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.

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)

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...

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

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.

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.

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

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

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

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

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.

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

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.

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.

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.

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.

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.

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.

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.

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...

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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....

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)

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.

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...

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.

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

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

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)

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

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.

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.

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)

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

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.

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...

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

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.

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.

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

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.

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

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.

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...

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.

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

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.

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.

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...

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.

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.

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

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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.

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

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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.

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.

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.

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.

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

Coupling movement and landscape ecology for animal conservation in production landscapes.

Science.gov (United States)

Doherty, Tim S; Driscoll, Don A

2018-01-10

Habitat conversion in production landscapes is among the greatest threats to biodiversity, not least because it can disrupt animal movement. Using the movement ecology framework, we review animal movement in production landscapes, including areas managed for agriculture and forestry. We consider internal and external drivers of altered animal movement and how this affects navigation and motion capacities and population dynamics. Conventional management approaches in fragmented landscapes focus on promoting connectivity using structural changes in the landscape. However, a movement ecology perspective emphasizes that manipulating the internal motivations or navigation capacity of animals represents untapped opportunities to improve movement and the effectiveness of structural connectivity investments. Integrating movement and landscape ecology opens new opportunities for conservation management in production landscapes. © 2018 The Authors.

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...

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,

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.

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.

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.

Human Needs as an Approach to Designed Landscapes

Directory of Open Access Journals (Sweden)

Dalia Aly

2018-03-01

Full Text Available The traditional approach of landscape architecture has always focused on the aesthetic and visual aspects of landscapes while giving less attention to other aspects. This view has limited the benefits that can be derived from designed landscapes, despite the wide-ranging potential they carry for humans; socially, environmentally and economically. As a result, many researchers and practitioners are currently challenging this view to develop a more holistic and multidimensional approach. The present research therefore aims at proposing a new perspective for public designed landscapes based on fundamental human needs. The study methodology was comprised of critical content analysis for three main domains: sustainable development, human needs in specific relation to public landscapes, and significant approaches to fundamental human needs. Reconciliation among these domains was achieved based on a modified version of Max-Neef’s matrix of fundamental human needs. Human needs in public landscapes were merged into the matrix to reach a comprehensive yet specific perspective. The study concluded with a conceptual framework that can provide a wider perspective to human needs in designed landscapes. It proposes a new tool for the analysis of the benefits of public landscapes and their value for humans, which can be further used in various applications.

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

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.

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).

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

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

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.

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

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.

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

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.

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.

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.

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.

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...

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

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

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)

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.

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.

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.

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.

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.

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.

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

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.

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.

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

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.

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.

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.

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

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

Fatal Attraction. Nazi Landscapes, Modernity and the Holocaust

NARCIS (Netherlands)

van der Laarse, R.; Kolen, J.C.A.; Renes, H.; Hermans, R.

2015-01-01

Geographical, Historical and Archaeological Perspectives on the Production and Transmission of Landscapes Landscape Biographies € 98,99 ISBN:9789048517800 Verschijningsdatum:07-05-2015 Leverbaar: Direct Uitvoering: PDF Aantal paginas:336 Redacteur:Jan Kolen, Rita Hermans, Hans Renes Ook verkrijgbaar

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.

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

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...

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.

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.

Proceedings: views from the ridge—considerations for planning at the landscape scale.

Science.gov (United States)

Hermann Gucinski; Cynthia Miner; Becky Bittner

2004-01-01

When resource managers, researchers, and policymakers approach landscape management, they bring perspectives that reflect their disciplines, the decisions they make, and their objectives. In working at a landscape level, they need to begin developing some common scales of perspective across the variety of forest ownerships and usages. This proceedings is a compilation...

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

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...

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.

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.)

Mind the gap: modelling event-based and millennial-scale landscape dynamics

NARCIS (Netherlands)

Baartman, J.E.M.

2012-01-01

This research looks at landscape dynamics – erosion and deposition – from two different perspectives: long-term landscape evolution over millennial timescales on the one hand and short-term event-based erosion and deposition at the other hand. For the first, landscape evolution models (LEMs) are

Introduction to Ecological Landscaping: A Holistic Description and Framework to Guide the Study and Management of Urban Landscape Parcels

Directory of Open Access Journals (Sweden)

Parwinder Grewal

2008-01-01

Full Text Available Urbanized ecosystems and urban human populations are expanding around the world causing many negative environmental effects. A challenge for achieving sustainable urban social-ecological systems is understanding how urbanized landscapes can be designed and managed to minimize negative outcomes. To this end, an interdisciplinary Ecological Landscaping conference was organized to examine the interacting sociocultural and ecological causes and consequences of landscaping practices and products. This special issue of Cities and the Environment contains a diverse set of articles arising from that conference. In this introductory paper, we describe the meaning of ecological landscaping and a new conceptual framework that helps organize the topic’s complex issues. The essence of ecological landscaping is a holistic systems-thinking perspective for understanding the interrelationships among physical-ecological and sociocultural variables that give rise to the patterns and processes of biodiversity, abiotic conditions, and ecosystem processes within and among individually-managed urban landscape parcels. This perspective suggests that 1 variables not considered part of traditional landscaping and 2 the effects of landscaping within an individual parcel on variables outside of it must both be considered when making design and management decisions about a parcel. To illustrate how these points help create a more holistic, ecological approach to landscaping, a traditional ecosystem model is used to create a framework for discussing how sociocultural and physical-ecological inputs to a landscape parcel affect its characteristics and outputs. As exemplified by papers in this issue, an integrated sociocultural-ecological approach to the study of urban landscaping practices and products is needed to 1 understand why and how humans design and mange urban landscape parcels, 2 describe how the combined characteristics and outputs of many parcels give rise to the

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...

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...

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

Ecological effects of harvesting biomass for energy in the Spanish Mediterranean

International Nuclear Information System (INIS)

Zavala, Miguel A.; Marcos, Francisco

1993-01-01

Biomass utilization for energy has major consequences for Spanish Mediterranean landscapes. In this paper we present a synthesis of the ecological effects of harvesting biomass for energy. We compare these effects with other fuel reduction procedures such as prescribed burning. Throughout history we see that some Iberian ecosystems are stabilized by long human interference. One of the stabilizing factors is the utilization of wood as a source of energy. New energy sources and massive human movements towards urban areas have changed the ecosystem dynamics. Reforested areas in Spain during the period from 1940 to 1970 included silviculture treatments that in some cases never took place. This has led to a greater accumulation of biomass. The current perspective of the problem must be analyzed from an economic and political viewpoint. For instance, the Middle East crisis has direct consequences for the budget dedicated to forest energetics, and consequently for the landscape. This shows how ecological problems must be dealt with using a very broad perspective. In Spain current biomass usage should be considered primarily as a complementary silvicultural treatment rather than as a way of producing great biomass outputs. If we are going to manage our forest from an ecological perspective, we have to analyze the effects of these operations at the stand level. At the landscape level fuel management plans should be included in the Forest Management Prescriptions (ordenaciones) whether in terms of harvesting or in a prescribed burning plan

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)

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.

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...

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.

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...

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

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...

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...

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

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.

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.

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

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.

Sustaining ecosystem services in cultural landscapes

Directory of Open Access Journals (Sweden)

Tobias Plieninger

2014-06-01

Full Text Available Classical conservation approaches focus on the man-made degradation of ecosystems and tend to neglect the social-ecological values that human land uses have imprinted on many environments. Throughout the world, ingenious land-use practices have generated unique cultural landscapes, but these are under pressure from agricultural intensification, land abandonment, and urbanization. In recent years, the cultural landscapes concept has been broadly adopted in science, policy, and management. The interest in both outstanding and vernacular landscapes finds expression in the UNESCO World Heritage Convention, the European Landscape Convention, and the IUCN Protected Landscape Approach. These policies promote the protection, management, planning, and governance of cultural landscapes. The ecosystem services approach is a powerful framework to guide such efforts, but has rarely been applied in landscape research and management. With this paper, we introduce a special feature that aims to enhance the theoretical, empirical and practical knowledge of how to safeguard the resilience of ecosystem services in cultural landscapes. It concludes (1 that the usefulness of the ecosystem services approach to the analysis and management of cultural landscapes should be reviewed more critically; (2 that conventional ecosystem services assessment needs to be complemented by socio-cultural valuation; (3 that cultural landscapes are inherently changing, so that a dynamic view on ecosystem services and a focus on drivers of landscape change are needed; and (4 that managing landscapes for ecosystem services provision may benefit from a social-ecological resilience perspective.

Landscaping and landscape ecology in the management of tree plantation. A reference to the city of Medellin, Colombia

International Nuclear Information System (INIS)

Velez Restrepo, Luis Anibal

2007-01-01

The paper constitutes a reflection around the urban landscape, whit reference to Medellin, likewise around the landscaping and ecological potential that the city has along its terrain, its empty lots, without urbanizing, and especially, thanks to the tree plantation that its streets display. It is questioned the absence of a landscaping dimension in the urban planning; the increasing deterioration of the panoramic qualities; and the gradual loss of green spaces. At the same time, it is emphasized the importance that such tree planting has in the landscape, from the visual, social and environmental point of view. The work discusses the tendency to the artificiality of tree planting on sidewalks and vial road separators, raising conceptual limitations associated to the scale tree to tree, to the lack of incorporation of ecological landscape relations related to its handling, and to the landscaping approach within the framework of the urban designing. The reflection leans on data of the concrete situation, suggesting the complementary role that the vegetation could accomplish in streets and avenues with a perspective of ecological connectivity of the landscape

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

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

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)

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

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.

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

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

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

Perspectives East and West

Directory of Open Access Journals (Sweden)

Ken-ichi Sasaki

2013-01-01

Full Text Available The object of this paper is to elucidate the sense of space peculiar to Japanese sensibility. To accomplish this task I consult not only paintings but also waka, distinctively Japanese poetry. I also compare the structures of Japanese and Western perspective in order to highlight the distinctive features of the Japanese sense of space. In China and Japan, traditional landscape painting was called sansui painting, literally, painting of “mountains and waters,” unlike fūkei painting, which is a modern adaptation of the Western notion of landscape. Landscape as sansui is characterized by its vitalistic conception: the cosmic space is filled with ki, a vital and spiritual element. This view is reflected in the Japanese notion of keshiki (literally, color of ki, another word meaning landscape, to which I pay particular attention because it is a vernacular word and expresses the genuine Japanese sense of space, differentiated even from the Chinese perspective found in Sansui paintings. Such a space as keshiki was to be felt rather than seen. The notion of the picturesque was associated in Japan with a spatial extent. It is a concept closely related to a humid climate that produces much fog or haze. A typical description is found in the Tale of Genji. It is in waka, from the thirteenth century, that we find the first expression of Japanese perspective, which consists the combination of a tactile, sometimes auditory close range with the visual, distant range, yet without a middle range (which is obscured by fog. This is very different from Western geometrical perspective, which is essentially constituted by the middle range relating the close continuously to the distant. In painting, this Japanese perspective was realized for the first time in ukiyo-e, particularly in the work of Hokusai and Hiroshige. I assume that this composition was transplanted to the Western world during the fashion for “japonisme,” and now determines the basic

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.

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.)

New energy horizons

International Nuclear Information System (INIS)

Berg, Eugene

2015-01-01

In a context of high oil price decrease, and based on various publications on energy (journals and books), the author proposes a synthetic overview of evolutions of the energy landscape. He first addresses the emergence of shale gas and oil which raises the issue of energy independence. He sheds a light on the different types of gas and on extraction techniques, comments statistics on the evolution of consumption and the status of reserves. He addresses issues related to the geopolitics of energies: the energy issue for Europe, the situation of historic Middle-East leader countries in front of emerging energy producing countries, the US dream of energy self-sufficiency, and the game between great powers. The last part addresses major energy perspectives in terms of sources, of fossil share in electric power production

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

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

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.

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.)

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

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.

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.

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.

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

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

Governing Forest Landscape Restoration: Cases from Indonesia

Directory of Open Access Journals (Sweden)

Cora van Oosten

2014-05-01

Full Text Available Forest landscape restoration includes both the planning and implementation of measures to restore degraded forests within the perspective of the wider landscape. Governing forest landscape restoration requires fundamental considerations about the conceptualisation of forested landscapes and the types of restoration measures to be taken, and about who should be engaged in the governance process. A variety of governance approaches to forest landscape restoration exist, differing in both the nature of the object to be governed and the mode of governance. This paper analyses the nature and governance of restoration in three cases of forest landscape restoration in Indonesia. In each of these cases, both the original aim for restoration and the initiators of the process differ. The cases also differ in how deeply embedded they are in formal spatial planning mechanisms at the various political scales. Nonetheless, the cases show similar trends. All cases show a dynamic process of mobilising the landscape’s stakeholders, plus a flexible process of crafting institutional space for conflict management, negotiation and decision making at the landscape level. As a result, the landscape focus changed over time from reserved forests to forested mosaic lands. The cases illustrate that the governance of forest landscape restoration should not be based on strict design criteria, but rather on a flexible governance approach that stimulates the creation of novel public-private institutional arrangements at the landscape level.

Probing Free-Energy Surfaces with Differential Scanning Calorimetry

Science.gov (United States)

Sanchez-Ruiz, Jose M.

2011-05-01

Many aspects of protein folding can be understood in terms of projections of the highly dimensional energy landscape onto a few (or even only one) particularly relevant coordinates. These free-energy surfaces can be probed conveniently from experimental differential scanning calorimetry (DSC) thermograms, as DSC provides a direct relation with the protein partition function. Free-energy surfaces thus obtained are consistent with two fundamental scenarios predicted by the energy-landscape perspective: (a) well-defined macrostates separated by significant free-energy barriers, in some cases, and, in many other cases, (b) marginal or even vanishingly small barriers, which furthermore show a good correlation with kinetics for fast- and ultrafast-folding proteins. Overall, the potential of DSC to assess free-energy surfaces for a wide variety of proteins makes it possible to address fundamental issues, such as the molecular basis of the barrier modulations produced by natural selection in response to functional requirements or to ensure kinetic stability.

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

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

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

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.)

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.

EVERYDAY LANDSCAPE AND MEANING IN URBAN LIVING

Directory of Open Access Journals (Sweden)

LAKSHMI PRIYA RAJENDRAN

2013-11-01

Full Text Available This paper conceptualizes landscape from a temporal and spatial perspective which emphasizes peoples’ interactions and activities as an inherent part of understanding the landscape itself. Today, peoples’ interaction with the landscape has become more complex, largely owing to the changing notions of place in contemporary urban living. In this context, the paper examines the role and significance of the landscapes of everyday life in urban environment and delineates how it (reconstructs ordinary human and social meanings that are necessary conditions for our existence. The paper is presented in three sections. In the first section, it discusses the concept of everyday life and its relevance in the contemporary urban living. In the following section, it examines the complexities encountered in urban landscapes today .The third section of the paper discusses how meaningful interaction experienced with everyday landscapes offer valuable insights for addressing the challenges posed by the complexities of urban city living. The paper concludes by highlighting the need for attention towards the largely neglected or overlooked domains of ‘ordinary’ everyday landscape by designer professionals, which plays a crucial role in creating meaningful relationship between people and place.

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

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)

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.

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.

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.

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.

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.

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.

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...

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)

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.

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.

Influence of forest planning alternatives on landscape pattern and ecosystem processes in northern Wisconsin, USA

Science.gov (United States)

Patrick A. Zollner; L. Jay Roberts; Eric J. Gustafson; Hong S. He; Volker Radeloff

2008-01-01

Incorporating an ecosystem management perspective into forest planning requires consideration of the impacts of timber management on a suite of landscape characteristics at broad spatial and long temporal scales. We used the LANDIS forest landscape simulation model to predict forest composition and landscape pattern under seven alternative forest management plans...

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.

Re-wilding Europe's traditional agricultural landscapes: Values and the link between science and practice

Science.gov (United States)

Paul H. Gobster

2014-01-01

Landscape and Urban Planning encourages multiple perspectives and approaches to help understand landscapes as social-ecological systems, with the goal that by building a robust science of landscape we can provide sustainable solutions for guiding its change. But the link between science and practice, or more simply put, between knowledge and action, is not always clear...

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.

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

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.

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,

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.

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.

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

Probing the string landscape: Implications, applications, and altercations

Science.gov (United States)

Dienes, Keith R.

2015-01-01

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.

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.

The heritage and landscapes: new concepts for old ideas?

Directory of Open Access Journals (Sweden)

Vanessa Gayego Bello Figueiredo

2013-12-01

Full Text Available This article investigates the relationship between landscape and heritage and brings a brief critical analysis of the United Nations Educational, Scientific and Cultural Organization (UNESCO practice since the institutionalization of cultural landscape category, created on the World Heritage list in 1992, until 2012. The text is structured in three parts. The first presents a brief historical approach about the concept of Western landscape. The second presents recent formulations on the cultural landscape based on international conventions, such as the Council of Europe (1995 and the Landscape European Convention (2000. The third part focuses on the analysis of the World Heritage Committee work, comprising the main characteristics and values of cultural landscapes listed. Finally, the study reveals how the employment of this new concept is still reflecting old conceptions of landscape and preservation, although points towards perspective in the heritage policies, especially as regards the own expansion of the heritage concept and the approximation between the natural and cultural, material and immaterial dimensions.

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.

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

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.

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.

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.)

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.

Smart Landscape. The architecture of the "micro smart grid" as a resilience strategy for landscape

OpenAIRE

Garbarini, Giulia

2018-01-01

“Smart Landscape”, starting from energy devices for the management and distribution of electricity resources, tends to define a possible vision of landscape. The main structure and process are based on the architecture of a “micro smart grid”, which is generally associated with urban energy grids and districts, but may become a figurative reference for new forms of landscape, such as “Smart Landscape”. The output of the research would be to show how the main strategies of “Smart Landsc...

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.

Classification of Farmland Landscape Structure in Multiple Scales

Science.gov (United States)

Jiang, P.; Cheng, Q.; Li, M.

2017-12-01

Farmland is one of the basic terrestrial resources that support the development and survival of human beings and thus plays a crucial role in the national security of every country. Pattern change is the intuitively spatial representation of the scale and quality variation of farmland. Through the characteristic development of spatial shapes as well as through changes in system structures, functions and so on, farmland landscape patterns may indicate the landscape health level. Currently, it is still difficult to perform positioning analyses of landscape pattern changes that reflect the landscape structure variations of farmland with an index model. Depending on a number of spatial properties such as locations and adjacency relations, distance decay, fringe effect, and on the model of patch-corridor-matrix that is applied, this study defines a type system of farmland landscape structure on the national, provincial, and city levels. According to such a definition, the classification model of farmland landscape-structure type at the pixel scale is developed and validated based on mathematical-morphology concepts and on spatial-analysis methods. Then, the laws that govern farmland landscape-pattern change in multiple scales are analyzed from the perspectives of spatial heterogeneity, spatio-temporal evolution, and function transformation. The result shows that the classification model of farmland landscape-structure type can reflect farmland landscape-pattern change and its effects on farmland production function. Moreover, farmland landscape change in different scales displayed significant disparity in zonality, both within specific regions and in urban-rural areas.

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

Initial conditions for slow-roll inflation in a random Gaussian landscape

Energy Technology Data Exchange (ETDEWEB)

Masoumi, Ali; Vilenkin, Alexander; Yamada, Masaki, E-mail: ali@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: Masaki.Yamada@tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)

2017-07-01

In the landscape perspective, our Universe begins with a quantum tunneling from an eternally-inflating parent vacuum, followed by a period of slow-roll inflation. We investigate the tunneling process and calculate the probability distribution for the initial conditions and for the number of e-folds of slow-roll inflation, modeling the landscape by a small-field one-dimensional random Gaussian potential. We find that such a landscape is fully consistent with observations, but the probability for future detection of spatial curvature is rather low, P ∼ 10{sup −3}.

Architecture as animate landscape: circular shrines in the ancient Maya lowlands.

Science.gov (United States)

Harrison-Buck, Eleanor

2012-01-01

In this study, I develop a theory of landscape archaeology that incorporates the concept of “animism” as a cognitive approach. Current trends in anthropology are placing greater emphasis on indigenous perspectives, and in recent decades animism has seen a resurgence in anthropological theory. As a means of relating in (not to) one's world, animism is a mode of thought that has direct bearing on landscape archaeology. Yet, Americanist archaeologists have been slow to incorporate this concept as a component of landscape theory. I consider animism and Nurit Bird-David's (1999) theory of “relatedness” and how such perspectives might be expressed archaeologically in Mesoamerica. I examine the distribution of marine shells and cave formations that appear incorporated as architectural elements on ancient Maya circular shrine architecture. More than just “symbols” of sacred geography, I suggest these materials represent living entities that animate shrines through their ongoing relationships with human and other-than-human agents in the world.

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

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.

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.

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.

Nonequilibrium landscape theory of neural networks.

Science.gov (United States)

Yan, Han; Zhao, Lei; Hu, Liang; Wang, Xidi; Wang, Erkang; Wang, Jin

2013-11-05

The brain map project aims to map out the neuron connections of the human brain. Even with all of the wirings mapped out, the global and physical understandings of the function and behavior are still challenging. Hopfield quantified the learning and memory process of symmetrically connected neural networks globally through equilibrium energy. The energy basins of attractions represent memories, and the memory retrieval dynamics is determined by the energy gradient. However, the realistic neural networks are asymmetrically connected, and oscillations cannot emerge from symmetric neural networks. Here, we developed a nonequilibrium landscape-flux theory for realistic asymmetrically connected neural networks. We uncovered the underlying potential landscape and the associated Lyapunov function for quantifying the global stability and function. 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. We applied our theory to rapid-eye movement sleep cycle. We identified the key regulation factors for function through global sensitivity analysis of landscape topography against wirings, which are in good agreements with experiments.

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

Social perception of the forest landscape in Trentino-Alto Adige (Italy: comparison of case studies

Directory of Open Access Journals (Sweden)

Pastorella F

2016-12-01

Full Text Available The landscape is the product of human activities and nature as developed during the centuries. However, the landscape has a symbolic value because it can be considered the identity and culture of a territory that includes the values and beliefs of local population. The Alpine landscape is a unicum in the world due to its geomorphologic, climatic and vegetation characteristics and socio-economic conditions of local population. Over the centuries the social perception of Alps has changed: in a first phase the Alps were considered “horrible and scary mountains”, later Alps were perceived as “beautiful and fascinating places”, and currently the Alpine mountains are considered a place of relaxation and recreation. The analysis of landscape perception aimed to investigate the visitors’ opinions about landscape is an important instrument to support the decision concerning the land planning and management. This study focuses on the analysis of the aesthetic perception of visitors on Alpine landscapes following two perspectives: a first overall perspective considering the landscape as a mosaic of different land uses and a second perspective of detail observing the individual components that characterize the forest landscape. The aim of the study is to identify the most appreciated elements of landscape from the aesthetic point of view and the influence of socio-demographic characteristics of respondents on individual perception. In order to investigate the perception about the Alpine landscapes 358 visitors of two sites of Trentino-Alto Adige (Val di Genova and Santa Maria lake were interviewed using a structured questionnaire. The results show that the most appreciated elements of the landscape by the visitors are water (lakes and rivers and forests. These preferences are also conditioned by the site where the interviews were made. In addition, the results show that for the respondents of this survey the forest with the highest attractiveness

Revolutionary landscapes: the PCTP/MRPP mural paintings in the Lisbon Metropolitan Area

Directory of Open Access Journals (Sweden)

Andre Carmo

2011-12-01

Full Text Available This article investigates the mural paintings made by the PCTP/MRPP in the Lisbon Metropolitan Area, in the aftermath of the 1974 Portuguese revolution. Drawing on Erwin Panofsky’s iconographic method of interpretation, murals are explored from an integrated landscape approach that combines two perspectives: landscapes as representations and landscapes as material artifacts. Findings suggest that the PCTP/MRPP mural paintings translated the visual ideology of social transformation and revolution underlying its politics. Furthermore, they also crystallized performative revolutionary landscapes, in the sense that they materialized acts of collective artistic citizenship, in which the social space of mural production played a fundamental role.

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...

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

Wind energy - Opinions of the ADEME

International Nuclear Information System (INIS)

2016-04-01

This publication proposes brief presentations and discussions and some data related to the production of electricity by means of wind energy: principle and description, key data (international context, electric power production in France, economic development of the sector), status of knowledge regarding various aspects (assets of wind energy, a clean and local energy, a predictable and manageable source, an increasing competitiveness, a focus on offshore wind energy, control of acoustic and landscape impacts, protection of biodiversity, management of interactions with radars, a steady and clear regulation), perspectives of evolution (a sector of innovations, an opportunity for the development of circular economy, promotion of a participative and citizen wind energy), the case a small units, actions undertaken by the ADEME, and global opinion by the ADEME

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.

Ecological economics of North American integration: the reshaping of the economic landscape in the Santiago river basin

Directory of Open Access Journals (Sweden)

Salvador Peniche Camps

2017-06-01

Full Text Available Ecological Economics studies social metabolism; that is, the material and energy flow into and out of the economy. Using the ecological economics perspective, we analyse the transformation of the economic landscape of the Santiago river basin, Mexico. We discuss why the appropriation of water resources is one of the most important drivers of North American economic integration. We argue that the theoretical model of neo-extractivism can explain the dynamics of social metabolism behind the North American Free Trade Agreement (NAFTA.

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 ...

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.

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.

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.

Concept of a landscape map according to Professor Franciszek Uhorczak

Directory of Open Access Journals (Sweden)

Meksuła Mirosław W.

2016-09-01

Full Text Available In the article, the concept of landscape maps by Franciszek Uhorczak (1902–1981, Professor of the Maria Curie-Skłodowska University in Lublin, was discussed. The maps constitute a cartographic illustration of volume III, IV and V of “Universal Geography” edited by Państwowe Wydawnictwo Naukowe (the National Scientific Publishing House (Warsaw 1965–1967 – the first Polish small-scale landscape maps of the world. From the perspective of the 50s, an attempt was undertaken to assess the editorial assumptions, landscape typology and selection of cartographic means used by the author, paying special attention to the selection of colours representing landscapes. Also, issues raising controversies related to the degree of generalization of particular elements of the content, typology of landscapes as well as map details were indicated. The performed analysis leads to the conclusion that landscape maps by Professor F. Uhorczak constituted one of the most significant achievements of Polish thematic cartography of the 20th century, and they are an unequaled model also for the contemporary cartographers.

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.

Opportunities and challenges for a sustainable energy future.

Science.gov (United States)

Chu, Steven; Majumdar, Arun

2012-08-16

Access to clean, affordable and reliable energy has been a cornerstone of the world's increasing prosperity and economic growth since the beginning of the industrial revolution. Our use of energy in the twenty-first century must also be sustainable. Solar and water-based energy generation, and engineering of microbes to produce biofuels are a few examples of the alternatives. This Perspective puts these opportunities into a larger context by relating them to a number of aspects in the transportation and electricity generation sectors. It also provides a snapshot of the current energy landscape and discusses several research and development opportunities and pathways that could lead to a prosperous, sustainable and secure energy future for the world.

Modern Christian Landscape in Nanjing, China: A Literature Review

Directory of Open Access Journals (Sweden)

Cheng Fang

2017-11-01

Full Text Available Between the First Opium War in 1840 and the founding of the People’s Republic of China in 1949, the development of modern Christianity in Nanjing expanded beyond the parameters of faith and spirituality, while interacting closely with Nanjing’s city life and space across a wider spectrum, such that a unique religious and cultural landscape was produced. Through an extensive literature review of 115 articles identified on this topic, this paper analyzes the development of the space of Christian churches in Nanjing, and further documents the pattern of interactions between Nanjing’s development as a modern city and its religious cultural landscape. Moreover, drawing from the theoretical perspective of Sense of Place, the paper summarizes the characteristics of religious cultural landscape in the aspects of vision and structure, function and modernization, and memory and identity, and points out that the Christian landscape should also be conducted from the activation of material form, local functions and historical meanings to achieve sustainable development of Christian landscape. Finally, the paper offers planning and design strategies for the continued growth of Christian landscape in Nanjing.

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)

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.)

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.)

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.

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.

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

Development of delta professionals: the need for fundamental change in mainstream education on landscape related issues

NARCIS (Netherlands)

Groot, A.M.E.

2003-01-01

Landscapes are under severe pressure. These landscapes are being used for several functions and interests that compete with each other for influence on and space in the countryside. The application of only a disciplinary or sectoral perspective does no longer provide us with satisfactory answers for

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.

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.

VIRTUAL MUSEUMS FOR LANDSCAPE VALORIZATION AND COMMUNICATION

Directory of Open Access Journals (Sweden)

E. Pietroni

2017-08-01

Full Text Available Research in the domain of landscape virtual reconstructions has been mainly focused on digitization and recording inside GIS systems, or real time visualization, paying a minor attention to the development of a methodological approach for the landscape narration, combing different registers, conceptual, emotional incitements and, thus, able to arouse in the public a feeling of emotional “sensing” and self- identification. The landscape reflects also the human activities in the territory and the communities’ cultural patterns, their sense of “belonging”. In a virtual museum of landscapes, the multidisciplinary approach, the multiplication of perspectives and voices, storytelling, acquire primary importance. A Virtual Museum of landscapes should integrate both holistic and delimited visions. The holistic vision requires a diachronic approach, including both present and past phases of life. On the other side, delimited, or “monographic”, representations are useful to go deeper into specific and exemplar stories, regarding specific groups of people. Beside, the emergence of new social media enhancing cultural interactions among people induce the creation of specific social platforms for Cultural Heritage for the active participation of a large number of stakeholders. Co-creation scenarios and tools can be particularly promising. Aton is an example of front-end VR social platform in the web end, for the efficient streaming of medium/large landscape, their exploration and characterization. The Tiber Valley Virtual Museum is an example of sensorial cultural landscape. Starting from the acquisition of topographical data through integrated technologies, several multi-sensory scenarios have been created, inside which visitors can feel embodied and involved.

Virtual Museums for Landscape Valorization and Communication

Science.gov (United States)

Pietroni, E.

2017-08-01

Research in the domain of landscape virtual reconstructions has been mainly focused on digitization and recording inside GIS systems, or real time visualization, paying a minor attention to the development of a methodological approach for the landscape narration, combing different registers, conceptual, emotional incitements and, thus, able to arouse in the public a feeling of emotional "sensing" and self- identification. The landscape reflects also the human activities in the territory and the communities' cultural patterns, their sense of "belonging". In a virtual museum of landscapes, the multidisciplinary approach, the multiplication of perspectives and voices, storytelling, acquire primary importance. A Virtual Museum of landscapes should integrate both holistic and delimited visions. The holistic vision requires a diachronic approach, including both present and past phases of life. On the other side, delimited, or "monographic", representations are useful to go deeper into specific and exemplar stories, regarding specific groups of people. Beside, the emergence of new social media enhancing cultural interactions among people induce the creation of specific social platforms for Cultural Heritage for the active participation of a large number of stakeholders. Co-creation scenarios and tools can be particularly promising. Aton is an example of front-end VR social platform in the web end, for the efficient streaming of medium/large landscape, their exploration and characterization. The Tiber Valley Virtual Museum is an example of sensorial cultural landscape. Starting from the acquisition of topographical data through integrated technologies, several multi-sensory scenarios have been created, inside which visitors can feel embodied and involved.

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.

AN EVALUATION OF THE SPATIAL DIMENSION OF LANDSCAPE ...

African Journals Online (AJOL)

Osondu

2012-03-30

Mar 30, 2012 ... with adequate landscaping, - using landscape elements, to create a ... air, water and energy cycles that replenish and rejuvenate ... First, using the street map of. Ogbomoso ... swimming pools, etc, were regarded as conscious.

Social acceptance of solar energy technologies in China-End users' perspective

International Nuclear Information System (INIS)

Yuan Xueliang; Zuo Jian; Ma Chunyuan

2011-01-01

Energy is essential to human beings. The increasing demand of energy has triggered the public scrutiny on the sustainability issues associated with the energy production and transmission. There have been a large number of studies focusing on reducing the environmental impacts associated with the energy sector. Renewable energy sources such as solar energy have been prompted to mitigate these environmental impacts. This research adopted a quantitative approach to investigate the social acceptance of solar energy technologies from end users' perspective in Shandong province, China. A large scale questionnaire survey was conducted. The results show that there is a considerable high level of social acceptance and public awareness of solar water heater. However, another major application of solar energy, solar PV has not gained a high level of social acceptance or public awareness in Shandong. This study provides useful references for policy makers to further promote the utilization of solar energy innovations. - Research Highlights: → Social acceptance of solar energy technologies from end users' perspective is investigated by a large scale questionnaire survey. → Higher level of social acceptance and public awareness of solar water heater than solar PV. → Impact factors for social acceptance of solar energy technologies are analyzed.

Nonequilibrium landscape theory of neural networks

Science.gov (United States)

Yan, Han; Zhao, Lei; Hu, Liang; Wang, Xidi; Wang, Erkang; Wang, Jin

2013-01-01

The brain map project aims to map out the neuron connections of the human brain. Even with all of the wirings mapped out, the global and physical understandings of the function and behavior are still challenging. Hopfield quantified the learning and memory process of symmetrically connected neural networks globally through equilibrium energy. The energy basins of attractions represent memories, and the memory retrieval dynamics is determined by the energy gradient. However, the realistic neural networks are asymmetrically connected, and oscillations cannot emerge from symmetric neural networks. Here, we developed a nonequilibrium landscape–flux theory for realistic asymmetrically connected neural networks. We uncovered the underlying potential landscape and the associated Lyapunov function for quantifying the global stability and function. 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. We applied our theory to rapid-eye movement sleep cycle. We identified the key regulation factors for function through global sensitivity analysis of landscape topography against wirings, which are in good agreements with experiments. PMID:24145451

Conservation biological control and enemy diversity on a landscape scale

NARCIS (Netherlands)

Tscharntke, T.; Bommarco, R.; Clough, Y.; Crist, T.O.; Kleijn, D.; Rand, T.A.; Tylianakis, J.M.; Nouhuys, S.; Vidal, S.

2007-01-01

Conservation biological control in agroecosystems requires a landscape management perspective, because most arthropod species experience their habitat at spatial scales beyond the plot level, and there is spillover of natural enemies across the crop–noncrop interface. The species pool in the

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.

The Global Landscape of GIS in Secondary Education

Science.gov (United States)

Kerski, Joseph J.; Demirci, Ali; Milson, Andrew J.

2013-01-01

This study analyzes the status of GIS in schools in thirty-three countries and proposes recommendations for advancing the implementation and effectiveness of GIS in secondary education from an international perspective. Thirty-three countries have been evaluated in the study to assess the global landscape of educational GIS by analyzing how GIS is…

School mathematical discourse in a learning landscape

DEFF Research Database (Denmark)

Valero, Paola; Meaney, Tamsin; Alrø, Helle

By bringing our research work together, we are able to discuss the potential of combining the notions of the learning landscape and school mathematical discourse. We do so in a search for concepts and methodological tools to challenge the simplification of issues in regard to mathematics learning...... in multicultural settings, when adopting restricted perspectives on issues of bilingualism. In the paper we discuss the relationship between the learning landscape and school mathematical discourse. We then use these notions to analyse two case studies in Danish and New Zealand schools. Our conclusion raises...... possibilities about how these notions can be used when researching mathematics education in multicultural settings....

A Study on the Campus Landscape Design of the National University of Singapore

Science.gov (United States)

Lin, Lusheng; Dong, Ya

2018-01-01

In this paper, we analyzed the functions, structure, layout, landscape and engineering measure of the campus of NUS by the way of such research methods as present situation research, interview and comparative study. And we get the spatial characteristics of landscape environment affected by political economy, human geography, geographical conditions which will provide a new perspective for building international, modern, high-level research universities.

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

A Landscape-level Model for Ecosystem Restoration in the San Francisco Estuary and Its Watershed

Directory of Open Access Journals (Sweden)

Wim Kimmerer

2005-03-01

Full Text Available The CALFED Bay-Delta Program is an ambitious effort to restore ecosystems and improve reliability of ecosystem services in California’s Central Valley. Key issues for CALFED and its Ecosystem Restoration Program (ERP include (1 meeting societal demand for multiple, potentially conflicting ecosystem services; (2 the tradeoff among more or less environmentally intrusive approaches to solving problems; (3 whether restoration should focus at the ecosystem level or on individual species; (4 the appropriate response to uncertainty; and (5 the tension between action and investigation. A long-term, landscape-scale perspective is essential for framing the scientific questions underlying these broad issues. We introduce a landscape-scale conceptual model that illustrates linkages, including material flows and animal migration, among the major ecosystem components being described in detail in a series of review papers. This model shows how linkages between ecosystem components result in remote consequences of locally applied restoration actions. The network of linkages is made more complicated by human interventions, which add components not previously a part of the landscape (e.g., salmonid hatcheries and alter or even reverse causal relations. A landscape perspective also helps identify conceptual gaps in CALFED’s restoration strategy, such as climate change and human population growth, which should be explicitly considered in forecasts of the long-term prospects for restoration. A landscape perspective is no panacea; in particular, the effects of restoration at this scale will be difficult to detect. Nevertheless, we advocate integrating investigations of processes at nested, smaller scales as an approach for evaluating effects of individual restoration actions and of the entire program. We believe CALFED and other large restoration programs will be most successful if they are able to integrate both societal expectations and scientific study at the

Thermal Infrared Remote Sensing for Analysis of Landscape Ecological Processes: Methods and Applications

Science.gov (United States)

Quattrochi, Dale A.; Luvall, Jeffrey C.

1998-01-01

Thermal Infrared (TIR) remote sensing data can provide important measurements of surface energy fluxes and temperatures, which are integral to understanding landscape processes and responses. One example of this is the successful application of TIR remote sensing data to estimate evapotranspiration and soil moisture, where results from a number of studies suggest that satellite-based measurements from TIR remote sensing data can lead to more accurate regional-scale estimates of daily evapotranspiration. With further refinement in analytical techniques and models, the use of TIR data from airborne and satellite sensors could be very useful for parameterizing surface moisture conditions and developing better simulations of landscape energy exchange over a variety of conditions and space and time scales. Thus, TIR remote sensing data can significantly contribute to the observation, measurement, and analysis of energy balance characteristics (i.e., the fluxes and redistribution of thermal energy within and across the land surface) as an implicit and important aspect of landscape dynamics and landscape functioning. The application of TIR remote sensing data in landscape ecological studies has been limited, however, for several fundamental reasons that relate primarily to the perceived difficulty in use and availability of these data by the landscape ecology community, and from the fragmentation of references on TIR remote sensing throughout the scientific literature. It is our purpose here to provide evidence from work that has employed TIR remote sensing for analysis of landscape characteristics to illustrate how these data can provide important data for the improved measurement of landscape energy response and energy flux relationships. We examine the direct or indirect use of TIR remote sensing data to analyze landscape biophysical characteristics, thereby offering some insight on how these data can be used more robustly to further the understanding and modeling of

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

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.

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.

Shapes of tree representations of spin-glass landscapes

International Nuclear Information System (INIS)

Hordijk, Wim; Fontanari, Jose F; Stadler, Peter F

2003-01-01

Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure - a barrier tree - the leaves and internal nodes of which represent, respectively, the local minima and the lowest energy saddles connecting those minima. Here we apply several statistics used in the study of phylogenetic trees to barrier trees that result from the energy landscapes of p-spin models. These statistics give information about the shape of these barrier trees, in particular about balance and symmetry. We then ask if they can be used to classify different types of landscapes, compare them with results obtained from random trees, and investigate the structure of subtrees of the barrier trees. We conclude that at least one of the used statistics is capable of distinguishing different types of landscapes, that the barrier trees from p-spin energy landscapes are quite different from random trees, and that subtrees of barrier trees do not reflect the overall tree structure, but their structure is correlated with their 'depth' in the tree

The Where-How of Leadership Emergence (WHOLE) Landscape: Charting Emergent Collective Leadership

OpenAIRE

Johnson, Norman; Watkins, Jennifer H

2008-01-01

Leadership resources are constantly adapting to the challenge of the dynamic and complex systems in which they must function. To understand the changing leadership types and to better guide the development of new leadership resources, we propose a two-dimensional leadership landscape that provides a perspective into past leadership resources and identifies new frontiers of leadership. In the Where-How of Leadership Emergence (WHOLE) Landscape, one dimension is where leadership occurs – rangi...

“Puerto Rico: gateway to landscape” from an ecological perspective

Science.gov (United States)

Grizelle Gonzalez

2015-01-01

The exhibit Puerto Rico: Gateway to Landscape proposes to explore various ways in which citizens approach the landscape, or construct it – inside and outside the city – and considers city planning, the creation of parks and natural reserves, and their interpretation. From a perspective of citizen involvement, this thematic scaffolding related to landscape and the...

Landscape Optimization in a Highly Urbanized Tourism Destination: An Integrated Approach in Nanjing, China

Directory of Open Access Journals (Sweden)

Lingling Chen

2017-12-01

Full Text Available Planning and developing urban tourism destinations must encompass landscape optimization to achieve healthy urban ecosystems, as well as for evolution sustainability. This study explored sustainable landscape planning by examining the optimization of landscape spatial distribution in an urban tourism destination–Nanjing, China—using an integrated approach that included remote sensing (RS, geographic information system (GIS, and landscape metrics in the context of an urban tourism destination evolution model. Least-cost modeling in GIS was also used to optimize decision-making from an ecological perspective. The results indicated that landscapes were more homogenous, fragmented, and less connected. Except for the eastern area, the landscape evolution showed characteristics of both degeneration and growth. A complete greenway network including sources, greenways, and nodes were constructed, and an increase in natural landscapes was strongly recommended. The findings provide geographic insights for sustainable urban tourism planning and development via comprehensive methodological applications.

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

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.

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.

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.

GIS-based landscape design research: Stourhead landscape garden as a case study

Directory of Open Access Journals (Sweden)

Steffen Nijhuis

2017-11-01

research, such as the visible form and kinaesthetic aspects, analysing the composition from eyelevel perspective. Moreover, the case study showcases that GIS has the potential to measure phenomena that are often subject to intuitive and experimental design, combining general scientific knowledge of, for instance, visual perception and way-finding, with the examination of site-specific design applications. GIS also enabled one to understand the landscape architectonic composition of Stourhead as a product of time, via the analysis of its development through reconstruction and evaluation of several crucial time-slice snapshots. The study illustrates that GIS can be regarded an external cognitive tool that facilitates and mediates in design knowledge acquisition. GIS facilitates in the sense that it can address the ‘same types of design-knowledge’ regarding the basic, spatial, symbolic and programmatic form, but in a more precise, systematic, transparent, and quantified manner. GIS mediates in the sense that it influences what and how aspects of the composition can be understood and therefore enables design researchers to generate ‘new types of design-knowledge’ by advanced spatial analysis and the possibility of linking or integrating other information layers, fields of science and data sources. The research contributes to the development and distribution of knowledge of GIS-applications in landscape architecture in two ways: (1 by ‘following’ the discipline and developing aspects of it, and (2 by setting in motion fundamental developments in the field, providing alternative readings of landscape architecture designs.

Visions of Restoration in Fire-Adapted Forest Landscapes: Lessons from the Collaborative Forest Landscape Restoration Program

Science.gov (United States)

Urgenson, Lauren S.; Ryan, Clare M.; Halpern, Charles B.; Bakker, Jonathan D.; Belote, R. Travis; Franklin, Jerry F.; Haugo, Ryan D.; Nelson, Cara R.; Waltz, Amy E. M.

2017-02-01

Collaborative approaches to natural resource management are becoming increasingly common on public lands. Negotiating a shared vision for desired conditions is a fundamental task of collaboration and serves as a foundation for developing management objectives and monitoring strategies. We explore the complex socio-ecological processes involved in developing a shared vision for collaborative restoration of fire-adapted forest landscapes. To understand participant perspectives and experiences, we analyzed interviews with 86 respondents from six collaboratives in the western U.S., part of the Collaborative Forest Landscape Restoration Program established to encourage collaborative, science-based restoration on U.S. Forest Service lands. Although forest landscapes and group characteristics vary considerably, collaboratives faced common challenges to developing a shared vision for desired conditions. Three broad categories of challenges emerged: meeting multiple objectives, collaborative capacity and trust, and integrating ecological science and social values in decision-making. Collaborative groups also used common strategies to address these challenges, including some that addressed multiple challenges. These included use of issue-based recommendations, field visits, and landscape-level analysis; obtaining support from local agency leadership, engaging facilitators, and working in smaller groups (sub-groups); and science engagement. Increased understanding of the challenges to, and strategies for, developing a shared vision of desired conditions is critical if other collaboratives are to learn from these efforts.

Visions of Restoration in Fire-Adapted Forest Landscapes: Lessons from the Collaborative Forest Landscape Restoration Program.

Science.gov (United States)

Urgenson, Lauren S; Ryan, Clare M; Halpern, Charles B; Bakker, Jonathan D; Belote, R Travis; Franklin, Jerry F; Haugo, Ryan D; Nelson, Cara R; Waltz, Amy E M

2017-02-01

Collaborative approaches to natural resource management are becoming increasingly common on public lands. Negotiating a shared vision for desired conditions is a fundamental task of collaboration and serves as a foundation for developing management objectives and monitoring strategies. We explore the complex socio-ecological processes involved in developing a shared vision for collaborative restoration of fire-adapted forest landscapes. To understand participant perspectives and experiences, we analyzed interviews with 86 respondents from six collaboratives in the western U.S., part of the Collaborative Forest Landscape Restoration Program established to encourage collaborative, science-based restoration on U.S. Forest Service lands. Although forest landscapes and group characteristics vary considerably, collaboratives faced common challenges to developing a shared vision for desired conditions. Three broad categories of challenges emerged: meeting multiple objectives, collaborative capacity and trust, and integrating ecological science and social values in decision-making. Collaborative groups also used common strategies to address these challenges, including some that addressed multiple challenges. These included use of issue-based recommendations, field visits, and landscape-level analysis; obtaining support from local agency leadership, engaging facilitators, and working in smaller groups (sub-groups); and science engagement. Increased understanding of the challenges to, and strategies for, developing a shared vision of desired conditions is critical if other collaboratives are to learn from these efforts.

Landscape Painting. Rewriting Painting in the Postmedium Condition

Directory of Open Access Journals (Sweden)

Gal, Nissim

2011-02-01

Full Text Available Is landscape painting still relevant today? To answer this question the article examines the work of the contemporary artist Yehudit Sasportas. Sasporas offers a unique kind of written-drawn landscape painting that moves between the manual and the mechanical. The theoretical perspectives from which it is approached are taken, among others, from Plato, Heidegger and Derrida on the issue of writing. Sasportas painting, which may be characterized as "painting under erasure" or "Landscape Painting", serves as a key to understanding the status of painting as a relevant medium, not because it defines medium according to the modernist Greenbergian formula, but because it enables an understanding of painting as a field that exists in a variety of media. Painting as a field, in Sasportas's art, works and lives within various techniques and materials, even when it includes within itself a melancholic mark indicating doubt about its own relevance.

[Impacts of urban cooling effect based on landscape scale: a review].

Science.gov (United States)

Yu, Zhao-wu; Guo, Qing-hai; Sun, Ran-hao

2015-02-01

The urban cooling island (UCI) effect is put forward in comparison with the urban heat island effect, and emphasizes on landscape planning for optimization of function and way of urban thermal environment. In this paper, we summarized current research of the UCI effects of waters, green space, and urban park from the perspective of patch area, landscape index, threshold value, landscape pattern and correlation analyses. Great controversy was found on which of the two factors patch area and shape index has a more significant impact, the quantification of UCI threshold is particularly lacking, and attention was paid too much on the UCI effect of landscape composition but little on that of landscape configuration. More attention should be paid on shape, width and location for water landscape, and on the type of green space, green area, configuration and management for green space landscape. The altitude of urban park and human activities could also influence UCI effect. In the future, the threshold determination should dominate the research of UCI effect, the reasons of controversy should be further explored, the study of time sequence should be strengthened, the UCI effects from landscape pattern and landscape configuration should be identified, and more attention should be paid to spatial scale and resolution for the precision and accuracy of the UCI results. Also, synthesizing the multidisciplinary research should be taken into consideration.

Atlantic energy and the strategic outlook

Directory of Open Access Journals (Sweden)

Paul Isbell

2013-09-01

Full Text Available Sweeping changes are beginning to transform energy scenarios around the world. The gas revolution, a renaissance in petroleum technology and exploration, and a chaotic but powerful movement toward the goal of low-carbon economies are three of the principal energy trends currently interacting with structural changes in the geo-economics of the Atlantic world to present new perspectives and opportunitiesfor the diverse actors in the ‘Atlantic Basin’. This article explores how changes in the energy landscape are contributing to a reassessment of the strategic horizon. The potential impacts of the shale revolution, deep-offshore oil, biofuels and other modern renewable energies on the geopolitics of the Atlantic Basin will be assessed, and the hypothesis that an Atlantic Basin energy system is now taking shape will be evaluated, along with an analysis of anticipated impacts.

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)

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)

Electric power in the competitive market - Investing capital for cleaner energy generation still a rewarding business? New perspectives for electrical energy efficiency improvement, the cogeneration technology, and renewable energy generation

International Nuclear Information System (INIS)

Schwanhold, E.

2000-01-01

The meeting gathered policymakers, members of the energy industry, the business consulting professions, and scientific institutes and relevant technology companies. New perspectives have been discussed in the context of required framework conditions and processes that have to/can be put in place, or further developed, in order to create a concrete basis or stronger incentives for realisation of climate protection and environmental policy goals in the energy sector. There have been two panel discussions on the issue of whether investing in clean generation technologies will be rewarding. Five papers each presented to these panels have been analysed and prepared for separate retrieval from the database, as well as five papers each of the discussion forum A, ''New perspectives for energy efficiency measures and contracting partnerships'', and the discussion forum B, ''New perspectives for distributed power generation with CHP systems''. From the discussion forum C, ''New perspectives for renewable energy sources'', one paper has been prepared for separate retrieval. (CB) [de

The Urban Fabric of the City as Its Affects Thermal Energy Responses Derived from Remote Sensing Data

Science.gov (United States)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

2000-01-01

The physical geography of the city affects numerous aspects of its interlinked biophysical, social, and land-atmosphere characteristics - those attributes that come together to form the total urban environment. One approach to studying the multitude of interactions that occur as a result of urbanization is to view the city from a systems ecology perspective, where energy and material cycle into and out of the urban milieu. Thus, the urban ecosystem is synergistic in linking land, air, water, and living organisms in a vast network of interrelated physical, human, and biological process. Given the number and the shear complexity of the exchanges and, ultimately, their effects, that occur within the urban environment, we are focusing our research on looking at how the morphology or urban fabric of the city, drives thermal energy exchanges across the urban landscape. The study of thermal energy attributes for different cities provides insight into how thermal fluxes and characteristics are partitioned across the city landscape in response to each city's morphology. We are using thermal infrared remote sensing data obtained at a high spatial resolution from aircraft, along with satellite data, to identify and quantify thermal energy characteristics for 4 U.S. cities: Atlanta, GA, Baton Rouge, LA, Salt Lake City, UT, and Sacramento, CA. Analysis of how thermal energy is spatially distributed across the urban landscapes for these cities provides a unique perspective for understanding how the differing morphology of cities forces land-atmosphere exchanges, such as the urban heat island effect, as well as related meteorological and air quality interactions. Keyword: urban ecosystems, remote sensing, urban heat island

Ecological Functions of Landscapes

Science.gov (United States)

Kiryushin, V. I.

2018-01-01

Ecological functions of landscapes are considered a system of processes ensuring the development, preservation, and evolution of ecosystems and the biosphere as a whole. The concept of biogeocenosis can be considered a model that integrates biotic and environmental functions. The most general biogeocenotic functions specify the biodiversity, biotic links, self-organization, and evolution of ecosystems. Close interaction between biocenosis and the biotope (ecotope) is ensured by the continuous exchange of matter, energy, and information. Ecotope determines the biocenosis. The group of ecotopic functions includes atmospheric (gas exchange, heat exchange, hydroatmospheric, climate-forming), lithospheric (geodynamic, geophysical, and geochemical), hydrologic and hydrogeologic functions of landscape and ecotopic functions of soils. Bioecological functions emerge as a result of the biotope and ecotope interaction; these are the bioproductive, destructive, organoaccumulative, biochemical (gas, concentration, redox, biochemical, biopedological), pedogenetic, and energy functions

2D Versus 3D: The Relevance of the Mode of Presentation for the Economic Valuation of an Alpine Landscape

NARCIS (Netherlands)

Getzner, Michael; Faerber, Barbara; Yamu, Claudia

In order to value the transformation of landscapes from an economic perspective, survey respondents are usually presented with pictures of various landscapes with the aim to visualize differences in their appearance. The current paper presents a classroom experiment ascertaining differences, and

Opportunites for Integrated Landscape Planning – the Broker, the Arena, the Tool

Directory of Open Access Journals (Sweden)

Julia Carlsson

2017-12-01

Full Text Available As an integrated social and ecological system, the forest landscape includes multiple values. The need for a landscape pproach in land use planning is being increasingly advocated in research, policy and practice. This paper explores how institutional conditions in the forest policy and management sector can be developed to meet demands for a multifunctional landscape perspective. Departing from obstacles recognised in collaborative planning literature, we build an analytical framework which is operationalised in a Swedish context at municipal level. Our case illustrating this is Vilhelmina Model Forest, where actual barriers and opportunities for a multiple-value landscape approach are identified through 32 semi-structured interviews displaying stakeholders’ views on forest values,ownership rights and willingness to consider multiple values, forest policy and management premises, and collaboration. As an opportunity to overcome the barriers, we suggest and discuss three key components by which an integrated landscape planning approach could be realized in forest management planning: the need for a landscape coordinator (broker, the need for a collaborative forum (arena, and the development of the existing forest management plan into an advanced multifunctional landscape plan (tool.

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...

Seeking a Landscape: Visions of the American West.

Science.gov (United States)

Kettler, Patricia E.

To adequately reflect the complexity of the U.S. West or any region, it is useful to represent the landscape through a variety of media and perspectives. Teachers need to supply the framework necessary to sustain a discourse about various media. These lesson plans are intended to be taught as part of a ninth or tenth grade English course. The…

Reheating-volume measure in the string theory landscape

International Nuclear Information System (INIS)

Winitzki, Sergei

2008-01-01

I recently proposed the ''reheating-volume'' (RV) prescription as a possible solution to the measure problem in ''multiverse'' cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.

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.

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.

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.)

Tools and methodologies for evaluation of energy chains and for technology perspective

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The challenge of climate change implies to accelerate the pace of innovation and consequently to lead long-term basic and applied research with a planning horizon of several decades, far beyond the conditions of current market development. In such a context, the availability of efficient decision-aiding tools and methodologies, far more advanced than those presently operated, is a critical stake.The different categories of tools will have to be more complementary by design and the overall decision-aiding processes will have to integrate numerous system analysis approaches in order to take into account more deeply all economical, environmental and societal impacts. The general goal of the workshop was to address this imperative to break new ground in decision-aiding tools and methodologies to help us to prioritize energy R and D options, comparing the needs jointly with the state of art and with the potentiality of breakthroughs, mainly in environmental and social sciences. The expected outcome was to characterize the scope and limits of existing decision-aiding processes, to highlight the perspectives towards more advanced new ones, and, as such, to foster interdisciplinary cooperation by linking more closely social and environmental sciences with energy socio-economic modelling research. The workshop included four parts. The first three addressed specialized sessions, outlining three different categories of tools. The fourth one was dedicated to the perspective of a combined use of these complementary tools in order to have methodologies available for covering the whole field of energy and social sciences issues. After this last session, there was a closing synthesis of the two day's work on the challenges to take up and the ways to go. This document gathers the transparencies of the following presentations: H2A Project/Evaluation of hydrogen chains (G. Sverdrup); E3DataBase/Evaluation of hydrogen chains (J. Schindler); Micro-economic modelling for evaluation

Tools and methodologies for evaluation of energy chains and for technology perspective

International Nuclear Information System (INIS)

2005-01-01

The challenge of climate change implies to accelerate the pace of innovation and consequently to lead long-term basic and applied research with a planning horizon of several decades, far beyond the conditions of current market development. In such a context, the availability of efficient decision-aiding tools and methodologies, far more advanced than those presently operated, is a critical stake.The different categories of tools will have to be more complementary by design and the overall decision-aiding processes will have to integrate numerous system analysis approaches in order to take into account more deeply all economical, environmental and societal impacts. The general goal of the workshop was to address this imperative to break new ground in decision-aiding tools and methodologies to help us to prioritize energy R and D options, comparing the needs jointly with the state of art and with the potentiality of breakthroughs, mainly in environmental and social sciences. The expected outcome was to characterize the scope and limits of existing decision-aiding processes, to highlight the perspectives towards more advanced new ones, and, as such, to foster interdisciplinary cooperation by linking more closely social and environmental sciences with energy socio-economic modelling research. The workshop included four parts. The first three addressed specialized sessions, outlining three different categories of tools. The fourth one was dedicated to the perspective of a combined use of these complementary tools in order to have methodologies available for covering the whole field of energy and social sciences issues. After this last session, there was a closing synthesis of the two day's work on the challenges to take up and the ways to go. This document gathers the transparencies of the following presentations: H2A Project/Evaluation of hydrogen chains (G. Sverdrup); E3DataBase/Evaluation of hydrogen chains (J. Schindler); Micro-economic modelling for evaluation of

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

Characterisation of Agri-Landscape Systems at a Regional Level: A Case Study in Northern Tuscany

Directory of Open Access Journals (Sweden)

Mariassunta Galli

2010-09-01

Full Text Available Preserving our landscape in sustainable development processes is now widely considered as fundamental. It is a complex and evolving issue that can be tackled from several perspectives. Agronomy can contribute to analyzing the relationships between agricultural production systems (cropping, farming and agricultural systems at different levels (field, farm, and region and the agricultural landscape (in terms of patches, matrixes, dynamics, etc. This is of particular interest where the relationships between “what and how” are produced by agricultural activities and the landscape are changing. In this case their own reciprocity may represent an opportunity to analyze complex systems, such as the characterization of agri-landscapes at a regional level. We propose a case study developed as an up-scaling analytical process from a farm to a regional level. The result was the identification of six main agri-landscape systems highlighting the landscape drivers that are changing the traditional landscape of a rural region in Northern Tuscany (Lunigiana.

Landscape equivalent of the shoving model

DEFF Research Database (Denmark)

Dyre, Jeppe; Olsen, Niels Boye

2004-01-01

It is shown that the shoving model expression for the average relaxation time of viscous liquids, according to which the activation energy is proportional to the instantaneous shear modulus, follows largely from a classical "landscape" estimation of barrier heights from curvature at energy minima...

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

The Boardroom Perspective: How Does Energy Efficiency Policy Influence Decision Making in Industry?

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

This report delves into the major factors or driving forces that decision makers within a large industrial company take into account when deciding to make new investments - the so-called {sup b}oardroom perspective{sup .} The rationale for an individual company making an investment that will reduce energy consumption varies considerably and depends on a range of factors. This report explores those factors that influence companies to invest in energy savings and proposes a methodology to evaluate the effectiveness of a country's energy efficiency and greenhouse gas mitigation policies mix from this boardroom perspective. This paper is the product of collaboration between the IEA and the Institute of Industrial Productivity (IIP).

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...

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...

Workshop tools and methodologies for evaluation of energy chains and for technology perspective

Energy Technology Data Exchange (ETDEWEB)

Appert, O. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Maillard, D. [Energy and Raw Materials, 75 - Paris (France); Pumphrey, D. [Energy Cooperation, US Dept. of Energy (United States); Sverdrup, G.; Valdez, B. [National Renewable Energy Laboratory, Golden, CO (United States); Schindler, J. [LB-Systemtechnik (LBST), GmbH, Ottobrunn (Germany); His, St.; Rozakis, St. [Centre International de Recherche sur Environnement Developpement (CIRED), 94 - Nogent sur Marne (France); Sagisaka, M. [LCA Research Centre (Japan); Bjornstad, D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States); Madre, J.L. [Institut National de Recherche sur les Transports et leur Securite, 94 - Arcueil (France); Hourcade, J.Ch. [Centre International de Recherche sur l' Environnement le Developpement (CIRED), 94 - Nogent sur Marne (France); Ricci, A.; Criqui, P.; Chateau, B.; Bunger, U.; Jeeninga, H. [EU/DG-R (Italy); Chan, A. [National Research Council (Canada); Gielen, D. [IEA-International Energy Associates Ltd., Fairfax, VA (United States); Tosato, G.C. [Energy Technology Systems Analysis Programme (ETSAP), 75 - Paris (France); Akai, M. [Agency of Industrial Science and technology (Japan); Ziesing, H.J. [Deutsches Institut fur Wirtschaftsforschung, DIW Berlin (Germany); Leban, R. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)

2005-07-01

The aims of this workshop is to better characterize the future in integrating all the dynamic interaction between the economy, the environment and the society. It offers presentations on the Hydrogen chains evaluation, the micro-economic modelling for evaluation of bio-fuel options, life cycle assessment evolution and potentialities, the consumer valuation of energy technologies attributes, the perspectives for evaluation of changing behavior, the incentive systems and barriers to social acceptability, the internalization of external costs, the endogenous technical change in long-tem energy models, ETSAP/technology dynamics in partial equilibrium energy models, very long-term energy environment modelling, ultra long-term energy technology perspectives, the socio-economic toolbox of the EU hydrogen road-map, the combined approach using technology oriented optimization and evaluation of impacts of individual policy measures and the application of a suite of basic research portfolio management tools. (A.L.B.)

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.

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.

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.

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.

Project D.I.R.T.: A landscape architect's excavation

International Nuclear Information System (INIS)

Bargmann, J.

1994-01-01

To a landscape architect interested in the creative manipulation of the land, mineral extraction presents a massive load for design exploration. The primary goal of Project D.I.R.T., Design Investigations Reclaiming Terrain, was to unearth the possibilities for renewing the perception of mining as creatively integral with the cultural and natural evolution of the landscape. The potential collaboration and planning inherent in the multidisciplinary task of reclamation became evident on a journey to document selected mining sites around the country. Various coal, gold, copper, and taconite operations visited represent a diversity of regional landscapes with specific mining and reclamation practices. Both active and abandoned mined sites serve as case studies presented from a landscape architect's perspective. Examining the legal, social, and economic factors uncovered the frustrations with the legislation governing reclamation and the financial and ethical dilemmas of future land use for dependent communities. Reviewing the technical and ecological aspects revealed the innovations and progress of reclamation technology, but also limited application of ecological principles. These current practices of mining and reclamation illustrate a need to revise the legislation and coordinate an interdisciplinary effort to form truly productive and sustainable landscapes. Moreover, from this landscape architect's point of view, a synthetic approach guided by a broader vision of mining must lead to the creation of meaningful places that objectively reveal and celebrate the industrial heritage of the landscape. Mined lands can be an expression of a reciprocal connection between communities and individuals with the land one cultivates and all nurture. These monumental landscapes may come to represent a dynamic relationship between culture and nature for the next century

Geographic techniques and recent applications of remote sensing to landscape-water quality studies

Science.gov (United States)

Griffith, J.A.

2002-01-01

This article overviews recent advances in studies of landscape-water quality relationships using remote sensing techniques. With the increasing feasibility of using remotely-sensed data, landscape-water quality studies can now be more easily performed on regional, multi-state scales. The traditional method of relating land use and land cover to water quality has been extended to include landscape pattern and other landscape information derived from satellite data. Three items are focused on in this article: 1) the increasing recognition of the importance of larger-scale studies of regional water quality that require a landscape perspective; 2) the increasing importance of remotely sensed data, such as the imagery-derived normalized difference vegetation index (NDVI) and vegetation phenological metrics derived from time-series NDVI data; and 3) landscape pattern. In some studies, using landscape pattern metrics explained some of the variation in water quality not explained by land use/cover. However, in some other studies, the NDVI metrics were even more highly correlated to certain water quality parameters than either landscape pattern metrics or land use/cover proportions. Although studies relating landscape pattern metrics to water quality have had mixed results, this recent body of work applying these landscape measures and satellite-derived metrics to water quality analysis has demonstrated their potential usefulness in monitoring watershed conditions across large regions.

Stealing Knowledge in a Landscape of Learning: Conceptualizations of Jazz Education

Science.gov (United States)

Bjerstedt, Sven

2016-01-01

Theoretical approaches to learning in practice-based jazz improvisation contexts include situated learning and ecological perspectives. This article focuses on how interest-driven, self-sustaining jazz learning activities can be matched against the concepts of stolen knowledge (Brown & Duguid, 1996) and landscape of learning (Bjerstedt, 2014).…

Flowscapes : Infrastructure as landscape, landscape as infrastructure. Graduation Lab Landscape Architecture 2012/2013

NARCIS (Netherlands)

Nijhuis, S.; Jauslin, D.; De Vries, C.

2012-01-01

Flowscapes explores infrastructure as a type of landscape and landscape as a type of infrastructure, and is focused on landscape architectonic design of transportation-, green- and water infrastructures. These landscape infrastructures are considered armatures for urban and rural development. With

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)

A New Vision for Public Art and Functional Landscape Design

Science.gov (United States)

Song, Young Imm Kang

2014-01-01

This article explores how Johanson's ecological public art and landscape design addresses current social issues and community necessities. It also examines how her designs may serve as a communication tool for the surrounding society, and how her public art may provide new perspectives for community members, scientists, artists, engineers,…

Landscape biography as research strategy: The case of the South Netherlands project

NARCIS (Netherlands)

Roymans, N.G.A.M.; Gerritsen, F.A.; Van der Heijden, C.; Bosma, J.E.; Kolen, J.C.A.

2009-01-01

This paper presents the outline of a biographical approach to landscape as developed in the Netherlands during the last 15 years by archaeologists, thereby integrating perspectives formulated by the social anthropologists Appadurai and Kopytoff and the cultural geographer Samuels. The result is a

Do geographically isolated wetlands influence landscape functions?

OpenAIRE

Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie; Basu, Nandita B.; Calhoun, Aram J. K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan

2016-01-01

Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bo...

Sites with nuclear facilities in the state of dismantling and their future from the public perspective

International Nuclear Information System (INIS)

Kretz, Simon Philipp

2015-01-01

The thesis on the public perspective at sites of nuclear facility dismantling covers the following issues: the change of German energy landscapes under social and political points of view, theoretical frame of the work, combination of empirical studies and the theoretical approaches in a space concept, action model and hypotheses on the situation and development in communities with nuclear facilities in the state of dismantling, description of the interviewees, and the empirical results of the interviews.

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...

Industrial Wasteland as Faced with Contemporary Landscape Architects’ Challenges

Science.gov (United States)

Tubielewicz-Michalczuk, Malwina

2017-10-01

The following article describes the problem of regeneration of industrial wasteland. It is illustrated with examples selected form various design projects created by outstanding contemporary landscape architects. It also shows how a correctly planned and performed project concerning regeneration of derelict industrial sites serves multiple functions, i. e. it serves as recreational zone as well as activates people. Moreover, it significantly enhances environmental value of a given area as well as stimulates emergence of innovative landscape investments. The paper presents innovative compositional arrangements used in creating projects concerning brownfields; balanced proportions of spatial elements, the possibility of approaching the area from different levels and perspectives and, also, the possibility of engaging fully with nature by physical contact with it.

Landscape metrics application in ecological and visual landscape assessment

Directory of Open Access Journals (Sweden)

Gavrilović Suzana

2017-01-01

Full Text Available The development of landscape-ecological approach application in spatial planning provides exact theoretical and empirical evidence for monitoring ecological consequences of natural and/or anthropogenic factors, particularly changes in spatial structures caused by them. Landscape pattern which feature diverse landscape values is the holder of the unique landscape character at different spatial levels and represents a perceptual domain for its users. Using the landscape metrics, the parameters of landscape composition and configuration are mathematical algorithms that quantify the specific spatial characteristics used for interpretation of landscape features and processes (physical and ecological aspect, as well as forms (visual aspect and the meaning (cognitive aspect of the landscape. Landscape metrics has been applied mostly in the ecological and biodiversity assessments as well as in the determination of the level of structural change of landscape, but more and more applied in the assessment of the visual character of the landscape. Based on a review of relevant literature, the aim of this work is to show the main trends of landscape metrics within the aspect of ecological and visual assessments. The research methodology is based on the analysis, classification and systematization of the research studies published from 2000 to 2016, where the landscape metrics is applied: (1 the analysis of landscape pattern and its changes, (2 the analysis of biodiversity and habitat function and (3 a visual landscape assessment. By selecting representative metric parameters for the landscape composition and configuration, for each category is formed the basis for further landscape metrics research and application for the integrated ecological and visual assessment of the landscape values. Contemporary conceptualization of the landscape is seen holistically, and the future research should be directed towards the development of integrated landscape assessment

A Most Redolent Tension: Understanding Landscape in a Post-colonial New Zealand

Directory of Open Access Journals (Sweden)

Jillian Walliss

2004-06-01

Full Text Available Within settler societies such as Australia and New Zealand, notions of landscape are influential in developing a sense of national distinctiveness while remaining a central point for reconciling the 'unsettlement' bought about by settlement. In this context, fundamental premises of landscape architecture such as 'sense of place' become complex propositions, inextricably interwoven with ideas of colonisation, romanticism, nationalism, identity and cultural representation. While common within post-colonial and cultural studies, these understandings of place are largely absent from landscape architecture discourse where the 'theoretical terrain' is largely derived from a Euro-American perspective. Encouraging students to engage with these understandings can prove difficult because many design students are reluctant to read material from outside their immediate discipline.

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

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

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.

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

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.

American security perspectives: public views on energy, environment, nuclear weapons and terrorism: 2008

International Nuclear Information System (INIS)

Herron, Kerry Gale; Jenkins-Smith, Hank C.

2008-01-01

We analyze and compare findings from matching national surveys of the US general public on US energy and environmental security administered by telephone and Internet in mid-2008. Key areas of investigation include: energy supplies and reliability; energy vulnerabilities and threats, and relationships among security, costs, energy dependence, alter-native sources, and research and investment priorities. We analyze public assessments of nuclear energy risks and benefits, nuclear materials management issues, and preferences for the future of nuclear energy in the US. Additionally, we investigate environmental issues as they relate to energy security, to include evolving perspectives on global climate change and relationships among environmental issues and potential policy options. We also report findings from an Internet survey of the general public conducted in mid-2008 that investigates assessments of threats to US security; valuations of US nuclear weapons and nuclear deterrence; perspectives on nuclear proliferation; and support for investments in nuclear weapons capabilities. Our analysis of public views on terrorism include assessments of the current threat, progress in the struggle against terrorism, preferences for responding to terrorist attacks at different levels of assumed casualties, and support for domestic policies intended to reduce the threat of terrorism.

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.

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....

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.

Landscape impact assessment of wind farm development in Dyfed

International Nuclear Information System (INIS)

Blandford, C.; White, S.; Garrad, A.D.; Morgan, C.A.

1992-01-01

Chris Blandford Associates, in association with Garrad Hassan and Partners, was commissioned to carry out a landscape impact assessment of wind turbine development in Dyfed. The study aims to identify those areas in Dyfed where, in terms of landscape impact, local authorities might seek either to exclude or encourage wind turbine development; provide guidelines to assist local authorities in judging the impact of wind turbine developments on the landscape; provide a basis and framework for the preparation of planning policy guidelines for acceptable wind turbine and wind farm developments in Dyfed. The study context reviews current Government energy and planning policies for the encouragement of wind turbine developments, as set out in the ''non-fossil fuel obligation'' and the draft planning policy guidance note for renewable energy published last December. (author)

The landscape genetics of infectious disease emergence and spread.

Science.gov (United States)

Biek, Roman; Real, Leslie A

2010-09-01

The spread of parasites is inherently a spatial process often embedded in physically complex landscapes. It is therefore not surprising that infectious disease researchers are increasingly taking a landscape genetics perspective to elucidate mechanisms underlying basic ecological processes driving infectious disease dynamics and to understand the linkage between spatially dependent population processes and the geographic distribution of genetic variation within both hosts and parasites. The increasing availability of genetic information on hosts and parasites when coupled to their ecological interactions can lead to insights for predicting patterns of disease emergence, spread and control. Here, we review research progress in this area based on four different motivations for the application of landscape genetics approaches: (i) assessing the spatial organization of genetic variation in parasites as a function of environmental variability, (ii) using host population genetic structure as a means to parameterize ecological dynamics that indirectly influence parasite populations, for example, gene flow and movement pathways across heterogeneous landscapes and the concurrent transport of infectious agents, (iii) elucidating the temporal and spatial scales of disease processes and (iv) reconstructing and understanding infectious disease invasion. Throughout this review, we emphasize that landscape genetic principles are relevant to infection dynamics across a range of scales from within host dynamics to global geographic patterns and that they can also be applied to unconventional 'landscapes' such as heterogeneous contact networks underlying the spread of human and livestock diseases. We conclude by discussing some general considerations and problems for inferring epidemiological processes from genetic data and try to identify possible future directions and applications for this rapidly expanding field.

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.

Social Landscape. A reading proposal for heritage areas in Bogota

Directory of Open Access Journals (Sweden)

Alonso Gutierrez Aristizabal

2015-09-01

Full Text Available This article offers a look to patrimonial urban areas in Bogotá from the perspective of Social Landscape. This point of view is proposed to recognize the social subject as a body that occupies and transforms the landscape, where the socio- political conflicts are linked to urban practices and the heritage urban areas as a social and metaphorical representation shape and give meaning to those places. From these looks, which are linked together, the possibility of a transverse reading values its holistically view to the sectors of urban and architectural interest, which are in conflict about identity-related values, memory and vulnerable domestic architecture that it is not effectively appropriated as a heritage asset.

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.)

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.)

Buildings Interoperability Landscape

Energy Technology Data Exchange (ETDEWEB)

Hardin, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephan, Eric G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Corbin, Charles D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-31

Through its Building Technologies Office (BTO), the United States Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE-EERE) is sponsoring an effort to advance interoperability for the integration of intelligent buildings equipment and automation systems, understanding the importance of integration frameworks and product ecosystems to this cause. This is important to BTO’s mission to enhance energy efficiency and save energy for economic and environmental purposes. For connected buildings ecosystems of products and services from various manufacturers to flourish, the ICT aspects of the equipment need to integrate and operate simply and reliably. Within the concepts of interoperability lie the specification, development, and certification of equipment with standards-based interfaces that connect and work. Beyond this, a healthy community of stakeholders that contribute to and use interoperability work products must be developed. On May 1, 2014, the DOE convened a technical meeting to take stock of the current state of interoperability of connected equipment and systems in buildings. Several insights from that meeting helped facilitate a draft description of the landscape of interoperability for connected buildings, which focuses mainly on small and medium commercial buildings. This document revises the February 2015 landscape document to address reviewer comments, incorporate important insights from the Buildings Interoperability Vision technical meeting, and capture thoughts from that meeting about the topics to be addressed in a buildings interoperability vision. In particular, greater attention is paid to the state of information modeling in buildings and the great potential for near-term benefits in this area from progress and community alignment.

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)

Perspective: Highly stable vapor-deposited glasses

Science.gov (United States)

Ediger, M. D.

2017-12-01

This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

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.

Identification and analysis of demands by nature protection at the supply of electricity and heat from energy crop; Identifikation und Analyse naturschutzseitiger Anforderungen an die Strom- und Waermebereitstellung aus Energieholz

Energy Technology Data Exchange (ETDEWEB)

Wirkner, Ronny [Deutsches Biomasseforschungszentrum g GmbH (DBFZ), Leipzig (Germany). Bereich Bioenergiesysteme

2013-10-01

The energetic use of biomass is currently a dominating part concerning the use of renewable energies and both federal and country-specific strategies will be continuously expanded in the course. However, energy and environmental policy objectives need viable sustainability requirements (ecological, economic, social), which is not always consistent due partly contradictory approaches. The article ''Identification and analysis of conservation-sided demands on the electricity and heat supply from energy wood'' is primarily devoted to the environmental analysis from the perspective of nature conservation and landscape management (SRC/woody biomass from landscape planning). The focus of the analysis is the amended Renewable Energy Sources Act (EEG 2012), where you can find also in the field of solid fuels new requirements and levels of compensation which increase the attractiveness of selected material flows for the system operator and the resulting consequences for the nature protection and landscape conservation. These arise primarily from a change in the type and intensity of agricultural and forestry land use systems, but also the final form of the energy use of biomass itself. (orig.)

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...

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.

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....

Landscape moderation of biodiversity patterns and processes - eight hypotheses.

Science.gov (United States)

Tscharntke, Teja; Tylianakis, Jason M; Rand, Tatyana A; Didham, Raphael K; Fahrig, Lenore; Batáry, Péter; Bengtsson, Janne; Clough, Yann; Crist, Thomas O; Dormann, Carsten F; Ewers, Robert M; Fründ, Jochen; Holt, Robert D; Holzschuh, Andrea; Klein, Alexandra M; Kleijn, David; Kremen, Claire; Landis, Doug A; Laurance, William; Lindenmayer, David; Scherber, Christoph; Sodhi, Navjot; Steffan-Dewenter, Ingolf; Thies, Carsten; van der Putten, Wim H; Westphal, Catrin

2012-08-01

Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: 'landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis-the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis-landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: 'landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis-landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis-spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: 'landscape moderation of functional trait selection' includes (5) the landscape-moderated functional trait selection hypothesis-landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis-landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: 'landscape constraints on

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...

Sustainable City Regions: Re-localising Landscapes in a Globalising World

Directory of Open Access Journals (Sweden)

Robert Thayer Jnr

2004-06-01

Full Text Available This paper emphasises physical, technological and economic variables in a globalising world, and how they might influence local economies and local landscapes. With the expected 'big rollover' in demand versus supply of oil in the next decade, the scale of the landscape will change in response to a permanent rise in the price of transportation and shipping fuels. Air travel will become less accessible, as will shipping of high mass, low value-added materials and goods. This will necessitate the re-establishment of more local supplies and shorter transport distances for people and goods, and for the first time in human history the perceived size of the world will expand. In response, the 'grain' of the landscape will become finer. More people will populate the rural landscape, while cities and towns will become more compact. The landscape is influenced by the three major operative technological systems (matter, energy and information. While the depletion of oil will greatly affect matter and energy, it will have less influence on information, which is relatively immune from entropic thermodynamic effects. While source-to-end-use distances will shorten, world per-capita energy expenditures will fall, and more local goods will be created and consumed, it remains to be seen whether this contraction in the scale of the instrumental landscape will be matched by more localised ownership, or by continued globalisation of corporate systems of production and distribution. Assuming the former is preferable, the paper concludes by suggesting that the bioregion, or natural 'life place', is the appropriate location for the protection of biodiversity, sustained use of resources, and identity and life satisfaction of local inhabitants.

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.

Proceedings of the 14. forum: Croatian Energy Day: Energy: Its reality and outlook - World - Europe - Croatia

International Nuclear Information System (INIS)

Granic, G.; Jelavic, B.

2005-01-01

This year the Croatian Energy Society is organizing its 14. Forum. For this occasion we chose the topic Energy perspectives today and tomorrow, World-Europe-Croatia, which in recent years is increasingly in the focus of interest not only of energy experts but of broad public as well. Namely, the end of the 20. and beginning of the 21st century saw the changes that, in many ways, influenced the energy market development. Views on the future and energy supply stability as they were in the era of divisions (free and communist world, developed and undeveloped world) must be substantially and urgently changed, because the geopolitical landscape of the world has been changing as well as development dynamics of countries and parts of continents. For Europe (Croatia included), which has deficit of primary energy sources and depends on energy import, reliability, availability security and economy of imported energy are key assumptions of sustainable economic and ecological development. The Forum shall discuss the following issues, which strongly influence or will influence the energy perspectives in the next 50 years: Reserves and potentials (size, geo-allocation of resources, transport possibilities, renewable sources); Technologies (exploitation, production, transport, distribution, consumption: appliances, consumers, and processes); Economic development and energy demand (development levels, richness and poverty, price of energy and social influence, energy efficiency); Environmental protection (Kyoto Protocol, legislation, economic capacities, nuclear energy); Energy trade liberalization (market development, restructuring, common legislation, privatization); Security of supply (local, European and global level); Population growth; Political changes and conflicts, military conflicts, terrorism. World Energy Council (WEC) initiated work on global study on energy development: Energy Scenario to 2050. The energy community around the world is equally interested in this study

Perspectives of energy technologies: scenarios and strategies at the 2050 vista

International Nuclear Information System (INIS)

2008-01-01

Every two years, the International Energy Agency (IEA) publishes the 'Energy Technology Perspectives' (ETP) report which analyses the foreseeable energy scenarios and strategies at the 2050 vista and stresses on the best available technologies. For the first time, the IEA describes in this study a scenario allowing to divide by two the CO 2 emissions at the world scale, i.e. compatible with the 'factor 4' scenario of industrialized countries. The study estimates the R and D needs and the necessary additional investments to meet the different tendentious and voluntaristic scenarios proposed by the IEA. This 15. session of the cycle of energy-climate conferences aimed at presenting, from the ETP 2008 study, a thorough examination of the present day situation and perspectives of existing or future 'clean' energy technologies through the analysis of several scenarios. An examination of the interpretation of these scenarios at the France and European levels is made in order to define what should be the trends of public policies and international cooperation. This document gathers the transparencies of the two presentations given during this conference. The first presentation by Pieter Boot, Director of the Office of Sustainable Energy Policy and Technology of IEA, makes a synthesis of the ETP study and presents the recommendations of the agency. The second presentation by Olivier Appert, President of the French institute of petroleum (IFP), gives a counterpoint of the first presentation by considering the financing and acceptance aspects, in particular from the French point of view. Finally a debate with the audience completes the presentations. (J.S.)

Landscape evolution space and the relative importance of geomorphic processes and controls

Science.gov (United States)

Phillips, Jonathan D.

2009-08-01

The concept of landscape evolution space (LES) is introduced as a tool for assessing landscapes and geomorphic systems, intended to be a systematic means for assessing the various factors that contribute to the potential for change in geomorphic systems. The LES conceptual model is based on the energy and mass available to drive and accommodate landscape evolution. An n-dimensional landscape evolution space is defined not only by spatial coordinates, but also by the availability of mass and energy. The LES is thus a space or hypervolume representing the resources available for geomorphic evolution and landscape change. An expression for LES is derived based on elevation, material density, surface area, and inputs of solar, meteoric, and biological energy and mass. Though primarily an heuristic device, the LES model can be used to address concrete problems. Two examples are given. In one, increased surface area due to topographic roughening and dissection of an incised plateau is found to only slightly offset erosional removals of mass in terms of the magnitude of the LES. In the other, sensitivity of coastal plain rivers to several impacts of sea level and climate change is explored. The LES model also leads to the concept of a geomorphological niche, representing the resources available to drive or support a specific process or suite of processes. Considerations of landscape evolution have traditionally focused on the interplay of endogenic vs. exogenic processes, uplift vs. denudation, or soil formation vs. erosion. The LES model explicitly broadens the conceptual framework of landscape evolution beyond the traditional dialectics.

European landscape architecture and territorial strategies for water landscapes

DEFF Research Database (Denmark)

Diedrich, Lisa Babette

2010-01-01

This article sums up the author’s lecture at the 2009 Sydney Resilient Water Landscapes Symposium and presents a series of realized or planned European landscape architectural and urbanistic projects on water landscapes taken from the recently published book On Site/ Landscape Architecture Europe...... and accompanying reflections. The hypothesis is that further scientific research can help defining weaknesses and strengths of the existing water landscape designs in terms of resilience, extract principles and tools, improve the weak ones and communicate the strong ones and develop general quality criteria...... and tools for future resilient water landscapes....

Ecological and economic conditions and associated institutional challenges for conservation banking in dynamic landscapes

NARCIS (Netherlands)

Teeffelen, van A.J.A.; Opdam, P.F.M.; Wätzold, F.; Hartig, F.; Johst, K.; Drechsler, M.; Vos, C.C.; Wissel, S.; Quétier, F.

2014-01-01

Protected areas are a cornerstone of current biodiversity policy. The continued loss of biodiversity, however, as well as the limited scope to extend protected area networks necessitates a conservation perspective that encompasses both protected areas and the wider landscape. This calls for policy

Microclimate landscape design at southern integrated terminal Bandar Tasik Selatan, Kuala Lumpur

Science.gov (United States)

Phin, L. H.; Krisantia, I.

2018-01-01

Bandar Tasik Selatan is the integrated transport terminal has high energy consuming, high carbon emission and poor linkage. However, microclimate can be reduced through landscape design. This paper is a study to achieve energy efficiency and improve microclimate in the urban area. The research area is at Southern integrated terminal Bandar Tasik Selatan Kuala Lumpur Malaysia. It is carried out through a case study and microclimate analyzed using System Modeling method. System modelling using in this research is system energy budget of the microclimate at a site is a balance between the radiant energy supplied and the energy removed by all consumers. The finding indicated the microclimatic components that can be modified through landscape design are solar radiation, wind and precipitation can create thermal comfort, energy efficiency and others benefits.Through this research, provide more green space to achieve energy efficiency and improve microclimate of the site, introducing vertical landscape and proper planting selection to improve air quality, introducing green energy as part of the source of power supply and to promote integration of terminal building and rail systems by unify them using softscape

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)

Report on the present day situation and technical perspectives of renewable energies; Rapport sur l'etat actuel et les perspectives techniques des energies renouvelables

Energy Technology Data Exchange (ETDEWEB)

Birraux, C; Le Deaut, J Y

2001-11-01

This work, carried out by the parliamentary office for the evaluation of scientific and technological choices on request of the French National Assembly and Senate, takes stock of the present day situation and technical perspectives of development of renewable energy sources and of research needs of the French industry in this domain: 1 - renewable energies: key-technologies for the energy supply of developing countries and for a rational consumption in transportation systems and accommodations of developed countries (energies technically different from fossil or nuclear energies; fundamental energy sources for a developing world; different national goals in Europe depending on the available natural resources and on the political realities; a minor interest in France for the domestic power generation but a major interest for transports, residential and tertiary sectors and export); 2 - priority choices given to the French renewable energy resources: renewable electricity (photovoltaic, wind, biomass), thermal technologies (solar, geothermal, biomass); 3 - future policy: sustain of renewable electricity production with the revival of research, industry and technical cooperation. (J.S.)

Perspectives of energy technologies: scenarios and strategies at the 2050 vista; Perspectives des technologies de l'energie: scenarios et strategies a l'horizon 2050

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

Every two years, the International Energy Agency (IEA) publishes the 'Energy Technology Perspectives' (ETP) report which analyses the foreseeable energy scenarios and strategies at the 2050 vista and stresses on the best available technologies. For the first time, the IEA describes in this study a scenario allowing to divide by two the CO{sub 2} emissions at the world scale, i.e. compatible with the 'factor 4' scenario of industrialized countries. The study estimates the R and D needs and the necessary additional investments to meet the different tendentious and voluntaristic scenarios proposed by the IEA. This 15. session of the cycle of energy-climate conferences aimed at presenting, from the ETP 2008 study, a thorough examination of the present day situation and perspectives of existing or future 'clean' energy technologies through the analysis of several scenarios. An examination of the interpretation of these scenarios at the France and European levels is made in order to define what should be the trends of public policies and international cooperation. This document gathers the transparencies of the two presentations given during this conference. The first presentation by Pieter Boot, Director of the Office of Sustainable Energy Policy and Technology of IEA, makes a synthesis of the ETP study and presents the recommendations of the agency. The second presentation by Olivier Appert, President of the French institute of petroleum (IFP), gives a counterpoint of the first presentation by considering the financing and acceptance aspects, in particular from the French point of view. Finally a debate with the audience completes the presentations. (J.S.)

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.

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)

Challenges and potentials in using alternative landscape futures during climate change: A literature review and survey study

Directory of Open Access Journals (Sweden)

Amin Rastandeh

2015-12-01

Full Text Available This study focuses on the feasibility of applying alternative futures and scenario analysis in landscape planning during climate change to provide a wider perspective and deeper understanding of this approach for better use and more effective application in the future. The study consists of a literature review and an analysis of recent applied projects carried out worldwide. In addition, an electronic survey was conducted from March to September 2014 to examine viewpoints on the use and application of this approach with reference to climate-change impacts. The survey participants were a group of highly experienced researchers from eighteen countries involved in at least one applied project since 2000 relating to this topic. After analysis of more than forty applied projects, the survey results were incorporated into the analysis to create a comprehensive picture regarding the potentials and limitations of alternative futures and scenario analysis in landscape planning with particular attention to climate change. The findings show that this method is one of the most effective decision-making approaches for adopting landscape policies where landscapes change rapidly under the pressure of urbanisation and climate change. Nevertheless, there is a gap between the advances offered by the approach in various dimensions and the complexity of patterns, uncertainties and upheavals in landscapes due to climate-change impacts in the urbanising world. The research indicates that the approach opens up a great opportunity for decision-makers to expand their perspective and adopt appropriate landscape policies before reaching a point of no return from the sustainability point of view. Meanwhile, there are challenges and barriers in the application of alternative futures and scenario analysis for envisioning the landscapes influenced by climate change and urbanisation that should be pushed back. Although informative, this research raises new questions about this

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.

From Synergy to Complexity: The Trend Toward Integrated Value Chain and Landscape Governance.

Science.gov (United States)

Ros-Tonen, Mirjam A F; Reed, James; Sunderland, Terry

2018-05-30

This Editorial introduces a special issue that illustrates a trend toward integrated landscape approaches. Whereas two papers echo older "win-win" strategies based on the trade of non-timber forest products, ten papers reflect a shift from a product to landscape perspective. However, they differ from integrated landscape approaches in that they emanate from sectorial approaches driven primarily by aims such as forest restoration, sustainable commodity sourcing, natural resource management, or carbon emission reduction. The potential of such initiatives for integrated landscape governance and achieving landscape-level outcomes has hitherto been largely unaddressed in the literature on integrated landscape approaches. This special issue addresses this gap, with a focus on actor constellations and institutional arrangements emerging in the transition from sectorial to integrated approaches. This editorial discusses the trends arising from the papers, including the need for a commonly shared concern and sense of urgency; inclusive stakeholder engagement; accommodating and coordinating polycentric governance in landscapes beset with institutional fragmentation and jurisdictional mismatches; alignment with locally embedded initiatives and governance structures; and a framework to assess and monitor the performance of integrated multi-stakeholder approaches. We conclude that, despite a growing tendency toward integrated approaches at the landscape level, inherent landscape complexity renders persistent and significant challenges such as balancing multiple objectives, equitable inclusion of all relevant stakeholders, dealing with power and gender asymmetries, adaptive management based on participatory outcome monitoring, and moving beyond existing administrative, jurisdictional, and sectorial silos. Multi-stakeholder platforms and bridging organizations and individuals are seen as key in overcoming such challenges.

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.)

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...

Complementary habitat use by wild bees in agro-natural landscapes.

Science.gov (United States)

Mandelik, Yael; Winfree, Rachael; Neeson, Thomas; Kremen, Claire

2012-07-01

-habitat perspective in managing these landscapes.

Exploring Neural Network Models with Hierarchical Memories and Their Use in Modeling Biological Systems

Science.gov (United States)

Pusuluri, Sai Teja

Energy landscapes are often used as metaphors for phenomena in biology, social sciences and finance. Different methods have been implemented in the past for the construction of energy landscapes. Neural network models based on spin glass physics provide an excellent mathematical framework for the construction of energy landscapes. This framework uses a minimal number of parameters and constructs the landscape using data from the actual phenomena. In the past neural network models were used to mimic the storage and retrieval process of memories (patterns) in the brain. With advances in the field now, these models are being used in machine learning, deep learning and modeling of complex phenomena. Most of the past literature focuses on increasing the storage capacity and stability of stored patterns in the network but does not study these models from a modeling perspective or an energy landscape perspective. This dissertation focuses on neural network models both from a modeling perspective and from an energy landscape perspective. I firstly show how the cellular interconversion phenomenon can be modeled as a transition between attractor states on an epigenetic landscape constructed using neural network models. The model allows the identification of a reaction coordinate of cellular interconversion by analyzing experimental and simulation time course data. Monte Carlo simulations of the model show that the initial phase of cellular interconversion is a Poisson process and the later phase of cellular interconversion is a deterministic process. Secondly, I explore the static features of landscapes generated using neural network models, such as sizes of basins of attraction and densities of metastable states. The simulation results show that the static landscape features are strongly dependent on the correlation strength and correlation structure between patterns. Using different hierarchical structures of the correlation between patterns affects the landscape features

Multiple coupled landscapes and non-adiabatic dynamics with applications to self-activating genes.

Science.gov (United States)

Chen, Cong; Zhang, Kun; Feng, Haidong; Sasai, Masaki; Wang, Jin

2015-11-21

Many physical, chemical and biochemical systems (e.g. electronic dynamics and gene regulatory networks) are governed by continuous stochastic processes (e.g. electron dynamics on a particular electronic energy surface and protein (gene product) synthesis) coupled with discrete processes (e.g. hopping among different electronic energy surfaces and on and off switching of genes). One can also think of the underlying dynamics as the continuous motion on a particular landscape and discrete hoppings among different landscapes. The main difference of such systems from the intra-landscape dynamics alone is the emergence of the timescale involved in transitions among different landscapes in addition to the timescale involved in a particular landscape. The adiabatic limit when inter-landscape hoppings are fast compared to continuous intra-landscape dynamics has been studied both analytically and numerically, but the analytical treatment of the non-adiabatic regime where the inter-landscape hoppings are slow or comparable to continuous intra-landscape dynamics remains challenging. In this study, we show that there exists mathematical mapping of the dynamics on 2(N) discretely coupled N continuous dimensional landscapes onto one single landscape in 2N dimensional extended continuous space. On this 2N dimensional landscape, eddy current emerges as a sign of non-equilibrium non-adiabatic dynamics and plays an important role in system evolution. Many interesting physical effects such as the enhancement of fluctuations, irreversibility, dissipation and optimal kinetics emerge due to non-adiabaticity manifested by the eddy current illustrated for an N = 1 self-activator. We further generalize our theory to the N-gene network with multiple binding sites and multiple synthesis rates for discretely coupled non-equilibrium stochastic physical and biological systems.

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

Sustainability and tourism in the cultural landscapes of industrialization

Directory of Open Access Journals (Sweden)

Carlos J. Pardo Abad

2017-11-01

Full Text Available Old mining and industrial areas, many of them already abandoned after prolonged extractive and productive activity, often put up good experiences associated with recovery heritage and landscapes. Initially promoted by public administrations, particularly municipal bodies, with the active participation of private companies and the local community, nowadays these projects are an extraordinary reference for valuing a peculiar legacy that offers extensive possibilities for reuse under the indispensable perspective of sustainable development.

Historical context of interventions in the landscape and in urban spaces

Directory of Open Access Journals (Sweden)

Letícia Peret Antunes Hardt

2007-06-01

Full Text Available Since the beginning of their existence, human beings have transformed the natural environment into another one modelled to fit their conveniences, promoting deep changes in the planet’s original environments. In this context, cities, one of Man’s greatest creation, is object of significant interventions on the landscape, as well as of relevant environmental pressures. With the purpose of retrieving experiences, diagnosing realities and forecasting trends, this study, structured into characteristic eras from Pre-History until the Contemporary Age and including perspectives for the future, starts from a worldwide scenario to the specific approach of the Brazilian case, identifying representative periods of the landscape and urban spaces design process. With the foremost purpose of setting up guidelines for projects of urban landscape interventions, subsidies for cities and regions management are presented, based upon theoretical-conceptual approaches and on sustainability principles.

Walking Women: Embodied Perception in Romantic and Contemporary Radical Landscape Poetry

Directory of Open Access Journals (Sweden)

Eleanore Widger

2017-01-01

Full Text Available Reading early Wordsworth through Adorno, this article suggests that Romantic walking entails the subjugation of external objects through the exercise of an imperial and elevated perception. It then considers Dorothy Wordsworth’s influence over her brother and the possibility that a Romantic ‘eco-poetic’ emerges from the ‘feminine’ perspective 'below' the mountain, and within the domestic landscape. I argue that this gesture away from walking and mountaineering as the demonstration of physical prowess, or as the pursuit of a real or ideal goal, is taken up by three contemporary women poets of landscape. Harriet Tarlo, Frances Presley and Helen Macdonald offer different ways of walking, which dispense with goal-orientation, explore the ethical choices available to perceptual beings, and attempt a more immersive, embodied engagement with the land. Their contribution to contemporary ‘radical landscape poetry’ combines the feminist discourse of ‘situated knowledge’ with an implicitly enactivist approach to human encounters with the environment.

Insights from Earth Sciences into Human Evolution studies: The example of prehistoric landscape use in Africa and the Levant

Science.gov (United States)

Devès, Maud H.; Reynolds, Sally; King, Geoffrey C. P.; Kuebler, Simon; Sturdy, Derek; Godet, Nan

2015-07-01

Fossil remains are embedded in a continually evolving landscape. Earth scientists have the methods and approaches to study the processes that shape the landscape at various temporal and spatial scales. Some of these methods can generate insights that are of potential use for researchers in other fields, such as archaeology and palaeoanthropology. Here we present two case studies to illustrate how a broader landscape perspective can provide new insights into the land use by Pliocene hominins in southern Africa, and more recently, by Palaeolithic hominins in the southern Levant. Key landscape attributes can help explain why humans, hominins and the wider animal community exploit certain types of landscapes in predictable ways. Our first case study examines how active tectonics or volcanism appears to be important in creating fertile regions with reliable water sources and complex topography. While relatively easy for agile primates such as hominins to negotiate, zones of complex topography are harder for certain predators and prey animals to traverse. In the second case study, we consider that differences in soil edaphics can exert a major control on animals by supplying or failing to supply necessary trace elements, such as selenium, copper, phosphate and potassium (Henkin et al., 1995). We show that the pattern of trace element distribution can accurately map animal movements between areas of suitable grazing. This predictability could have enabled Levantine humans to ambush megafauna during these seasonal migrations. By studying the landscape attributes around fossil site locations, Earth scientists can offer new insights and perspectives into the past, particularly on the ways in which the inhabitants would have used their landscapes.

Perceptions of Post-Wildfire Landscape Change and Recovery

Science.gov (United States)

Kooistra, C. M.; Hall, T. E.; Paveglio, T.; Carroll, M.; Smith, A. M.

2013-12-01

Considering the dynamic nature of the earth and climate systems and the increasing potential for widespread forest disturbances, it is important to understand the implications of landscape changes, and perceptions of changes, on people's responses to forest disturbances. Understanding how people perceive landscape change over time following forest disturbances helps researchers, land managers, and community leaders identify important biophysical and social characteristics that influence the vulnerability of people who experience forest disturbances, as well as their responses to those disturbances. This poster describes people's perceptions of landscape change following a significant wildfire. The lightning ignited Dahl fire burned 12 miles southeast of Roundup, MT mostly on private land in the summer of June 2012. The fire burned approximately 22,000 acres and destroyed 73 residences. We conducted interviews in the summer of 2013 with more than 40 residents, land managers, emergency personnel, and other stakeholders. While interviews covered several topics, this poster focuses on responses to questions regarding perceptions of short- and long-term landscape change after the fire, including both social and biophysical perspectives. Interviews revealed that people's understanding of the role of wildfires as a natural ecosystem process, as well as their connections with the landscape (i.e., sense of place), were important factors that influenced their perceptions of landscape change after the fire. Many respondents discussed the landscape ';recovering' to pre-fire conditions in longer-term timeframes, such as ';multiple generations.' They often referenced previous wildfires, the Hawk Creek fire (1984) and the Majeras fire (2006), by explaining how parts of the landscape affected by the Dahl fire might compare to certain areas of the previous fires. Variations in recovery expectations were often based on perceptions of the severity of the fire (especially temperature

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.

Economic Impacts of Future Changes in the Energy System - National Perspectives

DEFF Research Database (Denmark)

Glynn, James; Fortes, Patrícia; Krook-Riekkola, Anna

2015-01-01

climate change. This chapter summarises modelling methodologies developed in the ETSAP community to assess economic impacts of decarbonising energy systems at a national level. The preceding chapter focuses on a global perspective. The modelling studies outlined here show that burden sharing rules...... and national revenue recycling schemes for carbon tax are critical for the long-term viability of economic growth and equitable engagement on combating climate change. Traditional computable general equilibrium models and energy systems models solved in isolation can misrepresent the long run carbon cost...

The potential for integrated landscape management to fulfil Europe's commitments to the Sustainable Development Goals

NARCIS (Netherlands)

Mann, Carsten; Garcia-Martin, Maria; Raymond, Christopher M.; Shaw, Brian J.; Plieninger, Tobias

2018-01-01

The aim of this perspective essay is to discuss how integrated landscape management (ILM) can contribute to the implementation of the Sustainable Development Goals (SDG) agenda in Europe. Challenges for sustainable development become evident in the emergence of land-use conflicts. Facing multiple,

Landscape services as boundary concept in landscape governance: Building social capital in collaboration and adapting the landscape

NARCIS (Netherlands)

Westerink, Judith; Opdam, Paul; Rooij, Van Sabine; Steingröver, Eveliene

2017-01-01

The landscape services concept provides a lens to study relations within the social-ecological networks that landscapes are, and to identify stakeholders as either providers or beneficiaries. However, landscape services can also be used as a boundary concept in collaborative landscape governance. We

Critical Zone Services as a Measure for Evaluating the Trade-offs in Intensively Managed Landscapes

Science.gov (United States)

Richardson, M.; Kumar, P.

2015-12-01

The Critical Zone includes the range of biophysical processes occurring from the top of the vegetation canopy to the weathering zone below the groundwater table. These services (Field et al. 2015) provide a measure to value processes that support the goods and services from our landscapes. In intensively managed landscapes the provisioning and regulating services are being altered through anthropogenic energy inputs so as to derive more agricultural productivity from the landscapes. Land use change and other alterations to the environment result in positive and/or negative net Critical Zone services. Through studies in the Critical Zone Observatory for Intensively Managed Landscapes (IMLCZO), this research seeks to answer questions such as: Are perennial bioenergy crops or annual replaced crops better for the land and surrounding environment? How do we evaluate the products and services from the land for the energy and resources we put in? Before the economic valuation of Critical Zone services, these questions seemed abstract. However, with developments such as Critical Zone services and life cycle assessments, they are more concrete. To evaluate the trade-offs between positive and negative impacts, life cycle assessments are used to create an inventory of all the energy inputs and outputs in a landscape management system. Total energy is computed by summing the mechanical energy used to construct tile drains, fertilizer, and other processes involved in intensely managed landscapes and the chemical energy gained by the production of biofuels from bioenergy crops. A multi-layer canopy model (MLCan) computes soil, water, and nutrient outputs for each crop type, which can be translated into Critical Zone services. These values are then viewed alongside the energy inputs into the system to show the relationship between agricultural practices and their corresponding ecosystem and environmental impacts.

Trends of Forest Dynamics in Tiger Landscapes Across Asia

Science.gov (United States)

Mondal, Pinki; Nagendra, Harini

2011-10-01

Protected areas (PAs) are cornerstones of biodiversity conservation, but small parks alone cannot support wide-ranging species, such as the tiger. Hence, forest dynamics in the surrounding landscapes of PAs are also important to tiger conservation. Tiger landscapes often support considerable human population in proximity of the PA, sometimes within the core itself, and thus are subject to various land use activities (such as agricultural expansion and road development) driving habitat loss and fragmentation. We synthesize information from 27 journal articles in 24 tiger landscapes to assess forest-cover dynamics in tiger-range countries. Although 29% of the PAs considered in this study have negligible change in overall forest cover, approximately 71% are undergoing deforestation and fragmentation. Approximately 58% of the total case studies have human settlements within the core area. Most changes—including agricultural expansion, plantation, and farming (52%), fuelwood and fodder collection (43%), logging (38%), grazing (38%), and tourism and development (10%)—can be attributed to human impacts largely linked to the nature of the management regime. This study highlights the need for incorporating new perspectives, ideas, and lessons learned locally and across borders into management plans to ensure tiger conservation in landscapes dominated by human activities. Given the increasing isolation of most parks due to agricultural, infrastructural, and commercial developments at the periphery, it is imperative to conduct planning and evaluation at the landscape level, as well as incorporate multiple actors and institutions in planning, instead of focusing solely on conservation within the PAs as is currently the case in most tiger parks.

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

Report on the present day situation and technical perspectives of renewable energies; Rapport sur l'etat actuel et les perspectives techniques des energies renouvelables

Energy Technology Data Exchange (ETDEWEB)

Birraux, C.; Le Deaut, J.Y.

2001-11-01

This work, carried out by the parliamentary office for the evaluation of scientific and technological choices on request of the French National Assembly and Senate, takes stock of the present day situation and technical perspectives of development of renewable energy sources and of research needs of the French industry in this domain: 1 - renewable energies: key-technologies for the energy supply of developing countries and for a rational consumption in transportation systems and accommodations of developed countries (energies technically different from fossil or nuclear energies; fundamental energy sources for a developing world; different national goals in Europe depending on the available natural resources and on the political realities; a minor interest in France for the domestic power generation but a major interest for transports, residential and tertiary sectors and export); 2 - priority choices given to the French renewable energy resources: renewable electricity (photovoltaic, wind, biomass), thermal technologies (solar, geothermal, biomass); 3 - future policy: sustain of renewable electricity production with the revival of research, industry and technical cooperation. (J.S.)

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.

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.

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.)

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.

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.

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.

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.

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.

Geomorpho-Landscapes

Science.gov (United States)

Farabollini, Piero; Lugeri, Francesca; Amadio, Vittorio

2014-05-01

Landscape is the object of human perceptions, being the image of spatial organization of elements and structures: mankind lives the first approach with the environment, viewing and feeling the landscape. Many definitions of landscape have been given over time: in this case we refer to the Landscape defined as the result of interaction among physical, biotic and anthropic phenomena acting in a different spatial-temporal scale (Foreman & Godron) Following an Aristotelic approach in studying nature, we can assert that " Shape is synthesis": so it is possible to read the land features as the expression of the endogenous and exogenous processes that mould earth surfaces; moreover, Landscape is the result of the interaction of natural and cultural components, and conditions the spatial-temporal development of a region. The study of the Landscape offers results useful in order to promote sustainable development, ecotourism, enhancement of natural and cultural heritage, popularization of the scientific knowledge. In Italy, a very important GIS-based tool to represent the territory is the "Carta della Natura" ("Map of Nature", presently coordinated by the ISPRA) that aims at assessing the state of the whole Italian territory, analyzing Landscape. The methodology follows a holistic approach, taking into consideration all the components of a landscape and then integrating the information. Each individual landscape, studied at different scales, shows distinctive elements: structural, which depend on physical form and specific spatial organization; functional, which depend on relationships created between biotic and abiotic elements, and dynamic, which depend on the successive evolution of the structure. The identification of the landscape units, recognized at different scales of analysis, allows an evaluation of the state of the land, referring to the dual risk/resource which characterizes the Italian country. An interesting opportunity is to discover those areas of unusual

Using neutral theory to reveal the contribution of meta-community processes to assembly in complex landscapes

Directory of Open Access Journals (Sweden)

Dominique Gravel

2014-04-01

Full Text Available The metacommunity perspective appears as an appropriate conceptual framework to make ecology more predictive. It is particularly relevant to limnology, where exchanges of organisms and nutrients affect community and ecosystem properties from the local to the regional scales. The recent development of neutral theory appears as a step back in that direction because of the assumption of ecological equivalence and the absence of any effect of the environment on community organization. A remarkable strength of neutral theory is nonetheless to provide a general theory of diversity that accounts for a wide range of empirical observations. In this paper, we argue that neutral theory can be useful to understand the impact of dispersal on community assembly in landscapes of various complexities. Our analysis focus on spatially explicit landscapes conceptualized as networks of local communities (e.g., lakes connected to each other by dispersal channels (e.g., rivers. The main objective of the paper is to use neutral theory to stress the importance of landscape structure on the distribution of diversity. We refer to the landscape organization as a spatial contingency that could potentially affect the coexistence mechanisms at play. We briefly review the main approaches to describe spatial networks and describe three simple toy models of metacommunity dynamics. We take this opportunity to review their assumptions and main predictions. We then conduct simulations of these models to reveal with simple examples the impact of spatial network structure on diversity distribution. The simulation results show that competitive interactions buffer the potential impact of landscape structure. The strongest relationship between node position in the landscape and species richness was observed for the patch dynamics model without any interactions. On the other hand, strong and unequal competitive interactions minimized the effect of node position. We conclude that the

Landscape impact assessment for wind turbine development in Dyfed

International Nuclear Information System (INIS)

Blandford, C.; White, S.; Thomas, B.; Osment, F.

1994-01-01

The study aims to identify those areas in Dyfed where, in terms of landscape impact, local authorities might seek to exclude or encourage wind turbine development, provide guidelines which will assist local authorities in judging the impact of wind turbine developments on the landscape and provide a basis and framework for the preparation of planning policy guidelines for acceptable wind turbine and wind farm developments in Dyfed. The study context reviews current Government energy and planning policies for the encouragement of wind turbine developments. Dyfed County Council's relevant Structure Plan policies are also considered, as are the new draft policies relating directly to wind energy released by other authorities. The sizes and status of planning applications are summarised and the landscape implications and precedent set by the test case at Mynydd-y-Cemais is discussed. Public perception of wind power is reviewed in the context of research in Europe and the USA. (author)

The sustainable management of the landscape

Directory of Open Access Journals (Sweden)

Jean-David Gerber

2009-03-01

Full Text Available Le paysage est de plus en plus perçu comme une ressource. À ce titre, il est nécessaire de trouver des instruments juridiques, politiques ou économiques susceptibles de gérer cette « ressource-paysage » sur le long terme. Le gouvernement suisse a introduit récemment l’instrument des parcs naturels régionaux, organisés selon le modèle français, dans sa législation de protection de la nature et du paysage. Une mise en regard des nouveaux parcs avec des structures de gestion beaucoup plus anciennes, les bourgeoisies et les corporations, permet de mettre en évidence les forces et les faiblesses de chacun de ces instruments dans leur contribution à résoudre les rivalités d’usage entre acteurs utilisant ou influençant la ressource paysage. Cette comparaison permet de formuler des recommandations pratiques concernant la gestion de cette ressource.The landscape is increasingly perceived as a resource. For this reason, it is necessary to find legal, political and economic instruments that will succeed in managing this "resource landscape" in the long term. The Swiss government recently introduced the instrument of regional nature parks into the legislation governing nature and landscape preservation; the proposed parks are organized on the basis of the French model. The examination of the new parks from the perspective of much older management structures, i.e. the civic municipalities (bourgeoisies and corporations, makes it possible to demonstrate the strengths and weaknesses of each of these instruments in their contribution to the resolution of use rivalries between actors who use or influence the resource landscape. This comparison also enables the formulation of practical recommendations regarding the management of this resource.

Biomass yield from an urban landscape

Science.gov (United States)

Utilizing biomass from urban landscapes could significantly contribute to the nation’s renewable energy needs. In 2007, an experiment was begun to evaluate the biomass production from a bermudagrass, Cynodon dactylon var. dactylon (L.) Pers., lawn in Woodward, Oklahoma and to estimate the potential...

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.

Challenges of the urban peripheral landscapes

Directory of Open Access Journals (Sweden)

Catharina Pinheiro Cordeiro dos Santos Lima

2016-01-01

Full Text Available The peripheral regions of Sao Paulo reveal a profound contradiction in their landscapes – on the one hand, remnants of their original biophysical basis and, on the other, increasing pressure for the territory’s occupation. The northwest sector of the periphery, for example, presents environmentally sensitive areas which are at the same time under great pressure for occupation by those who do so by choice (the property market and those who have none (irregular and high-risk occupation. The poor inhabitants of these regions have increasingly organized themselves to achieve basic rights through community associations, social movements, and cultural groups ever since the recent re-democratization process in Brazil. It is precisely in these urban spaces, which are precarious in many ways, that significant subjectivities have emerged in participatory processes, expressing an awareness of environmental issues with an implicit desire for more humanized landscapes. These processes often include children and their teachers as protagonists. For thirteen years, the Landscape, Art and Culture Laboratory (LABPARC of the Faculty of Architecture and Urbanism (FAU at USP has been working with educators and children from municipal public schools, developing projects, research, and university extension work in the region. This article aims to discuss this experience with the objective of showing the gains achieved and the challenges that may arise within the perspective of a collective construction of the city, where urban interventions can be harmonized with water sources, streams, steep slopes, forests, and fauna.

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)

Outlining an analytical framework for mapping research evaluation landscapes

Energy Technology Data Exchange (ETDEWEB)

Åström, F.

2016-07-01

This paper suggests an infrastructure perspective, as suggested by Star and Bowker (2006), as an analytical framework for studying the research evaluation landscape. An infrastructure is suggested to be understood, not as a concrete technology, but as a system of contextual factors including ‘Actors/Stakeholders’, ‘Technical systems’, and ‘Evaluation practices’. How the framework can be operationationalized is exemplified by examples from previous and ongoing research, as well as by identify gaps in current research. (Author)

Do geographically isolated wetlands influence landscape functions?

Science.gov (United States)

Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie C.; Basu, Nandita; Calhoun, Aram J.K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward S.; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan; Leibowitz, Scott G.; Lewis, David Bruce; Marton, John; McLaughlin, Daniel L.; Mushet, David M.; Raanan-Kiperwas, Hadas; Rains, Mark C.; Smith, Lora; Walls, Susan C.

2015-01-01

Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bodies to create spatial and temporal heterogeneity in the timing, flow paths, and magnitude of network connectivity. These attributes signal a critical role for GIWs in sustaining a portfolio of landscape functions, but legal protections remain weak despite preferential loss from many landscapes. GIWs lack persistent surface water connections, but this condition does not imply the absence of hydrological, biogeochemical, and biological exchanges with nearby and downstream waters. Although hydrological and biogeochemical connectivity is often episodic or slow (e.g., via groundwater), hydrologic continuity and limited evaporative solute enrichment suggest both flow generation and solute and sediment retention. Similarly, whereas biological connectivity usually requires overland dispersal, numerous organisms, including many rare or threatened species, use both GIWs and downstream waters at different times or life stages, suggesting that GIWs are critical elements of landscape habitat mosaics. Indeed, weaker hydrologic connectivity with downstream waters and constrained biological connectivity with other landscape elements are precisely what enhances some GIW functions and enables others. Based on analysis of wetland geography and synthesis of wetland functions, we argue that sustaining landscape functions requires conserving the entire continuum of wetland connectivity, including GIWs.

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.)

A transition perspective on alternatives to coal in Chinese district heating

Directory of Open Access Journals (Sweden)

Jingjing Zhang

2015-06-01

Full Text Available China accounts for half of the world’s annual coal consumption. Coal is the primary energy source for heating in urban areas, particularly in northern China. This causes significant challenges for urban air quality problems in China and greenhouse gases emissions. Urban district heating (DH systems penetration is very high in northern China. It supplies space heating to more than 80% of urban buildings in the area. Unlike the electricity and transportation sectors, the heating sector has received little attention from policy makers and researchers in China, DH systems are an enabling infrastructure which facilitates energy efficiency improvements and the use of renewable energy sources. This study explores the dynamics and possibility to expand alternative energy sources (natural gas, biomass, direct geothermal heat, ground-source heat pump, municipal waste heat, industrial waste heat for DH in China. We apply an analytical framework largely based on the multi-level perspective in socio-technical transitions theory, in which transitions are interpreted as the result of the functioning of niche, regime and landscape elements, and interactions between them. The study provides an integrated picture of the socio-technical structure and functioning of DH in China. The results show that an energy transition in Chinese DH systems has barely started. The system is characterised by stability of the coal-based DH regime, while a number of alternative niches are struggling to emerge. Among these, natural gas is the most successful example. However, at local level different niches present opportunities in terms of physical availability, economic viability and technical capacity to address changes in landscape pressures. A sustainable heat roadmap based on integrated energy planning and policy attention at the national level could be developed as one mechanism for instigating a much needed energy transition in DH in China.

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

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...

Economic Impacts of Future Changes in the Energy System - Global Perspectives

DEFF Research Database (Denmark)

Glynn, James; Fortes, Patrícia; Krook-Riekkola, Anna

2015-01-01

climate change. This chapter summarises modelling methodologies developed in the ETSAP community to assess economic impacts of decarbonising energy systems at a global level. The next chapter of this book focuses on a national perspective. The range of economic impacts is regionally dependent upon...... the stage of economic development, the level of industrialisation, energy intensity of exports, and competition effects due to rates of relative decarbonisation. Developed nation’s decarbonisation targets are estimated to result in a manageable GDP loss in the region of 2 % by 2050. Energy intensive export...... driven developing countries such as China and India, and fossil fuel exporting nations can expect significantly higher GDP loss of up to 5 % GDP per year by mid-century....

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

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.

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

Renewable energy perspectives in the frame of Turkey’s and the EU’s energy policies

International Nuclear Information System (INIS)

Şekercioğlu, Selma; Yılmaz, Mustafa

2012-01-01

Highlights: ► We examined the renewable energy policies of the EU and Turkey in their historical perspectives. ► In the EU there is a progress in renewable energy planning and about support mechanisms. ► In Turkey there is a need for more struggles about increasing the effectiveness of support mechanism. ► The sustainability principle of the EU energy policy has to be a guide for Turkey. - Abstract: Renewable energy as one of the current and substantial issue needs to be investigated in terms of political outlook. So the researches on renewable energy policies under the energy policies of different countries are necessary. The emergence of renewable energy policy was the 20th century but it gained momentum in 21st century. The realization of the polluting nature of the petroleum products, their negative environment effects and the assumptions about the future of non-renewable energy sources were the driving forces behind these politics. The European Union in these conditions tries to play pioneer role. Turkey on the other hand as a candidate country has to harmonize its policies with the Union’s. In this context, objective of this work is to examine the EU and Turkey’s renewable energy policies, make a comparison and as a sustainability of Turkish renewable energy policy construct a future projection in short, medium and long terms.

Optical illusions and life-threatening traffic crashes: A perspective on aerial perspective.

Science.gov (United States)

Redelmeier, Donald A; Raza, Sheharyar

2018-05-01

Aerial perspective illusion is a feature of visual perception where landscapes appear relatively close in clear light and distant in dim light. We hypothesized that bright sunlight might cause drivers to perceive distant terrain as relatively close and misinterpret the approach speed of surrounding landscape as unduly slow. This hypothesis would mean, in turn, that drivers in bright sunlight may underestimate their progress on the road, compensate by traveling at a faster baseline speed, and ultimately increase the prevailing risk of a life-threatening traffic crash. We conducted three pilot studies to illustrate how the illusion might contribute to a life- threatening traffic crash. The first illustration used a questionnaire to demonstrate that most respondents were mistaken when judging the distance between simple balls in different positions. The second illustration involved an experimental manipulation to assess whether aerial perspective influenced judgments about the relative positions of vehicles in traffic. The third illustration analyzed a segment of high-volume fast-speed traffic and found an increased frequency of speeding under bright sunlight. Together with past work based on the visual arts, these examples illustrate how an aerial perspective illusion can affect distance perception, may appear in realistic traffic situations, and could potentially contribute to the risk of a life-threatening traffic crash. An awareness of this hypothesis might lead to applications on how optical illusions could extend to everyday traffic and might potentially inform safety warnings to prevent life- threatening crashes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Urban Landscape Architecture in the Reshaping of the Contemporary Cityscape

Science.gov (United States)

Ananiadou-Tzimopoulou, Maria; Bourlidou, Anastasia

2017-10-01

The contemporary urban landscape is the evolving image of dynamic social, economic and ecological changes and heterogeneity. It constitutes the mirror of history, natural and cultural, urban processes, as well as locations of hybrid character, such as degraded and fragmented spaces within the urban fabric or in the city boundaries -areas in between, infrastructures, post-industrial and waterfront sites, but also potential grounds for urban development. Along with the awakening of the global ecological awareness and the ongoing discussion on sustainability issues, the cityscape with its new attributes, constitutes a challenging field of research and planning for various disciplines, further more than landscape architecture, such as architecture, planning, ecology, environment and engineering. This paper focuses on the role of urban landscape architecture, via its theory and practice, in the reshaping of the city territory. It aspires to broaden the discussion concerning the upgrading of the contemporary cities, aiming firstly at the determination of a wider vocabulary for the urban landscape and its design, and secondly at the highlighting of landscape architecture’s contribution to the sustainable perspective of urban design and planning. The methodology is based on a comparative research implemented both on a theoretical level and on a level of applied work. Urban landscape architecture is described through theory and practice, along with correlative approaches deriving mainly from landscape urbanism and secondarily from the field of architecture. Urban landscape is approached as a socio-ecological and perceptual legible, a territory of culture, process and production; operating as an entity of ecological, infrastructural systems and planning needs, it is also regarded as a precedent for urban development. Furthermore, the research is supported by selected European and International urban landscape projects, presented in a cohesive multiscalar approach, from the

Perspectives on implementing energy efficiency in existing Swedish detached houses

Energy Technology Data Exchange (ETDEWEB)