and water use changes.

  1. The multi-state energy landscape of the SAM-I riboswitch: A single-molecule Förster resonance energy transfer spectroscopy study

    Science.gov (United States)

    Manz, Christoph; Kobitski, Andrei Yu.; Samanta, Ayan; Jäschke, Andres; Nienhaus, G. Ulrich

    2018-03-01

    RNA (ribonucleic acid) molecules are highly flexible biopolymers fluctuating at physiological temperatures among many different conformations that are represented by minima in a hierarchical conformational free energy landscape. Here we have employed single-molecule FRET (smFRET) to explore the energy landscape of the B. subtilis yitJ SAM-I riboswitch (RS). In this small RNA molecule, specific binding of an S-adenosyl-L-methionine (SAM) ligand in the aptamer domain regulates gene expression by inducing structural changes in another domain, the expression platform, causing transcription termination by the RNA polymerase. We have measured smFRET histograms over wide ranges of Mg2+ concentration for three RS variants that were specifically labeled with fluorescent dyes on different sites. In the analysis, different conformations are associated with discrete Gaussian model distributions, which are typically fairly broad on the FRET efficiency scale and thus can be extremely challenging to unravel due to their mutual overlap. Our earlier work on two SAM-I RS variants revealed four major conformations. By introducing a global fitting procedure which models both the Mg2+ concentration dependencies of the fractional populations and the average FRET efficiencies of the individual FRET distributions according to Mg2+ binding isotherms, we were able to consistently describe the histogram data of both variants at all studied Mg2+ concentrations. With the third FRET-labeled variant, however, we found significant deviations when applying the four-state model to the data. This can arise because the different FRET labeling of the new variant allows two states to be distinguished that were previously not separable due to overlap. Indeed, the resulting five-state model presented here consistently describes the smFRET histograms of all three variants as well as their variations with Mg2+ concentration. We also performed a triangulation of the donor position for two of the constructs

  2. Enabling innovations in energy access: An African perspective

    International Nuclear Information System (INIS)

    Agbemabiese, Lawrence; Nkomo, Jabavu; Sokona, Youba

    2012-01-01

    Conventional energy technologies and deployment approaches cannot be relied upon to eliminate energy poverty in Africa. Innovations in energy access are necessary. Previous attempts at introducing and scaling up innovative solutions do not sufficiently address dynamic and structural determinants of success. This limits their actual performance as scalable drivers of innovations in technology, policy and institutions. Using technological innovation systems theory, we demonstrate a practical approach to assess the sustainability of innovations in energy access, and develop a framework to guide energy policy makers, clean energy entrepreneurs and energy-development researchers. - Highlights: ► Innovative technologies and policies are needed to expand energy access. ► TIS approach can guide the formulation and deployment of sustainable energy innovations. ► Learning by exploring and doing are the keys to entrepreneurial success. ► Lack of infrastructure and institutional frameworks are major barriers to innovations. ► Government intervention is needed to eliminate barriers to innovations.

  3. Energy in the strategy to Sahel development : Situation- Perspectives- Recommendations

    International Nuclear Information System (INIS)

    1978-10-01

    Energy plays an important role in the development of the Sahel Countries. For instance, in these countries, the use of wood fire is essential as a source of energy. However, the increase in the wood supply leads to environmental problems; hence the necessity for the states to promote alternative source of energy to replace the wood. Used in the field of agriculture, transport, industry and construction, energy in Sahel countries hurts to financial problems such as difficulties in the funding of oil import and supply security. It is then indispensable to develop energy resources in the Sahel countries. Energy policies must emphasize on hydroelectric energy, nuclear energy and also better reorganize certain sources of energy such as gas, oil, and coal. Thus this political assumption of responsibility through a comprehensive approach will contribute to generate the development of the Sahel countries [fr

  4. Navigating the new deregulated landscape: Opportunities and risks for wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Fossum, D.J.; Hill, D.R. [Wiley, Rein & Fielding, Washington, DC (United States)

    1997-12-31

    Major changes in the law governing the electric industry are underway, fundamentally altering how the generation and sale of electric power is regulated and how electric power is marketed in the United States. Legislative and regulatory initiatives promoting competition will create a variety of opportunities, and commensurate risks, for power generators, marketers, brokers, sellers, and purchasers. To succeed in the new marketplace, suppliers of renewable energy must understand the changes occurring on the state and federal levels, and position themselves to take advantage of the opportunities available. In this environment, monitoring and participating in state and federal legislative and regulatory efforts will be crucial for maximizing opportunities for wind energy.

  5. Charting the energy landscape of metal/organic interfaces via machine learning

    Science.gov (United States)

    Scherbela, Michael; Hörmann, Lukas; Jeindl, Andreas; Obersteiner, Veronika; Hofmann, Oliver T.

    2018-04-01

    The rich polymorphism exhibited by inorganic/organic interfaces is a major challenge for materials design. In this work, we present a method to efficiently explore the potential energy surface and predict the formation energies of polymorphs and defects. This is achieved by training a machine learning model on a list of only 100 candidate structures that are evaluated via dispersion-corrected density functional theory (DFT) calculations. We demonstrate the power of this approach for tetracyanoethylene on Ag(100) and explain the anisotropic ordering that is observed experimentally.

  6. Imminent perspectives for industrial application of atomic energy; Perspectives imminentes de l'application industrielle de l'energie atomique

    Energy Technology Data Exchange (ETDEWEB)

    Kowarski, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    This conference raises an inventory of industrial applications and their perspectives for the year 1955. The speaker extrapolate for the forthcoming years the evolution of the role of the nuclear, the nuclear fuel, the different, types of atomic reactors and the state of advancement for different countries. (M.B.) [French] Cette conference dresse un etat des lieux des applications industrielles et de leurs perspectives pour l'annee 1955. L'orateur aborde entre autre l'evolution du role du nucleaire dans les annees a venir, le combustible nucleaire, les differents types de piles atomiques et l'etat d'avancement des differents pays. (M.B.)

  7. Storage Integration in Energy Systems: A New Perspective

    International Nuclear Information System (INIS)

    Faure-Schuyer, Aurelie

    2016-06-01

    Energy storage is partly an 'old story' and a new one. Energy storage is an essential stabilizing factor in existing electrical systems. Looking forward, energy storage is being considered as a key element of the transformation of energy systems, given the higher shares of renewable generation integrating the systems and demand-side management offered to end-customers. Today, the cost of electricity produced from battery storage is approaching parity with electricity bought from the grid. For this trend to gain strength and energy storage to be part of new business models, energy policies and regulatory frameworks need to be adapted. (author)

  8. Dissipation of solar energy in landscape - controlled by management of water and vegetation

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jan

    2001-01-01

    Roč. 24, - (2001), s. 641-645 ISSN 0960-1481 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6005908 Keywords : Solar energy dissipation * vegetation * production -evapotranspiration Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.224, year: 2001

  9. Potential energy landscape signatures of slow dynamics in glass forming liquids

    DEFF Research Database (Denmark)

    Sastry, S.; Debenedetti, P. G.; Stillinger, F. H.

    1999-01-01

    We study the properties of local potential energy minima (‘inherent structures’) sampled by liquids at low temperatures as an approach to elucidating the mechanisms of the observed dynamical slowing down observed as the glass transition temperature is approached. This onset of slow dynamics...

  10. Addressing the trade-climate change-energy nexus: China's explorations in a global governance landscape

    Directory of Open Access Journals (Sweden)

    Joachim Monkelbaan

    2014-12-01

    As a way forward, different approaches towards the governance of trade and climate change will be highlighted. Besides discussing the specific aspects of Chinese participation in global trade and climate change governance, this paper aims at offering broader insights into the nexus between trade, energy and climate governance in China.

  11. New perspectives on renewable energy systems based on hydrogen

    International Nuclear Information System (INIS)

    Bose, T. K.; Agbossou, K.; Benard, P.; St-Arnaud, J-M.

    1999-01-01

    Current hydrocarbon-based energy systems, current energy consumption and the push towards the utilization of renewable energy sources, fuelled by global warming and the need to reduce atmospheric pollution are discussed. The consequences of climatic change and the obligation of Annex B countries to reduce their greenhouse gas emissions in terms of the Kyoto Protocols are reviewed. The role that renewable energy sources such as hydrogen, solar and wind energy could play in avoiding the most catastrophic consequences of rapidly growing energy consumption and atmospheric pollution in the face of diminishing conventional fossil fuel resources are examined. The focus is on hydrogen energy as a means of storing and transporting primary energy. Some favorable characteristics of hydrogen is its abundance, the fact that it can be produced utilizing renewable or non-renewable sources, and the further fact that its combustion produces three times more energy per unit of mass than oil, and six times more than coal. The technology of converting hydrogen into energy, storing energy in the form of hydrogen, and its utilization, for example in the stabilization of wind energy by way of electrolytic conversion to hydrogen, are described. Development at Hydro-Quebec's Institute of Research of a hydrogen-based autonomous wind energy system to produce electricity is also discussed. 2 tabs., 11 refs

  12. The perspectives of fusion energy: The roadmap towards energy production and fusion energy in a distributed energy system

    DEFF Research Database (Denmark)

    Naulin, Volker; Juul Rasmussen, Jens; Korsholm, Søren Bang

    2014-01-01

    at very high temperature where all matter is in the plasma state as the involved energies are orders of magnitude higher than typical chemical binding energies. It is one of the great science and engineering challenges to construct a viable power plant based on fusion energy. Fusion research is a world...... The presentation will discuss the present status of the fusion energy research and review the EU Roadmap towards a fusion power plant. Further the cost of fusion energy is assessed as well as how it can be integrated in the distributed energy system......Controlled thermonuclear fusion has the potential of providing an environmentally friendly and inexhaustible energy source for mankind. Fusion energy, which powers our sun and the stars, is released when light elements, such as the hydrogen isotopes deuterium and tritium, fuse together. This occurs...

  13. Gazing at places we have never been: landscape, heritage and identity: a comment on Jörg Rekittke and Philip Paar: 'Past pictures: landscape visualization with digital tools'

    NARCIS (Netherlands)

    van der Laarse, R.; Bloemers, T.; Kars, H.; van der Valk, A.; Wijnen, M.

    2010-01-01

    Acknowledging the paradigmatic impact of new digital techniques, this contribution questions the depoliticized conceptualization of landscape in modern landscape visualizations from a theoretical and historical perspective. Long after the earlier periods of formal gardening and landscaping, the

  14. America's Changing Energy Landscape - USGS National Coal Resources Data System Changes to National Energy Resources Data System.

    Science.gov (United States)

    East, J. A., II

    2016-12-01

    The U.S. Geological Survey's (USGS) Eastern Energy Resources Science Center (EERSC) has an ongoing project which has mapped coal chemistry and stratigraphy since 1977. Over the years, the USGS has collected various forms of coal data and archived that data into the National Coal Resources Data System (NCRDS) database. NCRDS is a repository that houses data from the major coal basins in the United States and includes information on location, seam thickness, coal rank, geologic age, geographic region, geologic province, coalfield, and characteristics of the coal or lithology for that data point. These data points can be linked to the US Coal Quality Database (COALQUAL) to include ultimate, proximate, major, minor and trace-element data. Although coal is an inexpensive energy provider, the United States has shifted away from coal usage recently and branched out into other forms of non-renewable and renewable energy because of environmental concerns. NCRDS's primary method of data capture has been USGS field work coupled with cooperative agreements with state geological agencies and universities doing coal-related research. These agreements are on competitive five-year cycles that have evolved into larger scope research efforts including solid fuel resources such as coal-bed methane, shale gas and oil. Recently these efforts have expanded to include environmental impacts of the use of fossil fuels, which has allowed the USGS to enter into agreements with states for the Geologic CO2 Storage Resources Assessment as required by the Energy Independence and Security Act. In 2016 they expanded into research areas to include geothermal, conventional and unconventional oil and gas. The NCRDS and COALQUAL databases are now online for the public to use, and are in the process of being updated to include new data for other energy resources. Along with this expansion of scope, the database name will change to the National Energy Resources Data System (NERDS) in FY 2017.

  15. Review and analysis of renewable energy perspectives in Serbia

    Energy Technology Data Exchange (ETDEWEB)

    Karakosta, Charikleia; Doukas, Haris; Flouri, Maria; Dimopoulou, Stamatia; Papadopoulou, Alexandra G.; Psarras, John [National Technical University of Athens, School of Electrical and Computer Engineering, Management & Decision Support Systems Lab (NTUA-EPU), 9, Iroon Polytechniou str., 157 80, Athens (Greece)

    2011-07-01

    Nowadays, Serbia needs to disengage from the broad use of fossil fuels and turn to the 'attractive' Renewable Energy Sources (RES) for energy production, since the Kyoto Protocol ratification, so as to resolve systematically the problem of energy demand. In addition, research indicates that Serbia is a country with high potential and favourable conditions for RES energy production, as the country's potential could supply almost half of its primary energy needs. The paper provides an overview of Serbia's energy sector status quo, so as to emphasize the necessity for RES implementation in order to balance the country's energy deficit. The aim is to investigate and present the country's prospects in the RES sector, revealing the proven RES potential and pointing out that the unexploited RES potential together with an adequately well structured energy sector would create great possibilities and conditions for a new market.

  16. ACER: demystifying the European energy supervisor from a consumer perspective

    NARCIS (Netherlands)

    Lavrijssen, S.A.C.M.; Bordei, I.

    2012-01-01

    The European energy regulatory triangle, consisting of National Regulatory Authorities (NRAs), the European Commission and the newly established Agency for the Cooperation of Energy Regulators (ACER), has an important role in enhancing cross border trade and wholesale market competition and

  17. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.; Allaman, Igor

    2015-01-01

    The energy demands of the brain are high: they account for at least 20% of the body's energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization

  18. Energy in the strategy to Sahel Development : Situation - Perspectives - Recommendations

    International Nuclear Information System (INIS)

    1995-01-01

    Burkina Faso does not have fossil energy source. The problem of energy thus arises with acuity for the rural and urban populations. The energy sources used are primarily the hydrocarbons, electrical energy, the woody fuels as new and renewable energies which are the biomass, the solar energy and the wind energy. The hydrocarbons are 100% imported, which makes the country very depend on over sea with respect to its conventional energy supply. These imports represent, for the years 1987 to 1992, 12 to 29% of the export earnings of the country. In addition to this dependence, there is a great weakness of the electrical communication and the too high cost of energy which led to the development of a strategic planning of the scientific research centered on the energy sector. In this field, research made it possible to undertake a study of the Burkina Faso energy system, to evaluate and exploit solar energy and wind mill, to develop the use of new methods allowing the energy saving in the households and the safeguard of the environment. In addition research shows that an economy is possible in the administrative buildings. Work is undertaken on air-conditioning by evaporation, the technology of the cold and the valorization of nonfood plant oils. There is also a work done on the de-pollution of industrial waste water, the energy valorization of the biomass as well as the improvement of the technology of the dolo, local beer containing sorghum. All these scientific research activities aim at the definition of a development policy on the energetic sector which takes into account the reduction of the cost of energy, the access of the populations to this resource, the reduction in the invoice of oil products imports as well as the promotion of environmental protection, the industrial development and that of the new methods of local technology as regards energy in Burkina Faso [fr

  19. Perspective on the current realities confronting Canadian energy policy

    International Nuclear Information System (INIS)

    Oulton, D.

    1993-01-01

    The importance of the Canadian energy sector is indicated by the large proportion of energy investments in the economy, the significant contribution of energy exports to total exports, the major role of the energy sector in Canada's regional economies, the high per-capita energy consumption, and the high contribution of fossil fuels to Canadian greenhouse gas emissions. The history of Canadian energy policy is characterized by three relatively distinct periods: a period of strong growth and development in the energy sector starting in the late 1940s, a crisis management period starting with the oil crises in the 1970s, and a market orientation in the early 1980s which reduced the role of government in the energy sector. Energy policy has generally focused on two main themes: assuring access to competitively priced energy supplies, and ensuring maximum economic benefit from energy developments. A third theme, environmental responsibility, has emerged since the late 1980s. Current pressures on Canadian energy policies include the increasing integration of energy markets in North America, the influence of international conditions on energy prices, and environmental quality concerns relating to the costs and uncertainties of environmental assessment, climate change, and sustainable development. Further constraints and influences on energy policy come from multilateral agreements with other countries and international agencies, and the need for cooperation among the different levels of Canadian governments. Economic regulation has fallen out of favor with most governments, industry, and the public, and the increased use of regulation to pursue environmental goals in the energy sector seems likely to continue

  20. Perspective: Dynamic Shadowing Growth and its Energy Applications

    Directory of Open Access Journals (Sweden)

    Yiping eZhao

    2014-09-01

    Full Text Available The unique features of dynamic shadowing growth (DSG in structural and compositional design of nanomaterials are discussed. Their recent applications in energy storage, fuel cell, and solar energy conversion have been reviewed briefly. Future directions for applying DSG nanostructures in renewable energy applications are presented.

  1. Multi-perspective analysis of China's energy supply security

    International Nuclear Information System (INIS)

    Geng, Jiang-Bo; Ji, Qiang

    2014-01-01

    China's energy supply security has faced many challenges such as the drastic change of the international energy environment and the domestic energy situation and so on. This paper constructs a multi-dimensional indicator system for the main risks deriving from four aspects to evaluate the situation of China's energy supply security and analyze its evolution characteristics from 1994 to 2011. The results indicate that the situation of China's energy supply security generally presented a downtrend during 1994–2008, as a result of increasing international energy market monopoly and high volatility of international crude oil prices. After 2008, the overall level of China's energy supply security has improved to the level of 2003, which is attributed to the relatively stable international energy environment as well as the effective implementation of energy policies. - Highlights: • A multi-dimensional index system for energy supply security is constructed. • The dynamic influences of external and internal risks are analyzed. • China's energy supply security presents a downward trend during 1994–2008. • The level of China's energy supply security has improved since 2009

  2. Intelligent energy systems. A White Paper with Danish perspectives

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    This White Paper is intended as a basis for developing a partnership and a strategy on intelligent energy systems including all stakeholders: businesses, energy companies, research institutions, energy consumers and public authorities. The partnership initiative for intelligent energy systems is initiated by The Danish Energy Industries Federation together with DI ITEK (the Danish ICT and electronics federation for it, telecommunications, electronics and communication enterprises), EC Power A/S, Dong Energy A/S, Danfoss Solutions A/S, Dantherm A/S, Vestas A/S, Siemens A/S, SydEnergi Partner A/S, Technical University of Denmark (DTU), Aalborg University (AAU), the network VE-net and Ea Energy Analyses A/S. The White Paper has been prepared by Ea Energy Analyses with valuable assistance from the project participants. The proposed partnership initiative is presented in the first section: 'Strategy and partnership for intelligent energy'. The remaining chapters 1-9 of the report constitute the White Paper. Chapters 1 and 2 introduce the energy system, chapter 3 discusses the markets for energy and reserves, and chapter 4 covers some of the new active elements in the system - consumers and storage. Key technologies and solutions of the intelligent energy system are outlined in chapter 5, and chapter 6 describes the strategies for smart grids pursued by the EU, the International Energy Agency and the USA. Selected Danish research, development and demonstration projects related to demand management and other smart grid solutions are briefly described in chapter 7, and chapter 8 outlines current Danish policy and initiatives working towards the intelligent energy system. A list of references is given in chapter 6, and appendix 1 contains a preliminary list of potential members of the partnership. (LN)

  3. Intelligent energy systems. A White Paper with Danish perspectives

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    This White Paper is intended as a basis for developing a partnership and a strategy on intelligent energy systems including all stakeholders: businesses, energy companies, research institutions, energy consumers and public authorities. The partnership initiative for intelligent energy systems is initiated by The Danish Energy Industries Federation together with DI ITEK (the Danish ICT and electronics federation for it, telecommunications, electronics and communication enterprises), EC Power A/S, Dong Energy A/S, Danfoss Solutions A/S, Dantherm A/S, Vestas A/S, Siemens A/S, SydEnergi Partner A/S, Technical University of Denmark (DTU), Aalborg University (AAU), the network VE-net and Ea Energy Analyses A/S. The White Paper has been prepared by Ea Energy Analyses with valuable assistance from the project participants. The proposed partnership initiative is presented in the first section: 'Strategy and partnership for intelligent energy'. The remaining chapters 1-9 of the report constitute the White Paper. Chapters 1 and 2 introduce the energy system, chapter 3 discusses the markets for energy and reserves, and chapter 4 covers some of the new active elements in the system - consumers and storage. Key technologies and solutions of the intelligent energy system are outlined in chapter 5, and chapter 6 describes the strategies for smart grids pursued by the EU, the International Energy Agency and the USA. Selected Danish research, development and demonstration projects related to demand management and other smart grid solutions are briefly described in chapter 7, and chapter 8 outlines current Danish policy and initiatives working towards the intelligent energy system. A list of references is given in chapter 6, and appendix 1 contains a preliminary list of potential members of the partnership. (LN)

  4. Chinese hotel general managers' perspectives on energy-saving practices

    Science.gov (United States)

    Zhu, Yidan

    As hotels' concern about sustainability and budget-control is growing steadily, energy-saving issues have become one of the important management concerns hospitality industry face. By executing proper energy-saving practices, previous scholars believed that hotel operation costs can decrease dramatically. Moreover, they believed that conducting energy-saving practices may eventually help the hotel to gain other benefits such as an improved reputation and stronger competitive advantage. The energy-saving issue also has become a critical management problem for the hotel industry in China. Previous research has not investigated energy-saving in China's hotel segment. To achieve a better understanding of the importance of energy-saving, this document attempts to present some insights into China's energy-saving practices in the tourist accommodations sector. Results of the study show the Chinese general managers' attitudes toward energy-saving issues and the differences among the diverse hotel managers who responded to the study. Study results indicate that in China, most of the hotels' energy bills decrease due to the implementation of energy-saving equipments. General managers of hotels in operation for a shorter period of time are typically responsible for making decisions about energy-saving issues; older hotels are used to choosing corporate level concerning to this issue. Larger Chinese hotels generally have official energy-saving usage training sessions for employees, but smaller Chinese hotels sometimes overlook the importance of employee training. The study also found that for the Chinese hospitality industry, energy-saving practices related to electricity are the most efficient and common way to save energy, but older hotels also should pay attention to other ways of saving energy such as water conservation or heating/cooling system.

  5. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge

    OpenAIRE

    Dahle, H?kon; ?kland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-01-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent f...

  6. Landscapes of lost energy: counterfactual geographical imaginary for a more sustainable society

    Czech Academy of Sciences Publication Activity Database

    Van der Horst, Dan

    2014-01-01

    Roč. 22, č. 2 (2014), s. 66-72 ISSN 1210-8812 R&D Projects: GA MŠk EE2.3.20.0025 Institutional support: RVO:68145535 Keywords : counterfactual * imagery * imagination * energy literacy Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.872, year: 2014 http://www.geonika.cz/EN/research/ENMgr/MGR_2014_02.pdf

  7. The water-energy nexus: an earth science perspective

    Science.gov (United States)

    Healy, Richard W.; Alley, William M.; Engle, Mark A.; McMahon, Peter B.; Bales, Jerad D.

    2015-01-01

    Water availability and use are closely connected with energy development and use. Water cannot be delivered to homes, businesses, and industries without energy, and most forms of energy development require large amounts of water. The United States faces two significant and sometimes competing challenges: to provide sustainable supplies of freshwater for humans and ecosystems and to ensure adequate sources of energy for future generations. This report reviews the complex ways in which water and energy are interconnected and describes the earth science data collection and research that can help the Nation address these important challenges.

  8. Landscapes of Lost Energy: Counterfactual Geographical Imaginary for A More Sustainable Society

    Directory of Open Access Journals (Sweden)

    van der Horst Dan

    2014-07-01

    Full Text Available The quest for sustainable energy, one of the greatest challenges of the 21st century, calls for more input from academics than 'simply' producing good science. Geographical imaginations are as old as storytelling and mapmaking, but this essay is neither about 'long ago and far away', nor about utopian energy futures. This is a call to geographers to engage with 'alternative present' energy scenarios, using the full range of analytical and discursive tools at our disposal. Drawing on a diverse tradition of imagined spaces and the awareness of absences (material, relational or otherwise, geographers should be able to contribute to the quest for a more sustainable society by assessing, envisaging, and communicating a counterfactual 'here and now', based on good practices existing right now, but not (yet right here. We need to understand how much more sustainable our bit of the planet would be if we could just, environmentally speaking, 'keep up' with the best of our neighbours. This counterfactual present should be seen as neither radical nor utopian, because it only assumes the historic adoption of best practices which we now know to be feasible and successful. And if thi alternative current scenario looks radically different from the 'real' state we are in, then this goes to show how radically unsustainable our business-as-usual approach has been.

  9. RAAAF's office landscape The End of Sitting: Energy expenditure and temporary comfort when working in non-sitting postures.

    Directory of Open Access Journals (Sweden)

    Simone R Caljouw

    Full Text Available An earlier study suggested that the activity-inviting office landscape called "The End of Sitting", designed by Rietveld Architecture Art Affordances (RAAAF, should be considered as an alternative working environment to prevent sedentary behavior. The End of Sitting lacks chairs and tables but consists instead of a myriad of sloped surfaces at different heights that afford workers to stand, lean or recline at different locations. In this study, we assessed the impact of four of its workspaces on physical intensity, temporary comfort and productivity of office work and compared the outcomes with sitting and standing behind a desk. Twenty-four participants worked for 10 minutes in each of the six test conditions. Energy expenditure, measured by indirect calorimetry, and heart rate were recorded. Questionnaires were used to assess the perceived comfort. The number of words found in the word search test was counted as a measure of productivity. The majority of The End of Sitting workspaces led to a significant increase in energy expenditure compared with sitting behind a desk (ps < .05. Average MET values ranged from 1.40 to 1.58 which is a modest rise in energy expenditure compared to sitting (1.32 METs and not significantly different from standing (1.47 METs. The scores on the general comfort scale indicated that some workspaces were less comfortable than sitting (ps < .05, but the vast majority of participants reported that at least one of The End of Sitting workspaces was equally or more comfortable than sitting. No differences in productivity between the test conditions were found. Further long-term studies are required to assess the behavioral adaptations, productivity and the level of comfort when using The End of Sitting as a permanent office.

  10. Elucidation of the conformational free energy landscape in H.pylori LuxS and its implications to catalysis

    Directory of Open Access Journals (Sweden)

    Bhattacharyya Moitrayee

    2010-08-01

    Full Text Available Abstract Background One of the major challenges in understanding enzyme catalysis is to identify the different conformations and their populations at detailed molecular level in response to ligand binding/environment. A detail description of the ligand induced conformational changes provides meaningful insights into the mechanism of action of enzymes and thus its function. Results In this study, we have explored the ligand induced conformational changes in H.pylori LuxS and the associated mechanistic features. LuxS, a dimeric protein, produces the precursor (4,5-dihydroxy-2,3-pentanedione for autoinducer-2 production which is a signalling molecule for bacterial quorum sensing. We have performed molecular dynamics simulations on H.pylori LuxS in its various ligand bound forms and analyzed the simulation trajectories using various techniques including the structure network analysis, free energy evaluation and water dynamics at the active site. The results bring out the mechanistic details such as co-operativity and asymmetry between the two subunits, subtle changes in the conformation as a response to the binding of active and inactive forms of ligands and the population distribution of different conformations in equilibrium. These investigations have enabled us to probe the free energy landscape and identify the corresponding conformations in terms of network parameters. In addition, we have also elucidated the variations in the dynamics of water co-ordination to the Zn2+ ion in LuxS and its relation to the rigidity at the active sites. Conclusions In this article, we provide details of a novel method for the identification of conformational changes in the different ligand bound states of the protein, evaluation of ligand-induced free energy changes and the biological relevance of our results in the context of LuxS structure-function. The methodology outlined here is highly generalized to illuminate the linkage between structure and function in

  11. France: energy prospects for 2050; France: perspectives energetiques pour 2050

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C.; Bacher, P

    2005-07-01

    This study analyzes 4 simple energy policy scenarios and their impact on the abatement of carbon dioxide emissions. The first scenario considers the same consumption rates as today and assumes that no oil and gas shortage and no environmental policy pressure will lead to a significant abatement of CO{sub 2} emissions. Two other extreme scenarios, on the contrary, consider a maximum reduction of the use of fossil fuels, one with the development of nuclear energy and the other without. The last scenario is intermediate between the extreme ones and considers the development of renewable energy sources and the implementation of important energy saving. The backward analysis of these scenarios indicates that nuclear energy and the development of renewable energies is necessary to reach the CO{sub 2} abatement goals expected for 2050 and that energy saving must be a priority. (J.S.)

  12. Energy in the Mediterranean: status, perspectives, constraints, and challenges

    International Nuclear Information System (INIS)

    Faid, M.K.

    2009-01-01

    In its first part, this report comments the differences between the north and the south of the Mediterranean Sea in terms of energy consumption, highlights the fact that energy resources are mainly located in the South and that energy flows are corresponding to a stronger demand by the North, and shows the high potential of renewable energies for this region. Then, it analyses the various concerns and constraints which can be noticed: uncertain supplies on a fluctuating market, a strong dependence on diesel and petrol, an unequal access to electricity, a high sensitivity to climatic change. The third part aims at demonstrating that energy could play a major role in the project of Mediterranean Union. Several potential themes are identified: development of North-South partnerships, status of hydrocarbon supply platform, potential development of the petrochemical industry, development of local markets, promotion of sustainable development, diversification of energy supply with the nuclear energy

  13. Energy prospects in the USA; Les perspectives energetiques aux USA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    This article summarizes the main trends of the US national energy plan sustained by the administration of President Bush: national energy policy development (diversification of energy supplies, development of an hydrogen economy), energy legislation (energy saving, development of renewable energy sources, promoting national production, budget discussion), re-launching of the nuclear sector: situation of the nuclear operators, competitiveness of nuclear energy, impact of deregulation on fusion/acquisition operations, role and liability of the federal administration (development of the Yucca Mountain (Nevada) disposal site for spent fuels, 'Nuclear Power 2010' initiative, long-term 'Generation IV' program, advanced fuel cycle program, hydrogen initiative and project of very high temperature reactor (VHTR) at the Idaho national laboratory). (J.S.)

  14. Perspectives of energy investments: production system; Perspectivas do investimento em energia: sistema produtivo

    Energy Technology Data Exchange (ETDEWEB)

    Bicalho, Ronaldo

    2009-04-15

    This paper analyses the investment dynamic of energy production system in Brazil, from the identification of the determining factors and discussions on the perspectives of the evolution of the investment of the production dynamic system - establishing the key questions for the definition of the system future in the Brazil, and proposing strategies, investments and energy politic actions which guarantee the necessary energy to the productive development of Brazil. (author)

  15. Wind energy in France: which perspectives at the year 2010 vista?; Energie Eolienne en France: quelles perspectives a l'horizon 2010?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The aim of this 3. national colloquium on wind energy was, first, to analyze the European context of the development of wind energy and to make a status of the first years of the French wind energy program. The aim was also to analyze the regional approach of wind power in the national energy plan with its field problems. The perspectives of offshore wind energy development have been considered too, both in France and in the rest of Europe, and the presentations have stressed on the formidable technical potentialities but also on the legal and administrative constraints of the offshore wind farms exploitation. The colloquium was concluded with visits of wind farms in the Languedoc-Roussillon region (S France). (J.S.) (The activities of this conference are further described in separate records that have been prepared for each day of the conference.)

  16. Spatial demographic models to inform conservation planning of golden eagles in renewable energy landscapes

    Science.gov (United States)

    Wiens, J. David; Schumaker, Nathan H.; Inman, Richard D.; Esque, Todd C.; Longshore, Kathleen M.; Nussear, Kenneth E

    2017-01-01

    Spatial demographic models can help guide monitoring and management activities targeting at-risk species, even in cases where baseline data are lacking. Here, we provide an example of how site-specific changes in land use and anthropogenic stressors can be incorporated into a spatial demographic model to investigate effects on population dynamics of Golden Eagles (Aquila chrysaetos). Our study focused on a population of Golden Eagles exposed to risks associated with rapid increases in renewable energy development in southern California, U.S.A. We developed a spatially explicit, individual-based simulation model that integrated empirical data on demography of Golden Eagles with spatial data on the arrangement of nesting habitats, prey resources, and planned renewable energy development sites. Our model permitted simulated eagles of different stage-classes to disperse, establish home ranges, acquire prey resources, prospect for breeding sites, and reproduce. The distribution of nesting habitats, prey resources, and threats within each individual's home range influenced movement, reproduction, and survival. We used our model to explore potential effects of alternative disturbance scenarios, and proposed conservation strategies, on the future distribution and abundance of Golden Eagles in the study region. Results from our simulations suggest that probable increases in mortality associated with renewable energy infrastructure (e.g., collisions with wind turbines and vehicles, electrocution on power poles) could have negative consequences for population trajectories, but that site-specific conservation actions could reduce the magnitude of negative effects. Our study demonstrates the use of a flexible and expandable modeling framework to incorporate spatially dependent processes when determining relative effects of proposed management options to Golden Eagles and their habitats.

  17. Perspective of energy policy in the U.S

    International Nuclear Information System (INIS)

    Pasamehmetoglu, Kemal O.

    2004-01-01

    U.S. National Energy Policy encourages the expanded use of nuclear energy while emphasizing the need for improved safeguards and proliferation resistance. The National Energy Policy, published in May 2001 cites that 'The National Energy Policy Development (NEPD) Group recommends that the President support the expansion of nuclear energy in the United States as a major component of our national energy policy.' However, the U.S. policy also emphasizes that the expansion of nuclear energy must be supported by the development of advanced safeguards and more proliferation resistant technologies. U.S. energy policy promotes emission free energy that is sustainable and economically viable. Current carbon dioxide concentrations in the atmosphere are approaching a record levels Of 380 ppm. It is widely believed that we are quickly approaching a 'carbon wall' when the concentrations reach somewhere between 450 ppm and 750 ppm. Further increases in CO 2 concentrations in the atmosphere are likely to result in serious changes in the atmosphere, even though the severity of the consequences may be debatable. Thus, to meet the growing energy demand worldwide, emission free energy sources are needed. At present, nuclear power is the only large-scale energy production technology that is economically competitive with fossil fuels. U.S. energy policy promotes the expansion of nuclear power while continuing research in 'renewable energy' forms. Meeting the growing energy demand of developing nations by clean energy forms is essential for world peace, prosperity and environmental integrity. Energy use will grow as developing countries achieve affluence. Affluence in developing countries will lead to more stable and peaceful world. Note that a world of 10 billion people consuming energy as US citizens do today would raise the world energy demand by 10 fold. Such a growth via the use of fossil fuel will result in resource shortfalls and regional conflicts, and serious environmental

  18. Canvassing the Cyber Security Landscape: Why Energy Companies Need to Pay Attention

    OpenAIRE

    Averill, B.; Luiijf, H.A.M.

    2010-01-01

    Recent news of a “highly sophisticated and targeted” cyber attack on Google, Yahoo, and perhaps on as many as a dozen other companies has once again brought the issue of cyber security to the top of the news. Internet companies, however, are not the only ones vulnerable to such attacks. Over the past decade, a series of events has highlighted the vulnerability of the electric grid and other energy infrastructures to both cyber disruptions (due, e.g., to malware) and from outside attacks using...

  19. Energy perspectives 2035 - Volume 3, effects on the national economy

    International Nuclear Information System (INIS)

    Voehringer, F.; Mueller, A.

    2007-01-01

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at the effects of the four scenarios concerning future developments in Swiss energy supply policy on the Swiss national economy. The four energy scenarios include variants entitled 'business as usual', 'increased co-operation', 'new priorities' and 'on the way to a 2000-Watt society'. This report presents and discusses the results of a dynamic balance model and includes an appendix that presents data on the external costs of the energy sector in Switzerland. Swiss energy scenarios are discussed in an international context and five climate-policy scenarios are developed. Effects on CO 2 emissions and energy consumption are discussed, as are socio-economic effects. The results of a so-called cross-impact analysis are discussed and the opinions of Swiss climate experts are reviewed. External costs are reviewed in a comprehensive appendix to the report

  20. Perspectives on Promoting Regional Renewable Energy Research and Development

    International Nuclear Information System (INIS)

    Dresselhaus, M.

    2008-01-01

    Recent discussions at the Washington International Renewable Energy Conference (WIREC), hosted in March 2008 by the United States Government, with nearly 9000 participants including 103 ministers from 126 countries, concluded that a major acceleration in the adoption of renewable energy technologies was needed by mid-century. Because of different climatic conditions and societal preferences, regional cooperation is expected to play a major role in the efficient adoption of appropriate renewable energy technologies, and countries with special expertise in specific technologies seem eager to collaborate internationally to promote global goals in renewable energy. A review will be given of what we learned from this conference about renewable energy research and development strategies with a special focus given to using this basic knowledge base to promote the development of renewable energy technologies appropriate to specific regions of the world.(author)

  1. Asia energy mixes from socio-economic and environmental perspectives

    International Nuclear Information System (INIS)

    Thavasi, V.; Ramakrishna, S.

    2009-01-01

    Sustainable clean energy is the top social, economic, and environmental agenda of political leaders, policy makers, enlightened business executives, and civil society in Asia. Strong economic growth in Asia has caused a great demand for energy which has resulted in an enormous increase in CO 2 emissions. The association of Southeast Asian nations (ASEAN), India, China, South Korea and Japan are the most important regions in Asia as their economies have been growing steadily. These countries though heavily dependent on fossil fuels have stepped up their measures towards low-carbon society amid domestic affordability challenges and changing global mindset. This report highlights the current energy scenario in these countries and their effort towards an affordable and sustainable clean energy future. The energy policy to enhance energy security and improve environmental sustainability is also explicated in this article. (author)

  2. Austria's Energy Perspectives - It's the Demand Side, Stupid

    International Nuclear Information System (INIS)

    Lechner, H.

    2009-01-01

    During the last decade Austria made remarkable progress in developing renewable energy sources. But at the same time energy demand has steadily increased so that the share of renewables in the energy mix has remained more or less stable over the years. Rising energy demand and import dependence is also forecast in a business-as-usual scenario for the future. If Austria is to fulfill the EU obligatory target to increase the share of renewables up to 34% in 2020 (recently 25%) and to move on a sustainable, low-carbon track it will have to decrease energy consumption or at least stabilise it at the level of 2005. This requires considerable efforts to boost energy efficiency, especially in the building and transport sector.(author).

  3. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.

    2015-05-01

    The energy demands of the brain are high: they account for at least 20% of the body\\'s energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization and expression of energy metabolism genes. Functional brain imaging techniques such as fMRI and PET, which are widely used in human neuroscience studies, detect signals that monitor energy delivery and use in register with neuronal activity. Recent technological advances in metabolic studies with cellular resolution have afforded decisive insights into the understanding of the cellular and molecular bases of the coupling between neuronal activity and energy metabolism and pointat a key role of neuron-astrocyte metabolic interactions. This article reviews some of the most salient features emerging from recent studies and aims at providing an integration of brain energy metabolism across resolution scales. © 2015 Elsevier Inc.

  4. 3D modeling of satellite spectral images, radiation budget and energy budget of urban landscapes

    Science.gov (United States)

    Gastellu-Etchegorry, J. P.

    2008-12-01

    DART EB is a model that is being developed for simulating the 3D (3 dimensional) energy budget of urban and natural scenes, possibly with topography and atmosphere. It simulates all non radiative energy mechanisms (heat conduction, turbulent momentum and heat fluxes, water reservoir evolution, etc.). It uses DART model (Discrete Anisotropic Radiative Transfer) for simulating radiative mechanisms: 3D radiative budget of 3D scenes and their remote sensing images expressed in terms of reflectance or brightness temperature values, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (ray tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. This paper presents two major and recent improvements of DART for adapting it to urban canopies. (1) Simulation of the geometry and optical characteristics of urban elements (houses, etc.). (2) Modeling of thermal infrared emission by vegetation and urban elements. The new DART version was used in the context of the CAPITOUL project. For that, districts of the Toulouse urban data base (Autocad format) were translated into DART scenes. This allowed us to simulate visible, near infrared and thermal infrared satellite images of Toulouse districts. Moreover, the 3D radiation budget was used by DARTEB for simulating the time evolution of a number of geophysical quantities of various surface elements (roads, walls, roofs). Results were successfully compared with ground measurements of the CAPITOUL project.

  5. Energy landscape and dynamics of brain activity during human bistable perception.

    Science.gov (United States)

    Watanabe, Takamitsu; Masuda, Naoki; Megumi, Fukuda; Kanai, Ryota; Rees, Geraint

    2014-08-28

    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fluctuating between three spatially distributed energy minimums: visual-area-dominant, frontal-area-dominant and intermediate states. Transitions between these energy minimums predicted behaviour, with participants whose brain activity tend to reflect the visual-area-dominant state exhibiting more stable perception and those whose activity transits to frontal-area-dominant states reporting more frequent perceptual switches. Critically, these brain activity dynamics are correlated with individual differences in grey matter volume of the corresponding brain areas. Thus, individual differences in the large-scale dynamics of brain activity link focal brain structure with bistable perception.

  6. Long-term perspectives: energy, development and the environment

    International Nuclear Information System (INIS)

    Nakicenovic, N.

    1997-01-01

    The worldwide demand for energy and the need to minimize the environmental impact present a challenge which has been addressed by the International Institute for Applied Systems Analysis (IIASA) and the World Energy Council (WEC). This paper summarizes the findings of a joint two-year IIASA-WEC study to explore the prospects for improving the global availability and quality of energy services, and the wider implications that these improvements may have. (Author)

  7. Harnessing social innovation for energy justice: a business model perspective

    OpenAIRE

    Hiteva, Ralitsa; Sovacool, Benjamin

    2017-01-01

    This paper uses a business model framework to discuss how principles of energy justice - in particular, equitable distribution of costs and benefits, affordability, due process and greater participation in decision-making - can be embedded in business model innovations for energy, through social innovation. The paper discusses four cases at different scales (local, subnational, regional and global) to highlight opportunities for introducing principles of energy justice into the core of busine...

  8. A Systemic Perspective on Innovation from Energy Efficiency Policy efforts

    DEFF Research Database (Denmark)

    Ruby, Tobias Møller

    In order to reduce climate change, resource scarcity and other global environmental issues major increases in energy efficiency are necessary throughout our energy system. Despite this daunting outlook and the fact that energy efficiency in most instances makes economic and environmental sense...... efficiency innovation activities where market demand and policy efforts appear to have the most impact. The thesis also goes in depth with a single sector to describe the complexities of innovation processes in energy efficiency and the noticeable role of policy. Overall the doctoral thesis provides...

  9. Canada's energy perspectives and policies for sustainable development

    International Nuclear Information System (INIS)

    Hofman, Karen; Li Xianguo

    2009-01-01

    A regression analysis is performed to make projections for the Canadian energy production and consumption. These have been increasing and are projected to increase even further in the near future. The primary energy production and consumption are projected to increase by 52% and 34%, respectively, by 2025 over 2004 if business as usual. The amount of fossil energy resources is finite and the extraction, transportation and combustion of fossil fuels cause environmental pollution and climate change. On the other hand, energy plays an important role in the economic and social development of Canada. Canada can develop further from an energy balance point of view, but this alone cannot be sustainable, because of the negative consequences of the major energy use on the environment. Application of energy localization and diversification is a promising solution, but in order to reach that, better energy efficiency and more use of renewable energy are necessary. Instead of non-compulsory policies Canada's policy approach should have more compulsory policies. Only then Canada can be made to develop further in a sustainable manner

  10. Perspectives of the civil use of nuclear energy

    International Nuclear Information System (INIS)

    Dally, A.

    1994-01-01

    The opening paper dealt with the topic of ''orientations of energy engineering within the stress field of ethical standards of value and natural law constraints'' (H.D. Schilling). Four plenary discussion rounds were held with limited time for all speakers on the subjects of energy demand and availability of resources; development of the worldwide demand for civil nuclear technology; environmental effects and special risks of nuclear energy uses; development prospects of reactor engineering, and a concluding panel discussion on the subject of what kind of energy policy understanding we need and how we can reach it. (orig./HP) [de

  11. Energy Needs and Environmental Demand - Seen from a Banker's Perspective

    International Nuclear Information System (INIS)

    Tietmeyer, Hans

    1998-01-01

    This presentation was given by the president of the Deutschen Bundesbank, who is also Chairman of the Board of Trustees of the German Federal Environmental Foundation. He said that the current low oil price had contributed to slow down the worldwide rise in prices at the various levels. The development in Japan is very important for Asia as a whole. Early stabilization of the economic and financial situation in Russia is very important for the world economy. The situation may be difficult in Southeast Asia and in the former Soviet states. But in other areas the world economy is doing well. The crisis countries must put their financial sectors in order, which involves financial restructuring and the creation of viable supervision systems and market economy conditions. Climate and environmental considerations must be borne in mind in the future progress of national and international energy policy. In the long run, more energy must come from renewable energy sources and the total energy consumption must go down. Many petroleum groups and energy suppliers are already investing substantial sums in solar energy. The German Government is sponsoring renewable energy sources by a number of programmes. Energy conservation is the simplest and cheapest way of protecting the climate and conserving resources. The idea that all energy should be renewable is a pipe dream of the future

  12. Diffusion of renewable energy technologies - barriers and stakeholders' perspectives

    DEFF Research Database (Denmark)

    Reddy, S.; Painuly, Jyoti P.

    2004-01-01

    State, India, as a case study, the paper develops a systematic classification of barriers to the adoption of RETs (economic, technological, market and institutional) and ranking them based on the perceptions of various stakeholders. The results provide evidence of how the consumers receive RET...... information and make decisions using their limited analytical capabilities. The analysis is used to enhance the knowledge by introducing ideas based on behavioural theory. Not only do these ideas help understanding the consumer perspective, they also help develop policy interventions. The aim is to define...

  13. Nuclear energy and the destiny of mankind - some criminological perspectives

    International Nuclear Information System (INIS)

    Harding, R.

    1983-01-01

    A contribution to the nuclear debate from a criminological perspective is presented. Deviance in human affairs is inevitable, but in the nuclear power industry it is essential to find a model which eliminates deviance altogether. Several analyses of the Three Mile Island accident are criticised. Even if all suggestions were to be adopted the system would still be defective. Australia's involvement in the nuclear fuel cycle is summarized. It is argued that, as a nation, Australia is uniquely well placed to renounce every aspect of the nuclear fuel cycle and in doing so gain moral authority to influence the fate of the rest of the world

  14. Impacts of the cultivation of energy crops for generation of biogas on the landscape structure and avifauna; Auswirkungen des Energiepflanzenanbaus zur Biogaserzeugung auf Landschaftsstruktur und Avifauna

    Energy Technology Data Exchange (ETDEWEB)

    Ruehmkorf, Hilke

    2011-07-01

    In its effort to implement new climate and energy policies, Germany has been heavily promoting the adoption of renewable energies. This has brought about a dramatic change in the use of arable land during the last years. The primary objective of this study was therefore to assess the effect of energy cropping on existing landscape structures in intensively cultivated regions in the course of the year. According to the available structural parameters an investigation was conducted to ascertain the fallout of energy plant cultivation on both migratory and overwintering birds. The period covered entailed the winter months. Both the advent of the energy crops as well as the associated biogas facilities that sprang up outside built-in areas seem to have reshaped the existing agricultural landscape. Hence, an additional aim of this study was to identify birds that use biogas plants for breeding or as a feeding habitat in winter. In conclusion, it can be asserted that energy crops can definitely contribute to the expansion of structural diversity in the agricultural landscape provided those energy crops were not cultivated on a large scale prior to the advent of the biogas facilities. Hence, there is still room for further energy crop diversification as its potential has not been exhausted. During the winter months mostly common species such as the carrion crow or the wood pigeon consider the maize fields as a viable source of nutrition. Cranes are seen as newcomers, as they probably started resting in the 'Boerde' precisely due to the advent of energy maize cultivation. And more availability of nourishment when the ground is covered by snow is another benefit the avifauna reaps from biogas plants. However, for endangered farmland birds this type of nutrition is a rarely used source, as it runs counter to their escape strategies and food preferences. For these species the habitat function and the food availability depends especially on how the land is managed (e

  15. Information Resources in High-Energy Physics Surveying the Present Landscape and Charting the Future Course

    CERN Document Server

    Gentil-Beccot, Anne; Mele, Salvatore; Holtkamp, Annette; O'Connell, Heath B; Brooks, Travis C

    2009-01-01

    Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most importan...

  16. Photovoltaic performance and the energy landscape of CH3NH3PbI3.

    Science.gov (United States)

    Zhou, Yecheng; Huang, Fuzhi; Cheng, Yi-Bing; Gray-Weale, Angus

    2015-09-21

    Photovoltaic cells with absorbing layers of certain perovskites have power conversion efficiencies up to 20%. Among these materials, CH3NH3PbI3 is widely used. Here we use density-functional theory to calculate the energies and rotational energy barriers of a methylammonium ion in the α or β phase of CH3NH3PbI3 with differently oriented neighbouring methylammonium ions. Our results suggest the methylammonium ions in CH3NH3PbI3 prefer to rotate collectively, and to be parallel to their neighbours. Changes in polarization on rotation of methylammonium ions are two to three times larger than those on relaxation of the lead ion from the centre of its coordination shell. The preferences for parallel configuration and concerted rotation, with the polarisation changes, are consistent with ferroelectricity in the material, and indicate that this polarisation is governed by methylammonium orientational correlations. We show that the field due to this polarisation is strong enough to screen the field hindering charge transport, and find this screening field in agreement with experiment. We examine two possible mechanisms for the effect of methylammonium ion rotation on photovoltaic performance. One is that rearrangement of methylammoniums promotes the creation and transport of charge carriers. Some effective masses change greatly, but changes in band structure with methylammonium rotation are not large enough to explain current-voltage hysteresis behaviour. The second possible mechanism is that polarization screens the hindering electric field, which arises from charge accumulation in the transport layers. Polarization changes on methylammonium rotation favour this second mechanism, suggesting that collective reorientation of methylammonium ions in the bulk crystal are in significant part responsible for the hysteresis and power conversion characteristics of CH3NH3PbI3 photovoltaic cells.

  17. A landscape ecology approach to assessing development impacts in the tropics: A geothermal energy example in Hawaii

    Science.gov (United States)

    Griffith, J.A.; Trettin, C.C.; O'Neill, R. V.

    2002-01-01

    Geographic information systems (GIS) are increasingly being used in environmental impact assessments (EIA) because GIS is useful for analysing spatial impacts of various development scenarios. Spatially representing these impacts provides another tool for landscape ecology in environmental and geographical investigations by facilitating analysis of the effects of landscape patterns on ecological processes and examining change over time. Landscape ecological principles are applied in this study to a hypothetical geothermal development project on the Island of Hawaii. Some common landscape pattern metrics were used to analyse dispersed versus condensed development scenarios and their effect on landscape pattern. Indices of fragmentation and patch shape did not appreciably change with additional development. The amount of forest to open edge, however, greatly increased with the dispersed development scenario. In addition, landscape metrics showed that a human disturbance had a greater simplifying effect on patch shape and also increased fragmentation than a natural disturbance. The use of these landscape pattern metrics can advance the methodology of applying GIS to EIA.

  18. Nuclear energy perspectives for electric power generation. 2004 vision

    International Nuclear Information System (INIS)

    Dias, Marcio Soares; Mattos, Joao Roberto Loureiro de; Vasconcelos, Vanderley de; Jordao, Elizabete

    2004-01-01

    This document is based on the forecasting of the Energy Information Administration/US Department of Energy (EIA/DOE) for the period of 2001-2025 which indicates a growing of 9,800 billions of kWh (73.6 per cent) in the world electric power consumption in that period

  19. Structures and perspectives of the Austrian energy system

    International Nuclear Information System (INIS)

    Wohlgemut, N.

    1992-03-01

    The technical tools for projecting future energy demand can be grouped into two broad categories: Firstly, time series or cross section data based econometric models which contain information about customers' past behavior and thus enable to judge the causal effects of economic factors like incomes and prices on energy demand (passive forecasting). Secondly, structural simulation models which indicate how energy services transform to flows of useful, final and primary energy. These models enable to estimate the technical potential of improving the energy application and energy transformation systems (active scenario approach). Comparison of the two approaches with respect to projections for future energy demand yields that, typically, in the short run of econometric approach will dominate the structural simulation model. In the long run, however, this relation will be reversed. The econometric models suffer lack of technical information necessary to describe the demand for energy. The structural simulation model enables an incorporation of technical factors like efficiencies and fuel shares. An application of the structural model is a simulation run describing a scenario in order to reduce the Austrian CO 2 -emissions according to the recommendations of the conference of Toronto

  20. Energy efficiency improvements in ammonia production--perspectives and uncertainties

    International Nuclear Information System (INIS)

    Rafiqul, Islam; Weber, Christoph; Lehmann, Bianca; Voss, Alfred

    2005-01-01

    The paper discusses the energy consumption and energy saving potential for a major energy-intensive product in the chemical industry-ammonia, based on technologies currently in use and possible process improvements. The paper consists of four parts. In the first part, mainly references to various ammonia production technologies are given. Energy consumption, emissions and saving potentials are discussed in the second part. Thereby, the situation in Europe, the US and India is highlighted and various data sources are compared. In the third part of the paper, a novel approach for modeling energy efficiency improvements is described that accounts for uncertainties and unobserved heterogeneity in the production processes. Besides new investments, revamping investments are also included in the modeling and the development of the production stock is accounted for. Finally, in the fourth part, this approach is applied to the modeling of energy efficiency improvements and CO 2 emission reductions in ammonia production. Thereby, considerable improvements in specific energy use and CO 2 emissions are found in the reference scenario, yet under the assumption of high oil and gas prices, a partial switch to coal based technologies is expected which lowers notably the CO 2 efficiency. Introduction of a CO 2 penalty under a certificate trading or other regime is on contrary found to foster energy efficiency and the use of low carbon technologies