WorldWideScience

Sample records for field parameter sets

  1. A New Parameter Set for the Relativistic Mean Field Theory

    CERN Document Server

    Nerlo-Pomorska, B; Nerlo-Pomorska, Bozena; Sykut, Joanna

    2004-01-01

    Subtracting the Strutinsky shell corrections from the selfconsistent energies obtained within the Relativistic Mean Field Theory (RMFT) we have got estimates for the macroscopic part of the binding energies of 142 spherical even-even nuclei. By minimizing their root mean square deviations from the values obtained with the Lublin-Srasbourg Drop (LSD) model with respect to the nine RMFT parameters we have found the optimal set (NL4). The new parameters reproduce also the radii of these nuclei with an accuracy comparable with that obtained with the NL1 and NL3 sets.

  2. Setting Parameters by Example

    OpenAIRE

    1999-01-01

    We introduce a class of "inverse parametric optimization" problems, in which one is given both a parametric optimization problem and a desired optimal solution; the task is to determine parameter values that lead to the given solution. We describe algorithms for solving such problems for minimum spanning trees, shortest paths, and other "optimal subgraph" problems, and discuss applications in multicast routing, vehicle path planning, resource allocation, and board game programming.

  3. Validation of the GROMOS force-field parameter set 45A3 against nuclear magnetic resonance data of hen egg lysozyme

    Energy Technology Data Exchange (ETDEWEB)

    Soares, T. A. [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland); Daura, X. [Universitat Autonoma de Barcelona, InstitucioCatalana de Recerca i Estudis Avancats and Institut de Biotecnologia i Biomedicina (Spain); Oostenbrink, C. [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland); Smith, L. J. [University of Oxford, Oxford Centre for Molecular Sciences, Central Chemistry Laboratory (United Kingdom); Gunsteren, W. F. van [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland)], E-mail: wfvgn@igc.phys.chem.ethz.ch

    2004-12-15

    The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties about equally well. The 45A3 ensemble fulfills the atom-atom distance bounds derived from NMR spectroscopy slightly less well than the 43A1 ensemble, with most of the NOE distance violations in both ensembles involving residues located in loops or flexible regions of the protein. Convergence patterns are very similar in both simulations atom-positional root-mean-square differences (RMSD) with respect to the X-ray and NMR model structures and NOE inter-proton distances converge within 1.0-1.5 ns while backbone {sup 3}J{sub HN{alpha}}-coupling constants and {sup 1}H- {sup 1}5N order parameters take slightly longer, 1.0-2.0 ns. As expected, side-chain {sup 3}J{sub {alpha}}{sub {beta}}-coupling constants and {sup 1}H- {sup 1}5N order parameters do not reach full convergence for all residues in the time period simulated. This is particularly noticeable for side chains which display rare structural transitions. When comparing each simulation trajectory with an older and a newer set of experimental NOE data on lysozyme, it is found that the newer, larger, set of experimental data agrees as well with each of the

  4. Minimum QOS Parameter Set in Transport Layer

    Institute of Scientific and Technical Information of China (English)

    汪芸; 顾冠群

    1997-01-01

    QOS(Quality Of Service)parameter definitions are the basis of further QOS control.But QOS parameters defined by organizations such as ISO and ITU are incoherent and incompatible.It leads to the imefficiency of QOS controls.Based on the analysis of QOS parameters defined by ISO and ITU,this paper first promotes Minimum QOS Parameter Set in transport layer.It demonstrates that the parameters defined by ISO and ITU can be represented b parameters or a combination of parameters of the Set.The paper also expounds that the Set is open and manageable and it can be the potential unified base for QOS parameters.

  5. Quantum Fields on Causal Sets

    CERN Document Server

    Johnston, Steven

    2010-01-01

    Causal set theory provides a model of discrete spacetime in which spacetime events are represented by elements of a causal set---a locally finite, partially ordered set in which the partial order represents the causal relationships between events. The work presented here describes a model for matter on a causal set, specifically a theory of quantum scalar fields on a causal set spacetime background. The work starts with a discrete path integral model for particles on a causal set. Here quantum mechanical amplitudes are assigned to trajectories within the causal set. By summing these over all trajectories between two spacetime events we obtain a causal set particle propagator. With a suitable choice of amplitudes this is shown to agree (in an appropriate sense) with the retarded propagator for the Klein-Gordon equation in Minkowski spacetime. This causal set propagator is then used to define a causal set analogue of the Pauli-Jordan function that appears in continuum quantum field theories. A quantum scalar fi...

  6. Deriving force field parameters for coordination complexes

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Brandt, Peter

    2001-01-01

    The process of deriving molecular mechanics force fields for coordination complexes is outlined. Force field basics are introduced with an emphasis on special requirements for metal complexes. The review is then focused on how to set up the initial model, define the target, refine the parameters,...

  7. Setting parameters in the cold chain

    Directory of Open Access Journals (Sweden)

    Victoria Rodríguez

    2011-12-01

    Full Text Available Breaks in the cold chain are important economic losses in food and pharmaceutical companies. Many of the failures in the cold chain are due to improper adjustment of equipment parameters such as setting the parameters for theoretical conditions, without a corresponding check in normal operation. The companies that transport refrigeratedproducts must be able to adjust the parameters of the equipment in an easy and quick to adapt their functioning to changing environmental conditions. This article presents the results of a study carried out with a food distribution company. The main objective of the study is to verify the effectiveness of Six Sigma as a methodological toolto adjust the equipment in the cold chain. The second objective is more speciÞ c and is to study the impact of: reducing the volume of storage in the truck, the initial temperature of the storage areain the truck and the frequency of defrost in the transport of refrigerated products.

  8. Fuzzy Set Field and Fuzzy Metric

    OpenAIRE

    Gebru Gebray; B. Krishna Reddy

    2014-01-01

    The notation of fuzzy set field is introduced. A fuzzy metric is redefined on fuzzy set field and on arbitrary fuzzy set in a field. The metric redefined is between fuzzy points and constitutes both fuzziness and crisp property of vector. In addition, a fuzzy magnitude of a fuzzy point in a field is defined.

  9. Setting Parameters for Biological Models With ANIMO

    NARCIS (Netherlands)

    Schivo, Stefano; Scholma, Jetse; Karperien, Hermanus Bernardus Johannes; Post, Janine Nicole; van de Pol, Jan Cornelis; Langerak, Romanus; André, Étienne; Frehse, Goran

    2014-01-01

    ANIMO (Analysis of Networks with Interactive MOdeling) is a software for modeling biological networks, such as e.g. signaling, metabolic or gene networks. An ANIMO model is essentially the sum of a network topology and a number of interaction parameters. The topology describes the interactions

  10. Bayesian parameter estimation for effective field theories

    CERN Document Server

    Wesolowski, S; Furnstahl, R J; Phillips, D R; Thapaliya, A

    2015-01-01

    We present procedures based on Bayesian statistics for effective field theory (EFT) parameter estimation from data. The extraction of low-energy constants (LECs) is guided by theoretical expectations that supplement such information in a quantifiable way through the specification of Bayesian priors. A prior for natural-sized LECs reduces the possibility of overfitting, and leads to a consistent accounting of different sources of uncertainty. A set of diagnostic tools are developed that analyze the fit and ensure that the priors do not bias the EFT parameter estimation. The procedures are illustrated using representative model problems and the extraction of LECs for the nucleon mass expansion in SU(2) chiral perturbation theory from synthetic lattice data.

  11. Bayesian parameter estimation for effective field theories

    Science.gov (United States)

    Wesolowski, S.; Klco, N.; Furnstahl, R. J.; Phillips, D. R.; Thapaliya, A.

    2016-07-01

    We present procedures based on Bayesian statistics for estimating, from data, the parameters of effective field theories (EFTs). The extraction of low-energy constants (LECs) is guided by theoretical expectations in a quantifiable way through the specification of Bayesian priors. A prior for natural-sized LECs reduces the possibility of overfitting, and leads to a consistent accounting of different sources of uncertainty. A set of diagnostic tools is developed that analyzes the fit and ensures that the priors do not bias the EFT parameter estimation. The procedures are illustrated using representative model problems, including the extraction of LECs for the nucleon-mass expansion in SU(2) chiral perturbation theory from synthetic lattice data.

  12. Feminist Economics, Setting out the Parameters

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2010-01-01

    textabstract1. Introduction Feminist economics has developed its position over the past decade, towards a firmer embeddedness in economic science and a source of inspiration for activists, policy makers, and social science researchers in a wide variety of fields of research. This development has com

  13. Models for setting ATM parameter values

    DEFF Research Database (Denmark)

    Blaabjerg, Søren; Gravey, A.; Romæuf, L.

    1996-01-01

    In ATM networks, a user should negotiate at connection set-up a traffic contract which includes traffic characteristics and requested QoS. The traffic characteristics currently considered are the Peak Cell Rate, the Sustainable Cell Rate, the Intrinsic Burst Tolerance and the Cell Delay Variation...... to Network Interface (UNI) and at subsequent Inter Carrier Interfaces (ICIs), by algorithmic rules based on the Generic Cell Rate Algorithm (GCRA) formalism. Conformance rules are implemented by policing mechanisms that control the traffic submitted by the user and discard excess traffic. It is therefore...

  14. On Relative Accessibility Depending on a Set of Parameters

    Institute of Scientific and Technical Information of China (English)

    张明义

    1989-01-01

    Ewa Orlowska[1,2] presented a class of relationsd-accessibiltiy relations determined by a set of parameters.These parameters are a formal counterpart of properties or characteristics of states which are associated by means of accessibility relation.The author has shown how properties of sets of parameters in fluence properties of accessibility relations and given interesting results.In this paper,some further algebraic properties of relative accessibility are discussed.We also give a necessary and sufficient condition,under which the set of accessibility relations({R (p)}pPAR forms a lattice by means of usual set operations.

  15. On Relative Accessibility Depending on a Set of Parameters

    Institute of Scientific and Technical Information of China (English)

    张明义

    1989-01-01

    Ewa Orlowska presented a class of relations-accessibility relatios determined by a set of parameters. These parameters are a formal counterpart of properties or characteristies of states which are associated by meaas of accessibility relation The author bas showu how properties of sets of parameters influence properties of accessibility relations and give in teresting results. In this paper, some fiurther algebraic properties of relative accessibility are diseussed. We also give a necessary and snfticient condition, under which the set of accessibility relations {R(P)} p包含于PAR forms a lattice by means of usual set operations.

  16. Scalar Field Green Functions on Causal Sets

    OpenAIRE

    Ahmed, S. Nomaan; Dowker, Fay; Surya, Sumati

    2017-01-01

    We examine the validity and scope of Johnston's models for scalar field retarded Green functions on causal sets in 2 and 4 dimensions. As in the continuum, the massive Green function can be obtained from the massless one, and hence the key task in causal set theory is to first identify the massless Green function. We propose that the 2-d model provides a Green function for the massive scalar field on causal sets approximated by any topologically trivial 2 dimensional spacetime. We explicitly ...

  17. Parameter information from nonlinear cosmological fields

    CERN Document Server

    Watts, A T P

    2000-01-01

    We develop a general formalism for analysing parameter information from non-Gaussian cosmic fields. The method can be adapted to include the nonlinear effects in galaxy redshift surveys, weak lensing surveys and cosmic velocity field surveys as part of parameter estimation. It can also be used as a test of non-Gaussianity of the Cosmic Microwave Background. Generalising Maximum Likelihood analysis to second-order, we calculate the nonlinear Fisher Information matrix and likelihood surfaces in parameter space. To this order we find that the information content is always increased by including nonlinearity. Our methods are applied to a realistic model of a galaxy redshift survey, including nonlinear evolution, galaxy bias, shot-noise and redshift-space distortions to second-order. We find that including nonlinearities allows all of the degeneracies between parameters to be lifted. Marginalised parameter uncertainties of a few percent will then be obtainable using forthcoming galaxy redshift surveys.

  18. The structure of boundary parameter property satisfying sets

    CERN Document Server

    Whale, B E

    2010-01-01

    Precise definitions of singularities in General Relativity rely on a set of curves. Many boundary constructions force a particular set of curves by virtue of the construction. The abstract boundary, however, allows the set of curves to be chosen. This set, therefore, plays a very important role in the use of the abstract boundary as the definition of a singularity or point at infinity depends on it. The sets of curves used in the abstract boundary must satisfy the boundary parameter property. This property obfuscates the construction of and relationships between these sets of curves. In this paper we lay the ground work for an analysis of these sets of curves by showing that they are in one-to-one correspondence with certain sets of inextendible curves. As an application of this result we show how the usual set operations can be extended to boundary parameter property satisfying sets of curves, allowing for their comparison. These results provide an interpretation of what information boundary parameter proper...

  19. Design of Magnetic Field System for Calutron Ion Source Set

    Institute of Scientific and Technical Information of China (English)

    REN; Xiu-yan; ZENG; Zi-qiang

    2013-01-01

    The Calutron ion source is the most important equipment of EMIS,and the structure of the ion source is more complicated.Because the parameter of each part is interrelate,as experiment and test set,It is very convenient to adjust the parameter of ion source and make the ion source get a good quality.Magnetic field system is the leading and necessary auxiliary equipment of the Calutron ion source

  20. TRAPEZOIDAL PLATE BENDING ELEMENT WITH DOUBLE SET PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    Shao-chun Chen; Dong-yang Shi; I chiro Hagiwara

    2003-01-01

    Using double set parameter method, a 12-parameter trapezoidal plate bending element is presented. The first set of degrees of freedom, which make the element convergent, are the values at the four vertices and the middle points of the four sides together with the mean values of the outer normal derivatives along four sides. The second set of degree of freedom, which make the number of unknowns in the resulting discrete system small and computation convenient are values and the first derivatives at the four vertices of the element. The convergence of the element is proved.

  1. Analytical one parameter method for PID motion controller settings

    NARCIS (Netherlands)

    Dijk, van J.; Aarts, R.G.K.M.

    2012-01-01

    In this paper analytical expressions for PID-controllers settings for electromechanical motion systems are presented. It will be shown that by an adequate frequency domain oriented parametrization, the parameters of a PID-controller are analytically dependent on one variable only, the cross-over fre

  2. Revisiting Boltzmann learning: parameter estimation in Markov random fields

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Andersen, Lars Nonboe; Kjems, Ulrik

    1996-01-01

    This article presents a generalization of the Boltzmann machine that allows us to use the learning rule for a much wider class of maximum likelihood and maximum a posteriori problems, including both supervised and unsupervised learning. Furthermore, the approach allows us to discuss regularization...... and generalization in the context of Boltzmann machines. We provide an illustrative example concerning parameter estimation in an inhomogeneous Markov field. The regularized adaptation produces a parameter set that closely resembles the “teacher” parameters, hence, will produce segmentations that closely reproduce...

  3. Directed Subset Feedback Vertex Set is Fixed-Parameter Tractable

    CERN Document Server

    Chitnis, Rajesh; Hajiaghayi, MohammadTaghi; Marx, Dániel

    2012-01-01

    Given a graph $G$ and an integer $k$, the \\textsc{Feedback Vertex Set} (\\textsc{FVS}) problem asks if there is a vertex set $T$ of size at most $k$ that hits all cycles in the graph. Bodlaender (WG '91) gave the first fixed-parameter algorithm for \\textsc{FVS} in undirected graphs. The fixed-parameter tractability status of \\textsc{FVS} in directed graphs was a long-standing open problem until Chen et al. (STOC '08) showed that it is fixed-parameter tractable by giving an $4^{k}k!n^{O(1)}$ algorithm. In the subset versions of this problems, we are given an additional subset $S$ of vertices (resp. edges) and we want to hit all cycles passing through a vertex of $S$ (resp. an edge of $S$). Indeed both the edge and vertex versions are known to be equivalent in the parameterized sense. Recently the \\textsc{Subset Feedback Vertex Set} in undirected graphs was shown to be FPT by Cygan et al. (ICALP '11) and Kakimura et al. (SODA '12). We generalize the result of Chen et al. (STOC '08) by showing that \\textsc{Subset...

  4. Improved group contribution parameter set for the application of solubility parameters to melt extrusion.

    Science.gov (United States)

    Just, Susann; Sievert, Frank; Thommes, Markus; Breitkreutz, Jörg

    2013-11-01

    Hot-melt extrusion is gaining importance for the production of amorphous solid solutions; in parallel, predictive tools for estimating drug solubility in polymers are increasingly demanded. The Hansen solubility parameter (SP) approach is well acknowledged for its predictive power of the miscibility of liquids as well as the solubility of some amorphous solids in liquid solvents. By solely using the molecular structure, group contribution (GC) methods allow the calculation of Hansen SPs. The GC parameter sets available were derived from liquids and polymers which conflicts with the object of prediction, the solubility of solid drugs. The present study takes a step from the liquid based SPs toward their application to solid solutes. On the basis of published experimental Hansen SPs of solid drugs and excipients only, a new GC parameter set was developed. In comparison with established parameter sets by van Krevelen/Hoftyzer, Beerbower/Hansen, Breitkreutz and Stefanis/Panayiotou, the new GC parameter set provides the highest overall predictive power for solubility experiments (correlation coefficient r = -0.87 to -0.91) as well as for literature data on melt extrudates and casted films (r = -0.78 to -0.96).

  5. Lattice Gauge Field Theory and Prismatic Sets

    DEFF Research Database (Denmark)

    Akyar, Bedia; Dupont, Johan Louis

    We study prismatic sets analogously to simplicial sets except that realization involves prisms, i.e., products of simplices rather than just simplices. Particular examples are the prismatic subdivision of a simplicial set and the prismatic star of . Both have the same homotopy type as and in part......We study prismatic sets analogously to simplicial sets except that realization involves prisms, i.e., products of simplices rather than just simplices. Particular examples are the prismatic subdivision of a simplicial set and the prismatic star of . Both have the same homotopy type...

  6. The Virtual Fields Method Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements

    CERN Document Server

    Pierron, Fabrice

    2012-01-01

    The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is the first book on the Virtual Fields Method (VFM), a technique to identify materials mechanical properties from full-field measurements. Firmly rooted with extensive theoretical description of the method, the book presents numerous examples of application to a wide range of materials (composites, metals, welds, biomaterials) and situations (static, vibration, high strain rate). The authors give a detailed training section with examples of progressive difficulty to lead the reader to program the VFM and include a set of commented Matlab programs as well as GUI Matlab-based software for more general situations. The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is an ideal book for researchers, engineers, and students interested in applying the VFM to new situations motivated by their research.  

  7. Lattice Gauge Field Theory and Prismatic Sets

    DEFF Research Database (Denmark)

    Akyar, Bedia; Dupont, Johan Louis

    as and in particular the latter we use to study lattice gauge theory in the sense of Phillips and Stone. Thus for a Lie group and a set of parallel transport functions defining the transition over faces of the simplices, we define a classifying map from the prismatic star to a prismatic version of the classifying......We study prismatic sets analogously to simplicial sets except that realization involves prisms, i.e., products of simplices rather than just simplices. Particular examples are the prismatic subdivision of a simplicial set and the prismatic star of . Both have the same homotopy type...

  8. Parallel axes gear set optimization in two-parameter space

    Science.gov (United States)

    Theberge, Y.; Cardou, A.; Cloutier, L.

    1991-05-01

    This paper presents a method for optimal spur and helical gear transmission design that may be used in a computer aided design (CAD) approach. The design objective is generally taken as obtaining the most compact set for a given power input and gear ratio. A mixed design procedure is employed which relies both on heuristic considerations and computer capabilities. Strength and kinematic constraints are considered in order to define the domain of feasible designs. Constraints allowed include: pinion tooth bending strength, gear tooth bending strength, surface stress (resistance to pitting), scoring resistance, pinion involute interference, gear involute interference, minimum pinion tooth thickness, minimum gear tooth thickness, and profile or transverse contact ratio. A computer program was developed which allows the user to input the problem parameters, to select the calculation procedure, to see constraint curves in graphic display, to have an objective function level curve drawn through the design space, to point at a feasible design point and to have constraint values calculated at that point. The user can also modify some of the parameters during the design process.

  9. Static Magnetic Field Therapy: A Critical Review of Treatment Parameters

    Directory of Open Access Journals (Sweden)

    Agatha P. Colbert

    2009-01-01

    Full Text Available Static magnetic field (SMF therapy, applied via a permanent magnet attached to the skin, is used by people worldwide for self-care. Despite a lack of established SMF dosage and treatment regimens, multiple studies are conducted to evaluate SMF therapy effectiveness. Our objectives in conducting this review are to: (i summarize SMF research conducted in humans; (ii critically evaluate reporting quality of SMF dosages and treatment parameters and (iii propose a set of criteria for reporting SMF treatment parameters in future clinical trials. We searched 27 electronic databases and reference lists. Only English language human studies were included. Excluded were studies of electromagnetic fields, transcranial magnetic stimulation, magnets placed on acupuncture points, animal studies, abstracts, posters and editorials. Data were extracted on clinical indication, study design and 10 essential SMF parameters. Three reviewers assessed quality of reporting and calculated a quality assessment score for each of the 10 treatment parameters. Fifty-six studies were reviewed, 42 conducted in patient populations and 14 in healthy volunteers. The SMF treatment parameters most often and most completely described were site of application, magnet support device and frequency and duration of application. Least often and least completely described were characteristics of the SMF: magnet dimensions, measured field strength and estimated distance of the magnet from the target tissue. Thirty-four (61% of studies failed to provide enough detail about SMF dosage to permit protocol replication by other investigators. Our findings highlight the need to optimize SMF dosing parameters for individual clinical conditions before proceeding to a full-scale clinical trial.

  10. Frequentist limit setting in effective field theories

    CERN Document Server

    Gregersen, Kristian Damlund

    2015-01-01

    The original frequentist approach for computing confidence intervals involves the construction of the confidence belt which provides a mapping between the true value of the parameter and its maximum likelihood estimator. Alternative methods based on the frequentist idea exist, including the delta likelihood method, the $CL_s$ method and a method here referred to as the $p$-value method, which have all been commonly used in high energy experiments. The purpose of this article is to draw attention to a series of potential problems when applying these alternative methods to the important case where the predicted signal depends quadratically on the parameter of interest, a situation which is common in high energy physics as it covers scenarios encountered in effective theories. These include anomalous Higgs couplings and anomalous trilinear and quartic gauge couplings. It is found that the alternative methods, contrary to the original method using the confidence belt, in general do not manage to correctly describ...

  11. Multivector Fields and Jet Fields Setting Evolution Equations in Field Theories

    CERN Document Server

    Echeverría-Enríquez, A; Román-Roy, N

    1997-01-01

    The integrability of multivector fields in a differentiable manifold is studied. Then, given a jet bundle $J^1E\\to E\\to M$, it is shown that integrable multivector fields in $E$ are equivalent to integrable jet fields in $J^1E$ (connections in $E$). This result is applied to the particular case of multivector fields in the manifold $J^1E$ and jet fields in the repeated jet bundle $J^1J^1E$, in order to characterize integrable multivector fields and jet fields whose integral manifolds are canonical liftings of sections. These results allow us to set the lagrangian evolution equations for first-order classical field theories in three equivalent geometrical ways (in a form similar to that in which the lagrangian dynamical equations of non-autonomous mechanical systems are usually given).

  12. Transmission, Acquisition, Parameter-Setting, Reanalysis, and Language Change

    Science.gov (United States)

    Mufwene, Salikoko S.

    2011-01-01

    Jurgen Meisel's (JM) article is literally thought-provoking, especially for the issues that one can raise out of the central position that he develops, viz., "although bilingual acquisition in situations of language contact can be argued to be of significant importance for explanations of grammatical change, reanalysis affecting parameter settings…

  13. Emergence and spread of antibiotic resistance: setting a parameter space

    OpenAIRE

    Martínez, José Luis; Baquero, Fernando

    2014-01-01

    The emergence and spread of antibiotic resistance among human pathogens is a relevant problem for human health and one of the few evolution processes amenable to experimental studies. In the present review, we discuss some basic aspects of antibiotic resistance, including mechanisms of resistance, origin of resistance genes, and bottlenecks that modulate the acquisition and spread of antibiotic resistance among human pathogens. In addition, we analyse several parameters that modulate the evol...

  14. Emergence and spread of antibiotic resistance: setting a parameter space.

    Science.gov (United States)

    Martínez, José Luis; Baquero, Fernando

    2014-05-01

    The emergence and spread of antibiotic resistance among human pathogens is a relevant problem for human health and one of the few evolution processes amenable to experimental studies. In the present review, we discuss some basic aspects of antibiotic resistance, including mechanisms of resistance, origin of resistance genes, and bottlenecks that modulate the acquisition and spread of antibiotic resistance among human pathogens. In addition, we analyse several parameters that modulate the evolution landscape of antibiotic resistance. Learning why some resistance mechanisms emerge but do not evolve after a first burst, whereas others can spread over the entire world very rapidly, mimicking a chain reaction, is important for predicting the evolution, and relevance for human health, of a given mechanism of resistance. Because of this, we propose that the emergence and spread of antibiotic resistance can only be understood in a multi-parameter space. Measuring the effect on antibiotic resistance of parameters such as contact rates, transfer rates, integration rates, replication rates, diversification rates, and selection rates, for different genes and organisms, growing under different conditions in distinct ecosystems, will allow for a better prediction of antibiotic resistance and possibilities of focused interventions.

  15. Measures and dimensions of fractal sets in local fields

    Institute of Scientific and Technical Information of China (English)

    QIU Hua; SU Weiyi

    2006-01-01

    The study of fractal analysis over the local fields as underline spaces is very important since it can motivate new approaches and new ideas, and discover new techniques in the study of fractals. To study fractal sets in a local field K, in this paper, we define several kinds of fractal measures and dimensions of subsets in K. Some typical fractal sets in K are constructed. We also give out the Hausdorff dimensions and measures, Box-counting dimensions and Packing dimensions, and stress that there exist differences between fractal analysis on local fields and Euclidean spaces. Consequently, the theoretical foundation of fractal analysis on local fields is established.

  16. A SET OF 12-PARAMETER RECTANGULAR PLATE ELEMENT WITH HIGH ACCURACY

    Institute of Scientific and Technical Information of China (English)

    ChenShaochun; LuoLaixing

    1999-01-01

    Abstract. Using the method of undetermined function, a set of 12 parameter rectangular p|atedement with doub[e set parameter and geometry symmetry is constructed. Their consistencyerror are O(h2) , one order higher than the usua[ 12 parameter rectangu|ar p[ate elements.

  17. Level sets and extrema of random processes and fields

    CERN Document Server

    Azais, Jean-Marc

    2009-01-01

    A timely and comprehensive treatment of random field theory with applications across diverse areas of study Level Sets and Extrema of Random Processes and Fields discusses how to understand the properties of the level sets of paths as well as how to compute the probability distribution of its extremal values, which are two general classes of problems that arise in the study of random processes and fields and in related applications. This book provides a unified and accessible approach to these two topics and their relationship to classical theory and Gaussian processes and fields, and the most modern research findings are also discussed. The authors begin with an introduction to the basic concepts of stochastic processes, including a modern review of Gaussian fields and their classical inequalities. Subsequent chapters are devoted to Rice formulas, regularity properties, and recent results on the tails of the distribution of the maximum. Finally, applications of random fields to various areas of mathematics a...

  18. Standard target sets for field sensor performance measurements

    Science.gov (United States)

    O'Connor, John D.; O'Shea, Patrick; Palmer, John E.; Deaver, Dawne M.

    2006-05-01

    The US Army Night Vision and Electronic Sensors Directorate (NVESD) Modeling and Simulation Division develops sensors models (FLIR 92, NV Therm, NV Therm IP) that predict the comparative performance of electro-optical sensors. The NVESD modeling branch developed a 12-vehicle, 12-aspect target signature set in 1998 with a known cycle criteria. It will be referred to as the 12-target set. This 12-target set has and will continue to be the modeling "gold standard" for laboratory human perception experiments supporting sensor performance modeling, and has been employed in dozens of published experiments. The 12-target set is, however, too costly for most acquisition field tests and evaluations. The authors developed an 8-vehicle 3-aspect target set, referred to as the 8- target set, and measured its discrimination task difficulty, (N50 and V50). Target identification (ID) range performance predictions for several sensors were made based on those V50/N50 values. A field collection of the 8-target set using those sensors provided imagery for a human perception study. The human perception study found excellent agreement between predicted and measured range performance. The goal of this development is to create a "silver standard" target set that is as dependable in measuring sensor performance as the "gold standard", and is affordable for Milestone A and other field trials.

  19. Broadband matched-field inversion for shallow water environment parameters

    Institute of Scientific and Technical Information of China (English)

    YANG Kunde; MA Yuanliang

    2003-01-01

    In this paper, broadband multi-frequencies matched-field inversion method is used to determine the environmental parameters in shallow water. According to different conditions, several broadband objective functions are presented. Using ASIAEX2001 experiment data and genetic algorithms, environmental parameters are obtained, especially in sediment.

  20. Parameter estimation of hidden periodic model in random fields

    Institute of Scientific and Technical Information of China (English)

    何书元

    1999-01-01

    Two-dimensional hidden periodic model is an important model in random fields. The model is used in the field of two-dimensional signal processing, prediction and spectral analysis. A method of estimating the parameters for the model is designed. The strong consistency of the estimators is proved.

  1. An Improved Attention Parameter Setting Algorithm Based on Award Learning Mechanism

    Institute of Scientific and Technical Information of China (English)

    Fang Xiuduan; Liu Binhan; Wang Weizhi

    2002-01-01

    The setting of attention parameters plays a role in the performance of synergetic neural network based on PFAP model. This paper first analyzes the attention parameter setting algorithm based on award-penalty learning mechanism. Then, it presents an improved algorithm to overcome its drawbacks. The experimental results demonstrate that the novel algorithm is better than the original one under the same circumstances.

  2. Object–Parameter Approaches to Predicting Unknown Data in an Incomplete Fuzzy Soft Set

    Directory of Open Access Journals (Sweden)

    Liu Yaya

    2017-03-01

    Full Text Available The research on incomplete fuzzy soft sets is an integral part of the research on fuzzy soft sets and has been initiated recently. In this work, we first point out that an existing approach to predicting unknown data in an incomplete fuzzy soft set suffers from some limitations and then we propose an improved method. The hidden information between both objects and parameters revealed in our approach is more comprehensive. Furthermore, based on the similarity measures of fuzzy sets, a new adjustable object-parameter approach is proposed to predict unknown data in incomplete fuzzy soft sets. Data predicting converts an incomplete fuzzy soft set into a complete one, which makes the fuzzy soft set applicable not only to decision making but also to other areas. The compared results elaborated through rate exchange data sets illustrate that both our improved approach and the new adjustable object-parameter one outperform the existing method with respect to forecasting accuracy.

  3. EFFECT OF SETTING THE PARAMETERS OF FLAME WEEDER ON WEED CONTROL EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Miroslav Mojžiš

    2013-12-01

    Full Text Available Unconventional ways of growing plants, when we return to non-chemical methods of controlling weeds, require new weed control methods. One of the few physical methods, which found wider application in practice, is a flame weeder with heat burners based on the use of gas (LPG. However, the process of practical use of this flame weeder has a number of factors that positively or negatively affect the effectiveness of weed control. A precise setting of flame weeders is influenced, for example by weed species, weed growth stage, weather, type of crop grown, but also heat transmission and heat absorption by plant. Many variables that enter into the process must be eliminated for their negative impacts on achieving the best results in fighting against weeds. In this paper, we have focused on naming these parameters, on field trials that confirm the justification of the precise setting of parameters, and recommendations for practice to achieve a higher efficiency of thermal weed control.

  4. The determination of space parameters of the heliostatic collector field

    Directory of Open Access Journals (Sweden)

    Dušan Kudelas

    2006-04-01

    Full Text Available The assurance of perpetual perpendicular insolation of solar collector absorber surface may increase the insolation energy byca 42-45 %.. A consequence of theincrease in the energy production may be the reduction of the solar collectors’ surface area. For the large scale solar collector field conception is advantageous to build collector sections with several collectors in one heliostat. For the conception of the solar collector field with heliostat collectors is important to make a regular identification of space parameters of all parts of the solar system field. The placement of the heliostats is a basic condition for the optimal insolation conditions of heliostat solar collectors’ field.

  5. GRACE gravity field modeling with an investigation on correlation between nuisance parameters and gravity field coefficients

    Science.gov (United States)

    Zhao, Qile; Guo, Jing; Hu, Zhigang; Shi, Chuang; Liu, Jingnan; Cai, Hua; Liu, Xianglin

    2011-05-01

    The GRACE (Gravity Recovery And Climate Experiment) monthly gravity models have been independently produced and published by several research institutions, such as Center for Space Research (CSR), GeoForschungsZentrum (GFZ), Jet Propulsion Laboratory (JPL), Centre National d’Etudes Spatiales (CNES) and Delft Institute of Earth Observation and Space Systems (DEOS). According to their processing standards, above institutions use the traditional variational approach except that the DEOS exploits the acceleration approach. The background force models employed are rather similar. The produced gravity field models generally agree with one another in the spatial pattern. However, there are some discrepancies in the gravity signal amplitude between solutions produced by different institutions. In particular, 10%-30% signal amplitude differences in some river basins can be observed. In this paper, we implemented a variant of the traditional variational approach and computed two sets of monthly gravity field solutions using the data from January 2005 to December 2006. The input data are K-band range-rates (KBRR) and kinematic orbits of GRACE satellites. The main difference in the production of our two types of models is how to deal with nuisance parameters. This type of parameters is necessary to absorb low-frequency errors in the data, which are mainly the aliasing and instrument errors. One way is to remove the nuisance parameters before estimating the geopotential coefficients, called NPARB approach in the paper. The other way is to estimate the nuisance parameters and geopotential coefficients simultaneously, called NPESS approach. These two types of solutions mainly differ in geopotential coefficients from degree 2 to 5. This can be explained by the fact that the nuisance parameters and the gravity field coefficients are highly correlated, particularly at low degrees. We compare these solutions with the official and published ones by means of spectral analysis. It is

  6. Solar flare prediction using highly stressed longitudinal magnetic field parameters

    Institute of Scientific and Technical Information of China (English)

    Xin Huang; Hua-Ning Wang

    2013-01-01

    Three new longitudinal magnetic field parameters are extracted from SOHO/MDI magnetograms to characterize properties of the stressed magnetic field in active regions,and their flare productivities are calculated for 1055 active regions.We find that the proposed parameters can be used to distinguish flaring samples from non-flaring samples.Using the long-term accumulated MDI data,we build the solar flare prediction model by using a data mining method.Furthermore,the decision boundary,which is used to divide flaring from non-flaring samples,is determined by the decision tree algorithm.Finally,the performance of the prediction model is evaluated by 10-fold cross validation technology.We conclude that an efficient solar flare prediction model can be built by the proposed longitudinal magnetic field parameters with the data mining method.

  7. Magnetic field modeling with a set of individual localized coils.

    Science.gov (United States)

    Juchem, Christoph; Nixon, Terence W; McIntyre, Scott; Rothman, Douglas L; de Graaf, Robin A

    2010-06-01

    A set of generic, circular individual coils is shown to be capable of generating highly complex magnetic field distributions in a flexible fashion. Arbitrarily oriented linear field gradients can be generated in three-dimensional as well as sliced volumes at amplitudes that allow imaging applications. The multi-coil approach permits the simultaneous generation of linear MRI encoding fields and complex shim fields by the same setup, thereby reducing system complexity. The choice of the sensitive volume over which the magnetic fields are optimized remains temporally and spatially variable at all times. The restriction of the field synthesis to experimentally relevant, smaller volumes such as single slices directly translates into improved efficiency, i.e. higher magnetic field amplitudes and/or reduced coil currents. For applications like arterial spin labeling, signal spoiling and diffusion weighting, perfect linearity of the gradient fields is not required and reduced demands on accuracy can also be readily translated into improved efficiency. The first experimental realization was achieved for mouse head MRI with 24 coils that were mounted on the surface of a cylindrical former. Oblique linear field gradients of 20 kHz/cm (47 mT/m) were generated with a maximum current of 1.4A which allowed radial imaging of a mouse head. The potential of the new approach for generating arbitrary magnetic field shapes is demonstrated by synthesizing the more complex, higher order spherical harmonic magnetic field distributions X2-Y2, Z2 and Z2X. The new multi-coil approach provides the framework for the integration of conventional imaging and shim coils into a single multi-coil system in which shape, strength, accuracy and spatial coverage of the magnetic field can be specifically optimized for the application at hand.

  8. BF gravity with Immirzi parameter and matter fields

    CERN Document Server

    Montesinos, Merced

    2011-01-01

    We perform the coupling of the scalar, Maxwell, and Yang-Mills as well as the cosmological constant to BF gravity with Immirzi parameter. The proposed action principles employ auxiliary fields in order to keep a polynomial dependence on the two-forms. By handling the equations of motion for the B field and for the auxiliary fields, the latter can be expressed in terms of the physical fields and by substituting these expressions into the original action principles we recover the first-order (Holst) and second-order actions for gravity coupled to the physical matter fields. We consider these results a relevant step towards the understanding of the coupling of matter fields to gravity in the theoretical framework of BF theory.

  9. The Study of the Optimal Parameter Settings in a Hospital Supply Chain System in Taiwan

    Directory of Open Access Journals (Sweden)

    Hung-Chang Liao

    2014-01-01

    Full Text Available This study proposed the optimal parameter settings for the hospital supply chain system (HSCS when either the total system cost (TSC or patient safety level (PSL (or both simultaneously was considered as the measure of the HSCS’s performance. Four parameters were considered in the HSCS: safety stock, maximum inventory level, transportation capacity, and the reliability of the HSCS. A full-factor experimental design was used to simulate an HSCS for the purpose of collecting data. The response surface method (RSM was used to construct the regression model, and a genetic algorithm (GA was applied to obtain the optimal parameter settings for the HSCS. The results show that the best method of obtaining the optimal parameter settings for the HSCS is the simultaneous consideration of both the TSC and the PSL to measure performance. Also, the results of sensitivity analysis based on the optimal parameter settings were used to derive adjustable strategies for the decision-makers.

  10. Stellar magnetic fields from four Stokes parameter observations

    CERN Document Server

    Rusomarov, N; Piskunov, N

    2014-01-01

    Magnetic Doppler imaging from four Stokes parameter observations has uncovered a new level of complexity of stellar magnetic fields previously not known. This new information is of interest to the evolution and structure of magnetic fields of intermediate and high-mass stars. Recently, we performed magnetic Doppler imaging study of the chemically peculiar star HD 24712 using phase-resolved spectropolarimetric observations of line-profiles in all four Stokes parameters. The observations were obtained with the HARPSpol instrument on the 3.6-m ESO telescope. Our analysis shows that the magnetic field of HD 24712 has very strong dipolar component with weak small-scale contributions. The finding of dipole-like field for HD 24712 gives evidence for the hypothesis that old Ap stars have predominantly dipolar magnetic fields. We plan on performing magnetic Doppler imaging from four Stokes parameter observations for other Ap/Bp stars as well, which will help us understand the nature of magnetic fields in these stars.

  11. Magnetopause Reconnection Impact Parameters from Multiple Spacecraft Magnetic Field Measurements

    Science.gov (United States)

    Wendel, Deirdre E.; Reiff, Patricia H.

    2009-01-01

    We present a novel technique that exploits multiple spacecraft data to determine the impact parameters of the most general form of magnetic reconnection at the magnetopause. The method consists of a superposed epoch of multiple spacecraft magnetometer measurements that yields the instantaneous magnetic spatial gradients near a magnetopause reconnection site. The gradients establish the instantaneous positions of the spacecraft relative to the reconnection site. The analysis is well suited to evaluating the spatial scales of singular field line reconnection, which is characterized by a two-dimensional x-type topology adjacent and perpendicular to a reconnecting singular field line. Application of the method to Cluster data known to lie in the vicinity of a northward IMF reconnection site establishes a field topology consistent with singular field line reconnection and a normal magnetic field component of 20 nT. The corresponding current structure consists of a 130 km sheet possibly embedding a thinner. bifurcated sheet.

  12. Controllability of brushite structural parameters using an applied magnetic field.

    Science.gov (United States)

    Kuznetsov, V N; Yanovska, A A; Stanislavov, A S; Danilchenko, S N; Kalinkevich, A N; Sukhodub, L F

    2016-03-01

    The paper studies the influence of low intensity static magnetic field on brushite structural and microstructural parameters using the X-ray diffraction and the transmission electron microscopy. This effect was shown to have various influences on DCPD (Dicalcium Phosphate Dihydrate) structure depending on a magnetic field configuration or time of synthesis, which allows achieving controllability of the main properties of an obtained material. The influence of the magnetic field leads mostly to the decrease of crystallite sizes with no impact on the crystal lattice parameters. In (0 2 0) and (1 5 0) planes the growth of crystallite sizes is observed after 2 and 3 days of crystallization, respectively. The analysis of different contributions to peak broadening in [0 b 0] direction showed a similar trend for the crystallite sizes with the lower lattice microstrains after 2 days of synthesis. The effect similar to the preferred orientation was observed and classified with the Harris method.

  13. Unbounded dynamics and compact invariant sets of one Hamiltonian system defined by the minimally coupled field

    Energy Technology Data Exchange (ETDEWEB)

    Starkov, Konstantin E., E-mail: kstarkov@ipn.mx

    2015-06-12

    In this paper we study some features of global dynamics for one Hamiltonian system arisen in cosmology which is formed by the minimally coupled field; this system was introduced by Maciejewski et al. in 2007. We establish that under some simple conditions imposed on parameters of this system all trajectories are unbounded in both of time directions. Further, we present other conditions for system parameters under which we localize the domain with unbounded dynamics; this domain is defined with help of bounds for values of the Hamiltonian level surface parameter. We describe the case when our system possesses periodic orbits which are found explicitly. In the rest of the cases we get some localization bounds for compact invariant sets. - Highlights: • Domain with unbounded dynamics is localized. • Equations for periodic orbits are given in one level set. • Localizations for compact invariant sets are got.

  14. Determination of the Parameter Sets for the Best Performance of IPS-driven ENLIL Model

    Science.gov (United States)

    Yun, Jongyeon; Choi, Kyu-Cheol; Yi, Jonghyuk; Kim, Jaehun; Odstrcil, Dusan

    2016-12-01

    Interplanetary scintillation-driven (IPS-driven) ENLIL model was jointly developed by University of California, San Diego (UCSD) and National Aeronaucics and Space Administration/Goddard Space Flight Center (NASA/GSFC). The model has been in operation by Korean Space Weather Cetner (KSWC) since 2014. IPS-driven ENLIL model has a variety of ambient solar wind parameters and the results of the model depend on the combination of these parameters. We have conducted researches to determine the best combination of parameters to improve the performance of the IPS-driven ENLIL model. The model results with input of 1,440 combinations of parameters are compared with the Advanced Composition Explorer (ACE) observation data. In this way, the top 10 parameter sets showing best performance were determined. Finally, the characteristics of the parameter sets were analyzed and application of the results to IPS-driven ENLIL model was discussed.

  15. Nonparametric Comparison of Two Dynamic Parameter Setting Methods in a Meta-Heuristic Approach

    Directory of Open Access Journals (Sweden)

    Seyhun HEPDOGAN

    2007-10-01

    Full Text Available Meta-heuristics are commonly used to solve combinatorial problems in practice. Many approaches provide very good quality solutions in a short amount of computational time; however most meta-heuristics use parameters to tune the performance of the meta-heuristic for particular problems and the selection of these parameters before solving the problem can require much time. This paper investigates the problem of setting parameters using a typical meta-heuristic called Meta-RaPS (Metaheuristic for Randomized Priority Search.. Meta-RaPS is a promising meta-heuristic optimization method that has been applied to different types of combinatorial optimization problems and achieved very good performance compared to other meta-heuristic techniques. To solve a combinatorial problem, Meta-RaPS uses two well-defined stages at each iteration: construction and local search. After a number of iterations, the best solution is reported. Meta-RaPS performance depends on the fine tuning of two main parameters, priority percentage and restriction percentage, which are used during the construction stage. This paper presents two different dynamic parameter setting methods for Meta-RaPS. These dynamic parameter setting approaches tune the parameters while a solution is being found. To compare these two approaches, nonparametric statistic approaches are utilized since the solutions are not normally distributed. Results from both these dynamic parameter setting methods are reported.

  16. Sensitivity Analysis of the Optimal Parameter Settings of an LTE Packet Scheduler

    NARCIS (Netherlands)

    Fernandez Diaz, I.; Litjens, R.; Berg, J.L. van den; Dimitrova, D.C.; Spaey, K.

    2010-01-01

    Advanced packet scheduling schemes in 3G/3G+ mobile networks provide one or more parameters to optimise the trade-off between QoS and resource efficiency. In this paper we study the sensitivity of the optimal parameter setting for packet scheduling in LTE radio networks with respect to various traff

  17. Response analysis based on smallest interval-set of parameters for structures with uncertainty

    Institute of Scientific and Technical Information of China (English)

    Xiao-jun WANG; Lei WANG; Zhi-ping QIU

    2012-01-01

    An integral analytic process from quantification to propagation based on limited uncertain parameters is investigated to deal with practical engineering problems.A new method by use of the smallest interval-set/hyper-rectangle containing all experimental data is proposed to quantify the parameter uncertainties. With the smallest parameter interval-set,the uncertainty propagation evaluation of the most favorable response and the least favorable response of the structures is studied based on the interval analysis.The relationship between the proposed interval analysis method (IAM) and the classical IAM is discussed.Two numerical examples are presented to demonstrate the feasibility and validity of the proposed method.

  18. Extended chiral transformations including diquark fields as parameters

    CERN Document Server

    Novozhilov, V Yu; Vasilevich, D V; Novozhilov, Yuri; Pronko, Andrei; Vassilevich, Dmitri

    1994-01-01

    We introduce extended chiral transformation, which depends both on pseudoscalar and diquark fields as parameters and determine its group structure. Assuming soft symmetry breaking in diquark sector, bosonisation of a quasi-Goldstone ud-diquark is performed. In the chiral limit the ud-diquark mass is defined by the gluon condensate, m_{ud}\\approx 300 MeV. The diquark charge radius is \\langle r^2_{ud}\\rangle^{1/2}\\approx 0.5 fm.

  19. Determining material parameters using phase-field simulations and experiments

    DEFF Research Database (Denmark)

    Zhang, Jin; Poulsen, Stefan O.; Gibbs, John W.

    2017-01-01

    A method to determine material parameters by comparing the evolution of experimentally determined 3D microstructures to simulated 3D microstructures is proposed. The temporal evolution of a dendritic solid-liquid mixture is acquired in situ using x-ray tomography. Using a time step from these dat...... variation of the best-fit parameters and the fidelity of the fitting. We find a liquid diffusion coefficient that is different from that measured using directional solidification....... as an initial condition in a phase-field simulation, the computed structure is compared to that measured experimentally at a later time. An optimization technique is used to find the material parameters that yield the best match of the simulated microstructure to the measured microstructure in a global manner...

  20. Determining Relative Importance and Effective Settings for Genetic Algorithm Control Parameters.

    Science.gov (United States)

    Mills, K L; Filliben, J J; Haines, A L

    2015-01-01

    Setting the control parameters of a genetic algorithm to obtain good results is a long-standing problem. We define an experiment design and analysis method to determine relative importance and effective settings for control parameters of any evolutionary algorithm, and we apply this method to a classic binary-encoded genetic algorithm (GA). Subsequently, as reported elsewhere, we applied the GA, with the control parameter settings determined here, to steer a population of cloud-computing simulators toward behaviors that reveal degraded performance and system collapse. GA-steered simulators could serve as a design tool, empowering system engineers to identify and mitigate low-probability, costly failure scenarios. In the existing GA literature, we uncovered conflicting opinions and evidence regarding key GA control parameters and effective settings to adopt. Consequently, we designed and executed an experiment to determine relative importance and effective settings for seven GA control parameters, when applied across a set of numerical optimization problems drawn from the literature. This paper describes our experiment design, analysis, and results. We found that crossover most significantly influenced GA success, followed by mutation rate and population size and then by rerandomization point and elite selection. Selection method and the precision used within the chromosome to represent numerical values had least influence. Our findings are robust over 60 numerical optimization problems.

  1. Massless Dirac fields and Barbero-Immirzi parameter in Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Berredo-Peixoto, Guilherme de; Shapiro, Ilya Lvovich; Souza, Cleber Abrahao de [Universidade Federal de Juiz de Fora (ICE/UFJF), MG (Brazil). Instituto de Ciencias Exatas. Dept. de Fisica

    2011-07-01

    We consider cosmological solution for Einstein gravity with massless fermions with a four-fermion coupling, which emerges from the Holst action and is related to the Barbero-Immirzi (BI) parameter. The gravitational action of this sort is a popular object of investigation in a non-perturbative formalism of quantum gravity. After exploring the consistency conditions for Dirac field within the standard Friedman-Robertson-Walker (FRW) metric, one can rule out some classes of simplest solutions, related to conformal transformation of the field. It can be shown that the Dirac spinor components should be distinct complex functions of time. Finally, the theory with BI parameter and minimally coupling massless Dirac field is equivalent to a perfect fluid with the equation of state p = wρ, with w = 1/7. It is remarkable that the equation of state of the self-interacting spinor matter does not depend on the BI parameter. As a result, the theory does not allow smooth transition to the usual GR without Holst term. (author)

  2. Greedy Set Cover Field Selection for Multi-object Spectroscopy in C++ MPI

    Science.gov (United States)

    Stenborg, T. N.

    2015-09-01

    Multi-object spectrographs allow efficient observation of clustered targets. Observational programs of many targets not encompassed within a telescope's field of view, however, require multiple pointings. Here, a greedy set cover algorithmic approach to efficient field selection in such a scenario is examined. The goal of this approach is not to minimize the total number of pointings needed to cover a given target set, but rather maximize the observational return for a restricted number of pointings. Telescope field of view and maximum targets per field are input parameters, allowing algorithm application to observation planning for the current range of active multi-object spectrographs (e.g. the 2dF/AAOmega, Fiber Large Array Multi Element Spectrograph, Fiber Multi-Object Spectrograph, Hectochelle, Hectospec and Hydra systems), and for any future systems. A parallel version of the algorithm is implemented with the message passing interface, facilitating execution on both shared and distributed memory systems.

  3. Electromagnetic field limits set by the V-Curve.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jorgenson, Roy Eberhardt [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hudson, Howard Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-07-01

    When emitters of electromagnetic energy are operated in the vicinity of sensitive components, the electric field at the component location must be kept below a certain level in order to prevent the component from being damaged, or in the case of electro-explosive devices, initiating. The V-Curve is a convenient way to set the electric field limit because it requires minimal information about the problem configuration. In this report we will discuss the basis for the V-Curve. We also consider deviations from the original V-Curve resulting from inductive versus capacitive antennas, increases in directivity gain for long antennas, decreases in input impedance when operating in a bounded region, and mismatches dictated by transmission line losses. In addition, we consider mitigating effects resulting from limited antenna sizes.

  4. Nonlocal scalar quantum field theory from causal sets

    Science.gov (United States)

    Belenchia, Alessio; Benincasa, Dionigi M. T.; Liberati, Stefano

    2015-03-01

    We study a non-local scalar quantum field theory in flat spacetime derived from the dynamics of a scalar field on a causal set. We show that this non-local QFT contains a continuum of massive modes in any dimension. In 2 dimensions the Hamiltonian is positive definite and therefore the quantum theory is well-defined. In 4-dimensions, we show that the unstable modes of the non-local d'Alembertian are propagated via the so called Wheeler propagator and hence do not appear in the asymptotic states. In the free case studied here the continuum of massive mode are shown to not propagate in the asymptotic states. However the Hamiltonian is not positive definite, therefore potential issues with the quantum theory remain. Finally, we conclude with hints toward what kind of phenomenology one might expect from such non-local QFTs.

  5. Nonlocal Scalar Quantum Field Theory from Causal Sets

    CERN Document Server

    Belenchia, Alessio; Liberati, Stefano

    2014-01-01

    We study a non-local scalar quantum field theory in flat spacetime derived from the dynamics of a scalar field on a causal set. We show that this non-local QFT contains a continuum of massive modes in any dimension. In 2 dimensions the Hamiltonian is positive definite and therefore the quantum theory is well-defined. In 4-dimensions, we show that the unstable modes of the non-local d'Alembertian are propagated via the so called Wheeler propagator and hence do not appear in the asymptotic states. In the free case studied here the continuum of massive mode are shown to not propagate in the asymptotic states. However the Hamiltonian is not positive definite, therefore potential issues with the quantum theory remain. Finally, we conclude with hints toward what kind of phenomenology one might expect from such non-local QFTs.

  6. Optimizations of force-field parameters for protein systems with the secondary-structure stability and instability

    CERN Document Server

    Sakae, Yoshitake

    2013-01-01

    We propose a novel method for refining force-field parameters of protein systems. In this method, the agreement of the secondary-structure stability and instability between the protein conformations obtained by experiments and those obtained by molecular dynamics simulations is used as a criterion for the optimization of force-field parameters. As an example of the applications of the present method, we refined the force-field parameter set of the AMBER ff99SB force field by searching the torsion-energy parameter spaces of $\\psi$ (N-C$^{\\alpha}$-C-N) and $\\zeta$ (C$^{\\beta}$-C$^{\\alpha}$-C-N) of the backbone dihedral angles. We then performed folding simulations of $\\alpha$-helical and $\\beta$-hairpin peptides, using the optimized force field. The results showed that the new force-field parameters gave structures more consistent with the experimental implications than the original AMBER ff99SB force field.

  7. Determination of relevant parameters for the use of electronic dosemeters in pulsed fields of ionising radiation.

    Science.gov (United States)

    Zutz, H; Hupe, O; Ambrosi, P; Klammer, J

    2012-09-01

    Active electronic dosemeters using counting techniques are used for radioprotection purposes in pulsed radiation fields in X-ray diagnostics or therapy. The disadvantage of the limited maximum measurable dose rate becomes significant in these radiation fields and leads to some negative effects. In this study, a set of relevant parameters for a dosemeter is described, which can be used to decide whether it is applicable in a given radiation field or not. The determination of these relevant parameters-maximum measurable dose rate in the radiation pulse, dead time of the dosemeter, indication per counting event and measurement cycle time-is specified. The results of the first measurements on the determination of these parameters for an electronic personal dosemeter of the type Thermo Fisher Scientific EPD Mk2 are shown.

  8. Paramfit: automated optimization of force field parameters for molecular dynamics simulations.

    Science.gov (United States)

    Betz, Robin M; Walker, Ross C

    2015-01-15

    The generation of bond, angle, and torsion parameters for classical molecular dynamics force fields typically requires fitting parameters such that classical properties such as energies and gradients match precalculated quantum data for structures that scan the value of interest. We present a program, Paramfit, distributed as part of the AmberTools software package that automates and extends this fitting process, allowing for simplified parameter generation for applications ranging from single molecules to entire force fields. Paramfit implements a novel combination of a genetic and simplex algorithm to find the optimal set of parameters that replicate either quantum energy or force data. The program allows for the derivation of multiple parameters simultaneously using significantly fewer quantum calculations than previous methods, and can also fit parameters across multiple molecules with applications to force field development. Paramfit has been applied successfully to systems with a sparse number of structures, and has already proven crucial in the development of the Assisted Model Building with Energy Refinement Lipid14 force field.

  9. Barchan dune corridors: Field characterization and investigation of control parameters

    Science.gov (United States)

    Elbelrhiti, H.; Andreotti, B.; Claudin, P.

    2008-06-01

    The structure of the barchan field located between Tarfaya and Laayoune (Atlantic Sahara, Morocco) is quantitatively investigated and compared to that in La Pampa de la Joya (Arequipa, Peru). On the basis of field measurements, we show how the volume, the velocity, and the output sand flux of a dune can be computed from the value of its body and horn widths. The dune size distribution is obtained from the analysis of aerial photographs. It shows that these fields are in a statistically homogeneous state along the wind direction and present a "corridor" structure in the transverse direction, in which the dunes have a rather well selected size. Investigating the possible external parameters controlling these corridors, we demonstrate that none among topography, granulometry, wind, and sand flux is relevant. We finally discuss the dynamical processes at work in these fields (collisions and wind fluctuations) and investigate the way they could regulate the size of the dunes. Furthermore, we show that the overall sand flux transported by a dune field is smaller than the maximum transport that could be reached in the absence of dunes, i.e., in saltation over the solid ground.

  10. Global optimization of parameters in the reactive force field ReaxFF for SiOH.

    Science.gov (United States)

    Larsson, Henrik R; van Duin, Adri C T; Hartke, Bernd

    2013-09-30

    We have used unbiased global optimization to fit a reactive force field to a given set of reference data. Specifically, we have employed genetic algorithms (GA) to fit ReaxFF to SiOH data, using an in-house GA code that is parallelized across reference data items via the message-passing interface (MPI). Details of GA tuning turn-ed out to be far less important for global optimization efficiency than using suitable ranges within which the parameters are varied. To establish these ranges, either prior knowledge can be used or successive stages of GA optimizations, each building upon the best parameter vectors and ranges found in the previous stage. We have finally arrive-ed at optimized force fields with smaller error measures than those published previously. Hence, this optimization approach will contribute to converting force-field fitting from a specialist task to an everyday commodity, even for the more difficult case of reactive force fields.

  11. NATO SET-093 joint field experiment at Bourges, France

    Science.gov (United States)

    Marty, C.; Bruel, F.; Prieur, D.; Naz, P.; Miller, L. S.

    2009-05-01

    This paper describes the NATO Task Group SET-093/RTG53/MSE (referred to as TG-53 in this report) Acoustic Detection of Weapons Firing Joint Field Experiment II conducted at the Etablissement Technique de Bourges (ETBS), Bourges, France, during 16 to 27 June 2008. This field experiment is a follow-on to the NATO TG-53 Acoustic Detection of Weapons Firing Joint Field Experiment I conducted at the Yuma Proving Grounds (YPG), Yuma, Arizona, USA, during 31 October to 4 November 2005 [1]. The objectives of the joint experiment were: (i) to collect acoustic signatures of direct and indirect firings from weapons' such as small arms, mortars, artillery, rockets, and C4 explosives, (ii) to analyze the propagation effects of grassy, wooded, and urban terrains, (iii) to share signatures collected from a variety of acoustic sensors, on the ground and in the air, distributed over a wide area, and (iv) to demonstrate the interoperability of disparate sensors developed by the various nations involved. The participating NATO countries , including France, the Netherlands, the United Kingdom, Canada, and the United States of America, and Israel as well as part of the Mediterranean dialogue countries, deployed nearly 90 sensors and sensor systems over the test range area.

  12. Resonances of a hydrogen atom in strong parallel electric and magnetic fields using B-spline basis sets

    Institute of Scientific and Technical Information of China (English)

    Zhang Yue-Xia; Meng Hui-Yan; Shi Ting-Yun

    2008-01-01

    The B-spline basis set plus complex scaling method is applied to the numerical calculation of the exact resonance parameters Er and I/2 of a hydrogen atom in parallel electric and magnetic fields.The method can calculate the ground and higher excited resonances accurately and efficiently.The resonance parameters with accuracies of 10-9 - 10-12 for hydrogen atom in parallel fields with different field strengths and symmetries are presented and compared with previous ones.Extension to the calculation of Rydberg atom in crossed electric and magnetic fields and of atomic double excited states in external electric fields is discussed.

  13. Bayesian parameter estimation for chiral effective field theory

    Science.gov (United States)

    Wesolowski, Sarah; Furnstahl, Richard; Phillips, Daniel; Klco, Natalie

    2016-09-01

    The low-energy constants (LECs) of a chiral effective field theory (EFT) interaction in the two-body sector are fit to observable data using a Bayesian parameter estimation framework. By using Bayesian prior probability distributions (pdfs), we quantify relevant physical expectations such as LEC naturalness and include them in the parameter estimation procedure. The final result is a posterior pdf for the LECs, which can be used to propagate uncertainty resulting from the fit to data to the final observable predictions. The posterior pdf also allows an empirical test of operator redundancy and other features of the potential. We compare results of our framework with other fitting procedures, interpreting the underlying assumptions in Bayesian probabilistic language. We also compare results from fitting all partial waves of the interaction simultaneously to cross section data compared to fitting to extracted phase shifts, appropriately accounting for correlations in the data. Supported in part by the NSF and DOE.

  14. Crystal Field Parameters and Phase Transitions in ErSb

    DEFF Research Database (Denmark)

    Shapiro, S. M.; Bak, P.

    1975-01-01

    The crystal field levels of the Er ion in a single crystal of ErSb have been measured by inelastic neutron scattering. The crystal field parameters obtained by a least squares fit to the spectra at several temperatures are: B4 = (0·473 ± 0·005) × 10−2°K and B6 = (0·59 ± 0·06) × 10−5°K, which differ...... considerably from the values o by interpolation from measurements on other compounds. In addition the temperature dependence of the magnetic scattering in the vicinity of the Néel temperature (TN = 3·55°K) clearly demonstrates that the transition is second order in contrast to the first order behavior...

  15. Admissible Estimators in the General Multivariate Linear Model with Respect to Inequality Restricted Parameter Set

    Directory of Open Access Journals (Sweden)

    Liu Gang

    2009-01-01

    Full Text Available By using the methods of linear algebra and matrix inequality theory, we obtain the characterization of admissible estimators in the general multivariate linear model with respect to inequality restricted parameter set. In the classes of homogeneous and general linear estimators, the necessary and suffcient conditions that the estimators of regression coeffcient function are admissible are established.

  16. Estimating qualitative parameters for assessment of body balance in a simulated ambulatory setting

    NARCIS (Netherlands)

    Meulen, van Fokke B.; Reenalda, Jasper; Veltink, Peter H.

    2013-01-01

    Continuous daily-life monitoring of balance control of stroke survivors in an ambulatory setting, is essential for optimal guidance of rehabilitation. The purpose of this study is to demonstrate the relation between qualitative parameters of body balance while measuring in stroke patients in a simul

  17. Null subjects: a problem for parameter-setting models of language acquisition.

    Science.gov (United States)

    Valian, V

    1990-05-01

    Some languages, like English, require overt surface subjects, while others, like Italian and Spanish, allow "null" subjects. How does the young child determine whether or not her language allows null subjects? Modern parameter-setting theory has proposed a solution, in which the child begins acquisition with the null subject parameter set for either the English-like value or the Italian-like value. Incoming data, or the absence thereof, force a resetting of the parameter if the original value was incorrect. This paper argues that the single-value solution cannot work, no matter which value is chosen as the initial one, because of inherent limitations in the child's parser, and because of the presence of misleading input. An alternative dual-value solution is proposed, in which the child begins acquisition with both values available, and uses theory-confirmation procedures to decide which value is best supported by the available data.

  18. Solution of distributive problems with synthesis of radar information fields parameters

    Directory of Open Access Journals (Sweden)

    А. В. Нестеров

    1999-05-01

    Full Text Available Considered is the approach to solution of the problems of synthesis of radar and information fields parameters. It is proposed that, as the result of the synthesis, the structure of location of ground radar components should be determined. The optimal location of radar and information system is supposed to be determined by the results of the solution of the distribution problems. Considered are three sets of problems: method of linear programming, method of non-linear programming, method of scanning theory. Described are the distinctive features of each method, their advantages and disadvantages also the groups of determining parameters; an advice is given as to the use of particular approach

  19. Determination of a suitable parameter field for the active fluid jet polishing process

    Science.gov (United States)

    Maurer, Roland; Biskup, Heiko; Trum, Christian; Rascher, Rolf; Wünsche, Christine

    2013-09-01

    In 2012 a well-known company in the field of high precision optics assigned the University of Applied Sciences Deggendorf to determine a suitable parameter field for the active fluid jet polishing (AFJP) process in order to reach a surface accuracy of at least lambda / 5. The active fluid jet polishing is a relatively new and an affordable sub-aperture polishing process. For a fast and precise identification of the parameter field a considered design of experiment is necessary. The available control variables were the rotational speed of the nozzle, the distance between the test object and the jet, the feed rate, the material of the pin inside the nozzle and the material of the test object itself. In order to reach a significant data density on the one hand and to minimize the number of test runs on the other hand a meander shaped tool path was chosen. At each blank nine paths had been driven whereby at each path another parameter combination was picked. Thus with only one test object nine parameter settings may be evaluated. For the automatized analysis of the tracks a software tool was developed. The software evaluates ten sections which orthogonally intersect the nine tracks on the test-lens. The significant measurement parameters per section are the width and the height of each path as well as the surface roughness within the polished tracks. With the aid of these parameters and further statistical evaluations a suitable parameter field for the goal to find a constant and predictable removal spot was determined. Furthermore up to now over 60 test runs have been successfully finished with nine parameter combinations in each case. As a consequence a test evaluation by hand would be very time-consuming and the software facilitates it dramatically.

  20. Near-field focusing of dielectric microspheres: Super-resolution and field-invariant parameter scaling

    CERN Document Server

    Wang, Zengbo

    2013-01-01

    Optical near-fields of small dielectric particles are of particular importance and interests for nanoscale optical engineering such as field localization, fabrication, characterization, sensing and imaging. This paper represents a systematic investigation on the focusing characteristics (focal length, field enhancement, spot size) for a given refractive-index microsphere (n=1.6) with a varying size parameter pifield-invariant parameters scaling (size, wavelength, and refractive index) were revealed and demonstrated with example cases. It offers the new freedom to choose particles and background medium to gai...

  1. Evolving Non-Dominated Parameter Sets for Computational Models from Multiple Experiments

    Science.gov (United States)

    Lane, Peter C. R.; Gobet, Fernand

    2013-03-01

    Creating robust, reproducible and optimal computational models is a key challenge for theorists in many sciences. Psychology and cognitive science face particular challenges as large amounts of data are collected and many models are not amenable to analytical techniques for calculating parameter sets. Particular problems are to locate the full range of acceptable model parameters for a given dataset, and to confirm the consistency of model parameters across different datasets. Resolving these problems will provide a better understanding of the behaviour of computational models, and so support the development of general and robust models. In this article, we address these problems using evolutionary algorithms to develop parameters for computational models against multiple sets of experimental data; in particular, we propose the `speciated non-dominated sorting genetic algorithm' for evolving models in several theories. We discuss the problem of developing a model of categorisation using twenty-nine sets of data and models drawn from four different theories. We find that the evolutionary algorithms generate high quality models, adapted to provide a good fit to all available data.

  2. Quantitative genetic analysis of chlorophyll a fluorescence parameters in maize in the field environments

    Institute of Scientific and Technical Information of China (English)

    Domagojimi; Hrvoje Lepedu; Vlatka Jurkovi; Jasenka Antunovi; Vera Cesar

    2014-01-01

    Chlorophyl fluorescence transient from initial to maximum fluorescence (“P”step) throughout two intermedi-ate steps (“J”and“I”) (JIP-test) is considered a reliable early quantitative indicator of stress in plants. The JIP-test is particularly useful for crop plants when applied in variable field environments. The aim of the present study was to conduct a quantitative trait loci (QTL) analysis for nine JIP-test parameters in maize during flowering in four field environ-ments differing in weather conditions. QTL analysis and identification of putative candidate genes might help to explain the genetic relationship between photosynthesis and different field scenarios in maize plants. The JIP-test param-eters were analyzed in the intermated B73 ? Mo17 (IBM) maize population of 205 recombinant inbred lines. A set of 2,178 molecular markers across the whole maize genome was used for QTL analysis revealing 10 significant QTLs for seven JIP-test parameters, of which five were co-localized when combined over the four environments indicating polygenic inheritance and pleiotropy. Our results demonstrate that QTL analysis of chlorophyl fluorescence parameters was capable of detecting one pleiotropic locus on chromosome 7, coinciding with the gene gst23 that may be associated with efficient photosynthe-sis under different field scenarios.

  3. A set of nearest neighbor parameters for predicting the enthalpy change of RNA secondary structure formation.

    Science.gov (United States)

    Lu, Zhi John; Turner, Douglas H; Mathews, David H

    2006-01-01

    A complete set of nearest neighbor parameters to predict the enthalpy change of RNA secondary structure formation was derived. These parameters can be used with available free energy nearest neighbor parameters to extend the secondary structure prediction of RNA sequences to temperatures other than 37 degrees C. The parameters were tested by predicting the secondary structures of sequences with known secondary structure that are from organisms with known optimal growth temperatures. Compared with the previous set of enthalpy nearest neighbor parameters, the sensitivity of base pair prediction improved from 65.2 to 68.9% at optimal growth temperatures ranging from 10 to 60 degrees C. Base pair probabilities were predicted with a partition function and the positive predictive value of structure prediction is 90.4% when considering the base pairs in the lowest free energy structure with pairing probability of 0.99 or above. Moreover, a strong correlation is found between the predicted melting temperatures of RNA sequences and the optimal growth temperatures of the host organism. This indicates that organisms that live at higher temperatures have evolved RNA sequences with higher melting temperatures.

  4. Influence of Weaving Loom Setting Parameters on Changes of Woven Fabric Structure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Aušra ADOMAITIENĖ

    2011-11-01

    Full Text Available During the manufacturing of fabric of different raw material there was noticed, that after removing the fabric from weaving loom and after stabilization of fabric structure, the changes of parameters of fabric structure are not regular. During this investigation it was analysed, how weaving loom technological parameters (heald cross moment and initial tension of warp should be chosen and how to predict the changes of fabric structure parameters and its mechanical properties. The dependencies of changes of half-wool fabric structure parameters (weft setting, fabric thickness and projections of fabric cross-section and mechanical properties (breaking force, elongation at break, static friction force and static friction coefficient on weaving loom setting parameters (heald cross moment and initial warp tension were analysed. The orthogonal Box plan of two factors was used, the 3-D dependencies were drawn, and empirical equations of these dependencies were established.http://dx.doi.org/10.5755/j01.ms.17.4.780

  5. Forecasting with the Fokker-Planck model: Bayesian setting of parameter

    Science.gov (United States)

    Montagnon, Chris

    2017-04-01

    Using a closed solution to a Fokker-Planck model of a time series, a probability distribution for the next point in the time series is developed. This probability distribution has one free parameter. Various Bayesian approaches to setting this parameter are tested by forecasting some real world time series. Results show a more than 25 % reduction in the ' 95 % point' of the probability distribution (the safety stock required in these real world situations), versus the conventional ARMA approach, without a significant increase in actuals exceeding this level.

  6. La Shalle's invariant-set-theory based asymptotic synchronization of duffing system with unknown parameters

    Institute of Scientific and Technical Information of China (English)

    Yu Dong-Chuan; Wu Ai-Guo

    2006-01-01

    A novel La Shalle's invariant set theory (LSIST) based adaptive asymptotic synchronization (LSISAAS) method is proposed to asymptotically synchronize Duffing system with unknown parameters which also are considered as system states. The LSISASS strategy depends on the only information, i.e. one state of the master system. According to the LSIST, the LSISASS method can asymptotically synchronize fully the states of the master system and the unknown system parameters as well. Simulation results also validate that the LSISAAS approach can obtain asymptotic synchronization.

  7. Optimization of Saturn paraboloid magnetospheric field model parameters using Cassini equatorial magnetic field data

    Science.gov (United States)

    Belenkaya, Elena S.; Kalegaev, Vladimir V.; Cowley, Stanley W. H.; Provan, Gabrielle; Blokhina, Marina S.; Barinov, Oleg G.; Kirillov, Alexander A.; Grigoryan, Maria S.

    2016-07-01

    The paraboloid model of Saturn's magnetosphere describes the magnetic field as being due to the sum of contributions from the internal field of the planet, the ring current, and the tail current, all contained by surface currents inside a magnetopause boundary which is taken to be a paraboloid of revolution about the planet-Sun line. The parameters of the model have previously been determined by comparison with data from a few passes through Saturn's magnetosphere in compressed and expanded states, depending on the prevailing dynamic pressure of the solar wind. Here we significantly expand such comparisons through examination of Cassini magnetic field data from 18 near-equatorial passes that span wide ranges of local time, focusing on modelling the co-latitudinal field component that defines the magnetic flux passing through the equatorial plane. For 12 of these passes, spanning pre-dawn, via noon, to post-midnight, the spacecraft crossed the magnetopause during the pass, thus allowing an estimate of the concurrent subsolar radial distance of the magnetopause R1 to be made, considered to be the primary parameter defining the scale size of the system. The best-fit model parameters from these passes are then employed to determine how the parameters vary with R1, using least-squares linear fits, thus providing predictive model parameters for any value of R1 within the range. We show that the fits obtained using the linear approximation parameters are of the same order as those for the individually selected parameters. We also show that the magnetic flux mapping to the tail lobes in these models is generally in good accord with observations of the location of the open-closed field line boundary in Saturn's ionosphere, and the related position of the auroral oval. We then investigate the field data on six passes through the nightside magnetosphere, for which the spacecraft did not cross the magnetopause, such that in this case we compare the observations with three

  8. Evaluating climate model performance with various parameter sets using observations over the recent past

    Directory of Open Access Journals (Sweden)

    M. F. Loutre

    2011-05-01

    Full Text Available Many sources of uncertainty limit the accuracy of climate projections. Among them, we focus here on the parameter uncertainty, i.e. the imperfect knowledge of the values of many physical parameters in a climate model. Therefore, we use LOVECLIM, a global three-dimensional Earth system model of intermediate complexity and vary several parameters within a range based on the expert judgement of model developers. Nine climatic parameter sets and three carbon cycle parameter sets are selected because they yield present-day climate simulations coherent with observations and they cover a wide range of climate responses to doubled atmospheric CO2 concentration and freshwater flux perturbation in the North Atlantic. Moreover, they also lead to a large range of atmospheric CO2 concentrations in response to prescribed emissions. Consequently, we have at our disposal 27 alternative versions of LOVECLIM (each corresponding to one parameter set that provide very different responses to some climate forcings. The 27 model versions are then used to illustrate the range of responses provided over the recent past, to compare the time evolution of climate variables over the time interval for which they are available (the last few decades up to more than one century and to identify the outliers and the "best" versions over that particular time span. For example, between 1979 and 2005, the simulated global annual mean surface temperature increase ranges from 0.24 °C to 0.64 °C, while the simulated increase in atmospheric CO2 concentration varies between 40 and 50 ppmv. Measurements over the same period indicate an increase in global annual mean surface temperature of 0.45 °C (Brohan et al., 2006 and an increase in atmospheric CO2 concentration of 44 ppmv (Enting et al., 1994; GLOBALVIEW-CO2, 2006. Only a few parameter sets yield simulations that reproduce the observed key variables of the climate system over the last

  9. Assessment of Governor Control Parameter Settings of a Submarine Diesel Engine

    Science.gov (United States)

    2013-03-01

    University of Technology 15. Ogata , K. (1997) Modern control engineering. Upper Saddle River, NJ, Prentice-Hall 16. DiStephano, J., Stubberud, A. and...UNCLASSIFIED Assessment of Governor Control Parameter Settings of a Submarine Diesel Engine Peter Hield and Michael Newman...generators to provide power for propulsion and the hotel load. The governor, often a proportional-integral controller , attempts to maintain a constant

  10. A new LPV modeling approach using PCA-based parameter set mapping to design a PSS.

    Science.gov (United States)

    Jabali, Mohammad B Abolhasani; Kazemi, Mohammad H

    2017-01-01

    This paper presents a new methodology for the modeling and control of power systems based on an uncertain polytopic linear parameter-varying (LPV) approach using parameter set mapping with principle component analysis (PCA). An LPV representation of the power system dynamics is generated by linearization of its differential-algebraic equations about the transient operating points for some given specific faults containing the system nonlinear properties. The time response of the output signal in the transient state plays the role of the scheduling signal that is used to construct the LPV model. A set of sample points of the dynamic response is formed to generate an initial LPV model. PCA-based parameter set mapping is used to reduce the number of models and generate a reduced LPV model. This model is used to design a robust pole placement controller to assign the poles of the power system in a linear matrix inequality (LMI) region, such that the response of the power system has a proper damping ratio for all of the different oscillation modes. The proposed scheme is applied to controller synthesis of a power system stabilizer, and its performance is compared with a tuned standard conventional PSS using nonlinear simulation of a multi-machine power network. The results under various conditions show the robust performance of the proposed controller.

  11. Fault Detection of Wind Turbines with Uncertain Parameters: A Set-Membership Approach

    Directory of Open Access Journals (Sweden)

    Thomas Bak

    2012-07-01

    Full Text Available In this paper a set-membership approach for fault detection of a benchmark wind turbine is proposed. The benchmark represents relevant fault scenarios in the control system, including sensor, actuator and system faults. In addition we also consider parameter uncertainties and uncertainties on the torque coefficient. High noise on the wind speed measurement, nonlinearities in the aerodynamic torque and uncertainties on the parameters make fault detection a challenging problem. We use an effective wind speed estimator to reduce the noise on the wind speed measurements. A set-membership approach is used generate a set that contains all states consistent with the past measurements and the given model of the wind turbine including uncertainties and noise. This set represents all possible states the system can be in if not faulty. If the current measurement is not consistent with this set, a fault is detected. For representation of these sets we use zonotopes and for modeling of uncertainties we use matrix zonotopes, which yields a computationally efficient algorithm. The method is applied to the wind turbine benchmark problem without and with uncertainties. The result demonstrates the effectiveness of the proposed method compared to other proposed methods applied to the same problem. An advantage of the proposed method is that there is no need for threshold design, and it does not produce positive false alarms. In the case where uncertainty on the torque lookup table is introduced, some faults are not detectable. Previous research has not addressed this uncertainty. The method proposed here requires equal or less detection time than previous results.

  12. Effective field theory in time-dependent settings

    CERN Document Server

    Collins, Hael; Ross, Andreas

    2012-01-01

    We use the in-in or Schwinger-Keldysh formalism to explore the construction and interpretation of effective field theories for time-dependent systems evolving out of equilibrium. Starting with a simple model consisting of a heavy and a light scalar field taken to be in their free vacuum states at a finite initial time, we study the effects from the heavy field on the dynamics of the light field by analyzing the equation of motion for the expectation value of the light background field. New terms appear which cannot arise from a local action of an effective field theory in terms of the light field, though they disappear in the adiabatic limit. We discuss the origins of these terms as well as their possible implications for time dependent situations such as inflation.

  13. Moving to continuous facial expression space using the MPEG-4 facial definition parameter (FDP) set

    Science.gov (United States)

    Karpouzis, Kostas; Tsapatsoulis, Nicolas; Kollias, Stefanos D.

    2000-06-01

    Research in facial expression has concluded that at least six emotions, conveyed by human faces, are universally associated with distinct expressions. Sadness, anger, joy, fear, disgust and surprise are categories of expressions that are recognizable across cultures. In this work we form a relation between the description of the universal expressions and the MPEG-4 Facial Definition Parameter Set (FDP). We also investigate the relation between the movement of basic FDPs and the parameters that describe emotion-related words according to some classical psychological studies. In particular Whissel suggested that emotions are points in a space, which seem to occupy two dimensions: activation and evaluation. We show that some of the MPEG-4 Facial Animation Parameters (FAPs), approximated by the motion of the corresponding FDPs, can be combined by means of a fuzzy rule system to estimate the activation parameter. In this way variations of the six archetypal emotions can be achieved. Moreover, Plutchik concluded that emotion terms are unevenly distributed through the space defined by dimensions like Whissel's; instead they tend to form an approximately circular pattern, called 'emotion wheel,' modeled using an angular measure. The 'emotion wheel' can be defined as a reference for creating intermediate expressions from the universal ones, by interpolating the movement of dominant FDP points between neighboring basic expressions. By exploiting the relation between the movement of the basic FDP point and the activation and angular parameters we can model more emotions than the primary ones and achieve efficient recognition in video sequences.

  14. Indecomposability parameters in chiral Logarithmic Conformal Field Theory

    CERN Document Server

    Vasseur, Romain; Saleur, Hubert

    2011-01-01

    Work of the last few years has shown that the key algebraic features of Logarithmic Conformal Field Theories (LCFTs) are already present in some finite lattice systems (such as the XXZ spin-1/2 chain) before the continuum limit is taken. This has provided a very convenient way to analyze the structure of indecomposable Virasoro modules and to obtain fusion rules for a variety of models such as (boundary) percolation etc. LCFTs allow for additional quantum numbers describing the fine structure of the indecomposable modules, and generalizing the `b-number' introduced initially by Gurarie for the c=0 case. The determination of these indecomposability parameters has given rise to a lot of algebraic work, but their physical meaning has remained somewhat elusive. In a recent paper, a way to measure b for boundary percolation and polymers was proposed. We generalize this work here by devising a general strategy to compute matrix elements of Virasoro generators from the numerical analysis of lattice models and their ...

  15. Invariant sets techniques for Youla-Kučera parameter synthesis

    Science.gov (United States)

    Luca, Anamaria; Rodriguez-Ayerbe, Pedro; Dumur, Didier

    2011-09-01

    This article addresses an invariant sets approach for Youla-Kučera parameter synthesis using linear matrix inequality (LMI) techniques. Given a linear discrete-time observer-based system affected by bounded disturbances and constraints, the proposed technique furnishes the best Youla parameter in terms of finding an invariant ellipsoidal set satisfying the constraints and having the maximal ellipsoidal projection on the state space. Compared with the results obtained for an observer-based design, the synthesis of a Youla parameter provides a larger ellipsoidal projection and an improved sensitivity function. The price to pay for these achievements in terms of robustness is usually a slow closed-loop performance with degraded complementary sensitivity function. In order to obtain a compromise between robustness and performance two methods are proposed: the first method imposes a new bound on the Lyapunov function decreasing speed and the second refers to the pole placement concept. The aforementioned approaches are finally validated in simulation considering position control of an induction motor.

  16. Feynman propagator for a free scalar field on a causal set.

    Science.gov (United States)

    Johnston, Steven

    2009-10-30

    The Feynman propagator for a free bosonic scalar field on the discrete spacetime of a causal set is presented. The formalism includes scalar field operators and a vacuum state which define a scalar quantum field theory on a causal set. This work can be viewed as a novel regularization of quantum field theory based on a Lorentz invariant discretization of spacetime.

  17. Ground-based infrared surveys: imaging the thermal fields at volcanoes and revealing the controlling parameters.

    Science.gov (United States)

    Pantaleo, Michele; Walter, Thomas

    2013-04-01

    Temperature monitoring is a widespread procedure in the frame of volcano hazard monitoring. Indeed temperature changes are expected to reflect changes in volcanic activity. We propose a new approach, within the thermal monitoring, which is meant to shed light on the parameters controlling the fluid pathways and the fumarole sites by using infrared measurements. Ground-based infrared cameras allow one to remotely image the spatial distribution, geometric pattern and amplitude of fumarole fields on volcanoes at metre to centimetre resolution. Infrared mosaics and time series are generated and interpreted, by integrating geological field observations and modeling, to define the setting of the volcanic degassing system at shallow level. We present results for different volcano morphologies and show that lithology, structures and topography control the appearance of fumarole field by the creation of permeability contrasts. We also show that the relative importance of those parameters is site-dependent. Deciphering the setting of the degassing system is essential for hazard assessment studies because it would improve our understanding on how the system responds to endogenous or exogenous modification.

  18. Optimizing Design Parameters for Sets of Concentric Tube Robots using Sampling-based Motion Planning

    OpenAIRE

    Baykal, Cenk; Torres, Luis G.; Alterovitz, Ron

    2015-01-01

    Concentric tube robots are tentacle-like medical robots that can bend around anatomical obstacles to access hard-to-reach clinical targets. The component tubes of these robots can be swapped prior to performing a task in order to customize the robot’s behavior and reachable workspace. Optimizing a robot’s design by appropriately selecting tube parameters can improve the robot’s effectiveness on a procedure-and patient-specific basis. In this paper, we present an algorithm that generates sets ...

  19. On the Dimension of Sliced Measures and the Set of Exceptional Parameters

    CERN Document Server

    Orponen, Tuomas

    2010-01-01

    Let $(\\Omega,d)$ be a compact separable metric space, let $B \\subset \\Omega$ be a Borel set with $\\dim B > 1$, and let $\\pi_{\\lambda} \\colon \\Omega \\to \\R$, $\\lambda \\in J$, be a family of Lipschitz-mappings parametrised by an open interval $J \\subset \\R$. We consider some sufficient conditions for the mappings $\\pi_{\\lambda}$ under which, for almost all parameters $\\lambda \\in J$, it holds that $\\dim [B \\cap \\pi_{\\lambda}^{-1}\\{t\\}] = \\dim B - 1$ for $\\calL^{1}$ positively many points $t \\in \\R$. More precisely, we show that, under our hypotheses on the mappings $\\pi_{\\lambda}$, this happens for every $\\lambda \\in J \\setminus E$, where $E \\subset J$ is an exceptional set of dimension $\\dim E \\leq 2 - \\dim B$. We also indicate that this estimate cannot be improved.

  20. Setting prudent public health policy for electromagnetic field exposures.

    Science.gov (United States)

    Carpenter, David O; Sage, Cindy

    2008-01-01

    Electromagnetic fields (EMF) permeate our environment, coming both from such natural sources as the sun and from manmade sources like electricity, communication technologies and medical devices. Although life on earth would not be possible without sunlight, increasing evidence indicates that exposures to the magnetic fields associated with electricity and to communication frequencies associated with radio, television, WiFi technology, and mobile cellular phones pose significant hazards to human health. The evidence is strongest for leukemia from electricity-frequency fields and for brain tumors from communication-frequency fields, yet evidence is emerging for an association with other diseases as well, including neurodegenerative diseases. Some uncertainty remains as to the mechanism(s) responsible for these biological effects, and as to which components of the fields are of greatest importance. Nevertheless, regardless of whether the associations are causal, the strengths of the associations are sufficiently strong that in the opinion of the authors, taking action to reduce exposures is imperative, especially for the fetus and children. Inaction is not compatible with the Precautionary Principle, as enunciated by the Rio Declaration. Because of ubiquitous exposure, the rapidly expanding development of new EMF technologies and the long latency for the development of such serious diseases as brain cancers, the failure to take immediate action risks epidemics of potentially fatal diseases in the future.

  1. Validation and Parameter Sensitivity Tests for Reconstructing Swell Field Based on an Ensemble Kalman Filter

    Science.gov (United States)

    Wang, Xuan; Tandeo, Pierre; Fablet, Ronan; Husson, Romain; Guan, Lei; Chen, Ge

    2016-01-01

    The swell propagation model built on geometric optics is known to work well when simulating radiated swells from a far located storm. Based on this simple approximation, satellites have acquired plenty of large samples on basin-traversing swells induced by fierce storms situated in mid-latitudes. How to routinely reconstruct swell fields with these irregularly sampled observations from space via known swell propagation principle requires more examination. In this study, we apply 3-h interval pseudo SAR observations in the ensemble Kalman filter (EnKF) to reconstruct a swell field in ocean basin, and compare it with buoy swell partitions and polynomial regression results. As validated against in situ measurements, EnKF works well in terms of spatial–temporal consistency in far-field swell propagation scenarios. Using this framework, we further address the influence of EnKF parameters, and perform a sensitivity analysis to evaluate estimations made under different sets of parameters. Such analysis is of key interest with respect to future multiple-source routinely recorded swell field data. Satellite-derived swell data can serve as a valuable complementary dataset to in situ or wave re-analysis datasets. PMID:27898005

  2. Validation and Parameter Sensitivity Tests for Reconstructing Swell Field Based on an Ensemble Kalman Filter.

    Science.gov (United States)

    Wang, Xuan; Tandeo, Pierre; Fablet, Ronan; Husson, Romain; Guan, Lei; Chen, Ge

    2016-11-25

    The swell propagation model built on geometric optics is known to work well when simulating radiated swells from a far located storm. Based on this simple approximation, satellites have acquired plenty of large samples on basin-traversing swells induced by fierce storms situated in mid-latitudes. How to routinely reconstruct swell fields with these irregularly sampled observations from space via known swell propagation principle requires more examination. In this study, we apply 3-h interval pseudo SAR observations in the ensemble Kalman filter (EnKF) to reconstruct a swell field in ocean basin, and compare it with buoy swell partitions and polynomial regression results. As validated against in situ measurements, EnKF works well in terms of spatial-temporal consistency in far-field swell propagation scenarios. Using this framework, we further address the influence of EnKF parameters, and perform a sensitivity analysis to evaluate estimations made under different sets of parameters. Such analysis is of key interest with respect to future multiple-source routinely recorded swell field data. Satellite-derived swell data can serve as a valuable complementary dataset to in situ or wave re-analysis datasets.

  3. Use of transformed data sets in examination of relationship between growth of trees and weather parameters

    Directory of Open Access Journals (Sweden)

    Márton Edelényi

    2011-11-01

    Full Text Available Analysing and stability improving methods were studied for the examination of relationships between tree growth and meteorological factors according to our requirements. In order to explore more complex relations from primary data sets secondary data series had to be systematically transformed and a uniform analysis process was developed for their investigation. The structure of the Systematic Transformation Analysing Method (STAM has three main components. The first module derives input data from the original series without any essential changes. The transformation unit produces secondary data series using a moving window technique. The thirds component performs the examinations. STAM also allows the application in several other research fields.

  4. The dependence of the abstract boundary classification on a set of curves II: How the classification changes when the bounded parameter property satisfying set of curves changes

    CERN Document Server

    Whale, B E

    2012-01-01

    The abstract boundary uses sets of curves with the bounded parameter property (b.p.p.) to classify the elements of the abstract boundary into regular points, singular points, points at infinity and so on. Building on the material of Part one of this two part series, we show how this classification changes when the set of b.p.p. satisfying curves changes.

  5. Planning and setting objectives in field studies: Chapter 2

    Science.gov (United States)

    Fisher, Robert N.; Dodd, C. Kenneth

    2016-01-01

    This chapter enumerates the steps required in designing and planning field studies on the ecology and conservation of reptiles, as these involve a high level of uncertainty and risk. To this end, the chapter differentiates between goals (descriptions of what one intends to accomplish) and objectives (the measurable steps required to achieve the established goals). Thus, meeting a specific goal may require many objectives. It may not be possible to define some of them until certain experiments have been conducted; often evaluations of sampling protocols are needed to increase certainty in the biological results. And if sampling locations are fixed and sampling events are repeated over time, then both study-specific covariates and sampling-specific covariates should exist. Additionally, other critical design considerations for field study include obtaining permits, as well as researching ethics and biosecurity issues.

  6. Distributional Dimension of Fractal Sets in Local Fields

    Institute of Scientific and Technical Information of China (English)

    Hua QIU; Wei Yi SU

    2008-01-01

    The distributional dimension of fractal sets in Rn has been systematically studied by Triebel by virtue of the theory of function spaces.In this paper,we .rst discuss some important properties about the B type spaces and the F type spaces on local .elds,then we give the de .nition of the distributional dimension dim D in local .elds and study the relations between distributional dimension and Hausdor .dimension.Moreover,the analysis expression of the Hausdor .dimension is given.Lastly,we de .ne the Fourier dimension in local .elds,and obtain the relations among all the three dimensions.

  7. Structural parameter for estimating durability of composite materials with polymer components in strong electric fields

    Science.gov (United States)

    Minakova, N. N.; Ushakov, V. Ya.

    2016-11-01

    The purpose of the present work is to reveal and to substantiate the structural parameter for estimation of the durability of composite materials with polymeric components in strong electric fields. Rubbers filled with technical carbon are chosen as objects of research. They possess almost zero water absorption, resistance to aggressive media, high electrical and mechanical strengths, capability of acquiring practically any form, etc. Because of this, they are widely used in high-voltage electrophysics and electrical engineering. Composite materials are represented by an equivalent circuit of a series-parallel connection of a set of individual contacts conductive phase-dielectric-conductive phase formed by an electroconductive grid. The processes in the materials are considered on three hierarchical levels: individual contact conductive phase-dielectric-conductive phase, distribution of the set of individual contacts over their properties taking into account the dispersion of their parameters depending on the employed initial components, macrostructural level—the electricoconductive grid imbedded into a polymer matrix. As a result of our investigations, the structural parameter—the entropy of the textural parameter that can be used to estimate the durability of composite materials with polymer components in strong electric fields—has been chosen.

  8. Magnetic Field Effects on Relaxation Parameters of The Hexamethylenetetramine (HMT)

    Science.gov (United States)

    Dogan, Nurcan

    2013-03-01

    The use of low magnetic field is one of the method for improvement of the signal to noise ratio (SNR) of detection of the chemical compounds by nuclear quadrupole resonance (NQR). We investigated the FID phenomenon of nuclear quadrupole resonance (NQR) from hexamethylenetetramine (HMT), C6H12N4, under magnetic field. The influence of the low magnetic field (up to 30 mT) was investigated for the detection of the pulse NQR signal for HMT We detected the pure NQR FID signal of HMT with a short pulse interval. The intensity of the FID signal changed with applied magnetic field. The application of the low magnetic field produces the splitting and brodening of the NQR line. We observed T1, T2 and T2*. HMT has a long T2*(near 1.5ms). This one represents the suitable sample for investigation of the influence of low magnetic field for NQR detection. The application of the low magnetic field produces the splitting and brodening of the NQR line.

  9. Atmospheric parameters of 82 red giants in the Kepler field

    DEFF Research Database (Denmark)

    Overaa Thygesen, Anders; Frandsen, Søren; Bruntt, Hans;

    2012-01-01

    Context. Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims. We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. Methods...... elements were measured using equivalent widths of the spectral lines. Results. We identify discrepancies in log g and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue (larger than 2.0 dex for log g and [Fe/H] for individual stars). The Teff found from...... spectroscopy and photometry shows good agreement within the uncertainties. We find good agreement between the spectroscopic log g and the log g derived from asteroseismology. Also, we see indications of a potential metallicity effect on the stellar oscillations. Conclusions. We have determined the fundamental...

  10. PARAMETER SETS FOR 10 TEV AND 100 TEV MUON COLLIDERS, AND THEIR STUDY AT THE HEMC 99 WORKSHOP

    Energy Technology Data Exchange (ETDEWEB)

    KING,B.J.

    2000-05-05

    A focal point for the HEMC'99 workshop was the evaluation of straw-man parameter sets for the acceleration and collider rings of muon colliders at center of mass energies of 10 TeV and 100 TeV. These self-consistent parameter sets are presented and discussed. The methods and assumptions used in their generation are described and motivations are given for the specific choices of parameter values. The assessment of the parameter sets during the workshop is then reviewed and the implications for the feasibility of many-TeV muon colliders are evaluated. Finally, a preview is given of plans for iterating on the parameter sets and, more generally, for future feasibility studies on many-TeV muon colliders.

  11. Extracellular voltage threshold settings can be tuned for optimal encoding of movement and stimulus parameters

    Science.gov (United States)

    Oby, Emily R.; Perel, Sagi; Sadtler, Patrick T.; Ruff, Douglas A.; Mischel, Jessica L.; Montez, David F.; Cohen, Marlene R.; Batista, Aaron P.; Chase, Steven M.

    2016-06-01

    Objective. A traditional goal of neural recording with extracellular electrodes is to isolate action potential waveforms of an individual neuron. Recently, in brain-computer interfaces (BCIs), it has been recognized that threshold crossing events of the voltage waveform also convey rich information. To date, the threshold for detecting threshold crossings has been selected to preserve single-neuron isolation. However, the optimal threshold for single-neuron identification is not necessarily the optimal threshold for information extraction. Here we introduce a procedure to determine the best threshold for extracting information from extracellular recordings. We apply this procedure in two distinct contexts: the encoding of kinematic parameters from neural activity in primary motor cortex (M1), and visual stimulus parameters from neural activity in primary visual cortex (V1). Approach. We record extracellularly from multi-electrode arrays implanted in M1 or V1 in monkeys. Then, we systematically sweep the voltage detection threshold and quantify the information conveyed by the corresponding threshold crossings. Main Results. The optimal threshold depends on the desired information. In M1, velocity is optimally encoded at higher thresholds than speed; in both cases the optimal thresholds are lower than are typically used in BCI applications. In V1, information about the orientation of a visual stimulus is optimally encoded at higher thresholds than is visual contrast. A conceptual model explains these results as a consequence of cortical topography. Significance. How neural signals are processed impacts the information that can be extracted from them. Both the type and quality of information contained in threshold crossings depend on the threshold setting. There is more information available in these signals than is typically extracted. Adjusting the detection threshold to the parameter of interest in a BCI context should improve our ability to decode motor intent

  12. Probing neutrino parameters with a Two-Baseline Beta-beam set-up

    CERN Document Server

    Agarwalla, S K; Raychaudhuri, A

    2008-01-01

    We discuss the prospects of exploring the neutrino mass parameters with a CERN based Beta-beam experiment using two different detectors at two different baselines. The proposed set-up consists of a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We take 8B and 8Li source ions with a boost factor $\\gamma$ of 650 for the magic baseline while for the closer detector we consider 18Ne and 6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With $\\gamma=650$ for 8B/8Li and $\\gamma=575$ for 18Ne/6He and total luminosity corresponding to $5\\times (1.1\\times 10^{19})$ and $5\\times (2.9\\times 10^{19})$ useful ion decays in neutrino and antineutrino modes respectively, we find that the two-detector set-up can probe maximal CP violation and establish the ne...

  13. SIM parameter-based security for mobile e-commerce settings

    Directory of Open Access Journals (Sweden)

    Francisco Orlando Martínez Pabón

    2010-04-01

    Full Text Available Security requirements are more demanding in the e-commerce domain. However, mobile e -commerce settings not only insist on security requirements, they also require balance between security levels and hardware and usability device ability. These features require designing models having simple authentication and authorisation scheme which also ensures information integrity for each e -transaction. The Mobile and Wireless Applications’ Development Interest Group W@Pcolombia thus developed the P3SIM platform so that mobile applications might include SIM parameter-based security features. The P3SIM platform’s framework and compilation and simulation settings combines the advantages of identification provided by the SIM module with the security features provided by SATSA and Java Card APIs for Java ME environments, one of the most-used platforms for mobile application development. Developing an m-commerce-based prototype not only shows the platform’s ability to operate in secure environments, it also shows its ability to comply with environmental security requirements.

  14. Spectral signatures of hydrilla from a tank and field setting

    Institute of Scientific and Technical Information of China (English)

    Alfonso BLANCO; John J.QU; William E.ROPER

    2012-01-01

    The invasion of hydrilla in many waterways has caused significant problems resulting in high maintenance costs for eradicating this invasive aquatic weed.Present identification methods employed for detecting hydrilla invasions such as aerial photography and videos are difficult,costly,and time consuming.Remote sensing has been used for assessing wetlands and other aquatic vegetation,but very little information is available for detecting hydrilla invasions in coastal estuaries and other water bodies.The objective of this study is to construct a library of spectral signatures for identifying and classifying hydrilla invasions.Spectral signatures of hydrilla were collected from an experimental tank and field locations in a coastal estuary in the upper Chesapeake Bay.These measurements collected from the experimental tank,resulted in spectral signatures with an average peak surface reflectance in the near-infrared (NIR) region of 16% at a wavelength of 818 nm.However,the spectral measurements,collected in the estuary,resulted in a very different spectral signature with two surface reflectance peaks of 6% at wavelengths of 725 nm and 818 nm.The difference in spectral signatures between sites are a result of the components in the water column in the estuary because of increased turbidity (e.g.,nutrients,dissolved matter and suspended matter),and canopy being lower (submerged) in the water column.Spectral signatures of hydrilla observed in the tank and the field had similar characteristics with low reflectance in visible region of the spectrum from 400 to 700 nm,but high in the NIR region from 700 to 900 nm.

  15. Low-field NMR logging sensor for measuring hydraulic parameters of model soils

    Science.gov (United States)

    Sucre, Oscar; Pohlmeier, Andreas; Minière, Adrien; Blümich, Bernhard

    2011-08-01

    SummaryKnowing the exact hydraulic parameters of soils is very important for improving water management in agriculture and for the refinement of climate models. Up to now, however, the investigation of such parameters has required applying two techniques simultaneously which is time-consuming and invasive. Thus, the objective of this current study is to present only one technique, i.e., a new non-invasive method to measure hydraulic parameters of model soils by using low-field nuclear magnetic resonance (NMR). Hereby, two model clay or sandy soils were respectively filled in a 2 m-long acetate column having an integrated PVC tube. After the soils were completely saturated with water, a low-field NMR sensor was moved up and down in the PVC tube to quantitatively measure along the whole column the initial water content of each soil sample. Thereafter, both columns were allowed to drain. Meanwhile, the NMR sensor was set at a certain depth to measure the water content of that soil slice. Once the hydraulic equilibrium was reached in each of the two columns, a final moisture profile was taken along the whole column. Three curves were subsequently generated accordingly: (1) the initial moisture profile, (2) the evolution curve of the moisture depletion at that particular depth, and (3) the final moisture profile. All three curves were then inverse analyzed using a MATLAB code over numerical data produced with the van Genuchten-Mualem model. Hereby, a set of values ( α, n, θr and θs) was found for the hydraulic parameters for the soils under research. Additionally, the complete decaying NMR signal could be analyzed through Inverse Laplace Transformation and averaged on the 1/ T2 space. Through measurement of the decay in pure water, the effect on the relaxation caused by the sample could be estimated from the obtained spectra. The migration of the sample-related average with decreasing saturation speaks for a enhancement of the surface relaxation as the soil dries, in

  16. Bayesian Modal Estimation of the Four-Parameter Item Response Model in Real, Realistic, and Idealized Data Sets.

    Science.gov (United States)

    Waller, Niels G; Feuerstahler, Leah

    2017-03-17

    In this study, we explored item and person parameter recovery of the four-parameter model (4PM) in over 24,000 real, realistic, and idealized data sets. In the first analyses, we fit the 4PM and three alternative models to data from three Minnesota Multiphasic Personality Inventory-Adolescent form factor scales using Bayesian modal estimation (BME). Our results indicated that the 4PM fits these scales better than simpler item Response Theory (IRT) models. Next, using the parameter estimates from these real data analyses, we estimated 4PM item parameters in 6,000 realistic data sets to establish minimum sample size requirements for accurate item and person parameter recovery. Using a factorial design that crossed discrete levels of item parameters, sample size, and test length, we also fit the 4PM to an additional 18,000 idealized data sets to extend our parameter recovery findings. Our combined results demonstrated that 4PM item parameters and parameter functions (e.g., item response functions) can be accurately estimated using BME in moderate to large samples (N ⩾ 5, 000) and person parameters can be accurately estimated in smaller samples (N ⩾ 1, 000). In the supplemental files, we report annotated [Formula: see text] code that shows how to estimate 4PM item and person parameters in [Formula: see text] (Chalmers, 2012 ).

  17. Parameter optimization of temperature field in RF-capacitive hyperthermia

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To realize a certain target temperature distribution in tumor tissues and avoid over-heating in normal tissues in radio frequency (RF)-capacitive hyperthermia, an objective function and some weight coefficients are introduced. Then using the 2-D finite element method, the electromagnetic and bio-heat transfer equations are solved, and using the genetic algorithm the heating configurations are recursively modified to minimize the objective function. Finally an optimum solution of the expected heating field distribution in hyperthermia is achieved. And with a human heterogeneous tissue model extracted from X-ray CT images, satisfactory optimization results are obtained in the simulations on a biplate RF-capacitive hyperthermia device. This optimization technique for controlling the body temperature field has shown scientific importance and practical values in the research of hyperthermia.

  18. A Unifying Field in Logics: Neutrosophic Logic, Neutrosophic Set, Neutrosophic Probability and Statistics (fourth edition)

    OpenAIRE

    2001-01-01

    In this book one makes an introduction to non-standard analysis in the first part, needed to the next four chapters in order to study the neutrosophics: 1. Neutrosophy - a new branch of philosophy. 2. Neutrosophic Logic - a unifying field in logics. 3. Neutrosophic Set - a unifying field in sets. 4. Neutrosophic Probability - a generalization of classical and imprecise probabilities - and Neutrosophic Statistics.

  19. Exceptional sensitivity to neutrino parameters with a two-baseline Beta-beam set-up

    Energy Technology Data Exchange (ETDEWEB)

    Agarwalla, Sanjib Kumar [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India)], E-mail: sanjib@hri.res.in; Choubey, Sandhya [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India)], E-mail: sandhya@hri.res.in; Raychaudhuri, Amitava [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India)], E-mail: raychaud@hri.res.in

    2008-12-11

    We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL-INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose {sup 8}B and {sup 8}Li source ions with a boost factor {gamma} of 650 for the magic baseline while for the closer detector we consider {sup 18}Ne and {sup 6}He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With {gamma}=650 for {sup 8}B/{sup 8}Li and {gamma}=575 for {sup 18}Ne/{sup 6}He and total luminosity corresponding to 5x(1.1x10{sup 18}) and 5x(2.9x10{sup 18}) useful ion decays in neutrino and antineutrino modes respectively, we find that the two-detector set-up can probe maximal CP violation and establish the neutrino mass ordering if sin{sup 2}2{theta}{sub 13} is 1.4x10{sup -4} and 2.7x10{sup -4}, respectively, or more. The sensitivity reach for sin{sup 2}2{theta}{sub 13} itself is 5.5x10{sup -4}. With a factor of 10 higher luminosity, the corresponding sin{sup 2}2{theta}{sub 13} reach of this set-up would be 1.8x10{sup -5}, 4.6x10{sup -5} and 5.3x10{sup -5} respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible {delta}{sub CP} values for sin{sup 2}2{theta}{sub 13}{>=}10{sup -3} ({>=}8x10{sup -5}), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO-ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.

  20. Solar Cluster: multipoint magnetic field and plasma parameter measurements in the solar wind

    Science.gov (United States)

    Vieira, L. E.; Echer, E.; dal Lago, A.; Schuch, N. J.

    This paper has the objective to discus the technical-scientific feasibility of a deep space mission to be proposed to the Brazilian Space Agency (AEB). This mission will be proposed to study the interplanetary magnetic field and the plasma structure of the solar wind. It will consist of a set of identical spacecraft flying in formation in the inner heliosphere during the ascending and maximum phase of the solar cycle 24. It is know that the primary cause of magnetic storms are intense, long duration southward interplanetary magnetic field structures which interconnect with the earth's magnetic field and allow solar wind energy transport into the Earth's magnetotail/magnetosphere. During the most active phase of the solar cycle, solar maximum, the sun's activity is dominated by flares and disappearing filaments, and their concomitant Coronal Mass Ejections (CMEs). Coronal Holes are present, but the holes are small and do not extend from the poles to the equator as often happens in the descending phase of the solar cycle. The fast (>500 km/s) CMEs coming from the sun into the interplanetary space are the solar/coronal features that contain high magnetic fields. These intense southward magnetic fields are observed in the sheath, in the ejection itself and in the rear of the ejection. The interaction between CMEs and the background solar wind, fast co rotating streams and other CMEs are also very important sources of intense southward magnetic fields. In order to study the interplanetary origin of intense geomagnetic storms, several studies have analyzed plasma parameters, composition, ionization state and the interplanetary magnetic field measured by instruments on board of spacecraft as ISEE3, IMP8, Helios, Ulysses, Wind, SOHO and ACE. Great advance on the understanding of the CME structure and interaction with the background solar wind have been reached. However, the spatial scale of these structures could be greater than 0.2 AU, and this kind of observation usually

  1. Exceptional Sensitivity to Neutrino Parameters with a Two Baseline Beta-Beam Set-up

    CERN Document Server

    Agarwalla, Sanjib Kumar; Raychaudhuri, Amitava

    2008-01-01

    We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B/8Li source ions with a boost factor \\gamma of 650 for the magic baseline while for the closer detector we consider 18Ne/6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With \\gamma=650 for 8B/8Li and \\gamma=575 for 18Ne/6He and total luminosity corresponding to 5\\times (1.1 \\times 10^{18}) and 5\\times (2.9\\times 10^{18}) useful ion decays in neutrino and antineutrino modes respectively, we find that our two detector set-up can probe maximal CP violation and establish the neu...

  2. Hematologic parameters in raptor species in a rehabilitation setting before release.

    Science.gov (United States)

    Black, Peter A; McRuer, David L; Horne, Leigh-Ann

    2011-09-01

    To be considered for release, raptors undergoing rehabilitation must have recovered from their initial injury in addition to being clinically healthy. For that purpose, a good understanding of reference hematologic values is important in determining release criteria for raptors in a rehabilitation setting. In this study, retrospective data were tabulated from clinically normal birds within 10 days of release from a rehabilitation facility. Hematologic values were compiled from 71 red-tailed hawks (Buteo jamaicensis), 54 Eastern screech owls (Megascops asio), 31 Cooper's hawks (Accipiter cooperii), 30 great-horned owls (Bubo virginianus), 28 barred owls (Strix varia), 16 bald eagles (Haliaeetus leucocephalus), and 12 broad-winged hawks (Buteo platypterus). Parameters collected included a white blood cell count and differential, hematocrit, and total protein concentration. Comparisons were made among species and among previously published reports of reference hematologic values in free-ranging birds or permanently captive birds. This is the first published report of reference values for Eastern screech owls, barred owls, and broad-winged hawks; and the first prerelease reference values for all species undergoing rehabilitation. These data can be used as a reference when developing release criteria for rehabilitated raptors.

  3. Physical parameters of seven field RR Lyrae Stars in Bootes

    CERN Document Server

    Peña, J H; Miller, R Peña; Sareyan, J P; Alvarez, M

    2009-01-01

    Str\\"omgren uvby-beta photometry is reported for the RR Lyrae stars AE, RS, ST, TV, TW, UU, and XX in Bootes. The physical parameters M/Mo, log (L/Lo), M_V, log T_eff and [Fe/H], have been estimated from the Fourier decomposition of the light curves and the empirical calibrations developed for this type of stars. Detailed behavior of the stars along the cycle of pulsation has been determined from the observed photometric indices and the synthetic indices from atmospheric models. The reddening of the zone is found to be negligible, as estimated from the reddening of several objects in the same region of the sky. Hence the distances to the individual objects are also estimated.

  4. Integration of Field Geophysics and Geology in an International Setting: Multidisciplinary Geoscience Field Experience at the University of Western Ontario

    Science.gov (United States)

    Brenders, A. J.; Banerjee, N.; Pratt, R. G.

    2010-12-01

    The pedagogical value of the field experience is unequaled: students, teaching assistants, and professors alike return with a renewed sense of purpose, community, and the context in which to place classroom education. It is widely regarded as valuable to personal development, and is required by the Canadian Council of Professional Geoscientists for professional registration. As part of our ongoing International Geoscience Field Experience Initiative, Earth Sciences students at the University of Western Ontario have the opportunity to enhance their education through a study abroad program. The focus is on a residential field experience to world-class localities, offered with the collaboration of internationally recognized academic researchers, government survey personnel, and industry leaders. Recent trips have included the Sn-W mineralization in the Cornwall district of the U.K., the Iberian Pyrite Belt (IPB) in Portugal and Spain, and the metallogenic belts of Western Turkey. The integration of geological knowledge with geophysical data was one of the key organizing principles of our recent field trips to the IPB and Western Turkey. This integration is a foundation of modern Earth Sciences, and common practice in industry, it is relatively rare in classroom settings. Lectures before departure and evening exercises during the field trip supplemented the core undergraduate curriculum in geophysics, reviewing gravity, DC resistivity, induced polarization (IP), and magnetotelluric methods, focusing on application to mineral exploration. During our trip to the IPB, partnership with industry allowed students the opportunity to work with state of the art geophysical data, acquired on an exploration prospect visited during the field trip. Multi-parameter geophysical inversions of the IP and MT data produced cross-sections in depth - results interpretable by the students in the complex geological environment of the Iberian Pyrite Belt. Although the students gained valuable

  5. Efficient Parameter Estimation of Generalizable Coarse-Grained Protein Force Fields Using Contrastive Divergence: A Maximum Likelihood Approach.

    Science.gov (United States)

    Várnai, Csilla; Burkoff, Nikolas S; Wild, David L

    2013-12-10

    Maximum Likelihood (ML) optimization schemes are widely used for parameter inference. They maximize the likelihood of some experimentally observed data, with respect to the model parameters iteratively, following the gradient of the logarithm of the likelihood. Here, we employ a ML inference scheme to infer a generalizable, physics-based coarse-grained protein model (which includes Go̅-like biasing terms to stabilize secondary structure elements in room-temperature simulations), using native conformations of a training set of proteins as the observed data. Contrastive divergence, a novel statistical machine learning technique, is used to efficiently approximate the direction of the gradient ascent, which enables the use of a large training set of proteins. Unlike previous work, the generalizability of the protein model allows the folding of peptides and a protein (protein G) which are not part of the training set. We compare the same force field with different van der Waals (vdW) potential forms: a hard cutoff model, and a Lennard-Jones (LJ) potential with vdW parameters inferred or adopted from the CHARMM or AMBER force fields. Simulations of peptides and protein G show that the LJ model with inferred parameters outperforms the hard cutoff potential, which is consistent with previous observations. Simulations using the LJ potential with inferred vdW parameters also outperforms the protein models with adopted vdW parameter values, demonstrating that model parameters generally cannot be used with force fields with different energy functions. The software is available at https://sites.google.com/site/crankite/.

  6. Parameter governing the far-field features of round jets

    Science.gov (United States)

    Xia, Xi; Mohseni, Kamran

    2016-10-01

    This study is inspired by the observation and hypothesis that the spreading and decay behaviors of a jet directly depend on the momentum-mixing mechanism between the jet and surrounding fluid. This mixing behavior is dictated by the kinematic viscosity ν for a laminar jet, which can be dramatically enhanced in a turbulent flow and is represented by the eddy viscosity ɛ . Similarly, pulsation in a synthetic jet is identified as another mechanism for enhancing mixing, which can be captured by an enhanced eddy viscosity beyond what is observed in a corresponding turbulent continuous jet. To this end, an effective-eddy-viscosity concept is proposed to model any excitation of a jet that could result in enhanced mixing beyond what is predicted by the kinematic viscosity. Our previous study found that ɛ is actuator dependent and its relationship with the spreading or decay behavior of a jet is not obvious. To remove the actuator dependence, this study performs a dimensional analysis to relate the spreading and decay behaviors to a scaled effective eddy viscosity ɛ /√{K } (K is the momentum flux). This quantity physically represents a competition between the radial diffusion and the axial convection of the jet axial momentum. The experimental results confirm that ɛ /√{K } governs the spreading and decay rates of the far field for any round jets.

  7. Quantitative evaluation of ozone and selected climate parameters in a set of EMAC simulations

    Directory of Open Access Journals (Sweden)

    M. Righi

    2015-03-01

    Full Text Available Four simulations with the ECHAM/MESSy Atmospheric Chemistry (EMAC model have been evaluated with the Earth System Model Validation Tool (ESMValTool to identify differences in simulated ozone and selected climate parameters that resulted from (i different setups of the EMAC model (nudged vs. free-running and (ii different boundary conditions (emissions, sea surface temperatures (SSTs and sea ice concentrations (SICs. To assess the relative performance of the simulations, quantitative performance metrics are calculated consistently for the climate parameters and ozone. This is important for the interpretation of the evaluation results since biases in climate can impact on biases in chemistry and vice versa. The observational data sets used for the evaluation include ozonesonde and aircraft data, meteorological reanalyses and satellite measurements. The results from a previous EMAC evaluation of a model simulation with nudging towards realistic meteorology in the troposphere have been compared to new simulations with different model setups and updated emission data sets in free-running time slice and nudged quasi chemistry-transport model (QCTM mode. The latter two configurations are particularly important for chemistry-climate projections and for the quantification of individual sources (e.g., the transport sector that lead to small chemical perturbations of the climate system, respectively. With the exception of some specific features which are detailed in this study, no large differences that could be related to the different setups (nudged vs. free-running of the EMAC simulations were found, which offers the possibility to evaluate and improve the overall model with the help of shorter nudged simulations. The main differences between the two setups is a better representation of the tropospheric and stratospheric temperature in the nudged simulations, which also better reproduce stratospheric water vapor concentrations, due to the improved

  8. Establishing `fields of care': teaching settings as active participants in science education

    Science.gov (United States)

    Blatt, Erica N.

    2014-03-01

    In their article, "Space, relations, and the learning of science," Wolff-Michael Roth and Pei-Ling Hsu draw our attention to the importance of field in the teaching and learning of science. While the Roth and Hsu study is focused on the scientific research laboratory as an internship setting for the teaching of science, this response to their paper expands the discussion of the settings where science is taught in order to bring to the fore some of the affordances and challenges associated with teaching science in specific fields. By extending our thinking about the settings where science is taught/learned and the active role these settings play in teaching our students, we can re-envision how to better utilize a variety of fields in the teaching of science. The notion of `field of care' is explored as a way of both finding and building connections between students and the settings where science is experienced.

  9. Update on phosphate and charged post-translationally modified amino acid parameters in the GROMOS force field.

    Science.gov (United States)

    Margreitter, Christian; Reif, Maria M; Oostenbrink, Chris

    2017-04-15

    In this study, we propose newly derived parameters for phosphate ions in the context of the GROMOS force field parameter sets. The non-bonded parameters used up to now lead to a hydration free energy, which renders the dihydrogen phosphate ion too hydrophobic when compared to experimentally derived values, making a reparametrization of the phosphate moiety necessary. Phosphate species are of great importance in biomolecular simulations not only because of their crucial role in the backbone of nucleic acids but also as they represent one of the most important types of post-translational modifications to protein side-chains and are an integral part in many lipids. Our re-parametrization of the free dihydrogen phosphate (H 2PO 4-) and three derivatives (methyl phosphate, dimethyl phosphate, and phenyl phosphate) leads, in conjunction with the previously updated charged side-chains in the GROMOS parameter set 54A8, to new nucleic acid backbone parameters and a 54A8 version of the widely used GROMOS protein post-translational modification parameter set. © 2017 Wiley Periodicals, Inc.

  10. Optical properties of atmospheric particles: complete parameter sets obtained through polar photometry and an improved inversion technique.

    Science.gov (United States)

    Hänel, G

    1994-10-20

    Complete sets of optical parameters of dry particles sampled on a Nuclepore filter are derived through interpretation of photometric data with an improved inversion technique. The parameters are the volume-extinction and absorption coefficients, the single-scattering albedo, the asymmetry parameter of the volume scattering function, the apparent complex refractive index, and the apparent soot content. They may serve as input data for solar radiation-budget considerations. Results from preliminary measurements taken in Central Europe and Italy show an extreme variability of the optical parameters. Both large regional and temporal variabilities have been observed caused by the fluctuating midlatitude weather systems and human activities.

  11. Determination of needed parameters for measuring temperature fields in air by thermography

    Directory of Open Access Journals (Sweden)

    Pavelek Milan

    2012-04-01

    Full Text Available The aim of this article is the parameters determination of equipment for measuring temperature fields in air using an infrared camera. This method is based on the visualization of temperature fields in an auxiliary material, which is inserted into the non-isothermal air flow. The accuracy of air temperature measurement (or of surface temperature of supplies by this method depends especially on (except for parameters of infrared camera the determination of the static and the dynamic qualities of auxiliary material. The emissivity of support material is the static quality and the dynamic quality is time constant. Support materials with a high emissivity and a low time constant are suitable for the measurement. The high value of emissivity results in a higher measurement sensitivity and the radiation temperature independence. In this article the emissivity of examined kinds of auxiliary materials (papers and textiles is determined by temperature measuring of heated samples by a calibrated thermocouple and by thermography, with the emissivity setting on the camera to 1 and with the homogeneous radiation temperature. Time constants are determined by a step change of air temperature in the surrounding of auxiliary material. The time constant depends mainly on heat transfer by the convection from the air into the auxiliary material. That is why the effect of air temperature is examined in this article (or a temperature difference towards the environmental temperature and the flow velocity on the time constant with various types of auxiliary materials. The obtained results allow to define the conditions for using the method of measurement of temperature fields in air during various heating and air conditioning applications.

  12. A method of evaluating quantitative magnetospheric field models by an angular parameter alpha

    Science.gov (United States)

    Sugiura, M.; Poros, D. J.

    1979-01-01

    The paper introduces an angular parameter, termed alpha, which represents the angular difference between the observed, or model, field and the internal model field. The study discusses why this parameter is chosen and demonstrates its usefulness by applying it to both observations and models. In certain areas alpha is more sensitive than delta-B (the difference between the magnitude of the observed magnetic field and that of the earth's internal field calculated from a spherical harmonic expansion) in expressing magnetospheric field distortions. It is recommended to use both alpha and delta-B in comparing models with observations.

  13. Field rotor measurements. Data sets prepared for analysis of stall hysteresis

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard Madsen, H.; Thirstrup Petersen, J. [Risoe National Lab. (Denmark); Bruining, A. [Delft Univ. of Technology (Netherlands); Brand, A. [ECN (Netherlands); Graham, M. [Imperical College (United Kingdom)

    1998-05-01

    As part of the JOULE-3 project `STALLVIB` an analysis and synthesis of the data from the field rotor experiments at ECN, Delft University, Imperial College, NREL and Risoe has been carried out. This has been done in order to see to what extent the data could be used for further development and validation of engineering dynamic stall models. A detailed investigation of the influence of the post-processing of the different data sets has been performed. Further, important statistical functions such as PSD spectra, coherence and transfer functions have been derived for the data sets which can be used as basis for evaluation of the quality of the data seen relative to actual application of the data. The importance of using an appropriate low-pass filtering to remove high frequency noise has been demonstrated when the relation between instantaneous values of e.g. {alpha} and C{sub N} is considered. In general, the complicated measurement on a rotor of {alpha} and w and the interpretation of these parameters combined with the strongly three-dimensional, turbulent flow field around the rotating blade has the consequence that it seems difficult to derive systematic information from the different data sets about stall hysteresis. In particular, the measurement of {alpha}, which determination of the stagnation point gives reasonable data below stall but fails in stall. On the other hand, measurements of {alpha} with a five hole pitot tube can be used also in the stall region. Another main problem is the non-dimensionalization of the coefficients C{sub N} and C{sub r}. If the dynamic pressure used for the non-dimensionalization is not fully correlated with the aerodynamic pressure over the considered airfoil section due to e.g. influence of the gravity on the pressure pipes, the hysteresis loops will be distorted. However, using the data with caution and applying a suitable post-processing as described by the different participants, it will probably be possible to obtain some

  14. On the distribution of scaling hydraulic parameters in a spatially anisotropic banana field

    Science.gov (United States)

    Regalado, Carlos M.

    2005-06-01

    When modeling soil hydraulic properties at field scale it is desirable to approximate the variability in a given area by means of some scaling transformations which relate spatially variable local hydraulic properties to global reference characteristics. Seventy soil cores were sampled within a drip irrigated banana plantation greenhouse on a 14×5 array of 2.5 m×5 m rectangles at 15 cm depth, to represent the field scale variability of flow related properties. Saturated hydraulic conductivity and water retention characteristics were measured in these 70 soil cores. van Genuchten water retention curves (WRC) with optimized m ( m≠1-1/ n) were fitted to the WR data and a general Mualem-van Genuchten model was used to predict hydraulic conductivity functions for each soil core. A scaling law, of the form ν=ανi*, was fitted to soil hydraulic data, such that the original hydraulic parameters νi were scaled down to a reference curve with parameters νi*. An analytical expression, in terms of Beta functions, for the average suction value, hc, necessary to apply the above scaling method, was obtained. A robust optimization procedure with fast convergence to the global minimum is used to find the optimum hc, such that dispersion is minimized in the scaled data set. Via the Box-Cox transformation P(τ)=(αiτ-1)/τ, Box-Cox normality plots showed that scaling factors for the suction ( αh) and hydraulic conductivity ( αk) were approximately log-normally distributed (i.e. τ=0), as it would be expected for such dynamic properties involving flow. By contrast static soil related properties as αθ were found closely Gaussian, although a power τ=3/4 was best for approaching normality. Application of four different normality tests (Anderson-Darling, Shapiro-Wilk, Kolmogorov-Smirnov and χ2 goodness-of-fit tests) rendered some contradictory results among them, thus suggesting that this widely extended practice is not recommended for providing a suitable probability

  15. Laser parameter influence on quantum path selection in a bichromatic field

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shaoyi; Hong Weiyi; Lan Pengfei; Zhang Qingbin; Lu Peixiang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)], E-mail: lupeixiang@mail.hust.edu.cn

    2009-05-28

    We theoretically investigate the laser parameter influence on quantum path selection in a two-colour laser pulse, of which both fundamental field and its controlling field are linearly polarized. The laser's parameters, namely, the relative intensity of the controlling field and its relative phase with respect to the fundamental field, determine the quantum path selection by affecting their ionization probabilities. In both cases of the {omega} + 3{omega} and {omega} + 2{omega} laser fields, it is shown that the quantum path selection in the multi-cycle pulse is more dependent on the parameters than that in the few-cycle pulse, and the selection of the quantum path in the multi-cycle {omega} + 3{omega} pulse shows stability to the phase and intensity variation. Our results are very beneficial to choosing appropriate parameters for quantum path selection in experiments.

  16. Imaginary Scators Bound Set Under the Iterated Quadratic Mapping in 1 + 2 Dimensional Parameter Space

    Science.gov (United States)

    Fernández-Guasti, M.

    The quadratic iteration is mapped within a nondistributive imaginary scator algebra in 1 + 2 dimensions. The Mandelbrot set is identically reproduced at two perpendicular planes where only the scalar and one of the hypercomplex scator director components are present. However, the bound three-dimensional S set projections change dramatically even for very small departures from zero of the second hypercomplex plane. The S set exhibits a rich fractal-like boundary in three dimensions. Periodic points with period m, are shown to be necessarily surrounded by points that produce a divergent magnitude after m iterations. The scator set comprises square nilpotent elements that ineluctably belong to the bound set. Points that are square nilpotent on the mth iteration, have preperiod 1 and period m. Two-dimensional plots are presented to show some of the main features of the set. A three-dimensional rendering reveals the highly complex structure of its boundary.

  17. Effect of Antenna Parameters on the Field Coverage in Tunnel Environments

    Directory of Open Access Journals (Sweden)

    Dawei Li

    2016-01-01

    Full Text Available Radio wave propagation in confined spaces is consequent upon the reflections of boundaries; thus, the radiation characteristics of the antenna have significant influence on the field coverage in the confined space. This paper investigates the effects of antenna parameters on field coverage characteristics in a tunnel environment. A modified modal method is proposed to analyse the wave propagation properties along the tunnel. The relationships between the amplitudes of modes and the antenna parameters, including the beam width, beam direction, and antenna location, are analysed. The results indicate that by properly selecting the antenna parameters, optimum field coverage in tunnel environments can be realized.

  18. Interval finite difference method for steady-state temperature field prediction with interval parameters

    Science.gov (United States)

    Wang, Chong; Qiu, Zhi-Ping

    2014-04-01

    A new numerical technique named interval finite difference method is proposed for the steady-state temperature field prediction with uncertainties in both physical parameters and boundary conditions. Interval variables are used to quantitatively describe the uncertain parameters with limited information. Based on different Taylor and Neumann series, two kinds of parameter perturbation methods are presented to approximately yield the ranges of the uncertain temperature field. By comparing the results with traditional Monte Carlo simulation, a numerical example is given to demonstrate the feasibility and effectiveness of the proposed method for solving steady-state heat conduction problem with uncertain-but-bounded parameters. [Figure not available: see fulltext.

  19. Delineation and Prediction Uncertainty of Areas Contributing Recharge to Selected Well Fields in Wetland and Coastal Settings, Southern Rhode Island

    Science.gov (United States)

    Friesz, Paul J.

    2010-01-01

    coastal setting. The wells are screened in a coarse-grained, ice-proximal part of a morphosequence with saturated thicknesses generally less than 30 feet on the peninsula. The simulated area contributing recharge for the average withdrawal (16 gallons per minute) during 2003-07 was 0.018 square mile. The contributing area extended southwestward from the well fields to a simulated groundwater mound; it underlay part of a small nearby wetland, and it included isolated areas on the side of the wetland opposite the well fields. For the maximum pumping rate (230 gallons per minute), the simulated area contributing recharge (0.26 square mile) expanded in all directions; it included a till area on the peninsula, and it underlay part of a nearby pond. Because the well fields are screened in a thin aquifer, simulated groundwater traveltimes from recharge locations to the discharging wells were short: 94 percent of the traveltimes were 10 years or less, and the median traveltime was 1.3 years. Model-prediction uncertainty was evaluated using a Monte Carlo analysis; the parameter variance-covariance matrix from nonlinear regression was used to create parameter sets for the analysis. Important parameters for model prediction that could not be estimated by nonlinear regression were incorporated into the variance-covariance matrix. For the South Kingstown study site, observations provided enough information to constrain the uncertainty of these parameters within realistic ranges, but for the Charlestown study site, prior information on parameters was required. Thus, the uncertainty analysis for the South Kingstown study site was an outcome of calibrating the model to available observations, but the Charlestown study site was also dependent on information provided by the modeler. A water budget and model-fit statistical criteria were used to assess parameter sets so that prediction uncertainty was not overestimated. For the scenarios using maximum pumping rates at both study

  20. Biological parameters used in setting captive-breeding quotas for Indonesia's breeding facilities.

    Science.gov (United States)

    Janssen, Jordi; Chng, Serene C L

    2017-07-03

    The commercial captive breeding of wildlife is often seen as a potential conservation tool to relieve pressure on wild populations, but laundering of wild-sourced specimens as captive bred can seriously undermine conservation efforts and provide a false sense of sustainability. Indonesia is at the center of such controversy; therefore, we examined Indonesia's captive-breeding production plan (CBPP) for 2016. We compared the biological parameters used in the CBPP with parameters in the literature and with parameters suggested by experts on each species and identified shortcomings of the CBPP. Production quotas for 99 out of 129 species were based on inaccurate or unrealistic biological parameters and production quotas deviated more than 10% from what parameters in the literature allow for. For 38 species, the quota exceeded the number of animals that can be bred based on the biological parameters (range 100-540%) calculated with equations in the CBPP. We calculated a lower reproductive output for 88 species based on published biological parameters compared with the parameters used in the CBPP. The equations used in the production plan did not appear to account for other factors (e.g., different survival rate for juveniles compared to adult animals) involved in breeding the proposed large numbers of specimens. We recommend the CBPP be adjusted so that realistic published biological parameters are applied and captive-breeding quotas are not allocated to species if their captive breeding is unlikely to be successful or no breeding stock is available. The shortcomings in the current CBPP create loopholes that mean mammals, reptiles, and amphibians from Indonesia declared captive bred may have been sourced from the wild. © 2017 Society for Conservation Biology.

  1. Modeller subjectivity in estimating pesticide parameters for leaching models using the same laboratory data set

    NARCIS (Netherlands)

    Boesten, J.J.T.I.

    2000-01-01

    User-dependent subjectivity in the process of testing pesticide leaching models is relevant because it may result in wrong interpretation of model tests. About 20 modellers used the same data set to test pesticide leaching models (one or two models per modeller). The data set included laboratory stu

  2. Modeller subjectivity in estimating pesticide parameters for leaching models using the same laboratory data set

    NARCIS (Netherlands)

    Boesten, J.J.T.I.

    2000-01-01

    User-dependent subjectivity in the process of testing pesticide leaching models is relevant because it may result in wrong interpretation of model tests. About 20 modellers used the same data set to test pesticide leaching models (one or two models per modeller). The data set included laboratory

  3. Estimating qualitative parameters for assessment of body balance and arm function in a simulated ambulatory setting

    NARCIS (Netherlands)

    Meulen, van Fokke B.; Reenalda, Jasper; Veltink, Peter H.

    2013-01-01

    Continuous daily-life monitoring of balance control and arm function of stroke survivors in an ambulatory setting, is essential for optimal guidance of rehabilitation. In a simulated ambulatory setting, balance and arm function of seven stroke subjects is evaluated using on-body measurement systems

  4. IMPROVING MARKOV RANDOM FIELD BASED SUPER RESOLUTION MAPPING THROUGH FUZZY PARAMETER INTEGRATION

    Directory of Open Access Journals (Sweden)

    D. R . Welikanna

    2012-07-01

    Full Text Available The objective of this study was to improve the Markov Random Field (MRF based Super Resolution Mapping (SRM technique to account for the vague land-cover interpretations (class mixture and the intermediate conditions in an urban area. The algorithm has been improved to integrate the fuzzy mean and fuzzy covariance measurements, to a MRF based SRM scheme to optimize the classification results. The technique was tested on a WORLDVIEW-2 data set, acquired over a highway construction area, in Colombo, Sri Lanka. Based on the visual interpretation of the image, three major land-cover types of this area were identified for the study; those were vegetation, soil and exposed grass and impervious surface with low medium and high albedo. The membership values for each pixel were determined from training samples through Spectral Angle Mapper (SAM technique. The compulsory fuzzy mean and the covariance measurements were derived using these membership grades, and subsequently was applied in MRF based SRM technique. The primary reference data was generated using Maximum Likelihood Classification (MLC performed on the same data which was resampled to 1m resolution. The scale factor was set to be (S = 2, to generate SRM of 1m resolution. The smoothening parameter (λ which balances the prior and likelihood energy terms were tested in the range from 0.3 to 0.9. SRM were generated using fuzzy MRF and the conventional MRF models respectively. Results suggest that the fuzzy integrated model has improved the results with an overall accuracy of 85.60% and kappa value of 0.78 between the optimal results and the reference data, while in the conventional case it was 77.81% of overall accuracy with kappa being 0.65. Among the two MRF models, fuzzy parameter integrated model shows the highest agreement with class fractions from the reference image with a smallest average _MAE (MAE, Mean Absolute Error of 0.03.

  5. Deformable Registration of Feature-Endowed Point Sets Based on Tensor Fields

    Science.gov (United States)

    Wassermann, Demian; Ross, James; Washko, George; Wells, William M.; San Jose-Estepar, Raul

    2014-01-01

    The main contribution of this work is a framework to register anatomical structures characterized as a point set where each point has an associated symmetric matrix. These matrices can represent problem-dependent characteristics of the registered structure. For example, in airways, matrices can represent the orientation and thickness of the structure. Our framework relies on a dense tensor field representation which we implement sparsely as a kernel mixture of tensor fields. We equip the space of tensor fields with a norm that serves as a similarity measure. To calculate the optimal transformation between two structures we minimize this measure using an analytical gradient for the similarity measure and the deformation field, which we restrict to be a diffeomorphism. We illustrate the value of our tensor field model by comparing our results with scalar and vector field based models. Finally, we evaluate our registration algorithm on synthetic data sets and validate our approach on manually annotated airway trees. PMID:25473253

  6. An improved solution of local window parameters setting for local singularity analysis based on Excel VBA batch processing technology

    Science.gov (United States)

    Zhang, Daojun; Cheng, Qiuming; Agterberg, Frits; Chen, Zhijun

    2016-03-01

    In this paper Excel VBA is used for batch calculation in Local Singularity Analysis (LSA), which is for the information extracting from different kinds of geoscience data. Capabilities and advantages of a new module called Batch Tool for Local Singularity Index Mapping (BTLSIM) are: (1) batch production of series of local singularity maps with different settings of local window size, shape and orientation parameters; (2) local parameter optimization based on statistical tests; and (3) provision of extra output layers describing how spatial changes induced by parameter optimization are related to spatial structure of the original input layers.

  7. Two-parameter semigroups, evolutions and their applications to Markov and diffusion fields on the plane

    Directory of Open Access Journals (Sweden)

    Yu. Mishura

    1996-01-01

    Full Text Available We study two-parameter coordinate-wise C0-semigroups and their generators, as well as two-parameter evolutions and differential equations up to the second order for them. These results are applied to obtain the Hille-Yosida theorem for homogeneous Markov fields of the Feller type and to establish forward, backward, and mixed Kolmogorov equations for nonhomogeneous diffusion fields on the plane.

  8. Analyzing the Effect of Machining Parameters Setting to the Surface Roughness during End Milling of CFRP-Aluminium Composite Laminates

    Directory of Open Access Journals (Sweden)

    M. Nurhaniza

    2016-01-01

    Full Text Available The quality of the machining is measured from surface finished and it is considered as the most important aspect in composite machining. An appropriate and optimum machining parameters setting is crucial during machining operation in order to enhance the surface quality. The objective of this research is to analyze the effect of machining parameters on the surface quality of CFRP-Aluminium in CNC end milling operation with PCD tool. The milling parameters evaluated are spindle speed, feed rate, and depth of cut. The L9 Taguchi orthogonal arrays, signal-to-noise (S/N ratio, and analysis of variance (ANOVA are employed to analyze the effect of these cutting parameters. The analysis of the results indicates that the optimal cutting parameters combination for good surface finish is high cutting speed, low feed rate, and low depth of cut.

  9. Verification of the optimum tropospheric parameters setting for the kinematic PPP analysis

    Science.gov (United States)

    Hirata, Y.; Ohta, Y.

    2015-12-01

    Kinematic GNSS analysis is useful for extraction of the crustal deformation phenomena between seconds to one day such as coseismic and postseismic deformation after a large earthquake. The kinematic GNSS analysis, however, have fundamental difficulties for the separation between unknown parameters such as the site coordinate and tropospheric parameters, caused by a strong correlation between each other. Thus, we focused on the improvement of the separation precision between coordinate time series of kinematic PPP and wet zenith tropospheric delay (WZTD) based on the comprehensive search of the parameter space. We used GIPSY-OASIS II Ver. 6.3 software for kinematic PPP processing of whole GEONET sites in 10 March 2011. We applied the every 6 hours nominal WZTD value as a priori information based on the ECMWF global numerical climate model. For the coordinate time series and tropospheric parameters, we assumed white noise and random walk stochastic process, respectively. These unknown parameters are very sensitive to assumed process noise for each stochastic process. Thus, we searched for the optimum two variable parameters; wet zenith tropospheric parameter (named as TROP) and its gradient (named as GRAD). We defined the optimum parameters, which minimized the standard deviation of coordinate time series.We firstly checked the spatial distribution of optimum pair of TROP and GRAD. Even though the optimum parameters showed the certain range (TROP: 2×10-8 ~ 6×10-7 (horizontal), 5.5×10-9 ~ 2×10-8 (vertical); GRAD: 2×10-10 ~ 6×10-9 (horizontal), 2×10-10 ~ 1×10-8 (vertical) (unit: km·s-½)), we found they showed the large diversity. It suggests there are strong heterogeneity of atmospheric state. We also estimated temporal variations of optimum TROP and GRAD in specific site. We analyzed the data through 2010 at GEONET 940098 station located in the most southern part of Kyusyu, Japan. Obtained time series of optimum GRAD showed clear annual variation, and the

  10. SIM parameter-based security for mobile e-commerce settings

    National Research Council Canada - National Science Library

    Francisco Orlando Martínez Pabón; Jaime Caicedo Guerrero; Rodrigo Hernández Cuenca; Oscar Mauricio Caicedo Rendón; Javier Alexander Hurtado Guaca

    2010-01-01

    Security requirements are more demanding in the e-commerce domain. However, mobile e -commerce settings not only insist on security requirements, they also require balance between security levels and hardware and usability device ability...

  11. Representation and display of vector field topology in fluid flow data sets

    Science.gov (United States)

    Helman, James; Hesselink, Lambertus

    1989-01-01

    The visualization of physical processes in general and of vector fields in particular is discussed. An approach to visualizing flow topology that is based on the physics and mathematics underlying the physical phenomenon is presented. It involves determining critical points in the flow where the velocity vector vanishes. The critical points, connected by principal lines or planes, determine the topology of the flow. The complexity of the data is reduced without sacrificing the quantitative nature of the data set. By reducing the original vector field to a set of critical points and their connections, a representation of the topology of a two-dimensional vector field that is much smaller than the original data set but retains with full precision the information pertinent to the flow topology is obtained. This representation can be displayed as a set of points and tangent curves or as a graph. Analysis (including algorithms), display, interaction, and implementation aspects are discussed.

  12. Removing the gauge parameter dependence of the effective potential by a field redefinition

    DEFF Research Database (Denmark)

    Nielsen, N. K.

    2014-01-01

    The gauge parameter dependence of the effective potential is determined by partial differential equations involving also the Higgs boson field expectation value. Solving these equations by the method of characteristics leads to elimination of the gauge parameter dependence of the effective...

  13. A semi-supervised support vector machine approach for parameter setting in motor imagery-based brain computer interfaces

    Science.gov (United States)

    Long, Jinyi; Yu, Zhuliang

    2010-01-01

    Parameter setting plays an important role for improving the performance of a brain computer interface (BCI). Currently, parameters (e.g. channels and frequency band) are often manually selected. It is time-consuming and not easy to obtain an optimal combination of parameters for a BCI. In this paper, motor imagery-based BCIs are considered, in which channels and frequency band are key parameters. First, a semi-supervised support vector machine algorithm is proposed for automatically selecting a set of channels with given frequency band. Next, this algorithm is extended for joint channel-frequency selection. In this approach, both training data with labels and test data without labels are used for training a classifier. Hence it can be used in small training data case. Finally, our algorithms are applied to a BCI competition data set. Our data analysis results show that these algorithms are effective for selection of frequency band and channels when the training data set is small. PMID:21886673

  14. Consistency of QSAR models: Correct split of training and test sets, ranking of models and performance parameters.

    Science.gov (United States)

    Rácz, A; Bajusz, D; Héberger, K

    2015-01-01

    Recent implementations of QSAR modelling software provide the user with numerous models and a wealth of information. In this work, we provide some guidance on how one should interpret the results of QSAR modelling, compare and assess the resulting models, and select the best and most consistent ones. Two QSAR datasets are applied as case studies for the comparison of model performance parameters and model selection methods. We demonstrate the capabilities of sum of ranking differences (SRD) in model selection and ranking, and identify the best performance indicators and models. While the exchange of the original training and (external) test sets does not affect the ranking of performance parameters, it provides improved models in certain cases (despite the lower number of molecules in the training set). Performance parameters for external validation are substantially separated from the other merits in SRD analyses, highlighting their value in data fusion.

  15. Stochastic finite element analysis of coupled heat and mass transfer problems with random field parameters

    NARCIS (Netherlands)

    Scheerlinck, N.; Verboven, P.; Stigter, J.D.; Baerdenmaeker, de J.; Impe, van J.F.; Nicolai, B.A.

    2000-01-01

    A first-order perturbation algorithm for the computation of mean values and variances of transient temperature and moisture fields during coupled heat and mass transfer problems with random field parameters has been developed and implemented. The algorithm is based on the Galerkin finite-element dis

  16. THE DECISION OF THE OPTIMAL PARAMETERS IN MARKOV RANDOM FIELDS OF IMAGES BY GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper introduces the principle of genetic algorithm and the basic method of solving Markov random field parameters.Focusing on the shortcomings in present methods,a new method based on genetic algorithms is proposed to solve the parameters in the Markov random field.The detailed procedure is discussed.On the basis of the parameters solved by genetic algorithms,some experim ents on classification of aerial images are given.Experimental results show that the proposed method is effective and the classification results are satisfactory.

  17. The Geneva Minimalistic Acoustic Parameter Set (GeMAPS) for Voice Research and Affective Computing

    NARCIS (Netherlands)

    Eyben, Florian; Scherer, Klaus; Schuller, Björn; Sundberg, Johan; André, Elisabeth; Busso, Carlos; Devillers, Laurence; Epps, Julien; Laukka, Petri; Narayanan, Shrikanth; Truong, Khiet

    2015-01-01

    Work on voice sciences over recent decades has led to a proliferation of acoustic parameters that are used quite selectively and are not always extracted in a similar fashion. With many independent teams working in different research areas, shared standards become an essential safeguard to ensure co

  18. Ab initio localized basis set study of structural parameters and elastic properties of HfO{sub 2} polymorphs

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, M A [Facultad de Ingenieria, Universidad Nacional del Nordeste, Avenida Las Heras 727, 3500-Resistencia (Argentina); Casali, R A [Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad, 5600-Corrientes (Argentina)

    2005-09-21

    The SIESTA approach based on pseudopotentials and a localized basis set is used to calculate the electronic, elastic and equilibrium properties of P 2{sub 1}/c, Pbca, Pnma, Fm3m, P4{sub 2}nmc and Pa3 phases of HfO{sub 2}. Using separable Troullier-Martins norm-conserving pseudopotentials which include partial core corrections for Hf, we tested important physical properties as a function of the basis set size, grid size and cut-off ratio of the pseudo-atomic orbitals (PAOs). We found that calculations in this oxide with the LDA approach and using a minimal basis set (simple zeta, SZ) improve calculated phase transition pressures with respect to the double-zeta basis set and LDA (DZ-LDA), and show similar accuracy to that determined with the PPPW and GGA approach. Still, the equilibrium volumes and structural properties calculated with SZ-LDA compare better with experiments than the GGA approach. The bandgaps and elastic and structural properties calculated with DZ-LDA are accurate in agreement with previous state of the art ab initio calculations and experimental evidence and cannot be improved with a polarized basis set. These calculated properties show low sensitivity to the PAO localization parameter range between 40 and 100 meV. However, this is not true for the relative energy, which improves upon decrease of the mentioned parameter. We found a non-linear behaviour in the lattice parameters with pressure in the P 2{sub 1}/c phase, showing a discontinuity of the derivative of the a lattice parameter with respect to external pressure, as found in experiments. The common enthalpy values calculated with the minimal basis set give pressure transitions of 3.3 and 10.8?GPa for P2{sub 1}/c {yields} Pbca and Pbca {yields} Pnma, respectively, in accordance with different high pressure experimental values.

  19. Simulation of heterogeneous two-phase media using random fields and level sets

    Institute of Scientific and Technical Information of China (English)

    George STEFANOU[1,2

    2015-01-01

    The accurate and efficient simulation of random heterogeneous media is important in the framework of modeling and design of complex materials across multiple length scales. It is usually assumed that the morphology of a random microstructure can be described as a non-Gaussian random field that is completely defined by its multivariate distribution. A particular kind of non-Gaussian random fields with great practical importance is that of translation fields resulting from a simple memory-less transformation of an underlying Gaussian field with known second-order statistics. This paper provides a critical examination of existing random field models of heterogeneous two-phase media with emphasis on level-cut random fields which are a special case of translation fields. The case of random level sets, often used to represent the geometry of physical systems, is also examined. Two numerical examples are provided to illustrate the basic features of the different approaches.

  20. Analysis Variation of Drying Parameters of Corn Seeds Processed in Microwave Field. Thermal Field Analysis.

    OpenAIRE

    Darie SOPRONI; VICAS Simina; Carmen MOLNAR; ARION Mircea; HATHAZI Francisc Ioan

    2012-01-01

    The present research has the objective to analyze the drying characteristics of the corn seeds in the microwave field. During the experiment is being followed the germination of the seeds and thedistribution of temperature in the dielectric.

  1. Determination of best-fit potential parameters for a reactive force field using a genetic algorithm.

    Science.gov (United States)

    Pahari, Poonam; Chaturvedi, Shashank

    2012-03-01

    The ReaxFF interatomic potential, used for organic materials, involves more than 600 adjustable parameters, the best-fit values of which must be determined for different materials. A new method of determining the set of best-fit parameters for specific molecules containing carbon, hydrogen, nitrogen and oxygen is presented, based on a parameter reduction technique followed by genetic algorithm (GA) minimization. This work has two novel features. The first is the use of a parameter reduction technique to determine which subset of parameters plays a significant role for the species of interest; this is necessary to reduce the optimization space to manageable levels. The second is the application of the GA technique to a complex potential (ReaxFF) with a very large number of adjustable parameters, which implies a large parameter space for optimization. In this work, GA has been used to optimize the parameter set to determine best-fit parameters that can reproduce molecular properties to within a given accuracy. As a test problem, the use of the algorithm has been demonstrated for nitromethane and its decomposition products.

  2. Impact of magnetic field parameters and iron oxide nanoparticle properties on heat generation for use in magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Rhythm R. [Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL (United States); Davis, Todd P.; Glover, Amanda L.; Nikles, David E. [Department of Chemistry, The University of Alabama, Tuscaloosa, AL (United States); Brazel, Christopher S., E-mail: cbrazel@eng.ua.edu [Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL (United States)

    2015-08-01

    Heating of nanoparticles (NPs) using an AC magnetic field depends on several factors, and optimization of these parameters can improve the efficiency of heat generation for effective cancer therapy while administering a low NP treatment dose. This study investigated magnetic field strength and frequency, NP size, NP concentration, and solution viscosity as important parameters that impact the heating efficiency of iron oxide NPs with magnetite (Fe{sub 3}O{sub 4}) and maghemite (γ-Fe{sub 2}O{sub 3}) crystal structures. Heating efficiencies were determined for each experimental setting, with specific absorption rates (SARs) ranging from 3.7 to 325.9 W/g Fe. Magnetic heating was conducted on iron oxide NPs synthesized in our laboratories (with average core sizes of 8, 11, 13, and 18 nm), as well as commercially-available iron oxides (with average core sizes of 8, 9, and 16 nm). The experimental magnetic coil system made it possible to isolate the effect of magnetic field parameters and independently study the effect on heat generation. The highest SAR values were found for the 18 nm synthesized particles and the maghemite nanopowder. Magnetic field strengths were applied in the range of 15.1–47.7 kA/m, with field frequencies ranging from 123 to 430 kHz. The best heating was observed for the highest field strengths and frequencies tested, with results following trends predicted by the Rosensweig equation. An increase in solution viscosity led to lower heating rates in nanoparticle solutions, which can have significant implications for the application of magnetic fluid hyperthermia in vivo. - Highlights: • Heating was tested in seven iron oxide nanoparticles for different magnetic fields. • Confirms an optimal nanoparticle size for heating that agrees with the literature. • Verifies Rosenweig's equation to predict the effect of field frequency on heating. • Reports reduced heating in high viscosity environments.

  3. Comparison between different sets of suspension parameters and introduction of new modified skyhook control strategy incorporating varying road condition

    Science.gov (United States)

    Abul Kashem, Saad Bin; Ektesabi, Mehran; Nagarajah, Romesh

    2012-07-01

    This study examines the uncertainties in modelling a quarter car suspension system caused by the effect of different sets of suspension parameters of a corresponding mathematical model. To overcome this problem, 11 sets of identified parameters of a suspension system have been compared, taken from the most recent published work. From this investigation, a set of parameters were chosen which showed a better performance than others in respect of peak amplitude and settling time. These chosen parameters were then used to investigate the performance of a new modified continuous skyhook control strategy with adaptive gain that dictates the vehicle's semi-active suspension system. The proposed system first captures the road profile input over a certain period. Then it calculates the best possible value of the skyhook gain (SG) for the subsequent process. Meanwhile the system is controlled according to the new modified skyhook control law using an initial or previous value of the SG. In this study, the proposed suspension system is compared with passive and other recently reported skyhook controlled semi-active suspension systems. Its performances have been evaluated in terms of ride comfort and road handling performance. The model has been validated in accordance with the international standards of admissible acceleration levels ISO2631 and human vibration perception.

  4. The Efficiency of Setting Parameters in a Modified Shuffled Frog Leaping Algorithm Applied to Optimizing Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Daniel Mora-Melia

    2016-04-01

    Full Text Available This paper presents a modified Shuffled Frog Leaping Algorithm (SFLA applied to the design of water distribution networks. Generally, one of the major disadvantages of the traditional SFLA is the high number of parameters that need to be calibrated for proper operation of the algorithm. A method for calibrating these parameters is presented and applied to the design of three benchmark medium-sized networks widely known in the literature (Hanoi, New York Tunnel, and GoYang. For each of the problems, over 35,000 simulations were conducted. Then, a statistical analysis was performed, and the relative importance of each of the parameters was analyzed to achieve the best possible configuration of the modified SFLA. The main conclusion from this study is that not all of the original SFL algorithm parameters are important. Thus, the fraction of frogs in the memeplex q can be eliminated, while the other parameters (number of evolutionary steps Ns, number of memeplexes m, and number of frogs n may be set to constant values that run optimally for all medium-sized networks. Furthermore, the modified acceleration parameter C becomes the key parameter in the calibration process, vastly improving the results provided by the original SFLA.

  5. Effects of continuous and intermittent magnetic fields on oxidative parameters in vivo.

    Science.gov (United States)

    Coşkun, Sule; Balabanli, Barbaros; Canseven, Ayşe; Seyhan, Nesrin

    2009-02-01

    Continuous and intermittent 50 Hz, 1.5 mT magnetic field with the exposure period of 4 h/day for 4 days was used to investigate its possible effect on adult guinea pigs. Tissues and plasma specimens were assessed by biochemical parameters. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and myeloperoxidase activity (MPO) were examined in plasma, liver and brain tissues. All parameters were determined by spectrophotometer. While intermittent magnetic field was effective on plasma lipid peroxidation, continuous magnetic field was found to be effective on plasma MPO activity and NO levels. Augmentation of lipid peroxidation was also observed in liver tissue both intermittent and continuous magnetic field exposures. These results indicate that both the intermittent and continuous magnetic field exposures affect various tissues in a distinct manner because of having different tissue antioxidant status and responses.

  6. Deforming the theory lambda-phi-4 along the parameters and fields gradient flows

    CERN Document Server

    Cartas-Fuentevilla, R

    2014-01-01

    Considering the action for the theory $\\lambda\\phi^{4}$ for a massive scalar bosonic field as an entropy functional on the space of coupling constants and on the space of fields, we determine the gradient flows for the scalar field, the mass, and the self-interaction parameter. When the flow parameter is identified with the energy scale, we show that there exist phase transitions between unbroken exact symmetry scenarios and spontaneous symmetry breaking scenarios at increasingly high energies. Since a non-linear heat equation drives the scalar field through a {\\it reaction-diffusion} process, in general the flows are not reversible, mimicking the renormalization group flows of the $c$-theorem; the deformation of the field at increasingly high energies can be described as non-linear traveling waves, or solitons associated to self-similar solutions

  7. Effect of including torsional parameters for histidine-metal interactions in classical force fields for metalloproteins.

    Science.gov (United States)

    Mera-Adasme, Raúl; Sadeghian, Keyarash; Sundholm, Dage; Ochsenfeld, Christian

    2014-11-20

    Classical force-field parameters of the metal site of metalloproteins usually comprise only the partial charges of the involved atoms, as well as the bond-stretching and bending parameters of the metal-ligand interactions. Although for certain metal ligands such as histidine residues, the torsional motions at the metal site play an important role for the dynamics of the protein, no such terms have been considered to be crucial in the parametrization of the force fields, and they have therefore been omitted in the parametrization. In this work, we have optimized AMBER-compatible force-field parameters for the reduced state of the metal site of copper, zinc superoxide dismutase (SOD1) and assessed the effect of including torsional parameters for the histidine-metal interactions in molecular dynamics simulations. On the basis of the obtained results, we recommend that torsion parameters of the metal site are included when processes at the metal site are investigated or when free-energy calculations are performed. As the torsion parameters mainly affect the structure of the metal site, other kinds of structural studies can be performed without considering the torsional parameters of the metal site.

  8. Evaluation of accuracy of B-spline transformation-based deformable image registration with different parameter settings for thoracic images.

    Science.gov (United States)

    Kanai, Takayuki; Kadoya, Noriyuki; Ito, Kengo; Onozato, Yusuke; Cho, Sang Yong; Kishi, Kazuma; Dobashi, Suguru; Umezawa, Rei; Matsushita, Haruo; Takeda, Ken; Jingu, Keiichi

    2014-11-01

    Deformable image registration (DIR) is fundamental technique for adaptive radiotherapy and image-guided radiotherapy. However, further improvement of DIR is still needed. We evaluated the accuracy of B-spline transformation-based DIR implemented in elastix. This registration package is largely based on the Insight Segmentation and Registration Toolkit (ITK), and several new functions were implemented to achieve high DIR accuracy. The purpose of this study was to clarify whether new functions implemented in elastix are useful for improving DIR accuracy. Thoracic 4D computed tomography images of ten patients with esophageal or lung cancer were studied. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomical landmarks that had been manually identified. DIR between peak-inhale and peak-exhale images was performed with four types of parameter settings. The first one represents original ITK (Parameter 1). The second employs the new function of elastix (Parameter 2), and the third was created to verify whether new functions improve DIR accuracy while keeping computational time (Parameter 3). The last one partially employs a new function (Parameter 4). Registration errors for these parameter settings were calculated using the manually determined landmark pairs. 3D registration errors with standard deviation over all cases were 1.78 (1.57), 1.28 (1.10), 1.44 (1.09) and 1.36 (1.35) mm for Parameter 1, 2, 3 and 4, respectively, indicating that the new functions are useful for improving DIR accuracy, even while maintaining the computational time, and this B-spline-based DIR could be used clinically to achieve high-accuracy adaptive radiotherapy. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  9. Identification of a set of macroscopic elastic parameters in a 3D woven composite: Uncertainty analysis and regularization

    KAUST Repository

    Gras, Renaud

    2015-03-01

    Performing a single but complex mechanical test on small structures rather than on coupons to probe multiple strain states/histories for identification purposes is nowadays possible thanks to full-field measurements. The aim is to identify many parameters thanks to the heterogeneity of mechanical fields. Such an approach is followed herein, focusing on a blade root made of 3D woven composite. The performed test, which is analyzed using global Digital Image Correlation (DIC), provides heterogeneous kinematic fields due to the particular shape of the sample. This displacement field is further processed to identify the four in-plane material parameters of the macroscopic equivalent orthotropic behavior. The key point, which may limit the ability to draw reliable conclusions, is the presence of acquisition noise in the original images that has to be tracked along the DIC/identification processing to provide uncertainties on the identified parameters. A further regularization based on a priori knowledge is finally introduced to compensate for possible lack of experimental information needed for completing the identification.

  10. Accurate prediction of severe allergic reactions by a small set of environmental parameters (NDVI, temperature).

    Science.gov (United States)

    Notas, George; Bariotakis, Michail; Kalogrias, Vaios; Andrianaki, Maria; Azariadis, Kalliopi; Kampouri, Errika; Theodoropoulou, Katerina; Lavrentaki, Katerina; Kastrinakis, Stelios; Kampa, Marilena; Agouridakis, Panagiotis; Pirintsos, Stergios; Castanas, Elias

    2015-01-01

    Severe allergic reactions of unknown etiology,necessitating a hospital visit, have an important impact in the life of affected individuals and impose a major economic burden to societies. The prediction of clinically severe allergic reactions would be of great importance, but current attempts have been limited by the lack of a well-founded applicable methodology and the wide spatiotemporal distribution of allergic reactions. The valid prediction of severe allergies (and especially those needing hospital treatment) in a region, could alert health authorities and implicated individuals to take appropriate preemptive measures. In the present report we have collecterd visits for serious allergic reactions of unknown etiology from two major hospitals in the island of Crete, for two distinct time periods (validation and test sets). We have used the Normalized Difference Vegetation Index (NDVI), a satellite-based, freely available measurement, which is an indicator of live green vegetation at a given geographic area, and a set of meteorological data to develop a model capable of describing and predicting severe allergic reaction frequency. Our analysis has retained NDVI and temperature as accurate identifiers and predictors of increased hospital severe allergic reactions visits. Our approach may contribute towards the development of satellite-based modules, for the prediction of severe allergic reactions in specific, well-defined geographical areas. It could also probably be used for the prediction of other environment related diseases and conditions.

  11. Accurate prediction of severe allergic reactions by a small set of environmental parameters (NDVI, temperature.

    Directory of Open Access Journals (Sweden)

    George Notas

    Full Text Available Severe allergic reactions of unknown etiology,necessitating a hospital visit, have an important impact in the life of affected individuals and impose a major economic burden to societies. The prediction of clinically severe allergic reactions would be of great importance, but current attempts have been limited by the lack of a well-founded applicable methodology and the wide spatiotemporal distribution of allergic reactions. The valid prediction of severe allergies (and especially those needing hospital treatment in a region, could alert health authorities and implicated individuals to take appropriate preemptive measures. In the present report we have collecterd visits for serious allergic reactions of unknown etiology from two major hospitals in the island of Crete, for two distinct time periods (validation and test sets. We have used the Normalized Difference Vegetation Index (NDVI, a satellite-based, freely available measurement, which is an indicator of live green vegetation at a given geographic area, and a set of meteorological data to develop a model capable of describing and predicting severe allergic reaction frequency. Our analysis has retained NDVI and temperature as accurate identifiers and predictors of increased hospital severe allergic reactions visits. Our approach may contribute towards the development of satellite-based modules, for the prediction of severe allergic reactions in specific, well-defined geographical areas. It could also probably be used for the prediction of other environment related diseases and conditions.

  12. Optimal location and parameter setting of UPFC for enhancing power system security based on Differential Evolution algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Shaheen, Husam I.; Rashed, Ghamgeen I.; Cheng, S.J. [Electric Power Security and High Efficiency Lab, Department of Electrical Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China)

    2011-01-15

    This paper presents a new approach based on Differential Evolution (DE) technique to find out the optimal placement and parameter setting of Unified Power Flow Controller (UPFC) for enhancing power system security under single line contingencies. Firstly, we perform a contingency analysis and ranking process to determine the most severe line outage contingencies considering line overloads and bus voltage limit violations as a Performance Index. Secondly, we apply DE technique to find out the optimal location and parameter setting of UPFC under the determined contingency scenarios. To verify our proposed approach, we perform simulations on an IEEE 14-bus and an IEEE 30-bus power systems. The results we have obtained indicate that installing UPFC in the location optimized by DE can significantly enhance the security of power system by eliminating or minimizing the overloaded lines and the bus voltage limit violations. (author)

  13. A Uniform Set of DAV Atmospheric Parameters to Enable Differential Seismology

    Science.gov (United States)

    Fuchs, Joshua T.; Dunlap, Bart H.; Clemens, J. Christopher; Meza, Jesus; Dennihy, Erik

    2017-01-01

    We have observed over 130 hydrogen-atmosphere pulsating white dwarfs (DAVs) using the Goodman Spectrograph on the SOAR Telescope. This includes all known DAVs south of +10° declination as well as those observed by the K2 mission. Because it employs a single instrument, our sample allows us to carefully explore systematics in the determination of atmospheric parameters, Teff and log(g). While some systematics show changes of up to 300 K in Teff and 0.06 in log(g), the relative position of each star in the Teff-log(g) plane is more secure. These relative positions, combined with differences in pulsation spectra, will allow us to investigate relative differences in the structure and composition of over 130 DAVs through differential seismology.

  14. Design Parameters for Evaluating Light Settings and Light Atmosphere in Hospital Wards

    DEFF Research Database (Denmark)

    Stidsen, Lone; Kirkegaard, Poul Henning; Fisker, Anna Marie

    2010-01-01

    When constructing and designing Danish hospitals for the future, patients, staff and guests are in focus. It is found important to have a starting point in healing architecture and create an environment with knowledge of users sensory and functionally needs and looks at how hospital wards can...... support patients’ experience or maybe even have a positive influence on the recovery process. Thus at a general level, it is a crucial task to investigate how aspects such as the design of the environment, arts, lights, sounds can support and improve the patients’ recovery rate and the satisfaction...... of staff and guests in the future hospital. This paper is based on Böhmes G. concept of atmosphere dealing with the effect of light in experiencing atmosphere, and the importance having a holistic approach when designing a pleasurable light atmosphere. It shows important design parameters for pleasurable...

  15. Parameters for efficient growth of second harmonic field in nonlinear photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Shereena, E-mail: sherin5462@gmail.com; Khan, Mohd. Shahid; Hafiz, Aurangzeb Khurram

    2014-03-01

    The ultrashort pulse propagation and nonlinear second harmonic generation under the undepleted pump approximation in a quadratic nonlinear photonic crystal (NPC) structure is theoretically investigated and the optimized parameters for high second harmonic generation conversion efficiency are extracted. The transfer matrix method is used for the numerical formulation for oblique angle of incidence. A unique set of material combination GaInP/InAlP is selected as alternating nonlinear and linear layers. The NPC parameters like incident angle and layer thickness are manipulated to obtain the exact phase matching using double resonance condition for a fixed number of layers with known experimental material parameters.

  16. Valence state parameters of all transition metal atoms in metalloproteins--development of ABEEMσπ fluctuating charge force field.

    Science.gov (United States)

    Yang, Zhong-Zhi; Wang, Jian-Jiang; Zhao, Dong-Xia

    2014-09-05

    To promote accuracy of the atom-bond electronegativity equalization method (ABEEMσπ) fluctuating charge polarizable force fields, and extend it to include all transition metal atoms, a new parameter, the reference charge is set up in the expression of the total energy potential function. We select over 700 model molecules most of which model metalloprotein molecules that come from Protein Data Bank. We set reference charges for different apparent valence states of transition metals and calibrate the parameters of reference charges, valence state electronegativities, and valence state hardnesses for ABEEMσπ through linear regression and least square method. These parameters can be used to calculate charge distributions of metalloproteins containing transition metal atoms (Sc-Zn, Y-Cd, and Lu-Hg). Compared the results of ABEEMσπ charge distributions with those obtained by ab initio method, the quite good linear correlations of the two kinds of charge distributions are shown. The reason why the STO-3G basis set in Mulliken population analysis for the parameter calibration is specially explained in detail. Furthermore, ABEEMσπ method can also quickly and quite accurately calculate dipole moments of molecules. Molecular dynamics optimizations of five metalloproteins as the examples show that their structures obtained by ABEEMσπ fluctuating charge polarizable force field are very close to the structures optimized by the ab initio MP2/6–311G method. This means that the ABEEMσπ/MM can now be applied to molecular dynamics simulations of systems that contain metalloproteins with good accuracy.

  17. A singular one-parameter family of solutions in cubic superstring field theory

    Science.gov (United States)

    Arroyo, E. Aldo

    2016-05-01

    Performing a gauge transformation of a simple identity-like solution of superstring field theory, we construct a one-parameter family of solutions, and by evaluating the energy associated to this family, we show that for most of the values of the parameter the solution represents the tachyon vacuum, except for two isolated singular points where the solution becomes the perturbative vacuum and the half brane solution.

  18. Setting ventilation parameters guided by electrical impedance tomography in an animal trial of acute respiratory distress syndrome

    Science.gov (United States)

    Czaplik, Michael; Biener, Ingeborg; Leonhardt, Steffen; Rossaint, Rolf

    2014-03-01

    Since mechanical ventilation can cause harm to lung tissue it should be as protective as possible. Whereas numerous options exist to set ventilator parameters, an adequate monitoring is lacking up to date. The Electrical Impedance Tomography (EIT) provides a non-invasive visualization of ventilation which is relatively easy to apply and commercially available. Although there are a number of published measures and parameters derived from EIT, it is not clear how to use EIT to improve clinical outcome of e.g. patients suffering from acute respiratory distress syndrome (ARDS), a severe disease with a high mortality rate. On the one hand, parameters should be easy to obtain, on the other hand clinical algorithms should consider them to optimize ventilator settings. The so called Global inhomogeneity (GI) index bases on the fact that ARDS is characterized by an inhomogeneous injury pattern. By applying positive endexpiratory pressures (PEEP), homogeneity should be attained. In this study, ARDS was induced by a double hit procedure in six pigs. They were randomly assigned to either the EIT or the control group. Whereas in the control group the ARDS network table was used to set the PEEP according to the current inspiratory oxygen fraction, in the EIT group the GI index was calculated during a decremental PEEP trial. PEEP was kept when GI index was lowest. Interestingly, PEEP was significantly higher in the EIT group. Additionally, two of these animals died ahead of the schedule. Obviously, not only homogeneity of ventilation distribution matters but also limitation of over-distension.

  19. Ph.D. Thesis: Quantum Field Theory and Gravity in Causal Sets

    CERN Document Server

    Sverdlov, Roman

    2009-01-01

    This is is a copy of dissertation that I have submitted in defense of my ph.d. thesis, with some minor changes that I have made since then. The goal of the project is to generalize matter fields and their Lagrangians from regular space time to causal sets.

  20. Ph.D. Thesis: Quantum Field Theory and Gravity in Causal Sets

    Science.gov (United States)

    Sverdlov, Roman

    2009-05-01

    This is is a copy of dissertation that I have submitted in defense of my ph.d. thesis, with some minor changes that I have made since then. The goal of the project is to generalize matter fields and their Lagrangians from regular space time to causal sets.

  1. Campbell and Rubin: A Primer and Comparison of Their Approaches to Causal Inference in Field Settings

    Science.gov (United States)

    Shadish, William R.

    2010-01-01

    This article compares Donald Campbell's and Donald Rubin's work on causal inference in field settings on issues of epistemology, theories of cause and effect, methodology, statistics, generalization, and terminology. The two approaches are quite different but compatible, differing mostly in matters of bandwidth versus fidelity. Campbell's work…

  2. Campbell and Rubin: A Primer and Comparison of Their Approaches to Causal Inference in Field Settings

    Science.gov (United States)

    Shadish, William R.

    2010-01-01

    This article compares Donald Campbell's and Donald Rubin's work on causal inference in field settings on issues of epistemology, theories of cause and effect, methodology, statistics, generalization, and terminology. The two approaches are quite different but compatible, differing mostly in matters of bandwidth versus fidelity. Campbell's work…

  3. Setting a Neglected Variable in Science Education: Investigations Into Outdoor Field Trips. Final Report.

    Science.gov (United States)

    Falk, John H.; Balling, John D.

    Reported are three studies of attitudes towards and effects of science education field trips. In the first study, 425 fifth and sixth graders participated in outdoor science activities in one of three types of settings. Results indicated that more learning took place when the number of available examples of concepts to be learned and setting…

  4. Opening Options: Making Field Education Work in a Private Practice Clinic Setting

    Science.gov (United States)

    Mooradian, John K.; Knaggs, Constance; Hock, Robert; LaCharite, David

    2011-01-01

    This article describes the use of social work field placements in a private practice setting to prepare MSW students for clinical work. The authors used "autoethnography", which is personal narrative that explores the writer's experience of life, to describe interpersonal and contextual characteristics, as well as procedures implemented to conduct…

  5. Monitoring electro-magnetic field in urban areas: new set-ups and results

    Energy Technology Data Exchange (ETDEWEB)

    Lubritto, C.; Petraglia, A.; Paribello, G.; Formosi, R.; Rosa, M. de; Vetromile, C.; Palmieri, A.; D' Onofrio, A. [Seconda Universita di Napoli, Dipt. di Scienze Ambientali, Caserta (Italy); Di Bella, G.; Giannini, V. [Vector Group, Roma (Italy)

    2006-07-01

    In this paper two different set-ups for continuous monitoring of electromagnetic levels are presented: the first one (Continuous Time E.M.F. Monitoring System) is based upon a network of fixed stations, allowing a detailed field monitoring as function of the time; the second one (Mobile Measurements Units) resorts to portable stations mounted on standard bicycles, allowing a positional screening in limited time intervals. For both set-ups a particular attention has been paid to the data management, by means of tools like web geographic information systems (Web-Gis). Moreover the V.I.C.R.E.M./E.L.F. software has been used for a predictive analysis of the electromagnetic field levels along with the geo referenced data coming from the field measurements. Starting from these results it has been realized that there is a need for an efficient and correct action of monitoring and information/formation in this domain, where dis-information or bad information is very often spread in the population, in particular in a field where the process of the appreciation and assessment of risk does not necessarily make use of a rationale, technically-informed procedure, but the judgement is rather based on a personal feeling, which may derive from a limited, unstructured set of information, using a set of qualitative attributes rather than a quantity. (N.C.)

  6. Predictors of At-Risk Intoxication in a University Field Setting: Social Anxiety, Demographics, and Intentions

    Science.gov (United States)

    Smith, Ryan C.; Bowdring, Molly A.; Geller, E. Scott

    2015-01-01

    Objective: The determinants of alcohol consumption among university students were investigated in a downtown field setting with blood alcohol content (BAC) as the dependent variable. Participants: In total, 521 participants completed a brief survey and had their BAC assessed during April 2013. Methods: Between 10:00 pm and 2:00 am, teams of…

  7. Between Two Advisors: Interconnecting Academic and Workplace Settings in an Emerging Field

    Science.gov (United States)

    Hytönen, Kaisa; Palonen, Tuire; Lehtinen, Erno; Hakkarainen, Kai

    2016-01-01

    This article examines a new training design for continuing professional development that aims to support the learning of the novel knowledge and skills needed in emerging professional fields by interconnecting academic and workplace settings. The training design is based on using two advisors, one from working life and the other from an academic…

  8. Predictors of At-Risk Intoxication in a University Field Setting: Social Anxiety, Demographics, and Intentions

    Science.gov (United States)

    Smith, Ryan C.; Bowdring, Molly A.; Geller, E. Scott

    2015-01-01

    Objective: The determinants of alcohol consumption among university students were investigated in a downtown field setting with blood alcohol content (BAC) as the dependent variable. Participants: In total, 521 participants completed a brief survey and had their BAC assessed during April 2013. Methods: Between 10:00 pm and 2:00 am, teams of…

  9. Establishing "Fields of Care": Teaching Settings as Active Participants in Science Education

    Science.gov (United States)

    Blatt, Erica N.

    2014-01-01

    In their article, "Space, relations, and the learning of science," Wolff-Michael Roth and Pei-Ling Hsu draw our attention to the importance of field in the teaching and learning of science. While the Roth and Hsu study is focused on the scientific research laboratory as an internship setting for the teaching of science, this response to…

  10. Use of a probing pulsed magnetic field for determining plasma parameters

    Science.gov (United States)

    Rousskikh, A. G.; Oreshkin, V. I.; Zhigalin, A. S.; Yushkov, G. Yu.

    2016-11-01

    A novel, simple, and readily usable method is proposed for measuring the electrical conductivity and temperature of a plasma. The method is based on the interaction of the test plasma with a pulsed magnetic field. The electric signals induced by the magnetic field in the circuits of two probes (miniature solenoids), one immersed in the test plasma and the other placed outside the plasma, provide data for estimating the plasma parameters. The method was verified experimentally by determining the parameters of the plasma flows generated in the cathode spots high-current pulsed vacuum arcs that were used to form cylindrical shells of bismuth Z-pinch plasma.

  11. Interval analysis of transient temperature field with uncertain-but-bounded parameters

    Science.gov (United States)

    Wang, Chong; Qiu, ZhiPing

    2014-10-01

    Based on the traditional finite volume method, a new numerical technique is presented for the transient temperature field prediction with interval uncertainties in both the physical parameters and initial/boundary conditions. New stability theory applicable to interval discrete schemes is developed. Interval ranges of the uncertain temperature field can be approximately yielded by two kinds of parameter perturbation methods. Different order Neumann series are adopted to approximate the interval matrix inverse. By comparing the results with traditional Monte Carlo simulation, a numerical example is given to demonstrate the feasibility and effectiveness of the proposed model and methods.

  12. VFFDT: A New Software for Preparing AMBER Force Field Parameters for Metal-Containing Molecular Systems.

    Science.gov (United States)

    Zheng, Suqing; Tang, Qing; He, Jian; Du, Shiyu; Xu, Shaofang; Wang, Chaojie; Xu, Yong; Lin, Fu

    2016-04-25

    Force fields are fundamental to molecular dynamics simulations. However, the incompleteness of force field parameters has been a long-standing problem, especially for metal-related systems. In our previous work, we adopted the Seminario method based on the Hessian matrix to systematically derive the zinc-related force field parameters for AMBER. In this work, in order to further simplify the whole protocol, we have implemented a user-friendly Visual Force Field Derivation Toolkit (VFFDT) to derive the force field parameters via simply clicking on the bond or angle in the 3D viewer, and we have further extended our previous program to support the Hessian matrix output from a variety of quantum mechanics (QM) packages, including Gaussian 03/09, ORCA 3.0, QChem, GAMESS-US, and MOPAC 2009/2012. In this toolkit, a universal VFFDT XYZ file format containing the raw Hessian matrix is available for all of the QM packages, and an instant force field parametrization protocol based on a semiempirical quantum mechanics (SQM) method is introduced. The new function that can automatically obtain the relevant parameters for zinc, copper, iron, etc., which can be exported in AMBER Frcmod format, has been added. Furthermore, our VFFDT program can read and write files in AMBER Prepc, AMBER Frcmod, and AMBER Mol2 format and can also be used to customize, view, copy, and paste the force field parameters in the context of the 3D viewer, which provides utilities complementary to ANTECHAMBER, MCPB, and MCPB.py in the AmberTools.

  13. Electric field gradients of transition metal complexes from density functional theory: assessment of functionals, geometries and basis sets.

    Science.gov (United States)

    Bjornsson, Ragnar; Bühl, Michael

    2010-06-14

    Electric field gradients (EFGs) were computed for the first-row transition metal nuclei in Cr(C(6)H(6))(CO)(3), MnO(3)F, Mn(CO)(5)H, MnCp(CO)(3), Co(CO)(4)H, Co(CO)(3)(NO) and VCp(CO)(4), for which experimental gas-phase data (in form of nuclear quadrupole coupling constants) are available from microwave spectroscopy. A variety of exchange-correlation functionals were assessed, among which range-separated hybrids (such as CAM-B3LYP or LC-omegaPBE) perform best, followed by global hybrids (such as B3LYP and PBE0) and gradient-corrected functionals (such as BP86). While large basis sets are required on the metal atom for converged EFGs, smaller basis sets can be employed on the ligands. In most cases, EFGs show little sensitivity toward the geometrical parameters.

  14. Effects of Different Electromagnetic Fields on Circadian Rhythms of Some Haematochemical Parameters in Rats

    Institute of Scientific and Technical Information of China (English)

    LAURA CONTALBRIGO; CALOGERO STELLETTA; LAURA FALCIONI; STEFANIA CASELLA; GIUSEPPE PICCION; MORANDO SOFFRITTI; MASSIMO MORGANTE

    2009-01-01

    Objectives To investigate the effects of different electromagnetic fields on some haematochemical parameters of circadian rhythms in Sprague-Dawley rats. Methods The study was carried out in 18 male and 18 female rats in good health conditions exposed to 50 Hz magnetic sinusoid fields at the intensity of 1000μT, 100μT, and 0μT (control group) respectively, and in 18 male and 18 female rats in good health conditions exposed to 1.8 GHz electromagnetic fields at the intensity of 50 V/m, 25 V/m and 0 V/m (control group), respectively. Following haematochemical parameters for glucose, triglycerides, and total cholesterol were measured. Results Different effects of electromagnetic fields on circadian rhythms of both male and female rats were observed. Different changes occurred in some haematochemical parameters for glucose, triglycerides, and total cholesterol (P<0.05). Conclusion Exposure to different electromagnetic fields is responsible for the variations of some haematochemical parameters in rats.

  15. Magnetic field induced switching of the antiferromagnetic order parameter in thin films of magnetoelectric chromia

    Science.gov (United States)

    Fallarino, Lorenzo; Berger, Andreas; Binek, Christian

    2015-02-01

    A Landau-theoretical approach is utilized to model the magnetic field induced reversal of the antiferromagnetic order parameter in thin films of magnetoelectric antiferromagnets. A key ingredient of this peculiar switching phenomenon is the presence of a robust spin polarized state at the surface of the antiferromagnetic films. Surface or boundary magnetization is symmetry allowed in magnetoelectric antiferromagnets and experimentally established for chromia thin films. It couples rigidly to the antiferromagnetic order parameter and its Zeeman energy creates a pathway to switch the antiferromagnet via magnetic field application. In the framework of a minimalist Landau free energy expansion, the temperature dependence of the switching field and the field dependence of the transition width are derived. Least-squares fits to magnetometry data of (0001 ) textured chromia thin films strongly support this model of the magnetic reversal mechanism.

  16. Behaviour of the order parameter of the simple magnet in an external field

    Directory of Open Access Journals (Sweden)

    M.P.Kozlovskii

    2005-01-01

    Full Text Available The effect of a homogeneous external field on the three-dimensional uniaxial magnet behaviour near the critical point is investigated within the framework of the nonperturbative collective variables method using the ρ4 model. The research is carried out for the low-temperature region. The analytic explicit expressions for the free energy, average spin moment and susceptibility are obtained for weak and strong fields in comparison with the field value belonging to the pseudocritical line. The calculations are performed on the microscopic level without any adjusting parameters. It is established that the long-wave fluctuations of the order parameter play a crucial role in forming a crossover between the temperature-dependence and field-dependence critical behaviour of the system.

  17. DETERMINATION OF RELATIONAL CLASSIFICATION AMONG HULL FORM PARAMETERS AND SHIP MOTIONS PERFORMANCE FOR A SET OF SMALL VESSELS

    Directory of Open Access Journals (Sweden)

    Ayla Sayli

    2016-08-01

    Full Text Available Data science for engineers is the most recent research area which suggests to analyse large data sets in order to find data analytics and use them for better designing and modelling. Ship design practice reveals that conceptual ship design is critically important for a successful basic design. Conceptual ship design needs to identify the true set of design variables influencing vessel performance and costs to define the best possible basic design by the use of performance prediction model. This model can be constructed by design engineers. The main idea of this paper comes from this crucial idea to determine relational classification of a set of small vessels using their hull form parameters and performance characteristics defined by transfer functions of heave and pitch motions and of absolute vertical acceleration, by our in-house software application based on K-Means algorithm from data mining. This application is implemented in the C# programming language on Microsoft SQL Server database. We also use the Elbow method to estimate the true number of clusters for K-Means algorithm. The computational results show that the considered set of small vessels can be clustered in three categories according to their functional relations of their hull form parameters and transfer functions considering all cases of three loading conditions, seven ship speeds as non-dimensional Froude numbers (Fn and nine wave-length to ship-length values (λ/L.

  18. New determination of abundances and stellar parameters for a set of weak G-band stars

    CERN Document Server

    Palacios, A; Masseron, T; Thévenin, F; Itam-Pasquet, J; Parthasarathy, M

    2015-01-01

    Weak G-band (wGb) stars are very peculiar red giants almost devoided of carbon and often mildly enriched in lithium. Despite their very puzzling abundance patterns, very few detailed spectroscopic studies existed up to a few years ago, preventing any clear understanding of the wGb phenomenon. We recently proposed the first consistent analysis of published data for 28 wGb stars and identified them as descendants of early A-type to late B-type stars, without being able to conclude on their evolutionary status or the origin of their peculiar abundance pattern. We used newly obtained high-resolution and high SNR spectra for 19 wGb stars in the southern and northern hemisphere to homogeneously derive their fundamental parameters, metallicities, as well as the spectroscopic abundances for Li, C, N, O, Na, Sr, and Ba. We also computed dedicated stellar evolution models that we used to determine the masses and to investigate the evolutionary status and chemical history of the stars in our sample. We confirm that the ...

  19. Impact of magnetic field parameters and iron oxide nanoparticle properties on heat generation for use in magnetic hyperthermia

    Science.gov (United States)

    Shah, Rhythm R.; Davis, Todd P.; Glover, Amanda L.; Nikles, David E.; Brazel, Christopher S.

    2015-08-01

    Heating of nanoparticles (NPs) using an AC magnetic field depends on several factors, and optimization of these parameters can improve the efficiency of heat generation for effective cancer therapy while administering a low NP treatment dose. This study investigated magnetic field strength and frequency, NP size, NP concentration, and solution viscosity as important parameters that impact the heating efficiency of iron oxide NPs with magnetite (Fe3O4) and maghemite (γ-Fe2O3) crystal structures. Heating efficiencies were determined for each experimental setting, with specific absorption rates (SARs) ranging from 3.7 to 325.9 W/g Fe. Magnetic heating was conducted on iron oxide NPs synthesized in our laboratories (with average core sizes of 8, 11, 13, and 18 nm), as well as commercially-available iron oxides (with average core sizes of 8, 9, and 16 nm). The experimental magnetic coil system made it possible to isolate the effect of magnetic field parameters and independently study the effect on heat generation. The highest SAR values were found for the 18 nm synthesized particles and the maghemite nanopowder. Magnetic field strengths were applied in the range of 15.1-47.7 kA/m, with field frequencies ranging from 123 to 430 kHz. The best heating was observed for the highest field strengths and frequencies tested, with results following trends predicted by the Rosensweig equation. An increase in solution viscosity led to lower heating rates in nanoparticle solutions, which can have significant implications for the application of magnetic fluid hyperthermia in vivo.

  20. Impact of magnetic field parameters and iron oxide nanoparticle properties on heat generation for use in magnetic hyperthermia.

    Science.gov (United States)

    Shah, Rhythm R; Davis, Todd P; Glover, Amanda L; Nikles, David E; Brazel, Christopher S

    2015-08-01

    Heating of nanoparticles (NPs) using an AC magnetic field depends on several factors, and optimization of these parameters can improve the efficiency of heat generation for effective cancer therapy while administering a low NP treatment dose. This study investigated magnetic field strength and frequency, NP size, NP concentration, and solution viscosity as important parameters that impact the heating efficiency of iron oxide NPs with magnetite (Fe3O4) and maghemite (γ-Fe2O3) crystal structures. Heating efficiencies were determined for each experimental setting, with specific absorption rates (SARs) ranging from 3.7 to 325.9 W/g Fe. Magnetic heating was conducted on iron oxide NPs synthesized in our laboratories (with average core sizes of 8, 11, 13, and 18 nm), as well as commercially-available iron oxides (with average core sizes of 8, 9, and 16 nm). The experimental magnetic coil system made it possible to isolate the effect of magnetic field parameters and independently study the effect on heat generation. The highest SAR values were found for the 18 nm synthesized particles and the maghemite nanopowder. Magnetic field strengths were applied in the range of 15.1 to 47.7 kA/m, with field frequencies ranging from 123 to 430 kHz. The best heating was observed for the highest field strengths and frequencies tested, with results following trends predicted by the Rosensweig equation. An increase in solution viscosity led to lower heating rates in nanoparticle solutions, which can have significant implications for the application of magnetic fluid hyperthermia in vivo.

  1. Field investigation on effects of railway track geometric parameters on rail wear

    Institute of Scientific and Technical Information of China (English)

    SADEGHI J.; AKBARI B.

    2006-01-01

    Rail wear has dramatic impact on track performance, ride quality and maintenance costs. The amount of rail wear is influenced by various elements among which geometric parameters play an important role. The amount of wear in Iran's railway lines and its imposed maintenance costs oblige us to make modifications on the various geometrical parameters. In order to ensure the effectiveness of these changes, it is necessary to investigate these parameters and their effects on the wear. This research is aimed at studying the effects of different track geometrical parameters on the vertical and lateral wear by conducting a three phase field investigation. The first phase was carried out at the switches of a station, the second phase at a straight line, and the third at a curved line out of the station. The results obtained are analyzed and the role of each track geometrical parameter in the rail wear is discussed. Recommendations for prevention or reduction of rail wear are presented.

  2. Haematologic parameters as risk factors for cardiac infarction, in an occupational health care setting.

    Science.gov (United States)

    Knottnerus, J A; Swaen, G M; Slangen, J J; Volovics, A; Durinck, J

    1988-01-01

    It is still controversial, whether moderately high haematocrit (Ht) and haemoglobin (Hb) values are risk factors for coronary heart disease. Using the computerized data-system of the Periodical Medical Examination (PME) of Phillips' International Electrical Company, a case-control study was carried out. Cases were male workers (n = 104, from 50 to 60 years of age) who had suffered a first, non-fatal myocardial infarction, and who had had a PME prior (on the average 16 months) to the occurrence of infarction. For each case two age-matched healthy controls were selected from the PME-attendancy list (= 208). For each subject information was abstracted from the PME-records about haematologic parameters and covariates (smoking, cholesterol, blood pressure, pulse-rate, weight, height, FEV5, consumption of antihypertensive agents). After dichotomizing the haematocrit and haemoglobin values at their whole sample means (0.46 l/l and 9.7 mmol/l respectively) in "low" (lower than or equal to the mean) and "high" (greater than the mean), crude odds-ratio's of 2.7 (95% CI: 1.6-4.6) and 2.1 (95% CI: 1.2-3.6) were found for Ht and Hb respectively, when comparing "high" with "low" levels. The associations between Ht and Hb, and the occurrence of myocardial infarction were still present after controlling for covariates using multiple logistic regression models, entering the continuous variables with their exact values. After adjustment, mean corpuscular volume (MCV) also appeared to be correlated with infarction. Our results confirm the hypothesis that moderately high haematocrit and--to a lesser extent--haemoglobin and MCV-values are risk factors for the occurrence of myocardial infarction.

  3. A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Hosseini-Tabesh Behnaz

    2015-01-01

    Full Text Available Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h and field conditions (23-43°C, and relative humidity of 27-95%. The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r, net reproductive rate (R0, and the finite rate of increase (λ under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops

  4. Statistical analysis of electric field parameters for negative lightning in Malaysia

    Science.gov (United States)

    Wooi, Chin-Leong; Abdul-Malek, Zulkurnain; Ahmad, Noor-Azlinda; El Gayar, Ali I.

    2016-08-01

    This paper presents a comparative study on the electric field and its derivative parameters of negative lightning in Malaysia and other regions. This study is the first in Malaysia where the parameters of negative electric field and its derivative are thoroughly analyzed. 104 negative lightning flashes containing 277 negative return strokes occurring within 10-100 km from the measuring station and recorded during monsoon period in the state of Johor, Malaysia had been analyzed. It was found that 73% of the recorded flashes are multiple strokes with an average multiplicity of 2.6 strokes per flash. For first return strokes, the arithmetic mean (AM) of initial peak electric field and the AM of initial peak electric field derivative are 21.8 V/m and 11.3 V/m/μs, respectively. The initial peaks of electric field and its derivative for first return strokes are larger than those for the subsequent return strokes. Comparison of overall results with those obtained earlier in Sri Lanka, Germany, Sweden, Japan, Florida indicates that several electric field and its derivative parameters are affected by propagation media and geographical region. Similarity of results with other countries having the same climatic condition is also observed.

  5. EVALUATION OF ERRORS IN PARAMETERS DETERMINATION FOR THE EARTH HIGHLY ANOMALOUS GRAVITY FIELD

    Directory of Open Access Journals (Sweden)

    L. P. Staroseltsev

    2016-05-01

    Full Text Available Subject of Research.The paper presents research results and the simulation of errors caused by determining the Earth gravity field parameters for regions with high segmentation of gravity field. The Kalman filtering estimation of determining errors is shown. Method. Simulation model for the realization of inertial geodetic method for determining the Earth gravity field parameters is proposed. The model is based on high-precision inertial navigation system (INS at the free gyro and high-accuracy satellite system. The possibility of finding the conformity between the determined and stochastic approaches in gravity potential modeling is shown with the example of a point-mass model. Main Results. Computer simulation shows that for determining the Earth gravity field parameters gyro error model can be reduced to two significant indexes, one for each gyro. It is also shown that for regions with high segmentation of gravity field point-mass model can be used. This model is a superposition of attractive and repulsive masses - the so-called gravitational dipole. Practical Relevance. The reduction of gyro error model can reduce the dimension of the Kalman filter used in the integrated system, which decreases the computation time and increases the visibility of the state vector. Finding the conformity between the determined and stochastic approaches allows the application of determined and statistical terminology. Also it helps to create a simulation model for regions with high segmentation of gravity field.

  6. Correlation between optic nerve head structural parameters and glaucomatous visual field indices.

    Science.gov (United States)

    Mizumoto, Kyoichi; Gosho, Masahiko; Zako, Masahiro

    2014-01-01

    We examined associations between optic nerve head structural parameters and glaucomatous visual field indices. The study population included patients with glaucomatous optic neuropathy who were evaluated at Aichi Medical University, Nagakute, Aichi, Japan, from October 2010 to January 2011. A total of 57 eyes from 33 patients were assessed. We measured visual field using a Humphrey field analyzer, peripapillary retinal nerve fiber layer thickness (RNFL-T), and Bruch's membrane opening-minimum rim width (BMO-MRW) using spectral domain optical coherence tomography, and rim area with referring three-dimensional photography. Spearman's rank correlation coefficients were calculated between the threshold of visual sensitivity or total deviation of visual field and the following five optic nerve head structural parameters: RNFL-T length, BMO-MRW length, rim area, and calculated RNFL-T and BMO-MRW volumes (each length multiplied by rim area). The Akaike information criterion was calculated to determine which structural parameter was the best predictor of each visual field index. Threshold of visual sensitivity had correlation coefficients of 0.23 with global sector of RNFL-T, 0.32 with BMO-MRW, 0.14 with rim area, 0.21 with RNFL-T volume, and 0.26 with BMO-MRW volume. The correlation coefficients for each parameter with total deviation of visual field were 0.22, 0.33, 0.28, 0.36, and 0.37, respectively. The Akaike information criterion of BMO-MRW showed the smallest values in analyses of both threshold of visual sensitivity and total deviation. The present results show that RNFL-T volume and BMO-MRW volume were more strongly correlated with total deviation than BMO-MRW, but BMO-MRW appeared to be the best predictor of the two glaucomatous visual field indices.

  7. Asymptotic Behavior of Soliton Solutions with a Double Spectral Parameter for Principal Chiral Field

    Institute of Scientific and Technical Information of China (English)

    SONG Quan-Fu; ZHOU Zi-Xiang

    2005-01-01

    The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speeds of the peaks in the asymptotic solutions are not constants.

  8. Scaling of crystal field parameters between Pd 2REIn and Pd 2RESn

    Science.gov (United States)

    Babateen, M.; Neumann, K.-U.; Ziebeck, K. R. A.

    1995-02-01

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd 2REIn and Pd 2RESn (RE = rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation.

  9. DETERMINATION OF OPERATING FIELDS OF TOLERANCES OF HYDRAULIC SYSTEMS PARAMETERS FOR AIRCRAFT BOARD COMPUTER COMPLEX

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available To determine the operating fields of the tolerances of hydraulic systems parameters for various conditions of work and phases of flight given mathematical relationships and the results obtained in Mathcad in analytical form for the board computer system.

  10. Field-effect-based multifunctional hybrid sensor module for the determination of both (bio-)chemical and physical parameters

    Science.gov (United States)

    Schoening, Michael J.; Poghossian, Arshak; Schultze, J. Walter; Lueth, Hans

    2002-02-01

    Sensor systems for multi-parameter detection in fluidics usually combine different sensors, which are designed to detect either a physical or (bio-)chemical parameter. Therefore, such systems include a more complicated fabrication technology and measuring set-up. In this work, an ISFET (ion-sensitive field-effect transistor), which is well known as a (bio-)chemical sensor, is utilized as transducer for the detection of both (bio-)chemical and physical parameters. A multifunctional hybrid module for the determination of two (bio-)chemical parameters (pH, penicillin concentration) and three physical parameters (temperature, flow velocity and flow direction) using only two sensor structures, an ion generator and a reference electrode, is realized and its performance has been investigated. Here, a multifunctionality of the sensor system is achieved by means of different sensor arrangements and/or different operation modes. A Ta2O5-gate ISFET was used as transducer for all sensors. A novel time-of-flight type ISFET-based flow-velocity (flow rate) and flow-direction sensor using in-situ electrochemical generation of chemical tracers is presented. Due to the fast response of the ISFET (usually in the millisecond range), an ISFET-based flow sensor is suitable for the measurement of the flow velocity in a wide range. With regard to practical applications, pH measurements with this ISFET were performed in rain droplets.

  11. Geotechnical Parameters from Seismic Measurements: Two Field Examples from Egypt and Saudi Arabia

    KAUST Repository

    Khalil, Mohamed H.

    2016-03-18

    © 2016 EEGS. Geotechnical parameters were used to determine subsurface rock quality for construction purposes. We summarize the mathematical relationships used to calculate the geotechnical parameters from P- and S-wave velocities and density values. These relationships are applied to two field examples; the first is a regional seismic study in Egypt and the second is a 2-D seismic profile recorded in Saudi Arabia. Results from both field examples are used to determine the subsurface rock quality and locate zones that should be avoided during construction. We suggest combining all geotechnical parameters into one map using a normalized-weighted relation, which helps to locate the zones with high versus low rock quality for engineering purposes.

  12. STUDY ON PARAMETERS FOR TOPOLOGICAL VARIABLES FIELD INTERPOLATED BY MOVING LEAST SQUARE APPROXIMATION

    Institute of Scientific and Technical Information of China (English)

    Kal Long; Zhengxing Zuo; Rehan H.Zuberi

    2009-01-01

    This paper presents a new approach to the structural topology optimization of con-tinuum structures. Material-point independent variables are presented to illustrate the existence condition, or inexistence of the material points and their vicinity instead of elements or nodes in popular topology optimization methods. Topological variables field is constructed by moving least square approximation which is used as a shape function in the meshless method. Combined with finite element analyses, not only checkerboard patterns and mesh-dependence phenomena are overcome by this continuous and smooth topological variables field, but also the locations and numbers of topological variables can be arbitrary. Parameters including the number of quadrature points, scaling parameter, weight function and so on upon optimum topological configurations are discussed. Two classic topology optimization problems are solved successfully by the pro-posed method. The method is found robust and no numerical instabilities are found with proper parameters.

  13. Accounting for baryonic effects in cosmic shear tomography: Determining a minimal set of nuisance parameters using PCA

    Energy Technology Data Exchange (ETDEWEB)

    Eifler, Tim; Krause, Elisabeth; Dodelson, Scott; Zentner, Andrew; Hearin, Andrew; Gnedin, Nickolay

    2014-05-28

    Systematic uncertainties that have been subdominant in past large-scale structure (LSS) surveys are likely to exceed statistical uncertainties of current and future LSS data sets, potentially limiting the extraction of cosmological information. Here we present a general framework (PCA marginalization) to consistently incorporate systematic effects into a likelihood analysis. This technique naturally accounts for degeneracies between nuisance parameters and can substantially reduce the dimension of the parameter space that needs to be sampled. As a practical application, we apply PCA marginalization to account for baryonic physics as an uncertainty in cosmic shear tomography. Specifically, we use CosmoLike to run simulated likelihood analyses on three independent sets of numerical simulations, each covering a wide range of baryonic scenarios differing in cooling, star formation, and feedback mechanisms. We simulate a Stage III (Dark Energy Survey) and Stage IV (Large Synoptic Survey Telescope/Euclid) survey and find a substantial bias in cosmological constraints if baryonic physics is not accounted for. We then show that PCA marginalization (employing at most 3 to 4 nuisance parameters) removes this bias. Our study demonstrates that it is possible to obtain robust, precise constraints on the dark energy equation of state even in the presence of large levels of systematic uncertainty in astrophysical processes. We conclude that the PCA marginalization technique is a powerful, general tool for addressing many of the challenges facing the precision cosmology program.

  14. Ligand field and Judd-Ofelt intensity parameters of samarium doped tellurite glass

    Science.gov (United States)

    Tanko, Y. A.; Ghoshal, S. K.; Sahar, M. R.

    2016-08-01

    We report the samarium ions (Sm3+) contents dependent ligand field and Judd-Ofelt (JO) intensity parameters (Ω2, Ω4, Ω6) of zinc tellurite glass. The amorphous nature of the melt-quench synthesized glasses is confirmed using XRD. The lower energy region of the absorption spectra is used to calculate JO intensity parameters and the UV edge is exploited to determine the Nephelauxetic ratio, bonding, and Racah parameters. The Nephelauxetic ratio and Racah parameter is reduced and the bonding parameter is enhanced with the increase of Sm3+ concentration. The enhancement in covalency is found to increase the non-bridging oxygen and crystal field strength by delocalizing more d-shell electrons. Furthermore, Nephelauxetic function revealed an increase due to the reduction of localized d-electrons that is aroused from the overlap of d-orbital and ligand orbital. The JO intensity parameters displayed the Ω4>Ω6>Ω2 trend. Increase in Ω2 and decrease in Ω2 and Ω2 with the increase of Sm3+ concentration indicated an increase in the Smsbnd O covalency and coordination in the asymmetry of the prepared glasses. The large vale of spectroscopic quality factor (greater than unity) makes the proposed glass system prospective for various optical devices fabrication.

  15. Contribution of the Magnetic Field of Eddy Currents to the Gilbert Damping Parameter

    Directory of Open Access Journals (Sweden)

    S.I. Denisov

    2014-06-01

    Full Text Available We study the role of the magnetic field of eddy currents, which are induced in conducting single-domain particles of spherical form, in the magnetization dynamics. To describe the dynamic behavior of magnetization and electromagnetic field generating by the time-dependent magnetization, we use the coupled system of the Landau-Lifshitz-Gilbert (LLG and Maxwell equations. Assuming that the magnetization direction depends on time in an arbitrary way, we find the solution of the Maxwell equations in the quasi-stationary approximation and calculate the averaged (over the particle volume magnetic field of eddy currents. Considering this field as an extra contribution to the effective magnetic field acting on the particle magnetic moment, we derive the LLG equation in which the influence of eddy currents is completely accounted for by introducing an additional Gilbert damping parameter of electrodynamic origin.

  16. On intermediate level sets of two-dimensional discrete Gaussian Free Field

    OpenAIRE

    Biskup, Marek; Louidor, Oren

    2016-01-01

    We consider the discrete Gaussian Free Field (DGFF) in scaled-up (square-lattice) versions of suitably regular continuum domains $D\\subset\\mathbb C$ and describe the scaling limit, including local structure, of the level sets at heights growing as a $\\lambda$-multiple of the height of the absolute maximum, for any $\\lambda\\in(0,1)$. We prove that, in the scaling limit, the scaled spatial position of a typical point $x$ sampled from this level set is distributed according to a Liouville Quantu...

  17. The limiting behavior of the estimated parameters in a misspecified random field regression model

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Qin, Yu

    convenient new uniform convergence results that we propose. This theory may have applications beyond those presented here. Our results indicate that classical statistical inference techniques, in general, works very well for random field regression models in finite samples and that these models succesfully......This paper examines the limiting properties of the estimated parameters in the random field regression model recently proposed by Hamilton (Econometrica, 2001). Though the model is parametric, it enjoys the flexibility of the nonparametric approach since it can approximate a large collection...... of nonlinear functions and it has the added advantage that there is no "curse of dimensionality."Contrary to existing literature on the asymptotic properties of the estimated parameters in random field models our results do not require that the explanatory variables are sampled on a grid. However...

  18. A goal-oriented field measurement filtering technique for the identification of material model parameters

    KAUST Repository

    Lubineau, Gilles

    2009-05-16

    The post-processing of experiments with nonuniform fields is still a challenge: the information is often much richer, but its interpretation for identification purposes is not straightforward. However, this is a very promising field of development because it would pave the way for the robust identification of multiple material parameters using only a small number of experiments. This paper presents a goal-oriented filtering technique in which data are combined into new output fields which are strongly correlated with specific quantities of interest (the material parameters to be identified). Thus, this combination, which is nonuniform in space, constitutes a filter of the experimental outputs, whose relevance is quantified by a quality function based on global variance analysis. Then, this filter is optimized using genetic algorithms. © 2009 Springer-Verlag.

  19. Comparing Outcomes from Field and Classroom Based Settings for Undergraduate Geoscience Courses

    Science.gov (United States)

    Skinner, M. R.; Harris, R. A.; Flores, J.

    2011-12-01

    Field based learning can be found in nearly every course offered in Geology at Brigham Young University. For example, in our Structural Geology course field studies substitute for labs. Students collect data their own data from several different structural settings of the Wasatch Range. Our curriculum also includes a two-week, sophomore-level field course that introduces students to interpreting field relations themselves and sets the stage for much of what they learn in their upper-division courses. Our senior-level six-week field geology course includes classical field mapping with exercises in petroleum and mineral exploration, environmental geology and geological hazards. Experiments with substituting field-based general education courses for those in traditional classroom settings indicate that student cognition, course enjoyment and recruiting of majors significantly increase in a field-based course. We offer a field-based introductory geology course (Geo 102) that is taught in seven, six-hour field trips during which students travel to localities of geologic interest to investigate a variety of fundamental geological problems. We compare the outcomes of Geo 102 with a traditional classroom-based geology course (Geo 101). For the comparison both courses are taught by the same instructor, use the same text and supplementary materials and take the same exams. The results of 7 years of reporting indicate that test scores and final grades are one-half grade point higher for Geo 102 students versus those in traditional introductory courses. Student evaluations of the course are also 0.8-1.4 points higher on a scale of 1-8, and are consistently the highest in the Department and College. Other observations include increased attendance, attention and curiosity. The later two are measured by the number of students asking questions of other students as well as the instructors, and the total number of questions asked during class time in the field versus the classroom

  20. Excursion sets of infinitely divisible random fields with convolution equivalent Lévy measure

    DEFF Research Database (Denmark)

    Rønn-Nielsen, Anders; Jensen, Eva B. Vedel

    We consider a continuous, infinitely divisible random field in R d , d = 1, 2, 3, given as an integral of a kernel function with respect to a Lévy basis with convolution equivalent Lévy measure. For a large class of such random fields we compute the asymptotic probability that the excursion set a...... at level x contains some rotation of an object with fixed radius as x → ∞. Our main result is that the asymptotic probability is equivalent to the right tail of the underlying Lévy measure...

  1. Multi-Scale Entropy Analysis of Body Sway for Investigating Balance Ability During Exergame Play Under Different Parameter Settings

    Directory of Open Access Journals (Sweden)

    Chia-Hsuan Lee

    2015-11-01

    Full Text Available The goal of this study was to investigate the parameters affecting exergame performance using multi-scale entropy analysis, with the aim of informing the design of exergames for personalized balance training. Test subjects’ center of pressure (COP displacement data were recorded during exergame play to examine their balance ability at varying difficulty levels of a balance-based exergame; the results of a multi-scale entropy-based analysis were then compared to traditional COP indicators. For games involving static posture frames, variation in posture frame travel time was found to significantly affect the complexity of both the anterior-posterior (MSE-AP and medio-lateral (MSE-ML components of balancing movements. However, in games involving dynamic posture frames, only MSE-AP was found to be sensitive to the variation of parameters, namely foot-lifting speed. Findings were comparable to the COP data published by Sun et al., indicating that the use of complexity data is a feasible means of distinguishing between different parameter sets and of understanding how human design considerations must be taken into account in exergame development. Not only can this method be used as another assessment index in the future, it can also be used in the optimization of parameters within the virtual environments of exergames.

  2. Evolution of magnetotelluric, total magnetic field, and VLF field parameters in Central Italy. Relations to local seismic activity

    Energy Technology Data Exchange (ETDEWEB)

    Meloni, A.; Di Mauro, D.; Mele, G.; Palangio, P. [Istituto Nazionale di Geofisica e Vulcanologia, Rome (Italy); Ernst, T.; Teisseyre, R. [Institute of Geophysics, Warszawa (Poland)

    2001-04-01

    Magnetotelluric data were collected at Collemeluccio (41.72{sup 0}N, 14.37{sup 0}E) in Central Italy from summer 1991 to spring 1998. Analyzed by means of tensor decomposition on the geoelectric potential and robust estimation on the geomagnetic field, this set of data allowed the investigation of the electromagnetic induction, is presented here in its time evolution and compared to local and regional seismic activity. Tecto magnetic field observations from absolute magnetic field level in Central Italy were also made on data simultaneously recorded at four magnetometer stations, using L'Aquila Geomagnetic Observatory as a reference for differentiation. Recent results gathered from a system of two VLF search coil wide-band antennas, installed in the L'Aquila Observatory, are also discussed in relation to local seismic activity.

  3. Critical behavior in the presence of an order-parameter pinning field

    Science.gov (United States)

    Parisen Toldin, Francesco; Assaad, Fakher F.; Wessel, Stefan

    2017-01-01

    We apply a recently advocated simulation scheme that employs a local order-parameter pinning field to study quantum critical phenomena in the two-dimensional square-lattice bilayer quantum Heisenberg model. Using a world-line quantum Monte Carlo approach, we show that for this model, the pinning-field approach allows to locate the quantum critical point over a wide range of pinning-field strengths. However, the identification of the quantum critical scaling behavior is found to be hard since the pinning field introduces strong corrections to scaling. In order to further elucidate the scaling behavior in this situation, we also study an improved classical lattice model in the three-dimensional Ising universality class by means of Monte Carlo simulations on large lattice sizes, which allow us to employ refined finite-size scaling considerations. A renormalization group analysis exhibits the presence of an important crossover effect from the zero pinning-field to a critical adsorption fixed point. In line with field-theoretical results, we find that at the critical adsorption fixed point the short-distance expansion of the order-parameter profile exhibits a new universal critical exponent. This result also implies the presence of slowly decaying scaling corrections, which we analyze in detail.

  4. Techno-economic sensitivity study of heliostat field parameters for micro-gas turbine CSP

    Science.gov (United States)

    Landman, Willem A.; Gauché, Paul; Dinter, Frank; Myburgh, J. T.

    2017-06-01

    Concentrating solar power systems based on micro-gas turbines potentially offer numerous benefits should they become commercially viable. Heliostat fields for such systems have unique requirements in that the number of heliostats and the focal ratios are typically much lower than conventional central receiver systems. This paper presents a techno-economic sensitivity study of heliostat field parameters for a micro-gas turbine central receiver system. A 100 kWe minitower system is considered for the base case and a one-at-a-time strategy is used to investigate parameter sensitivities. Increasing heliostat focal ratios are found to have significant optical performance benefits due to both a reduction in astigmatic aberrations and a reduction in the number of facet focal lengths required; confirming the hypothesis that smaller heliostats offer a techno-economic advantage. Fixed Horizontal Axis tracking mechanism is shown to outperform the conventional Azimuth Zenith tracking mechanism in high density heliostat fields. Although several improvements to heliostat field performance are discussed, the capex fraction of the heliostat field for such system is shown to be almost half that of a conventional central receiver system and optimum utilization of the higher capex components, namely; the receiver and turbine subsystems, are more rewarding than that of the heliostat field.

  5. A Database of Force-Field Parameters, Dynamics, and Properties of Antimicrobial Compounds

    Directory of Open Access Journals (Sweden)

    Giuliano Malloci

    2015-08-01

    Full Text Available We present an on-line database of all-atom force-field parameters and molecular properties of compounds with antimicrobial activity (mostly antibiotics and some beta-lactamase inhibitors. For each compound, we provide the General Amber Force Field parameters for the major species at physiological pH, together with an analysis of properties of interest as extracted from µs-long molecular dynamics simulations in explicit water solution. The properties include number and population of structural clusters, molecular flexibility, hydrophobic and hydrophilic molecular surfaces, the statistics of intraand inter-molecular H-bonds, as well as structural and dynamical properties of solvent molecules within first and second solvation shells. In addition, the database contains several key molecular parameters, such as energy of the frontier molecular orbitals, vibrational properties, rotational constants, atomic partial charges and electric dipole moment, computed by Density Functional Theory. The present database (to our knowledge the first extensive one including dynamical properties is part of a wider project aiming to build-up a database containing structural, physico-chemical and dynamical properties of medicinal compounds using different force-field parameters with increasing level of complexity and reliability. The database is freely accessible at http://www.dsf.unica.it/translocation/db/.

  6. The effect of spin polarization on zero field splitting parameters in paramagnetic pi-electron molecules.

    Science.gov (United States)

    van Gastel, Maurice

    2009-09-28

    Spin polarization effects play an important role in the theory of isotropic hyperfine interactions for aromatic protons. The spin polarization gives rise to significant isotropic proton hyperfine interactions--spin-dependent one-electron properties--smaller than 0 MHz and the effect has been theoretically described [H. M. McConnell and D. B. J. Chesnut, Chem. Phys. 28, 107 (1958)]. The influence of spin polarization on the zero field splitting parameters, which are spin-dependent two-electron properties, has not been clearly identified yet. A phenomenological equation is proposed here for the contribution of spin polarization to the zero field splitting parameter D in analogy to McConnell's equation for hyperfine interactions. The presence of the effect is demonstrated in a series of calculations on polyacenes in the triplet state and turns out to be responsible for up to 50% of the D parameter in the case of naphthalene! It is found that spin-unrestricted single-determinant methods, including the widely used density functional theory methods, do not accurately reproduce the two-electron reduced electron density required for the evaluation of two-electron spin-dependent properties. For the accurate calculation of zero field splitting parameters by quantum chemical methods, it thus seems necessary to resort to correlated ab initio methods which do not give rise to spin contamination and which do provide an accurate description of the two-electron reduced electron density.

  7. The resolution of the identity approximation for calculations of spin-spin contribution to zero-field splitting parameters

    Science.gov (United States)

    Ganyushin, Dmitry; Gilka, Natalie; Taylor, Peter R.; Marian, Christel M.; Neese, Frank

    2010-04-01

    In this work, the resolution of the identity (RI) approximation is developed for the calculation of the electron-electron spin-spin coupling (SSC) interaction that is a central component of the zero-field splitting (ZFS) term in the effective spin Hamiltonian. The approximated integrals are then used in large-scale multireference configuration interaction treatments of the SSC interaction. The SSC contribution to the ZFS is treated using the Breit-Pauli spin-spin Hamiltonian in conjunction with first-order perturbation theory. Test calculations on a set of diatomic molecules reveal that the error of the RI approximation does not exceed 0.01 cm-1 even if standard auxiliary basis sets are used. This error of less than 1% is considered to be negligible compared to the presently achievable accuracy of the SSC calculations relative to experimental data. The present development allows the correlated ab initio calculation of ZFS parameters of larger systems such as linear polyenes and linear polyacenes. The basis set convergence of the calculated ZFS values was investigated, and the effect of electronic correlation on the calculated ZFS parameters is discussed.

  8. Determination of ductile damage parameters by local deformation fields: Measurement and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Springmann, M. [Chair of Structural Mechanics and Vehicle Vibrational Technology, BTU Cottbus, Cottbus (Germany); Kuna, M. [Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg (Germany)

    2006-10-15

    This work comprises the development, implementation and application of methods for the parameter identification of damage mechanical constitutive laws. Ductile damage is described on a continuum mechanical basis by extension of the von Mises yield condition with the Gurson-Tvergaard-Needleman as well as with the Rousselier model. The classical Rousselier model is complemented by accelerated void growth and void nucleation. The non-linear boundary and initial value problem is solved by the finite element system SPC-PMHP, which was developed in the frame of the special research program SFB393 for parallel computers. The material parameters are identified by locally measured displacement fields and measured force-displacement curves. For the material parameter identification a non-linear optimization algorithm is used, which renders the objective function to a minimum by means of a gradient based method. A useful strategy to identify the material parameters was found by careful numerical studies. Finally, using the object grating method the local displacement fields as well as the force-displacement curves are measured at notched flat bar tension specimens made of StE 690 and the parameters of the material are identified. (orig.)

  9. Estimating parameters of aquifer heterogeneity using pumping tests - implications for field applications

    Science.gov (United States)

    Zech, Alraune; Arnold, Sven; Schneider, Christoph; Attinger, Sabine

    2015-09-01

    The knowledge of subsurface heterogeneity is a prerequisite to describe flow and transport in porous media. Of particular interest are the variance and the correlation scale of hydraulic conductivity. In this study, we present how these aquifer parameters can be inferred using empirical steady state pumping test data. We refer to a previously developed analytical solution of "effective well flow" and examine its applicability to pumping test data as under field conditions. It is examined how the accuracy and confidence of parameter estimates of variance and correlation length depend on the number and location of head measurements. Simulations of steady state pumping tests in a confined virtual aquifer are used to systematically reduce sampling size while determining the rating of the estimates at each level of data density. The method was then applied to estimate the statistical parameters of a fluvial heterogeneous aquifer at the test site Horkheimer Insel, Germany. We conclude that the "effective well flow" solution is a simple alternative to laboratory investigations to estimate the statistical heterogeneity parameter using steady state pumping tests. However, the accuracy and uncertainty of the estimates depend on the design of the field study. In this regard, our results can help to improve the conceptual design of pumping tests with regard to the parameter of interest.

  10. A multi-domain Chebyshev collocation method for predicting ultrasonic field parameters in complex material geometries

    DEFF Research Database (Denmark)

    Nielsen, S.A.; Hesthaven, J.S.

    2002-01-01

    The use of ultrasound to measure elastic field parameters as well as to detect cracks in solid materials has received much attention, and new important applications have been developed recently, e.g., the use of laser generated ultrasound in non-destructive evaluation (NDE). To model such applica......The use of ultrasound to measure elastic field parameters as well as to detect cracks in solid materials has received much attention, and new important applications have been developed recently, e.g., the use of laser generated ultrasound in non-destructive evaluation (NDE). To model...... such applications requires a realistic calculation of field parameters in complex geometries with discontinuous, layered materials. In this paper we present an approach for solving the elastic wave equation in complex geometries with discontinuous layered materials. The approach is based on a pseudospectral...... solutions by means of characteristic variables. Finally, the global solution is advanced in time using a fourth order Runge-Kutta scheme. Examples of field prediction in discontinuous solids with complex geometries are given and related to ultrasonic NDE. (C) 2002 Elsevier Science B.V. All rights reserved....

  11. Calculation of crystal-field parameters for rare-earth noble metal alloys

    Energy Technology Data Exchange (ETDEWEB)

    Steinbeck, L. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Richter, M. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Eschrig, H. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany); Nitzsche, U. [MPG Research Group `Electron Systems`, Department of Physics, University of Technology, Mommsenstr. 13, D-01062, Dresden (Germany)

    1995-02-09

    The crystal-field (CF) parameters for 4f electrons of a series of rare-earth impurities in Ag and Au have been evaluated from first-principles density functional calculations of the charge distribution which are based on an optimized LCAO scheme. The localized 4f states are treated as `open core shell`. By including the self-interaction correction for the 4f states, artificial constraints on the 4f charge density employed in earlier density functional CF calculations are avoided. The calculated parameters are compared with recent neutron scattering data. ((orig.)).

  12. Calculation of crystal-field parameters for rare-earth noble metal alloys

    Science.gov (United States)

    Steinbeck, L.; Richter, M.; Eschrig, H.; Nitzsche, U.

    1995-02-01

    The crystal-field (CF) parameters for 4f electrons of a series of rare earth impurities in Ag and Au have been evaluated from first-principles density functional calculations of the charge distribution which are based on an optimized LCAO scheme. The localized 4f states are treated as 'open core shell'. By including the self-interaction correction for the 4f states, artificial constraints on the 4f charge density employed in earlier density functional CF calculations are avoided. The calculated parameters are compared with recent neutron scattering data.

  13. Vibrations of micro-beams actuated by an electric field via Parameter Expansion Method

    Science.gov (United States)

    Sedighi, Hamid M.; Shirazi, Kourosh H.

    2013-04-01

    This paper presents a new asymptotic procedure to predict the nonlinear vibrational behavior of micro-beams pre-deformed by an electric field. The nonlinear equation of motion includes both even and odd nonlinearities. A powerful analytical method called Parameter Expansion Method (PEM) is employed to obtain the approximated solution and frequency-amplitude relationship. It is demonstrated that the first two terms in series expansions are sufficient to produce an acceptable solution of mentioned system. The obtained results from numerical methods verify the soundness of the analytical procedure. Finally, the influences of basic parameters on pull-in instability and natural frequency are investigated.

  14. Real time measurement of plasma macroscopic parameters on RFX-mod using a limited set of sensors

    Science.gov (United States)

    Kudlacek, Ondrej; Zanca, Paolo; Finotti, Claudio; Marchiori, Giuseppe; Cavazzana, Roberto; Marrelli, Lionello

    2015-10-01

    A method to estimate the plasma boundary and global parameters such as βp+li/2 and the edge safety factor q95 is described. The method is based on poloidal flux extrapolation in the vacuum region between the plasma and the magnetic measurements, and it is efficient and accurate even if a limited set of sensors is used. The discrepancy between the plasma boundary provided by this method and the boundary computed by the Grad-Shafranov solver MAXFEA is lower than 8 mm in all the considered cases. Moreover, the method is robust against the noise level present in the RFX-mod measurements. The difference between the estimated global parameters and the MAXFEA simulation results is lower than 4%. The method was finally implemented in the RFX-mod shape control system, working at 5 kHz cycle frequency, to provide a reliable set of plasma-wall distances (gaps) used as feedback signals. Experimental results obtained in one year of RFX-mod operation are shown.

  15. Fair Access Provisioning through Contention Parameter Adaptation in the IEEE 802.11e Infrastructure Basic Service Set

    CERN Document Server

    Keceli, Feyza; Ayanoglu, Ender

    2008-01-01

    We present the station-based unfair access problem among the uplink and the downlink stations in the IEEE 802.11e infrastructure Basic Service Set (BSS) when the default settings of the Enhanced Distributed Channel Access (EDCA) parameters are used. We discuss how the transport layer protocol characteristics alleviate the unfairness problem. We design a simple, practical, and standard-compliant framework to be employed at the Access Point (AP) for fair and efficient access provisioning. A dynamic measurement-based EDCA parameter adaptation block lies in the core of this framework. The proposed framework is unique in the sense that it considers the characteristic differences of Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) flows and the coexistence of stations with varying bandwidth or Quality-of-Service (QoS) requirements. Via simulations, we show that our solution provides short- and long-term fair access for all stations in the uplink and downlink employing TCP and UDP flows with non-...

  16. Comparison of conventional ERG parameters and high-intensity A-wave analysis in a clinical setting.

    Science.gov (United States)

    Marmor, Michael F; Serrato, Alexandra; Tzekov, Radouil

    2003-05-01

    Computational analysis of high-intensity a-waves yields direct information about the rod and cone receptor potential. However, it is not clear whether such information adds materially to the diagnostic value of the standard ERG in a routine clinical setting. We recorded both conventional ISCEV standard and computational high intensity ERG parameters from 38 patients referred to a clinical laboratory for ERG testing, and also from eight normal volunteers. The patients were grouped as: (1) macular dysfunction; (2) diffuse cone dysfunction; (3) diffuse rod-cone dysfunction. The results showed moderate variation in both conventional and computational parameters, but in general a similar pattern of normality or abnormality for both among the disease groups. There were only a few outlying subjects for which one or the other approach seemed more sensitive. We conclude that a-wave analysis is an important tool for clinical research and the study of special patients, but adding it to the standard ERG protocol does not, at our present state of knowledge, add markedly to clinical evaluations in a routine clinical setting.

  17. Considerations for estimating microbial environmental data concentrations collected from a field setting.

    Science.gov (United States)

    Silvestri, Erin E; Yund, Cynthia; Taft, Sarah; Bowling, Charlena Yoder; Chappie, Daniel; Garrahan, Kevin; Brady-Roberts, Eletha; Stone, Harry; Nichols, Tonya L

    2017-03-01

    In the event of an indoor release of an environmentally persistent microbial pathogen such as Bacillus anthracis, the potential for human exposure will be considered when remedial decisions are made. Microbial site characterization and clearance sampling data collected in the field might be used to estimate exposure. However, there are many challenges associated with estimating environmental concentrations of B. anthracis or other spore-forming organisms after such an event before being able to estimate exposure. These challenges include: (1) collecting environmental field samples that are adequate for the intended purpose, (2) conducting laboratory analyses and selecting the reporting format needed for the laboratory data, and (3) analyzing and interpreting the data using appropriate statistical techniques. This paper summarizes some key challenges faced in collecting, analyzing, and interpreting microbial field data from a contaminated site. Although the paper was written with considerations for B. anthracis contamination, it may also be applicable to other bacterial agents. It explores the implications and limitations of using field data for determining environmental concentrations both before and after decontamination. Several findings were of interest. First, to date, the only validated surface/sampling device combinations are swabs and sponge-sticks on stainless steel surfaces, thus limiting availability of quantitative analytical results which could be used for statistical analysis. Second, agreement needs to be reached with the analytical laboratory on the definition of the countable range and on reporting of data below the limit of quantitation. Finally, the distribution of the microbial field data and statistical methods needed for a particular data set could vary depending on these data that were collected, and guidance is needed on appropriate statistical software for handling microbial data. Further, research is needed to develop better methods to

  18. The limiting behavior of the estimated parameters in a misspecified random field regression model

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Qin, Yu

    , as a consequence the random field model specification introduces non-stationarity and non-ergodicity in the misspecified model and it becomes non-trivial, relative to the existing literature, to establish the limiting behavior of the estimated parameters. The asymptotic results are obtained by applying some...... convenient new uniform convergence results that we propose. This theory may have applications beyond those presented here. Our results indicate that classical statistical inference techniques, in general, works very well for random field regression models in finite samples and that these models succesfully...

  19. Estimate of Seismological Parameters for the 1908 Messina Earthquake Through a new Data set Within the SISMOS Project.

    Science.gov (United States)

    Palombo, B.; Ferrari, G.; Bernardi, F.; Hunstad, I.; Perniola, B.

    2008-12-01

    The 1908 earthquake is one of the most catastrophic events in Italian history, recorded by most of the historical seismic stations existing at that time. Some of the seismograms recorded by these stations have already been used by many authors for the purpose of studying source characteristics, although only copies of the original recordings were available. Thanks to the Euroseismos project (2002-2007) and to the Sismos project, most of the original data (seismogram recordings and instrument parameter calibrations) for these events are now available in digital formats. Sismos technical facilities now allow us to apply the modern methods of digital-data analysis for the earthquakes recorded by mechanical and electromagnetic seismographs. The Sismos database has recently acquired many original seismograms and related instrumental parameters for the 1908 Messina earthquake, recorded by 14 stations distributed worldwide and never before used in previous works. We have estimated the main event parameters (i.e. location, Ms, Mw and focal mechanism) with the new data set. The aim of our work is to provide the scientific community with a reliable size and source estimation for accurate and consistent seismic hazard evaluation in Sicily, a region characterized by high long-term seismicity.

  20. A study on regularization parameter choice in near-field acoustical holography

    DEFF Research Database (Denmark)

    Gomes, Jesper; Hansen, Per Christian

    2008-01-01

    Cumulative Periodogram (NCP). The latter method is new within NAH and it is based on the Fourier transform of the residual vector. The methods are used in connection with three NAH methods: Statistically Optimized Near-field Acoustical Holography (SONAH), the Inverse Boundary Element Method (IBEM......Regularization plays an important role in Near-field Acoustical Holography (NAH), and choosing the right amount of regularization is crucial in order to get a meaningful solution. An automated method such as the L-curve or Generalized Cross-Validation (GCV) is often used in NAH to choose...... a regularization parameter. These parameter choice methods (PCMs) are attractive, since they require no a priori knowledge about the noise. However, there seems to be no clear understanding of when one PCM is better than the other. This paper presents comparisons of three PCMs: GCV, L-curve and Normalized...

  1. Measurement of the acoustic nonlinearity parameter B/A of lossy medium in a focused field

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An analytical description for the linear and nonlinear acoustic fields in lossy medium of a focusing source is derived. The relationship of pressure amplitudes at focus for fundamental and the second harmonic waves is discussed. At high linear focusing gain G, a new method using the insert substitution method for measuring the acoustic nonlinear parameter B /A of biological tissues is presented. Results for some biological tissues are experimentally obtained.

  2. A GPS Backpack System for Mapping Soil and Crop Parameters in Agricultural Fields

    Science.gov (United States)

    Stafford, J. V.; Lebars, J. M.

    Farmers are having to gather increasing amounts of data on their soils and crops. Precision agriculture metre-by-metre is based on a knowledge of the spatial variation of soil and crop parameters across a field. The data has to be spatially located and GPS is an effective way of doing this. A backpack data logging system with GPS position tagging is described which has been designed to aid a fanner in the manual collection of data.

  3. Estimation of Land Surface Parameters by LDAS-UT: Model Development and Validation on Tanashi Field Experiment

    Science.gov (United States)

    Lu, H.; Koike, T.; Yang, K.; Li, X.; Graf, T.; Boussetta, S.; Tsutsui, H.; Kuria, D. N.

    2007-12-01

    The estimation of soil moisture and surface energy fluxes at various temporal and spatial scales remains to be an outstanding problem in hydrologic and meteorological researches. Remote sensed data retrieval algorithms, land surface models and data assimilation systems are highly expected to provide a solution to this problem. But the parameters required by those algorithms and systems, such as the soil texture, porosity, roughness parameters and so on, are highly variable or unavailable. In this study, a land data assimilation system (LDAS- UT) is employed to inversely estimate the optimal values of those land surface parameters with meteorological forcing data and remote sensed data. And a field experiment is designed to provide a well-controlled data set for the system validation. The Tanashi experiment has been in operation since November, 2006 in the farm of the University of Tokyo. Continuous ground measurements of meteorological variables, soil moisture and temperature profiles and vegetation status have been taken over a plot, in which winter wheat was planted. At the same time, the ground based microwave radiometers (GBMR) are employed to provide accurate field measurements of brightness temperature up-welling from the plot, at the frequencies of 6.925, 10.65, 18.7, 23.8, 36.5 and 89 GHz. The LDAS_UT is then run with using data obtained from this experiment to retrieval parameters for two periods. One is the period from December 2006 to February 2007, the germination period of winter wheat, and during which the vegetation effects are small. The second period is from April to May 2007, during which the winter wheat was developing rapidly. The optimize parameters were compared with the in situ observed ¡®real' ones. It found that, for the first period, the retrieved parameters are close to the ¡®real' values, while for the second period, the gap between the retrieved parameters and the ¡®real' values are much bigger. The difference between the

  4. Effect of a transverse magnetic field on the parameters of a trap using a combination of the second and third harmonics of a helical field

    Energy Technology Data Exchange (ETDEWEB)

    Akshanov, B.S.; Pyatov, V.N.; Sebko, V.P.; Tyupa, V.I.

    1975-01-01

    In an analysis of the effect of a transverse magnetic field on the parameters of a trap using a combination of the second and third harmonics of a helical field, an averaging method is used to calculate the parameters of a hybrid (l = 2 plus l = 3) stellarator magnetic trap in a homogeneous, external, transverse magnetic field B/sub perpendicular/. The stabilizing effect of the second harmonic of the magnetic field on the configuration is discussed.

  5. Relation between Fresnel transform of input light field and the two-parameter Radon transform of Wigner function of the field

    Institute of Scientific and Technical Information of China (English)

    Fan Hong-Yi; Hu Li-Yun

    2009-01-01

    This paper proves a new theorem on the relationship between optical field Wigner function's two-parameter Radon transform and optical Fresnel transform of the field, I.e., when an input field ψ(x') propagates through an optical [D (-B) (-C) A] system, the energy density of the output field is equal to the Radon transform of the Wigner function of the input field, where the Radon transform parameters are D, B. It prove this theorem in both spatial-domain and frequency-domain, in the latter case the Radon transform parameters are A, C 7.

  6. Non-commutative field theory and the parameters of Lorentz violation in QED

    Directory of Open Access Journals (Sweden)

    S Aghababaei

    2011-09-01

    Full Text Available Non-commutative field theory as a theory including the Lorentz violation can be constructed in two different ways. In the first method, the non-commutative fields are the same as the ordinary ones while the gauge group is restricted to U(n. For example, the symmetry group of standard model in non-commutative space is U(3×(2×U(1 which can be reduced to SU(3×SU(2×U(1 by two appropriate spontaneous symmetry breaking. In contrast, in the second method, the non-commutative gauge theory can be constructed for SU(n gauge group via Seiberg- Witten map. In this work, we want to find the relation between the NC-parameter and the Lorentz violation parameters for the first method and compare our results with what is already found in the second one. At the end, we obtain new limits on non-commutative parameter by using the existing bounds on the Lorentz Violation parameters.

  7. A Five-Parameter Wind Field Estimation Method Based on Spherical Upwind Lidar Measurements

    Science.gov (United States)

    Kapp, S.; Kühn, M.

    2014-12-01

    Turbine mounted scanning lidar systems of focussed continuous-wave type are taken into consideration to sense approaching wind fields. The quality of wind information depends on the lidar technology itself but also substantially on the scanning technique and reconstruction algorithm. In this paper a five-parameter wind field model comprising mean wind speed, vertical and horizontal linear shear and homogeneous direction angles is introduced. A corresponding parameter estimation method is developed based on the assumption of upwind lidar measurements scanned over spherical segments. As a main advantage of this method all relevant parameters, in terms of wind turbine control, can be provided. Moreover, the ability to distinguish between shear and skew potentially increases the quality of the resulting feedforward pitch angles when compared to three-parameter methods. It is shown that minimal three measurements, each in turn from two independent directions are necessary for the application of the algorithm, whereas simpler measurements, each taken from only one direction, are not sufficient.

  8. Unsupervised Pattern Recognition of Physical Fitness Related Performance Parameters among Terengganu Youth Female Field Hockey Players

    Directory of Open Access Journals (Sweden)

    Razali M. R.

    2017-02-01

    Full Text Available This study aims to identify the most significant physical fitness parameters among youth female Terengganu field hockey players. Multivariate methods of unsupervised pattern recognition of principal component analysis (PCA and descriptive statistic were used to determine the most significant physical fitness related performance parameters on 42 Terengganu youth female field hockey players. The first PC’s projected high factor loading in BMI (0.86 and predicted VO2max (-0.82 as the most significant parameters indicating the requirements of body composition in this sport. The second PC’s displayed high factor loading in 1-minute sit up (0.89 and 20-meter speed (-0.84 highlighting the need for core muscle strength. The third PC’s demonstrated high factor loading in V-sit and reach (0.71 and maximum push up (0.82 recognising the importance of upper muscle strength in the sport. The results from the current study revealed that certain physical fitness components are seemed to be more pronounced in the performance of the game by the Terengganu female youth hockey players. The study has indicated that body composition, core muscle strength and upper muscle strength are the most outstanding physical fitness variables possess by the players for the enactment of the game compared to other fitness parameters. Highlighting the physical fitness performance related parameters might help to evaluate the strength and weakness of the players on the relevant parameters which could prompt to the adjustment of the training programme for the inclusive improvement of the players.

  9. Indirect Effects of Field Management on Pollination Service and Seed Set in Hybrid Onion Seed Production.

    Science.gov (United States)

    Gillespie, Sandra; Long, Rachael; Williams, Neal

    2015-12-01

    Pollination in crops, as in native ecosystems, is a stepwise process that can be disrupted at any stage. Healthy pollinator populations are critical for adequate visitation, but pollination still might fail if crop management interferes with the attraction and retention of pollinators. Farmers must balance the direct benefits of applying insecticide and managing irrigation rates against their potential to indirectly interfere with the pollination process. We investigated these issues in hybrid onion seed production, where previous research has shown that high insecticide use reduces pollinator attraction. We conducted field surveys of soil moisture, nectar production, pollinator visitation, pollen-stigma interactions, and seed set at multiple commercial fields across 2 yr. We then examined how management actions, such as irrigation rate (approximated by soil moisture), or insecticide use could affect the pollination process. Onions produced maximum nectar at intermediate soil moisture, and high nectar production attracted more pollinators. Insecticide use weakly affected pollinator visitation, but when applied close to bloom reduced pollen germination and pollen tube growth. Ultimately, neither soil moisture nor insecticide use directly affected seed set, but the high correlation between pollinator visitation and seed set suggests that crop management will ultimately affect yields via indirect effects on the pollination process. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Implementation and Evaluation of the Virtual Fields Method: Determining Constitutive Model Parameters From Full-Field Deformation Data.

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Sharlotte Lorraine Bolyard; Scherzinger, William M.

    2014-09-01

    The Virtual Fields Method (VFM) is an inverse method for constitutive model parameter identication that relies on full-eld experimental measurements of displacements. VFM is an alternative to standard approaches that require several experiments of simple geometries to calibrate a constitutive model. VFM is one of several techniques that use full-eld exper- imental data, including Finite Element Method Updating (FEMU) techniques, but VFM is computationally fast, not requiring iterative FEM analyses. This report describes the im- plementation and evaluation of VFM primarily for nite-deformation plasticity constitutive models. VFM was successfully implemented in MATLAB and evaluated using simulated FEM data that included representative experimental noise found in the Digital Image Cor- relation (DIC) optical technique that provides full-eld displacement measurements. VFM was able to identify constitutive model parameters for the BCJ plasticity model even in the presence of simulated DIC noise, demonstrating VFM as a viable alternative inverse method. Further research is required before VFM can be adopted as a standard method for constitu- tive model parameter identication, but this study is a foundation for ongoing research at Sandia for improving constitutive model calibration.

  11. Sensitivity of storage field performance to geologic and cavern design parameters in salt domes.

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon

    2009-03-01

    A sensitivity study was performed utilizing a three dimensional finite element model to assess allowable cavern field sizes for strategic petroleum reserve salt domes. A potential exists for tensile fracturing and dilatancy damage to salt that can compromise the integrity of a cavern field in situations where high extraction ratios exist. The effects of salt creep rate, depth of salt dome top, dome size, caprock thickness, elastic moduli of caprock and surrounding rock, lateral stress ratio of surrounding rock, cavern size, depth of cavern, and number of caverns are examined numerically. As a result, a correlation table between the parameters and the impact on the performance of storage field was established. In general, slower salt creep rates, deeper depth of salt dome top, larger elastic moduli of caprock and surrounding rock, and a smaller radius of cavern are better for structural performance of the salt dome.

  12. Measurement of the magnetic-field parameters of the NICA Booster dipole magnet

    Science.gov (United States)

    Kostromin, S. A.; Borisov, V. V.; Bichkov, A. V.; Golubitsky, O. M.; Donyagin, A. N.; Morozov, N. A.; Samsonov, E. V.; Omelyanenko, M. M.; Khodzhibagiyan, H. G.; Shemchuk, A. V.

    2016-12-01

    Serial assembly and tests of dipole and quadrupole magnets of the NICA Booster have started at the Laboratory of High Energy Physics of the Joint Institute for Nuclear Research (JINR). The accelerator is fitted with Nuclotron-type magnets with a superconducting winding and an iron yoke for shaping the needed magnetic field. The design of magnets for NICA was optimized (based on the experience gained in constructing and operating the JINR Nuclotron) for the production of magnetic fields of the required configuration in terms of the beam dynamics in the accelerator and the collider. Measurements of parameters of the field of each magnet are expected to be performed in the process of assembly and testing of each module of the magnet-cryostat system of the NICA Booster and Collider. The results of magnetic measurements for the NICA Booster dipole magnet are presented.

  13. A domain decomposition approach for full-field measurements based identification of local elastic parameters

    KAUST Repository

    Lubineau, Gilles

    2015-03-01

    We propose a domain decomposition formalism specifically designed for the identification of local elastic parameters based on full-field measurements. This technique is made possible by a multi-scale implementation of the constitutive compatibility method. Contrary to classical approaches, the constitutive compatibility method resolves first some eigenmodes of the stress field over the structure rather than directly trying to recover the material properties. A two steps micro/macro reconstruction of the stress field is performed: a Dirichlet identification problem is solved first over every subdomain, the macroscopic equilibrium is then ensured between the subdomains in a second step. We apply the method to large linear elastic 2D identification problems to efficiently produce estimates of the material properties at a much lower computational cost than classical approaches.

  14. The influence of pulsed electric field on hematological parameters in rat.

    Science.gov (United States)

    Coskun, Ozlem; Comlekci, Selcuk

    2013-10-01

    The aim of the present study is to investigate whether or not pulsed electric field (PEF) affects some hematological parameters in rats. Sixteen healthy male Wistar rats weighting 150-200 g were used and were randomly divided into two groups. Exposure group (n = 8) was exposed to a PEF (10 kV m⁻¹ for 1 h d⁻¹) for 10 consecutive days. The control group rats (n = 8) were not exposed to PEF. The following hematological parameters were measured in both the groups: white blood cells (WBCs), red blood cells (RBCs), hemoglobin (Hb), hematocrit (Ht) and platelets (PLTs). Some of the hematological parameters under investigation were similar in both the groups. Exposure group, exposed for 1 h d⁻¹ during 10 consecutive days, induced a significant increase in the rates of WBC (p < 0.05), RBC (p < 0.05), Hb (p < 0.05), Ht (p < 0.05) and PLTs (p < 0.05) in blood when compared with control. These results suggest that PEFs affect the hematological parameters in rat. Results of the parameters are statistically significant.

  15. Relaxation time and excess entropy in viscous liquids: Electric field versus temperature as control parameter

    Science.gov (United States)

    Richert, Ranko

    2017-02-01

    On the basis of adiabatic calorimetry data and results obtained from dielectric relaxation studies in the presence of a high static electric field, the effects of temperature and electric field induced changes of the excess entropy are compared for the same sample: supercooled cresolphthalein dimethylether. A field induced reduction of the excess entropy by 45 mJ K-1 mol-1 at constant temperature increases the structural relaxation time by 0.75%, while the same entropy change originating from lowering the temperature at constant field increases the time constant by 3.5%. Therefore, there is no simple link connecting excess entropy and relaxation time that is independent of the control parameter that is used to modify the entropy. A consequence is that the Adam-Gibbs approach does not provide a quantitative prediction for how the dynamics of liquids depend on the electric field, and, more generally, on excess entropy. This work compares the dynamics for temperature versus field induced changes of isobaric excess entropy, thereby eliminating previous uncertainties arising from isochoric versus isobaric conditions and from unknown relations between thermodynamic, excess, and configurational entropies.

  16. Comparison between advected-field and level-set methods in the study of vesicle dynamics

    CERN Document Server

    Maitre, E; Peyla, P; Raoult, A

    2010-01-01

    Phospholipidic membranes and vesicles constitute a basic element in real biological functions. Vesicles are viewed as a model system to mimic basic viscoelastic behaviors of some cells, like red blood cells. Phase field and level-set models are powerful tools to tackle dynamics of membranes and their coupling to the flow. These two methods are somewhat similar, but to date no bridge between them has been made. This is a first focus of this paper. Furthermore, a constitutive viscoelastic law is derived for the composite fluid: the ambient fluid and the membranes. We present two different approaches to deal with the membrane local incompressibility, and point out differences. Some numerical results following from the level-set approach are presented.

  17. Teaching Sustainabilty in the Setting of a Field-based Class on the Oceans in Captivity

    Science.gov (United States)

    Macko, Stephen; Tuite, Michael; O'Connell, Matthew

    2013-04-01

    Sustainability awareness is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapsenin fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. During regular session (13 week) or shorter term (4 week) summer classes such long trips are logistically difficult owing to large numbers of students involved or timing. This new approach to such a course supplement addresses the requests by utilizing local resources and short field trips for a limited number of students (20) to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time, readings, along with paper and laboratories. In addition short day-long trips to locations where the ocean was "captured" were also used to supplement the experience as well as speakers involved with aquaculture ("cultivated") Central Virginia is a fortunate location for such a class, with close access for "day travel" to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and National Zoo) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore, Washington and Virginia Beach. Furthermore, visits to local seafood markets at local grocery stores, or larger city markets) enhance the exposure to productivity in the ocean, and viability of the fisheries sustainability. The course could then address not only the particulars of the marine science, but also aspects of sustainability with discussions on ethics, including keeping animals in captivity or overfishing of particular species and the special difficulties that arise from captive or culturing ocean populations. In addition, the class was encouraged to post web

  18. Children’s everyday lives (re)constructed as variable sets of ‘field bodies’

    DEFF Research Database (Denmark)

    Winther, Ida Wentzel

    2013-01-01

    How do you study everyday life? Everyday life happens. It is solid and liquid, embedded and changeable. The article is based on fieldwork I conducted on an isolated island, where I was interested in how children play, interact with each other and use social media. I brought my son, a camcorder...... inter-methodic (person and method) as well as inter-material (person and materiality/surroundings) aspects are brought into play, and the patterns and dynamics of the social and cultural landscapes can be reconfigured. This article scrutinizes how the researcher (me) works with variable sets of ‘field...

  19. General quantum-mechanical setting for field-antifield formalism as a hyper-gauge theory

    CERN Document Server

    Batalin, Igor A

    2016-01-01

    A general quantum-mechanical setting is proposed for the field-antifield formalism as a unique hyper-gauge theory in the field-antifield space. We formulate a Schr\\"{o}dinger-type equation to describe the quantum evolution in a "current time" purely formal in its nature. The corresponding Hamiltonian is defined in the form of a supercommutator of the delta-operator with a hyper-gauge Fermion. The initial wave function is restricted to be annihilated with the delta-operator. The Schr\\"{o}dinger's equation is resolved in a closed form of the path integral, whose action contains the symmetric Weyl's symbol of the Hamiltonian. We take the path integral explicitly in the case of being a hyper-gauge Fermion an arbitrary function rather than an operator.

  20. General quantum-mechanical setting for field-antifield formalism as a hyper-gauge theory

    Science.gov (United States)

    Batalin, Igor A.; Lavrov, Peter M.

    2016-09-01

    A general quantum-mechanical setting is proposed for the field-antifield formalism as a unique hyper-gauge theory in the field-antifield space. We formulate a Schr\\"odinger-type equation to describe the quantum evolution in a "current time" purely formal in its nature. The corresponding Hamiltonian is defined in the form of a supercommutator of the delta-operator with a hyper-gauge Fermion. The initial wave function is restricted to be annihilated with the delta-operator. The Schr\\"odinger's equation is resolved in a closed form of the path integral, whose action contains the symmetric Weyl's symbol of the Hamiltonian. We take the path integral explicitly in the case of being a hyper-gauge Fermion an arbitrary function rather than an operator.

  1. Field scale variability of solute transport parameters and related soil properties

    Directory of Open Access Journals (Sweden)

    B. Lennartz

    1997-01-01

    Full Text Available The spatial variability of transport parameters has to be taken into account for a reliable assessment of solute behaviour in natural field soils. Two field sites were studied by collecting 24 and 36 small undisturbed soil columns at an uniform grid of 15 m spacing. Displacement experiments were conducted in these columns with bromide traced water under unsaturated steady state transport conditions. Measured breakthrough curves (BTCs were evaluated with the simple convective-dispersive equation (CDE. The solute mobility index (MI calculated as the ratio of measured to fitted pore water velocity and the dispersion coefficient (D were used to classify bromide breakthrough behaviour. Experimental BTCs were classified into two groups: type I curves expressed classical solute behaviour while type II curves were characterised by the occurrence of a bromide concentration maximum before 0.35 pore volumes of effluent (MI<0.35 resulting from preferential flow conditions. Six columns from site A and 8 from site B were identified as preferential. Frequency distributions of the transport parameters (MI and D of both sites were either extremely skewed or bimodal. Log-transformation did not lead to a normal distribution in any case. Contour maps of bromide mass flux at certain time steps indicated the clustering of preferential flow regions at both sites. Differences in the extent of preferential flow between sites seemed to be governed by soil structure. Linear cross correlations among transport parameters and independently measured soil properties revealed relations between solute mobility and volumetric soil water content at time of sampling, texture and organic carbon content. The volumetric field soil water content, a simple measure characterising the soil hydraulic behaviour at the sampling location, was found to be a highly sensitive parameter with respect to solute mobility and preferential flow situations. Almost no relation was found between solute

  2. Parameters of training, academic involvement, and practice setting predictive of retention in combined medical-psychiatric practice.

    Science.gov (United States)

    Silberman, Edward; Summergrad, Paul; Price, Lori

    2014-08-01

    The authors contrasted physicians trained in both psychiatry and another specialty who continue to practice both specialties vs. those who practice only psychiatry, in terms of their training, academic profile, and practice setting. The authors analyzed survey responses from 132 doubly boarded physicians who vary in whether or not they continue to practice both specialties. Group results were compared using chi square, Fisher exact, and t tests. Of graduates of double-board programs, 79.2% continue in dual practice. Other factors associated with continued combined practice were training in neurology-psychiatry, greater academic involvement, high motivation, practice in a non-public hospital setting, and demonstrated leadership capacity. Double-board training programs have been successful in producing a group of clinicians committed to long-term combined medical-psychiatric practice, but this effect is stronger in psychiatry-neurology than in other types of combined practice. Future research should investigate other practice parameters that foster or impede integrated medical-psychiatric care.

  3. Conditions Within The Nucleus Nadi, Nagi,mdi ,mgiAnd Nuclear Energy Density And The Electric Field Parameters

    Directory of Open Access Journals (Sweden)

    Huang Zhenqiang and Huang Yuxiang

    2013-10-01

    Full Text Available By (7.2, charged elementary particles in the fluctuation, the spin track movement in the direction of comprehensive force analysis and calculation results show that charged particle in electric and magnetic field force, nuclear power field force, under the action of centrifugal force is along the wave vector rail inside diameter automatic shrinkage in the center of the trend. From figure 7.1 and figure 7.1 within the nucleus of the high and low particles spiral loop combination structure can also be seen in: each layer low-energy particles spiral ring of the spin track occupied space should be minimal, get recently, and not overlap. 2 ~ 5 layers of each pair of high and low particles spiral ring on the inside of the spin track Rθgi(0, Rθdi(0 in also is such. All high, low-energy particle spiral ring in addition to the first layer, the quantum fluctuations of Nadi, Nagi shall take natural number.Refer to section 7.1 of the nucleus kernel forces forming principle, by figure 9.1 low-energy particles spiralring layer combination that: the bottom low-energy particles spiral ring in excess πd-both in the spin track intersec ting in the formation of ampere force can cover the economical and the upper surplus high and low π± muon solenoid ring particles of the axial electric field force, should be comprehensive comparison a, b, c, d,... each boundary point, internal non-oil imports all the ampere force and comprehensive relationship between the size of the axial electric field force and. That as space limit set of geometric conditions, by figure 9.1, the first a1 a1 > 150°. According to the set position and fluctuation, the relationship between the spin track parameters, low-energy particles spiral ring of n side by side, we

  4. Estimation of a Self-Consistent Set of Radiobiological Parameters From Hypofractionated Versus Standard Radiation Therapy of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, Istituto di Ricovero e Cura a Carattere Scientifico Centro di Riferimento Oncologico della Basilicata, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Istituto Nazionale Tumori Regina Elena, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (Italy)

    2013-04-01

    Purpose: To determine a self-consistent set of radiobiological parameters in prostate cancer. Methods and Materials: A method to estimate intrinsic radiosensitivity (α), fractionation sensitivity (α/β), repopulation doubling time, number of clonogens, and kick-off time for accelerated repopulation of prostate cancer has been developed. Based on the generalized linear-quadratic model and without assuming the isoeffective hypothesis, the potential applications of the method were investigated using the clinical outcome of biochemical relapse-free survival recently reviewed in the literature. The strengths and limitations of the method, regarding the fitted parameters and 95% confidence intervals (CIs), are also discussed. Results: Our best estimate of α/β is 2.96 Gy (95% CI 2.41-3.53 Gy). The corresponding α value is 0.16 Gy{sup −1} (95% CI 0.14-0.18 Gy{sup −1}), which is compatible with a realistic number of clonogens: 6.5 × 10{sup 6} (95% CI 1.5 × 10{sup 6}-2.1 × 10{sup 7}). The estimated cell doubling time is 5.1 days (95% CI 4.2-7.2 days), very low if compared with that reported in the literature. This corresponds to the dose required to offset the repopulation occurring in 1 day of 0.52 Gy/d (95% CI 0.32-0.68 Gy/d). However, a long kick-off time of 31 days (95% CI 22-41 days) from the start of radiation therapy was found. Conclusion: The proposed analytic/graphic method has allowed the fitting of clinical data, providing a self-consistent set of radiobiological parameters for prostate cancer. With our analysis we confirm a low value for α/β with a correspondingly high value of intrinsic radiosensitivity, a realistic average number of clonogens, a long kick-off time for accelerated repopulation, and a surprisingly fast repopulation that suggests the involvement of subpopulations of specifically tumorigenic stem cells during continuing radiation therapy.

  5. Effect of synthesis parameters on morphology of polyaniline (PANI) and field emission investigation of PANI nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Bankar, Prashant K.; More, Mahendra A., E-mail: mam@physics.unipune.ac.in [Center for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune-411007 (India); Patil, Sandip S. [Department of Physics, Modern College of Arts, Science and Commerce, Shivajinagar, Pune-411005. India (India)

    2015-06-24

    Polyaniline (PANI) nanostructures have been synthesized by simple chemical oxidation route at different monomer concentration along with variation in synthesis temperature. The effect of variation of synthesis parameters has been revealed using different characterization techniques. The structural and morphological characterization of the synthesized PANI nanostructures was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), whereas Fourier Transform Infrared spectroscopy (FTIR) has been used to reveal the chemical properties. With the variation in the synthesis temperature and monomer concentration, various morphologies characterized by formation of PANI nanoparticles, nanofibres, nanotubes and nanospheres, are revealed from the SEM analysis. The FTIR analysis reveals the formation of conducting state of PANI under prevailing experimental conditions. The field emission investigation of the conducting PANI nanotubes was performed in all metal UHV system at base pressure of 1x10{sup −8} mbar. The turn on field required to draw emission of 1 nA current was observed to be ∼ 2.2 V/μm and threshold field (corresponding to emission current density of 1 µA/cm2) was found to be 3.2 V/μm. The emission current was observed to be stable for more than three hours at a preset value 1 µA. The simple synthesis route and good field emission characteristics indicate potential of PANI nanofibres as a promising emitter for field emission based micro/nano devices.

  6. A multi-domain Chebyshev collocation method for predicting ultrasonic field parameters in complex material geometries.

    Science.gov (United States)

    Nielsen, S A; Hesthaven, J S

    2002-05-01

    The use of ultrasound to measure elastic field parameters as well as to detect cracks in solid materials has received much attention, and new important applications have been developed recently, e.g., the use of laser generated ultrasound in non-destructive evaluation (NDE). To model such applications requires a realistic calculation of field parameters in complex geometries with discontinuous, layered materials. In this paper we present an approach for solving the elastic wave equation in complex geometries with discontinuous layered materials. The approach is based on a pseudospectral elastodynamic formulation, giving a direct solution of the time-domain elastodynamic equations. A typical calculation is performed by decomposing the global computational domain into a number of subdomains. Every subdomain is then mapped on a unit square using transfinite blending functions and spatial derivatives are calculated efficiently by a Chebyshev collocation scheme. This enables that the elastodynamic equations can be solved within spectral accuracy, and furthermore, complex interfaces can be approximated smoothly, hence avoiding staircasing. A global solution is constructed from the local solutions by means of characteristic variables. Finally, the global solution is advanced in time using a fourth order Runge-Kutta scheme. Examples of field prediction in discontinuous solids with complex geometries are given and related to ultrasonic NDE.

  7. Effect of acoustic field parameters on arc acoustic binding during ultrasonic wave-assisted arc welding.

    Science.gov (United States)

    Xie, Weifeng; Fan, Chenglei; Yang, Chunli; Lin, Sanbao

    2016-03-01

    As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius.

  8. Smoothing parameter estimation framework for Markov random field by using contextual and spectral information

    Science.gov (United States)

    Aghighi, Hossein; Trinder, John

    2013-10-01

    Markov random field (MRF) is currently the most common method to find the optimal solution for the classification of image data incorporating contextual visual information. The labeling for a site in MRF is dependent on smoothing parameters. Therefore, this paper deals with the development of a new robust two-step method to determine the smoothing parameter which balances spatial and spectral energies for the purpose of maximizing the classification accuracy. Multispectral images obtained by WorldView-2 satellite were employed in this research. In the first step, a support vector machine (SVM) was used to provide a vector of multi-class probability and a class label for each pixel. Then, the summation of the maximum probability of each pixel and its 8 neighbors is calculated for a dynamic block and this value is assigned to the central pixels of each block. The blocks of each class are sorted and an equal proportion of blocks of each class with the highest probability are selected. Then, the class codes and spectral information of the selected blocks are extracted from the classified map and multispectral image, respectively. This information is used to calculate class label co-occurrence matrices of the blocks (CLCMB), class label co-occurrence matrix (CLCM) and class separability indices. Finally, different smoothing parameters are calculated and the results show that estimated smoothing parameter can produce a more accurate map.

  9. Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

    Energy Technology Data Exchange (ETDEWEB)

    Boscá, A., E-mail: alberto.bosca@upm.es [Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Dpto. de Ingeniería Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Pedrós, J. [Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Campus de Excelencia Internacional, Campus Moncloa UCM-UPM, Madrid 28040 (Spain); Martínez, J. [Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Dpto. de Ciencia de Materiales, E.T.S.I de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Calle, F. [Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Dpto. de Ingeniería Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040 (Spain); Campus de Excelencia Internacional, Campus Moncloa UCM-UPM, Madrid 28040 (Spain)

    2015-01-28

    Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method output values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.

  10. Calculated crystal-field parameters for rare-earth impurities in noble metals

    Science.gov (United States)

    Steinbeck, Lutz; Richter, Manuel; Eschrig, Helmut; Nitzsche, Ulrike

    1994-06-01

    From first-principles density-functional calculations of the charge distribution the crystal-field (CF) parameters for 4f states of Er and Dy impurities in Ag and Au have been evaluated. The calculations are based on an optimized linear combination of atomic orbitals scheme, where the local-density approximation (LDA) is used for the conduction-electron states, while the localized rare-earth 4f states are treated as ``open core shell.'' As the 4f localization cannot be properly described within LDA, a self-interaction correction for the 4f states is included. In this way, any artificial constraints on the 4f charge density employed in earlier first-principles CF calculations are avoided. The calculated CF parameters agree well with recent neutron scattering data.

  11. The constitutive compatibility method for identification of material parameters based on full-field measurements

    KAUST Repository

    Moussawi, Ali

    2013-10-01

    We revisit here the concept of the constitutive relation error for the identification of elastic material parameters based on image correlation. An additional concept, so called constitutive compatibility of stress, is introduced defining a subspace of the classical space of statically admissible stresses. The key idea is to define stresses as compatible with the observed deformation field through the chosen class of constitutive equation. This makes possible the uncoupling of the identification of stress from the identification of the material parameters. As a result, the global cost of the identification is strongly reduced. This uncoupling also leads to parametrized solutions in cases where the solution is non-unique as demonstrated on 2D numerical examples. © 2013 Elsevier B.V.

  12. Information escaping the correlation hierarchy of the convergence field in the study of cosmological parameters.

    Science.gov (United States)

    Carron, Julien

    2012-02-17

    Using fits to numerical simulations, we show that the entire hierarchy of moments quickly ceases to provide a complete description of the convergence one-point probability density function leaving the linear regime. This suggests that the full N-point correlation function hierarchy of the convergence field becomes quickly generically incomplete and a very poor cosmological probe on nonlinear scales. At the scale of unit variance, only 5% of the Fisher information content of the one-point probability density function is still contained in its hierarchy of moments, making clear that information escaping the hierarchy is a far stronger effect than information propagating to higher order moments. It follows that the constraints on cosmological parameters achievable through extraction of the entire hierarchy become suboptimal by large amounts. A simple logarithmic mapping makes the moment hierarchy well suited again for parameter extraction.

  13. Molecular Simulations of Dodecyl-β-maltoside Micelles in Water: Influence of the Headgroup Conformation and Force field Parameters

    Science.gov (United States)

    Abel, Stéphane; Dupradeau, François-Yves; Raman, E. Prabhu; MacKerell, Alexander D.; Marchi, Massimo

    2011-01-01

    This paper deals with the development and validation of new potential parameter sets, based on the CHARMM36 and GLYCAM06 force fields, to simulate micelles of the two anomeric forms (α and β) of N-Dodecyl-ß-maltoside (C12G2), a surfactant widely used in the extraction and purification of membrane proteins. In this context, properties such as size, shape, internal structure and hydration of the C12G2 anomer micelles were thoroughly investigated by molecular dynamics simulations and the results compared with experiments. Additional simulations were also performed with the older CHARMM22 force field for carbohydrates (Kuttel, M. et al. J. Comp. Chem. 2002, 23, 1236-1243). We find that our CHARMM and GLYCAM parameter sets yields similar results in case of properties related to the micelle structure, but differ for other properties such as the headgroup conformation or the micelle hydration. In agreement with experiments, our results show that for all model potentials the β-C12G2 micelles have a more pronounced ellipsoidal shape than those containing α anomers. The computed radius of gyration is 20.2 Å and 25.4 Å for the α- and β-anomer micelles, respectively. Finally, we show that depending on the potential the water translational diffusion of the interfacial water is 7 - 11.5 times slower than that of bulk water due to the entrapment of the water in the micelle crevices. This retardation is independent of the headgroup in α- or β- anomers. PMID:21192681

  14. Typical Profiles and Distributions of Plasma and Magnetic Field Parameters in Magnetic Clouds at 1 AU

    Science.gov (United States)

    Rodriguez, L.; Masías-Meza, J. J.; Dasso, S.; Démoulin, P.; Zhukov, A. N.; Gulisano, A. M.; Mierla, M.; Kilpua, E.; West, M.; Lacatus, D.; Paraschiv, A.; Janvier, M.

    2016-08-01

    Magnetic clouds (MCs) are a subset of interplanetary coronal mass ejections (ICMEs). They are important because of their simple internal magnetic field configuration, which resembles a magnetic flux rope, and because they represent one of the most geoeffective types of solar transients. In this study, we analyze their internal structure using a superposed epoch method on 63 events observed at L1 by the Advance Composition Explorer (ACE), between 1998 and 2006. In this way, we obtain an average profile for each plasma and magnetic field parameter at each point of the cloud. Furthermore, we take a fixed time-window upstream and downstream from the MC to also sample the regions preceding the cloud and the wake trailing it. We then perform a detailed analysis of the internal characteristics of the clouds and their surrounding solar wind environments. We find that the parameters studied are compatible with log-normal distribution functions. The plasma β and the level of fluctuations in the magnetic field vector are the best parameters to define the boundaries of MCs. We find that one third of the events shows a peak in plasma density close to the trailing edge of the flux ropes. We provide several possible explanations for this result and investigate if the density peak is of a solar origin ( e.g. erupting prominence material) or formed during the magnetic cloud travel from the Sun to 1 AU. The most plausible explanation is the compression due to a fast overtaking flow, coming from a coronal hole located to the east of the solar source region of the magnetic cloud.

  15. Numerical Simulation of Solidification Microstructure and Effects of Phase-field Parameters on Grain Growth Morphologies

    Institute of Scientific and Technical Information of China (English)

    Jingfeng LIU; Ruixiang LIU; Liliang CHEN

    2005-01-01

    By a simple phase field model, a series of numerical simulations of solidification microstructure was performed to show a rich variety of dendritic patterns. At the same time, the relation between the morphology of grain growth and some parameters including the strength of anisotropy, dimensionless latent heat and the size of initial solid zone was studied. It is for the first time that patterns of grain growth were associated with the size of initial solid zone,which is an interesting issue. The possible reason for this may be that variation in the size of initial solid zone may bring about fluctuation of the interface energy, making the interface unstable.

  16. Theoretical calculation of zero field splitting parameters of Cr{sup 3+} doped ammonium oxalate monohydrate

    Energy Technology Data Exchange (ETDEWEB)

    Kripal, Ram, E-mail: ram_kripal2001@rediffmail.com; Yadav, Awadhesh Kumar, E-mail: aky.physics@gmail.com

    2015-06-15

    Zero field splitting parameters (ZFSPs) D and E of Cr{sup 3+} ion doped ammonium oxalate monohydrate (AOM) are calculated with formula using the superposition model. The theoretically calculated ZFSPs for Cr{sup 3+} in AOM crystal are compared with the experimental value obtained by electron paramagnetic resonance (EPR). Theoretical ZFSPs are in good agreement with the experimental ones. The energy band positions of optical absorption spectra of Cr{sup 3+} in AOM crystal calculated with CFA package are in good match with the experimental values.

  17. Dynamic response of carbon nanotube field-effect transistors analyzed by S-parameters measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bethoux, J.-M. [Institut d' Electronique, de Microelectronique et de Nanotechnologie, C.N.R.S. U.M.R. 8520, BP 60069, F-59652, Villeneuve d' Ascq Cedex (France); Happy, H. [Institut d' Electronique, de Microelectronique et de Nanotechnologie, C.N.R.S. U.M.R. 8520, BP 60069, F-59652, Villeneuve d' Ascq Cedex (France)]. E-mail: henri.happy@iemn.univ-lille1.fr; Dambrine, G. [Institut d' Electronique, de Microelectronique et de Nanotechnologie, C.N.R.S. U.M.R. 8520, BP 60069, F-59652, Villeneuve d' Ascq Cedex (France); Derycke, V. [Laboratoire d' Electronique Moleculaire, SPEC, Commissariat a l' Energie Atomique, Saclay F-91191, Gif sur Yvette Cedex (France); Goffman, M. [Laboratoire d' Electronique Moleculaire, SPEC, Commissariat a l' Energie Atomique, Saclay F-91191, Gif sur Yvette Cedex (France); Bourgoin, J.-P. [Laboratoire d' Electronique Moleculaire, SPEC, Commissariat a l' Energie Atomique, Saclay F-91191, Gif sur Yvette Cedex (France)

    2006-12-15

    Carbon nanotube field-effect transistors (CN-FET) with a metallic back gate have been fabricated. By assembling a number of CNs in parallel, driving currents in the mA range have been obtained. The dynamic response of the CN-FETs has been investigated through S-parameters measurements. A current gain (|H {sub 21}|{sup 2}) cut-off frequency (f {sub t}) of 8 GHz, and a maximum stable gain (MSG) value of 10 dB at 1 GHz have been obtained. The extraction of an equivalent circuit is proposed.

  18. Influence of electromagnetic field parameters on the morphology of graphite in grey cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2009-01-01

    Full Text Available One way to improve the unification of the casting structure may be the application of forced convection of liquid metal during thecrystallization in the form or continuous casting mould. This paper presents the results describing the influence of selected parameters of rotating electromagnetic field enforcing the movement of liquid metal in the form on the morphology of graphite in grey cast iron. The results were fragmented graphite flakes in conditions of regulating the rate of cooling in the range of temperature TZAL

  19. Induction heating of rotating nonmagnetic billet in magnetic field produced by high-parameter permanent magnets

    Directory of Open Access Journals (Sweden)

    Ivo Doležel

    2014-04-01

    Full Text Available An advanced way of induction heating of nonmagnetic billets is discussed and modeled. The billet rotates in a stationary magnetic field produced by unmoving high-parameter permanent magnets fixed on magnetic circuit of an appropriate shape. The mathematical model of the problem consisting of two coupled partial differential equations is solved numerically, in the monolithic formulation. Computations are carried out using our own code Agros2D based on a fully adaptive higher-order finite element method. The most important results are verified experimentally on our own laboratory device.

  20. Diffuse-flow hydrothermal field in an oceanic fracture zone setting, Northeast Pacific: Deposit composition

    Science.gov (United States)

    Hein, J.R.; Koski, R.A.; Embley, R.W.; Reid, J.; Chang, S.-W.

    1999-01-01

    This is the first reported occurrence of an active hydrothermal field in an oceanic fracture zone setting. The hydrothermal field occurs in a pull-apart basin within the Blanco Fracture Zone (BFZ), which has four distinct mineral deposit types: (1) barite mounds and chimneys, (2) barite stockwork breccia, (3) silica-barite beds, and (4) silica, barite, and Fe-Mn oxyhydroxide in sediments. All deposit types contain minor amounts of sulfides. In barite stockwork, silica-barite beds, and mineralized sediment, Ba, Ph, Ag, S, Au, Zn, Cu, Hg, TI, As, Mo, Sb, U, Cd, and Cu are enriched relative to unmineralized rocks and sediments of the BFZ. Fe and Mn are not enriched in the barite stockwork or silica-barite beds, but along with P, Co, and Mg are enriched in the mineralized sediments. Silver contents in deposits of the hydrothermal field range up to 86 ppm, gold to 0.7 ppm, zinc to 3.2%, copper to 0.8%, and barium to 22%. Mineralization occurred by diffuse, low to intermediate temperature (mostly Metallurgy and Petroleum. All rights reserved.

  1. The state of the art of predicting noise-induced sleep disturbance in field settings

    Directory of Open Access Journals (Sweden)

    Sanford Fidell

    2010-01-01

    Full Text Available Several relationships between intruding noises (largely aircraft and sleep disturbance have been inferred from the findings of a handful of field studies. Comparisons of sleep disturbance rates predicted by the various relationships are complicated by inconsistent data collection methods and definitions of predictor variables and predicted quantities. None of the relationships is grounded in theory-based understanding, and some depend on questionable statistical assumptions and analysis procedures. The credibility, generalizability, and utility of sleep disturbance predictions are also limited by small and nonrepresentative samples of test participants, and by restricted (airport-specific and relatively short duration circumstances of exposure. Although expedient relationships may be the best available, their predictions are of only limited utility for policy analysis and regulatory purposes, because they account for very little variance in the association between environmental noise and sleep disturbance, have characteristically shallow slopes, have not been well validated in field settings, are highly context-dependent, and do not squarely address the roles and relative importance of nonacoustic factors in sleep disturbance. Such relationships offer the appearance more than the substance of precision and objectivity. Truly useful, population-level prediction and genuine understanding of noise-induced sleep disturbance will remain beyond reach for the foreseeable future, until the findings of field studies of broader scope and more sophisticated design become available.

  2. Anthropogenic seismicity rates and operational parameters at the Salton Sea Geothermal Field.

    Science.gov (United States)

    Brodsky, Emily E; Lajoie, Lia J

    2013-08-01

    Geothermal power is a growing energy source; however, efforts to increase production are tempered by concern over induced earthquakes. Although increased seismicity commonly accompanies geothermal production, induced earthquake rate cannot currently be forecast on the basis of fluid injection volumes or any other operational parameters. We show that at the Salton Sea Geothermal Field, the total volume of fluid extracted or injected tracks the long-term evolution of seismicity. After correcting for the aftershock rate, the net fluid volume (extracted-injected) provides the best correlation with seismicity in recent years. We model the background earthquake rate with a linear combination of injection and net production rates that allows us to track the secular development of the field as the number of earthquakes per fluid volume injected decreases over time.

  3. Can Simple Soil Parameters Explain Field-Scale Variations in Glyphosate-, Bromoxyniloctanoate-, Diflufenican-, and Bentazone Mineralization?

    DEFF Research Database (Denmark)

    Norgaard, Trine; de Jonge, Lis Wollesen; Møldrup, Per

    2015-01-01

    is the major process for the complete degradation of pesticides without generation of metabolites. The aim of our study was to determine field-scale variation in the potential for mineralization of the herbicides glyphosate, bromoxyniloctanoate, diflufenican, and bentazone and to investigate whether......-radiorespirometric method. Initial mineralization rates were determined using first-order kinetics for glyphosate and bromoxyniloctanoate and zeroorder kinetics for diflufenican and bentazone. The mineralization rates of the four pesticides varied between the different pesticides and the different soil samples, but we...... could not establish correlations between the pesticide mineralization rates and the measured soil parameters. Only the glyphosate mineralization rates showed slightly increasing mineralization potentials towards the northern area of the field, with increasing clay and decreasing OC contents...

  4. Comparison of Five Hydrothermal Vent Fields at the Mid-Atlantic Ridge: Which Parameters Control the Differences in Fluid Geochemistry?

    Science.gov (United States)

    Schmidt, K.; Koschinsky, A.; Garbe-Schönberg, D.; Seifert, R.

    2006-12-01

    Five different high-temperature hydrothermal vent sites along the Mid-Atlantic Ridge are investigated within a special priority program funded by the German Research Foundation (SPP 1144). The sites are all located at 3000 m water depth (near the critical point of seawater). Comparing the geochemical signature of the hydrothermal fluids with respect to the individual setting, it is possible to distinguish between the major controlling parameters as they are phase separation in the supercritical region of seawater, temperature, and host rock composition. Three of the vent sites were found at 4°49'S on the MAR in a young post-eruptive basaltic setting. Two of them are characterized by strong phase separation and the highest temperatures measured so far along the MAR (up to 407°C), assuming a very shallow heat source. It is assumed, that this hydrothermal system newly formed after a big eruption event in this region. The other one, although located at a distance of maximum 2 km from the other two, emanates somewhat cooler fluids (up to 349°C), with no indications for boiling and phase separation Despite their spatial proximity and the identical basaltic host rock in which these fields are situated, the vent fields show a clearly different fluid chemistry with depletion of alkali and earth alkali elements and some trace metals in the very hot, phase separated fluids. The Logatchev field at 14°45'N is located in an ultramafic setting with outcropping peridotitic and gabbroic rocks. The chlorinity of the fluids does not clearly indicate phase separation. Compared to the non-phase separated basaltic system at 4°49'S MAR the fluids are characterized by significantly higher concentrations of hydrogen and methane due to the serpentinization reactions, lower silica and lithium concentrations and a depletion of boron. A identical chemical signature characterizes a recently discovered system at 8°18'S, the Nibelungen field. Host rock composition with both mafic and

  5. Connecting Anthropogenic Seismicity Rates To Operational Parameters At The Salton Sea Geothermal Field, Southern California (Invited)

    Science.gov (United States)

    Brodsky, E. E.; Lajoie, L. J.

    2013-12-01

    Geothermal power is generated at several major volcanic fields in California. As efforts to monitor seismicity increase, methods to understand the anthropogenic component need to improve. Ideally, induced earthquake rate should be forecast based on publicly-reported volumes of fluid injection or other operational parameters. At the flash facilities in the Salton Sea Geothermal Field, the total volume of fluid extracted or injected tracks the long-term evolution of seismicity. However, for recent years net fluid volume (extracted-injected) is better correlated with seismicity. After correcting for the variable aftershock rate using an Epidemic-Type Aftershock Sequence model (ETAS), we fit the background earthquake rate with a linear combination of injection and net production rate that allows us to track the secular evolution of the field. The number of earthquakes per fluid volume injected decreases gradually over time. In the Salton Sea Geothermal Field, the new analysis of induced seismicity provides a template for future evaluation of hazard directly based on measureable, controllable operational quantities. The interactions of these anthropogenic events with the larger-scale tectonic and volcanic systems remains to be investigated. Results of the linear model of seismicity based on a combination of net production and injection. (a) Example of observed seismicity rate and model prediction using the reported fluid data and the best-fit linear model. (b) Number of earthquakes triggered per net volume of fluid extracted or total fluid injection.

  6. Effect of applying static electric field on the physical parameters and dynamics of laser-induced plasma

    Directory of Open Access Journals (Sweden)

    Asmaa Elhassan

    2010-04-01

    Full Text Available In order to improve the performance of the LIBS technique – in particular its sensitivity, reproducibility and limit of detection – we studied the effect of applying a static electric field with different polarities on the emission spectra obtained in a typical LIBS set-up. The physical parameters of the laser-induced plasma, namely the electron density Ne and the plasma temperature Te, were studied under such circumstances. In addition to the spectroscopic analysis of the plasma plume emission, the laser-induced shock waves were exploited to monitor the probable changes in the plasma plume dynamics due to the application of the electric field. The study showed a pronounced enhancement in the signal-to-noise (S/N ratio of different Al, neutral and ionic lines under forward biasing voltage (negative target and positive electrode. On the other hand, a clear deterioration of the emission line intensities was observed under conditions of reversed polarity. This negative effect may be attributed to the reduction in electron-ion recombinations due to the stretched plasma plume. The plasma temperature showed a constant value in the average with the increasing electric field in both directions. This effect may be due to the fact that the measured values of Te were averaged over the whole plasma emission volume. The electron density was observed to decrease slightly in the case of forward biasing while no significant effect was noticed in the case of reversed biasing. This slight decrease in Ne can be interpreted in view of the increase in the rate of electron–ion recombinations due to the presence of the electric field. No appreciable effects of the applied electric field on the plasma dynamics were noticed.

  7. Application of acid whey and set milk to marinate beef with reference to quality parameters and product safety.

    Science.gov (United States)

    Wójciak, Karolina M; Krajmas, Paweł; Solska, Elżbieta; Dolatowski, Zbigniew J

    2015-01-01

    The aim of the study was to evaluate the potential of acid whey and set milk as a marinade in the traditional production of fermented eye round. Studies involved assaying pH value, water activity (aw), oxidation-reduction potential and TBARS value, colour parameters in CIE system (L*, a*, b*), assaying the number of lactic acid bacteria and certain pathogenic bacteria after ripening process and after 60-day storing in cold storage. Sensory analysis and analysis of the fatty acids profile were performed after completion of the ripening process. Analysis of pH value in the products revealed that application of acid whey to marinate beef resulted in increased acidity of ripening eye round (5.14). The highest value of the colour parameter a* after ripening process and during storage was observed in sample AW (12.76 and 10.07 respectively), the lowest on the other hand was observed in sample SM (10.06 and 7.88 respectively). The content of polyunsaturated fatty acids (PUFA) was higher in eye round marinated in acid whey by approx. 4% in comparison to other samples. Application of acid whey to marinade beef resulted in increased share of red colour in general colour tone as well as increased oxidative stability of the product during storage. It also increased the content of polyunsaturated fatty acids (PUFA) in the product. All model products had high content of lactic acid bacteria and there were no pathogenic bacteria such as: L. monocytogenes, Y. enterocolitica, S. aureus, Clostridium sp.

  8. A field study of effects of road traffic and railway noise on polysomnographic sleep parameters.

    Science.gov (United States)

    Aasvang, Gunn Marit; Øverland, Britt; Ursin, Reidun; Moum, Torbjørn

    2011-06-01

    The aim of this study was to explore and compare the effect of noise from railway and road traffic on sleep in subjects habitually exposed to nocturnal noise. Forty young and middle aged healthy subjects were studied with polysomnography (PSG) during two consecutive nights in their own bedroom. Noise measurements and recordings were conducted concurrently outside of the bedroom façade as well as inside the bedroom of each participant. Different noise exposure parameters were calculated (L(p,A,eq,night), L(p,A,Fmax,night), and L(AF5,night)) and analyzed in relation to whole-night sleep parameters. The group exposed to railway noise had significantly less Rapid eye movement, (REM) sleep than the group exposed to road traffic noise. A significant association was found between the maximum level (L(p,A,Fmax,night)) of railway noise and time spent in REM sleep. REM sleep was significantly shorter in the group exposed to at least a single railway noise event above 50 dB inside the bedroom. These results, obtained in an ecological valid setting, support previous laboratory findings that railway noise has a stronger impact than road traffic noise on physiological parameters during sleep, and that the maximum noise level is an important predictor of noise effects on sleep assessed by PSG, at least for railway noise. © 2011 Acoustical Society of America

  9. Setting the process parameters for the coating process in order to assure tablet appearance based on multivariate analysis of prior data.

    Science.gov (United States)

    Tanabe, Shuichi; Nakagawa, Hiroshi; Watanabe, Tomoyuki; Minami, Hidemi; Kano, Manabu; Urbanetz, Nora A

    2016-09-10

    Designing efficient, robust process parameters in drug product manufacturing is important to assure a drug's critical quality attributes. In this research, an efficient, novel procedure for a coating process parameter setting was developed, which establishes a prediction model for setting suitable input process parameters by utilizing prior manufacturing knowledge for partial least squares regression (PLSR). In the proposed procedure, target values or ranges of the output parameters are first determined, including tablet moisture content, spray mist condition, and mechanical stress on tablets. Following the preparation of predictive models relating input process parameters to corresponding output parameters, optimal input process parameters are determined using these models so that the output parameters hold within the target ranges. In predicting the exhaust air temperature output parameter, which reflects the tablets' moisture content, PLSR was employed based on prior measured data (such as batch records of other products rather than design of experiments), leading to minimal new experiments. The PLSR model was revealed to be more accurate at predicting the exhaust air temperature than a conventional semi-empirical thermodynamic model. A commercial scale verification demonstrated that the proposed process parameter setting procedure enabled assurance of the quality of tablet appearance without any trial-and-error experiments.

  10. Parameters Relevant to Bubble Detachment when Gas-injecting into Polymer Melt Flow Field

    Institute of Scientific and Technical Information of China (English)

    CHEN Zailiang; CAI Yebin; GUO Mingcheng; PENG Yucheng

    2005-01-01

    The bubble deformation processes were reported when gas was injected into polymer melt flow field in another paper, the experiments showed that the deformation was severely affected by the volume of the bubble, and in turn, for the different bubbles, several different deformation processes were presented during their movement along the flow channel. In addition, we could find that the magnitude of the bubble volume was dependent upon the pressure difference of the gas injection pressure and the melt pressure. In this paper, more experimental conditions were changed to investigate the parameters relevant to the detachment of bubbles from the injection nozzle. The experimental results show that the pressure difference, the melt flow velocity as well as the melt pressure were all critical for the parameters, such as the bubble detachment time, the maximum bubble diameters and the magnitude of the bubble volume. The morphology changes of bubble were very large when the flow field was abruptly changed, and the situations were more complicated.

  11. How external magnetic fields alter the parameter dependence of reflectivity in stimulated Raman scattering

    Science.gov (United States)

    Winjum, B. J.; Tableman, A.; Tsung, F. S.; Mori, W. B.

    2016-10-01

    We show the parameter dependence of stimulated Raman scattering (SRS) reflectivity over a range of electron temperatures and densities, laser intensities, and external magnetic field (B0) amplitudes and orientations in particle-in-cell simulations with kλD = 0.2 - 0.4 for the backscatter plasma wave. B0 can modify kinetic SRS by altering the phasespace dynamics of trapped particles. We show how B0 (both in amplitude and in orientation relative to the incident laser wavevector) affects the onset intensity and threshold values for reflectivity. Without an external field, and for constant kλD , lower electron densities have lower reflectivities, since SRS saturates at amplitudes for which the detuning rate due to the nonlinear frequency shift is on the order of the growth rate. Lower reflectivities are also seen for shorter speckle lengths in multi-speckle ensembles. The sensitivity of SRS reflectivity to B0 depends on the underlying kinetic physics, though we comment on generalities and the parameter regimes for which B0 eliminates kinetic SRS reflectivity. Supported under Grant DE-NA0001833; simulations were carried out on the Dawson2 cluster, Edison, Mira, and BlueWaters.

  12. Observed Changes in Some Biochemical Parameters After Magnetic Field Exposure to 1,5 Tesla

    Directory of Open Access Journals (Sweden)

    Turan Akdağ

    2012-10-01

    Full Text Available Aim: In daily life, individuals are exposed to electromagnetic contamination at different levels. Magnetic resonance imaging (MRI is a radiodiagnostic imaging technique using non-ionizing radiofrequency radiation. Considering possible adverse effects of magnetic fields may occur at long time, complications are difficult to determined earlier. Therefore, the effects of MRI on some biochemical parameters were evaluated before and after MRI.Material and Method: In the present study, applying for MRI and with no systemic disorders, total 40 volunteers between the ages of 25-45 were enrolled. Blood samples were investigated before and after MRI, and subjects were exposed to magnetic field of 1.5 T for 30 min. Blood samples were soon centrifuged and studied in terms of the levels of serum Ca, Fe, Fe binding, triglyceride, cholesterol, TT3, TT4, free T3, free T4, TSH, ferritin, insulin, lipase, HDL, LDL and glucose. Results: In the study, levels of Ca, cholesterol, triglyceride, HDL, TT3, Fe, Fe binding, lipase, TSH and insulin after MRI were found to be lower than those before the procedure. This changs was observed to be statistically significant(P<0.05, and the difference related to levels of LDL, glukoz, ferritin, Free T3, Free T and TT4 were found to be statistically insignificant. Discussion: It was concluded that some biochemical parameters ocur after MRI, and further studies are needed to evaluate longterm consequences and biological effects and whether the changes are temporary.

  13. The NOAA-9 Earth Radiation Budget Experiment Wide Field-of-View Data Set

    Science.gov (United States)

    Bush, Kathryn A.; Smith, G. Louis; Young, David F.

    1999-01-01

    The Earth Radiation Budget Experiment (ERBE) consisted of wide field-of-view (WFOV) radiometers and scanning radiometers for measuring outgoing longwave radiation and solar radiation reflected from the Earth. These instruments were carried by the dedicated Earth Radiation Budget Satellite (ERBS) and by the NOAA-9 and -10 operational spacecraft. The WFOV radiometers provided data from which instantaneous fluxes at the top of the atmosphere (TOA) are computed by use of a numerical filter algorithm. Monthly mean fluxes over a 5-degree equal angle grid are computed from the instantaneous TOA fluxes. The WFOV radiometers aboard the NOAA-9 spacecraft operated from February 1985 through December 1992, at which time a failure of the shortwave radiometer ended the usable data after nearly 8 years. This paper examines the monthly mean products from that data set.

  14. Photometric Variability in the CSTAR Field: Results from the 2008 Data Set

    Science.gov (United States)

    Wang, Songhu; Zhang, Hui; Zhou, Xu; Zhou, Ji-Lin; Fu, Jian-Ning; Yang, Ming; Liu, Huigen; Xie, Jiwei; Wang, Lifan; Wang, Lingzhi; Wittenmyer, R. A.; Ashley, M. C. B.; Feng, Long-Long; Gong, Xuefei; Lawrence, J. S.; Liu, Qiang; Luong-Van, D. M.; Ma, Jun; Peng, Xiyan; Storey, J. W. V.; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhang, Xiaojia; Zhu, Zhenxi; Zou, Hu

    2015-06-01

    The Chinese Small Telescope Array (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 {{deg }2} CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes, and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.

  15. Photometric Variability in the CSTAR Field: Results From the 2008 Data Set

    CERN Document Server

    Wang, Songhu; Zhou, Xu; Zhou, Ji-Lin; Fu, Jian-Ning; Yang, Ming; Liu, Huigen; Xie, Jiwei; Wang, Lifan; Wang, Lingzhi; Wittenmyer, R A; Ashley, M C B; Feng, Long-Long; Gong, Xuefei; Lawrence, J S; Liu, Qiang; Luong-Van, D M; Ma, Jun; Peng, Xiyan; Storey, J W V; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhang, Xiaojia; Zhu, Zhenxi; Zou, Hu

    2015-01-01

    The Chinese Small Telescope ARray (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 deg2 CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.

  16. Extraction of 3D velocity and porosity fields from GeoPET data sets

    Energy Technology Data Exchange (ETDEWEB)

    Lippmann-Pipke, Johanna; Kulenkampff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Eichelbaum, S. [Nemtics Visualization, Leipzig (Germany)

    2017-06-01

    Geoscientific process monitoring with positron emission tomography (GeoPET) is proven to be applicable for quantitative tomographic transport process monitoring in natural geological materials. We benchmarked GeoPET by inversely fitting a numerical finite element model to a diffusive transport experiment in Opalinus clay. The obtained effective diffusion coefficients, D{sub e}, parallel and D{sub e}, perpendicular to, are well in line with data from literature. But more complex, heterogeneous migration, and flow patterns cannot be similarly evaluated by inverse fitting using optimization tools. Alternatively, we started developing an algorithm that allows the quantitative extraction of velocity and porosity fields, v{sub i=x,y,z} (x,y,z) and n(x,y,z) from GeoPET time series, c{sub PET}(x,y,z,t). They may serve as constituent data sets for reactive transport modelling.

  17. Parameter-free effective field theory calculation for the solar proton-fusion and hep processes

    Energy Technology Data Exchange (ETDEWEB)

    T.S. Park; L.E. Marcucci; R. Schiavilla; M. Viviani; A. Kievsky; S. Rosati; K. Kubodera; D.P. Min; M. Rho

    2002-08-01

    Spurred by the recent complete determination of the weak currents in two-nucleon systems up to {Omicron}(Q{sup 3}) in heavy-baryon chiral perturbation theory, we carry out a parameter-free calculation of the threshold S-factors for the solar pp (proton-fusion) and hep processes in an effective field theory that combines the merits of the standard nuclear physics method and systematic chiral expansion. The power of the EFT adopted here is that one can correlate in a unified formalism the weak-current matrix elements of two-, three- and four-nucleon systems. Using the tritium {beta}-decay rate as an input to fix the only unknown parameter in the theory, we can evaluate the threshold S factors with drastically improved precision; the results are S{sub pp}(0) = 3.94 x (1 {+-} 0.004) x 10{sup -25} MeV-b and S{sub hep}(0) = (8.6 {+-} 1.3) x 10{sup -20} keV-b. The dependence of the calculated S-factors on the momentum cutoff parameter {Lambda} has been examined for a physically reasonable range of {Lambda}. This dependence is found to be extremely small for the pp process, and to be within acceptable levels for the hep process, substantiating the consistency of our calculational scheme.

  18. Sensitivity analysis of torsional vibration behavior of the shafting of a turbo generator set to changes of its mechanical parameters

    Institute of Scientific and Technical Information of China (English)

    XIE Danmei; LIU Zhanhui; ZHANG Hengliang; YANG Changzhu; DONG Chuan

    2007-01-01

    Aiming at a 300 MW turbo-generator model,the sensitivity of natural torsional frequencies and modes of torsional vibration (TV) to the rotational inertia and stiffness of the turbo-generator were analyzed.Calculation results show that the variation of the rotational inertia or stiffness either of the rotor system as a whole (namely shafting) or only locally may both remarkably influence the TV characteristics of the rotor.The influence of localized variation is still notable although it is not as great as that of the rotor as a whole.The segments on the shafting,which contribute more to a certain mode of vibration,have a greater influence on the pertaining order of TV.Compared with the modal shape,a larger slope can be observed at these sections of the rotor for the particular mode.Thus,frequencies can be modulated by modifying the local construction of the rotor to make the natural TV frequency of a certain order avoid some specific value,herewith arriving at the objective of tuning.Therefore,it is very important,in the course of modeling for the purpose of studying the TV of the shafting of a turbo-set,to accurately determine the structural parameters of parts that have a relatively sensitive effect on the TV behavior.

  19. Model parameter uncertainty analysis for an annual field-scale P loss model

    Science.gov (United States)

    Bolster, Carl H.; Vadas, Peter A.; Boykin, Debbie

    2016-08-01

    Phosphorous (P) fate and transport models are important tools for developing and evaluating conservation practices aimed at reducing P losses from agricultural fields. Because all models are simplifications of complex systems, there will exist an inherent amount of uncertainty associated with their predictions. It is therefore important that efforts be directed at identifying, quantifying, and communicating the different sources of model uncertainties. In this study, we conducted an uncertainty analysis with the Annual P Loss Estimator (APLE) model. Our analysis included calculating parameter uncertainties and confidence and prediction intervals for five internal regression equations in APLE. We also estimated uncertainties of the model input variables based on values reported in the literature. We then predicted P loss for a suite of fields under different management and climatic conditions while accounting for uncertainties in the model parameters and inputs and compared the relative contributions of these two sources of uncertainty to the overall uncertainty associated with predictions of P loss. Both the overall magnitude of the prediction uncertainties and the relative contributions of the two sources of uncertainty varied depending on management practices and field characteristics. This was due to differences in the number of model input variables and the uncertainties in the regression equations associated with each P loss pathway. Inspection of the uncertainties in the five regression equations brought attention to a previously unrecognized limitation with the equation used to partition surface-applied fertilizer P between leaching and runoff losses. As a result, an alternate equation was identified that provided similar predictions with much less uncertainty. Our results demonstrate how a thorough uncertainty and model residual analysis can be used to identify limitations with a model. Such insight can then be used to guide future data collection and model

  20. Automation of the CHARMM General Force Field (CGenFF) II: Assignment of bonded parameters and partial atomic charges

    Science.gov (United States)

    Vanommeslaeghe, K.; Raman, E. Prabhu; MacKerell, A. D.

    2012-01-01

    Molecular mechanics force fields are widely used in computer-aided drug design for the study of drug candidates interacting with biological systems. In these simulations, the biological part is typically represented by a specialized biomolecular force field, while the drug is represented by a matching general (organic) force field. In order to apply these general force fields to an arbitrary drug-like molecule, functionality for assignment of atom types, parameters and partial atomic charges is required. In the present article, algorithms for the assignment of parameters and charges for the CHARMM General Force Field (CGenFF) are presented. These algorithms rely on the existing parameters and charges that were determined as part of the parametrization of the force field. Bonded parameters are assigned based on the similarity between the atom types that define said parameters, while charges are determined using an extended bond-charge increment scheme. Charge increments were optimized to reproduce the charges on model compounds that were part of the parametrization of the force field. A “penalty score” is returned for every bonded parameter and charge, allowing the user to quickly and conveniently assess the quality of the force field representation of different parts of the compound of interest. Case studies are presented to clarify the functioning of the algorithms and the significance of their output data. PMID:23145473

  1. Human Rights: Its Meaning and Practice in Social Work Field Settings.

    Science.gov (United States)

    Steen, Julie A; Mann, Mary; Restivo, Nichole; Mazany, Shellene; Chapple, Reshawna

    2017-01-01

    The goal of the study reported in this article was to explore the conceptualizations of human rights and human rights practice among students and supervisors in social work field settings. Data were collected from 35 students and 48 supervisors through an online survey system that featured two open-ended questions regarding human rights issues in their agency and human rights practice tasks. Responses suggest that participants encountered human rights issues related to poverty, discrimination, participation/self-determination/autonomy, violence, dignity/respect, privacy, and freedom/liberty. They saw human rights practice as encompassing advocacy, service provision, assessment, awareness of threats to clients' rights, and the nature of the worker-client relationship. These results have implications for the social work profession, which has an opportunity to focus more intently on change efforts that support clients' rights. The study points to the possibilities of expanding the scope of the human rights competency within social work education and addressing the key human rights issues in field education. © 2016 National Association of Social Workers.

  2. Low-level 14C methane oxidation rate measurements modified for remote field settings

    Science.gov (United States)

    Pack, M. A.; Pohlman, J.; Ruppel, C. D.; Xu, X.

    2012-12-01

    Aerobic methane oxidation limits atmospheric methane emissions from degraded subsea permafrost and dissociated methane hydrates in high latitude oceans. Methane oxidation rate measurements are a crucial tool for investigating the efficacy of this process, but are logistically challenging when working on small research vessels in remote settings. We modified a low-level 14C-CH4 oxidation rate measurement for use in the Beaufort Sea above hydrate bearing sediments during August 2012. Application of the more common 3H-CH4 rate measurement that uses 106 times more radioactivity was not practical because the R/V Ukpik cannot accommodate a radiation van. The low-level 14C measurement does not require a radiation van, but careful isolation of the 14C-label is essential to avoid contaminating natural abundance 14C measurements. We used 14C-CH4 with a total activity of 1.1 μCi, which is far below the 100 μCi permitting level. In addition, we modified field procedures to simplify and shorten sample processing. The original low-level 14C-CH4 method requires 6 steps in the field: (1) collect water samples in glass serum bottles, (2) inject 14C-CH4 into bottles, (3) incubate for 24 hours, (4) filter to separate the methanotrophic bacterial cells from the aqueous sample, (5) kill the filtrate with sodium hydroxide (NaOH), and (6) purge with nitrogen to remove unused 14C-CH4. Onshore, the 14C-CH4 respired to carbon dioxide or incorporated into cell material by methanotrophic bacteria during incubation is quantified by accelerator mass spectrometry (AMS). We conducted an experiment to test the possibility of storing samples for purging and filtering back onshore (steps 4 and 6). We subjected a series of water samples to steps 1-3 & 5, and preserved with mercuric chloride (HgCl2) instead of NaOH because HgCl2 is less likely to break down cell material during storage. The 14C-content of the carbon dioxide in samples preserved with HgCl2 and stored for up to 2 weeks was stable

  3. Analysis and design of photobioreactors for microalgae production I: method and parameters for radiation field simulation.

    Science.gov (United States)

    Heinrich, Josué Miguel; Niizawa, Ignacio; Botta, Fausto Adrián; Trombert, Alejandro Raúl; Irazoqui, Horacio Antonio

    2012-01-01

    Having capabilities for the simulation of the radiation field in suspensions of microalgae constitutes a great asset for the analysis, optimization and scaling-up of photobioreactors. In this study, a combined experimental and computational procedure is presented, specifically devised for the assessment of the coefficients of absorption and scattering, needed for the simulation of such fields. The experimental procedure consists in measuring the radiant energy transmitted through samples of suspensions of microalgae of different biomass concentrations, as well as the forward and backward scattered light. At a microscopic level, suspensions of microalgae are complex heterogeneous media and due to this complexity, in this study they are modeled as a pseudocontinuum, with centers of absorption and scattering randomly distributed throughout its volume. This model was tested on suspensions of two algal species of dissimilar cell shapes: Chlorella sp. and Scenedesmus quadricauda. The Monte Carlo simulation algorithm developed in this study, when used as a supporting subroutine of a main optimization program based on a genetic algorithm, permits the assessment of the physical parameters of the radiation field model. The Monte Carlo algorithm simulates the experiments, reproducing the events that photons can undergo while they propagate through culture samples or at its physical boundaries.

  4. A simplified dynamic method for field capacity estimation and its parameter analysis

    Institute of Scientific and Technical Information of China (English)

    Zhen-tao CONG; Hua-fang LÜ; Guang-heng NI

    2014-01-01

    This paper presents a simplified dynamic method based on the definition of field capacity. Two soil hydraulic characteristics models, the Brooks-Corey (BC) model and the van Genuchten (vG) model, and four soil data groups were used in this study. The relative drainage rate, which is a unique parameter and independent of the soil type in the simplified dynamic method, was analyzed using the pressure-based method with a matric potential of−1/3 bar and the flux-based method with a drainage flux of 0.005 cm/d. As a result, the relative drainage rate of the simplified dynamic method was determined to be 3% per day. This was verified by the similar field capacity results estimated with the three methods for most soils suitable for cultivating plants. In addition, the drainage time calculated with the simplified dynamic method was two to three days, which agrees with the classical definition of field capacity. We recommend the simplified dynamic method with a relative drainage rate of 3% per day due to its simple application and clearly physically-based concept.

  5. Before–After Field Study of Effects of Wind Turbine Noise on Polysomnographic Sleep Parameters

    Science.gov (United States)

    Jalali, Leila; Bigelow, Philip; Nezhad-Ahmadi, Mohammad-Reza; Gohari, Mahmood; Williams, Diane; McColl, Steve

    2016-01-01

    Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P=0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted. PMID:27569407

  6. Before–after field study of effects of wind turbine noise on polysomnographic sleep parameters

    Directory of Open Access Journals (Sweden)

    Leila Jalali

    2016-01-01

    Full Text Available Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG, the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P = 0.008 worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.

  7. Before-after field study of effects of wind turbine noise on polysomnographic sleep parameters.

    Science.gov (United States)

    Jalali, Leila; Bigelow, Philip; Nezhad-Ahmadi, Mohammad-Reza; Gohari, Mahmood; Williams, Diane; McColl, Steve

    2016-01-01

    Wind is considered one of the most advantageous alternatives to fossil energy because of its low operating cost and extensive availability. However, alleged health-related effects of exposure to wind turbine (WT) noise have attracted much public attention and various symptoms, such as sleep disturbance, have been reported by residents living close to wind developments. Prospective cohort study with synchronous measurement of noise and sleep physiologic signals was conducted to explore the possibility of sleep disturbance in people hosting new industrial WTs in Ontario, Canada, using a pre and post-exposure design. Objective and subjective sleep data were collected through polysomnography (PSG), the gold standard diagnostic test, and sleep diary. Sixteen participants were studied before and after WT installation during two consecutive nights in their own bedrooms. Both audible and infrasound noises were also concurrently measured inside the bedroom of each participant. Different noise exposure parameters were calculated (LAeq, LZeq) and analyzed in relation to whole-night sleep parameters. Results obtained from PSG show that sleep parameters were not significantly changed after exposure. However, reported sleep qualities were significantly (P = 0.008) worsened after exposure. Average noise levels during the exposure period were low to moderate and the mean of inside noise levels did not significantly change after exposure. The result of this study based on advanced sleep recording methodology together with extensive noise measurements in an ecologically valid setting cautiously suggests that there are no major changes in the sleep of participants who host new industrial WTs in their community. Further studies with a larger sample size and including comprehensive single-event analyses are warranted.

  8. A Parameter Study of the Dust and Gas Temperature in a Field of Young Stars

    CERN Document Server

    Urban, Andrea; Doty, Steven D

    2007-01-01

    We model the thermal effect of young stars on their surrounding environment in order to understand clustered star formation. We take radiative heating of dust, dust-gas collisional heating, cosmic-ray heating, and molecular cooling into account. Using Dusty, a spherical continuum radiative transfer code, we model the dust temperature distribution around young stellar objects with various luminosities and surrounding gas and dust density distributions. We have created a grid of dust temperature models, based on our modeling with Dusty, which we can use to calculate the dust temperature in a field of stars with various parameters. We then determine the gas temperature assuming energy balance. Our models can be used to make large-scale simulations of clustered star formation more realistic.

  9. Determining the exchange parameters of spin-1 metal-organic molecular magnets in pulsed magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Mcdonald, Ross D [Los Alamos National Laboratory; Singleton, John [Los Alamos National Laboratory; Lancaster, Tom [OXFORD UNIV.; Goddard, Paul [OXFORD UNIV.; Manson, Jamie [EASTERN WASHINGTON UNIV.

    2011-01-14

    We nave measured the high-field magnetization of a number of Ni-based metal-organic molecular magnets. These materials are self-assembly coordination polymers formed from transition metal ions and organic ligands. The chemistry of the compounds is versatile allowing many structures with different magnetic properties to be formed. These studies follow on from previous measurements of the Cu-based analogues in which we showed it was possible to extract the exchange parameters of low-dimensional magnets using pulsed magnetic fields. In our recent experiments we have investigated the compound (Ni(HF{sub 2})(pyz){sub 2})PF{sub 6}, where pyz = pyrazine, and the Ni-ions are linked in a quasi-two-dimensional (Q2D) square lattice via the pyrazine molecules, with the layers held together by HF{sub 2} ligands. We also investigated Ni(NCS){sub 2}(pyzdo){sub 2}, where pyzdo = pyrazine dioxide. The samples are grown at Eastern Washington University using techniques described elsewhere. Measurements are performed at the pulsed magnetic field laboratory in Los Alamos. The magnetization of powdered samples is determined using a compensated coil magnetometer in a 65 T short pulse magnet. Temperatures as low as 500 mK are achievable using a {sup 3}He cryostat. The main figure shows the magnetization of the spin-1 [Ni(HF{sub 2})(pyz){sub 2}]PF{sub 6} compound at 1.43 K. The magnetization rises slowly at first, achieving a rounded saturation whose midpoint is around 19 T. A small anomaly is also seen in the susceptibility at low fields ({approx}3 T), which might be attributed to a spin-flop transition. In contrast, the spin-1/2 [Cu(HF{sub 2})(pyz){sub 2}]PF{sub 6} measured previously has a saturation magnetization of 35.5 T and a strongly concave form of M(B) below this field. This latter compound was shown to be a good example of a Q2D Heisenberg antiferromagnet with the strong exchange coupling (J{sub 2D} = 12.4 K, J{sub {perpendicular}}/J{sub 2D} {approx} 10{sup -2}) directed along

  10. A Survey of Compact Star Clusters in the South-West Field of the M31 Disk. Structural Parameters

    CERN Document Server

    Sableviciute, I; Kodaira, K; Narbutis, D; Stonkute, R; Bridzius, A

    2006-01-01

    We present structural parameters for 51 compact star clusters from the survey of star clusters conducted in the South-West field of the M31 disk by Kodaira et al. (2004). Structural parameters of the clusters were derived by fitting the 2-D King and EFF (Elson, Fall and Freeman 1987) models to the V-band cluster images. Structural parameters derived for two M31 clusters, which are in common with the study based on the HST data (Barmby et al. 2002), are consistent with earlier determination. The M31 star cluster structural parameters in general are compatible with the corresponding Milky Way galaxy and Magellanic Clouds cluster parameters.

  11. Determination of the third critical field of superconductors using constrained effective wave function containing two variational parameters

    Energy Technology Data Exchange (ETDEWEB)

    Xu Longdao; Gao Yuliang

    1985-09-01

    Two variational parameters are included in the most probable constrained effective wave function with the accurate Hamiltonian remained. The third critical field which coincides with the result in paper (1) has been easily obtained through the variational principle.

  12. Polarizable simulations with second order interaction model (POSSIM) force field: developing parameters for protein side-chain analogues.

    Science.gov (United States)

    Li, Xinbi; Ponomarev, Sergei Y; Sa, Qina; Sigalovsky, Daniel L; Kaminski, George A

    2013-05-30

    A previously introduced polarizable simulations with second-order interaction model (POSSIM) force field has been extended to include parameters for small molecules serving as models for peptide and protein side-chains. Parameters have been fitted to permit reproducing many-body energies, gas-phase dimerization energies, and geometries and liquid-phase heats of vaporization and densities. Quantum mechanical and experimental data have been used as the target for the fitting. The POSSIM framework combines accuracy of a polarizable force field and computational efficiency of the second-order approximation of the full-scale induced point dipole polarization formalism. The resulting parameters can be used for simulations of the parameterized molecules themselves or their analogues. In addition to this, these force field parameters are currently being used in further development of the POSSIM fast polarizable force field for proteins.

  13. Fluid flow in discrete joint sets: Field observations and numerical simulations

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W. Lansing [Department of Geological and Environmental Sciences, Stanford University, Stanford, California (United States); Pollard, David D. [Department of Geological and Environmental Sciences, Stanford University, Stanford, California (United States); Aydin, Atilla [Department of Geological and Environmental Sciences, Stanford University, Stanford, California (United States)

    1999-12-10

    The distribution of flow within conductive joint sets is influenced by the geometric arrangement of joints and the hydraulic properties of both joints and matrix. We use finite element simulations with an equivalent porous media joint representation to understand the distribution of flow through joints and porous matrix. Isolated joints in a porous media create characteristic flow perturbations in the matrix with reduced fluid potentials near the upstream joint tip, elevated potentials near the downstream tip, and flow shadows adjacent to the joint. In more complex joint systems, flow in any given joint is influenced by its proximity to other joints, resulting in characteristic enhancement or reduction of flow velocities. The permeability ratio (equivalent joint permeability divided by matrix permeability) plays a major role in determining the distribution of flow within complex joint systems. When the permeability ratio is <3.0 orders of magnitude, all joints are indirectly connected to the flow system through the matrix. As joint conductivity increases, flow becomes increasingly localized into directly connected joints. When the permeability ratio exceeds 6.5 orders of magnitude, significant flow occurs only in the directly connected joints. We compare these numerical results with field observations from an ancient reactive flow system now exposed at the Earth's surface. In the field, 32% of joints are associated with chemically altered halos. By explicitly representing mapped joint distributions in numerical simulations, we estimate that 32% of the joints would conduct significant volumes of fluid if joint permeability is 5 orders of magnitude greater than the matrix permeability. This corresponds to an insitu joint aperture of 2.3 mm, closely resembling the 1.8-mm average joint aperture measured on the present-day outcrop. (c) 1999 American Geophysical Union.

  14. Exploring the Effects of Pulsed Electric Field Processing Parameters on Polyacetylene Extraction from Carrot Slices

    Directory of Open Access Journals (Sweden)

    Ingrid Aguiló-Aguayo

    2015-03-01

    Full Text Available The effects of various pulsed electric field (PEF parameters on the extraction of polyacetylenes from carrot slices were investigated. Optimised conditions with regard to electric field strength (1–4 kV/cm, number of pulses (100–1500, pulse frequency (10–200 Hz and pulse width (10–30 μs were identified using response surface methodology (RSM to maximise the extraction of falcarinol (FaOH, falcarindiol (FaDOH and falcarindiol-3-acetate (FaDOAc from carrot slices. Data obtained from RSM and experiments fitted significantly (p < 0.0001 the proposed second-order response functions with high regression coefficients (R2 ranging from 0.82 to 0.75. Maximal FaOH (188%, FaDOH (164.9% and FaDOAc (166.8% levels relative to untreated samples were obtained from carrot slices after applying PEF treatments at 4 kV/cm with 100 number of pulses of 10 μs at 10 Hz. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E% ranging from 0.68% to 3.58%.

  15. Exploring the effects of pulsed electric field processing parameters on polyacetylene extraction from carrot slices.

    Science.gov (United States)

    Aguiló-Aguayo, Ingrid; Abreu, Corina; Hossain, Mohammad B; Altisent, Rosa; Brunton, Nigel; Viñas, Inmaculada; Rai, Dilip K

    2015-03-02

    The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes from carrot slices were investigated. Optimised conditions with regard to electric field strength (1-4 kV/cm), number of pulses (100-1500), pulse frequency (10-200 Hz) and pulse width (10-30 μs) were identified using response surface methodology (RSM) to maximise the extraction of falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol-3-acetate (FaDOAc) from carrot slices. Data obtained from RSM and experiments fitted significantly (p < 0.0001) the proposed second-order response functions with high regression coefficients (R2) ranging from 0.82 to 0.75. Maximal FaOH (188%), FaDOH (164.9%) and FaDOAc (166.8%) levels relative to untreated samples were obtained from carrot slices after applying PEF treatments at 4 kV/cm with 100 number of pulses of 10 μs at 10 Hz. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E%) ranging from 0.68% to 3.58%.

  16. Comparative Mapping of Soil Physical-Chemical and Structural Parameters at Field Scale to Identify Zones of Enhanced Leaching Risk

    DEFF Research Database (Denmark)

    Nørgaard, Trine; Møldrup, Per; Olsen, Preben

    2013-01-01

    characteristics including soil texture, bulk density, dissolved tracer, particle and phosphorus transport parameters identified the northern one-third of the field as a zone with higher leaching risk. This risk assessment based on parameter mapping from measurements on intact samples was in good agreement...

  17. Calculation of the zero-field splitting D and g(perp)parameters in EPR for d3 spin systems in strong and moderate axial fields

    NARCIS (Netherlands)

    Kool, Th.W.; Bollegraaf, B.

    2010-01-01

    Numerical and analytical methods are used to investigate the calculation of the zero field splitting |2D| and g(perp) parameters in EPR for octahedrally surrounded d3 spin systems (S = 3/2) in strong and moderate axial crystal fields (|D|>=h{\

  18. Pharmacometrics: a multidisciplinary field to facilitate critical thinking in drug development and translational research settings.

    Science.gov (United States)

    Barrett, Jeffrey S; Fossler, Michael J; Cadieu, K David; Gastonguay, Marc R

    2008-05-01

    Pharmacometrics has evolved beyond quantitative analysis methods used to facilitate decision making in drug development, although the application of the discipline in this arena continues to represent the primary emphasis of scientists calling themselves pharmacometricians. While related fields populate and interface with pharmacometrics, there is a natural synergy with clinical pharmacology due to common areas of research and the decision-making expectation with respect to evolving conventional and translational research paradigms. Innovative and adaptable training programs and resources are essential in this regard as both disciplines promise to be key elements of the clinical research workplace of the future. The demand for scientists with pharmacometrics skills has risen substantially. Likewise, the salary garnered by those with these skills appears to be surpassing their counterparts without such backgrounds. Given the paucity of existing training programs, available training materials, and academic champions, a virtual faculty and online curriculum would allow students to matriculate into one of several programs associated with their advisor but take instruction from faculty at multiple institutions, including instructors in both industrial and regulatory settings. Flexibility in both the curriculum and the governance of the degree would provide the greatest hope of addressing the short supply of trained pharmacometricians.

  19. Estimates for Parameters and Characteristics of the Confining SU(3)-gluonic Field in $\\phi$-meson from Leptonic Widths

    CERN Document Server

    Goncharov, Yu P

    2014-01-01

    The paper is devoted to applying the confinement mechanism proposed earlier by one of the authors to estimate the possible parameters of the confining SU(3)-gluonic field in vector $\\phi$-meson. The estimates obtained are consistent with the leptonic widths of the given meson. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the meson under consideration.

  20. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Science.gov (United States)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3 / 2 , 5 / 2 , 7 / 2, and 9 / 2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  1. Advances in three-dimensional field analysis and evaluation of performance parameters of electrical machines

    Science.gov (United States)

    Sivasubramaniam, Kiruba

    This thesis makes advances in three dimensional finite element analysis of electrical machines and the quantification of their parameters and performance. The principal objectives of the thesis are: (1)the development of a stable and accurate method of nonlinear three-dimensional field computation and application to electrical machinery and devices; and (2)improvement in the accuracy of determination of performance parameters, particularly forces and torque computed from finite elements. Contributions are made in two general areas: a more efficient formulation for three dimensional finite element analysis which saves time and improves accuracy, and new post-processing techniques to calculate flux density values from a given finite element solution. A novel three-dimensional magnetostatic solution based on a modified scalar potential method is implemented. This method has significant advantages over the traditional total scalar, reduced scalar or vector potential methods. The new method is applied to a 3D geometry of an iron core inductor and a permanent magnet motor. The results obtained are compared with those obtained from traditional methods, in terms of accuracy and speed of computation. A technique which has been observed to improve force computation in two dimensional analysis using a local solution of Laplace's equation in the airgap of machines is investigated and a similar method is implemented in the three dimensional analysis of electromagnetic devices. A new integral formulation to improve force calculation from a smoother flux-density profile is also explored and implemented. Comparisons are made and conclusions drawn as to how much improvement is obtained and at what cost. This thesis also demonstrates the use of finite element analysis to analyze torque ripples due to rotor eccentricity in permanent magnet BLDC motors. A new method for analyzing torque harmonics based on data obtained from a time stepping finite element analysis of the machine is

  2. Microbiological parameters of aggregates in typical chernozems of long-term field experiments

    Science.gov (United States)

    Zhelezova, A. D.; Tkhakakhova, A. K.; Yaroslavtseva, N. V.; Garbuz, S. A.; Lazarev, V. I.; Kogut, B. M.; Kutovaya, O. V.; Kholodov, V. A.

    2017-06-01

    The changes in microbiological parameters of aggregates (1-2 mm) in typical chernozems under different land uses as dependent on the intensity and character of anthropogenic loads were studied with the help of the real-time polymerase chain reaction (PCR). The samples from the following long-term field experiments were examined: permanent black fallow, continuous cultivation of potato, 17-year-old unmanaged fallow after permanent black fallow, and annually mown reserved steppe. The soil samples were treated in two ways. In the first case, the samples were air-dried, sieved through the screens to separate aggregate fraction of 1-2 mm, and microbiological parameters were determined in this fraction. In the second case, the samples were frozen immediately after the sampling, and the aggregates of 1-2 mm were manually separated from the samples before the PCR analysis. It was shown that air-dry aggregates of chernozems could be used for the quantitative analysis of DNA of microbial community in comparative studies. According to the quantitative estimate of the content of DNA fragments from different phylogenetic groups, the bacterial community was most sensitive to the type of the soil use, and its restoration after the removal of extreme anthropogenic loads proceeded faster than that of other microorganisms. The content of archaeal DNA in the chernozem under the 17-year-old unmanaged fallow did not differ significantly from its content in the annually plowed chernozems. The changes in the content of micromycetal DNA related to anthropogenic load decrease were intermediate between changes in the contents of archaeal and bacterial DNA.

  3. GeV electron acceleration by a Gaussian field laser with effect of beam width parameter in magnetized plasma

    Science.gov (United States)

    Ghotra, Harjit Singh; Kant, Niti

    2017-01-01

    Electron acceleration due to a circularly polarized (CP) Gaussian laser field has been investigated theoretically in magnetized plasma. A Gaussian laser beam possesses trapping forces on electrons during its propagation through plasma. A single particle simulation indicates a resonant enhancement of electron acceleration with a Gaussian laser beam. The plasma is magnetized with an axial magnetic field in same direction as that of laser beam propagation. The dependence of laser beam width parameter on electron energy gain with propagation distance has been presented graphically for different values of laser intensity. Electron energy gain is relatively high where the laser beam parameter is at its minimum value. Enhanced energy gain of the order of GeV is reported with magnetic field under 20 MG in plasma. It is also seen that the axial magnetic field maintains the electron acceleration for large propagation distance even with an increasing beam width parameter.

  4. Improved determination of FID signal parameters in low-field NMR.

    Science.gov (United States)

    Dabek, Juhani; Nieminen, Jaakko O; Vesanen, Panu T; Sepponen, Raimo; Ilmoniemi, Risto J

    2010-07-01

    In this work, novel methods are suggested for assessing signal parameters of the free induction decay (FID) in nuclear magnetic resonance (NMR) experiments. The FID signal was recorded in a microtesla field and analysed to determine its relaxation time, amplitude, Larmor frequency and phase. The challenge was posed by the narrow line width, whose related effects were investigated through simulations, also. The developed methods give a new view on FID signal estimation in microtesla as well as lower and higher fields. It is shown that the transverse relaxation time of a sample can be accurately determined in the frequency domain by other means than the Lorentz peak half width. Also, with some realistic approximations, a simple functional form for the power spectrum Lorentz peak shape is proposed. As shown in this work, the inspection of the power spectrum instead of the absorption and dispersion Lorentzians is advantageous in the sense that the waveform is independent of the FID phase. The automatic and efficient methods presented in this work incorporate an integral exponential fit, the fit of the power spectrum Lorentz peak and two ways to determine the FID phase. When there are sufficiently many data points in the Lorentz peak, the power spectrum Lorentz peak shape fit provides a quick, simple and accurate way of determining the amplitude, relaxation time and Larmor frequency of the FID. In the measurements of this work, however, the narrow line width led to establishing a more applicable method which is based on the exponential decay of the Lorentz peak with a temporally moving power spectrum window.

  5. Influence of parameter settings in voxel-based morphometry 8. Using DARTEL and region-of-interest on reproducibility in gray matter volumetry.

    Science.gov (United States)

    Goto, M; Abe, O; Aoki, S; Hayashi, N; Miyati, T; Takao, H; Matsuda, H; Yamashita, F; Iwatsubo, T; Mori, H; Kunimatsu, A; Ino, K; Yano, K; Ohtomo, K

    2015-01-01

    To investigate whether reproducibility of gray matter volumetry is influenced by parameter settings for VBM 8 using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) with region-of-interest (ROI) analyses. We prepared three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects. All subjects were imaged with each of five MRI systems. Voxel-based morphometry 8 (VBM 8) and WFU PickAtlas software were used for gray matter volumetry. The bilateral ROI labels used were those provided as default settings with the software: Frontal Lobe, Hippocampus, Occipital Lobe, Orbital Gyrus, Parietal Lobe, Putamen, and Temporal Lobe. All 3D-T1WIs were segmented to gray matter with six parameters of VBM 8, with each parameter having between three and eight selectable levels. Reproducibility was evaluated as the standard deviation (mm³) of measured values for the five MRI systems. Reproducibility was influenced by 'Bias regularization (BiasR)', 'Bias FWHM', and 'De-noising filter' settings, but not by 'MRF weighting', 'Sampling distance', or 'Warping regularization' settings. Reproducibility in BiasR was influenced by ROI. Superior reproducibility was observed in Frontal Lobe with the BiasR1 setting, and in Hippocampus, Parietal Lobe, and Putamen with the BiasR3*, BiasR1, and BiasR5 settings, respectively. Reproducibility of gray matter volumetry was influenced by parameter settings in VBM 8 using DARTEL and ROI. In multi-center studies, the use of appropriate settings in VBM 8 with DARTEL results in reduced scanner effect.

  6. A field technique for estimating aquifer parameters using flow log data

    Science.gov (United States)

    Paillet, Frederick L.

    2000-01-01

    A numerical model is used to predict flow along intervals between producing zones in open boreholes for comparison with measurements of borehole flow. The model gives flow under quasi-steady conditions as a function of the transmissivity and hydraulic head in an arbitrary number of zones communicating with each other along open boreholes. The theory shows that the amount of inflow to or outflow from the borehole under any one flow condition may not indicate relative zone transmissivity. A unique inversion for both hydraulic-head and transmissivity values is possible if flow is measured under two different conditions such as ambient and quasi-steady pumping, and if the difference in open-borehole water level between the two flow conditions is measured. The technique is shown to give useful estimates of water levels and transmissivities of two or more water-producing zones intersecting a single interval of open borehole under typical field conditions. Although the modeling technique involves some approximation, the principle limit on the accuracy of the method under field conditions is the measurement error in the flow log data. Flow measurements and pumping conditions are usually adjusted so that transmissivity estimates are most accurate for the most transmissive zones, and relative measurement error is proportionately larger for less transmissive zones. The most effective general application of the borehole-flow model results when the data are fit to models that systematically include more production zones of progressively smaller transmissivity values until model results show that all accuracy in the data set is exhausted.A numerical model is used to predict flow along intervals between producing zones in open boreholes for comparison with measurements of borehole flow. The model gives flow under quasi-steady conditions as a function of the transmissivity and hydraulic head in an arbitrary number of zones communicating with each other along open boreholes. The

  7. Determination of Watershed Infiltration and Erosion Parameters from Field Rainfall Simulation Analyses

    Directory of Open Access Journals (Sweden)

    Mark E. Grismer

    2016-06-01

    Full Text Available Realistic modeling of infiltration, runoff and erosion processes from watersheds requires estimation of the effective hydraulic conductivity (Km of the hillslope soils and how it varies with soil tilth, depth and cover conditions. Field rainfall simulation (RS plot studies provide an opportunity to assess the surface soil hydraulic and erodibility conditions, but a standardized interpretation and comparison of results of this kind from a wide variety of test conditions has been difficult. Here, we develop solutions to the combined set of time-to-ponding/runoff and Green– Ampt infiltration equations to determine Km values from RS test plot results and compare them to the simpler calculation of steady rain minus runoff rates. Relating soil detachment rates to stream power, we also examine the determination of “erodibility” as the ratio thereof. Using data from over 400 RS plot studies across the Lake Tahoe Basin area that employ a wide range of rain rates across a range of soil slopes and conditions, we find that the Km values can be determined from the combined infiltration equation for ~80% of the plot data and that the laminar flow form of stream power best described a constant “erodibility” across a range of volcanic skirun soil conditions. Moreover, definition of stream power based on laminar flows obviates the need for assumption of an arbitrary Mannings “n” value and the restriction to mild slopes (<10%. The infiltration equation based Km values, though more variable, were on average equivalent to that determined from the simpler calculation of steady rain minus steady runoff rates from the RS plots. However, these Km values were much smaller than those determined from other field test methods. Finally, we compare RS plot results from use of different rainfall simulators in the basin and demonstrate that despite the varying configurations and rain intensities, similar erodibilities were determined across a range of

  8. Exploration of solar photospheric magnetic field data sets using the UCSD tomography

    Science.gov (United States)

    Jackson, B. V.; Yu, H.-S.; Buffington, A.; Hick, P. P.; Nishimura, N.; Nozaki, N.; Tokumaru, M.; Fujiki, K.; Hayashi, K.

    2016-12-01

    This article investigates the use of two different types of National Solar Observatory magnetograms and two different coronal field modeling techniques over 10 years. Both the "open-field" Current Sheet Source Surface (CSSS) and a "closed-field" technique using CSSS modeling are compared. The University of California, San Diego, tomographic modeling, using interplanetary scintillation data from Japan, provides the global velocities to extrapolate these fields outward, which are then compared with fields measured in situ near Earth. Although the open-field technique generally gives a better result for radial and tangential fields, we find that a portion of the closed extrapolated fields measured in situ near Earth comes from the direct outward mapping of these fields in the low solar corona. All three closed-field components are nonzero at 1 AU and are compared with the appropriate magnetometer values. A significant positive correlation exists between these closed-field components and the in situ measurements over the last 10 years. We determine that a small fraction of the static low-coronal component flux, which includes the Bn (north-south) component, regularly escapes from closed-field regions. The closed-field flux fraction varies by about a factor of 3 from a mean value during this period, relative to the magnitude of the field components measured in situ near Earth, and maximizes in 2014. This implies that a relatively more efficient process for closed-flux escape occurs near solar maximum. We also compare and find that the popular Potential Field Source Surface and CSSS model closed fields are nearly identical in sign and strength.

  9. Synthesis of parameters of a machine set, according to amplitudes of vibration, in the case of coaxial misalignment of shafts

    Science.gov (United States)

    Rondomanskas, M. S.; Ragulskis, K. M.; Ionushas, R. A.; Bansevichyus, R. Y.

    1973-01-01

    Dynamic synthesis of the coupling parameters permits the building of coaxially aligned connected machines with very small disturbing forces. Considered is the case of two machines connected by a flexible coupling; one machine is installed on shock absorbers with four degrees of freedom. A movement leveling synthesis considers the coaxial nonalignment parameters for the shaft arrangement and determines the optimum coupling rigidity at which the vibration amplitude is at a minimum.

  10. Hyperspectral measurements for estimating biophysical parameters and CO2 exchanges in a rice field

    Science.gov (United States)

    Rossini, M.; Migliavacca, M.; Meroni, M.; Manca, G.; Cogliati, S.; Busetto, L.; Picchi, V.; Galvagno, M.; Colombo, R.; Seufert, G.

    2009-04-01

    The objective of this work was to monitor the main biophysical and structural parameters as well as the CO2 exchanges between atmosphere and a terrestrial ecosystem from remote and high spectral resolution spectroradiometric measurements. Estimation of photosynthetic rate or gross primary productivity from remotely sensed data is based on the light use efficiency model (LUE), which states that carbon exchange is a function of the photosynthetically active radiation absorbed by vegetation (APAR) and the radiation use efficiency (ɛ) which represents the conversion efficiency of energy to fixed carbon. Hyperspectral data were used in this study in order to derived both the APAR of green vegetation and the ɛ term. The experimental site was a rice paddy field in North Italy equipped with an Eddy Covariance (EC) flux measurement tower (Castellaro IES-JRC site). Intensive field campaigns were conducted during summer 2007 and 2008. In each sampling day, canopy optical properties, canopy structure, biophysical and ecophysiological parameters were measured. EC fluxes were calculated with a time step of 30 minutes according to EUROFLUX methodology. Measured half-hourly net ecosystem exchange (NEE) was partitioned to derive half hourly gross ecosystem production (GEP). Canopy reflectance spectra were collected under clear sky conditions using two portable spectrometers (HR4000, OceanOptics, USA) characterised by different spectral resolutions. A spectrometer characterised by a Full Width at Half Maximum (FWHM) of 0.13 nm was used to estimate steady-state fluorescence (F) and a second one with a FWHM of 2.8 nm was used for the computation of traditional vegetation indices (e.g. NVDI, Normalized Difference Vegetation Index and SAVI, Soil Adjusted Vegetation Index) and PRI (Photochemical Reflectance Index, Gamon et al. 1992). F was estimated by exploiting a variation of the Fraunhofer Line Depth (FLD) principle (Plascyk 1975): the spectral fitting method described in Meroni

  11. Field and numerical determinations of pneumatic flow parameters of unsaturated fractured porous rocks on various scales

    Science.gov (United States)

    Guillon, S.; Vu, M. T.; Pili, E.; Adler, P. M.

    2013-05-01

    Air permeability is measured in the fractured crystalline rocks of the Roselend Natural Laboratory (France). Single-hole pneumatic injection tests as well as differential barometric pressure monitoring are conducted on scales ranging from 1 to 50 m, in both shallow and deep boreholes, as well as in an isolated 60 m3 chamber at 55 m depth. The field experiments are interpreted using numerical simulations in equivalent homogeneous porous media with their real 3-D geometry in order to estimate pneumatic parameters. For pneumatic injection tests, steady-state data first allow to estimate air permeability. Then, pressure recovery after a pneumatic injection test allows to estimate the air-filled porosity. Comparison between the various studied cases clarifies the influence of the boundary conditions on the accuracy of the often used 1-D estimate of air permeability. It also shows that permeabilities correlate slightly with fracture density. In the chamber, a 1 order-of-magnitude difference is found between the air permeabilities obtained from pneumatic injection tests and from differential barometric pressure monitoring. This discrepancy is interpreted as a scale effect resulting from the approximation of the heterogeneous fractured rock by a homogeneous numerical model. The difference between the rock volumes investigated by pneumatic injection tests and by differential barometric pressure monitoring may also play a role. No clear dependence of air permeability on saturation has been found so far.

  12. Renormalized parameters and perturbation theory in dynamical mean-field theory for the Hubbard model

    Science.gov (United States)

    Hewson, A. C.

    2016-11-01

    We calculate the renormalized parameters for the quasiparticles and their interactions for the Hubbard model in the paramagnetic phase as deduced from the low-energy Fermi-liquid fixed point using the results of a numerical renormalization-group calculation (NRG) and dynamical mean-field theory (DMFT). Even in the low-density limit there is significant renormalization of the local quasiparticle interaction U ˜, in agreement with estimates based on the two-particle scattering theory of J. Kanamori [Prog. Theor. Phys. 30, 275 (1963), 10.1143/PTP.30.275]. On the approach to the Mott transition we find a finite ratio for U ˜/D ˜ , where 2 D ˜ is the renormalized bandwidth, which is independent of whether the transition is approached by increasing the on-site interaction U or on increasing the density to half filling. The leading ω2 term in the self-energy and the local dynamical spin and charge susceptibilities are calculated within the renormalized perturbation theory (RPT) and compared with the results calculated directly from the NRG-DMFT. We also suggest, more generally from the DMFT, how an approximate expression for the q ,ω spin susceptibility χ (q ,ω ) can be derived from repeated quasiparticle scattering with a local renormalized scattering vertex.

  13. Integrating cross-case analyses and process tracing in set-theoretic research: Strategies and parameters of debate

    DEFF Research Database (Denmark)

    Beach, Derek; Rohlfing, Ingo

    2016-01-01

    – and their combination with process tracing. Our goal is to broaden and deepen set-theoretic empirical research and equip scholars with guidance on how to implement it in multi-method research (MMR). At first glance, set-theoretic cross-case methods and process tracing seem to be highly compatible when causal...... relationships are conceptualized in terms of set-theory. However, multiple issues have not so far been thoroughly addressed. Our paper builds on the emerging MMR literature and seeks to enhance it in four ways. First, we offer a comprehensive and coherent elaboration of the two sequences in which case studies...

  14. Enabling Interoperation of High Performance, Scientific Computing Applications: Modeling Scientific Data with the Sets & Fields (SAF) Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M C; Reus, J F; Matzke, R P; Arrighi, W J; Schoof, L A; Hitt, R T; Espen, P K; Butler, D M

    2001-02-07

    This paper describes the Sets and Fields (SAF) scientific data modeling system. It is a revolutionary approach to interoperation of high performance, scientific computing applications based upon rigorous, math-oriented data modeling principles. Previous technologies have required all applications to use the same data structures and/or meshes to represent scientific data or lead to an ever expanding set of incrementally different data structures and/or meshes. SAF addresses this problem by providing a small set of mathematical building blocks--sets, relations and fields--out of which a wide variety of scientific data can be characterized. Applications literally model their data by assembling these building blocks. A short historical perspective, a conceptual model and an overview of SAF along with preliminary results from its use in a few ASCI codes are discussed.

  15. Corneal Biomechanical Parameters and Asymmetric Visual Field Damage in Patients with Untreated Normal Tension Glaucoma

    Science.gov (United States)

    Li, Bai-Bing; Cai, Yu; Pan, Ying-Zi; Li, Mei; Qiao, Rong-Hua; Fang, Yuan; Tian, Tian

    2017-01-01

    Background: High intraocular pressure (IOP) and low central corneal thickness (CCT) are important validated risk factors for glaucoma, and some studies also have suggested that eyes with more deformable corneas may be in higher risk of the development and worsening of glaucoma. In the present study, we aimed to evaluate the association between corneal biomechanical parameters and asymmetric visual field (VF) damage using a Corvis-ST device in patients with untreated normal tension glaucoma (NTG). Methods: In this observational, cross-sectional study, 44 newly diagnosed NTG patients were enrolled. Of these, 31 had asymmetric VF damage, which was defined as a 5-point difference between the eyes according to the Advanced Glaucoma Intervention Study scoring system. Corneal biomechanical parameters were obtained using a Corvis-ST device, such as time from start until the first and second applanation is reached (time A1 and time A2, respectively), cord length of the first and second applanation (length A1 and length A2, respectively), corneal speed during the first and second applanation (velocity A1 and velocity A2, respectively), time from start until highest concavity is reached (time HC), maximum amplitude at the apex of highest concavity (def ampl HC), distance between the two peaks at highest concavity (peak dist HC), and central concave curvature at its highest concavity (radius HC). Results: Time A1 (7.19 ± 0.28 vs. 7.37 ± 0.41 ms, P = 0.010), length A1 (1.73 [1.70–1.76] vs. 1.78 [1.76–1.79] mm, P = 0.007), length A2 (1.58 [1.46–1.70] vs. 1.84 [1.76–1.92] mm, P < 0.001), peak dist HC (3.53 [3.08–4.00] vs. 4.33 [3.92–4.74] mm, P = 0.010), and radius HC (6.20 ± 0.69 vs. 6.59 ± 1.18 mm, P = 0.032) were significantly lower in the worse eyes than in the better eyes, whereas velocity A1 and def ampl HC were significantly higher (0.156 [0.149–0.163] vs. 0.145 [0.138–0.152] m/s, P = 0.002 and 1.19 ± 0.13 vs. 1.15 ± 0.13 mm, P = 0.005, respectively

  16. Evaluating Speed Enforcement Field Set-Ups Used by Regional Police in Belgium: An Analysis of Speed Outcome Indicators

    Directory of Open Access Journals (Sweden)

    Brenda Wilmots

    2016-12-01

    Full Text Available In this paper the results from a field experiment (conducted in 2012 are presented, in which 3 regional police units in the Flemish region of Belgium each tested a particular combination of a speed control (with mobile radar in an anonymous car with communicative signage. The goal of this paper was to scientifically evaluate frequently used field set-ups. The following set-ups were tested in one week: (1 police unit 1: speed control with and without a static feedback sign placed after the control; (2 police unit 2: speed control with and without a digital feedback sign placed after the control; (3 police unit 3: speed display followed by a second speed display further along the road section. During certain time frames, speed control took place in between both signs. All tested field set-ups generated significant reductions in the speed level. Studying the effect of the different variations for each set-up reveals that the effect of the speed control is generally larger in combination with the signage alongside the road. After the period during which the police activities took place, speed levels again reached their initial level. Based on the before–after analysis, only in police area 2 was a small ‘time halo-effect’ found. To generalize results from this pilot study, repetition of tested set-ups in the field is recommended as well as testing on a larger scale.

  17. Building the field of population health intervention research: The development and use of an initial set of competencies

    Directory of Open Access Journals (Sweden)

    Barbara Riley

    2015-01-01

    This initial set of competencies, released in 2013, may be used to develop graduate student curriculum, recruit trainees and faculty to academic institutions, plan non-degree professional development, and develop job descriptions for PHIR-related research and professional positions. The competencies provide some initial guideposts for the field and will need to be adapted as the PHIR field matures and to meet unique needs of different jurisdictions.

  18. Parameter sets for upper and lower bounds on soil-to-indoor-air contaminant attenuation predicted by the Johnson and Ettinger vapor intrusion model

    Science.gov (United States)

    Tillman, Fred D.; Weaver, James W.

    Migration of volatile chemicals from the subsurface into overlying buildings is known as vapor intrusion (VI). Under certain circumstances, people living in homes above contaminated soil or ground water may be exposed to harmful levels of these vapors. A popular VI screening-level algorithm widely used in the United States, Canada and the UK to assess this potential risk is the "Johnson and Ettinger" (J&E) model. Concern exists over using the J&E model for deciding whether or not further action is necessary at sites, as many parameters are not routinely measured (or are un-measurable). Using EPA-recommended ranges of parameter values for nine soil-type/source depth combinations, input parameter sets were identified that correspond to bounding results of the J&E model. The results established the existence of generic upper and lower bound parameter sets for maximum and minimum exposure for all soil types and depths investigated. Using the generic upper and lower bound parameter sets, an analysis can be performed that, given the limitations of the input ranges and the model, bounds the attenuation factor in a VI investigation.

  19. Crystal field parameters and crystal field linewidths in the (REY)Pd/sub 3/ and (REY)Al/sub 2/ alloys

    Energy Technology Data Exchange (ETDEWEB)

    Walter, U.; Holland-Moritz, E.

    1981-12-01

    The LLW-parameters x and W of dilute rare earth impurities (RE = Pr, Nd, Tb, Dy, Ho, Er, Tm; c approx. equal to 0.05) in the cubic matrices YPd/sub 3/ and YAl/sub 2/ could be determined unequivocally in the crystal field scheme of Lea, Leask and Wolf by inelastic neutron scattering. The crystal field parameters derived from x and W are not consistent with the point charge model. The ratio of N(Esub(F))Jsub(ex) for the (REY)Al/sub 2/ extracted from the RE-linewidths correlates with the corresponding ratio extracted from their magnetic ordering temperatures.

  20. Exact Results on Potts Model Partition Functions in a Generalized External Field and Weighted-Set Graph Colorings

    Science.gov (United States)

    Shrock, Robert; Xu, Yan

    2010-12-01

    We present exact results on the partition function of the q-state Potts model on various families of graphs G in a generalized external magnetic field that favors or disfavors spin values in a subset I s ={1,…, s} of the total set of possible spin values, Z( G, q, s, v, w), where v and w are temperature- and field-dependent Boltzmann variables. We remark on differences in thermodynamic behavior between our model with a generalized external magnetic field and the Potts model with a conventional magnetic field that favors or disfavors a single spin value. Exact results are also given for the interesting special case of the zero-temperature Potts antiferromagnet, corresponding to a set-weighted chromatic polynomial Ph( G, q, s, w) that counts the number of colorings of the vertices of G subject to the condition that colors of adjacent vertices are different, with a weighting w that favors or disfavors colors in the interval I s . We derive powerful new upper and lower bounds on Z( G, q, s, v, w) for the ferromagnetic case in terms of zero-field Potts partition functions with certain transformed arguments. We also prove general inequalities for Z( G, q, s, v, w) on different families of tree graphs. As part of our analysis, we elucidate how the field-dependent Potts partition function and weighted-set chromatic polynomial distinguish, respectively, between Tutte-equivalent and chromatically equivalent pairs of graphs.

  1. Deriving structural parameters of semi-resolved star clusters. FitClust: a program for crowded fields

    CERN Document Server

    Narbutis, D; Stonkutė, R; de Meulenaer, P; Mineikis, T; Bridžius, A; Vansevičius, V

    2014-01-01

    Context. An automatic tool to derive structural parameters of semi-resolved star clusters located in crowded stellar fields in nearby galaxies is needed for homogeneous processing of archival frames. Aims. We have developed a program that automatically derives the structural parameters of star clusters and estimates errors by accounting for individual stars and variable sky background. Methods. Models of observed frames consist of the cluster's surface brightness distribution, convolved with a point spread function; the stars, represented by the same point spread function; and a smoothly variable sky background. The cluster's model is fitted within a large radius by using the Levenberg-Marquardt and Markov chain Monte Carlo algorithms to derive structural parameters, the flux of the cluster, and individual fluxes of all well-resolved stars. Results. FitClust, a program to derive structural parameters of semi-resolved clusters in crowded stellar fields, was developed and is available for free use. The program ...

  2. A Descriptive Analysis of Music Therapists' Perceptions of Delivering Services in Inclusive Settings: A Challenge to the Field.

    Science.gov (United States)

    Jones; Cardinal

    1999-01-01

    The purpose of this study was to examine the perceptions of music therapists toward inclusion (providing services within general education settings) and to determine their willingness to provide their services in these settings. A questionnaire was sent to 560 music therapists of which 373 responded (67%). A descriptive analysis indicated that although the vast majority of music therapists are providing their services in a segregated setting, they (a) overwhelmingly know about inclusion, (b) perceive benefits to clients with and without disabilities, and (c) are willing to provide their services within an inclusive setting. Why then do therapists so overwhelmingly provide their services in noninclusive settings? Possible answers to this question as well as the challenge this creates to the field of music therapy are discussed.

  3. Robust Approximation to Adaptive Control by Use of Representative Parameter Sets with Particular Reference to Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Anthony Shannon

    2006-04-01

    Full Text Available This paper describes an approach to adaptive optimal control in the presence of model parameter calculation difficulties. This has wide application in a variety of biological and biomedical research and clinical problems. To illustrate the techniques, the approach is applied to the development and implementation of a practical adaptive insulin infusion algorithm for use with patients with Type 1 diabetes mellitus.

  4. Exploring parameter effects on the economic outcomes of groundwater-based developments in remote, low-resource settings

    Science.gov (United States)

    Abramson, Adam; Adar, Eilon; Lazarovitch, Naftali

    2014-06-01

    Groundwater is often the most or only feasible safe drinking water source in remote, low-resource areas, yet the economics of its development have not been systematically outlined. We applied AWARE (Assessing Water Alternatives in Remote Economies), a recently developed Decision Support System, to investigate the costs and benefits of groundwater access and abstraction for non-networked, rural supplies. Synthetic profiles of community water services (n = 17,962), defined across 13 parameters' values and ranges relevant to remote areas, were applied to the decision framework, and the parameter effects on economic outcomes were investigated. Regressions and analysis of output distributions indicate that the most important factors determining the cost of water improvements include the technological approach, the water service target, hydrological parameters, and population density. New source construction is less cost-effective than the use or improvement of existing wells, but necessary for expanding access to isolated households. We also explored three financing approaches - willingness-to-pay, -borrow, and -work - and found that they significantly impact the prospects of achieving demand-driven cost recovery. The net benefit under willingness to work, in which water infrastructure is coupled to community irrigation and cash payments replaced by labor commitments, is impacted most strongly by groundwater yield and managerial factors. These findings suggest that the cost-benefit dynamics of groundwater-based water supply improvements vary considerably by many parameters, and that the relative strengths of different development strategies may be leveraged for achieving optimal outcomes.

  5. A Survey of Compact Star Clusters in the S-W Field of the M31 Disk. Structural Parameters. II

    CERN Document Server

    Sableviciute, I; Kodaira, K; Narbutis, D; Stonkute, R; Bridzius, A

    2007-01-01

    The King and the EFF (Elson, Fall & Freeman 1987) analytical models are employed to determine the structural parameters of star clusters using an 1-D surface brightness profile fitting method. The structural parameters are derived and a catalogue is provided for 51 star cluster candidates from the survey of compact star clusters in the South-West field of the M31 disk performed by Kodaira et al. (2004).

  6. Behavior of Plasma and Field Parameters and their Relationship with Geomagnetic Indices during Intense Geomagnetic Storms of Solar Cycle 23

    CERN Document Server

    Joshi, Navin Chandra; Pande, Seema; Pande, Bimal; Pandey, Kavita

    2010-01-01

    A correlative study between the geomagnetic indices and the peak values of various plasma and field parameters during rising, maximum and decay phases as well as during complete solar cycle 23 have been presented. We have also presented the lag/lead analysis between the maximum of Dst and peak values of plasma and field parameters and found that peak values of lag/lead time lies in the +/-10 hr interval. Three geomagnetic storms (GMSs) and associated solar sources observed during these phases of this solar cycle have also been studied and found that GMSs are associated with large flares and halo CMEs.

  7. A Novel Approach for Deriving Force Field Torsion Angle Parameters Accounting for Conformation-Dependent Solvation Effects.

    Science.gov (United States)

    Zgarbová, Marie; Luque, F Javier; Šponer, Jiří; Otyepka, Michal; Jurečka, Petr

    2012-09-11

    A procedure for deriving force field torsion parameters including certain previously neglected solvation effects is suggested. In contrast to the conventional in vacuo approaches, the dihedral parameters are obtained from the difference between the quantum-mechanical self-consistent reaction field and Poisson-Boltzmann continuum solvation models. An analysis of the solvation contributions shows that two major effects neglected when torsion parameters are derived in vacuo are (i) conformation-dependent solute polarization and (ii) solvation of conformation-dependent charge distribution. Using the glycosidic torsion as an example, we demonstrate that the corresponding correction for the torsion potential is substantial and important. Our approach avoids double counting of solvation effects and provides parameters that may be used in combination with any of the widely used nonpolarizable discrete solvent models, such as TIPnP or SPC/E, or with continuum solvent models. Differences between our model and the previously suggested solvation models are discussed. Improvements were demonstrated for the latest AMBER RNA χOL3 parameters derived with inclusion of solvent effects in a previous publication (Zgarbova et al. J. Chem. Theory Comput.2011, 7, 2886). The described procedure may help to provide consistently better force field parameters than the currently used parametrization approaches.

  8. RUPTURES IN THE ANALYTIC SETTING AND DISTURBANCES IN THE TRANSFORMATIONAL FIELD OF DREAMS.

    Science.gov (United States)

    Brown, Lawrence J

    2015-10-01

    This paper explores some implications of Bleger's (1967, 2013) concept of the analytic situation, which he views as comprising the analytic setting and the analytic process. The author discusses Bleger's idea of the analytic setting as the depositary for projected painful aspects in either the analyst or patient or both-affects that are then rendered as nonprocess. In contrast, the contents of the analytic process are subject to an incessant process of transformation (Green 2005). The author goes on to enumerate various components of the analytic setting: the nonhuman, object relational, and the analyst's "person" (including mental functioning). An extended clinical vignette is offered as an illustration.

  9. Fostering Transformative Learning in Non-Formal Settings: Farmer-Field Schools in East Africa

    Science.gov (United States)

    Taylor, Edward W.; Duveskog, Deborah; Friis-Hansen, Esbern

    2012-01-01

    The purpose of this study was to explore the practice of Farmer-Field Schools (FFS) theoretically framed from the perspective of transformative learning theory and non-formal education (NFE). Farmer-Field Schools are community-led NFE programs that provide a platform where farmers meet regularly to study the "how and why" of farming and engage in…

  10. Fostering Transformative Learning in Non-Formal Settings: Farmer-Field Schools in East Africa

    Science.gov (United States)

    Taylor, Edward W.; Duveskog, Deborah; Friis-Hansen, Esbern

    2012-01-01

    The purpose of this study was to explore the practice of Farmer-Field Schools (FFS) theoretically framed from the perspective of transformative learning theory and non-formal education (NFE). Farmer-Field Schools are community-led NFE programs that provide a platform where farmers meet regularly to study the "how and why" of farming and…

  11. Teacher Training in Urban Settings: Inquiry, Efficacy, and Culturally Diverse Field Placements

    Science.gov (United States)

    McGlamery, Sheryl L.; Franks, Bridget A.; Shillingstad, Saundra L.

    2016-01-01

    This study describes two years of findings with a unique field experience (teaching science inquiry activities to African-American girls in a summer STEM camp) for preservice elementary education majors. It reports on the effects of the field experience, in conjunction with blocked science and mathematics methods courses, on preservice teachers'…

  12. The Change in Parameters of Fowler—Nordheim Tunneling Current in Ultrathin MOSFETs under Constant High Field Stress

    Institute of Scientific and Technical Information of China (English)

    HUOZongliang; WEIJianlin; MAOLingfeng; TANChanghua; XUMingzhen

    2003-01-01

    In this paper, the change in parameters of FN tunneling current has been investigated. Experiments show that parameters (I ln(A)l and B) decrease during ini-tial stress stage and then saturates after long stress time.By fitting method based on two exponential decay func-tions, we found that there exist two types of traps at least and a threshold electric field. Both types of traps might be natural traps and will play different roles according to stress electric field. When the stress electric field is higher than the threshold electric field, the traps play a role of electronic trap; whereas the traps play a role of hole trap.

  13. Support Vector Data Description Model to Map Specific Land Cover with Optimal Parameters Determined from a Window-Based Validation Set

    Directory of Open Access Journals (Sweden)

    Jinshui Zhang

    2017-04-01

    Full Text Available This paper developed an approach, the window-based validation set for support vector data description (WVS-SVDD, to determine optimal parameters for support vector data description (SVDD model to map specific land cover by integrating training and window-based validation sets. Compared to the conventional approach where the validation set included target and outlier pixels selected visually and randomly, the validation set derived from WVS-SVDD constructed a tightened hypersphere because of the compact constraint by the outlier pixels which were located neighboring to the target class in the spectral feature space. The overall accuracies for wheat and bare land achieved were as high as 89.25% and 83.65%, respectively. However, target class was underestimated because the validation set covers only a small fraction of the heterogeneous spectra of the target class. The different window sizes were then tested to acquire more wheat pixels for validation set. The results showed that classification accuracy increased with the increasing window size and the overall accuracies were higher than 88% at all window size scales. Moreover, WVS-SVDD showed much less sensitivity to the untrained classes than the multi-class support vector machine (SVM method. Therefore, the developed method showed its merits using the optimal parameters, tradeoff coefficient (C and kernel width (s, in mapping homogeneous specific land cover.

  14. Support Vector Data Description Model to Map Specific Land Cover with Optimal Parameters Determined from a Window-Based Validation Set.

    Science.gov (United States)

    Zhang, Jinshui; Yuan, Zhoumiqi; Shuai, Guanyuan; Pan, Yaozhong; Zhu, Xiufang

    2017-04-26

    This paper developed an approach, the window-based validation set for support vector data description (WVS-SVDD), to determine optimal parameters for support vector data description (SVDD) model to map specific land cover by integrating training and window-based validation sets. Compared to the conventional approach where the validation set included target and outlier pixels selected visually and randomly, the validation set derived from WVS-SVDD constructed a tightened hypersphere because of the compact constraint by the outlier pixels which were located neighboring to the target class in the spectral feature space. The overall accuracies for wheat and bare land achieved were as high as 89.25% and 83.65%, respectively. However, target class was underestimated because the validation set covers only a small fraction of the heterogeneous spectra of the target class. The different window sizes were then tested to acquire more wheat pixels for validation set. The results showed that classification accuracy increased with the increasing window size and the overall accuracies were higher than 88% at all window size scales. Moreover, WVS-SVDD showed much less sensitivity to the untrained classes than the multi-class support vector machine (SVM) method. Therefore, the developed method showed its merits using the optimal parameters, tradeoff coefficient (C) and kernel width (s), in mapping homogeneous specific land cover.

  15. Effect of storage temperature in a Cambodian field setting on the fatty acid composition in whole blood

    DEFF Research Database (Denmark)

    Nurhasan, Mulia; Roos, Nanna; Aristizabal Henao, J J

    2015-01-01

    Fatty acid analysis requires standardized collection and storage of samples, which can be a challenge under field conditions. This study describes the effect of storage temperature on fatty acid composition in two sets of whole blood samples collected from 66 children in a rural area in Cambodia...

  16. Magnetic field-induced changes of lattice parameters and thermal expansion behavior of the CoMnSi compound

    Energy Technology Data Exchange (ETDEWEB)

    Kou, R. H.; Gao, J.; Wang, G.; Liu, Y. D.; Wang, Y. D.; Ren, Y.; Brown, D. E.

    2016-02-01

    The crystal structure of the CoMnSi compound during zero-field cooling and field cooling from room temperature down to 200 K was studied using the synchrotron radiation X-ray diffraction technique. The results show that the lattice parameters and thermal expansion behavior of the sample are changed by the applied magnetic fields. The lattice contracts along the a axis, but expands along the b and c axes. Due to enlarged and anisotropic changes under a magnetic field of 6 T, the lattice shows an invar-like behavior along all three axes. Critical interatomic distances and bond angles also show large changes under the influence of such a high magnetic field. These magnetic field-induced changes of the lattice are discussed with respect to their contributions to the large magnetocaloric effect of the CoMnSi compound.

  17. Estimating the flash flood quantitative parameters affecting the oil-fields infrastructures in Ras Sudr, Sinai, Egypt, during the January 2010 event

    Directory of Open Access Journals (Sweden)

    Safwat Gabr

    2015-12-01

    Full Text Available This paper aims to quantify the hydrological parameters for the flash flood event of 17th January 2010 in Sinai using multiple sets of remote sensing data and field work for the nongaged catchments (approximately 2100 sq km of the wadis affecting Ras Sudr area, which is heavily occupied by numerous oil fields and related activities. The affected areas were visited, and several cross sections of the main active channels were surveyed to estimate the peak discharge rates. The Tropical Rainfall Monitoring Mission (TRMM data have been used to estimate rainfall parameters for the catchments due to the absence of in situ data. The digital elevation model (DEM of the Shuttle Radar Topography Mission (SRTM was used to extract the hydrographic data following standard procedures and techniques of the Geographic Information Systems (GIS. Both of the surveyed and extracted parameters for the active channels were integrated into GIS to estimate the runoff parameters using the open-channel flow equation of Manning’s. The simulated hydrographs show that the total discharge exceeded 5.7 million cubic meters and the peak discharge rate was 70 cubic meters per second. The mitigation of extreme flash flood is possible by altering the natural flow dispersion over the alluvial fan, and conveying the resulting flows into one adjusted channel.

  18. LAMOST Observations in the Kepler Field. Analysis of the Stellar Parameters Measured with LASP Based on Low-resolution Spectra

    Science.gov (United States)

    Ren, Anbing; Fu, Jianning; De Cat, Peter; Wu, Yue; Yang, Xiaohu; Shi, Jianrong; Luo, Ali; Zhang, Haotong; Dong, Subo; Zhang, Ruyuan; Zhang, Yong; Hou, Yonghui; Wang, Yuefei; Cao, Zihuang; Du, Bing

    2016-08-01

    All 14 subfields of the Kepler field were observed at least once with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (lamost, Xinglong Observatory, China) during the 2012-2014 observation seasons. There are 88,628 reduced spectra with a signal-to-noise ratio in the g band (S/N g ) ≥ 6 after the first round (2012-2014) of observations of the lamost- Kepler project (LK-project). By adopting the upgraded version of the lamost Stellar Parameter pipeline (lasp), we have determined the atmospheric parameters ({T}{eff}, {log}g, and [Fe/H]) and heliocentric radial velocity v rad for 51,406 stars with 61,226 spectra. Compared with the atmospheric parameters derived from both high-resolution spectroscopy and asteroseismology for common stars in Huber et al., an external calibration of lasp atmospheric parameters was made, leading to the determination of the external errors for giants and dwarfs. Multiple spectroscopic observations of the same objects in the LK-project were used to estimate the internal uncertainties of the atmospheric parameters as a function of S/N g with the unbiased estimation method. The lasp atmospheric parameters were calibrated based on both the external and internal uncertainties for the giants and dwarfs. A general statistical analysis of the stellar parameters leads to the discovery of 106 candidate metal-poor stars, 9 candidate very metal-poor stars, and 18 candidate high-velocity stars. Fitting formulae were obtained segmentally for both the calibrated atmospheric parameters of the LK-project and the Kepler Input Catalog (KIC) parameters with common stars. The calibrated atmospheric parameters and radial velocities of the LK-project will be useful for studying stars in the Kepler field. ) located at the Xinglong Observatory, China.

  19. Generation of physiological parameter sets for hip joint motions and loads during daily life activities for application in wear simulators of the artificial hip joint.

    Science.gov (United States)

    Fabry, Christian; Herrmann, Sven; Kaehler, Michael; Klinkenberg, Ernst-Dieter; Woernle, Christoph; Bader, Rainer

    2013-01-01

    At present, wear investigations of total hip replacements are performed in accordance with the ISO standard 14242, which is based on simplified kinematic and force data of the gait cycle. The aim of this analytical study was to generate parameter sets of daily life activities in order to replicate more realistic joint load situations in wear testing. Hence, published in vivo motion and force data of daily life activities were evaluated and adjusted using analytical techniques. The created kinematically and dynamically consistent parameter sets comprised time trajectories of three Cardan angles to describe the motion of the femur with respect to the pelvis and time trajectories of three force components, representing the hip joint contact force. The parameter sets include the activities of walking, knee bending, stair climbing and a combined load case of sitting down and standing up. Additionally, a motion sequence following the frequency of daily life activities was presented. Differences of the evaluated angular motions and joint contact forces in comparison to the ISO standard 14242-1 were pointed out. The results of this study offer the possibility to extend the kinematics and dynamics of the ISO standard test protocol and to support the loading conditions of hip wear simulators with a comprehensive set of motions and loads close to reality.

  20. Climate engineering field research : The favorable setting of international environmental law

    NARCIS (Netherlands)

    Reynolds, J.L.(Jesse)

    2014-01-01

    As forecasts for climate change and its impacts have become more dire, climate engineering proposals have come under increasing consideration and are presently moving toward field trials. This article examines the relevant international environmental law, distinguishing between climate engineering r

  1. Climate engineering field research : The favorable setting of international environmental law

    NARCIS (Netherlands)

    Reynolds, J.L.(Jesse)

    2014-01-01

    As forecasts for climate change and its impacts have become more dire, climate engineering proposals have come under increasing consideration and are presently moving toward field trials. This article examines the relevant international environmental law, distinguishing between climate engineering

  2. On the topology of the level sets of a scalar field

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, V

    2000-12-12

    This paper introduces a new simple algorithm for the construction of the Contour Tree of a 3D scalar field augmented with the Betti numbers of each contour component. The algorithm has {Omicron}(n log n) time complexity and {Omicron}(n) auxiliary storage. where n is the number of vertices in the domain of the field. The algorithm can be applied to fields of any dimension in which case it computes the Contour Tree augmented, with the Euler characteristic of each contour. The complexity in any dimension remains {Omicron}(n logn). This is the same complexity as in [4] but with correct computation of the tree for fields with bounded domains.

  3. Novel Texture-based Visualization Methods for High-dimensional Multi-field Data Sets

    Science.gov (United States)

    2013-07-06

    gradient image is multiplied with the first texture image, resulting in the second texture image appearing as “bumps”. The concept of Gestalt ...originates from the fine arts and expresses the notion that the whole contains more information than the parts. Perception of Gestalt is influenced by...We exploit Gestalt perception by using different masks, which subdivide the domain of two fields, and show for each section only one field. By

  4. Work-Identity in Ethnographic Research: Developing Field Roles in a Demanding Workplace Setting

    Directory of Open Access Journals (Sweden)

    Gunilla Jansson PhD

    2013-02-01

    Full Text Available In this article we problematize our field roles as two linguistic ethnographers who aim to study the communication and documentation practices drawn upon by care workers in elderly care facilities in Sweden. Our field roles are discussed in relation to the complex nature of care workers' knowledge and competence, which results from three different aspects of their work-identities: institutional, professional, and individual. As researchers, we found ourselves in constant dialogue with the research participants, and our field roles were continuously shaped and reshaped according to the individuals and the situations in which we became involved. Even aspects of our own identities taken into the field, such as our background and personal qualities, proved to be important in establishing good relations with the care staff. Coming closer to the participants' professional identity proved to be of utmost importance for interpreting their choices and decisions in the workplace. Identity negotiation is presented here as a constructive way of discussing ethnographic field roles in the research field.

  5. Effects of the isostretching method on morphological parameters and on a set of motor tests in the elderly

    Directory of Open Access Journals (Sweden)

    Christina Cruz Cepeda

    2013-07-01

    Full Text Available Moderate intensity resistance training seems to be effective in providing significant improvements on strength, balance and function in the elderly. This study aimed to analyze the effect of a 12-week isostretching training on functional capacity and muscle architecture in elderly women. The sample included 25 volunteers (n = 25 divided into a control group (CG, n = 11, 62.3 ± 1.9 years old, 1.58 ± 0.06 m, 73.4 ± 1.4 kg that followed their physical activity habits and an experimental group (EG, n = 14, 64.2 ± 4.3 years, 1.56 ± 0.05 m, 74.2 ± 1.6 kg that was submitted to an isostretching program. The following assessments were used: Timed Up and Go-TUGT, Tinetti balance test and evaluation of morphological parameters through ultrasound imaging technique. The results showed that the EG improved (p <0.05 in both TUGT and Tinetti. In the morphologic parameters of the vastus lateralis muscle in the EG, we observed the following: mean increase of 3.6 mm in length issue relaxation (p <0.05, ES = 1.15; increase of 4.9 mm in isometric contraction (p <0.05; ES = 1.94; increase of 16% in the pennation angle in the relaxed condition (p <0.05; ES = 0.70; increase of 12% in isometric contraction (p <0.05; ES = 0.50; increase of 8% in thickness in the relaxed condition (p <0.05, EF = 0.52; and increase of 9% in isometric contraction (p <0.05, EF = 0.43. The GC did not show any significant changes. The isometric training through the isostretching method promoted changes in the morphological and muscle parameters and also improved the functional abilities in elderly women.

  6. Canadian participation in NATO SET-093 field experiment at Bourges, France

    Science.gov (United States)

    Bédard, Jacques

    2009-05-01

    As part of the NATO SET-093 experiment, Defence R&D Canada - Valcartier collected acoustic signatures using two Ferret systems. The new set of data was used to assess the performance of Ferret not only for the detection of small arms fire but also to determine whether weapons other than small arms could trigger the system and create false alarms. Ferret is an acoustic signal processing system that detects, recognizes and localizes the source and direction of small arms fire. New detection algorithms have been developed at DRDC Valcartier and incorporated into a recent software upgrade of the system. This paper presents an overview of the improvements, the reasons behind those changes and the performance of Ferret when exposed to the new set of data. The author also proposes metrics for future data collection that would allow a better evaluation of performance.

  7. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2, 5/2, 7/2, and 9/2. These results may be used to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences, Heavy Element Chemistry program.

  8. A two-parameter family of exact asymptotically flat solutions to the Einstein-scalar field equations

    Energy Technology Data Exchange (ETDEWEB)

    Nikonov, V V; Tchemarina, Ju V; Tsirulev, A N [Department of Mathematics, Tver State University, Sadovyi per. 35, Tver 170002 (Russian Federation)], E-mail: tsirulev@tversu.ru

    2008-07-07

    We consider a static spherically symmetric real scalar field, minimally coupled to Einstein gravity. A two-parameter family of exact asymptotically flat solutions is obtained by using the inverse problem method. This family includes non-singular solutions, black holes and naked singularities. For each of these solutions the respective potential is partially negative but positive near spatial infinity. (comments, replies and notes)

  9. Scaling of crystal field parameters between Pd{sub 2}REIn and Pd{sub 2}RESn

    Energy Technology Data Exchange (ETDEWEB)

    Babateen, M. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Neumann, K.U. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom); Ziebeck, K.R.A. [Department of Physics, Loughborough University of Technology, Loughborough, Leics. LE11 3TU (United Kingdom)

    1995-02-09

    Experimentally it is found that crystal field (CF) parameters between the same rare earth compounds in the alloy series Pd{sub 2}REIn and Pd{sub 2}RESn (RE=rare earth element) exhibit scaling properties. A phenomenological model is put forward to explain this observation. ((orig.)).

  10. Application of the RIMARC algorithm to a large data set of action potentials and clinical parameters for risk prediction of atrial fibrillation.

    Science.gov (United States)

    Ravens, Ursula; Katircioglu-Öztürk, Deniz; Wettwer, Erich; Christ, Torsten; Dobrev, Dobromir; Voigt, Niels; Poulet, Claire; Loose, Simone; Simon, Jana; Stein, Agnes; Matschke, Klaus; Knaut, Michael; Oto, Emre; Oto, Ali; Güvenir, H Altay

    2015-03-01

    Ex vivo recorded action potentials (APs) in human right atrial tissue from patients in sinus rhythm (SR) or atrial fibrillation (AF) display a characteristic spike-and-dome or triangular shape, respectively, but variability is huge within each rhythm group. The aim of our study was to apply the machine-learning algorithm ranking instances by maximizing the area under the ROC curve (RIMARC) to a large data set of 480 APs combined with retrospectively collected general clinical parameters and to test whether the rules learned by the RIMARC algorithm can be used for accurately classifying the preoperative rhythm status. APs were included from 221 SR and 158 AF patients. During a learning phase, the RIMARC algorithm established a ranking order of 62 features by predictive value for SR or AF. The model was then challenged with an additional test set of features from 28 patients in whom rhythm status was blinded. The accuracy of the risk prediction for AF by the model was very good (0.93) when all features were used. Without the seven AP features, accuracy still reached 0.71. In conclusion, we have shown that training the machine-learning algorithm RIMARC with an experimental and clinical data set allows predicting a classification in a test data set with high accuracy. In a clinical setting, this approach may prove useful for finding hypothesis-generating associations between different parameters.

  11. Use of natural clays as sorbent materials for rare earth ions: Materials characterization and set up of the operative parameters.

    Science.gov (United States)

    Iannicelli-Zubiani, Elena Maria; Cristiani, Cinzia; Dotelli, Giovanni; Gallo Stampino, Paola; Pelosato, Renato; Mesto, Ernesto; Schingaro, Emanuela; Lacalamita, Maria

    2015-12-01

    Two mineral clays of the montmorillonite group were tested as sorbents for the removal of Rare Earths (REs) from liquid solutions. Lanthanum and neodymium model solutions were used to perform uptake tests in order to: (a) verify the clays sorption capability, (b) investigate the sorption mechanisms and (c) optimize the experimental parameters, such as contact time and pH. The desorption was also studied, in order to evaluate the feasibility of REs recovery from waters. The adsorption-desorption procedure with the optimized parameters was also tested on a leaching solution obtained by dissolution of a dismantled NdFeB magnet of a hard-disk. The clays were fully characterized after REs adsorption and desorption by means of X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS); the liquid phase was characterized via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) analyses. The experimental results show that both clays are able to capture and release La and Nd ions, with an ion exchange mechanism. The best total efficiency (capture ≈ 50%, release ≈ 70%) is obtained when the uptake and release processes are performed at pH=5 and pH=1 respectively; in real leached scrap solutions, the uptake is around 40% but release efficiency is strongly decreased passing from a mono-ion system to a real system (from 80% to 5%). Furthermore, a strong matrix effect is found, with the matrix largely affecting both the uptake and the release of neodymium.

  12. Polynomial Chaos Acceleration for the Bayesian Inference of Random Fields with Gaussian Priors and Uncertain Covariance Hyper-Parameters

    KAUST Repository

    Le Maitre, Olivier

    2015-01-07

    We address model dimensionality reduction in the Bayesian inference of Gaussian fields, considering prior covariance function with unknown hyper-parameters. The Karhunen-Loeve (KL) expansion of a prior Gaussian process is traditionally derived assuming fixed covariance function with pre-assigned hyperparameter values. Thus, the modes strengths of the Karhunen-Loeve expansion inferred using available observations, as well as the resulting inferred process, dependent on the pre-assigned values for the covariance hyper-parameters. Here, we seek to infer the process and its the covariance hyper-parameters in a single Bayesian inference. To this end, the uncertainty in the hyper-parameters is treated by means of a coordinate transformation, leading to a KL-type expansion on a fixed reference basis of spatial modes, but with random coordinates conditioned on the hyper-parameters. A Polynomial Chaos (PC) expansion of the model prediction is also introduced to accelerate the Bayesian inference and the sampling of the posterior distribution with MCMC method. The PC expansion of the model prediction also rely on a coordinates transformation, enabling us to avoid expanding the dependence of the prediction with respect to the covariance hyper-parameters. We demonstrate the efficiency of the proposed method on a transient diffusion equation by inferring spatially-varying log-diffusivity fields from noisy data.

  13. Diffraction corrections for second harmonic beam fields and effects on the nonlinearity parameter evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyun Jo; Cho, Sung Jong; Nam, Ki Woong; Lee, Jang Hyun [Division of Mechanical and Automotive Engineering, Wonkwang University, Iksan (Korea, Republic of)

    2016-04-15

    The nonlinearity parameter is frequently measured as a sensitive indicator in damaged material characterization or tissue harmonic imaging. Several previous studies have employed the plane wave solution, and ignored the effects of beam diffraction when measuring the non-linearity parameter β. This paper presents a multi-Gaussian beam approach to explicitly derive diffraction corrections for fundamental and second harmonics under quasilinear and paraxial approximation. Their effects on the nonlinearity parameter estimation demonstrate complicated dependence of β on the transmitter-receiver geometries, frequency, and propagation distance. The diffraction effects on the non-linearity parameter estimation are important even in the nearfield region. Experiments are performed to show that improved β values can be obtained by considering the diffraction effects.

  14. Determiner use in Italian Swedish and Italian German children: Do Swedish and German represent the same parameter setting?

    Directory of Open Access Journals (Sweden)

    Tanja Kupisch

    2008-02-01

    Full Text Available In this article we compare the acquisition of determiners in bilingual children acquiring Italian simultaneously with German or Swedish. We are concerned with cross-linguistic differences in the rate of acquisition and we discuss in particular the Nominal Mapping Parameter, a model according to which the syntax-semantics interface is crucial in acquisition and which predicts similar developmental patterns for children acquiring a Germanic language. We show that Swedish determiners are acquired more easily than German determiners, which implies that predictions for developmental patterns should not be based on syntactic factors alone, but must make reference to typological differences in morphology and phonology. Furthermore, we show that the acquisition of Italian determiners is affected positively by the simultaneous acquisition of Swedish but that no such effect arises when Italian is acquired simultaneously with German.

  15. Effect of software version and parameter settings on the marginal and internal adaptation of crowns fabricated with the CAD/CAM system

    Directory of Open Access Journals (Sweden)

    Ji Suk SHIM

    2015-10-01

    Full Text Available Objective This study investigated the marginal and internal adaptation of individual dental crowns fabricated using a CAD/CAM system (Sirona’s BlueCam, also evaluating the effect of the software version used, and the specific parameter settings in the adaptation of crowns.Material and Methods Forty digital impressions of a master model previously prepared were acquired using an intraoral scanner and divided into four groups based on the software version and on the spacer settings used. The versions 3.8 and 4.2 of the software were used, and the spacer parameter was set at either 40 μm or 80 μm. The marginal and internal fit of the crowns were measured using the replica technique, which uses a low viscosity silicone material that simulates the thickness of the cement layer. The data were analyzed using a Friedman two-way analysis of variance (ANOVA and paired t-tests with significance level set at p<0.05.Results The two-way ANOVA analysis showed the software version (p<0.05 and the spacer parameter (p<0.05 significantly affected the crown adaptation. The crowns designed with the version 4.2 of the software showed a better fit than those designed with the version 3.8, particularly in the axial wall and in the inner margin. The spacer parameter was more accurately represented in the version 4.2 of the software than in the version 3.8. In addition, the use of the version 4.2 of the software combined with the spacer parameter set at 80 μm showed the least variation. On the other hand, the outer margin was not affected by the variables.Conclusion Compared to the version 3.8 of the software, the version 4.2 can be recommended for the fabrication of well-fitting crown restorations, and for the appropriate regulation of the spacer parameter.

  16. Nodal sets for ground-states of Schroedinger operators with zero magnetic field in non simply connected domains

    Energy Technology Data Exchange (ETDEWEB)

    Helffer, B. [Paris-11 Univ., 91 - Orsay (France). Dept. de Mathematiques; Hoffmann-Ostenhof, M. [Institut fuer Mathematik, Universitaet Wien, Strudthofgasse 4, A-1090 Wien (Austria); Hoffmann-Ostenhof, T. [Institut fuer Theoretische Chemie, Universitaet Wien, Waehringerstrasse 17, A-1090 Wien (Austria)]|[International Erwin Schroedinger Inst. for Mathematical Physics, Vienna (Austria); Owen, M.P. [International Erwin Schroedinger Inst. for Mathematical Physics, Vienna (Austria)

    1999-05-01

    We investigate nodal sets of magnetic Schroedinger operators with zero magnetic field, acting on a non-simply connected domain in R{sup 2}. For the case of circulation 1/2 of the magnetic vector potential around each hole in the region, we obtain a characterisation of the nodal set, and use this to obtain bounds on the multiplicity of the ground state. For the case of one hole and a fixed electric potential, we show that the first eigenvalue takes its highest value for circulation 1/2. (orig.) With 8 figs., 20 refs.

  17. Using a verbal prompt to increase protein consumption in a hospital setting: a field study

    NARCIS (Netherlands)

    Zanden, van der L.D.T.; Essen, van H.; Kleef, van E.; Wijk, de R.A.; Trijp, van J.C.M.

    2015-01-01

    Background: Sufficient protein intake among hospitalized patients may contribute to faster recovery and a decrease in healthcare costs. Nevertheless, hospitalized patients are often found to consume too little protein. This field study explored the success of a small, inexpensive intervention adapte

  18. Accuracy of electromagnetic tracking with a prototype field generator in an interventional OR setting

    Energy Technology Data Exchange (ETDEWEB)

    Boe, Lars Eirik; Leira, Haakon Olav; Tangen, Geir Arne; Hofstad, Erlend Fagertun; Amundsen, Tore; Langoe, Thomas [Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway) and Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway) and Department of Thoracic Medicine, St. Olavs Hospital, Trondheim (Norway); Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway); Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway) and Department of Thoracic Medicine, St. Olavs Hospital, Trondheim (Norway); Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway)

    2012-01-15

    Purpose: The authors have studied the accuracy and robustness of a prototype electromagnetic window field generator (WFG) in an interventional radiology suite with a robotic C-arm. The overall purpose is the development of guidance systems combining real-time imaging with tracking of flexible instruments for bronchoscopy, laparoscopic ultrasound, endoluminal surgery, endovascular therapy, and spinal surgery. Methods: The WFG has a torus shape, which facilitates x-ray imaging through its centre. The authors compared the performance of the WFG to that of a standard field generator (SFG) under the influence of the C-arm. Both accuracy and robustness measurements were performed with the C-arm in different positions and poses. Results: The system was deemed robust for both field generators, but the accuracy was notably influenced as the C-arm was moved into the electromagnetic field. The SFG provided a smaller root-mean-square position error but was more influenced by the C-arm than the WFG. The WFG also produced smaller maximum and variance of the error. Conclusions: Electromagnetic (EM) tracking with the new WFG during C-arm based fluoroscopy guidance seems to be a step forward, and with a correction scheme implemented it should be feasible.

  19. Setting occupational exposure limits in humans: contributions from the field of experimental psychology

    NARCIS (Netherlands)

    Smeets, M.A.M.; Kroeze, J.H.A.; Dalton, P.M.

    2006-01-01

    Psychophysical methods from the field of experimental psychology are evaluated for their utility in the derivation of occupational exposure limits (OELs) for volatile chemicals based on acute sensory irritation in humans. The lateralization threshold method, which involves the localization of trigem

  20. Geometrical parameters effects on local electric field enhancement of silver-dielectric-silver multilayer nanoshell

    Energy Technology Data Exchange (ETDEWEB)

    Shirzaditabar, Farzad; Saliminasab, Maryam [Department of Physics, Razi University, Kermanshah 67144-15111 (Iran, Islamic Republic of)

    2013-05-15

    The local electric field enhancement at different points of silver-dielectric-silver nanoshell is investigated using quasi-static theory. Because of the symmetric and anti-symmetric coupling between surface plasmon of inner silver core and outer silver shell, the local electric field spectrum of silver-dielectric-silver has two distinct peaks at resonance wavelengths. The silver core size and middle dielectric thickness affect the local electric field enhancement at different points of silver-dielectric-silver nanoshell. Increasing the silver core radius always leads to blue shift of shorter resonance wavelength and red shift of longer resonance wavelength. We observed two distinct local electric field peaks, which are corresponded to the symmetric and anti-symmetric coupling between inner and outer surface plasmons. In a system with thick silver shell, local electric field enhancement is greater than a system with thin silver shell. However, the local electric field variations as a function of silver core radius in both systems are different at different points of nanoshell. The effects of the dielectric thickness variations on local electric field are different from those from silver core size variations. As the dielectric thickness is about 3 nm, the highest local electric field enhancement occurs at the surface of the inner silver core, where the symmetric and anti-symmetric modes are mixed together.

  1. A Unifying Field in Logics: Neutrosophic Logic. Neutrosophy, Neutrosophic Set, Neutrosophic Probability (fifth edition)

    OpenAIRE

    Smarandache, Florentin

    2006-01-01

    The neutrosophy, neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics etc. were introduced by Florentin Smarandache in 1995. 1. Neutrosophy is a new branch of philosophy that studies the origin, nature, and scope of neutralities, as well as their interactions with different ideational spectra. This theory considers every notion or idea together with its opposite or negation and with their spectrum of neutralities ...

  2. A quantum molecular similarity analysis of changes in molecular electron density caused by basis set flotation and electric field application

    Science.gov (United States)

    Simon, Sílvia; Duran, Miquel

    1997-08-01

    Quantum molecular similarity (QMS) techniques are used to assess the response of the electron density of various small molecules to application of a static, uniform electric field. Likewise, QMS is used to analyze the changes in electron density generated by the process of floating a basis set. The results obtained show an interrelation between the floating process, the optimum geometry, and the presence of an external field. Cases involving the Le Chatelier principle are discussed, and an insight on the changes of bond critical point properties, self-similarity values and density differences is performed.

  3. Distinguished hyperbolic trajectories in time-dependent fluid flows: analytical and computational approach for velocity fields defined as data sets

    Directory of Open Access Journals (Sweden)

    K. Ide

    2002-01-01

    Full Text Available In this paper we develop analytical and numerical methods for finding special hyperbolic trajectories that govern geometry of Lagrangian structures in time-dependent vector fields. The vector fields (or velocity fields may have arbitrary time dependence and be realized only as data sets over finite time intervals, where space and time are discretized. While the notion of a hyperbolic trajectory is central to dynamical systems theory, much of the theoretical developments for Lagrangian transport proceed under the assumption that such a special hyperbolic trajectory exists. This brings in new mathematical issues that must be addressed in order for Lagrangian transport theory to be applicable in practice, i.e. how to determine whether or not such a trajectory exists and, if it does exist, how to identify it in a sequence of instantaneous velocity fields. We address these issues by developing the notion of a distinguished hyperbolic trajectory (DHT. We develop an existence criteria for certain classes of DHTs in general time-dependent velocity fields, based on the time evolution of Eulerian structures that are observed in individual instantaneous fields over the entire time interval of the data set. We demonstrate the concept of DHTs in inhomogeneous (or "forced" time-dependent linear systems and develop a theory and analytical formula for computing DHTs. Throughout this work the notion of linearization is very important. This is not surprising since hyperbolicity is a "linearized" notion. To extend the analytical formula to more general nonlinear time-dependent velocity fields, we develop a series of coordinate transforms including a type of linearization that is not typically used in dynamical systems theory. We refer to it as Eulerian linearization, which is related to the frame independence of DHTs, as opposed to the Lagrangian linearization, which is typical in dynamical systems theory, which is used in the computation of Lyapunov exponents. We

  4. Stochastic analyses of field-scale pesticide leaching risk as influenced by spatial variability in physical and biochemical parameters

    Science.gov (United States)

    Loll, Per; Moldrup, Per

    2000-04-01

    Field-scale pesticide leaching risk assessments were performed by incorporating a numerical, one-dimensional, water and pesticide transport and fate model into the two-step stochastic modeling approach by Loll and Moldrup [1998]. The numerical model included first-order pesticide degradation, linear equilibrium adsorption, and plant uptake of water and pesticide. Simazine was used as a model pesticide, and leaching risk was expressed as the cumulative mass fraction of applied pesticide leached below 100 cm after 1 year. Spatial variability in soil physical and biochemical data, as well as measured meteorological data from an average and a relatively wet year, was considered for two Danish field sites: (1) a coarse sandy soil, with relatively small variability in hydraulic properties, and (2) a sandy loam, with large variability in hydraulic properties. The two-step stochastic modeling approach was used to investigate the relative impact of spatial variability in saturated hydraulic conductivity Ks, soil-water retention through the Campbell [974] soil-water retention parameter b, and pesticide sorption through the organic carbon content (OC). For the coarse sandy soil, field-scale spatial variability in OC was the single most important parameter influencing leaching risk, whereas for the sandy loam, Ks was found more important than OC. The relative impact of field-scale spatial variability in these parameters was found independent of the meteorological conditions, whereas the absolute level of leaching risk was highly dependent on the meteorological conditions. Assuming a linear dependency between pesticide half-life and OC, a unified approach to modeling simultaneous field-scale variability in biodegradation and adsorption was proposed. Leaching risk assessments based on this approach showed that the parts of the field with both low biological activity and low adsorption capacity contributed with a dramatic increase in leaching risk, and suggested that field

  5. On polynomial vector fields having a given affine variety as attractive and invariant set: application to robotics

    Science.gov (United States)

    Possieri, Corrado; Tornambè, Antonio

    2015-05-01

    The main goal of this paper is to compute a class of polynomial vector fields, whose associated dynamical system has a given affine variety as attractive and invariant set, a given point in such an affine variety as invariant and attractive and another given affine variety as invariant set, solving the application of this technique in the robotic area. This objective is reached by using some tools taken from algebraic geometry. Practical examples of how these vector fields can be computed are reported. Moreover, by using these techniques, two feedback control laws, respectively, for a unicycle-like mobile robot and for a car-like mobile robot, which make them move, within the workspace, approaching to a selected algebraic curve, are given.

  6. Estimating Parameters of Aquifer Heterogeneity Using Pumping Tests - a Paradigm for Field Applications

    Science.gov (United States)

    Zech, Alraune; Arnold, Sven; Schneider, Christoph; Attinger, Sabine

    2013-04-01

    The vast majority of natural aquifers are characterized by heterogeneity which can be statistically represented by parameters such as geometric mean, correlation lengths and variance of hydraulic conductivity. Head measurements of pumping tests are commonly used to estimate the hydraulic properties of porous media. Zech et al. 2012, WRR introduced the effective well flow method allowing a direct parameter estimation from steady state pumping test drawdowns. However, in contrast to simulated pumping tests, the number and spatial distribution of piezometers is limited for on-site pumping tests. We analyze the capability of the effective well flow method to provide accurate and confident parameter estimates of a heterogeneous aquifer under limited availability of head measurements. We use simulated pumping tests to systematically reduce sampling size while also determining the accuracy and uncertainty of estimates at each level of data availability. The same analytical solution is then applied to estimate the statistical parameters of a fluvial heterogeneous aquifer at the test site Horkheimer Insel, Germany. We thereby close the gap between theoretical and practical application of an analytical solution describing three-dimensional steady state well flow. Our findings indicate how accuracy and uncertainty of estimated parameters, like mean conductivities and correlation lengths correlate to number and spatial distribution of head measurements. The results provide valuable implications regarding the conceptual design of ground water pumping tests and the predictive power of established pumping test sites.

  7. Production of whey protein cold-set hydrogels through application of moderate electric fields

    OpenAIRE

    Rodrigues, Rui M.; Ramos, Óscar L.; Teixeira, J. A; A.A. Vicente; Pereira,Ricardo

    2014-01-01

    ISBN 978-989-98541-5-4 Whey, a liquid by-product from dairy industry is now recognized as a functional food due to the presence of bioactive and highly nutritional components, such as globular whey proteins. Denaturation and aggregation kinetic behavior of these proteins is of particular relevance when properly engineered and controlled, as it results in the production of novel micro and nano-systems with many potential uses in food compositions. Application of moderate electric fields (ME...

  8. Edge of Field Nitrate Loss and Oxygen-18 Dynamics in a Dryland Agriculture Setting

    Science.gov (United States)

    Wannamaker, C. N.; Goodwin, A. J.; Keller, C.; Allen-King, R.; Smith, J. L.

    2004-12-01

    Four complete water years of nitrate concentrations and oxygen isotope (δ O18) ratios have been monitored in a tile drain and adjacent soil-water sampling lysimeters beneath a dryland, agricultural field in the Palouse Region of Washington State, USA. The Palouse is semi-arid and is characterized by undulating loess hills and swales drained by ephemeral to perennial streams. Soil type is dominated by silt-loam Mollisols. Our field is subject to typical farming practices and crop rotations, receiving ammonia fertilizer during fall and spring planting at a rate of ˜70kg of nitrogen per acre. Tile drains play an essential role in environmental nitrogen dynamics in this region as they are widely utilized to drain water from lower fields. Nitrate concentrations in tile drainage fluctuate on a seasonal basis ranging from low concentrations of ˜1mg/ NO3-N/L in late October/November to higher concentrations of 20-30mg NO3-N/L in late January/February. Rise in concentration occurs rapidly with the onset of high flow conditions differing from a typical dilution effect. Lysimeter waters show similar nitrate patterns ranging in concentration from ~10mg NO3-N/L to as high as 120mg NO3-N/L. In the lysimeters, nitrate concentrations are apparently positively correlated with δ O18 values. Precipitation collected at the field site shows a 12 per mil seasonal variation in δ O18. A seasonal pattern is also observed in soil water with a smaller range of about 6 per mil. These seasonal fluctuations are not observed in tile drainage, where values vary only 2 per mil with a mean of -15 per ml. We hypothesize that residence-time and scaling effects can explain the δ O18 fluctuation differences between soil water and tile drainage. The very large nitrate fluctuations throughout the system may be due in part to the seasonality of soil nitrogen cycling.

  9. Ab-initio calculations of Judd–Ofelt intensity parameters for transitions between crystal-field levels

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Jun, E-mail: wenjunkd@mail.ustc.edu.cn [School of Physics and Electric Engineering, Anqing Normal University, Anqing 246011 (China); Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Reid, Michael F. [Department of Physics and Astronomy and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, PB4800 Christchurch (New Zealand); Ning, Lixin [Department of Physics, Anhui Normal University, Wuhu 241000 (China); Zhang, Jie [School of Physics and Electric Engineering, Anqing Normal University, Anqing 246011 (China); Zhang, Yongfan [Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); Duan, Chang-Kui; Yin, Min [Department of Physics, University of Science and Technology of China, Hefei 230026 (China)

    2014-08-01

    Wavefunction-based ab-initio calculations of the electric-dipole moments of 4f{sup N}–4f{sup N} transitions of lanthanide ions are performed to extract the A{sub tp}{sup λ} intensity parameters. The extraction method is an extension of our earlier calculations of crystal-field (CF) parameters for lanthanide ions in crystals. The CASSCF/RASSI-SO (Complete-Active-Space Self-Consistent-Field/Restricted-Active-Space State-Interaction Spin-Orbit) calculations have been carried out on the chosen model system of CaF{sub 2}: Ce{sup 3+} with an interstitial fluoride ion (F{sub i}{sup −}) on z-axis (Ce{sup 3+} ion occupying the C{sub 4v} symmetry site). In consideration of the site symmetry and the coordination situation of Ce{sup 3+} ion at C{sub 4v} site in CaF{sub 2} as well as the superposition model (SM), the calculated intensity parameters for Ce{sup 3+} ion can be classified into three categories, and detailed discussions are then given. - Highlights: • Extraction of transition intensity parameters from ab-initio calculations. • CASSCF/RASSI-SO calculations are performed for Ce{sup 3+}-doped CaF{sub 2} crystal (C{sub 4v} case). • Extracted parameters are analyzed and compared with experiment and other calculation.

  10. Full field modeling of dynamic recrystallization in a global level set framework, application to 304L stainless steel

    Directory of Open Access Journals (Sweden)

    Boulais-Sinou Romain

    2016-01-01

    Full Text Available A new full field numerical approach for the simulation of dynamic and post-dynamic recrystallization will be detailed. A level Set framework is employed to link a crystal plasticity finite element method with the modeling of recrystallization. Plasticity is calculated through the activation of slip systems and provides predictions for both SSDs and GNDs densities. These predictions control the activation and kinetics of recrystallization. All the developments are applied on 304L stainless steel.

  11. Comparison of infinite and wedge fringe settings in Mach Zehnder interferometer for temperature field measurement

    Energy Technology Data Exchange (ETDEWEB)

    Haridas, Divya [Department of Physics, National Institute of Technology Calicut, Kerala, 673601 (India); P, Vibin Antony; Sajith, V.; Sobhan, C. B. [School of Nano Science and Technology, National Institute of Technology Calicut, Kerala, 673601 (India)

    2014-10-15

    Interferometric method, which utilizes the interference of coherent light beams, is used to determine the temperature distribution in the vicinity of a vertical heater plate. The optical components are arranged so as to obtain wedge fringe and infinite fringe patterns and isotherms obtained in each case were compared. In wedge fringe setting, image processing techniques has been used for obtaining isotherms by digital subtraction of initial parallel fringe pattern from deformed fringe pattern. The experimental results obtained are compared with theoretical correlations. The merits and demerits of the fringe analysis techniques are discussed on the basis of the experimental results.

  12. Pulsed-field capillary electrophoresis: optimizing separation parameters with model mixtures of sulfonated polystyrenes.

    Science.gov (United States)

    Sudor, J; Novotny, M V

    1994-07-01

    The electrophoretic transport of high molecular weight charged solutes, both flexible and stiff polymers, has been studied by capillary electrophoresis under constant-field and pulsed-field conditions. Sulfonated polystyrenes were used as model solutes in different entangled polymer solutions. First, changes of the end-to-end distance vectors of flexible polymers were examined through the mobility/potential-gradient curves. Under pulsed-field conditions, the influence of different pulse shapes, frequencies, and amplitudes of forward and backward pulses on the electrophoretic mobilities of model solutes was studied. Resolution of the mixture components was strongly affected by changes in frequency of both sine-wave and square-wave pulses. The experimental results obtained under pulse-field conditions are roughly in agreement with the existing theories of electrophoretic transport.

  13. Final Report for NFE-07-00912: Development of Model Fuels Experimental Engine Data Base & Kinetic Modeling Parameter Sets

    Energy Technology Data Exchange (ETDEWEB)

    Bunting, Bruce G [ORNL

    2012-10-01

    The automotive and engine industries are in a period of very rapid change being driven by new emission standards, new types of after treatment, new combustion strategies, the introduction of new fuels, and drive for increased fuel economy and efficiency. The rapid pace of these changes has put more pressure on the need for modeling of engine combustion and performance, in order to shorten product design and introduction cycles. New combustion strategies include homogeneous charge compression ignition (HCCI), partial-premixed combustion compression ignition (PCCI), and dilute low temperature combustion which are being developed for lower emissions and improved fuel economy. New fuels include bio-fuels such as ethanol or bio-diesel, drop-in bio-derived fuels and those derived from new crude oil sources such as gas-to-liquids, coal-to-liquids, oil sands, oil shale, and wet natural gas. Kinetic modeling of the combustion process for these new combustion regimes and fuels is necessary in order to allow modeling and performance assessment for engine design purposes. In this research covered by this CRADA, ORNL developed and supplied experimental data related to engine performance with new fuels and new combustion strategies along with interpretation and analysis of such data and consulting to Reaction Design, Inc. (RD). RD performed additional analysis of this data in order to extract important parameters and to confirm engine and kinetic models. The data generated was generally published to make it available to the engine and automotive design communities and also to the Reaction Design Model Fuels Consortium (MFC).

  14. Guidelines for Setting Up an Extended Field Trip to Florida and the Florida Keys: An Interactive Experiential Training Field Biology Program Consisting of Pretrip Instruction, Search Image Training, Field Exercises, and Observations of Tropical Habitats and Coral Reefs.

    Science.gov (United States)

    Baker, Claude D.; And Others

    The importance of experiential aspects of biological study is addressed using multi-dimensional classroom and field classroom approaches to student learning. This document includes a guide to setting up this style of field experience. Several teaching innovations are employed to introduce undergraduate students to the literature, techniques, and…

  15. The evaluation and validation of copper (II) force field parameters of the Auxiliary Activity family 9 enzymes

    Science.gov (United States)

    Moses, Vuyani; Tastan Bishop, Özlem; Lobb, Kevin A.

    2017-06-01

    The Auxiliary Activity family 9 (AA9) proteins are Cu2+ coordinating enzymes which are crucial for the early stages of cellulose degradation. In this study, the force field parameters for copper-containing bonds in the Type 1 AA9 protein active site were established and used in a molecular dynamics simulation on a solvated, neutralized system containing an AA9 protein, Cu2+ and a β-cellulose surface. The copper to cellulose interaction was evident during the dynamics, which could also be accelerated by the use of high Cusbnd O van der Waals parameters. The interaction of AA9, Cu2+ and cellulose is described in detail.

  16. Molecular Modeling of Bifunctional Chelate Peptide Conjugates. 1. Copper and Indium Parameters for the AMBER Force Field

    DEFF Research Database (Denmark)

    Reichert, David E.; Norrby, Per-Ola; Welch, Michael J.

    2001-01-01

    In this work we describe the development of parameters for In(III) and Cu(II) for the AMBER* force field as found in the modeling package MacroModel. These parameters were developed using automated procedures from a combination of crystallographic structures and ab initio calculations. The new pa...... then utilized to examine the conformational effects caused by the conjugation of InDTPA (DTPA = diethylenetriaminepentaacetic acid) and CuDOTA (DOTA 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) to the cyclic octapeptide octreotide....

  17. SubPatch: random kd-tree on a sub-sampled patch set for nearest neighbor field estimation

    Science.gov (United States)

    Pedersoli, Fabrizio; Benini, Sergio; Adami, Nicola; Okuda, Masahiro; Leonardi, Riccardo

    2015-02-01

    We propose a new method to compute the approximate nearest-neighbors field (ANNF) between image pairs using random kd-tree and patch set sub-sampling. By exploiting image coherence we demonstrate that it is possible to reduce the number of patches on which we compute the ANNF, while maintaining high overall accuracy on the final result. Information on missing patches is then recovered by interpolation and propagation of good matches. The introduction of the sub-sampling factor on patch sets also allows for setting the desired trade off between accuracy and speed, providing a flexibility that lacks in state-of-the-art methods. Tests conducted on a public database prove that our algorithm achieves superior performance with respect to PatchMatch (PM) and Coherence Sensitivity Hashing (CSH) algorithms in a comparable computational time.

  18. Field surveys of carbon monoxide in commercial settings using personal exposure monitors

    Science.gov (United States)

    Flachsbart, P. G.; Ott, W. R.

    1984-02-01

    Miniaturized personal exposure monitors (PEMs) were employed to measure carbon monoxide (CO) in 588 different commercial settings (e.g., retail stores, office buildings, hotels, restaurants) in five California cities. Altogether, 5000 CO observations were made by recording the instantaneous instrument reading at 1-minute intervals as the investigators walked along sidewalks and into buildings. For 11 of 15 survey dates, two investigators walked side-by-side, permitting two adjacent PEMs to be compared. Quality assurance tests for 1706 pairs of values showed a very high degree of agreement. CO levels for indoor commercial settings were similar to those measured outdoors on sidewalks, apparently because the pollutant seeps into the structures from traffic outside. Although indoor levels usually were above 0 ppm, they seldom were above 9 ppm (the National Ambient Air Quality Standard for an 8-hour exposure), unless some indoor source could be identified. Carbon monoxide levels on outdoor streets did not vary greatly on different sides of the street, on corners and faces of blocks, and intersections.

  19. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    Science.gov (United States)

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.

  20. Capillary electrophoresis-atmospheric pressure chemical ionization-mass spectrometry using an orthogonal interface: set-up and system parameters.

    Science.gov (United States)

    Hommerson, Paul; Khan, Amjad M; de Jong, Gerhardus J; Somsen, Govert W

    2009-07-01

    The feasibility of atmospheric pressure chemical ionization (APCI) as an alternative ionization technique for capillary electrophoresis-mass spectrometry (CE-MS) was investigated using a grounded sheath-flow CE-MS sprayer and an orthogonal APCI source. Infusion experiments indicated that highest analyte signals were achieved when the sprayer tip was in close vicinity of the vaporizer entrance. The APCI-MS set-up enabled detection of basic, neutral, and acidic compounds, whereas apolar and ionic compounds could not be detected. In the positive ion mode, analytes could be detected in the entire transfer voltage range (0-5 kV), whereas highest signal intensities were observed when the corona discharge current was between 1000 and 2000 nA. In the negative ion mode, the transfer voltage typically was 500 V and the optimum corona discharge current was 6000 nA. Analyte signals were raised with increasing nebulizing gas pressure, but the pressure was limited to 25 psi to avoid siphoning and current drops. Signal intensities appeared to be optimal and constant over a wide range of sheath liquid flow rate (5-25 microL/min) and vaporizer temperature (200-350 degrees C). APCI-MS signals were unaffected by the composition of the background electrolyte (BGE), even when it contained sodium phosphate and sodium dodecyl sulfate (SDS). Consequently, BGE composition, sheath-liquid flow rate, and vaporizer temperature can be optimized with respect to the CE separation without affecting the APCI-MS response. The analysis of a mixture of basic compounds and a steroid using volatile and nonvolatile BGEs further demonstrates the feasibility of CE-APCI-MS. Detection limits (S/N = 3) were 1.6-10 microM injected concentrations.

  1. Extending the Standard Model Effective Field Theory with the Complete Set of Dimension-7 Operators

    CERN Document Server

    Lehman, Landon

    2014-01-01

    We present a complete list of the independent dimension-7 operators that are constructed using the Standard Model degrees of freedom and are invariant under the Standard Model gauge group. This list contains only 20 independent operators; far fewer than the 63 operators available at dimension 6. All of these dimension-7 operators contain fermions and violate lepton number, and 7 of the 20 violate baryon number as well. This result extends the Standard Model Effective Field Theory (SMEFT) and allows a more detailed exploration of the structure and properties of possible deformations from the Standard Model Lagrangian.

  2. Extending the standard model effective field theory with the complete set of dimension-7 operators

    Science.gov (United States)

    Lehman, Landon

    2014-12-01

    We present a complete list of the independent dimension-7 operators that are constructed using the standard model degrees of freedom and are invariant under the standard model gauge group. This list contains only 20 independent operators, far fewer than the 63 operators available at dimension 6. All of these dimension-7 operators contain fermions and violate lepton number, and 7 of the 20 violate baryon number as well. This result extends the standard model effective field theory and allows a more detailed exploration of the structure and properties of possible deformations from the standard model Lagrangian.

  3. Jet Drilling and Optimizing Parameter Drilling Technology in Shengli Oil Fields

    Institute of Scientific and Technical Information of China (English)

    Chen Yue; Peng Junsheng

    1996-01-01

    @@ In Shengli oilfield, remarkable achievements have been obtained in research and tests on the technologies of jet drilling and optimizing parameter drilling, extensive applications of the technologies have greatly improved drilling speed and sharply decreased drilling time and costs, thus achieving excellent social and economic benefits.

  4. Marching on in anything : Solving electromagnetic field equations with a varying physical parameter

    NARCIS (Netherlands)

    Tijhuis, A.G.; Zwamborn, A.P.M.

    2003-01-01

    In this paper, we consider the determination of electromagnetic flelds for a (large) number of values of a physical parameter. We restrict ourselves to the case where the linear system originates from one or more integral equations. we apply an iterative procedure based on the minimization of an int

  5. Building the field of population health intervention research: The development and use of an initial set of competencies.

    Science.gov (United States)

    Riley, Barbara; Harvey, Jean; Di Ruggiero, Erica; Potvin, Louise

    2015-01-01

    Population health intervention research (PHIR) is a relatively new research field that studies interventions that can improve health and health equity at a population level. Competencies are one way to give legitimacy and definition to a field. An initial set of PHIR competencies was developed with leadership from a multi-sector group in Canada. This paper describes the development process for these competencies and their possible uses. Methods to develop the competencies included key informant interviews; a targeted review of scientific and gray literature; a 2-round, online adapted Delphi study with a 24-member panel; and a focus group with 9 international PHIR experts. The resulting competencies consist of 25 items grouped into 6 categories. They include principles of good science applicable though not exclusive to PHIR, and more suitable for PHIR teams rather than individuals. This initial set of competencies, released in 2013, may be used to develop graduate student curriculum, recruit trainees and faculty to academic institutions, plan non-degree professional development, and develop job descriptions for PHIR-related research and professional positions. The competencies provide some initial guideposts for the field and will need to be adapted as the PHIR field matures and to meet unique needs of different jurisdictions.

  6. Polarizable Simulations with Second order Interaction Model (POSSIM) force field: Developing parameters for alanine peptides and protein backbone

    Science.gov (United States)

    Ponomarev, Sergei Y.; Kaminski, George A.

    2011-01-01

    A previously introduced POSSIM (POlarizable Simulations with Second order Interaction Model) force field has been extended to include parameters for alanine peptides and protein backbones. New features were introduced into the fitting protocol, as compared to the previous generation of the polarizable force field for proteins. A reduced amount of quantum mechanical data was employed in fitting the electrostatic parameters. Transferability of the electrostatics between our recently developed NMA model and the protein backbone was confirmed. Binding energy and geometry for complexes of alanine dipeptide with a water molecule were estimated and found in a good agreement with high-level quantum mechanical results (for example, the intermolecular distances agreeing within ca. 0.06Å). Following the previously devised procedure, we calculated average errors in alanine di- and tetra-peptide conformational energies and backbone angles and found the agreement to be adequate (for example, the alanine tetrapeptide extended-globular conformational energy gap was calculated to be 3.09 kcal/mol quantim mechanically and 3.14 kcal/mol with the POSSIM force field). However, we have now also included simulation of a simple alpha-helix in both gas-phase and water as the ultimate test of the backbone conformational behavior. The resulting alanine and protein backbone force field is currently being employed in further development of the POSSIM fast polarizable force field for proteins. PMID:21743799

  7. First-principles calculation of crystal field parameters of Dy ions substituted for Nd in Nd-Fe-B magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, S; Moriya, H; Tsuchiura, H; Sakuma, A [Department of Applied Physics, Tohoku University, Sendai 980-8579 (Japan); Divis, M [Department of Condensed Matter, Charles University, FMF, Prague (Czech Republic); Novak, P, E-mail: tanaka@olive.apph.tohoku.ac.jp [Institute of Physics of ASCR, Cukrovarnicka 10, 162 53 Prague 6 (Czech Republic)

    2011-01-01

    We study the electronic structures of crystalline Nd{sub 2}Fe{sub 14}B, Dy{sub 2}Fe{sub 14}B and Dy-doped Nd-Fe-B, and estimate the crystal field parameter A{sup 0}{sub 2}(r{sup 2}) of the rare earth ions of these systems based on the first principles calculations. We find that the crystal field of the Dy ions is appreciably insensitive to its crystallographic location than that of Nd ions.

  8. Variability in electromagnetic field levels over time, and Monte-Carlo simulation of exposure parameters.

    Science.gov (United States)

    Pachón-García, F T; Paniagua-Sánchez, J M; Rufo-Pérez, M; Jiménez-Barco, A

    2014-12-01

    This article analyses the electric field levels around medium-wave transmitters, delimiting the temporal variability of the levels received at a pre-established reception point. One extensively used dosimetric criterion is to consider historical levels of the field recorded over a certain period of time so as to provide an overall perspective of radio-frequency electric field exposure in a particular environment. This aspect is the focus of the present study, in which the measurements will be synthesised in the form of exposure coefficients. Two measurement campaigns were conducted: one short term (10 days) and the other long term (1 y). The short-term data were used to study which probability density functions best approximate the measured levels. The long-term data were used to compute the principal statistics that characterise the field values over a year. The data that form the focus of the study are the peak traces, since these are the most representative from the standpoint of exposure. The deviations found were around 6 % for short periods and 12 % for long periods. The information from the two campaigns was used to develop and implement a computer application based on the Monte Carlo method to simulate values of the field, allowing one to carry out robust statistics.

  9. On the importance of electrode parameters for shaping electric field patterns generated by tDCS

    DEFF Research Database (Denmark)

    B. Saturnino, Guilherme; Antunes, André; Thielscher, Axel

    2015-01-01

    Transcranial direct current stimulation (tDCS) uses electrode pads placed on the head to deliver weak direct current to the brain and modulate neuronal excitability. The effects depend on the intensity and spatial distribution of the electric field. This in turn depends on the geometry and electric...... electrode modeling influences the calculated electric field in the brain. We take into account electrode shape, size, connector position and conductivities of different electrode materials (including saline solutions and electrode gels). These factors are systematically characterized to demonstrate...

  10. Index and Bulk Parameters for Frequency-Direction Spectra Measured at CERC Field Research Facility, September 1991 to August 1992

    Science.gov (United States)

    1994-05-01

    Index and Bulk Parameters for Frequency- Direction Spectra Measured at CERC Field Research Facility, September 1991 to August 1992 Accion For by...Prepared for U.S. Army Corps of Engineers Washington, DC 20314-1000 Under Civil Works Research Work Unit 32484 M US Army Corps of Engineers Waterways...that affect coastal engineering pro- jects. This effort was authorized by Headquarters, U.S. Army Corps o.’ Engi- neers (HQUSACE), under Civil Works

  11. Uncertainty Reduction Via Parameter Design of A Fast Digital Integrator for Magnetic Field Measurement

    CERN Document Server

    Arpaia, P; Lucariello, G; Spiezia, G

    2007-01-01

    At European Centre of Nuclear Research (CERN), within the new Large Hadron Collider (LHC) project, measurements of magnetic flux with uncertainty of 10 ppm at a few of decades of Hz for several minutes are required. With this aim, a new Fast Digital Integrator (FDI) has been developed in cooperation with University of Sannio, Italy [1]. This paper deals with the final design tuning for achieving target uncertainty by means of experimental statistical parameter design.

  12. CoastColour Round Robin data sets: a database to evaluate the performance of algorithms for the retrieval of water quality parameters in coastal waters

    Science.gov (United States)

    Nechad, B.; Ruddick, K.; Schroeder, T.; Oubelkheir, K.; Blondeau-Patissier, D.; Cherukuru, N.; Brando, V.; Dekker, A.; Clementson, L.; Banks, A. C.; Maritorena, S.; Werdell, P. J.; Sá, C.; Brotas, V.; Caballero de Frutos, I.; Ahn, Y.-H.; Salama, S.; Tilstone, G.; Martinez-Vicente, V.; Foley, D.; McKibben, M.; Nahorniak, J.; Peterson, T.; Siliò-Calzada, A.; Röttgers, R.; Lee, Z.; Peters, M.; Brockmann, C.

    2015-11-01

    The use of in situ measurements is essential in the validation and evaluation of the algorithms that provide coastal water quality data products from ocean colour satellite remote sensing. Over the past decade, various types of ocean colour algorithms have been developed to deal with the optical complexity of coastal waters. Yet there is a lack of a comprehensive intercomparison due to the availability of quality checked in situ databases. The CoastColour Round Robin (CCRR) project, funded by the European Space Agency (ESA), was designed to bring together three reference data sets using these to test algorithms and to assess their accuracy for retrieving water quality parameters. This paper provides a detailed description of these reference data sets, which include the Medium Resolution Imaging Spectrometer (MERIS) level 2 match-ups, in situ reflectance measurements, and synthetic data generated by a radiative transfer model (HydroLight). These data sets, representing mainly coastal waters, are available from doi:10.1594/PANGAEA.841950. The data sets mainly consist of 6484 marine reflectance (either multispectral or hyperspectral) associated with various geometrical (sensor viewing and solar angles) and sky conditions and water constituents: total suspended matter (TSM) and chlorophyll a (CHL) concentrations, and the absorption of coloured dissolved organic matter (CDOM). Inherent optical properties are also provided in the simulated data sets (5000 simulations) and from 3054 match-up locations. The distributions of reflectance at selected MERIS bands and band ratios, CHL and TSM as a function of reflectance, from the three data sets are compared. Match-up and in situ sites where deviations occur are identified. The distributions of the three reflectance data sets are also compared to the simulated and in situ reflectances used previously by the International Ocean Colour Coordinating Group (IOCCG, 2006) for algorithm testing, showing a clear extension of the CCRR

  13. The generalized Erlangen program and setting a geometry for four- dimensional conformal fields

    Energy Technology Data Exchange (ETDEWEB)

    Ne`eman, Y. [Tel Aviv Univ. (Israel). Sackler Faculty of Exact Sciences]|[Texas Univ., Austin, TX (United States). Center for Particle Physics; Hehl, F.W.; Mielke, E.W. [Koeln Univ. (Germany). Inst. fuer Theoretische Physik

    1993-10-22

    This is the text of a talk at the International Symposium on ``Mathematical Physics towards the XXI Century`` held in March 1993 at Beersheva, Israel. In the first part we attempt to summarize XXth Century Physics, in the light of Kelvin`s 1900 speech ``Dark Clouds over XIXth Century Physics.`` Contrary to what is usually said, Kelvin predicted that the ``clouds`` (relativity and quantum mechanics) would revolutionize physics and that one hundred years might be needed to harmonize them with classical physics. Quantum Gravity can be considered as a leftover from Kelvin`s program -- so are the problems with the interpretation of quantum mechanics. At the end of the XXth Century, the Standard Model is the new panoramic synthesis, drawn in gauge-geometric lines -- realizing the Erlangen program beyond F. Klein`s expectations. The hierarchy problem and the smallness of the cosmological constant are our ``clouds``, generations and the Higgs sector are to us what radioactivity was in 1900. In the second part we describe Metric-Affine spacetimes. We construct the Noether machinery and provide expressions for the conserved energy and hypermomentum. Superimposing conformal invariance over the affine structure induces the Virasoro-like infinite constraining algebra of diffeomorphisms, applied with constant parameters and opening the possibility of a 4DCFT, similar to 2DCFT.

  14. Atmospheric Parameters of 169 F, G, K and M-type Stars in the Kepler Field

    CERN Document Server

    Molenda-Zakowicz, J; Frasca, A; Uytterhoeven, K; Briquet, M; Van Winckel, H; Drobek, D; Niemczura, E; Lampens, P; Lykke, J; Bloemen, S; Gameiro, J F; Jean, C; Volpi, D; Gorlova, N; Mortier, A; Tsantaki, M; Raskin, G

    2013-01-01

    The asteroseismic and planetary studies, like all research related to stars, need precise and accurate stellar atmospheric parameters as input. We aim at deriving the effective temperature (Teff), the surface gravity (log g), the metallicity ([Fe/H]), the projected rotational velocity (v sin i) and the MK type for 169 F, G, K, and M-type Kepler targets which were observed spectroscopically from the ground with five different instruments. We use two different spectroscopic methods to analyse 189 high-resolution, high-signal-to-noise spectra acquired for the 169 stars. For 67 stars, the spectroscopic atmospheric parameters are derived for the ?first time. KIC 9693187 and 11179629 are discovered to be double-lined spectroscopic binary systems. The results obtained for those stars for which independent determinations of the atmospheric parameters are available in the literature are used for a comparative analysis. As a result, we show that for solar-type stars the accuracy of present determinations of atmospheric...

  15. Influence of frequency-dependent soil electrical parameters on the evaluation of lightning electromagnetic fields in air and underground

    Science.gov (United States)

    Delfino, Federico; Procopio, Renato; Rossi, Mansueto; Rachidi, Farhad

    2009-06-01

    This paper is aimed at analyzing the influence of the frequency-dependent behavior of the ground electrical parameters (conductivity and ground permittivity) on the electromagnetic field radiated by a cloud-to-ground lightning return stroke. Both radiation in air (over the conducting ground plane) and underground are considered in the analysis. The adopted method is based on the classical Sommerfeld's theory and takes advantage of an efficient ad hoc numerical procedure to face with the slow converging Sommerfeld's integrals. This feature allows the electromagnetic field to be computed without any sort of mathematical approximation and, since it is carried out in the frequency domain, can be used either if the ground permittivity and conductivity are considered constant or if they vary with the working frequency with any functional law. Simulations have been performed to identify the cases in which the approximation of constant ground permittivity and conductivity leads to satisfactory results. It is shown that for soils with water contents of 2% to 10% (ground conductivities in the order of 0.001 to 0.01 S/m), the assumption of constant electrical parameters appears to be reasonable. However, for either very poorly conducting soils (10-4 S/m or so) or highly conducting soils (10-1 S/m), the electromagnetic field components appear to be significantly affected by the frequency dependence of the ground electrical parameters.

  16. Loop-mediated isothermal DNA amplification for asymptomatic malaria detection in challenging field settings: Technical performance and pilot implementation in the Peruvian Amazon.

    Science.gov (United States)

    Serra-Casas, Elisa; Manrique, Paulo; Ding, Xavier C; Carrasco-Escobar, Gabriel; Alava, Freddy; Gave, Anthony; Rodriguez, Hugo; Contreras-Mancilla, Juan; Rosas-Aguirre, Angel; Speybroeck, Niko; González, Iveth J; Rosanas-Urgell, Anna; Gamboa, Dionicia

    2017-01-01

    Loop-mediated isothermal DNA amplification (LAMP) methodology offers an opportunity for point-of-care (POC) molecular detection of asymptomatic malaria infections. However, there is still little evidence on the feasibility of implementing this technique for population screenings in isolated field settings. Overall, we recruited 1167 individuals from terrestrial ('road') and hydric ('riverine') communities of the Peruvian Amazon for a cross-sectional survey to detect asymptomatic malaria infections. The technical performance of LAMP was evaluated in a subgroup of 503 samples, using real-time Polymerase Chain Reaction (qPCR) as reference standard. The operational feasibility of introducing LAMP testing in the mobile screening campaigns was assessed based on field-suitability parameters, along with a pilot POC-LAMP assay in a riverine community without laboratory infrastructure. LAMP had a sensitivity of 91.8% (87.7-94.9) and specificity of 91.9% (87.8-95.0), and the overall accuracy was significantly better among samples collected during road screenings than riverine communities (p≤0.004). LAMP-based diagnostic strategy was successfully implemented within the field-team logistics and the POC-LAMP pilot in the riverine community allowed for a reduction in the turnaround time for case management, from 12-24 hours to less than 5 hours. Specimens with haemolytic appearance were regularly observed in riverine screenings and could help explaining the hindered performance/interpretation of the LAMP reaction in these communities. LAMP-based molecular malaria diagnosis can be deployed outside of reference laboratories, providing similar performance as qPCR. However, scale-up in remote field settings such as riverine communities needs to consider a number of logistical challenges (e.g. environmental conditions, labour-intensiveness in large population screenings) that can influence its optimal implementation.

  17. Model parameter uncertainty analysis for an annual field-scale phosphorus loss model

    Science.gov (United States)

    Phosphorous (P) loss models are important tools for developing and evaluating conservation practices aimed at reducing P losses from agricultural fields. All P loss models, however, have an inherent amount of uncertainty associated with them. In this study, we conducted an uncertainty analysis with ...

  18. Model parameter uncertainty analysis for annual field-scale P loss model

    Science.gov (United States)

    Phosphorous (P) loss models are important tools for developing and evaluating conservation practices aimed at reducing P losses from agricultural fields. All P loss models, however, have an inherent amount of uncertainty associated with them. In this study, we conducted an uncertainty analysis with ...

  19. A Method of Computing Electric Field Parameters on Boundaries between Two Media

    Science.gov (United States)

    Rizhov, Alexander

    2010-01-01

    Many problems of electric field strength on a boundary between two media require college-level mathematical analysis. However, when the boundary between media is represented by a sphere or a flat plane, these types of problems can be solved algebraically, placing them within reach of high school students. This article presents a solution analysis…

  20. Field-scale water flow and solute transport : Swap model concepts, parameter estimation and case studies

    NARCIS (Netherlands)

    Dam, van J.C.

    2000-01-01

    Water flow and solute transport in top soils are important elements in many environmental studies. The agro- and ecohydrological model SWAP (Soil-Water-Plant-Atmosphere) has been developed to simulate simultaneously water flow, solute transport, heat flow and crop growth at field scale level. The ma

  1. Field measurements give biased estimates of functional response parameters, but help explain foraging distributions

    NARCIS (Netherlands)

    Duijns, S.; Knot, I.E.; Piersma, T.; van Gils, J.A.

    2015-01-01

    1.Mechanistic insights and predictive understanding of the spatial distributions of foragers are typically derived by fitting either field measurements on intake rates and food abundance, or observations from controlled experiments, to functional response models. It has remained unclear, however, wh

  2. A Method of Computing Electric Field Parameters on Boundaries between Two Media

    Science.gov (United States)

    Rizhov, Alexander

    2010-01-01

    Many problems of electric field strength on a boundary between two media require college-level mathematical analysis. However, when the boundary between media is represented by a sphere or a flat plane, these types of problems can be solved algebraically, placing them within reach of high school students. This article presents a solution analysis…

  3. Stellar Flares in the CSTAR Field: Results from the 2008 Data Set

    Science.gov (United States)

    Liang, En-Si; Wang, Songhu; Zhou, Ji-Lin; Zhou, Xu; Zhang, Hui; Xie, Jiwei; Liu, Huigen; Wang, Lifan; Ashley, M. C. B.

    2016-12-01

    The Chinese Small Telescope ARray (CSTAR) is the first Chinese astronomical instrument placed in Antarctica. It is a group of four identical, fully automatic 14.5 {cm} telescopes, with a field of view (FOV) of 20 {\\deg }2 centered on the South Celestial Pole. Placed at Antarctic Dome A, CSTAR is designed to provide high-cadence photometry for site monitoring and variable sources detection. During the 2008 observing season, CSTAR took high-precision photometric data of 18,145 stars around the South Celestial Pole. At i=7.5 and 12, the photometric precision reaches ∼8 mmag and ∼30 mmag with a cadence of 20 s or 30 s, respectively. Using a robust detection method, we have found 15 stellar flares on 13 sources, including two classified variables. We have also found a linear relation between the decay times and the total durations of the stellar flares. The details of all the detected flares along with their stellar properties are presented in this work.

  4. Men set their own cites high: Gender and self-citation across fields and over time

    CERN Document Server

    King, Molly M; Correll, Shelley J; Jacquet, Jennifer; West, Jevin D

    2016-01-01

    How common is self-citation in scholarly publication and does the practice vary by gender? Using novel methods and a dataset of 1.5 million research papers in the scholarly database JSTOR published between 1779-2011, we find that nearly 10% of references are self-citations by a paper's authors. We further find that over the years between 1779-2011, men cite their own papers 56% more than women do. In the last two decades of our data, men self-cite 70% more than women. Women are also more than ten percentage points more likely than men to not cite their own previous work at all. Despite increased representation of women in academia, this gender gap in self-citation rates has remained stable over the last 50 years. We break down self-citation patterns by academic field and number of authors, and comment on potential mechanisms behind these observations. These findings have important implications for scholarly visibility and likely consequences for academic careers.

  5. Stellar Flares in the CSTAR Field: Results from the 2008 Data Set

    CERN Document Server

    Liang, En-Si; Zhou, Ji-Lin; Zhou, Xu; Zhang, Hui; Xie, Jiwei; Liu, Huigen; Wang, Lifan; Ashley, M C B

    2016-01-01

    The Chinese Small Telescope ARray (CSTAR) is the first Chinese astronomical instrument placed in Antarctica. It is a group of four identical, fully automatic $14.5\\,\\rm{cm}$ telescopes, with an field of view (FOV) of $20\\,\\rm{deg^2}$ centered on the South Celestial Pole. Placed at Antarctic Dome A, CSTAR is designed to provide high-cadence photometry for site monitoring and variable sources detection. During the 2008 observing season, CSTAR has taken high-precision photometric data for 18,145 stars around the South Celestial Pole. At $i\\,=\\,7.5$ and $12$, the photometric precision reaches $\\sim 8$ mmag and $\\sim 30$ mmag with a cadence of 20s or 30s, respectively. Using robust detection method, we have found 15 stellar flares on 13 sources, including two classified variables. We have also found a linear relation between the decay times and the total durations of the stellar flares. The details of all detected flares along with their stellar properties are presented in this work.

  6. Rough Sets and Stomped Normal Distribution for Simultaneous Segmentation and Bias Field Correction in Brain MR Images.

    Science.gov (United States)

    Banerjee, Abhirup; Maji, Pradipta

    2015-12-01

    The segmentation of brain MR images into different tissue classes is an important task for automatic image analysis technique, particularly due to the presence of intensity inhomogeneity artifact in MR images. In this regard, this paper presents a novel approach for simultaneous segmentation and bias field correction in brain MR images. It integrates judiciously the concept of rough sets and the merit of a novel probability distribution, called stomped normal (SN) distribution. The intensity distribution of a tissue class is represented by SN distribution, where each tissue class consists of a crisp lower approximation and a probabilistic boundary region. The intensity distribution of brain MR image is modeled as a mixture of finite number of SN distributions and one uniform distribution. The proposed method incorporates both the expectation-maximization and hidden Markov random field frameworks to provide an accurate and robust segmentation. The performance of the proposed approach, along with a comparison with related methods, is demonstrated on a set of synthetic and real brain MR images for different bias fields and noise levels.

  7. Determining the Effects of Environment and Atmospheric Parameters on PV Field Performance

    Energy Technology Data Exchange (ETDEWEB)

    Micheli, Leonardo; Muller, Matthew; Kurtz, Sarah

    2016-11-21

    The performance losses due to soiling occurring on any photovoltaic (PV) device are caused by a complex mechanism that involves numerous factors and their interactions. For this reason, the present work analyzes the outputs of reference PV cells installed in various locations, with the aim of contributing to the identification of the most important factors influencing the accumulation of dust on a PV surface. Parameters such as the air-quality indexes, the recurrence and the amount of rainfall and the climate zone are investigated and related to the soiling losses of the PV device.

  8. Effect of pulsed electric field treatment during cold maceration and alcoholic fermentation on major red wine qualitative and quantitative parameters.

    Science.gov (United States)

    El Darra, Nada; Rajha, Hiba N; Ducasse, Marie-Agnès; Turk, Mohammad F; Grimi, Nabil; Maroun, Richard G; Louka, Nicolas; Vorobiev, Eugène

    2016-12-15

    This work studies the effect of pulsed electric field (PEF) treatment at moderate and high field strengths (E=0.8kV/cm & 5kV/cm) prior and during alcoholic fermentation (AF) of red grapes on improving different parameters of pre-treated extracts: pH, °Brix, colour intensity (CI), total polyphenols content (TPI) of Cabernet Sauvignon red wine. Similar trends were observed for treating grapes using moderate and high electric field strength on the enhancement of CI and TPI of the wine after AF. The application of PEF using moderate strengths at different times during cold maceration (CM) (0, 2 and 4days) was more efficient for treatment during CM. The treatment during AF showed lower extraction rate compared to treating during CM and prior to AF. Our results clearly show that the best time for applying the PEF-treatment through the red fermentation is during the CM step.

  9. Methodology for the Construction of a Rule-Based Knowledge Base Enabling the Selection of Appropriate Bronze Heat Treatment Parameters Using Rough Sets

    Directory of Open Access Journals (Sweden)

    Górny Z.

    2015-04-01

    Full Text Available Decisions regarding appropriate methods for the heat treatment of bronzes affect the final properties obtained in these materials. This study gives an example of the construction of a knowledge base with application of the rough set theory. Using relevant inference mechanisms, knowledge stored in the rule-based database allows the selection of appropriate heat treatment parameters to achieve the required properties of bronze. The paper presents the methodology and the results of exploratory research. It also discloses the methodology used in the creation of a knowledge base.

  10. Statistics on the parameters of nonisothermal ionospheric plasma in large mesospheric electric fields

    Science.gov (United States)

    Martynenko, S.; Rozumenko, V.; Tyrnov, O.; Manson, A.; Meek, C.

    The large V/m electric fields inherent in the mesosphere play an essential role in lower ionospheric electrodynamics. They must be the cause of large variations in the electron temperature and the electron collision frequency at D region altitudes, and consequently the ionospheric plasma in the lower part of the D region undergoes a transition into a nonisothermal state. This study is based on the databases on large mesospheric electric fields collected with the 2.2-MHz radar of the Institute of Space and Atmospheric Studies, University of Saskatchewan, Canada (52°N geographic latitude, 60.4°N geomagnetic latitude) and with the 2.3-MHz radar of the Kharkiv V. Karazin National University (49.6°N geographic latitude, 45.6°N geomagnetic latitude). The statistical analysis of these data is presented in Meek, C. E., A. H. Manson, S. I. Martynenko, V. T. Rozumenko, O. F. Tyrnov, Remote sensing of mesospheric electric fields using MF radars, Journal of Atmospheric and Solar-Terrestrial Physics, in press. The large mesospheric electric fields is experimentally established to follow a Rayleigh distribution in the interval 0

  11. Investigation of optimal parameters for finite element solution of the forward problem in magnetic field tomography based on magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Aristovich, K Y; Khan, S H [School of Engineering and Mathematical Sciences, City University London, Northampton Square, London EC1V 0HB (United Kingdom); Borovkov, A I, E-mail: kirill.aristovich.1@city.ac.uk [St Petersburg State Polytechnic University, Polytechnicheskaya Street 29, St Petersburg, 195251 (Russian Federation)

    2011-08-17

    This paper presents an investigation of optimal parameters for finite element (FE) solution of the forward problem in magnetic field tomography (MFT) brain imaging based on magnetoencephalography (MEG). It highlights detailed analyses of the main parameters involved and evaluates their optimal values for various cases of FE model solutions (e.g., steady-state, transient, etc.). In each case, a detail study of some of the main parameters and their effects on FE solution and its accuracy are carefully tested and evaluated. These parameters include: total number and size of 3D FE elements used, number and size of elements used in surface discretisation (of both white and grey matters of the brain), number and size of elements used for approximation of current sources, number of anisotropic properties used in steady-state and transient solutions, and the time steps used in transient analyses. The optimal values of these parameters in relation to solution accuracy and mesh convergence criteria have been found and presented.

  12. Investigation of optimal parameters for finite element solution of the forward problem in magnetic field tomography based on magnetoencephalography

    Science.gov (United States)

    Aristovich, K. Y.; Khan, S. H.; Borovkov, A. I.

    2011-08-01

    This paper presents an investigation of optimal parameters for finite element (FE) solution of the forward problem in magnetic field tomography (MFT) brain imaging based on magnetoencephalography (MEG). It highlights detailed analyses of the main parameters involved and evaluates their optimal values for various cases of FE model solutions (e.g., steady-state, transient, etc.). In each case, a detail study of some of the main parameters and their effects on FE solution and its accuracy are carefully tested and evaluated. These parameters include: total number and size of 3D FE elements used, number and size of elements used in surface discretisation (of both white and grey matters of the brain), number and size of elements used for approximation of current sources, number of anisotropic properties used in steady-state and transient solutions, and the time steps used in transient analyses. The optimal values of these parameters in relation to solution accuracy and mesh convergence criteria have been found and presented.

  13. How the Strength and Thickness of Field-aligned Currents Depend on Solar Wind and Ionospheric Parameters

    Science.gov (United States)

    Johnson, J.; Wing, S.

    2012-12-01

    Recently, Wing et al. [2011] examined the dependence of field-aligned currents, peak electron energy, and electron energy flux on solar wind parameters. We provide an analytical analysis of how velocity shear layers couple to the ionosphere via field-aligned currents. In the model, we use the Knight relation to express the field-aligned current in terms of the potential drop between the magnetosphere and ionosphere and solve for the ionospheric potential using current continuity. We obtain an analytic expression for the dependence of the current, the current maximum, and the current thickness on the magnetosheath velocity, magnetopause shear layer thickness, magnetospheric density and temperature, and ionospheric conductivity. We compare the analytical results for the current profiles using the magnetic field instruments on board the DMSP satellites. Estimates for FAC strength and thickness allow us to constrain the model to estimate the thickness of the magnetopause velocity shear layer, which is consistent with in situ observations and kinetic simulations. Finally, we discuss how the presence of waves could affect the field-aligned currents. Wing, S., S. Ohtani, J. R. Johnson, M. Echim, P. T. Newell, T. Higuchi, G. Ueno, and G. R. Wilson (2011), Solar wind driving of dayside field-aligned currents, J. Geophys. Res., 116, A08208, doi:10.1029/2011JA016579.

  14. Use of airborne hyperspectral imagery to map soil parameters in tilled agricultural fields

    Science.gov (United States)

    Hively, W. Dean; McCarty, Gregory W.; Reeves, James B.; Lang, Megan W.; Oesterling, Robert A.; Delwiche, Stephen R.

    2011-01-01

    Soil hyperspectral reflectance imagery was obtained for six tilled (soil) agricultural fields using an airborne imaging spectrometer (400–2450 nm, ~10 nm resolution, 2.5 m spatial resolution). Surface soil samples (n = 315) were analyzed for carbon content, particle size distribution, and 15 agronomically important elements (Mehlich-III extraction). When partial least squares (PLS) regression of imagery-derived reflectance spectra was used to predict analyte concentrations, 13 of the 19 analytes were predicted with R2 > 0.50, including carbon (0.65), aluminum (0.76), iron (0.75), and silt content (0.79). Comparison of 15 spectral math preprocessing treatments showed that a simple first derivative worked well for nearly all analytes. The resulting PLS factors were exported as a vector of coefficients and used to calculate predicted maps of soil properties for each field. Image smoothing with a 3 × 3 low-pass filter prior to spectral data extraction improved prediction accuracy. The resulting raster maps showed variation associated with topographic factors, indicating the effect of soil redistribution and moisture regime on in-field spatial variability. High-resolution maps of soil analyte concentrations can be used to improve precision environmental management of farmlands.

  15. Features of metabolic disturbances in rat myocardium under effect of alternating magnetic fields of different parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kolodub, F.A.; Chernysheva, O.N.; Yevtushenko, G.I.

    1981-04-01

    The high sensitivity of the cardiovascular system, in particular of the myocardium, to the effect of constant and, especially, alternating magnetic fields was demonstrated by many authors. However, the biochemical mechanisms forming the basis for the development of functional and structural disturbances in the myocardium have not been clarified in many respects. N.A. Udintsev and N.V. Kanskaya have established that the effect of alternating magnetic fields leads to the activation in the heart muscle of glycolysis and glycogenolysis and to the inhibition of the pentose cycle. In the literature there are no data on the state of oxidation processes and phosphorylation associated with them, in the course of which energy needed both for synthesis and contraction processes' in the myocardium is accumulated. The study of the features of metabolism of carbohydrates, macroergic phosphates and low-molecular nitrogen compounds in the rat heart under the effect of alternating magnetic fields of various voltages and exposures was the object of this investigation.

  16. Field data sets for seagrass biophysical properties for the Eastern Banks, Moreton Bay, Australia, 2004-2014.

    Science.gov (United States)

    Roelfsema, Chris M; Kovacs, Eva M; Phinn, Stuart R

    2015-01-01

    This paper describes seagrass species and percentage cover point-based field data sets derived from georeferenced photo transects. Annually or biannually over a ten year period (2004-2014) data sets were collected using 30-50 transects, 500-800 m in length distributed across a 142 km(2) shallow, clear water seagrass habitat, the Eastern Banks, Moreton Bay, Australia. Each of the eight data sets include seagrass property information derived from approximately 3000 georeferenced, downward looking photographs captured at 2-4 m intervals along the transects. Photographs were manually interpreted to estimate seagrass species composition and percentage cover (Coral Point Count excel; CPCe). Understanding seagrass biology, ecology and dynamics for scientific and management purposes requires point-based data on species composition and cover. This data set, and the methods used to derive it are a globally unique example for seagrass ecological applications. It provides the basis for multiple further studies at this site, regional to global comparative studies, and, for the design of similar monitoring programs elsewhere.

  17. A modified hybrid uncertain analysis method for dynamic response field of the LSOAAC with random and interval parameters

    Science.gov (United States)

    Zi, Bin; Zhou, Bin

    2016-07-01

    For the prediction of dynamic response field of the luffing system of an automobile crane (LSOAAC) with random and interval parameters, a hybrid uncertain model is introduced. In the hybrid uncertain model, the parameters with certain probability distribution are modeled as random variables, whereas, the parameters with lower and upper bounds are modeled as interval variables instead of given precise values. Based on the hybrid uncertain model, the hybrid uncertain dynamic response equilibrium equation, in which different random and interval parameters are simultaneously included in input and output terms, is constructed. Then a modified hybrid uncertain analysis method (MHUAM) is proposed. In the MHUAM, based on random interval perturbation method, the first-order Taylor series expansion and the first-order Neumann series, the dynamic response expression of the LSOAAC is developed. Moreover, the mathematical characteristics of extrema of bounds of dynamic response are determined by random interval moment method and monotonic analysis technique. Compared with the hybrid Monte Carlo method (HMCM) and interval perturbation method (IPM), numerical results show the feasibility and efficiency of the MHUAM for solving the hybrid LSOAAC problems. The effects of different uncertain models and parameters on the LSOAAC response field are also investigated deeply, and numerical results indicate that the impact made by the randomness in the thrust of the luffing cylinder F is larger than that made by the gravity of the weight in suspension Q . In addition, the impact made by the uncertainty in the displacement between the lower end of the lifting arm and the luffing cylinder a is larger than that made by the length of the lifting arm L .

  18. Setting boundary conditions on the Khokhlov-Zabolotskaya equation for modeling ultrasound fields generated by strongly focused transducers

    Science.gov (United States)

    Rosnitskiy, P. B.; Yuldashev, P. V.; Vysokanov, B. A.; Khokhlova, V. A.

    2016-03-01

    An equivalent source model is developed for setting boundary conditions on the parabolic diffraction equation in order to simulate ultrasound fields radiated by strongly focused medical transducers. The equivalent source is defined in a plane; corresponding boundary conditions for pressure amplitude, aperture, and focal distance are chosen so that the axial solution to the parabolic model in the focal region of the beam matches the solution to the full diffraction model (Rayleigh integral) for a spherically curved uniformly vibrating source. It is shown that the proposed approach to transferring the boundary condition from a spherical surface to a plane makes it possible to match the solutions over an interval of several diffraction maxima around the focus even for focused sources with F-numbers less than unity. This method can be used to accurately simulate nonlinear effects in the fields of strongly focused therapeutic transducers using the parabolic Khokhlov-Zabolotskaya equation.

  19. Novel field test design for acquisition of DC and AC parameters during service

    DEFF Research Database (Denmark)

    Thorsteinsson, Sune; Poulsen, Peter Behrensdorff; Schou, Jørgen;

    2016-01-01

    potential for more. In this work we describe a field test design where the modules are operating at their maximum power point, and via relays is switched out one by one for acquisition of an IV curve and an impedance spectrum. Some of the modules involved will undergo stimuli to accelerate certain......Being able to monitor early signs of PV module degradation, is needed to ensure stable power production throughout the service life of a PV installation. Recently, impedance spectroscopy is proven to be a useful tool for detection of the presence and location of significant errors, and may have...

  20. Asymptotic properties of ground states of scalar field equations with a vanishing parameter

    CERN Document Server

    Moroz, Vitaly

    2012-01-01

    We study the leading order behaviour of positive solutions of the equation -\\Delta u +\\varepsilon u-|u|^{p-2}u+|u|^{q-2}u=0,\\qquad x\\in\\R^N, where $N\\ge 3$, $q>p>2$ and when $\\varepsilon>0$ is a small parameter. We give a complete characterization of all possible asymptotic regimes as a function of $p$, $q$ and $N$. The behavior of solutions depends sensitively on whether $p$ is less, equal or bigger than the critical Sobolev exponent $p^\\ast=\\frac{2N}{N-2}$. For $pp^\\ast$ the solution asymptotically coincides with the solution of the equation with $\\varepsilon=0$. In the most delicate case $p=p^\\ast$ the asymptotic behaviour of the solutions is given by a particular solution of the critical Emden--Fowler equation, whose choice depends on $\\varepsilon$ in a nontrivial way.

  1. Estimation of constitutive parameters for the Belridge Diatomite, South Belridge Diatomite Field

    Energy Technology Data Exchange (ETDEWEB)

    Fossum, A.F.; Fredrich, J.T.

    1998-06-01

    A cooperative national laboratory/industry research program was initiated in 1994 that improved understanding of the geomechanical processes causing well casing damage during oil production from weak, compactible formations. The program focused on the shallow diatomaceous oil reservoirs located in California`s San Joaquin Valley, and combined analyses of historical field data, experimental determination of rock mechanical behavior, and geomechanical simulation of the reservoir and overburden response to production and injection. Sandia National Laboratories` quasi-static, large-deformation structural mechanics finite element code JAS3D was used to perform the three-dimensional geomechanical simulations. One of the material models implemented in JAS3D to simulate the time-independent inelastic (non-linear) deformation of geomaterials is a generalized version of the Sandler and Rubin cap plasticity model (Sandler and Rubin, 1979). This report documents the experimental rock mechanics data and material cap plasticity models that were derived to describe the Belridge Diatomite reservoir rock at the South Belridge Diatomite Field, Section 33.

  2. Cosmological Parameters from the Comparison of the 2MASS Gravity Field with Peculiar Velocity Surveys

    CERN Document Server

    Pike, R W; Hudson, Michael J.

    2005-01-01

    We compare the peculiar velocity field within 65 $h^{-1}$ Mpc predicted from 2MASS photometry and public redshift data to three independent peculiar velocity surveys based on type Ia supernovae, surface brightness fluctuations in ellipticals, and Tully-Fisher distances to spirals. The three peculiar velocity samples are each in good agreement with the predicted velocities and produce consistent results for $\\beta_{K}=\\Omega\\sbr{m}^{0.6}/b_{K}$. Taken together the best fit $\\beta_{K} = 0.49 \\pm 0.04$. We explore the effects of morphology on the determination of $\\beta$ by splitting the 2MASS sample into E+S0 and S+Irr density fields and find both samples are equally good tracers of the underlying dark matter distribution, but that early-types are more clustered by a relative factor $b\\sbr{E}/b\\sbr{S} \\sim 1.6$. The density fluctuations of 2MASS galaxies in $8 h^{-1}$ Mpc spheres in the local volume is found to be $\\sigma\\sbr{8,K} = 0.9$. From this result and our value of $\\beta_{K}$, we find $\\sigma_8 (\\Omega\\...

  3. Models of field-aligned currents needful to simulate the substorm variations of the electric field and other parameters observed by EISCAT

    Directory of Open Access Journals (Sweden)

    M. A. Volkov

    Full Text Available We have used the global numerical model of the coupled ionosphere-thermosphere-protonosphere system to simulate the electric-field, ion- and electron-temperature and -concentration variations observed by EISCAT during the substorm event of 25 March 1987. In our previous studies we adopted the model input data for field-aligned currents and precipitating electron fluxes to obtain an agreement between observed and modelled ionospheric variations. Now, we have calculated the field-aligned currents needful to simulate the substrom variations of the electric field and other parameters observed by EISCAT. The calculations of the field-aligned currents have been performed by means of numerical integration of the time-dependent continuity equation for the cold magnetospheric electrons. This equation was added to the system of the modelling equations including the equation for the electric-field potential to be solved jointly. In this case the inputs of the model are the spatial and time variations of the electric-field potential at the polar-cap boundaries and those of the cold magnetospheric electron concentration which have been adopted to obtain the agreement between the observed and modelled ionospheric variations for the substorm event of 25 March 1987. By this means it has been found that during the active phase of the substorm the current wedge is formed. It is connected with the region of the decreased cold magnetospheric electron content travelling westwards with a velocity of about 1 km s–1 at ionospheric levels.

  4. Evolution of shifted cosmological parameter and shifted dust matter in a two-phase tachyonic field universe

    CERN Document Server

    Verma, Murli Manohar

    2012-01-01

    We propose a model of the evolution of the tachyonic scalar field over two phases in the universe. The field components do not interact in phase I, while in the subsequent phase II, they change flavours due to relative suppression of the radiation contribution. In phase II, we allow them to interact mutually with time-independent perturbation in their equations of state, as Shifted Cosmological Parameter (SCP) and Shifted Dust Matter (SDM). We determine the solutions of their scaling with the cosmic redshift in both phases. We further suggest the normalized Hubble function diagnostic, which, together with the low- and high-redshift $H(z)$ data and the concordance values of the present density parameters from the CMBR, BAO statistics etc., constrains the strength of interaction, by imposing the viable conditions to break degeneracy in 3-parameter $(\\gamma, \\varepsilon, \\dot{\\phi}^2)$ space. The range of redshifts $(z=0.1$ to $z=1.75)$ is chosen to highlight the role of interaction during structure formation, a...

  5. Effect of Friction Models and Parameters on the Lagrangian Flow Fields in High-Temperature Compression Testing

    Science.gov (United States)

    Kundalkar, Deepak; Singh, Rajkumar; Tewari, Asim

    2017-07-01

    Friction plays an important role in high-temperature deformation process. Friction affects local displacement field in the tool-workpiece interface region, thus affecting the overall material flow. Under high-temperature compression, macro-indicators like bulge radius and load displacement curves are not sensitive enough to distinguish subtle differences between various friction models. Hence, a new approach to match the experimental Lagrangian flow field with flow field obtained from FE simulation is proposed. For this uniaxial barreling, compression tests at constant temperature were conducted on Gleeble thermo-mechanical simulator. The compression tests were conducted at different strain, strain rate and friction conditions. Finite element simulations employing various friction models and parameters were performed for matching the experimental conditions. Experimental Lagrangian flow fields were obtained from the grain flow lines observed on high-resolution larger area micrographs of the specimen. It was observed that all the investigated friction models provided equally good fit with the macro-experimental indicators (bulge radius and load displacement curves). However, Coulomb friction model was the only friction model that provided the closest fit with the experimentally obtained Lagrangian flow fields. Coulomb friction model provided the best agreement between experimental and numerical simulation for both lubricated and non-lubricated conditions using friction coefficients μ = 0.2993 and μ = 0.3895, respectively.

  6. Unravelling the zero-field-splitting parameters in Pt-rich polymers with tuned spin-orbit coupling

    Science.gov (United States)

    Peroncik, Peter; McLaughlin, Ryan; Sun, Dali; Vardeny, Z. Valy

    2014-03-01

    Recently pi-conjugated polymers that contain heavy metal Platinum (Pt-polymers, Scientific Reports 3, 2653, 2013) have attracted substantial interest due to their strong and tunable spin-orbit coupling (SOC). The magnetic field effect (MFE), such as magneto-photoluminescence (MPL) is considered to be a viable approach to address the SOC strength in the organics. Alas conventional MFE up to several hundred Gauss is unable to overcome the relative large spin splitting energies in Pt-polymers due to their strong SOC. To overcome this difficulty we study the MPL response in two Pt-polymers at high magnetic field (up to several Telsa). We found that the MPL response is dominated by triplet excitons that are generated in record time, and from the MPL(B) response width we could obtained the triplet zero-field splitting (ZFS) parameters. We found that the ZFS parameters in the Pt-polymers are proportional to the intrachain Pt atom concentration. Research sponsored by the NSF (Grant No. DMR-1104495) and NSF-MRSEC (DMR 1121252) at the University of Utah.

  7. Parameter sensitivity study of a Field II multilayer transducer model on a convex transducer

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2009-01-01

    .ResultsPredictions using the ZR give a pressure pulse error (PPE) and an intensity error (IE) of 32 % and 23 %, respectively, relative to the measured. Altering the piezoelectric permittivity +12 % from ZR decreases the PPE to 30 % and the IE to 2 % relative to the measured. Changing the stiffness constant of the lens -4......A multilayer transducer model for predicting a transducer impulse response has in earlier works been developed and combined with the Field II software. This development was tested on current, voltage, and intensity measurements on piezoceramics discs (Bæk et al. IUS 2008) and a convex 128 element...... ultrasound imaging transducer (Bæk et al. ICU 2009). The model benefits from its 1D simplicity and hasshown to give an amplitude error around 1.7‐2 dB. However, any prediction of amplitude, phase, and attenuation of pulses relies on the accuracy of manufacturer supplied material characteristics, which may...

  8. Real time kinetic flow cytometry measurements of cellular parameter changes evoked by nanosecond pulsed electric field.

    Science.gov (United States)

    Orbán, Csaba; Pérez-García, Esther; Bajnok, Anna; McBean, Gethin; Toldi, Gergely; Blanco-Fernandez, Alfonso

    2016-05-01

    Nanosecond pulsed electric field (nsPEF) is a novel method to increase cell proliferation rate. The phenomenon is based on the microporation of cellular organelles and membranes. However, we have limited information on the effects of nsPEF on cell physiology. Several studies have attempted to describe the effects of this process, however no real time measurements have been conducted to date. In this study we designed a model system which allows the measurement of cellular processes before, during and after nsPEF treatment in real time. The system employs a Vabrema Mitoplicator(TM) nsPEF field generating instrument connected to a BD Accuri C6 cytometer with a silicon tube led through a peristaltic pump. This model system was applied to observe the effects of nsPEF in mammalian C6 glioblastoma (C6 glioma) and HEK-293 cell lines. Viability (using DRAQ7 dye), intracellular calcium levels (using Fluo-4 dye) and scatter characteristics were measured in a kinetic manner. Data were analyzed using the FACSKin software. The viability and morphology of the investigated cells was not altered upon nsPEF treatment. The response of HEK-293 cells to ionomycin as positive control was significantly lower in the nsPEF treated samples compared to non-treated cells. This difference was not observed in C6 cells. FSC and SSC values were not altered significantly by the nsPEF treatment. Our results indicate that this model system is capable of reliably investigating the effects of nsPEF on cellular processes in real time. © 2016 International Society for Advancement of Cytometry.

  9. Systematic study of the effect of HSE functional internal parameters on the electronic structure and band gap of a representative set of metal oxides.

    Science.gov (United States)

    Viñes, Francesc; Lamiel-García, Oriol; Chul Ko, Kyoung; Yong Lee, Jin; Illas, Francesc

    2017-04-30

    The effect of the amount of Hartree-Fock mixing parameter (α) and of the screening parameter (w) defining the range separated HSE type hybrid functional is systematically studied for a series of seven metal oxides: TiO2 , ZrO2 , CuO2 , ZnO, MgO, SnO2 , and SrTiO3 . First, reliable band gap values were determined by comparing the optimal α reproducing the experiment with the inverse of the experimental dielectric constant. Then, the effect of the w in the HSE functional on the calculated band gap was explored in detail. Results evidence the existence of a virtually infinite number of combinations of the two parameters which are able to reproduce the experimental band gap, without a unique pair able to describe the full studied set of materials. Nevertheless, the results point out the possibility of describing the electronic structure of these materials through a functional including a screened HF exchange and an appropriate correlation contribution. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Effect of Static Magnetic Field on Oxidant/Antioxidant Parameters in Cancerous and Noncancerous Human Gastric Tissues

    Directory of Open Access Journals (Sweden)

    Bahadır Öztürk

    2016-01-01

    Full Text Available Aim. To investigate the effects of static magnetic field (SMF on oxidant and antioxidant parameters of the cancerous and noncancerous human gastric tissues. Materials and Methods. Gastric tissues obtained from patients with gastric cancer were used in the study. SMF was created by using two static magnets. Before and after treatment with SMF, oxidant and antioxidant parameters were measured in the tissue samples. Results. In the cancerous tissue, superoxide dismutase (SOD activity was found higher and malondialdehyde (MDA level was found lower as compared with noncancerous tissue. SMF affects oxidant/antioxidant parameters differently in the cancerous and noncancerous tissues. In this regard, SMF causes increase in SOD activity and decrease in MDA level in the noncancerous tissue. However, it decreases SOD and glutathione peroxidase (GSH-Px activities and increases MDA level and catalase (CAT activity in the cancerous tissue. There were no differences between nitric oxide (NO and nitric oxide synthase (NOS parameters in or among the cancerous and noncancerous tissues. Conclusions. SMF accelerates peroxidation reactions possibly by suppressing SOD and GSH-Px enzymes in the cancerous gastric tissue. This event caused by SMF might play part in the death of cancer cells, which may be a good supportive vehicle for the cancer therapy.

  11. Orbital parameters, chemical composition, and magnetic field of the Ap binary HD 98088

    CERN Document Server

    Folsom, C P; Wade, G A; Kochukhov, O; Alecian, E; Shulyak, D

    2013-01-01

    HD 98088 is a synchronised, double-lined spectroscopic binary system with a magnetic Ap primary component and an Am secondary component. We study this rare system using high-resolution MuSiCoS spectropolarimetric data, to gain insight into the effect of binarity on the origin of stellar magnetism and the formation of chemical peculiarities in A-type stars. Using a new collection of 29 high-resolution Stokes VQU spectra we re-derive the orbital and stellar physical parameters and conduct the first disentangling of spectroscopic observations of the system to conduct spectral analysis of the individual stellar components. From this analysis we determine the projected rotational velocities of the stars and conduct a detailed chemical abundance analysis of each component using both the SYNTH3 and ZEEMAN spectrum synthesis codes. The surface abundances of the primary component are typical of a cool Ap star, while those of the secondary component are typical of an Am star. We present the first magnetic analysis of b...

  12. Spatial variability of isoproturon mineralizing activity within an agricultural field: geostatistical analysis of simple physicochemical and microbiological soil parameters.

    Science.gov (United States)

    El Sebai, T; Lagacherie, B; Soulas, G; Martin-Laurent, F

    2007-02-01

    We assessed the spatial variability of isoproturon mineralization in relation to that of physicochemical and biological parameters in fifty soil samples regularly collected along a sampling grid delimited across a 0.36 ha field plot (40 x 90 m). Only faint relationships were observed between isoproturon mineralization and the soil pH, microbial C biomass, and organic nitrogen. Considerable spatial variability was observed for six of the nine parameters tested (isoproturon mineralization rates, organic nitrogen, genetic structure of the microbial communities, soil pH, microbial biomass and equivalent humidity). The map of isoproturon mineralization rates distribution was similar to that of soil pH, microbial biomass, and organic nitrogen but different from those of structure of the microbial communities and equivalent humidity. Geostatistics revealed that the spatial heterogeneity in the rate of degradation of isoproturon corresponded to that of soil pH and microbial biomass.

  13. The Dependence of the Strength and Thickness of Field-Aligned Currents on Solar Wind and Ionospheric Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay R. [PPPL; Wing, Simon [Johns Hopkins University

    2014-08-01

    Sheared plasma flows at the low-latitude boundary layer correlate well with early afternoon auroral arcs and eld-aligned currents [Sonnerup, 1980; Lundin and Evans, 1985]. We present a simple analytic model that relates solar wind and ionospheric parameters to the strength and thickness of field-aligned currents in a region of sheared velocity, such as the low latitude boundary layer. We compare the predictions of the model with DMSP observations and nd remarkably good scaling of the currents with solar wind and ionospheric parameters. The sheared boundary layer thickness is inferred to be around 3000km consistent with observational studies. The analytic model provides a simple way to organize data and to infer boundary layer structures from ionospheric data.

  14. Effects of Monoculture, Crop Rotation, and Soil Moisture Content on Selected Soil Physicochemical and Microbial Parameters in Wheat Fields

    Directory of Open Access Journals (Sweden)

    A. Marais

    2012-01-01

    Full Text Available Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN, community level physiological profiling (CLPP, and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant.

  15. A dedicated setup for the measurement of the electron transport parameters in gases at large electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Fonte, P. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Departamento de Fisica da Universidade de Coimbra, 3004-516 Coimbra (Portugal); Instituto Superior de Engenharia de Coimbra, Rua Pedro Nunes, 3030-199 Coimbra (Portugal); Mangiarotti, A. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Departamento de Fisica da Universidade de Coimbra, 3004-516 Coimbra (Portugal); Botelho, S.; Goncalves, J.A.C. [Instituto de Pesquisas Energeticas e Nucleares, 05508-000 Cidade Universitaria, Sao Paulo (Brazil); Departamento de Fisica, Pontificia Universidade Catolica de Sao Paulo, 01303-050 Sao Paulo (Brazil); Ridenti, M.A. [Instituto de Fisica, Universidade de Sao Paulo, 05508-090 Cidade Universitaria, Sao Paulo (Brazil); Bueno, C.C., E-mail: ccbueno@ipen.b [Instituto de Pesquisas Energeticas e Nucleares, 05508-000 Cidade Universitaria, Sao Paulo (Brazil); Departamento de Fisica, Pontificia Universidade Catolica de Sao Paulo, 01303-050 Sao Paulo (Brazil)

    2010-01-21

    Electron transport parameters are important in several areas ranging from particle detectors to plasma-assisted processing reactors. Nevertheless, especially at high fields strengths and for complex gases, relatively few data are published. A dedicated setup has been developed to measure the electron drift velocity and the first Townsend coefficient in parallel plate geometry. An RPC-like cell has been adopted to reach high field strengths without the risk of destructive sparks. The validation data obtained with pure Nitrogen will be presented and compared to a selection of the available literature and to calculations performed with Magboltz 2 version 8.6. The new data collected in pure Isobutane will then be discussed. This is the first time the electron drift velocity in pure Isobutane is measured well into the saturation region. Good agreement is found with expectations from Magboltz.

  16. RELATIONSHIPS BETWEEN SOME SOIL PARAMETERS AND WEED COMMUNITY (CASE STUDY: WINTER WHEAT FIELDS OF UREMIA-IRAN).

    Science.gov (United States)

    Hassannejad, S; Pirouie, M Saleh; Haghi, D Zare

    2015-01-01

    In order to find relationships between weed species distribution and soil pH, calcium carbonate (CaCO₃), electrical conductivity (EC), and organic matter percentage (OM %), fields surveys were done in 50 wheats (Triticum aestivum L.) fields of Uremia county (one of the northwest counties of Iran) in 2013. Data sampling of weeds was conducted from the beginning of stem elongation until the end of heading stages of wheat. In each field, 20 quadrates (0.25 m²) were randomly placed along a "W" pattern (5 quadrates in each line of this pattern) and in each quadrat, weed species were coded and recorded (density and cover percentage) for subsequent data entry and analysis. Canonical correspondence analysis (CCA) was used to find relationships between presence and absence of weeds in wheat fields and some of soil parameters. A total 169 weed species belonging to 35 plant families were recorded. CCA showed that four soil factors including soil pH, calcium carbonate (CaCO3), electrical conductivity (EC), and organic matter percentage (OM %) showed 58.6 percentage of weed species distribution variance. Abutilon theophrasti Medicus, Datura stramonium L., Malva neglecta Wallr., Portulaca oleracea L., Sisymbrium irio L., Atriplex patulum (L.). Aellen., and Heliotropium europaeum L. had maximum correlation with soil's pH. Euphorbia peplus L. and Salvia spinosa L. had negative correlation with pH, so that increasing pH caused reduction in the presence of these weeds. The presence of Chondrilla juncea L., Lepidium perfoliatum L., and Turgenia latifolia (L.) Hoff in the center of CCA biplot indicated that these weeds were correlated with all of these soil parameters.

  17. Studies of the Impact of Magnetic Field Uncertainties on Physics Parameters of the Mu2e Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bradascio, Federica [Pisa U.

    2016-01-01

    The Mu2e experiment at Fermilab will search for a signature of charged lepton flavor violation, an effect prohibitively too small to be observed within the Standard Model of particle physics. Therefore, its observation is a signal of new physics. The signature that Mu2e will search for is the ratio of the rate of neutrinoless coherent conversion of muons into electrons in the field of a nucleus, relative to the muon capture rate by the nucleus. The conversion process is an example of charged lepton flavor violation. This experiment aims at a sensitivity of four orders of magnitude higher than previous related experiments. The desired sensitivity implies highly demanding requirements of accuracy in the design and conduct of the experiment. It is therefore important to investigate the tolerance of the experiment to instrumental uncertainties and provide specifications that the design and construction must meet. This is the core of the work reported in this thesis. The design of the experiment is based on three superconducting solenoid magnets. The most important uncertainties in the magnetic field of the solenoids can arise from misalignments of the Transport Solenoid, which transfers the beam from the muon production area to the detector area and eliminates beam-originating backgrounds. In this thesis, the field uncertainties induced by possible misalignments and their impact on the physics parameters of the experiment are examined. The physics parameters include the muon and pion stopping rates and the scattering of beam electrons off the capture target, which determine the signal, intrinsic background and late-arriving background yields, respectively. Additionally, a possible test of the Transport Solenoid alignment with low momentum electrons is examined, as an alternative option to measure its field with conventional probes, which is technically difficult due to mechanical interference. Misalignments of the Transport Solenoid were simulated using standard

  18. Jet quenching parameter of quark-gluon plasma in strong magnetic field: perturbative QCD and AdS/CFT correspondence

    CERN Document Server

    Li, Shiyong; Yee, Ho-Ung

    2016-01-01

    We compute the jet quenching parameter $\\hat q$ of QCD plasma in the presence of strong magnetic field in both weakly and strongly coupled regimes. In weakly coupled regime, we compute $\\hat q$ in perturbative QCD at complete leading order (that is, leading log as well as the constant under the log) in QCD coupling constant $\\alpha_s$, assuming the hierarchy of scales $\\alpha_s eB\\ll T^2\\ll eB$. We consider two cases of jet orientations with respect to the magnetic field: 1) the case of jet moving parallel to the magnetic field, 2) the case jet moving perpendicular to the magnetic field. In the former case, we find $\\hat q\\sim \\alpha_s^2 (eB)T\\log(1/\\alpha_s)$, while in the latter we have $\\hat q\\sim \\alpha_s^2 (eB)T\\log(T^2/\\alpha_seB)$. In both cases, this leading order result arises from the scatterings with thermally populated lowest Landau level quarks. In strongly coupled regime described by AdS/CFT correspondence, we find $\\hat q\\sim \\sqrt{\\lambda}(eB)T$ or $\\hat q\\sim\\sqrt{\\lambda}\\sqrt{eB}T^2$ in the...

  19. Effects of static magnetic field exposure on hematological and biochemical parameters in rats

    Directory of Open Access Journals (Sweden)

    Salem Amara

    2006-11-01

    Full Text Available The present work was undertaken in order to investigate the effects of static magnetic field (SMF on growth rates, hematopoiesis, plasmatic proteins levels, glucose concentration, lactate dehydrogenase (LDH and transaminases activities in male rats. Sub-acute exposure of rats during 5 consecutive days to SMF (1h/day at 128mT induced an increase of plasma LDH activity (+38%, pEste estudo foi realizado com o obejtivo de investigar os efeitos do campo magnético estático (CMS nas taxas de crescimento, hematopoiese, concentrações de proteínas plasmáticas, glicemia, da desidrogenase lática (DHL e transaminases (alanina aminotransferase-ALT e aspartato aminotransferase-AST em ratos machos. Após exposição de modo sub-agudo durante 5 dias consecutivos ao CMS (1 hora/dia, a 128mT, houve aumento em 38% na concentração de DHL (p<0.05, porém não houve mudanças nos índices hematimétricos, nas proteínas plasmáticas e nas transaminases. Duas semans após exposição ao CMS durante 30 dias consecutivos (CMS (1 hora/dia, a 128mT houve diminuição significativa das taxas de crescimento e aumento significativo das concetrações de proteínas (+62%, p<0.05, da hemoglobina (+10%, p<0.05, eritrócitos (+7%, p<0.05, leucócitos (+17%, p<0.05 e plaquetas (+10%, p<0.05. A exposição sub-crônica ao CMS induziu aumento da DHL (+43%, p<0.05, AST (+ 41%, p<0.05 e ALT (+95%, p<0.05. Em contraste não houve aumento da glicemia. Estas alterações sugerem que a exposição ao CMS possivelmente influencia a proliferação de células do sistema hematopoiético e a produção enzimática, indicando alterações teciduais.

  20. Low-energy photons in high-energy photon fields--Monte Carlo generated spectra and a new descriptive parameter.

    Science.gov (United States)

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay; Rühmann, Antje; Poppe, Björn

    2011-09-01

    detector responses and dose conversion factors, as well as increases of the RBE have to be anticipated. Parameter P(D)(200 keV) can also be used as a guidance supporting the selection of a calibration geometry suitable for radiation dosimeters to be used in small radiation fields.

  1. A Setting for a Field-based Class for Improved Understanding of Sustainability Through the Evaluation of Aquaculture and Fisheries

    Science.gov (United States)

    Macko, S. A.; O'Connell, M. T.

    2015-12-01

    An improved understanding of sustainability is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapse in fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. During regular session (13 week) or shorter term (4 week) summer classes such long trips are logistically difficult owing to large numbers of students involved or timing. This new approach to such a course supplement addresses the requests by utilizing local resources and short field trips for a limited number of students (20) to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time, readings, along with paper and laboratories. In addition, short day-long trips to locations where the ocean was "captured" were also used to supplement the experience as well as speakers involved with aquaculture. Central Virginia is a fortunate location for such a class, with close access for travel to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and National Zoo) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore and Virginia Beach. Furthermore, visits to local seafood markets at local grocery stores, or larger city markets in Washington, Baltimore and Virginia Beach, enhance the exposure to productivity in the ocean, and viability of the fisheries sustainability. The course could then address not only the particulars of the marine science, but also aspects of sustainability with discussions on ethics, including keeping animals in captivity or overfishing of particular species and the special difficulties that arise from captive or culturing ocean populations. In addition, the class was

  2. "A Future for Fisheries?" Setting of a Field-based Class for Evaluation of Aquaculture and Fisheries Sustainability

    Science.gov (United States)

    Macko, Stephen; O'Connell, Matthew

    2016-04-01

    For the first time in 2015, aquaculture yields approximately equaled global wild capture fisheries. Are either of these levels of production sustainable? This course explored the limitations of both sources of fishery landings and included legal limitations, environmental concerns and technological problems and adaptations. It made use of visits to aquaculture facilities, government laboratories like NOAA , as well as large fish distribution centers like J.J. McDowell's Seafood (Jessup, MD), and included presentations by experts on legalities including the Law of the Sea. In addition, short day-long trips to "ocean-related" locations were also used to supplement the experience and included speakers involved with aquaculture. Central Virginia is a fortunate location for such a class, with close access for travel to the Chesapeake Bay and numerous field stations, museums with ocean-based exhibits (the Smithsonian and National Zoo) that address both extant and extinct Earth history, as well as national/state aquaria in Baltimore and Virginia Beach. Furthermore, visits to local seafood markets at local grocery stores, or larger city markets in Washington, Baltimore and Virginia Beach, enhance the exposure to productivity in the ocean, and viability of the fisheries sustainability. Sustainability awareness is increasingly a subject in educational settings. Marine science classes are perfect settings of establishing sustainability awareness owing to declining populations of organisms and perceived collapse in fisheries worldwide. Students in oceanography classes often request more direct exposure to actual ocean situations or field trips. This new approach to such a course supplement addresses the requests by utilizing local resources and short field trips for a limited number of students to locations in which Ocean experiences are available, and are often supported through education and outreach components. The vision of the class was a mixture of classroom time

  3. A Dissipation Gap Method for full-field measurement-based identification of elasto-plastic material parameters

    KAUST Repository

    Blaysat, Benoît

    2012-05-18

    Using enriched data such as displacement fields obtained from digital image correlation is a pathway to the local identification of material parameters. Up to now, most of the identification techniques for nonlinear models are based on Finite Element Updating Methods. This article explains how an appropriate use of the Dissipation Gap Method can help in this context and be an interesting alternative to these classical techniques. The Dissipation Gap Methods rely on the concept of error in dissipation that has been used mainly for the verification of finite element simulations. We provide here an original application of these founding developments to the identification of material parameters for nonlinear behaviors. The proposed technique and especially the main technical keypoint of building the admissible fields are described in detail. The approach is then illustrated through the identification of heterogeneous isotropic elasto-plastic properties. The basic numerical features highlighted through these simple examples demonstrate this approach to be a promising tool for nonlinear identification. © 2012 John Wiley & Sons, Ltd.

  4. Apparent Diffusion Coefficient Value Is Not Dependent on Magnetic Resonance Systems and Field Strength Under Fixed Imaging Parameters in Brain.

    Science.gov (United States)

    Ogura, Akio; Tamura, Takayuki; Ozaki, Masanori; Doi, Tsukasa; Fujimoto, Koji; Miyati, Tosiaki; Ito, Yukiko; Maeda, Fumie; Tarewaki, Hiroyuki; Takahashi, Mitsuyuki

    2015-01-01

    The aim of the study was to investigate the causes of apparent diffusion coefficient (ADC) measurement errors and to determine the optimal scanning parameters that are independent of the field strength and vendors of the magnetic resonance (MR) system. Brain MR images of 10 healthy volunteers were scanned using 6 MR scanners of different field strengths and vendors in 2 different institutions. Ethical review board approvals were obtained for this study, and all volunteers gave their informed consents. Coefficient of variation (CV) of ADC values were compared for their differences in various MR scanners and in the scanned subjects. The CV of ADC values for 6 different scanners of 6 brains was 3.32%. The CV for repeated measurements in 1 day (10 scans per day) and in 10 days (scan per day for 10 days) for 1 subject was 1.72% and 2.96%, respectively (n = 5, P variance for the same subject but were lower than the intersubject variance for the same scanner. The variance in the ADC values for different MR scanners is reasonably small if appropriate scanning parameters (repetition time, >3000 ms; echo time, minimum; and high enough signal-to-noise ratio of high-b diffusion-weighted image) are used.

  5. CH3D photomixing spectroscopy up to 2.5 THz: New set of rotational and dipole parameters, first THz self-broadening measurements

    Science.gov (United States)

    Bray, Cédric; Cuisset, Arnaud; Hindle, Francis; Bocquet, Robin; Mouret, Gaël; Drouin, Brian J.

    2017-03-01

    Several previously unmeasured transitions of 12CH3D have been recorded by a terahertz photomixing continuous-wave spectrometer up to QR(10) branch at 2.5 THz. An improved set of rotational constants has been obtained utilizing a THz frequency metrology based on a frequency comb that achieved an averaged frequency position better than 150 kHz on more than fifty ground-state transitions. A detailed analysis of the measured line intensities was undertaken using the multispectrum fitting program and has resulted in a determination of new dipole moment parameters. Measurements at different pressures of the QR(7) transitions provide the first determination of self-broadening coefficients from pure rotational CH3D lines. The THz rotational measurements are consistent with IR rovibrational data but no significant vibrational dependence of self-broadening coefficient may be observed by comparison.

  6. The Effects of Electromagnetic Fields Generated from 1800 MHz Cell Phones on Erythrocyte Rheological Parameters and Zinc Level in Rats

    Directory of Open Access Journals (Sweden)

    Ümit Divrikli

    2012-06-01

    Full Text Available Objective: The aim of this study was to investigate the effects of the electromagnetic field generated from the 1800 MHz radiofrequency radiation (EF on erythrocyte rheological parameters and erythrocyte zinc levels. Material and Methods: Twenty-four male Wistar Albino rats were randomly grouped as follows: 1 two control groups and 2 study groups: i Group A: EF exposed group (2.5 h/day for 30 days, the phone on stand-by, and ii Group B: EF exposed group (2.5 min/day for 30 days, the phone ringing in silent mode. At the end of the experimental period erythrocyte rheological parameters such as erythrocyte deformability and aggregation were determined by an ectacytometer. Erythrocyte zinc level, which affects hemorheological parameters, was also measured by atomic absorption spectrophotometer. Results: Erythrocyte deformability was decreased in both study groups but the decrease in group A was not statistically significant. Exposure to EF did not have any significant effect on erythrocyte aggregation. On the other hand, erythrocyte zinc level was significantly reduced in both study groups. Conclusion: Exposure to EF may have decreased tissue oxygenation due to reduced erythrocyte deformability. Decrease in erythrocyte zinc level may have caused the impairment in erythrocyte deformability.

  7. Benchmark Data Set for Wheat Growth Models: Field Experiments and AgMIP Multi-Model Simulations.

    Science.gov (United States)

    Asseng, S.; Ewert, F.; Martre, P.; Rosenzweig, C.; Jones, J. W.; Hatfield, J. L.; Ruane, A. C.; Boote, K. J.; Thorburn, P.J.; Rotter, R. P.

    2015-01-01

    The data set includes a current representative management treatment from detailed, quality-tested sentinel field experiments with wheat from four contrasting environments including Australia, The Netherlands, India and Argentina. Measurements include local daily climate data (solar radiation, maximum and minimum temperature, precipitation, surface wind, dew point temperature, relative humidity, and vapor pressure), soil characteristics, frequent growth, nitrogen in crop and soil, crop and soil water and yield components. Simulations include results from 27 wheat models and a sensitivity analysis with 26 models and 30 years (1981-2010) for each location, for elevated atmospheric CO2 and temperature changes, a heat stress sensitivity analysis at anthesis, and a sensitivity analysis with soil and crop management variations and a Global Climate Model end-century scenario.

  8. A unified methodology based on sparse field level sets and boosting algorithms for false positives reduction in lung nodules detection.

    Science.gov (United States)

    Saien, Soudeh; Moghaddam, Hamid Abrishami; Fathian, Mohsen

    2017-08-09

    This work aims to develop a unified methodology for the false positives reduction in lung nodules computer-aided detection schemes. The 3D region of each detected nodule candidate is first reconstructed using the sparse field method for accurately segmenting the objects. This technique enhances the level set modeling by restricting the computations to a narrow band near the evolving curve. Then, a set of 2D and 3D relevant features are extracted for each segmented candidate. Subsequently, a hybrid undersampling/boosting algorithm called RUSBoost is applied to analyze the features and discriminate real nodules from non-nodules. The performance of the proposed scheme was evaluated by using 70 CT images, randomly selected from the Lung Image Database Consortium and containing 198 nodules. Applying RUSBoost classifier exhibited a better performance than some commonly used classifiers. It effectively reduced the average number of FPs to only 3.9 per scan based on a fivefold cross-validation. The practical implementation, applicability for different nodule types and adaptability in handling the imbalanced data classification insure the improvement in lung nodules detection by utilizing this new approach.

  9. Effect of parameters on local stress field in single-lap bolted joints with the interference fit

    Directory of Open Access Journals (Sweden)

    Jiefeng Jiang

    2016-05-01

    Full Text Available From the interference fit bolt installation to tensile loading stage in single-lap joint with a hi-lock bolt, the stress and strain fields were studied experimentally and numerically. A three-dimensional finite element model was generated to simulate the experimental setup, which was validated using the experimental data. The fatigue behavior of the bolted joint is influenced by the local stress fields on the faying surface near the holes in single-lap joints. Therefore, with the aim to improve design awareness, the effects of the parameters on the local stress fields were investigated by means of finite element simulation. With an increase in the interference fit size, the occurred position of the maximum stress values on the upper plate faying surface moves away from the hole edge gradually. As the clamping force or friction coefficient increases, the position of larger stress area is changed to the side of bearing load from the transverse direction. The lap geometry of the bolted joint as well as the amplitude of tensile load has apparent impact on the maximum stress value.

  10. An experimental study on variation of thermal fields during the deformation of a compressive en echelon fault set

    Institute of Scientific and Technical Information of China (English)

    LIU Peixun; MA Jin; LIU Liqiang; MA Shengli; CHEN Guoqiang

    2007-01-01

    The temperature variations during deformation of a compressive en echelon fault set in a rock sample were measured by a surface measurement system with multi-point platinum resistance thermometers and an infrared thermal image system. The measurements obtained by the two systems were in agreement with each other, indicating a relationship between temporal-spatial variations of the thermal field and changes of stress and strain. At varied structural positions of the rock sample, the rising of the temperature was different, implying distinct stress distributions at these positions. In the experiment, the deformation process of the sample included three stages: elastic deformation, stick-slip, and rupture. Correspondingly, the variation process of temperature had also three stages, each of which had its own temperature rising profile. And the thermal radiation field showed a similar process. These phenomena mean that the dominant mechanisms of temperature rising in all stages of deformation are different. Experimental results provide a physical basis for the study of current fault activities by using data of satellite infrared images.

  11. Acoustic data analysis and scenario over watch from an aerostat at the NATO SET-153 field experiment

    Science.gov (United States)

    Reiff, Christian; Scanlon, Michael

    2012-06-01

    The purpose of the NATO SET-153 field experiment was to provide an opportunity to demonstrate multiple sensor technologies in an urban environment and determine integration capabilities for future development. The Army Research Laboratory (ARL) experimental aerostat was used primarily as a persistent over watch capability as a substitute for a UAV. Continuous video was recorded on the aerostat and segments of video were captured of the scenarios on the ground that the camera was following manually. Some of the segments showing scenario activities will be presented. The captured pictures and video frames have telemetry in the headers that provides the UTM time and the Inertial Navigation System (INS) GPS location and the inertial roll, pitch, and yaw as well as the camera gimbal pan and tilt angles. The timing is useful to synchronize the images with the scenario events providing activity ground truth. The INS, GPS, and camera gimbal angle values can be used with the acoustic solution for the location of a sound source to determine the relative accuracy of the solution if the camera is pointed at the sound source. This method will be confirmed by the use of a propane cannon whose GPS location is logged. During the field experiment, other interesting acoustic events such as vehicle convoys, platoon level firefights with vehicles using blanks, and a UAV helicopter were recorded and will be presented in a quick analysis.

  12. An analysis of sensitivity of CLIMEX parameters in mapping species potential distribution and the broad-scale changes observed with minor variations in parameters values: an investigation using open-field Solanum lycopersicum and Neoleucinodes elegantalis as an example

    Science.gov (United States)

    da Silva, Ricardo Siqueira; Kumar, Lalit; Shabani, Farzin; Picanço, Marcelo Coutinho

    2017-02-01

    A sensitivity analysis can categorize levels of parameter influence on a model's output. Identifying parameters having the most influence facilitates establishing the best values for parameters of models, providing useful implications in species modelling of crops and associated insect pests. The aim of this study was to quantify the response of species models through a CLIMEX sensitivity analysis. Using open-field Solanum lycopersicum and Neoleucinodes elegantalis distribution records, and 17 fitting parameters, including growth and stress parameters, comparisons were made in model performance by altering one parameter value at a time, in comparison to the best-fit parameter values. Parameters that were found to have a greater effect on the model results are termed "sensitive". Through the use of two species, we show that even when the Ecoclimatic Index has a major change through upward or downward parameter value alterations, the effect on the species is dependent on the selection of suitability categories and regions of modelling. Two parameters were shown to have the greatest sensitivity, dependent on the suitability categories of each species in the study. Results enhance user understanding of which climatic factors had a greater impact on both species distributions in our model, in terms of suitability categories and areas, when parameter values were perturbed by higher or lower values, compared to the best-fit parameter values. Thus, the sensitivity analyses have the potential to provide additional information for end users, in terms of improving management, by identifying the climatic variables that are most sensitive.

  13. Effect of power parameter and induction coil on magnetic field in cold crucible during continuous melting and directional solidification

    Directory of Open Access Journals (Sweden)

    Chen Ruirun

    2012-02-01

    Full Text Available Bottomless electromagnetic cold crucible is a new apparatus for continuous melting and directional solidification; however, improving its power efficiency and optimizing the configuration are important for experiment and production. In this study, a 3-D finite element (FE method based on experimental verification was applied to calculate the magnetic flux density (Bz. The effects of the power parameters and the induction coil on the magnetic field distribution in the cold crucible were investigated. The results show that higher current intensity and lower frequency are beneficial to the increase of Bz at both the segment midpoint and the slit location. The induction coil with racetrack section can induce greater Bz, and a larger gap between the induction coil and the shield ring increases Bz. The mechanism for this effect is also discussed.

  14. Low field magnetic resonance imaging of the lumbar spine: Reliability of qualitative evaluation of disc and muscle parameters

    DEFF Research Database (Denmark)

    Sørensen, Joan Solgaard; Kjaer, Per; Jensen, Tue Secher

    2006-01-01

    for grading lumbar discs were based on the spinal nomenclature of the Combined Task Force and the literature. Consensus in rating was achieved by evaluating 50 MRI examinations in tandem. The remaining 50 examinations were evaluated independently by the observers to determine interobserver agreement and re......PURPOSE: To determine the intra- and interobserver reliability in grading disc and muscle parameters using low-field magnetic resonance imaging (MRI). MATERIAL AND METHODS: MRI scans of 100 subjects representative of the general population were evaluated blindly by two radiologists. Criteria......-evaluated by one of the observers to determine intra-observer agreement. RESULTS: Intra- and interobserver agreement was substantial when grading changes in the lumbar discs. Interobserver agreement was fair to moderate in grading the lumbar muscles, whereas intra-observer agreement was almost perfect. CONCLUSION...

  15. Polarizable Simulations with Second order Interaction Model – force field and software for fast polarizable calculations: Parameters for small model systems and free energy calculations

    Science.gov (United States)

    Kaminski, George A.; Ponomarev, Sergei Y.; Liu, Aibing B.

    2009-01-01

    We are presenting POSSIM (POlarizable Simulations with Second order Interaction Model) – a software package and a set of parameters designed for molecular simulations. The key feature of POSSIM is that the electrostatic polarization is taken into account using a previously introduced fast formalism. This permits cutting computational cost of using the explicit polarization by about an order of magnitude. In this article, parameters for water, methane, ethane, propane, butane, methanol and NMA are introduced. These molecules are viewed as model systems for protein simulations. We have achieved our goal of ca. 0.5 kcal/mol accuracy for gas-phase dimerization energies and no more than 2% deviations in liquid state heats of vaporization and densities. Moreover, free energies of hydration of the polarizable methane, ethane and methanol have been calculated using the statistical perturbation theory. These calculations are a model for calculating protein pKa shifts and ligand binding affinities. The free energies of hydration were found to be 2.12 kcal/mol, 1.80 kcal/mol and −4.95 kcal/mol for methane, ethane and methanol, respectively. The experimentally determined literature values are 1.91 kcal/mol, 1.83 kcal/mol and −5.11 kcal/mol. The POSSIM average error in these absolute free energies of hydration is only about 0.13 kcal/mol. Using the statistical perturbation theory with polarizable force fields is not widespread, and we believe that this work opens road to further development of the POSSIM force field and its applications for obtaining accurate energies in protein-related computer modeling. PMID:20209038

  16. Capacitively-Coupled Resistivity measurements to determine frequency dependent electrical parameters in periglacial environment - theoretical considerations and first field tests.

    Science.gov (United States)

    Przyklenk, A.; Hördt, A.; Radić, T.

    2016-05-01

    Capacitively-Coupled Resistivity (CCR) is conventionally used to emulate DC resistivity measurements and may provide important information about the ice content of material in periglacial areas. The application of CCR theoretically enables the determination of both electrical parameters, i.e. the resistivity and the electrical permittivity, by analyzing magnitude and phase shift spectra. The electrical permittivity may dominate the impedance, especially in periglacial areas or regions of hydrogeological interest. However, previous theoretical work suggested that the phase shift may strongly depend on electrode height above ground, implying that electrode height must be known with great accuracy to determine electrical permittivity. Here, we demonstrate with laboratory test measurements, theoretical modelling and by analysing the Jacobian matrix of the inversion, that the sensitivity towards electrode height is drastically reduced if the electrical permittivity is frequency dependent in a way that is typical for ice. For the fist time, we used a novel broadband CCR device "Chameleon" for a field test located in one of the ridge galleries beneath the crest of Mount Zugspitze. A permanently ice covered bottom of a tunnel was examined. For the inversion of the measured spectra, the frequency dependance of the electrical parameters was parameterized in 3 different ways. A Debye Model for pure ices, a Cole-Cole Model for pure ices and a dual Cole-Cole Model including interfacial water additionally. The frequency-dependent resistivity and permittivity spectra obtained from the inversion, including low and high frequency limits, agree reasonably well with laboratory and field measurements reported in the literature.

  17. Effect of Structure Parameters on Power and Magnetic Field in Electromagnetic Soft-Contact Continuous Casting System

    Institute of Scientific and Technical Information of China (English)

    DENG An-yuan; WANG En-gang; HE Ji-cheng

    2008-01-01

    To design a power source system and mold for electromagnetic soft-contact continuous casting process and to theoretically estimate the heat losses from the charges and the system power, the effect of structure parameters on system power and magnetic flux density distribution was calculated using finite element method. The results show that as for electromagnetic soft-contact continuous casting system with partial-segment type mold, the power consumption is much more than that with a full-segment type mold; about 62% of electric power is dissipated in the mold, and the effective acting range of magnetic field is relatively narrow. Optimizing mold structure is a crucial measure of remarkably reducing mold power consumption and saving electric energy. Increasing slit number, width, and length can remarkably increase the magnetic flux density in the mold and can reduce the electric energy consumption. Among structure parameters, slit number and slit width are relatively more effective to reduce energy consumption. For a round billet electromagnetic continuous casting system with diameter of 178 mm, the reasonable slit number, width, and length are about 24-32, 0.5-1.0 mm, and 160 mm, respectively.

  18. The SEGUE Stellar Parameter Pipeline. III. Comparison with High-Resolution Spectroscopy of SDSS/SEGUE Field Stars

    Energy Technology Data Exchange (ETDEWEB)

    Allende Prieto, C.; Sivarani, T.; Beers, T.C.; Lee, Y.S.; Koesterke, L.; Shetrone, M.; Sneden, C.; Lambert, D.L.; Wilhelm, R.; Rockosi, C.M.; Lai, D.

    2007-10-01

    The authors report high-resolution spectroscopy of 125 field stars previously observed as part of the Sloan Digital Sky Survey and its program for Galactic studies, the Sloan Extension for Galactic Understanding and Exploration (SEGUE). These spectra are used to measure radial velocities and to derive atmospheric parameters, which they compare with those reported by the SEGUE Stellar Parameter Pipeline (SSPP). The SSPP obtains estimates of these quantities based on SDSS ugriz photometry and low-resolution (R {approx} 2000) spectroscopy. For F- and G-type stars observed with high signal-to-noise ratios (S/N), they empirically determine the typical random uncertainties in the radial velocities, effective temperatures, surface gravities, and metallicities delivered by the SSPP to be 2.4 km s{sup -1}, 130 K (2.2%), 0.21 dex, and 0.11 dex, respectively, with systematic uncertainties of a similar magnitude in the effective temperatures and metallicities. They estimate random errors for lower S/N spectra based on numerical simulations.

  19. Peaks in the cosmological density field: parameter constraints from 2dF Galaxy Redshift Survey data

    CERN Document Server

    De, S

    2009-01-01

    We use the number density of peaks in the smoothed cosmological density field taken from the 2dF Galaxy Redshift Survey to constrain parameters related to the power spectrum of mass fluctuations, n (the spectral index), dn/d(lnk) (rolling in the spectral index), and the neutrino mass, m_nu. In a companion paper we use N-body simulations to study how the peak density responds to changes in the power spectrum, the presence of redshift distortions and the relationship between galaxies and dark matter halos. In the present paper we make measurements of the peak density from 2dF Galaxy Redshift Survey data, for a range of smoothing filter scales from 4-33 h^-1 Mpc. We use these measurements to constrain the cosmological parameters, finding n=1.36 (+0.75)(-0.64), m_nu < 1.76 eV, dn/d(lnk)=-0.012 (+0.192)(-0.208), at the 68 % confidence level, where m_nu is the total mass of three massive neutrinos. At 95% confidence we find m_nu< 2.48 eV. These measurements represent an alternative way to constrain cosmologic...

  20. Some feature of interpretation of tension single pulsed electromagnetic field of the Earth to create the model parameter fields physical properties

    Directory of Open Access Journals (Sweden)

    Mokritskaya T.P.

    2014-12-01

    Full Text Available Stochastic analysis of the results of different methods of obtaining and processing of information allows us to solve problems on a qualitatively different level. This is important when creating complex earth models and fields of its parameters, particularly the physical properties. Application of remote sensing methods (geophysical investigations with the registration of a single pulse intensity of the electromagnetic field of the Earth (EIEMPZ seismic profiling, is expanding. Interesting results of the joint interpretation of the results of geophysical and laboratory studies of physical soil. Interesting results of the joint interpretation of the results of geophysical and laboratory studies of physical soil. For the first time a methodology for assessing the state of the soil [3] applied for a joint interpretation of materials determine the field strength EMPZ, seismic profiling, and laboratory techniques. This has allowed to characterize the state of the geological environment and to build a model of inhomogeneous density distribution of fractured rocks at depth. In this paper we made a mathematical analysis of the results of research and talus deposits eluvial clay Taurian series, studied at one of the construction sites southern coast at a depth of 12.0 -25.0 m. Methods of statistical analysis, assessment of homogeneity and symmetrically distributed, rank correlation and multiple regression analysis described in [3]. The analysis of the spatial distribution of areas extrem value of EMPZ, heterogeneity of seismic rigidity. Statistical characteristics of indicators of physical properties reflect the genetic characteristics of the formation and the current state of silty-clay sediments of different genesis.It is proved that the regression model can be applied to interpret the state of the array in the construction of geodynamic model. It is established that the creation of forward-looking (dynamic models for the distribution of the physical

  1. Analysis of small field percent depth dose and profiles: Comparison of measurements with various detectors and effects of detector orientation with different jaw settings

    Directory of Open Access Journals (Sweden)

    Henry Finlay Godson

    2016-01-01

    Full Text Available The advent of modern technologies in radiotherapy poses an increased challenge in the determination of dosimetric parameters of small fields that exhibit a high degree of uncertainty. Percent depth dose and beam profiles were acquired using different detectors in two different orientations. The parameters such as relative surface dose (DS, depth of dose maximum (Dmax, percentage dose at 10 cm (D10, penumbral width, flatness, and symmetry were evaluated with different detectors. The dosimetric data were acquired for fields defined by jaws alone, multileaf collimator (MLC alone, and by MLC while the jaws were positioned at 0, 0.25, 0.5, and 1.0 cm away from MLC leaf-end using a Varian linear accelerator with 6 MV photon beam. The accuracy in the measurement of dosimetric parameters with various detectors for three different field definitions was evaluated. The relative DS(38.1% with photon field diode in parallel orientation was higher than electron field diode (EFD (27.9% values for 1 cm ×1 cm field. An overestimation of 5.7% and 8.6% in D10depth were observed for 1 cm ×1 cm field with RK ion chamber in parallel and perpendicular orientation, respectively, for the fields defined by MLC while jaw positioned at the edge of the field when compared to EFD values in parallel orientation. For this field definition, the in-plane penumbral widths obtained with ion chamber in parallel and perpendicular orientation were 3.9 mm, 5.6 mm for 1 cm ×1 cm field, respectively. Among all detectors used in the study, the unshielded diodes were found to be an appropriate choice of detector for the measurement of beam parameters in small fields.

  2. Revisiting the droplet simulation approach to derive force-field parameters for water on molybdenum disulfide from wetting angle measurements

    Science.gov (United States)

    Leroy, Frédéric

    2016-10-01

    Owing to its peculiar electronic properties, molybdenum disulfide (MoS2) has been the subject of a growing number of studies in the recent years. In applications, this material and other transition metal dichalcogenides (TMDs) may have to interact with a liquid or polymer phase as well as solutions of biomolecules. It is therefore of primary importance to understand the wetting and adhesion properties of TMDs. Starting from existing models, we derive Lennard-Jones parameters for the interaction between water and the basal plane of MoS2 that are consistent with recent wetting experiments. Molecular dynamics simulations indicate that a stack of only two MoS2 monolayers is necessary to capture the wetting behavior of bulk MoS2. It is found that the Coulomb interaction between water and monolayer and bilayer MoS2 plays no role in the related interfacial thermodynamics. Calculations with the optimized parameters show that the depth of the well of the interaction potential between water and bulk MoS2 is of the order of 8.2 kJ/mol. Such a value is comparable with what was found for graphite and consistent with the fact that the wetting angles of water on graphite and MoS2 are almost equal. The derivation of the force-field parameters is performed using a methodology which, contrary to previous studies, makes a consistent use of droplet calculations. The results of our work should find application in further simulation studies on the wetting behavior of TMDs and other dispersive materials.

  3. Teachers' Perceptions of Their Mentoring Role in Three Different Clinical Settings: Student Teaching, Early Field Experiences, and Entry Year Teaching

    Science.gov (United States)

    Gut, Dianne M.; Beam, Pamela C.; Henning, John E.; Cochran, Deborah C.; Knight, Rhonda Talford

    2014-01-01

    The purpose of this study was to determine the differences in mentoring across three different clinical settings: student teaching, early field experiences, and entry year teachers. Eighteen teachers with mentoring experience in all three clinical settings were selected and interviewed. The teachers' expectations for teacher development,…

  4. Teachers' Perceptions of Their Mentoring Role in Three Different Clinical Settings: Student Teaching, Early Field Experiences, and Entry Year Teaching

    Science.gov (United States)

    Gut, Dianne M.; Beam, Pamela C.; Henning, John E.; Cochran, Deborah C.; Knight, Rhonda Talford

    2014-01-01

    The purpose of this study was to determine the differences in mentoring across three different clinical settings: student teaching, early field experiences, and entry year teachers. Eighteen teachers with mentoring experience in all three clinical settings were selected and interviewed. The teachers' expectations for teacher development,…

  5. Influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium

    Energy Technology Data Exchange (ETDEWEB)

    Ostrovskaya, G. V., E-mail: galya-ostr@mail.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Markov, V. S.; Frank, A. G., E-mail: annfrank@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2016-01-15

    The influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium plasma in 2D and 3D magnetic configurations with X-type singular lines is studied by the methods of holographic interferometry and magnetic measurements. Significant differences in the structures of plasma and current sheets formed at close parameters of the initial plasma and similar configurations of the initial magnetic fields are revealed.

  6. Quality assessment of fluorodeoxyglucose positron emission tomography imaging in clinical setting: definition of standard quality control parameters for patients treated for lymphoma.

    Science.gov (United States)

    Retif, Paul; Jegouic, Claude; Slosman, Daniel O

    2011-09-01

    We designed standard parameters for quality controls (QCs) of F-fluorodeoxyglucose positron emission tomography (FDG PET) images in the clinical setting, and validated them in both cross-sectional and longitudinal cohorts of patients with lymphoma under treatment. The procedure is based on the measurement of mean standardized uptake value (SUV mean) in three specific regions of interest drawn within pulmonary, liver, and bone tissues [reference (Ref)]. Intraobserver and interobserver reproducibility [percentage of coefficient of variation (CV%)] were calculated using PET scans of healthy participants. Cross-sectional interpatient QCs were defined as the 95% ranges of normal values of Ref-SUV mean. Transversal QCs were applied on PET scans of patients treated for lymphoma (n=378) looking at Ref-SUV mean out of range. Longitudinal intrapatient QCs were defined as the 95% limits of the SUV mean variation between two consecutive scans (ΔSUV limits). Longitudinal QCs were applied in a group of 94 pairs of consecutive PET scans under treatment for lymphoma looking at patients having Ref-ΔSUV limits out of range. Intraobserver CV% remained below 3%, whereas interobserver CV% was a maximum of 5.3%. Both in transversal and longitudinal cohorts of patients treated for lymphoma, none of the PET scans simultaneously showed the three Ref-SUV mean out of range. Similar results were obtained with ΔSUV limits. Situations in which these limits were exeeded were associated with a recent history of acute infectious pulmonary disease (lung tissues) and granulocytes colony-stimulating factors concomitant treatment and stimulation of bone marrow (bone tissues). A standardized and reproducible FDG PET QC protocol using SUV mean measurements using three tissues of Ref was validated, and may be applied in the clinical setting or in a clinical trial.

  7. Linking hydropedology and ecosystem services: differential controls of surface field saturated hydraulic conductivity in a volcanic setting in central Mexico

    Directory of Open Access Journals (Sweden)

    A. Gómez-Tagle

    2009-03-01

    Full Text Available In this study the variation of field saturated soil hydraulic conductivity (Kfs as key control variable and descriptor of infiltration was examined by means of a constant head single ring infiltrometer. The study took place in five coverage types and land uses in a volcanic setting in central Mexico. The tested hypothesis was that there exist a positive relationship between plant cover and surface Kfs for the study area. The examined coverage types included; Second growth pine-oak forest, pasture land, fallow land, gully and Cupresus afforestation. Results indicate that Kfs did not depend exclusively of plant cover; it was related to surface horizontal expression of the unburied soil horizons and linked to land use history. Therefore the Kfs measured at a certain location did not depend exclusively of the actual land use, it was also influenced by soil bioturbation linked to plant succession patterns and land use management practices history. The hypothesis accounts partially the variation between sites. Kfs under dense plant cover at the Cupresus afforestation was statistically equal to that measured at the fallow land or the gully sites, while second growth pine-oak forest Kfs figures were over an order of magnitude higher than the rest of the coverage types. The results suggest the relevance of unburied soil horizons in the soil hydrologic response when present at the surface. Under these conditions loosing surface soil horizons due to erosion, not only fertility is lost, but environmental services generation potential. A conceptual model within the hydropedological approach is proposed. It explains the possible controls of Kfs, for this volcanic setting. Land use history driven erosion plays a decisive role in subsurface horizon presence at the surface and soil matrix characteristic determination, while plant succession patterns seem to be strongly linked to soil bioturbation and

  8. Evaluation of hormonal change, biochemical parameters, and histopathological status of uterus in rats exposed to 50-Hz electromagnetic field.

    Science.gov (United States)

    Aydin, M; Cevik, A; Kandemir, F M; Yuksel, M; Apaydin, A M

    2009-04-01

    This study investigates the effects of the electromagnetic field (EMF) resulting from the 170 kV high-voltage power lines on hormonal status, on progesterone and 17-beta estradiol levels, and on morphology of the uterus and ovaries associated with biochemical parameters of adult Wistar female rats. The rats were assigned to experimental (21) and control groups (7). The rats in the experimental group were housed in a wooden barn with 7.5 m vertical distance to the power line. Groups 1, 2, and 3 were exposed continuously (24 h) to electric-electromagnetic fields (ELF-EMFs) (48.21 +/- 1.58 mG) for 1, 2, and 3 months, respectively. The rats of group 4 served as the control and were placed in laboratory conditions (The average value of the ELF was 0.75 +/- 0.05 V/m. The value of the EMF was calculated to be 0.48 +/- 0.05 mG.). Significant (P glutathione and malondialdehyde levels. It is concluded that exposure to the ELF-EMFs for different time periods produced significant decreases in plasma catalase activities in the 3-month exposure groups but no effects on progesterone level, on 17-beta estradiol level, or on the morphology and weight of uterus and ovaries.

  9. LOW-FREQUENCY LOW INTENSITY MAGNETIC FIELD (50 Hz; 2,7 mT INFLUENCES ON HEMATOLOGICAL PARAMETERS FOLLOWING CHEMICAL SYMPATHECTOMY IN WISTAR RATS

    Directory of Open Access Journals (Sweden)

    Calin Maniu

    2007-08-01

    hydroxydopamine infusion with 25 mg/kg i.p. desipramine (Sigma to protect noradrenergic projections. 12 days after the operation, the hematological parameters (the total number of erythrocytes, hematocrit and hemoglobin level were evaluated. The sympathectomy-induced severe reduction in hematological parameters under low-frequency low intensity magnetic field exposure.

  10. Grain yield losses in yellow-rusted durum wheat estimated using digital and conventional parameters under field conditions

    Institute of Scientific and Technical Information of China (English)

    Omar; Vergara-Diaz; Shawn; C.Kefauver; Abdelhalim; Elazab; Maria; Teresa; Nieto-Taladriz; José; Luis; Araus

    2015-01-01

    The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen(Warrior/Ambition),against which the present cultivated wheat varieties have no resistance, appeared and spread rapidly. It threatens cereal production in most of Europe. The search for sources of resistance to this strain is proposed as the most efficient and safe solution to ensure high grain production. This will be helped by the development of high performance and low cost techniques for field phenotyping. In this study we analyzed vegetation indices in the Red,Green, Blue(RGB) images of crop canopies under field conditions. We evaluated their accuracy in predicting grain yield and assessing disease severity in comparison to other field measurements including the Normalized Difference Vegetation Index(NDVI), leaf chlorophyll content, stomatal conductance, and canopy temperature. We also discuss yield components and agronomic parameters in relation to grain yield and disease severity.RGB-based indices proved to be accurate predictors of grain yield and grain yield losses associated with yellow rust(R2= 0.581 and R2= 0.536, respectively), far surpassing the predictive ability of NDVI(R2= 0.118 and R2= 0.128, respectively). In comparison to potential yield, we found the presence of disease to be correlated with reductions in the number of grains per spike, grains per square meter, kernel weight and harvest index. Grain yield losses in the presence of yellow rust were also greater in later heading varieties. The combination of RGB-based indices and days to heading together explained 70.9% of the variability in grain yield and 62.7% of the yield losses.

  11. Grain yield losses in yellow-rusted durum wheat estimated using digital and conventional parameters under field conditions

    Institute of Scientific and Technical Information of China (English)

    Omar Vergara-Diaz; Shawn C. Kefauver; Abdelhalim Elazab; Maria Teresa Nieto-Taladriz; José Luis Araus

    2015-01-01

    The biotrophic fungus Puccinia striiformis f. sp. tritici is the causal agent of the yellow rust in wheat. Between the years 2010–2013 a new strain of this pathogen (Warrior/Ambition), against which the present cultivated wheat varieties have no resistance, appeared and spread rapidly. It threatens cereal production in most of Europe. The search for sources of resistance to this strain is proposed as the most efficient and safe solution to ensure high grain production. This will be helped by the development of high performance and low cost techniques for field phenotyping. In this study we analyzed vegetation indices in the Red, Green, Blue (RGB) images of crop canopies under field conditions. We evaluated their accuracy in predicting grain yield and assessing disease severity in comparison to other field measurements including the Normalized Difference Vegetation Index (NDVI), leaf chlorophyll content, stomatal conductance, and canopy temperature. We also discuss yield components and agronomic parameters in relation to grain yield and disease severity. RGB-based indices proved to be accurate predictors of grain yield and grain yield losses associated with yellow rust (R2=0.581 and R2=0.536, respectively), far surpassing the predictive ability of NDVI (R2=0.118 and R2=0.128, respectively). In comparison to potential yield, we found the presence of disease to be correlated with reductions in the number of grains per spike, grains per square meter, kernel weight and harvest index. Grain yield losses in the presence of yellow rust were also greater in later heading varieties. The combination of RGB-based indices and days to heading together explained 70.9% of the variability in grain yield and 62.7%of the yield losses.

  12. SpaGrOW—A Derivative-Free Optimization Scheme for Intermolecular Force Field Parameters Based on Sparse Grid Methods

    Directory of Open Access Journals (Sweden)

    Dirk Reith

    2013-09-01

    Full Text Available Molecular modeling is an important subdomain in the field of computational modeling, regarding both scientific and industrial applications. This is because computer simulations on a molecular level are a virtuous instrument to study the impact of microscopic on macroscopic phenomena. Accurate molecular models are indispensable for such simulations in order to predict physical target observables, like density, pressure, diffusion coefficients or energetic properties, quantitatively over a wide range of temperatures. Thereby, molecular interactions are described mathematically by force fields. The mathematical description includes parameters for both intramolecular and intermolecular interactions. While intramolecular force field parameters can be determined by quantum mechanics, the parameterization of the intermolecular part is often tedious. Recently, an empirical procedure, based on the minimization of a loss function between simulated and experimental physical properties, was published by the authors. Thereby, efficient gradient-based numerical optimization algorithms were used. However, empirical force field optimization is inhibited by the two following central issues appearing in molecular simulations: firstly, they are extremely time-consuming, even on modern and high-performance computer clusters, and secondly, simulation data is affected by statistical noise. The latter provokes the fact that an accurate computation of gradients or Hessians is nearly impossible close to a local or global minimum, mainly because the loss function is flat. Therefore, the question arises of whether to apply a derivative-free method approximating the loss function by an appropriate model function. In this paper, a new Sparse Grid-based Optimization Workflow (SpaGrOW is presented, which accomplishes this task robustly and, at the same time, keeps the number of time-consuming simulations relatively small. This is achieved by an efficient sampling procedure

  13. The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis. I. Homogeneous set of atmospheric parameters

    Science.gov (United States)

    Mashonkina, L.; Jablonka, P.; Pakhomov, Yu.; Sitnova, T.; North, P.

    2017-08-01

    We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Boötes I, Ursa Major II, and Leo IV. We also deliver a Milky Way (MW) comparison sample of giant stars covering the - 4 - 3.5 regime, the Ti i/Ti ii ionisation equilibrium is fulfilled in the NLTE calculations. In the log g - Teff plane, all the stars sit on the giant branch of the evolutionary tracks corresponding to [Fe/H] = - 2 to - 4, in line with their metallicities. For some of the most metal-poor stars of our sample, we achieve relatively inconsistent NLTE abundances from the two ionisation stages for both iron and titanium. We suggest that this is a consequence of the uncertainty in the Teff-colour relation at those metallicities. The results of this work provide the basis for a detailed abundance analysis presented in a companion paper. Tables A.1 and A.2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A129

  14. Testing Allele Transmission of an SNP Set Using a Family-Based Generalized Genetic Random Field Method.

    Science.gov (United States)

    Li, Ming; Li, Jingyun; He, Zihuai; Lu, Qing; Witte, John S; Macleod, Stewart L; Hobbs, Charlotte A; Cleves, Mario A

    2016-05-01

    Family-based association studies are commonly used in genetic research because they can be robust to population stratification (PS). Recent advances in high-throughput genotyping technologies have produced a massive amount of genomic data in family-based studies. However, current family-based association tests are mainly focused on evaluating individual variants one at a time. In this article, we introduce a family-based generalized genetic random field (FB-GGRF) method to test the joint association between a set of autosomal SNPs (i.e., single-nucleotide polymorphisms) and disease phenotypes. The proposed method is a natural extension of a recently developed GGRF method for population-based case-control studies. It models offspring genotypes conditional on parental genotypes, and, thus, is robust to PS. Through simulations, we presented that under various disease scenarios the FB-GGRF has improved power over a commonly used family-based sequence kernel association test (FB-SKAT). Further, similar to GGRF, the proposed FB-GGRF method is asymptotically well-behaved, and does not require empirical adjustment of the type I error rates. We illustrate the proposed method using a study of congenital heart defects with family trios from the National Birth Defects Prevention Study (NBDPS).

  15. The visual light field in paintings of Museum Prinsenhof: comparing settings in empty space and on objects

    Science.gov (United States)

    Kartashova, Tatiana; de Ridder, Huib; te Pas, Susan F.; Schoemaker, Marga; Pont, Sylvia C.

    2015-03-01

    The aim of this study was to investigate whether inferences of light in the empty space of a painting and on objects in that painting are congruent with each other. We conducted an experiment in which we tested the perception of light qualities (direction, intensity of directed and ambient components) for two conditions: a) for a position in empty space in a painting and b) on the convex object that was replaced by the probe in the first condition. We found that the consistency of directional settings both between conditions and within paintings is highly dependent on painting content, specifically on the number of qualitatively different light zones[1] in a scene. For uniform lighting observers are very consistent, but when there are two or more light zones present in a painting the individual differences become prominent. We discuss several possible explanations of such results, the most plausible of which is that human observers are blind to complex features of a light field2.

  16. Improved Variable Star Search in Large Photometric Data Sets -- New Variables in CoRoT Field LRa02 Detected ba BEST II

    CERN Document Server

    Fruth, T; Cabrera, J; Chini, R; Csizmadia, Sz; Eigmüller, P; Erikson, A; Kirste, S; Lemke, R; Murphy, M; Pasternacki, T; Rauer, H; Titz-Weider, R; 10.1088/0004-6256/143/6/140

    2012-01-01

    The CoRoT field LRa02 has been observed with the Berlin Exoplanet Search Telescope II (BEST II) during the southern summer 2007/2008. A first analysis of stellar variability led to the publication of 345 newly discovered variable stars. Now, a deeper analysis of this data set was used to optimize the variability search procedure. Several methods and parameters have been tested in order to improve the selection process compared to the widely used J index for variability ranking. This paper describes an empirical approach to treat systematic trends in photometric data based upon the analysis of variance statistics that can significantly decrease the rate of false detections. Finally, the process of reanalysis and method improvement has virtually doubled the number of variable stars compared to the first analysis by Kabath et al. A supplementary catalog of 272 previously unknown periodic variables plus 52 stars with suspected variability is presented. Improved ephemerides are given for 19 known variables in the ...

  17. Set up of a method for the adjustment of resonance parameters on integral experiments; Mise au point d`une methode d`ajustement des parametres de resonance sur des experiences integrales

    Energy Technology Data Exchange (ETDEWEB)

    Blaise, P.

    1996-12-18

    Resonance parameters for actinides play a significant role in the neutronic characteristics of all reactor types. All the major integral parameters strongly depend on the nuclear data of the isotopes in the resonance-energy regions.The author sets up a method for the adjustment of resonance parameters taking into account the self-shielding effects and restricting the cross section deconvolution problem to a limited energy region. (N.T.).

  18. Influence of the substrate on maar-diatreme volcanoes — An example of a mixed setting from the Pali Aike volcanic field, Argentina

    Science.gov (United States)

    Ross, Pierre-Simon; Delpit, Séverine; Haller, Miguel J.; Németh, Károly; Corbella, Hugo

    2011-04-01

    The morphologic parameters, pyroclastic deposits and evolution of maar-diatreme volcanoes are affected by the type of environment in which they are emplaced. End-member cases are a hard substrate (rocks) and a soft substrate (unconsolidated volcaniclastic or sedimentary deposits). In this paper, we present an example of a volcanic complex emplaced in a mixed hard-soft setting from the Pali Aike volcanic field (PAVF) near the Argentina-Chile border. The Plio-Pleistocene PAVF is an alkaline, mafic, back-arc monogenetic field which contains over 100 phreatomagmatic volcanoes. The studied volcanic complex contains two large coalescent maars overlain by scoria and spatter. The 1.4 × 1.3 km East Maar has better exposures than the shallower, 1.9 km-wide West Maar and seems to have been less modified by post-eruptive processes. The tephra rim of the East Maar was studied in detail and we infer it was produced mostly by base surges from phreatomagmatic eruption columns, with rare instances of intercalated scoria fall layers. Based on regional information, the general pre-maar stratigraphy is dominated by sedimentary and volcaniclastic rocks of the Magallanes Basin, including a thick poorly consolidated upper unit dating from the Miocene. These are overlain by Plio-Pleistocene fluvio-glacial deposits and PAVF lavas, some of which are exposed in the East Maar just below the phreatomagmatic deposits. All of these units are represented as lithic clasts in the tephra rim of the East Maar, the most abundant being the clasts from the earlier basaltic lavas and rock fragments derived from the glacial deposits. There is no specific evidence for a deep diatreme under the East Maar, and in this particular case, the mixed environment seems to have produced a maar-diatreme volcano typical of a soft substrate.

  19. Topologies, structures and parameter files for lipid simulations in GROMACS with the OPLS-aa force field: DPPC, POPC, DOPC, PEPC, and cholesterol

    Directory of Open Access Journals (Sweden)

    Waldemar Kulig

    2015-12-01

    Full Text Available In this data article we provide topologies and force field parameters files for molecular dynamics simulations of lipids in the OPLS-aa force field using the GROMACS package. This is the first systematic parameterization of lipid molecules in this force field. Topologies are provided for four phosphatidylcholines: saturated DPPC, mono-cis unsaturated POPC and DOPC, and mono-trans unsaturated PEPC. Parameterization of the phosphatidylcholines was achieved in two steps: first, we supplemented the OPLS force field parameters for DPPC with new parameters for torsion angles and van der Waals parameters for the carbon and hydrogen atoms in the acyl chains, as well as new partial atomic charges and parameters for torsion angles in the phosphatidylcholine and glycerol moieties [1]. Next, we derived parameters for the cis and trans double bonds and the neighboring them single bonds [2]. Additionally, we provide GROMACS input files with parameters describing simulation conditions (md.mdp, which are strongly recommended to be used with these lipids models. The data are associated with the research article “Cis and trans unsaturated phosphatidylcholine bilayers: a molecular dynamics simulation study” [2] and provided as supporting materials.

  20. Calculation of reactivities using ionization chamber currents with different sets of kinetic parameters for reduced scram system efficiency in the VVER-1000 of the third unit of the Kalinin nuclear power plant at the stage of physical start-up

    Energy Technology Data Exchange (ETDEWEB)

    Zizin, M. N., E-mail: zizin@adis.vver.kiae.ru [Russian Research Centre Kurchatov Institute (Russian Federation); Zizina, S. N.; Kryakvin, L. V.; Pitilimov, V. A.; Tereshonok, V. A. [JSC VNIIAES (Russian Federation)

    2011-12-15

    The effectiveness of the VVER-1000 reactor scram system is analyzed using ionization chamber currents with different sets of kinetic parameters with allowance for the isotopic composition in the calculation of these parameters. The most 'correct, aesthetically acceptable' results are obtained using the eight-group constants of the ROSFOND (BNAB-RF) library. The difference between the maximum and minimum values of the scram system effectiveness calculated with different sets of kinetic parameters slightly exceeds 2{beta}. The problems of introducing corrections due to spatial effects are not considered in this study.