WorldWideScience

Sample records for cluster dynamics transcending

  1. Cluster dynamics transcending chemical dynamics toward nuclear fusion.

    Science.gov (United States)

    Heidenreich, Andreas; Jortner, Joshua; Last, Isidore

    2006-07-11

    Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10(15)-10(20) W.cm(-2)). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C(4+)(D(+))(4))(n) and (D(+)I(22+))(n) at I(M) = 10(18) W.cm(-2), that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D(2))(n), (HT)(n), (CD(4))(n), (DI)(n), (CD(3)I)(n), and (CH(3)I)(n) clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D(2))(n) clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., (12)C(P,gamma)(13)N driven by CE of (CH(3)I)(n) clusters, were explored.

  2. Exploring transcendence in EFL learners’ reading comprehension through computerized dynamic assessment

    Directory of Open Access Journals (Sweden)

    Saman Ebadi

    2016-01-01

    Full Text Available Derived from Vygotsky’s works, dynamic assessment (DA enables learners to move beyond their current level of functioning through offering needs-sensitized mediation. This study aimed at exploring the learners’ development in novel and increasingly more challenging situations called transcendence (TR in an L2 context focusing on reading comprehension through computerized dynamic assessment (CDA. An overall number of 32 BA TEFL advanced students were selected from among undergraduates of a university in Iran to participate in this study. To fulfil the purpose of the study, the researchers developed Computerized Dynamic Reading Assessment to examine Transcendence (CDRAT software which included reading comprehension CDA tests. To monitor the maintenance of learning in different time intervals, two software programs named CDRAT1 and CDRAT2 were utilized in specific time intervals after the posttest. The results indicated that not only did increased task complexity not lead to regression of students’ development, but also it had an effect on enhancing their development. Thus, transcendence had an effect on the generalizability of the contentions to a great extent. In conclusion, it was disclosed that there is no endpoint to progress and merely gaining a low or high score should not be interpreted as the inability of a special learner to surpass. This would more reinforce the need for applying TR in other future DA studies.

  3. Introduction to cluster dynamics

    CERN Document Server

    Reinhard, Paul-Gerhard

    2008-01-01

    Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a ""small"" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy. Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subje

  4. Transcendence and Revelation: from Phenomenology to Theology

    OpenAIRE

    Nicolae Turcan

    2016-01-01

    Thinking on transcendence falls into a paradox: if transcendence is a radical one, we cannot speak about it; if we speak about it, it is no longer radical. The aim of this paper is to overcome this paradox and to analyze the concept of transcendence considering (1) the dynamic of self-transcending that is natural to man, (2) the limit beyond which one can speak about transcendence, and (3) the phenomena of mystery whereby the transcendence appears. Inasmuch as tr...

  5. Dynamics of star clusters

    International Nuclear Information System (INIS)

    Goodman, J.; Hut, P.

    1985-01-01

    The enigma of core collapse receives much attention in this volume. In addition, several observational papers summarize recent techniques and results and discuss the stellar dynamical implications of the enormous progress in the quality of surface photometry, proper motion studies, radial velocity determinations, as well as space-based measurements in a variety of wavelengths. The value of these Proceedings as a standard reference work is enhanced by the inclusion of two appendices, featuring English translations of two seminal papers on stellar dynamics published in Russian and not previously available in a Western language. A third appendix contains an up-to-date catalogue of observationally determined parameters of galactic globular clusters, as well as theoretically inferred parameters. This catalogue will prove to be an essential reference for phenomenonological studies and an ideal testing ground for new theoretical developments. (orig.)

  6. Epistemic communities and cluster dynamics

    DEFF Research Database (Denmark)

    Håkanson, Lars

    2003-01-01

    This paper questions the prevailing notions that firms within industrial clusters have privi-leged access to `tacit knowledge' that is unavailable - or available only at high cost - to firms located elsewhere, and that such access provides competitive advantages that help to explain the growth...... and development of both firms and regions. It outlines a model of cluster dynam-ics emphasizing two mutually interdependent processes: the concentration of specialized and complementary epistemic communities, on the one hand, and entrepreneurship and a high rate of new firm formation on the other....

  7. Innovation, learning and cluster dynamics

    NARCIS (Netherlands)

    B. Nooteboom (Bart)

    2004-01-01

    textabstractThis chapter offers a theory and method for the analysis of the dynamics, i.e. the development, of clusters for innovation. It employs an analysis of three types of embedding: institutional embedding, which is often localized, structural embedding (network structure), and relational

  8. Transcendence and Revelation: from Phenomenology to Theology

    Directory of Open Access Journals (Sweden)

    Nicolae Turcan

    2016-03-01

    Full Text Available Thinking on transcendence falls into a paradox: if transcendence is a radical one, we cannot speak about it; if we speak about it, it is no longer radical. The aim of this paper is to overcome this paradox and to analyze the concept of transcendence considering (1 the dynamic of self-transcending that is natural to man, (2 the limit beyond which one can speak about transcendence, and (3 the phenomena of mystery whereby the transcendence appears. Inasmuch as transcendence does not escape from the suspicion that the movement of selftranscending postulates it according to its desires and reaches Kantian “transcendental appearance,” this text tries to delineate the possible phenomenon of the maximum manifestation of transcendence in this world: how could transcendence give itself? The answer engages the revelation, namely, transcendence’s intention of donating itself, the presence of paradox, and the solution of mediation between transcendence and immanence by transcendence itself. Each of these possible solutions has examples in Christian Orthodox theology.

  9. DSCOVR Transcendance

    Science.gov (United States)

    Herman, J. R.; Boccara, M.; Albers, S. C.

    2017-12-01

    server to ensure constant interval between key images, this work brings transcendance to EPIC's tribute. Enriched by two years of actual service in space, the most real holistic view of the Earth will be continued at a high degree of fidelity, regardless of EPIC limitations or interruptions.

  10. Cluster dynamics at different cluster size and incident laser wavelengths

    International Nuclear Information System (INIS)

    Desai, Tara; Bernardinello, Andrea

    2002-01-01

    X-ray emission spectra from aluminum clusters of diameter -0.4 μm and gold clusters of dia. ∼1.25 μm are experimentally studied by irradiating the cluster foil targets with 1.06 μm laser, 10 ns (FWHM) at an intensity ∼10 12 W/cm 2 . Aluminum clusters show a different spectra compared to bulk material whereas gold cluster evolve towards bulk gold. Experimental data are analyzed on the basis of cluster dimension, laser wavelength and pulse duration. PIC simulations are performed to study the behavior of clusters at higher intensity I≥10 17 W/cm 2 for different size of the clusters irradiated at different laser wavelengths. Results indicate the dependence of cluster dynamics on cluster size and incident laser wavelength

  11. Exploring personality clusters among parents of ED subjects. Relationship with parents' psychopathology, attachment, and family dynamics.

    Science.gov (United States)

    Amianto, Federico; Daga, Giovanni Abbate; Bertorello, Antonella; Fassino, Secondo

    2013-10-01

    Eating disorders are some of the most difficult mental disorders to treat and manage. Family interacts with genetic dispositions and other pathogenic factors, and may influence the outburst, development and outcome of EDs. The present study explores with a cluster analysis the personality traits of parents of ED subjects. One-hundred-eight mothers and 104 fathers were tested with Temperament Character Inventory (TCI), Eating Disorder Inventory-2 (EDI-2), State-Trait Anger Expression Inventory (STAX), Family Assessment Device (FAD), Attachment Style Questionnaire (ASQ), Symptom Questionnaire (SQ), Psychological Well-Being scales (PWB). The cluster distribution of parents based on personality traits was explored. Parents' clusters TCI scores were compared as regards personality, psychopathology, attachment and family features. Cross distribution of temperament and character clusters in mothers and fathers, among couples and ED diagnoses of the daughters was explored. Two clusters of mothers and fathers were identified with temperament clustering. Character traits led to two mothers and three fathers clusters. Mothers temperament cluster 1 (MTC1) correspond to a explosive/adventurous profile, MTC2 to a cautious/passive-dependent profile. Fathers temperament cluster 1 (FTC1) was explosive/methodic, FTC2 was independent/methodic. Character clustering distinguished very immature mothers (MCC1) and majority (65%) of character mature mothers with low self-transcendence (MCC2). A third of fathers was severely immature (FCC1), a third impaired as regards relationships (poor cooperativeness and self-transcendence; FCC2), and one third character mature fathers with low self-transcendence (FCC3). Each cluster evidences specific psychopathology and attachment characteristics. FTC1 was more frequently associated with character immaturity. No significant clusters' cross correlation was found in parental couples. Parents' clusters analyze in depth the univocal picture of

  12. The Dynamics of Overlapping Clusters

    DEFF Research Database (Denmark)

    Reckendrees, Alfred

    The economic transition characterizing the process of European industrialization in the 19th century was concentrated on regions rather than on states. In the first half of the 19th century, the region of Aachen (in the west of Prussia) pioneered on the territory of the German states and developed...... to a powerful industrial region. The implementation and diffusion of the factory system and the economic impact of adapted and new institutions make the core of this paper. Reciprocal interconnections between firms of different clusters shaped the region and created economic dynamics. Investments transgressed...... the boundaries of single industries and new industries emerged. One important feature of the regional production system was cross-sectional knowledge transfer; a second was institutions supportive to this process....

  13. Dynamical aspects of galaxy clustering

    International Nuclear Information System (INIS)

    Fall, S.M.

    1980-01-01

    Some recent work on the origin and evolution of galaxy clustering is reviewed, particularly within the context of the gravitational instability theory and the hot big-bang cosmological model. Statistical measures of clustering, including correlation functions and multiplicity functions, are explained and discussed. The close connection between galaxy formation and clustering is emphasized. Additional topics include the dependence of galaxy clustering on the spectrum of primordial density fluctuations and the mean mass density of the Universe. (author)

  14. Exploring the Internal Dynamics of Globular Clusters

    Science.gov (United States)

    Watkins, Laura L.; van der Marel, Roeland; Bellini, Andrea; Luetzgendorf, Nora; HSTPROMO Collaboration

    2018-01-01

    Exploring the Internal Dynamics of Globular ClustersThe formation histories and structural properties of globular clusters are imprinted on their internal dynamics. Energy equipartition results in velocity differences for stars of different mass, and leads to mass segregation, which results in different spatial distributions for stars of different mass. Intermediate-mass black holes significantly increase the velocity dispersions at the centres of clusters. By combining accurate measurements of their internal kinematics with state-of-the-art dynamical models, we can characterise both the velocity dispersion and mass profiles of clusters, tease apart the different effects, and understand how clusters may have formed and evolved.Using proper motions from the Hubble Space Telescope Proper Motion (HSTPROMO) Collaboration for a set of 22 Milky Way globular clusters, and our discrete dynamical modelling techniques designed to work with large, high-quality datasets, we are studying a variety of internal cluster properties. We will present the results of theoretical work on simulated clusters that demonstrates the efficacy of our approach, and preliminary results from application to real clusters.

  15. Dynamical evolution of galaxies in clusters

    International Nuclear Information System (INIS)

    Ostriker, J.P.

    1977-01-01

    In addition to the processes involved in the evolution of star clusters, there are three kinds of processes that are peculiar to, or far more important in, galaxy clusters than in star clusters: galaxy interactions with gas, high-velocity tidal interactions, and accretion and cannibalism. The latter is discussed at some length; analytical calculations for the apparent luminosity evolution of the first brightest galaxy and the apparent luminosity evolution of M 12 are described, along with the numerical simulation of cluster evolution. It appears that many of the notable features of centrally condensed clusters of galaxies, particularly the presence of very luminous but low-surface-brightness central cD systems, can be understood in terms of a straightforward dynamical theory of galactic cannibalism. It is possible to maintain the hypothesis that dynamical evolution gradually transforms Bautz--Morgan III clusters to type II systems or type I systems. 36 references, 5 figures

  16. Modified Newtonian dynamics and the Coma cluster

    International Nuclear Information System (INIS)

    The, L.S.; White, S.D.M.

    1988-01-01

    The consistency of Milgrom's theory of modified Newtonian dynamics is checked against optical and X-ray data for the Coma cluster of galaxies. It is found that viable models for the cluster containing no dark matter can be constructed. They require an extensive gaseous atmosphere through which galaxies move on near-radial orbits. The gas temperature is predicted to have a shallow minimum near the cluster center; this structure may conflict with the best X-ray spectra of the cluster. 18 references

  17. CLUSTER DYNAMICS LARGELY SHAPES PROTOPLANETARY DISK SIZES

    Energy Technology Data Exchange (ETDEWEB)

    Vincke, Kirsten; Pfalzner, Susanne, E-mail: kvincke@mpifr-bonn.mpg.de [Max Planck Institute for Radio Astronomy, Auf dem Hügel 69, D-53121 Bonn (Germany)

    2016-09-01

    To what degree the cluster environment influences the sizes of protoplanetary disks surrounding young stars is still an open question. This is particularly true for the short-lived clusters typical for the solar neighborhood, in which the stellar density and therefore the influence of the cluster environment change considerably over the first 10 Myr. In previous studies, the effect of the gas on the cluster dynamics has often been neglected; this is remedied here. Using the code NBody6++, we study the stellar dynamics in different developmental phases—embedded, expulsion, and expansion—including the gas, and quantify the effect of fly-bys on the disk size. We concentrate on massive clusters (M {sub cl} ≥ 10{sup 3}–6 ∗ 10{sup 4} M {sub Sun}), which are representative for clusters like the Orion Nebula Cluster (ONC) or NGC 6611. We find that not only the stellar density but also the duration of the embedded phase matters. The densest clusters react fastest to the gas expulsion and drop quickly in density, here 98% of relevant encounters happen before gas expulsion. By contrast, disks in sparser clusters are initially less affected, but because these clusters expand more slowly, 13% of disks are truncated after gas expulsion. For ONC-like clusters, we find that disks larger than 500 au are usually affected by the environment, which corresponds to the observation that 200 au-sized disks are common. For NGC 6611-like clusters, disk sizes are cut-down on average to roughly 100 au. A testable hypothesis would be that the disks in the center of NGC 6611 should be on average ≈20 au and therefore considerably smaller than those in the ONC.

  18. Small clusters: Between dynamics and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R S

    1989-06-01

    The relation between equilibrium properties and dynamical properties, and between the two kinds of descriptions, is explored by examining the dynamics of isomerization of argon clusters. The same general subject, from the viewpoint of ergodicity and chaos is examined through the fractal dimension of the trajectory in phase space and the Kolmogorov entropy.

  19. Hydration dynamics in water clusters via quantum molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Turi, László, E-mail: turi@chem.elte.hu [Department of Physical Chemistry, Eötvös Loránd University, Budapest 112, P. O. Box 32, H-1518 (Hungary)

    2014-05-28

    We have investigated the hydration dynamics in size selected water clusters with n = 66, 104, 200, 500, and 1000 water molecules using molecular dynamics simulations. To study the most fundamental aspects of relaxation phenomena in clusters, we choose one of the simplest, still realistic, quantum mechanically treated test solute, an excess electron. The project focuses on the time evolution of the clusters following two processes, electron attachment to neutral equilibrated water clusters and electron detachment from an equilibrated water cluster anion. The relaxation dynamics is significantly different in the two processes, most notably restoring the equilibrium final state is less effective after electron attachment. Nevertheless, in both scenarios only minor cluster size dependence is observed. Significantly different relaxation patterns characterize electron detachment for interior and surface state clusters, interior state clusters relaxing significantly faster. This observation may indicate a potential way to distinguish surface state and interior state water cluster anion isomers experimentally. A comparison of equilibrium and non-equilibrium trajectories suggests that linear response theory breaks down for electron attachment at 200 K, but the results converge to reasonable agreement at higher temperatures. Relaxation following electron detachment clearly belongs to the linear regime. Cluster relaxation was also investigated using two different computational models, one preferring cavity type interior states for the excess electron in bulk water, while the other simulating non-cavity structure. While the cavity model predicts appearance of several different hydrated electron isomers in agreement with experiment, the non-cavity model locates only cluster anions with interior excess electron distribution. The present simulations show that surface isomers computed with the cavity predicting potential show similar dynamical behavior to the interior clusters of

  20. Dynamics of rich clusters of galaxies. I. The Coma cluster

    International Nuclear Information System (INIS)

    Kent, S.M.; Gunn, J.E.

    1982-01-01

    The structure and dynamics of the Coma cluster are analyzed using self-consistent equilibrium dynamical models. Observational material for Coma is culled from a variety of sources. Projected surface, density, and velocity-dispersion profiles are derived extending out to a radius of 3 0 from the cluster center, which are essentially free from field contamination. Segregation of galaxies by luminosity and morphology are discussed and a quantitative estimate of the latter is made. The method of constructing self-consistent dynamical models is discussed. Four different forms of the distribution function are analyzed allowing for different possible dependences of f on energy and angular momentum. Properties of typical models that might resemble actual clusters are presented, and the importance of having velocity-dispersion information is empha sized. The effect of a central massive object such as a cD galaxy on the core structure is illustrated. A comparison of these models with Coma reveals that only models with a distribution function in which the ratio of tangential to radial velocity dispersions is everywhere constant give acceptable fits. In particular, it is possible to rule out models that have isotropic motions in the core and predominantly radial motions in the halo. For H 0 = 50, the best-fitting models give a total projected mass inside 3 0 of 2.9 x 10 15 M/sub sun/ , a core radius of 340--400 kpc (8.5'--10'), an upper limit to any central massive object of approx.10 13 M/sub sun/ , and a mass-to-blue-light ratio of M/L = 181. From cosmological considerations the cluster ''edge'' is determined to lie at rapprox.5 0 --6 0 . The possible distribution of ''dark matter'' in Coma is discussed and it is argued that this distribution cannot be significantly different from that of the galaxies. The dynamics of morphological segregation are examined quantitatively, and are explained at least qualitatively

  1. Dynamically allocated virtual clustering management system

    Science.gov (United States)

    Marcus, Kelvin; Cannata, Jess

    2013-05-01

    The U.S Army Research Laboratory (ARL) has built a "Wireless Emulation Lab" to support research in wireless mobile networks. In our current experimentation environment, our researchers need the capability to run clusters of heterogeneous nodes to model emulated wireless tactical networks where each node could contain a different operating system, application set, and physical hardware. To complicate matters, most experiments require the researcher to have root privileges. Our previous solution of using a single shared cluster of statically deployed virtual machines did not sufficiently separate each user's experiment due to undesirable network crosstalk, thus only one experiment could be run at a time. In addition, the cluster did not make efficient use of our servers and physical networks. To address these concerns, we created the Dynamically Allocated Virtual Clustering management system (DAVC). This system leverages existing open-source software to create private clusters of nodes that are either virtual or physical machines. These clusters can be utilized for software development, experimentation, and integration with existing hardware and software. The system uses the Grid Engine job scheduler to efficiently allocate virtual machines to idle systems and networks. The system deploys stateless nodes via network booting. The system uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex, private networks eliminating the need to map each virtual machine to a specific switch port. The system monitors the health of the clusters and the underlying physical servers and it maintains cluster usage statistics for historical trends. Users can start private clusters of heterogeneous nodes with root privileges for the duration of the experiment. Users also control when to shutdown their clusters.

  2. Dynamical processes in space: Cluster results

    Directory of Open Access Journals (Sweden)

    C. P. Escoubet

    2013-06-01

    Full Text Available After 12 years of operations, the Cluster mission continues to successfully fulfil its scientific objectives. The main goal of the Cluster mission, comprised of four identical spacecraft, is to study in three dimensions small-scale plasma structures in key plasma regions of the Earth's environment: solar wind and bow shock, magnetopause, polar cusps, magnetotail, plasmasphere and auroral zone. During the course of the mission, the relative distance between the four spacecraft has been varied from 20 km to 36 000 km to study the scientific regions of interest at different scales. Since summer 2005, new multi-scale constellations have been implemented, wherein three spacecraft (C1, C2, C3 are separated by 10 000 km, while the fourth one (C4 is at a variable distance ranging between 20 km and 10 000 km from C3. Recent observations were conducted in the auroral acceleration region with the spacecraft separated by 1000s km. We present highlights of the results obtained during the last 12 years on collisionless shocks, magnetopause waves, magnetotail dynamics, plasmaspheric structures, and the auroral acceleration region. In addition, we highlight Cluster results on understanding the impact of Coronal Mass Ejections (CME on the Earth environment. We will also present Cluster data accessibility through the Cluster Science Data System (CSDS, and the Cluster Active Archive (CAA, which was implemented to provide a permanent and public archive of high resolution Cluster data from all instruments.

  3. Open Cluster Dynamics via Fundamental Plane

    Science.gov (United States)

    Lin, Chien-Cheng; Pang, Xiao-Ying

    2018-04-01

    Open clusters (OCs) are important objects for stellar dynamics studies. The short survival timescale of OCs makes them closely related to the formation of Galactic field stars. We motivate to investigate the dynamical evolution of OCs on the aspect of internal effect and the external influence. Firstly, we make use of the known OC catalog to obtain OCs masses, effective radii. Additionally, we estimate OCs kinematics properties by OC members cross-matched with radial velocity and metallicity from SDSSIV/APOGEE2. We then establish the fundamental plane of OCs based on the radial velocity dispersion, the effective radius, and average surface brightness. The deviation of the fundamental plane from the Virial Plane, so called the tilt, and the r.m.s. dispersion of OCs around the average plane are used to indicate the dynamical status of OCs. Parameters of the fitted plane will vary with cluster age and distance.

  4. Transcendence and Sensoriness

    DEFF Research Database (Denmark)

    Protestant theology and culture are known for a reserved, at times skeptical, attitude to the use of art and aesthetic forms of expression in a religious context. In Transcendence and Sensoriness, this attitude is analysed and discussed both theoretically and through case studies considered...

  5. Implications of Quantum Logic to the Notion of Transcendence

    Directory of Open Access Journals (Sweden)

    Jerome Manyahi

    2015-02-01

    Full Text Available This article attempts to study the notion of Transcendence from the perspective of Quantum Mechanics. The Laws of Physics reveal that nature is dynamic and it is understood in terms of mathematical models and relations. Uncertainty is a fundamental feature of the Quantum reality. Quantum structural pattern is the fundamental nature of reality, whether observable or unobservable. Transcendence in Quantum Mechanics is a dynamic concept which must be understood in terms of dynamic state. Transcendencein Quantum Mechanics is the process of uncovering deep treasures of the reality, which is dynamic. A movement toward the deeper reality of God is what is behind the notion of transcendence.

  6. Spatial cluster detection using dynamic programming

    Directory of Open Access Journals (Sweden)

    Sverchkov Yuriy

    2012-03-01

    Full Text Available Abstract Background The task of spatial cluster detection involves finding spatial regions where some property deviates from the norm or the expected value. In a probabilistic setting this task can be expressed as finding a region where some event is significantly more likely than usual. Spatial cluster detection is of interest in fields such as biosurveillance, mining of astronomical data, military surveillance, and analysis of fMRI images. In almost all such applications we are interested both in the question of whether a cluster exists in the data, and if it exists, we are interested in finding the most accurate characterization of the cluster. Methods We present a general dynamic programming algorithm for grid-based spatial cluster detection. The algorithm can be used for both Bayesian maximum a-posteriori (MAP estimation of the most likely spatial distribution of clusters and Bayesian model averaging over a large space of spatial cluster distributions to compute the posterior probability of an unusual spatial clustering. The algorithm is explained and evaluated in the context of a biosurveillance application, specifically the detection and identification of Influenza outbreaks based on emergency department visits. A relatively simple underlying model is constructed for the purpose of evaluating the algorithm, and the algorithm is evaluated using the model and semi-synthetic test data. Results When compared to baseline methods, tests indicate that the new algorithm can improve MAP estimates under certain conditions: the greedy algorithm we compared our method to was found to be more sensitive to smaller outbreaks, while as the size of the outbreaks increases, in terms of area affected and proportion of individuals affected, our method overtakes the greedy algorithm in spatial precision and recall. The new algorithm performs on-par with baseline methods in the task of Bayesian model averaging. Conclusions We conclude that the dynamic

  7. Space, Art and Transcendence

    Directory of Open Access Journals (Sweden)

    Ricardo Pinilla Burgos

    2017-09-01

    Full Text Available In the light of Heidegger’s analysis of space and art, and its link with a milestone for modern sculpture such as Eduardo Chillida, space is presented, together with time, as a fundamental element of art and especially of sculpture and architecture. Space is not a homogeneous neutral background, but an original phenomenon that compromises from the beginning the creation and the peculiar kind of transcendence to which every work of art invites us. Every work submerges us on one side in a feverish, sensitive and bodily immanence, in the mystery of the sensitive (aesthetic that we are, but aswell it takes us beyond or nearer than the conventional meanings and relations and our situation. From here, we will consider whether and how we can put the aesthetic experience of space in relation to the transcendence of which religion commonly speaks, illuminated in turn from the study of the sacred of Mircea Eliade.

  8. Cluster Dynamics: Laying the Foundation for Tailoring the Design of Cluster ASSE

    Science.gov (United States)

    2016-02-25

    AFRL-AFOSR-VA-TR-2016-0081 CLUSTER DYNAMICS: LAYING THE FOUNDATION FOR TAILORING THE DESIGN OF CLUSTER ASSE Albert Castleman PENNSYLVANIA STATE...15-10-2015 4. TITLE AND SUBTITLE CLUSTER DYNAMICS: LAYING THE FOUNDATION FOR TAILORING THE DESIGN OF CLUSTER ASSEMBLED NANOSCALE MATERIALS 5a... clusters as the building blocks of new materials with tailored properties that are beneficial to the AFOSR. Our continuing program is composed of two

  9. Cluster analysis of word frequency dynamics

    Science.gov (United States)

    Maslennikova, Yu S.; Bochkarev, V. V.; Belashova, I. A.

    2015-01-01

    This paper describes the analysis and modelling of word usage frequency time series. During one of previous studies, an assumption was put forward that all word usage frequencies have uniform dynamics approaching the shape of a Gaussian function. This assumption can be checked using the frequency dictionaries of the Google Books Ngram database. This database includes 5.2 million books published between 1500 and 2008. The corpus contains over 500 billion words in American English, British English, French, German, Spanish, Russian, Hebrew, and Chinese. We clustered time series of word usage frequencies using a Kohonen neural network. The similarity between input vectors was estimated using several algorithms. As a result of the neural network training procedure, more than ten different forms of time series were found. They describe the dynamics of word usage frequencies from birth to death of individual words. Different groups of word forms were found to have different dynamics of word usage frequency variations.

  10. Cluster analysis of word frequency dynamics

    International Nuclear Information System (INIS)

    Maslennikova, Yu S; Bochkarev, V V; Belashova, I A

    2015-01-01

    This paper describes the analysis and modelling of word usage frequency time series. During one of previous studies, an assumption was put forward that all word usage frequencies have uniform dynamics approaching the shape of a Gaussian function. This assumption can be checked using the frequency dictionaries of the Google Books Ngram database. This database includes 5.2 million books published between 1500 and 2008. The corpus contains over 500 billion words in American English, British English, French, German, Spanish, Russian, Hebrew, and Chinese. We clustered time series of word usage frequencies using a Kohonen neural network. The similarity between input vectors was estimated using several algorithms. As a result of the neural network training procedure, more than ten different forms of time series were found. They describe the dynamics of word usage frequencies from birth to death of individual words. Different groups of word forms were found to have different dynamics of word usage frequency variations

  11. Shifting frontiers of transcendence in theology, philosophy and science

    Directory of Open Access Journals (Sweden)

    Cornelius W. du Toit

    2011-04-01

    Full Text Available This article dealt cursorily with developments in theology, philosophy and the sciences that have contributed to what one might call horizontal transcendence. The premise is that humans have evolved into beings that are wired for transcendence. Transcendence is described in terms of the metaphor of frontiers and frontier posts. Although the frontiers of transcendence shift according to the insights, understanding and needs of every epoch and world view, it remains transcendent, even in its immanent mode. Diverse perceptions of that frontier normally coexist in every era and we can only discern a posteriori which was the dominant one. Frontiers are fixed with reference to the epistemologies, notions of the subject and power structures of a given era. From a theological point of view, encounter with the transcendent affords insight, not into the essence of transcendence, but into human self-understanding and understanding of our world. Transcendence enters into the picture when an ordinary human experience acquires a depth and an immediacy that are attributed to an act of God. In philosophy, transcendence evolved from a noumenal metaphysics focused on the object (Plato, via emphasis on the epistemological structure and limits of the knowing subject (Kant and an endeavour to establish a dynamic subject-object dialectics (Hegel, to the assimilation of transcendence into human existence (Heidegger. In the sciences certain developments opened up possibilities for God to act in non-interventionist ways. The limitations of such an approach are considered, as well as promising new departures – and their limitations – in the neurosciences. From all of this I conclude that an immanent-transcendent approach is plausible for our day and age.

  12. Fluctuations, dynamical instabilities and clusterization processes

    International Nuclear Information System (INIS)

    Burgio, G.F.; Chomaz, Ph.; Randrup, J.

    1992-01-01

    Recent progress with regard to the numerical simulation of fluctuations in nuclear dynamics is reported. Cluster formation in unstable nuclear matter is studied within the framework of a Boltzmann-Langevin equation developed to describe large amplitude fluctuations. Through the Fourier analysis of the fluctuating nuclear density in coordinate space, the onset of the clusterization is related to the dispersion relation of harmonic density oscillations. This detailed study on the simple two-dimensional case demonstrates the validity of the general approach. It is also shown, how the inclusion of fluctuations implies a description in terms of ensemble of trajectories and it is discussed why the presence of a stochastic term may cure the intrinsic unpredictability of deterministic theories (such as mean-field approximation) in presence of instabilities and/or chaos. (author) 8 refs., 3 figs

  13. Single-cluster dynamics for the random-cluster model

    NARCIS (Netherlands)

    Deng, Y.; Qian, X.; Blöte, H.W.J.

    2009-01-01

    We formulate a single-cluster Monte Carlo algorithm for the simulation of the random-cluster model. This algorithm is a generalization of the Wolff single-cluster method for the q-state Potts model to noninteger values q>1. Its results for static quantities are in a satisfactory agreement with those

  14. Spirituality and leadership through transcendence

    OpenAIRE

    2015-01-01

    M. Phil. (Personal, Interpersonal and Professional Leadership) Orientation: Personal experience of the phenomenon of transcendence and a preliminary literature review indicates that the phenomenon of transcendence can be better integrated within the Personal, Interpersonal and Professional Leadership (PPL) framework as well as within other leadership theories. Research purpose: The aim of the study is to conceptualise transcendence within PPL and leadership in general using auto-ethnograph...

  15. Transcending the nation state

    DEFF Research Database (Denmark)

    Cort, Pia

    2009-01-01

    competition. This article surveys vocational education and training models in Europe, applying a discursive institutionalist perspective in order to describe how vocational education and training as an institution is being reframed by means of the Copenhagen Process, and concludes that a European model......Throughout Europe, vocational education and training is undergoing reform and modernisation as part of a common EU policy process, the Copenhagen Process. The aim of this Process is initiate a pan-European modernisation of vocational education and training in order to meet the challenges of global...... is under construction which aims to transcend the nation state by introducing a new way of "thinking" vocational education and training....

  16. Dynamically Allocated Virtual Clustering Management System Users Guide

    Science.gov (United States)

    2016-11-01

    ARL-SR-0366 ● NOV 2016 US Army Research Laboratory Dynamically Allocated Virtual Clustering Management System User’s Guide by... Clustering Management System User’s Guide by Kelvin M Marcus Computational and Information Sciences Directorate, ARL...

  17. Transcending Organizational Boundaries

    DEFF Research Database (Denmark)

    Kringelum, Louise Tina Brøns

    by applying the engaged scholarship approach, thereby providing a methodological contribution to both port and business model research. Emphasizing the interplay of intra- and inter-organizational business model innovation, the thesis adds insight into the roles of port authorities, business model trends......This thesis explores how processes of business model innovation can unfold in a port authority by transcending organizational boundaries through inter-organizational collaboration. The findings contribute to two fields of academic inquiry: the study of business model innovation and the study of how...... the roles of port authorities evolve. This contribution is made by combining the two fields, where the study of business model innovation is used as an analytical concept for understanding the evolution of port authorities, and where the study of port authorities is used as a contextual setting...

  18. The affective discourse dynamics of metaphor clustering The affective discourse dynamics of metaphor clustering

    Directory of Open Access Journals (Sweden)

    Lynne Cameron

    2010-05-01

    Full Text Available

    Metaphor is examined in the very different iscourse contexts of the classroom and of reconciliation talk to highlight the neglected affective dimension. The distribution of metaphors across discourse shows clustering at certain points, often where speakers are engaged in critical interpersonal discourse activity. Clusters in classroom talk co-occur with sequences of agenda management where teachers prepare students for upcoming lessons and with giving feedback to students, both of which require careful management of interpersonal and affective issues. Clusters in reconciliation talk co-occur with discourse management and with two situations with significant affective dynamics: appropriation of metaphor and exploration of alternative scenarios.

    Metaphor is examined in the very different iscourse contexts of the classroom and of reconciliation talk to highlight the neglected affective dimension. The distribution of metaphors across discourse shows clustering at certain points, often where speakers are engaged in critical interpersonal discourse activity. Clusters in classroom talk co-occur with sequences of agenda management where teachers prepare students for upcoming lessons and with giving feedback to students, both of which require careful management of interpersonal and affective issues. Clusters in reconciliation talk co-occur with discourse management and with two situations with significant affective dynamics: appropriation of metaphor and exploration of alternative scenarios.

  19. Molecular dynamics simulations of cluster fission and fusion processes

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.; Solov'yov, Ilia

    2004-01-01

    Results of molecular dynamics simulations of fission reactions Na_10^2+ --> Na_7^+ +Na_3^+ and Na_18^2+ --> 2Na_9^+ are presented. The dependence of the fission barriers on the isomer structure of the parent cluster is analyzed. It is demonstrated that the energy necessary for removing homothetic...... separation of the daughter fragments begins and/or forming a "neck" between the separating fragments. A novel algorithm for modeling the cluster growth process is described. This approach is based on dynamic search for the most stable cluster isomers and allows one to find the optimized cluster geometries...... groups of atoms from the parent cluster is largely independent of the isomer form of the parent cluster. The importance of rearrangement of the cluster structure during the fission process is elucidated. This rearrangement may include transition to another isomer state of the parent cluster before actual...

  20. Dynamic Trajectory Extraction from Stereo Vision Using Fuzzy Clustering

    Science.gov (United States)

    Onishi, Masaki; Yoda, Ikushi

    In recent years, many human tracking researches have been proposed in order to analyze human dynamic trajectory. These researches are general technology applicable to various fields, such as customer purchase analysis in a shopping environment and safety control in a (railroad) crossing. In this paper, we present a new approach for tracking human positions by stereo image. We use the framework of two-stepped clustering with k-means method and fuzzy clustering to detect human regions. In the initial clustering, k-means method makes middle clusters from objective features extracted by stereo vision at high speed. In the last clustering, c-means fuzzy method cluster middle clusters based on attributes into human regions. Our proposed method can be correctly clustered by expressing ambiguity using fuzzy clustering, even when many people are close to each other. The validity of our technique was evaluated with the experiment of trajectories extraction of doctors and nurses in an emergency room of a hospital.

  1. Dynamics of Galaxy Clusters and their Outskirts

    DEFF Research Database (Denmark)

    Falco, Martina

    Galaxy clusters have demonstrated to be powerful probes of cosmology, since their mass and abundance depend on the cosmological model that describes the Universe and on the gravitational formation process of cosmological structures. The main challenge in using clusters to constrain cosmology...... is that their masses cannot be measured directly, but need to be inferred indirectly through their observable properties. The most common methods extract the cluster mass from their strong X-ray emission or from the measured redshifts of the galaxy members. The gravitational lensing effect caused by clusters...... on the background galaxies is also an important trace of their total mass distribution.In the work presented within this thesis, we exploit the connection between the gravitational potential of galaxy clusters and the kinematical properties of their surroundings, in order to determine the total cluster mass...

  2. Dynamic multifactor clustering of financial networks

    Science.gov (United States)

    Ross, Gordon J.

    2014-02-01

    We investigate the tendency for financial instruments to form clusters when there are multiple factors influencing the correlation structure. Specifically, we consider a stock portfolio which contains companies from different industrial sectors, located in several different countries. Both sector membership and geography combine to create a complex clustering structure where companies seem to first be divided based on sector, with geographical subclusters emerging within each industrial sector. We argue that standard techniques for detecting overlapping clusters and communities are not able to capture this type of structure and show how robust regression techniques can instead be used to remove the influence of both sector and geography from the correlation matrix separately. Our analysis reveals that prior to the 2008 financial crisis, companies did not tend to form clusters based on geography. This changed immediately following the crisis, with geography becoming a more important determinant of clustering structure.

  3. Advances in molecular vibrations and collision dynamics molecular clusters

    CERN Document Server

    Bacic, Zatko

    1998-01-01

    This volume focuses on molecular clusters, bound by van der Waals interactions and hydrogen bonds. Twelve chapters review a wide range of recent theoretical and experimental advances in the areas of cluster vibrations, spectroscopy, and reaction dynamics. The authors are leading experts, who have made significant contributions to these topics.The first chapter describes exciting results and new insights in the solvent effects on the short-time photo fragmentation dynamics of small molecules, obtained by combining heteroclusters with femtosecond laser excitation. The second is on theoretical work on effects of single solvent (argon) atom on the photodissociation dynamics of the solute H2O molecule. The next two chapters cover experimental and theoretical aspects of the energetics and vibrations of small clusters. Chapter 5 describes diffusion quantum Monte Carlo calculations and non additive three-body potential terms in molecular clusters. The next six chapters deal with hydrogen-bonded clusters, refle...

  4. Validating clustering of molecular dynamics simulations using polymer models

    Directory of Open Access Journals (Sweden)

    Phillips Joshua L

    2011-11-01

    Full Text Available Abstract Background Molecular dynamics (MD simulation is a powerful technique for sampling the meta-stable and transitional conformations of proteins and other biomolecules. Computational data clustering has emerged as a useful, automated technique for extracting conformational states from MD simulation data. Despite extensive application, relatively little work has been done to determine if the clustering algorithms are actually extracting useful information. A primary goal of this paper therefore is to provide such an understanding through a detailed analysis of data clustering applied to a series of increasingly complex biopolymer models. Results We develop a novel series of models using basic polymer theory that have intuitive, clearly-defined dynamics and exhibit the essential properties that we are seeking to identify in MD simulations of real biomolecules. We then apply spectral clustering, an algorithm particularly well-suited for clustering polymer structures, to our models and MD simulations of several intrinsically disordered proteins. Clustering results for the polymer models provide clear evidence that the meta-stable and transitional conformations are detected by the algorithm. The results for the polymer models also help guide the analysis of the disordered protein simulations by comparing and contrasting the statistical properties of the extracted clusters. Conclusions We have developed a framework for validating the performance and utility of clustering algorithms for studying molecular biopolymer simulations that utilizes several analytic and dynamic polymer models which exhibit well-behaved dynamics including: meta-stable states, transition states, helical structures, and stochastic dynamics. We show that spectral clustering is robust to anomalies introduced by structural alignment and that different structural classes of intrinsically disordered proteins can be reliably discriminated from the clustering results. To our

  5. Analysis of the dynamical cluster approximation for the Hubbard model

    OpenAIRE

    Aryanpour, K.; Hettler, M. H.; Jarrell, M.

    2002-01-01

    We examine a central approximation of the recently introduced Dynamical Cluster Approximation (DCA) by example of the Hubbard model. By both analytical and numerical means we study non-compact and compact contributions to the thermodynamic potential. We show that approximating non-compact diagrams by their cluster analogs results in a larger systematic error as compared to the compact diagrams. Consequently, only the compact contributions should be taken from the cluster, whereas non-compact ...

  6. Clustering promotes switching dynamics in networks of noisy neurons

    Science.gov (United States)

    Franović, Igor; Klinshov, Vladimir

    2018-02-01

    Macroscopic variability is an emergent property of neural networks, typically manifested in spontaneous switching between the episodes of elevated neuronal activity and the quiescent episodes. We investigate the conditions that facilitate switching dynamics, focusing on the interplay between the different sources of noise and heterogeneity of the network topology. We consider clustered networks of rate-based neurons subjected to external and intrinsic noise and derive an effective model where the network dynamics is described by a set of coupled second-order stochastic mean-field systems representing each of the clusters. The model provides an insight into the different contributions to effective macroscopic noise and qualitatively indicates the parameter domains where switching dynamics may occur. By analyzing the mean-field model in the thermodynamic limit, we demonstrate that clustering promotes multistability, which gives rise to switching dynamics in a considerably wider parameter region compared to the case of a non-clustered network with sparse random connection topology.

  7. THE DYNAMICAL STATE OF BRIGHTEST CLUSTER GALAXIES AND THE FORMATION OF CLUSTERS

    International Nuclear Information System (INIS)

    Coziol, R.; Andernach, H.; Caretta, C. A.; Alamo-MartInez, K. A.; Tago, E.

    2009-01-01

    A large sample of Abell clusters of galaxies, selected for the likely presence of a dominant galaxy, is used to study the dynamical properties of the brightest cluster members (BCMs). From visual inspection of Digitized Sky Survey images combined with redshift information we identify 1426 candidate BCMs located in 1221 different redshift components associated with 1169 different Abell clusters. This is the largest sample published so far of such galaxies. From our own morphological classification we find that ∼92% of the BCMs in our sample are early-type galaxies and 48% are of cD type. We confirm what was previously observed based on much smaller samples, namely, that a large fraction of BCMs have significant peculiar velocities. From a subsample of 452 clusters having at least 10 measured radial velocities, we estimate a median BCM peculiar velocity of 32% of their host clusters' radial velocity dispersion. This suggests that most BCMs are not at rest in the potential well of their clusters. This phenomenon is common to galaxy clusters in our sample, and not a special trait of clusters hosting cD galaxies. We show that the peculiar velocity of the BCM is independent of cluster richness and only slightly dependent on the Bautz-Morgan type. We also find a weak trend for the peculiar velocity to rise with the cluster velocity dispersion. The strongest dependence is with the morphological type of the BCM: cD galaxies tend to have lower relative peculiar velocities than elliptical galaxies. This result points to a connection between the formation of the BCMs and that of their clusters. Our data are qualitatively consistent with the merging-groups scenario, where BCMs in clusters formed first in smaller subsystems comparable to compact groups of galaxies. In this scenario, clusters would have formed recently from the mergers of many such groups and would still be in a dynamically unrelaxed state.

  8. Dynamical evolution of clusters with two stellar groups

    Energy Technology Data Exchange (ETDEWEB)

    Angeletti, L; Giannone, P. (Rome Univ. (Italy))

    1977-08-01

    The generalization of the fluid-dynamical approach from one-component star clusters to clusters with several stellar groups (as far as the star masses are concerned) has been applied to the study of two-component clusters. Rather extreme values of stellar masses and masses of groups were chosen in order to emphasize the different dynamical evolutions and asymptotic behaviors. Escape of stars from clusters and the problem of equipartition of kinetic energy among the two star groups are discussed. Comparisons of the main features of the results with those obtained by other authors have shown a good agreement. Some characteristic properties of the last computed models with an age of 18x10/sup 9/ yr have been pointed out and discussed in relation with some observed features of galactic globular clusters.

  9. Ananke: temporal clustering reveals ecological dynamics of microbial communities

    Directory of Open Access Journals (Sweden)

    Michael W. Hall

    2017-09-01

    Full Text Available Taxonomic markers such as the 16S ribosomal RNA gene are widely used in microbial community analysis. A common first step in marker-gene analysis is grouping genes into clusters to reduce data sets to a more manageable size and potentially mitigate the effects of sequencing error. Instead of clustering based on sequence identity, marker-gene data sets collected over time can be clustered based on temporal correlation to reveal ecologically meaningful associations. We present Ananke, a free and open-source algorithm and software package that complements existing sequence-identity-based clustering approaches by clustering marker-gene data based on time-series profiles and provides interactive visualization of clusters, including highlighting of internal OTU inconsistencies. Ananke is able to cluster distinct temporal patterns from simulations of multiple ecological patterns, such as periodic seasonal dynamics and organism appearances/disappearances. We apply our algorithm to two longitudinal marker gene data sets: faecal communities from the human gut of an individual sampled over one year, and communities from a freshwater lake sampled over eleven years. Within the gut, the segregation of the bacterial community around a food-poisoning event was immediately clear. In the freshwater lake, we found that high sequence identity between marker genes does not guarantee similar temporal dynamics, and Ananke time-series clusters revealed patterns obscured by clustering based on sequence identity or taxonomy. Ananke is free and open-source software available at https://github.com/beiko-lab/ananke.

  10. A novel approach to dynamic livelihood clustering

    DEFF Research Database (Denmark)

    Walelign, Solomon Zena; Pouliot, Mariéve; Larsen, Helle Overgaard

    -wave panel dataset from 427 households in three locations of Nepal, we proposed an approach that combines households’ income and assets to identify different livelihood strategy clusters. Based on a Latent Markov Model we identify seven distinct livelihood strategies and analyse households’ movements between...

  11. Luce Irigaray and Horizontal Transcendence

    NARCIS (Netherlands)

    Halsema, J.M.

    2010-01-01

    This book offers an interpretation of the work of the Belgian philosopher Luce Irigaray (1930) as an ethical and phenomenological endeavor and – building upon that interpretation – considers her thoughts about transcendence and spirituality. It continues and extends the investigation of Irigaray’s

  12. Sensitivity evaluation of dynamic speckle activity measurements using clustering methods

    International Nuclear Information System (INIS)

    Etchepareborda, Pablo; Federico, Alejandro; Kaufmann, Guillermo H.

    2010-01-01

    We evaluate and compare the use of competitive neural networks, self-organizing maps, the expectation-maximization algorithm, K-means, and fuzzy C-means techniques as partitional clustering methods, when the sensitivity of the activity measurement of dynamic speckle images needs to be improved. The temporal history of the acquired intensity generated by each pixel is analyzed in a wavelet decomposition framework, and it is shown that the mean energy of its corresponding wavelet coefficients provides a suited feature space for clustering purposes. The sensitivity obtained by using the evaluated clustering techniques is also compared with the well-known methods of Konishi-Fujii, weighted generalized differences, and wavelet entropy. The performance of the partitional clustering approach is evaluated using simulated dynamic speckle patterns and also experimental data.

  13. From clusters to biomolecules: electric dipole, structure and dynamics

    International Nuclear Information System (INIS)

    Broyer, M; Antoine, R; Compagnon, I; Rayane, D; Dugourd, P

    2007-01-01

    In this paper, it is demonstrated that the electric dipole of complex molecules or clusters can be measured by beam deviation in an inhomogeneous electric field. This measurement, associated to appropriate theoretical calculations and simulations, allows us to determine the geometry of these systems and their dynamical behaviour as a function of temperature. Selected examples for mixed clusters (metal-fullerene, metal-benzene, salt) and biomolecules (hydrogen bound amino acids and glycine based polypeptides) are discussed

  14. Clustering properties of dynamical dark energy models

    International Nuclear Information System (INIS)

    Avelino, P. P.; Beca, L. M. G.; Martins, C. J. A. P.

    2008-01-01

    We provide a generic but physically clear discussion of the clustering properties of dark energy models. We explicitly show that in quintessence-type models the dark energy fluctuations, on scales smaller than the Hubble radius, are of the order of the perturbations to the Newtonian gravitational potential, hence necessarily small on cosmological scales. Moreover, comparable fluctuations are associated with different gauge choices. We also demonstrate that the often used homogeneous approximation is unrealistic, and that the so-called dark energy mutation is a trivial artifact of an effective, single fluid description. Finally, we discuss the particular case where the dark energy fluid is nonminimally coupled to dark matter

  15. Neutron rich clusters and the dynamics of fission and fusion

    International Nuclear Information System (INIS)

    Armbruster, P.

    1988-07-01

    In this lecture I want to discuss experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangement processes, as fusion and fission. Clusters in the sense as used in my lecture are the strongly bound doubly magic nuclei as 20 Ca 28 48 , 28 Ni 50 78 , 132 50 Sn 82 , and 208 82 Pb 126 and the superheavy nucleus 298 114 184 . Two of these nuclei, 78 Ni and 298 114 have not yet been identified. I discuss first the experimental findings from heavy element production. Then I cover the stability of cluster aspects to intrinsic excitation energy in fusion and fission. (orig./HSI)

  16. Thermodynamics of small clusters of atoms: A molecular dynamics simulation

    DEFF Research Database (Denmark)

    Damgaard Kristensen, W.; Jensen, E. J.; Cotterill, Rodney M J

    1974-01-01

    The thermodynamic properties of clusters containing 55, 135, and 429 atoms have been calculated using the molecular dynamics method. Structural and vibrational properties of the clusters were examined at different temperatures in both the solid and the liquid phase. The nature of the melting...... transition was investigated, and a number of properties, such as melting temperature, latent heat of melting, and premelting phenomena, were found to vary with cluster size. These properties were also found to depend on the structure of the solid phase. In this phase the configuration of lowest free energy...

  17. Dynamic Extension of a Virtualized Cluster by using Cloud Resources

    International Nuclear Information System (INIS)

    Oberst, Oliver; Hauth, Thomas; Kernert, David; Riedel, Stephan; Quast, Günter

    2012-01-01

    The specific requirements concerning the software environment within the HEP community constrain the choice of resource providers for the outsourcing of computing infrastructure. The use of virtualization in HPC clusters and in the context of cloud resources is therefore a subject of recent developments in scientific computing. The dynamic virtualization of worker nodes in common batch systems provided by ViBatch serves each user with a dynamically virtualized subset of worker nodes on a local cluster. Now it can be transparently extended by the use of common open source cloud interfaces like OpenNebula or Eucalyptus, launching a subset of the virtual worker nodes within the cloud. This paper demonstrates how a dynamically virtualized computing cluster is combined with cloud resources by attaching remotely started virtual worker nodes to the local batch system.

  18. Self-transcendence: conceptualization and measurement.

    Science.gov (United States)

    Levenson, Michael R; Jennings, Patricia A; Aldwin, Carolyn M; Shiraishi, Ray W

    2005-01-01

    Self-transcendence has been hypothesized to be a critical component of wisdom (Curnow, 1999) and adaptation in later life (Tornstam, 1994). It reflects a decreasing reliance on externals for definition of the self, increasing interiority and spirituality, and a greater sense of connectedness with past and future generations. The Adult Self-Transcendence Inventory was administered to 351 individuals along with the NEO-FFI Personality Scale (McCrae & Costa, 1989). A principal axis factor analysis identified two factors: self-transcendence and alienation. The relationships between self-transcendence and neuroticism, openness to experience, extraversion, and agreeableness were significant, although modest, suggesting that self-transcendence cannot be accounted for in terms of positive personality traits alone. As expected, a multiple regression analysis indicated that self-transcendence was negatively related to neuroticism and positively related to meditation practice. The present study appears to lend support to the construct of self-transcendence.

  19. Simulation of the dynamics of laser-cluster interaction

    International Nuclear Information System (INIS)

    Deiss, C.

    2009-01-01

    Ranging in size from a few atoms to several million atoms, clusters form a link between gases and solids. When irradiating clusters with intense femtosecond laser pulses, the production of energetic and highly charged ions, hot electrons, and extreme UV and X-ray photons, gives evidence of a very efficient energy conversion. The size of the system and the multitude of mechanisms at play provide a considerable challenge for the theoretical treatment of the interaction. In this thesis, we have developed a Classical Trajectory Monte Carlo simulation that gives insight into the particle dynamics during the interaction of laser pulses with large argon clusters (with more than 10000 atoms per cluster). Elastic electron-ion scattering, electron-electron scattering, electron-impact ionization and excitation, as well as three-body recombination and Auger decay are included via stochastic events. In a strongly simplified picture, the dynamics of the laser-cluster interaction can be summarized as follows: the intense laser field ionizes the cluster atoms and drives the population of quasi-free electrons. In collision events, further free electrons and high ionic charge states are created. As some electrons leave the cluster, the ions feel a net positive charge, and the cluster ultimately disintegrates in a Coulomb explosion. Even at moderate laser intensities (approx. 10 15 W/cm 2 ), impact ionization produces inner-shell vacancies in the cluster ions that decay by emitting characteristic X-ray radiation. The small population of fast electrons responsible for these ionization events is produced near the cluster poles, where the combination of polarization and charging of the cluster leads to strongly enhanced field strengths. We achieve a good agreement over large parameter ranges between the simulation and X-ray spectroscopy experiments. We also investigate the dependence of X-ray emission on laser intensity, pulse duration and cluster size. We find that in order to

  20. Method for discovering relationships in data by dynamic quantum clustering

    Science.gov (United States)

    Weinstein, Marvin; Horn, David

    2014-10-28

    Data clustering is provided according to a dynamical framework based on quantum mechanical time evolution of states corresponding to data points. To expedite computations, we can approximate the time-dependent Hamiltonian formalism by a truncated calculation within a set of Gaussian wave-functions (coherent states) centered around the original points. This allows for analytic evaluation of the time evolution of all such states, opening up the possibility of exploration of relationships among data-points through observation of varying dynamical-distances among points and convergence of points into clusters. This formalism may be further supplemented by preprocessing, such as dimensional reduction through singular value decomposition and/or feature filtering.

  1. Transcending Organization in Temporary Systems

    DEFF Research Database (Denmark)

    Stjerne, Iben Sandal

    in temporary systems that lack stability and formal order. It advances our understanding of transcending organization in creative industries by adopting a practice based perspective. Empirically, the dissertation presents an in-depth study of the Danish film industry, which is an extreme case of a project...... film workers with different functional roles and six months of ethnographic study of film projects in the Danish film industry, in particular delving into the film project Antboy and its sequels....

  2. Test computations on the dynamical evolution of star clusters

    International Nuclear Information System (INIS)

    Angeletti, L.; Giannone, P.

    1977-01-01

    Test calculations have been carried out on the evolution of star clusters using the fluid-dynamical method devised by Larson (1970). Large systems of stars have been considered with specific concern with globular clusters. With reference to the analogous 'standard' model by Larson, the influence of varying in turn the various free parameters (cluster mass, star mass, tidal radius, mass concentration of the initial model) has been studied for the results. Furthermore, the partial release of some simplifying assumptions with regard to the relaxation time and distribution of the 'target' stars has been considered. The change of the structural properties is discussed, and the variation of the evolutionary time scale is outlined. An indicative agreement of the results obtained here with structural properties of globular clusters as deduced from previous theoretical models is pointed out. (Auth.)

  3. Metal cluster fission: jellium model and Molecular dynamics simulations

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.; Solov'yov, Ilia

    2004-01-01

    Fission of doubly charged sodium clusters is studied using the open-shell two-center deformed jellium model approximation and it ab initio molecular dynamic approach accounting for all electrons in the system. Results of calculations of fission reactions Na_10^2+ --> Na_7^+ + Na_3^+ and Na_18...

  4. Dynamics, Chemical Abundances, and ages of Globular Clusters in the Virgo Cluster of Galaxies

    Science.gov (United States)

    Guhathakurta, Puragra; NGVS Collaboration

    2018-01-01

    We present a study of the dynamics, metallicities, and ages of globular clusters (GCs) in the Next Generation Virgo cluster Survey (NGVS), a deep, multi-band (u, g, r, i, z, and Ks), wide-field (104 deg2) imaging survey carried out using the 3.6-m Canada-France-Hawaii Telescope and MegaCam imager. GC candidates were selected from the NGVS survey using photometric and image morphology criteria and these were followed up with deep, medium-resolution, multi-object spectroscopy using the Keck II 10-m telescope and DEIMOS spectrograph. The primary spectroscopic targets were candidate GC satellites of dwarf elliptical (dE) and ultra-diffuse galaxies (UDGs) in the Virgo cluster. While many objects were confirmed as GC satellites of Virgo dEs and UDGs, many turned out to be non-satellites based on their radial velocity and/or positional mismatch any identifiable Virgo cluster galaxy. We have used a combination of spectral characteristics (e.g., presence of absorption vs. emission lines), new Gaussian mixture modeling of radial velocity and sky position data, and a new extreme deconvolution analysis of ugrizKs photometry and image morphology, to classify all the objects in our sample into: (1) GC satellites of dE galaxies, (2) GC satellites of UDGs, (3) intra-cluster GCs (ICGCs) in the Virgo cluster, (4) GCs in the outer halo of the central cluster galaxy M87, (5) foreground Milky Way stars, and (6) distant background galaxies. We use these data to study the dynamics and dark matter content of dE and UDGs in the Virgo cluster, place important constraints on the nature of dE nuclei, and study the origin of ICGCs versus GCs in the remote M87 halo.We are grateful for financial support from the NSF and NASA/STScI.

  5. Lattice dynamics of impurity clusters : application to pairs

    International Nuclear Information System (INIS)

    Chandralekha Devi, N.; Behera, S.N.

    1979-01-01

    A general solution is obtained for the lattice dynamics of a cluster of n-impurity atoms using the double-time Green's function formalism. The cluster is characterized by n-mass defect and m-force constant change parameters. It is shown that this general solution for the Green's function for the n-impurity cluster can also be expressed in terms of the Green's function for the (n-1)-impurity cluster. As an application, the cluster impurity modes for a pair are calculated using the Debye model for the host lattice dynamics. The splitting of the high frequency local modes and nearly zero frequency resonant modes due to pairs show an oscillatory behaviour on varying the distance of separation between the two impurity atoms. These oscillations are most prominent for two similar impurities and get damped for two dissimilar impurities or if one of the impurities produces a force constant change. The predictions of the calculation provide qualitative explanation of the data obtained from the infrared measurements of the resonant modes in mixed crystal system of KBrsub(1-c)Clsub(c):Lisup(+) and KBrsub(1-c)Isub(c):Lisup(+). (author)

  6. Cluster Optimization and Parallelization of Simulations with Dynamically Adaptive Grids

    KAUST Repository

    Schreiber, Martin; Weinzierl, Tobias; Bungartz, Hans-Joachim

    2013-01-01

    The present paper studies solvers for partial differential equations that work on dynamically adaptive grids stemming from spacetrees. Due to the underlying tree formalism, such grids efficiently can be decomposed into connected grid regions (clusters) on-the-fly. A graph on those clusters classified according to their grid invariancy, workload, multi-core affinity, and further meta data represents the inter-cluster communication. While stationary clusters already can be handled more efficiently than their dynamic counterparts, we propose to treat them as atomic grid entities and introduce a skip mechanism that allows the grid traversal to omit those regions completely. The communication graph ensures that the cluster data nevertheless are kept consistent, and several shared memory parallelization strategies are feasible. A hyperbolic benchmark that has to remesh selected mesh regions iteratively to preserve conforming tessellations acts as benchmark for the present work. We discuss runtime improvements resulting from the skip mechanism and the implications on shared memory performance and load balancing. © 2013 Springer-Verlag.

  7. Cluster Dynamics Modeling with Bubble Nucleation, Growth and Coalescence

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Blondel, Sophie [Univ. of Tennessee, Knoxville, TN (United States); Bernholdt, David E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian D. [Univ. of Tennessee, Knoxville, TN (United States)

    2017-06-01

    The topic of this communication pertains to defect formation in irradiated solids such as plasma-facing tungsten submitted to helium implantation in fusion reactor com- ponents, and nuclear fuel (metal and oxides) submitted to volatile ssion product generation in nuclear reactors. The purpose of this progress report is to describe ef- forts towards addressing the prediction of long-time evolution of defects via continuum cluster dynamics simulation. The di culties are twofold. First, realistic, long-time dynamics in reactor conditions leads to a non-dilute di usion regime which is not accommodated by the prevailing dilute, stressless cluster dynamics theory. Second, long-time dynamics calls for a large set of species (ideally an in nite set) to capture all possible emerging defects, and this represents a computational bottleneck. Extensions beyond the dilute limit is a signi cant undertaking since no model has been advanced to extend cluster dynamics to non-dilute, deformable conditions. Here our proposed approach to model the non-dilute limit is to monitor the appearance of a spatially localized void volume fraction in the solid matrix with a bell shape pro le and insert an explicit geometrical bubble onto the support of the bell function. The newly cre- ated internal moving boundary provides the means to account for the interfacial ux of mobile species into the bubble, and the growth of bubbles allows for coalescence phenomena which captures highly non-dilute interactions. We present a preliminary interfacial kinematic model with associated interfacial di usion transport to follow the evolution of the bubble in any number of spatial dimensions and any number of bubbles, which can be further extended to include a deformation theory. Finally we comment on a computational front-tracking method to be used in conjunction with conventional cluster dynamics simulations in the non-dilute model proposed.

  8. Dynamic Portfolio Strategy Using Clustering Approach.

    Science.gov (United States)

    Ren, Fei; Lu, Ya-Nan; Li, Sai-Ping; Jiang, Xiong-Fei; Zhong, Li-Xin; Qiu, Tian

    2017-01-01

    The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market.

  9. Dynamic Portfolio Strategy Using Clustering Approach.

    Directory of Open Access Journals (Sweden)

    Fei Ren

    Full Text Available The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market.

  10. Rumors of transcendence in physics

    International Nuclear Information System (INIS)

    Pollard, W.G.

    1984-01-01

    There are several hints in physics of a domain of external reality transcendent to three-dimensional space and time. This paper calls attention to several of these intimations of a real world beyond the natural order. Examples are the complex state functions in configuration space of quantum mechanics, the singularity at the birth of the universe, the anthropic principle, the role of chance in evolution, and the unaccountable fruitfulness of mathematics for physics. None of these examples touch on the existence or activity of God, but they do suggest that external reality may be much richer than the natural world which it is the task of physics to describe

  11. Dynamic analysis of clustered building structures using substructures methods

    International Nuclear Information System (INIS)

    Leimbach, K.R.; Krutzik, N.J.

    1989-01-01

    The dynamic substructure approach to the building cluster on a common base mat starts with the generation of Ritz-vectors for each building on a rigid foundation. The base mat plus the foundation soil is subjected to kinematic constraint modes, for example constant, linear, quadratic or cubic constraints. These constraint modes are also imposed on the buildings. By enforcing kinematic compatibility of the complete structural system on the basis of the constraint modes a reduced Ritz model of the complete cluster is obtained. This reduced model can now be analyzed by modal time history or response spectrum methods

  12. Clustering Molecular Dynamics Trajectories for Optimizing Docking Experiments

    Directory of Open Access Journals (Sweden)

    Renata De Paris

    2015-01-01

    Full Text Available Molecular dynamics simulations of protein receptors have become an attractive tool for rational drug discovery. However, the high computational cost of employing molecular dynamics trajectories in virtual screening of large repositories threats the feasibility of this task. Computational intelligence techniques have been applied in this context, with the ultimate goal of reducing the overall computational cost so the task can become feasible. Particularly, clustering algorithms have been widely used as a means to reduce the dimensionality of molecular dynamics trajectories. In this paper, we develop a novel methodology for clustering entire trajectories using structural features from the substrate-binding cavity of the receptor in order to optimize docking experiments on a cloud-based environment. The resulting partition was selected based on three clustering validity criteria, and it was further validated by analyzing the interactions between 20 ligands and a fully flexible receptor (FFR model containing a 20 ns molecular dynamics simulation trajectory. Our proposed methodology shows that taking into account features of the substrate-binding cavity as input for the k-means algorithm is a promising technique for accurately selecting ensembles of representative structures tailored to a specific ligand.

  13. High-performance dynamic quantum clustering on graphics processors

    Energy Technology Data Exchange (ETDEWEB)

    Wittek, Peter, E-mail: peterwittek@acm.org [Swedish School of Library and Information Science, University of Boras, Boras (Sweden)

    2013-01-15

    Clustering methods in machine learning may benefit from borrowing metaphors from physics. Dynamic quantum clustering associates a Gaussian wave packet with the multidimensional data points and regards them as eigenfunctions of the Schroedinger equation. The clustering structure emerges by letting the system evolve and the visual nature of the algorithm has been shown to be useful in a range of applications. Furthermore, the method only uses matrix operations, which readily lend themselves to parallelization. In this paper, we develop an implementation on graphics hardware and investigate how this approach can accelerate the computations. We achieve a speedup of up to two magnitudes over a multicore CPU implementation, which proves that quantum-like methods and acceleration by graphics processing units have a great relevance to machine learning.

  14. High-performance dynamic quantum clustering on graphics processors

    International Nuclear Information System (INIS)

    Wittek, Peter

    2013-01-01

    Clustering methods in machine learning may benefit from borrowing metaphors from physics. Dynamic quantum clustering associates a Gaussian wave packet with the multidimensional data points and regards them as eigenfunctions of the Schrödinger equation. The clustering structure emerges by letting the system evolve and the visual nature of the algorithm has been shown to be useful in a range of applications. Furthermore, the method only uses matrix operations, which readily lend themselves to parallelization. In this paper, we develop an implementation on graphics hardware and investigate how this approach can accelerate the computations. We achieve a speedup of up to two magnitudes over a multicore CPU implementation, which proves that quantum-like methods and acceleration by graphics processing units have a great relevance to machine learning.

  15. Dynamical Friction in Multi-component Evolving Globular Clusters

    Science.gov (United States)

    Alessandrini, Emiliano; Lanzoni, Barbara; Miocchi, Paolo; Ciotti, Luca; Ferraro, Francesco R.

    2014-11-01

    We use the Chandrasekhar formalism and direct N-body simulations to study the effect of dynamical friction on a test object only slightly more massive than the field stars, orbiting a spherically symmetric background of particles with a mass spectrum. The main goal is to verify whether the dynamical friction time (t DF) develops a non-monotonic radial dependence that could explain the bimodality of the blue straggler radial distributions observed in globular clusters. In these systems, in fact, relaxation effects lead to a mass and velocity radial segregation of the different mass components, so that mass-spectrum effects on t DF are expected to be dependent on radius. We find that in spite of the presence of different masses, t DF is always a monotonic function of radius, at all evolutionary times and independently of the initial concentration of the simulated cluster. This is because the radial dependence of t DF is largely dominated by the total mass density profile of the background stars (which is monotonically decreasing with radius). Hence, a progressive temporal erosion of the blue straggler star (BSS) population at larger and larger distances from the cluster center remains the simplest and the most likely explanation of the shape of the observed BSS radial distributions, as suggested in previous works. We also confirm the theoretical expectation that approximating a multi-mass globular cluster as made of (averaged) equal-mass stars can lead to significant overestimations of t DF within the half-mass radius.

  16. Dynamic parallel ROOT facility clusters on the Alice Environment

    International Nuclear Information System (INIS)

    Luzzi, C; Betev, L; Carminati, F; Grigoras, C; Saiz, P; Manafov, A

    2012-01-01

    The ALICE collaboration has developed a production environment (AliEn) that implements the full set of the Grid tools enabling the full offline computational work-flow of the experiment, simulation, reconstruction and data analysis, in a distributed and heterogeneous computing environment. In addition to the analysis on the Grid, ALICE uses a set of local interactive analysis facilities installed with the Parallel ROOT Facility (PROOF). PROOF enables physicists to analyze medium-sized (order of 200-300 TB) data sets on a short time scale. The default installation of PROOF is on a static dedicated cluster, typically 200-300 cores. This well-proven approach, has its limitations, more specifically for analysis of larger datasets or when the installation of a dedicated cluster is not possible. Using a new framework called PoD (Proof on Demand), PROOF can be used directly on Grid-enabled clusters, by dynamically assigning interactive nodes on user request. The integration of Proof on Demand in the AliEn framework provides private dynamic PROOF clusters as a Grid service. This functionality is transparent to the user who will submit interactive jobs to the AliEn system.

  17. Dynamic cluster generation for a fuzzy classifier with ellipsoidal regions.

    Science.gov (United States)

    Abe, S

    1998-01-01

    In this paper, we discuss a fuzzy classifier with ellipsoidal regions that dynamically generates clusters. First, for the data belonging to a class we define a fuzzy rule with an ellipsoidal region. Namely, using the training data for each class, we calculate the center and the covariance matrix of the ellipsoidal region for the class. Then we tune the fuzzy rules, i.e., the slopes of the membership functions, successively until there is no improvement in the recognition rate of the training data. Then if the number of the data belonging to a class that are misclassified into another class exceeds a prescribed number, we define a new cluster to which those data belong and the associated fuzzy rule. Then we tune the newly defined fuzzy rules in the similar way as stated above, fixing the already obtained fuzzy rules. We iterate generation of clusters and tuning of the newly generated fuzzy rules until the number of the data belonging to a class that are misclassified into another class does not exceed the prescribed number. We evaluate our method using thyroid data, Japanese Hiragana data of vehicle license plates, and blood cell data. By dynamic cluster generation, the generalization ability of the classifier is improved and the recognition rate of the fuzzy classifier for the test data is the best among the neural network classifiers and other fuzzy classifiers if there are no discrete input variables.

  18. Dynamical evolution of star clusters with a changing gravitational constant

    International Nuclear Information System (INIS)

    Angeletti, L.; Giannone, P.

    1978-01-01

    The dynamical evolution of massive star clusters was studied, taking into account variations with time of the gravitional constant. The rates of change of G were adopted according to theoretical and observational indications. Various conditions concerning the number of star groups, star masses, mass loss from stars, and initial star concentration were tested for the clusters. The comparison with analogous evolutionary sequences computed with a constant value of G showed that the effects of changes of G may be conspicuous. The analytical dependence of basic structural functions on the law of variation of G with time was determined from the numerical results. They allow an estimate of the consequences of G in a large range of cases. The effects of a decrease of G tended to prevent the formation of dense cores, which is a specific feature of the evolution of 'standard' models of star clusters. The expansion of the whole cluster structure was noteworthy. However, there was not a significant increase of escape of stars from cluster compared with the cases computed with constant G. Although detailed comparison with observations was beyond our present aims, it appears that a varaition of G according to the Brans-Dicke theory is not in conflict with observational data, as is the case for an exponential decrease of G consistent with Van Flandern's result. (orig.) [de

  19. Binary cluster collision dynamics and minimum energy conformations

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, Francisco [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Germany); Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Rogan, José; Valdivia, J.A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Varas, A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Nano-Bio Spectroscopy Group, ETSF Scientific Development Centre, Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Av. Tolosa 72, E-20018 San Sebastián (Spain); Kiwi, Miguel, E-mail: m.kiwi.t@gmail.com [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile)

    2013-10-15

    The collision dynamics of one Ag or Cu atom impinging on a Au{sub 12} cluster is investigated by means of DFT molecular dynamics. Our results show that the experimentally confirmed 2D to 3D transition of Au{sub 12}→Au{sub 13} is mostly preserved by the resulting planar Au{sub 12}Ag and Au{sub 12}Cu minimum energy clusters, which is quite remarkable in view of the excess energy, well larger than the 2D–3D potential barrier height. The process is accompanied by a large s−d hybridization and charge transfer from Au to Ag or Cu. The dynamics of the collision process mainly yields fusion of projectile and target, however scattering and cluster fragmentation also occur for large energies and large impact parameters. While Ag projectiles favor fragmentation, Cu favors scattering due to its smaller mass. The projectile size does not play a major role in favoring the fragmentation or scattering channels. By comparing our collision results with those obtained by an unbiased minimum energy search of 4483 Au{sub 12}Ag and 4483 Au{sub 12}Cu configurations obtained phenomenologically, we find that there is an extra bonus: without increase of computer time collisions yield the planar lower energy structures that are not feasible to obtain using semi-classical potentials. In fact, we conclude that phenomenological potentials do not even provide adequate seeds for the search of global energy minima for planar structures. Since the fabrication of nanoclusters is mainly achieved by synthesis or laser ablation, the set of local minima configurations we provide here, and their distribution as a function of energy, are more relevant than the global minimum to analyze experimental results obtained at finite temperatures, and is consistent with the dynamical coexistence of 2D and 3D liquid Au clusters conformations obtained previously.

  20. Can cluster environment modify the dynamical evolution of spiral galaxies?

    Science.gov (United States)

    Amram, P.; Balkowski, C.; Cayatte, V.; Marcelin, M.; Sullivan, W. T., III

    1993-01-01

    Over the past decade many effects of the cluster environment on member galaxies have been established. These effects are manifest in the amount and distribution of gas in cluster spirals, the luminosity and light distributions within galaxies, and the segregation of morphological types. All these effects could indicate a specific dynamical evolution for galaxies in clusters. Nevertheless, a more direct evidence, such as a different mass distribution for spiral galaxies in clusters and in the field, is not yet clearly established. Indeed, Rubin, Whitmore, and Ford (1988) and Whitmore, Forbes, and Rubin (1988) (referred to as RWF) presented evidence that inner cluster spirals have falling rotation curves, unlike those of outer cluster spirals or the great majority of field spirals. If falling rotation curves exist in centers of clusters, as argued by RWF, it would suggest that dark matter halos were absent from cluster spirals, either because the halos had become stripped by interactions with other galaxies or with an intracluster medium, or because the halos had never formed in the first place. Even if they didn't disagree with RWF, other researchers pointed out that the behaviour of the slope of the rotation curves of spiral galaxies (in Virgo) is not so clear. Amram, using a different sample of spiral galaxies in clusters, found only 10% of declining rotation curves (2 declining vs 17 flat or rising) in opposition to RWF who find about 40% of declining rotation curves in their sample (6 declining vs 10 flat or rising), we will hereafter briefly discuss the Amram data paper and compare it to the results of RWF. We have measured the rotation curves for a sample of 21 spiral galaxies in 5 nearby clusters. These rotation curves have been constructed from detailed two-dimensional maps of each galaxy's velocity field as traced by emission from the Ha line. This complete mapping, combined with the sensitivity of our CFHT 3.60 m. + Perot-Fabry + CCD observations, allows

  1. A New Transcendence Model of Identity Construction

    Science.gov (United States)

    Elliott, Christopher L. Wilcox

    2012-01-01

    What does it mean for college men to be authentic? How can we support their efforts to transcend their own immediate needs? And what roles do trusted others play in one's construction of identity? This article describes a preliminary new theoretical model--a Transcendence Model of Identity Construction--based on original research studying…

  2. Music Making, Transcendence, Flow, and Music Education

    Science.gov (United States)

    Bernard, Rhoda

    2009-01-01

    This study explores the relationship between flow, transcendent music making experiences, transcendent religious experiences, and music education. As a teacher-researcher, I studied my graduate students' autobiographical accounts of their experiences making music. Across these narrative writings produced over the past four years, a pattern…

  3. THE DYNAMICAL EVOLUTION OF STELLAR BLACK HOLES IN GLOBULAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Morscher, Meagan; Pattabiraman, Bharath; Rodriguez, Carl; Rasio, Frederic A.; Umbreit, Stefan, E-mail: m.morscher@u.northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL (United States)

    2015-02-10

    Our current understanding of the stellar initial mass function and massive star evolution suggests that young globular clusters (GCs) may have formed hundreds to thousands of stellar-mass black holes (BHs), the remnants of stars with initial masses from ∼20-100 M {sub ☉}. Birth kicks from supernova explosions may eject some BHs from their birth clusters, but most should be retained. Using a Monte Carlo method we investigate the long-term dynamical evolution of GCs containing large numbers of stellar BHs. We describe numerical results for 42 models, covering a broad range of realistic initial conditions, including up to 1.6 × 10{sup 6} stars. In almost all models we find that significant numbers of BHs (up to ∼10{sup 3}) are retained all the way to the present. This is in contrast to previous theoretical expectations that most BHs should be ejected dynamically within a few gigayears The main reason for this difference is that core collapse driven by BHs (through the Spitzer {sup m}ass segregation instability{sup )} is easily reverted through three-body processes, and involves only a small number of the most massive BHs, while lower-mass BHs remain well-mixed with ordinary stars far from the central cusp. Thus the rapid segregation of stellar BHs does not lead to a long-term physical separation of most BHs into a dynamically decoupled inner core, as often assumed previously. Combined with the recent detections of several BH X-ray binary candidates in Galactic GCs, our results suggest that stellar BHs could still be present in large numbers in many GCs today, and that they may play a significant role in shaping the long-term dynamical evolution and the present-day dynamical structure of many clusters.

  4. Psychosomatic symptoms as biomarkers: transcending the psyche-soma dichotomy.

    Science.gov (United States)

    Neuman, Yair

    2010-01-01

    Following the advancement in understanding dynamical systems, the author presents a novel metaphor of psychosomatic symptoms as low-dimensional biomarkers. This metaphor, which transcends the old binary of psyche-soma, resonates with classical psychoanalytic concepts and with Matte-Blanco's idea of repetition as indicative of dimensionality reduction. The relevance of this metaphor for explanation, diagnosis, and treatment is illustrated through a case study of a male patient suffering from hyperprolactinemia.

  5. Transcendence and Transcending in the Theology of Father Dumitru Stăniloae

    Directory of Open Access Journals (Sweden)

    Grigore Dinu Mοș

    2016-03-01

    Full Text Available From the perspective of man’s relation to the transcendent God, a central concept in the thought of father Dumitru Stăniloae is that of “transcending”, of self-transcendence, of man going beyond himself towards his neighbours and towards his deeper self, towards the mystery of the world and of existence in general, culminating with the fundamental act of transcending towards the divine Absolute. He uses this concept in almost all areas of theology: gnoseology, anthropology, cosmology, ecclesiology, mysteriology, eschatology, spirituality, as well as when discussing ideas of important existentialist and personalist philosophers of the 20th century. According to Stăniloae, God’s transcendence reveals itself as holiness, while Christ, the God-Man, who makes possible man’s convergent and unitary act of transcending, is the “true transcendence”. The real correspondence between transcendent and transcendental emphasizes the Christological foundation of Christian anthropology. For father Stăniloae, man’s self-transcendence is determined by his attraction towards the divine Absolute, as well as by his lack of fulfilment in this world. Monotony is defined as the absence of transcendence, hell – as the impossibility of transcending, and pride as a negative and delusive transcendence. The mystery is a sign of the Transcendent, while man is characterised by an endless act of transcending towards his own mystery, enlightened by the mystery of God. Words and logoi are means of transcending which urge us to purify our mind and to act immediately. The necessity and meaning of the act of transcending are emphasized by the image of the Cross, which makes the world transparent, revealing its Creator. According to Stăniloae, man is a being which transcends time through repentance and hope, while the Church is the immanent which incorporates the transcendent. Moreover, he sees the Holy Sacraments as steps in the act of transcending from the

  6. Structure and dynamics of molecular clusters. 2. Melting and freezing of CCl4 clusters

    International Nuclear Information System (INIS)

    Bartell, L.S.; Chen, Jian

    1992-01-01

    Phase transitions of a 225-molecule cluster of carbon tetrachloride have been studied by a molecular dynamics simulation. A five-site model potential function was developed to reproduce the density and heat of vaporization of the bulk liquid. Computations began with orientationally disordered molecules distributed in fcc lattice sites of a nearly spherical cluster. The cluster was heated from a low temperature to 200 K in 10-deg steps of 50 ps each and then cooled to 10 K. Translational and rotational transitions were monitored by following several indicators including the translational and rotational diffusion and rotational entropies of individual molecules. Melting began at the surface and propagated inward as the temperature increased. Solidification of the molten cluster proceeded from the center to the surface. At the high cooling rate of the simulation, however, molecules were unable to organize into a crystalline array and solidified into a glassy structure instead. Except for spatial order, the indicators of degree of liquefaction exhibited almost the same temperature dependence in the crystsl → liquid as in the liquid → glass transition, a behavior that could be rationalized on the basis of Lindemann's theory of melting. Results were compared with predictions of an illustrative model due to Reiss, Mirabel, and Whetten. Qualitatively, the model included all of the features of the simulation. Quantitatively, the model grossly underestimated the range over which the melting transition took place. 40 refs., 10 figs., 1 tab

  7. IoT Service Clustering for Dynamic Service Matchmaking.

    Science.gov (United States)

    Zhao, Shuai; Yu, Le; Cheng, Bo; Chen, Junliang

    2017-07-27

    As the adoption of service-oriented paradigms in the IoT (Internet of Things) environment, real-world devices will open their capabilities through service interfaces, which enable other functional entities to interact with them. In an IoT application, it is indispensable to find suitable services for satisfying users' requirements or replacing the unavailable services. However, from the perspective of performance, it is inappropriate to find desired services from the service repository online directly. Instead, clustering services offline according to their similarity and matchmaking or discovering service online in limited clusters is necessary. This paper proposes a multidimensional model-based approach to measure the similarity between IoT services. Then, density-peaks-based clustering is employed to gather similar services together according to the result of similarity measurement. Based on the service clustering, the algorithms of dynamic service matchmaking, discovery, and replacement will be performed efficiently. Evaluating experiments are conducted to validate the performance of proposed approaches, and the results are promising.

  8. A mathematical programming approach for sequential clustering of dynamic networks

    Science.gov (United States)

    Silva, Jonathan C.; Bennett, Laura; Papageorgiou, Lazaros G.; Tsoka, Sophia

    2016-02-01

    A common analysis performed on dynamic networks is community structure detection, a challenging problem that aims to track the temporal evolution of network modules. An emerging area in this field is evolutionary clustering, where the community structure of a network snapshot is identified by taking into account both its current state as well as previous time points. Based on this concept, we have developed a mixed integer non-linear programming (MINLP) model, SeqMod, that sequentially clusters each snapshot of a dynamic network. The modularity metric is used to determine the quality of community structure of the current snapshot and the historical cost is accounted for by optimising the number of node pairs co-clustered at the previous time point that remain so in the current snapshot partition. Our method is tested on social networks of interactions among high school students, college students and members of the Brazilian Congress. We show that, for an adequate parameter setting, our algorithm detects the classes that these students belong more accurately than partitioning each time step individually or by partitioning the aggregated snapshots. Our method also detects drastic discontinuities in interaction patterns across network snapshots. Finally, we present comparative results with similar community detection methods for time-dependent networks from the literature. Overall, we illustrate the applicability of mathematical programming as a flexible, adaptable and systematic approach for these community detection problems. Contribution to the Topical Issue "Temporal Network Theory and Applications", edited by Petter Holme.

  9. Cluster dynamics models of irradiation damage accumulation in ferritic iron. I. Trap mediated interstitial cluster diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Kohnert, Aaron A.; Wirth, Brian D. [University of Tennessee, Knoxville, Tennessee 37996-2300 (United States)

    2015-04-21

    The microstructure that develops under low temperature irradiation in ferritic alloys is dominated by a high density of small (2–5 nm) defects. These defects have been widely observed to move via occasional discrete hops during in situ thin film irradiation experiments. Cluster dynamics models are used to describe the formation of these defects as an aggregation process of smaller clusters created as primary damage. Multiple assumptions regarding the mobility of these damage features are tested in the models, both with and without explicit consideration of such irradiation induced hops. Comparison with experimental data regarding the density of these defects demonstrates the importance of including such motions in a valid model. In particular, discrete hops inform the limited dependence of defect density on irradiation temperature observed in experiments, which the model was otherwise incapable of producing.

  10. A cluster dynamics study of fission gases in uranium dioxide

    International Nuclear Information System (INIS)

    Skorek, Richard

    2013-01-01

    During in-pile irradiation of nuclear fuels a lot of rare gases are produced, mainly xenon and krypton. The behaviour of these highly insoluble fission gases may lead to an additional load of the cladding, which may have detrimental safety consequences. For these reasons, fission gas behaviour (diffusion and clustering) has been extensively studied for years.In this work, we present an application of Cluster Dynamics to address the behaviour of fission gases in UO_2 which simultaneously describes changes in rare gas atom and point defect concentrations in addition to the bubble size distribution. This technique, applied to Kr implanted and annealed samples, yields a precise interpretation of the release curves and helps justifying the estimation of the Kr diffusion coefficient, which is a data very difficult to obtain due to the insolubility of the gas. (author) [fr

  11. Molecular dynamics simulation of gold cluster growth during sputter deposition

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, J. W., E-mail: abraham@theo-physik.uni-kiel.de; Bonitz, M., E-mail: bonitz@theo-physik.uni-kiel.de [Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 15, D-24098 Kiel (Germany); Strunskus, T.; Faupel, F. [Institut für Materialwissenschaft, Lehrstuhl für Materialverbunde, Christian-Albrechts-Universität zu Kiel, Kaiserstraße 2, D-24143 Kiel (Germany)

    2016-05-14

    We present a molecular dynamics simulation scheme that we apply to study the time evolution of the self-organized growth process of metal cluster assemblies formed by sputter-deposited gold atoms on a planar surface. The simulation model incorporates the characteristics of the plasma-assisted deposition process and allows for an investigation over a wide range of deposition parameters. It is used to obtain data for the cluster properties which can directly be compared with recently published experimental data for gold on polystyrene [M. Schwartzkopf et al., ACS Appl. Mater. Interfaces 7, 13547 (2015)]. While good agreement is found between the two, the simulations additionally provide valuable time-dependent real-space data of the surface morphology, some of whose details are hidden in the reciprocal-space scattering images that were used for the experimental analysis.

  12. Structure and Dynamics of the Globular Cluster Palomar 13

    Science.gov (United States)

    Bradford, J. D.; Geha, M.; Muñoz, R. R.; Santana, F. A.; Simon, J. D.; Côté, P.; Stetson, P. B.; Kirby, E.; Djorgovski, S. G.

    2011-12-01

    We present Keck/DEIMOS spectroscopy and Canada-France-Hawaii Telescope/MegaCam photometry for the Milky Way globular cluster Palomar 13. We triple the number of spectroscopically confirmed members, including many repeat velocity measurements. Palomar 13 is the only known globular cluster with possible evidence for dark matter, based on a Keck/High Resolution Echelle Spectrometer 21 star velocity dispersion of σ = 2.2 ± 0.4 km s-1. We reproduce this measurement, but demonstrate that it is inflated by unresolved binary stars. For our sample of 61 stars, the velocity dispersion is σ = 0.7+0.6 -0.5 km s-1. Combining our DEIMOS data with literature values, our final velocity dispersion is σ = 0.4+0.4 -0.3 km s-1. We determine a spectroscopic metallicity of [Fe/H] = -1.6 ± 0.1 dex, placing a 1σ upper limit of σ[Fe/H] ~ 0.2 dex on any internal metallicity spread. We determine Palomar 13's total luminosity to be MV = -2.8 ± 0.4, making it among the least luminous known globular clusters. The photometric isophotes are regular out to the half-light radius and mildly irregular outside this radius. The outer surface brightness profile slope is shallower than typical globular clusters (Σvpropr η, η = -2.8 ± 0.3). Thus at large radius, tidal debris is likely affecting the appearance of Palomar 13. Combining our luminosity with the intrinsic velocity dispersion, we find a dynamical mass of M 1/2 = 1.3+2: 7 -1.3 × 103 M ⊙ and a mass-to-light ratio of M/LV = 2.4+5.0 -2.4 M ⊙/L ⊙. Within our measurement errors, the mass-to-light ratio agrees with the theoretical predictions for a single stellar population. We conclude that, while there is some evidence for tidal stripping at large radius, the dynamical mass of Palomar 13 is consistent with its stellar mass and neither significant dark matter, nor extreme tidal heating, is required to explain the cluster dynamics. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a

  13. Nonuniform Sparse Data Clustering Cascade Algorithm Based on Dynamic Cumulative Entropy

    Directory of Open Access Journals (Sweden)

    Ning Li

    2016-01-01

    Full Text Available A small amount of prior knowledge and randomly chosen initial cluster centers have a direct impact on the accuracy of the performance of iterative clustering algorithm. In this paper we propose a new algorithm to compute initial cluster centers for k-means clustering and the best number of the clusters with little prior knowledge and optimize clustering result. It constructs the Euclidean distance control factor based on aggregation density sparse degree to select the initial cluster center of nonuniform sparse data and obtains initial data clusters by multidimensional diffusion density distribution. Multiobjective clustering approach based on dynamic cumulative entropy is adopted to optimize the initial data clusters and the best number of the clusters. The experimental results show that the newly proposed algorithm has good performance to obtain the initial cluster centers for the k-means algorithm and it effectively improves the clustering accuracy of nonuniform sparse data by about 5%.

  14. Shear-driven dynamic clusters in a colloidal glass

    Science.gov (United States)

    Eisenmann, Christoph; Kim, Chanjoong; Mattsson, Johan; Weitz, David

    2007-03-01

    We investigate the effect of shear applied to a colloidal glass on a microscopic level using a shear device that can be mounted on top of a confocal microscope. We find that the glass yields at a critical strain of about 10%, independently of the shear rate. Surprisingly, the yielding is accompanied by an increase of cooperative particle movements and a formation of dynamic clusters which is in contrast to the normal glass transition where one typically finds heterogeneity increasing whilst moving towards the glass transition.

  15. Test computations on the dynamical evolution of star clusters. [Fluid dynamic method

    Energy Technology Data Exchange (ETDEWEB)

    Angeletti, L; Giannone, P. (Rome Univ. (Italy))

    1977-01-01

    Test calculations have been carried out on the evolution of star clusters using the fluid-dynamical method devised by Larson (1970). Large systems of stars have been considered with specific concern with globular clusters. With reference to the analogous 'standard' model by Larson, the influence of varying in turn the various free parameters (cluster mass, star mass, tidal radius, mass concentration of the initial model) has been studied for the results. Furthermore, the partial release of some simplifying assumptions with regard to the relaxation time and distribution of the 'target' stars has been considered. The change of the structural properties is discussed, and the variation of the evolutionary time scale is outlined. An indicative agreement of the results obtained here with structural properties of globular clusters as deduced from previous theoretical models is pointed out.

  16. Dynamic integration of remote cloud resources into local computing clusters

    Energy Technology Data Exchange (ETDEWEB)

    Fleig, Georg; Erli, Guenther; Giffels, Manuel; Hauth, Thomas; Quast, Guenter; Schnepf, Matthias [Institut fuer Experimentelle Kernphysik, Karlsruher Institut fuer Technologie (Germany)

    2016-07-01

    In modern high-energy physics (HEP) experiments enormous amounts of data are analyzed and simulated. Traditionally dedicated HEP computing centers are built or extended to meet this steadily increasing demand for computing resources. Nowadays it is more reasonable and more flexible to utilize computing power at remote data centers providing regular cloud services to users as they can be operated in a more efficient manner. This approach uses virtualization and allows the HEP community to run virtual machines containing a dedicated operating system and transparent access to the required software stack on almost any cloud site. The dynamic management of virtual machines depending on the demand for computing power is essential for cost efficient operation and sharing of resources with other communities. For this purpose the EKP developed the on-demand cloud manager ROCED for dynamic instantiation and integration of virtualized worker nodes into the institute's computing cluster. This contribution will report on the concept of our cloud manager and the implementation utilizing a remote OpenStack cloud site and a shared HPC center (bwForCluster located in Freiburg).

  17. Dynamical history of a binary cluster: Abell 3653

    Science.gov (United States)

    Caglar, Turgay; Hudaverdi, Murat

    2017-12-01

    We study the dynamical structure of a bimodal galaxy cluster Abell 3653 at z = 0.1089 using optical and X-ray data. Observations include archival data from the Anglo-Australian Telescope, X-ray observatories XMM-Newton and Chandra. We draw a global picture for A3653 using galaxy density, X-ray luminosity and temperature maps. The galaxy distribution has a regular morphological shape at the 3 Mpc size. The galaxy density map shows an elongation in the east-west direction, which perfectly aligns with the extended diffuse X-ray emission. We detect two dominant groups around the two brightest cluster galaxies (BCGs). BCG1 (z = 0.1099) can be associated with the main cluster A3653E, and a foreground subcluster A3653W is concentrated at BCG2 (z = 0.1075). Both X-ray peaks are dislocated from the BCGs by ∼35 kpc, which suggest an ongoing merger process. We measure the subcluster gas temperatures of 4.67 and 3.66 keV, respectively. Two-body dynamical analysis shows that A3653E and A3653W are very likely gravitationally bound (93.5 per cent probability). The highly favoured scenario suggests that the two subclusters have a mass ratio of 1.4 and are colliding close to the plane of sky (α = 17.61°) at 2400 km s-1, and will undergo core passage in 380 Myr. The temperature map also significantly shows a shock-heated gas (6.16 keV) between the subclusters, which confirms the supersonic infalling scenario.

  18. Catching Galactic open clusters in advanced stages of dynamical evolution

    Science.gov (United States)

    Angelo, M. S.; Piatti, A. E.; Dias, W. S.; Maia, F. F. S.

    2018-04-01

    During their dynamical evolution, Galactic open clusters (OCs) gradually lose their stellar content mainly because of internal relaxation and tidal forces. In this context, the study of dynamically evolved OCs is necessary to properly understand such processes. We present a comprehensive Washington CT1 photometric analysis of six sparse OCs, namely: ESO 518-3, Ruprecht 121, ESO 134-12, NGC 6573, ESO 260-7 and ESO 065-7. We employed Markov chain Monte-Carlo simulations to robustly determine the central coordinates and the structural parameters and T1 × (C - T1) colour-magnitude diagrams (CMDs) cleaned from field contamination were used to derive the fundamental parameters. ESO 518-03, Ruprecht 121, ESO 134-12 and NGC 6573 resulted to be of nearly the same young age (8.2 ≤log(t yr-1) ≤ 8.3); ESO 260-7 and ESO065-7 are of intermediate age (9.2 ≤log(t yr-1) ≤ 9.4). All studied OCs are located at similar Galactocentric distances (RG ˜ 6 - 6.9 kpc), considering uncertainties, except for ESO 260-7 (RG = 8.9 kpc). These OCs are in a tidally filled regime and are dynamically evolved, since they are much older than their half-mass relaxation times (t/trh ≳ 30) and present signals of low-mass star depletion. We distinguished two groups: those dynamically evolving towards final disruptions and those in an advanced dynamical evolutionary stage. Although we do not rule out that the Milky Way potential could have made differentially faster their dynamical evolutions, we speculate here with the possibility that they have been mainly driven by initial formation conditions.

  19. Structures and dynamical properties of Cn, Sin, Gen, and Snn clusters with n up to 13

    International Nuclear Information System (INIS)

    Lu, Zhong-Yi; Wang, Cai-Zhuang; Ho, Kai-Ming

    2000-01-01

    Car-Parrinello molecular dynamics simulated annealings were carried out for clusters Si n , Ge n , and Sn n (n≤13). We investigate the temperature regions in which these clusters transform from a ''liquidlike'' phase to a ''solidlike'' phase, and then from the ''solidlike'' phase to the ground-state structures. Additional simulated annealing was also performed for the cluster C 13 which is selected as a prototype of small carbon clusters. In addition to the discovery of structures for Sn and Ge clusters, our simulation results also provide insights into the dynamics of cluster formation. (c) 2000 The American Physical Society

  20. The merging cluster Abell 1758: an optical and dynamical view

    Science.gov (United States)

    Monteiro-Oliveira, Rogerio; Serra Cypriano, Eduardo; Machado, Rubens; Lima Neto, Gastao B.

    2015-08-01

    The galaxy cluster Abell 1758-North (z=0.28) is a binary system composed by the sub-structures NW and NE. This is supposed to be a post-merging cluster due to observed detachment between the NE BCG and the respective X-ray emitting hot gas clump in a scenario very close to the famous Bullet Cluster. On the other hand, the projected position of the NW BCG coincides with the local hot gas peak. This system was been targeted previously by several studies, using multiple wavelengths and techniques, but there is still no clear picture of the scenario that could have caused this unusual configuration. To help solving this complex puzzle we added some pieces: firstly, we have used deep B, RC and z' Subaru images to perform both weak lensing shear and magnification analysis of A1758 (including here the South component that is not in interaction with A1758-North) modeling each sub-clump as an NFW profile in order to constrain masses and its center positions through MCMC methods; the second piece is the dynamical analysis using radial velocities available in the literature (143) plus new Gemini-GMOS/N measurements (68 new redshifts).From weak lensing we found that independent shear and magnification mass determinations are in excellent agreement between them and combining both we could reduce mass error bar by ~30% compared to shear alone. By combining this two weak-lensing probes we found that the position of both Northern BCGs are consistent with the masses centers within 2σ and and the NE hot gas peak to be offseted of the respective mass peak (M200=5.5 X 1014 M⊙) with very high significance. The most massive structure is NW (M200=7.95 X 1014 M⊙ ) where we observed no detachment between gas, DM and BCG.We have calculated a low line-of-sight velocity difference (plane of collision and the sky (<40 degrees). Dynamic modeling shows that the point of maximum approximation taken place 0.55 Gyr ago, pointing Abell 1758-North as a young merger cluster.

  1. Innovation performance and clusters : a dynamic capability perspective on regional technology clusters

    NARCIS (Netherlands)

    Röttmer, Nicole

    2009-01-01

    This research provides a novel, empirically tested, actionable theory of cluster innovativeness. Cluster innovativeness has for long been subject of research and resulting policy efforts. The cluster's endowment with assets, such as specialized labor, firms, research institutes, existing regional

  2. Thermal dynamics of silver clusters grown on rippled silica surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, Mukul, E-mail: mkbh10@gmail.com [FCIPT, Institute for Plasma Research, Gandhinagar, Gujarat (India); Nirma University, Ahmedabad, Gujarat (India); Ranjan, Mukesh [FCIPT, Institute for Plasma Research, Gandhinagar, Gujarat (India); Nirma University, Ahmedabad, Gujarat (India); Jolley, Kenny; Lloyd, Adam; Smith, Roger [Dept. of Mathematical Sciences, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Mukherjee, Subroto [FCIPT, Institute for Plasma Research, Gandhinagar, Gujarat (India); Nirma University, Ahmedabad, Gujarat (India)

    2017-02-15

    Highlights: • Low energy oblique angle ion bombardment forms ripple pattern on silicon surface. • The ripple patterns have wavelengths between 20 and 45 nm and correspondingly low height. • Silver nanoparticles have been deposited at an angle of 70° on patterned silicon templates. • The as-deposited np are annealed in vacuo at temperature of 573 K for a time duration of 1 h. • MD simulation is used to model the process and compare the results to the experiment. • Results show that silver clusters grow preferentially along parallel to the rippled surface. • Mobility of silver atoms depends on the site to which they are bonded on this amorphous surface. • MD simulations show contour ordered coalescence which is dependent on ripple periodicity. - Abstract: Silver nanoparticles have been deposited on silicon rippled patterned templates at an angle of incidence of 70° to the surface normal. The templates are produced by oblique incidence argon ion bombardment and as the fluence increases, the periods and heights of the structures increase. Structures with periods of 20 nm, 35 nm and 45 nm have been produced. Moderate temperature vacuum annealing shows the phenomenon of cluster coalescence following the contour of the more exposed faces of the ripple for the case of 35 nm and 45 nm but not at 20 nm where the silver aggregates into larger randomly distributed clusters. In order to understand this effect, the morphological changes of silver nanoparticles deposited on an asymmetric rippled silica surface are investigated through the use of molecular dynamics simulations for different deposition angles of incidence between 0° and 70° and annealing temperatures between 500 K and 900 K. Near to normal incidence, clusters are observed to migrate over the entire surface but for deposition at 70°, a similar patterning is observed as in the experiment. The random distribution of clusters for the periodicity ≈ of 20 nm is linked to the geometry of the silica

  3. Functional clustering in hippocampal cultures: relating network structure and dynamics

    International Nuclear Information System (INIS)

    Feldt, S; Dzakpasu, R; Olariu, E; Żochowski, M; Wang, J X; Shtrahman, E

    2010-01-01

    In this work we investigate the relationship between gross anatomic structural network properties, neuronal dynamics and the resultant functional structure in dissociated rat hippocampal cultures. Specifically, we studied cultures as they developed under two conditions: the first supporting glial cell growth (high glial group), and the second one inhibiting it (low glial group). We then compared structural network properties and the spatio-temporal activity patterns of the neurons. Differences in dynamics between the two groups could be linked to the impact of the glial network on the neuronal network as the cultures developed. We also implemented a recently developed algorithm called the functional clustering algorithm (FCA) to obtain the resulting functional network structure. We show that this new algorithm is useful for capturing changes in functional network structure as the networks evolve over time. The FCA detects changes in functional structure that are consistent with expected dynamical differences due to the impact of the glial network. Cultures in the high glial group show an increase in global synchronization as the cultures age, while those in the low glial group remain locally synchronized. We additionally use the FCA to quantify the amount of synchronization present in the cultures and show that the total level of synchronization in the high glial group is stronger than in the low glial group. These results indicate an interdependence between the glial and neuronal networks present in dissociated cultures

  4. Dissipation and energy balance in electronic dynamics of Na clusters

    Science.gov (United States)

    Vincendon, Marc; Suraud, Eric; Reinhard, Paul-Gerhard

    2017-06-01

    We investigate the impact of dissipation on the energy balance in the electron dynamics of metal clusters excited by strong electro-magnetic pulses. The dynamics is described theoretically by Time-Dependent Density-Functional Theory (TDDFT) at the level of Local Density Approximation (LDA) augmented by a self interaction correction term and a quantum collision term in Relaxation-Time Approximation (RTA). We evaluate the separate contributions to the total excitation energy, namely energy exported by electron emission, potential energy due to changing charge state, intrinsic kinetic and potential energy, and collective flow energy. The balance of these energies is studied as function of the laser parameters (frequency, intensity, pulse length) and as function of system size and charge. We also look at collisions with a highly charged ion and here at the dependence on the impact parameter (close versus distant collisions). Dissipation turns out to be small where direct electron emission prevails namely for laser frequencies above any ionization threshold and for slow electron extraction in distant collisions. Dissipation is large for fast collisions and at low laser frequencies, particularly at resonances. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.

  5. The Dynamical Properties of Virgo Cluster Disk Galaxies

    Science.gov (United States)

    Ouellette, N. N. Q.; Courteau, S.; Holtzman, J. A.; Dalcanton, J. J.; McDonald, M.; Zhu, Y.

    2014-03-01

    By virtue of its proximity, the Virgo Cluster is an ideal laboratory for testing our understanding of structure formation in the Universe. In this spirit, we present a dynamical study of Virgo galaxies as part of the Spectroscopic and H-band Imaging of Virgo (SHIVir) survey. Hα rotation curves (RC) for our gas-rich galaxies were modeled with a multi-parameter fit function from which various velocity measurements were inferred. Our study takes advantage of archival and our own new data as we aim to compile the largest Tully-Fisher relation (TFR) for a cluster to date. Extended velocity dispersion profiles (VDP) are integrated over varying aperture sizes to extract representative velocity dispersions (VDs) for gas-poor galaxies. Considering the lack of a common standard for the measurement of a fiducial galaxy VD in the literature, we rectify this situation by determining the radius at which the measured VD yields the tightest Fundamental Plane (FP). We found that radius to be at least 1 Re, which exceeds the extent of most dispersion profiles in other works.

  6. Dynamic configuration of the CMS Data Acquisition cluster

    CERN Document Server

    Bauer, Gerry; Biery, Kurt; Boyer, Vincent; Branson, James; Cano, Eric; Cheung, Harry; Ciganek, Marek; Cittolin, Sergio; Coarasa, Jose Antonio; Deldicque, Christian; Dusinberre, Elizabeth; Erhan, Samim; Fortes Rodrigues, Fabiana; Gigi, Dominique; Glege, Frank; Gomez-Reino, Robert; Gutleber, Johannes; Hatton, Derek; Laurens, Jean-Francois; Lopez Perez, Juan Antonio; Meijers, Frans; Meschi, Emilio; Meyer, Andreas; Mommsen, Remigius K; Moser, Roland; O'Dell, Vivian; Oh, Alexander; Orsini, Luciano; Patras, Vaios; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Sakulin, Hannes; Sani, Matteo; Schieferdecker, Philipp; Schwick, Christoph; Shpakov, Dennis; Simon, Sean; Sumorok, Konstanty; Zanetti, Marco

    2010-01-01

    The CMS Data Acquisition cluster, which runs around 10000 applications, is configured dynamically at run time. XML configuration documents determine what applications are executed on each node and over what networks these applications communicate. Through this mechanism the DAQ System may be adapted to the required performance, partitioned in order to perform (test-) runs in parallel, or re-structured in case of hardware faults. This paper presents the CMS DAQ Configurator tool, which is used to generate comprehensive configurations of the CMS DAQ system based on a high-level description given by the user. Using a database of configuration templates and a database containing a detailed model of hardware modules, data and control links, nodes and the network topology, the tool automatically determines which applications are needed, on which nodes they should run, and over which networks the event traffic will flow. The tool computes application parameters and generates the XML configuration documents as well a...

  7. NMR study of spin dynamics in mesoscopic molecular clusters

    Science.gov (United States)

    Borsa, Ferdinando

    1998-03-01

    Recent published and umpublished work regarding the magnetic properties and the spin dynamics of molecules containing rings of 6,8 and 10 spins and of molecules containing clusters of 8 and 12 spins are reviewed. The 1H nuclear spin-lattice relaxation rate (NSLR) and the Muon Spin Resonance relaxation in Mn12 (A.Lascialfari, D.Gatteschi, F.Borsa, A.Shastri, Z.H.Jang and P.Carretta, Phys.Rev. B 1 January 1998) and Fe8 clusters are presented and discussed with regards to the high temperature spin dynamics of the Mn (Fe) magnetic moments and with regards to the low temperature superparamagnetic behavior. 1H and 63Cu NMR results are presented for two "quantum" spin rings : Cu6 and Cu8. The Cu6 is a weakly coupled (J/k=60K) ferromagnetic S=1/2 spin ring while Cu8 is a strongly coupled (J/k greater than 400K) antiferromagnetic S=1/2 spin ring.The dependence of the NSRL from temperature and from applied magnetic field are analyzed in terms of the calculated magnetic energy levels of the magnetic ring. The values of the energy gap between the ground state and the first excited state are extracted from the exponential decrease of the NSLR as the temperature is lowered. The results in the Cu ( S=1/2) "quantum" rings are compared with the results in "quantum" chains and ladders and with the results in "classical" Fe (S=5/2) antiferromagnetic rings : Fe6 and Fe10 (A.Lascialfari, D.Gatteschi, F.Borsa and A.Cornia , Phys.Rev. 55B,14341,1997) ).

  8. Properties of liquid clusters in large-scale molecular dynamics nucleation simulations

    International Nuclear Information System (INIS)

    Angélil, Raymond; Diemand, Jürg; Tanaka, Kyoko K.; Tanaka, Hidekazu

    2014-01-01

    We have performed large-scale Lennard-Jones molecular dynamics simulations of homogeneous vapor-to-liquid nucleation, with 10 9 atoms. This large number allows us to resolve extremely low nucleation rates, and also provides excellent statistics for cluster properties over a wide range of cluster sizes. The nucleation rates, cluster growth rates, and size distributions are presented in Diemand et al. [J. Chem. Phys. 139, 74309 (2013)], while this paper analyses the properties of the clusters. We explore the cluster temperatures, density profiles, potential energies, and shapes. A thorough understanding of the properties of the clusters is crucial to the formulation of nucleation models. Significant latent heat is retained by stable clusters, by as much as ΔkT = 0.1ε for clusters with size i = 100. We find that the clusters deviate remarkably from spherical—with ellipsoidal axis ratios for critical cluster sizes typically within b/c = 0.7 ± 0.05 and a/c = 0.5 ± 0.05. We examine cluster spin angular momentum, and find that it plays a negligible role in the cluster dynamics. The interfaces of large, stable clusters are thinner than planar equilibrium interfaces by 10%−30%. At the critical cluster size, the cluster central densities are between 5% and 30% lower than the bulk liquid expectations. These lower densities imply larger-than-expected surface areas, which increase the energy cost to form a surface, which lowers nucleation rates

  9. Ultrafast dynamics of electronically excited molecules and clusters

    International Nuclear Information System (INIS)

    Lietard, Aude

    2014-01-01

    This PhD thesis investigated the ultrafast dynamics of photo-chromic molecules and argon clusters in the gas phase at the femtosecond timescale. Pump-probe experiments are performed in a set-up which associates a versatile pulsed molecular beam coupled to a photoelectron/photoion velocity map imager (VMI) and a time-of-flight mass spectrometer (TOF-MS). Theses pump-probe experiments provides the temporal evolution of the electronic distribution for each system of interest. Besides, a modelization has been performed in order to characterize the density and the velocity distribution in the pulsed beam. Regarding the photo-chromic di-thienyl-ethene molecules, parallel electronic relaxation pathways were observed. This contrasts with the observation of sequential relaxation processes in most molecules studied so far. In the present case, the initial wave packet splits in two parts. One part is driven to the ground state at the femtosecond time scale through a conical intersection, and the second part remains for ps in the excited state and experiences oscillations in a suspended well. This study has shed light into the intrinsic dynamics of the molecules under study and a general relaxation mechanism has been proposed, which applies to the whole family of di-thienyl-ethene molecules whatever the state of matter (gas phase or solution) in which they have been investigated. Concerning argon clusters excited at about 14 eV, two behaviors of different time scale have been observed at different time scales. The first one occurs in the first picoseconds of the dynamics. It corresponds to the electronic relaxation of an excitonic state at a rate of 1 eV.ps -1 . The second phenomenon corresponds to the localization of the exciton on the excimer Ar 2 *. This phenomenon is observed 4-5 ps after the excitation. In this study, we also observed the ejection of excited argon atoms, addressing the lifetime of the delocalized excitonic state. This work provide additional informations

  10. Psychometric Properties of the Persian Version of Self-Transcendence Scale: Adolescent Version.

    Science.gov (United States)

    Farahani, Azam Shirinabadi; Rassouli, Maryam; Yaghmaie, Farideh; Majd, Hamid Alavi; Sajjadi, Moosa

    2016-04-01

    Given the greater tendency during adolescence toward risk-taking, identifying and measuring the factors affecting the adolescents' health is highly important to ensure the efficacy of health promoting interventions. One of these factors is self-transcendence. The aim of this study was to assess the psychometric features of the Self-Transcendence Scale (adolescents' version) in students in Tehran, the capital city of Iran. This research was conducted in 2015. For this purpose, 1210 high school students were selected through the multistage cluster sampling method. After the backward-forward translation, the psychometric properties of the scale were examined through the assessment of the (face and construct) validity and reliability (internal consistency and stability) of the scale. The construct validity was assessed using two methods, factor analysis, and convergence of the scale with the Hopefulness Scale for Adolescents. The result of face validity was minor modifications in some words. The exploratory factor analysis resulted in the extraction of two dimensions, with explaining 52.79% of the variance collectively. In determining the convergent validity, the correlation between hopefulness score and self-transcendence score was r=0.47 (PSelf-Transcendence Scale showed an acceptable validity and reliability and can be used in the assessment of self-transcendence in Iranian adolescents.

  11. Molecular dynamics calculation of half-lives for thermal decay of Lennard-Jones clusters

    International Nuclear Information System (INIS)

    Smith, R.W.

    1991-01-01

    Molecular dynamics has been used with a Lenard-Jones (6-12) potential in order to study the decay behavior of neutral Argon clusters containing between 12 and 14 atoms. The clusters were heated to temperatures well above their melting points and then tracked in time via molecular dynamics until evaporation of one or more atoms was observed. In each simulation, the mode of evaporation, energy released during evaporation, and cluster lifetime were recorded. Results from roughly 2000 simulation histories were combined in order to compute statistically significant values of cluster half-lives and decay energies. It was found that cluster half-life decreases with increasing energy and that for a given value of excess energy (defined as E=(E tot -E gnd )/n), the 13 atom cluster is more stable against decay than clusters containing either 12 or 14 atoms. The dominant decay mechanism for all clusters was determined to be single atom emission. (orig.)

  12. Comparison of various clustered interaction regions with regard to chromatic and dynamic behavior

    International Nuclear Information System (INIS)

    Leemann, B.; Wrulich, A.

    1986-05-01

    Clustered interaction regions for the SSC may be preferable from the viewpoint of costs and operation. In going from distributed to clustered IR's the superperiodicity of the machine is reduced and therefore the number of resonances induced by chromaticity correcting sextupoles is increased. This break in symmetry may cause a reduction in dynamic stability. The chromatic and dynamic behavior of the bare lattice is investigated for various cluster configurations. That means only chromaticity correcting sextupoles have been included and no magnetic imperfection errors have been considered. Then, the dynamic apertures of lattices with various IR clustering schemes are compared when random magnetic imperfections are included

  13. Clustering Timber Harvests and the Effects of Dynamic Forest Management Policy on Forest Fragmentation

    Science.gov (United States)

    Eric J. Gustafson

    1998-01-01

    To integrate multiple uses (mature forest and commodity production) better on forested lands, timber management strategies that cluster harvests have been proposed. One such approach clusters harvest activity in space and time, and rotates timber production zones across the landscape with a long temporal period (dynamic zoning). Dynamic zoning has...

  14. The Continuing Relevance of the Marxist Tradition for Transcending Capitalism

    Directory of Open Access Journals (Sweden)

    Erik Olin Wright

    2018-05-01

    Full Text Available No idea is more closely associated with Marx than the claim that the intrinsic, contradictory dynamics of capitalism ultimately lead to its self-destruction while simultaneously creating conditions favourable for a revolutionary rupture needed to create an emancipatory alternative in which the control by the capitalist class of investments and production is displaced by radical economic democracy. Marx’s formulation of a theory of transcending capitalism is unsatisfactory for two main reasons: 1 the dynamics of capitalism may generate great harms, but they do not inherently make capitalism unsustainable nor do they generate the structural foundations of a collective actor with a capacity to overthrow capitalism; 2 the vision of a system-level rupture with capitalism is not a plausible strategy replacing capitalism by a democratic-egalitarian economic system. Nevertheless, there are four central propositions anchored in the Marxist tradition that remain essential for understanding the possibility of transcending capitalism: 1. Capitalism obstructs the realization of conditions for human flourishing. 2. Another world is possible. 3. Capitalism’s dynamics are intrinsically contradictory. 4. Emancipatory transformation requires popular mobilization and struggle. These four propositions can underwrite a strategic vision of eroding the dominance of capitalism by building democratic-egalitarian economic relations within the contradictory spaces of capitalism.

  15. Innovation performance and clusters: a dynamic capability perspective on regional technology clusters

    OpenAIRE

    Röttmer, Nicole

    2009-01-01

    This research provides a novel, empirically tested, actionable theory of cluster innovativeness. Cluster innovativeness has for long been subject of research and resulting policy efforts. The cluster's endowment with assets, such as specialized labor, firms, research institutes, existing regional networks and a specific culture are, among others, recognized as sources of innovativeness. While the asset structure of clusters as been subject to a variety of research efforts, the evidence on the...

  16. Self-transcendence and depression in middle-age adults.

    Science.gov (United States)

    Ellermann, C R; Reed, P G

    2001-11-01

    Self-transcendence has been found to be an important correlate of mental health in older adults and adults facing the end of life. This study extends current theory by examining the relationship of transcendence and other transcendence variables to depression in middle-age adults (N = 133). Reed's Self-Transcendence Scale, the Center for Epidemiological Studies-Depression Scale, and measures of parenting, acceptance and spirituality were administered. Findings indicating significant inverse correlations between self-transcendence and depression, as well as between other measures of transcendence and depression support Reed's (1991b) theory. Multiple regression analysis indicated that acceptance may be another significant correlate of depression. Significant gender differences and age-related patterns of increased levels of self-transcendence were found. Study results illuminate the need to continue research into developmentally based transcendence variables related to various experiences of health and well-being across the life span.

  17. Some Reflections on Logic and Transcendence

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter

    2010-01-01

    It is sometimes argued that the very existence of a notion of validity of logical inference on which all rational persons should agree is an indication of the existence of something transcendent. It has also been argued that logic can be used in order to demonstrate the problematic status of natu...

  18. Resonance and Transcendence of a Bodily Presence

    DEFF Research Database (Denmark)

    Petersen, Rikke Munck; Farsø, Mads

    2018-01-01

    This article elucidates how film may offer itself as ‘resonance tool’ for both representation and conception of space that can strengthen an alternative, phenomenological and haptic position of transcendence in architecture, a position from which landscapes and cities are thought, planned and dev...

  19. Cluster fusion-fission dynamics in the Singapore stock exchange

    Science.gov (United States)

    Teh, Boon Kin; Cheong, Siew Ann

    2015-10-01

    In this paper, we investigate how the cross-correlations between stocks in the Singapore stock exchange (SGX) evolve over 2008 and 2009 within overlapping one-month time windows. In particular, we examine how these cross-correlations change before, during, and after the Sep-Oct 2008 Lehman Brothers Crisis. To do this, we extend the complete-linkage hierarchical clustering algorithm, to obtain robust clusters of stocks with stronger intracluster correlations, and weaker intercluster correlations. After we identify the robust clusters in all time windows, we visualize how these change in the form of a fusion-fission diagram. Such a diagram depicts graphically how the cluster sizes evolve, the exchange of stocks between clusters, as well as how strongly the clusters mix. From the fusion-fission diagram, we see a giant cluster growing and disintegrating in the SGX, up till the Lehman Brothers Crisis in September 2008 and the market crashes of October 2008. After the Lehman Brothers Crisis, clusters in the SGX remain small for few months before giant clusters emerge once again. In the aftermath of the crisis, we also find strong mixing of component stocks between clusters. As a result, the correlation between initially strongly-correlated pairs of stocks decay exponentially with average life time of about a month. These observations impact strongly how portfolios and trading strategies should be formulated.

  20. Self-transcendence: a concept analysis for nursing praxis.

    Science.gov (United States)

    Teixeira, M Elizabeth

    2008-01-01

    Self-transcendence is a quality inherent in every human being. This process toward personal transformation is instrumental in finding true meaning and purpose in life. When faced with adversity, self-transcendence can be a powerful coping strategy. Clarity of this concept will assist nurses in providing holistic interventions that promote and facilitate self-transcendence.

  1. A Dynamic Fuzzy Cluster Algorithm for Time Series

    Directory of Open Access Journals (Sweden)

    Min Ji

    2013-01-01

    clustering time series by introducing the definition of key point and improving FCM algorithm. The proposed algorithm works by determining those time series whose class labels are vague and further partitions them into different clusters over time. The main advantage of this approach compared with other existing algorithms is that the property of some time series belonging to different clusters over time can be partially revealed. Results from simulation-based experiments on geographical data demonstrate the excellent performance and the desired results have been obtained. The proposed algorithm can be applied to solve other clustering problems in data mining.

  2. Deformation of Ag clusters deposited on Au(111) - Experiment and molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Miroslawski, Natalie; Groenhagen, Niklas; Hoevel, Heinz [TU Dortmund, Experimentelle Physik I (Germany); Issendorff, Bernd von [Universitaet Freiburg, Fakultaet Physik (Germany); Jaervi, Tommi [Fraunhofer Institut fuer Werkstoffmechanik, Freiburg (Germany); Moseler, Michael [Universitaet Freiburg, Fakultaet Physik (Germany); Fraunhofer Institut fuer Werkstoffmechanik, Freiburg (Germany); Freiburger Materialforschungszentrum (Germany)

    2011-07-01

    Mass selected clusters from Ag{sup +}{sub 55} to Ag{sup +}{sub 147{+-}}{sub 2} were deposited with different deposition energies at 77 K on Au(111) and imaged with STM at 77 K. We observed a deformation of the cluster shape due to the strong metallic interaction between the cluster and the substrate. The clusters became epitaxial and developed a structure composed of several Ag monolayers. The number of these monolayers depends on the number of atoms in the cluster and the deposition energy. The larger the cluster mass the more monolayers the cluster develops on Au(111) and the larger the deposition energy the fewer monolayers occur. These results were verified by molecular dynamic simulations. Additionally the behaviour of Ag{sub N} clusters on Au(111) after different annealing steps was investigated.

  3. Low energy Cu clusters slow deposition on a Fe (001) surface investigated by molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shixu [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Laboratory of Advanced Nuclear Materials, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Gong, Hengfeng [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Division of Nuclear Materials Science and Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Chen, Xuanzhi [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Li, Gongping, E-mail: ligp@lzu.edu.cn [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Wang, Zhiguang, E-mail: zhgwang@impcas.ac.cn [Laboratory of Advanced Nuclear Materials, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-09-30

    Highlights: • We study the deposition of low energy Cu clusters on Fe (001) surface by molecular dynamics. • The interaction between low energy cluster and substrate can be divided to the landing and the thermal diffusion phases. • The phenomenon of contact epitaxy of cluster occurred. • The thermal diffusion of cluster atoms was analyzed. - Abstract: The slow deposition of low energy Cu clusters on a Fe (001) surface was investigated by molecular dynamics simulation. A many-body potential based on Finnis–Sinclair model was used to describe the interactions among atoms. Three clusters comprising of 13, 55 and 147 atoms, respectively, were deposited with incident energies ranging from 0.0 to 1.0 eV/atom at various substrate temperatures (0, 300 and 800 K). The rearrangement and the diffusion of cluster can occur, only when the cluster atoms are activated and obtained enough migration energy. The interaction between low energy cluster and substrate can be divided to the landing and the thermal diffusion phases. In the former, the migration energy originates from the latent heat of binding energy for the soft deposition regime and primarily comes from the incident energy of cluster for the energetic cluster deposition regime. In the latter, the thermal vibration would result in some cluster atoms activated again at medium and high substrate temperatures. Also, the effects of incident energy, cluster size and substrate temperature on the interaction potential energy between cluster and substrate, the final deposition morphology of cluster, the spreading index and the structure parameter of cluster are analyzed.

  4. Dynamic Load Balanced Clustering using Elitism based Random Immigrant Genetic Approach for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    K. Mohaideen Pitchai

    2017-07-01

    Full Text Available Wireless Sensor Network (WSN consists of a large number of small sensors with restricted energy. Prolonged network lifespan, scalability, node mobility and load balancing are important needs for several WSN applications. Clustering the sensor nodes is an efficient technique to reach these goals. WSN have the characteristics of topology dynamics because of factors like energy conservation and node movement that leads to Dynamic Load Balanced Clustering Problem (DLBCP. In this paper, Elitism based Random Immigrant Genetic Approach (ERIGA is proposed to solve DLBCP which adapts to topology dynamics. ERIGA uses the dynamic Genetic Algorithm (GA components for solving the DLBCP. The performance of load balanced clustering process is enhanced with the help of this dynamic GA. As a result, the ERIGA achieves to elect suitable cluster heads which balances the network load and increases the lifespan of the network.

  5. State selective dynamics of molecules, clusters, and nanostructures

    International Nuclear Information System (INIS)

    John W. Keto

    2005-01-01

    Early objectives of this grant were: (1) Measure two-photon excitation of even parity excitons in liquid an solid xenon, (2) Study state-to-state energy transfer between two-photon laser excited states or rare-gas atoms to other rare has atoms, (3) study reactive half-collisions between xenon and chlorine leading to the XeCl* B state, (4) measure the spectra of ro-vibrational states of cluster ions and radicals formed in high-pressure discharges and to study their dynamics, (5) measure the surface and bulk electronic states of nanoparticles produced by a unique method of synthesis--laser ablation of microspheres (LAM). Using near-field and microluminescence techniques, we obtained spectra of single nanocrystals to compare with spectra obtained in a supersonic jet apparatus using resonance excitation followed by photoionization (REMPI) with time-of-flight mass analysis. These materials combine the functional advantages obtained from the size-tunable properties of nanocomposite materials with the fabrication and direct-write advantages of NPs manufactured by LAM. We demonstrated that CdSe nanoparticles produced by LAM were efficient fluorescers, even when deposited dry on sapphire substrates. Si nanoparticles were fluorescent when captured in ethylene glycol. We also obtained efficient fluorescence from Er doped phosphate glass nanoparticles which have application to gain waveguides in integrated optics or to nanoslush lasers. We used a femptosecond laser to study the nonlinear spectra of NC composites. We are currently measuring fluorescence and second and third-order susceptibilities of composites of Ag, Si, and GaN nanoparticles encapsulated within thin films of sapphire or SiO2

  6. State selective dynamics of molecules, clusters, and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Keto, John W. [Univ. of Texas, Austin, TX (United States)

    2005-06-01

    Early objectives of this grant were: (1) Measure two-photon excitation of even parity excitons in liquid an solid xenon, (2) Study state-to-state energy transver between two-photon laser excited states or rare-gas atoms to other rare has atoms, (3) study reactive half-collisions between xenon and chlorine leading to the XeCl* B state, (4) measure the spectra of ro-vibrational states of cluster ions and radicals formed in high-pressure discharges and to study their dynamics, (5) measure the surface and bulk electronic states of nanoparticles produced by a unique method of synthesis--laser ablation of microspheres (LAM). Using near-field and microluminescence techniques, we obtained spectra of single nanocrystals to compare with spectra obtained in a supersonic jet apparatus using resonance excitation followed by photoionization (REMPI) with time-of-flight mass analysis. These materials combine the functional advantages obtained from the size-tunable properties of nanocomposite materials with the fabrication and direct-write advantages of NPs manufactured by LAM. We demostrated that CdSe nanoparticles produced by LAM were efficiient fluorescers, even when deposited dry on sapphire substrates. Si nanoparticles were fluorescent when captured in ethylene glycol. We also obtiained efficient fluorescence from Er doped phosphate glass nanopartiicles which have application to gain wafeguides in integrated optics or to nanoslush lasers. We used a femptosecond laser to study the nonlinear spectra of NC composites. We are currently measuring fluorescence and second and third-order susceptibilities of composites of Ag, Si, and GaN nanoparticles encapsulated within thin films of sapphire or SiO 2.

  7. Orbital magnetism and dynamics in alkali metal clusters

    International Nuclear Information System (INIS)

    Nesterenko, V.O.; Kleinig, W.; Souza Cruz, FF. de; Marinelli, J.R.

    2000-01-01

    Two remarkable orbital magnetic resonances, M1 scissor mode and M2 twist mode, are predicted in deformed and spherical metal clusters, respectively. We show that these resonances provide a valuable information about many cluster properties (quadrupole deformation, magnetic susceptibility, single-particle spectrum, etc.)

  8. Atomistic interactions of clusters on surfaces using molecular dynamics and hyper molecular dynamics

    International Nuclear Information System (INIS)

    Sanz-Navarro, Carlos F.

    2002-01-01

    The work presented in this thesis describes the results of Molecular Dynamics (MD) simulations applied to the interaction of silver clusters with graphite surfaces and some numerical and theoretical methods concerning the extension of MD simulations to longer time scales (hyper-MD). The first part of this thesis studies the implantation of clusters at normal incidence onto a graphite surface in order to determine the scaling of the penetration depth (PD) against the impact energy. A comparison with experimental results is made with good agreement. The main physical observations of the impact process are described and analysed. It is shown that there is a threshold impact velocity above which the linear dependence on PD on impact energy changes to a linear dependence on velocity. Implantation of silver clusters at oblique incidence is also considered. The second part of this work analyses the validity and feasibility of the three minimisation methods for the hyper-MD simulation method whereby time scales of an MD simulation can be extended. A correct mathematical basis for the iterative method is derived. It is found that one of the iterative methods, upon which hyper-lD is based, is very likely to fail in high-dimensional situations because it requires a too expensive convergence. Two new approximations to the hyper-MD approach are proposed, which reduce the computational effort considerably. Both approaches, although not exact, can help to search for some of the most likely transitions in the system. Some examples are given to illustrate this. (author)

  9. Ab Initio Molecular Dynamics Studies of Pb m Sb n ( m + n ≤ 9) Alloy Clusters

    Science.gov (United States)

    Song, Bingyi; Xu, Baoqiang; Yang, Bin; Jiang, Wenlong; Chen, Xiumin; Xu, Na; Liu, Dachun; Dai, Yongnian

    2017-10-01

    Structure, stability, and dynamics of Pb m Sb n ( m + n ≤ 9) clusters were investigated using ab initio molecular dynamics. Size dependence of binding energies, the second-order energy difference of clusters, dissociation energy, HOMO-LUMO gaps, Mayer bond order, and the diffusion coefficient of Pb m Sb n clusters were discussed. Results suggest that Pb3Sb2, Pb4Sb2, and Pb5Sb4 ( n = 2 or 4) clusters have higher stability than other clusters, which is consistent with previous findings. In case of Pb-Sb alloy, the dynamics results show that Pb4Sb2 (Pb-22.71 wt pct Sb) can exist in gas phase at 1073 K (800 °C), which reasonably explains the azeotropic phenomenon, and the calculated values are in agreement with the experimental results (Pb-22 wt pct Sb).

  10. One- and two-cluster synchronized dynamics of non-diffusively coupled Tchebycheff map networks

    International Nuclear Information System (INIS)

    Schäfer, Mirko; Greiner, Martin

    2012-01-01

    We use the master stability formalism to discuss one- and two-cluster synchronization of coupled Tchebycheff map networks. For diffusively coupled map systems, the one-cluster synchronized dynamics is given by the behaviour of the individual maps, and the coupling only determines the stability of the coherent state. For the case of non-diffusive coupling and for two-cluster synchronization, the synchronized dynamics on networks is different from the behaviour of the single individual map. Depending on the coupling, we study numerically the characteristics of various forms of the resulting synchronized dynamics. The stability properties of the respective one-cluster synchronized states are discussed for arbitrary network structures. For the case of two-cluster synchronization on bipartite networks we also present analytical expressions for fixed points and zig-zag patterns, and explicitly determine the linear stability of these orbits for the special case of ring-networks.

  11. Classical plasma dynamics of Mie-oscillations in atomic clusters

    Science.gov (United States)

    Kull, H.-J.; El-Khawaldeh, A.

    2018-04-01

    Mie plasmons are of basic importance for the absorption of laser light by atomic clusters. In this work we first review the classical Rayleigh-theory of a dielectric sphere in an external electric field and Thomson’s plum-pudding model applied to atomic clusters. Both approaches allow for elementary discussions of Mie oscillations, however, they also indicate deficiencies in describing the damping mechanisms by electrons crossing the cluster surface. Nonlinear oscillator models have been widely studied to gain an understanding of damping and absorption by outer ionization of the cluster. In the present work, we attempt to address the issue of plasmon relaxation in atomic clusters in more detail based on classical particle simulations. In particular, we wish to study the role of thermal motion on plasmon relaxation, thereby extending nonlinear models of collective single-electron motion. Our simulations are particularly adopted to the regime of classical kinetics in weakly coupled plasmas and to cluster sizes extending the Debye-screening length. It will be illustrated how surface scattering leads to the relaxation of Mie oscillations in the presence of thermal motion and of electron spill-out at the cluster surface. This work is intended to give, from a classical perspective, further insight into recent work on plasmon relaxation in quantum plasmas [1].

  12. In your face: Transcendence in embodied interaction

    Directory of Open Access Journals (Sweden)

    Shaun eGallagher

    2014-07-01

    Full Text Available In cognitive psychology, studies concerning the face tend to focus on questions about face recognition, theory of mind and empathy. Questions about the face, however, also fit into a very different set of issues that are central to ethics. Based especially on the work of Levinas, philosophers have come to see that reference to the face of another person can anchor conceptions of moral responsibility and ethical demand. Levinas points to a certain irreducibility and transcendence implicit in the face of the other. In this paper I argue that the notion of transcendence involved in this kind of analysis can be given a naturalistic interpretation by drawing on recent interactive approaches to social cognition found in developmental psychology, phenomenology, and the study of autism.

  13. Ckmeans.1d.dp: Optimal k-means Clustering in One Dimension by Dynamic Programming.

    Science.gov (United States)

    Wang, Haizhou; Song, Mingzhou

    2011-12-01

    The heuristic k -means algorithm, widely used for cluster analysis, does not guarantee optimality. We developed a dynamic programming algorithm for optimal one-dimensional clustering. The algorithm is implemented as an R package called Ckmeans.1d.dp . We demonstrate its advantage in optimality and runtime over the standard iterative k -means algorithm.

  14. An adaptive immune optimization algorithm with dynamic lattice searching operation for fast optimization of atomic clusters

    International Nuclear Information System (INIS)

    Wu, Xia; Wu, Genhua

    2014-01-01

    Highlights: • A high efficient method for optimization of atomic clusters is developed. • Its performance is studied by optimizing Lennard-Jones clusters and Ag clusters. • The method is proved to be quite efficient. • A new Ag 61 cluster with stacking-fault face-centered cubic motif is found. - Abstract: Geometrical optimization of atomic clusters is performed by a development of adaptive immune optimization algorithm (AIOA) with dynamic lattice searching (DLS) operation (AIOA-DLS method). By a cycle of construction and searching of the dynamic lattice (DL), DLS algorithm rapidly makes the clusters more regular and greatly reduces the potential energy. DLS can thus be used as an operation acting on the new individuals after mutation operation in AIOA to improve the performance of the AIOA. The AIOA-DLS method combines the merit of evolutionary algorithm and idea of dynamic lattice. The performance of the proposed method is investigated in the optimization of Lennard-Jones clusters within 250 atoms and silver clusters described by many-body Gupta potential within 150 atoms. Results reported in the literature are reproduced, and the motif of Ag 61 cluster is found to be stacking-fault face-centered cubic, whose energy is lower than that of previously obtained icosahedron

  15. MASSIVE CLUSTERS IN THE INNER REGIONS OF NGC 1365: CLUSTER FORMATION AND GAS DYNAMICS IN GALACTIC BARS

    International Nuclear Information System (INIS)

    Elmegreen, Bruce G.; Galliano, Emmanuel; Alloin, Danielle

    2009-01-01

    Cluster formation and gas dynamics in the central regions of barred galaxies are not well understood. This paper reviews the environment of three 10 7 M sun clusters near the inner Lindblad resonance (ILR) of the barred spiral NGC 1365. The morphology, mass, and flow of H I and CO gas in the spiral and barred regions are examined for evidence of the location and mechanism of cluster formation. The accretion rate is compared with the star formation rate to infer the lifetime of the starburst. The gas appears to move from inside corotation in the spiral region to looping filaments in the interbar region at a rate of ∼6 M sun yr -1 before impacting the bar dustlane somewhere along its length. The gas in this dustlane moves inward, growing in flux as a result of the accretion to ∼40 M sun yr -1 near the ILR. This inner rate exceeds the current nuclear star formation rate by a factor of 4, suggesting continued buildup of nuclear mass for another ∼0.5 Gyr. The bar may be only 1-2 Gyr old. Extrapolating the bar flow back in time, we infer that the clusters formed in the bar dustlane outside the central dust ring at a position where an interbar filament currently impacts the lane. The ram pressure from this impact is comparable to the pressure in the bar dustlane, and both are comparable to the pressure in the massive clusters. Impact triggering is suggested. The isothermal assumption in numerical simulations seems inappropriate for the rarefaction parts of spiral and bar gas flows. The clusters have enough lower-mass counterparts to suggest they are part of a normal power-law mass distribution. Gas trapping in the most massive clusters could explain their [Ne II] emission, which is not evident from the lower-mass clusters nearby.

  16. Dynamics diffusion behaviors of Pd small clusters on a Pd(1 1 1) surface

    International Nuclear Information System (INIS)

    Liu, Fusheng; Hu, Wangyu; Deng, Huiqiu; He, Rensheng; Yang, Xiyuan; Lu, Kuilin; Deng, Lei; Luo, Wenhua

    2010-01-01

    Using molecular dynamics, nudged elastic band and modified analytic embedded atom methods, the self-diffusion dynamics properties of palladium atomic clusters up to seven atoms on the Pd (1 1 1) surface have been studied at temperatures ranging from 300 to 1000 K. The simulation time varies from 20 to 75 ns according to the cluster sizes and the temperature ranges. The heptamer and trimer are more stable than the other neighboring clusters. The diffusion coefficients of the clusters are derived from the mean square displacement of the cluster's mass-center, and the diffusion prefactors D 0 and activation energies E a are derived from the Arrhenius relation. The activation energy of the clusters increases with the increasing atom number in the clusters, especially for Pd 6 to Pd 7 . The analysis of trajectories shows the noncompact clusters diffuse by the local diffusion mechanism but the compact clusters diffuse mainly by the whole gliding mechanism, and some static energy barriers of the diffusion modes are calculated. From Pd 2 to Pd 6 , the prefactors are in the range of the standard value 10 −3  cm 2  s −1 , and the prefactor of Pd 7 cluster is 2 orders of magnitude greater than that of the single Pd adatom because of a large number of nonequivalent diffusion processes. The heptamer can be the nucleus in the room temperature range according to nucleation theory

  17. Dynamics of cluster structures in a financial market network

    Science.gov (United States)

    Kocheturov, Anton; Batsyn, Mikhail; Pardalos, Panos M.

    2014-11-01

    In the course of recent fifteen years the network analysis has become a powerful tool for studying financial markets. In this work we analyze stock markets of the USA and Sweden. We study cluster structures of a market network constructed from a correlation matrix of returns of the stocks traded in each of these markets. Such cluster structures are obtained by means of the P-Median Problem (PMP) whose objective is to maximize the total correlation between a set of stocks called medians of size p and other stocks. Every cluster structure is an undirected disconnected weighted graph in which every connected component (cluster) is a star, or a tree with one central node (called a median) and several leaf nodes connected with the median by weighted edges. Our main observation is that in non-crisis periods of time cluster structures change more chaotically, while during crises they show more stable behavior and fewer changes. Thus an increasing stability of a market graph cluster structure obtained via the PMP could be used as an indicator of a coming crisis.

  18. Generation of clusters in complex dynamical networks via pinning control

    International Nuclear Information System (INIS)

    Li Kezan; Fu Xinchu; Small, Michael

    2008-01-01

    Many real-world networks show community structure, i.e., groups (or clusters) of nodes that have a high density of links within them but with a lower density of links between them. In this paper, by applying feedback injections to a fraction of network nodes, various clusters are synchronized independently according to the community structure generated by the group partition of the network (cluster synchronization). This control is achieved by pinning (i.e. applying linear feedback control) to a subset of the network nodes. Those pinned nodes are selected not randomly but according to the topological structure of communities of a given network. Specifically, for a given group partition of a network, those nodes with direct connections between groups must be pinned in order to achieve cluster synchronization. Both the local stability and global stability of cluster synchronization are investigated. Taking the tree-shaped network and the most modular network as two particular examples, we illustrate in detail how the pinning strategy influences the generation of clusters. The simulations verify the efficiency of the pinning schemes used in this paper

  19. Dynamics and stability of charged clusters and droplets

    International Nuclear Information System (INIS)

    Manil, B.; Lebius, H.; Chandezon, F.; Huber, B.A.; Duft, D.; Leisner, T.; Guet, C.

    2002-01-01

    Lord Raleigh predicted (Phil. Mag. 14, 184(1982) ) that a charged, incompressible liquid droplet becomes unstable as soon as the cohesive forces, which create the surface tension and which try to keep the droplet in its spherical form, are equal to the Coulomb forces, which try to destabilise it. This means that that the Coulomb energy E c corresponds to twice the surface energy E s . The ratio X = E c / 2 E s (feasibility), thus characterising the Raleigh limit by X = 1. In order to test its validity, metal clusters were ionized in collisions with highly charged ions, allowing for the first time to prepare charged systems with a feasibility greater than 1. Multiply charged sodium clusters were produced through collisions of Ar 11+ or Xe 28+ with neutral sodium clusters. It was observed, with increasing cluster charge and consequently cluster size the detected system indeed approach the Raleigh limit (for q = 10 X = 0.85). However, it was not reached due to the initial cluster temperature and the energy transfer in the collision. Subsequent, the stability and the explosion of highly charge microdroplets which were injected into a Paul trap levitator were studied, specifically, glycol was irradiated with a HeNe laser. It was observed that a resonance phenomena appeared just before each explosion. As the resonance is linked to X ∼ 1, this is the first proof that the Coulomb instability of charge glycol microdroplets occurs at X ∼ 1, as predicted by Lord Raleigh. (nevyjel)

  20. Structure and dynamics of ion clusters in linear octupole traps: Phase diagrams, chirality, and melting mechanisms

    International Nuclear Information System (INIS)

    Yurtsever, E.; Onal, E. D.; Calvo, F.

    2011-01-01

    The stable structures and melting dynamics of clusters of identical ions bound by linear octupole radiofrequency traps are theoretically investigated by global optimization methods and molecular dynamics simulations. By varying the cluster sizes in the range of 10-1000 ions and the extent of trap anisotropy by more than one order of magnitude, we find a broad variety of stable structures based on multiple rings at small sizes evolving into tubular geometries at large sizes. The binding energy of these clusters is well represented by two contributions arising from isotropic linear and octupolar traps. The structures generally exhibit strong size effects, and chiral arrangements spontaneously emerge in many crystals. Sufficiently large clusters form nested, coaxial tubes with different thermal stabilities. As in isotropic octupolar clusters, the inner tubes melt at temperatures that are lower than the overall melting point.

  1. Transformation dynamics of Ni clusters into NiO rings under electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Knez, Daniel, E-mail: daniel.knez@felmi-zfe.at [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Thaler, Philipp; Volk, Alexander [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Kothleitner, Gerald [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Ernst, Wolfgang E. [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Hofer, Ferdinand [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria)

    2017-05-15

    We report the transformation of nickel clusters into NiO rings by an electron beam induced nanoscale Kirkendall effect. High-purity nickel clusters consisting of a few thousand atoms have been used as precursors and were synthesized with the superfluid helium droplet technique. Aberration-corrected, analytical scanning transmission electron microscopy was applied to oxidise and simultaneously analyse the nanostructures. The transient dynamics of the oxidation could be documented by time lapse series using high-angle annular dark-field imaging and electron energy-loss spectroscopy. A two-step Cabrera-Mott oxidation mechanism was identified. It was found that water adsorbed adjacent to the clusters acts as oxygen source for the electron beam induced oxidation. The size-dependent oxidation rate was estimated by quantitative EELS measurements combined with molecular dynamics simulations. Our findings could serve to better control sample changes during examination in an electron microscope, and might provide a methodology to generate other metal oxide nanostructures. - Highlights: • Beam induced conversion of Ni clusters into crystalline NiO rings has been observed. • Ni clusters were grown with the superfluid He-droplet technique. • oxidizeSTEM was utilized to investigate and simultaneously oxidize these clusters. • Oxidation dynamics was captured in real-time. • Cluster sizes and the oxidation rate were estimated via EELS and molecular dynamics.

  2. Running and rotating: modelling the dynamics of migrating cell clusters

    Science.gov (United States)

    Copenhagen, Katherine; Gov, Nir; Gopinathan, Ajay

    Collective motion of cells is a common occurrence in many biological systems, including tissue development and repair, and tumor formation. Recent experiments have shown cells form clusters in a chemical gradient, which display three different phases of motion: translational, rotational, and random. We present a model for cell clusters based loosely on other models seen in the literature that involves a Vicsek-like alignment as well as physical collisions and adhesions between cells. With this model we show that a mechanism for driving rotational motion in this kind of system is an increased motility of rim cells. Further, we examine the details of the relationship between rim and core cells, and find that the phases of the cluster as a whole are correlated with the creation and annihilation of topological defects in the tangential component of the velocity field.

  3. Molecular dynamics modelling of EGCG clusters on ceramide bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, Jingjie; Cheng, Yuan; Li, Weifeng; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 (Singapore)

    2015-12-31

    A novel method of atomistic modelling and characterization of both pure ceramide and mixed lipid bilayers is being developed, using only the General Amber ForceField. Lipid bilayers modelled as pure ceramides adopt hexagonal packing after equilibration, and the area per lipid and bilayer thickness are consistent with previously reported theoretical results. Mixed lipid bilayers are modelled as a combination of ceramides, cholesterol, and free fatty acids. This model is shown to be stable after equilibration. Green tea extract, also known as epigallocatechin-3-gallate, is introduced as a spherical cluster on the surface of the mixed lipid bilayer. It is demonstrated that the cluster is able to bind to the bilayers as a cluster without diffusing into the surrounding water.

  4. Stochastic dynamics of spatial effects in fragmentation of clusters

    International Nuclear Information System (INIS)

    Salinas-Rodriguez, E.; Rodriguez, R.F.; Zamora, J.M.

    1991-01-01

    We use a stochastic approach to study the effects of spatial in homogeneities in the kinetics of a fragmentation model which occurs in cluster breakup and polymer degradation. The analytical form of the cluster size distribution function is obtained for both the discrete and continuous limits. From it we calculate numerically the average size and volume of the clusters, their total concentration and the total scattering of the dispersion in both limits. The influence of spatial effects is explicitly shown in the last two quantities. From our description the equations for the equal-time and the two times density correlation functions are also derived in the continuous limit. Finally, the perspectives and limitations of our approach are discussed (Author)

  5. Exploring the Dynamics of Exoplanetary Systems in a Young Stellar Cluster

    Science.gov (United States)

    Thornton, Jonathan Daniel; Glaser, Joseph Paul; Wall, Joshua Edward

    2018-01-01

    I describe a dynamical simulation of planetary systems in a young star cluster. One rather arbitrary aspect of cluster simulations is the choice of initial conditions. These are typically chosen from some standard model, such as Plummer or King, or from a “fractal” distribution to try to model young clumpy systems. Here I adopt the approach of realizing an initial cluster model directly from a detailed magnetohydrodynamical model of cluster formation from a 1000-solar-mass interstellar gas cloud, with magnetic fields and radiative and wind feedback from massive stars included self-consistently. The N-body simulation of the stars and planets starts once star formation is largely over and feedback has cleared much of the gas from the region where the newborn stars reside. It continues until the cluster dissolves in the galactic field. Of particular interest is what would happen to the free-floating planets created in the gas cloud simulation. Are they captured by a star or are they ejected from the cluster? This method of building a dynamical cluster simulation directly from the results of a cluster formation model allows us to better understand the evolution of young star clusters and enriches our understanding of extrasolar planet development in them. These simulations were performed within the AMUSE simulation framework, and combine N-body, multiples and background potential code.

  6. Ultrafast relaxation dynamics of electrons in Au clusters capped with dodecanethiol molecules

    International Nuclear Information System (INIS)

    Hamanaka, Y.; Fukagawa, K.; Tai, Y.; Murakami, J.; Nakamura, A.

    2006-01-01

    We have investigated electron relaxation dynamics of size-selected Au clusters capped by dodecanethiol molecules in the cluster sizes of 28-142 atoms using femtosecond pump-probe spectroscopy. Absorption spectra of 28-71-atom clusters show discrete peaks due to the optical transitions between quantized states, while an absorption band due to the surface plasmon is observed in 142-atom clusters. In the differential absorption spectra measured by the pump-probe experiments, a large redshift of 140 meV lasting over 10 ps and absorption bleaching decaying within 2 ps are observed at the absorption peaks of 28-atom clusters. The redshift is ascribed to a charge transfer between Au clusters and dodecanethiol molecules adsorbed on the cluster surface, and the bleaching is due to blocking of the optical transitions between the ground state and the occupied electronic states due to the Pauli's-exclusion principle. Such behavior is in contrast to the 142-atom clusters, where the cooling of hot electrons generated by photo-excitation determines the relaxation dynamics. These results indicate molecular properties of the 28-atom Au cluster-dodecanethiol system

  7. Dynamic Characteristics Analysis and Stabilization of PV-Based Multiple Microgrid Clusters

    DEFF Research Database (Denmark)

    Zhao, Zhuoli; Yang, Ping; Wang, Yuewu

    2018-01-01

    -based multiple microgrid clusters. A detailed small-signal model for PV-based microgrid clusters considering local adaptive dynamic droop control mechanism of the voltage-source PV system is developed. The complete dynamic model is then used to access and compare the dynamic characteristics of the single...... microgrid and interconnected microgrids. In order to enhance system stability of the PV microgrid clusters, a tie-line flow and stabilization strategy is proposed to suppress the introduced interarea and local oscillations. Robustly selecting of the key control parameters is transformed to a multiobjective......As the penetration of PV generation increases, there is a growing operational demand on PV systems to participate in microgrid frequency regulation. It is expected that future distribution systems will consist of multiple microgrid clusters. However, interconnecting PV microgrids may lead to system...

  8. A dynamic lattice searching method with rotation operation for optimization of large clusters

    International Nuclear Information System (INIS)

    Wu Xia; Cai Wensheng; Shao Xueguang

    2009-01-01

    Global optimization of large clusters has been a difficult task, though much effort has been paid and many efficient methods have been proposed. During our works, a rotation operation (RO) is designed to realize the structural transformation from decahedra to icosahedra for the optimization of large clusters, by rotating the atoms below the center atom with a definite degree around the fivefold axis. Based on the RO, a development of the previous dynamic lattice searching with constructed core (DLSc), named as DLSc-RO, is presented. With an investigation of the method for the optimization of Lennard-Jones (LJ) clusters, i.e., LJ 500 , LJ 561 , LJ 600 , LJ 665-667 , LJ 670 , LJ 685 , and LJ 923 , Morse clusters, silver clusters by Gupta potential, and aluminum clusters by NP-B potential, it was found that both the global minima with icosahedral and decahedral motifs can be obtained, and the method is proved to be efficient and universal.

  9. Molecular dynamic simulation on boron cluster implantation for shallow junction formation

    International Nuclear Information System (INIS)

    Yuan Li; Yu Min; Li Wei; Ji Huihui; Ren Liming; Zhan Kai; Huang Ru; Zhang Xing; Wang Yangyuan; Zhang Jinyu; Oka, Hideki

    2006-01-01

    Boron cluster ion implantation is a potential technology for shallow junction formation in integrated circuits manufacture. A molecular dynamic method for cluster implantation simulation, aiming at microelectronics application, is presented in this paper. Accurate geometric structures of boron clusters are described by the model, and the H atoms in clusters are included. A potential function taking the form of combining the ZBL and the SW potentials is presented here to model interaction among the atoms in the boron cluster. The impact of these models on cluster implantation simulation is investigated. There are notable impact on dopant distribution and amount of implantation defects with consideration of these models. The simulation on the distributions of B and H are verified by SIMS data

  10. Effect of Policy Analysis on Indonesia’s Maritime Cluster Development Using System Dynamics Modeling

    Science.gov (United States)

    Nursyamsi, A.; Moeis, A. O.; Komarudin

    2018-03-01

    As an archipelago with two third of its territory consist of water, Indonesia should address more attention to its maritime industry development. One of the catalyst to fasten the maritime industry growth is by developing a maritime cluster. The purpose of this research is to gain understanding of the effect if Indonesia implement maritime cluster policy to the growth of maritime economic and its role to enhance the maritime cluster performance, hence enhancing Indonesia’s maritime industry as well. The result of the constructed system dynamic model simulation shows that with the effect of maritime cluster, the growth of employment rate and maritime economic is much bigger that the business as usual case exponentially. The result implies that the government should act fast to form a legitimate cluster maritime organizer institution so that there will be a synergize, sustainable, and positive maritime cluster environment that will benefit the performance of Indonesia’s maritime industry.

  11. Self-transcendence and correlates in a healthy population.

    Science.gov (United States)

    Coward, D D

    1996-01-01

    The purpose of this study was to document the presence of self-transcendence perspectives in a healthy population and to compare self-transcendence and related concepts with previous findings in elderly well persons and in those with life-threatening illness. Levels of self-transcendence, as assessed by the Self-Transcendence Scale and the Purpose-in-Life Test in a sample of 152 persons (mean age = 46 years), were similar to those found in other populations. Moderate correlations with self-transcendence and female gender; older age, and higher self-report of health status were found. Self-transcendence was strongly correlated with sense of coherence, self-esteem, hope, and variables assessing emotional well-being.

  12. Molecular-dynamics analysis of mobile helium cluster reactions near surfaces of plasma-exposed tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-9303 (United States); Hammond, Karl D. [Department of Chemical Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2015-10-28

    We report the results of a systematic atomic-scale analysis of the reactions of small mobile helium clusters (He{sub n}, 4 ≤ n ≤ 7) near low-Miller-index tungsten (W) surfaces, aiming at a fundamental understanding of the near-surface dynamics of helium-carrying species in plasma-exposed tungsten. These small mobile helium clusters are attracted to the surface and migrate to the surface by Fickian diffusion and drift due to the thermodynamic driving force for surface segregation. As the clusters migrate toward the surface, trap mutation (TM) and cluster dissociation reactions are activated at rates higher than in the bulk. TM produces W adatoms and immobile complexes of helium clusters surrounding W vacancies located within the lattice planes at a short distance from the surface. These reactions are identified and characterized in detail based on the analysis of a large number of molecular-dynamics trajectories for each such mobile cluster near W(100), W(110), and W(111) surfaces. TM is found to be the dominant cluster reaction for all cluster and surface combinations, except for the He{sub 4} and He{sub 5} clusters near W(100) where cluster partial dissociation following TM dominates. We find that there exists a critical cluster size, n = 4 near W(100) and W(111) and n = 5 near W(110), beyond which the formation of multiple W adatoms and vacancies in the TM reactions is observed. The identified cluster reactions are responsible for important structural, morphological, and compositional features in the plasma-exposed tungsten, including surface adatom populations, near-surface immobile helium-vacancy complexes, and retained helium content, which are expected to influence the amount of hydrogen re-cycling and tritium retention in fusion tokamaks.

  13. The Dynamics of Technical and Business Knowledge Networks in Industrial Clusters: Embeddedness, status or proximity?

    NARCIS (Netherlands)

    Balland, Pierre-Alexandre; Belso-Martinez, Jose-Antonio; Morrison, Andrea

    2016-01-01

    Although informal knowledge networks have often been regarded as a key ingredient behind the success of industrial clusters, the forces that shape their structure and dynamics remain largely unknown. Drawing on recent network dynamic models, we analyze the evolution of business and technical

  14. Differential dynamic microscopy of weakly scattering and polydisperse protein-rich clusters

    Science.gov (United States)

    Safari, Mohammad S.; Vorontsova, Maria A.; Poling-Skutvik, Ryan; Vekilov, Peter G.; Conrad, Jacinta C.

    2015-10-01

    Nanoparticle dynamics impact a wide range of biological transport processes and applications in nanomedicine and natural resource engineering. Differential dynamic microscopy (DDM) was recently developed to quantify the dynamics of submicron particles in solutions from fluctuations of intensity in optical micrographs. Differential dynamic microscopy is well established for monodisperse particle populations, but has not been applied to solutions containing weakly scattering polydisperse biological nanoparticles. Here we use bright-field DDM (BDDM) to measure the dynamics of protein-rich liquid clusters, whose size ranges from tens to hundreds of nanometers and whose total volume fraction is less than 10-5. With solutions of two proteins, hemoglobin A and lysozyme, we evaluate the cluster diffusion coefficients from the dependence of the diffusive relaxation time on the scattering wave vector. We establish that for weakly scattering populations, an optimal thickness of the sample chamber exists at which the BDDM signal is maximized at the smallest sample volume. The average cluster diffusion coefficient measured using BDDM is consistently lower than that obtained from dynamic light scattering at a scattering angle of 90∘. This apparent discrepancy is due to Mie scattering from the polydisperse cluster population, in which larger clusters preferentially scatter more light in the forward direction.

  15. Dynamical Mass Measurements of Contaminated Galaxy Clusters Using Support Distribution Machines

    Science.gov (United States)

    Ntampaka, Michelle; Trac, Hy; Sutherland, Dougal; Fromenteau, Sebastien; Poczos, Barnabas; Schneider, Jeff

    2018-01-01

    We study dynamical mass measurements of galaxy clusters contaminated by interlopers and show that a modern machine learning (ML) algorithm can predict masses by better than a factor of two compared to a standard scaling relation approach. We create two mock catalogs from Multidark’s publicly available N-body MDPL1 simulation, one with perfect galaxy cluster membership infor- mation and the other where a simple cylindrical cut around the cluster center allows interlopers to contaminate the clusters. In the standard approach, we use a power-law scaling relation to infer cluster mass from galaxy line-of-sight (LOS) velocity dispersion. Assuming perfect membership knowledge, this unrealistic case produces a wide fractional mass error distribution, with a width E=0.87. Interlopers introduce additional scatter, significantly widening the error distribution further (E=2.13). We employ the support distribution machine (SDM) class of algorithms to learn from distributions of data to predict single values. Applied to distributions of galaxy observables such as LOS velocity and projected distance from the cluster center, SDM yields better than a factor-of-two improvement (E=0.67) for the contaminated case. Remarkably, SDM applied to contaminated clusters is better able to recover masses than even the scaling relation approach applied to uncon- taminated clusters. We show that the SDM method more accurately reproduces the cluster mass function, making it a valuable tool for employing cluster observations to evaluate cosmological models.

  16. Dynamical entropy, quantum K-systems and clustering

    International Nuclear Information System (INIS)

    Narnhofer, H.

    1989-01-01

    The two possibilities to define a quantum K-system, either using algebraic relations or using properties of the dynamical entropy, are compared. It is shown that under the additional assumption of strong asymptotic abelianess the algebraic relations imply the properties of the dynamical entropy. 14 refs. (Author)

  17. Photoelectron imaging, probe of the dynamics: from atoms... to clusters

    International Nuclear Information System (INIS)

    Lepine, F.

    2003-06-01

    This thesis concerns the study of the deexcitation of clusters and atoms by photoelectron imaging. The first part is dedicated to thermionic emission of a finite size system. A 3-dimensional imaging setup allows us to measure the time evolution of the kinetic energy spectrum of electrons emitted from different clusters (W n - , C n - , C 60 ). Then we have a direct access to the fundamental quantities which characterize this statistical emission: the temperature of the finite heat bath and the decay rate. The second part concerns the ionization of atomic Rydberg states placed in a static electric field. We performed the first experiment of photoionization microscopy which allows us to obtain a picture which is the macroscopic projection of the electronic wave function. Then we have access to the detail of the photoionization and particularly to the quantum properties of the electron usually confined at the atomic scale. (author)

  18. Multi-cluster dynamics in CΛ13 and analogy to clustering in 12C

    Directory of Open Access Journals (Sweden)

    Y. Funaki

    2017-10-01

    Full Text Available We investigate structure of CΛ13 and discuss the difference and similarity between the structures of C12 and CΛ13 by answering the questions if the linear-chain and gaslike cluster states, which are proposed to appear in C12, survives, or new structure states appear or not. We introduce a microscopic cluster model called, Hyper-Tohsaki–Horiuchi–Schuck–Röpke (H-THSR wave function, which is an extended version of the THSR wave function so as to describe Λ hypernuclei. We obtained two bound states and two resonance (quasi-bound states for Jπ=0+ in CΛ13, corresponding to the four 0+ states in C12. However, the inversion of level ordering between the spectra of C12 and CΛ13, i.e. that the 03+ and 04+ states in CΛ13 correspond to the 04+ and 03+ states in C12, respectively, is shown to occur. The additional Λ particle reduces sizes of the 02+ and 03+ states in CΛ13 very much, but the shrinkage of the 04+ state is only a half of the other states, in spite of the fact that attractive Λ-N interaction makes nucleus contracted so much when the Λ particle occupies an S-orbit. In conclusion, the Hoyle state becomes quite a compact object with BeΛ9+α configuration in CΛ13 and is no more gaslike state composed of the 3α clusters. Instead, the 04+ state in CΛ13, coming from the C12(03+ state, appears as a gaslike state composed of α+α+Λ5He configuration, i.e. the Hoyle analog state. A linear-chain state in a Λ hypernucleus is for the first time predicted to exist as the 03+ state in CΛ13 with more shrunk arrangement of the 3α clusters along z-axis than the 3α linear-chain configuration realized in the C12(04+ state. All the excited states are shown to appear around the corresponding cluster-decay threshold, reflecting the threshold rule.

  19. EVOLUTION AND DISTRIBUTION OF MAGNETIC FIELDS FROM ACTIVE GALACTIC NUCLEI IN GALAXY CLUSTERS. II. THE EFFECTS OF CLUSTER SIZE AND DYNAMICAL STATE

    International Nuclear Information System (INIS)

    Xu Hao; Li Hui; Collins, David C.; Li, Shengtai; Norman, Michael L.

    2011-01-01

    Theory and simulations suggest that magnetic fields from radio jets and lobes powered by their central super massive black holes can be an important source of magnetic fields in the galaxy clusters. This is Paper II in a series of studies where we present self-consistent high-resolution adaptive mesh refinement cosmological magnetohydrodynamic simulations that simultaneously follow the formation of a galaxy cluster and evolution of magnetic fields ejected by an active galactic nucleus. We studied 12 different galaxy clusters with virial masses ranging from 1 x 10 14 to 2 x 10 15 M sun . In this work, we examine the effects of the mass and merger history on the final magnetic properties. We find that the evolution of magnetic fields is qualitatively similar to those of previous studies. In most clusters, the injected magnetic fields can be transported throughout the cluster and be further amplified by the intracluster medium (ICM) turbulence during the cluster formation process with hierarchical mergers, while the amplification history and the magnetic field distribution depend on the cluster formation and magnetism history. This can be very different for different clusters. The total magnetic energies in these clusters are between 4 x 10 57 and 10 61 erg, which is mainly decided by the cluster mass, scaling approximately with the square of the total mass. Dynamically older relaxed clusters usually have more magnetic fields in their ICM. The dynamically very young clusters may be magnetized weakly since there is not enough time for magnetic fields to be amplified.

  20. The meaning of healing: transcending suffering.

    Science.gov (United States)

    Egnew, Thomas R

    2005-01-01

    Medicine is traditionally considered a healing profession, but it has neither an operational definition of healing nor an explanation of its mechanisms beyond the physiological processes related to curing. The objective of this study was to determine a definition of healing that operationalizes its mechanisms and thereby identifies those repeatable actions that reliably assist physicians to promote holistic healing. This study was a qualitative inquiry consisting of in-depth, open-ended, semistructured interviews with Drs. Eric J. Cassell, Carl A. Hammerschlag, Thomas S. Inui, Elisabeth Kubler-Ross, Cicely Saunders, Bernard S. Siegel, and G. Gayle Stephens. Their perceptions regarding the definition and mechanisms of healing were subjected to grounded theory content analysis. Healing was associated with themes of wholeness, narrative, and spirituality. Healing is an intensely personal, subjective experience involving a reconciliation of the meaning an individual ascribes to distressing events with his or her perception of wholeness as a person. Healing may be operationally defined as the personal experience of the transcendence of suffering. Physicians can enhance their abilities as healers by recognizing, diagnosing, minimizing, and relieving suffering, as well as helping patients transcend suffering.

  1. Molecular dynamics simulation of nanoscale surface diffusion of heterogeneous adatoms clusters

    International Nuclear Information System (INIS)

    Imran, Muhammad; Hussain, Fayyaz; Ullah, Hafeez; Ahmad, Ejaz; Rashid, Muhammad; Ismail, Muhammad; Cai, Yongqing; Javid, M Arshad; Ahmad, S A

    2016-01-01

    Molecular dynamics simulation employing the embedded atom method potential is utilized to investigate nanoscale surface diffusion mechanisms of binary heterogeneous adatoms clusters at 300 K, 500 K, and 700 K. Surface diffusion of heterogeneous adatoms clusters can be vital for the binary island growth on the surface and can be useful for the formation of alloy-based thin film surface through atomic exchange process. The results of the diffusion process show that at 300 K, the diffusion of small adatoms clusters shows hopping, sliding, and shear motion; whereas for large adatoms clusters (hexamer and above), the diffusion is negligible. At 500 K, small adatoms clusters, i.e., dimer, show almost all possible diffusion mechanisms including the atomic exchange process; however no such exchange is observed for adatoms clusters greater than dimer. At 700 K, the exchange mechanism dominates for all types of clusters, where Zr adatoms show maximum tendency and Ag adatoms show minimum or no tendency toward the exchange process. Separation and recombination of one or more adatoms are also observed at 500 K and 700 K. The Ag adatoms also occupy pop-up positions over the adatoms clusters for short intervals. At 700 K, the vacancies are also generated in the vicinity of the adatoms cluster, vacancy formation, filling, and shifting can be observed from the results. (paper)

  2. Influence of system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Song, Y. L.; Huang, F., E-mail: huangfeng@cau.edu.cn [College of Science, China Agricultural University, Beijing 100083 (China); He, Y. F.; Wu, L. [College of Information and Electrical Engineering, China Agricultural University, Beijing 100083 (China); Liu, Y. H. [School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025 (China); Chen, Z. Y. [Department of Physics, Beijing University of Chemical Technology, Beijing 100029 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, D-44801 Bochum (Germany)

    2015-06-15

    Influence of the system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas is investigated through laboratory experiment and molecular dynamics simulation. The micro-structures, defect numbers, and pair correlation function of the dust clusters are studied for different system temperatures. The dust grains' trajectories, the mean square displacement, and the corresponding self-diffusion coefficient of the clusters are calculated for different temperatures for illustrating the phase properties of the dust clusters. The simulation results confirm that with the increase in system temperature, the micro-structures and dynamics of dust clusters are gradually changed, which qualitatively agree with experimental results.

  3. On dynamical evolution of the bright star subsystem in the Orion Sword cluster

    International Nuclear Information System (INIS)

    Dolgachev, V.P.; Kalinina, E.P.; Kholopov, P.N.

    1989-01-01

    With the help of numerical integration of the system of ordinary differential equations of the 102nd order, a possible dynamical evolution of the subsystem of 17 brightest stars in the Orion Sword open cluster has been examined in the interval of 20,1x10 6 years. In the process of transition through the region occupied by the cluster core taking place with a ''cycle'' of about 7 million years, the brightest stars of the cluster begin to concentrate mostly in the core region. Some of them acquire motions along elongated orbits, remaining during a long time in the limits of the cluster's corona, while one of stars is thrown away from the cluster with the hyperbolic velocity. Moreover, two wide pairs of stars are originating, which are analogous to those observed in the galactic field

  4. Evidence for feedback and stellar-dynamically regulated bursty star cluster formation: the case of the Orion Nebula Cluster

    Science.gov (United States)

    Kroupa, Pavel; Jeřábková, Tereza; Dinnbier, František; Beccari, Giacomo; Yan, Zhiqiang

    2018-04-01

    A scenario for the formation of multiple co-eval populations separated in age by about 1 Myr in very young clusters (VYCs, ages less than 10 Myr) and with masses in the range 600-20 000 M⊙ is outlined. It rests upon a converging inflow of molecular gas building up a first population of pre-main sequence stars. The associated just-formed O stars ionise the inflow and suppress star formation in the embedded cluster. However, they typically eject each other out of the embedded cluster within 106 yr, that is before the molecular cloud filament can be ionised entirely. The inflow of molecular gas can then resume forming a second population. This sequence of events can be repeated maximally over the life-time of the molecular cloud (about 10 Myr), but is not likely to be possible in VYCs with mass <300 M⊙, because such populations are not likely to contain an O star. Stellar populations heavier than about 2000 M⊙ are likely to have too many O stars for all of these to eject each other from the embedded cluster before they disperse their natal cloud. VYCs with masses in the range 600-2000 M⊙ are likely to have such multi-age populations, while VYCs with masses in the range 2000-20 000 M⊙ can also be composed solely of co-eval, mono-age populations. More massive VYCs are not likely to host sub-populations with age differences of about 1 Myr. This model is applied to the Orion Nebula Cluster (ONC), in which three well-separated pre-main sequences in the colour-magnitude diagram of the cluster have recently been discovered. The mass-inflow history is constrained using this model and the number of OB stars ejected from each population are estimated for verification using Gaia data. As a further consequence of the proposed model, the three runaway O star systems, AE Aur, μ Col and ι Ori, are considered as significant observational evidence for stellar-dynamical ejections of massive stars from the oldest population in the ONC. Evidence for stellar-dynamical

  5. Radiation-Induced Chemical Dynamics in Ar Clusters Exposed to Strong X-Ray Pulses

    Science.gov (United States)

    Kumagai, Yoshiaki; Jurek, Zoltan; Xu, Weiqing; Fukuzawa, Hironobu; Motomura, Koji; Iablonskyi, Denys; Nagaya, Kiyonobu; Wada, Shin-ichi; Mondal, Subhendu; Tachibana, Tetsuya; Ito, Yuta; Sakai, Tsukasa; Matsunami, Kenji; Nishiyama, Toshiyuki; Umemoto, Takayuki; Nicolas, Christophe; Miron, Catalin; Togashi, Tadashi; Ogawa, Kanade; Owada, Shigeki; Tono, Kensuke; Yabashi, Makina; Son, Sang-Kil; Ziaja, Beata; Santra, Robin; Ueda, Kiyoshi

    2018-06-01

    We show that electron and ion spectroscopy reveals the details of the oligomer formation in Ar clusters exposed to an x-ray free electron laser (XFEL) pulse, i.e., chemical dynamics triggered by x rays. With guidance from a dedicated molecular dynamics simulation tool, we find that van der Waals bonding, the oligomer formation mechanism, and charge transfer among the cluster constituents significantly affect ionization dynamics induced by an XFEL pulse of moderate fluence. Our results clearly demonstrate that XFEL pulses can be used not only to "damage and destroy" molecular assemblies but also to modify and transform their molecular structure. The accuracy of the predictions obtained makes it possible to apply the cluster spectroscopy, in connection with the respective simulations, for estimation of the XFEL pulse fluence in the fluence regime below single-atom multiple-photon absorption, which is hardly accessible with other diagnostic tools.

  6. Self-diffusion dynamic behavior of atomic clusters on Re(0 0 0 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Liu Fusheng [Department of Applied Physics, Hunan University, Changsha 410082 (China); Hu Wangyu, E-mail: wangyuhu2001cn@yahoo.com.cn [Department of Applied Physics, Hunan University, Changsha 410082 (China); Deng Huiqiu; Luo Wenhua; Xiao Shifang [Department of Applied Physics, Hunan University, Changsha 410082 (China); Yang Jianyu [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China)

    2009-08-15

    Using molecular dynamics simulations and a modified analytic embedded atom potential, the self-diffusion dynamics of rhenium atomic clusters up to seven atoms on Re(0 0 0 1) surface have been studied in the temperature ranges from 600 K to 1900 K. The simulation time varies from 20 ns to 200 ns according to the cluster sizes and the temperature. The heptamer and trimer are more stable comparing to other neighboring non-compact clusters. The diffusion coefficients of clusters are derived from the mean square displacement of cluster's mass-center, and diffusion prefactors D{sub 0} and activation energies E{sub a} are derived from the Arrhenius relation. It is found that the Arrhenius relation of the adatom can be divided into two parts at different temperature range. The activation energy of clusters increases with the increasing of the atom number in clusters. The prefactor of the heptamer is 2-3 orders of magnitude higher than a usual prefactor because of a large number of nonequivalent diffusion processes. The trimer and heptamer are the nuclei at different temperature range according to the nucleation theory.

  7. Wounded Leader: An Archetypal Embodiment of Compassionate Transcendent Leadership

    Science.gov (United States)

    Mears, Kathryn

    2009-01-01

    The purpose of this study was to seek to further the formation of the emerging transcendent leadership model by exploring the archetypal image identified as wounded leader. The wounded leader archetype is introduced as a leadership style of influence that fits well within the framework of the transcendent leadership model. This study…

  8. Approximate Solutions of Interactive Dynamic Influence Diagrams Using Model Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Doshi, Prashant; Qiongyu, Cheng

    2007-01-01

    Interactive dynamic influence diagrams (I-DIDs) offer a transparent and semantically clear representation for the sequential decision-making problem over multiple time steps in the presence of other interacting agents. Solving I-DIDs exactly involves knowing the solutions of possible models...

  9. Cavitation cluster dynamics in shock-wave lithotripsy: Part I

    NARCIS (Netherlands)

    Arora, M.; Junge, L.; Junge, L.; Ohl, C.D.

    2005-01-01

    The spatiotemporal dynamics of cavitation bubble growth and collapse in shock-wave lithotripsy in a free field was studied experimentally. The lithotripter was equipped with two independently triggerable layers of piezoceramics. The front and back layers generated positive pressure amplitudes of 30

  10. RSAT matrix-clustering: dynamic exploration and redundancy reduction of transcription factor binding motif collections.

    Science.gov (United States)

    Castro-Mondragon, Jaime Abraham; Jaeger, Sébastien; Thieffry, Denis; Thomas-Chollier, Morgane; van Helden, Jacques

    2017-07-27

    Transcription factor (TF) databases contain multitudes of binding motifs (TFBMs) from various sources, from which non-redundant collections are derived by manual curation. The advent of high-throughput methods stimulated the production of novel collections with increasing numbers of motifs. Meta-databases, built by merging these collections, contain redundant versions, because available tools are not suited to automatically identify and explore biologically relevant clusters among thousands of motifs. Motif discovery from genome-scale data sets (e.g. ChIP-seq) also produces redundant motifs, hampering the interpretation of results. We present matrix-clustering, a versatile tool that clusters similar TFBMs into multiple trees, and automatically creates non-redundant TFBM collections. A feature unique to matrix-clustering is its dynamic visualisation of aligned TFBMs, and its capability to simultaneously treat multiple collections from various sources. We demonstrate that matrix-clustering considerably simplifies the interpretation of combined results from multiple motif discovery tools, and highlights biologically relevant variations of similar motifs. We also ran a large-scale application to cluster ∼11 000 motifs from 24 entire databases, showing that matrix-clustering correctly groups motifs belonging to the same TF families, and drastically reduced motif redundancy. matrix-clustering is integrated within the RSAT suite (http://rsat.eu/), accessible through a user-friendly web interface or command-line for its integration in pipelines. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

    Directory of Open Access Journals (Sweden)

    Muthukkumar R.

    2017-04-01

    Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

  12. Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

    Directory of Open Access Journals (Sweden)

    Muthukkumar R.

    2016-07-01

    Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

  13. Condensation and dissociation rates for gas phase metal clusters from molecular dynamics trajectory calculations

    Science.gov (United States)

    Yang, Huan; Goudeli, Eirini; Hogan, Christopher J.

    2018-04-01

    In gas phase synthesis systems, clusters form and grow via condensation, in which a monomer binds to an existing cluster. While a hard-sphere equation is frequently used to predict the condensation rate coefficient, this equation neglects the influences of potential interactions and cluster internal energy on the condensation process. Here, we present a collision rate theory-molecular dynamics simulation approach to calculate condensation probabilities and condensation rate coefficients. We use this approach to examine atomic condensation onto 6-56-atom Au and Mg clusters. The probability of condensation depends upon the initial relative velocity (v) between atom and cluster and the initial impact parameter (b). In all cases, there is a well-defined region of b-v space where condensation is highly probable, and outside of which the condensation probability drops to zero. For Au clusters with more than 10 atoms, we find that at gas temperatures in the 300-1200 K range, the condensation rate coefficient exceeds the hard-sphere rate coefficient by a factor of 1.5-2.0. Conversely, for Au clusters with 10 or fewer atoms and for 14- and 28-atom Mg clusters, as cluster equilibration temperature increases, the condensation rate coefficient drops to values below the hard-sphere rate coefficient. Calculations also yield the self-dissociation rate coefficient, which is found to vary considerably with gas temperature. Finally, calculations results reveal that grazing (high b) atom-cluster collisions at elevated velocity (>1000 m s-1) can result in the colliding atom rebounding (bounce) from the cluster surface or binding while another atom dissociates (replacement). The presented method can be applied in developing rate equations to predict material formation and growth rates in vapor phase systems.

  14. Antisymmetrized molecular dynamics studies for exotic clustering phenomena in neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M. [Hokkaido University, Department of Physics, Sapporo (Japan); Hokkaido University, Nuclear Reaction Data Centre, Faculty of Science, Sapporo (Japan); Suhara, T. [Matsue College of Technology, Matsue (Japan); Kanada-En' yo, Y. [Kyoto University, Department of Physics, Kyoto (Japan)

    2016-12-15

    We present a review of recent works on clustering phenomena in unstable nuclei studied by antisymmetrized molecular dynamics (AMD). The AMD studies in these decades have uncovered novel types of clustering phenomena brought about by the excess neutrons. Among them, this review focuses on the molecule-like structure of unstable nuclei. One of the earliest discussions on the clustering in unstable nuclei was made for neutron-rich Be and B isotopes. AMD calculations predicted that the ground state clustering is enhanced or reduced depending on the number of excess neutrons. Today, the experiments are confirming this prediction as the change of the proton radii. Behind this enhancement and reduction of the clustering, there are underlying shell effects called molecular and atomic orbits. These orbits form covalent and ionic bonding of the clusters analogous to the atomic molecules. It was found that this ''molecular-orbit picture'' reasonably explains the low-lying spectra of Be isotopes. The molecular-orbit picture is extended to other systems having parity asymmetric cluster cores and to the three cluster systems. O and Ne isotopes are the candidates of the former, while the 3α linear chains in C isotopes are the latter. For both subjects, many intensive studies are now in progress. We also pay a special attention to the observables which are the fingerprint of the clustering. In particular, we focus on the monopole and dipole transitions which are recently regarded as good probe for the clustering. We discuss how they have and will reveal the exotic clustering. (orig.)

  15. HIV, self-transcendence, and quality of life.

    Science.gov (United States)

    Mellors, M P; Riley, T A; Erlen, J A

    1997-01-01

    Self-transcendence is a developmental characteristic that expands one's boundaries of the self to take on broader life perspectives, activities, and purposes that help one discover or make meaning of one's life. However, no quantitative studies were found in the research literature that focused on self-transcendence or on the relationship between self-transcendence and quality of life in people infected with HIV. To examine these variables in this population, 46 HIV-positive subjects completed Reed's Self-Transcendence Scale and Ferrans and Powers' Quality of Life Index. The results demonstrated that overall self-transcendence for this sample was relatively high; quality of life was higher than that reported in previous research; and there were some significant group differences among the three HIV clinical categories.

  16. Dynamics analysis of SIR epidemic model with correlation coefficients and clustering coefficient in networks.

    Science.gov (United States)

    Zhang, Juping; Yang, Chan; Jin, Zhen; Li, Jia

    2018-07-14

    In this paper, the correlation coefficients between nodes in states are used as dynamic variables, and we construct SIR epidemic dynamic models with correlation coefficients by using the pair approximation method in static networks and dynamic networks, respectively. Considering the clustering coefficient of the network, we analytically investigate the existence and the local asymptotic stability of each equilibrium of these models and derive threshold values for the prevalence of diseases. Additionally, we obtain two equivalent epidemic thresholds in dynamic networks, which are compared with the results of the mean field equations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Static and dynamic properties of two-dimensional Coulomb clusters.

    Science.gov (United States)

    Ash, Biswarup; Chakrabarti, J; Ghosal, Amit

    2017-10-01

    We study the temperature dependence of static and dynamic responses of Coulomb interacting particles in two-dimensional confinements across the crossover from solid- to liquid-like behaviors. While static correlations that investigate the translational and bond orientational order in the confinements show the footprints of hexatic-like phase at low temperatures, dynamics of the particles slow down considerably in this phase, reminiscent of a supercooled liquid. Using density correlations, we probe long-lived heterogeneities arising from the interplay of the irregularity in the confinement and long-range Coulomb interactions. The relaxation at multiple time scales show stretched-exponential decay of spatial correlations in irregular traps. Temperature dependence of characteristic time scales, depicting the structural relaxation of the system, show striking similarities with those observed for the glassy systems, indicating that some of the key signatures of supercooled liquids emerge in confinements with lower spatial symmetries.

  18. Photodissociation spectroscopy and dynamics of free radicals, clusters, and ions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeon [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    The photodissociation spectroscopy and dynamics of free radicals and ions is studied to characterize the dissociative electronic states in these species. To accomplish this, a special method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with the technique of fast beam photofragment translational spectroscopy. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states. Branching ratios to various product channels, the translational energy distributions of the fragments, and bond dissociation energies are then determined at selected photon energies. The detailed picture of photodissociation dynamics is provided with the aid of ab initio calculations and a statistical model to interpret the observed data. Important reaction intermediates in combustion reactions have been studied: CCO, C2H5O, and linear Cn (n = 4--6).

  19. The Dynamical Evolution of Stellar-Mass Black Holes in Dense Star Clusters

    Science.gov (United States)

    Morscher, Maggie

    Globular clusters are gravitationally bound systems containing up to millions of stars, and are found ubiquitously in massive galaxies, including the Milky Way. With densities as high as a million stars per cubic parsec, they are one of the few places in the Universe where stars interact with one another. They therefore provide us with a unique laboratory for studying how gravitational interactions can facilitate the formation of exotic systems, such as X-ray binaries containing black holes, and merging double black hole binaries, which are produced much less efficiently in isolation. While telescopes can provide us with a snapshot of what these dense clusters look like at present, we must rely on detailed numerical simulations to learn about their evolution. These simulations are quite challenging, however, since dense star clusters are described by a complicated set of physical processes occurring on many different length and time scales, including stellar and binary evolution, weak gravitational scattering encounters, strong resonant binary interactions, and tidal stripping by the host galaxy. Until very recently, it was not possible to model the evolution of systems with millions of stars, the actual number contained in the largest clusters, including all the relevant physics required describe these systems accurately. The Northwestern Group's Henon Monte Carlo code, CMC, which has been in development for over a decade, is a powerful tool that can be used to construct detailed evolutionary models of large star clusters. With its recent parallelization, CMC is now capable of addressing a particularly interesting unsolved problem in astrophysics: the dynamical evolution of stellar black holes in dense star clusters. Our current understanding of the stellar initial mass function and massive star evolution suggests that young globular clusters may have formed hundreds to thousands of stellar-mass black holes, the remnants of stars with initial masses from 20 - 100

  20. clusters

    Indian Academy of Sciences (India)

    2017-09-27

    Sep 27, 2017 ... Author for correspondence (zh4403701@126.com). MS received 15 ... lic clusters using density functional theory (DFT)-GGA of the DMOL3 package. ... In the process of geometric optimization, con- vergence thresholds ..... and Postgraduate Research & Practice Innovation Program of. Jiangsu Province ...

  1. clusters

    Indian Academy of Sciences (India)

    environmental as well as technical problems during fuel gas utilization. ... adsorption on some alloys of Pd, namely PdAu, PdAg ... ried out on small neutral and charged Au24,26,27, Cu,28 ... study of Zanti et al.29 on Pdn (n = 1–9) clusters.

  2. Fast optimization of binary clusters using a novel dynamic lattice searching method

    International Nuclear Information System (INIS)

    Wu, Xia; Cheng, Wen

    2014-01-01

    Global optimization of binary clusters has been a difficult task despite of much effort and many efficient methods. Directing toward two types of elements (i.e., homotop problem) in binary clusters, two classes of virtual dynamic lattices are constructed and a modified dynamic lattice searching (DLS) method, i.e., binary DLS (BDLS) method, is developed. However, it was found that the BDLS can only be utilized for the optimization of binary clusters with small sizes because homotop problem is hard to be solved without atomic exchange operation. Therefore, the iterated local search (ILS) method is adopted to solve homotop problem and an efficient method based on the BDLS method and ILS, named as BDLS-ILS, is presented for global optimization of binary clusters. In order to assess the efficiency of the proposed method, binary Lennard-Jones clusters with up to 100 atoms are investigated. Results show that the method is proved to be efficient. Furthermore, the BDLS-ILS method is also adopted to study the geometrical structures of (AuPd) 79 clusters with DFT-fit parameters of Gupta potential

  3. Mobility of hydrogen-helium clusters in tungsten studied by molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Grigorev, Petr, E-mail: grigorievpit@gmail.com [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol, 2400 (Belgium); Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnologies, and Telecommunications, Peter the Great St.Petersburg Polytechnic University, St. Petersburg (Russian Federation); Terentyev, Dmitry; Bonny, Giovanni [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol, 2400 (Belgium); Zhurkin, Evgeny E. [Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnologies, and Telecommunications, Peter the Great St.Petersburg Polytechnic University, St. Petersburg (Russian Federation); Oost, Guido van [Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Noterdaeme, Jean-Marie [Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2016-06-15

    Tungsten is a primary candidate material for plasma facing components in fusion reactors. Interaction of plasma components with the material is unavoidable and will lead to degradation of the performance and the lifetime of the in-vessel components. In order to gain better understanding the mechanisms driving the material degradation at atomic level, atomistic simulations are employed. In this work we study migration, stability and self-trapping properties of pure helium and mixed helium-hydrogen clusters in tungsten by means of molecular dynamics simulations. We test two versions of an embedded atom model interatomic potential by comparing it with ab initio data regarding the binding properties of He clusters. By analysing the trajectories of the clusters during molecular dynamics simulations at finite temperatures we obtain the diffusion parameters. The results show that the diffusivity of mixed clusters is significantly lower, than that of pure helium clusters. The latter suggest that the formation of mixed clusters during mixed hydrogen helium plasma exposure will affect the helium diffusivity in the material.

  4. Cluster-based Dynamic Energy Management for Collaborative Target Tracking in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-07-01

    Full Text Available A primary criterion of wireless sensor network is energy efficiency. Focused onthe energy problem of target tracking in wireless sensor networks, this paper proposes acluster-based dynamic energy management mechanism. Target tracking problem isformulated by the multi-sensor detection model as well as energy consumption model. Adistributed adaptive clustering approach is investigated to form a reasonable routingframework which has uniform cluster head distribution. Dijkstra’s algorithm is utilized toobtain optimal intra-cluster routing. Target position is predicted by particle filter. Thepredicted target position is adopted to estimate the idle interval of sensor nodes. Hence,dynamic awakening approach is exploited to prolong sleep time of sensor nodes so that theoperation energy consumption of wireless sensor network can be reduced. The sensornodes around the target wake up on time and act as sensing candidates. With the candidatesensor nodes and predicted target position, the optimal sensor node selection is considered.Binary particle swarm optimization is proposed to minimize the total energy consumptionduring collaborative sensing and data reporting. Experimental results verify that theproposed clustering approach establishes a low-energy communication structure while theenergy efficiency of wireless sensor networks is enhanced by cluster-based dynamic energymanagement.

  5. Dynamics of the baryonic component in hierarchical clustering universes

    Science.gov (United States)

    Navarro, Julio

    1993-01-01

    I present self-consistent 3-D simulations of the formation of virialized systems containing both gas and dark matter in a flat universe. A fully Lagrangian code based on the Smoothed Particle Hydrodynamics technique and a tree data structure has been used to evolve regions of comoving radius 2-3 Mpc. Tidal effects are included by coarse-sampling the density of the outer regions up to a radius approx. 20 Mpc. Initial conditions are set at high redshift (z greater than 7) using a standard Cold Dark Matter perturbation spectrum and a baryon mass fraction of 10 percent (omega(sub b) = 0.1). Simulations in which the gas evolves either adiabatically or radiates energy at a rate determined locally by its cooling function were performed. This allows us to investigate with the same set of simulations the importance of radiative losses in the formation of galaxies and the equilibrium structure of virialized systems where cooling is very inefficient. In the absence of radiative losses, the simulations can be rescaled to the density and radius typical of galaxy clusters. A summary of the main results is presented.

  6. Space and time dynamical heterogeneity in glassy relaxation. The role of democratic clusters

    International Nuclear Information System (INIS)

    Appignanesi, G A; Rodriguez Fris, J A

    2009-01-01

    In this work we review recent computational advances in the understanding of the relaxation dynamics of supercooled glass-forming liquids. In such a supercooled regime these systems experience a striking dynamical slowing down which can be rationalized in terms of the picture of dynamical heterogeneities, wherein the dynamics can vary by orders of magnitude from one region of the sample to another and where the sizes and timescales of such slowly relaxing regions are expected to increase considerably as the temperature is decreased. We shall focus on the relaxation events at a microscopic level and describe the finding of the collective motions of particles responsible for the dynamical heterogeneities. In so doing, we shall demonstrate that the dynamics in different regions of the system is not only heterogeneous in space but also in time. In particular, we shall be interested in the events relevant to the long-time structural relaxation or α relaxation. In this regard, we shall focus on the discovery of cooperatively relaxing units involving the collective motion of relatively compact clusters of particles, called 'democratic clusters' or d-clusters. These events have been shown to trigger transitions between metabasins of the potential energy landscape (collections of similar configurations or structures) and to consist of the main steps in the α relaxation. Such events emerge in systems quite different in nature such as simple model glass formers and supercooled amorphous water. Additionally, another relevant issue in this context consists in the determination of a link between structure and dynamics. In this context, we describe the relationship between the d-cluster events and the constraints that the local structure poses on the relaxation dynamics, thus revealing their role in reformulating structural constraints. (topical review)

  7. Water droplet excess free energy determined by cluster mitosis using guided molecular dynamics

    Science.gov (United States)

    Lau, Gabriel V.; Hunt, Patricia A.; Müller, Erich A.; Jackson, George; Ford, Ian J.

    2015-12-01

    Atmospheric aerosols play a vital role in affecting climate by influencing the properties and lifetimes of clouds and precipitation. Understanding the underlying microscopic mechanisms involved in the nucleation of aerosol droplets from the vapour phase is therefore of great interest. One key thermodynamic quantity in nucleation is the excess free energy of cluster formation relative to that of the saturated vapour. In our current study, the excess free energy is extracted for clusters of pure water modelled with the TIP4P/2005 intermolecular potential using a method based on nonequilibrium molecular dynamics and the Jarzynski relation. The change in free energy associated with the "mitosis" or division of a cluster of N water molecules into two N/2 sub-clusters is evaluated. This methodology is an extension of the disassembly procedure used recently to calculate the excess free energy of argon clusters [H. Y. Tang and I. J. Ford, Phys. Rev. E 91, 023308 (2015)]. Our findings are compared to the corresponding excess free energies obtained from classical nucleation theory (CNT) as well as internally consistent classical theory (ICCT). The values of the excess free energy that we obtain with the mitosis method are consistent with CNT for large cluster sizes but for the smallest clusters, the results tend towards ICCT; for intermediate sized clusters, we obtain values between the ICCT and CNT predictions. Furthermore, the curvature-dependent surface tension which can be obtained by regarding the clusters as spherical droplets of bulk density is found to be a monotonically increasing function of cluster size for the studied range. The data are compared to other values reported in the literature, agreeing qualitatively with some but disagreeing with the values determined by Joswiak et al. [J. Phys. Chem. Lett. 4, 4267 (2013)] using a biased mitosis approach; an assessment of the differences is the main motivation for our current study.

  8. Water droplet excess free energy determined by cluster mitosis using guided molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Gabriel V.; Müller, Erich A.; Jackson, George [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Hunt, Patricia A. [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Ford, Ian J. [Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2015-12-28

    Atmospheric aerosols play a vital role in affecting climate by influencing the properties and lifetimes of clouds and precipitation. Understanding the underlying microscopic mechanisms involved in the nucleation of aerosol droplets from the vapour phase is therefore of great interest. One key thermodynamic quantity in nucleation is the excess free energy of cluster formation relative to that of the saturated vapour. In our current study, the excess free energy is extracted for clusters of pure water modelled with the TIP4P/2005 intermolecular potential using a method based on nonequilibrium molecular dynamics and the Jarzynski relation. The change in free energy associated with the “mitosis” or division of a cluster of N water molecules into two N/2 sub-clusters is evaluated. This methodology is an extension of the disassembly procedure used recently to calculate the excess free energy of argon clusters [H. Y. Tang and I. J. Ford, Phys. Rev. E 91, 023308 (2015)]. Our findings are compared to the corresponding excess free energies obtained from classical nucleation theory (CNT) as well as internally consistent classical theory (ICCT). The values of the excess free energy that we obtain with the mitosis method are consistent with CNT for large cluster sizes but for the smallest clusters, the results tend towards ICCT; for intermediate sized clusters, we obtain values between the ICCT and CNT predictions. Furthermore, the curvature-dependent surface tension which can be obtained by regarding the clusters as spherical droplets of bulk density is found to be a monotonically increasing function of cluster size for the studied range. The data are compared to other values reported in the literature, agreeing qualitatively with some but disagreeing with the values determined by Joswiak et al. [J. Phys. Chem. Lett. 4, 4267 (2013)] using a biased mitosis approach; an assessment of the differences is the main motivation for our current study.

  9. Dynamics and molecular determinants of cytoplasmic lipid droplet clustering and dispersion.

    Directory of Open Access Journals (Sweden)

    David J Orlicky

    Full Text Available Perilipin-1 (Plin1, a prominent cytoplasmic lipid droplet (CLD binding phosphoprotein and key physiological regulator of triglyceride storage and lipolysis in adipocytes, is thought to regulate the fragmentation and dispersion of CLD that occurs in response to β-adrenergic activation of adenylate cyclase. Here we investigate the dynamics and molecular determinants of these processes using cell lines stably expressing recombinant forms of Plin1 and/or other members of the perilipin family. Plin1 and a C-terminal CLD-binding fragment of Plin1 (Plin1CT induced formation of single dense CLD clusters near the microtubule organizing center, whereas neither an N-terminal CLD-binding fragment of Plin1, nor Plin2 or Plin3 induced clustering. Clustered CLD coated by Plin1, or Plin1CT, dispersed in response to isoproterenol, or other agents that activate adenylate cyclase, in a process inhibited by the protein kinase A inhibitor, H89, and blocked by microtubule disruption. Isoproterenol-stimulated phosphorylation of CLD-associated Plin1 on serine 492 preceded their dispersion, and live cell imaging showed that cluster dispersion involved initial fragmentation of tight clusters into multiple smaller clusters, which then fragmented into well-dispersed individual CLD. siRNA knockdown of the cortical actin binding protein, moesin, induced disaggregation of tight clusters into multiple smaller clusters, and inhibited the reaggregation of dispersed CLD into tight clusters. Together these data suggest that the clustering and dispersion processes involve a complex orchestration of phosphorylation-dependent, microtubule-dependent and independent, and microfilament dependent steps.

  10. Dynamics and molecular determinants of cytoplasmic lipid droplet clustering and dispersion.

    Science.gov (United States)

    Orlicky, David J; Monks, Jenifer; Stefanski, Adrianne L; McManaman, James L

    2013-01-01

    Perilipin-1 (Plin1), a prominent cytoplasmic lipid droplet (CLD) binding phosphoprotein and key physiological regulator of triglyceride storage and lipolysis in adipocytes, is thought to regulate the fragmentation and dispersion of CLD that occurs in response to β-adrenergic activation of adenylate cyclase. Here we investigate the dynamics and molecular determinants of these processes using cell lines stably expressing recombinant forms of Plin1 and/or other members of the perilipin family. Plin1 and a C-terminal CLD-binding fragment of Plin1 (Plin1CT) induced formation of single dense CLD clusters near the microtubule organizing center, whereas neither an N-terminal CLD-binding fragment of Plin1, nor Plin2 or Plin3 induced clustering. Clustered CLD coated by Plin1, or Plin1CT, dispersed in response to isoproterenol, or other agents that activate adenylate cyclase, in a process inhibited by the protein kinase A inhibitor, H89, and blocked by microtubule disruption. Isoproterenol-stimulated phosphorylation of CLD-associated Plin1 on serine 492 preceded their dispersion, and live cell imaging showed that cluster dispersion involved initial fragmentation of tight clusters into multiple smaller clusters, which then fragmented into well-dispersed individual CLD. siRNA knockdown of the cortical actin binding protein, moesin, induced disaggregation of tight clusters into multiple smaller clusters, and inhibited the reaggregation of dispersed CLD into tight clusters. Together these data suggest that the clustering and dispersion processes involve a complex orchestration of phosphorylation-dependent, microtubule-dependent and independent, and microfilament dependent steps.

  11. Melting behaviour of gold-platinum nanoalloy clusters by molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Yee Pin; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)

    2015-04-24

    The melting behavior of bimetallic gold-platinum nanoclusters is studied by applying Brownian-type isothermal molecular dynamics (MD) simulation, a program modified from the cubic coupling scheme (CCS). The process begins with the ground-state structures obtained from global minimum search algorithm and proceeds with the investigation of the effect of temperature on the thermal properties of gold-platinum nanoalloy clusters. N-body Gupta potential has been employed in order to account for the interactions between gold and platinum atoms. The ground states of the nanoalloy clusters, which are core-shell segregated, are heated until they become thermally segregated. The detailed melting mechanism of the nanoalloy clusters is studied via this approach to provide insight into the thermal stability of the nanoalloy clusters.

  12. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2016-07-01

    Full Text Available The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2On after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects.

  13. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

    Science.gov (United States)

    Li, Zheng; Vendrell, Oriol

    2016-01-01

    The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects. PMID:26798842

  14. Dynamic stabilities of icosahedral-like clusters and their ability to form quasicrystals

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xiaogang; Hamid, Ilyar; Duan, Haiming, E-mail: dhm@xju.edu.cn [College of Physics Science and Technology. Xinjiang University, Urumqi 830046 (China)

    2016-06-15

    The dynamic stabilities of the icosahedral-like clusters containing up to 2200 atoms are investigated for 15 metal elements. The clusters originate from five different initial structures (icosahedron, truncated decahedron, octahedron, closed-shell fragment of an HCP structure, and non-closed-shell fragment of an HCP structure). The obtained order of the dynamic stabilities of the icosahedral-like clusters can be assigned to three groups, from stronger to weaker, according to the size ranges involved: (Zr, Al, Ti) > (Cu, Fe, Co, Ni, Mg, Ag) > (Pb, Au, Pd, Pt, Rh, Ir), which correspond to the predicted formation ability of the quasicrystals. The differences of the sequences can be explained by analyzing the parameters of the Gupta-type many-body inter-atomic potentials.

  15. Experimental and theoretical investigation of the magnetization dynamics of an artificial square spin ice cluster

    Energy Technology Data Exchange (ETDEWEB)

    Pohlit, Merlin, E-mail: pohlit@physik.uni-frankfurt.de; Porrati, Fabrizio; Huth, Michael; Müller, Jens [Institute of Physics, Goethe-University Frankfurt, Frankfurt/Main (Germany); Stockem, Irina; Schröder, Christian [Bielefeld Institute for Applied Materials Research, FH Bielefeld-University of Applied Sciences, Bielefeld (Germany)

    2016-10-14

    We study the magnetization dynamics of a spin ice cluster which is a building block of an artificial square spin ice fabricated by focused electron-beam-induced deposition both experimentally and theoretically. The spin ice cluster is composed of twelve interacting Co nanoislands grown directly on top of a high-resolution micro-Hall sensor. By employing micromagnetic simulations and a macrospin model, we calculate the magnetization and the experimentally investigated stray field emanating from a single nanoisland. The parameters determined from a comparison with the experimental hysteresis loop are used to derive an effective single-dipole macrospin model that allows us to investigate the dynamics of the spin ice cluster. Our model reproduces the experimentally observed non-deterministic sequences in the magnetization curves as well as the distinct temperature dependence of the hysteresis loop.

  16. Stopping dynamics of ions passing through correlated honeycomb clusters

    Science.gov (United States)

    Balzer, Karsten; Schlünzen, Niclas; Bonitz, Michael

    2016-12-01

    A combined nonequilibrium Green functions-Ehrenfest dynamics approach is developed that allows for a time-dependent study of the energy loss of a charged particle penetrating a strongly correlated system at zero and finite temperatures. Numerical results are presented for finite inhomogeneous two-dimensional Fermi-Hubbard models, where the many-electron dynamics in the target are treated fully quantum mechanically and the motion of the projectile is treated classically. The simulations are based on the solution of the two-time Dyson (Keldysh-Kadanoff-Baym) equations using the second-order Born, third-order, and T -matrix approximations of the self-energy. As application, we consider protons and helium nuclei with a kinetic energy between 1 and 500 keV/u passing through planar fragments of the two-dimensional honeycomb lattice and, in particular, examine the influence of electron-electron correlations on the energy exchange between projectile and electron system. We investigate the time dependence of the projectile's kinetic energy (stopping power), the electron density, the double occupancy, and the photoemission spectrum. Finally, we show that, for a suitable choice of the Hubbard model parameters, the results for the stopping power are in fair agreement with ab initio simulations for particle irradiation of single-layer graphene.

  17. Incremental fuzzy C medoids clustering of time series data using dynamic time warping distance

    Science.gov (United States)

    Chen, Jingli; Wu, Shuai; Liu, Zhizhong; Chao, Hao

    2018-01-01

    Clustering time series data is of great significance since it could extract meaningful statistics and other characteristics. Especially in biomedical engineering, outstanding clustering algorithms for time series may help improve the health level of people. Considering data scale and time shifts of time series, in this paper, we introduce two incremental fuzzy clustering algorithms based on a Dynamic Time Warping (DTW) distance. For recruiting Single-Pass and Online patterns, our algorithms could handle large-scale time series data by splitting it into a set of chunks which are processed sequentially. Besides, our algorithms select DTW to measure distance of pair-wise time series and encourage higher clustering accuracy because DTW could determine an optimal match between any two time series by stretching or compressing segments of temporal data. Our new algorithms are compared to some existing prominent incremental fuzzy clustering algorithms on 12 benchmark time series datasets. The experimental results show that the proposed approaches could yield high quality clusters and were better than all the competitors in terms of clustering accuracy. PMID:29795600

  18. Incremental fuzzy C medoids clustering of time series data using dynamic time warping distance.

    Science.gov (United States)

    Liu, Yongli; Chen, Jingli; Wu, Shuai; Liu, Zhizhong; Chao, Hao

    2018-01-01

    Clustering time series data is of great significance since it could extract meaningful statistics and other characteristics. Especially in biomedical engineering, outstanding clustering algorithms for time series may help improve the health level of people. Considering data scale and time shifts of time series, in this paper, we introduce two incremental fuzzy clustering algorithms based on a Dynamic Time Warping (DTW) distance. For recruiting Single-Pass and Online patterns, our algorithms could handle large-scale time series data by splitting it into a set of chunks which are processed sequentially. Besides, our algorithms select DTW to measure distance of pair-wise time series and encourage higher clustering accuracy because DTW could determine an optimal match between any two time series by stretching or compressing segments of temporal data. Our new algorithms are compared to some existing prominent incremental fuzzy clustering algorithms on 12 benchmark time series datasets. The experimental results show that the proposed approaches could yield high quality clusters and were better than all the competitors in terms of clustering accuracy.

  19. Analyzing Dynamic Probabilistic Risk Assessment Data through Topology-Based Clustering

    Energy Technology Data Exchange (ETDEWEB)

    Diego Mandelli; Dan Maljovec; BeiWang; Valerio Pascucci; Peer-Timo Bremer

    2013-09-01

    We investigate the use of a topology-based clustering technique on the data generated by dynamic event tree methodologies. The clustering technique we utilizes focuses on a domain-partitioning algorithm based on topological structures known as the Morse-Smale complex, which partitions the data points into clusters based on their uniform gradient flow behavior. We perform both end state analysis and transient analysis to classify the set of nuclear scenarios. We demonstrate our methodology on a dataset generated for a sodium-cooled fast reactor during an aircraft crash scenario. The simulation tracks the temperature of the reactor as well as the time for a recovery team to fix the passive cooling system. Combined with clustering results obtained previously through mean shift methodology, we present the user with complementary views of the data that help illuminate key features that may be otherwise hidden using a single methodology. By clustering the data, the number of relevant test cases to be selected for further analysis can be drastically reduced by selecting a representative from each cluster. Identifying the similarities of simulations within a cluster can also aid in the drawing of important conclusions with respect to safety analysis.

  20. Oxidation of ligand-protected aluminum clusters: An ab initio molecular dynamics study

    International Nuclear Information System (INIS)

    Alnemrat, Sufian; Hooper, Joseph P.

    2014-01-01

    We report Car-Parrinello molecular dynamics simulations of the oxidation of ligand-protected aluminum clusters that form a prototypical cluster-assembled material. These clusters contain a small aluminum core surrounded by a monolayer of organic ligand. The aromatic cyclopentadienyl ligands form a strong bond with surface Al atoms, giving rise to an organometallic cluster that crystallizes into a low-symmetry solid and is briefly stable in air before oxidizing. Our calculations of isolated aluminum/cyclopentadienyl clusters reacting with oxygen show minimal reaction between the ligand and O 2 molecules at simulation temperatures of 500 and 1000 K. In all cases, the reaction pathway involves O 2 diffusing through the ligand barrier, splitting into atomic oxygen upon contact with the aluminum, and forming an oxide cluster with aluminum/ligand bonds still largely intact. Loss of individual aluminum-ligand units, as expected from unimolecular decomposition calculations, is not observed except following significant oxidation. These calculations highlight the role of the ligand in providing a steric barrier against oxidizers and in maintaining the large aluminum surface area of the solid-state cluster material

  1. PoD: dynamically create and use remote PROOF clusters. A thin client concept.

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    PoD’s newly developed “pod-remote” command made it possible for users to utilize a thin client concept. In order to create dynamic PROOF clusters, users are now able to select a remote computer, even behind a firewall, to control a PoD server on...

  2. Semiclassical Hybrid Approach to Condensed Phase Molecular Dynamics: Application to the I2Kr17 Cluster

    Czech Academy of Sciences Publication Activity Database

    Buchholz, M.; Goletz, Ch. M.; Grossman, F.; Schmidt, B.; Heyda, J.; Jungwirth, Pavel

    2012-01-01

    Roč. 116, č. 46 (2012), s. 11199-11210 ISSN 1089-5639 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : semiclassical molecular dynamics * cluster * wavepacket * coherence * spectra Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.771, year: 2012

  3. Dynamical resonance shift and unification of resonances in short-pulse laser-cluster interaction

    Science.gov (United States)

    Mahalik, S. S.; Kundu, M.

    2018-06-01

    Pronounced maximum absorption of laser light irradiating a rare-gas or metal cluster is widely expected during the linear resonance (LR) when Mie-plasma wavelength λM of electrons equals the laser wavelength λ . On the contrary, by performing molecular dynamics (MD) simulations of an argon cluster irradiated by short 5-fs (FWHM) laser pulses it is revealed that, for a given laser pulse energy and a cluster, at each peak intensity there exists a λ —shifted from the expected λM—that corresponds to a unified dynamical LR at which evolution of the cluster happens through very efficient unification of possible resonances in various stages, including (i) the LR in the initial time of plasma creation, (ii) the LR in the Coulomb expanding phase in the later time, and (iii) anharmonic resonance in the marginally overdense regime for a relatively longer pulse duration, leading to maximum laser absorption accompanied by maximum removal of electrons from cluster and also maximum allowed average charge states for the argon cluster. Increasing the laser intensity, the absorption maxima is found to shift to a higher wavelength in the band of λ ≈(1 -1.5 ) λM than permanently staying at the expected λM. A naive rigid sphere model also corroborates the wavelength shift of the absorption peak as found in MD and unequivocally proves that maximum laser absorption in a cluster happens at a shifted λ in the marginally overdense regime of λ ≈(1 -1.5 ) λM instead of λM of LR. The present study is important for guiding an optimal condition laser-cluster interaction experiment in the short-pulse regime.

  4. The dynamics of cyclone clustering in re-analysis and a high-resolution climate model

    Science.gov (United States)

    Priestley, Matthew; Pinto, Joaquim; Dacre, Helen; Shaffrey, Len

    2017-04-01

    Extratropical cyclones have a tendency to occur in groups (clusters) in the exit of the North Atlantic storm track during wintertime, potentially leading to widespread socioeconomic impacts. The Winter of 2013/14 was the stormiest on record for the UK and was characterised by the recurrent clustering of intense extratropical cyclones. This clustering was associated with a strong, straight and persistent North Atlantic 250 hPa jet with Rossby wave-breaking (RWB) on both flanks, pinning the jet in place. Here, we provide for the first time an analysis of all clustered events in 36 years of the ERA-Interim Re-analysis at three latitudes (45˚ N, 55˚ N, 65˚ N) encompassing various regions of Western Europe. The relationship between the occurrence of RWB and cyclone clustering is studied in detail. Clustering at 55˚ N is associated with an extended and anomalously strong jet flanked on both sides by RWB. However, clustering at 65(45)˚ N is associated with RWB to the south (north) of the jet, deflecting the jet northwards (southwards). A positive correlation was found between the intensity of the clustering and RWB occurrence to the north and south of the jet. However, there is considerable spread in these relationships. Finally, analysis has shown that the relationships identified in the re-analysis are also present in a high-resolution coupled global climate model (HiGEM). In particular, clustering is associated with the same dynamical conditions at each of our three latitudes in spite of the identified biases in frequency and intensity of RWB.

  5. Mass profile and dynamical status of the z ~ 0.8 galaxy cluster LCDCS 0504

    Science.gov (United States)

    Guennou, L.; Biviano, A.; Adami, C.; Limousin, M.; Lima Neto, G. B.; Mamon, G. A.; Ulmer, M. P.; Gavazzi, R.; Cypriano, E. S.; Durret, F.; Clowe, D.; LeBrun, V.; Allam, S.; Basa, S.; Benoist, C.; Cappi, A.; Halliday, C.; Ilbert, O.; Johnston, D.; Jullo, E.; Just, D.; Kubo, J. M.; Márquez, I.; Marshall, P.; Martinet, N.; Maurogordato, S.; Mazure, A.; Murphy, K. J.; Plana, H.; Rostagni, F.; Russeil, D.; Schirmer, M.; Schrabback, T.; Slezak, E.; Tucker, D.; Zaritsky, D.; Ziegler, B.

    2014-06-01

    Context. Constraints on the mass distribution in high-redshift clusters of galaxies are currently not very strong. Aims: We aim to constrain the mass profile, M(r), and dynamical status of the z ~ 0.8 LCDCS 0504 cluster of galaxies that is characterized by prominent giant gravitational arcs near its center. Methods: Our analysis is based on deep X-ray, optical, and infrared imaging as well as optical spectroscopy, collected with various instruments, which we complemented with archival data. We modeled the mass distribution of the cluster with three different mass density profiles, whose parameters were constrained by the strong lensing features of the inner cluster region, by the X-ray emission from the intracluster medium, and by the kinematics of 71 cluster members. Results: We obtain consistent M(r) determinations from three methods based on kinematics (dispersion-kurtosis, caustics, and MAMPOSSt), out to the cluster virial radius, ≃1.3 Mpc and beyond. The mass profile inferred by the strong lensing analysis in the central cluster region is slightly higher than, but still consistent with, the kinematics estimate. On the other hand, the X-ray based M(r) is significantly lower than the kinematics and strong lensing estimates. Theoretical predictions from ΛCDM cosmology for the concentration-mass relation agree with our observational results, when taking into account the uncertainties in the observational and theoretical estimates. There appears to be a central deficit in the intracluster gas mass fraction compared with nearby clusters. Conclusions: Despite the relaxed appearance of this cluster, the determinations of its mass profile by different probes show substantial discrepancies, the origin of which remains to be determined. The extension of a dynamical analysis similar to that of other clusters of the DAFT/FADA survey with multiwavelength data of sufficient quality will allow shedding light on the possible systematics that affect the determination of mass

  6. Clustering Effect on the Dynamics in a Spatial Rock-Paper-Scissors System

    Science.gov (United States)

    Hashimoto, Tsuyoshi; Sato, Kazunori; Ichinose, Genki; Miyazaki, Rinko; Tainaka, Kei-ichi

    2018-01-01

    The lattice dynamics for rock-paper-scissors games is related to population theories in ecology. In most cases, simulations are performed by local and global interactions. It is known in the former case that the dynamics is usually stable. We find two types of non-random distributions in the stationary state. One is a cluster formation of endangered species: when the density of a species approaches zero, its clumping degree diverges to infinity. The other is the strong aggregations of high-density species. Such spatial pattern formations play important roles in population dynamics.

  7. Global Analysis of miRNA Gene Clusters and Gene Families Reveals Dynamic and Coordinated Expression

    Directory of Open Access Journals (Sweden)

    Li Guo

    2014-01-01

    Full Text Available To further understand the potential expression relationships of miRNAs in miRNA gene clusters and gene families, a global analysis was performed in 4 paired tumor (breast cancer and adjacent normal tissue samples using deep sequencing datasets. The compositions of miRNA gene clusters and families are not random, and clustered and homologous miRNAs may have close relationships with overlapped miRNA species. Members in the miRNA group always had various expression levels, and even some showed larger expression divergence. Despite the dynamic expression as well as individual difference, these miRNAs always indicated consistent or similar deregulation patterns. The consistent deregulation expression may contribute to dynamic and coordinated interaction between different miRNAs in regulatory network. Further, we found that those clustered or homologous miRNAs that were also identified as sense and antisense miRNAs showed larger expression divergence. miRNA gene clusters and families indicated important biological roles, and the specific distribution and expression further enrich and ensure the flexible and robust regulatory network.

  8. Correlation of bistranded clustered abasic DNA lesion processing with structural and dynamic DNA helix distortion

    Science.gov (United States)

    Bignon, Emmanuelle; Gattuso, Hugo; Morell, Christophe; Dehez, François; Georgakilas, Alexandros G.; Monari, Antonio; Dumont, Elise

    2016-01-01

    Clustered apurinic/apyrimidinic (AP; abasic) DNA lesions produced by ionizing radiation are by far more cytotoxic than isolated AP lesion entities. The structure and dynamics of a series of seven 23-bp oligonucleotides featuring simple bistranded clustered damage sites, comprising of two AP sites, zero, one, three or five bases 3′ or 5′ apart from each other, were investigated through 400 ns explicit solvent molecular dynamics simulations. They provide representative structures of synthetically engineered multiply damage sites-containing oligonucleotides whose repair was investigated experimentally (Nucl. Acids Res. 2004, 32:5609-5620; Nucl. Acids Res. 2002, 30: 2800–2808). The inspection of extrahelical positioning of the AP sites, bulge and non Watson–Crick hydrogen bonding corroborates the experimental measurements of repair efficiencies by bacterial or human AP endonucleases Nfo and APE1, respectively. This study provides unprecedented knowledge into the structure and dynamics of clustered abasic DNA lesions, notably rationalizing the non-symmetry with respect to 3′ to 5′ position. In addition, it provides strong mechanistic insights and basis for future studies on the effects of clustered DNA damage on the recognition and processing of these lesions by bacterial or human DNA repair enzymes specialized in the processing of such lesions. PMID:27587587

  9. Photoionization dynamics of glycine adsorbed on a silicon cluster: ''On-the-fly'' simulations

    International Nuclear Information System (INIS)

    Shemesh, Dorit; Baer, Roi; Seideman, Tamar; Gerber, R. Benny

    2005-01-01

    Dynamics of glycine chemisorbed on the surface of a silicon cluster is studied for a process that involves single-photon ionization, followed by recombination with the electron after a selected time delay. The process is studied by ''on-the-fly'' molecular dynamics simulations, using the semiempirical parametric method number 3 (PM3) potential energy surface. The system is taken to be in the ground state prior to photoionization, and time delays from 5 to 50 fs before the recombination are considered. The time evolution is computed over 10 ps. The main findings are (1) the positive charge after ionization is initially mostly distributed on the silicon cluster. (2) After ionization the major structural changes are on the silicon cluster. These include Si-Si bond breaking and formation and hydrogen transfer between different silicon atoms. (3) The transient ionization event gives rise to dynamical behavior that depends sensitively on the ion state lifetime. Subsequent to 45 fs evolution in the charged state, the glycine molecule starts to rotate on the silicon cluster. Implications of the results to various processes that are induced by transient transition to a charged state are discussed. These include inelastic tunneling in molecular devices, photochemistry on conducting surfaces, and electron-molecule scattering

  10. The immanence and transcendence of God in Adamic incarnational Christology: An African ethical reflection for the public

    Directory of Open Access Journals (Sweden)

    Vhumani Magezi

    2016-03-01

    Full Text Available This article argues that the transcendence and immanence of God amplified in Christ should influence African believers� private and public ethics. It accomplishes this by engaging transcendence and immanence of God in the traditional African worldview. The African traditional worldview in many respects believes the transcendent God whose immanence is mediated by lesser spiritual intermediary powers. In responding to this view of God�s transcendence and immanence, we discuss the amplified transcendence and immanence of God in the Adamic incarnational Christological model. This model argues that in the incarnation, God�s transcendence and immanence is amplified by his assumption of our human mode of existence as the New Adam for our redemption. That is, even though God has always been transcendent and present within his creation before the incarnation, his immanence within humanity is amplified by God becoming man in and through Jesus Christ as the New Adam. The ascension of Jesus Christ does not diminish God�s presence within Christians. God continues to have his personal presence within believers through the dynamic presence of the Holy Spirit among them. The transcendence and immanence of God (amplified in Christ therefore is brought to bear in the private and public ethics of Christians. In contrast to the limited immanence of human beings, God�s immanence is infinite. That is, there is nothing human beings can do which is outside of God�s reach and knowledge. It is from this perspective that African Christians are encouraged to live lives conscious of the infinite-immanent God, who sees both their private and public lives. The private and public life of believers should resemble God�s character and behaviour demonstrated by Jesus Christ, God incarnate, in his earthly ministry. Thus, the transcendence and immanence of God amplified in Christ influences African believers to live as the true ambassadors of Christ who exhibit

  11. PREFACE: 10th International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER'12)

    Science.gov (United States)

    Lovas, R. G.; Dombrádi, Zs; Kiss, G. G.; Kruppa, A. T.; Lévai, G.

    2013-04-01

    , but we had some invited talks even in the parallel sessions. Written versions of 86 talks have been submitted. Quite a number of the speakers have modified the title of their talk in the written version. To keep the correspondence between the Programme list and the written papers, we have accordingly changed the titles in the Programme list as well. The papers are arranged according to their subjects, without regard to whether they were delivered in a plenary or in a parallel session. There was a talk classified wrongly; this is now classified correctly. In the Programme list and in the list of the papers submitted the names are those of the speakers. You can read in the Opening Address that, by ruling of the organizing institution, no members of the Debrecen Institute of Nuclear Research were selected as invited speakers and no contributions were accepted from them. We doubted the wisdom of this rigour ourselves, and I think the criticism we received for it is justifiable. The success of a conference depends primarily on the speakers. In retrospect, we can say that this conference was extremely successful, and that is owing to the great many wonderful talks delivered. This reflects very well on the present status of the field as well as on the work of the International Advisory Board, which proposed the list of excellent speakers. The Japanese dominance characteristic of all cluster conferences has only been complained about by some of the Japanese who came to Europe primarily to learn things that they could not learn at home. We would like to express our gratitude to our sponsors: the Hungarian Academy of Sciences the Paks Nuclear Power Ltd HMP Logic Ltd International Workshop for Theoretical Physics(Budapest) We were also supported indirectly by a JSPS-MTA bilateral cooperation project, which made it possible for five Japanese colleagues to participate. It just remains to be announced that the next, number 11 in this series of conferences, will be held in Naples in

  12. Dynamic Change in p63 Protein Expression during Implantation of Urothelial Cancer Clusters

    Directory of Open Access Journals (Sweden)

    Takahiro Yoshida

    2015-07-01

    Full Text Available Although the dissemination of urothelial cancer cells is supposed to be a major cause of the multicentricity of urothelial tumors, the mechanism of implantation has not been well investigated. Here, we found that cancer cell clusters from the urine of patients with urothelial cancer retain the ability to survive, grow, and adhere. By using cell lines and primary cells collected from multiple patients, we demonstrate that △Np63α protein in cancer cell clusters was rapidly decreased through proteasomal degradation when clusters were attached to the matrix, leading to downregulation of E-cadherin and upregulation of N-cadherin. Decreased △Np63α protein level in urothelial cancer cell clusters was involved in the clearance of the urothelium. Our data provide the first evidence that clusters of urothelial cancer cells exhibit dynamic changes in △Np63α expression during attachment to the matrix, and decreased △Np63α protein plays a critical role in the interaction between cancer cell clusters and the urothelium. Thus, because △Np63α might be involved in the process of intraluminal dissemination of urothelial cancer cells, blocking the degradation of △Np63α could be a target of therapy to prevent the dissemination of urothelial cancer.

  13. Novel approaches to pin cluster synchronization on complex dynamical networks in Lur'e forms

    Science.gov (United States)

    Tang, Ze; Park, Ju H.; Feng, Jianwen

    2018-04-01

    This paper investigates the cluster synchronization of complex dynamical networks consisted of identical or nonidentical Lur'e systems. Due to the special topology structure of the complex networks and the existence of stochastic perturbations, a kind of randomly occurring pinning controller is designed which not only synchronizes all Lur'e systems in the same cluster but also decreases the negative influence among different clusters. Firstly, based on an extended integral inequality, the convex combination theorem and S-procedure, the conditions for cluster synchronization of identical Lur'e networks are derived in a convex domain. Secondly, randomly occurring adaptive pinning controllers with two independent Bernoulli stochastic variables are designed and then sufficient conditions are obtained for the cluster synchronization on complex networks consisted of nonidentical Lur'e systems. In addition, suitable control gains for successful cluster synchronization of nonidentical Lur'e networks are acquired by designing some adaptive updating laws. Finally, we present two numerical examples to demonstrate the validity of the control scheme and the theoretical analysis.

  14. Phase diagram and quench dynamics of the cluster-XY spin chain.

    Science.gov (United States)

    Montes, Sebastián; Hamma, Alioscia

    2012-08-01

    We study the complete phase space and the quench dynamics of an exactly solvable spin chain, the cluster-XY model. In this chain, the cluster term and the XY couplings compete to give a rich phase diagram. The phase diagram is studied by means of the quantum geometric tensor. We study the time evolution of the system after a critical quantum quench using the Loschmidt echo. The structure of the revivals after critical quantum quenches presents a nontrivial behavior depending on the phase of the initial state and the critical point.

  15. Sensitivity Sampling Over Dynamic Geometric Data Streams with Applications to $k$-Clustering

    OpenAIRE

    Song, Zhao; Yang, Lin F.; Zhong, Peilin

    2018-01-01

    Sensitivity based sampling is crucial for constructing nearly-optimal coreset for $k$-means / median clustering. In this paper, we provide a novel data structure that enables sensitivity sampling over a dynamic data stream, where points from a high dimensional discrete Euclidean space can be either inserted or deleted. Based on this data structure, we provide a one-pass coreset construction for $k$-means %and M-estimator clustering using space $\\widetilde{O}(k\\mathrm{poly}(d))$ over $d$-dimen...

  16. Roles of dynamical symmetry breaking in driving oblate-prolate transitions of atomic clusters

    International Nuclear Information System (INIS)

    Oka, Yurie; Yanao, Tomohiro; Koon, Wang Sang

    2015-01-01

    This paper explores the driving mechanisms for structural transitions of atomic clusters between oblate and prolate isomers. We employ the hyperspherical coordinates to investigate structural dynamics of a seven-atom cluster at a coarse-grained level in terms of the dynamics of three gyration radii and three principal axes, which characterize overall mass distributions of the cluster. Dynamics of gyration radii is governed by two kinds of forces. One is the potential force originating from the interactions between atoms. The other is the dynamical forces called the internal centrifugal forces, which originate from twisting and shearing motions of the system. The internal centrifugal force arising from twisting motions has an effect of breaking the symmetry between two gyration radii. As a result, in an oblate isomer, activation of the internal centrifugal force that has the effect of breaking the symmetry between the two largest gyration radii is crucial in triggering structural transitions into prolate isomers. In a prolate isomer, on the other hand, activation of the internal centrifugal force that has the effect of breaking the symmetry between the two smallest gyration radii is crucial in triggering structural transitions into oblate isomers. Activation of a twisting motion that switches the movement patterns of three principal axes is also important for the onset of structural transitions between oblate and prolate isomers. Based on these trigger mechanisms, we finally show that selective activations of specific gyration radii and twisting motions, depending on the isomer of the cluster, can effectively induce structural transitions of the cluster. The results presented here could provide further insights into the control of molecular reactions

  17. Power, uncertainty, self-transcendence, and quality of life in breast cancer survivors.

    Science.gov (United States)

    Farren, Arlene T

    2010-01-01

    The purpose of the study was to examine the relations among power, uncertainty, self-transcendence, and quality of life in breast cancer survivors from the perspective of Rogers' science of unitary human beings. A correlational, cross-sectional study with purposive sampling (n = 104) was conducted. The results included statistically significant correlations, explained variance, and mediating relations among the pattern manifestations. The researcher concluded that there are complex and synergistic relations among the cluster of field pattern manifestations that contribute to quality of life in breast cancer survivors. Implications for theory, research, and practice are discussed.

  18. Self-transcendence and family caregivers of adults with dementia.

    Science.gov (United States)

    Acton, G J; Wright, K B

    2000-06-01

    Research has documented that caring for a family member with dementia is stressful and burdensome. However, difficult life experiences such as fear, loss, and grief may help persons move beyond a concern for self toward a larger perspective and concern for others. Both positive and negative experiences can promote positive movement toward growth and development. This movement has been described as self-transcendence, or the ability to look beyond the self and present difficulties, to extend concern to others, and to find personal meaning and wholeness in the context of life-changing events. The family caregiving experience with its inherent difficulties might provide the impetus for such a movement toward self-transcendence. The purpose of this article is to examine the concept of self-transcendence, explore its linkages to the caregiving experience, and suggest potential strategies to assist family caregivers to achieve self-transcendence.

  19. Surprised by Bird, Bard, and Bach: Language, Silence, and Transcendence.

    Science.gov (United States)

    Suhor, Charles

    1991-01-01

    Argues the importance of the relationships among silence and literature, the arts, and other experiences that point toward transcendence. Suggests that English teachers can expand the repertoire of classroom activities and teaching techniques that make use of silence. (KEH)

  20. 3.5D dynamic PET image reconstruction incorporating kinetics-based clusters

    International Nuclear Information System (INIS)

    Lu Lijun; Chen Wufan; Karakatsanis, Nicolas A; Rahmim, Arman; Tang Jing

    2012-01-01

    Standard 3D dynamic positron emission tomographic (PET) imaging consists of independent image reconstructions of individual frames followed by application of appropriate kinetic model to the time activity curves at the voxel or region-of-interest (ROI). The emerging field of 4D PET reconstruction, by contrast, seeks to move beyond this scheme and incorporate information from multiple frames within the image reconstruction task. Here we propose a novel reconstruction framework aiming to enhance quantitative accuracy of parametric images via introduction of priors based on voxel kinetics, as generated via clustering of preliminary reconstructed dynamic images to define clustered neighborhoods of voxels with similar kinetics. This is then followed by straightforward maximum a posteriori (MAP) 3D PET reconstruction as applied to individual frames; and as such the method is labeled ‘3.5D’ image reconstruction. The use of cluster-based priors has the advantage of further enhancing quantitative performance in dynamic PET imaging, because: (a) there are typically more voxels in clusters than in conventional local neighborhoods, and (b) neighboring voxels with distinct kinetics are less likely to be clustered together. Using realistic simulated 11 C-raclopride dynamic PET data, the quantitative performance of the proposed method was investigated. Parametric distribution-volume (DV) and DV ratio (DVR) images were estimated from dynamic image reconstructions using (a) maximum-likelihood expectation maximization (MLEM), and MAP reconstructions using (b) the quadratic prior (QP-MAP), (c) the Green prior (GP-MAP) and (d, e) two proposed cluster-based priors (CP-U-MAP and CP-W-MAP), followed by graphical modeling, and were qualitatively and quantitatively compared for 11 ROIs. Overall, the proposed dynamic PET reconstruction methodology resulted in substantial visual as well as quantitative accuracy improvements (in terms of noise versus bias performance) for parametric DV

  1. Dynamical cluster approximation plus semiclassical approximation study for a Mott insulator and d-wave pairing

    Science.gov (United States)

    Kim, SungKun; Lee, Hunpyo

    2017-06-01

    Via a dynamical cluster approximation with N c = 4 in combination with a semiclassical approximation (DCA+SCA), we study the doped two-dimensional Hubbard model. We obtain a plaquette antiferromagnetic (AF) Mott insulator, a plaquette AF ordered metal, a pseudogap (or d-wave superconductor) and a paramagnetic metal by tuning the doping concentration. These features are similar to the behaviors observed in copper-oxide superconductors and are in qualitative agreement with the results calculated by the cluster dynamical mean field theory with the continuous-time quantum Monte Carlo (CDMFT+CTQMC) approach. The results of our DCA+SCA differ from those of the CDMFT+CTQMC approach in that the d-wave superconducting order parameters are shown even in the high doped region, unlike the results of the CDMFT+CTQMC approach. We think that the strong plaquette AF orderings in the dynamical cluster approximation (DCA) with N c = 4 suppress superconducting states with increasing doping up to strongly doped region, because frozen dynamical fluctuations in a semiclassical approximation (SCA) approach are unable to destroy those orderings. Our calculation with short-range spatial fluctuations is initial research, because the SCA can manage long-range spatial fluctuations in feasible computational times beyond the CDMFT+CTQMC tool. We believe that our future DCA+SCA calculations should supply information on the fully momentum-resolved physical properties, which could be compared with the results measured by angle-resolved photoemission spectroscopy experiments.

  2. Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

    Science.gov (United States)

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2017-08-01

    Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

  3. Single Molecule Cluster Analysis Identifies Signature Dynamic Conformations along the Splicing Pathway

    Science.gov (United States)

    Blanco, Mario R.; Martin, Joshua S.; Kahlscheuer, Matthew L.; Krishnan, Ramya; Abelson, John; Laederach, Alain; Walter, Nils G.

    2016-01-01

    The spliceosome is the dynamic RNA-protein machine responsible for faithfully splicing introns from precursor messenger RNAs (pre-mRNAs). Many of the dynamic processes required for the proper assembly, catalytic activation, and disassembly of the spliceosome as it acts on its pre-mRNA substrate remain poorly understood, a challenge that persists for many biomolecular machines. Here, we developed a fluorescence-based Single Molecule Cluster Analysis (SiMCAn) tool to dissect the manifold conformational dynamics of a pre-mRNA through the splicing cycle. By clustering common dynamic behaviors derived from selectively blocked splicing reactions, SiMCAn was able to identify signature conformations and dynamic behaviors of multiple ATP-dependent intermediates. In addition, it identified a conformation adopted late in splicing by a 3′ splice site mutant, invoking a mechanism for substrate proofreading. SiMCAn presents a novel framework for interpreting complex single molecule behaviors that should prove widely useful for the comprehensive analysis of a plethora of dynamic cellular machines. PMID:26414013

  4. Clustering Effects on Dynamics in Ionomer Solutions: A Neutron Spin Echo Insight

    Science.gov (United States)

    Perahia, Dvora; Wijesinghe, Sidath; Senanayake, Manjula; Wickramasinghe, Anuradhi; Mohottalalage, Supun S.; Ohl, Michael

    Ionizable blocks in ionomers associate into aggregates serving as physical cross-links and concurrently form transport pathways. The dynamics of ionomers underline their functionality. Incorporating small numbers of ionic groups into polymers significantly constraint their dynamics. Recent computational studies demonstrated a direct correlation between ionic cluster morphology and polymer dynamics. Here using neutron spin echo, we probe the segmental dynamics of polystyrene sulfonate (PSS) as the degree of sulfonation of the PSS and the solution dielectrics are varied. Specifically, 20Wt% PSS of 11,000 g/mol with polydispersity of 1.02 with 3% and 9% sulfonation were studies in toluene (dielectric constant ɛ = 2.8), a good solvent for polystyrene, and with 5Wt% of ethanol (ɛ = 24.3l) added. The dynamic structure factor S(q,t) was analyzed with a single exponential except for a limited q range where two time constants associated with constraint and mobile segments were detected. S(q,t) exhibits several distinctive time and length scales for the dynamics with a crossover appearing at the length scale of the ionic clusters. NSF DMR 1611136.

  5. Molecular dynamics computer simulation study of Pdn (n=13, 19, 38 and 55) clusters

    International Nuclear Information System (INIS)

    Karabacak, M.; Oezcelik, S.; Guevenc, Z.B.

    2002-01-01

    Using constant-energy molecular dynamics and thermal quenching simulations, we have studied minimum-energy structures and energetics, Pd n (n=13, 19, 38, and 55) clusters employing the Voter and Chen's version of parameterisation of the embedded-atom potential surface. Isomer statistics for Pdn ( n = 13 and 19 ) is obtained from 10000 initial independent configurations, which have been generated along high-energy trajectories (chosen energy values are high enough to melt the clusters). The thermal quenching technique is employed to remove the internal kinetic energy of the clusters. The locally stable isomers are separated from metastable ones. Probabilities belonging to sampling the basins of attractions of each isomers are computed, and then, isomers' energy spectra are analyzed

  6. Molecular dynamics simulations of sputtering of organic overlayers by slow, large clusters

    International Nuclear Information System (INIS)

    Rzeznik, L.; Czerwinski, B.; Garrison, B.J.; Winograd, N.; Postawa, Z.

    2008-01-01

    The ion-stimulated desorption of organic molecules by impact of large and slow clusters is examined using molecular dynamics (MDs) computer simulations. The investigated system, represented by a monolayer of benzene deposited on Ag{1 1 1}, is irradiated with projectiles composed of thousands of noble gas atoms having a kinetic energy of 0.1-20 eV/atom. The sputtering yield of molecular species and the kinetic energy distributions are analyzed and compared to the results obtain for PS4 overlayer. The simulations demonstrate quite clearly that the physics of ejection by large and slow clusters is distinct from the ejection events stimulated by the popular SIMS clusters, like C 60 , Au 3 and SF 5 at tens of keV energies.

  7. Dynamics of photoprocesses induced by femtosecond infrared radiation in free molecules and clusters of iron pentacarbonyl

    International Nuclear Information System (INIS)

    Kompanets, V. O.; Lokhman, V. N.; Poydashev, D. G.; Chekalin, S. V.; Ryabov, E. A.

    2016-01-01

    The dynamics of photoprocesses induced by femtosecond infrared radiation in free Fe(CO) 5 molecules and their clusters owing to the resonant excitation of vibrations of CO bonds in the 5-μm range has been studied. The technique of infrared excitation and photoionization probing (λ = 400 nm) by femtosecond pulses has been used in combination with time-of-flight mass spectrometry. It has been found that an infrared pulse selectively excites vibrations of CO bonds in free molecules, which results in a decrease in the yield of the Fe(CO) 5 + molecular ion. Subsequent relaxation processes have been analyzed and the results have been interpreted. The time of the energy transfer from excited vibrations to other vibrations of the molecule owing to intramolecular relaxation has been measured. The dynamics of dissociation of [Fe(CO) 5 ] n clusters irradiated by femtosecond infrared radiation has been studied. The time dependence of the yield of free molecules has been measured under different infrared laser excitation conditions. We have proposed a model that well describes the results of the experiment and makes it possible, in particular, to calculate the profile of variation of the temperature of clusters within the “evaporation ensemble” concept. The intramolecular and intracluster vibrational relaxation rates in [Fe(CO) 5 ] n clusters have been estimated.

  8. Dynamical evolution of stars and gas of young embedded stellar sub-clusters

    Science.gov (United States)

    Sills, Alison; Rieder, Steven; Scora, Jennifer; McCloskey, Jessica; Jaffa, Sarah

    2018-03-01

    We present simulations of the dynamical evolution of young embedded star clusters. Our initial conditions are directly derived from X-ray, infrared, and radio observations of local systems, and our models evolve both gas and stars simultaneously. Our regions begin with both clustered and extended distributions of stars, and a gas distribution which can include a filamentary structure in addition to gas surrounding the stellar subclusters. We find that the regions become spherical, monolithic, and smooth quite quickly, and that the dynamical evolution is dominated by the gravitational interactions between the stars. In the absence of stellar feedback, the gas moves gently out of the centre of our regions but does not have a significant impact on the motions of the stars at the earliest stages of cluster formation. Our models at later times are consistent with observations of similar regions in the local neighbourhood. We conclude that the evolution of young proto-star clusters is relatively insensitive to reasonable choices of initial conditions. Models with more realism, such as an initial population of binary and multiple stars and ongoing star formation, are the next step needed to confirm these findings.

  9. Dynamics of Brokerage Positions in Clusters: Evidence from the Spanish Foodstuffs Industry

    Directory of Open Access Journals (Sweden)

    José Antonio Belso-Martínez

    2017-02-01

    Full Text Available Shifting away from traditional approaches orientated towards the analysis of the benefits associated with brokerage, this paper provides valuable insights into the dynamics of this network position and the opportunities to innovate that it provides. Using fine grain micro data collected in a foodstuff Spanish cluster, the evolution of different brokerage profiles is analyzed in depth. It was particularly evident how firm-level characteristics (status, former mediating experience and external openness and their interactions may generate changes in the different brokerage roles over a period of time. The findings of this work partially validate expectations based on the network dynamics approaches. Status and previous mediating experience facilitate the creation of partnerships, fostering brokerage. Conversely, interaction effects demote brokerage activity at the intra-cluster level, suggesting the selective nature of brokers’ relational behavior.

  10. Communication: Time-dependent optimized coupled-cluster method for multielectron dynamics

    Science.gov (United States)

    Sato, Takeshi; Pathak, Himadri; Orimo, Yuki; Ishikawa, Kenichi L.

    2018-02-01

    Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled-cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived the equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method of intense-laser driven correlated electron dynamics in Ar atom is reported.

  11. Role of the cluster structure of {sup 7}Li in the dynamics of fragment capture

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, A., E-mail: aradhana@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Navin, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Diaz-Torres, A. [ECT, Villa Tambosi, I-38123 Villazzano, Trento (Italy); Nanal, V. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Ramachandran, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rejmund, M. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A.; Kailas, S. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Lemasson, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Palit, R. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Parkar, V.V. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pillay, R.G. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Rout, P.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sawant, Y. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2013-01-08

    Exclusive measurements of prompt {gamma}-rays from the heavy-residues with various light charged particles in the {sup 7}Li + {sup 198}Pt system, at an energy near the Coulomb barrier (E/V{sub b}{approx}1.6) are reported. Recent dynamic classical trajectory calculations, constrained by the measured fusion, {alpha}- and t-capture cross-sections have been used to explain the excitation energy dependence of the residue cross-sections. These calculations distinctly illustrate a two-step process, breakup followed by fusion, in case of the capture of t and {alpha} clusters; whereas for {sup 6}He+p and {sup 5}He+d configurations, massive transfer is inferred to be the dominant mechanism. The present work clearly demonstrates the role played by the cluster structures of {sup 7}Li in understanding the reaction dynamics at energies around the Coulomb barrier.

  12. Spin dynamics study of magnetic molecular clusters by means of Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Cianchi, L.; Del Giallo, F.; Spina, G.; Reiff, W.; Caneschi, A.

    2002-01-01

    Spin dynamics of the two magnetic molecular clusters Fe4 and Fe8, with four and eight Fe(III) ions, respectively, was studied by means of Moessbauer spectroscopy. The transition probabilities W's between the spin states of the ground multiplet were obtained from the fitting of the spectra. For the Fe4 cluster we found that, in the range from 1.38 to 77 K, the trend of W's versus the temperature corresponds to an Orbach's process involving an excited state with energy of about 160 K. For the Fe8, which, due to the presence of a low-energy excited state, could not be studied at temperatures greater than 20 K, the trend of W's in the range from 4 to 18 K seems to correspond to a direct process. The correlation functions of the magnetization were then calculated in terms of the W's. They have an exponential trend for the Fe4 cluster, while a small oscillating component is also present for the Fe8 cluster. For the first of the clusters, τ vs T (τ is the decay time of the magnetization) has a trend which, at low temperatures (T 15 K, τ follows the trend of W -1 . For the Fe8, τ follows an Arrhenius law, but with a prefactor which is smaller than the one obtained susceptibility measurements

  13. Improving estimation of kinetic parameters in dynamic force spectroscopy using cluster analysis

    Science.gov (United States)

    Yen, Chi-Fu; Sivasankar, Sanjeevi

    2018-03-01

    Dynamic Force Spectroscopy (DFS) is a widely used technique to characterize the dissociation kinetics and interaction energy landscape of receptor-ligand complexes with single-molecule resolution. In an Atomic Force Microscope (AFM)-based DFS experiment, receptor-ligand complexes, sandwiched between an AFM tip and substrate, are ruptured at different stress rates by varying the speed at which the AFM-tip and substrate are pulled away from each other. The rupture events are grouped according to their pulling speeds, and the mean force and loading rate of each group are calculated. These data are subsequently fit to established models, and energy landscape parameters such as the intrinsic off-rate (koff) and the width of the potential energy barrier (xβ) are extracted. However, due to large uncertainties in determining mean forces and loading rates of the groups, errors in the estimated koff and xβ can be substantial. Here, we demonstrate that the accuracy of fitted parameters in a DFS experiment can be dramatically improved by sorting rupture events into groups using cluster analysis instead of sorting them according to their pulling speeds. We test different clustering algorithms including Gaussian mixture, logistic regression, and K-means clustering, under conditions that closely mimic DFS experiments. Using Monte Carlo simulations, we benchmark the performance of these clustering algorithms over a wide range of koff and xβ, under different levels of thermal noise, and as a function of both the number of unbinding events and the number of pulling speeds. Our results demonstrate that cluster analysis, particularly K-means clustering, is very effective in improving the accuracy of parameter estimation, particularly when the number of unbinding events are limited and not well separated into distinct groups. Cluster analysis is easy to implement, and our performance benchmarks serve as a guide in choosing an appropriate method for DFS data analysis.

  14. Parallel variable selection of molecular dynamics clusters as a tool for calculation of spectroscopic properties

    Czech Academy of Sciences Publication Activity Database

    Kessler, Jiří; Dračínský, Martin; Bouř, Petr

    2013-01-01

    Roč. 34, č. 5 (2013), s. 366-371 ISSN 0192-8651 R&D Projects: GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : molecular dynamics * clusters * density functional theory * Raman optical activity * NMR Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.601, year: 2013

  15. Nonequilibrium dynamics of polariton entanglement in a cluster of coupled traps

    Energy Technology Data Exchange (ETDEWEB)

    Quiroga, L [Departamento de Fisica, Universidad de Los Andes, A.A.4976, Bogota D.C. (Colombia); Tejedor, C, E-mail: lquiroga@uniandes.edu.c [Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, Cantoblanco, E-28049, Madrid (Spain)

    2009-05-01

    We study in detail the generation and relaxation of quantum coherences (entanglement) in a system of coupled polariton traps. By exploiting a Lie algebraic based super-operator technique we provide an analytical exact solution for the Markovian dissipative dynamics (Master equation) of such system which is valid for arbitrary cluster size, polariton-polariton interaction strength, temperature and initial state. Based on the exact solution of the Master equation at T = OK, we discuss how dissipation affects the quantum entanglement dynamics of coupled polariton systems.

  16. UAV-Assisted Dynamic Clustering of Wireless Sensor Networks for Crop Health Monitoring.

    Science.gov (United States)

    Uddin, Mohammad Ammad; Mansour, Ali; Jeune, Denis Le; Ayaz, Mohammad; Aggoune, El-Hadi M

    2018-02-11

    In this study, a crop health monitoring system is developed by using state of the art technologies including wireless sensors and Unmanned Aerial Vehicles (UAVs). Conventionally data is collected from sensor nodes either by fixed base stations or mobile sinks. Mobile sinks are considered a better choice nowadays due to their improved network coverage and energy utilization. Usually, the mobile sink is used in two ways: either it goes for random walk to find the scattered nodes and collect data, or follows a pre-defined path established by the ground network/clusters. Neither of these options is suitable in our scenario due to the factors like dynamic data collection, the strict targeted area required to be scanned, unavailability of a large number of nodes, dynamic path of the UAV, and most importantly, none of these are known in advance. The contribution of this paper is the formation of dynamic runtime clusters of field sensors by considering the above mentioned factors. Furthermore a mechanism (Bayesian classifier) is defined to select best node as cluster head. The proposed system is validated through simulation results, lab and infield experiments using concept devices. The obtained results are encouraging, especially in terms of deployment time, energy, efficiency, throughput and ease of use.

  17. Simulating The Dynamical Evolution Of Galaxies In Group And Cluster Environments

    Science.gov (United States)

    Vijayaraghavan, Rukmani

    2015-07-01

    Galaxy clusters are harsh environments for their constituent galaxies. A variety of physical processes effective in these dense environments transform gas-rich, spiral, star-forming galaxies to elliptical or spheroidal galaxies with very little gas and therefore minimal star formation. The consequences of these processes are well understood observationally. Galaxies in progressively denser environments have systematically declining star formation rates and gas content. However, a theoretical understanding of of where, when, and how these processes act, and the interplay between the various galaxy transformation mechanisms in clusters remains elusive. In this dissertation, I use numerical simulations of cluster mergers as well as galaxies evolving in quiescent environments to develop a theoretical framework to understand some of the physics of galaxy transformation in cluster environments. Galaxies can be transformed in smaller groups before they are accreted by their eventual massive cluster environments, an effect termed `pre-processing'. Galaxy cluster mergers themselves can accelerate many galaxy transformation mechanisms, including tidal and ram pressure stripping of galaxies and galaxy-galaxy collisions and mergers that result in reassemblies of galaxies' stars and gas. Observationally, cluster mergers have distinct velocity and phase-space signatures depending on the observer's line of sight with respect to the merger direction. Using dark matter only as well as hydrodynamic simulations of cluster mergers with random ensembles of particles tagged with galaxy models, I quantify the effects of cluster mergers on galaxy evolution before, during, and after the mergers. Based on my theoretical predictions of the dynamical signatures of these mergers in combination with galaxy transformation signatures, one can observationally identify remnants of mergers and quantify the effect of the environment on galaxies in dense group and cluster environments. The presence of

  18. Electronic relaxation dynamics of a metal atom deposited on argon cluster

    International Nuclear Information System (INIS)

    Awali, Slim

    2014-01-01

    This thesis is a study on the interaction between electronically excited atomic states and a non-reactive environment. We have theoretically and experimentally studied situations where a metal atom (Ba or K) is placed in a finite size environment (argon cluster). The presence of the medium affects the electronic levels of the atom. On the other side, the excitation of the atom induces a relaxation dynamics of the electronic energy through the deformation of the cluster. The experimental part of this work focuses on two aspects: the spectroscopy and the dynamics. In both cases a first laser electronically excites the metal atom and the second ionizes the excited system. The observable is the photoelectron spectrum recorded after photoionization and possibly information on the photoion which are also produced. This pump/probe technique, with also two lasers, provide the ultrafast dynamic when the lasers pulses used are of ultrashort (60 fs). The use of nanosecond lasers leads to resonance spectroscopic measurement, unresolved temporally, which give information on the position of the energy levels of the studied system. From a theoretical point-of-view, the excited states of M-Ar n were calculated at the ab initio level, using large core pseudo-potential to limit the active electrons of the metal to valence electrons. The study of alkali metals (potassium) is especially well adapted to this method since only one electron is active. The ab-initio calculation and a Monte-Carlo simulation where coupled to optimize the geometry of the KAr n (n = 1-10) cluster when K is in the ground state of the neutral and the ion, or excited in the 4p or 5s state. Calculations were also conducted in collaboration with B. Gervais (CIMAP, Caen) on KAr n clusters having several tens of argon atoms. Absorption spectra were also calculated. From an experimental point-of-view, we were able to characterize the excited states of potassium and barium perturbed by the clusters. In both cases a

  19. Cluster analysis of accelerated molecular dynamics simulations: A case study of the decahedron to icosahedron transition in Pt nanoparticles

    Science.gov (United States)

    Huang, Rao; Lo, Li-Ta; Wen, Yuhua; Voter, Arthur F.; Perez, Danny

    2017-10-01

    Modern molecular-dynamics-based techniques are extremely powerful to investigate the dynamical evolution of materials. With the increase in sophistication of the simulation techniques and the ubiquity of massively parallel computing platforms, atomistic simulations now generate very large amounts of data, which have to be carefully analyzed in order to reveal key features of the underlying trajectories, including the nature and characteristics of the relevant reaction pathways. We show that clustering algorithms, such as the Perron Cluster Cluster Analysis, can provide reduced representations that greatly facilitate the interpretation of complex trajectories. To illustrate this point, clustering tools are used to identify the key kinetic steps in complex accelerated molecular dynamics trajectories exhibiting shape fluctuations in Pt nanoclusters. This analysis provides an easily interpretable coarse representation of the reaction pathways in terms of a handful of clusters, in contrast to the raw trajectory that contains thousands of unique states and tens of thousands of transitions.

  20. Application of the dynamically allocated virtual clustering management system to emulated tactical network experimentation

    Science.gov (United States)

    Marcus, Kelvin

    2014-06-01

    The U.S Army Research Laboratory (ARL) has built a "Network Science Research Lab" to support research that aims to improve their ability to analyze, predict, design, and govern complex systems that interweave the social/cognitive, information, and communication network genres. Researchers at ARL and the Network Science Collaborative Technology Alliance (NS-CTA), a collaborative research alliance funded by ARL, conducted experimentation to determine if automated network monitoring tools and task-aware agents deployed within an emulated tactical wireless network could potentially increase the retrieval of relevant data from heterogeneous distributed information nodes. ARL and NS-CTA required the capability to perform this experimentation over clusters of heterogeneous nodes with emulated wireless tactical networks where each node could contain different operating systems, application sets, and physical hardware attributes. Researchers utilized the Dynamically Allocated Virtual Clustering Management System (DAVC) to address each of the infrastructure support requirements necessary in conducting their experimentation. The DAVC is an experimentation infrastructure that provides the means to dynamically create, deploy, and manage virtual clusters of heterogeneous nodes within a cloud computing environment based upon resource utilization such as CPU load, available RAM and hard disk space. The DAVC uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex private networks. Clusters created by the DAVC system can be utilized for software development, experimentation, and integration with existing hardware and software. The goal of this paper is to explore how ARL and the NS-CTA leveraged the DAVC to create, deploy and manage multiple experimentation clusters to support their experimentation goals.

  1. Are superluminous supernovae and long GRBs the products of dynamical processes in young dense star clusters?

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, E. P. J. [Astronomical Institute Anton Pannekoek, University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Portegies Zwart, S. F. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2013-12-20

    Superluminous supernovae (SLSNe) occur almost exclusively in small galaxies (Small/Large Magellanic Cloud (SMC/LMC)-like or smaller), and the few SLSNe observed in larger star-forming galaxies always occur close to the nuclei of their hosts. Another type of peculiar and highly energetic supernovae are the broad-line Type Ic SNe (SN Ic-BL) that are associated with long-duration gamma-ray bursts (LGRBs). Also these have a strong preference for occurring in small (SMC/LMC-like or smaller) star-forming galaxies, and in these galaxies LGRBs always occur in the brightest spots. Studies of nearby star-forming galaxies that are similar to the hosts of LGRBs show that these brightest spots are giant H II regions produced by massive dense young star clusters with many hundreds of O- and Wolf-Rayet-type stars. Such dense young clusters are also found in abundance within a few hundred parsecs from the nucleus of larger galaxies like our own. We argue that the SLSNe and the SNe Ic-BL/LGRBs are exclusive products of two types of dynamical interactions in dense young star clusters. In our model the high angular momentum of the collapsing stellar cores required for the engines of an SN Ic-BL results from the post-main-sequence mergers of dynamically produced cluster binaries with almost equal-mass components. The merger produces a critically rotating single helium star with sufficient angular momentum to produce an LGRB; the observed 'metal aversion' of LGRBs is a natural consequence of the model. We argue that, on the other hand, SLSNe could be the products of runaway multiple collisions in dense clusters, and we present (and quantize) plausible scenarios of how the different types of SLSNe can be produced.

  2. Molecular dynamics simulations of nucleation and phase transitions in molecular clusters of hexafluorides

    International Nuclear Information System (INIS)

    Xu, S.

    1993-01-01

    Molecular dynamics simulations of nucleation and phase transitions in TeF 6 and SeF 6 clusters containing 100-350 molecules were carried out. Simulations successfully reproduced the crystalline structures observed in electron diffraction studies of large clusters (containing about 10 4 molecules) of the same materials. When the clusters were cooled, they spontaneously underwent the same bcc the monoclinic phase transition in simulations as in experiment, despite the million-fold difference in the time scales involved. Other transitions observed included melting and freezing. Several new techniques based on molecular translation and orientation were introduced to identify different condensed phases, to study nucleation and phase transitions, and to define characteristic temperatures of transitions. The solid-state transition temperatures decreased with cluster size in the same way as did the melting temperature, in that the depression of transition temperature was inversely proportional to the cluster radius. Rotational melting temperatures, as inferred from the rotational diffusion of molecules, coincided with those of the solid-state transition. Nucleation in liquid-solid and bcc-monoclinic transitions started in the interior of clusters on cooling, and at the surface on heating. Transition temperatures on cooling were always lower than those on heating due to the barriers to nucleation. Linear growth rates of nuclei in freezing were an order of magnitude lower than those in the bcc-monoclinic transition. Revealing evidence about the molecular behavior associated with phase changes was found. Simulations showed the formation of the actual transition complexes along the transition pathway, i.e., the critical nuclei of the new phase. These nuclei, consisting of a few dozen molecules, were distinguishable in the midst of the surrounding matter

  3. Increased self-transcendence in patients with intractable diseases.

    Science.gov (United States)

    Iwamoto, Rie; Yamawaki, Niwako; Sato, Takeshi

    2011-12-01

    Patients with intractable disease require long-term treatment and experience repeated bouts of progressive symptoms and resolutions, which cause them severe suffering. The aim of this study was to elucidate the concepts of self-transcendence and subjective well-being in patients with intractable disease. Forty-four patients with intractable disease (men/women: 22/22) participated. The diseases of the participants were classified into five systems: (i) neural/muscle system; (ii) digestive system; (iii) immunity/blood system; (iv) visual system; and (v) bone/joint system. The controls were 1854 healthy individuals (men/women: 935/869). Participants completed the Self-Transcendence Scale (STS) and the Japanese version of the World Health Organization-Subjective Inventory. The Japanese version of the Mini-International Neuropsychiatric Interview was also used for the intractable disease group. Analysis of covariance found a significant increase in STS score among the intractable disease group (P self-transcendence. The results also showed that there was a strong correlation between self-transcendence and respondents' subjective well-being. Our results suggest that patients with life-changing intractable disease can have a high level of self-transcendence, which may lead them to regain mental well-being, and increase their psychological health even in situations that cause physical and mental suffering. © 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology.

  4. VR-Cluster: Dynamic Migration for Resource Fragmentation Problem in Virtual Router Platform

    Directory of Open Access Journals (Sweden)

    Xianming Gao

    2016-01-01

    Full Text Available Network virtualization technology is regarded as one of gradual schemes to network architecture evolution. With the development of network functions virtualization, operators make lots of effort to achieve router virtualization by using general servers. In order to ensure high performance, virtual router platform usually adopts a cluster of general servers, which can be also regarded as a special cloud computing environment. However, due to frequent creation and deletion of router instances, it may generate lots of resource fragmentation to prevent platform from establishing new router instances. In order to solve “resource fragmentation problem,” we firstly propose VR-Cluster, which introduces two extra function planes including switching plane and resource management plane. Switching plane is mainly used to support seamless migration of router instances without packet loss; resource management plane can dynamically move router instances from one server to another server by using VR-mapping algorithms. Besides, three VR-mapping algorithms including first-fit mapping algorithm, best-fit mapping algorithm, and worst-fit mapping algorithm are proposed based on VR-Cluster. At last, we establish VR-Cluster protosystem by using general X86 servers, evaluate its migration time, and further analyze advantages and disadvantages of our proposed VR-mapping algorithms to solve resource fragmentation problem.

  5. Real-time dynamics of RNA Polymerase II clustering in live human cells

    Science.gov (United States)

    Cisse, Ibrahim

    2014-03-01

    Transcription is the first step in the central dogma of molecular biology, when genetic information encoded on DNA is made into messenger RNA. How this fundamental process occurs within living cells (in vivo) is poorly understood,[1] despite extensive biochemical characterizations with isolated biomolecules (in vitro). For high-order organisms, like humans, transcription is reported to be spatially compartmentalized in nuclear foci consisting of clusters of RNA Polymerase II, the enzyme responsible for synthesizing all messenger RNAs. However, little is known of when these foci assemble or their relative stability. We developed an approach based on photo-activation localization microscopy (PALM) combined with a temporal correlation analysis, which we refer to as tcPALM. The tcPALM method enables the real-time characterization of biomolecular spatiotemporal organization, with single-molecule sensitivity, directly in living cells.[2] Using tcPALM, we observed that RNA Polymerase II clusters form transiently, with an average lifetime of 5.1 (+/- 0.4) seconds. Stimuli affecting transcription regulation yielded orders of magnitude changes in the dynamics of the polymerase clusters, implying that clustering is regulated and plays a role in the cells ability to effect rapid response to external signals. Our results suggest that the transient crowding of enzymes may aid in rate-limiting steps of genome regulation.

  6. Energetics and dynamics of the neutralization of clustered ions in ammonia and water vapour

    International Nuclear Information System (INIS)

    Sennhauser, E.S.; Armstrong, D.A.

    1978-01-01

    The energetics and dynamics of neutralization reactions of clustered ions in ammonia and water vapour have been analysed. Neutralization rate coefficients were calculated for the ions in ammonia and for H + .(H 2 O)sub(n) combining with various clustered anions in water vapour up to densities of 4 x 10 19 molecule cm -3 at 390 K. In the case of ammonia, calculations were also performed at 298 K. For all systems, fractional contributions of the neutralization coefficients for specific cluster sizes to the overall coefficient αsub(eff) were evaluated. The computed value of αsub(eff) for NH 3 was in reasonable agreement with experimental data in the [NH 3 ] range 0.3 to 4 x 10 19 molecule cm -3 , and general trends stemming from the effects of increasing ion mass were pointed out. Calculations of energies of individual cluster sizes indicate possible neutralization reaction mechanisms. With some exception, proton transfer is the only possible path and no H atoms should be formed. This is in general agreement with literature results for water vapour at approximately 390 K and with [H 2 O] >= 2 x 10 x 10 19 molecule cm -3 . (author)

  7. On helium cluster dynamics in tungsten plasma facing components of fusion devices

    International Nuclear Information System (INIS)

    Krasheninnikov, S.I.; Faney, T.; Wirth, B.D.

    2014-01-01

    This paper describes the dynamics of helium clustering behaviour within either a nanometer-sized tendril of fuzz, or a half-space domain, as predicted by a reaction–diffusion model. This analysis has identified a dimensionless parameter, P Δ , which is a balance of the reaction and diffusion actions of insoluble He in a metal matrix and which governs the self-trapping effects of He into growing bubbles within a tendril. The impact of He self-trapping, as well as trapping caused by pre-existing traps in the form of lattice defects or clusters of impurities, within a half-space domain results in the formation of a densely packed layer of nanometer-sized bubbles with high number density. This prediction is consistent with available experimental observations in which a dense zone of helium bubbles is observed in tungsten, which are compared to estimates of the layer characteristics. Direct numerical simulation of the reaction–diffusion cluster dynamics supports the analysis presented here. (paper)

  8. Cluster dynamics models of irradiation damage accumulation in ferritic iron. II. Effects of reaction dimensionality

    Energy Technology Data Exchange (ETDEWEB)

    Kohnert, Aaron A.; Wirth, Brian D. [University of Tennessee, Knoxville, Tennessee 37996-2300 (United States)

    2015-04-21

    The black dot damage features which develop in iron at low temperatures exhibit significant mobility during in situ irradiation experiments via a series of discrete, intermittent, long range hops. By incorporating this mobility into cluster dynamics models, the temperature dependence of such damage structures can be explained with a surprising degree of accuracy. Such motion, however, is one dimensional in nature. This aspect of the physics has not been fully considered in prior models. This article describes one dimensional reaction kinetics in the context of cluster dynamics and applies them to the black dot problem. This allows both a more detailed description of the mechanisms by which defects execute irradiation-induced hops while allowing a full examination of the importance of kinetic assumptions in accurately assessing the development of this irradiation microstructure. Results are presented to demonstrate whether one dimensional diffusion alters the dependence of the defect population on factors such as temperature and defect hop length. Finally, the size of interstitial loops that develop is shown to depend on the extent of the reaction volumes between interstitial clusters, as well as the dimensionality of these interactions.

  9. Automatic segmentation of dynamic neuroreceptor single-photon emission tomography images using fuzzy clustering

    International Nuclear Information System (INIS)

    Acton, P.D.; Pilowsky, L.S.; Kung, H.F.; Ell, P.J.

    1999-01-01

    The segmentation of medical images is one of the most important steps in the analysis and quantification of imaging data. However, partial volume artefacts make accurate tissue boundary definition difficult, particularly for images with lower resolution commonly used in nuclear medicine. In single-photon emission tomography (SPET) neuroreceptor studies, areas of specific binding are usually delineated by manually drawing regions of interest (ROIs), a time-consuming and subjective process. This paper applies the technique of fuzzy c-means clustering (FCM) to automatically segment dynamic neuroreceptor SPET images. Fuzzy clustering was tested using a realistic, computer-generated, dynamic SPET phantom derived from segmenting an MR image of an anthropomorphic brain phantom. Also, the utility of applying FCM to real clinical data was assessed by comparison against conventional ROI analysis of iodine-123 iodobenzamide (IBZM) binding to dopamine D 2 /D 3 receptors in the brains of humans. In addition, a further test of the methodology was assessed by applying FCM segmentation to [ 123 I]IDAM images (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio] benzyl alcohol) of serotonin transporters in non-human primates. In the simulated dynamic SPET phantom, over a wide range of counts and ratios of specific binding to background, FCM correlated very strongly with the true counts (correlation coefficient r 2 >0.99, P 123 I]IBZM data comparable with manual ROI analysis, with the binding ratios derived from both methods significantly correlated (r 2 =0.83, P<0.0001). Fuzzy clustering is a powerful tool for the automatic, unsupervised segmentation of dynamic neuroreceptor SPET images. Where other automated techniques fail completely, and manual ROI definition would be highly subjective, FCM is capable of segmenting noisy images in a robust and repeatable manner. (orig.)

  10. Dynamic connectivity algorithms for Monte Carlo simulations of the random-cluster model

    International Nuclear Information System (INIS)

    Elçi, Eren Metin; Weigel, Martin

    2014-01-01

    We review Sweeny's algorithm for Monte Carlo simulations of the random cluster model. Straightforward implementations suffer from the problem of computational critical slowing down, where the computational effort per edge operation scales with a power of the system size. By using a tailored dynamic connectivity algorithm we are able to perform all operations with a poly-logarithmic computational effort. This approach is shown to be efficient in keeping online connectivity information and is of use for a number of applications also beyond cluster-update simulations, for instance in monitoring droplet shape transitions. As the handling of the relevant data structures is non-trivial, we provide a Python module with a full implementation for future reference.

  11. Estimation of radiation hardening in ferritic steels using the cluster dynamics models

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jun Hyun; Kim, Whung Whoe; Hong, Jun Hwa [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    Evolution of microstructure under irradiation brings about the mechanical property changes of materials, of which the major concern is radiation hardening in this work. Radiation hardening is generally expressed in terms of an increase in yield strength as a function of radiation dose and temperature. Cluster dynamics model for radiation hardening has been developed to describe the evolution of point defects clusters (PDCs) and copperrich precipitates (CRPs). While the mathematical models developed by Stoller focus on the evolution of PDCs in ferritic steels under neutron irradiation, we slightly modify the model by including the CRP growth and estimate the magnitude of hardening induced by PDC and CRP. The model is then used to calculate the changes in yield strength of RPV steels. The calculation results are compared to measured yield strength values, obtained from surveillance testing of PWR vessel steels in France.

  12. Resistivity recovery simulations of electron-irradiated iron: Kinetic Monte Carlo versus cluster dynamics

    International Nuclear Information System (INIS)

    Dalla Torre, J.; Fu, C.-C.; Willaime, F.; Barbu, A.; Bocquet, J.-L.

    2006-01-01

    The isochronal resistivity recovery in high purity α-iron irradiated by electrons was successfully reproduced by a multiscale modelling approach. The stability and mobility of small self-defect clusters determined by ab initio methods were used as input data for an event based Kinetic Monte Carlo (KMC) model, used to explore the defect population evolution during the annealing and to extract the resistivity recovery peaks. In this paper, we investigate the possibility of using an efficient mesoscale model, the Cluster Dynamics (CD), instead of KMC in this approach. The comparison between the two methods for various CD initial conditions shows the importance of spatial correlations between defects, which are neglected in the CD model. However, using appropriate initial conditions, e.g. starting from the concentration of Frenkel pairs after the uncorrelated stage I E , the CD model captures the main characteristics of subsequent defect population evolution, and it can therefore be used for fast and semi-quantitative investigations

  13. Molecular dynamics study of B18H22 cluster implantation into silicon

    International Nuclear Information System (INIS)

    Marques, Luis A.; Pelaz, Lourdes; Santos, Ivan

    2007-01-01

    We have carried out molecular dynamics simulations of monatomic B and octadecaborane cluster implantations into Si in order to make a comparative study and determine the advantages and drawbacks of each approach when used to fabricate shallow junctions. We have simulated a total of 1000 cascades of monatomic boron and an equivalent of 56 cascades of octadecaborane in order to have good statistics. We have obtained and analyzed the doping profiles and the amount and morphology of the damage produced within the target. Our simulation results indicate that the use of octadecaborane clusters for the implantation process shows several advantages with respect to monatomic B beams, mainly related to the reduction of channeling and the lower amount of residual damage at the end of range

  14. The structure, dynamics, and star formation rate of the Orion nebula cluster

    International Nuclear Information System (INIS)

    Da Rio, Nicola; Tan, Jonathan C.; Jaehnig, Karl

    2014-01-01

    The spatial morphology and dynamical status of a young, still-forming stellar cluster provide valuable clues to the conditions during the star formation event and the processes that regulated it. We analyze the Orion Nebula Cluster (ONC), utilizing the latest censuses of its stellar content and membership estimates over a large wavelength range. We determine the center of mass of the ONC and study the radial dependence of angular substructure. The core appears rounder and smoother than the outskirts, which is consistent with a higher degree of dynamical processing. At larger distances, the departure from circular symmetry is mostly driven by the elongation of the system, with very little additional substructure, indicating a somewhat evolved spatial morphology or an expanding halo. We determine the mass density profile of the cluster, which is well fitted by a power law that is slightly steeper than a singular isothermal sphere. Together with the interstellar medium density, which is estimated from average stellar extinction, the mass content of the ONC is insufficient by a factor ∼1.8 to reproduce the observed velocity dispersion from virialized motions, in agreement with previous assessments that the ONC is moderately supervirial. This may indicate recent gas dispersal. Based on the latest estimates for the age spread in the system and our density profiles, we find that at the half-mass radius, 90% of the stellar population formed within ∼5-8 free-fall times (t ff ). This implies a star formation efficiency per t ff of ε ff ∼ 0.04-0.07 (i.e., relatively slow and inefficient star formation rates during star cluster formation).

  15. Dynamic PROOF clusters with PoD: architecture and user experience

    Science.gov (United States)

    Manafov, Anar

    2011-12-01

    PROOF on Demand (PoD) is a tool-set, which sets up a PROOF cluster on any resource management system. PoD is a user oriented product with an easy to use GUI and a command-line interface. It is fully automated. No administrative privileges or special knowledge is required to use it. PoD utilizes a plug-in system, to use different job submission front-ends. The current PoD distribution is shipped with LSF, Torque (PBS), Grid Engine, Condor, gLite, and SSH plug-ins. The product is to be extended. We therefore plan to implement a plug-in for AliEn Grid as well. Recently developed algorithms made it possible to efficiently maintain two types of connections: packet-forwarding and native PROOF connections. This helps to properly handle most kinds of workers, with and without firewalls. PoD maintains the PROOF environment automatically and, for example, prevents resource misusage in case when workers idle for too long. As PoD matures as a product and provides more plug-ins, it's used as a standard for setting up dynamic PROOF clusters in many different institutions. The GSI Analysis Facility (GSIAF) is in production since 2007. The static PROOF cluster has been phased out end of 2009. GSIAF is now completely based on PoD. Users create private dynamic PROOF clusters on the general purpose batch farm. This provides an easier resource sharing between interactive local batch and Grid usage. The main user communities are FAIR and ALICE.

  16. Evolution of rotating star clusters at the inelastic-collision stage. II. Dynamics of a disk of gas and stars

    International Nuclear Information System (INIS)

    Romanova, M.M.

    1985-01-01

    The dynamics of a gas--star disk embedded in a dense, mildly oblate (flattening epsilon-c or approx. =0.2--0.3 the stable disk will survive for at least half the cluster evolution time. The possibility of a thin disk of stars existing inside a dense star cluster is considered. For small epsilon-c and for disk member stars having > or approx. =0.04 the mass of the cluster members, collisions between cluster and disk stars will have no effect on the disk evolution prior to instability

  17. Molecular dynamics simulations of the interaction between 60 deg. dislocation and self-interstitial cluster in silicon

    International Nuclear Information System (INIS)

    Jing Yuhang; Meng Qingyuan; Zhao Wei

    2009-01-01

    Molecular dynamics simulations are performed to investigate the interaction between 60 deg. shuffle dislocation and tetrainterstitial (I 4 ) cluster in silicon, using Stillinger-Weber (SW) potential to calculate the interatomic forces. Based on Parrinello-Rahman method, shear stress is exerted on the model to move the dislocation. Simulation results show that the I 4 cluster can bend the dislocation line and delay the dislocation movement. During the course of intersection the dislocation line sections relatively far away from the I 4 cluster accelerate first, and then decelerate. The critical shear stress unpinning the 60 deg. dislocation from the I 4 cluster decreases as the temperature increases in the models.

  18. The energy and stability of helium-related cluster in nickel: A study of molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Hengfeng, E-mail: gonghengfeng@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Division of Nuclear Materials and Engineering, Shanghai 201800 (China); Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciences, Shanghai 201800 (China); Wang, Chengbin; Zhang, Wei; Xu, Jian [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Division of Nuclear Materials and Engineering, Shanghai 201800 (China); Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciences, Shanghai 201800 (China); Huai, Ping, E-mail: huaiping@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Division of Nuclear Materials and Engineering, Shanghai 201800 (China); Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800 (China); Deng, Huiqiu; Hu, Wangyu [Hunan University, Department of Applied Physics, Changsha 410082 (China)

    2016-02-01

    Highlights: • The He-related clusters exhibit the very high symmetry. • The trapping capability of vacancy to defects becomes weak due to the pre-existed SIA. • The average length of He{sub N}V{sub 1} clusters is longer than one of He{sub N} and He{sub N}V{sub 1}SIA{sub 1} cluster. - Abstract: Using molecular dynamics simulation, we investigated the energy and stability of helium-related cluster in nickel. All the binding energies of the He-related clusters are demonstrated to be positive and increase with the cluster sizes. Due to the pre-existed self-interstitial nickel atom, the trapping capability of vacancy to defects becomes weak. Besides, the minimum energy configurations of He-related clusters exhibit the very high symmetry in the local atomistic environment. And for the He{sub N} and He{sub N}V{sub 1}SIA{sub 1} clusters, the average length of He–He bonds shortens, but it elongates for the He{sub N}V{sub 1} clusters with helium cluster sizes. The helium-to-vacancy ratio plays a decisive role on the binding energies of He{sub N}V{sub M} cluster. These results can provide some excellent clues to insight the initial stage of helium bubbles nucleation and growth in the Ni-based alloys for the Generation-IV Molten Salt Reactor.

  19. Dynamics of water clusters confined in proteins: a molecular dynamics simulation study of interfacial waters in a dimeric hemoglobin.

    Science.gov (United States)

    Gnanasekaran, Ramachandran; Xu, Yao; Leitner, David M

    2010-12-23

    Water confined in proteins exhibits dynamics distinct from the dynamics of water in the bulk or near the surface of a biomolecule. We examine the water dynamics at the interface of the two globules of the homodimeric hemoglobin from Scapharca inaequivalvis (HbI) by molecular dynamics (MD) simulations, with focus on water-protein hydrogen bond lifetimes and rotational anisotropy of the interfacial waters. We find that relaxation of the waters at the interface of both deoxy- and oxy-HbI, which contain a cluster of 17 and 11 interfacial waters, respectively, is well described by stretched exponentials with exponents from 0.1 to 0.6 and relaxation times of tens to thousands of picoseconds. The interfacial water molecules of oxy-HbI exhibit slower rotational relaxation and hydrogen bond rearrangement than those of deoxy-HbI, consistent with an allosteric transition from unliganded to liganded conformers involving the expulsion of several water molecules from the interface. Though the interfacial waters are translationally and rotationally static on the picosecond time scale, they contribute to fast communication between the globules via vibrations. We find that the interfacial waters enhance vibrational energy transport across the interface by ≈10%.

  20. The effect of gas dynamics on semi-analytic modelling of cluster galaxies

    Science.gov (United States)

    Saro, A.; De Lucia, G.; Dolag, K.; Borgani, S.

    2008-12-01

    We study the degree to which non-radiative gas dynamics affect the merger histories of haloes along with subsequent predictions from a semi-analytic model (SAM) of galaxy formation. To this aim, we use a sample of dark matter only and non-radiative smooth particle hydrodynamics (SPH) simulations of four massive clusters. The presence of gas-dynamical processes (e.g. ram pressure from the hot intra-cluster atmosphere) makes haloes more fragile in the runs which include gas. This results in a 25 per cent decrease in the total number of subhaloes at z = 0. The impact on the galaxy population predicted by SAMs is complicated by the presence of `orphan' galaxies, i.e. galaxies whose parent substructures are reduced below the resolution limit of the simulation. In the model employed in our study, these galaxies survive (unaffected by the tidal stripping process) for a residual merging time that is computed using a variation of the Chandrasekhar formula. Due to ram-pressure stripping, haloes in gas simulations tend to be less massive than their counterparts in the dark matter simulations. The resulting merging times for satellite galaxies are then longer in these simulations. On the other hand, the presence of gas influences the orbits of haloes making them on average more circular and therefore reducing the estimated merging times with respect to the dark matter only simulation. This effect is particularly significant for the most massive satellites and is (at least in part) responsible for the fact that brightest cluster galaxies in runs with gas have stellar masses which are about 25 per cent larger than those obtained from dark matter only simulations. Our results show that gas dynamics has only a marginal impact on the statistical properties of the galaxy population, but that its impact on the orbits and merging times of haloes strongly influences the assembly of the most massive galaxies.

  1. Multicolor photometry of the merging galaxy cluster A2319: Dynamics and star formation properties

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Peng-Fei; Yuan, Qi-Rong [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023 (China); Zhang, Li [QuFu Education Bureau, QuFu 273100 (China); Zhou, Xu, E-mail: pfyan0822@sina.com, E-mail: yuanqirong@njnu.edu.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-05-01

    Asymmetric X-ray emission and a powerful cluster-scale radio halo indicate that A2319 is a merging cluster of galaxies. This paper presents our multicolor photometry for A2319 with 15 optical intermediate filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) system. There are 142 galaxies with known spectroscopic redshifts within the viewing field of 58' × 58' centered on this rich cluster, including 128 member galaxies (called sample I). A large velocity dispersion in the rest frame, 1622{sub −70}{sup +91} km s{sup –1}, suggests merger dynamics in A2319. The contour map of projected density and localized velocity structure confirm the so-called A2319B substructure, at ∼10' northwest to the main concentration A2319A. The spectral energy distributions (SEDs) of more than 30,000 sources are obtained in our BATC photometry down to V ∼ 20 mag. A u-band (∼3551 Å) image with better seeing and spatial resolution, obtained with the Bok 2.3 m telescope at Kitt Peak, is taken to make star-galaxy separation and distinguish the overlapping contamination in the BATC aperture photometry. With color-color diagrams and photometric redshift technique, 233 galaxies brighter than h {sub BATC} = 19.0 are newly selected as member candidates after an exclusion of false candidates with contaminated BATC SEDs by eyeball-checking the u-band Bok image. The early-type galaxies are found to follow a tight color-magnitude correlation. Based on sample I and the enlarged sample of member galaxies (called sample II), subcluster A2319B is confirmed. The star formation properties of cluster galaxies are derived with the evolutionary synthesis model, PEGASE, assuming a Salpeter initial mass function and an exponentially decreasing star formation rate (SFR). A strong environmental effect on star formation histories is found in the manner that galaxies in the sparse regions have various star formation histories, while galaxies in the dense regions are found to have

  2. Dynamics of voids and clusters and fluctuations in the cosmic background radiation

    International Nuclear Information System (INIS)

    Salpeter, E.E.

    1983-01-01

    The author summarizes briefly calculations on spherically symmetric models without dissipation for the dynamical development of large voids and galaxy (super)clusters from small underdensities and overdensities, respectively, at the recombination era. Implications are mentioned and conjectures for more complex geometries are discussed. He infers the density fluctuations which must have been present just after the recombination era to produce some present-day configuration. Fluctuations in the present-day cosmic background radiation are related to this and their inferred amplitude depends very strongly on the present-day value of the cosmological density parameter. The relation to observed upper limits on these fluctuations are discussed. (Auth.)

  3. Detecting brain dynamics during resting state: a tensor based evolutionary clustering approach

    Science.gov (United States)

    Al-sharoa, Esraa; Al-khassaweneh, Mahmood; Aviyente, Selin

    2017-08-01

    Human brain is a complex network with connections across different regions. Understanding the functional connectivity (FC) of the brain is important both during resting state and task; as disruptions in connectivity patterns are indicators of different psychopathological and neurological diseases. In this work, we study the resting state functional connectivity networks (FCNs) of the brain from fMRI BOLD signals. Recent studies have shown that FCNs are dynamic even during resting state and understanding the temporal dynamics of FCNs is important for differentiating between different conditions. Therefore, it is important to develop algorithms to track the dynamic formation and dissociation of FCNs of the brain during resting state. In this paper, we propose a two step tensor based community detection algorithm to identify and track the brain network community structure across time. First, we introduce an information-theoretic function to reduce the dynamic FCN and identify the time points that are similar topologically to combine them into a tensor. These time points will be used to identify the different FC states. Second, a tensor based spectral clustering approach is developed to identify the community structure of the constructed tensors. The proposed algorithm applies Tucker decomposition to the constructed tensors and extract the orthogonal factor matrices along the connectivity mode to determine the common subspace within each FC state. The detected community structure is summarized and described as FC states. The results illustrate the dynamic structure of resting state networks (RSNs), including the default mode network, somatomotor network, subcortical network and visual network.

  4. One- and two-particle correlation functions in the dynamical quantum cluster approach

    International Nuclear Information System (INIS)

    Hochkeppel, Stephan

    2008-01-01

    This thesis is dedicated to a theoretical study of the 1-band Hubbard model in the strong coupling limit. The investigation is based on the Dynamical Cluster Approximation (DCA) which systematically restores non-local corrections to the Dynamical Mean Field approximation (DMFA). The DCA is formulated in momentum space and is characterised by a patching of the Brillouin zone where momentum conservation is only recovered between two patches. The approximation works well if k-space correlation functions show a weak momentum dependence. In order to study the temperature and doping dependence of the spin- and charge excitation spectra, we explicitly extend the Dynamical Cluster Approximation to two-particle response functions. The full irreducible two-particle vertex with three momenta and frequencies is approximated by an effective vertex dependent on the momentum and frequency of the spin and/or charge excitations. The effective vertex is calculated by using the Quantum Monte Carlo method on the finite cluster whereas the analytical continuation of dynamical quantities is performed by a stochastic version of the maximum entropy method. A comparison with high temperature auxiliary field quantum Monte Carlo data serves as a benchmark for our approach to two-particle correlation functions. Our method can reproduce basic characteristics of the spin- and charge excitation spectrum. Near and beyond optimal doping, our results provide a consistent overall picture of the interplay between charge, spin and single-particle excitations: a collective spin mode emerges at optimal doping and sufficiently low temperatures in the spin response spectrum and exhibits the energy scale of the magnetic exchange interaction J. Simultaneously, the low energy single-particle excitations are characterised by a coherent quasiparticle with bandwidth J. The origin of the quasiparticle can be quite well understood in a picture of a more or less antiferromagnetic ordered background in which holes

  5. Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California

    Energy Technology Data Exchange (ETDEWEB)

    Nadeau, Robert Michael [Univ. of California, Berkeley, CA (United States)

    1995-10-01

    This document contains information about the characterization and application of microearthquake clusters and fault zone dynamics. Topics discussed include: Seismological studies; fault-zone dynamics; periodic recurrence; scaling of microearthquakes to large earthquakes; implications of fault mechanics and seismic hazards; and wave propagation and temporal changes.

  6. Effects of incident cluster size, substrate temperature, and incident energy on bombardment of Ni clusters onto Cu (0 0 1) surface studied using molecular dynamics simulation

    International Nuclear Information System (INIS)

    Lin, Shiang-Jiun; Wu, Cheng-Da; Fang, Te-Hua; Chen, Guan-Hung

    2012-01-01

    The bombardment process of a Ni cluster onto a Cu (0 0 1) surface is studied using molecular dynamics (MD) simulations based on the tight-binding second-moment approximation (TB-SMA) many-body potential. The effects of incident cluster size, substrate temperature, and incident energy are evaluated in terms of molecular trajectories, kinetic energy, stress, self-diffusion coefficient, and sputtering yield. The simulation results clearly show that the penetration depth and Cu surface damage increase with increasing incident cluster size for a given incident energy per atom. The self-diffusion coefficient and the penetration depth of a cluster significantly increase with increasing substrate temperature. An incident cluster can be scattered into molecules or atoms that become embedded in the surface after incidence. When the incident energy is increased, the number of volcano-like defects and the penetration depth increase. A high sputtering yield can be obtained by increasing the incident energy at high temperature. The sputtering yield significantly increases with cluster size when the incident energy is above 5 eV/atom.

  7. Dynamics of fragment capture for cluster structures of weakly bound 7Li

    Directory of Open Access Journals (Sweden)

    Shrivastava A.

    2013-12-01

    Full Text Available Role of cluster structures of 7Li on reaction dynamics have been studied by performing exclusive measurements of prompt-γ rays from residues with scattered particles at energy, E/Vb = 1.6, with 198Pt target. Yields of the residues resulting after capture of t and 4,5,6He, corresponding to different excitation energies of the composite system were estimated. The results were compared with three body classical-dynamical model for breakup fusion, constrained by the measured fusion, α and t capture cross-sections. The cross-section of residues from capture of α and t agreed well with the prediction of the model showing dominance of the two step process - breakup fusion, while those from tightly bound 6He showed massive transfer to be the dominant mechanism.

  8. A survey of energy conservation mechanisms for dynamic cluster based wireless sensor networks

    International Nuclear Information System (INIS)

    Enam, R.N.; Tahir, M.; Ahmed, S.; Qureshi, R.

    2018-01-01

    WSN (Wireless Sensor Network) is an emerging technology that has unlimited potential for numerous application areas including military, crisis management, environmental, transportation, medical, home/ city automations and smart spaces. But energy constrained nature of WSNs necessitates that their architecture and communicating protocols to be designed in an energy aware manner. Sensor data collection through clustering mechanisms has become a common strategy in WSN. This paper presents a survey report on the major perspectives with which energy conservation mechanisms has been proposed in dynamic cluster based WSNs so far. All the solutions discussed in this paper focus on the cluster based protocols only.We have covered a vast scale of existing energy efficient protocols and have categorized them in six categories. In the beginning of this paper the fundamentals of the energy constraint issues of WSNs have been discussed and an overview of the causes of energy consumptions at all layers of WSN has been given. Later in this paper several previously proposed energy efficient protocols of WSNs are presented. (author)

  9. Theoretical study of electronic and dynamic properties of simple metal clusters in jellium model

    International Nuclear Information System (INIS)

    El-Amine Madjet, M.

    1994-01-01

    We have studied the electronic properties of alkali-metal clusters in various theoretical approximations and in the framework of the spherical jellium model. We have investigated the ground state properties of alkali clusters both in the LDA (local density approximation) and in HF (Hartree-Fock) theory. We have compared the LDA predictions of the ground state properties to predictions obtained within the HF theory. Such a comparison permitted us to check the validity of the local density functional theory in describing the ground state of a finite fermion system. For the study of collective dipolar excitations in clusters, we have considered an electromagnetic excitation. We have investigated the collective modes in the following approximations: random phase approximation (RPA), time-dependent local-density approximation (TDLDA) and the sum-rules approach. An assessment of the approximation for the continuum state within the RPA is made by comparing with TDLDA calculations for the static and dynamic electronic properties. The comparative study that we have done on the exchange-correlation effects on the electronic and optical properties have shown that the discrepancies with measured data are due mostly to the jellium approximation for the ionic background. (author). 69 refs., 30 figs., 18 tabs

  10. Displacement rate and temperature equivalence in stochastic cluster dynamics simulations of irradiated pure α-Fe

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Aaron [Sandia National Laboratories, Albuquerque, 87185 NM (United States); George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, 30332 GA (United States); Muntifering, Brittany [Sandia National Laboratories, Albuquerque, 87185 NM (United States); Northwestern University, Chicago, 60208 IL (United States); Dingreville, Rémi; Hattar, Khalid [Sandia National Laboratories, Albuquerque, 87185 NM (United States); Capolungo, Laurent, E-mail: laurent@lanl.gov [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, 30332 GA (United States); Material Science and Technology Division, MST-8, Los Alamos National Laboratory, Los Alamos, 87545 NM (United States)

    2016-11-15

    Charged particle irradiation is a frequently used experimental tool to study damage accumulation in metals expected during neutron irradiation. Understanding the correspondence between displacement rate and temperature during such studies is one of several factors that must be taken into account in order to design experiments that produce equivalent damage accumulation to neutron damage conditions. In this study, spatially resolved stochastic cluster dynamics (SRSCD) is used to simulate damage evolution in α-Fe and find displacement rate/temperature pairs under ‘target’ and ‘proxy’ conditions for which the local distribution of vacancies and vacancy clusters is the same as a function of displacement damage. The SRSCD methodology is chosen for this study due to its computational efficiency and ability to simulate damage accumulation in spatially inhomogeneous materials such as thin films. Results are presented for Frenkel pair irradiation and displacement cascade damage in thin films and bulk α-Fe. Holding all other material and irradiation conditions constant, temperature adjustments are shown to successfully make up for changes in displacement rate such that defect concentrations and cluster sizes remain relatively constant. The methodology presented in this study allows for a first-order prediction of the temperature at which ion irradiation experiments (‘proxy’ conditions) should take place in order to approximate neutron irradiation (‘target’ conditions).

  11. A Human Activity Recognition System Based on Dynamic Clustering of Skeleton Data

    Directory of Open Access Journals (Sweden)

    Alessandro Manzi

    2017-05-01

    Full Text Available Human activity recognition is an important area in computer vision, with its wide range of applications including ambient assisted living. In this paper, an activity recognition system based on skeleton data extracted from a depth camera is presented. The system makes use of machine learning techniques to classify the actions that are described with a set of a few basic postures. The training phase creates several models related to the number of clustered postures by means of a multiclass Support Vector Machine (SVM, trained with Sequential Minimal Optimization (SMO. The classification phase adopts the X-means algorithm to find the optimal number of clusters dynamically. The contribution of the paper is twofold. The first aim is to perform activity recognition employing features based on a small number of informative postures, extracted independently from each activity instance; secondly, it aims to assess the minimum number of frames needed for an adequate classification. The system is evaluated on two publicly available datasets, the Cornell Activity Dataset (CAD-60 and the Telecommunication Systems Team (TST Fall detection dataset. The number of clusters needed to model each instance ranges from two to four elements. The proposed approach reaches excellent performances using only about 4 s of input data (~100 frames and outperforms the state of the art when it uses approximately 500 frames on the CAD-60 dataset. The results are promising for the test in real context.

  12. A Human Activity Recognition System Based on Dynamic Clustering of Skeleton Data.

    Science.gov (United States)

    Manzi, Alessandro; Dario, Paolo; Cavallo, Filippo

    2017-05-11

    Human activity recognition is an important area in computer vision, with its wide range of applications including ambient assisted living. In this paper, an activity recognition system based on skeleton data extracted from a depth camera is presented. The system makes use of machine learning techniques to classify the actions that are described with a set of a few basic postures. The training phase creates several models related to the number of clustered postures by means of a multiclass Support Vector Machine (SVM), trained with Sequential Minimal Optimization (SMO). The classification phase adopts the X-means algorithm to find the optimal number of clusters dynamically. The contribution of the paper is twofold. The first aim is to perform activity recognition employing features based on a small number of informative postures, extracted independently from each activity instance; secondly, it aims to assess the minimum number of frames needed for an adequate classification. The system is evaluated on two publicly available datasets, the Cornell Activity Dataset (CAD-60) and the Telecommunication Systems Team (TST) Fall detection dataset. The number of clusters needed to model each instance ranges from two to four elements. The proposed approach reaches excellent performances using only about 4 s of input data (~100 frames) and outperforms the state of the art when it uses approximately 500 frames on the CAD-60 dataset. The results are promising for the test in real context.

  13. Dynamic Fuzzy Clustering Method for Decision Support in Electricity Markets Negotiation

    Directory of Open Access Journals (Sweden)

    Ricardo FAIA

    2016-10-01

    Full Text Available Artificial Intelligence (AI methods contribute to the construction of systems where there is a need to automate the tasks. They are typically used for problems that have a large response time, or when a mathematical method cannot be used to solve the problem. However, the application of AI brings an added complexity to the development of such applications. AI has been frequently applied in the power systems field, namely in Electricity Markets (EM. In this area, AI applications are essentially used to forecast / estimate the prices of electricity or to search for the best opportunity to sell the product. This paper proposes a clustering methodology that is combined with fuzzy logic in order to perform the estimation of EM prices. The proposed method is based on the application of a clustering methodology that groups historic energy contracts according to their prices’ similarity. The optimal number of groups is automatically calculated taking into account the preference for the balance between the estimation error and the number of groups. The centroids of each cluster are used to define a dynamic fuzzy variable that approximates the tendency of contracts’ history. The resulting fuzzy variable allows estimating expected prices for contracts instantaneously and approximating missing values in the historic contracts.

  14. Automatic detection of arterial input function in dynamic contrast enhanced MRI based on affinity propagation clustering.

    Science.gov (United States)

    Shi, Lin; Wang, Defeng; Liu, Wen; Fang, Kui; Wang, Yi-Xiang J; Huang, Wenhua; King, Ann D; Heng, Pheng Ann; Ahuja, Anil T

    2014-05-01

    To automatically and robustly detect the arterial input function (AIF) with high detection accuracy and low computational cost in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In this study, we developed an automatic AIF detection method using an accelerated version (Fast-AP) of affinity propagation (AP) clustering. The validity of this Fast-AP-based method was proved on two DCE-MRI datasets, i.e., rat kidney and human head and neck. The detailed AIF detection performance of this proposed method was assessed in comparison with other clustering-based methods, namely original AP and K-means, as well as the manual AIF detection method. Both the automatic AP- and Fast-AP-based methods achieved satisfactory AIF detection accuracy, but the computational cost of Fast-AP could be reduced by 64.37-92.10% on rat dataset and 73.18-90.18% on human dataset compared with the cost of AP. The K-means yielded the lowest computational cost, but resulted in the lowest AIF detection accuracy. The experimental results demonstrated that both the AP- and Fast-AP-based methods were insensitive to the initialization of cluster centers, and had superior robustness compared with K-means method. The Fast-AP-based method enables automatic AIF detection with high accuracy and efficiency. Copyright © 2013 Wiley Periodicals, Inc.

  15. A Survey of Energy Conservation Mechanisms for Dynamic Cluster Based Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rabia Noor Enam

    2018-04-01

    Full Text Available WSN (Wireless Sensor Network is an emerging technology that has unlimited potential for numerous application areas including military, crisis management, environmental, transportation, medical, home/ city automations and smart spaces. But energy constrained nature of WSNs necessitates that their architecture and communicating protocols to be designed in an energy aware manner. Sensor data collection through clustering mechanisms has become a common strategy in WSN. This paper presents a survey report on the major perspectives with which energy conservation mechanisms has been proposed in dynamic cluster based WSNs so far. All the solutions discussed in this paper focus on the cluster based protocols only.We have covered a vast scale of existing energy efficient protocols and have categorized them in six categories. In the beginning of this paper the fundamentals of the energy constraint issues of WSNs have been discussed and an overview of the causes of energy consumptions at all layers of WSN has been given. Later in this paper several previously proposed energy efficient protocols of WSNs are presented.

  16. Dynamic clustering and dispersion of lipid rafts contribute to fusion competence of myogenic cells

    Energy Technology Data Exchange (ETDEWEB)

    Mukai, Atsushi [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 36-3 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan); Kurisaki, Tomohiro [Department of Growth Regulation, Institute for Frontier Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Sato, Satoshi B. [Research Center for Low Temperature and Material Sciences, Kyoto University, Yoshida-honmachi, Kyoto 606-8501 (Japan); Kobayashi, Toshihide [Lipid Biology Laboratory, Discovery Research Institute, RIKEN, Wako, Saitama 351-0198 (Japan); Kondoh, Gen [Laboratory of Animal Experiments for Regeneration, Institute for Frontier Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Hashimoto, Naohiro, E-mail: nao@nils.go.jp [Department of Regenerative Medicine, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 36-3 Gengo, Morioka, Oobu, Aichi 474-8522 (Japan)

    2009-10-15

    Recent research indicates that the leading edge of lamellipodia of myogenic cells (myoblasts and myotubes) contains presumptive fusion sites, yet the mechanisms that render the plasma membrane fusion-competent remain largely unknown. Here we show that dynamic clustering and dispersion of lipid rafts contribute to both cell adhesion and plasma membrane union during myogenic cell fusion. Adhesion-complex proteins including M-cadherin, {beta}-catenin, and p120-catenin accumulated at the leading edge of lamellipodia, which contains the presumptive fusion sites of the plasma membrane, in a lipid raft-dependent fashion prior to cell contact. In addition, disruption of lipid rafts by cholesterol depletion directly prevented the membrane union of myogenic cell fusion. Time-lapse recording showed that lipid rafts were laterally dispersed from the center of the lamellipodia prior to membrane fusion. Adhesion proteins that had accumulated at lipid rafts were also removed from the presumptive fusion sites when lipid rafts were laterally dispersed. The resultant lipid raft- and adhesion complex-free area at the leading edge fused with the opposing plasma membrane. These results demonstrate a key role for dynamic clustering/dispersion of lipid rafts in establishing fusion-competent sites of the myogenic cell membrane, providing a novel mechanistic insight into the regulation of myogenic cell fusion.

  17. The shape of velocity dispersion profiles and the dynamical state of galaxy clusters

    Science.gov (United States)

    Costa, A. P.; Ribeiro, A. L. B.; de Carvalho, R. R.

    2018-01-01

    Motivated by the existence of the relationship between the dynamical state of clusters and the shape of the velocity dispersion profiles (VDPs), we study the VDPs for Gaussian (G) and non-Gaussian (NG) systems for a subsample of clusters from the Yang catalogue. The groups cover a redshift interval of 0.03 ≤ z ≤ 0.1 with halo mass ≥1014 M⊙. We use a robust statistical method, Hellinger Distance, to classify the dynamical state of the systems according to their velocity distribution. The stacked VDP of each class, G and NG, is then determined using either Bright or Faint galaxies. The stacked VDP for G groups displays a central peak followed by a monotonically decreasing trend which indicates a predominance of radial orbits, with the Bright stacked VDP showing lower velocity dispersions in all radii. The distinct features we find in NG systems are manifested not only by the characteristic shape of VDP, with a depression in the central region, but also by a possible higher infall rate associated with galaxies in the Faint stacked VDP.

  18. Dynamic clustering and dispersion of lipid rafts contribute to fusion competence of myogenic cells

    International Nuclear Information System (INIS)

    Mukai, Atsushi; Kurisaki, Tomohiro; Sato, Satoshi B.; Kobayashi, Toshihide; Kondoh, Gen; Hashimoto, Naohiro

    2009-01-01

    Recent research indicates that the leading edge of lamellipodia of myogenic cells (myoblasts and myotubes) contains presumptive fusion sites, yet the mechanisms that render the plasma membrane fusion-competent remain largely unknown. Here we show that dynamic clustering and dispersion of lipid rafts contribute to both cell adhesion and plasma membrane union during myogenic cell fusion. Adhesion-complex proteins including M-cadherin, β-catenin, and p120-catenin accumulated at the leading edge of lamellipodia, which contains the presumptive fusion sites of the plasma membrane, in a lipid raft-dependent fashion prior to cell contact. In addition, disruption of lipid rafts by cholesterol depletion directly prevented the membrane union of myogenic cell fusion. Time-lapse recording showed that lipid rafts were laterally dispersed from the center of the lamellipodia prior to membrane fusion. Adhesion proteins that had accumulated at lipid rafts were also removed from the presumptive fusion sites when lipid rafts were laterally dispersed. The resultant lipid raft- and adhesion complex-free area at the leading edge fused with the opposing plasma membrane. These results demonstrate a key role for dynamic clustering/dispersion of lipid rafts in establishing fusion-competent sites of the myogenic cell membrane, providing a novel mechanistic insight into the regulation of myogenic cell fusion.

  19. A clustering approach to examine the dynamics of the NASDAQ topology in times of crisis

    Directory of Open Access Journals (Sweden)

    Salim Lahmiri

    2012-10-01

    Full Text Available This paper investigates the dynamics of the NASDAQ topology before, during, and after 2008 financial crisis. First, multiresolution analysis by virtue of wavelet transform is employed to denoise each NASDAQ sector return series. Second, the correlation matrix of sectors is built and analyzed in each time period to view comovements of sectors. Third, hierarchical clustering trees are constructed in each time period to find out how the structure of the NASDAQ market evolves through time. Our results suggest that interrelationships between sectors become stronger in times of crisis and especially in post-crisis period. In addition, some markets tend to form the same cluster in all time periods; for instance the Industrial and Bank sectors and the Telecommunication and Computer sectors. However, the general topology of the NASDAQ market has been considerably changed over periods. In sum, the complex structure of the NASDAQ market is dynamic and is more integrated after 2008 financial crisis. This result indicates that there are less diversification opportunities in the post-crisis period in comparison with pre-crisis period. These empirical findings are important for the development of subsequent portfolio strategies.

  20. Transcendence, ethics, and Mobil Oil: a rhetorical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, L.A.

    1982-01-01

    Since 1970 the Mobil Oil Corporation has been widely recognized as the self-appointed champion of corporate America's right to advocate. Corporate advocacy, as distinguished from other forms of external corporate communication, is concerned with the modification of corporate images and those social and political issues directly linked to the well-being of the corporation. Kenneth Burke's theory of transcendence serves as the central critical referent in the critique of Mobil's advocacy. By evoking elaborate transcendent frames of reference, Mobil seeks to identify its actions with higher syntheses that allow them to transcend the guilt produced by identifications with lesser orders. Mobil evokes two ultimate frames which are recurrent in their transcendent identifications: American energy independence and freedom of expression. In the latter part of this investigation, Sidney Hook's ethics of controversy was offered as an ethical referent. Two levels of analysis were conducted: first, three major types of arguments against Mobil's advocacy were evaluated; second, Mobil's discourse was evaluated. The conclusion was reached that Mobil's advocacy is largely an ethical form of American democratic discourse. In the final section of this investigation, the heuristic values of this critique were discussed.

  1. Self-Transcendence: Integrating Ends and Means in Value Counseling.

    Science.gov (United States)

    Conn, Walter E.

    1994-01-01

    Compares pastoral and secular counseling, suggesting that pastoral counseling is distinctively specified by limit experiences. Relates Lonergan's view of self-transcendence to Egan's three-stage model and various approaches summarized by Corey. Concludes that, although distinctive in some ways, pastoral counseling and secular counseling are…

  2. Self-transcendence and well-being in homeless adults.

    Science.gov (United States)

    Runquist, Jennifer J; Reed, Pamela G

    2007-03-01

    This study examines the relationships of spiritually and physically related variables to well-being among homeless adults. A convenience sample of 61 sheltered homeless persons completed the Spiritual Perspective Scale, the Self-Transcendence Scale, the Index of Well-Being, and items measuring fatigue and health status. The data were subjected to correlational and multiple regression analysis. Positive, significant correlations were found among spiritual perspective, self-transcendence, health status, and well-being. Fatigue was inversely correlated with health status and well-being. Self-transcendence and health status together explained 59% of the variance in well-being. The findings support Reed's theory of self-transcendence, in which there is the basic assumption that human beings have the potential to integrate difficult life situations. This study contributes to the growing body of evidence that conceptualizes homeless persons as having spiritual, emotional, and physical capacities that can be used by health care professionals to promote well-being in this vulnerable population.

  3. Sacred Uncertainty: Hope, Fear, and the Quest for Transcendence ...

    African Journals Online (AJOL)

    ... fear, and certainty to both the notion of God and the experience of the physical body. Finally, this article locates in the works of both thinkers the establishment and maintenance of an illusory self as grasping at a primal form of certainty, and a link between spiritual transcendence and a relinquishment of hope, fear, and the ...

  4. Transcendence, Taxis, Trust: Richard Kearney and Jacques Derrida

    Directory of Open Access Journals (Sweden)

    Ulrich Schmiedel

    2017-03-01

    Full Text Available Whatever else it takes to drive a taxi, it takes trust. Day after day, the driver has to decide whether the other is or is not trustworthy. I take the taxi as a test case to analyze and assess Richard Kearney’s diacritical hermeneutics of the other. I argue that Kearney functionalizes the concept of transcendence in order to connect the transcendence of the finite other to the transcendence of the infinite other. However, in his central critique of the deconstructionists following Jacques Derrida, Kearney counters his connection. While Kearney’s critique of Derrida’s account of absolute alterity is correct and compelling, I argue that Derrida’s critique of a distinction between the trustworthy other and the non-trustworthy other might be more crucial than Kearney contends. Insisting on openness to the other’s otherness, Derrida provokes any hermeneutic of the other to trust in transcendence. The taxi is taken as a test to illustrate the implications which diacritical and deconstructive drivers might have for evaluating the entanglement of ethics and eschatology—inside and outside the taxi.

  5. The Levels of Leadership and Transcendent Servant Leadership Development

    Science.gov (United States)

    McClellan, Jeffrey L.

    2009-01-01

    This paper addresses the challenges associated with defining and conceptualizing leadership amidst the plethora of theoretical constructs and definitions of leadership and proposes a model for developing transcendent servant-leaders. Based on a review of the literature, three categorical levels of leadership are outlined and discussed that…

  6. The relation between evil and transcendence: new possibilities ...

    African Journals Online (AJOL)

    In this article I will analyse the concept of evil in terms of the typology of transcendence that was developed by Wessel Stoker. I will argue that there are, within the (post-) modern discourse, and ... This notion of evil may enhance our ethical responsibility towards it. South African Journal of Philosophy 2014, 33(3): 259–269 ...

  7. U1 snDNA clusters in grasshoppers: chromosomal dynamics and genomic organization

    Science.gov (United States)

    Anjos, A; Ruiz-Ruano, F J; Camacho, J P M; Loreto, V; Cabrero, J; de Souza, M J; Cabral-de-Mello, D C

    2015-01-01

    The spliceosome, constituted by a protein set associated with small nuclear RNA (snRNA), is responsible for mRNA maturation through intron removal. Among snRNA genes, U1 is generally a conserved repetitive sequence. To unveil the chromosomal/genomic dynamics of this multigene family in grasshoppers, we mapped U1 genes by fluorescence in situ hybridization in 70 species belonging to the families Proscopiidae, Pyrgomorphidae, Ommexechidae, Romaleidae and Acrididae. Evident clusters were observed in all species, indicating that, at least, some U1 repeats are tandemly arrayed. High conservation was observed in the first four families, with most species carrying a single U1 cluster, frequently located in the third or fourth longest autosome. By contrast, extensive variation was observed among Acrididae, from a single chromosome pair carrying U1 to all chromosome pairs carrying it, with occasional occurrence of two or more clusters in the same chromosome. DNA sequence analysis in Eyprepocnemis plorans (species carrying U1 clusters on seven different chromosome pairs) and Locusta migratoria (carrying U1 in a single chromosome pair) supported the coexistence of functional and pseudogenic lineages. One of these pseudogenic lineages was truncated in the same nucleotide position in both species, suggesting that it was present in a common ancestor to both species. At least in E. plorans, this U1 snDNA pseudogenic lineage was associated with 5S rDNA and short interspersed elements (SINE)-like mobile elements. Given that we conclude in grasshoppers that the U1 snDNA had evolved under the birth-and-death model and that its intragenomic spread might be related with mobile elements. PMID:25248465

  8. TH-CD-207A-09: Stay On Target: Dynamic, Patient-Specific Templates of Fiducial Marker Clusters for IGRT

    International Nuclear Information System (INIS)

    Campbell, W; Miften, M; Jones, B

    2016-01-01

    Purpose: Pancreatic SBRT relies on extremely accurate delivery of ablative radiation doses to the target, and intra-fractional tracking of fiducial markers can facilitate improvements in dose delivery. However, this requires algorithms that are able to find fiducial markers with high speed and accuracy. The purpose of this study was to develop a novel marker tracking algorithm that is robust against many of the common errors seen with traditional template matching techniques. Methods: Using CBCT projection images, a method was developed to create detailed template images of fiducial marker clusters without prior knowledge of the number of markers, their positions, or their orientations. Briefly, the method (i) enhances markers in projection images, (ii) stabilizes the cluster’s position, (iii) reconstructs the cluster in 3D, and (iv) precomputes a set of static template images dependent on gantry angle. Furthermore, breathing data were used to produce 4D reconstructions of clusters, yielding dynamic template images dependent on gantry angle and breathing amplitude. To test these two approaches, static and dynamic templates were used to track the motion of marker clusters in more than 66,000 projection images from 75 CBCT scans of 15 pancreatic SBRT patients. Results: For both static and dynamic templates, the new technique was able to locate marker clusters present in projection images 100% of the time. The algorithm was also able to correctly locate markers in several instances where only some of the markers were visible due to insufficient field-of-view. In cases where clusters exhibited deformation and/or rotation during breathing, dynamic templates resulted in cross-correlation scores up to 70% higher than static templates. Conclusion: Patient-specific templates provided complete tracking of fiducial marker clusters in CBCT scans, and dynamic templates helped to provide higher cross-correlation scores for deforming/rotating clusters. This novel algorithm

  9. TH-CD-207A-09: Stay On Target: Dynamic, Patient-Specific Templates of Fiducial Marker Clusters for IGRT

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, W; Miften, M; Jones, B [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO (United States)

    2016-06-15

    Purpose: Pancreatic SBRT relies on extremely accurate delivery of ablative radiation doses to the target, and intra-fractional tracking of fiducial markers can facilitate improvements in dose delivery. However, this requires algorithms that are able to find fiducial markers with high speed and accuracy. The purpose of this study was to develop a novel marker tracking algorithm that is robust against many of the common errors seen with traditional template matching techniques. Methods: Using CBCT projection images, a method was developed to create detailed template images of fiducial marker clusters without prior knowledge of the number of markers, their positions, or their orientations. Briefly, the method (i) enhances markers in projection images, (ii) stabilizes the cluster’s position, (iii) reconstructs the cluster in 3D, and (iv) precomputes a set of static template images dependent on gantry angle. Furthermore, breathing data were used to produce 4D reconstructions of clusters, yielding dynamic template images dependent on gantry angle and breathing amplitude. To test these two approaches, static and dynamic templates were used to track the motion of marker clusters in more than 66,000 projection images from 75 CBCT scans of 15 pancreatic SBRT patients. Results: For both static and dynamic templates, the new technique was able to locate marker clusters present in projection images 100% of the time. The algorithm was also able to correctly locate markers in several instances where only some of the markers were visible due to insufficient field-of-view. In cases where clusters exhibited deformation and/or rotation during breathing, dynamic templates resulted in cross-correlation scores up to 70% higher than static templates. Conclusion: Patient-specific templates provided complete tracking of fiducial marker clusters in CBCT scans, and dynamic templates helped to provide higher cross-correlation scores for deforming/rotating clusters. This novel algorithm

  10. The Transcendence in Lucian Blaga’s Philosophical Thinking

    Directory of Open Access Journals (Sweden)

    Stelian Manolache

    2016-03-01

    Full Text Available On the occasion of the conference on Transcendence and Immanence - a topic buiding on the dialogue between philosophy and theology in the modern and post-modern time -, among the produced subjects, a discussion was held on the role played in respect with this dailogue by the inter-war famous philosophers, such as Lucian Blaga and Dumitru Stăniloaie. Below, we will present the issue of Transcendence according the the philosopher-poet Lucian Blaga’s vision; his vision is tructured into a Trilogy in his work: The Trilogy of Knowledge - The Dogmatic Aeon, The Luciferic Knowledge, The Transcendental Censorship - The Trilogy of the Culture - Horizon and Style; The Mioritic Space; The Genesis of the Metaphor and The Meaning of Culture - and The Trilogy of Values - Science and Creation; Magic Thinking and Religion; Art and Value. In these trilogies, the philosopher - poet elaborates, from an original metaphysical point of view, on the dimension of the knowledge of Transcendence - which he would define in in The Horizon of Mystery and Revelation. His vision will be addressed in a new theory of knowledge, which the philosopherpoet Lucian Blaga would distinguish as Paradisiac knowledge and Lucifer knowledge, within a new Metaphysics that would allow access to Transcendence and to the wonders beyond. Postulating the existence of certain faculties of Conscience, his Metaphysics would become, according to the Theory of Transcendence, a must for the human spirit; a proof for his approach would be the great philosophical systems of the world, from the antique to the modern.

  11. Theory of Transcendent unity of Religion

    Directory of Open Access Journals (Sweden)

    Hossein Ali Torkamany

    2015-09-01

    community". The Important result of The difference between vertical understanding from the horizontalis in the unity of religion. by the witness of nation of Islam - meaning the mediator between God and the Prophet of the People, the context of the unity and conflict resolution among the people to be provided. According toShiacommentators , the"moderate community" have minimal meaning and not maximal. Obtained on Shia traditions "moderate community" composed of some and not all Muslims, and some commentators have argued that the Quran is clear and apparent in dissatisfaction with some Muslims. According to the inward interpretation of Islam and "transcendent unity of religion", one religion over other religions have placed, it is the unity of religions. In general, the Quran, have especial comment on religions and none of the current theories do not fully explain the Quran's view. Quran calls into the word of God equally between religions, but this call to Islam is for all and no one is not who excluded from the invitation. and also the belief of the Prophet vertical, household, community center Shiites and people can be people through Bit interpreted not all Muslims claim Islam. Another important point is that the starting point should be first religion of anyone. At the end we can say: the theory of "transcendent unity of religions", with a focus on the true Islam and monotheistic religions version of the possibility of unity, has the following unique features: • the need to penetration in religionand religious invitation to unity of the religious path unique to each of them • struggle with exclusivismand requirement for progress of Muslims in unity • minimalistic interpretation of the moderate nation and the vertical understanding of witness. • The Holy Qur'an • Azizan, Mehdi, 2007, Pluralism In Islamic Thought , marifat, Vol:16, No:10(121, 13-25 • Asadi, Mohammad,2009, The religious pluralists unsuccessful in appealing to divine names and attributes ,Quran

  12. Theoretical studies of zirconium and carbon clusters with molecular dynamics simulations

    International Nuclear Information System (INIS)

    Zhang, B.

    1993-01-01

    With the aim of understanding the anomalous phonon behavior near the martensitic phase transition in Zr, we have simulated the dynamics of atomic motion in the high temperature bcc phase of Zr using an embedded-atom potential. The calculated dynamical structure factors reproduce the strong asymmetry in the scattering cross-sections in different Brillouin zones observed in inelastic neutron scattering experiments. From the real-space atomic picture, we observed the phase fluctuations between bcc and low temperature phase hcp. The anomalous phonon behavior arises from the incompleteness of the phase fluctuations. Combining an efficient simulated annealing scheme for generating closed, hollow, spheroidal cage structures with a tight-binding molecular-dynamics method for energy optimization. We have systematically studied the ground-state structure of every even-numbered carbon fullerene from C 20 to C 100 . Clusters of sizes 60, 70, and 84 are found to be energetically more stable than their neighbors. Most ground-state structures of fullerenes have relatively low symmetries. In many cases, several isomers of a fullerene are found to have competitively low energies, which suggests that a mixture of these isomers can be observed in experimentally prepared samples. We also simulate the collisions between fullerene and the thermal disintegration of fullerenes. We observed three different regimes of behavior as the collisions become more and more energetic: bouncing, fusion and fragmentation. The critical energies for fusion and fragmentation as well as details of the energy transfer process during the collisions are investigated. In simulations of the thermal disintegration of fullerene cages, the most commonly observed fragments after the disintegration of the carbon cages are dimers, rings, and multiple rings. The fragmentation temperature increases almost linearly with cluster size for small cages (n ≤ 58), but remains constant for larger fullerenes

  13. Molecular dynamics simulations to examine structure, energetics, and evaporation/condensation dynamics in small charged clusters of water or methanol containing a single monatomic ion.

    Science.gov (United States)

    Daub, Christopher D; Cann, Natalie M

    2012-11-01

    We study small clusters of water or methanol containing a single Ca(2+), Na(+), or Cl(-) ion with classical molecular dynamics simulations, using models that incorporate polarizability via the Drude oscillator framework. Evaporation and condensation of solvent from these clusters is examined in two systems, (1) for isolated clusters initially prepared at different temperatures and (2) those with a surrounding inert (Ar) gas of varying temperature. We examine these clusters over a range of sizes, from almost bare ions up to 40 solvent molecules. We report data on the evaporation and condensation of solvent from the clusters and argue that the observed temperature dependence of evaporation in the smallest clusters demonstrates that the presence of heated gas alone cannot, in most cases, solely account for bare ion production in electrospray ionization (ESI), neglecting the key contribution of the electric field. We also present our findings on the structure and energetics of the clusters as a function of size. Our data agree well with the abundant literature on hydrated ion clusters and offer some novel insight into the structure of methanol and ion clusters, especially those with a Cl(-) anion, where we observe the presence of chain-like structures of methanol molecules. Finally, we provide some data on the reparameterizations necessary to simulate ions in methanol using the separately developed Drude oscillator models for methanol and for ions in water.

  14. Post-Newtonian Dynamics in Dense Star Clusters: Highly Eccentric, Highly Spinning, and Repeated Binary Black Hole Mergers.

    Science.gov (United States)

    Rodriguez, Carl L; Amaro-Seoane, Pau; Chatterjee, Sourav; Rasio, Frederic A

    2018-04-13

    We present models of realistic globular clusters with post-Newtonian dynamics for black holes. By modeling the relativistic accelerations and gravitational-wave emission in isolated binaries and during three- and four-body encounters, we find that nearly half of all binary black hole mergers occur inside the cluster, with about 10% of those mergers entering the LIGO/Virgo band with eccentricities greater than 0.1. In-cluster mergers lead to the birth of a second generation of black holes with larger masses and high spins, which, depending on the black hole natal spins, can sometimes be retained in the cluster and merge again. As a result, globular clusters can produce merging binaries with detectable spins regardless of the birth spins of black holes formed from massive stars. These second-generation black holes would also populate any upper mass gap created by pair-instability supernovae.

  15. Post-Newtonian Dynamics in Dense Star Clusters: Highly Eccentric, Highly Spinning, and Repeated Binary Black Hole Mergers

    Science.gov (United States)

    Rodriguez, Carl L.; Amaro-Seoane, Pau; Chatterjee, Sourav; Rasio, Frederic A.

    2018-04-01

    We present models of realistic globular clusters with post-Newtonian dynamics for black holes. By modeling the relativistic accelerations and gravitational-wave emission in isolated binaries and during three- and four-body encounters, we find that nearly half of all binary black hole mergers occur inside the cluster, with about 10% of those mergers entering the LIGO/Virgo band with eccentricities greater than 0.1. In-cluster mergers lead to the birth of a second generation of black holes with larger masses and high spins, which, depending on the black hole natal spins, can sometimes be retained in the cluster and merge again. As a result, globular clusters can produce merging binaries with detectable spins regardless of the birth spins of black holes formed from massive stars. These second-generation black holes would also populate any upper mass gap created by pair-instability supernovae.

  16. 2nd International Symposium "Atomic Cluster Collisions : Structure and Dynamics from the Nuclear to the Biological Scale"

    CERN Document Server

    Solov'yov, Andrey; ISACC 2007; Latest advances in atomic cluster collisions

    2008-01-01

    This book presents a 'snapshot' of the most recent and significant advances in the field of cluster physics. It is a comprehensive review based on contributions by the participants of the 2nd International Symposium on Atomic Cluster Collisions (ISACC 2007) held in July 19-23, 2007 at GSI, Darmstadt, Germany. The purpose of the Symposium is to promote the growth and exchange of scientific information on the structure and properties of nuclear, atomic, molecular, biological and complex cluster systems studied by means of photonic, electronic, heavy particle and atomic collisions. Particular attention is devoted to dynamic phenomena, many-body effects taking place in cluster systems of a different nature - these include problems of fusion and fission, fragmentation, collective electron excitations, phase transitions, etc.Both the experimental and theoretical aspects of cluster physics, uniquely placed between nuclear physics on the one hand and atomic, molecular and solid state physics on the other, are discuss...

  17. EISCAT and Cluster observations in the vicinity of the dynamical polar cap boundary

    Directory of Open Access Journals (Sweden)

    A. T. Aikio

    2008-02-01

    Full Text Available The dynamics of the polar cap boundary and auroral oval in the nightside ionosphere are studied during late expansion and recovery of a substorm from the region between Tromsø (66.6° cgmLat and Longyearbyen (75.2° cgmLat on 27 February 2004 by using the coordinated EISCAT incoherent scatter radar, MIRACLE magnetometer and Cluster satellite measurements. During the late substorm expansion/early recovery phase, the polar cap boundary (PCB made zig-zag-type motion with amplitude of 2.5° cgmLat and period of about 30 min near magnetic midnight. We suggest that the poleward motions of the PCB were produced by bursts of enhanced reconnection at the near-Earth neutral line (NENL. The subsequent equatorward motions of the PCB would then represent the recovery of the merging line towards the equilibrium state (Cowley and Lockwood, 1992. The observed bursts of enhanced westward electrojet just equatorward of the polar cap boundary during poleward expansions were produced plausibly by particles accelerated in the vicinity of the neutral line and thus lend evidence to the Cowley-Lockwood paradigm.

    During the substorm recovery phase, the footpoints of the Cluster satellites at a geocentric distance of 4.4 RE mapped in the vicinity of EISCAT measurements. Cluster data indicate that outflow of H+ and O+ ions took place within the plasma sheet boundary layer (PSBL as noted in some earlier studies as well. We show that in this case the PSBL corresponded to a region of enhanced electron temperature in the ionospheric F region. It is suggested that the ion outflow originates from the F region as a result of increased ambipolar diffusion. At higher altitudes, the ions could be further energized by waves, which at Cluster altitudes were observed as BBELF (broad band extra low frequency fluctuations.

    The four-satellite configuration of Cluster revealed a sudden poleward expansion of the PSBL by 2° during

  18. Hydration structure and dynamics of a hydroxide ion in water clusters of varying size and temperature: Quantum chemical and ab initio molecular dynamics studies

    International Nuclear Information System (INIS)

    Bankura, Arindam; Chandra, Amalendu

    2012-01-01

    Highlights: ► A theoretical study of hydroxide ion-water clusters is carried for varying cluster size and temperature. ► The structures of OH − (H 2 O) n are found out through quantum chemical calculations for n = 4, 8, 16 and 20. ► The finite temperature behavior of the clusters is studied through ab initio dynamical simulations. ► The spectral features of OH modes (deuterated) and their dependence on hydrogen bonding states of water are discussed. ► The mechanism and kinetics of proton transfer processes in these anionic clusters are also investigated. - Abstract: We have investigated the hydration structure and dynamics of OH − (H 2 O) n clusters (n = 4, 8, 16 and 20) by means of quantum chemical and ab initio molecular dynamics calculations. Quantum chemical calculations reveal that the solvation structure of the hydroxide ion transforms from three and four-coordinated surface states to five-coordinated interior state with increase in cluster size. Several other isomeric structures with energies not very different from the most stable isomer are also found. Ab initio simulations show that the most probable configurations at higher temperatures need not be the lowest energy isomeric structure. The rates of proton transfer in these clusters are found to be slower than that in bulk water. The vibrational spectral calculations reveal distinct features for free OH (deuterated) stretch modes of water in different hydrogen bonding states. Effects of temperature on the structural and dynamical properties are also investigated for the largest cluster considered here.

  19. Dynamics of electron solvation in I-(CH3OH)n clusters (4 ≤n≤ 11)

    International Nuclear Information System (INIS)

    Young, Ryan M.; Yandell, Margaret A.; Neumark, Daniel M.

    2011-01-01

    The dynamics of electron solvation following excitation of the charge-transfer-to-solvent precursor state in iodide-doped methanol clusters, I - (CH 3 OH) n=4-11 , are studied with time-resolved photoelectron imaging. This excitation produces a I ... (CH 3 OH) n - cluster that is unstable with respect to electron autodetachment and whose autodetachment lifetime increases monotonically from ∼800 fs to 85 ps as n increases from 4 to 11. The vertical detachment energy (VDE) and width of the excited state feature in the photoelectron spectrum show complex time dependence during the lifetime of this state. The VDE decreases over the first 100-400 fs, then rises exponentially to a maximum with a ∼1 ps time constant, and finally decreases by as much as 180 meV with timescales of 3-20 ps. The early dynamics are associated with electron transfer from the iodide to the methanol cluster, while the longer-time changes in VDE are attributed to solvent reordering, possibly in conjunction with ejection of neutral iodine from the cluster. Changes in the observed width of the spectrum largely follow those of the VDEs; the dynamics of both are attributed to the major rearrangement of the solvent cluster during relaxation. The relaxation dynamics are interpreted as a reorientation of at least one methanol molecule and the disruption and formation of the solvent network in order to accommodate the excess charge.

  20. Dynamics of electron solvation in I(-)(CH3OH)n clusters (4 ≤ n ≤ 11).

    Science.gov (United States)

    Young, Ryan M; Yandell, Margaret A; Neumark, Daniel M

    2011-03-28

    The dynamics of electron solvation following excitation of the charge-transfer-to-solvent precursor state in iodide-doped methanol clusters, I(-)(CH(3)OH)(n = 4-11), are studied with time-resolved photoelectron imaging. This excitation produces a I···(CH(3)OH)(n)(-) cluster that is unstable with respect to electron autodetachment and whose autodetachment lifetime increases monotonically from ~800 fs to 85 ps as n increases from 4 to 11. The vertical detachment energy (VDE) and width of the excited state feature in the photoelectron spectrum show complex time dependence during the lifetime of this state. The VDE decreases over the first 100-400 fs, then rises exponentially to a maximum with a ~1 ps time constant, and finally decreases by as much as 180 meV with timescales of 3-20 ps. The early dynamics are associated with electron transfer from the iodide to the methanol cluster, while the longer-time changes in VDE are attributed to solvent reordering, possibly in conjunction with ejection of neutral iodine from the cluster. Changes in the observed width of the spectrum largely follow those of the VDEs; the dynamics of both are attributed to the major rearrangement of the solvent cluster during relaxation. The relaxation dynamics are interpreted as a reorientation of at least one methanol molecule and the disruption and formation of the solvent network in order to accommodate the excess charge.

  1. Dimension dependence of clustering dynamics in models of ballistic aggregation and freely cooling granular gas

    Science.gov (United States)

    Paul, Subhajit; Das, Subir K.

    2018-03-01

    Via event-driven molecular dynamics simulations we study kinetics of clustering in assemblies of inelastic particles in various space dimensions. We consider two models, viz., the ballistic aggregation model (BAM) and the freely cooling granular gas model (GGM), for each of which we quantify the time dependence of kinetic energy and average mass of clusters (that form due to inelastic collisions). These quantities, for both the models, exhibit power-law behavior, at least in the long time limit. For the BAM, corresponding exponents exhibit strong dimension dependence and follow a hyperscaling relation. In addition, in the high packing fraction limit the behavior of these quantities become consistent with a scaling theory that predicts an inverse relation between energy and mass. On the other hand, in the case of the GGM we do not find any evidence for such a picture. In this case, even though the energy decay, irrespective of packing fraction, matches quantitatively with that for the high packing fraction picture of the BAM, it is inversely proportional to the growth of mass only in one dimension, and the growth appears to be rather insensitive to the choice of the dimension, unlike the BAM.

  2. The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

    International Nuclear Information System (INIS)

    Tremaine, Scott

    2003-01-01

    focus on N 10 6 for two main reasons: first, direct numerical integrations of N-body systems are beginning to approach this threshold, and second, globular star clusters provide remarkably accurate physical instantiations of the idealized N-body problem with N = 10 5 - 10 6 . The authors are distinguished contributors to the study of star-cluster dynamics and the gravitational N-body problem. The book contains lucid and concise descriptions of most of the important tools in the subject, with only a modest bias towards the authors' own interests. These tools include the two-body relaxation approximation, the Vlasov and Fokker-Planck equations, regularization of close encounters, conducting fluid models, Hill's approximation, Heggie's law for binary star evolution, symplectic integration algorithms, Liapunov exponents, and so on. The book also provides an up-to-date description of the principal processes that drive the evolution of idealized N-body systems - two-body relaxation, mass segregation, escape, core collapse and core bounce, binary star hardening, gravothermal oscillations - as well as additional processes such as stellar collisions and tidal shocks that affect real star clusters but not idealized N-body systems. In a relatively short (300 pages plus appendices) book such as this, many topics have to be omitted. The reader who is hoping to learn about the phenomenology of star clusters will be disappointed, as the description of their properties is limited to only a page of text; there is also almost no discussion of other, equally interesting N-body systems such as galaxies(N ∼ 10 6 - 10 12 ), open clusters (N ≅ 10 2 - 10 4 ), planetary systems, or the star clusters surrounding black holes that are found in the centres of most galaxies. All of these omissions are defensible decisions. Less defensible is the uneven set of references in the text; for example, nowhere is the reader informed that the classic predecessor to this work was Spitzer's 1987 monograph

  3. Prediction of line failure fault based on weighted fuzzy dynamic clustering and improved relational analysis

    Science.gov (United States)

    Meng, Xiaocheng; Che, Renfei; Gao, Shi; He, Juntao

    2018-04-01

    With the advent of large data age, power system research has entered a new stage. At present, the main application of large data in the power system is the early warning analysis of the power equipment, that is, by collecting the relevant historical fault data information, the system security is improved by predicting the early warning and failure rate of different kinds of equipment under certain relational factors. In this paper, a method of line failure rate warning is proposed. Firstly, fuzzy dynamic clustering is carried out based on the collected historical information. Considering the imbalance between the attributes, the coefficient of variation is given to the corresponding weights. And then use the weighted fuzzy clustering to deal with the data more effectively. Then, by analyzing the basic idea and basic properties of the relational analysis model theory, the gray relational model is improved by combining the slope and the Deng model. And the incremental composition and composition of the two sequences are also considered to the gray relational model to obtain the gray relational degree between the various samples. The failure rate is predicted according to the principle of weighting. Finally, the concrete process is expounded by an example, and the validity and superiority of the proposed method are verified.

  4. Effect of binary stars on the dynamical evolution of stellar clusters. II. Analytic evolutionary models

    International Nuclear Information System (INIS)

    Hills, J.G.

    1975-01-01

    We use analytic models to compute the evolution of the core of a stellar system due simultaneously to stellar evaporation which causes the system (core) to contract and to its binaries which cause it to expand by progressively decreasing its binding energy. The evolution of the system is determined by two parameters: the initial number of stars in the system N 0 , and the fraction f/subb/ of its stars which are binaries. For a fixed f/subb/, stellar evaporation initially dominates the dynamical evolution if N 0 is sufficiently large due to the fact that the rate of evaporation is determined chiefly by long-range encounters which increase in importance as the number of stars in the system increases. If stellar evaporation initially dominates, the system first contracts, but as N/subc/, the number of remaining stars in the system, decreases by evaporation, the system reaches a minimum radius and a maximum density and then it expands monotonically as N/subc/ decreases further. Open clusters expand monotonically from the beginning if they have anything approaching average Population I binary frequencies. Globular clusters are highly deficient in binaries in order to have formed and retained the high-density stellar cores observed in most of them. We estimate that for these system f/subb/ < or = 0.15

  5. BOOK REVIEW: The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

    Science.gov (United States)

    Heggie, D.; Hut, P.

    2003-10-01

    focus on N = 106 for two main reasons: first, direct numerical integrations of N-body systems are beginning to approach this threshold, and second, globular star clusters provide remarkably accurate physical instantiations of the idealized N-body problem with N = 105 - 106. The authors are distinguished contributors to the study of star-cluster dynamics and the gravitational N-body problem. The book contains lucid and concise descriptions of most of the important tools in the subject, with only a modest bias towards the authors' own interests. These tools include the two-body relaxation approximation, the Vlasov and Fokker-Planck equations, regularization of close encounters, conducting fluid models, Hill's approximation, Heggie's law for binary star evolution, symplectic integration algorithms, Liapunov exponents, and so on. The book also provides an up-to-date description of the principal processes that drive the evolution of idealized N-body systems - two-body relaxation, mass segregation, escape, core collapse and core bounce, binary star hardening, gravothermal oscillations - as well as additional processes such as stellar collisions and tidal shocks that affect real star clusters but not idealized N-body systems. In a relatively short (300 pages plus appendices) book such as this, many topics have to be omitted. The reader who is hoping to learn about the phenomenology of star clusters will be disappointed, as the description of their properties is limited to only a page of text; there is also almost no discussion of other, equally interesting N-body systems such as galaxies(N approx 106 - 1012), open clusters (N simeq 102 - 104), planetary systems, or the star clusters surrounding black holes that are found in the centres of most galaxies. All of these omissions are defensible decisions. Less defensible is the uneven set of references in the text; for example, nowhere is the reader informed that the classic predecessor to this work was Spitzer's 1987 monograph

  6. Calculations of Helium Bubble Evolution in the PISCES Experiments with Cluster Dynamics

    Science.gov (United States)

    Blondel, Sophie; Younkin, Timothy; Wirth, Brian; Lasa, Ane; Green, David; Canik, John; Drobny, Jon; Curreli, Davide

    2017-10-01

    Plasma surface interactions in fusion tokamak reactors involve an inherently multiscale, highly non-equilibrium set of phenomena, for which current models are inadequate to predict the divertor response to and feedback on the plasma. In this presentation, we describe the latest code developments of Xolotl, a spatially-dependent reaction diffusion cluster dynamics code to simulate the divertor surface response to fusion-relevant plasma exposure. Xolotl is part of a code-coupling effort to model both plasma and material simultaneously; the first benchmark for this effort is the series of PISCES linear device experiments. We will discuss the processes leading to surface morphology changes, which further affect erosion, as well as how Xolotl has been updated in order to communicate with other codes. Furthermore, we will show results of the sub-surface evolution of helium bubbles in tungsten as well as the material surface displacement under these conditions.

  7. Coupled cluster calculations for static and dynamic polarizabilities of C60

    Science.gov (United States)

    Kowalski, Karol; Hammond, Jeff R.; de Jong, Wibe A.; Sadlej, Andrzej J.

    2008-12-01

    New theoretical predictions for the static and frequency dependent polarizabilities of C60 are reported. Using the linear response coupled cluster approach with singles and doubles and a basis set especially designed to treat the molecular properties in external electric field, we obtained 82.20 and 83.62 Å3 for static and dynamic (λ =1064 nm) polarizabilities. These numbers are in a good agreement with experimentally inferred data of 76.5±8 and 79±4 Å3 [R. Antoine et al., J. Chem. Phys.110, 9771 (1999); A. Ballard et al., J. Chem. Phys.113, 5732 (2000)]. The reported results were obtained with the highest wave function-based level of theory ever applied to the C60 system.

  8. Multivariate cluster analysis of dynamic iodine-123 iodobenzamide SPET dopamine D2receptor images in schizophrenia

    International Nuclear Information System (INIS)

    Acton, P.D.; Pilowsky, L.S.; Costa, D.C.; Ell, P.J.

    1997-01-01

    This paper describes the application of a multivariate statistical technique to investigate striatal dopamine D 2 receptor concentrations measured by iodine-123 iodobenzamide ( 123 I-IBZM) single-photon emission tomography (SPET). This technique enables the automatic segmentation of dynamic nuclear medicine images based on the underlying time-activity curves present in the data. Once the time-activity curves have been extracted, each pixel can be mapped back on to the underlying distribution, considerably reducing image noise. Cluster analysis has been verified using computer simulations and phantom studies. The technique has been applied to SPET images of dopamine D 2 receptors in a total of 20 healthy and 20 schizophrenic volunteers (22 male, 18 female), using the ligand 123 I-IBZM. Following automatic image segmentation, the concentration of striatal dopamine D 2 receptors shows a significant left-sided asymmetry in male schizophrenics compared with male controls. The mean left-minus-right laterality index for controls is -1.52 (95% CI -3.72-0.66) and for patients 4.04 (95% CI 1.07-7.01). Analysis of variance shows a case-by-sex-by-side interaction, with F=10.01, P=0.005. We can now demonstrate that the previously observed male sex-specific D 2 receptor asymmetry in schizophrenia, which had failed to attain statistical significance, is valid. Cluster analysis of dynamic nuclear medicine studies provides a powerful tool for automatic segmentation and noise reduction of the images, removing much of the subjectivity inherent in region-of-interest analysis. The observed striatal D 2 asymmetry could reflect long hypothesized disruptions in dopamine-rich cortico-striatal-limbic circuits in schizophrenic males. (orig.). With 4 figs., 2 tabs

  9. The role of self-transcendence: a missing variable in the pursuit of successful aging?

    Science.gov (United States)

    McCarthy, Valerie Lander; Ling, Jiying; Carini, Robert M

    2013-07-01

    While successful aging is often defined as the absence of disease and disability or as life satisfaction, self-transcendence may also play an important role. The objective of this research was to test a nursing theory of successful aging proposing that transcendence and adaptation predict successful aging. In this cross-sectional exploratory study, a convenience sample of older adults (N = 152) were surveyed about self-transcendence, proactive coping, and successful aging. Using hierarchical multiple regression, self-transcendence, proactive coping, and all control variables (i.e., sex, race, perceived health, place of residence) together explained 50% of the variance in successful aging (p self-transcendence and proactive coping predict successful aging. Self-transcendence was the only significant contributor to this multidimensional view of successful aging. Self-transcendence is an important variable in the pursuit of successful aging, which merits further investigation. Copyright 2013, SLACK Incorporated.

  10. Simulations of the dissociation of small helium clusters with ab initio molecular dynamics in electronically excited states

    International Nuclear Information System (INIS)

    Closser, Kristina D.; Head-Gordon, Martin; Gessner, Oliver

    2014-01-01

    The dynamics resulting from electronic excitations of helium clusters were explored using ab initio molecular dynamics. The simulations were performed with configuration interaction singles and adiabatic classical dynamics coupled to a state-following algorithm. 100 different configurations of He 7 were excited into the 2s and 2p manifold for a total of 2800 trajectories. While the most common outcome (90%) was complete fragmentation to 6 ground state atoms and 1 excited state atom, 3% of trajectories yielded bound, He 2 * , and <0.5% yielded an excited helium trimer. The nature of the dynamics, kinetic energy release, and connections to experiments are discussed

  11. Enriched gas in clusters and the dynamics of galaxies and clusters: implications for theories of galaxy formation

    International Nuclear Information System (INIS)

    Binney, J.; Silk, J.

    1978-01-01

    Recent developments in relation to the origin of galaxies are cited: the discovery that the intergalactic medium which seems to pervade rich clusters of galaxies has an iron abundance that lies within an order of magnitude of the solar value; the discovery that elliptical galaxies rotate much more slowly than the models of these galaxies had predicted; and the results of studies of cosmological infall in the context of the formation of galaxies and galaxy clusters, which have shown that the resulting density profile is fairly insensitive to initial conditions. After discussing the implications of these recent observations of X-ray clusters and of the rotation of elliptical galaxies, an attempt is made to construct a picture of the formation of elliptical and spiral galaxies in which galaxies form continuously from redshift z approximately 100 onwards. It is suggested that at a redshift z of roughly 5, a fundamental change occurred in the manner in which the cosmic material fragmented into stellar objects. It seems possible that explanations of a variety of puzzling aspects of galactic evolution, including the formation of Population I disks, the origin of the hot intracluster gas, the mass-to-light ratio stratification of galaxies, and the nature of the galaxy luminosity function, should all be sought in the context of this change of regime. Some remarks are made about gas in poor groups of galaxies and the interaction of disk galaxies with their environments. (U.K.)

  12. Quantum dynamics of small H2 and D2 clusters in the large cage of structure II clathrate hydrate: Energetics, occupancy, and vibrationally averaged cluster structures

    Science.gov (United States)

    Sebastianelli, Francesco; Xu, Minzhong; Bačić, Zlatko

    2008-12-01

    We report diffusion Monte Carlo (DMC) calculations of the quantum translation-rotation (T-R) dynamics of one to five para-H2 (p-H2) and ortho-D2 (o-D2) molecules inside the large hexakaidecahedral (51264) cage of the structure II clathrate hydrate, which was taken to be rigid. These calculations provide a quantitative description of the size evolution of the ground-state properties, energetics, and the vibrationally averaged geometries, of small (p-H2)n and (o-D2)n clusters, n=1-5, in nanoconfinement. The zero-point energy (ZPE) of the T-R motions rises steeply with the cluster size, reaching 74% of the potential well depth for the caged (p-H2)4. At low temperatures, the rapid increase of the cluster ZPE as a function of n is the main factor that limits the occupancy of the large cage to at most four H2 or D2 molecules, in agreement with experiments. Our DMC results concerning the vibrationally averaged spatial distribution of four D2 molecules, their mean distance from the cage center, the D2-D2 separation, and the specific orientation and localization of the tetrahedral (D2)4 cluster relative to the framework of the large cage, agree very well with the low-temperature neutron diffraction experiments involving the large cage with the quadruple D2 occupancy.

  13. Nurse-patient interaction is a resource for hope, meaning in life and self-transcendence in nursing home patients.

    Science.gov (United States)

    Haugan, Gørill

    2014-03-01

    Spiritual dimensions such as hope, meaning in life and self-transcendence have been found to be predictors of successful ageing, life satisfaction and well-being in older individuals. Connectedness and communicating with others have been seen to facilitate hope, meaning in life and self-transcendence among nursing home patients. This study aimed to investigate the associations between hope, meaning in life, self-transcendence and nurse-patient interaction in a nursing home population. A cross-sectional design was employed, collecting data in 44 different Norwegian nursing homes (NHs) from 250 patients who met the inclusion criteria. Approval by all regulatory institutions dealing with research issues in Norway and the Management Unit at the 44 NHs was obtained. A sample of 202 cognitively intact nursing home patients responded to the Herth Hope Index, the Purpose in Life test, the Self-Transcendence Scale and the Nurse-Patient Interaction Scale. A structural equation model (SEM) of the hypothesized relationships between the constructs was tested. The SEM model fit well with the present data. Significant direct relationships of nurse-patient interaction on hope, meaning in life and self-transcendence were displayed. Meaning and the interconnectedness dimension of hope appeared to be particularly dynamic resources, revealing significant influences on all the constructs in the SEM model tested. Nurse-patient interaction influences hope, meaning in life and self-transcendence in cognitively intact nursing home patients and might be an important resource in relation to patients' health and global well-being. Thus, care providers are above all fundamental for nursing home patients. Advancing caregivers' interacting and communicating skills might facilitate patients' health and global well-being and inspire professional caregivers as they perform their daily care practices. More research of the effectiveness of such strategies is greatly needed. The SEM model tested

  14. Newly-graduated midwives transcending barriers: a grounded theory study.

    Science.gov (United States)

    Barry, Michele J; Hauck, Yvonne L; O'Donoghue, Thomas; Clarke, Simon

    2013-12-01

    Midwifery has developed its own philosophy to formalise its unique identity as a profession. Newly-graduated midwives are taught, and ideally embrace, this philosophy during their education. However, embarking in their career within a predominantly institutionalised and the medically focused health-care model may challenge this application. The research question guiding this study was as follows: 'How do newly graduated midwives deal with applying the philosophy of midwifery in their first six months of practice?' The aim was to generate a grounded theory around this social process. This Western Australian grounded theory study is conceptualised within the social theory of symbolic interactionism. Data were collected by means of in-depth, semi-structured interviews with 11 recent midwifery graduates. Participant and interviewer's journals provided supplementary data. The 'constant comparison' approach was used for data analysis. The substantive theory of transcending barriers was generated. Three stages in transcending barriers were identified: Addressing personal attributes, Understanding the 'bigger picture', and finally, 'Evaluating, planning and acting' to provide woman-centred care. An overview of these three stages provides the focus of this article. The theory of transcending barriers provides a new perspective on how newly-graduated midwives deal with applying the philosophy of midwifery in their first six months of practice. A number of implications for pre and post registration midwifery education and policy development are suggested, as well as recommendations for future research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Spectroscopic characterization of galaxy clusters in RCS-1: spectroscopic confirmation, redshift accuracy, and dynamical mass-richness relation

    Science.gov (United States)

    Gilbank, David G.; Barrientos, L. Felipe; Ellingson, Erica; Blindert, Kris; Yee, H. K. C.; Anguita, T.; Gladders, M. D.; Hall, P. B.; Hertling, G.; Infante, L.; Yan, R.; Carrasco, M.; Garcia-Vergara, Cristina; Dawson, K. S.; Lidman, C.; Morokuma, T.

    2018-05-01

    We present follow-up spectroscopic observations of galaxy clusters from the first Red-sequence Cluster Survey (RCS-1). This work focuses on two samples, a lower redshift sample of ˜30 clusters ranging in redshift from z ˜ 0.2-0.6 observed with multiobject spectroscopy (MOS) on 4-6.5-m class telescopes and a z ˜ 1 sample of ˜10 clusters 8-m class telescope observations. We examine the detection efficiency and redshift accuracy of the now widely used red-sequence technique for selecting clusters via overdensities of red-sequence galaxies. Using both these data and extended samples including previously published RCS-1 spectroscopy and spectroscopic redshifts from SDSS, we find that the red-sequence redshift using simple two-filter cluster photometric redshifts is accurate to σz ≈ 0.035(1 + z) in RCS-1. This accuracy can potentially be improved with better survey photometric calibration. For the lower redshift sample, ˜5 per cent of clusters show some (minor) contamination from secondary systems with the same red-sequence intruding into the measurement aperture of the original cluster. At z ˜ 1, the rate rises to ˜20 per cent. Approximately ten per cent of projections are expected to be serious, where the two components contribute significant numbers of their red-sequence galaxies to another cluster. Finally, we present a preliminary study of the mass-richness calibration using velocity dispersions to probe the dynamical masses of the clusters. We find a relation broadly consistent with that seen in the local universe from the WINGS sample at z ˜ 0.05.

  16. Network Signaling Channel for Improving ZigBee Performance in Dynamic Cluster-Tree Networks

    Directory of Open Access Journals (Sweden)

    D. Hämäläinen

    2008-03-01

    Full Text Available ZigBee is one of the most potential standardized technologies for wireless sensor networks (WSNs. Yet, sufficient energy-efficiency for the lowest power WSNs is achieved only in rather static networks. This severely limits the applicability of ZigBee in outdoor and mobile applications, where operation environment is harsh and link failures are common. This paper proposes a network channel beaconing (NCB algorithm for improving ZigBee performance in dynamic cluster-tree networks. NCB reduces the energy consumption of passive scans by dedicating one frequency channel for network beacon transmissions and by energy optimizing their transmission rate. According to an energy analysis, the power consumption of network maintenance operations reduces by 70%–76% in dynamic networks. In static networks, energy overhead is negligible. Moreover, the service time for data routing increases up to 37%. The performance of NCB is validated by ns-2 simulations. NCB can be implemented as an extension on MAC and NWK layers and it is fully compatible with ZigBee.

  17. Theoretical studies of zirconium and carbon clusters with molecular dynamics simulations

    International Nuclear Information System (INIS)

    Zhang, B.

    1993-08-01

    In this dissertation, we will present a systematic study of structures of fullerenes ranging from C 20 to C 100 by introducing a novel scheme. Using our new scheme, we not only reproduce all known fullerene structures but also successfully predicted several other fullerene structures which were confirmed by experiments. By utilizing the tight-binding molecular-dynamic (TBMD) simulation, we also studied the dynamical behavior of fullerenes: Vibrations, thermal disintegration of individual clusters as well as collisions between fullerenes. If the beauty of carbon fullerene is not enough, people found that carbon can also form tubules and even speculated that they can form three-dimensional graphite-like networks. By extending our fullerene structure searching scheme, we performed a search for the ground-state structure of three dimensional carbon network. We found the most stable structure people ever proposed for simple cubic based networks. From the difference of this new form of carbon and graphite in the electronic and vibrational properties, we propose an experimental probe to identify these novel three-dimensional carbon networks

  18. Classical photodissociation dynamics with Bohr quantization: Application to the fragmentation of a van der Waals cluster

    International Nuclear Information System (INIS)

    Arbelo-González, W.; Bonnet, L.; Larrégaray, P.; Rayez, J.-C.; Rubayo-Soneira, J.

    2012-01-01

    Graphical abstract: A recent classical description of photodissociation dynamics in a quantum spirit is applied for the first time to a realistic process, the fragmentation of NeBr 2 . Highlights: ► The photo-dissociation of NeBr 2 is studied by means of two approaches. ► The first is the standard classical one with Gaussian binning. ► The second is a new method applied for the first time to a realistic system. ► The new method leads to exactly the same results as the standard one. ► However, it requires about 10 times less trajectories in the present case. - Abstract: The recent classical dynamical approach of photodissociations with Bohr quantization [L. Bonnet, J. Chem. Phys. 133 (2010) 174108] is applied for the first time to a realistic process, the photofragmentation of the van der Waals cluster NeBr 2 . We illustrate the fact that this approach, formally equivalent to the standard one, may be numerically much more efficient.

  19. Multiscale modelling of precipitation in concentrated alloys: from atomistic Monte Carlo simulations to cluster dynamics I thermodynamics

    Science.gov (United States)

    Lépinoux, J.; Sigli, C.

    2018-01-01

    In a recent paper, the authors showed how the clusters free energies are constrained by the coagulation probability, and explained various anomalies observed during the precipitation kinetics in concentrated alloys. This coagulation probability appeared to be a too complex function to be accurately predicted knowing only the cluster distribution in Cluster Dynamics (CD). Using atomistic Monte Carlo (MC) simulations, it is shown that during a transformation at constant temperature, after a short transient regime, the transformation occurs at quasi-equilibrium. It is proposed to use MC simulations until the system quasi-equilibrates then to switch to CD which is mean field but not limited by a box size like MC. In this paper, we explain how to take into account the information available before the quasi-equilibrium state to establish guidelines to safely predict the cluster free energies.

  20. Molecular dynamic simulation of interaction of low-energy Ar and Xe ions with copper clusters at graphite surface

    International Nuclear Information System (INIS)

    Kornich, G.V.; Lozovskaya, L.I.; Betts, G.; Zaporozhchenko, V.I.; Faupel, F.

    2005-01-01

    One conducted molecular and dynamic simulation of sputtering of isolated clusters consisting of 13, 27 and 195 Cu atoms from the (0001) graphite surface by 200 eV energy Ar and Xe ions. It is shown that the factors of reflection of Ar and Xe ions from copper clusters differ from one another insignificantly, though the energy of the reflected Xe ions is essentially lower than that of Ar ions. The values of the factor of cluster sputtering by Xe ions are higher in contrast to sputtering by Ar ions. One identified two mechanisms of cluster sputtering resulting in the maximum of sputtering intensity at the polar angles near the normal one, and in periodicity of maximums within the azimuth distributions of sputtering intensity with 60 deg period [ru

  1. Cluster-cluster clustering

    International Nuclear Information System (INIS)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.; Yale Univ., New Haven, CT; California Univ., Santa Barbara; Cambridge Univ., England; Sussex Univ., Brighton, England)

    1985-01-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales. 30 references

  2. The Atacama Cosmology Telescope: Dynamical Masses for 44 SZ-Selected Galaxy Clusters over 755 Square Degrees

    Science.gov (United States)

    Sifon, Cristobal; Battaglia, Nick; Hasselfield, Matthew; Menanteau, Felipe; Barrientos, L. Felipe; Bond, J. Richard; Crichton, Devin; Devlin, Mark J.; Dunner, Rolando; Hilton, Matt; hide

    2016-01-01

    We present galaxy velocity dispersions and dynamical mass estimates for 44 galaxy clusters selected via the Sunyaev-Zeldovich (SZ) effect by the Atacama Cosmology Telescope. Dynamical masses for 18 clusters are reported here for the first time. Using N-body simulations, we model the different observing strategies used to measure the velocity dispersions and account for systematic effects resulting from these strategies. We find that the galaxy velocity distributions may be treated as isotropic, and that an aperture correction of up to 7 per cent in the velocity dispersion is required if the spectroscopic galaxy sample is sufficiently concentrated towards the cluster centre. Accounting for the radial profile of the velocity dispersion in simulations enables consistent dynamical mass estimates regardless of the observing strategy. Cluster masses M200 are in the range (1 - 15) times 10 (sup 14) Solar Masses. Comparing with masses estimated from the SZ distortion assuming a gas pressure profile derived from X-ray observations gives a mean SZ-to-dynamical mass ratio of 1:10 plus or minus 0:13, but there is an additional 0.14 systematic uncertainty due to the unknown velocity bias; the statistical uncertainty is dominated by the scatter in the mass-velocity dispersion scaling relation. This ratio is consistent with previous determinations at these mass scales.

  3. Molecular dynamics simulation investigations of H2/D2 dissocitive chemisorption dynamics on Cun(n=13-14) Rigid/nonrigid clusters

    International Nuclear Information System (INIS)

    Elzein, N.

    2004-01-01

    In this work with a use of molecular dynamic simulations we have reported the results of a quasiclassical simulation study of the interaction of H2/(D2) with Cu N (N=13-14) atoms in both rigid /(non rigid) clusters.The geometry of the cluster is obtained by an embedded-atom (EA) mode potential, and the interaction between the molecule and cIuster is described by a LEPS -London-Eyring -Polanyi-Sato) potential energy function.Both channels the reactive dissociative adsorption of the molecule on the cIuster) and non reactive (scattering of the molecule from the cluster) are considered. The dissociative chemisorption probability, cross section and rate constant are studied as functions of the initial quantal rovibrational state of the molecule, collision energy, impact parameter and the temperature (OK,296K,834K ,1014K,1554K) of the clusters

  4. Dynamical transitions in large systems of mean field-coupled Landau-Stuart oscillators: Extensive chaos and cluster states.

    Science.gov (United States)

    Ku, Wai Lim; Girvan, Michelle; Ott, Edward

    2015-12-01

    In this paper, we study dynamical systems in which a large number N of identical Landau-Stuart oscillators are globally coupled via a mean-field. Previously, it has been observed that this type of system can exhibit a variety of different dynamical behaviors. These behaviors include time periodic cluster states in which each oscillator is in one of a small number of groups for which all oscillators in each group have the same state which is different from group to group, as well as a behavior in which all oscillators have different states and the macroscopic dynamics of the mean field is chaotic. We argue that this second type of behavior is "extensive" in the sense that the chaotic attractor in the full phase space of the system has a fractal dimension that scales linearly with N and that the number of positive Lyapunov exponents of the attractor also scales linearly with N. An important focus of this paper is the transition between cluster states and extensive chaos as the system is subjected to slow adiabatic parameter change. We observe discontinuous transitions between the cluster states (which correspond to low dimensional dynamics) and the extensively chaotic states. Furthermore, examining the cluster state, as the system approaches the discontinuous transition to extensive chaos, we find that the oscillator population distribution between the clusters continually evolves so that the cluster state is always marginally stable. This behavior is used to reveal the mechanism of the discontinuous transition. We also apply the Kaplan-Yorke formula to study the fractal structure of the extensively chaotic attractors.

  5. 11th International Conference on Clustering Aspects of Nuclear Structure and Dynamics

    International Nuclear Information System (INIS)

    2017-01-01

    Preface The 11 th edition of the International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER‘16) was held in Napoli, Italy, on May 23-27 2016. All the Conference Sessions took place in the magnificent Complesso Monumentale dei Ss. Marcellino e Festo , located in the Historical Centre of Naples. This is one of the most prestigious building complexes of the Federico II University of Naples, the main home institution of the organizers, together with the Istituto Nazionale di Fisica Nucleare (Naples division). This building is 500 years old; in the XVIII century, it was reshaped by Luigi Vanvitelli, a famous architect of the pre-Neoclassical period in Italy, designer of the prestigious Royal Palace in the near town of Caserta. The site of Plenary Sessions was the Church of Ss. Marcellino e Festo , where all the participants were surrounded by the Baroque frescoes by Belisario Corenzio and, among the others, the paintings of Battistello Caracciolo, Massimo Stanzione, Giuseppe Simonelli and Francesco De Mura, important artists of the late Baroque period in South Italy. The sites of Parallel Sessions were two halls in the arcade of the S. Marcellino cloister: this gave the opportunity to the participants to enjoy the beauty of the architecture of the cloister with its fountains, gardens, sculptures. As organizers of the Conference, our main aims were: (1) to provide an excellent programme, with the expectation to be a reference point for the Nuclear Cluster Physics in the next four years; (2) to assure a very relaxing stay to the participants, allowing them to explore the bounty of artistic, and also culinary, masterpieces that Naples offers to its guests. The first point was assured by all the conveners that, with their excellent talks, gave a very precise and complete overview of the most recent achievements on Nuclear Cluster Physics, both from the experimental and theoretical point of view. We are indebted with the International

  6. Effects of the mean-field dynamics and the phase-space geometry on the cluster formation

    International Nuclear Information System (INIS)

    Basrak, Z.; Eudes, P.; Abgrall, P.; Haddad, F.; Sebille, F.

    1997-01-01

    A model allowing to simulate the production of clusters is developed and applied to heavy-ion reactions at intermediate energies. The model investigates the geometrical properties of the dynamically generated one-body phase space. The collision process is entirely governed by the Landau-Vlasov model, which provides the time evolution of the one-body phase-space distribution. Particles emitted during successive time intervals of the dynamics are gathered together into subensembles to which a clusterization procedure is applied. Comparison with the experimental data for the Ar(65 MeV/nucleon) + Al reaction shows that the average behaviour of particle-dependent global observables is correctly reproduced within this framework. These results point out that the studied global properties of heavy-ion collisions greatly rely on the dynamical effects of the primary non-steady stage of the nuclear reaction. (orig.)

  7. Molecular dynamics study on the interaction of a dislocation and radiation induced defect clusters in Fcc crystals

    International Nuclear Information System (INIS)

    Hideo, Kaburaki; Tomoko, Kadoyoshi; Futoshi, Shimizu; Hajime; Kimizuka; Shiro, Jitsukawa

    2003-01-01

    Irradiation of high-energy neutrons and charged particles into solids is known to cause a significant change in mechanical properties, in particular, hardening of metals. Hardening of solids arises as a result of interactions of dislocations with irradiation induced defect clusters. Molecular dynamics method combined with the visualization method has been used to elucidate these complex pinning structures in details. In particular, we have successfully observed the transient process for the formation of a super-jog from an edge dislocation and interstitial and vacancy clusters under irradiation cascade conditions. Parallel molecular dynamics programs, called as Parallel Molecular Dynamics Stencil (PMDS), have been developed in order to perform these large scale simulations for materials simulations. The contents of the program and its parallel performance are also reported. (authors)

  8. Dynamical evolution in clusters of galaxies with low-frequency radio emission

    International Nuclear Information System (INIS)

    Guthrie, B.N.G.

    1977-01-01

    Clusters of galaxies in which radio emission at low frequencies ( approximately 10 9 yr). Confinement would probably occur for radio sources associated with bright galaxies in the cores of clusters and cD galaxies in clusters. However, cD galaxies may have recurrent radio outbursts so that steep spectra are not always observed. (Auth.)

  9. The mond external field effect on the dynamics of the globular clusters: general considerations and application to NGC 2419

    Energy Technology Data Exchange (ETDEWEB)

    Derakhshani, Kamran, E-mail: kderakhshani@iasbs.ac.ir [Institute for Advanced Studies in Basic Sciences, P. O. Box 45195-1159 Zanjan (Iran, Islamic Republic of)

    2014-03-01

    In this paper, we investigate the external field effect in the context of the MOdified Newtonian Dynamics (MOND) on the surface brightness and velocity dispersion profiles of globular clusters (GCs). Using N-MODY, which is an N-body simulation code with a MOND potential solver, we show that the general effect of the external field for diffuse clusters, which obey MOND in most of their parts, is that it pushes the dynamics toward the Newtonian regime. On the other hand, for more compact clusters, which are essentially Newtonian in their inner parts, the external field is effective mainly in the outer parts of compact clusters. As a case study, we then choose the remote Galactic GC NGC 2419. By varying the cluster mass, half-light radius, and mass-to-light ratio, we aim to find a model that will reproduce the observational data most effectively, using N-MODY. We find that even if we take the Galactic external field into account, a Newtonian Plummer sphere represents the observational data better than MOND to an order of magnitude in terms of the total χ{sup 2} of surface brightness and velocity dispersion.

  10. The mond external field effect on the dynamics of the globular clusters: general considerations and application to NGC 2419

    International Nuclear Information System (INIS)

    Derakhshani, Kamran

    2014-01-01

    In this paper, we investigate the external field effect in the context of the MOdified Newtonian Dynamics (MOND) on the surface brightness and velocity dispersion profiles of globular clusters (GCs). Using N-MODY, which is an N-body simulation code with a MOND potential solver, we show that the general effect of the external field for diffuse clusters, which obey MOND in most of their parts, is that it pushes the dynamics toward the Newtonian regime. On the other hand, for more compact clusters, which are essentially Newtonian in their inner parts, the external field is effective mainly in the outer parts of compact clusters. As a case study, we then choose the remote Galactic GC NGC 2419. By varying the cluster mass, half-light radius, and mass-to-light ratio, we aim to find a model that will reproduce the observational data most effectively, using N-MODY. We find that even if we take the Galactic external field into account, a Newtonian Plummer sphere represents the observational data better than MOND to an order of magnitude in terms of the total χ 2 of surface brightness and velocity dispersion.

  11. Quantum molecular dynamics: Numerical methods and physical study of the structure, thermodynamics, stability and fragmentation of sodium metallic clusters

    International Nuclear Information System (INIS)

    Blaise, Philippe

    1998-01-01

    The aim of this thesis is to study metallic sodium clusters by numerical simulation. We have developed two ab initio molecular dynamics programs within the formalism of density functional theory. The first is based on the semi-classical extended Thomas-Fermi approach. We use a real-space grid and a Car-Parrinello-like scheme. The computational cost is O(N), and we have built a pseudopotential that speeds up the calculations. By neglecting quantum shell effects, we are able to study a very large set of clusters. We show that sodium cluster energies fit well a liquid drop formula, by adjusting a few parameters. We have investigated breathing modes, surface oscillations and the net charge density. We have shown that the surface energy varies strongly with temperature, and that clusters have a lower melting point than bulk material. We have calculated fission barriers by a constraint method. The second program is based on the quantum Kohn-Sham approach. We use a real-space grid, and combine a generalized Broyden scheme for assuring self-consistency with an iterative Davidson-Lanczos algorithm for solving the Eigen-problem. The cost of the method is much higher. First of all, we have calculated some stable structures for small clusters and their energetics. We obtained very good agreement with previous works. Then, we have investigated highly charged cluster dynamics. We have identified a chaotic fission process. For high fissility systems, we observe a multi-fragmentation dynamics and we find preferential emission of monomers on a characteristic time scale less than a pico-second. This has been simulated for the first time, with the help of our adaptive grid method which follows each fragment as they move apart during the fragmentation. (author)

  12. Cluster dynamics modeling of the effect of high dose irradiation and helium on the microstructure of austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Brimbal, Daniel, E-mail: Daniel.brimbal@areva.com [AREVA NP, Tour AREVA, 1 Place Jean Millier, 92084 Paris La Défense (France); Fournier, Lionel [AREVA NP, Tour AREVA, 1 Place Jean Millier, 92084 Paris La Défense (France); Barbu, Alain [Alain Barbu Consultant, 6 Avenue Pasteur Martin Luther King, 78230 Le Pecq (France)

    2016-01-15

    A mean field cluster dynamics model has been developed in order to study the effect of high dose irradiation and helium on the microstructural evolution of metals. In this model, self-interstitial clusters, stacking-fault tetrahedra and helium-vacancy clusters are taken into account, in a configuration well adapted to austenitic stainless steels. For small helium-vacancy cluster sizes, the densities of each small cluster are calculated. However, for large sizes, only the mean number of helium atoms per cluster size is calculated. This aspect allows us to calculate the evolution of the microstructural features up to high irradiation doses in a few minutes. It is shown that the presence of stacking-fault tetrahedra notably reduces cavity sizes below 400 °C, but they have little influence on the microstructure above this temperature. The binding energies of vacancies to cavities are calculated using a new method essentially based on ab initio data. It is shown that helium has little effect on the cavity microstructure at 300 °C. However, at higher temperatures, even small helium production rates such as those typical of sodium-fast-reactors induce a notable increase in cavity density compared to an irradiation without helium. - Highlights: • Irradiation of steels with helium is studied through a new cluster dynamics model. • There is only a small effect of helium on cavity distributions in PWR conditions. • An increase in helium production causes an increase in cavity density over 500 °C. • The role of helium is to stabilize cavities via reduced emission of vacancies.

  13. Cluster dynamics modeling and experimental investigation of the effect of injected interstitials

    Science.gov (United States)

    Michaut, B.; Jourdan, T.; Malaplate, J.; Renault-Laborne, A.; Sefta, F.; Décamps, B.

    2017-12-01

    The effect of injected interstitials on loop and cavity microstructures is investigated experimentally and numerically for 304L austenitic stainless steel irradiated at 450 °C with 10 MeV Fe5+ ions up to about 100 dpa. A cluster dynamics model is parametrized on experimental results obtained by transmission electron microscopy (TEM) in a region where injected interstitials can be safely neglected. It is then used to model the damage profile and study the impact of self-ion injection. Results are compared to TEM observations on cross-sections of specimens. It is shown that injected interstitials have a significant effect on cavity density and mean size, even in the sink-dominated regime. To quantitatively match the experimental data in the self-ions injected area, a variation of some parameters is necessary. We propose that the fraction of freely migrating species may vary as a function of depth. Finally, we show that simple rate theory considerations do not seem to be valid for these experimental conditions.

  14. Effect of self-interstitial diffusion anisotropy in electron-irradiated zirconium: A cluster dynamics modeling

    International Nuclear Information System (INIS)

    Christien, F.; Barbu, A.

    2005-01-01

    A model based on the cluster dynamics approach was proposed in [A. Hardouin Duparc, C. Moingeon, N. Smetniansky-de-Grande, A. Barbu, J. Nucl. Mater. 302 (2002) 143] to describe point defect agglomeration in metals under irradiation. This model is restricted to materials where point defect diffusion is isotropic and is thus not applicable to anisotropic metals such as zirconium. Following the approach proposed by Woo [C.H. Woo, J. Nucl. Mater. 159 (1988) 237], we extended in this work the model to the case where self-interstitial atoms (SIA) diffusion is anisotropic. The model was then applied to the loop microstructure evolution of a zirconium thin foil irradiated with electrons in a high-voltage microscope. First, the inputs were validated by comparing the numerical results with Hellio et al. experimental results [C. Hellio, C.H. de Novion, L. Boulanger, J. Nucl. Mater. 159 (1988) 368]. Further calculations were made to evidence the effect of the thin foil orientation on the dislocation loop microstructure under irradiation. The result is that it is possible to reproduce for certain orientations the 'unexpected' vacancy loop growth experimentally observed in electron-irradiated zirconium [M. Griffiths, M.H. Loretto, R.E. Sallmann, J. Nucl. Mater. 115 (1983) 313; J. Nucl. Mater. 115 (1983) 323; Philos. Mag. A 49 (1984) 613]. This effect is directly linked to SIA diffusion anisotropy

  15. "Divide-and-conquer" semiclassical molecular dynamics: An application to water clusters

    Science.gov (United States)

    Di Liberto, Giovanni; Conte, Riccardo; Ceotto, Michele

    2018-03-01

    We present an investigation of vibrational features in water clusters performed by means of our recently established divide-and-conquer semiclassical approach [M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017)]. This technique allows us to simulate quantum vibrational spectra of high-dimensional systems starting from full-dimensional classical trajectories and projection of the semiclassical propagator onto a set of lower dimensional subspaces. The potential energy surface employed is a many-body representation up to three-body terms, in which monomers and two-body interactions are described by the high level Wang-Huang-Braams-Bowman (WHBB) water potential, while, for three-body interactions, calculations adopt a fast permutationally invariant ab initio surface at the same level of theory of the WHBB 3-body potential. Applications range from the water dimer up to the water decamer, a system made of 84 vibrational degrees of freedom. Results are generally in agreement with previous variational estimates in the literature. This is particularly true for the bending and the high-frequency stretching motions, while estimates of modes strongly influenced by hydrogen bonding are red shifted, in a few instances even substantially, as a consequence of the dynamical and global picture provided by the semiclassical approach.

  16. An efficient implementation of parallel molecular dynamics method on SMP cluster architecture

    International Nuclear Information System (INIS)

    Suzuki, Masaaki; Okuda, Hiroshi; Yagawa, Genki

    2003-01-01

    The authors have applied MPI/OpenMP hybrid parallel programming model to parallelize a molecular dynamics (MD) method on a symmetric multiprocessor (SMP) cluster architecture. In that architecture, it can be expected that the hybrid parallel programming model, which uses the message passing library such as MPI for inter-SMP node communication and the loop directive such as OpenMP for intra-SNP node parallelization, is the most effective one. In this study, the parallel performance of the hybrid style has been compared with that of conventional flat parallel programming style, which uses only MPI, both in cases the fast multipole method (FMM) is employed for computing long-distance interactions and that is not employed. The computer environments used here are Hitachi SR8000/MPP placed at the University of Tokyo. The results of calculation are as follows. Without FMM, the parallel efficiency using 16 SMP nodes (128 PEs) is: 90% with the hybrid style, 75% with the flat-MPI style for MD simulation with 33,402 atoms. With FMM, the parallel efficiency using 16 SMP nodes (128 PEs) is: 60% with the hybrid style, 48% with the flat-MPI style for MD simulation with 117,649 atoms. (author)

  17. [Development and evaluation of the medical imaging distribution system with dynamic web application and clustering technology].

    Science.gov (United States)

    Yokohama, Noriya; Tsuchimoto, Tadashi; Oishi, Masamichi; Itou, Katsuya

    2007-01-20

    It has been noted that the downtime of medical informatics systems is often long. Many systems encounter downtimes of hours or even days, which can have a critical effect on daily operations. Such systems remain especially weak in the areas of database and medical imaging data. The scheme design shows the three-layer architecture of the system: application, database, and storage layers. The application layer uses the DICOM protocol (Digital Imaging and Communication in Medicine) and HTTP (Hyper Text Transport Protocol) with AJAX (Asynchronous JavaScript+XML). The database is designed to decentralize in parallel using cluster technology. Consequently, restoration of the database can be done not only with ease but also with improved retrieval speed. In the storage layer, a network RAID (Redundant Array of Independent Disks) system, it is possible to construct exabyte-scale parallel file systems that exploit storage spread. Development and evaluation of the test-bed has been successful in medical information data backup and recovery in a network environment. This paper presents a schematic design of the new medical informatics system that can be accommodated from a recovery and the dynamic Web application for medical imaging distribution using AJAX.

  18. Phase transformation during silica cluster impact on crystal silicon substrate studied by molecular dynamics simulation

    International Nuclear Information System (INIS)

    Chen Ruling; Luo Jianbin; Guo Dan; Lu Xinchun

    2008-01-01

    The process of a silica cluster impact on a crystal silicon substrate is studied by molecular dynamics simulation. At the impact loading stage, crystal silicon of the impact zone transforms to a locally ordered molten with increasing the local temperature and pressure of the impact zone. And then the transient molten forms amorphous silicon directly as the local temperature and pressure decrease at the impact unloading stage. Moreover, the phase behavior between the locally ordered molten and amorphous silicon exhibits the reversible structural transition. The transient molten contains not only lots of four-fold atom but also many three- and five-fold atoms. And the five-fold atom is similar to the mixture structure of semi-Si-II and semi-bct5-Si. The structure transformation between five- and four-fold atoms is affected by both pressure and temperature. The structure transformation between three- and four-fold atoms is affected mostly by temperature. The direct structure transformation between five- and three-fold atoms is not observed. Finally, these five- and three-fold atoms are also different from the usual five- and three-fold deficient atoms of amorphous silicon. In addition, according to the change of coordination number of atoms the impact process is divided into six stages: elastic, plastic, hysteresis, phase regressive, adhesion and cooling stages

  19. [Dynamic study of small metallic clusters]; Estudio Dinamico de Pequenos Agregados Metalicos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, M.J. [Valladolid Univ. (Spain). Dept. de Fisica Teorica; Jellinek, J. [Argonne National Lab., IL (United States)

    1995-12-31

    We present a brief introduction to computer simulation techniques (particularly to classical molecular dynamics) and their application to the study of the thermodynamic properties of a material system. The basic concepts are illustrated in the study of structural and energetic properties such as the liquid-solid transition and the fragmentation of small clusters of nickel. [Espanol] Presentamos una breve introducci{acute o}n de las t{acute e}cnicas de simulaci{acute o}n por ordenador (en particular de la Din{acute a}mica Molecular cl{acute a}sica) y de su aplicaci{acute o}n al estudio de las propiedades termodin{acute a}micas de un sistema material. Los conceptos b{acute a}sicos se ilustran en el estudio de las propieades estructurales y energ{acute e}ticas, as{acute i} como de la transici{acute o}n de fase s{acute o}lido-l{acute i}quido y de las fragmentaciones de peque{tilde n}os agregados de n{acute i}quel.

  20. Self-transcendence and work engagement in acute care staff registered nurses.

    Science.gov (United States)

    Palmer, Beth; Quinn Griffin, Mary T; Reed, Pamela; Fitzpatrick, Joyce J

    2010-01-01

    The ability of human beings to find meaning by being directed toward something, or someone, other than themselves is termed "self-transcendence." Previous research indicated that the ability of nurses to self-transcend and thus derive positive meaning from patient-caring experiences increased work commitment and fostered work engagement. However, the relationship between self-transcendence and work engagement had not been investigated. The purpose of this study was to explore the levels and relationships of self-transcendence and work engagement in acute care staff registered nurses (ACSRNs). This was a descriptive correlational study using Reed's theory of self-transcendence. The Self-transcendence Scale, the Utrecht Work Engagement Scale, and a demographic questionnaire were completed by a convenience sample of 84 ACSRNs who attended an annual acute care nursing conference in northern Illinois. ACSRNs level of self-transcendence was high, similar to that of other nurses, but higher than that of nonnurses. ACSRNs level of work engagement was at the high end of the "average" range. There was a significant positive correlation between self-transcendence and work engagement. Nurses with higher levels of self-transcendence had more energy toward and were more dedicated and absorbed in their work.

  1. The self-transcendence scale: an investigation of the factor structure among nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Rannestad, Toril; Garåsen, Helge; Hammervold, Randi; Espnes, Geir Arild

    2012-09-01

    Self-transcendence, the ability to expand personal boundaries in multiple ways, has been found to provide well-being. The purpose of this study was to examine the dimensionality of the Norwegian version of the Self-Transcendence Scale, which comprises 15 items. Reed's empirical nursing theory of self-transcendence provided the theoretical framework; self-transcendence includes an interpersonal, intrapersonal, transpersonal, and temporal dimension. Cross-sectional data were obtained from a sample of 202 cognitively intact elderly patients in 44 Norwegian nursing homes. Exploratory factor analysis revealed two and four internally consistent dimensions of self-transcendence, explaining 35.3% (two factors) and 50.7% (four factors) of the variance, respectively. Confirmatory factor analysis indicated that the hypothesized two- and four-factor models fitted better than the one-factor model (cx (2), root mean square error of approximation, standardized root mean square residual, normed fit index, nonnormed fit index, comparative fit index, goodness-of-fit index, and adjusted goodness-of-fit index). The findings indicate self-transcendence as a multifactorial construct; at present, we conclude that the two-factor model might be the most accurate and reasonable measure of self-transcendence. This research generates insights in the application of the widely used Self-Transcendence Scale by investigating its psychometric properties by applying a confirmatory factor analysis. It also generates new research-questions on the associations between self-transcendence and well-being.

  2. Growth of CdTe on Si(100) surface by ionized cluster beam technique: Experimental and molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Araghi, Houshang, E-mail: araghi@aut.ac.ir [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Zabihi, Zabiholah [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nayebi, Payman [Department of Physics, College of Technical and Engineering, Saveh Branch, Islamic Azad University, Saveh (Iran, Islamic Republic of); Ehsani, Mohammad Mahdi [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2016-10-15

    II–VI semiconductor CdTe was grown on the Si(100) substrate surface by the ionized cluster beam (ICB) technique. In the ICB method, when vapors of solid materials such as CdTe were ejected through a nozzle of a heated crucible into a vacuum region, nanoclusters were created by an adiabatic expansion phenomenon. The clusters thus obtained were partially ionized by electron bombardment and then accelerated onto the silicon substrate at 473 K by high potentials. The cluster size was determined using a retarding field energy analyzer. The results of X-ray diffraction measurements indicate the cubic zinc blende (ZB) crystalline structure of the CdTe thin film on the silicon substrate. The CdTe thin film prepared by the ICB method had high crystalline quality. The microscopic processes involved in the ICB deposition technique, such as impact and coalescence processes, have been studied in detail by molecular dynamics (MD) simulation.

  3. Molecular dynamics computer simulation study of Pd{sub n} (n=13, 19, 38 and 55) clusters

    Energy Technology Data Exchange (ETDEWEB)

    Karabacak, M [Afyon Kocatepe University, Department of Physics, Afyon (Turkey); Oezcelik, S [Gazi University, Department of Physics, Ankara (Turkey); Guevenc, Z B [Cankaya University, Department of Electronics and Communication Engineering, Ankara (Turkey)

    2002-07-01

    Using constant-energy molecular dynamics and thermal quenching simulations, we have studied minimum-energy structures and energetics, Pd{sub n} (n=13, 19, 38, and 55) clusters employing the Voter and Chen's version of parameterisation of the embedded-atom potential surface. Isomer statistics for Pdn ( n = 13 and 19 ) is obtained from 10000 initial independent configurations, which have been generated along high-energy trajectories (chosen energy values are high enough to melt the clusters). The thermal quenching technique is employed to remove the internal kinetic energy of the clusters. The locally stable isomers are separated from metastable ones. Probabilities belonging to sampling the basins of attractions of each isomers are computed, and then, isomers' energy spectra are analyzed.

  4. Ab initio dynamics and photoionization mass spectrometry reveal ion-molecule pathways from ionized acetylene clusters to benzene cation.

    Science.gov (United States)

    Stein, Tamar; Bandyopadhyay, Biswajit; Troy, Tyler P; Fang, Yigang; Kostko, Oleg; Ahmed, Musahid; Head-Gordon, Martin

    2017-05-23

    The growth mechanism of hydrocarbons in ionizing environments, such as the interstellar medium (ISM), and some combustion conditions remains incompletely understood. Ab initio molecular dynamics (AIMD) simulations and molecular beam vacuum-UV (VUV) photoionization mass spectrometry experiments were performed to understand the ion-molecule growth mechanism of small acetylene clusters (up to hexamers). A dramatic dependence of product distribution on the ionization conditions is demonstrated experimentally and understood from simulations. The products change from reactive fragmentation products in a higher temperature, higher density gas regime toward a very cold collision-free cluster regime that is dominated by products whose empirical formula is (C 2 H 2 ) n + , just like ionized acetylene clusters. The fragmentation products result from reactive ion-molecule collisions in a comparatively higher pressure and temperature regime followed by unimolecular decomposition. The isolated ionized clusters display rich dynamics that contain bonded C 4 H 4 + and C 6 H 6 + structures solvated with one or more neutral acetylene molecules. Such species contain large amounts (>2 eV) of excess internal energy. The role of the solvent acetylene molecules is to affect the barrier crossing dynamics in the potential energy surface (PES) between (C 2 H 2 ) n + isomers and provide evaporative cooling to dissipate the excess internal energy and stabilize products including the aromatic ring of the benzene cation. Formation of the benzene cation is demonstrated in AIMD simulations of acetylene clusters with n > 3, as well as other metastable C 6 H 6 + isomers. These results suggest a path for aromatic ring formation in cold acetylene-rich environments such as parts of the ISM.

  5. Ab initio dynamics and photoionization mass spectrometry reveal ion–molecule pathways from ionized acetylene clusters to benzene cation

    Science.gov (United States)

    Stein, Tamar; Bandyopadhyay, Biswajit; Troy, Tyler P.; Fang, Yigang; Kostko, Oleg

    2017-01-01

    The growth mechanism of hydrocarbons in ionizing environments, such as the interstellar medium (ISM), and some combustion conditions remains incompletely understood. Ab initio molecular dynamics (AIMD) simulations and molecular beam vacuum-UV (VUV) photoionization mass spectrometry experiments were performed to understand the ion–molecule growth mechanism of small acetylene clusters (up to hexamers). A dramatic dependence of product distribution on the ionization conditions is demonstrated experimentally and understood from simulations. The products change from reactive fragmentation products in a higher temperature, higher density gas regime toward a very cold collision-free cluster regime that is dominated by products whose empirical formula is (C2H2)n+, just like ionized acetylene clusters. The fragmentation products result from reactive ion–molecule collisions in a comparatively higher pressure and temperature regime followed by unimolecular decomposition. The isolated ionized clusters display rich dynamics that contain bonded C4H4+ and C6H6+ structures solvated with one or more neutral acetylene molecules. Such species contain large amounts (>2 eV) of excess internal energy. The role of the solvent acetylene molecules is to affect the barrier crossing dynamics in the potential energy surface (PES) between (C2H2)n+ isomers and provide evaporative cooling to dissipate the excess internal energy and stabilize products including the aromatic ring of the benzene cation. Formation of the benzene cation is demonstrated in AIMD simulations of acetylene clusters with n > 3, as well as other metastable C6H6+ isomers. These results suggest a path for aromatic ring formation in cold acetylene-rich environments such as parts of the ISM. PMID:28484019

  6. THE DYNAMICAL EFFECTS OF WHITE DWARF BIRTH KICKS IN GLOBULAR STAR CLUSTERS

    International Nuclear Information System (INIS)

    Fregeau, John M.; Richer, Harvey B.; Rasio, Frederic A.; Hurley, Jarrod R.

    2009-01-01

    Recent observations of the white dwarf (WD) populations in the Galactic globular cluster NGC 6397 suggest that WDs receive a kick of a few km s -1 shortly before they are born. Using our Monte Carlo cluster evolution code, which includes accurate treatments of all relevant physical processes operating in globular clusters, we study the effects of the kicks on their host cluster and on the WD population itself. We find that in clusters whose velocity dispersion is comparable to the kick speed, WD kicks are a significant energy source for the cluster, prolonging the initial cluster core contraction phase significantly so that at late times the cluster core-to-half-mass radius ratio is a factor of up to ∼10 larger than in the no-kick case. WD kicks thus represent a possible resolution of the large discrepancy between observed and theoretically predicted values of this key structural parameter. Our modeling also reproduces the observed trend for younger WDs to be more extended in their radial distribution in the cluster than older WDs.

  7. A multi-Poisson dynamic mixture model to cluster developmental patterns of gene expression by RNA-seq.

    Science.gov (United States)

    Ye, Meixia; Wang, Zhong; Wang, Yaqun; Wu, Rongling

    2015-03-01

    Dynamic changes of gene expression reflect an intrinsic mechanism of how an organism responds to developmental and environmental signals. With the increasing availability of expression data across a time-space scale by RNA-seq, the classification of genes as per their biological function using RNA-seq data has become one of the most significant challenges in contemporary biology. Here we develop a clustering mixture model to discover distinct groups of genes expressed during a period of organ development. By integrating the density function of multivariate Poisson distribution, the model accommodates the discrete property of read counts characteristic of RNA-seq data. The temporal dependence of gene expression is modeled by the first-order autoregressive process. The model is implemented with the Expectation-Maximization algorithm and model selection to determine the optimal number of gene clusters and obtain the estimates of Poisson parameters that describe the pattern of time-dependent expression of genes from each cluster. The model has been demonstrated by analyzing a real data from an experiment aimed to link the pattern of gene expression to catkin development in white poplar. The usefulness of the model has been validated through computer simulation. The model provides a valuable tool for clustering RNA-seq data, facilitating our global view of expression dynamics and understanding of gene regulation mechanisms. © The Author 2014. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  8. Hydrogen migration dynamics in hydrated Al clusters: The Al17(−)·H2O system as an example

    International Nuclear Information System (INIS)

    Álvarez-Barcia, S.; Flores, J. R.

    2014-01-01

    The Al m (−) ·(H 2 O) n systems are known to undergo water splitting processes in the gas phase giving H k Al m (OH) k (−) ·(H 2 O) n−k systems, which can generate H 2 . The migration of H atoms from one Al atom to another on the cluster's surface is of critical importance to the mechanism of the complete H 2 production process. We have applied a combination of Molecular Dynamics and Rice-Ramsperger-Kassel-Marcus theory including tunneling effects to study the gas-phase evolution of HAl 17 (OH) (−) , which can be considered a model system. First, we have performed an extensive search for local minima and the connecting saddle points using a density functional theory method. It is found that in the water-splitting process Al 17 (−) ·(H 2 O) → HAl 17 (OH) (−) , the H atom which bonds to the Al cluster losses rather quickly its excess energy, which is easily “absorbed” by the cluster because of its flexibility. This fact ultimately determines that long-range hydrogen migration is not a very fast process and that, probably, tunneling only plays a secondary role in the migration dynamics, at least for moderate energies. Reduction of the total energy results in the process being very much slowed down. The consequences on the possible mechanisms of H 2 generation from the interaction of Al clusters and water molecules are discussed

  9. Self-sacrifice, self-transcendence and nurses' professional self.

    Science.gov (United States)

    Pask, Elizabeth J

    2005-10-01

    In this paper I elaborate a notion of nurses' professional self as one who is attracted towards intrinsic value. My previous work in 2003 has shown how nurses, who see intrinsic value in their work, experience self-affirmation when they believe that they have made a difference to that which they see to have value. The aim of this work is to reveal a further aspect of nurses' professional self. I argue that nurses' desire towards that which they see to have intrinsic value, is a necessary and self-transcending aspect of a nurses' professional self. I argue further that nurses' desire towards intrinsic value inevitably involves their vulnerability. Nurses who see intrinsic value are shown to be vulnerable to self-sacrifice in their inclination to work for the good of their patients, at the expense of themselves. Yet an ability to transcend their self in this way remains a necessary aspect of a nurse's professional self, which requires nurture and support through nurse education.

  10. Fragmentation dynamics of ionized neon clusters (Ne(n), n=3-14) embedded in helium nanodroplets.

    Science.gov (United States)

    Bonhommeau, David; Halberstadt, Nadine; Viel, Alexandra

    2006-01-14

    We report a theoretical study of the nonadiabatic fragmentation dynamics of ionized neon clusters embedded in helium nanodroplets for cluster sizes up to n=14 atoms. The dynamics of the neon atoms is modeled using the molecular dynamics with quantum transitions method of Tully [J. Chem. Phys. 93, 1061 (1990)] with the nuclei treated classically and transitions between electronic states quantum mechanically. The potential-energy surfaces are derived from a diatomics-in-molecules model to which induced dipole-induced dipole interactions are added. The effect of the spin-orbit interaction is also discussed. The helium environment is modeled by a friction force acting on charged atoms whose speed exceeds the critical Landau velocity. The dependence of the fragment size distribution on the friction strength and on the initial nanodroplet size is investigated. By comparing with the available experimental data obtained for Ne3+ and Ne4+, a reasonable value for the friction coefficient, the only parameter of the model, is deduced. This value is then used to predict the effect of the helium environment on the dissociation dynamics of larger neon clusters, n=5-14. The results show stabilization of larger fragments than in the gas phase, but fragmentation is not completely caged. In addition, two types of dynamics are characterized for Ne4+: fast and explosive, therefore leaving no time for friction to cool down the process when dynamics starts on one of the highest electronic states, and slower, therefore leading to some stabilization by helium when it starts on one of the lowest electronic states.

  11. Dynamic lifetimes of cagelike water clusters immersed in liquid water and their implications for hydrate nucleation studies

    Energy Technology Data Exchange (ETDEWEB)

    Guo, G.J.; Zhang, Y.G.; Li, M.; Wu, C.H. [Chinese Academy of Sciences, Inst. of Geology and Geophysics, Beijing (China). Key Laboratory of the Study of Earth' s Deep Interior

    2008-07-01

    In hydrate research fields, the hydrate nucleation mechanism still remains as an unsolved question. The static lifetimes of cagelike water clusters (CLWC) immersed in bulk liquid water have recently been measured by performing molecular dynamics simulations in the methane-water system, during which the member-water molecules of CLWCs are not allowed to exchange with their surrounding water molecules. This paper presented a study that measured the dynamic lifetimes of CLWCs permitting such water exchanges. The study involved re-analysis of previous simulation data that were used to study the effect of methane adsorption on the static lifetimes of a dodecahedral water cluster (DWC). The dynamic lifetimes of the DWC were calculated. The results of lifetime measurements of DWC in different systems were provided. The implications of this study for hydrate nucleation were also discussed. It was found that the dynamic lifetimes of CLWCs were not less than the static lifetimes previously obtained, and their ratio increased with the lifetime values. The results strengthened that CLWCs are metastable structures in liquid water and the occurrence probability of long-lived CLWCs will increase if one uses the dynamic lifetimes instead of the static lifetimes. 13 refs., 1 tab., 3 figs.

  12. Ab-initio molecular dynamics studies of magnesium-doped sodium clusters

    International Nuclear Information System (INIS)

    Roethlisberger, U.; Andreoni, W.

    1993-01-01

    Structural, electronic, and vibrational properties of magnesium-doped sodium clusters have been determined using the Car-Parrinello method. It is found that in the energetically preferred structures the magnesium impurity never is located at the centre of the cluster. The validity of spherical jellium models and the effects of temperature are discussed. 9 refs, 3 figs, 1 tab

  13. Competetive clustering in a bidisperse granular gas : experiment, molecular dynamics, and flux model

    NARCIS (Netherlands)

    Mikkelsen, René; van der Meer, Devaraj; van der Weele, Ko; Lohse, Detlef

    2004-01-01

    A compartmentalized bidisperse granular gas clusters competitively [R. Mikkelsen, D. van der Meer, K. van der Weele, and D. Lohse, Phys. Rev. Lett. 89, 214301 (2002)]: By tuning the shaking strength, the clustering can be directed either towards the compartment initially containing mainly small

  14. How clustering dynamics influence lumber utilization patterns in the Amish-based furniture industry in Ohio

    Science.gov (United States)

    Matthew S. Bumgardner; Gary W. Graham; P. Charles Goebel; Robert L. Romig

    2011-01-01

    Preliminary studies have suggested that the Amish-based furniture and related products manufacturing cluster located in and around Holmes County, Ohio, uses sizeable quantities of hardwood lumber. The number of firms within the cluster has grown even as the broader domestic furniture manufacturing sector has contracted. The present study was undertaken in 2008 (spring/...

  15. Prediction of chemotherapeutic response in bladder cancer using K-means clustering of dynamic contrast-enhanced (DCE)-MRI pharmacokinetic parameters.

    Science.gov (United States)

    Nguyen, Huyen T; Jia, Guang; Shah, Zarine K; Pohar, Kamal; Mortazavi, Amir; Zynger, Debra L; Wei, Lai; Yang, Xiangyu; Clark, Daniel; Knopp, Michael V

    2015-05-01

    To apply k-means clustering of two pharmacokinetic parameters derived from 3T dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict the chemotherapeutic response in bladder cancer at the mid-cycle timepoint. With the predetermined number of three clusters, k-means clustering was performed on nondimensionalized Amp and kep estimates of each bladder tumor. Three cluster volume fractions (VFs) were calculated for each tumor at baseline and mid-cycle. The changes of three cluster VFs from baseline to mid-cycle were correlated with the tumor's chemotherapeutic response. Receiver-operating-characteristics curve analysis was used to evaluate the performance of each cluster VF change as a biomarker of chemotherapeutic response in bladder cancer. The k-means clustering partitioned each bladder tumor into cluster 1 (low kep and low Amp), cluster 2 (low kep and high Amp), cluster 3 (high kep and low Amp). The changes of all three cluster VFs were found to be associated with bladder tumor response to chemotherapy. The VF change of cluster 2 presented with the highest area-under-the-curve value (0.96) and the highest sensitivity/specificity/accuracy (96%/100%/97%) with a selected cutoff value. The k-means clustering of the two DCE-MRI pharmacokinetic parameters can characterize the complex microcirculatory changes within a bladder tumor to enable early prediction of the tumor's chemotherapeutic response. © 2014 Wiley Periodicals, Inc.

  16. Combining in situ transmission electron microscopy irradiation experiments with cluster dynamics modeling to study nanoscale defect agglomeration in structural metals

    International Nuclear Information System (INIS)

    Xu Donghua; Wirth, Brian D.; Li Meimei; Kirk, Marquis A.

    2012-01-01

    We present a combinatorial approach that integrates state-of-the-art transmission electron microscopy (TEM) in situ irradiation experiments and high-performance computing techniques to study irradiation defect dynamics in metals. Here, we have studied the evolution of visible defect clusters in nanometer-thick molybdenum foils under 1 MeV krypton ion irradiation at 80 °C through both cluster dynamics modeling and in situ TEM experiments. The experimental details are reported elsewhere; we focus here on the details of model construction and comparing the model with the experiments. The model incorporates continuous production of point defects and/or small clusters, and the accompanying interactions, which include clustering, recombination and loss to the surfaces that result from the diffusion of the mobile defects. To account for the strong surface effect in thin TEM foils, the model includes one-dimensional spatial dependence along the foil depth, and explicitly treats the surfaces as black sinks. The rich amount of data (cluster number density and size distribution at a variety of foil thickness, irradiation dose and dose rate) offered by the advanced in situ experiments has allowed close comparisons with computer modeling and permitted significant validation and optimization of the model in terms of both physical model construct (damage production mode, identities of mobile defects) and parameterization (diffusivities of mobile defects). The optimized model exhibits good qualitative and quantitative agreement with the in situ TEM experiments. The combinatorial approach is expected to bring a unique opportunity for the study of radiation damage in structural materials.

  17. K-means clustering for optimal partitioning and dynamic load balancing of parallel hierarchical N-body simulations

    International Nuclear Information System (INIS)

    Marzouk, Youssef M.; Ghoniem, Ahmed F.

    2005-01-01

    A number of complex physical problems can be approached through N-body simulation, from fluid flow at high Reynolds number to gravitational astrophysics and molecular dynamics. In all these applications, direct summation is prohibitively expensive for large N and thus hierarchical methods are employed for fast summation. This work introduces new algorithms, based on k-means clustering, for partitioning parallel hierarchical N-body interactions. We demonstrate that the number of particle-cluster interactions and the order at which they are performed are directly affected by partition geometry. Weighted k-means partitions minimize the sum of clusters' second moments and create well-localized domains, and thus reduce the computational cost of N-body approximations by enabling the use of lower-order approximations and fewer cells. We also introduce compatible techniques for dynamic load balancing, including adaptive scaling of cluster volumes and adaptive redistribution of cluster centroids. We demonstrate the performance of these algorithms by constructing a parallel treecode for vortex particle simulations, based on the serial variable-order Cartesian code developed by Lindsay and Krasny [Journal of Computational Physics 172 (2) (2001) 879-907]. The method is applied to vortex simulations of a transverse jet. Results show outstanding parallel efficiencies even at high concurrencies, with velocity evaluation errors maintained at or below their serial values; on a realistic distribution of 1.2 million vortex particles, we observe a parallel efficiency of 98% on 1024 processors. Excellent load balance is achieved even in the face of several obstacles, such as an irregular, time-evolving particle distribution containing a range of length scales and the continual introduction of new vortex particles throughout the domain. Moreover, results suggest that k-means yields a more efficient partition of the domain than a global oct-tree

  18. Demystifying self-transcendence for mental health nursing practice and research.

    Science.gov (United States)

    Reed, Pamela G

    2009-10-01

    Because human development is an integral aspect of life, pathways to mental health necessarily involve developmentally based issues or resources. This column provides an overview of self-transcendence as one developmentally based resource for mental health. The Self-Transcendence Scale is presented to encourage its use in mental health nursing practice and research.

  19. College Stress and Psychological Well-Being: Self-Transcendence Meaning of Life as a Moderator

    Science.gov (United States)

    Hong, Li

    2008-01-01

    The central aim of this study is to examine the moderating effects of self-transcendence meaning on psychological well-being in respective of college students. The theoretical background of self-transcendence meaning is mainly oriental Buddhism and Taoism philosophy. Measures of stress and psychological well-being are College Stress Scale (CSS)…

  20. The Rothko Chapel Paintings and the Urgency of the Transcendent Experience

    NARCIS (Netherlands)

    Stoker, W.

    2008-01-01

    Since the Romantic period, painters have no longer made use of traditional Christian iconography to express religious transcendence. Taking their cue from Schleiermacher's Reden Über die Religion, painters have sought for new, personal ways to express religious transcendence. One example is Caspar

  1. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks.

    Science.gov (United States)

    Gholami, Mohammad; Brennan, Robert W

    2016-01-06

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  2. Mean-cluster approach indicates cell sorting time scales are determined by collective dynamics

    Science.gov (United States)

    Beatrici, Carine P.; de Almeida, Rita M. C.; Brunnet, Leonardo G.

    2017-03-01

    Cell migration is essential to cell segregation, playing a central role in tissue formation, wound healing, and tumor evolution. Considering random mixtures of two cell types, it is still not clear which cell characteristics define clustering time scales. The mass of diffusing clusters merging with one another is expected to grow as td /d +2 when the diffusion constant scales with the inverse of the cluster mass. Cell segregation experiments deviate from that behavior. Explanations for that could arise from specific microscopic mechanisms or from collective effects, typical of active matter. Here we consider a power law connecting diffusion constant and cluster mass to propose an analytic approach to model cell segregation where we explicitly take into account finite-size corrections. The results are compared with active matter model simulations and experiments available in the literature. To investigate the role played by different mechanisms we considered different hypotheses describing cell-cell interaction: differential adhesion hypothesis and different velocities hypothesis. We find that the simulations yield normal diffusion for long time intervals. Analytic and simulation results show that (i) cluster evolution clearly tends to a scaling regime, disrupted only at finite-size limits; (ii) cluster diffusion is greatly enhanced by cell collective behavior, such that for high enough tendency to follow the neighbors, cluster diffusion may become independent of cluster size; (iii) the scaling exponent for cluster growth depends only on the mass-diffusion relation, not on the detailed local segregation mechanism. These results apply for active matter systems in general and, in particular, the mechanisms found underlying the increase in cell sorting speed certainly have deep implications in biological evolution as a selection mechanism.

  3. Vulnerability to alcohol consumption, spiritual transcendence and psychosocial well-being: test of a theory 1

    Science.gov (United States)

    Heredia, Luz Patricia Díaz; Sanchez, Alba Idaly Muñoz

    2016-01-01

    Abstract Objective: to demonstrate the relations among vulnerability, self-transcendence and well-being in the young adult population and the effect of each of these variables on the adoption of low-risk consumption conducts. Method: quantitative and cross-sectional correlation study using structural equations analysis to test the relation among the variables. Results: an inverse relation was evidenced between vulnerability to alcohol consumption and spiritual transcendence (β-0.123, p 0.025) and a direct positive relation between spiritual transcendence and psychosocial well-being (β 0.482, p 0.000). Conclusions: the relations among the variables spiritual transcendence, vulnerability to alcohol consumption and psychosocial well-being, based on Reed's Theory, are confirmed in the population group of young college students, concluding that psychosocial well-being can be achieved when spiritual transcendence is enhanced, as the vulnerability to alcohol consumption drops. PMID:27276017

  4. Self-transcendence as a measure of spirituality in a sample of older Australian twins.

    Science.gov (United States)

    Kirk, K M; Eaves, L J; Martin, N G

    1999-06-01

    Measures of self-transcendence, physical health and psychological well-being were included in a self-report Health and Lifestyle questionnaire administered to Australian twins aged over 50 between 1993 and 1995. Self-transcendence appears to be higher among older Australian women than men, and was significantly associated with religious affiliation, marital status (in women) and age (in men). No strong correlations were observed between self-transcendence and any measure of psychological or physical health. Additive genetic effects were found to be important in influencing self-transcendence, with heritability estimates of 0.37 and 0.41 for men and women respectively, whilst shared environment effects were not found to be significant. Multivariate modelling of self-transcendence scores and self-reported church attendance behavior indicated substantially different etiologies for these variables, with implications for methods of investigation of religiosity and spirituality.

  5. Vulnerability to alcohol consumption, spiritual transcendence and psychosocial well-being: test of a theory

    Directory of Open Access Journals (Sweden)

    Luz Patricia Díaz Heredia

    2016-01-01

    Full Text Available Abstract Objective: to demonstrate the relations among vulnerability, self-transcendence and well-being in the young adult population and the effect of each of these variables on the adoption of low-risk consumption conducts. Method: quantitative and cross-sectional correlation study using structural equations analysis to test the relation among the variables. Results: an inverse relation was evidenced between vulnerability to alcohol consumption and spiritual transcendence (β-0.123, p 0.025 and a direct positive relation between spiritual transcendence and psychosocial well-being (β 0.482, p 0.000. Conclusions: the relations among the variables spiritual transcendence, vulnerability to alcohol consumption and psychosocial well-being, based on Reed's Theory, are confirmed in the population group of young college students, concluding that psychosocial well-being can be achieved when spiritual transcendence is enhanced, as the vulnerability to alcohol consumption drops.

  6. Birth and death: opportunities for self-transcendence.

    Science.gov (United States)

    Budin, W C

    2001-01-01

    One thing that is often absent in childbirth education classes is a discussion of the spiritual aspect of giving birth. Birth offers women a wonderful opportunity to awaken their spirituality. Natural childbirth, in particular, has the potential for self-transcendence, offering an even greater appreciation for the miracle of life. The normal, natural pain in labor can challenge the core of one's being-it is a healthy sensation that provides direction for women moving through the maze of labor. The challenge of giving birth today is to develop confidence and trust in one's inner wisdom and allow nature to do its thing. When this is accomplished, a woman's body is often permeated and nourished by spiritual energy and guidance. She emerges from her labor bed with a renewed sense of her body's strength and power and with an enhanced spirituality.

  7. Self-Transcendence, Sexual Desire, and Sexual Frequency.

    Science.gov (United States)

    Costa, Rui Miguel; Pestana, José; Costa, David

    2018-01-02

    Self-forgetfulness is a facet of self-transcendence characterized by tendency to experience altered states of consciousness. We examined associations of self-forgetfulness with sexual desire and frequency. Two hundred sixty-one Portuguese men and women completed the self-forgetfulness subscale of the Temperament and Character Inventory-Revised, a measure of openness to experience, and a questionnaire on desired and actual frequency of vaginal intercourse, noncoital sex, and masturbation in the past month. In simple and partial correlations controlling for openness to experience and relationship status, women's self-forgetfulness correlated with desired frequency of intercourse and noncoital sex. For men, self-forgetfulness correlated with actual frequency of intercourse and noncoital sex.

  8. Narcissistic biographies--third age self-transcendence abilities.

    Science.gov (United States)

    Nirestean, Aurel; Lukacs, Emese; Cimpan, Dana; Nirestean, Tudor

    2014-02-01

    Narcissistic traits interfere in the process of self-determination and the individual motivational strategies of human beings. The grandiose and vulnerable narcissistic personality subtypes have difficulties in their education, interpersonal relationships and quality of life. The latter is also affected by ageing, whose attributes influence, above all, one's self-esteem, especially in women. Though very fearful of suffering and death, narcissists have a powerful desire to overcome them by cultivating their grandiosity, especially through the mystical and paranormal experiences they relate. The spiritual means of transcending one's self, including the components of magical thinking, can prevent the destruction of self-esteem in narcissists in their third-age. Copyright © 2014 John Wiley & Sons, Ltd.

  9. Transposing, Transforming and Transcending Tradition in Creative Digital Media

    DEFF Research Database (Denmark)

    Prager, Phillip; Thomas, Maureen; Selsjord, Marianne

    2015-01-01

    and storytelling arts combine to create rich, complex, and engaging moving-image based artworks with wide appeal. It examines how dramatist and interactive media artist Maureen Thomas and 3D media artist and conservator Marianne Selsjord deploy creative digital technologies to transpose, transform, and transcend......How can digital media technologies, contemporary theories of creativity, and tradition combine to develop the aesthetics of computer-based art today and in the future? Through contextualised case-studies, this chapter investigates how games, information technologies, and traditional visual...... pre-page arts and crafts for the digital era, making fresh work for new audiences. Researcher in digital aesthetics, creative cognition, and play behaviour Dr. Phillip Prager examines how such work is conducive to creative insight and worthwhile play, discussing its remediation of some...

  10. Self-transcendence and nurse-patient interaction in cognitively intact nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Rannestad, Toril; Hanssen, Brith; Espnes, Geir A

    2012-12-01

    The aim of this study was to test whether nurse-patient interaction affects cognitively intact nursing home patients' interpersonal and intrapersonal self-transcendence, as well as testing the psychometric properties of the Nurse-Patient Interaction Scale (NPIS). Self-transcendence is considered a spiritual developmental process of maturity in adulthood, and a vital resource of well-being at the end of life. The concept of self-transcendence has previously been explored in various populations, yet the nurse-patient interactions' potential influence on self-transcendence in nursing home patients has not been published previously. A cross-sectional design employing the Self-Transcendence Scale and the NPIS was adopted. A sample of 202 cognitively well-functioning nursing home patients in Norway was selected. The statistical analyses were carried out using lisrel 8.8 and structural equation modelling. Structural equation modelling-analysis indicates statistical significant effect of nurse-patient interaction on the patients' self-transcendence. Direct influence on the intrapersonal and indirect influence on the interpersonal self-transcendence aspects was disclosed. Nurse-patient interaction significantly affected both interpersonal and intrapersonal self-transcendence among cognitively intact nursing home patients. Hence, facilitating caring interventions can be significantly beneficial to older patients' self-transcendence and thereby well-being, both emotional and physical. Caring behaviour signifies the vital and ultimate qualitative nursing behaviour, which promotes self-transcendence and thereby well-being. These findings are important for clinical nursing that intends to increase patients' well-being. © 2012 Blackwell Publishing Ltd.

  11. Large-scale dynamics associated with clustering of extratropical cyclones affecting Western Europe

    OpenAIRE

    Pinto, Joaquim G.; Gómara, Iñigo; Masato, Giacomo; Dacre, Helen F.; Woollings, Tim; Caballero, Rodrigo

    2014-01-01

    Some recent winters in Western Europe have been characterized by the occurrence of multiple extratropical cyclones following a similar path. The occurrence of such cyclone clusters leads to large socio-economic impacts due to damaging winds, storm surges, and floods. Recent studies have statistically characterized the clustering of extratropical cyclones over the North Atlantic and Europe and hypothesized potential physical mechanisms responsible for their formation. Here we analyze 4 months ...

  12. Multi-agent grid system Agent-GRID with dynamic load balancing of cluster nodes

    Science.gov (United States)

    Satymbekov, M. N.; Pak, I. T.; Naizabayeva, L.; Nurzhanov, Ch. A.

    2017-12-01

    In this study the work presents the system designed for automated load balancing of the contributor by analysing the load of compute nodes and the subsequent migration of virtual machines from loaded nodes to less loaded ones. This system increases the performance of cluster nodes and helps in the timely processing of data. A grid system balances the work of cluster nodes the relevance of the system is the award of multi-agent balancing for the solution of such problems.

  13. Dynamical Competition of IC-Industry Clustering from Taiwan to China

    Science.gov (United States)

    Tsai, Bi-Huei; Tsai, Kuo-Hui

    2009-08-01

    Most studies employ qualitative approach to explore the industrial clusters; however, few research has objectively quantified the evolutions of industry clustering. The purpose of this paper is to quantitatively analyze clustering among IC design, IC manufacturing as well as IC packaging and testing industries by using the foreign direct investment (FDI) data. The Lotka-Volterra system equations are first adopted here to capture the competition or cooperation among such three industries, thus explaining their clustering inclinations. The results indicate that the evolution of FDI into China for IC design industry significantly inspire the subsequent FDI of IC manufacturing as well as IC packaging and testing industries. Since IC design industry lie in the upstream stage of IC production, the middle-stream IC manufacturing and downstream IC packing and testing enterprises tend to cluster together with IC design firms, in order to sustain a steady business. Finally, Taiwan IC industry's FDI amount into China is predicted to cumulatively increase, which supports the industrial clustering tendency for Taiwan IC industry. Particularly, the FDI prediction of Lotka-Volterra model performs superior to that of the conventional Bass model after the forecast accuracy of these two models are compared. The prediction ability is dramatically improved as the industrial mutualism among each IC production stage is taken into account.

  14. ODE, RDE and SDE models of cell cycle dynamics and clustering in yeast.

    Science.gov (United States)

    Boczko, Erik M; Gedeon, Tomas; Stowers, Chris C; Young, Todd R

    2010-07-01

    Biologists have long observed periodic-like oxygen consumption oscillations in yeast populations under certain conditions, and several unsatisfactory explanations for this phenomenon have been proposed. These ‘autonomous oscillations’ have often appeared with periods that are nearly integer divisors of the calculated doubling time of the culture. We hypothesize that these oscillations could be caused by a form of cell cycle synchronization that we call clustering. We develop some novel ordinary differential equation models of the cell cycle. For these models, and for random and stochastic perturbations, we give both rigorous proofs and simulations showing that both positive and negative growth rate feedback within the cell cycle are possible agents that can cause clustering of populations within the cell cycle. It occurs for a variety of models and for a broad selection of parameter values. These results suggest that the clustering phenomenon is robust and is likely to be observed in nature. Since there are necessarily an integer number of clusters, clustering would lead to periodic-like behaviour with periods that are nearly integer divisors of the period of the cell cycle. Related experiments have shown conclusively that cell cycle clustering occurs in some oscillating yeast cultures.

  15. The existence of a plastic phase and a solid-liquid dynamical bistability region in small fullerene cluster (C60)7: molecular dynamics simulation

    International Nuclear Information System (INIS)

    Piatek, A; Dawid, A; Gburski, Z

    2006-01-01

    We have simulated (by the molecular dymanics (MD) method) the dynamics of fullerenes (C 60 ) in an extremely small cluster composed of only as many as seven C 60 molecules. The interaction is taken to be the full 60-site pairwise additive Lennard-Jones (LJ) potential which generates both translational and anisotropic rotational motions of each molecule. Our atomically detailed MD simulations discover the plastic phase (no translations but active reorientations of fullerenes) at low energies (temperatures) of the (C 60 ) 7 cluster. We provide the in-depth evidence of the dynamical solid-liquid bistability region in the investigated cluster. Moreover, we confirm the existence of the liquid phase in (C 60 ) 7 , the finding of Gallego et al (1999 Phys. Rev. Lett. 83 5258) obtained earlier on the basis of Girifalco's model, which assumes single-site only and spherically symmetrical interaction between C 60 molecules. We have calculated the translational and angular velocity autocorrelation functions and estimated the diffusion coefficient of fullerene in the liquid phase

  16. Cluster galaxy dynamics and the effects of large-scale environment

    Science.gov (United States)

    White, Martin; Cohn, J. D.; Smit, Renske

    2010-11-01

    Advances in observational capabilities have ushered in a new era of multi-wavelength, multi-physics probes of galaxy clusters and ambitious surveys are compiling large samples of cluster candidates selected in different ways. We use a high-resolution N-body simulation to study how the influence of large-scale structure in and around clusters causes correlated signals in different physical probes and discuss some implications this has for multi-physics probes of clusters (e.g. richness, lensing, Compton distortion and velocity dispersion). We pay particular attention to velocity dispersions, matching galaxies to subhaloes which are explicitly tracked in the simulation. We find that not only do haloes persist as subhaloes when they fall into a larger host, but groups of subhaloes retain their identity for long periods within larger host haloes. The highly anisotropic nature of infall into massive clusters, and their triaxiality, translates into an anisotropic velocity ellipsoid: line-of-sight galaxy velocity dispersions for any individual halo show large variance depending on viewing angle. The orientation of the velocity ellipsoid is correlated with the large-scale structure, and thus velocity outliers correlate with outliers caused by projection in other probes. We quantify this orientation uncertainty and give illustrative examples. Such a large variance suggests that velocity dispersion estimators will work better in an ensemble sense than for any individual cluster, which may inform strategies for obtaining redshifts of cluster members. We similarly find that the ability of substructure indicators to find kinematic substructures is highly viewing angle dependent. While groups of subhaloes which merge with a larger host halo can retain their identity for many Gyr, they are only sporadically picked up by substructure indicators. We discuss the effects of correlated scatter on scaling relations estimated through stacking, both analytically and in the simulations

  17. Pressure and cooling rate effect on polyhedron clusters in Cu-Al alloy by using molecular dynamics simulation

    Science.gov (United States)

    Celik, Fatih Ahmet

    2014-10-01

    In this study, the microstructural evolution of crystal-type and icosahedral (icos)-type polyhedrons in Cu-50 at%Al alloy based on the embedded atom method (EAM) model is studied at two cooling rates under normal and high pressures by using the molecular dynamics (MD) simulation method. The cluster-type index method (CTIM) which describes icos and defective icos polyhedrons and the new cluster-type index method (CTIM-2) which describes crystal-type polyhedrons have been used to perform polyhedron analysis in the model alloy system. The results of our simulations demonstrate that the effects of the cooling rate and pressure play an important role in the numbers of polyhedrons and their structures in the system.

  18. Pressure and cooling rate effect on polyhedron clusters in Cu–Al alloy by using molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Fatih Ahmet, E-mail: facelik@beu.edu.tr

    2014-10-01

    In this study, the microstructural evolution of crystal-type and icosahedral (icos)-type polyhedrons in Cu–50 at%Al alloy based on the embedded atom method (EAM) model is studied at two cooling rates under normal and high pressures by using the molecular dynamics (MD) simulation method. The cluster-type index method (CTIM) which describes icos and defective icos polyhedrons and the new cluster-type index method (CTIM-2) which describes crystal-type polyhedrons have been used to perform polyhedron analysis in the model alloy system. The results of our simulations demonstrate that the effects of the cooling rate and pressure play an important role in the numbers of polyhedrons and their structures in the system.

  19. Human object-similarity judgments reflect and transcend the primate-IT object representation

    Directory of Open Access Journals (Sweden)

    Marieke eMur

    2013-03-01

    Full Text Available Primate inferior temporal (IT cortex is thought to contain a high-level representation of objects at the interface between vision and semantics. This suggests that the perceived similarity of real-world objects might be predicted from the IT representation. Here we show that objects that elicit similar activity patterns in human IT tend to be judged as similar by humans. The IT representation explained the human judgments better than early visual cortex, other ventral stream regions, and a range of computational models. Human similarity judgments exhibited category clusters that reflected several categorical divisions that are prevalent in the IT representation of both human and monkey, including the animate/inanimate and the face/body division. Human judgments also reflected the within-category representation of IT. However, the judgments transcended the IT representation in that they introduced additional categorical divisions. In particular, human judgments emphasized human-related additional divisions between human and nonhuman animals and between man-made and natural objects. Human IT was more similar to monkey IT than to human judgments. One interpretation is that IT has evolved visual feature detectors that distinguish between animates and inanimates and between faces and bodies because these divisions are fundamental to survival and reproduction for all primate species, and that other brain systems serve to more flexibly introduce species-dependent and evolutionarily more recent divisions.

  20. Category dynamics and cluster spanning during the emergence of the Lebanese newspaper industry (1851–1879

    Directory of Open Access Journals (Sweden)

    Najib A. Mozahem

    2018-03-01

    Full Text Available Recently, researchers have started to pay more attention to a usually ignored topic: audience perceptions. Legitimacy, for example, is no longer modeled as the number of organizations in a population. It is now thought to be dependent on how audience members perceive these organizations. This paper will study how the newspaper industry in Lebanon emerged. The paper studies the period 1851–1879, building on the theoretic formulation of Hannan et al. (2007. The concept of cluster formation will also be introduced in order to help answer the question of whether unified identity projection is a necessary condition for successful legitimation and emergence. So far, research has produced diverging results as to the necessary conditions for successful legitimation. Cluster Analysis is used to show that in the case of the Lebanese newspaper industry, successful emergence was attained without the need to project a unified identity. In fact, the analysis clearly shows that there were two separate groups of clusters that had emerged by the end of the period. The nature of these two clusters will be investigated by looking at the category spanning activities of the newspapers that were members of the clusters. Keywords: TBC, Business, Industry, Information science

  1. Category dynamics and cluster spanning during the emergence of the Lebanese newspaper industry (1851-1879).

    Science.gov (United States)

    Mozahem, Najib A

    2018-03-01

    Recently, researchers have started to pay more attention to a usually ignored topic: audience perceptions. Legitimacy, for example, is no longer modeled as the number of organizations in a population. It is now thought to be dependent on how audience members perceive these organizations. This paper will study how the newspaper industry in Lebanon emerged. The paper studies the period 1851-1879, building on the theoretic formulation of Hannan et al. (2007). The concept of cluster formation will also be introduced in order to help answer the question of whether unified identity projection is a necessary condition for successful legitimation and emergence. So far, research has produced diverging results as to the necessary conditions for successful legitimation. Cluster Analysis is used to show that in the case of the Lebanese newspaper industry, successful emergence was attained without the need to project a unified identity. In fact, the analysis clearly shows that there were two separate groups of clusters that had emerged by the end of the period. The nature of these two clusters will be investigated by looking at the category spanning activities of the newspapers that were members of the clusters.

  2. First principles study of vibrational dynamics of ceria-titania hybrid clusters

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Abdul, E-mail: abdulmajid40@yahoo.com; Bibi, Maryam [University of Gujrat, Department of Physics (Pakistan)

    2017-04-15

    Density functional theory based calculations were performed to study vibrational properties of ceria, titania, and ceria-titania hybrid clusters. The findings revealed the dominance of vibrations related to oxygen when compared to those of metallic atoms in the clusters. In case of hybrid cluster, the softening of normal modes related to exterior oxygen atoms in ceria and softening/hardening of high/low frequency modes related to titania dimmers are observed. The results calculated for monomers conform to symmetry predictions according to which three IR and three Raman active modes were detected for TiO{sub 2}, whereas two IR active and one Raman active modes were observed for CeO{sub 2}. The comparative analysis indicates that the hybrid cluster CeTiO{sub 4} contains simultaneous vibrational fingerprints of the component dimmers. The symmetry, nature of vibrations, IR and Raman activity, intensities, and atomic involvement in different modes of the clusters are described in detail. The study points to engineering of CeTiO{sub 4} to tailor its properties for technological visible region applications in photocatalytic and electrochemical devices.

  3. Cluster geometry and survival probability in systems driven by reaction-diffusion dynamics

    International Nuclear Information System (INIS)

    Windus, Alastair; Jensen, Henrik J

    2008-01-01

    We consider a reaction-diffusion model incorporating the reactions A→φ, A→2A and 2A→3A. Depending on the relative rates for sexual and asexual reproduction of the quantity A, the model exhibits either a continuous or first-order absorbing phase transition to an extinct state. A tricritical point separates the two phase lines. While we comment on this critical behaviour, the main focus of the paper is on the geometry of the population clusters that form. We observe the different cluster structures that arise at criticality for the three different types of critical behaviour and show that there exists a linear relationship for the survival probability against initial cluster size at the tricritical point only.

  4. Cluster geometry and survival probability in systems driven by reaction-diffusion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Windus, Alastair; Jensen, Henrik J [The Institute for Mathematical Sciences, 53 Prince' s Gate, South Kensington, London SW7 2PG (United Kingdom)], E-mail: h.jensen@imperial.ac.uk

    2008-11-15

    We consider a reaction-diffusion model incorporating the reactions A{yields}{phi}, A{yields}2A and 2A{yields}3A. Depending on the relative rates for sexual and asexual reproduction of the quantity A, the model exhibits either a continuous or first-order absorbing phase transition to an extinct state. A tricritical point separates the two phase lines. While we comment on this critical behaviour, the main focus of the paper is on the geometry of the population clusters that form. We observe the different cluster structures that arise at criticality for the three different types of critical behaviour and show that there exists a linear relationship for the survival probability against initial cluster size at the tricritical point only.

  5. Fast electrons from multi-electron dynamics in xenon clusters induced by inner-shell ionization

    International Nuclear Information System (INIS)

    Bostedt, Christoph; Thomas, Heiko; Hoener, Matthias; Moeller, Thomas; Saalmann, Ulf; Georgescu, Ionut; Gnodtke, Christian; Rost, Jan-Michael

    2010-01-01

    Fast electrons emitted from xenon clusters in strong femtosecond 90 eV pulses have been measured at the Free-electron Laser in Hamburg (FLASH). Energy absorption occurs mainly through atomic inner-shell photo-ionization. Photo-electrons are trapped in the strong Coulomb potential of the cluster ions and form a non-equilibrium plasma with supra-atomic density. Its equilibration through multiple energy-exchanging collisions within the entire cluster volume produces electrons with energies well beyond the dominant emission line of atomic xenon. Here, in contrast to traditional low-frequency laser plasma heating, the plasma gains energy from electrons delivered through massive single-photon excitation from bound states. Electron emission induced by thermalization of a non-equilibrium plasma is expected to be a general phenomenon occurring for strong atomic x-ray absorption in extended systems.

  6. Consequences of dynamical disruption and mass segregation for the binary frequencies of star clusters

    International Nuclear Information System (INIS)

    Geller, Aaron M.; De Grijs, Richard; Li, Chengyuan; Hurley, Jarrod R.

    2013-01-01

    The massive (13,000-26,000 M ☉ ) and young (15-30 Myr) Large Magellanic Cloud star cluster NGC 1818 reveals an unexpected increasing binary frequency with radius for F-type stars (1.3-2.2 M ☉ ). This is in contrast to many older star clusters that show a decreasing binary frequency with radius. We study this phenomenon with sophisticated N-body modeling, exploring a range of initial conditions, from smooth virialized density distributions to highly substructured and collapsing configurations. We find that many of these models can reproduce the cluster's observed properties, although with a modest preference for substructured initial conditions. Our models produce the observed radial trend in binary frequency through disruption of soft binaries (with semi-major axes, a ≳ 3000 AU), on approximately a crossing time (∼5.4 Myr), preferentially in the cluster core. Mass segregation subsequently causes the binaries to sink toward the core. After roughly one initial half-mass relaxation time (t rh (0) ∼ 340 Myr) the radial binary frequency distribution becomes bimodal, the innermost binaries having already segregated toward the core, leaving a minimum in the radial binary frequency distribution that marches outward with time. After 4-6 t rh (0), the rising distribution in the halo disappears, leaving a radial distribution that rises only toward the core. Thus, both a radial binary frequency distribution that falls toward the core (as observed for NGC 1818) and one that rises toward the core (as for older star clusters) can arise naturally from the same evolutionary sequence owing to binary disruption and mass segregation in rich star clusters.

  7. Self-transcendence and emotional well-being in women with advanced breast cancer.

    Science.gov (United States)

    Coward, D D

    1991-07-01

    Self-transcendence has been associated, in previous studies, with stressful life events and emotional well-being. This study examined the relationships among self-transcendence, emotional well-being, and illness-related distress in women with advanced breast cancer. The study employed a cross-sectional correlational design in a convenience sample (n = 107) of women with Stage IIIb and Stage IV breast cancer. Subjects completed a questionnaire that included Reed's Self-Transcendence Scale; Bradburn's Affect Balance Scale (ABS); a Cognitive Well-Being (CWB) Scale based on work by Campbell, Converse, and Rogers; McCorkle and Young's Symptom Distress Scale (SDS); and the Karnofsky Performance Scale (KPS). Data were analyzed using factor analytic structural equations modeling. Self-transcendence decreased illness distress (assessed by the SDS and the KPS) through the mediating effect of emotional well-being (assessed by the ABS and the CWB Scale). Self-transcendence directly affected emotional well-being (beta = 0.69), and emotional well-being had a strong negative effect on illness distress (beta = -0.84). A direct path from self-transcendence to illness distress (beta = -0.31) became nonsignificant (beta = -0.08) when controlling for emotional well-being. Further research using longitudinal data will seek to validate these relationships and to explain how nurses can promote self-transcendence in women with advanced breast cancer, as well as in others with life-threatening illnesses.

  8. Self-transcendence and depression among AIDS Memorial Quilt panel makers.

    Science.gov (United States)

    Kausch, Kurt D; Amer, Kim

    2007-06-01

    Self-transcendence is a process that can help individuals reestablish well-being after experiencing a significant, life-altering event. In this study, we sought to identify the relationship between self-transcendence and depression in individuals who lost loved ones to HIV/AIDS and to describe and compare self-transcendence, self-transcendence variables of acceptance and spirituality, and depression among bereaved individuals who created AIDS Memorial Quilt panels with those who did not. The findings support Reed's self-transcendence theory, with inverse correlations between self-transcendence and depression obtained from both the total group and the panel makers. Significant differences were also found between certain self-transcendence variables and depression among the study participants related to gender and ethnicity. In addition, thematic analysis of panel maker interviews revealed five themes: Quilt panel making provides validation, Quilt panel making creates a living memory, liberating acceptance of loss, community of survivors, and connection to a higher power. These findings assist in understanding the complexities of the grief process and support the usefulness of Quilt panel making as an intervention for coping with grief related to HIV/AIDS.

  9. A study of the dynamical state of the hot plasma in galaxy clusters using XMM-Newton data and numerical simulation

    International Nuclear Information System (INIS)

    Solovyeva, Lilia

    2008-01-01

    Cluster of galaxies are the largest and youngest objects in the Universe and these objects are very interesting for study the cosmology. In this moment with the capacity of the instruments (XMM-Newton, Chandra) and with numerical simulations it is possible to study the dynamical state of gas in the cluster during their formation. And plus, now, we have the possibility to study the cluster in different wavelengths (optics, radio, X-ray). Our study helps us to understand the physics processes in clusters. In our work we studied the galaxy cluster around the maximum core collapse. We used the X-ray data, how the first indicators of dynamical state of gas. After with the help of numerical simulation and optics data we performed the completed analysis with the proposition of merger scenario possible. We performed the detailed analysis of two clusters (CL0016+16 and A548b), these clusters presents the signature of major merger and also we studied the cluster from numerical simulation (Cluster 6) around the major merger. (author) [fr

  10. Probing the structure and dynamics of cage-like clusters: from water to Met-Cars

    International Nuclear Information System (INIS)

    Castleman, A.W. Jr.

    1995-01-01

    Our recent work on metal compounds led to the discovery of a new class of metal-carbon clusters which are of finite size and have specific geometry, but exhibit varying electronic character because of the different metals of which they can be comprised. We term these metallo-carbohedrenes or Met-Cars for short. This paper reviews the progress made in elucidating the structures if these two classes of clusters which seem to be quite different, but have some interesting common features involving structural considerations. (orig.)

  11. Fragmentation dynamics of size selected pyrrole clusters prepared by electron impact ionization: Forming a solvated dimer ion core

    Czech Academy of Sciences Publication Activity Database

    Profant, V.; Poterya, Viktoriya; Fárník, Michal; Slavíček, P.; Buck, U.

    2007-01-01

    Roč. 111, č. 49 (2007), s. 12477-12486 ISSN 1089-5639 R&D Projects: GA AV ČR KAN400400651; GA ČR GA203/06/1290 Grant - others:GA ČR GP203/07/P449; University Grant(CZ) 8113-10/257852 Institutional research plan: CEZ:AV0Z40400503 Source of funding: V - iné verejné zdroje Keywords : pyrrole cluster s * structure * dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.918, year: 2007

  12. Self-transcendence in cognitively intact nursing-home patients: a resource for well-being.

    Science.gov (United States)

    Haugan, Gørill; Rannestad, Toril; Hammervold, Randi; Garåsen, Helge; Espnes, Geir Arild

    2013-05-01

    This article reports an empirical study of self-transcendence in cognitively intact nursing-home patients. The aim was to investigate the interrelationships between self-transcendence and nursing-home patients' physical, social, emotional and functional well-being. Finding new and alternative approaches to increase well-being among nursing-home patients is highly warranted. Self-transcendence is considered a developmental process of maturity in adulthood and a vital resource for well-being at the end of life, thus self-transcendence could be a useful approach. Cross-sectional The self-transcendence scale and the Functional Assessment of Cancer Therapy General (FACT-G) Quality of Life questionnaire were used. A sample of 202 cognitively intact nursing-home patients in Mid-Norway was selected to respond to the instruments in 2008 and 2009. Analysis was applied by means of LISREL 8·8 Structural Equation Modelling. A two-factor construct of self-transcendence showed that intrapersonal self-transcendence directly affected functional well-being and indirectly influenced physical, emotional and functional well-being. Interpersonal self-transcendence directly affected social and emotional well-being. Additionally important influences were disclosed from functional to emotional and from emotional to physical well-being. Finding nursing interventions to enhance both intrapersonal and interpersonal self-transcendence might benefit nursing-home patients' overall well-being. In a holistic perspective of body-mind-spirit, this research generates new-research questions about the pathways between the different dimensions of well-being in nursing-home patients, which is important to holistic nursing practice. © 2012 Blackwell Publishing Ltd.

  13. Hydrogen isotope dynamic effects on partially reduced paramagnetic six-atom Ag clusters in low-symmetry cage of zeolite A

    Directory of Open Access Journals (Sweden)

    Amgalanbaatar Baldansuren

    2016-12-01

    Full Text Available A well-defined, monodisperse Ag6+ cluster was prepared by mild chemical treatments including aqueous ion-exchange, dehydration, oxygen calcination at 673 K and hydrogen reduction 293 K, rather than autoreduction and irradiations with γ-ray and X-ray. H2 reduction was proved as a crucial step to form the nanosize cluster with six equivalent silver atoms. Hydrogen isotope exchange and dynamics were probed by EPR and HYSCORE to provide information relevant to the cluster geometry, size, charge state and spin state. Desorption experiments result in the deuterium desorption energy of 0.78 eV from the cluster, exceeding the experimental value of 0.38 eV for the single crystal Ag(111 surface. These experiments indicate that the EPR-active clusters are in delicate equilibrium with EPR-silent clusters.

  14. Family Interdependence, Spiritual Perspective, Self-Transcendence, and Depression Among Korean College Students.

    Science.gov (United States)

    Kim, Suk-Sun; Hayward, R David; Gil, Minji

    2017-07-17

    The purpose of this study was to examine the mechanisms that might account for the effects of spirituality and self-transcendence on Korean college students' depression among 197 Korean fathers, mothers, and children. A structural equation analysis indicated that spiritual perspective related to lower depression through the mediating pathway of self-transcendence for individuals. Mothers' spiritual perspective and self-transcendence related to their children's depression through the mediating pathway of their own depression, but the same was not true for fathers. Findings help explicate the intergenerational transmission of depression and important predictors of depression related to spirituality.

  15. 5-HT 1A polymorphism and self-transcendence in mood disorders.

    Science.gov (United States)

    Lorenzi, Cristina; Serretti, Alessandro; Mandelli, Laura; Tubazio, Viviana; Ploia, Cristina; Smeraldi, Enrico

    2005-08-05

    Recently, an association between serotonin 1A receptor binding potential and self-transcendence scores at the temperament and character inventory (TCI) has been reported. We tested involvement of 5-HT(1A) gene in this trait, in a sample of 40 remitted mood disorder patients. Subjects with the 5-HT(1A)*C/C genotype showed significantly lower scores at the total self-transcendence and at the sub-scales of transpersonal identification and spiritual acceptance. Our preliminary results further support the involvement of the serotoninergic pattern in the self-transcendence character trait. (c) 2005 Wiley-Liss, Inc.

  16. A Closer Look at Transcendence and Its Relationship to Mental Health.

    Science.gov (United States)

    Peteet, John R

    2018-04-01

    Experiences of transcendence can promote growth, creativity and altruism, but often exist in tension with critical thought and can feature problematically in certain mental disorders. Identification of the core elements in the experience of transcendence-suspending disbelief, being moved or inspired, surrendering oneself and identifying within a larger context, can clarify its relationship to psychopathology, and the basis for a clinician's role. To help individuals engage transcendent resources well, clinicians can help patients recognize how depression and trauma may interfere with engagement, masochistic and magical tendencies may distort healthy self-surrender, and vulnerability to social pressure may interfere with mature identification with a larger context or community.

  17. Photochemistry of Nitrophenol Molecules and Clusters: Intra- vs Intermolecular Hydrogen Bond Dynamics

    Czech Academy of Sciences Publication Activity Database

    Grygoryeva, Kateřina; Kubečka, J.; Pysanenko, Andriy; Lengyel, Jozef; Slavíček, Petr; Fárník, Michal

    2016-01-01

    Roč. 120, č. 24 (2016), s. 4139-4146 ISSN 1089-5639 R&D Projects: GA ČR(CZ) GA15-12386S Institutional support: RVO:61388955 Keywords : photochemistry * clusters * laser techniques Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.847, year: 2016

  18. Electronic structure and dynamics of ordered clusters with ME or RE ions on oxide surface

    Energy Technology Data Exchange (ETDEWEB)

    Kulagin, N.A., E-mail: nkulagin@bestnet.kharkov.u [Kharkiv National University for Radio Electronics, Avenue Shakespeare 6-48, 61045 Kharkiv (Ukraine)

    2011-03-15

    Selected data of ab initio simulation of the electronic structure and spectral properties of either cluster with ions of iron, rare earth or actinium group elements have been presented here. Appearance of doped Cr{sup +4} ions in oxides, Cu{sup +2} in HTSC, Nd{sup +2} in solids has been discussed. Analysis of experimental data for plasma created ordered structures of crystallites with size of about 10{sup -9} m on surface of separate oxides are given, too. Change in the spectroscopic properties of clusters and nano-structures on surface of strontium titanate crystals discussed shortly using the X-ray line spectroscopy experimental results. - Research highlights: External influence and variation of technology induce changes in valence of nl ions in compounds. Wave function of cluster presented as anti-symmetrical set of ions wave functions. The main equation describes the self-consistent field depending on state of all electrons of cluster. Level scheme of Cr{sup 4+} ions in octo- and tetra-site corresponds to doped oxides spectra after treatment. Plasma treatment effects in appearance of systems of unit crystallites with size of about 10{sup -6}-10{sup -9} m.

  19. Electronic structure and dynamics of ordered clusters with ME or RE ions on oxide surface

    International Nuclear Information System (INIS)

    Kulagin, N.A.

    2011-01-01

    Selected data of ab initio simulation of the electronic structure and spectral properties of either cluster with ions of iron, rare earth or actinium group elements have been presented here. Appearance of doped Cr +4 ions in oxides, Cu +2 in HTSC, Nd +2 in solids has been discussed. Analysis of experimental data for plasma created ordered structures of crystallites with size of about 10 -9 m on surface of separate oxides are given, too. Change in the spectroscopic properties of clusters and nano-structures on surface of strontium titanate crystals discussed shortly using the X-ray line spectroscopy experimental results. - Research highlights: → External influence and variation of technology induce changes in valence of nl ions in compounds. → Wave function of cluster presented as anti-symmetrical set of ions wave functions. → The main equation describes the self-consistent field depending on state of all electrons of cluster. → Level scheme of Cr 4+ ions in octo- and tetra-site corresponds to doped oxides spectra after treatment. → Plasma treatment effects in appearance of systems of unit crystallites with size of about 10 -6 -10 -9 m.

  20. Agglomeration and Clustering Over the Industry Life Cycle: Toward a Dynamic Model of Geographic Concentration

    NARCIS (Netherlands)

    Wang, L.; Madhok, A.; Li, S.X.

    2014-01-01

    Research on agglomeration finds that either a higher survival rate of incumbent firms or a higher founding rate of new entrants, or both, can sustain an industry cluster. The conditioning effects of time on the two distinct mechanisms of survival and founding are, however, rarely examined. We argue

  1. Large-scale dynamics associated with clustering of extratropical cyclones affecting Western Europe

    Science.gov (United States)

    Pinto, Joaquim G.; Gómara, Iñigo; Masato, Giacomo; Dacre, Helen F.; Woollings, Tim; Caballero, Rodrigo

    2015-04-01

    Some recent winters in Western Europe have been characterized by the occurrence of multiple extratropical cyclones following a similar path. The occurrence of such cyclone clusters leads to large socio-economic impacts due to damaging winds, storm surges, and floods. Recent studies have statistically characterized the clustering of extratropical cyclones over the North Atlantic and Europe and hypothesized potential physical mechanisms responsible for their formation. Here we analyze 4 months characterized by multiple cyclones over Western Europe (February 1990, January 1993, December 1999, and January 2007). The evolution of the eddy driven jet stream, Rossby wave-breaking, and upstream/downstream cyclone development are investigated to infer the role of the large-scale flow and to determine if clustered cyclones are related to each other. Results suggest that optimal conditions for the occurrence of cyclone clusters are provided by a recurrent extension of an intensified eddy driven jet toward Western Europe lasting at least 1 week. Multiple Rossby wave-breaking occurrences on both the poleward and equatorward flanks of the jet contribute to the development of these anomalous large-scale conditions. The analysis of the daily weather charts reveals that upstream cyclone development (secondary cyclogenesis, where new cyclones are generated on the trailing fronts of mature cyclones) is strongly related to cyclone clustering, with multiple cyclones developing on a single jet streak. The present analysis permits a deeper understanding of the physical reasons leading to the occurrence of cyclone families over the North Atlantic, enabling a better estimation of the associated cumulative risk over Europe.

  2. Nuclear clustering - a cluster core model study

    International Nuclear Information System (INIS)

    Paul Selvi, G.; Nandhini, N.; Balasubramaniam, M.

    2015-01-01

    Nuclear clustering, similar to other clustering phenomenon in nature is a much warranted study, since it would help us in understanding the nature of binding of the nucleons inside the nucleus, closed shell behaviour when the system is highly deformed, dynamics and structure at extremes. Several models account for the clustering phenomenon of nuclei. We present in this work, a cluster core model study of nuclear clustering in light mass nuclei

  3. Photo fragmentation dynamics of small argon clusters and biological molecular: new tools by trapping and vectorial correlation

    International Nuclear Information System (INIS)

    Lepere, V.

    2006-09-01

    The present work concerns the building up of a complex set-up whose aim being the investigation of the photo fragmentation of ionised clusters and biological molecules. This new tool is based on the association of several techniques. Two ion sources are available: clusters produced in a supersonic beam are ionised by 70 eV electrons while ions of biological interest are produced in an 'electro-spray'. Ro-vibrational cooling is achieved in a 'Zajfman' electrostatic ion trap. The lifetime of ions can also be measured using the trap. Two types of lasers are used to excite the ionised species: the femtosecond laser available at the ELYSE facilities and a nanosecond laser. Both lasers have a repetition rate of 1 kHz. The neutral and ionised fragments are detected in coincidence using a sophisticated detection system allowing time and localisation of the various fragments to be determined. With such a tool, I was able to investigate in details the fragmentation dynamics of ionised clusters and bio-molecules. The first experiments deal with the measurement of the lifetime of the Ar 2+ dimer II(1/2)u metastable state. The relative population of this state was also determined. The Ar 2+ and Ar 3+ photo-fragmentation was then studied and electronic transitions responsible for their dissociation identified. The detailed analysis of our data allowed to distinguish the various fragmentation mechanisms. Finally, a preliminary investigation of the protonated tryptamine fragmentation is presented. (author)

  4. The HoxD cluster is a dynamic and resilient TAD boundary controlling the segregation of antagonistic regulatory landscapes.

    Science.gov (United States)

    Rodríguez-Carballo, Eddie; Lopez-Delisle, Lucille; Zhan, Ye; Fabre, Pierre J; Beccari, Leonardo; El-Idrissi, Imane; Huynh, Thi Hanh Nguyen; Ozadam, Hakan; Dekker, Job; Duboule, Denis

    2017-11-15

    The mammalian HoxD cluster lies between two topologically associating domains (TADs) matching distinct enhancer-rich regulatory landscapes. During limb development, the telomeric TAD controls the early transcription of Hoxd genes in forearm cells, whereas the centromeric TAD subsequently regulates more posterior Hoxd genes in digit cells. Therefore, the TAD boundary prevents the terminal Hoxd13 gene from responding to forearm enhancers, thereby allowing proper limb patterning. To assess the nature and function of this CTCF-rich DNA region in embryos , we compared chromatin interaction profiles between proximal and distal limb bud cells isolated from mutant stocks where various parts of this boundary region were removed. The resulting progressive release in boundary effect triggered inter-TAD contacts, favored by the activity of the newly accessed enhancers. However, the boundary was highly resilient, and only a 400-kb deletion, including the whole-gene cluster, was eventually able to merge the neighboring TADs into a single structure. In this unified TAD, both proximal and distal limb enhancers nevertheless continued to work independently over a targeted transgenic reporter construct. We propose that the whole HoxD cluster is a dynamic TAD border and that the exact boundary position varies depending on both the transcriptional status and the developmental context. © 2017 Rodríguez-Carballo et al.; Published by Cold Spring Harbor Laboratory Press.

  5. Assessing the Psychoeducational Approach to Transcendence and Health Program: An Intervention to Foster Self-Transcendence and Well-Being in Community-Dwelling Older Adults.

    Science.gov (United States)

    McCarthy, Valerie Lander; Bowland, Sharon; Hall, Lynne A; Connelly, Jennifer

    2015-12-01

    The late-life developmental process of self-transcendence shapes elders' perspectives on self, others, the nature of this world, and of a dimension beyond the here and now. This qualitative pilot study evaluated the Psychoeducational Approach to Transcendence and Health (PATH) Program, a psychoeducational intervention to promote self-transcendence and well-being in community-dwelling women at a senior center. The intervention involved eight weekly group sessions using group processes, mindfulness practices, creative experiences, and independent at-home practice. The findings supported the underlying theory-based structure and content of the intervention and indicated the intervention may empower elders to attend to self-care, develop acceptance, and learn new skills associated with health and well-being, thus merits further study. Based on insights gained from facilitators' and participants' experiences and perceptions, the intervention will be revised and strengthened. © The Author(s) 2015.

  6. THE ATACAMA COSMOLOGY TELESCOPE: DYNAMICAL MASSES AND SCALING RELATIONS FOR A SAMPLE OF MASSIVE SUNYAEV-ZEL'DOVICH EFFECT SELECTED GALAXY CLUSTERS ,

    International Nuclear Information System (INIS)

    Sifón, Cristóbal; Barrientos, L. Felipe; González, Jorge; Infante, Leopoldo; Dünner, Rolando; Menanteau, Felipe; Hughes, John P.; Baker, Andrew J.; Hasselfield, Matthew; Marriage, Tobias A.; Crichton, Devin; Gralla, Megan B.; Addison, Graeme E.; Dunkley, Joanna; Battaglia, Nick; Bond, J. Richard; Hajian, Amir; Das, Sudeep; Devlin, Mark J.; Hilton, Matt

    2013-01-01

    We present the first dynamical mass estimates and scaling relations for a sample of Sunyaev-Zel'dovich effect (SZE) selected galaxy clusters. The sample consists of 16 massive clusters detected with the Atacama Cosmology Telescope (ACT) over a 455 deg 2 area of the southern sky. Deep multi-object spectroscopic observations were taken to secure intermediate-resolution (R ∼ 700-800) spectra and redshifts for ≈60 member galaxies on average per cluster. The dynamical masses M 200c of the clusters have been calculated using simulation-based scaling relations between velocity dispersion and mass. The sample has a median redshift z = 0.50 and a median mass M 200c ≅12×10 14 h 70 -1 M sun with a lower limit M 200c ≅6×10 14 h 70 -1 M sun , consistent with the expectations for the ACT southern sky survey. These masses are compared to the ACT SZE properties of the sample, specifically, the match-filtered central SZE amplitude y 0 -tilde, the central Compton parameter y 0 , and the integrated Compton signal Y 200c , which we use to derive SZE-mass scaling relations. All SZE estimators correlate with dynamical mass with low intrinsic scatter (∼< 20%), in agreement with numerical simulations. We explore the effects of various systematic effects on these scaling relations, including the correlation between observables and the influence of dynamically disturbed clusters. Using the three-dimensional information available, we divide the sample into relaxed and disturbed clusters and find that ∼50% of the clusters are disturbed. There are hints that disturbed systems might bias the scaling relations, but given the current sample sizes, these differences are not significant; further studies including more clusters are required to assess the impact of these clusters on the scaling relations

  7. An Effective Approach for Clustering InhA Molecular Dynamics Trajectory Using Substrate-Binding Cavity Features.

    Directory of Open Access Journals (Sweden)

    Renata De Paris

    Full Text Available Protein receptor conformations, obtained from molecular dynamics (MD simulations, have become a promising treatment of its explicit flexibility in molecular docking experiments applied to drug discovery and development. However, incorporating the entire ensemble of MD conformations in docking experiments to screen large candidate compound libraries is currently an unfeasible task. Clustering algorithms have been widely used as a means to reduce such ensembles to a manageable size. Most studies investigate different algorithms using pairwise Root-Mean Square Deviation (RMSD values for all, or part of the MD conformations. Nevertheless, the RMSD only may not be the most appropriate gauge to cluster conformations when the target receptor has a plastic active site, since they are influenced by changes that occur on other parts of the structure. Hence, we have applied two partitioning methods (k-means and k-medoids and four agglomerative hierarchical methods (Complete linkage, Ward's, Unweighted Pair Group Method and Weighted Pair Group Method to analyze and compare the quality of partitions between a data set composed of properties from an enzyme receptor substrate-binding cavity and two data sets created using different RMSD approaches. Ensembles of representative MD conformations were generated by selecting a medoid of each group from all partitions analyzed. We investigated the performance of our new method for evaluating binding conformation of drug candidates to the InhA enzyme, which were performed by cross-docking experiments between a 20 ns MD trajectory and 20 different ligands. Statistical analyses showed that the novel ensemble, which is represented by only 0.48% of the MD conformations, was able to reproduce 75% of all dynamic behaviors within the binding cavity for the docking experiments performed. Moreover, this new approach not only outperforms the other two RMSD-clustering solutions, but it also shows to be a promising strategy to

  8. Unravelling the escape dynamics and the nature of the normally hyperbolic invariant manifolds in tidally limited star clusters

    Science.gov (United States)

    Zotos, Euaggelos E.; Jung, Christof

    2017-02-01

    The escape mechanism of orbits in a star cluster rotating around its parent galaxy in a circular orbit is investigated. A three degrees of freedom model is used for describing the dynamical properties of the Hamiltonian system. The gravitational field of the star cluster is represented by a smooth and spherically symmetric Plummer potential. We distinguish between ordered and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. The Smaller ALignment Index (SALI) method is used for determining the regular or chaotic nature of the orbits. The basins of escape are located and they are also correlated with the corresponding escape time of the orbits. Areas of bounded regular or chaotic motion and basins of escape were found to coexist in the (x, z) plane. The properties of the normally hyperbolic invariant manifolds (NHIMs), located in the vicinity of the index-1 Lagrange points L1 and L2, are also explored. These manifolds are of paramount importance as they control the flow of stars over the saddle points, while they also trigger the formation of tidal tails observed in star clusters. Bifurcation diagrams of the Lyapunov periodic orbits as well as restrictions of the Poincaré map to the NHIMs are deployed for elucidating the dynamics in the neighbourhood of the saddle points. The extended tidal tails, or tidal arms, formed by stars with low velocity which escape through the Lagrange points are monitored. The numerical results of this work are also compared with previous related work.

  9. CHEMICAL ABUNDANCES IN NGC 5053: A VERY METAL-POOR AND DYNAMICALLY COMPLEX GLOBULAR CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Boberg, Owen M.; Friel, Eileen D.; Vesperini, Enrico [Astronomy Department, Indiana University, Bloomington, IN 47405 (United States)

    2015-05-10

    NGC 5053 provides a rich environment to test our understanding of the complex evolution of globular clusters (GCs). Recent studies have found that this cluster has interesting morphological features beyond the typical spherical distribution of GCs, suggesting that external tidal effects have played an important role in its evolution and current properties. Additionally, simulations have shown that NGC 5053 could be a likely candidate to belong to the Sagittarius dwarf galaxy (Sgr dSph) stream. Using the Wisconsin–Indiana–Yale–NOAO–Hydra multi-object spectrograph, we have collected high quality (signal-to-noise ratio ∼ 75–90), medium-resolution spectra for red giant branch stars in NGC 5053. Using these spectra we have measured the Fe, Ca, Ti, Ni, Ba, Na, and O abundances in the cluster. We measure an average cluster [Fe/H] abundance of −2.45 with a standard deviation of 0.04 dex, making NGC 5053 one of the most metal-poor GCs in the Milky Way (MW). The [Ca/Fe], [Ti/Fe], and [Ba/Fe] we measure are consistent with the abundances of MW halo stars at a similar metallicity, with alpha-enhanced ratios and slightly depleted [Ba/Fe]. The Na and O abundances show the Na–O anti-correlation found in most GCs. From our abundance analysis it appears that NGC 5053 is at least chemically similar to other GCs found in the MW. This does not, however, rule out NGC 5053 being associated with the Sgr dSph stream.

  10. Chemical Abundances in NGC 5053: A Very Metal-poor and Dynamically Complex Globular Cluster

    Science.gov (United States)

    Boberg, Owen M.; Friel, Eileen D.; Vesperini, Enrico

    2015-05-01

    NGC 5053 provides a rich environment to test our understanding of the complex evolution of globular clusters (GCs). Recent studies have found that this cluster has interesting morphological features beyond the typical spherical distribution of GCs, suggesting that external tidal effects have played an important role in its evolution and current properties. Additionally, simulations have shown that NGC 5053 could be a likely candidate to belong to the Sagittarius dwarf galaxy (Sgr dSph) stream. Using the Wisconsin-Indiana-Yale-NOAO-Hydra multi-object spectrograph, we have collected high quality (signal-to-noise ratio ˜ 75-90), medium-resolution spectra for red giant branch stars in NGC 5053. Using these spectra we have measured the Fe, Ca, Ti, Ni, Ba, Na, and O abundances in the cluster. We measure an average cluster [Fe/H] abundance of -2.45 with a standard deviation of 0.04 dex, making NGC 5053 one of the most metal-poor GCs in the Milky Way (MW). The [Ca/Fe], [Ti/Fe], and [Ba/Fe] we measure are consistent with the abundances of MW halo stars at a similar metallicity, with alpha-enhanced ratios and slightly depleted [Ba/Fe]. The Na and O abundances show the Na-O anti-correlation found in most GCs. From our abundance analysis it appears that NGC 5053 is at least chemically similar to other GCs found in the MW. This does not, however, rule out NGC 5053 being associated with the Sgr dSph stream.

  11. Electron and nuclear dynamics of molecular clusters in ultraintense laser fields. IV. Coulomb explosion of molecular heteroclusters.

    Science.gov (United States)

    Last, Isidore; Jortner, Joshua

    2004-11-01

    In this paper we present a theoretical and computational study of the temporal dynamics and energetics of Coulomb explosion of (CD4)(n) and (CH4)(n) (n=55-4213) molecular heteroclusters in ultraintense (I=10(16)-10(19) W cm(-2)) laser fields, addressing the manifestation of electron dynamics, together with nuclear energetic and kinematic effects on the heterocluster Coulomb instability. The manifestations of the coupling between electron and nuclear dynamics were explored by molecular dynamics simulations for these heteroclusters coupled to Gaussian laser fields (pulse width tau=25 fs), elucidating outer ionization dynamics, nanoplasma screening effects (being significant for Icharges and masses. Nonuniform heterocluster Coulomb explosion (eta >1) manifests an overrun effect of the light ions relative to the heavy ions, exhibiting the expansion of two spatially separated subclusters, with the light ions forming the outer subcluster at the outer edge of the spatial distribution. Important features of the energetics of heterocluster Coulomb explosion originate from energetic triggering effects of the driving of the light ions by the heavy ions (C(4+) for I=10(17)-10(18) W cm(-2) and C(6+) for I=10(19) W cm(-2)), as well as for kinematic effects. Based on the CVI assumption, scaling laws for the cluster size (radius R(0)) dependence of the energetics of uniform Coulomb explosion of heteroclusters (eta=1) were derived, with the size dependence of the average (E(j,av)) and maximal (E(j,M)) ion energies being E(j,av)=aR(0) (2) and E(j,M)=(5a/3)R(0) (2), as well as for the ion energy distributions P(E(j)) proportional to E(j) (1/2); E(j)1) result in an isotope effect, predicting the enhancement (by 9%-11%) of E(H,av) for Coulomb explosion of (C(4+)H(4) (+))(eta) (eta=3) relative to E(D,av) for Coulomb explosion of (C(4+)D(4) (+))(eta) (eta=1.5), with the isotope effect being determined by the ratio of the kinematic parameters for the pair of Coulomb exploding clusters

  12. Adiabatic invariants in stellar dynamics, 3: Application to globular cluster evolution

    Science.gov (United States)

    Weinberg, Martin D.

    1994-01-01

    The previous two companion papers demonstrate that slowly varying perturbations may not result in adiabatic cutoffs and provide a formalism for computing the long-term effects of time-dependent perturbations on stellar systems. Here, the theory is implemented in a Fokker-Planck code and a suite of runs illustrating the effects of shock heating on globular cluster evolution are described. Shock heating alone results in considerable mass loss for clusters with R(sub g) less than or approximately 8 kpc: a concentration c = 1.5 cluster with R(sub g) kpc loses up to 95% of its initial mass in 15 Gyr. Only those with concentration c greater than or approximately 1.3 survive disk shocks inside of this radius. Other effects, such as mass loss by stellar evolution, will decrease this survival bound. Loss of the initial halo together with mass segregation leads to mass spectral indices, x, which may be considerably larger than their initial values.

  13. Identification and status revisited: the moderating role of self-enhancement and self-transcendence values.

    Science.gov (United States)

    Roccas, Sonia

    2003-06-01

    Two studies examined the moderating role of the importance attributed to self-enhancement and self-transcendence values on the association of group status with identification. In the first study, students reported their personal value priorities, their identification with a group, and their perception of the status of that group. The more importance respondents attributed to self-enhancement and the less importance to self-transcendence, the more their identification with a group depended on the group's status. In the second study, the salience of self-enhancement and of self-transcendence values was experimentally manipulated. Identification with a group depended more on the status of that group when self-enhancement values were salient than when self-transcendence values were salient.

  14. A Case for Self-Transcendence as a Purpose of Adult Education.

    Science.gov (United States)

    Wacks, V. Quinton, Jr.

    1987-01-01

    Reviews the purposes of adult education and the history of transcendentalism. Argues that the transcendent nature and needs of humankind are not addressed by adult education theory or practice. Provides implications for adult educators. (CH)

  15. Transcendentální aspekty ve filmové tvorbě

    OpenAIRE

    TRUBKA, Jiří

    2015-01-01

    The work deals with transcendence and its portrayal in the film. It deals with the film from the perspective of different aesthetic theories. Other parts are nenarrativní film types and analysis of the individual authors and works.

  16. ‘Don’t make it a doctrine’: Material religion, transcendence, critique

    NARCIS (Netherlands)

    Reinhardt, B.M.N.

    Once a matter of beliefs, symbols, values and worldviews, religion has progressively appeared in recent anthropological works as material religion, a highly concrete phenomenon based on affects, senses, substances, places, artifacts, and technologies. But what happened to transcendence, the

  17. Some Mid-Life Ruminations on the Human Capacity to Transcend One's Acculturation.

    Science.gov (United States)

    Rousseve, Ronald J.

    1983-01-01

    The dialectical capacity of human consciousness enables us to generate alternatives in opposition to previous conditioning. Transcending one's acculturation need not leave one searching for gurus. Authentic personal meaning may be attained from an existential reawakening. (RM)

  18. The galactic globular cluster NGC 1851: its dynamical and evolutionary properties

    Science.gov (United States)

    Saviane, I.; Piotto, G.; Fagotto, F.; Zaggia, S.; Capaccioli, M.; Aparicio, A.

    1998-05-01

    We have completely mapped the Galactic globular cluster NGC 1851 with large-field, ground-based VI CCD photometry and pre-repair HST/WFPC1 data for the central region. The photometric data set has allowed a V vs. (V-I) colour-magnitude diagram for ~ 20500 stars to be constructed. >From the apparent luminosity of the horizontal branch (HB) we derive a true distance modulus (m-M)_0 = 15.44 +/- 0.20. An accurate inspection of the cluster's bright and blue objects confirms the presence of seven ``supra-HB'' stars, six of which are identified as evolved descendants from HB progenitors. The HB morphology is found to be clearly bimodal, showing both a red clump and a blue tail, which are not compatible with standard evolutionary models. Synthetic Hertzsprung-Russell (HR) diagrams demonstrate that the problem could be solved by assuming a bimodal efficiency of the mass loss along the red giant branch (RGB). With the aid of Kolmogorov-Smirnov statistics we find evidence that the radial distribution of the blue HB stars is different from that of the red HB and sub-giant branch (SGB) stars. We give the first measurement of the mean absolute I magnitude for 22 known RR Lyr variables ( = 0.12 +/- 0.20 mag at a metallicity [Fe/H] = -1.28). The mean absolute V magnitude is = 0.58 +/- 0.20 mag, and we confirm that these stars are brighter than those of the zero-age HB (ZAHB). Moreover, we found seven new RR Lyr candidates (six ab type and one c type). With these additional variables the ratio of the two types is now N_c/Nab = 0.38. >From a sample of 25 globular clusters a new calibration for Delta V_bump() HB as a function of cluster metallicity is derived. NGC 1851 follows this general trend fairly well. From a comparison with the theoretical models, we also find some evidence for an age-metallicity relation among globular clusters. We identify 13 blue straggler stars, which do not show any sign of variability. The blue stragglers are less concentrated than the subgiant branch

  19. Promotion of Self-Transcendence in a Multiple Sclerosis Peer Support Groups

    Directory of Open Access Journals (Sweden)

    Tahereh Ashktorab

    2014-05-01

    Full Text Available Background: Self-transcendence can organize the challenges of multiple sclerosis patients to achieve and maintain a constant state of well-being and sense of integrity in the disease process. As a research based on self-transcendence didn't done in Iran, the present study was conducted to evaluate the effectiveness of peer groups on promoting selftranscendence level in multiple sclerosis (MS patients. Materials and Methods: This study is a before and after quasi-experimental study that was conducted on 33 patients with confirmed MS participated in three peer support groups: 10 men in male group, 11 women in female group and 12 men and women in mixed group. Eight weekly sessions and each session was 2 hours were held. Data collection tool was Self-Transcendence Scale (STS with 15 item and Cronbach's coefficient was 0.68 that after modifying, it increased to 0.81. Patients completed self administered questionnaires pre- and post of sessions. Results: Results showed that peer support groups promote the self-transcendence (p=0.001 with increases in mean self-transcendence scores in all 3 groups (men group: 0.008, women group 0.005 and mixed group: 0.003. Comparing scores before and after intervention demonstrated that self-transcendence increased equally in all groups. Conclusion: The results showed an improving in self-transcendence in peer support group participants at the end of the intervention. The results can be used in areas of nursing education and management. It is proposed that the self-transcendence assessment to be done in other chronic disease in order to evaluate its efficiency.

  20. Structural dynamics of N-ethylpropionamide clusters examined by nonlinear infrared spectroscopy

    International Nuclear Information System (INIS)

    Wang, Jianping; Yang, Fan; Zhao, Juan; Shi, Jipei

    2015-01-01

    In this work, the structural dynamics of N-ethylpropionamide (NEPA), a model molecule of β-peptides, in four typical solvents (DMSO, CH 3 CN, CHCl 3 , and CCl 4 ), were examined using the N—H stretching vibration (or the amide-A mode) as a structural probe. Steady-state and transient infrared spectroscopic methods in combination with quantum chemical computations and molecular dynamics simulations were used. It was found that in these solvents, NEPA exists in different aggregation forms, including monomer, dimer, and oligomers. Hydrogen-bonding interaction and local-solvent environment both affect the amide-A absorption profile and its vibrational relaxation dynamics and also affect the structural dynamics of NEPA. In particular, a correlation between the red-shifted frequency for the NEPA monomer from nonpolar to polar solvent and the vibrational excitation relaxation rate of the N—H stretching mode was observed

  1. Biosensor based on measurements of the clustering dynamics of magnetic particles

    DEFF Research Database (Denmark)

    2014-01-01

    Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample.......Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample....

  2. Cross-cultural comparison of self-transcendent wisdom between the United States and Korea.

    Science.gov (United States)

    Lee, Sulim; Choun, Soyoung; Aldwin, Carolyn M; Levenson, Michael R

    2015-06-01

    Whether wisdom is a culturally-specific or universal construct is a matter of some debate (see Curnow 1999; Grossman et al. Psychological Science, 2012). This study compared similarities and differences in the factor structure of a measure of wisdom focused on self-transcendence in U.S. (n = 305, M(age) = 33.99) and Korean samples (n = 838, M(age) = 30.28), with ages ranging from 20 to 73). The Adult Self-Transcendence Inventory (ASTI; Levenson et al. International Journal of Aging and Human Development, 60, 127-143, 2005) has two factors, self-transcendence and alienation, the latter of which was included to differentiate between social withdrawals due to contemplative practices versus that due to depression. Confirmatory factor analyses found a partial scalar factorial invariance model fit the data best, indicating that the factor structure of the ASTI is largely equivalent and that the construct is comparable across the two cultures. Regression analyses showed that age and religiousness were related to self-transcendence and alienation. Education was related to self-transcendence only. The interaction between age and culture was significant on alienation; alienation was higher in mid-life Koreans but not in Americans, which may reflect either age or cohort effects. Thus, self-transcendence may be a more universal measure of wisdom than those based on pragmatics or cognitive functioning.

  3. Spiritual Transcendence and Psychological Adjustment: The Moderating Role of Personality in Burn Patients.

    Science.gov (United States)

    Jibeen, Tahira; Mahfooz, Musferah; Fatima, Shamem

    2017-08-30

    The current study examined the moderating role of personality traits (neuroticism and extraversion) on the relationship between spiritual transcendence and positive change, and spiritual transcendence and distress in burn patients. The sample (N = 98) comprised adult burn patients (age = 25-50) admitted to three hospitals in Lahore, Pakistan. They were assessed according to a demographic information sheet, the NEO Personality Inventory (McCrae and Costa in J Personal Soc Psychol 52:81-90, 1987), the Spiritual Transcendence Index (Seidlitz et al. in J Sci Study Relig 41:439-453, 2002), the Depression, Anxiety, Stress Scales-21 (Lovibond and Lovibond in Manual for the Depression Anxiety Stress scales, Psychology Foundation, Sydney, 1995), and the Perceived Benefit Scales (McMillen and Fisher in Soc Work Res 22(3):173-186, 1998). Stepwise moderated regression analysis showed that both personality traits (neuroticism and extraversion) played a moderating role in the relationship between spiritual transcendence and positive change, and spiritual transcendence and distress in burn patients. The findings highlight the potential role spiritual transcendence may have in understanding and improving the psychological adjustment of burn patients.

  4. Self-transcendence in older men attending a prostate cancer support group.

    Science.gov (United States)

    Chin-A-Loy, S S; Fernsler, J I

    1998-10-01

    Self-transcendence has been shown to be related to well-being in older adults, women with breast cancer, women with AIDS, gay men with AIDS, and a healthy population. The purpose of this descriptive pilot study was to examine self-transcendence in another high-priority population: older men with prostate cancer. A convenience sample of 23 men, age 60 and older (M = 69), from three prostate cancer support groups completed Reed's Self-Transcendence Scale (STS) and a demographic data form. The men were predominantly white (82.6%), of the Catholic faith (56.5%), married (78.3%), and not working (87.0%). Over half (65.2%) had a college degree or higher; most viewed their health as good (69.6%) or excellent (21.7%); and the majority (56.5%) viewed their prostate cancer as affecting some of their daily activities. These men scored high on the STS (M = 50.07), which was consistent with previous findings in other populations. Findings of this study contribute to Reed's middle-range theory of self-transcendence. The discovery that self-transcendence is relevant to this group of older men with prostate cancer provides a basis for nurses to investigate the phenomenon in this population and help their clients explore the benefits of the self-transcendence resource.

  5. An adaptive clustering approach to dynamic load balancing and energy efficiency in wireless sensor networks

    International Nuclear Information System (INIS)

    Gherbi, Chirihane; Aliouat, Zibouda; Benmohammed, Mohamed

    2016-01-01

    Clustering is a well known approach to cope with large nodes density and efficiently conserving energy in Wireless Sensor Networks (WSN). Load balancing is an effective approach for optimizing resources like channel bandwidth, the main objective of this paper is to combine these two valuable approaches in order to significantly improve the main WSN service such as information routing. So, our proposal is a routing protocol in which load traffic is shared among cluster members in order to reduce the dropping probability due to queue overflow at some nodes. To this end, a novel hierarchical approach, called Hierarchical Energy-Balancing Multipath routing protocol for Wireless Sensor Networks (HEBM) is proposed. The HEBM approach aims to fulfill the following purposes: decreasing the overall network energy consumption, balancing the energy dissipation among the sensor nodes and as direct consequence: extending the lifetime of the network. In fact, the cluster-heads are optimally determined and suitably distributed over the area of interest allowing the member nodes reaching them with adequate energy dissipation and appropriate load balancing utilization. In addition, nodes radio are turned off for fixed time duration according to sleeping control rules optimizing so their energy consumption. The performance evaluation of the proposed protocol is carried out through the well-known NS2 simulator and the exhibited results are convincing. Like this, the residual energy of sensor nodes was measured every 20 s throughout the duration of simulation, in order to calculate the total number of alive nodes. Based on the simulation results, we concluded that our proposed HEBM protocol increases the profit of energy, and prolongs the network lifetime duration from 32% to 40% compared to DEEAC reference protocol and from 25% to 28% compared to FEMCHRP protocol. The authors also note that the proposed protocol is 41.7% better than DEEAC with respect to FND (Fist node die), and 25

  6. Dynamical effects in the formation and evolution of galaxies and clusters

    International Nuclear Information System (INIS)

    White, S.D.M.

    1977-01-01

    The development of computer programs capable of simulating the self-consistent evolution of systems of a thousand or more self-gravitating particles has opened to experiment many aspects of problems concerning the dissipationless formation of galaxies and galaxy clusters which could previously only be treated at the cost of extreme oversimplification. As a result of experiments now being carried out, the range of validity, the inadequacies and the mistaken emphasis of many previous analyses are becoming evident. The applications of numerical experiments are discussed and illustrated. (U.K.)

  7. Effects of bursting dynamic features on the generation of multi-clustered structure of neural network with symmetric spike-timing-dependent plasticity learning rule

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui; Song, Yongduan; Xue, Fangzheng; Li, Xiumin, E-mail: xmli@cqu.edu.cn [Key Laboratory of Dependable Service Computing in Cyber Physical Society of Ministry of Education, Chongqing University, Chongqing 400044 (China); College of Automation, Chongqing University, Chongqing 400044 (China)

    2015-11-15

    In this paper, the generation of multi-clustered structure of self-organized neural network with different neuronal firing patterns, i.e., bursting or spiking, has been investigated. The initially all-to-all-connected spiking neural network or bursting neural network can be self-organized into clustered structure through the symmetric spike-timing-dependent plasticity learning for both bursting and spiking neurons. However, the time consumption of this clustering procedure of the burst-based self-organized neural network (BSON) is much shorter than the spike-based self-organized neural network (SSON). Our results show that the BSON network has more obvious small-world properties, i.e., higher clustering coefficient and smaller shortest path length than the SSON network. Also, the results of larger structure entropy and activity entropy of the BSON network demonstrate that this network has higher topological complexity and dynamical diversity, which benefits for enhancing information transmission of neural circuits. Hence, we conclude that the burst firing can significantly enhance the efficiency of clustering procedure and the emergent clustered structure renders the whole network more synchronous and therefore more sensitive to weak input. This result is further confirmed from its improved performance on stochastic resonance. Therefore, we believe that the multi-clustered neural network which self-organized from the bursting dynamics has high efficiency in information processing.

  8. Effects of bursting dynamic features on the generation of multi-clustered structure of neural network with symmetric spike-timing-dependent plasticity learning rule

    International Nuclear Information System (INIS)

    Liu, Hui; Song, Yongduan; Xue, Fangzheng; Li, Xiumin

    2015-01-01

    In this paper, the generation of multi-clustered structure of self-organized neural network with different neuronal firing patterns, i.e., bursting or spiking, has been investigated. The initially all-to-all-connected spiking neural network or bursting neural network can be self-organized into clustered structure through the symmetric spike-timing-dependent plasticity learning for both bursting and spiking neurons. However, the time consumption of this clustering procedure of the burst-based self-organized neural network (BSON) is much shorter than the spike-based self-organized neural network (SSON). Our results show that the BSON network has more obvious small-world properties, i.e., higher clustering coefficient and smaller shortest path length than the SSON network. Also, the results of larger structure entropy and activity entropy of the BSON network demonstrate that this network has higher topological complexity and dynamical diversity, which benefits for enhancing information transmission of neural circuits. Hence, we conclude that the burst firing can significantly enhance the efficiency of clustering procedure and the emergent clustered structure renders the whole network more synchronous and therefore more sensitive to weak input. This result is further confirmed from its improved performance on stochastic resonance. Therefore, we believe that the multi-clustered neural network which self-organized from the bursting dynamics has high efficiency in information processing

  9. Transcending the caesura: reverie, dreaming and counter-dreaming.

    Science.gov (United States)

    Bergstein, Avner

    2013-08-01

    The author reflects about our capacity to get in touch with primitive, irrepresentable, seemingly unreachable parts of the Self and with the unrepressed unconscious. It is suggested that when the patient's dreaming comes to a halt, or encounters a caesura, the analyst dreams that which the patient cannot. Getting in touch with such primitive mental states and with the origin of the Self is aspired to, not so much for discovering historical truth or recovering unconscious content, as for generating motion between different parts of the psyche. The movement itself is what expands the mind and facilitates psychic growth. Bion's brave and daring notion of 'caesura', suggesting a link between mature emotions and thinking and intra-uterine life, serves as a model for bridging seemingly unbridgeable states of mind. Bion inspires us to 'dream' creatively, to let our minds roam freely, stressing the analyst's speculative imagination and intuition often bordering on hallucination. However, being on the seam between conscious and unconscious, dreaming subverts the psychic equilibrium and poses a threat of catastrophe as a result of the confusion it affords between the psychotic and the non-psychotic parts of the personality. Hence there is a tendency to try and evade it through a more saturated mode of thinking, often relying on external reality. The analyst's dreaming and intuition, perhaps a remnant of intra-uterine life, is elaborated as means of penetrating and transcending the caesura, thus facilitating patient and analyst to bear unbearable states of mind and the painful awareness of the unknowability of the emotional experience. This is illustrated clinically. Copyright © 2013 Institute of Psychoanalysis.

  10. Independent center, independent electron approximation for dynamics of molecules and clusters

    International Nuclear Information System (INIS)

    McGuire, J.H.; Straton, J.C.; Wang, J.; Wang, Y.D.; Weaver, O.L.; Corchs, S.E.; Rivarola, R.D.

    1996-01-01

    A formalism is developed for evaluating probabilities and cross sections for multiple-electron transitions in scattering of molecules and clusters by charged collision partners. First, the molecule is divided into subclusters each made up of identical centers (atoms). Within each subcluster coherent scattering from identical centers may lead to observable phase terms and a geometrical structure factor. Then, using a mean field approximation to describe the interactions between centers we obtain A I ∼ summation k product ke iδ k I A Ik . Second, the independent electron approximation for each center may be obtained by neglecting the correlation between electrons in each center. The probability amplitude for each center is then a product of single electron transition probability amplitudes, a Ik i , i.e. A Ik ≅ product iaik i . Finally, the independent subcluster approximation is introduced by neglecting the interactions between different subclusters in the molecule or cluster. The total probability amplitude then reduces to a simple product of amplitudes for each subcluster, A≅ product IAI . Limitations of this simple approximation are discussed. copyright 1996 American Institute of Physics

  11. Dark field differential dynamic microscopy enables accurate characterization of the roto-translational dynamics of bacteria and colloidal clusters

    Science.gov (United States)

    Cerbino, Roberto; Piotti, Davide; Buscaglia, Marco; Giavazzi, Fabio

    2018-01-01

    Micro- and nanoscale objects with anisotropic shape are key components of a variety of biological systems and inert complex materials, and represent fundamental building blocks of novel self-assembly strategies. The time scale of their thermal motion is set by their translational and rotational diffusion coefficients, whose measurement may become difficult for relatively large particles with small optical contrast. Here we show that dark field differential dynamic microscopy is the ideal tool for probing the roto-translational Brownian motion of anisotropic shaped particles. We demonstrate our approach by successful application to aqueous dispersions of non-motile bacteria and of colloidal aggregates of spherical particles.

  12. A Systematic Review of Transcendent States Across Meditation and Contemplative Traditions.

    Science.gov (United States)

    Wahbeh, Helané; Sagher, Amira; Back, Wallis; Pundhir, Pooja; Travis, Frederick

    Across cultures and throughout history, transcendent states achieved through meditative practices have been reported. The practices to attain transcendent states vary from transcendental meditation to yoga to contemplative prayer, to other various forms of sitting meditation. While these transcendent states are ascribed many different terms, those who experience them describe a similar unitive, ineffable state of consciousness. Despite the common description, few studies have systematically examined transcendent states during meditation. The objectives of this systematic review were to: 1) characterize studies evaluating transcendent states associated with meditation in any tradition; 2) qualitatively describe physiological and phenomenological outcomes collected during transcendent states and; 3) evaluate the quality of these studies using the Quality Assessment Tool. Medline, PsycINFO, CINAHL, AltHealthWatch, AMED, and the Institute of Noetic Science Meditation Library were searched for relevant papers in any language. Included studies required adult participants and the collection of outcomes before, during, or after a reported transcendent state associated with meditation. Twenty-five studies with a total of 672 combined participants were included in the final review. Participants were mostly male (61%; average age 39 ± 11 years) with 12.7 ± 6.6 (median 12.6; range 2-40) average years of meditation practice. A variety of meditation traditions were represented: (Buddhist; Christian; Mixed (practitioners from multiple traditions); Vedic: Transcendental Meditation and Yoga). The mean quality score was 67 ± 13 (100 highest score possible). Subjective phenomenology and the objective outcomes of electroencephalography (EEG), electrocardiography, electromyography, electrooculogram, event-related potentials, functional magnetic resonance imaging, magnetoencephalography, respiration, and skin conductance and response were measured. Transcendent states were most

  13. The influence of 150-cavity binders on the dynamics of influenza A neuraminidases as revealed by molecular dynamics simulations and combined clustering.

    Directory of Open Access Journals (Sweden)

    Kyle T Greenway

    Full Text Available Neuraminidase inhibitors are the main pharmaceutical agents employed for treatments of influenza infections. The neuraminidase structures typically exhibit a 150-cavity, an exposed pocket that is adjacent to the catalytic site. This site offers promising additional contact points for improving potency of existing pharmaceuticals, as well as generating entirely new candidate inhibitors. Several inhibitors based on known compounds and designed to interact with 150-cavity residues have been reported. However, the dynamics of any of these inhibitors remains unstudied and their viability remains unknown. This work reports the outcome of long-term, all-atom molecular dynamics simulations of four such inhibitors, along with three standard inhibitors for comparison. Each is studied in complex with four representative neuraminidase structures, which are also simulated in the absence of ligands for comparison, resulting in a total simulation time of 9.6 µs. Our results demonstrate that standard inhibitors characteristically reduce the mobility of these dynamic proteins, while the 150-binders do not, instead giving rise to many unique conformations. We further describe an improved RMSD-based clustering technique that isolates these conformations--the structures of which are provided to facilitate future molecular docking studies--and reveals their interdependence. We find that this approach confers many advantages over previously described techniques, and the implications for rational drug design are discussed.

  14. Electrons as probes of dynamics in molecules and clusters: A contribution from Time Dependent Density Functional Theory

    International Nuclear Information System (INIS)

    Wopperer, P.; Dinh, P.M.; Reinhard, P.-G.; Suraud, E.

    2015-01-01

    There are various ways to analyze the dynamical response of clusters and molecules to electromagnetic perturbations. Particularly rich information can be obtained from measuring the properties of electrons emitted in the course of the excitation dynamics. Such an analysis of electron signals covers observables such as total ionization, Photo-Electron Spectra (PES), Photoelectron Angular Distributions (PAD), and ideally combined PES/PAD. It has a long history in molecular physics and was increasingly used in cluster physics as well. Recent progress in the design of new light sources (high intensity, high frequency, ultra short pulses) opens new possibilities for measurements and thus has renewed the interest on these observables, especially for the analysis of various dynamical scenarios, well beyond a simple access to electronic density of states. This, in turn, has motivated many theoretical investigations of the dynamics of electronic emission for molecules and clusters up to such a complex and interesting system as C 60 . A theoretical tool of choice is here Time-Dependent Density Functional Theory (TDDFT) propagated in real time and on a spatial grid, and augmented by a Self-Interaction Correction (SIC). This provides a pertinent, robust, and efficient description of electronic emission including the detailed pattern of PES and PAD. A direct comparison between experiments and well founded elaborate microscopic theories is thus readily possible, at variance with more demanding observables such as for example fragmentation or dissociation cross sections. The purpose of this paper is to describe the theoretical tools developed on the basis of real-time and real-space TDDFT and to address in a realistic manner the analysis of electronic emission following irradiation of clusters and molecules by various laser pulses. After a general introduction, we shall present in a second part the available experimental results motivating such studies, starting from the simplest

  15. Flexibility dynamics in clusters of residential demand response and distributed generation

    NARCIS (Netherlands)

    MacDougall, P.A.; Kok, J.K.; Warmer, C.; Roossien, B.

    2013-01-01

    Supply and demand response is a untapped resource in the current electrical system. However little work has been done to investigate the dynamics of utilizing such flexibility as well as the potential effects it could have on the infrastructure. This paper provides a starting point to seeing the

  16. Cluster formation restricts dynamic nuclear polarization of xenon in solid mixtures

    DEFF Research Database (Denmark)

    Kuzma, N. N.; Pourfathi, M.; Kara, H.

    2012-01-01

    During dynamic nuclear polarization (DNP) at 1.5 K and 5 T, Xe-129 nuclear magnetic resonance (NMR) spectra of a homogeneous xenon/1-propanol/trityl-radical solid mixture exhibit a single peak, broadened by H-1 neighbors. A second peak appears upon annealing for several hours at 125 K. Its...

  17. Biosensor based on the measurements of clustering dynamics of magnetic particles using a double pass setup

    DEFF Research Database (Denmark)

    2014-01-01

    Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample. The setup may be implemented in a disc...

  18. Molecular dynamics simulations with electronic stopping can reproduce experimental sputtering yields of metals impacted by large cluster ions

    Science.gov (United States)

    Tian, Jiting; Zhou, Wei; Feng, Qijie; Zheng, Jian

    2018-03-01

    An unsolved problem in research of sputtering from metals induced by energetic large cluster ions is that molecular dynamics (MD) simulations often produce sputtering yields much higher than experimental results. Different from the previous simulations considering only elastic atomic interactions (nuclear stopping), here we incorporate inelastic electrons-atoms interactions (electronic stopping, ES) into MD simulations using a friction model. In this way we have simulated continuous 45° impacts of 10-20 keV C60 on a Ag(111) surface, and found that the calculated sputtering yields can be very close to the experimental results when the model parameter is appropriately assigned. Conversely, when we ignore the effect of ES, the yields are much higher, just like the previous studies. We further expand our research to the sputtering of Au induced by continuous keV C60 or Ar100 bombardments, and obtain quite similar results. Our study indicates that the gap between the experimental and the simulated sputtering yields is probably induced by the ignorance of ES in the simulations, and that a careful treatment of this issue is important for simulations of cluster-ion-induced sputtering, especially for those aiming to compare with experiments.

  19. Molecular dynamics simulations of diffusion and clustering along critical isotherms of medium-chain n-alkanes.

    Science.gov (United States)

    Mutoru, J W; Smith, W; O'Hern, C S; Firoozabadi, A

    2013-01-14

    Understanding the transport properties of molecular fluids in the critical region is important for a number of industrial and natural systems. In the literature, there are conflicting reports on the behavior of the self diffusion coefficient D(s) in the critical region of single-component molecular systems. For example, D(s) could decrease to zero, reach a maximum, or remain unchanged and finite at the critical point. Moreover, there is no molecular-scale understanding of the behavior of diffusion coefficients in molecular fluids in the critical regime. We perform extensive molecular dynamics simulations in the critical region of single-component fluids composed of medium-chain n-alkanes-n-pentane, n-decane, and n-dodecane-that interact via anisotropic united-atom potentials. For each system, we calculate D(s), and average molecular cluster sizes κ(cl) and numbers N(cl) at various cluster lifetimes τ, as a function of density ρ in the range 0.2ρ(c) ≤ ρ ≤ 2.0ρ(c) at the critical temperature T(c). We find that D(s) decreases with increasing ρ but remains finite at the critical point. Moreover, for any given τ critical point.

  20. Effects of incident energy and angle on carbon cluster ions implantation on silicon substrate: a molecular dynamics study

    Science.gov (United States)

    Wei, Ye; Sang, Shengbo; Zhou, Bing; Deng, Xiao; Chai, Jing; Ji, Jianlong; Ge, Yang; Huo, Yuanliang; Zhang, Wendong

    2017-09-01

    Carbon cluster ion implantation is an important technique in fabricating functional devices at micro/nanoscale. In this work, a numerical model is constructed for implantation and implemented with a cutting-edge molecular dynamics method. A series of simulations with varying incident energies and incident angles is performed for incidence on silicon substrate and correlated effects are compared in detail. Meanwhile, the behavior of the cluster during implantation is also examined under elevated temperatures. By mapping the nanoscopic morphology with variable parameters, numerical formalism is proposed to explain the different impacts on phrase transition and surface pattern formation. Particularly, implantation efficiency (IE) is computed and further used to evaluate the performance of the overall process. The calculated results could be properly adopted as the theoretical basis for designing nano-structures and adjusting devices’ properties. Project supported by the National Natural Science Foundation of China (Nos. 51622507, 61471255, 61474079, 61403273, 51502193, 51205273), the Natural Science Foundation of Shanxi (Nos. 201601D021057, 201603D421035), the Youth Foundation Project of Shanxi Province (Nos. 2015021097), the Doctoral Fund of MOE of China (No. 20131402110013), the National High Technology Research and Development Program of China (No. 2015AA042601), and the Specialized Project in Public Welfare from The Ministry of Water Resources of China (Nos. 1261530110110).

  1. Electron and photon reconstruction and performance in ATLAS using a dynamical, topological cell clustering-based approach

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    The electron and photon reconstruction in ATLAS has moved towards the use of a dynamical, topo- logical cell-based approach for cluster building, owing to advancements in the calibration procedure which allow for such a method to be applied. The move to this new technique allows for improved measurements of electron and photon energies, particularly in situations where an electron radiates a bremsstrahlung photon, or a photon converts to an electron-poistron pair. This note details the changes to the ATLAS electron and photon reconstruction software, and assesses its performance under current LHC luminosity conditions using simulated data. Changes to the converted photon reconstruction are also detailed, which improve the reconstruction efficiency of double-track converted photons, as well as reducing the reconstruction of spurious one-track converted photons. The performance of the new reconstruction algorithm is also presented in a number of important topologies relevant to precision Standard Model physics,...

  2. Molecular dynamics studies of the transient nucleation regime in the freezing of (RbCl)108 clusters

    International Nuclear Information System (INIS)

    Huang, Jinfan; Bartell, L.S.Lawrence S.

    2004-01-01

    The freezing of supercooled liquids in the transient period before a steady state of nucleation is attained has been the subject of a number of theoretical treatments. To our knowledge, no published experimental studies or computer simulations have been carried out in sufficient detail to test definitively the behavior predicted by the various theories. The present molecular dynamics (MD) simulation of 375 nucleation events in small, liquid RbCl clusters, however, yields a reasonably accurate account of the transient region. Despite published criticisms of a 1969 treatment by Kashchiev, it turns out that the behavior observed in the present study agrees with that predicted by Kashchiev. The study also obtains a much more accurate nucleation rate and time lag than reported for MD studies of RbCl previously published in this journal. In addition, it provides estimates of the solid-liquid interfacial free energy and the Granasy thickness of the diffuse solid-liquid interface

  3. Resolving the anomalous infrared spectrum of the MeCN-HCl molecular cluster using ab Initio molecular dynamics

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Loukonen, Ville; Kjærgaard, Henrik Grum

    2014-01-01

    We present a molecular dynamics (MD) based study of the acetonitrile-hydrogen chloride molecular cluster in the gas phase, aimed at resolving the anomalous features often seen in infrared spectra of hydrogen bonded complexes. We find that the infrared spectrum obtained from the Fourier transform...... of the electric dipole moment autocorrelation function converges very slowly due to the floppy nature of the complex. Even after 55 picoseconds of simulation, significant differences in the modelled and experimental spectrum are seen, likely due to insufficient configurational sampling. Instead, we utilize the MD...... trajectory for a structural based analysis. We find that the most populated values of the N-H-Cl angle are around 162°. The global minimum energy conformation at 180.0° is essentially unpopulated. We re-model the spectrum by combining population data from the MD simulations with optimizations constraining...

  4. Intuitionistic Trapezoidal Fuzzy Group Decision-Making Based on Prospect Choquet Integral Operator and Grey Projection Pursuit Dynamic Cluster

    Directory of Open Access Journals (Sweden)

    Jiahang Yuan

    2017-01-01

    Full Text Available In consideration of the interaction among attributes and the influence of decision makers’ risk attitude, this paper proposes an intuitionistic trapezoidal fuzzy aggregation operator based on Choquet integral and prospect theory. With respect to a multiattribute group decision-making problem, the prospect value functions of intuitionistic trapezoidal fuzzy numbers are aggregated by the proposed operator; then a grey relation-projection pursuit dynamic cluster method is developed to obtain the ranking of alternatives; the firefly algorithm is used to optimize the objective function of projection for obtaining the best projection direction of grey correlation projection values, and the grey correlation projection values are evaluated, which are applied to classify, rank, and prefer the alternatives. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.

  5. Dynamics of Rb{sup +}-benzene and Rb{sup +}-benzene-Ar {sub n} (n {<=} 3) clusters

    Energy Technology Data Exchange (ETDEWEB)

    Alberti, M. [Centre de Recerca en Quimica Teorica, Departament de Quimica Fisica, Parc Cientific, Universitat de Barcelona, Marti i Franques, 1, 08028 Barcelona (Spain)], E-mail: m.alberti@ub.edu; Aguilar, A. [Centre de Recerca en Quimica Teorica, Departament de Quimica Fisica, Parc Cientific, Universitat de Barcelona, Marti i Franques, 1, 08028 Barcelona (Spain); Lucas, J.M. [Centre de Recerca en Quimica Teorica, Departament de Quimica Fisica, Parc Cientific, Universitat de Barcelona, Marti i Franques, 1, 08028 Barcelona (Spain); Cappelletti, D. [Dipartimento di Ingegneria Civile ed Ambientale, Universita di Perugia, 06123 Perugia (Italy); Lagana, A. [Dipartimento di Chimica, Universita di Perugia, 06123 Perugia (Italy); Pirani, F. [Dipartimento di Chimica, Universita di Perugia, 06123 Perugia (Italy)

    2006-09-29

    The potential energy function of the Rb{sup +}-benzene cluster and of some of its Ar solvated variants is here modeled using a combination (pairwise sum) of ion(atom)-molecular bond and ion-molecular charges interaction contributions which provide, respectively, the non electrostatic and the electrostatic terms of the total non covalent intermolecular potential energy. In particular, such interaction contributions have been represented using, in addition to the ion(atom) polarizability, the bond polarizability tensor components and the charge distribution which account, respectively, for the polarizability and the quadrupolar moment of the benzene molecule. On the resulting potential energy surface, dynamical calculations have been carried out for the microcanonical ensemble by focusing on isomerization processes and on the effect of the mass of the cation.

  6. Dynamical analysis of nearby clusters. Automated astrometry from the ground: precision proper motions over a wide field

    Science.gov (United States)

    Bouy, H.; Bertin, E.; Moraux, E.; Cuillandre, J.-C.; Bouvier, J.; Barrado, D.; Solano, E.; Bayo, A.

    2013-06-01

    Context. The kinematic properties of the different classes of objects in a given association hold important clues about the history of its members, and offer a unique opportunity to test the predictions of the various models of stellar formation and evolution. Aims: DANCe (standing for dynamical analysis of nearby clusters) is a survey program aimed at deriving a comprehensive and homogeneous census of the stellar and substellar content of a number of nearby (history, and the presence of reference extragalactic sources for the anchoring onto the ICRS. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii.

  7. Cluster dynamics: A classical trajectory study of A + A/sub n/arrow-right-leftA*/sub n/+1

    International Nuclear Information System (INIS)

    Brady, J.W.; Doll, J.D.; Thompson, D.L.

    1979-01-01

    The dynamics of the collision of an atom A with a small cluster of atoms, A/sub n/, leading to the formation of a quasibound A*/sub n/+1 complex, which subsequently decays, has been studied using classical trajectories. Pairwise Lennard-Jones potentials (with parameters appropriate for argon) were used to describe the identical point masses (Ar). The results illustrate the feasibility of direct calculations of microscopic rates for nucleation processes. The dissociation of collisionally formed A*/sub n/+1 (n=3,4, and 5) occurs by first-order exponential decay. Furthermore the energy dependence of the dissociation rate constants appears to be well described by the RRK functional form

  8. Multivariate cluster analysis of dynamic iodine-123 iodobenzamide SPET dopamine D{sub 2}receptor images in schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Acton, P.D. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom); Pilowsky, L.S. [Institute of Psychiatry, London (United Kingdom); Costa, D.C. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom); Ell, P.J. [Inst. of Nuclear Medicine, Univ. Coll. London Medical School, London (United Kingdom)

    1997-02-01

    This paper describes the application of a multivariate statistical technique to investigate striatal dopamine D{sub 2}receptor concentrations measured by iodine-123 iodobenzamide ({sup 123}I-IBZM) single-photon emission tomography (SPET). This technique enables the automatic segmentation of dynamic nuclear medicine images based on the underlying time-activity curves present in the data. Once the time-activity curves have been extracted, each pixel can be mapped back on to the underlying distribution, considerably reducing image noise. Cluster analysis has been verified using computer simulations and phantom studies. The technique has been applied to SPET images of dopamine D {sub 2}receptors in a total of 20 healthy and 20 schizophrenic volunteers (22 male, 18 female), using the ligand {sup 123}I-IBZM. Following automatic image segmentation, the concentration of striatal dopamine D {sub 2}receptors shows a significant left-sided asymmetry in male schizophrenics compared with male controls. The mean left-minus-right laterality index for controls is -1.52 (95% CI -3.72-0.66) and for patients 4.04 (95% CI 1.07-7.01). Analysis of variance shows a case-by-sex-by-side interaction, with F=10.01, P=0.005. We can now demonstrate that the previously observed male sex-specific D {sub 2}receptor asymmetry in schizophrenia, which had failed to attain statistical significance, is valid. Cluster analysis of dynamic nuclear medicine studies provides a powerful tool for automatic segmentation and noise reduction of the images, removing much of the subjectivity inherent in region-of-interest analysis. The observed striatal D {sub 2}asymmetry could reflect long hypothesized disruptions in dopamine-rich cortico-striatal-limbic circuits in schizophrenic males. (orig.). With 4 figs., 2 tabs.

  9. The Body and the Transcendence of the Self Brief Notes on the Issue of Subjectivity and Responsibility in Levinas

    Directory of Open Access Journals (Sweden)

    Fernando Escobar Díaz

    2014-08-01

    Full Text Available The article offers a possible reading of transcendence in Levinas from the perspective of the phenomenon of responsibility, a reading that is only possible from the logic of freedom as the transcendence of returning without having ever left. This entails accepting that sensibility is the ground zero of the situation, which makes evident that human beings are embodied before transcending and responding. Therefore, the body’s corporality is the fact that makes possible a responsible subject.

  10. The effect of self-transcendence on depression in cognitively intact nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Innstrand, Siw Tone

    2012-01-01

    Aims. This study's aim was to test the effects of self-transcendence on depression among cognitively intact nursing home patients. Background. Depression is considered the most frequent mental disorder among the elderly population. Specifically, the depression rate among nursing home patients is three to four times higher than that among community-dwelling elderly. Therefore, finding new and alternative ways to prevent and decrease depression is of great importance for nursing home patients' well-being. Self-transcendence is related to spiritual as well as nonspiritual factors, and it is described as a correlate and resource for well-being among vulnerable populations and at the end of life. Methods. A two-factor construct of the self-transcendence scale (interpersonal and intrapersonal) and the hospital anxiety and depression scale (HADS) was applied. A sample of 202 cognitively intact nursing home patients in central Norway was selected to respond to the questionnaires in 2008/2009. Results. A hypothesized SEM model demonstrated significant direct relationships and total effects of self-transcendence on depression. Conclusion and Implication for Practice. Facilitating patients' self-transcendence, both interpersonally and intrapersonally, might decrease depression among cognitively intact nursing home patients.

  11. Molecular Dynamics Simulation of Solidification of Pd-Ni Clusters with Different Nickel Content

    Directory of Open Access Journals (Sweden)

    Chen Gang

    2014-01-01

    Full Text Available Molecular dynamics simulation has been performed for investigating the glass transition of Pd-Ni alloy nanoparticles in the solidification process. The results showed that the Pd-Ni nanoparticles with composition far from pure metal should form amorphous structure more easily, which is in accordance with the results of the thermodynamic calculation. There are some regular and distorted fivefold symmetry in the amorphous Pd-Ni alloy nanoparticles. The nanoclusters with bigger difference value between formation enthalpies of solutions and glasses will transform to glass more easily than the other Pd-Ni alloy nanoclusters.

  12. Real-time observation of formation and relaxation dynamics of NH4 in (CH3OH)m(NH3)n clusters.

    Science.gov (United States)

    Yamada, Yuji; Nishino, Yoko; Fujihara, Akimasa; Ishikawa, Haruki; Fuke, Kiyokazu

    2009-03-26

    The formation and relaxation dynamics of NH4(CH3OH)m(NH3)n clusters produced by photolysis of ammonia-methanol mixed clusters has been observed by a time-resolved pump-probe method with femtosecond pulse lasers. From the detailed analysis of the time evolutions of the protonated cluster ions, NH4(+)(CH3OH)m(NH3)n, the kinetic model has been constructed, which consists of sequential three-step reaction: ultrafast hydrogen-atom transfer producing the radical pair (NH4-NH2)*, the relaxation process of radical-pair clusters, and dissociation of the solvated NH4 clusters. The initial hydrogen transfer hardly occurs between ammonia and methanol, implying the unfavorable formation of radical pair, (CH3OH2-NH2)*. The remarkable dependence of the time constants in each step on the number and composition of solvents has been explained by the following factors: hydrogen delocalization within the clusters, the internal conversion of the excited-state radical pair, and the stabilization of NH4 by solvation. The dependence of the time profiles on the probe wavelength is attributed to the different ionization efficiency of the NH4(CH3OH)m(NH3)n clusters.

  13. XMM-Newton and Chandra Observations of the Remarkable Dynamics of the Intracluster Medium and Radio Sources in the Clusters Abell 2061 and 3667

    Science.gov (United States)

    Sarazin, C.; Hogge, T.; Chatzikos, M.; Wik, D.; Giacintucci, S.; Clarke, T.; Wong, K.; Gitti, M.; Finoguenov, A.

    2014-07-01

    XMM-Newton and Chandra observations of remarkable dynamic structures in the X-ray gas and connected radio sources in three clusters are presented. Abell 2061 is a highly irregular, merging cluster in the Corona Borealis supercluster. X-ray observations show that there is a plume of very cool gas (˜1 keV) to the NE of the cluster, and a hot (7.6 keV) shock region just NE of the center. There is a very bright radio relic to the far SW of the cluster, and a central radio halo/relic with an extension to the NE. Comparison to SLAM simulations show that this is an offset merger of a ˜5 × 10^{13} M⊙ subcluster with a ˜2.5 × 10^{14} M⊙ cluster seen after first core passage. The plume is the cool-core gas from the subcluster, which has been ``slingshot'' to the NE of the cluster. The plume gas is now falling back into the cluster center, and shocks when it hits the central gas. The model predicts a strong shock to the SW at the location of the bright radio relic, and another shock at the NE radio extension. Time permitting, the observations of Abell 2626 and Abell 3667 will also be presented.

  14. Spin-glass-like dynamics of ferromagnetic clusters in La0.75Ba0.25CoO3

    International Nuclear Information System (INIS)

    Kumar, Devendra

    2014-01-01

    We report a magnetization study of the compound La 0.75 Ba 0.25 CoO 3 where the Ba 2+ doping is just above the critical limit for percolation of ferromagnetic clusters. The field cooled and zero-field cooled (ZFC) magnetization exhibit thermomagnetic irreversibility and the ac susceptibility shows a frequency dependent peak at the ferromagnetic ordering temperature (T C  ≈ 203 K) of the clusters. These features indicate the presence of a non-equilibrium state below T C . For the non-equilibrium state, the dynamic scaling of the imaginary part of the ac susceptibility and the static scaling of the nonlinear susceptibility clearly establish a spin-glass-like cooperative freezing of ferromagnetic clusters at 200.9(2) K. The assertion of the occurrence of spin-glass-like freezing of ferromagnetic clusters is further substantiated by ZFC ageing and memory experiments. We also observe certain dynamical features which are not present in a typical spin glass, such as: the initial magnetization after ZFC ageing first increases and then decreases with the waiting time; and there is an imperfect recovery of relaxation in negative temperature cycling experiments. This imperfect recovery transforms to perfect recovery for concurrent field cycling. Our analysis suggests that these additional dynamical features have their origin in the inter-cluster exchange interaction and cluster size distribution. The inter-cluster exchange interaction above the magnetic percolation level gives a superferromagnetic state in some granular thin films, but our results show the absence of a typical superferromagnetic-like state in La 0.75 Ba 0.25 CoO 3 . (paper)

  15. Brome isotope selective control of CF3Br molecule clustering by IR laser radiation in gas-dynamic expansion of CF3Br - Ar mixture

    Science.gov (United States)

    Apatin, V. M.; Lokhman, V. N.; Makarov, G. N.; Ogurok, N.-D. D.; Ryabov, E. A.

    2018-02-01

    We report the results of research on the experimental control of CF3Br molecule clustering under gas-dynamic expansion of the CF3Br - Ar mixture at a nozzle exit by using IR laser radiation. A cw CO2 laser is used for exciting molecules and clusters in the beam and a time-of-flight mass-spectrometer with laser UV ionisation of particles for their detection. The parameters of the gas above the nozzle are determined (compositions and pressure) at which intensive molecule clustering occurs. It is found that in the case of the CF3Br gas without carrier when the pressure P0 above the nozzle does not exceed 4 atm, molecular clusters actually are not generated in the beam. If the gas mixture of CF3Br with argon is used at a pressure ratio 1 : N, where N >= 3, and the total pressure above the nozzle is P0 >= 2 atm, then there occurs molecule clustering. We study the dependences of the efficiency of suppressing the molecule clustering on parameters of the exciting pulse, gas parameters above the nozzle, and on a distance of the molecule irradiation zone from the nozzle exit section. It is shown that in the case of resonant vibrational excitation of gas-dynamically cooled CF3Br molecules at the nozzle exit one can realise isotope-selective suppression of molecule clustering with respect to bromine isotopes. With the CF3Br - Ar mixtures having the pressure ratio 1 : 3 and 1 : 15, the enrichment factors obtained with respect to bromine isotopes are kenr ≈ 1.05 ± 0.005 and kenr ≈ 1.06 ± 0.007, respectively, under jet irradiation by laser emission in the 9R(30) line (1084.635 cm-1). The results obtained let us assume that this method can be used to control clustering of molecules comprising heavy element isotopes, which have a small isotopic shift in IR absorption spectra.

  16. First-principles investigation of the dissociation and coupling of methane on small copper clusters: Interplay of collision dynamics and geometric and electronic effects

    Energy Technology Data Exchange (ETDEWEB)

    Varghese, Jithin J.; Mushrif, Samir H., E-mail: shmushrif@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)

    2015-05-14

    Small metal clusters exhibit unique size and morphology dependent catalytic activity. The search for alternate minimum energy pathways and catalysts to transform methane to more useful chemicals and carbon nanomaterials led us to investigate collision induced dissociation of methane on small Cu clusters. We report here for the first time, the free energy barriers for the collision induced activation, dissociation, and coupling of methane on small Cu clusters (Cu{sub n} where n = 2–12) using ab initio molecular dynamics and metadynamics simulations. The collision induced activation of the stretching and bending vibrations of methane significantly reduces the free energy barrier for its dissociation. Increase in the cluster size reduces the barrier for dissociation of methane due to the corresponding increase in delocalisation of electron density within the cluster, as demonstrated using the electron localisation function topology analysis. This enables higher probability of favourable alignment of the C–H stretching vibration of methane towards regions of high electron density within the cluster and makes higher number of sites available for the chemisorption of CH{sub 3} and H upon dissociation. These characteristics contribute in lowering the barrier for dissociation of methane. Distortion and reorganisation of cluster geometry due to high temperature collision dynamics disturb electron delocalisation within them and increase the barrier for dissociation. Coupling reactions of CH{sub x} (x = 1–3) species and recombination of H with CH{sub x} have free energy barriers significantly lower than complete dehydrogenation of methane to carbon. Thus, competition favours the former reactions at high hydrogen saturation on the clusters.

  17. First-principles investigation of the dissociation and coupling of methane on small copper clusters: Interplay of collision dynamics and geometric and electronic effects

    International Nuclear Information System (INIS)

    Varghese, Jithin J.; Mushrif, Samir H.

    2015-01-01

    Small metal clusters exhibit unique size and morphology dependent catalytic activity. The search for alternate minimum energy pathways and catalysts to transform methane to more useful chemicals and carbon nanomaterials led us to investigate collision induced dissociation of methane on small Cu clusters. We report here for the first time, the free energy barriers for the collision induced activation, dissociation, and coupling of methane on small Cu clusters (Cu n where n = 2–12) using ab initio molecular dynamics and metadynamics simulations. The collision induced activation of the stretching and bending vibrations of methane significantly reduces the free energy barrier for its dissociation. Increase in the cluster size reduces the barrier for dissociation of methane due to the corresponding increase in delocalisation of electron density within the cluster, as demonstrated using the electron localisation function topology analysis. This enables higher probability of favourable alignment of the C–H stretching vibration of methane towards regions of high electron density within the cluster and makes higher number of sites available for the chemisorption of CH 3 and H upon dissociation. These characteristics contribute in lowering the barrier for dissociation of methane. Distortion and reorganisation of cluster geometry due to high temperature collision dynamics disturb electron delocalisation within them and increase the barrier for dissociation. Coupling reactions of CH x (x = 1–3) species and recombination of H with CH x have free energy barriers significantly lower than complete dehydrogenation of methane to carbon. Thus, competition favours the former reactions at high hydrogen saturation on the clusters

  18. Two Stage Secure Dynamic Load Balancing Architecture for SIP Server Clusters

    Directory of Open Access Journals (Sweden)

    G. Vennila

    2014-08-01

    Full Text Available Session Initiation Protocol (SIP is a signaling protocol emerged with an aim to enhance the IP network capabilities in terms of complex service provision. SIP server scalability with load balancing has a greater concern due to the dramatic increase in SIP service demand. Load balancing of session method (request/response and security measures optimizes the SIP server to regulate of network traffic in Voice over Internet Protocol (VoIP. Establishing a honeywall prior to the load balancer significantly reduces SIP traffic and drops inbound malicious load. In this paper, we propose Active Least Call in SIP Server (ALC_Server algorithm fulfills objectives like congestion avoidance, improved response times, throughput, resource utilization, reducing server faults, scalability and protection of SIP call from DoS attacks. From the test bed, the proposed two-tier architecture demonstrates that the ALC_Server method dynamically controls the overload and provides robust security, uniform load distribution for SIP servers.

  19. Transcendence in the current theology, philosophy and metaphysics in Russian cosmism

    Directory of Open Access Journals (Sweden)

    Emanuel George Oprea

    2016-03-01

    Full Text Available Human interests to Religion and Metaphysics are well explained by the desire of the people to answer to fundamental and eternal questions as “what is the sense of life” and “what is the purpose of life”. These questions have accompanied them from the beginning of conscious life. Many intellectuals, scientists and writers of former USSR and democratic Russia have brought essential contributions, opened new directions and finally have enriched with new concepts, ideas, ideologies and systems the worldwide Philosophy and Religion. A possible answer is the Creation allowing to Divinity to transcend in common life. Soul as Spiritual reflection of Divinity tends to perfection, reiterating in every generation the transcendence to God. At first sight there are no meeting points between Transcendence and Cosmism because the last notion has its beginning in the progress of Science. The evolution of modern Sciences, philosophical concepts and Religion gradually demonstrates correlated aspects which must be discovered in the future.

  20. Self-transcendence and medication adherence in older adults with hypertension.

    Science.gov (United States)

    Thomas, Nezbile F; Dunn, Karen S

    2014-12-01

    The purpose of this study was to examine the relationship between self-transcendence and medication adherence among older adults prescribed antihypertensive medication. Descriptive, correlational research design. Forty-six older adults who were prescribed antihypertensive medications from an independent living facility participated in this study. Participants were given a survey that included a demographic questionnaire, the Morisky Medication Adherence Scale, and Reed's Self-Transcendence Scale. No significant relationship was found between medication adherence and self-transcendence (r = -.20, p = .18). Ninety percent of the participants however, admitted to cutting back or stopping their medication without notifying their providers. Continued investigation is needed to identify reasons why older adults fail to adhere to taking prescribed hypertension medications in order to improve health outcomes in this population. © The Author(s) 2014.

  1. Facilitating Self-Transcendence: An Intervention to Enhance Well-Being in Late Life.

    Science.gov (United States)

    McCarthy, Valerie Lander; Hall, Lynne A; Crawford, Timothy N; Connelly, Jennifer

    2018-06-01

    This randomized controlled pilot study evaluated the effects of the Psychoeducational Approach to Transcendence and Health (PATH) Program, an 8-week intervention hypothesized to increase self-transcendence and improve well-being in community-dwelling women aged 60 years and older ( N = 20). The PATH combined mindfulness exercises, group processes, creative activities, and at-home practice using community engaged research methods. Findings provided some support for the effectiveness of PATH. Although there was no significant Group × Time interaction, self-transcendence, psychological well-being, and life satisfaction differed significantly pre- and postintervention in the wait-listed control group, which received a revised version of the program. Further study is needed with a larger sample to determine the effectiveness of PATH. Potentially, PATH may be a convenient and affordable activity to support personal development and improve well-being among older adults at senior centers, retirement communities, nursing homes, church groups, and other places where older adults gather.

  2. Dynamics of Neutral Cluster Growth and Cluster Ion Fragmentation for Toluene/Water, Aniline/Argon, and 4-Fluorostyrene/Argon Clusters: Covariance Mapping of the Mass Spectral Data

    National Research Council Canada - National Science Library

    Foltin, M

    1998-01-01

    .... To explore sensitivity of the parent ion/fragment ion correlation coefficient to cluster fragmentation, correlation coefficients are measured as a function of ionization photon energy as thresholds...

  3. THE ATACAMA COSMOLOGY TELESCOPE: DYNAMICAL MASSES AND SCALING RELATIONS FOR A SAMPLE OF MASSIVE SUNYAEV-ZEL'DOVICH EFFECT SELECTED GALAXY CLUSTERS {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Sifon, Cristobal; Barrientos, L. Felipe; Gonzalez, Jorge; Infante, Leopoldo; Duenner, Rolando [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Menanteau, Felipe; Hughes, John P.; Baker, Andrew J. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Hasselfield, Matthew [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Marriage, Tobias A.; Crichton, Devin; Gralla, Megan B. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218-2686 (United States); Addison, Graeme E.; Dunkley, Joanna [Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Battaglia, Nick; Bond, J. Richard; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Devlin, Mark J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Hilton, Matt [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); and others

    2013-07-20

    We present the first dynamical mass estimates and scaling relations for a sample of Sunyaev-Zel'dovich effect (SZE) selected galaxy clusters. The sample consists of 16 massive clusters detected with the Atacama Cosmology Telescope (ACT) over a 455 deg{sup 2} area of the southern sky. Deep multi-object spectroscopic observations were taken to secure intermediate-resolution (R {approx} 700-800) spectra and redshifts for Almost-Equal-To 60 member galaxies on average per cluster. The dynamical masses M{sub 200c} of the clusters have been calculated using simulation-based scaling relations between velocity dispersion and mass. The sample has a median redshift z = 0.50 and a median mass M{sub 200c}{approx_equal}12 Multiplication-Sign 10{sup 14} h{sub 70}{sup -1} M{sub sun} with a lower limit M{sub 200c}{approx_equal}6 Multiplication-Sign 10{sup 14} h{sub 70}{sup -1} M{sub sun}, consistent with the expectations for the ACT southern sky survey. These masses are compared to the ACT SZE properties of the sample, specifically, the match-filtered central SZE amplitude y{sub 0}-tilde, the central Compton parameter y{sub 0}, and the integrated Compton signal Y{sub 200c}, which we use to derive SZE-mass scaling relations. All SZE estimators correlate with dynamical mass with low intrinsic scatter ({approx}< 20%), in agreement with numerical simulations. We explore the effects of various systematic effects on these scaling relations, including the correlation between observables and the influence of dynamically disturbed clusters. Using the three-dimensional information available, we divide the sample into relaxed and disturbed clusters and find that {approx}50% of the clusters are disturbed. There are hints that disturbed systems might bias the scaling relations, but given the current sample sizes, these differences are not significant; further studies including more clusters are required to assess the impact of these clusters on the scaling relations.

  4. Space-time clustering of childhood malaria at the household level: a dynamic cohort in a Mali village

    Directory of Open Access Journals (Sweden)

    Ouattara Amed

    2006-11-01

    Full Text Available Abstract Background Spatial and temporal heterogeneities in the risk of malaria have led the WHO to recommend fine-scale stratification of the epidemiological situation, making it possible to set up actions and clinical or basic researches targeting high-risk zones. Before initiating such studies it is necessary to define local patterns of malaria transmission and infection (in time and in space in order to facilitate selection of the appropriate study population and the intervention allocation. The aim of this study was to identify, spatially and temporally, high-risk zones of malaria, at the household level (resolution of 1 to 3 m. Methods This study took place in a Malian village with hyperendemic seasonal transmission as part of Mali-Tulane Tropical Medicine Research Center (NIAID/NIH. The study design was a dynamic cohort (22 surveys, from June 1996 to June 2001 on about 1300 children (Plasmodium falciparum, P. malariae and P. ovale infection and P. falciparum gametocyte carriage by means of time series and Kulldorff's scan statistic for space-time cluster detection. Results The time series analysis determined that malaria parasitemia (primarily P. falciparum was persistently present throughout the population with the expected seasonal variability pattern and a downward temporal trend. We identified six high-risk clusters of P. falciparum infection, some of which persisted despite an overall tendency towards a decrease in risk. The first high-risk cluster of P. falciparum infection (rate ratio = 14.161 was detected from September 1996 to October 1996, in the north of the village. Conclusion This study showed that, although infection proportions tended to decrease, high-risk zones persisted in the village particularly near temporal backwaters. Analysis of this heterogeneity at the household scale by GIS methods lead to target preventive actions more accurately on the high-risk zones identified. This mapping of malaria risk makes it possible

  5. Self-transcendence facilitates meaning-making and flow: Evidence from a pilot experimental study

    Directory of Open Access Journals (Sweden)

    Osin, Evgeny N.

    2016-06-01

    Full Text Available We review the psychological theory of flow and focus on the notion of the autotelic personality, arguing that self-transcendence (understood within the existential tradition of Frankl and Längle as the individual’s ability to establish inner relationships with values can be viewed as a personality disposition conducive to flow experience. The study aimed to investigate the effects of situational task meaning and dispositional self-transcendence on productivity and flow experience. We present a pilot quasi-experimental study conducted in a student sample (N = 82 Students were asked to work in small-group settings on a creative task, which consisted in finding solutions to a social problem. Each group was randomly assigned to an instruction presenting the problem as happening either in a distant country (low-meaning or in their home country (high-meaning condition. The outcome variables were measures of flow, perceived meaning of the task, and satisfaction with time spent working. The solutions generated by the students were rated by three experts. The experimental manipulation had a main effect on the quality of the resulting solutions, but not on the subjective experience of the participants. A number of significant interaction effects were found, indicating that the associations of self-transcendence with experiential outcomes tended to be linear under the low-meaning condition, but curvilinear under the high-meaning condition. The findings suggest that self-transcendence is particularly beneficial to flow in situations with unclear meaning, but very high levels of self-transcendence may hinder flow in highly meaningful situations. Overall, the findings suggest that self-transcendence can be considered as a disposition of the autotelic personality.

  6. Facilitation of self-transcendence in a breast cancer support group.

    Science.gov (United States)

    Coward, D D

    1998-01-01

    To examine the feasibility and patterns of effectiveness of a breast cancer support group intervention specifically designed to facilitate self-transcendence views and perspectives that would enhance emotional and physical well-being. Pre-experimental design pilot intervention study with a quantitative approach to data analysis. Survivor-established breast cancer resource center in Austin, TX. Women with recently diagnosed breast cancer (N = 16) participating in 90-minute support group sessions that met weekly for eight weeks. Theory-driven support group intervention facilitated by an oncology clinical nurse specialist, a psychotherapist, and a breast cancer survivor. Activities planned for individual sessions were based on self-transcendence theory, cancer support group literature, and the facilitators' extensive previous support group experience. Self-transcendence, emotional well-being, physical well-being. Good networking, coordination, and follow-up were essential for participant recruitment and retention throughout the intervention period. Although specific theory-driven activities were planned for group sessions, facilitators maintained flexibility in meeting immediate concerns of the participants. Relationships among participants' scores on study variables indicated an association between self-transcendence and emotional well-being. Scores on self-transcendence and well-being variables at the end of the intervention increased from baseline, but only functional performance status, mood state, and satisfaction with life reached statistical significance. The pilot study was invaluable in providing direction for the conduct of future experimental studies. Provides preliminary support for the use of theory-driven activities for promotion of self-transcendence views and behaviors within a cancer support group setting.

  7. Clustering of near clusters versus cluster compactness

    International Nuclear Information System (INIS)

    Yu Gao; Yipeng Jing

    1989-01-01

    The clustering properties of near Zwicky clusters are studied by using the two-point angular correlation function. The angular correlation functions for compact and medium compact clusters, for open clusters, and for all near Zwicky clusters are estimated. The results show much stronger clustering for compact and medium compact clusters than for open clusters, and that open clusters have nearly the same clustering strength as galaxies. A detailed study of the compactness-dependence of correlation function strength is worth investigating. (author)

  8. The Relationship with Yourself when Praying to Transcendent God and to an Immanent God

    Directory of Open Access Journals (Sweden)

    Larisa Ileana Casangiu

    2017-05-01

    Full Text Available In this article, we aim to discuss on prayer, trying to identify a kind of relationship with yourself during the praying to a transcendent God and an immanent God, according to the religious literature and the Romanian social reality. For this purpose, we have conducted an experimental research ascertaining the investigation based on interview and questionnaire aimed the relationship with yourself indirectly when praying to a transcendent God and an immanent God among the believers/faithful persons who pray (almost daily.

  9. Transcending binary logic by gating three coupled quantum dots.

    Science.gov (United States)

    Klein, Michael; Rogge, S; Remacle, F; Levine, R D

    2007-09-01

    Physical considerations supported by numerical solution of the quantum dynamics including electron repulsion show that three weakly coupled quantum dots can robustly execute a complete set of logic gates for computing using three valued inputs and outputs. Input is coded as gating (up, unchanged, or down) of the terminal dots. A nanosecond time scale switching of the gate voltage requires careful numerical propagation of the dynamics. Readout is the charge (0, 1, or 2 electrons) on the central dot.

  10. Cosmic transcendence, loneliness, and exchange of emotional support with adult children: a study among older parents in The Netherlands.

    Science.gov (United States)

    Sadler, E A; Braam, A W; Broese van Groenou, M I; Deeg, D J H; van der Geest, S

    2006-09-01

    Gerotranscendence defines a shift in meta-perspective from earlier materialistic and pragmatic concerns, toward more cosmic and transcendent ones in later life. Population-based studies that have empirically examined this concept using Tornstam's gerotranscendence scale, highlight cosmic transcendence as a core component, which includes a sense of belongingness with past and future generations. Such generative concerns may increase expectations regarding the quality of the bond with one's children in later life. This study examined whether the association between emotional support exchanged with children and feelings of loneliness later in life varied by the degree of cosmic transcendence of the older parent. Data from 1,845 older parents participating in a population-based study living in The Netherlands were analyzed from the 1995/1996 cycle of the Longitudinal Aging Study Amsterdam. Interviews included self-report measures of cosmic transcendence, loneliness, emotional support exchanged with children, health indicators, and marital status. Results indicated that a negative association between loneliness and level of emotional support exchanged with children was more pronounced among older parents with higher cosmic transcendence scores, in particular among the married. It is argued that cosmic transcendence reflects a sense of generativity and an increased emotional dependency on children in later life. Under favorable social conditions (supportive relationships with children and being married) cosmic transcendent views had a positive impact on social well-being in later life. When children no longer met emotional needs of older parents, cosmic transcendence increased feelings of loneliness.

  11. Investigating the effect of external trauma through a dynamic system modeling approach for clustering causality in diabetic foot ulcer development.

    Science.gov (United States)

    Salimi, Parisa; Hamedi, Mohsen; Jamshidi, Nima; Vismeh, Milad

    2017-04-01

    Diabetes and its associated complications are realized as one of the most challenging medical conditions threatening more than 29 million people only in the USA. The forecasts suggest a suffering of more than half a billion worldwide by 2030. Amid all diabetic complications, diabetic foot ulcer (DFU) has attracted much scientific investigations to lead to a better management of this disease. In this paper, a system thinking methodology is adopted to investigate the dynamic nature of the ulceration. The causal loop diagram as a tool is utilized to illustrate the well-researched relations and interrelations between causes of the DFU. The result of clustering causality evaluation suggests a vicious loop that relates external trauma to callus. Consequently a hypothesis is presented which localizes development of foot ulceration considering distribution of normal and shear stress. It specifies that normal and tangential forces, as the main representatives of external trauma, play the most important role in foot ulceration. The evaluation of this hypothesis suggests the significance of the information related to both normal and shear stress for managing DFU. The results also discusses how these two react on different locations on foot such as metatarsal head, heel and hallux. The findings of this study can facilitate tackling the complexity of DFU problem and looking for constructive mitigation measures. Moreover they lead to developing a more promising methodology for managing DFU including better prognosis, designing prosthesis and insoles for DFU and patient caring recommendations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Proton affinity of the histidine-tryptophan cluster motif from the influenza A virus from ab initio molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bankura, Arindam; Klein, Michael L.; Carnevale, Vincenzo, E-mail: vincenzo.carnevale@temple.edu

    2013-08-30

    Highlights: • The estimated pK{sub a} is in agreement with the experimental one. • The affinity for protons is similar to that of a histidine residue in aqueous solution. • The electrostatic environment is responsible for the stabilization of the charged imidazolium moiety. - Abstract: Ab initio molecular dynamics calculations have been used to compare and contrast the deprotonation reaction of a histidine residue in aqueous solution with the situation arising in a histidine-tryptophan cluster. The latter is used as a model of the proton storage unit present in the pore of the M2 proton conducting ion channel. We compute potentials of mean force for the dissociation of a proton from the Nδ and N∊ positions of the imidazole group to estimate the pK{sub a}s. Anticipating our results, we will see that the estimated pK{sub a} for the first protonation event of the M2 channel is in good agreement with experimental estimates. Surprisingly, despite the fact that the histidine is partially desolvated in the M2 channel, the affinity for protons is similar to that of a histidine in aqueous solution. Importantly, the electrostatic environment provided by the indoles is responsible for the stabilization of the charged imidazolium.

  13. Empirical potential and elasticity theory modelling of interstitial dislocation loops in UO2 for cluster dynamics application

    International Nuclear Information System (INIS)

    Le-Prioux, Arno

    2017-01-01

    During irradiation in reactor, the microstructure of UO 2 changes and deteriorates, causing modifications of its physical and mechanical properties. The kinetic models used to describe these changes such as cluster dynamics (CRESCENDO calculation code) consider the main microstructural elements that are cavities and interstitial dislocation loops, and provide a rather rough description of the loop thermodynamics. In order to tackle this issue, this work has led to the development of a thermodynamic model of interstitial dislocation loops based on empirical potential calculations. The model considers two types of interstitial dislocation loops on two different size domains: Type 1: Dislocation loops similar to Frank partials in F.C.C. materials which are stable in the smaller size domain. Type 2: Perfect dislocation loops of Burgers vector (a/2)(110) stable in the larger size domain. The analytical formula used to compute the interstitial dislocation loop formation energies is the one for circular loops which has been modified in order to take into account the effects of the dislocation core, which are significant at smaller sizes. The parameters have been determined by empirical potential calculations of the formation energies of prismatic pure edge dislocation loops. The effect of the habit plane reorientation on the formation energies of perfect dislocation loops has been taken into account by a simple interpolation method. All the different types of loops seen during TEM observations are thus accounted for by the model. (author) [fr

  14. The effect of HIV/AIDS disease progression on spirituality and self-transcendence in a multicultural population.

    Science.gov (United States)

    Ramer, Lois; Johnson, Debra; Chan, Linda; Barrett, Mary Theresa

    2006-07-01

    This study examined the relationship of sociodemographic and clinical factors with spirituality and self-transcendence in people with HIV/AIDS. It involved 420 HIV/AIDS patients from an HIV clinic who were predominantly Hispanic (79%) and male (82%), with a mean age of 39 years. Subjects completed spirituality, self-transcendence, health status, and depression scales. Medical charts were reviewed to obtain demographics, current therapies, depression diagnosis, CD4 cells (sometimes called T-cells), and viral load levels. Self-transcendence was related to levels of energy (p self-transcendence or spirituality. The findings suggest the concept of self-transcendence may not be culturally meaningful to Hispanic patients. The development of valid and reliable tools specific for this population is important for future research.

  15. Self-transcendence, spiritual well-being, and spiritual practices of women with breast cancer.

    Science.gov (United States)

    Thomas, Jeani C; Burton, Mattie; Griffin, Mary T Quinn; Fitzpatrick, Joyce J

    2010-06-01

    As women recover from the experience of breast cancer and its treatment, it is important for them to find meaning in their lives and to understand their experiences from a holistic perspective. This study was designed to provide additional information about how women and their experiences recovering from breast cancer. The specific purpose was to describe the relationship between self-transcendence and spiritual well-being, and to identify the spiritual practices used by older women recovering from breast cancer. The theoretical framework for this study was Reed's theory of self-transcendence. A total of 87 community-residing women who had been diagnosed with breast cancer within the past 5 years participated in the study. There was a significant positive relationship between self-transcendence and spiritual well-being. The women used a mean of 9.72 spiritual practices with the most frequent being exercise, visiting a house of worship, and praying alone. The study results provide further support for the theory of self-transcendence. Future research recommendations are to expand the research to include a larger, more diverse group of women of all ages and backgrounds who have been diagnosed with breast cancer.

  16. Self-transcendence in stem cell transplantation recipients: a phenomenologic inquiry.

    Science.gov (United States)

    Williams, Barbara J

    2012-01-01

    To understand the meaning of self-transcendence, or the ability to go beyond the self, for patients who have had a stem cell transplantation. A phenomenologic investigation guided by the interpretive philosophy of Heidegger. A cancer center in a major urban academic medical center. 4 men and 4 women ages 45-63 who had received a stem cell transplantation in the previous year. Two or three unstructured, open-ended interviews were conducted with each participant. Data were extracted, analyzed, and interpreted according to the Colaizzi method. Self-transcendence. Self-transcendence emerged as a process that was triggered by the suffering the participants experienced as they lived through the physical effects of the treatment, faced death, drew strength from within themselves, and perceived a spiritually influenced turning point. The experience of a human connection lessened their feelings of vulnerability in the process. As the participants recovered, they described being transformed both physically and personally. The findings from this study highlight the power inherent in patients to not only meet the challenges they face, but to grow from their experiences. The findings also highlight patients' deep need for a human connection and the power that nurses and other healthcare professionals have to provide that connection. The caring connections established by health-care professionals can ease the ability of patients to access the inner resource of self-transcendence and reduce their feelings of vulnerability.

  17. Particular transcendent solution of the Ernst system generalized on n fields

    International Nuclear Information System (INIS)

    Leaute, B.; Marcilhacy, G.

    1986-01-01

    A particular solution, a function of a particular form of the fifth Painleve transcendent, of the Ernst system generalized to n fields is determined, which characterizes both the stationary axially symmetric fields, the solution of the Einstein (n-1) Maxwell equations, and one class of axially symmetric static self-dual SU(n+1) Yang--Mills fields

  18. Construction of a Creative and Self-Transcending Life: George Sudarshan's Conception and Experience of Creativity

    Science.gov (United States)

    Raina, Maharaj

    2013-01-01

    This article presents a philosophical perspective on creativity as described in the writings of George Sudarshan, a highly accomplished theoretical physicist and natural philosopher whose vision of creativity was influenced by "the direct experience of transcendence." The article reviews his conceptualization of the various mental states…

  19. Self-Transcendence as a Normative Philosophy and Psychology Underlying the Teaching of Literature and Composition.

    Science.gov (United States)

    Wheeler, Robert Walter

    The self-transcendence theory addressed primarily to teachers of literature and related composition in secondary schools and community colleges is distilled from extensive readings in two mainstreams of contemporary thought: the "romantic thread" in educational philosophy and the work of Third Force psychologists, particularly Carl R. Rogers and…

  20. Learning to Laugh at Ourselves: Humor, Self-Transcendence, and the Cultivation of Moral Virtues

    Science.gov (United States)

    Gordon, Mordechai

    2010-01-01

    In this essay Mordechai Gordon begins to address the neglect of humor among philosophers of education by focusing on some interesting connections between humor, self-transcendence, and the development of moral virtues. More specifically, he explores the kind of humor that makes fun of oneself and how it can affect educational encounters. Gordon…

  1. Boring but important: a self-transcendent purpose for learning fosters academic self-regulation.

    Science.gov (United States)

    Yeager, David S; Henderson, Marlone D; Paunesku, David; Walton, Gregory M; D'Mello, Sidney; Spitzer, Brian J; Duckworth, Angela Lee

    2014-10-01

    Many important learning tasks feel uninteresting and tedious to learners. This research proposed that promoting a prosocial, self-transcendent purpose could improve academic self-regulation on such tasks. This proposal was supported in 4 studies with over 2,000 adolescents and young adults. Study 1 documented a correlation between a self-transcendent purpose for learning and self-reported trait measures of academic self-regulation. Those with more of a purpose for learning also persisted longer on a boring task rather than giving in to a tempting alternative and, many months later, were less likely to drop out of college. Study 2 addressed causality. It showed that a brief, one-time psychological intervention promoting a self-transcendent purpose for learning could improve high school science and math grade point average (GPA) over several months. Studies 3 and 4 were short-term experiments that explored possible mechanisms. They showed that the self-transcendent purpose manipulation could increase deeper learning behavior on tedious test review materials (Study 3), and sustain self-regulation over the course of an increasingly boring task (Study 4). More self-oriented motives for learning--such as the desire to have an interesting or enjoyable career--did not, on their own, consistently produce these benefits (Studies 1 and 4). 2014 APA, all rights reserved

  2. Bearing and Transcending Suffering with Nature and the World: A Humanistic Account

    Science.gov (United States)

    Hong Chen, Rosa

    2011-01-01

    To conceptualise moral education as "living and learning to bear suffering" offers a humanistic vision for choices people make in the face of drastic threats to their existence. This essay proposes that bearing and transcending suffering--part of the human narrative--helps human beings to realise their ethical potential. Grounded in…

  3. Self-transcendence and Eros: The human condition between desire and the infinite

    Directory of Open Access Journals (Sweden)

    Cornel W. du Toit

    2011-07-01

    Full Text Available This article treats self-transcendence – like all transcendence – as a fact of human life. Inter alia this means that the human mind perforce operates in terms of binary concepts such as finitude–infinity, inner world–outside world, self–other, desire–fulfilment, separation–union and the like. We find these concepts in most myths of origin. The concept of desire (Eros, combining unfulfilment and the infinite, particularly epitomises self-transcendence. Ralph Waldo Emerson is cited as a precursor of the mid-19th century transcendentalists, whose ideas are resurfacing in present-day secular spirituality. In this article, we examined desire in the Christian conception of the Fall as envisioned by the Jewish philosopher Martin Buber and by Hegel, who integrates mind and nature in his philosophy of Spirit. The works of Emmanuel Levinas and Paul Ricoeur are used as points of reference to help us understand self and other in a framework of self-transcendence. The impact of these ideas on a postmetaphysical epistemology was also explored. Affectivity is a neglected area in Western thought and displays the same infinitude as rationality. The article concluded with present-day strategies of self-construction in a techno-scientific consumer culture.

  4. Reflexive awareness, transcendence and witnessing - in contemplative awareness cultures in school

    DEFF Research Database (Denmark)

    Nielsen, Anne Maj

    The paper presents reflections about contemplative education as a way to learn openness and witnessing phenomena of the mind and of lived experiences of oneself and others. The reflections include concepts of transcendence and witnessing and results from a qualitative study of contemplative educa...... and to adopt an open and reflective self-perception and understanding of others....

  5. Structured reminiscence: an intervention to decrease depression and increase self-transcendence in older women.

    Science.gov (United States)

    Stinson, Cynthia Kellam; Kirk, Edythe

    2006-02-01

    The purpose of this study was to assess the effect of group reminiscing on depression and self-transcendence of older women residing in an assisted living facility in southeast Texas. There were two major objectives for this study. One objective was to determine if depression decreased in older women after structured reminiscence group sessions held twice weekly for a six-week period. A second objective was to determine if self-transcendence increased after structured reminiscence group sessions held twice weekly for a six-week period. Reminiscence has been studied to determine its impact on a variety of conditions including but not limited to depression, self-esteem, fatigue, isolation, socialization, well-being, language acquisition and cognitive functioning. This review of research specifically focused on reminiscence, depression, self-transcendence and older people. Two groups were assessed at baseline, three and six weeks to answer the research questions. A sample of 24 women between the ages of 72 and 96 years were randomly assigned to either a reminiscence (experimental) group or the activity (control) group of the facility. Pearson's r was used to determine the magnitude of the relationship between subjects' responses on the Geriatric Depression Scale and the Self-Transcendence Scale. A mixed design analysis of variance (anova) was used to determine if there was a difference between the experimental and control groups on scores of the Geriatric Depression Scale and the Self-Transcendence Scale at baseline, three and six weeks. Data revealed a non-significant decrease in depression and increase in self-transcendence in the reminiscence group at the completion of six weeks, indicating a trend toward a positive result with reminiscence group sessions. The study also revealed an inverse relationship between depression and self-transcendence. These findings underscore the importance of screening older people for depression. One of the primary modalities used for

  6. Facilitation of self-transcendence in a breast cancer support group: II.

    Science.gov (United States)

    Coward, Doris Dickerson

    2003-01-01

    To pilot a second support group intervention study promoting self-transcendence perspectives and activities and to document changes over time in well-being in support group participants compared with nonparticipants. Quasiexperimental, partial randomization, preference trial design. An urban breast cancer resource center established by survivors. 41 women with newly diagnosed breast cancer were recruited, and 39 completed the study. 22 women participated in three intervention support groups; 17 were in a comparison group. The intervention was an eight-week, closed support group based on self-transcendence theory. Data were collected three times during 14 months. Support group intervention, self-transcendence, and emotional and physical well-being. The intervention group had lower scores than the comparison group on self-transcendence and well-being variables at baseline (time [T] 1). Scores were higher for both groups postintervention (T2), with no differences between groups. One year postintervention (T3), intervention group scores again were lower than comparison group scores. Intervention group T3 scores were unchanged from T2. Most potential participants were unwilling to risk being randomized into a nonpreferred group. Activities based on self-transcendence theory were associated with expanded perspectives and activities and an improved sense of well-being in support group participants at the end of the intervention, but not one year later. Findings from the pilot studies informed a study currently in progress. Nurses should maintain awareness of local resources for support and make that information available to women when they are newly diagnosed with breast cancer, during their treatment, and later.

  7. Transcendence, historicity and temporality of being elderly: nursing reflection-using Heidegger.

    Science.gov (United States)

    Guerrero-Castañeda, Raúl Fernando; Prado, Marta Lenise do; Kempfer, Silvana Silveira; Vargas, Maria Guadalupe Ojeda

    2017-01-01

    The objective is to reflect on historicity and temporality as paths for the transcendence of being elderly, based on the phenomenological concepts of Martin Heiddeger. A review of the concepts of transcendence, historicity and temporality was carried out in the work of Martín Heidegger, integrating them in the perspective of nursing for the elderly. The transcendence of the elderly adult is feasible by accessing the temporality of self in the path of its historicity to arrive at the understanding of itself that he has achieved: transcending, which is but a process of the Being itself. Being is time in itself existing in the world, existence given by the encounter of the past (to have been), present and future (becoming), the same encounter that determines the historicity of the Being. The encounter has been consummated and the Being is transcendence, with the understanding of the Being itself as a supreme point. RESUMEN El objetivo es reflexionar en la historicidad y temporalidad como caminos para la trascendencia del ser adulto mayor, basado en los conceptos fenomenológicos de Martín Heiddeger. Se llevó a cabo una revisión de los conceptos de trascendencia, historicidad y temporalidad en la obra de Martín Heidegger, realizando su integración en la perspectiva de enfermería al adulto mayor. La trascendencia del ser adulto mayor es factible accediendo a la temporalidad del mismo en el camino de su historicidad para llegar a la comprensión de sí a la que ha llegado: trascendiendo, que no es sino un proceso del mismo ser. El ser es el tiempo en sí mismo existiendo en el mundo, existencia dada por el encuentro del pasado (haber sido), presente y futuro (devenir), mismo encuentro que determina la historicidad del ser. El encuentro se ha consumado y el ser es trascendencia, como punto supremo la comprensión del ser mismo.

  8. A general framework to test gravity using galaxy clusters - I. Modelling the dynamical mass of haloes in f(R) gravity

    Science.gov (United States)

    Mitchell, Myles A.; He, Jian-hua; Arnold, Christian; Li, Baojiu

    2018-06-01

    We propose a new framework for testing gravity using cluster observations, which aims to provide an unbiased constraint on modified gravity models from Sunyaev-Zel'dovich (SZ) and X-ray cluster counts and the cluster gas fraction, among other possible observables. Focusing on a popular f(R) model of gravity, we propose a novel procedure to recalibrate mass scaling relations from Λ cold dark matter (ΛCDM) to f(R) gravity for SZ and X-ray cluster observables. We find that the complicated modified gravity effects can be simply modelled as a dependence on a combination of the background scalar field and redshift, fR(z)/(1 + z), regardless of the f(R) model parameter. By employing a large suite of N-body simulations, we demonstrate that a theoretically derived tanh fitting formula is in excellent agreement with the dynamical mass enhancement of dark matter haloes for a large range of background field parameters and redshifts. Our framework is sufficiently flexible to allow for tests of other models and inclusion of further observables, and the one-parameter description of the dynamical mass enhancement can have important implications on the theoretical modelling of observables and on practical tests of gravity.

  9. A full-potential linear-muffin-tin-orbital molecular-dynamics study of B{sub 7}, B{sub 10} and B{sub 13} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Cao Peilin Cao; Zhao Wei; Li Baoxing; Song Bin; Zhou Xuyan [Department of Physics and State Key Laboratory of Silicon Material, Zhejiang University, Hangzhou, Zhejiang (China)

    2001-06-04

    The structures of B{sub 7}, B{sub 10} and B{sub 13} boron clusters are studied using the full-potential linear-muffin-tin-orbital molecular-dynamics method. Seven stable structures for B{sub 7} and fifteen for B{sub 10} have been obtained. C{sub 2h}-B{sub 10} is the most stable among the 15 structures, but C{sub 2v}-B{sub 10} is not stable. For B{sub 13}, three degenerate ground-state structures have been found. The potential surface near C{sub 2v}-B{sub 7} (ground state) and D{sub 6h}-B{sub 7} is very flat. As a fundamental unit in constructing bigger clusters, C{sub 2v}-B{sub 7} will change its form easily. The most stable structures for B{sub 7}, B{sub 10} and B{sub 13} clusters are two-dimensional (quasi-) planar clusters, rather than the three-dimensional ones. General speaking, these clusters obey the 'Aufbau principle'. (author)

  10. Surface Solvation of Halogen Anions in Water Clusters: An ab initio Molecular Dynamics Study of the Cl-(H.sub.2./sub.O).sub.6./sub. Complex

    Czech Academy of Sciences Publication Activity Database

    Tobias, D. J.; Jungwirth, Pavel; Parrinello, M.

    2001-01-01

    Roč. 114, č. 16 (2001), s. 7036-7044 ISSN 0021-9606 R&D Projects: GA MŠk LN00A032 Grant - others:NATO Science Program(XE) CLG-974459 Institutional research plan: CEZ:AV0Z4040901 Keywords : cluster * ab initio molecular dynamics * anionic solvation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.147, year: 2001

  11. DYNAMICS INSIDE THE RADIO AND X-RAY CLUSTER CAVITIES OF CYGNUS A AND SIMILAR FRII SOURCES

    International Nuclear Information System (INIS)

    Mathews, William G.; Guo Fulai

    2012-01-01

    We describe approximate axisymmetric computations of the dynamical evolution of material inside radio lobes and X-ray cluster gas cavities in Fanaroff-Riley II (FRII) sources such as Cygnus A. All energy is delivered by a jet to the lobe/cavity via a moving hotspot where jet energy dissipates in a reverse shock. Our calculations describe the evolution of hot plasma, cosmic rays (CRs), and toroidal magnetic fields flowing from the hotspot into the cavity. Many important observational features are explained. Gas, CRs, and field flow back along the cavity surface in a 'boundary backflow' consistent with detailed FRII observations. Computed ages of backflowing CRs are consistent with observed radio-synchrotron age variations only if shear instabilities in the boundary backflow are damped and we assume this is done with viscosity of unknown origin. We compute a faint thermal jet along the symmetry axis and suggest that it is responsible for redirecting the Cygnus A nonthermal jet. Magnetic fields estimated from synchrotron self-Compton (SSC) X-radiation observed near the hotspot evolve into radio lobe fields. Computed profiles of radio-synchrotron lobe emission perpendicular to the jet reveal dramatically limb-brightened emission in excellent agreement with FRII observation, although computed lobe fields exceed those observed. Strong winds flowing from hotspots naturally create kiloparsec-sized spatial offsets between hotspot nonthermal X-ray inverse Compton (IC-CMB) emission and radio-synchrotron emission that peaks 1-2 kpc ahead where the field increases due to wind compression. In our computed version of Cygnus A, nonthermal X-ray emission increases from the hotspot (some IC-CMB, mostly SSC) toward the offset radio-synchrotron peak (mostly SSC).

  12. Roche-lobe overflow systems powered by black holes in young star clusters: the importance of dynamical exchanges

    Energy Technology Data Exchange (ETDEWEB)

    Mapelli, Michela; Zampieri, Luca, E-mail: michela.mapelli@oapd.inaf.it [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122, Padova (Italy)

    2014-10-10

    We have run 600 N-body simulations of intermediate-mass (∼3500 M {sub ☉}) young star clusters (SCs; with three different metallicities (Z = 0.01, 0.1, and 1 Z {sub ☉}). The simulations include the dependence of stellar properties and stellar winds on metallicity. Massive stellar black holes (MSBHs) with mass >25 M {sub ☉} are allowed to form through direct collapse of very massive metal-poor stars (Z < 0.3 Z {sub ☉}). We focus on the demographics of black hole (BH) binaries that undergo mass transfer via Roche lobe overflow (RLO). We find that 44% of all binaries that undergo an RLO phase (RLO binaries) formed through dynamical exchange. RLO binaries that formed via exchange (RLO-EBs) are powered by more massive BHs than RLO primordial binaries (RLO-PBs). Furthermore, the RLO-EBs tend to start the RLO phase later than the RLO-PBs. In metal-poor SCs (0.01-0.1 Z {sub ☉}), >20% of all RLO binaries are powered by MSBHs. The vast majority of RLO binaries powered by MSBHs are RLO-EBs. We have produced optical color-magnitude diagrams of the simulated RLO binaries, accounting for the emission of both the donor star and the irradiated accretion disk. We find that RLO-PBs are generally associated with bluer counterparts than RLO-EBs. We compare the simulated counterparts with the observed counterparts of nine ultraluminous X-ray sources. We discuss the possibility that IC 342 X-1, Ho IX X-1, NGC 1313 X-2, and NGC 5204 X-1 are powered by an MSBH.

  13. Dynamical mass of a star cluster in M 83: a test of fibre-fed multi-object spectroscopy

    NARCIS (Netherlands)

    Moll, S.L.; Grijs, R.; Anders, P.; Crowther, P.A.; Larsen, S.S.; Smith, L.J.; Portegies Zwart, S.F.

    2008-01-01

    Aims. We obtained VLT/FLAMES+UVES high-resolution, fibre-fed spectroscopy of five young massive clusters (YMCs) in M 83 (NGC 5236). This forms the basis of a pilot study testing the feasibility of using fibre-fed spectroscopy to measure the velocity dispersions of several clusters simultaneously, in

  14. Dynamical mass of a star cluster in M 83: A test of fibre-fed multi-object spectroscopy

    NARCIS (Netherlands)

    Moll, S.L.; de Grijs, R.; Anders, P.; Crowther, P.A.; Larsen, S.S.; Smith, L.J.; Portegies Zwart, S.F.

    2008-01-01

    Aims. We obtained VLT/FLAMES+UVES high-resolution, fibre-fed spectroscopy of five young massive clusters (YMCs) in M 83 (NGC 5236). This forms the basis of a pilot study testing the feasibility of using fibre-fed spectroscopy to measure the velocity dispersions of several clusters simultaneously, in

  15. Ab initio nonadiabatic dynamics study of ultrafast radiationless decay over conical intersections illustrated on the Na3F cluster

    Czech Academy of Sciences Publication Activity Database

    Mitrić, R.; Bonačič-Koutecký, V.; Pittner, Jiří; Lischka, H.

    2006-01-01

    Roč. 125, č. 2 (2006), 021303 ISSN 0021-9606 Grant - others:Deutsche Forschungsgemeinschaft(DE) SFB 450; Austrian Science Fund(AT) P18411-N19 Institutional research plan: CEZ:AV0Z40400503 Keywords : alkali-halide clusters * optical-responce properties * sodium - fluoride clusters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.166, year: 2006

  16. Vulnerability to alcohol consumption, spiritual transcendence and psychosocial well-being: test of a theory.

    Science.gov (United States)

    Heredia, Luz Patricia Díaz; Sanchez, Alba Idaly Muñoz

    2016-06-07

    to demonstrate the relations among vulnerability, self-transcendence and well-being in the young adult population and the effect of each of these variables on the adoption of low-risk consumption conducts. quantitative and cross-sectional correlation study using structural equations analysis to test the relation among the variables. an inverse relation was evidenced between vulnerability to alcohol consumption and spiritual transcendence (β-0.123, p 0.025) and a direct positive relation between spiritual transcendence and psychosocial well-being (β 0.482, p 0.000). the relations among the variables spiritual transcendence, vulnerability to alcohol consumption and psychosocial well-being, based on Reed's Theory, are confirmed in the population group of young college students, concluding that psychosocial well-being can be achieved when spiritual transcendence is enhanced, as the vulnerability to alcohol consumption drops. demonstrar as relações entre vulnerabilidade, autotranscendência e bem-estar na população adulta jovem e o efeito de cada uma destas variáveis na adoção de condutas de baixo risco de consumo. estudo quantitativo, transversal do tipo correlacional que utilizou a análise estatística de Equações Estruturais para comprovar a relação entre as variáveis. evidenciou-se uma relação inversa entre a vulnerabilidade ao consumo do álcool e a transcendência espiritual (β-0.123, p 0.025) e uma relação direta positiva entre a transcendência espiritual e o bem-estar psicossocial (β 0.482, p 0.000). Conclusões: as relações das variáveis transcendência espiritual, vulnerabilidade ao consumo do álcool e bem-estar psicossocial, fundamentadas na Teoria de Reed, são confirmadas no grupo populacional de jovens adultos universitários, concluindo que é possível alcançar o bem-estar psicossocial quando se incrementa a transcendência espiritual, enquanto a vulnerabilidade ao consumo do álcool se reduz. demostrar las relaciones entre

  17. The relationships between self-transcendence and spiritual well-being in cognitively intact nursing home patients.

    Science.gov (United States)

    Haugan, Gørill; Rannestad, Toril; Hammervold, Randi; Garåsen, Helge; Espnes, Geir A

    2014-03-01

    Self-transcendence is considered a developmental process of personal maturity and a vital resource of well-being in later adulthood. Measurement of the associations between self-transcendence and spiritual well-being in cognitively intact nursing home patients has not been previously published. The aim of this study was to identify the relationships between self-transcendence and spiritual well-being in cognitively intact nursing home patients. A cross-sectional design using the self-transcendence scale and the FACIT-Sp spiritual well-being questionnaire was adopted. A sample of 202 cognitively intact nursing home patients in mid-Norway was selected to respond to the questionnaires in 2008 and 2009. Statistical analyses were conducted using lisrel 8.8 (Scientific Software International, Chicago, IL, USA) and structural equation modelling. A hypothesised structural equation model comprising a two-factor construct of self-transcendence and a three-factor construct of spiritual well-being demonstrated significant direct relationships between self-transcendence and spiritual well-being and total effects of self-transcendence on spiritual