Political Dynamics Affected by Turncoats

NASA Astrophysics Data System (ADS)

Di Salvo, Rosa; Gorgone, Matteo; Oliveri, Francesco

2017-11-01

An operatorial theoretical model based on raising and lowering fermionic operators for the description of the dynamics of a political system consisting of macro-groups affected by turncoat-like behaviors is presented. The analysis of the party system dynamics is carried on by combining the action of a suitable quadratic Hamiltonian operator with specific rules (depending on the variations of the mean values of the observables) able to adjust periodically the conservative model to the political environment.

Coherent Change Detection: Theoretical Description and Experimental Results

DTIC Science & Technology

2006-08-01

Elementary Linear Algebra With Applications. John Wiley and sons, 1987. 49. J. Lee, K. W. Hoppel, and A. R. Miller, “Intensity and phase statistics of...kx, ky, kz = 0). The nature of the image recovered by the PFA may be ascertained by considering a scene consisting of an elementary point scatter...registered image pair estimate any dominant relative linear phase term between the primary image and the resampled repeat pass image and remove this

Nanopore Current Oscillations: Nonlinear Dynamics on the Nanoscale.

PubMed

Hyland, Brittany; Siwy, Zuzanna S; Martens, Craig C

2015-05-21

In this Letter, we describe theoretical modeling of an experimentally realized nanoscale system that exhibits the general universal behavior of a nonlinear dynamical system. In particular, we consider the description of voltage-induced current fluctuations through a single nanopore from the perspective of nonlinear dynamics. We briefly review the experimental system and its behavior observed and then present a simple phenomenological nonlinear model that reproduces the qualitative behavior of the experimental data. The model consists of a two-dimensional deterministic nonlinear bistable oscillator experiencing both dissipation and random noise. The multidimensionality of the model and the interplay between deterministic and stochastic forces are both required to obtain a qualitatively accurate description of the physical system.

The viability of phantom dark energy: A review

NASA Astrophysics Data System (ADS)

Ludwick, Kevin J.

2017-09-01

In this brief review, we examine the theoretical consistency and viability of phantom dark energy. Almost all data sets from cosmological probes are compatible with the dark energy of the phantom variety (i.e. equation-of-state parameter w < -1) and may even favor evolving dark energy, and since we expect every physical entity to have some kind of field description, we set out to examine the case for phantom dark energy as a field theory. We discuss the many attempts at frameworks that may mitigate and eliminate theoretical pathologies associated with phantom dark energy. We also examine frameworks that provide an apparent measurement w < -1 while avoiding the need for a phantom field theory.

Description and Recognition of the Concept of Social Capital in Higher Education System

ERIC Educational Resources Information Center

Tonkaboni, Forouzan; Yousefy, Alireza; Keshtiaray, Narges

2013-01-01

The current research is intended to describe and recognize the concept of social capital in higher education based on theoretical method in a descriptive-analytical approach. Description and Recognition of the data, gathered from theoretical and experimental studies, indicated that social capital is one of the most important indices for…

Spin localization, magnetic ordering, and electronic properties of strongly correlated Ln2O3 sesquioxides (Ln=La, Ce, Pr, Nd)

NASA Astrophysics Data System (ADS)

El-Kelany, Kh. E.; Ravoux, C.; Desmarais, J. K.; Cortona, P.; Pan, Y.; Tse, J. S.; Erba, A.

2018-06-01

Lanthanide sesquioxides are strongly correlated materials characterized by highly localized unpaired electrons in the f band. Theoretical descriptions based on standard density functional theory (DFT) formulations are known to be unable to correctly describe their peculiar electronic and magnetic features. In this study, electronic and magnetic properties of the first four lanthanide sesquioxides in the series are characterized through a reliable description of spin localization as ensured by hybrid functionals of the DFT, which include a fraction of nonlocal Fock exchange. Because of the high localization of the f electrons, multiple metastable electronic configurations are possible for their ground state depending on the specific partial occupation of the f orbitals: the most stable configuration is here found and characterized for all systems. Magnetic ordering is explicitly investigated, and the higher stability of an antiferromagnetic configuration with respect to the ferromagnetic one is predicted. The critical role of the fraction of exchange on the description of their electronic properties (notably, on spin localization and on the electronic band gap) is addressed. In particular, a recently proposed theoretical approach based on a self-consistent definition—through the material dielectric response—of the optimal fraction of exchange in hybrid functionals is applied to these strongly correlated materials.

Characterising an implementation intervention in terms of behaviour change techniques and theory: the 'Sepsis Six' clinical care bundle.

PubMed

Steinmo, Siri; Fuller, Christopher; Stone, Sheldon P; Michie, Susan

2015-08-08

Sepsis is a major cause of death from infection, with a mortality rate of 36 %. This can be halved by implementing the 'Sepsis Six' evidence-based care bundle within 1 h of presentation. A UK audit has shown that median implementation rates are 27-47 % and interventions to improve this have demonstrated minimal effects. In order to develop more effective implementation interventions, it is helpful to obtain detailed characterisations of current interventions and to draw on behavioural theory to identify mechanisms of change. The aim of this study was to illustrate this process by using the Behaviour Change Wheel; Behaviour Change Technique (BCT) Taxonomy; Capability, Opportunity, Motivation model of behaviour; and Theoretical Domains Framework to characterise the content and theoretical mechanisms of action of an existing intervention to implement Sepsis Six. Data came from documentary, interview and observational analyses of intervention delivery in several wards of a UK hospital. A broad description of the intervention was created using the Template for Intervention Description and Replication framework. Content was specified in terms of (i) component BCTs using the BCT Taxonomy and (ii) intervention functions using the Behaviour Change Wheel. Mechanisms of action were specified using the Capability, Opportunity, Motivation model and the Theoretical Domains Framework. The intervention consisted of 19 BCTs, with eight identified using all three data sources. The BCTs were delivered via seven functions of the Behaviour Change Wheel, with four ('education', 'enablement', 'training' and 'environmental restructuring') supported by the three data sources. The most frequent mechanisms of action were reflective motivation (especially 'beliefs about consequences' and 'beliefs about capabilities') and psychological capability (especially 'knowledge'). The intervention consisted of a wide range of BCTs targeting a wide range of mechanisms of action. This study demonstrates the utility of the Behaviour Change Wheel, the BCT Taxonomy and the Theoretical Domains Framework, tools recognised for providing guidance for intervention design, for characterising an existing intervention to implement evidence-based care.

The self-consistent multiparticle-multihole configuration mixing. Motivations, state of the art and perspectives

NASA Astrophysics Data System (ADS)

Pillet, N.; Robin, C.; Dupuis, M.; Hupin, G.; Berger, J.-F.

2017-03-01

The main objective of this paper is to review the state of the art of the multiparticle-multihole configuration mixing approach which was proposed and implemented using the Gogny interaction ˜ 10 years ago. Various theoretical aspects are re-analyzed when a Hamiltonian description is chosen: the link with exact many-body theories, the impact of truncations in the multiconfigurational space, the importance of defining single-particle orbitals which are consistent with the correlations introduced in the many-body wave function, the role of the self-consistency, and more practically the numerical convergence algorithm. Several applications done with the phenomenological effective Gogny interaction are discussed. Finally, future directions to extend and generalize the method are discussed.

A biologically consistent hierarchical framework for self-referencing survivalist computation

NASA Astrophysics Data System (ADS)

Cottam, Ron; Ranson, Willy; Vounckx, Roger

2000-05-01

Extensively scaled formally rational hardware and software are indirectly fallible, at the very least through temporal restrictions on the evaluation of their correctness. In addition, the apparent inability of formal rationality to successfully describe living systems as anything other than inanimate structures suggests that the development of self-referencing computational machines will require a different approach. There is currently a strong movement towards the adoption of semiotics as a descriptive medium in theoretical biology. We present a related computational semiosic construction (1, 2) consistent with evolutionary hierarchical emergence (3), which may serve as a framework for implementing anticipatory-oriented survivalist processing in real environments.

Localized excitations in hydrogen-bonded molecular crystals

NASA Astrophysics Data System (ADS)

Alexander, D. M.; Krumhansl, J. A.

1986-05-01

Localized excitations analogous to the small Holstein polaron, to localized modes in alkali halides, and to localized excitonic states, are postulated for a set of internal vibrational modes in crystalline acetanilide. The theoretical framework in which one can describe the characteristics of the ir and Raman spectroscopy peaks associated with these localized states is adequately provided by the Davydov model (formally equivalent to the Holstein polaron model). The possible low-lying excitations arising from this model are determined using a variational approach. Hence, the contribution to the spectral function due to each type of excitation can be calculated. The internal modes of chief concern here are the amide-I (CO stretch) and the N-H stretch modes for which we demonstrate consistency of the theoretical model with the available ir data. Past theoretical approaches will be discussed and reasons why one should prefer one description over another will be examined.

Fault-tolerant, high-level quantum circuits: form, compilation and description

NASA Astrophysics Data System (ADS)

Paler, Alexandru; Polian, Ilia; Nemoto, Kae; Devitt, Simon J.

2017-06-01

Fault-tolerant quantum error correction is a necessity for any quantum architecture destined to tackle interesting, large-scale problems. Its theoretical formalism has been well founded for nearly two decades. However, we still do not have an appropriate compiler to produce a fault-tolerant, error-corrected description from a higher-level quantum circuit for state-of the-art hardware models. There are many technical hurdles, including dynamic circuit constructions that occur when constructing fault-tolerant circuits with commonly used error correcting codes. We introduce a package that converts high-level quantum circuits consisting of commonly used gates into a form employing all decompositions and ancillary protocols needed for fault-tolerant error correction. We call this form the (I)initialisation, (C)NOT, (M)measurement form (ICM) and consists of an initialisation layer of qubits into one of four distinct states, a massive, deterministic array of CNOT operations and a series of time-ordered X- or Z-basis measurements. The form allows a more flexible approach towards circuit optimisation. At the same time, the package outputs a standard circuit or a canonical geometric description which is a necessity for operating current state-of-the-art hardware architectures using topological quantum codes.

Charging-induced asymmetry in molecular conductors

NASA Astrophysics Data System (ADS)

Zahid, F.; Ghosh, A. W.; Paulsson, M.; Polizzi, E.; Datta, S.

2004-12-01

We investigate the origin of asymmetry in various measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry, with particular focus on a recent break junction measurement. We argue that such asymmetry arises due to unequal coupling with the contacts and a consequent difference in charging effects, which can only be captured in a self-consistent model for molecular conduction. The direction of the asymmetry depends on the sign of the majority carriers in the molecule. For conduction through highest occupied molecular orbitals (i.e., HOMO or p -type conduction), the current is smaller for positive voltage on the stronger contact, while for conduction through lowest unoccupied molecular orbitals (i.e., LUMO or n -type conduction), the sense of the asymmetry is reversed. Within an extended Hückel description of the molecular chemistry and the contact microstructure (with two adjustable parameters, the position of the Fermi energy and the sulphur-gold bond length), an appropriate description of Poisson’s equation, and a self-consistently coupled nonequilibrium Green’s function description of transport, we achieve good agreement between theoretical and experimental I-V characteristics, both in shape as well as overall magnitude.

Fragmentation dynamics of ionized neon trimer inside helium nanodroplets: a theoretical study.

PubMed

Bonhommeau, David; Viel, Alexandra; Halberstadt, Nadine

2004-06-22

We report a theoretical study of the fragmentation dynamics of Ne(3) (+) inside helium nanodroplets, following vertical ionization of the neutral neon trimer. The motion of the neon atoms is treated classically, while transitions between the electronic states of the ionic cluster are treated quantum mechanically. A diatomics-in-molecules description of the potential energy surfaces is used, in a minimal basis set consisting of three effective p orbitals on each neon atom for the missing electron. The helium environment is modeled by a friction force acting on the neon atoms when their speed exceeds the Landau velocity. A reasonable range of values for the corresponding friction coefficient is obtained by comparison with existing experimental measurements. (c) 2004 American Institute of Physics.

Density functional theory for the description of spherical non-associating monomers in confined media using the SAFT-VR equation of state and weighted density approximations.

PubMed

Malheiro, Carine; Mendiboure, Bruno; Plantier, Frédéric; Blas, Felipe J; Miqueu, Christelle

2014-04-07

As a first step of an ongoing study of thermodynamic properties and adsorption of complex fluids in confined media, we present a new theoretical description for spherical monomers using the Statistical Associating Fluid Theory for potential of Variable Range (SAFT-VR) and a Non-Local Density Functional Theory (NLDFT) with Weighted Density Approximations (WDA). The well-known Modified Fundamental Measure Theory is used to describe the inhomogeneous hard-sphere contribution as a reference for the monomer and two WDA approaches are developed for the dispersive terms from the high-temperature Barker and Henderson perturbation expansion. The first approach extends the dispersive contributions using the scalar and vector weighted densities introduced in the Fundamental Measure Theory (FMT) and the second one uses a coarse-grained (CG) approach with a unique weighted density. To test the accuracy of this new NLDFT/SAFT-VR coupling, the two versions of the theoretical model are compared with Grand Canonical Monte Carlo (GCMC) molecular simulations using the same molecular model. Only the version with the "CG" approach for the dispersive terms provides results in excellent agreement with GCMC calculations in a wide range of conditions while the "FMT" extension version gives a good representation solely at low pressures. Hence, the "CG" version of the theoretical model is used to reproduce methane adsorption isotherms in a Carbon Molecular Sieve and compared with experimental data after a characterization of the material. The whole results show an excellent agreement between modeling and experiments. Thus, through a complete and consistent comparison both with molecular simulations and with experimental data, the NLDFT/SAFT-VR theory has been validated for the description of monomers.

Growth of wormlike micelles in nonionic surfactant solutions: Quantitative theory vs. experiment.

PubMed

Danov, Krassimir D; Kralchevsky, Peter A; Stoyanov, Simeon D; Cook, Joanne L; Stott, Ian P; Pelan, Eddie G

2018-06-01

Despite the considerable advances of molecular-thermodynamic theory of micelle growth, agreement between theory and experiment has been achieved only in isolated cases. A general theory that can provide self-consistent quantitative description of the growth of wormlike micelles in mixed surfactant solutions, including the experimentally observed high peaks in viscosity and aggregation number, is still missing. As a step toward the creation of such theory, here we consider the simplest system - nonionic wormlike surfactant micelles from polyoxyethylene alkyl ethers, C i E j . Our goal is to construct a molecular-thermodynamic model that is in agreement with the available experimental data. For this goal, we systematized data for the micelle mean mass aggregation number, from which the micelle growth parameter was determined at various temperatures. None of the available models can give a quantitative description of these data. We constructed a new model, which is based on theoretical expressions for the interfacial-tension, headgroup-steric and chain-conformation components of micelle free energy, along with appropriate expressions for the parameters of the model, including their temperature and curvature dependencies. Special attention was paid to the surfactant chain-conformation free energy, for which a new more general formula was derived. As a result, relatively simple theoretical expressions are obtained. All parameters that enter these expressions are known, which facilitates the theoretical modeling of micelle growth for various nonionic surfactants in excellent agreement with the experiment. The constructed model can serve as a basis that can be further upgraded to obtain quantitative description of micelle growth in more complicated systems, including binary and ternary mixtures of nonionic, ionic and zwitterionic surfactants, which determines the viscosity and stability of various formulations in personal-care and house-hold detergency. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Theoretical study of the kinetics of reactions of the monohalogenated methanes with atomic chlorine.

PubMed

Brudnik, Katarzyna; Twarda, Maria; Sarzyński, Dariusz; Jodkowski, Jerzy T

2013-04-01

Ab initio calculations at the G2 level were used in a theoretical description of the kinetics and mechanism of the hydrogen abstraction reactions from fluoro-, chloro- and bromomethane by chlorine atoms. The profiles of the potential energy surfaces show that mechanism of the reactions under investigation is complex and consists of two - in the case of CH3F+Cl - and of three elementary steps for CH3Cl+Cl and CH3Br+Cl. The heights of the energy barrier related to the H-abstraction are of 8-10 kJ mol(-1), the lowest value corresponds to CH3Cl+Cl and the highest one to CH3F+Cl. The rate constants were calculated using the theoretical method based on the RRKM theory and the simplified version of the statistical adiabatic channel model. The kinetic equations derived in this study[Formula: see text]and[Formula: see text]allow a description of the kinetics of the reactions under investigation in the temperature range of 200-3000 K. The kinetics of reactions of the entirely deuterated reactants were also included in the kinetic analysis. Results of ab initio calculations show that D-abstraction process is related with the energy barrier of 5 kJ mol(-1) higher than the H-abstraction from the corresponding non-deuterated reactant molecule. The derived analytical equations for the reactions, CD3X+Cl, CH2X+HCl and CD2X+DCl (X = F, Cl and Br) are a substantial supplement of the kinetic data necessary for the description and modeling of the processes of importance in the atmospheric chemistry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gómez, A. M., E-mail: amgomezl-1@uqvirtual.edu.co; Torres, D. A., E-mail: datorresg@unal.edu.co

The experimental study of nuclear magnetic moments, using the Transient Field technique, makes use of spin-orbit hyperfine interactions to generate strong magnetic fields, above the kilo-Tesla regime, capable to create a precession of the nuclear spin. A theoretical description of such magnetic fields is still under theoretical research, and the use of parametrizations is still a common way to address the lack of theoretical information. In this contribution, a review of the main parametrizations utilized in the measurements of Nuclear Magnetic Moments will be presented, the challenges to create a theoretical description from first principles will be discussed.

TIE: an ability test of emotional intelligence.

PubMed

Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S

2014-01-01

The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions.

A method to integrate descriptive and experimental field studies at the level of data and empirical concepts1

PubMed Central

Bijou, Sidney W.; Peterson, Robert F.; Ault, Marion H.

1968-01-01

It is the thesis of this paper that data from descriptive and experimental field studies can be interrelated at the level of data and empirical concepts if both sets are derived from frequency-of-occurrence measures. The methodology proposed for a descriptive field study is predicated on three assumptions: (1) The primary data of psychology are the observable interactions of a biological organism and environmental events, past and present. (2) Theoretical concepts and laws are derived from empirical concepts and laws, which in turn are derived from the raw data. (3) Descriptive field studies describe interactions between behavioral and environmental events; experimental field studies provide information on their functional relationships. The ingredients of a descriptive field investigation using frequency measures consist of: (1) specifying in objective terms the situation in which the study is conducted, (2) defining and recording behavioral and environmental events in observable terms, and (3) measuring observer reliability. Field descriptive studies following the procedures suggested here would reveal interesting new relationships in the usual ecological settings and would also provide provocative cues for experimental studies. On the other hand, field-experimental studies using frequency measures would probably yield findings that would suggest the need for describing new interactions in specific natural situations. PMID:16795175

[Systemic inflammation: theoretical and methodological approaches to description of general pathological process model. Part 3. Backgroung for nonsyndromic approach].

PubMed

Gusev, E Yu; Chereshnev, V A

2013-01-01

Theoretical and methodological approaches to description of systemic inflammation as general pathological process are discussed. It is shown, that there is a need of integration of wide range of types of researches to develop a model of systemic inflammation.

Walsh, Da Silva, and Wei Reply

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, A.; Da Silva, J. L. F.; Wei, S. H.

2009-04-17

This is a reply to Stefano Sanvito and Chaitanya Das Pemmaraju's, Comment on Theoretical Description of Carrier Mediated Magnetism in Cobalt Doped ZnO, Phys. Rev. Lett. 102, 159701 (2009); and the original article is Theoretical Description of Carrier Mediated Magnetism in Cobalt Doped ZnO, Phys. Rev. Lett. 100, 256401 (2008).

Nonlinear elasticity in rocks: A comprehensive three-dimensional description

DOE PAGES

Lott, Martin; Remillieux, Marcel; Garnier, Vincent; ...

2017-07-17

Here we study theoretically and experimentally the mechanisms of nonlinear and nonequilibrium dynamics in geomaterials through dynamic acoustoelasticity testing. In the proposed theoretical formulation, the classical theory of nonlinear elasticity is extended to include the effects of conditioning. This formulation is adapted to the context of dynamic acoustoelasticity testing in which a low-frequency “pump” wave induces a strain field in the sample and modulates the propagation of a high-frequency “probe” wave. Experiments are conducted to validate the formulation in a long thin bar of Berea sandstone. Several configurations of the pump and probe are examined: the pump successively consists ofmore » the first longitudinal and first torsional mode of vibration of the sample while the probe is successively based on (pressure) $P$ and (shear) $S$ waves. The theoretical predictions reproduce many features of the elastic response observed experimentally, in particular, the coupling between nonlinear and nonequilibrium dynamics and the three-dimensional effects resulting from the tensorial nature of elasticity.« less

Kinetic and spectral descriptions of autoionization phenomena associated with atomic processes in plasmas

NASA Astrophysics Data System (ADS)

Jacobs, Verne L.

2017-06-01

This investigation has been devoted to the theoretical description and computer modeling of atomic processes giving rise to radiative emission in energetic electron and ion beam interactions and in laboratory plasmas. We are also interested in the effects of directed electron and ion collisions and of anisotropic electric and magnetic fields. In the kinetic-theory description, we treat excitation, de-excitation, ionization, and recombination in electron and ion encounters with partially ionized atomic systems, including the indirect contributions from processes involving autoionizing resonances. These fundamental collisional and electromagnetic interactions also provide particle and photon transport mechanisms. From the spectral perspective, the analysis of atomic radiative emission can reveal detailed information on the physical properties in the plasma environment, such as non-equilibrium electron and charge-state distributions as well as electric and magnetic field distributions. In this investigation, a reduced-density-matrix formulation is developed for the microscopic description of atomic electromagnetic interactions in the presence of environmental (collisional and radiative) relaxation and decoherence processes. Our central objective is a fundamental microscopic description of atomic electromagnetic processes, in which both bound-state and autoionization-resonance phenomena can be treated in a unified and self-consistent manner. The time-domain (equation-of-motion) and frequency-domain (resolvent-operator) formulations of the reduced-density-matrix approach are developed in a unified and self-consistent manner. This is necessary for our ultimate goal of a systematic and self-consistent treatment of non-equilibrium (possibly coherent) atomic-state kinetics and high-resolution (possibly overlapping) spectral-line shapes. We thereby propose the introduction of a generalized collisional-radiative atomic-state kinetics model based on a reduced-density-matrix formulation. It will become apparent that the full atomic data needs for the precise modeling of extreme non-equilibrium plasma environments extend beyond the conventional radiative-transition-probability and collisional-cross-section data sets.

Physics in one dimension: theoretical concepts for quantum many-body systems.

PubMed

Schönhammer, K

2013-01-09

Various sophisticated approximation methods exist for the description of quantum many-body systems. It was realized early on that the theoretical description can simplify considerably in one-dimensional systems and various exact solutions exist. The focus in this introductory paper is on fermionic systems and the emergence of the Luttinger liquid concept.

Effect of the three-dimensional structure of laser emission on the dynamics of low-threshold optical breakdown plasmas

NASA Astrophysics Data System (ADS)

Anisimov, V. N.; Arutiunian, R. V.; Bol'Shov, L. A.; Derkach, O. N.; Kanevskii, M. F.

1989-03-01

The effect of the transverse structure of pulsed CO2 laser emission on the dynamics of laser-induced detonation waves propagating from a metal surface and on plasma transparency recovery is investigated theoretically and experimentally. Particular attention is given to breakdown initiation near the surface. It is suggested that the inclusion of refraction in the plasma into a self-consistent numerical mode is essential for the adequate quantitative description of experimental data on the interaction of laser emission with low-threshold optical breakdown plasmas.

Derivation of an applied nonlinear Schroedinger equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pitts, Todd Alan; Laine, Mark Richard; Schwarz, Jens

We derive from first principles a mathematical physics model useful for understanding nonlinear optical propagation (including filamentation). All assumptions necessary for the development are clearly explained. We include the Kerr effect, Raman scattering, and ionization (as well as linear and nonlinear shock, diffraction and dispersion). We explain the phenomenological sub-models and each assumption required to arrive at a complete and consistent theoretical description. The development includes the relationship between shock and ionization and demonstrates why inclusion of Drude model impedance effects alters the nature of the shock operator. Unclassified Unlimited Release

Basic methods for measuring the reflectance color of iron oxides

NASA Astrophysics Data System (ADS)

Pospisil, Jaroslav; Hrdy, Jan; Hrdy Jan, Jr.

2007-06-01

The main contribution of the present article consists in coherent description and interpretation of the principles of basic measuring methods and colorimeters for color classification and evaluation of light reflecting samples containing iron oxides. The chosen relevant theoretical background is based on the CIE tristimulus colorimetric system (X,Y,Z), the CIE colorimetric system (L*,a*,b*) and the Munsell colorimetric system (H,V,C). As an example of color identification and evaluation, some specific mathematical and graphical relationships between the soil redness rate and the corresponding hematite content are shown.

Thermo-electric transport in gauge/gravity models with momentum dissipation

NASA Astrophysics Data System (ADS)

Amoretti, Andrea; Braggio, Alessandro; Maggiore, Nicola; Magnoli, Nicodemo; Musso, Daniele

2014-09-01

We present a systematic definition and analysis of the thermo-electric linear response in gauge/gravity systems focusing especially on models with massive gravity in the bulk and therefore momentum dissipation in the dual field theory. A precise treatment of finite counter-terms proves to be essential to yield a consistent physical picture whose hydrodynamic and beyond-hydrodynamics behaviors noticeably match with field theoretical expectations. The model furnishes a possible gauge/gravity description of the crossover from the quantum-critical to the disorder-dominated Fermi-liquid behaviors, as expected in graphene.

Theoretical Foundations of Appeals Used in Alcohol-Abuse and Drunk-Driving Public Service Announcements in the United States, 1995-2010.

PubMed

Niederdeppe, Jeff; Avery, Rosemary J; Miller, Emily Elizabeth Namaste

2018-05-01

The study identifies the extent to which theoretical constructs drawn from well-established message effect communication theories are reflected in the content of alcohol-related public service announcements (PSAs) airing in the United States over a 16-year period. Content analysis of 18 530 141 alcohol-abuse (AA) and drunk-driving (DD) PSAs appearing on national network and local cable television stations in the 210 largest designated marketing areas (DMAs) from January 1995 through December 2010. The authors developed a detailed content analytic codebook and trained undergraduate coders to reliably identify the extent to which theoretical constructs and other creative ad elements are reflected in the PSAs. We show these patterns using basic descriptive statistics. Although both classes of alcohol-related PSAs used strategies that are consistent with major message effect theories, their specific theoretical orientations differed dramatically. The AA PSAs were generally consistent with constructs emphasized by the Extended Parallel Process Model (EPPM), whereas DD PSAs were more likely to use normative strategies emphasized by the Focus Theory of Narrative Conduct (FTNC) or source credibility appeals central to the Elaboration Likelihood Model. Having identified message content, future research should use deductive approaches to determine if volume and message content of alcohol-control PSAs have an impact on measures of alcohol consumption and/or measures of drunk driving, such as fatalities or driving while intoxicated/driving under the influence arrests.

The construct-behavior gap in behavioral decision research: A challenge beyond replicability.

PubMed

Regenwetter, Michel; Robinson, Maria M

2017-10-01

Behavioral decision research compares theoretical constructs like preferences to behavior such as observed choices. Three fairly common links from constructs to behavior are (1) to tally, across participants and decision problems, the number of choices consistent with one predicted pattern of pairwise preferences; (2) to compare what most people choose in each decision problem against a predicted preference pattern; or (3) to enumerate the decision problems in which two experimental conditions generate a 1-sided significant difference in choice frequency 'consistent' with the theory. Although simple, these theoretical links are heuristics. They are subject to well-known reasoning fallacies, most notably the fallacy of sweeping generalization and the fallacy of composition. No amount of replication can alleviate these fallacies. On the contrary, reiterating logically inconsistent theoretical reasoning over and again across studies obfuscates science. As a case in point, we consider pairwise choices among simple lotteries and the hypotheses of overweighting or underweighting of small probabilities, as well as the description-experience gap. We discuss ways to avoid reasoning fallacies in bridging the conceptual gap between hypothetical constructs, such as, for example, "overweighting" to observable pairwise choice data. Although replication is invaluable, successful replication of hard-to-interpret results is not. Behavioral decision research stands to gain much theoretical and empirical clarity by spelling out precise and formally explicit theories of how hypothetical constructs translate into observable behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The relationship between symbolic interactionism and interpretive description.

PubMed

Oliver, Carolyn

2012-03-01

In this article I explore the relationship between symbolic interactionist theory and interpretive description methodology. The two are highly compatible, making symbolic interactionism an excellent theoretical framework for interpretive description studies. The pragmatism underlying interpretive description supports locating the methodology within this cross-disciplinary theory to make it more attractive to nonnursing researchers and expand its potential to address practice problems across the applied disciplines. The theory and method are so compatible that symbolic interactionism appears to be part of interpretive description's epistemological foundations. Interpretive description's theoretical roots have, to date, been identified only very generally in interpretivism and the philosophy of nursing. A more detailed examination of its symbolic interactionist heritage furthers the contextualization or forestructuring of the methodology to meet one of its own requirements for credibility.

Grand Canonical adaptive resolution simulation for molecules with electrons: A theoretical framework based on physical consistency

NASA Astrophysics Data System (ADS)

Delle Site, Luigi

2018-01-01

A theoretical scheme for the treatment of an open molecular system with electrons and nuclei is proposed. The idea is based on the Grand Canonical description of a quantum region embedded in a classical reservoir of molecules. Electronic properties of the quantum region are calculated at constant electronic chemical potential equal to that of the corresponding (large) bulk system treated at full quantum level. Instead, the exchange of molecules between the quantum region and the classical environment occurs at the chemical potential of the macroscopic thermodynamic conditions. The Grand Canonical Adaptive Resolution Scheme is proposed for the treatment of the classical environment; such an approach can treat the exchange of molecules according to first principles of statistical mechanics and thermodynamic. The overall scheme is build on the basis of physical consistency, with the corresponding definition of numerical criteria of control of the approximations implied by the coupling. Given the wide range of expertise required, this work has the intention of providing guiding principles for the construction of a well founded computational protocol for actual multiscale simulations from the electronic to the mesoscopic scale.

Simple and Multivariate Relationships Between Spiritual Intelligence with General Health and Happiness.

PubMed

Amirian, Mohammad-Elyas; Fazilat-Pour, Masoud

2016-08-01

The present study examined simple and multivariate relationships of spiritual intelligence with general health and happiness. The employed method was descriptive and correlational. King's Spiritual Quotient scales, GHQ-28 and Oxford Happiness Inventory, are filled out by a sample consisted of 384 students, which were selected using stratified random sampling from the students of Shahid Bahonar University of Kerman. Data are subjected to descriptive and inferential statistics including correlations and multivariate regressions. Bivariate correlations support positive and significant predictive value of spiritual intelligence toward general health and happiness. Further analysis showed that among the Spiritual Intelligence' subscales, Existential Critical Thinking Predicted General Health and Happiness, reversely. In addition, happiness was positively predicted by generation of personal meaning and transcendental awareness. The findings are discussed in line with the previous studies and the relevant theoretical background.

A fluid description of plasma double-layers

NASA Technical Reports Server (NTRS)

Levine, J. S.; Crawford, F. W.

1979-01-01

The space-charge double-layer that forms between two plasmas with different densities and thermal energies was investigated using three progressively realistic models which are treated by fluid theory, and take into account four species of particles: electrons and ions reflected by the double-layer, and electrons and ions transmitted through it. The two plasmas are assumed to be cold, and the self-consistent potential, electric field and space-charge distributions within the double-layer are determined. The effects of thermal velocities are taken into account for the reflected particles, and the modifications to the cold plasma solutions are established. Further modifications due to thermal velocities of the transmitted particles are examined. The applicability of a one dimensional fluid description, rather than plasma kinetic theory, is discussed. Theoretical predictions are compared with double layer potentials and lengths deduced from laboratory and space plasma experiments.

Neutrino-induced reactions on nuclei

NASA Astrophysics Data System (ADS)

Gallmeister, K.; Mosel, U.; Weil, J.

2016-09-01

Background: Long-baseline experiments such as the planned deep underground neutrino experiment (DUNE) require theoretical descriptions of the complete event in a neutrino-nucleus reaction. Since nuclear targets are used this requires a good understanding of neutrino-nucleus interactions. Purpose: Develop a consistent theory and code framework for the description of lepton-nucleus interactions that can be used to describe not only inclusive cross sections, but also the complete final state of the reaction. Methods: The Giessen-Boltzmann-Uehling-Uhlenbeck (GiBUU) implementation of quantum-kinetic transport theory is used, with improvements in its treatment of the nuclear ground state and of 2p2h interactions. For the latter an empirical structure function from electron scattering data is used as a basis. Results: Results for electron-induced inclusive cross sections are given as a necessary check for the overall quality of this approach. The calculated neutrino-induced inclusive double-differential cross sections show good agreement data from neutrino and antineutrino reactions for different neutrino flavors at MiniBooNE and T2K. Inclusive double-differential cross sections for MicroBooNE, NOvA, MINERvA, and LBNF/DUNE are given. Conclusions: Based on the GiBUU model of lepton-nucleus interactions a good theoretical description of inclusive electron-, neutrino-, and antineutrino-nucleus data over a wide range of energies, different neutrino flavors, and different experiments is now possible. Since no tuning is involved this theory and code should be reliable also for new energy regimes and target masses.

Hip and pelvic fracture patients with fear of falling: development and description of the "Step by Step" treatment protocol.

PubMed

Kampe, Karin; Kohler, Michaela; Albrecht, Diana; Becker, Clemens; Hautzinger, Martin; Lindemann, Ulrich; Pfeiffer, Klaus

2017-05-01

Based on a theoretical framework and sound evidence, this article describes a rehabilitation programme for patients with fear of falling after hip and pelvic fracture. Based on exercise science principles, current knowledge from fall prevention, emotion regulation, and the Health Action Process Approach we developed a theoretical framework, from which the components of the intervention were derived. Description of the intervention: The intervention consists of 6 components: (1) relaxation, (2) meaningful activities and mobility-based goals, (3) falls related cognitions and emotions, coping with high risk tasks and situations, (4) individual exercise programme, (5) planning and implementing exercises and activities, and (6) fall risks and hazards. The intervention comprises of 8 individual sessions during 3 to 5 weeks of inpatient rehabilitation and 4 telephone calls and 1 home visit over a 2-month post-discharge period. Each session or telephone call takes about 30-60 minutes. It is provided to geriatric hip and pelvic fracture patients with concerns about falling and no cognitive impairment. To ensure completeness of reporting, the Template for Intervention Description and Replication (TIDierR) is used. Fifty-seven patients were assigned to the intervention group. All 46 completers met all pre-defined criteria for an intervention per protocol. The programme is feasible to administer. We have completed a randomised controlled trial, which will be submitted in due time (for trial protocol: www.isrctn.org ; ISRCTN79191813).

Systematic text condensation: a strategy for qualitative analysis.

PubMed

Malterud, Kirsti

2012-12-01

To present background, principles, and procedures for a strategy for qualitative analysis called systematic text condensation and discuss this approach compared with related strategies. Giorgi's psychological phenomenological analysis is the point of departure and inspiration for systematic text condensation. The basic elements of Giorgi's method and the elaboration of these in systematic text condensation are presented, followed by a detailed description of procedures for analysis according to systematic text condensation. Finally, similarities and differences compared with other frequently applied methods for qualitative analysis are identified, as the foundation of a discussion of strengths and limitations of systematic text condensation. Systematic text condensation is a descriptive and explorative method for thematic cross-case analysis of different types of qualitative data, such as interview studies, observational studies, and analysis of written texts. The method represents a pragmatic approach, although inspired by phenomenological ideas, and various theoretical frameworks can be applied. The procedure consists of the following steps: 1) total impression - from chaos to themes; 2) identifying and sorting meaning units - from themes to codes; 3) condensation - from code to meaning; 4) synthesizing - from condensation to descriptions and concepts. Similarities and differences comparing systematic text condensation with other frequently applied qualitative methods regarding thematic analysis, theoretical methodological framework, analysis procedures, and taxonomy are discussed. Systematic text condensation is a strategy for analysis developed from traditions shared by most of the methods for analysis of qualitative data. The method offers the novice researcher a process of intersubjectivity, reflexivity, and feasibility, while maintaining a responsible level of methodological rigour.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelis, François; Schenke, Björn

In this work, we review recent developments in the ab initio theoretical description of the initial state in heavy-ion collisions. We emphasize the importance of fluctuations, both for the phenomenological description of experimental data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) and for the theoretical understanding of the nonequilibrium early-time dynamics and thermalization of the medium.

TIE: An Ability Test of Emotional Intelligence

PubMed Central

Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S.

2014-01-01

The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions. PMID:25072656

Exploring the relation between masculinity and mental illness stigma using the stereotype content model and BIAS map.

PubMed

Boysen, Guy A

2017-01-01

The current research explored the association of masculinity and stigma toward mental illness using theoretical predictions stemming from the stereotype content model and BIAS map. Two correlational studies (Ns = 245, 163) measured stereotypes, emotions, and behavioral intentions in relation to masculine, feminine, and gender-neutral disorders. Participants perceived masculine disorders as lacking personal warmth and competence. Masculine disorders also elicited more negative emotions and behavioral intentions. Two experimental studies (Ns = 161, 431) manipulated personal warmth, sex, and type of disorder in descriptions of people with mental illness. Low warmth and stereotypically masculine disorders consistently elicited negative emotions and behavioral intentions, but sex had limited effects. Overall, the results supported the theoretical models and illustrated the importance of warmth and symptomatic behavior in explaining the masculinity-stigma relation.

Towards a unified description of total and diffractive structure functions at DESY HERA in the QCD dipole picture

NASA Astrophysics Data System (ADS)

Bialas, A.; Peschanski, R.; Royon, Ch.

1998-06-01

It is argued that the QCD dipole picture allows us to build a unified theoretical description, based on Balitskii-Fadin-Kuraev-Lipatov dynamics, of the total and diffractive nucleon structure functions. This description is in qualitative agreement with the present collection of data obtained by the H1 Collaboration. More precise theoretical estimates, in particular the determination of the normalizations and proton transverse momentum behavior of the diffractive components, are shown to be required in order to reach definite conclusions.

Experiment and speculation in seventeenth-century Italy: The case of Geminiano Montanari.

PubMed

Vanzo, Alberto

2016-04-01

This paper reconstructs the natural philosophical method of Geminiano Montanari, one of the most prominent Italian natural philosophers of the late seventeenth century. Montanari's views are used as a case study to assess recent claims concerning early modern experimental philosophy. Having presented the distinctive tenets of seventeenth-century experimental philosophers, I argue that Montanari adheres to them explicitly, thoroughly, and consistently. The study of Montanari's views supports three claims. First, experimental philosophy was not an exclusively British phenomenon. Second, in spite of some portrayals of experimental philosophy as an 'atheoretical' or 'purely descriptive' enterprise, experimental philosophers could consistently endorse a variety of natural philosophical explanations and postulate theoretical entities. Third, experimental philosophy and mechanical philosophy were not, as such, antagonistic. They could be consistently combined in a single philosophical enterprise. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

Gauge-transformation properties of cosmological observables and its application to the light-cone average

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, Jaiyul; Durrer, Ruth, E-mail: jyoo@physik.uzh.ch, E-mail: ruth.durrer@unige.ch

Theoretical descriptions of observable quantities in cosmological perturbation theory should be independent of coordinate systems. This statement is often referred to as gauge-invariance of observable quantities, and the sanity of their theoretical description is verified by checking its gauge-invariance. We argue that cosmological observables are invariant scalars under diffeomorphisms and their theoretical description is gauge-invariant, only at linear order in perturbations. Beyond linear order, they are usually not gauge-invariant, and we provide the general law for the gauge-transformation that the perturbation part of an observable does obey. We apply this finding to derive the second-order expression for the observational light-conemore » average in cosmology and demonstrate that our expression is indeed invariant under diffeomorphisms.« less

A Lie-theoretic Description of the Solution Space of the tt*-Toda Equations

NASA Astrophysics Data System (ADS)

Guest, Martin A.; Ho, Nan-Kuo

2017-12-01

We give a Lie-theoretic explanation for the convex polytope which parametrizes the globally smooth solutions of the topological-antitopological fusion equations of Toda type (tt ∗-Toda equations) which were introduced by Cecotti and Vafa. It is known from Guest and Lin (J. Reine Angew. Math. 689, 1-32 2014) Guest et al. (It. Math. Res. Notices 2015, 11745-11784 2015) and Mochizuki (2013, 2014) that these solutions can be parametrized by monodromy data of a certain flat S L n+ 1 ℝ-connection. Using Boalch's Lie-theoretic description of Stokes data, and Steinberg's description of regular conjugacy classes of a linear algebraic group, we express this monodromy data as a convex subset of a Weyl alcove of S U n+ 1.

Automation of reliability evaluation procedures through CARE - The computer-aided reliability estimation program.

NASA Technical Reports Server (NTRS)

Mathur, F. P.

1972-01-01

Description of an on-line interactive computer program called CARE (Computer-Aided Reliability Estimation) which can model self-repair and fault-tolerant organizations and perform certain other functions. Essentially CARE consists of a repository of mathematical equations defining the various basic redundancy schemes. These equations, under program control, are then interrelated to generate the desired mathematical model to fit the architecture of the system under evaluation. The mathematical model is then supplied with ground instances of its variables and is then evaluated to generate values for the reliability-theoretic functions applied to the model.

Observational learning from a radical-behavioristic viewpoint

PubMed Central

Deguchi, Hikaru

1984-01-01

Bandura (1972, 1977b) has argued that observational learning has some distinctive features that set it apart from the operant paradigm: (1) acquisition simply through observation, (2) delayed performance through cognitive mediation, and (3) vicarious reinforcement. The present paper first redefines those three features at the descriptive level, and then adopts a radical-behavioristic viewpoint to show how those redefined distinctive features can be explained and tested experimentally. Finally, the origin of observational learning is discussed in terms of recent data of neonatal imitation. The present analysis offers a consistent theoretical and practical understanding of observational learning from a radical-behavioristic viewpoint. PMID:22478602

Initial-State Quantum Fluctuations in the Little Bang

DOE PAGES

Gelis, François; Schenke, Björn

2016-06-01

In this work, we review recent developments in the ab initio theoretical description of the initial state in heavy-ion collisions. We emphasize the importance of fluctuations, both for the phenomenological description of experimental data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) and for the theoretical understanding of the nonequilibrium early-time dynamics and thermalization of the medium.

Nursing Doctorates in Brazil: research formation and theses production.

PubMed

Scochi, Carmen Gracinda Silvan; Gelbcke, Francine Lima; Ferreira, Márcia de Assunção; Lima, Maria Alice Dias da Silva; Padilha, Katia Grillo; Padovani, Nátali Artal; Munari, Denize Bouttelet

2015-01-01

to analyze the formation of nursing doctorates in Brazil, from theses production, disciplines and other strategies focusing on research offered by courses. a descriptive and analytical study of the performance of 18 doctoral courses in nursing, running from 1982 to 2010, and defended their theses between 2010-2012. 502 theses were defended in this period, most linked to the online research process of health and nursing care. There are gaps in the knowledge of theoretical and philosophical foundations of care, nursing history and ethics. There are also weaknesses in the methodological design of the theses, with a predominance of descriptive and/or exploratory studies. This was consistent with international standards set with regards to the proposition of research of disciplines and complementary strategies in forming the doctorate. despite the efforts and advances in research formation, it is essential to expand to more robust research designs with a greater impact on production knowledge that is incorporated into practice.

Quantum field-theoretical description of neutrino and neutral kaon oscillations

NASA Astrophysics Data System (ADS)

Volobuev, Igor P.

2018-05-01

It is shown that the neutrino and neutral kaon oscillation processes can be consistently described in quantum field theory using only plane waves of the mass eigenstates of neutrinos and neutral kaons. To this end, the standard perturbative S-matrix formalism is modified so that it can be used for calculating the amplitudes of the processes passing at finite distances and finite time intervals. The distance-dependent and time-dependent parts of the amplitudes of the neutrino and neutral kaon oscillation processes are calculated and the results turn out to be in accordance with those of the standard quantum mechanical description of these processes based on the notion of neutrino flavor states and neutral kaon states with definite strangeness. However, the physical picture of the phenomena changes radically: now, there are no oscillations of flavor or definite strangeness states, but, instead of it, there is interference of amplitudes due to different virtual mass eigenstates.

The role of affect in the positive self: Two longitudinal investigations of young adolescents in the United States and China.

PubMed

Zhang, Xin; Pomerantz, Eva M; Setoh, Peipei; Qu, Yang; Wang, Meifang

2016-07-01

This research investigated the role of American and Chinese children's affect in the valence of their views of themselves. In 2 studies (Ns = 825 and 397), children in the United States and China reported on their affect (e.g., positive and negative emotions) and described themselves multiple times over the 7th and 8th grades. The more positive and less negative children's affect, the more positive their descriptions of themselves over time in both studies. These pathways were more consistent than those in the reverse direction (i.e., from children's self-descriptions to their affect). Notably, regardless of direction, the strength of the pathways was similar in the United States and China. The findings suggest that counter to some theoretical perspectives, affect is not more important in American than Chinese children's judgments about the self. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Reprint of "Theoretical description of metal/oxide interfacial properties: The case of MgO/Ag(001)"

NASA Astrophysics Data System (ADS)

Prada, Stefano; Giordano, Livia; Pacchioni, Gianfranco; Goniakowski, Jacek

2017-02-01

We compare the performances of different DFT functionals applied to ultra-thin MgO(100) films supported on the Ag(100) surface, a prototypical system of a weakly interacting oxide/metal interface, extensively studied in the past. Beyond semi-local DFT-GGA approximation, we also use the hybrid DFT-HSE approach to improve the description of the oxide electronic structure. Moreover, to better account for the interfacial adhesion, we include the van de Waals interactions by means of either the semi-empirical force fields by Grimme (DFT-D2 and DFT-D2*) or the self-consistent density functional optB88-vdW. We compare and discuss the results on the structural, electronic, and adhesion characteristics of the interface as obtained for pristine and oxygen-deficient Ag-supported MgO films in the 1-4 ML thickness range.

Theoretical description of metal/oxide interfacial properties: The case of MgO/Ag(001)

NASA Astrophysics Data System (ADS)

Prada, Stefano; Giordano, Livia; Pacchioni, Gianfranco; Goniakowski, Jacek

2016-12-01

We compare the performances of different DFT functionals applied to ultra-thin MgO(100) films supported on the Ag(100) surface, a prototypical system of a weakly interacting oxide/metal interface, extensively studied in the past. Beyond semi-local DFT-GGA approximation, we also use the hybrid DFT-HSE approach to improve the description of the oxide electronic structure. Moreover, to better account for the interfacial adhesion, we include the van de Waals interactions by means of either the semi-empirical force fields by Grimme (DFT-D2 and DFT-D2*) or the self-consistent density functional optB88-vdW. We compare and discuss the results on the structural, electronic, and adhesion characteristics of the interface as obtained for pristine and oxygen-deficient Ag-supported MgO films in the 1-4 ML thickness range.

Annular electromagnetic pumps-construction and testing-theory, and comparison with experimental results; Pompes electromagnetiques annulaires - construction et essais - theorie et confrontation avec l'experience (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cambillard, Etienne P.; Schwab, Bernard L.

1964-07-15

This report consists of three sections. the first is concerned with the description of different pumps which have been constructed, tests on these which have been completed, and the results obtained. The second section presents a theoretical method for the determination of the coefficients, taking in account the break of the magnetic circuit. It is shown that the preliminary design calculations of the annular pumps can be made, neglecting the break of the magnetic circuit, by further assigning essential magnitudes (pressure, losses) with easily calculated coefficients. the third section of this report uses the theoretical bases exposed in the secondmore » section, and develops a new annular pump calculation method which takes into account bot the current out of balance and any type of winding.« less

A description of the pseudorapidity distributions in heavy ion collisions at RHIC and LHC energies

NASA Astrophysics Data System (ADS)

Jiang, Z. J.; Zhang, Y.; Zhang, H. L.; Deng, H. P.

2015-09-01

The charged particles produced in nucleus-nucleus collisions are classified into two parts: One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand and generate particles according to BJP hydrodynamics, a theory put forward by A. Bialas, R.A. Janik and R. Peschanski. The leading particles are argued to possess a Gaussian rapidity distribution with the normalization constant equaling the number of participants. A comparison is made between the theoretical results and the experimental measurements performed by BRAHMS and PHOBOS Collaborations at BNL-RHIC in Au-Au and Cu-Cu collisions at √{sNN} = 200 GeV and by ALICE Collaboration at CERN-LHC in Pb-Pb collisions at √{sNN} = 2.76 TeV. The theoretical results are well consistent with experimental data.

Modeling and simulating the neuromuscular mechanisms regulating ankle and knee joint stiffness during human locomotion.

PubMed

Sartori, Massimo; Maculan, Marco; Pizzolato, Claudio; Reggiani, Monica; Farina, Dario

2015-10-01

This work presents an electrophysiologically and dynamically consistent musculoskeletal model to predict stiffness in the human ankle and knee joints as derived from the joints constituent biological tissues (i.e., the spanning musculotendon units). The modeling method we propose uses electromyography (EMG) recordings from 13 muscle groups to drive forward dynamic simulations of the human leg in five healthy subjects during overground walking and running. The EMG-driven musculoskeletal model estimates musculotendon and resulting joint stiffness that is consistent with experimental EMG data as well as with the experimental joint moments. This provides a framework that allows for the first time observing 1) the elastic interplay between the knee and ankle joints, 2) the individual muscle contribution to joint stiffness, and 3) the underlying co-contraction strategies. It provides a theoretical description of how stiffness modulates as a function of muscle activation, fiber contraction, and interacting tendon dynamics. Furthermore, it describes how this differs from currently available stiffness definitions, including quasi-stiffness and short-range stiffness. This work offers a theoretical and computational basis for describing and investigating the neuromuscular mechanisms underlying human locomotion. Copyright © 2015 the American Physiological Society.

Modeling and simulating the neuromuscular mechanisms regulating ankle and knee joint stiffness during human locomotion

PubMed Central

Maculan, Marco; Pizzolato, Claudio; Reggiani, Monica; Farina, Dario

2015-01-01

This work presents an electrophysiologically and dynamically consistent musculoskeletal model to predict stiffness in the human ankle and knee joints as derived from the joints constituent biological tissues (i.e., the spanning musculotendon units). The modeling method we propose uses electromyography (EMG) recordings from 13 muscle groups to drive forward dynamic simulations of the human leg in five healthy subjects during overground walking and running. The EMG-driven musculoskeletal model estimates musculotendon and resulting joint stiffness that is consistent with experimental EMG data as well as with the experimental joint moments. This provides a framework that allows for the first time observing 1) the elastic interplay between the knee and ankle joints, 2) the individual muscle contribution to joint stiffness, and 3) the underlying co-contraction strategies. It provides a theoretical description of how stiffness modulates as a function of muscle activation, fiber contraction, and interacting tendon dynamics. Furthermore, it describes how this differs from currently available stiffness definitions, including quasi-stiffness and short-range stiffness. This work offers a theoretical and computational basis for describing and investigating the neuromuscular mechanisms underlying human locomotion. PMID:26245321

Neuroscience from a mathematical perspective: key concepts, scales and scaling hypothesis, universality.

PubMed

van Hemmen, J Leo

2014-10-01

This article analyzes the question of whether neuroscience allows for mathematical descriptions and whether an interaction between experimental and theoretical neuroscience can be expected to benefit both of them. It is argued that a mathematization of natural phenomena never happens by itself. First, appropriate key concepts must be found that are intimately connected with the phenomena one wishes to describe and explain mathematically. Second, the scale on, and not beyond, which a specific description can hold must be specified. Different scales allow for different conceptual and mathematical descriptions. This is the scaling hypothesis. Third, can a mathematical description be universally valid and, if so, how? Here we put forth the argument that universals also exist in theoretical neuroscience, that evolution proves the rule, and that theoretical neuroscience is a domain with still lots of space for new developments initiated by an intensive interaction with experiment. Finally, major insight is provided by a careful analysis of the way in which particular brain structures respond to perceptual input and in so doing induce action in an animal's surroundings.

Normative and Descriptive Aspects of Management Education: Differentiation and Integration

ERIC Educational Resources Information Center

Meirovich, Gavriel

2015-01-01

This study advocates strongly for clear differentiation and synthesis of descriptive and normative approaches in management education. There is a certain isolation of normative and descriptive theoretical frameworks presented in management courses. Normative frameworks in management explain how organizations "should be" managed, while…

Aerodynamic design and analysis system for supersonic aircraft. Part 1: General description and theoretical development

NASA Technical Reports Server (NTRS)

Middleton, W. D.; Lundry, J. L.

1975-01-01

An integrated system of computer programs has been developed for the design and analysis of supersonic configurations. The system uses linearized theory methods for the calculation of surface pressures and supersonic area rule concepts in combination with linearized theory for calculation of aerodynamic force coefficients. Interactive graphics are optional at the user's request. This part presents a general description of the system and describes the theoretical methods used.

Connecting single cell to collective cell behavior in a unified theoretical framework

NASA Astrophysics Data System (ADS)

George, Mishel; Bullo, Francesco; Campàs, Otger

Collective cell behavior is an essential part of tissue and organ morphogenesis during embryonic development, as well as of various disease processes, such as cancer. In contrast to many in vitro studies of collective cell migration, most cases of in vivo collective cell migration involve rather small groups of cells, with large sheets of migrating cells being less common. The vast majority of theoretical descriptions of collective cell behavior focus on large numbers of cells, but fail to accurately capture the dynamics of small groups of cells. Here we introduce a low-dimensional theoretical description that successfully captures single cell migration, cell collisions, collective dynamics in small groups of cells, and force propagation during sheet expansion, all within a common theoretical framework. Our description is derived from first principles and also includes key phenomenological aspects of cell migration that control the dynamics of traction forces. Among other results, we explain the counter-intuitive observations that pairs of cells repel each other upon collision while they behave in a coordinated manner within larger clusters.

A new theoretical approach to analyze complex processes in cytoskeleton proteins.

PubMed

Li, Xin; Kolomeisky, Anatoly B

2014-03-20

Cytoskeleton proteins are filament structures that support a large number of important biological processes. These dynamic biopolymers exist in nonequilibrium conditions stimulated by hydrolysis chemical reactions in their monomers. Current theoretical methods provide a comprehensive picture of biochemical and biophysical processes in cytoskeleton proteins. However, the description is only qualitative under biologically relevant conditions because utilized theoretical mean-field models neglect correlations. We develop a new theoretical method to describe dynamic processes in cytoskeleton proteins that takes into account spatial correlations in the chemical composition of these biopolymers. Our approach is based on analysis of probabilities of different clusters of subunits. It allows us to obtain exact analytical expressions for a variety of dynamic properties of cytoskeleton filaments. By comparing theoretical predictions with Monte Carlo computer simulations, it is shown that our method provides a fully quantitative description of complex dynamic phenomena in cytoskeleton proteins under all conditions.

Leadership profiles of senior nurse executives.

PubMed

Hemman, E A

2000-01-01

As hospitals reorganize to meet the demand for accessible, cost-effective quality healthcare, nursing's active participation as part of the top management team is vital. The purpose of this study was to describe the leadership profiles of four senior nurse executives and determine their congruence with the theoretical perspectives of the stratified systems theory. A multiple case study methodology was employed to develop individual and group leadership profiles through related experiences obtained during an interview, the organization's expectations based on their job descriptions, and a survey of their self-perceptions of how they spent most of their time. The findings indicated that the executives' leadership behavior was consistent with the theory in that they reported more frequent leadership behaviors at the strategic domain, less activity at the organizational domain, and infrequent activity at the production domain. Individual profiles were uniformly consistent with the group profile.

[What are we doing in neighborhoods? Description of health-promoting community activities in primary care: the FrAC Project].

PubMed

March, Sebastià; Jordán Martín, Matilde; Montaner Gomis, Isabel; Benedé Azagra, Carmen Belén; Elizalde Soto, Lázaro; Ramos, María

2014-01-01

To describe the health-promoting community activities developed in primary health care and compare types of activities and how they are performed among autonomous regions. A descriptive multicenter study was carried out in primary care in 5 Spanish regions. We included community activities consisting of non-sporadic activities, carried out in the previous year, with the participation of the primary care team, and the active participation of the community or as a cross-sector activity. The persons responsible for each of the 194 teams were asked if the team participated in community activities and, if so, a questionnaire was completed by the person responsible for each activity. The variables consisted of the topic addressed, the target population, the professionals involved, the time and scope of implementation, evaluation, theoretical perspectives, network registration, the involvement of the community and other agents, and evaluation of this involvement. A descriptive analysis was performed, stratified by region. We identified 183 community activities in 104 teams. Although there was wide variability among regions, most activities were related to general health, nutrition and emotional-sexual health and targeted the general population, children or parents and were carried out in educational or health centers. Participating professionals had a median of 4 years of experience and a median of 2.8 professionals were involved in each activity. A total of 72.5% of the activities were performed during working hours, 75% were evaluated, and 70% were supported by theoretical and methodological perspectives. Non-health sectors were involved in 65%, local government in 60%, and nongovernmental organizations in 58.5%. Nurses were involved in 85.8% of the activities, physicians in 38.5%, and social workers in 35%. Substantial variability was detected among regions. Wide variability was found in the types of activities and their application among the community activities developed by primary care, as well as in institutional recognition and community involvement in the development and evaluation of these activities. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

Dielectric constant of ionic solutions: a field-theory approach.

PubMed

Levy, Amir; Andelman, David; Orland, Henri

2012-06-01

We study the variation of the dielectric response of a dielectric liquid (e.g. water) when a salt is added to the solution. Employing field-theoretical methods, we expand the Gibbs free energy to first order in a loop expansion and calculate self-consistently the dielectric constant. We predict analytically the dielectric decrement which depends on the ionic strength in a complex way. Furthermore, a qualitative description of the hydration shell is found and is characterized by a single length scale. Our prediction fits rather well a large range of concentrations for different salts using only one fit parameter related to the size of ions and dipoles.

Clearance flow-generated transverse forces at the rotors of thermal turbomachines. Ph.D. Thesis - Technische Univ., 1975

NASA Technical Reports Server (NTRS)

Urlichs, K.

1983-01-01

Self-excited rotor whirl represents a serious hazard in the operation of turbomachines. The reported investigation has, therefore, the objective to measure the lateral forces acting on the rotor and to determine the characteristic pressure distribution in the rotor clearance area. A description is presented of an approach for calculating the leakage flow in the case of an eccentric rotor position on the basis of empirical loss coefficients. The results are reported of an experimental investigation with a turbine stage, taking into account a variation of the clearance characteristics. The pressure data measured are consistent with the theoretical considerations.

Stokes-correlometry of polarization-inhomogeneous objects

NASA Astrophysics Data System (ADS)

Ushenko, O. G.; Dubolazov, A.; Bodnar, G. B.; Bachynskiy, V. T.; Vanchulyak, O.

2018-01-01

The paper consists of two parts. The first part presents short theoretical basics of the method of Stokes-correlometry description of optical anisotropy of biological tissues. It was provided experimentally measured coordinate distributions of modulus (MSV) and phase (PhSV) of complex Stokes vector of skeletal muscle tissue. It was defined the values and ranges of changes of statistic moments of the 1st-4th orders, which characterize the distributions of values of MSV and PhSV. The second part presents the data of statistic analysis of the distributions of modulus MSV and PhSV. It was defined the objective criteria of differentiation of samples with urinary incontinence.

Book review: Physics of tsunamis

USGS Publications Warehouse

Geist, Eric L.

2017-01-01

“Physics of Tsunamis”, second edition, provides a comprehensive analytical treatment of the hydrodynamics associated with the tsunami generation process. The book consists of seven chapters covering 388 pages. Because the subject matter within each chapter is distinct, an abstract appears at the beginning and references appear at the end of each chapter, rather than at the end of the book. Various topics of tsunami physics are examined largely from a theoretical perspective, although there is little information on how the physical descriptions are applied in numerical models.“Physics of Tsunamis”, by B. W. Levin and M. A. Nosov, Second Edition, Springer, 2016; ISBN-10: 33-1933106X, ISBN-13: 978-331933-1065

Theoretical Studies of Processes Affecting the Stratospheric and Free Tropospheric Aerosols

NASA Technical Reports Server (NTRS)

Hamill, Patrick

1999-01-01

This report describes the work done with funding from NASA Grant during the past three years. Funding commenced in June, 1996 and had a planned duration of three years. This report covers the time period June 1996 to June 1999. Here we present a short description of the projects carried out and documentation of the work done in terms of publications, papers presented, and conferences attended: microphysical modeling consist of two related tasks (1) development of a simple microphysical model for modeling the Pinatubo plume and (2) carrying out a study of sulfate particle formation in volcanic plume.Also analysis of sun photometer measurements are presented.

A theoretical description of the polarization dependence of the sum frequency generation spectroscopy of the water/vapor interface

NASA Astrophysics Data System (ADS)

Perry, Angela; Neipert, Christine; Kasprzyk, Christina Ridley; Green, Tony; Space, Brian; Moore, Preston B.

2005-10-01

An improved time correlation function (TCF) description of sum frequency generation (SFG) spectroscopy was developed and applied to theoretically describing the spectroscopy of the ambient water/vapor interface. A more general TCF expression than was published previously is presented—it is valid over the entire vibrational spectrum for both the real and imaginary parts of the signal. Computationally, earlier time correlation function approaches were limited to short correlation times that made signal processing challenging. Here, this limitation is overcome, and well-averaged spectra are presented for the three independent polarization conditions that are possible for electronically nonresonant SFG. The theoretical spectra compare quite favorably in shape and relative magnitude to extant experimental results in the O H stretching region of water for all polarization geometries. The methodological improvements also allow the calculation of intermolecular SFG spectra. While the intermolecular spectrum of bulk water shows relatively little structure, the interfacial spectra (for polarizations that are sensitive to dipole derivatives normal to the interface—SSP and PPP) show a well-defined intermolecular mode at 875cm-1 that is comparable in intensity to the rest of the intermolecular structure, and has an intensity that is approximately one-sixth of the magnitude of the intense free OH stretching peak. Using instantaneous normal mode methods, the resonance is shown to be due to a wagging mode localized on a single water molecule, almost parallel to the interface, with two hydrogens displaced normal to the interface, and the oxygen anchored in the interface. We have also uncovered the origin of another intermolecular mode at 95cm-1 for the SSP and PPP spectra, and at 220cm-1 for the SPS spectra. These resonances are due to hindered translations perpendicular to the interface for the SSP and PPP spectra, and translations parallel to the interface for the SPS spectra. Further, by examining the real and imaginary parts of the SFG signal, several resonances are shown to be due to a single spectroscopic species while the "donor" OH region is shown to consist of three distinct species—consistent with an earlier experimental analysis.

Nursing management of sensory overload in psychiatry – development of a theoretical framework model

PubMed

Scheydt, Stefan; Needham, Ian; Nielsen, Gunnar H; Behrens, Johann

2016-09-01

Background: The concept of “removal from stimuli” has already been examined by a Delphi-Study. However, some knowledge gaps remained open, which have now been further investigated. Aim: Examination of the concept “management of sensory overload in inpatient psychiatry” including its sub-concepts and specific measures. Method: Analysis of qualitative data about “removal from stimuli” by content analysis according to Mayring. Results: A theoretical description and definition of the concept could be achieved. In addition, sub-concepts (removal from stimuli, modulation of environmental factors, help somebody to help him-/herself) could be identified, theoretical defined and complemented by possible specific measures. Conclusions: The conceptual descriptions provide a further step to raise awareness of professionals in the subject area. Furthermore, we created a theoretical basis for further empirical studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malheiro, Carine; Mendiboure, Bruno; Plantier, Frédéric

As a first step of an ongoing study of thermodynamic properties and adsorption of complex fluids in confined media, we present a new theoretical description for spherical monomers using the Statistical Associating Fluid Theory for potential of Variable Range (SAFT-VR) and a Non-Local Density Functional Theory (NLDFT) with Weighted Density Approximations (WDA). The well-known Modified Fundamental Measure Theory is used to describe the inhomogeneous hard-sphere contribution as a reference for the monomer and two WDA approaches are developed for the dispersive terms from the high-temperature Barker and Henderson perturbation expansion. The first approach extends the dispersive contributions using the scalarmore » and vector weighted densities introduced in the Fundamental Measure Theory (FMT) and the second one uses a coarse-grained (CG) approach with a unique weighted density. To test the accuracy of this new NLDFT/SAFT-VR coupling, the two versions of the theoretical model are compared with Grand Canonical Monte Carlo (GCMC) molecular simulations using the same molecular model. Only the version with the “CG” approach for the dispersive terms provides results in excellent agreement with GCMC calculations in a wide range of conditions while the “FMT” extension version gives a good representation solely at low pressures. Hence, the “CG” version of the theoretical model is used to reproduce methane adsorption isotherms in a Carbon Molecular Sieve and compared with experimental data after a characterization of the material. The whole results show an excellent agreement between modeling and experiments. Thus, through a complete and consistent comparison both with molecular simulations and with experimental data, the NLDFT/SAFT-VR theory has been validated for the description of monomers.« less

General Description of Fission Observables: GEF Model Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, K.-H.; Jurado, B., E-mail: jurado@cenbg.in2p3.fr; Amouroux, C.

2016-01-15

The GEF (“GEneral description of Fission observables”) model code is documented. It describes the observables for spontaneous fission, neutron-induced fission and, more generally, for fission of a compound nucleus from any other entrance channel, with given excitation energy and angular momentum. The GEF model is applicable for a wide range of isotopes from Z = 80 to Z = 112 and beyond, up to excitation energies of about 100 MeV. The results of the GEF model are compared with fission barriers, fission probabilities, fission-fragment mass- and nuclide distributions, isomeric ratios, total kinetic energies, and prompt-neutron and prompt-gamma yields and energymore » spectra from neutron-induced and spontaneous fission. Derived properties of delayed neutrons and decay heat are also considered. The GEF model is based on a general approach to nuclear fission that explains a great part of the complex appearance of fission observables on the basis of fundamental laws of physics and general properties of microscopic systems and mathematical objects. The topographic theorem is used to estimate the fission-barrier heights from theoretical macroscopic saddle-point and ground-state masses and experimental ground-state masses. Motivated by the theoretically predicted early localisation of nucleonic wave functions in a necked-in shape, the properties of the relevant fragment shells are extracted. These are used to determine the depths and the widths of the fission valleys corresponding to the different fission channels and to describe the fission-fragment distributions and deformations at scission by a statistical approach. A modified composite nuclear-level-density formula is proposed. It respects some features in the superfluid regime that are in accordance with new experimental findings and with theoretical expectations. These are a constant-temperature behaviour that is consistent with a considerably increased heat capacity and an increased pairing condensation energy that is consistent with the collective enhancement of the level density. The exchange of excitation energy and nucleons between the nascent fragments on the way from saddle to scission is estimated according to statistical mechanics. As a result, excitation energy and unpaired nucleons are predominantly transferred to the heavy fragment in the superfluid regime. This description reproduces some rather peculiar observed features of the prompt-neutron multiplicities and of the even-odd effect in fission-fragment Z distributions. For completeness, some conventional descriptions are used for calculating pre-equilibrium emission, fission probabilities and statistical emission of neutrons and gamma radiation from the excited fragments. Preference is given to simple models that can also be applied to exotic nuclei compared to more sophisticated models that need precise empirical input of nuclear properties, e.g. spectroscopic information. The approach reveals a high degree of regularity and provides a considerable insight into the physics of the fission process. Fission observables can be calculated with a precision that complies with the needs for applications in nuclear technology without specific adjustments to measured data of individual systems. The GEF executable runs out of the box with no need for entering any empirical data. This unique feature is of valuable importance, because the number of systems and energies of potential significance for fundamental and applied science will never be possible to be measured. The relevance of the approach for examining the consistency of experimental results and for evaluating nuclear data is demonstrated.« less

Pattern formation and filamentation in low temperature, magnetized plasmas - a numerical approach

NASA Astrophysics Data System (ADS)

Menati, Mohamad; Konopka, Uwe; Thomas, Edward

2017-10-01

In low-temperature discharges under the influence of high magnetic field, pattern and filament formation in the plasma has been reported by different groups. The phenomena present themselves as bright plasma columns (filaments) oriented parallel to the magnetic field lines at high magnetic field regime. The plasma structure can filament into different shapes from single columns to spiral and bright rings when viewed from the top. In spite of the extensive experimental observations, the observed effects lack a detailed theoretical and numerical description. In an attempt to numerically explain the plasma filamentation, we present a simplified model for the plasma discharge and power deposition into the plasma. Based on the model, 2-D and 3-D codes are being developed that solve Poisson's equation along with the fluid equations to obtain a self-consistent description of the plasma. The model and preliminary results applied to the specific plasma conditions will be presented. This work was supported by the US Dept. of Energy and NSF, DE-SC0016330, PHY-1613087.

Computer modeling describes gravity-related adaptation in cell cultures.

PubMed

Alexandrov, Ludmil B; Alexandrova, Stoyana; Usheva, Anny

2009-12-16

Questions about the changes of biological systems in response to hostile environmental factors are important but not easy to answer. Often, the traditional description with differential equations is difficult due to the overwhelming complexity of the living systems. Another way to describe complex systems is by simulating them with phenomenological models such as the well-known evolutionary agent-based model (EABM). Here we developed an EABM to simulate cell colonies as a multi-agent system that adapts to hyper-gravity in starvation conditions. In the model, the cell's heritable characteristics are generated and transferred randomly to offspring cells. After a qualitative validation of the model at normal gravity, we simulate cellular growth in hyper-gravity conditions. The obtained data are consistent with previously confirmed theoretical and experimental findings for bacterial behavior in environmental changes, including the experimental data from the microgravity Atlantis and the Hypergravity 3000 experiments. Our results demonstrate that it is possible to utilize an EABM with realistic qualitative description to examine the effects of hypergravity and starvation on complex cellular entities.

Failure of Local Thermal Equilibrium in Quantum Friction

NASA Astrophysics Data System (ADS)

Intravaia, F.; Behunin, R. O.; Henkel, C.; Busch, K.; Dalvit, D. A. R.

2016-09-01

Recent progress in manipulating atomic and condensed matter systems has instigated a surge of interest in nonequilibrium physics, including many-body dynamics of trapped ultracold atoms and ions, near-field radiative heat transfer, and quantum friction. Under most circumstances the complexity of such nonequilibrium systems requires a number of approximations to make theoretical descriptions tractable. In particular, it is often assumed that spatially separated components of a system thermalize with their immediate surroundings, although the global state of the system is out of equilibrium. This powerful assumption reduces the complexity of nonequilibrium systems to the local application of well-founded equilibrium concepts. While this technique appears to be consistent for the description of some phenomena, we show that it fails for quantum friction by underestimating by approximately 80% the magnitude of the drag force. Our results show that the correlations among the components of driven, but steady-state, quantum systems invalidate the assumption of local thermal equilibrium, calling for a critical reexamination of this approach for describing the physics of nonequilibrium systems.

Nursing Doctorates in Brazil: research formation and theses production

PubMed Central

Scochi, Carmen Gracinda Silvan; Gelbcke, Francine Lima; Ferreira, Márcia de Assunção; Lima, Maria Alice Dias da Silva; Padilha, Katia Grillo; Padovani, Nátali Artal; Munari, Denize Bouttelet

2015-01-01

OBJECTIVE: to analyze the formation of nursing doctorates in Brazil, from theses production, disciplines and other strategies focusing on research offered by courses. METHOD: a descriptive and analytical study of the performance of 18 doctoral courses in nursing, running from 1982 to 2010, and defended their theses between 2010-2012. RESULTS: 502 theses were defended in this period, most linked to the online research process of health and nursing care. There are gaps in the knowledge of theoretical and philosophical foundations of care, nursing history and ethics. There are also weaknesses in the methodological design of the theses, with a predominance of descriptive and/or exploratory studies. This was consistent with international standards set with regards to the proposition of research of disciplines and complementary strategies in forming the doctorate. CONCLUSION: despite the efforts and advances in research formation, it is essential to expand to more robust research designs with a greater impact on production knowledge that is incorporated into practice. PMID:26312630

Weak Galilean invariance as a selection principle for coarse-grained diffusive models.

PubMed

Cairoli, Andrea; Klages, Rainer; Baule, Adrian

2018-05-29

How does the mathematical description of a system change in different reference frames? Galilei first addressed this fundamental question by formulating the famous principle of Galilean invariance. It prescribes that the equations of motion of closed systems remain the same in different inertial frames related by Galilean transformations, thus imposing strong constraints on the dynamical rules. However, real world systems are often described by coarse-grained models integrating complex internal and external interactions indistinguishably as friction and stochastic forces. Since Galilean invariance is then violated, there is seemingly no alternative principle to assess a priori the physical consistency of a given stochastic model in different inertial frames. Here, starting from the Kac-Zwanzig Hamiltonian model generating Brownian motion, we show how Galilean invariance is broken during the coarse-graining procedure when deriving stochastic equations. Our analysis leads to a set of rules characterizing systems in different inertial frames that have to be satisfied by general stochastic models, which we call "weak Galilean invariance." Several well-known stochastic processes are invariant in these terms, except the continuous-time random walk for which we derive the correct invariant description. Our results are particularly relevant for the modeling of biological systems, as they provide a theoretical principle to select physically consistent stochastic models before a validation against experimental data.

Effects of the target aspect ratio and intrinsic reactivity onto diffusive search in bounded domains

NASA Astrophysics Data System (ADS)

Grebenkov, Denis S.; Metzler, Ralf; Oshanin, Gleb

2017-10-01

We study the mean first passage time (MFPT) to a reaction event on a specific site in a cylindrical geometry—characteristic, for instance, for bacterial cells, with a concentric inner cylinder representing the nuclear region of the bacterial cell. A similar problem emerges in the description of a diffusive search by a transcription factor protein for a specific binding region on a single strand of DNA. We develop a unified theoretical approach to study the underlying boundary value problem which is based on a self-consistent approximation of the mixed boundary condition. Our approach permits us to derive explicit, novel, closed-form expressions for the MFPT valid for a generic setting with an arbitrary relation between the system parameters. We analyse this general result in the asymptotic limits appropriate for the above-mentioned biophysical problems. Our investigation reveals the crucial role of the target aspect ratio and of the intrinsic reactivity of the binding region, which were disregarded in previous studies. Theoretical predictions are confirmed by numerical simulations.

Motion of Euglena gracilis: Active fluctuations and velocity distribution

NASA Astrophysics Data System (ADS)

Romanczuk, P.; Romensky, M.; Scholz, D.; Lobaskin, V.; Schimansky-Geier, L.

2015-07-01

We study the velocity distribution of unicellular swimming algae Euglena gracilis using optical microscopy and active Brownian particle theory. To characterize a peculiar feature of the experimentally observed distribution at small velocities we use the concept of active fluctuations, which was recently proposed for the description of stochastically self-propelled particles [Romanczuk, P. and Schimansky-Geier, L., Phys. Rev. Lett. 106, 230601 (2011)]. In this concept, the fluctuating forces arise due to internal random performance of the propulsive motor. The fluctuating forces are directed in parallel to the heading direction, in which the propulsion acts. In the theory, we introduce the active motion via the depot model [Schweitzer, et al., Phys. Rev. Lett. 80(23), 5044 (1998)]. We demonstrate that the theoretical predictions based on the depot model with active fluctuations are consistent with the experimentally observed velocity distributions. In addition to the model with additive active noise, we obtain theoretical results for a constant propulsion with multiplicative noise.

Basic medium oxidation of aromatic α-hydroxy-ketones: A free radical mechanism

NASA Astrophysics Data System (ADS)

Gómez-Vidales, Virginia; Vargas, Marina; Meléndez, Iván; Salmón, Manuel; Sansón-O, Carmen; Zaragoza, I. P.; Zolotukhin, Mikhail; Salcedo, Roberto

2010-01-01

A systematic study was undertaken of the EPR of sodium hydroxide solutions of Benzoin, Anisoin and Thenoin in both ethanol and DMSO as well as their corresponding ionised species of varying colours. In all cases, the EPR consist of symmetric spectra, resulting from the generation of a free radical-anion. Furthermore, theoretical DFT methods were applied in order to study the radical anions, revealing the reason for the colour change in the solutions and in the case of benzoin, found to be related to the interaction between the cis and trans-isomers with the molecules in the two solvents. We have defined the structure of the cis-isomer and for the first time we have described how the adduct between the cis-isomer and the solvent molecule, results in a stable conformer. This corresponds with the EPR results which indicated a significant difference between the cis and trans-isomers. Both the theoretical and experimental results inspired similar descriptions of the significant differences between the cis and trans-isomers in solution.

Uncertainties of predictions from parton distributions II: theoretical errors

NASA Astrophysics Data System (ADS)

Martin, A. D.; Roberts, R. G.; Stirling, W. J.; Thorne, R. S.

2004-06-01

We study the uncertainties in parton distributions, determined in global fits to deep inelastic and related hard scattering data, due to so-called theoretical errors. Amongst these, we include potential errors due to the change of perturbative order (NLO to NNLO), ln(1/x) and ln(1-x) effects, absorptive corrections and higher-twist contributions. We investigate these uncertainties both by including explicit corrections to our standard global analysis and by examining the sensitivity to changes of the x, Q 2, W 2 cuts on the data that are fitted. In this way we expose those kinematic regions where the conventional DGLAP description is inadequate. As a consequence we obtain a set of NLO, and of NNLO, conservative partons where the data are fully consistent with DGLAP evolution, but over a restricted kinematic domain. We also examine the potential effects of such issues as the choice of input parametrisation, heavy target corrections, assumptions about the strange quark sea and isospin violation. Hence we are able to compare the theoretical errors with those uncertainties due to errors on the experimental measurements, which we studied previously. We use W and Higgs boson production at the Tevatron and the LHC as explicit examples of the uncertainties arising from parton distributions. For many observables the theoretical error is dominant, but for the cross section for W production at the Tevatron both the theoretical and experimental uncertainties are small, and hence the NNLO prediction may serve as a valuable luminosity monitor.

Computer Series, 13.

ERIC Educational Resources Information Center

Moore, John W., Ed.

1981-01-01

Provides short descriptions of chemists' applications of computers in instruction: an interactive instructional program for Instrumental-Qualitative Organic Analysis; question-and-answer exercises in organic chemistry; computerized organic nomenclature drills; integration of theoretical and descriptive materials; acid-base titration simulation;…

Kinetic description of rotating Tokamak plasmas with anisotropic temperatures in the collisionless regime

NASA Astrophysics Data System (ADS)

Cremaschini, Claudio; Tessarotto, Massimo

2011-11-01

A largely unsolved theoretical issue in controlled fusion research is the consistent kinetic treatment of slowly-time varying plasma states occurring in collisionless and magnetized axisymmetric plasmas. The phenomenology may include finite pressure anisotropies as well as strong toroidal and poloidal differential rotation, characteristic of Tokamak plasmas. Despite the fact that physical phenomena occurring in fusion plasmas depend fundamentally on the microscopic particle phase-space dynamics, their consistent kinetic treatment remains still essentially unchallenged to date. The goal of this paper is to address the problem within the framework of Vlasov-Maxwell description. The gyrokinetic treatment of charged particles dynamics is adopted for the construction of asymptotic solutions for the quasi-stationary species kinetic distribution functions. These are expressed in terms of the particle exact and adiabatic invariants. The theory relies on a perturbative approach, which permits to construct asymptotic analytical solutions of the Vlasov-Maxwell system. In this way, both diamagnetic and energy corrections are included consistently into the theory. In particular, by imposing suitable kinetic constraints, the existence of generalized bi-Maxwellian asymptotic kinetic equilibria is pointed out. The theory applies for toroidal rotation velocity of the order of the ion thermal speed. These solutions satisfy identically also the constraints imposed by the Maxwell equations, i.e., quasi-neutrality and Ampere's law. As a result, it is shown that, in the presence of nonuniform fluid and EM fields, these kinetic equilibria can sustain simultaneously toroidal differential rotation, quasi-stationary finite poloidal flows and temperature anisotropy.

Toward a Theoretical Model of Decision-Making and Resistance to Change among Higher Education Online Course Designers

ERIC Educational Resources Information Center

Dodd, Bucky J.

2013-01-01

Online course design is an emerging practice in higher education, yet few theoretical models currently exist to explain or predict how the diffusion of innovations occurs in this space. This study used a descriptive, quantitative survey research design to examine theoretical relationships between decision-making style and resistance to change…

Speech-Language and Nutritional Sciences in hospital environment: analysis of terminology of food consistencies classification.

PubMed

Amaral, Ana Cláudia Fernandes; Rodrigues, Lívia Azevedo; Furlan, Renata Maria Moreira Moraes; Vicente, Laélia Cristina Caseiro; Motta, Andréa Rodrigues

2015-01-01

To verify if there is an agreement between speech-language pathologists and nutritionists about the classification of food textures used in hospitals and their opinions about the possible consequences of differences in this classification. This is a descriptive, cross-sectional study with 30 speech-language pathologists and 30 nutritionists who worked in 14 hospitals of public and/or private network in Belo Horizonte, Brazil. The professionals answered a questionnaire, prepared by the researchers, and classified five different foods, with and without theoretical direction. The data were analyzed using Fisher's exact and Z -tests to compare ratios with a 5% significance level. Both speech-language therapists (100%) and nutritionists (90%) perceive divergence in the classification and, 86.2% and 100% of them, respectively, believe that this difference may affect the patients' recovery. Aspiration risk was the most mentioned problem. For the general classification of food textures, most of the professionals (88.5%) suggested four to six terms. As to the terminology used in the classification of food presented without theoretical direction, the professionals cited 49 terms and agreed only in the solid and liquid classifications. With theoretical direction, the professionals also agreed in the classification of thick and thin paste. Both the professionals recognized divergences in the classification of food textures and the consequent risk of damage to patient's recovery. The use of theoretical direction increased the agreement between these professionals.

Mueller matrix mapping of biological polycrystalline layers using reference wave

NASA Astrophysics Data System (ADS)

Dubolazov, A.; Ushenko, O. G.; Ushenko, Yu. O.; Pidkamin, L. Y.; Sidor, M. I.; Grytsyuk, M.; Prysyazhnyuk, P. V.

2018-01-01

The paper consists of two parts. The first part is devoted to the short theoretical basics of the method of differential Mueller-matrix description of properties of partially depolarizing layers. It was provided the experimentally measured maps of differential matrix of the 1st order of polycrystalline structure of the histological section of brain tissue. It was defined the statistical moments of the 1st-4th orders, which characterize the distribution of matrix elements. In the second part of the paper it was provided the data of statistic analysis of birefringence and dichroism of the histological sections of mice liver tissue (normal and with diabetes). It were defined the objective criteria of differential diagnostics of diabetes.

The comparison of approaches to the solid-state NMR-based structural refinement of vitamin B1 hydrochloride and of its monohydrate

NASA Astrophysics Data System (ADS)

Czernek, Jiří; Pawlak, Tomasz; Potrzebowski, Marek J.; Brus, Jiří

2013-01-01

The 13C and 15N CPMAS SSNMR measurements were accompanied by the proper theoretical description of the solid-phase environment, as provided by the density functional theory in the pseudopotential plane-wave scheme, and employed in refining the atomic coordinates of the crystal structures of thiamine chloride hydrochloride and of its monohydrate. Thus, using the DFT functionals PBE, PW91 and RPBE, the SSNMR-consistent solid-phase structures of these compounds are derived from the geometrical optimization, which is followed by an assessment of the fits of the GIPAW-predicted values of the chemical shielding parameters to their experimental counterparts.

On the computation of the turbulent flow near rough surface

NASA Astrophysics Data System (ADS)

Matveev, S. K.; Jaychibekov, N. Zh.; Shalabayeva, B. S.

2018-05-01

One of the problems in constructing mathematical models of turbulence is a description of the flows near a rough surface. An experimental study of such flows is also difficult because of the impossibility of measuring "inside" the roughness. The theoretical calculation is difficult because of the lack of equations describing the flow in this zone. In this paper, a new turbulence model based on the differential equation of turbulent viscosity balance was used to describe a turbulent flow near a rough surface. The difference between the new turbulence model and the previously known consists in the choice of constants and functions that determine the generation, dissipation and diffusion of viscosity.

A Theoretical Construct for Interpreting Photographs.

ERIC Educational Resources Information Center

Barrett, Terry

1986-01-01

Past categorizations of photographs are critiqued, and a new category system is offered that asks viewers to consider photographs as if they were analogous to various types of language statements: descriptive, explanatory, interpretive, ethically evaluative, aesthetically evaluative, and theoretical. (Author/RM)

How important is self-consistency for the dDsC density dependent dispersion correction?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brémond, Éric; Corminboeuf, Clémence, E-mail: clemence.corminboeuf@epfl.ch; Golubev, Nikolay

2014-05-14

The treatment of dispersion interactions is ubiquitous but computationally demanding for seamless ab initio approaches. A highly popular and simple remedy consists in correcting for the missing interactions a posteriori by adding an attractive energy term summed over all atom pairs to standard density functional approximations. These corrections were originally based on atom pairwise parameters and, hence, had a strong touch of empiricism. To overcome such limitations, we recently proposed a robust system-dependent dispersion correction, dDsC, that is computed from the electron density and that provides a balanced description of both weak inter- and intramolecular interactions. From the theoretical pointmore » of view and for the sake of increasing reliability, we here verify if the self-consistent implementation of dDsC impacts ground-state properties such as interaction energies, electron density, dipole moments, geometries, and harmonic frequencies. In addition, we investigate the suitability of the a posteriori scheme for molecular dynamics simulations, for which the analysis of the energy conservation constitutes a challenging tests. Our study demonstrates that the post-SCF approach in an excellent approximation.« less

Characteristics of Qualitative Descriptive Studies: A Systematic Review

PubMed Central

Kim, Hyejin; Sefcik, Justine S.; Bradway, Christine

2016-01-01

Qualitative description (QD) is a term that is widely used to describe qualitative studies of health care and nursing-related phenomena. However, limited discussions regarding QD are found in the existing literature. In this systematic review, we identified characteristics of methods and findings reported in research articles published in 2014 whose authors identified the work as QD. After searching and screening, data were extracted from the sample of 55 QD articles and examined to characterize research objectives, design justification, theoretical/philosophical frameworks, sampling and sample size, data collection and sources, data analysis, and presentation of findings. In this review, three primary findings were identified. First, despite inconsistencies, most articles included characteristics consistent with limited, available QD definitions and descriptions. Next, flexibility or variability of methods was common and desirable for obtaining rich data and achieving understanding of a phenomenon. Finally, justification for how a QD approach was chosen and why it would be an appropriate fit for a particular study was limited in the sample and, therefore, in need of increased attention. Based on these findings, recommendations include encouragement to researchers to provide as many details as possible regarding the methods of their QD study so that readers can determine whether the methods used were reasonable and effective in producing useful findings. PMID:27686751

Self-consistent DFT +U method for real-space time-dependent density functional theory calculations

NASA Astrophysics Data System (ADS)

Tancogne-Dejean, Nicolas; Oliveira, Micael J. T.; Rubio, Angel

2017-12-01

We implemented various DFT+U schemes, including the Agapito, Curtarolo, and Buongiorno Nardelli functional (ACBN0) self-consistent density-functional version of the DFT +U method [Phys. Rev. X 5, 011006 (2015), 10.1103/PhysRevX.5.011006] within the massively parallel real-space time-dependent density functional theory (TDDFT) code octopus. We further extended the method to the case of the calculation of response functions with real-time TDDFT+U and to the description of noncollinear spin systems. The implementation is tested by investigating the ground-state and optical properties of various transition-metal oxides, bulk topological insulators, and molecules. Our results are found to be in good agreement with previously published results for both the electronic band structure and structural properties. The self-consistent calculated values of U and J are also in good agreement with the values commonly used in the literature. We found that the time-dependent extension of the self-consistent DFT+U method yields improved optical properties when compared to the empirical TDDFT+U scheme. This work thus opens a different theoretical framework to address the nonequilibrium properties of correlated systems.

Metalinguistic Negation in English and Arabic

ERIC Educational Resources Information Center

Nedwick, Kelly M.

2014-01-01

Negation is a unique and fascinating property of human language which has been given extensive theoretical and typological treatment. One categorization divides negation use into metalinguistic negation and descriptive negation (Horn, 1985). Descriptive negation (DN) is the truth-functional semantic operator which has received the most attention…

A Behavior-Analytic Account of Motivational Interviewing

ERIC Educational Resources Information Center

Christopher, Paulette J.; Dougher, Michael J.

2009-01-01

Several published reports have now documented the clinical effectiveness of motivational interviewing (MI). Despite its effectiveness, there are no generally accepted or empirically supported theoretical accounts of its effects. The theoretical accounts that do exist are mentalistic, descriptive, and not based on empirically derived behavioral…

Self-consistent field theory and numerical scheme for calculating the phase diagram of wormlike diblock copolymers

NASA Astrophysics Data System (ADS)

Jiang, Ying; Chen, Jeff Z. Y.

2013-10-01

This paper concerns establishing a theoretical basis and numerical scheme for studying the phase behavior of AB diblock copolymers made of wormlike chains. The general idea of a self-consistent field theory is the combination of the mean-field approach together with a statistical weight that describes the configurational properties of a polymer chain. In recent years, this approach has been extensively used for structural prediction of block copolymers, based on the Gaussian-model description of a polymer chain. The wormlike-chain model has played an important role in the description of polymer systems, covering the semiflexible-to-rod crossover of the polymer properties and the highly stretching regime, which the Gaussian-chain model has difficulties to describe. Although the idea of developing a self-consistent field theory for wormlike chains could be traced back to early development in polymer physics, the solution of such a theory has been limited due to technical difficulties. In particular, a challenge has been to develop a numerical algorithm enabling the calculation of the phase diagram containing three-dimensional structures for wormlike AB diblock copolymers. This paper describes a computational algorithm that combines a number of numerical tricks, which can be used for such a calculation. A phase diagram covering major parameter areas was constructed for the wormlike-chain system and reported by us, where the ratio between the total length and the persistence length of a constituent polymer is suggested as another tuning parameter for the microphase-separated structures; all detailed technical issues are carefully addressed in the current paper.

Vesicle solubilization by bile salts: comparison of macroscopic theory and simulation.

PubMed

Haustein, M; Wahab, M; Mögel, H-J; Schiller, P

2015-04-14

Lipid metabolism is accompanied by the solubilization of lipid bilayer membranes by bile salts. We use Brownian dynamics simulations to study the solubilization of model membranes and vesicles by sodium cholate. The solubilization pathways of small and large vesicles are found to be different. Both results for small and large vesicles can be compared with predictions of a macroscopic theoretical description. The line tension of bilayer edges is an important parameter in the solubilization process. We propose a simple method to determine the line tension by analyzing the shape fluctuations of planar membrane patches. Macroscopic mechanical models provide a reasonable explanation for processes observed when a spherical vesicle consisting of lipids and adsorbed bile salt molecules is transformed into mixed lipid-bile salt micelles.

Higher-order correlations for fluctuations in the presence of fields.

PubMed

Boer, A; Dumitru, S

2002-10-01

The higher-order moments of the fluctuations for thermodynamic systems in the presence of fields are investigated in the framework of a theoretical method. The method uses a generalized statistical ensemble consistent with an adequate expression for the internal energy. The applications refer to the case of a system in a magnetoquasistatic field. In the case of linear magnetic media, one finds that, for the description of the magnetic induction fluctuations, the Gaussian approximation is satisfactory. For nonlinear media, the corresponding fluctuations are non-Gaussian, having a non-null asymmetry. Furthermore, the respective fluctuations have characteristics of leptokurtic, mesokurtic and platykurtic type, depending on the value of the magnetic field strength as compared with a scaling factor of the magnetization curve.

3D Mueller-matrix mapping of biological optically anisotropic networks

NASA Astrophysics Data System (ADS)

Ushenko, O. G.; Ushenko, V. O.; Bodnar, G. B.; Zhytaryuk, V. G.; Prydiy, O. G.; Koval, G.; Lukashevich, I.; Vanchuliak, O.

2018-01-01

The paper consists of two parts. The first part presents short theoretical basics of the method of azimuthally-invariant Mueller-matrix description of optical anisotropy of biological tissues. It was provided experimentally measured coordinate distributions of Mueller-matrix invariants (MMI) of linear and circular birefringences of skeletal muscle tissue. It was defined the values of statistic moments, which characterize the distributions of amplitudes of wavelet coefficients of MMI at different scales of scanning. The second part presents the data of statistic analysis of the distributions of amplitude of wavelet coefficients of the distributions of linear birefringence of myocardium tissue died after the infarction and ischemic heart disease. It was defined the objective criteria of differentiation of the cause of death.

Multiscale polarization diagnostics of birefringent networks in problems of necrotic changes diagnostics

NASA Astrophysics Data System (ADS)

Sakhnovskiy, M. Yu.; Ushenko, Yu. O.; Ushenko, V. O.; Besaha, R. N.; Pavlyukovich, N.; Pavlyukovich, O.

2018-01-01

The paper consists of two parts. The first part presents short theoretical basics of the method of azimuthally-invariant Mueller-matrix description of optical anisotropy of biological tissues. It was provided experimentally measured coordinate distributions of Mueller-matrix invariants (MMI) of linear and circular birefringences of skeletal muscle tissue. It was defined the values of statistic moments, which characterize the distributions of amplitudes of wavelet coefficients of MMI at different scales of scanning. The second part presents the data of statistic analysis of the distributions of amplitude of wavelet coefficients of the distributions of linear birefringence of myocardium tissue died after the infarction and ischemic heart disease. It was defined the objective criteria of differentiation of the cause of death.

Wavelet analysis of birefringence images of myocardium tissue

NASA Astrophysics Data System (ADS)

Sakhnovskiy, M. Yu.; Ushenko, Yu. O.; Kushnerik, L.; Soltys, I. V.; Pavlyukovich, N.; Pavlyukovich, O.

2018-01-01

The paper consists of two parts. The first part presents short theoretical basics of the method of azimuthally-invariant Mueller-matrix description of optical anisotropy of biological tissues. It was provided experimentally measured coordinate distributions of Mueller-matrix invariants (MMI) of linear and circular birefringences of skeletal muscle tissue. It was defined the values of statistic moments, which characterize the distributions of amplitudes of wavelet coefficients of MMI at different scales of scanning. The second part presents the data of statistic analysis of the distributions of amplitude of wavelet coefficients of the distributions of linear birefringence of myocardium tissue died after the infarction and ischemic heart disease. It was defined the objective criteria of differentiation of the cause of death.

Stratospheric warmings: Synoptic, dynamic and general-circulation aspects

NASA Technical Reports Server (NTRS)

Mcinturff, R. M. (Editor)

1978-01-01

Synoptic descriptions consist largely of case studies, which involve a distinction between major and minor warmings. Results of energetics studies show the importance of tropospheric-stratospheric interaction, and the significance of the pressure-work term near the tropopause. Theoretical studies have suggested the role of wave-zonal flow interaction as well as nonlinear interaction between eddies, chemical and photochemical reactions, boundary forcing, and other factors. Numerical models have been based on such considerations, and these are discussed under various categories. Some indication is given as to why some of the models have been more successful than others in simulating warnings. The question of ozone and its role in warmings is briefly discussed. Finally, a broad view is taken of stratospheric warmings in relation to man's activities.

Continuing Education for E-Resources

ERIC Educational Resources Information Center

Grogg, Jill E.

2008-01-01

Library schools may be teaching some of the theoretical framework necessary to perform the duties of electronic resource librarianship. However, a gap remains "between practical needs, as expressed in position descriptions, and the theoretical way in which library school courses address those needs." To fill this gap, professional associations…

Complete integrability of information processing by biochemical reactions

PubMed Central

Agliari, Elena; Barra, Adriano; Dello Schiavo, Lorenzo; Moro, Antonio

2016-01-01

Statistical mechanics provides an effective framework to investigate information processing in biochemical reactions. Within such framework far-reaching analogies are established among (anti-) cooperative collective behaviors in chemical kinetics, (anti-)ferromagnetic spin models in statistical mechanics and operational amplifiers/flip-flops in cybernetics. The underlying modeling – based on spin systems – has been proved to be accurate for a wide class of systems matching classical (e.g. Michaelis–Menten, Hill, Adair) scenarios in the infinite-size approximation. However, the current research in biochemical information processing has been focusing on systems involving a relatively small number of units, where this approximation is no longer valid. Here we show that the whole statistical mechanical description of reaction kinetics can be re-formulated via a mechanical analogy – based on completely integrable hydrodynamic-type systems of PDEs – which provides explicit finite-size solutions, matching recently investigated phenomena (e.g. noise-induced cooperativity, stochastic bi-stability, quorum sensing). The resulting picture, successfully tested against a broad spectrum of data, constitutes a neat rationale for a numerically effective and theoretically consistent description of collective behaviors in biochemical reactions. PMID:27812018

Titan's Ionic Species: Theoretical Treatment of N2H+ and Related Ions

NASA Astrophysics Data System (ADS)

Brites, V.; Hochlaf, M.

2009-06-01

We use different ab initio methods to compute the three-dimensional potential energy surface (3D-PES) of the ground state of N2H+. This includes the standard coupled cluster, the complete active space self-consistent field, the internally contacted multi reference configuration interaction, and the newly developed CCSD(T)-F12 methods. For the description of H and N atoms, several basis sets are tested. Then, we incorporate the 3D-PES analytical representations into variational calculations of the rovibrational spectrum of N2H+(X˜1Σ+) up to 7200 cm-1 above the zero point vibrational energy. Our data show that the CCSD(T)-F12/aug-cc-pVTZ approach represents a compromise for good description of the PES and computation cost. This technique is recommended for full dimensional PES generation of atmospheric and astrophysical relevant polyatomic systems. We applied this method to derive the rovibrational spectra of N2H+(X˜1Σ+) and of N2H++(X˜2Σ+). Finally, we discuss the existence of the N2H++(X˜2Σ+) in Titan's atmosphere.

Failure of local thermal equilibrium in quantum friction

DOE PAGES

Intravaia, Francesco; Behunin, Ryan; Henkel, Carsten; ...

2016-09-01

Recent progress in manipulating atomic and condensed matter systems has instigated a surge of interest in nonequilibrium physics, including many-body dynamics of trapped ultracold atoms and ions, near-field radiative heat transfer, and quantum friction. Under most circumstances the complexity of such nonequilibrium systems requires a number of approximations to make theoretical descriptions tractable. In particular, it is often assumed that spatially separated components of a system thermalize with their immediate surroundings, although the global state of the system is out of equilibrium. This powerful assumption reduces the complexity of nonequilibrium systems to the local application of well-founded equilibrium concepts. Whilemore » this technique appears to be consistent for the description of some phenomena, we show that it fails for quantum friction by underestimating by approximately 80% the magnitude of the drag force. Here, our results show that the correlations among the components of driven, but steady-state, quantum systems invalidate the assumption of local thermal equilibrium, calling for a critical reexamination of this approach for describing the physics of nonequilibrium systems.« less

Complete integrability of information processing by biochemical reactions

NASA Astrophysics Data System (ADS)

Agliari, Elena; Barra, Adriano; Dello Schiavo, Lorenzo; Moro, Antonio

2016-11-01

Statistical mechanics provides an effective framework to investigate information processing in biochemical reactions. Within such framework far-reaching analogies are established among (anti-) cooperative collective behaviors in chemical kinetics, (anti-)ferromagnetic spin models in statistical mechanics and operational amplifiers/flip-flops in cybernetics. The underlying modeling - based on spin systems - has been proved to be accurate for a wide class of systems matching classical (e.g. Michaelis-Menten, Hill, Adair) scenarios in the infinite-size approximation. However, the current research in biochemical information processing has been focusing on systems involving a relatively small number of units, where this approximation is no longer valid. Here we show that the whole statistical mechanical description of reaction kinetics can be re-formulated via a mechanical analogy - based on completely integrable hydrodynamic-type systems of PDEs - which provides explicit finite-size solutions, matching recently investigated phenomena (e.g. noise-induced cooperativity, stochastic bi-stability, quorum sensing). The resulting picture, successfully tested against a broad spectrum of data, constitutes a neat rationale for a numerically effective and theoretically consistent description of collective behaviors in biochemical reactions.

Complete integrability of information processing by biochemical reactions.

PubMed

Agliari, Elena; Barra, Adriano; Dello Schiavo, Lorenzo; Moro, Antonio

2016-11-04

Statistical mechanics provides an effective framework to investigate information processing in biochemical reactions. Within such framework far-reaching analogies are established among (anti-) cooperative collective behaviors in chemical kinetics, (anti-)ferromagnetic spin models in statistical mechanics and operational amplifiers/flip-flops in cybernetics. The underlying modeling - based on spin systems - has been proved to be accurate for a wide class of systems matching classical (e.g. Michaelis-Menten, Hill, Adair) scenarios in the infinite-size approximation. However, the current research in biochemical information processing has been focusing on systems involving a relatively small number of units, where this approximation is no longer valid. Here we show that the whole statistical mechanical description of reaction kinetics can be re-formulated via a mechanical analogy - based on completely integrable hydrodynamic-type systems of PDEs - which provides explicit finite-size solutions, matching recently investigated phenomena (e.g. noise-induced cooperativity, stochastic bi-stability, quorum sensing). The resulting picture, successfully tested against a broad spectrum of data, constitutes a neat rationale for a numerically effective and theoretically consistent description of collective behaviors in biochemical reactions.

Unconventional and conventional quantum criticalities in CeRh0.58Ir0.42In5

NASA Astrophysics Data System (ADS)

Luo, Yongkang; Lu, Xin; Dioguardi, Aadm P.; Rosa, Priscila F. S.; Bauer, Eric D.; Si, Qimiao; Thompson, Joe D.

2018-03-01

An appropriate description of the state of matter that appears as a second order phase transition is tuned toward zero temperature, viz. quantum-critical point (QCP), poses fundamental and still not fully answered questions. Experiments are needed both to test basic conclusions and to guide further refinement of theoretical models. Here, charge and entropy transport properties as well as AC specific heat of the heavy-fermion compound CeRh0.58Ir0.42In5, measured as a function of pressure, reveal two qualitatively different QCPs in a single material driven by a single non-symmetry-breaking tuning parameter. A discontinuous sign-change jump in thermopower suggests an unconventional QCP at pc1 accompanied by an abrupt Fermi-surface reconstruction that is followed by a conventional spin-density-wave critical point at pc2 across which the Fermi surface evolves smoothly to a heavy Fermi-liquid state. These experiments are consistent with some theoretical predictions, including the sequence of critical points and the temperature dependence of the thermopower in their vicinity.

Particle Interactions Mediated by Dynamical Networks: Assessment of Macroscopic Descriptions

NASA Astrophysics Data System (ADS)

Barré, J.; Carrillo, J. A.; Degond, P.; Peurichard, D.; Zatorska, E.

2018-02-01

We provide a numerical study of the macroscopic model of Barré et al. (Multiscale Model Simul, 2017, to appear) derived from an agent-based model for a system of particles interacting through a dynamical network of links. Assuming that the network remodeling process is very fast, the macroscopic model takes the form of a single aggregation-diffusion equation for the density of particles. The theoretical study of the macroscopic model gives precise criteria for the phase transitions of the steady states, and in the one-dimensional case, we show numerically that the stationary solutions of the microscopic model undergo the same phase transitions and bifurcation types as the macroscopic model. In the two-dimensional case, we show that the numerical simulations of the macroscopic model are in excellent agreement with the predicted theoretical values. This study provides a partial validation of the formal derivation of the macroscopic model from a microscopic formulation and shows that the former is a consistent approximation of an underlying particle dynamics, making it a powerful tool for the modeling of dynamical networks at a large scale.

Multidisciplinary approaches to understanding collective cell migration in developmental biology.

PubMed

Schumacher, Linus J; Kulesa, Paul M; McLennan, Rebecca; Baker, Ruth E; Maini, Philip K

2016-06-01

Mathematical models are becoming increasingly integrated with experimental efforts in the study of biological systems. Collective cell migration in developmental biology is a particularly fruitful application area for the development of theoretical models to predict the behaviour of complex multicellular systems with many interacting parts. In this context, mathematical models provide a tool to assess the consistency of experimental observations with testable mechanistic hypotheses. In this review, we showcase examples from recent years of multidisciplinary investigations of neural crest cell migration. The neural crest model system has been used to study how collective migration of cell populations is shaped by cell-cell interactions, cell-environmental interactions and heterogeneity between cells. The wide range of emergent behaviours exhibited by neural crest cells in different embryonal locations and in different organisms helps us chart out the spectrum of collective cell migration. At the same time, this diversity in migratory characteristics highlights the need to reconcile or unify the array of currently hypothesized mechanisms through the next generation of experimental data and generalized theoretical descriptions. © 2016 The Authors.

Instability of elliptic liquid jets: Temporal linear stability theory and experimental analysis

NASA Astrophysics Data System (ADS)

Amini, Ghobad; Lv, Yu; Dolatabadi, Ali; Ihme, Matthias

2014-11-01

The instability dynamics of inviscid liquid jets issuing from elliptical orifices is studied, and effects of the surrounding gas and the liquid surface tension on the stability behavior are investigated. A dispersion relation for the zeroth azimuthal (axisymmetric) instability mode is derived. Consistency of the analysis is confirmed by demonstrating that these equations reduce to the well-known dispersion equations for the limiting cases of round and planar jets. It is shown that the effect of the ellipticity is to increase the growth rate over a large range of wavenumbers in comparison to those of a circular jet. For higher Weber numbers, at which capillary forces have a stabilizing effect, the growth rate decreases with increasing ellipticity. Similar to circular and planar jets, increasing the density ratio between gas and liquid increases the growth of disturbances significantly. These theoretical investigations are complemented by experiments to validate the local linear stability results. Comparisons of predicted growth rates with measurements over a range of jet ellipticities confirm that the theoretical model provides a quantitatively accurate description of the instability dynamics in the Rayleigh and first wind-induced regimes.

Particle Interactions Mediated by Dynamical Networks: Assessment of Macroscopic Descriptions.

PubMed

Barré, J; Carrillo, J A; Degond, P; Peurichard, D; Zatorska, E

2018-01-01

We provide a numerical study of the macroscopic model of Barré et al. (Multiscale Model Simul, 2017, to appear) derived from an agent-based model for a system of particles interacting through a dynamical network of links. Assuming that the network remodeling process is very fast, the macroscopic model takes the form of a single aggregation-diffusion equation for the density of particles. The theoretical study of the macroscopic model gives precise criteria for the phase transitions of the steady states, and in the one-dimensional case, we show numerically that the stationary solutions of the microscopic model undergo the same phase transitions and bifurcation types as the macroscopic model. In the two-dimensional case, we show that the numerical simulations of the macroscopic model are in excellent agreement with the predicted theoretical values. This study provides a partial validation of the formal derivation of the macroscopic model from a microscopic formulation and shows that the former is a consistent approximation of an underlying particle dynamics, making it a powerful tool for the modeling of dynamical networks at a large scale.

The Large-Scale Structure of Scientific Method

ERIC Educational Resources Information Center

Kosso, Peter

2009-01-01

The standard textbook description of the nature of science describes the proposal, testing, and acceptance of a theoretical idea almost entirely in isolation from other theories. The resulting model of science is a kind of piecemeal empiricism that misses the important network structure of scientific knowledge. Only the large-scale description of…

Chiral electroweak currents in nuclei

DOE PAGES

Riska, D. O.; Schiavilla, R.

2017-01-10

Here, the development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown’s role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.

Two Types of Definites in Natural Language

ERIC Educational Resources Information Center

Schwarz, Florian

2009-01-01

This thesis is concerned with the description and analysis of two semantically different types of definite articles in German. While the existence of distinct article paradigms in various Germanic dialects and other languages has been acknowledged in the descriptive literature for quite some time, the theoretical implications of their existence…

Prose Style and Critical Reading.

ERIC Educational Resources Information Center

Cluett, Robert

This book is based on the York Computer Inventory of Prose Style, which seeks to provide a quantitative description of the syntactic characteristics of the literary language of specific authors over the last 400 years. After a brief theoretical introduction and a description of texts and sampling procedures, the discussion turns to specific…

Therapeutic Theory and Social Context: A Social Constructionist Perspective.

ERIC Educational Resources Information Center

Lynch, Gordon

1997-01-01

Explores the foundation of therapeutic theory from the perspective of social constructionism. Proposes a theoretical description of the interaction between an individual and the social context in the formation of therapeutic theory. Then explores this description in relation to the early life and subsequent therapeutic theory of Carl Rogers. (RJM)

Semiotic and Theoretic Control in Argumentation and Proof Activities

ERIC Educational Resources Information Center

Arzarello, Ferdinando; Sabena, Cristina

2011-01-01

We present a model to analyze the students' activities of argumentation and proof in the graphical context of Elementary Calculus. The theoretical background is provided by the integration of Toulmin's structural description of arguments, Peirce's notions of sign, diagrammatic reasoning and abduction, and Habermas' model for rational behavior.…

A Theoretical Trombone

ERIC Educational Resources Information Center

LoPresto, Michael C.

2014-01-01

What follows is a description of a theoretical model designed to calculate the playing frequencies of the musical pitches produced by a trombone. The model is based on quantitative treatments that demonstrate the effects of the flaring bell and cup-shaped mouthpiece sections on these frequencies and can be used to calculate frequencies that…

An experimental and theoretical study of the flow phenomena within a vortex sink rate sensor. Ph.D. Thesis - Old Dominion Univ.

NASA Technical Reports Server (NTRS)

Patel, D. K.

1974-01-01

A description of the flow field within a vortex sink rate sensor was obtained, and the influence of viscous effects on its performance was observed. The sensor basically consisted of a vortex chamber and a sink tube. The vortex chamber consisted of two circular coaxial disks held apart, at their periphery, by a porous coupling. One circular disk had an opening to permit the mounting of the sink tube, in such a manner that the vortex chamber as well as the sink tube had a common axis of rotation. Air was supplied radially to the sensor through its porous coupling as the sensor was rotated at various speeds. Particular emphasis was directed toward an understanding of the flow field in the sink tube region. Thus velocity measurements at various stations along the length of the sink tube as well as along a given radius at any designated station were taken.

Work production of quantum rotor engines

NASA Astrophysics Data System (ADS)

Seah, Stella; Nimmrichter, Stefan; Scarani, Valerio

2018-04-01

We study the mechanical performance of quantum rotor heat engines in terms of common notions of work using two prototypical models: a mill driven by the heat flow from a hot to a cold mode, and a piston driven by the alternate heating and cooling of a single working mode. We evaluate the extractable work in terms of ergotropy, the kinetic energy associated to net directed rotation, as well as the intrinsic work based on the exerted torque under autonomous operation, and we compare them to the energy output for the case of an external dissipative load and for externally driven engine cycles. Our results connect work definitions from both physical and information-theoretical perspectives. In particular, we find that apart from signatures of angular momentum quantization, the ergotropy is consistent with the intuitive notion of work in the form of net directed motion. It also agrees with the energy output to an external load or agent under optimal conditions. This sets forth a consistent thermodynamical description of rotating quantum motors, flywheels, and clocks.

The pull in olympic weightlifting.

PubMed

Enoka, R M

1979-01-01

Data from five experienced weightlifters on the vertical forces applied to the barbell and system (barbell and lifter) during the pull were in excellent agreement with earlier displacement-time descriptions of the double knee bend as consisting of two stages of extension interrupted by a period of realignment (second knee bend). The vertical component of the ground reaction force (Rz) consisted of three phases: Weighting I, Unweighting, and Weighting II. The relative magnitude of the Rz impulse with respect to the system weight impulse (as an indicant of the proportion of the Rz impulse contributing to system acceleration) ranged from 118--141% for Weighting I, 74--89% for Unweighting, and 122--135% for Weighting II. In agreement with published theoretical calculations the most experienced and successful lifter produced the larger phase of positive acceleration first. The rebending of the knees was associated with the Unweighting phase. Although this latter interval corresponded to a phase of barbell deceleration, it appeared that the concomitant enhancement of the back, hip, and knee extensor activity outweighed any adverse effects.

Derivation and Applicability of Asymptotic Results for Multiple Subtests Person-Fit Statistics

PubMed Central

Albers, Casper J.; Meijer, Rob R.; Tendeiro, Jorge N.

2016-01-01

In high-stakes testing, it is important to check the validity of individual test scores. Although a test may, in general, result in valid test scores for most test takers, for some test takers, test scores may not provide a good description of a test taker’s proficiency level. Person-fit statistics have been proposed to check the validity of individual test scores. In this study, the theoretical asymptotic sampling distribution of two person-fit statistics that can be used for tests that consist of multiple subtests is first discussed. Second, simulation study was conducted to investigate the applicability of this asymptotic theory for tests of finite length, in which the correlation between subtests and number of items in the subtests was varied. The authors showed that these distributions provide reasonable approximations, even for tests consisting of subtests of only 10 items each. These results have practical value because researchers do not have to rely on extensive simulation studies to simulate sampling distributions. PMID:29881053

Flory-type theories of polymer chains under different external stimuli

NASA Astrophysics Data System (ADS)

Budkov, Yu A.; Kiselev, M. G.

2018-01-01

In this Review, we present a critical analysis of various applications of the Flory-type theories to a theoretical description of the conformational behavior of single polymer chains in dilute polymer solutions under a few external stimuli. Different theoretical models of flexible polymer chains in the supercritical fluid are discussed and analysed. Different points of view on the conformational behavior of the polymer chain near the liquid-gas transition critical point of the solvent are presented. A theoretical description of the co-solvent-induced coil-globule transitions within the implicit-solvent-explicit-co-solvent models is discussed. Several explicit-solvent-explicit-co-solvent theoretical models of the coil-to-globule-to-coil transition of the polymer chain in a mixture of good solvents (co-nonsolvency) are analysed and compared with each other. Finally, a new theoretical model of the conformational behavior of the dielectric polymer chain under the external constant electric field in the dilute polymer solution with an explicit account for the many-body dipole correlations is discussed. The polymer chain collapse induced by many-body dipole correlations of monomers in the context of statistical thermodynamics of dielectric polymers is analysed.

Nature of electrogenerated intermediates in nitro-substituted nor-β-lapachones: the structure of radical species during successive electron transfer in multiredox centers.

PubMed

Armendáriz-Vidales, Georgina; Hernández-Muñoz, Lindsay S; González, Felipe J; de Souza, Antonio A; de Abreu, Fabiane C; Jardim, Guilherme A M; da Silva, Eufrânio N; Goulart, Marilia O F; Frontana, Carlos

2014-06-06

Electrochemical, spectroelectrochemical, and theoretical studies of the reduction reactions in nor-β-lapachone derivatives including a nitro redox center showed that reduction of the compounds involves the formation of several radical intermediates, including a biradical dianion resultant from the separate reduction of the quinone and nitro groups in the molecules. Theoretical descriptions of the corresponding Fukui functions f(αα)⁺ and f(ββ)⁺(r) and LUMO densities considering finite differences and frozen core approximations for describing the changes in electron and spin densities of the system allowed us to confirm these results. A description of the potential relationship with the obtained results and biological activity selectivity indexes suggests that both the formation of stable biradical dianion species and the stability of the semiquinone intermediates during further reduction are determining factors in the description of their biological activity.

Animal Metacognition: A Tale of Two Comparative Psychologies

PubMed Central

Smith, J. David; Couchman, Justin J.; Beran, Michael J.

2014-01-01

A growing literature considers whether animals have capacities that are akin to human metacognition (i. e., humans’ capacity to monitor their states of uncertainty and knowing). Comparative psychologists have approached this question by testing a dolphin, pigeons, rats, monkeys and apes using perception, memory and food-concealment paradigms. As part of this consideration, some associative modelers have attempted to describe animals’ “metacognitive” performances in low-level, associative terms—an important goal if achievable. The authors summarize the empirical and theoretical situation regarding these associative descriptions. The associative descriptions in the animal-metacognition literature fail to encompass important phenomena. The sharp focus on abstract, mathematical associative models creates serious interpretative problems. The authors compare these failed associative descriptions to an alternative theoretical approach within contemporary comparative psychology. The alternative approach has the potential to strengthen comparative psychology as an empirical science and integrate it more fully within the mainstream of experimental psychology and cognitive science. PMID:23957740

Multiblob coarse-graining for mixtures of long polymers and soft colloids

NASA Astrophysics Data System (ADS)

Locatelli, Emanuele; Capone, Barbara; Likos, Christos N.

2016-11-01

Soft nanocomposites represent both a theoretical and an experimental challenge due to the high number of the microscopic constituents that strongly influence the behaviour of the systems. An effective theoretical description of such systems invokes a reduction of the degrees of freedom to be analysed, hence requiring the introduction of an efficient, quantitative, coarse-grained description. We here report on a novel coarse graining approach based on a set of transferable potentials that quantitatively reproduces properties of mixtures of linear and star-shaped homopolymeric nanocomposites. By renormalizing groups of monomers into a single effective potential between a f-functional star polymer and an homopolymer of length N0, and through a scaling argument, it will be shown how a substantial reduction of the to degrees of freedom allows for a full quantitative description of the system. Our methodology is tested upon full monomer simulations for systems of different molecular weight, proving its full predictive potential.

Creating an Innovative Learning Organization

ERIC Educational Resources Information Center

Salisbury, Mark

2010-01-01

This article describes how to create an innovative learning (iLearning) organization. It begins by discussing the life cycle of knowledge in an organization, followed by a description of the theoretical foundation for iLearning. Next, the article presents an example of iLearning, followed by a description of the distributed nature of work, the…

Sentence Adverbs in the Kingdom of Agree

ERIC Educational Resources Information Center

Shu, Chih-hsiang

2011-01-01

This dissertation offers a novel account of the syntax of sentence adverbs. The need for a new account is clear from the lack of descriptive coverage and theoretical coherence in current work on adverbial syntax. Descriptively, the majority of work has so far neglected the fact that sentence adverbs behave syntactically like typical focusing…

Mobile Router Testing with Diverse RF Communications Links

NASA Technical Reports Server (NTRS)

Brooks, David; Hoder, Doug; Wilkins, Ryan

2004-01-01

This is a short report on demonstrations using Mobile IP and several diverse physical communications links to connect a mobile network to a fixed IPv4 internet. The first section is a description of the equipment used, followed by descriptions of the tests, the theoretical results, and finally conclusions and the actual data.

The Status of the Concept of "Phoneme" in Psycholinguistics

ERIC Educational Resources Information Center

Uppstad, Per Henning; Tonnessen, Finn Egil

2010-01-01

The notion of the phoneme counts as a break-through of modern theoretical linguistics in the early twentieth century. It paved the way for descriptions of distinctive features at different levels in linguistics. Although it has since then had a turbulent existence across altering theoretical positions, it remains a powerful concept of a…

Content Based Image Retrieval and Information Theory: A General Approach.

ERIC Educational Resources Information Center

Zachary, John; Iyengar, S. S.; Barhen, Jacob

2001-01-01

Proposes an alternative real valued representation of color based on the information theoretic concept of entropy. A theoretical presentation of image entropy is accompanied by a practical description of the merits and limitations of image entropy compared to color histograms. Results suggest that image entropy is a promising approach to image…

Preparing Teachers to Teach English as an International Language

ERIC Educational Resources Information Center

Matsuda, Aya, Ed.

2017-01-01

This book explores ways to prepare teachers to teach English as an International Language (EIL) and provides theoretically-grounded models for EIL-informed teacher education. The volume includes two chapters that present a theoretical approach and principles in EIL teacher education, followed by a collection of descriptions of field-tested teacher…

From information theory to quantitative description of steric effects.

PubMed

Alipour, Mojtaba; Safari, Zahra

2016-07-21

Immense efforts have been made in the literature to apply the information theory descriptors for investigating the electronic structure theory of various systems. In the present study, the information theoretic quantities, such as Fisher information, Shannon entropy, Onicescu information energy, and Ghosh-Berkowitz-Parr entropy, have been used to present a quantitative description for one of the most widely used concepts in chemistry, namely the steric effects. Taking the experimental steric scales for the different compounds as benchmark sets, there are reasonable linear relationships between the experimental scales of the steric effects and theoretical values of steric energies calculated from information theory functionals. Perusing the results obtained from the information theoretic quantities with the two representations of electron density and shape function, the Shannon entropy has the best performance for the purpose. On the one hand, the usefulness of considering the contributions of functional groups steric energies and geometries, and on the other hand, dissecting the effects of both global and local information measures simultaneously have also been explored. Furthermore, the utility of the information functionals for the description of steric effects in several chemical transformations, such as electrophilic and nucleophilic reactions and host-guest chemistry, has been analyzed. The functionals of information theory correlate remarkably with the stability of systems and experimental scales. Overall, these findings show that the information theoretic quantities can be introduced as quantitative measures of steric effects and provide further evidences of the quality of information theory toward helping theoreticians and experimentalists to interpret different problems in real systems.

Characteristics of Qualitative Descriptive Studies: A Systematic Review.

PubMed

Kim, Hyejin; Sefcik, Justine S; Bradway, Christine

2017-02-01

Qualitative description (QD) is a term that is widely used to describe qualitative studies of health care and nursing-related phenomena. However, limited discussions regarding QD are found in the existing literature. In this systematic review, we identified characteristics of methods and findings reported in research articles published in 2014 whose authors identified the work as QD. After searching and screening, data were extracted from the sample of 55 QD articles and examined to characterize research objectives, design justification, theoretical/philosophical frameworks, sampling and sample size, data collection and sources, data analysis, and presentation of findings. In this review, three primary findings were identified. First, although there were some inconsistencies, most articles included characteristics consistent with the limited available QD definitions and descriptions. Next, flexibility or variability of methods was common and effective for obtaining rich data and achieving understanding of a phenomenon. Finally, justification for how a QD approach was chosen and why it would be an appropriate fit for a particular study was limited in the sample and, therefore, in need of increased attention. Based on these findings, recommendations include encouragement to researchers to provide as many details as possible regarding the methods of their QD studies so that readers can determine whether the methods used were reasonable and effective in producing useful findings. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Hybrid-DFT  +  V w method for band structure calculation of semiconducting transition metal compounds: the case of cerium dioxide.

PubMed

Ivády, Viktor; Gali, Adam; Abrikosov, Igor A

2017-11-15

Hybrid functionals' non-local exchange-correlation potential contains a derivative discontinuity that improves on standard semi-local density functional theory (DFT) band gaps. Moreover, by careful parameterization, hybrid functionals can provide self-interaction reduced description of selected states. On the other hand, the uniform description of all the electronic states of a given system is a known drawback of these functionals that causes varying accuracy in the description of states with different degrees of localization. This limitation can be remedied by the orbital dependent exact exchange extension of hybrid functionals; the hybrid-DFT  +  V w method (Ivády et al 2014 Phys. Rev. B 90 035146). Based on the analogy of quasi-particle equations and hybrid-DFT single particle equations, here we demonstrate that parameters of hybrid-DFT  +  V w functional can be determined from approximate theoretical quasi-particle spectra without any fitting to experiment. The proposed method is illustrated on the charge self-consistent electronic structure calculation for cerium dioxide where itinerant valence states interact with well-localized 4f atomic like states, making this system challenging for conventional methods, either hybrid-DFT or LDA  +  U, and therefore allowing for a demonstration of the advantages of the proposed scheme.

Building Vietnamese Herbal Database Towards Big Data Science in Nature-Based Medicine

DTIC Science & Technology

2018-01-04

metabolites, diseases, and geography in order to convey a composite description of each individual species. VHO consists of 2881 species, 10887 metabolites...plants, metabolites, diseases, and geography in order to convey a composite description of each individual species. VHO consists of 2881 species...feature description are extremely diverse and highly redundant. Besides the original words or the key words for description , there are millions of

Apollo 14 rock samples

NASA Technical Reports Server (NTRS)

Carlson, I. C.

1978-01-01

Petrographic descriptions of all Apollo 14 samples larger than 1 cm in any dimension are presented. The sample description format consists of: (1) an introductory section which includes information on lunar sample location, orientation, and return containers, (2) a section on physical characteristics, which contains the sample mass, dimensions, and a brief description; (3) surface features, including zap pits, cavities, and fractures as seen in binocular view; (4) petrographic description, consisting of a binocular description and, if possible, a thin section description; and (5) a discussion of literature relevant to sample petrology is included for samples which have previously been examined by the scientific community.

Self-Consistent Ring Current Modeling with Propagating Electromagnetic Ion Cyclotron Waves in the Presence of Heavy Ions

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Gamayunov, K. V.; Gallagher, D. L.; Kozyra, J. U.; Liemohn, M. W.

2006-01-01

The self-consistent treatment of the RC ion dynamics and EMlC waves, which are thought to exert important influences on the ion dynamical evolution, is an important missing element in our understanding of the storm-and recovery-time ring current evolution. Under certain conditions, relativistic electrons, with energies greater than or equal to 1 MeV, can be removed from the outer radiation belt by EMlC wave scattering during a magnetic storm (Summers and Thorne, 2003; Albert, 2003). That is why the modeling of EMlC waves is critical and timely issue in magnetospheric physics. This study will generalize the self-consistent theoretical description of RC ions and EMlC waves that has been developed by Khazanov et al. [2002, 2003] and include the heavy ions and propagation effects of EMlC waves in the global dynamic of self-consistent RC - EMlC waves coupling. The results of our newly developed model that will be presented at Huntsville 2006 meeting, focusing mainly on the dynamic of EMlC waves and comparison of these results with the previous global RC modeling studies devoted to EMlC waves formation. We also discuss RC ion precipitations and wave induced thermal electron fluxes into the ionosphere.

Baryon spectrum of SU(4) composite Higgs theory with two distinct fermion representations

NASA Astrophysics Data System (ADS)

Ayyar, Venkitesh; DeGrand, Thomas; Hackett, Daniel C.; Jay, William I.; Neil, Ethan T.; Shamir, Yigal; Svetitsky, Benjamin

2018-06-01

We use lattice simulations to compute the baryon spectrum of SU(4) lattice gauge theory coupled to dynamical fermions in the fundamental and two-index antisymmetric (sextet) representations simultaneously. This model is closely related to a composite Higgs model in which the chimera baryon made up of fermions from both representations plays the role of a composite top-quark partner. The dependence of the baryon masses on each underlying fermion mass is found to be generally consistent with a quark-model description and large-Nc scaling. We combine our numerical results with experimental bounds on the scale of the new strong sector to estimate a lower bound on the mass of the top-quark partner. We discuss some theoretical uncertainties associated with this estimate.

Observation of a novel stapler band in 75As

NASA Astrophysics Data System (ADS)

Li, C. G.; Chen, Q. B.; Zhang, S. Q.; Xu, C.; Hua, H.; Li, X. Q.; Wu, X. G.; Hu, S. P.; Meng, J.; Xu, F. R.; Liang, W. Y.; Li, Z. H.; Ye, Y. L.; Jiang, D. X.; Sun, J. J.; Han, R.; Niu, C. Y.; Chen, X. C.; Li, P. J.; Wang, C. G.; Wu, H. Y.; Li, G. S.; He, C. Y.; Zheng, Y.; Li, C. B.; Chen, Q. M.; Zhong, J.; Zhou, W. K.

2017-03-01

The heavy ion fusion-evaporation reaction study for the high-spin spectroscopy of 75As has been performed via the reaction channel 70Zn(9Be, 1p3n)75As at a beam energy of 42 MeV. The collective structure especially a dipole band in 75As is established for the first time. The properties of this dipole band are investigated in terms of the self-consistent tilted axis cranking covariant density functional theory. Based on the theoretical description and the examination of the angular momentum components, this dipole band can be interpreted as a novel stapler band, where the valence neutrons in (1g9/2) orbital rather than the collective core are responsible for the closing of the stapler of angular momentum.

Neutrino-nucleus interactions at the LBNF near detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosel, Ulrich

2015-10-15

The reaction mechanisms for neutrino interactions with an {sup 40}Ar nucleus with the LBNF flux are calculated with the Giessen-Boltzmann-Uehling-Uhlenbeck (GiBUU) transport-theoretical implementation of these interactions. Quasielastic scattering, many-body effects, pion production and absorption and Deep Inelastic Scattering are discussed; they all play a role at the LBNF energies and are experimentally entangled with each other. Quasielastic scattering makes up for only about 1/3 of the total cross section whereas pion production channels make up about 2/3 of the total. This underlines the need for a consistent description of the neutrino-nucleus reaction that treats all channels on an equal, consistentmore » footing. The results discussed here can also serve as useful guideposts for the Intermediate Neutrino Program.« less

Variable Sweep Transition Flight Experiment (VSTFE): Unified Stability System (USS). Description and Users' Manual

NASA Technical Reports Server (NTRS)

Rozendaal, Rodger A.; Behbehani, Roxanna

1990-01-01

NASA initiated the Variable Sweep Transition Flight Experiment (VSTFE) to establish a boundary layer transition database for laminar flow wing design. For this experiment, full-span upper surface gloves were fitted to a variable sweep F-14 aircraft. The development of an improved laminar boundary layer stability analysis system called the Unified Stability System (USS) is documented and results of its use on the VSTFE flight data are shown. The USS consists of eight computer codes. The theoretical background of the system is described, as is the input, output, and usage hints. The USS is capable of analyzing boundary layer stability over a wide range of disturbance frequencies and orientations, making it possible to use different philosophies in calculating the growth of disturbances on sweptwings.

Differential 3D Mueller-matrix mapping of optically anisotropic depolarizing biological layers

NASA Astrophysics Data System (ADS)

Ushenko, O. G.; Grytsyuk, M.; Ushenko, V. O.; Bodnar, G. B.; Vanchulyak, O.; Meglinskiy, I.

2018-01-01

The paper consists of two parts. The first part is devoted to the short theoretical basics of the method of differential Mueller-matrix description of properties of partially depolarizing layers. It was provided the experimentally measured maps of differential matrix of the 2nd order of polycrystalline structure of the histological section of rectum wall tissue. It was defined the values of statistical moments of the1st-4th orders, which characterize the distribution of matrix elements. In the second part of the paper it was provided the data of statistic analysis of birefringence and dichroism of the histological sections of connecting component of vagina wall tissue (normal and with prolapse). It were defined the objective criteria of differential diagnostics of pathologies of vagina wall.

A revised B(E2;2+ 1 → 0+ 1) value in the semi-magic nucleus 210Po

NASA Astrophysics Data System (ADS)

Kocheva, D.; Rainovski, G.; Jolie, J.; Pietralla, N.; Blazhev, A.; Astier, A.; Altenkirch, R.; Ansari, S.; Braunroth, Th.; Cortés, M. L.; Dewald, A.; Diel, F.; Djongolov, M.; Fransen, C.; Gladnishki, K.; Hennig, A.; Karayonchev, V.; Keatings, J. M.; Kluge, E.; Litzinger, J.; Müller-Gatermann, C.; Petkov, P.; Rudigier, M.; Scheck, M.; Scholz, Ph.; Spagnoletti, P.; Spieker, M.; Stahl, C.; Stegmann, R.; Stoyanova, M.; Thöle, P.; Warr, N.; Werner, V.; Witt, W.; Wölk, D.; Zell, K. O.; Van Isacker, P.; Ponomarev, V. Yu.

2017-09-01

The lifetimes of the 2^+_1 , the 2^+_2 and the 3^-_1 states of 210Po have been measured in the 208Pb(12C,10Be)210Po transfer reaction by the Doppler-shift attenuation method. The result for the lifetime of the 2^+_1 state is about three times shorter than the adopted value. However, the new value still does not allow for a consistent description of the properties of the yrast 2^+_1 , 4^+_1 , 6^+_1 , and 8^+_1 states of 210Po in the framework of nuclear shell models. Quasi-particle Phonon Model (QPM) calculations also cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

Field theories and fluids for an interacting dark sector

NASA Astrophysics Data System (ADS)

Carrillo González, Mariana; Trodden, Mark

2018-02-01

We consider the relationship between fluid models of an interacting dark sector and the field theoretical models that underlie such descriptions. This question is particularly important in light of suggestions that such interactions may help alleviate a number of current tensions between different cosmological datasets. We construct consistent field theory models for an interacting dark sector that behave exactly like the coupled fluid ones, even at the level of linear perturbations, and can be trusted deep in the nonlinear regime. As a specific example, we focus on the case of a Dirac, Born-Infeld (DBI) field conformally coupled to a quintessence field. We show that the fluid linear regime breaks before the field gradients become large; this means that the field theory is valid inside a large region of the fluid nonlinear regime.

Theory of periodic swarming of bacteria: Application to Proteus mirabilis

NASA Astrophysics Data System (ADS)

Czirók, A.; Matsushita, M.; Vicsek, T.

2001-03-01

The periodic swarming of bacteria is one of the simplest examples for pattern formation produced by the self-organized collective behavior of a large number of organisms. In the spectacular colonies of Proteus mirabilis (the most common species exhibiting this type of growth), a series of concentric rings are developed as the bacteria multiply and swarm following a scenario that periodically repeats itself. We have developed a theoretical description for this process in order to obtain a deeper insight into some of the typical processes governing the phenomena in systems of many interacting living units. Our approach is based on simple assumptions directly related to the latest experimental observations on colony formation under various conditions. The corresponding one-dimensional model consists of two coupled differential equations investigated here both by numerical integrations and by analyzing the various expressions obtained from these equations using a few natural assumptions about the parameters of the model. We determine the phase diagram corresponding to systems exhibiting periodic swarming, and discuss in detail how the various stages of the colony development can be interpreted in our framework. We point out that all of our theoretical results are in excellent agreement with the complete set of available observations. Thus the present study represents one of the few examples where self-organized biological pattern formation is understood within a relatively simple theoretical approach, leading to results and predictions fully compatible with experiments.

Signals of strong electronic correlation in ion scattering processes

NASA Astrophysics Data System (ADS)

Bonetto, F.; Gonzalez, C.; Goldberg, E. C.

2016-05-01

Previous measurements of neutral atom fractions for S r+ scattered by gold polycrystalline surfaces show a singular dependence with the target temperature. There is still not a theoretical model that can properly describe the magnitude and the temperature dependence of the neutralization probabilities found. Here, we applied a first-principles quantum-mechanical theoretical formalism to describe the time-dependent scattering process. Three different electronic correlation approaches consistent with the system analyzed are used: (i) the spinless approach, where two charge channels are considered (S r0 and S r+ ) and the spin degeneration is neglected; (ii) the infinite-U approach, with the same charge channels (S r0 and S r+ ) but considering the spin degeneration; and (iii) the finite-U approach, where the first ionization and second ionization energy levels are considered very, but finitely, separated. Neutral fraction magnitudes and temperature dependence are better described by the finite-U approach, indicating that e -correlation plays a significant role in charge-transfer processes. However, none of them is able to explain the nonmonotonous temperature dependence experimentally obtained. Here, we suggest that small changes in the surface work function introduced by the target heating, and possibly not detected by experimental standard methods, could be responsible for that singular behavior. Additionally, we apply the same theoretical model using the infinite-U approximation for the Mg-Au system, obtaining an excellent description of the experimental neutral fractions measured.

Detection Identification and Quantification of Keto-Hydroperoxides in Low-Temperature Oxidation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, Nils; Moshammer, Kai; Jasper, Ahren W.

2017-07-01

Keto-hydroperoxides are reactive partially oxidized intermediates that play a central role in chain-branching reactions during the low-temperature oxidation of hydrocarbons. In this Perspective, we outline how these short lived species can be detected, identified, and quantified using integrated experimental and theoretical approaches. The procedures are based on direct molecular-beam sampling from reactive environments, followed by mass spectrometry with single-photon ionization, identification of fragmentation patterns, and theoretical calculations of ionization thresholds, fragment appearance energies, and photoionization cross sections. Using the oxidation of neo-pentane and tetrahydrofuran as examples, the individual steps of the experimental approaches are described in depth together with amore » detailed description of the theoretical efforts. For neo-pentane, the experimental data are consistent with the calculated ionization and fragment appearance energies of the keto-hydroperoxide, thus adding confidence to the analysis routines and the employed levels of theory. For tetrahydrofuran, multiple keto-hydroperoxide isomers are possible due to the presence of nonequivalent O 2 addition sites. Despite this additional complexity, the experimental data allow for the identification of two to four keto-hydroperoxides. Mole fraction profiles of the keto-hydroperoxides, which are quantified using calculated photoionization cross sections, are provided together with estimated uncertainties as function of the temperature of the reactive mixture and can serve as validation targets for chemically detailed mechanisms.« less

Contact Kinetics in Fractal Macromolecules.

PubMed

Dolgushev, Maxim; Guérin, Thomas; Blumen, Alexander; Bénichou, Olivier; Voituriez, Raphaël

2015-11-13

We consider the kinetics of first contact between two monomers of the same macromolecule. Relying on a fractal description of the macromolecule, we develop an analytical method to compute the mean first contact time for various molecular sizes. In our theoretical description, the non-Markovian feature of monomer motion, arising from the interactions with the other monomers, is captured by accounting for the nonequilibrium conformations of the macromolecule at the very instant of first contact. This analysis reveals a simple scaling relation for the mean first contact time between two monomers, which involves only their equilibrium distance and the spectral dimension of the macromolecule, independently of its microscopic details. Our theoretical predictions are in excellent agreement with numerical stochastic simulations.

Experimental validation of a quasi-steady theory for the flow through the glottis

NASA Astrophysics Data System (ADS)

Vilain, C. E.; Pelorson, X.; Fraysse, C.; Deverge, M.; Hirschberg, A.; Willems, J.

2004-09-01

In this paper a theoretical description of the flow through the glottis based on a quasi-steady boundary layer theory is presented. The Thwaites method is used to solve the von Kármán equations within the boundary layers. In practice this makes the theory much easier to use compared to Pohlhausen's polynomial approximations. This theoretical description is evaluated on the basis of systematic comparison with experimental data obtained under steady flow or unsteady (oscillating) flow without and with moving vocal folds. Results tend to show that the theory reasonably explains the measured data except when unsteady or viscous terms become predominant. This happens particularly during the collision of the vocal folds.

Issues in Developing a Normative Descriptive Model for Dyadic Decision Making

NASA Technical Reports Server (NTRS)

Serfaty, D.; Kleinman, D. L.

1984-01-01

Most research in modelling human information processing and decision making has been devoted to the case of the single human operator. In the present effort, concepts from the fields of organizational behavior, engineering psychology, team theory and mathematical modelling are merged in an attempt to consider first the case of two cooperating decisionmakers (the Dyad) in a multi-task environment. Rooted in the well-known Dynamic Decision Model (DDM), the normative descriptive approach brings basic cognitive and psychophysical characteristics inherent to human behavior into a team theoretic analytic framework. An experimental paradigm, involving teams in dynamic decision making tasks, is designed to produce the data with which to build the theoretical model.

Feature highlighting enhances learning of a complex natural-science category.

PubMed

Miyatsu, Toshiya; Gouravajhala, Reshma; Nosofsky, Robert M; McDaniel, Mark A

2018-04-26

Learning naturalistic categories, which tend to have fuzzy boundaries and vary on many dimensions, can often be harder than learning well defined categories. One method for facilitating the category learning of naturalistic stimuli may be to provide explicit feature descriptions that highlight the characteristic features of each category. Although this method is commonly used in textbooks and classrooms, theoretically it remains uncertain whether feature descriptions should advantage learning complex natural-science categories. In three experiments, participants were trained on 12 categories of rocks, either without or with a brief description highlighting key features of each category. After training, they were tested on their ability to categorize both old and new rocks from each of the categories. Providing feature descriptions as a caption under a rock image failed to improve category learning relative to providing only the rock image with its category label (Experiment 1). However, when these same feature descriptions were presented such that they were explicitly linked to the relevant parts of the rock image (feature highlighting), participants showed significantly higher performance on both immediate generalization to new rocks (Experiment 2) and generalization after a 2-day delay (Experiment 3). Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Experiencing Mathematics for Connected Understanding: Using the RAMR Framework for Accelerating Students' Learning

ERIC Educational Resources Information Center

Nutchey, David; Grant, Edlyn; English, Lyn

2016-01-01

This paper reports on the use of the RAMR framework within a curriculum project. Description of the RAMR framework's theoretical bases is followed by two descriptions of students' learning in the classroom. Implications include the need for the teacher to connect student activities in a structured sequence, although this may be predicated on the…

Failover Switching Tests Between Two RF Communications Links

NASA Technical Reports Server (NTRS)

Brooks, David; Frantz, Brian; Hoder, Doug; Wilkins, Ryan

2003-01-01

This work presents a short report on the routing tests of the Ku band satcom and VHF line-of-sight communications systems on the Advanced Air Transportation Technologies (AATT) Aero/Mobile van. The first section is a description of the equipment used, followed by descriptions of the tests, the theoretical results, and finally, conclusions and the actual data.

Numerical Investigation of Plasma Detachment in Magnetic Nozzle Experiments

NASA Technical Reports Server (NTRS)

Sankaran, Kamesh; Polzin, Kurt A.

2008-01-01

At present there exists no generally accepted theoretical model that provides a consistent physical explanation of plasma detachment from an externally-imposed magnetic nozzle. To make progress towards that end, simulation of plasma flow in the magnetic nozzle of an arcjet experiment is performed using a multidimensional numerical simulation tool that includes theoretical models of the various dispersive and dissipative processes present in the plasma. This is an extension of the simulation tool employed in previous work by Sankaran et al. The aim is to compare the computational results with various proposed magnetic nozzle detachment theories to develop an understanding of the physical mechanisms that cause detachment. An applied magnetic field topology is obtained using a magnetostatic field solver (see Fig. I), and this field is superimposed on the time-dependent magnetic field induced in the plasma to provide a self-consistent field description. The applied magnetic field and model geometry match those found in experiments by Kuriki and Okada. This geometry is modeled because there is a substantial amount of experimental data that can be compared to the computational results, allowing for validation of the model. In addition, comparison of the simulation results with the experimentally obtained plasma parameters will provide insight into the mechanisms that lead to plasma detachment, revealing how they scale with different input parameters. Further studies will focus on modeling literature experiments both for the purpose of additional code validation and to extract physical insight regarding the mechanisms driving detachment.

Using synthetic biology to make cells tomorrow's test tubes.

PubMed

Garcia, Hernan G; Brewster, Robert C; Phillips, Rob

2016-04-18

The main tenet of physical biology is that biological phenomena can be subject to the same quantitative and predictive understanding that physics has afforded in the context of inanimate matter. However, the inherent complexity of many of these biological processes often leads to the derivation of complex theoretical descriptions containing a plethora of unknown parameters. Such complex descriptions pose a conceptual challenge to the establishment of a solid basis for predictive biology. In this article, we present various exciting examples of how synthetic biology can be used to simplify biological systems and distill these phenomena down to their essential features as a means to enable their theoretical description. Here, synthetic biology goes beyond previous efforts to engineer nature and becomes a tool to bend nature to understand it. We discuss various recent and classic experiments featuring applications of this synthetic approach to the elucidation of problems ranging from bacteriophage infection, to transcriptional regulation in bacteria and in developing embryos, to evolution. In all of these examples, synthetic biology provides the opportunity to turn cells into the equivalent of a test tube, where biological phenomena can be reconstituted and our theoretical understanding put to test with the same ease that these same phenomena can be studied in the in vitro setting.

Academic training and clinical placement problems to achieve nursing competency

PubMed Central

RAHMATI SHARGHI, NARJES; ALAMI, ALI; KHOSRAVAN, SHAHLA; MANSOORIAN, MOHAMMAD REZA; EKRAMI, ALI

2015-01-01

Introduction: High quality of care is one of the requirements of nursing which depends on the nursing competency. In this connection, the aim of this research was to determine the problems related to the academic training (nursing' educational program) and clinical practice to achieve competency from the viewpoint of nurses, faculty members, and nursing students. Methods: the study was an analytical cross-sectional one. The sample consisted of the academic staff, the third and the fourth year nursing students and nurses in practice. The instrument of the study was a two-part researcher-made questionnaire with 22 questions in the theoretical- clinical realm to assess  problems related to the theoretical and clinical teaching in nursing, and 23 questions to assess the clinical functions. The questionnaire was validated in terms of both face and content validity. Its reliability, using Cronbach's Alpha coefficient, was 0.72 in the theoretical-clinical and 0.73 in the clinical realm. Both descriptive and analytical statistics were used to analyze the data, using SPSS software. Results: The results of this study indicated that from the participants’ viewpoints, the most important problems in the academic education for nursea to acquire competency were as follows: lack of academic research the clinical period (88.9%), no application of theoretical aspects of the nursing process in practice (85.6%), insufficient knowledgeable and professional educators (81.1%), the use of traditional routine-oriented methods on the wards (75.6%); also insufficient time for performance based on knowledge in relation to  the nurse's workload (86.5%), weakness and usefulness of scientific function encouragement systems in clinic (85.2%), and learnt theoretical subjects not coming into practice in clinical fields after graduation (75.6%). Conclusion: Efforts to reduce the gap between the theoretical and practical (clinical function) knowledge in educational and work environment are required to improve the training of qualified nurses. PMID:25587550

Steepest entropy ascent model for far-nonequilibrium thermodynamics: Unified implementation of the maximum entropy production principle

NASA Astrophysics Data System (ADS)

Beretta, Gian Paolo

2014-10-01

By suitable reformulations, we cast the mathematical frameworks of several well-known different approaches to the description of nonequilibrium dynamics into a unified formulation valid in all these contexts, which extends to such frameworks the concept of steepest entropy ascent (SEA) dynamics introduced by the present author in previous works on quantum thermodynamics. Actually, the present formulation constitutes a generalization also for the quantum thermodynamics framework. The analysis emphasizes that in the SEA modeling principle a key role is played by the geometrical metric with respect to which to measure the length of a trajectory in state space. In the near-thermodynamic-equilibrium limit, the metric tensor is directly related to the Onsager's generalized resistivity tensor. Therefore, through the identification of a suitable metric field which generalizes the Onsager generalized resistance to the arbitrarily far-nonequilibrium domain, most of the existing theories of nonequilibrium thermodynamics can be cast in such a way that the state exhibits the spontaneous tendency to evolve in state space along the path of SEA compatible with the conservation constraints and the boundary conditions. The resulting unified family of SEA dynamical models is intrinsically and strongly consistent with the second law of thermodynamics. The non-negativity of the entropy production is a general and readily proved feature of SEA dynamics. In several of the different approaches to nonequilibrium description we consider here, the SEA concept has not been investigated before. We believe it defines the precise meaning and the domain of general validity of the so-called maximum entropy production principle. Therefore, it is hoped that the present unifying approach may prove useful in providing a fresh basis for effective, thermodynamically consistent, numerical models and theoretical treatments of irreversible conservative relaxation towards equilibrium from far nonequilibrium states. The mathematical frameworks we consider are the following: (A) statistical or information-theoretic models of relaxation; (B) small-scale and rarefied gas dynamics (i.e., kinetic models for the Boltzmann equation); (C) rational extended thermodynamics, macroscopic nonequilibrium thermodynamics, and chemical kinetics; (D) mesoscopic nonequilibrium thermodynamics, continuum mechanics with fluctuations; and (E) quantum statistical mechanics, quantum thermodynamics, mesoscopic nonequilibrium quantum thermodynamics, and intrinsic quantum thermodynamics.

Instability of surface electron cyclotron TM-modes influenced by non-monochromatic alternating electric field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Girka, I. O., E-mail: igorgirka@karazin.ua; Girka, V. O.; Sydora, R. D.

2016-06-15

The influence of non-monochromaticity of an external alternating electric field on excitation of TM eigenmodes at harmonics of the electron cyclotron frequency is considered here. These TM-modes propagate along the plasma interface in a metal waveguide. An external static constant magnetic field is oriented perpendicularly to the plasma interface. The problem is solved theoretically using the kinetic Vlasov-Boltzmann equation for description of plasma particles motion and the Maxwell equations for description of the electromagnetic mode fields. The external alternating electric field is supposed to be a superposition of two waves, whose amplitudes are different and their frequencies correlate as 2:1.more » An infinite set of equations for electric field harmonics of these modes is derived with the aid of nonlinear boundary conditions. This set is solved using the wave packet approach consisting of the main harmonic frequency and two nearest satellite temporal harmonics. Analytical studies of the obtained set of equations allow one to find two different regimes of parametric instability, namely, enhancement and suppression of the instability. Numerical analysis of the instability is carried out for the three first electron cyclotron harmonics.« less

Investigation of Fluctuation-Induced Electron Transport in Hall Thrusters with a 2D Hybrid Code in the Azimuthal and Axial Coordinates

NASA Astrophysics Data System (ADS)

Fernandez, Eduardo; Borelli, Noah; Cappelli, Mark; Gascon, Nicolas

2003-10-01

Most current Hall thruster simulation efforts employ either 1D (axial), or 2D (axial and radial) codes. These descriptions crucially depend on the use of an ad-hoc perpendicular electron mobility. Several models for the mobility are typically invoked: classical, Bohm, empirically based, wall-induced, as well as combinations of the above. Experimentally, it is observed that fluctuations and electron transport depend on axial distance and operating parameters. Theoretically, linear stability analyses have predicted a number of unstable modes; yet the nonlinear character of the fluctuations and/or their contribution to electron transport remains poorly understood. Motivated by these observations, a 2D code in the azimuthal and axial coordinates has been written. In particular, the simulation self-consistently calculates the azimuthal disturbances resulting in fluctuating drifts, which in turn (if properly correlated with plasma density disturbances) result in fluctuation-driven electron transport. The characterization of the turbulence at various operating parameters and across the channel length is also the object of this study. A description of the hybrid code used in the simulation as well as the initial results will be presented.

[3-dimensional cephalometry in orthodontics. The current possibilities of Cepha 3DT software].

PubMed

Faure, Jacques; Treil, Jacques; Borianne, Philippe; Casteigt, Jean; Baron, Pascal

2002-03-01

A 3D cephalometric analysis method from a scanner acquisition, has been developed thanks to a long collaboration between the CIRAD modeling Laboratory and Jacques Treil. The model of skeletal description is based on eight landmarks related to the neuromatrical axis of facial growth (heads of the mallei, supraorbital, suborbital, submental points); it has been abundantly described. The purpose of this work consists in presenting the dentoalveolar level of the analysis. The description and the marking of the arches and the teeth mainly rest on the systematic use of a mathematical tool, the calculation of the central matrix of inertia, and on three fundamental choices: the identification of the dental arches from their constituting teeth leaving aside any alveolar marking, the marking of each tooth relative to the arch, as it can be observed by the orthodontist's eye, and not relative to the craniofacial architecture, the definition of the position of each tooth by the orientation of its coronoradicular axis and not its sole buccal side, Their uses in orthodontics are numerous: diagnosis, choice of the mechanics, therapeutic simulation, therapeutic follow up, analysis of the findings... Clinical applications illustrate the theoretical presentation.

Choguita Rarámuri (Tarahumara) Language Description and Documentation: A Guide to the Deposited Collection and Associated Materials

ERIC Educational Resources Information Center

Caballero, Gabriela

2017-01-01

Choguita Rarámuri (Tarahumara) is a Uto-Aztecan language spoken in Northern Mexico of great typological, theoretical, and historical significance. This paper presents an overview and background of the Choguita Rarámuri language description and documentation project and provides a guide to the documentary collection emerging from this project. This…

A Short German Version of the Self Description Questionnaire I: Theoretical and Empirical Comparability

ERIC Educational Resources Information Center

Arens, A. Katrin; Yeung, Alexander Seeshing; Craven, Rhonda G.; Hasselhorn, Marcus

2013-01-01

This study aims to develop a short German version of the Self Description Questionnaire (SDQ I-GS) in order to present a robust economical instrument for measuring German preadolescents' multidimensional self-concept. A full German version of the SDQ I (SDQ I-G) that maintained the original structure and thus length of the English original SDQ I…

Kant on the history of nature: the ambiguous heritage of the critical philosophy for natural history.

PubMed

Sloan, Phillip R

2006-12-01

This paper seeks to show Kant's importance for the formal distinction between descriptive natural history and a developmental history of nature that entered natural history discussions in the late eighteenth century. It is argued that he developed this distinction initially upon Buffon's distinctions of 'abstract' and 'physical' truths, and applied these initially in his distinction of 'varieties' from 'races' in anthropology. In the 1770s, Kant appears to have given theoretical preference to the 'history' of nature [Naturgeschichte] over 'description' of nature [Naturbeschreibung]. Following Kant's confrontations with Johann Herder and Georg Forster in the late 1780s, Kant weakened the epistemic status of the 'history of nature' and gave theoretical preference to 'description of nature'. As a result, Kant's successors, such as Goethe, could draw from Kant either a justification for a developmental history of nature, or, as this paper argues, a warrant from the critical philosophy for denying the validity of the developmental history of nature as anything more than a 'regulative' idea of reason.

Understanding diagnosis and management of dementia and guideline implementation in general practice: a qualitative study using the theoretical domains framework.

PubMed

Murphy, Kerry; O'Connor, Denise A; Browning, Colette J; French, Simon D; Michie, Susan; Francis, Jill J; Russell, Grant M; Workman, Barbara; Flicker, Leon; Eccles, Martin P; Green, Sally E

2014-03-03

Dementia is a growing problem, causing substantial burden for patients, their families, and society. General practitioners (GPs) play an important role in diagnosing and managing dementia; however, there are gaps between recommended and current practice. The aim of this study was to explore GPs' reported practice in diagnosing and managing dementia and to describe, in theoretical terms, the proposed explanations for practice that was and was not consistent with evidence-based guidelines. Semi-structured interviews were conducted with GPs in Victoria, Australia. The Theoretical Domains Framework (TDF) guided data collection and analysis. Interviews explored the factors hindering and enabling achievement of 13 recommended behaviours. Data were analysed using content and thematic analysis. This paper presents an in-depth description of the factors influencing two behaviours, assessing co-morbid depression using a validated tool, and conducting a formal cognitive assessment using a validated scale. A total of 30 GPs were interviewed. Most GPs reported that they did not assess for co-morbid depression using a validated tool as per recommended guidance. Barriers included the belief that depression can be adequately assessed using general clinical indicators and that validated tools provide little additional information (theoretical domain of 'Beliefs about consequences'); discomfort in using validated tools ('Emotion'), possibly due to limited training and confidence ('Skills'; 'Beliefs about capabilities'); limited awareness of the need for, and forgetting to conduct, a depression assessment ('Knowledge'; 'Memory, attention and decision processes'). Most reported practising in a manner consistent with the recommendation that a formal cognitive assessment using a validated scale be undertaken. Key factors enabling this were having an awareness of the need to conduct a cognitive assessment ('Knowledge'); possessing the necessary skills and confidence ('Skills'; 'Beliefs about capabilities'); and having adequate time and resources ('Environmental context and resources'). This is the first study to our knowledge to use a theoretical approach to investigate the barriers and enablers to guideline-recommended diagnosis and management of dementia in general practice. It has identified key factors likely to explain GPs' uptake of the guidelines. The results have informed the design of an intervention aimed at supporting practice change in line with dementia guidelines, which is currently being evaluated in a cluster randomised trial.

Fully differential cross sections for Li2+-impact ionization of Li(2s) and Li(2p)

NASA Astrophysics Data System (ADS)

Ghorbani, Omid; Ghanbari-Adivi, Ebrahim; Fabian Ciappina, Marcelo

2018-05-01

A semiclassical impact parameter version of the continuum distorted wave-Eikonal initial state theory is developed to study the differential ionization of Li atoms in collisions with Li2+ ions. Both post and prior forms of the transition amplitude are considered. The fully differential cross sections are calculated for the lithium targets in their ground and their first excited states and for the projectile ions at 16 MeV impact energy. The role of the inter-nuclear interaction as well as the significance of the post-prior discrepancy in the ejected electron spectra are investigated. The obtained results for ejection of the electron into the azimuthal plane are compared with the recent measurements and with their corresponding values obtained using a fully quantum mechanical version of the theory. In most of the cases, the consistency of the present approach with the experimental and the quantum theoretical data is reasonable. However, for 2p-state ionization, in the cases where no experimental data exist, there is a considerable difference between the two theoretical approaches. This difference is questionable and further experiments are needed to judge which theory makes a more accurate description of the collision dynamics.

An Alternative to the Gauge Theoretic Setting

NASA Astrophysics Data System (ADS)

Schroer, Bert

2011-10-01

The standard formulation of quantum gauge theories results from the Lagrangian (functional integral) quantization of classical gauge theories. A more intrinsic quantum theoretical access in the spirit of Wigner's representation theory shows that there is a fundamental clash between the pointlike localization of zero mass (vector, tensor) potentials and the Hilbert space (positivity, unitarity) structure of QT. The quantization approach has no other way than to stay with pointlike localization and sacrifice the Hilbert space whereas the approach built on the intrinsic quantum concept of modular localization keeps the Hilbert space and trades the conflict creating pointlike generation with the tightest consistent localization: semiinfinite spacelike string localization. Whereas these potentials in the presence of interactions stay quite close to associated pointlike field strengths, the interacting matter fields to which they are coupled bear the brunt of the nonlocal aspect in that they are string-generated in a way which cannot be undone by any differentiation. The new stringlike approach to gauge theory also revives the idea of a Schwinger-Higgs screening mechanism as a deeper and less metaphoric description of the Higgs spontaneous symmetry breaking and its accompanying tale about "God's particle" and its mass generation for all the other particles.

Near-magnetopause magnetosheath in 3D gasdynamic module of the numerical magnetosheath-magnetosphere model

NASA Astrophysics Data System (ADS)

Dobreva, P. S.; Kartalev, M. D.; Borodkova, N. L.; Zastenker, G. N.

2016-07-01

This paper describes an approach to a theoretical interpretation of Interball-1 satellite measurements data in two cases of the satellite's crossings of the magnetosheath. An interpretation is made of both the measured crossings of the magnetosheath boundaries and the behavior of the registered plasma parameters. In our case, it is the value of the ion flux along the spacecraft trajectory. The magnetosheath-magnetosphere model, developed at the Institute of Mechanics, Sofia, Bulgaria, is used as a theoretical basis. It describes the interaction between the solar wind and the Earth's magnetosphere in a simplified gas-dynamic approximation. A characteristic feature of the model is that it allows for the self-consistent description of the magnetosheath boundaries - the bow shock (BS) and the magnetopause (MP). The three-dimensional picture of the magnetosheath fluid flow is also obtained as part of the solution. The magnetosheath characteristics thus obtained are in correspondence with a given momentary state of the interplanetary medium, defined on the basis of WIND satellite data (appropriately shifted by time). The results are discussed in the context of advantages and limitations of using the gas-dynamic model for the interpretation of magnetosheath plasma measurements in the near-magnetopause magnetosheath.

Theoretical simulation of the dual-heat-flux method in deep body temperature measurements.

PubMed

Huang, Ming; Chen, Wenxi

2010-01-01

Deep body temperature reveals individual physiological states, and is important in patient monitoring and chronobiological studies. An innovative dual-heat-flux method has been shown experimentally to be competitive with the conventional zero-heat-flow method in its performance, in terms of measurement accuracy and step response to changes in the deep temperature. We have utilized a finite element method to model and simulate the dynamic process of a dual-heat-flux probe in deep body temperature measurements to validate the fundamental principles of the dual-heat-flux method theoretically, and to acquire a detailed quantitative description of the thermal profile of the dual-heat-flux probe. The simulation results show that the estimated deep body temperature is influenced by the ambient temperature (linearly, at a maximum rate of 0.03 °C/°C) and the blood perfusion rate. The corresponding depth of the estimated temperature in the skin and subcutaneous tissue layer is consistent when using the dual-heat-flux probe. Insights in improving the performance of the dual-heat-flux method were discussed for further studies of dual-heat-flux probes, taking into account structural and geometric considerations.

Single resonance monolithic Fabry-Perot filters formed by volume Bragg gratings and multilayer dielectric mirrors

NASA Astrophysics Data System (ADS)

Lumeau, Julien; Koc, Cihan; Mokhun, Oleksiy; Smirnov, Vadim; Lequime, Michel; Glebov, Leonid B.

2012-02-01

High efficiency reflecting volume Bragg gratings (VBGs) recorded in PTR glass plates have shown un-preceded performances that make them very good candidates for narrowband spectral filtering with sub-nanometer spectral widths. However, decreasing the bandwidth to value below 30-50 pm is very challenging as it requires increasing the thickness of the RBG to more than 15-20 mm. To overcome this limitation, we propose a new approach which is a monolithic Fabry-Perot cavity which consists from a reflecting VBG with a multilayer dielectric mirror (MDM) deposited on its surface. A VBG with a grating vector perpendicular to its surface and a MDM produce a Fabry-Perot resonator with a single transmission band inside of the reflection spectrum of the VBG. We present a theoretical description of this new class of filters that allow achieving a single ultra-narrowband resonance associated with several hundred nanometers rejection band. Then we show the methods for designing and fabricating such filter. Finally, we present the steps that we followed in order to fabricate a first prototype for 852 nm and 1062 nm region that demonstrates a 30 pm bandwidth, 90+% transmission at resonance and a good agreement with theoretical simulation.

Vocational Interests and Performance: A Quantitative Summary of Over 60 Years of Research.

PubMed

Nye, Christopher D; Su, Rong; Rounds, James; Drasgow, Fritz

2012-07-01

Despite early claims that vocational interests could be used to distinguish successful workers and superior students from their peers, interest measures are generally ignored in the employee selection literature. Nevertheless, theoretical descriptions of vocational interests from vocational and educational psychology have proposed that interest constructs should be related to performance and persistence in work and academic settings. Moreover, on the basis of Holland's (1959, 1997) theoretical predictions, congruence indices, which quantify the degree of similarity or person-environment fit between individuals and their occupations, should be more strongly related to performance than interest scores alone. Using a comprehensive review of the interest literature that spans more than 60 years of research, a meta-analysis was conducted to examine the veracity of these claims. A literature search identified 60 studies and approximately 568 correlations that addressed the relationship between interests and performance. Results showed that interests are indeed related to performance and persistence in work and academic contexts. In addition, the correlations between congruence indices and performance were stronger than for interest scores alone. Thus, consistent with interest theory, the fit between individuals and their environment was more predictive of performance than interest alone. © The Author(s) 2012.

A Schema-Theoretic View of Reading. Technical Report No. 32.

ERIC Educational Resources Information Center

Adams, Marilyn Jager; Collins, Allan

This paper provides a general description of schema-theoretic models of language comprehension and examines some extensions of such models to the study of reading. The goal of schema theory is to specify the interface between the reader and the text: to specify how the reader's knowledge interacts with and shapes the information on the page and to…

A Theoretical Analysis of the Influence of Electroosmosis on the Effective Ionic Mobility in Capillary Zone Electrophoresis

ERIC Educational Resources Information Center

Hijnen, Hens

2009-01-01

A theoretical description of the influence of electroosmosis on the effective mobility of simple ions in capillary zone electrophoresis is presented. The mathematical equations derived from the space-charge model contain the pK[subscript a] value and the density of the weak acid surface groups as parameters characterizing the capillary. It is…

Towards a Deeper Understanding of the Nucleus with Exotic Nuclei

NASA Astrophysics Data System (ADS)

Ormand, Erich

2006-10-01

Despite more than fifty years of study, many questions about now nuclei are put together remain. While nuclei near the valley of stability have provided a wealth of information, they are not sufficient to provide us with a comprehensive and unified description of the nucleus. Especially lacking is an accurate picture of those exotic species that are the basis of cosmic alchemy. The missing pieces in the puzzle can be filled in with a determined experimental and theoretical effort focusing on nuclei lying far from the valley of stability. Here, I will outline the intellectual challenges that can be addressed by proposed exotic-beam facilities, and how new experimental data will quide and refine theoretical descriptions of the nucleus.

A Comparison of Descriptive Tagging Practices by Library, Archive and Museum Professionals Using an Inter-Indexing Consistency Approach

ERIC Educational Resources Information Center

Angel, Christine Marie

2012-01-01

This study is a comparison of the descriptive tagging practices among library, archive, and museum professionals using an inter-indexing consistency approach. The first purpose of this study was to determine the extent of the similarities and differences among professional groups when assigning descriptive tags to a wide variety of objects that…

Swing and Lift

ERIC Educational Resources Information Center

Barnes, Francis; Potter, Ann

1974-01-01

Presents theoretical fundamentals of sideways forces exerted on a cricket ball, an aerofoil, and a yacht, involving the properties of boundary layers and a description of velocity and circulation. (CC)

A low-energy compatible SU(4)-type model for vector leptoquarks of mass ≤ 1 TeV

NASA Astrophysics Data System (ADS)

Blumhofer, A.; Lampe, B.

1999-02-01

The Standard Model is extended by a SU(2)_L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made in such a way that no conflict with low energy restrictions is encountered. The SU(2)_L singlet mediates interactions between the right-handed leptons and up type quarks for which only moderate low energy restrictions M_{LQ}/g_{LQ} > few hundred GeV exist. However, it is not a candidate to explain the anomalous HERA data at large Q^2 because theoretical reasons imply that g_{LQ} ≥ g_s which would give a much stronger anomalous HERA effect. We furthermore argue that the inequality g_{LQ} ≥ g_s is a general feature of consistent vector leptoquark models. Although our model is not relevant for HERA, it is interesting per se as a description of leptoquarks of mass ≤ 1 TeV consistent with all low-energy requirements.

The habilitation nursing of children with developmental disabilities—Beyond traditional nursing practices and principles?

PubMed Central

Olli, Johanna; Vehkakoski, Tanja

2014-01-01

Research-based descriptions of the contents of the habilitation nursing of children with developmental disabilities are lacking. The objective of this qualitative study was to describe the habilitation nursing of children with developmental disabilities in a Finnish children's neurological ward. In addition, the purpose was to outline the principles that directed the nursing functions (which consisted of various nursing interventions). The data collection included observation, a retrospective think-aloud method with video-taped nursing situations, the nursing records, and an open-ended questionnaire. The data were analysed with a qualitative content analysis of the manifest and latent content. The findings show that habilitation nursing in a children's neurological ward consists of assessing the child's skills, supporting the child's development, and collaborating with the child's immediate adults. When implementing those functions with nursing interventions, the nurses demonstrated four principles: client-originated and professional-originated principles, and individual-centred and community-centred principles. Becoming conscious of these principles and the theoretical frameworks behind them enables the development of a nursing science–based model for habilitation nursing. PMID:24656260

Surface symmetry energy of nuclear energy density functionals

NASA Astrophysics Data System (ADS)

Nikolov, N.; Schunck, N.; Nazarewicz, W.; Bender, M.; Pei, J.

2011-03-01

We study the bulk deformation properties of the Skyrme nuclear energy density functionals (EDFs). Following simple arguments based on the leptodermous expansion and liquid drop model, we apply the nuclear density functional theory to assess the role of the surface symmetry energy in nuclei. To this end, we validate the commonly used functional parametrizations against the data on excitation energies of superdeformed band heads in Hg and Pb isotopes and fission isomers in actinide nuclei. After subtracting shell effects, the results of our self-consistent calculations are consistent with macroscopic arguments and indicate that experimental data on strongly deformed configurations in neutron-rich nuclei are essential for optimizing future nuclear EDFs. The resulting survey provides a useful benchmark for further theoretical improvements. Unlike in nuclei close to the stability valley, whose macroscopic deformability hangs on the balance of surface and Coulomb terms, the deformability of neutron-rich nuclei strongly depends on the surface symmetry energy; hence, its proper determination is crucial for the stability of deformed phases of the neutron-rich matter and description of fission rates for r-process nucleosynthesis.

A New Self-Consistent Field Model of Polymer/Nanoparticle Mixture

NASA Astrophysics Data System (ADS)

Chen, Kang; Li, Hui-Shu; Zhang, Bo-Kai; Li, Jian; Tian, Wen-De

2016-02-01

Field-theoretical method is efficient in predicting assembling structures of polymeric systems. However, it’s challenging to generalize this method to study the polymer/nanoparticle mixture due to its multi-scale nature. Here, we develop a new field-based model which unifies the nanoparticle description with the polymer field within the self-consistent field theory. Instead of being “ensemble-averaged” continuous distribution, the particle density in the final morphology can represent individual particles located at preferred positions. The discreteness of particle density allows our model to properly address the polymer-particle interface and the excluded-volume interaction. We use this model to study the simplest system of nanoparticles immersed in the dense homopolymer solution. The flexibility of tuning the interfacial details allows our model to capture the rich phenomena such as bridging aggregation and depletion attraction. Insights are obtained on the enthalpic and/or entropic origin of the structural variation due to the competition between depletion and interfacial interaction. This approach is readily extendable to the study of more complex polymer-based nanocomposites or biology-related systems, such as dendrimer/drug encapsulation and membrane/particle assembly.

The habilitation nursing of children with developmental disabilities--beyond traditional nursing practices and principles?

PubMed

Olli, Johanna; Vehkakoski, Tanja; Salanterä, Sanna

2014-01-01

Research-based descriptions of the contents of the habilitation nursing of children with developmental disabilities are lacking. The objective of this qualitative study was to describe the habilitation nursing of children with developmental disabilities in a Finnish children's neurological ward. In addition, the purpose was to outline the principles that directed the nursing functions (which consisted of various nursing interventions). The data collection included observation, a retrospective think-aloud method with video-taped nursing situations, the nursing records, and an open-ended questionnaire. The data were analysed with a qualitative content analysis of the manifest and latent content. The findings show that habilitation nursing in a children's neurological ward consists of assessing the child's skills, supporting the child's development, and collaborating with the child's immediate adults. When implementing those functions with nursing interventions, the nurses demonstrated four principles: client-originated and professional-originated principles, and individual-centred and community-centred principles. Becoming conscious of these principles and the theoretical frameworks behind them enables the development of a nursing science-based model for habilitation nursing.

Physical Kinetics of Electrons in a High-Voltage Pulsed High-Pressure Discharge with Cylindrical Geometry

NASA Astrophysics Data System (ADS)

Kozhevnikov, V. Yu.; Kozyrev, A. V.; Semeniuk, N. S.

2017-12-01

Results of theoretical modeling of the phenomenon of a high-voltage discharge in nitrogen at atmospheric pressure are presented, based on a consistent kinetic theory of the electrons. A mathematical model of a nonstationary high-pressure discharge has been constructed for the first time, based on a description of the electron component from first principles. The physical kinetics of the electrons are described with the help of the Boltzmann kinematic equation for the electron distribution function over momenta with only ionization and elastic collisions taken into account. A detailed spatiotemporal picture of a nonstationary discharge with runaway electrons under conditions of coaxial geometry of the gas diode is presented. The model describes in a self-consistent way both the process of formation of the runaway electron flux in the discharge and the influence of this flux on the rate of ionization processes in the gas. Total energy spectra of the electron flux incident on the anode are calculated. The obtained parameters of the current pulse of the beam of fast electrons correlate well with the known experimental data.

Acoustic fluidization and the scale dependence of impact crater morphology

NASA Technical Reports Server (NTRS)

Melosh, H. J.; Gaffney, E. S.

1983-01-01

A phenomenological Bingham plastic model has previously been shown to provide an adequate description of the collapse of impact craters. This paper demonstrates that the Bingham parameters may be derived from a model in which acoustic energy generated during excavation fluidizes the rock debris surrounding the crater. Experimental support for the theoretical flow law is presented. Although the Bingham yield stress cannot be computed without detailed knowledge of the initial acoustic field, the Bingham viscosity is derived from a simple argument which shows that it increases as the 3/2 power of crater diameter, consistent with observation. Crater collapse may occur in material with internal dissipation Q as low as 100, comparable to laboratory observations of dissipation in granular materials. Crater collapse thus does not require that the acoustic field be regenerated during flow.

Strain-induced insulator-to-metal transition in LaTiO3 within DFT + DMFT

NASA Astrophysics Data System (ADS)

Dymkowski, Krzysztof; Ederer, Claude

2014-04-01

We present results of combined density functional theory plus dynamical mean-field theory (DFT + DMFT) calculations, which show that the Mott insulator LaTiO3 undergoes an insulator-to-metal transition under compressive epitaxial strain of about -2%. This transition is driven by strain-induced changes in the crystal-field splitting between the Ti t2g orbitals, which in turn are intimately related to the collective tilts and rotations of the oxygen octahedra in the orthorhombically distorted Pbnm perovskite structure. An accurate treatment of the underlying crystal structure is therefore crucial for a correct description of the observed metal-insulator transition. Our theoretical results are consistent with recent experimental observations and demonstrate that metallic behavior in heterostructures of otherwise insulating materials can emerge also from mechanisms other than genuine interface effects.

[How are the hypothesis and the objectives established in a Radiology research project?].

PubMed

Alústiza Echeverría, J M; Salvador Pardo, E; Castiella Eguzkiza, A

2012-01-01

Research is a systematic process designed to answer a question. This is the starting point of the whole project and specifically formulates a problem observed in the analysis of the reality. The answer to this attempts to clarify an uncertainty in our knowledge. The conceptual hypothesis is the theoretical answer to the question set out. The operational hypothesis is the particular form that which sets out to demonstrate the conceptual hypothesis. The objectives are the justification for conducting the research. They help to define what it attempts to obtain, and what answers it will give to the formulated questions. It must show a clear and consistent relationship with the description of the problem and, specifically, with the questions and/or hypothesis that are to be resolved. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Analysis and Management of Animal Populations: Modeling, Estimation and Decision Making

USGS Publications Warehouse

Williams, B.K.; Nichols, J.D.; Conroy, M.J.

2002-01-01

This book deals with the processes involved in making informed decisions about the management of animal populations. It covers the modeling of population responses to management actions, the estimation of quantities needed in the modeling effort, and the application of these estimates and models to the development of sound management decisions. The book synthesizes and integrates in a single volume the methods associated with these themes, as they apply to ecological assessment and conservation of animal populations. KEY FEATURES * Integrates population modeling, parameter estimation and * decision-theoretic approaches to management in a single, cohesive framework * Provides authoritative, state-of-the-art descriptions of quantitative * approaches to modeling, estimation and decision-making * Emphasizes the role of mathematical modeling in the conduct of science * and management * Utilizes a unifying biological context, consistent mathematical notation, * and numerous biological examples

[Systematization of nursing care in urgency and emergency services: feasibility of implementation].

PubMed

Maria, Monica Antonio; Quadros, Fátima Alice Aguiar; Grassi, Maria de Fátima Oliveira

2012-01-01

This study analyzes the feasibility of implementing the Nursing Care Systematization in an emergency and urgency hospital department. This is a field study, descriptive, qualitative structured according to the content analysis described by Bardin (2009). It was performed in a hospital specialized in emergency care. The sample consisted of eight practical nurses, five nurses and two assistants, all of them with experience of at least six months in the emergency room. The difficulties referred to the implementation of the NCS are: complexity in their steps; disinterest of the institution; theoretical unpreparedness of nursing, its devaluation by other professionals, inadequate sizing of employees and inadequacy of the hospital physical structure. In this context, it was note that the nurse loses representation in the health team and the application of SAE turns out to be often underestimated.

Healthcare Professionals' Attitudes to Rehabilitation Programming for Male Cancer Survivors.

PubMed

Handberg, Charlotte; Midtgaard, Julie; Nielsen, Claus Vinther; Thorne, Sally; Lomborg, Kirsten

The purpose of this study is to describe and interpret the attitudes and conduct of hospital healthcare professionals (HCPs) in association with male cancer survivors and their municipal rehabilitation participation. Ethnographic fieldwork was conducted, consisting of participant observation and nine semistructured focus group interviews with 58 hospital HCPs. Using interpretive description methodology with symbolic interaction as a theoretical framework, data were collected through fieldwork in three oncology wards in Denmark. Attitudes about both gender and rehabilitation were identified as overarching obstructions within hospital HCP conduct toward promoting men's participation in cancer rehabilitation. Gender and rehabilitation perceptions formed barriers in this context, suggesting that male cancer survivors' rehabilitation outcomes may be compromised by HCP attitudes and conduct. These findings provide insight into approaches to guide HCPs to take responsibility for rehabilitation and to take gender into account in their work.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernards, C.; Heinze, S.; Jolie, J.

We present the results of a {gamma}{gamma} angular correlation experiment investigating the nucleus {sup 196}Hg and compare these with a theoretical description of {sup 196}Hg within the U{sub {nu}}(6/12) x U{sub {pi}}(6/4) extended supersymmetry. To populate excited {sup 196}Hg states, we used the Cologne FN Tandem accelerator inducing the reaction {sup 194}Pt({alpha},2n){sup 196}Hg and analyzed the {gamma} decays of levels up to an excitation energy of 2.4 MeV with the HORUS cube spectrometer. The new results on this mercury isotope allow a comparison between the experimental data and the supersymmetrical predictions and show good agreement. This way we can addmore » {sup 196}Hg as a fifth supermultiplet member to the so-called magical quartet consisting of {sup 194,195}Pt and {sup 195,196}Au.« less

Low-energy dynamics of gravitation

NASA Astrophysics Data System (ADS)

Torma, Tibor

The present status of theories of quantum gravity are reviewed from the low energy point of view. String theory relates classical black-hole type solutions of Einstein- like equations (e.g. axidilaton gravity) to the string vacuum. Several such solutions are proposed and their properties are investigated, including their behavior under supersymmetry transformations. A general feature of all possible quantum theories of gravitation is that they lead to a field theory description at low (as compared to the Planck mass) energies. The theoretical consistency, uniqueness and consequences of such an effective theory are investigated. I show that a power counting theorem allows for the momentum expansion that defines the effective theory even in the presence of large masses. I also show that graviton-graviton scattering is free of potential infrared and collinear divergencies that plague perturbative discussions of Yang-Mills theories.

Kinds of access: different methods for report reveal different kinds of metacognitive access

PubMed Central

Overgaard, Morten; Sandberg, Kristian

2012-01-01

In experimental investigations of consciousness, participants are asked to reflect upon their own experiences by issuing reports about them in different ways. For this reason, a participant needs some access to the content of her own conscious experience in order to report. In such experiments, the reports typically consist of some variety of ratings of confidence or direct descriptions of one's own experiences. Whereas different methods of reporting are typically used interchangeably, recent experiments indicate that different results are obtained with different kinds of reporting. We argue that there is not only a theoretical, but also an empirical difference between different methods of reporting. We hypothesize that differences in the sensitivity of different scales may reveal that different types of access are used to issue direct reports about experiences and metacognitive reports about the classification process. PMID:22492747

Ground-based plasma contractor characterization

NASA Technical Reports Server (NTRS)

Patterson, Michael J.; Aadland, Randall S.

1987-01-01

Presented are recent NASA Lewis Research Center (LeRC) plasma contractor experimental results, as well as a description of the plasma contractor test facility. The operation of a 24 cm diameter plasma source with hollow cathode was investigated in the lighted-mode regime of electron current collection from 0.1 to 7.0 A. These results are compared to those obtained with a 12 cm plasma source. Full two-dimensional plasma potential profiles were constructed from emissive probe traces of the contractor plume. The experimentally measured dimensions of the plume sheaths were then compared to those theoretically predicted using a model of a spherical double sheath. Results are consistent for currents up to approximately 1.0 A. For currents above 1.0 A, substantial deviations from theory occur. These deviations are due to sheath asphericity, and possibly volume ionization in the double-sheath region.

A new theoretical basis for numerical simulations of nonlinear acoustic fields

NASA Astrophysics Data System (ADS)

Wójcik, Janusz

2000-07-01

Nonlinear acoustic equations can be considerably simplified. The presented model retains the accuracy of a more complex description of nonlinearity and a uniform description of near and far fields (in contrast to the KZK equation). A method has been presented for obtaining solutions of Kuznetsov's equation from the solutions of the model under consideration. Results of numerical calculations, including comparative ones, are presented.

Neural electrical activity and neural network growth.

PubMed

Gafarov, F M

2018-05-01

The development of central and peripheral neural system depends in part on the emergence of the correct functional connectivity in its input and output pathways. Now it is generally accepted that molecular factors guide neurons to establish a primary scaffold that undergoes activity-dependent refinement for building a fully functional circuit. However, a number of experimental results obtained recently shows that the neuronal electrical activity plays an important role in the establishing of initial interneuronal connections. Nevertheless, these processes are rather difficult to study experimentally, due to the absence of theoretical description and quantitative parameters for estimation of the neuronal activity influence on growth in neural networks. In this work we propose a general framework for a theoretical description of the activity-dependent neural network growth. The theoretical description incorporates a closed-loop growth model in which the neural activity can affect neurite outgrowth, which in turn can affect neural activity. We carried out the detailed quantitative analysis of spatiotemporal activity patterns and studied the relationship between individual cells and the network as a whole to explore the relationship between developing connectivity and activity patterns. The model, developed in this work will allow us to develop new experimental techniques for studying and quantifying the influence of the neuronal activity on growth processes in neural networks and may lead to a novel techniques for constructing large-scale neural networks by self-organization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrocardiogram reading: a randomized study comparing 2 e‑learning methods for medical students.

PubMed

Kopeć, Grzegorz; Waligóra, Marcin; Pacia, Michał; Chmielak, Wojciech; Stępień, Agnieszka; Janiec, Sebastian; Magoń, Wojciech; Jonas, Kamil; Podolec, Piotr

2018-02-28

INTRODUCTION    Interpretation of the electrocardiogram (ECG) is an essential skill in most medical specialties; however, the best method of teaching how to read ECGs has not been determined. OBJECTIVES    The aim of the study was to compare the effectiveness of collaborative (C‑eL) and self (S‑eL) e‑learning of ECG reading among medical students. PATIENTS AND METHODS    A total of 60 fifth‑year medical students were randomly assigned to the C‑eL and S‑eL groups. S‑eL students received 15 ECG recordings with a comprehensive description by email (one every 48 hours), while C‑eL students received the same ECG recordings without description. C‑eL students were expected to analyze each ECG together within the subgroups using an internet platform and to submit the interpretation within 48 hours. Afterwards, they received a description of each ECG. C‑eL students' activity was assessed based on the number of words written on the internet platform during discussion. A final test consisted of 10 theoretical questions and 10 ECG recordings. The final score was a sum of points obtained for the interpretation of ECG recordings. The main endpoint of the study was the number of students whose final score was 56% or higher. RESULTS    The final test was completed by 53 students (88.3%). The main endpoint was achieved in 20 C‑eL students (77%) and in 13 S‑eL students (48.1%), P = 0.03. The final score was 6.4 (interquartile range [IQR], 5.8-7.6) in the C‑eL group and 5.6 (IQR, 4.2-7.2) in the S‑eL group, P = 0.04. It correlated with the results of the theoretical test and students' activity during C‑eL (r = 0.42, P = 0.002 and r = 0.4, P = 0.04, respectively). CONCLUSIONS    C‑eL of ECG reading among fifth‑year medical students is superior to S‑eL.

DYAD: A Computer Program for the Analysis of Interpersonal Communication

ERIC Educational Resources Information Center

Fogel, Daniel S.

1978-01-01

A computer program which generates descriptions of conversational patterns of dyads based on sound-silence data is described. Input consists of talk/no-talk designations; output consists of descriptive matrices, histograms, and individual talk parameters. (Author/JKS)

High frequency variations of the main magnetic field: convergence of observations and theory (Petrus Peregrinus Medal Lecture)

NASA Astrophysics Data System (ADS)

Jault, Dominique

2013-04-01

Understanding the main magnetic field variations has been hindered by the discrepancy between the periods (from months to years) of the simplest linear wave phenomena and the relatively long time intervals (10 to 100 years) over which magnetic field changes can be confidently monitored. A theoretical description of short-period waves within the Earth's fluid core is at hand. Quasi-geostrophic inertial waves (akin to Rossby waves in the atmosphere) are slightly modified in the presence of magnetic fields and torsional oscillations consist of differential motion between coaxial rigid cylindrical annuli. Torsional oscillations are sensitive to the whole magnetic field that they shear in the course of their propagation. From their modelling, we have thus gained an estimate for the magnetic field strength in the core interior. There is now ongoing work to extend the theoretical framework to longer times. Furthermore, data collected from the Swarm constellation of three satellites to be launched this year by ESA will permit to better separate the internal and external magnetic signals. We may thus dream to detect quasi-geostrophic inertial waves. As the spectral ranges of theoretical models and observations begin to overlap, we can now go beyond the understanding of the magnetic field variations as the juxtaposition of partial models, arranged as a set of nested Matryoshka dolls. This talk will give illustrations for this statement, among which the question of induction in the lower mantle.

Medication competency of nurses according to theoretical and drug calculation online exams: A descriptive correlational study.

PubMed

Sneck, Sami; Saarnio, Reetta; Isola, Arja; Boigu, Risto

2016-01-01

Medication administration is an important task of registered nurses. According to previous studies, nurses lack theoretical knowledge and drug calculation skills and knowledge-based mistakes do occur in clinical practice. Finnish health care organizations started to develop a systematic verification processes for medication competence at the end of the last decade. No studies have yet been made of nurses' theoretical knowledge and drug calculation skills according to these online exams. The aim of this study was to describe the medication competence of Finnish nurses according to theoretical and drug calculation exams. A descriptive correlation design was adopted. Participants and settings All nurses who participated in the online exam in three Finnish hospitals between 1.1.2009 and 31.05.2014 were selected to the study (n=2479). Quantitative methods like Pearson's chi-squared tests, analysis of variance (ANOVA) with post hoc Tukey tests and Pearson's correlation coefficient were used to test the existence of relationships between dependent and independent variables. The majority of nurses mastered the theoretical knowledge needed in medication administration, but 5% of the nurses struggled with passing the drug calculation exam. Theoretical knowledge and drug calculation skills were better in acute care units than in the other units and younger nurses achieved better results in both exams than their older colleagues. The differences found in this study were statistically significant, but not high. Nevertheless, even the tiniest deficiency in theoretical knowledge and drug calculation skills should be focused on. It is important to identify the nurses who struggle in the exams and to plan targeted educational interventions for supporting them. The next step is to study if verification of medication competence has an effect on patient safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laursen, T.A.; Attaway, S.W.; Zadoks, R.I.

1999-03-01

This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples ofmore » the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.« less

Materials by numbers: Computations as tools of discovery

PubMed Central

Landman, Uzi

2005-01-01

Current issues pertaining to theoretical simulations of materials, with a focus on systems of nanometer-scale dimensions, are discussed. The use of atomistic simulations as high-resolution numerical experiments, enabling and guiding formulation and testing of analytic theoretical descriptions, is demonstrated through studies of the generation and breakup of nanojets, which have led to the derivation of a stochastic hydrodynamic description. Subsequently, I illustrate the use of computations and simulations as tools of discovery, with examples that include the self-organized formation of nanowires, the surprising nanocatalytic activity of small aggregates of gold that, in the bulk form, is notorious for being chemically inert, and the emergence of rotating electron molecules in two-dimensional quantum dots. I conclude with a brief discussion of some key challenges in nanomaterials simulations. PMID:15870210

Cold fission description with constant and varying mass asymmetries

NASA Astrophysics Data System (ADS)

Duarte, S. B.; Rodríguez, O.; Tavares, O. A. P.; Gonçalves, M.; García, F.; Guzmán, F.

1998-05-01

Different descriptions for varying the mass asymmetry in the fragmentation process are used to calculate the cold fission barrier penetrability. The relevance of the appropriate choice for both the description of the prescission phase and inertia coefficient to unify alpha decay, cluster radioactivity, and spontaneous cold fission processes in the same theoretical framework is explicitly shown. We calculate the half-life of all possible partition modes of nuclei of A>200 following the most recent Mass Table by Audi and Wapstra. It is shown that if one uses the description in which the mass asymmetry is maintained constant during the fragmentation process, the experimental half-life values and mass yield of 234U cold fission are satisfactorily reproduced.

Evaporation, diffusion and self-assembly at drying interfaces.

PubMed

Roger, K; Sparr, E; Wennerström, H

2018-04-18

Water evaporation from complex aqueous solutions leads to the build-up of structure and composition gradients at their interface with air. We recently introduced an experimental setup for quantitatively studying such gradients and discussed how structure formation can lead to a self-regulation mechanism for controlling water evaporation through self-assembly. Here, we provide a detailed theoretical analysis using an advection/diffusion transport equation that takes into account thermodynamically non-ideal conditions and we directly relate the theoretical description to quantitative experimental data. We derive that the concentration profile develops according to a general square root of time scaling law, which fully agrees with experimental observations. The evaporation rate notably decreases with time as t-1/2, which shows that diffusion in the liquid phase is the rate limiting step for this system, in contrast to pure water evaporation. For the particular binary system that was investigated experimentally, which is composed of water and a sugar-based surfactant (α-dodecylmaltoside), the interfacial layer consists in a sequence of liquid crystalline phases of different mesostructures. We extract values for mutual diffusion coefficients of lamellar, hexagonal and micellar cubic phases, which are consistent with previously reported values and simple models. We thus provide a method to estimate the transport properties of oriented mesophases. The macroscopic humidity-independence of the evaporation rate up to 85% relative humidities is shown to result from both an extremely low mutual diffusion coefficient and the large range of water activities corresponding to relative humidities below 85%, at which the lamellar phase exists. Such a humidity self-regulation mechanism is expected for a large variety of complex system.

[Assessment of psychometric properties of the academic involvement questionnaire, expectations version].

PubMed

Pérez V, Cristhian; Ortiz M, Liliana; Fasce H, Eduardo; Parra P, Paula; Matus B, Olga; McColl C, Peter; Torres A, Graciela; Meyer K, Andrea; Márquez U, Carolina; Ortega B, Javiera

2015-11-01

Academic Involvement Questionnaire, Expectations version (CIA-A), assesses the expectations of involvement in studies. It is a relevant predictor of student success. However, the evidence of its validity and reliability in Chile is low, and in the case of Medical students, there is no evidence at all. To evaluate the factorial structure and internal consistency of the CIA-A in Chilean Medical school freshmen. The survey was applied to 340 Medicine freshmen, chosen by non-probability quota sampling. They answered a back-translated version of CIA-A from Portuguese to Spanish, plus a sociodemographic questionnaire. For psychometric analysis of the CIA-A, an exploratory factor analysis was carried on, the reliability of the factors was calculated, a descriptive analysis was conducted and their correlation was assessed. Five factors were identified: vocational, institutional and social involvement, use of resources and student participation. Their reliabilities ranged between Cronbach's alpha values of 0.71 to 0.87. Factors also showed statistically significant correlations between each other. Identified factor structure is theoretically consistent with the structure of original version. It just disagrees in one factor. In addition, the factors' internal consistency were adequate for using them in research. This supports the construct validity and reliability of the CIA-A to assess involvement expectations in medical school freshmen.

Curso: Auxiliar de Farmacia. Guia. Farmacia Teorica: Manual del Estudiante. Matematica General: Manual del Estudiante. Documento de Trabajo (Pharmacy Assistant Course Guide. Theoretical Pharmacy Student Manual. General Mathematics Student Manual. Working Document).

ERIC Educational Resources Information Center

Puerto Rico State Dept. of Education, Hato Rey. Area for Vocational and Technical Education.

The three parts of this document are intended for a 3-semester course for pharmacy assistants. The course guide contains the following sections: occupational description; educational philosophy; general objectives; tasks/competencies for each unit; course organization; brief description of the topics; student standards; and evaluation methods.…

Searle's"Dualism Revisited"

DOE Office of Scientific and Technical Information (OSTI.GOV)

P., Henry

2008-11-20

A recent article in which John Searle claims to refute dualism is examined from a scientific perspective. John Searle begins his recent article 'Dualism Revisited' by stating his belief that the philosophical problem of consciousness has a scientific solution. He then claims to refute dualism. It is therefore appropriate to examine his arguments against dualism from a scientific perspective. Scientific physical theories contain two kinds of descriptions: (1) Descriptions of our empirical findings, expressed in an every-day language that allows us communicate to each other our sensory experiences pertaining to what we have done and what we have learned; andmore » (2) Descriptions of a theoretical model, expressed in a mathematical language that allows us to communicate to each other certain ideas that exist in our mathematical imaginations, and that are believed to represent, within our streams of consciousness, certain aspects of reality that we deem to exist independently of their being perceived by any human observer. These two parts of our scientific description correspond to the two aspects of our general contemporary dualistic understanding of the total reality in which we are imbedded, namely the empirical-mental aspect and the theoretical-physical aspect. The duality question is whether this general dualistic understanding of ourselves should be regarded as false in some important philosophical or scientific sense.« less

A theoretical trombone

NASA Astrophysics Data System (ADS)

LoPresto, Michael C.

2014-09-01

What follows is a description of a theoretical model designed to calculate the playing frequencies of the musical pitches produced by a trombone. The model is based on quantitative treatments that demonstrate the effects of the flaring bell and cup-shaped mouthpiece sections on these frequencies and can be used to calculate frequencies that compare well to both the desired frequencies of the musical pitches and those actually played on a real trombone.

Theoretical investigation of gas-surface interactions

NASA Technical Reports Server (NTRS)

Lee, Timothy J.

1989-01-01

Four reprints are presented from four projects which are to be published in a refereed journal. Two are of interest to us and are presented herein. One is a description of a very detailed theoretical study of four anionic hydrogen bonded complexes. The other is a detailed study of the first generally reliable diagnostic for determining the quality of results that may be expected from single reference based electron correlation methods.

Computer program system for dynamic simulation and stability analysis of passive and actively controlled spacecraft. Volume 1. Theory

NASA Technical Reports Server (NTRS)

Bodley, C. S.; Devers, D. A.; Park, C. A.

1975-01-01

A theoretical development and associated digital computer program system is presented. The dynamic system (spacecraft) is modeled as an assembly of rigid and/or flexible bodies not necessarily in a topological tree configuration. The computer program system may be used to investigate total system dynamic characteristics including interaction effects between rigid and/or flexible bodies, control systems, and a wide range of environmental loadings. Additionally, the program system may be used for design of attitude control systems and for evaluation of total dynamic system performance including time domain response and frequency domain stability analyses. Volume 1 presents the theoretical developments including a description of the physical system, the equations of dynamic equilibrium, discussion of kinematics and system topology, a complete treatment of momentum wheel coupling, and a discussion of gravity gradient and environmental effects. Volume 2, is a program users' guide and includes a description of the overall digital program code, individual subroutines and a description of required program input and generated program output. Volume 3 presents the results of selected demonstration problems that illustrate all program system capabilities.

Universal description of III-V/Si epitaxial growth processes

NASA Astrophysics Data System (ADS)

Lucci, I.; Charbonnier, S.; Pedesseau, L.; Vallet, M.; Cerutti, L.; Rodriguez, J.-B.; Tournié, E.; Bernard, R.; Létoublon, A.; Bertru, N.; Le Corre, A.; Rennesson, S.; Semond, F.; Patriarche, G.; Largeau, L.; Turban, P.; Ponchet, A.; Cornet, C.

2018-06-01

Here, we experimentally and theoretically clarify III-V/Si crystal growth processes. Atomically resolved microscopy shows that monodomain three-dimensional islands are observed at the early stages of AlSb, AlN, and GaP epitaxy on Si, independently of misfit. It is also shown that complete III-V/Si wetting cannot be achieved in most III-V/Si systems. Surface/interface contributions to the free-energy variations are found to be prominent over strain relief processes. We finally propose a general and unified description of III-V/Si growth processes, including a description of the formation of antiphase boundaries.

Les Houches 2017: Physics at TeV Colliders Standard Model Working Group Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, J.R.; et al.

This Report summarizes the proceedings of the 2017 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) theoretical uncertainties and dataset dependence of parton distribution functions, (III) new developments in jet substructure techniques, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (V) phenomenological studies essential for comparing LHC data from Run II with theoretical predictions and projections for future measurements, and (VI) new developments in Monte Carlo event generators.

Imaging the atomic structure and local chemistry of platelets in natural type Ia diamond

NASA Astrophysics Data System (ADS)

Olivier, E. J.; Neethling, J. H.; Kroon, R. E.; Naidoo, S. R.; Allen, C. S.; Sawada, H.; van Aken, P. A.; Kirkland, A. I.

2018-03-01

In the past decades, many efforts have been devoted to characterizing {001} platelet defects in type Ia diamond. It is known that N is concentrated at the defect core. However, an accurate description of the atomic structure of the defect and the role that N plays in it is still unknown. Here, by using aberration-corrected transmission electron microscopy and electron energy-loss spectroscopy we have determined the atomic arrangement within platelet defects in a natural type Ia diamond and matched it to a prevalent theoretical model. The platelet has an anisotropic atomic structure with a zigzag ordering of defect pairs along the defect line. The electron energy-loss near-edge fine structure of both carbon K- and nitrogen K-edges obtained from the platelet core is consistent with a trigonal bonding arrangement at interstitial sites. The experimental observations support an interstitial aggregate mode of formation for platelet defects in natural diamond.

Imaging the atomic structure and local chemistry of platelets in natural type Ia diamond.

PubMed

Olivier, E J; Neethling, J H; Kroon, R E; Naidoo, S R; Allen, C S; Sawada, H; van Aken, P A; Kirkland, A I

2018-03-01

In the past decades, many efforts have been devoted to characterizing {001} platelet defects in type Ia diamond. It is known that N is concentrated at the defect core. However, an accurate description of the atomic structure of the defect and the role that N plays in it is still unknown. Here, by using aberration-corrected transmission electron microscopy and electron energy-loss spectroscopy we have determined the atomic arrangement within platelet defects in a natural type Ia diamond and matched it to a prevalent theoretical model. The platelet has an anisotropic atomic structure with a zigzag ordering of defect pairs along the defect line. The electron energy-loss near-edge fine structure of both carbon K- and nitrogen K-edges obtained from the platelet core is consistent with a trigonal bonding arrangement at interstitial sites. The experimental observations support an interstitial aggregate mode of formation for platelet defects in natural diamond.

Interpersonal Autonomic Physiology: A Systematic Review of the Literature.

PubMed

Palumbo, Richard V; Marraccini, Marisa E; Weyandt, Lisa L; Wilder-Smith, Oliver; McGee, Heather A; Liu, Siwei; Goodwin, Matthew S

2017-05-01

Interpersonal autonomic physiology is defined as the relationship between people's physiological dynamics, as indexed by continuous measures of the autonomic nervous system. Findings from this field of study indicate that physiological activity between two or more people can become associated or interdependent, often referred to as physiological synchrony. Physiological synchrony has been found in both new and established relationships across a range of contexts, and it correlates with a number of psychosocial constructs. Given these findings, interpersonal physiological interactions are theorized to be ubiquitous social processes that co-occur with observable behavior. However, this scientific literature is fragmented, making it difficult to evaluate consistency across reports. In an effort to facilitate more standardized scholarly approaches, this systematic review provides a description of existing work in the area and highlights theoretical, methodological, and statistical issues to be addressed in future interpersonal autonomic physiology research.

Generalized One-Band Model Based on Zhang-Rice Singlets for Tetragonal CuO.

PubMed

Hamad, I J; Manuel, L O; Aligia, A A

2018-04-27

Tetragonal CuO (T-CuO) has attracted attention because of its structure similar to that of the cuprates. It has been recently proposed as a compound whose study can give an end to the long debate about the proper microscopic modeling for cuprates. In this work, we rigorously derive an effective one-band generalized t-J model for T-CuO, based on orthogonalized Zhang-Rice singlets, and make an estimative calculation of its parameters, based on previous ab initio calculations. By means of the self-consistent Born approximation, we then evaluate the spectral function and the quasiparticle dispersion for a single hole doped in antiferromagnetically ordered half filled T-CuO. Our predictions show very good agreement with angle-resolved photoemission spectra and with theoretical multiband results. We conclude that a generalized t-J model remains the minimal Hamiltonian for a correct description of single-hole dynamics in cuprates.

Assessing musical skills in autistic children who are not savants.

PubMed

Heaton, Pamela

2009-05-27

Descriptions of autistic musical savants suggest that they possess extraordinary skills within the domain. However, until recently little was known about the musical skills and potential of individuals with autism who are not savants. The results from these more recent studies investigating music perception, cognition and learning in musically untrained children with autism have revealed a pattern of abilities that are either enhanced or spared. For example, increased sensitivity to musical pitch and timbre is frequently observed, and studies investigating perception of musical structure and emotions have consistently failed to reveal deficits in autism. While the phenomenon of the savant syndrome is of considerable theoretical interest, it may have led to an under-consideration of the potential talents and skills of that vast majority of autistic individuals, who do not meet savant criteria. Data from empirical studies show that many autistic children possess musical potential that can and should be developed.

Assessing musical skills in autistic children who are not savants

PubMed Central

Heaton, Pamela

2009-01-01

Descriptions of autistic musical savants suggest that they possess extraordinary skills within the domain. However, until recently little was known about the musical skills and potential of individuals with autism who are not savants. The results from these more recent studies investigating music perception, cognition and learning in musically untrained children with autism have revealed a pattern of abilities that are either enhanced or spared. For example, increased sensitivity to musical pitch and timbre is frequently observed, and studies investigating perception of musical structure and emotions have consistently failed to reveal deficits in autism. While the phenomenon of the savant syndrome is of considerable theoretical interest, it may have led to an under-consideration of the potential talents and skills of that vast majority of autistic individuals, who do not meet savant criteria. Data from empirical studies show that many autistic children possess musical potential that can and should be developed. PMID:19528029

Proposed changes in personality and personality disorder assessment and diagnosis for DSM-5 Part I: Description and rationale.

PubMed

Skodol, Andrew E; Clark, Lee Anna; Bender, Donna S; Krueger, Robert F; Morey, Leslie C; Verheul, Roel; Alarcon, Renato D; Bell, Carl C; Siever, Larry J; Oldham, John M

2011-01-01

A major reconceptualization of personality psychopathology has been proposed for DSM-5 that identifies core impairments in personality functioning, pathological personality traits, and prominent pathological personality types. A comprehensive personality assessment consists of four components: levels of personality functioning, personality disorder types, pathological personality trait domains and facets, and general criteria for personality disorder. This four-part assessment focuses attention on identifying personality psychopathology with increasing degrees of specificity, based on a clinician's available time, information, and expertise. In Part I of this two-part article, we describe the components of the new model and present brief theoretical and empirical rationales for each. In Part II, we will illustrate the clinical application of the model with vignettes of patients with varying degrees of personality psychopathology, to show how assessments might be conducted and diagnoses reached.

Skating on a Film of Air: Drops Impacting on a Surface

NASA Astrophysics Data System (ADS)

Kolinski, John M.; Rubinstein, Shmuel M.; Mandre, Shreyas; Brenner, Michael P.; Weitz, David A.; Mahadevan, L.

2012-02-01

The commonly accepted description of drops impacting on a surface typically ignores the essential role of the air that is trapped between the impacting drop and the surface. Here we describe a new imaging modality that is sensitive to the behavior right at the surface. We show that a very thin film of air, only a few tens of nanometers thick, remains trapped between the falling drop and the surface as the drop spreads. The thin film of air serves to lubricate the drop enabling the fluid to skate on the air film laterally outward at surprisingly high velocities, consistent with theoretical predictions. Eventually this thin film of air breaks down as the fluid wets the surface via a spinodal-like mechanism. Our results show that the dynamics of impacting drops are much more complex than previously thought, with a rich array of unexpected phenomena that require rethinking classic paradigms.

Role of Entropy and Structural Parameters in the Spin State Transition of LaCoO3

NASA Astrophysics Data System (ADS)

Chakrabarti, Bismayan; Birol, Turan; Haule, Kristjan

The spin state transition in LaCoO3 has eluded description for decades despite concerted theoretical and experimental effort. In this study, we approach this problem using fully charge consistent Density Functional Theory + Dynamical Mean Field Theory (DFT+DMFT). We show, from first principles, that LaCoO3 cannot be described by a single, pure spin state at any temperature, but instead shows a gradual change in the population of higher spin multiples as temperature is increased. We explicitly elucidate the critical role of the lattice expansion and oxygen octahedral rotations in the spin state transition. We also show that the spin state transition and the metal-insulator transition in the compound occur at different temperatures. In addition, our results shed light on the importance of electronic entropy, which has so far been ignored in all first principles studies of this material.

Theoretical investigation of the electron capture and loss processes in the collisions of He2+ + Ne.

PubMed

Hong, Xuhai; Wang, Feng; Jiao, Yalong; Su, Wenyong; Wang, Jianguo; Gou, Bingcong

2013-08-28

Based on the time-dependent density functional theory, a method is developed to study ion-atom collision dynamics, which self-consistently couples the quantum mechanical description of electron dynamics with the classical treatment of the ion motion. Employing real-time and real-space method, the coordinate space translation technique is introduced to allow one to focus on the region of target or projectile depending on the actual concerned process. The benchmark calculations are performed for the collisions of He(2+) + Ne, and the time evolution of electron density distribution is monitored, which provides interesting details of the interaction dynamics between the electrons and ion cores. The cross sections of single and many electron capture and loss have been calculated in the energy range of 1-1000 keV/amu, and the results show a good agreement with the available experiments over a wide range of impact energies.

Towards a self-consistent dynamical nuclear model

NASA Astrophysics Data System (ADS)

Roca-Maza, X.; Niu, Y. F.; Colò, G.; Bortignon, P. F.

2017-04-01

Density functional theory (DFT) is a powerful and accurate tool, exploited in nuclear physics to investigate the ground-state and some of the collective properties of nuclei along the whole nuclear chart. Models based on DFT are not, however, suitable for the description of single-particle dynamics in nuclei. Following the field theoretical approach by A Bohr and B R Mottelson to describe nuclear interactions between single-particle and vibrational degrees of freedom, we have taken important steps towards the building of a microscopic dynamic nuclear model. In connection with this, one important issue that needs to be better understood is the renormalization of the effective interaction in the particle-vibration approach. One possible way to renormalize the interaction is by the so-called subtraction method. In this contribution, we will implement the subtraction method in our model for the first time and study its consequences.

A Behavior Analytic Interpretation of Alexithymia

PubMed Central

Darrow, Sabrina M.; Follette, William C.

2014-01-01

Alexithymia is a term used to describe individuals who seem unable to experience or at least describe emotions. This paper offers a theoretical interpretation of alexithymia from a radical behaviorist perspective. While there have been attempts to explain the etiology of alexithymia, the current analysis is unique in that it provides direct treatment implications. The pragmatic analysis described focuses on the verbal behavior of individuals rather than looking “inside” for explanations. This is supported by a review of experimental research that has failed to find consistencies among alexithymic individuals’ physiological responding. Descriptions of the various discriminative and consequential stimulus conditions involved in the complex learning histories of individuals that could result in an alexithymic presentation are provided. This analysis helps situate the alexithymia construct in a broader behavior analytic understanding of emotions. Finally this paper outlines implications for assessment and treatment, which involve influencing discriminative and consequential interpersonal stimulus conditions to shape verbal behavior about emotions. PMID:25473602

Critical Landau Velocity in Helium Nanodroplets

NASA Astrophysics Data System (ADS)

Brauer, Nils B.; Smolarek, Szymon; Loginov, Evgeniy; Mateo, David; Hernando, Alberto; Pi, Marti; Barranco, Manuel; Buma, Wybren J.; Drabbels, Marcel

2013-10-01

The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concept can still be applied to nanometer-scale, finite size helium systems. To this end, atoms and molecules embedded in helium nanodroplets of various sizes are accelerated out of the droplets by means of optical excitation, and the speed distributions of the ejected particles are determined. The measurements reveal the existence of a critical velocity in these systems, even for nanodroplets consisting of only a thousand helium atoms. Accompanying theoretical simulations based on a time-dependent density functional description of the helium confirm and further elucidate this experimental finding.

Framework for cognitive analysis of dynamic perfusion computed tomography with visualization of large volumetric data

NASA Astrophysics Data System (ADS)

Hachaj, Tomasz; Ogiela, Marek R.

2012-10-01

The proposed framework for cognitive analysis of perfusion computed tomography images is a fusion of image processing, pattern recognition, and image analysis procedures. The output data of the algorithm consists of: regions of perfusion abnormalities, anatomy atlas description of brain tissues, measures of perfusion parameters, and prognosis for infracted tissues. That information is superimposed onto volumetric computed tomography data and displayed to radiologists. Our rendering algorithm enables rendering large volumes on off-the-shelf hardware. This portability of rendering solution is very important because our framework can be run without using expensive dedicated hardware. The other important factors are theoretically unlimited size of rendered volume and possibility of trading of image quality for rendering speed. Such rendered, high quality visualizations may be further used for intelligent brain perfusion abnormality identification, and computer aided-diagnosis of selected types of pathologies.

Generalized One-Band Model Based on Zhang-Rice Singlets for Tetragonal CuO

NASA Astrophysics Data System (ADS)

Hamad, I. J.; Manuel, L. O.; Aligia, A. A.

2018-04-01

Tetragonal CuO (T-CuO) has attracted attention because of its structure similar to that of the cuprates. It has been recently proposed as a compound whose study can give an end to the long debate about the proper microscopic modeling for cuprates. In this work, we rigorously derive an effective one-band generalized t -J model for T-CuO, based on orthogonalized Zhang-Rice singlets, and make an estimative calculation of its parameters, based on previous ab initio calculations. By means of the self-consistent Born approximation, we then evaluate the spectral function and the quasiparticle dispersion for a single hole doped in antiferromagnetically ordered half filled T-CuO. Our predictions show very good agreement with angle-resolved photoemission spectra and with theoretical multiband results. We conclude that a generalized t -J model remains the minimal Hamiltonian for a correct description of single-hole dynamics in cuprates.

Calorimetric determination of the magnetic phase diagram of underdoped ortho II YBa2Cu3O6.54 single crystals

PubMed Central

Marcenat, C.; Demuer, A.; Beauvois, K.; Michon, B.; Grockowiak, A.; Liang, R.; Hardy, W.; Bonn, D. A.; Klein, T.

2015-01-01

The recent discovery of a charge order in underdoped YBa2Cu3Oy raised the question of the interplay between superconductivity and this competing phase. Understanding the normal state of high-temperature superconductors is now an essential step towards the description of the pairing mechanism in those materials and determining the upper critical field is therefore of fundamental importance. We present here a calorimetric determination of the field–temperature phase diagram in underdoped YBa2Cu3Oy single crystals. We show that the specific heat saturates in high magnetic fields. This saturation is consistent with a normal state without any significant superconducting contribution and a total Sommerfeld coefficient γN∼6.5±1.5 mJ mol−1 K−2 putting strong constraints on the theoretical models for the Fermi surface reconstruction. PMID:26294047

SPY: A new scission point model based on microscopic ingredients to predict fission fragments properties

NASA Astrophysics Data System (ADS)

Lemaître, J.-F.; Dubray, N.; Hilaire, S.; Panebianco, S.; Sida, J.-L.

2013-12-01

Our purpose is to determine fission fragments characteristics in a framework of a scission point model named SPY for Scission Point Yields. This approach can be considered as a theoretical laboratory to study fission mechanism since it gives access to the correlation between the fragments properties and their nuclear structure, such as shell correction, pairing, collective degrees of freedom, odd-even effects. Which ones are dominant in final state? What is the impact of compound nucleus structure? The SPY model consists in a statistical description of the fission process at the scission point where fragments are completely formed and well separated with fixed properties. The most important property of the model relies on the nuclear structure of the fragments which is derived from full quantum microscopic calculations. This approach allows computing the fission final state of extremely exotic nuclei which are inaccessible by most of the fission model available on the market.

Organizational ethics: a literature review.

PubMed

Suhonen, Riitta; Stolt, Minna; Virtanen, Heli; Leino-Kilpi, Helena

2011-05-01

The aim of the study was to report the results of a systematically conducted literature review of empirical studies about healthcare organizations' ethics and management or leadership issues. Electronic databases MEDLINE and CINAHL yielded 909 citations. After a two stage application of the inclusion and exclusion criteria 56 full-text articles were included in the review. No large research programs were identified. Most of the studies were in acute hospital settings from the 1990s onwards. The studies focused on ethical challenges, dilemmas in practice, employee moral distress and ethical climates or environments. Study samples typically consisted of healthcare practitioners, operational, executive and strategic managers. Data collection was mainly by questionnaires or interviews and most of the studies were descriptive, correlational and cross-sectional. There is need to develop conceptual clarity and a theoretical framework around the subject of organizational ethics and the breadth of the contexts and scope of the research needs to be increased. © The Author(s) 2011

Thermally induced oscillations in fluid flow

NASA Technical Reports Server (NTRS)

Zuber, N.

1970-01-01

Theoretical investigation distinguishes the various mechanisms responsible for oscillations of pressure, temperature, and flow velocity, derives a quantitative description of the most troublesome mechanisms, and develops a capability to predict the occurrence of unstable flow.

Biology: A Hypothetico-Deductive Science.

ERIC Educational Resources Information Center

Lewis, Ralph W.

1988-01-01

Examines the change and general view of methods in biological science and the possible consequences for biology education. States that the transition was from descriptive biology to theoretical biology. Lists the postulates of some theories. (RT)

Flavor and baryon quantum numbers and their nondiffractive renormalizations of the Pomeron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dash, J.W.; Jones, S.T.; Manesis, E.K.

We present a theoretical review and a detailed phonomenological description of the ''flavoring'' of the bare Pomeron pole at t = 0 (i.e., the nondiffractive renormalization of its multiperipheral unitarity sum by strange quarks, charmed quarks, diquarks,...) from an ''unflavored'' intercept alpha-circumflex = 0.85 to a ''flavored'' intercept ..cap alpha.. approx. = 1.08. Experimentally, flavoring effects seem to converge rapidly; hence this number is probably close to the bare intercept of the Reggeon field theory. We treat NN, ..pi..N, and KN total cross sections and real to imaginary amplitude ratios. We do not observe oscillations. We pay particular attention tomore » 2sigma/sub K/N - sigma/sub piN/ which rises monotonically. We present a closely related combination of inelastic diffraction cross sections which decreases monotonically, indicating that vacuum amplitudes are not simply the sum of a Pomeron pole and an ideally mixed f. In fact we argue that a Pomeron + f structure is neither compatible with flavoring nor with schemes in which flavoring is somehow absorbed away. In contrast, flavoring is required for consistency with experiment by the Chew-Rosenzweig hypothesis of the Pomeron-f identity. We close with a description of flavoring threshold effects on the Reggeon field theory at current energies.« less

Testing the conditional mass function of dark matter haloes against numerical N-body simulations

NASA Astrophysics Data System (ADS)

Tramonte, D.; Rubiño-Martín, J. A.; Betancort-Rijo, J.; Dalla Vecchia, C.

2017-05-01

We compare the predicted conditional mass function (CMF) of dark matter haloes from two theoretical prescriptions against numerical N-body simulations, both in overdense and underdense regions and at different Eulerian scales ranging from 5 to 30 h-1 Mpc. In particular, we consider in detail a locally implemented rescaling of the unconditional mass function (UMF) already discussed in the literature, and also a generalization of the standard rescaling method described in the extended Press-Schechter formalism. First, we test the consistency of these two rescalings by verifying the normalization of the CMF at different scales, and showing that none of the proposed cases provides a normalized CMF. In order to satisfy the normalization condition, we include a modification in the rescaling procedure. After this modification, the resulting CMF generally provides a better description of numerical results. We finally present an analytical fit to the ratio between the CMF and the UMF (also known as the matter-to-halo bias function) in underdense regions, which could be of special interest to speed up the computation of the halo abundance when studying void statistics. In this case, the CMF prescription based on the locally implemented rescaling provides a slightly better description of the numerical results when compared to the standard rescaling.

A multichain polymer slip-spring model with fluctuating number of entanglements for linear and nonlinear rheology

DOE PAGES

Ramírez-Hernández, Abelardo; Peters, Brandon L.; Andreev, Marat; ...

2015-12-15

A theoretically informed entangled polymer simulation approach is presented for description of the linear and non-linear rheology of entangled polymer melts. The approach relies on a many-chain representation and introduces the topological effects that arise from the non-crossability of molecules through effective fluctuating interactions, mediated by slip-springs, between neighboring pairs of macromolecules. The total number of slip-springs is not preserved but, instead, it is controlled through a chemical potential that determines the average molecular weight between entanglements. The behavior of the model is discussed in the context of a recent theory for description of homogeneous materials, and its relevance ismore » established by comparing its predictions to experimental linear and non-linear rheology data for a series of well-characterized linear polyisoprene melts. Furthermore, the results are shown to be in quantitative agreement with experiment and suggest that the proposed formalism may also be used to describe the dynamics of inhomogeneous systems, such as composites and copolymers. Importantly, the fundamental connection made here between our many-chain model and the well-established, thermodynamically consistent single-chain mean-field models provides a path to systematic coarse-graining for prediction of polymer rheology in structurally homogeneous and heterogeneous materials.« less

Ultimate Gradient Limitation in Niobium Superconducting Accelerating Cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Checchin, Mattia; Grassellino, Anna; Martinello, Martina

2016-06-01

The present study is addressed to the theoretical description of the ultimate gradient limitation in SRF cavities. Our intent is to exploit experimental data to confirm models which provide feed-backs on how to improve the current state-of-art. New theoretical insight on the cavities limiting factor can be suitable to improve the quench field of N-doped cavities, and therefore to take advantage of high Q 0 at high gradients.

Two-dimensional Layered MoS2 Biosensors Enable Highly Sensitive Detection of Biomolecules

NASA Astrophysics Data System (ADS)

Lee, Joonhyung; Dak, Piyush; Lee, Yeonsung; Park, Heekyeong; Choi, Woong; Alam, Muhammad A.; Kim, Sunkook

2014-12-01

We present a MoS2 biosensor to electrically detect prostate specific antigen (PSA) in a highly sensitive and label-free manner. Unlike previous MoS2-FET-based biosensors, the device configuration of our biosensors does not require a dielectric layer such as HfO2 due to the hydrophobicity of MoS2. Such an oxide-free operation improves sensitivity and simplifies sensor design. For a quantitative and selective detection of PSA antigen, anti-PSA antibody was immobilized on the sensor surface. Then, introduction of PSA antigen, into the anti-PSA immobilized sensor surface resulted in a lable-free immunoassary format. Measured off-state current of the device showed a significant decrease as the applied PSA concentration was increased. The minimum detectable concentration of PSA is 1 pg/mL, which is several orders of magnitude below the clinical cut-off level of ~4 ng/mL. In addition, we also provide a systematic theoretical analysis of the sensor platform - including the charge state of protein at the specific pH level, and self-consistent channel transport. Taken together, the experimental demonstration and the theoretical framework provide a comprehensive description of the performance potential of dielectric-free MoS2-based biosensor technology.

How authors did it - a methodological analysis of recent engineering education research papers in the European Journal of Engineering Education

NASA Astrophysics Data System (ADS)

Malmi, Lauri; Adawi, Tom; Curmi, Ronald; de Graaff, Erik; Duffy, Gavin; Kautz, Christian; Kinnunen, Päivi; Williams, Bill

2018-03-01

We investigated research processes applied in recent publications in the European Journal of Engineering Education (EJEE), exploring how papers link to theoretical work and how research processes have been designed and reported. We analysed all 155 papers published in EJEE in 2009, 2010 and 2013, classifying the papers using a taxonomy of research processes in engineering education research (EER) (Malmi et al. 2012). The majority of the papers presented either empirical work (59%) or were case reports (27%). Our main findings are as follows: (1) EJEE papers build moderately on a wide selection of theoretical work; (2) a great majority of papers have a clear research strategy, but data analysis methods are mostly simple descriptive statistics or simple/undocumented qualitative research methods; and (3) there are significant shortcomings in reporting research questions, methodology and limitations of studies. Our findings are consistent with and extend analyses of EER papers in other publishing venues; they help to build a clearer picture of the research currently published in EJEE and allow us to make recommendations for consideration by the editorial team of the journal. Our employed procedure also provides a framework that can be applied to monitor future global evolution of this and other EER journals.

Biomolecular Dynamics: Order-Disorder Transitions and Energy Landscapes

PubMed Central

Whitford, Paul C.; Sanbonmatsu, Karissa Y.; Onuchic, José N.

2013-01-01

While the energy landscape theory of protein folding is now a widely accepted view for understanding how relatively-weak molecular interactions lead to rapid and cooperative protein folding, such a framework must be extended to describe the large-scale functional motions observed in molecular machines. In this review, we discuss 1) the development of the energy landscape theory of biomolecular folding, 2) recent advances towards establishing a consistent understanding of folding and function, and 3) emerging themes in the functional motions of enzymes, biomolecular motors, and other biomolecular machines. Recent theoretical, computational, and experimental lines of investigation are providing a very dynamic picture of biomolecular motion. In contrast to earlier ideas, where molecular machines were thought to function similarly to macroscopic machines, with rigid components that move along a few degrees of freedom in a deterministic fashion, biomolecular complexes are only marginally stable. Since the stabilizing contribution of each atomic interaction is on the order of the thermal fluctuations in solution, the rigid body description of molecular function must be revisited. An emerging theme is that functional motions encompass order-disorder transitions and structural flexibility provide significant contributions to the free-energy. In this review, we describe the biological importance of order-disorder transitions and discuss the statistical-mechanical foundation of theoretical approaches that can characterize such transitions. PMID:22790780

Religiousness and Alcohol Use in College Students: Examining Descriptive Drinking Norms as Mediators

ERIC Educational Resources Information Center

Brechting, Emily H.; Carlson, Charles R.

2015-01-01

Religiousness has consistently emerged in the literature as a protective factor for alcohol use. Relatively few studies have empirically explored possible mechanisms for this robust effect. The present study examines descriptive drinking norms as a potential mediator of the religiousness--alcohol consumption association. Consistent with the…

Concomitant occurrence of cochleosaccular dysplasia and Down's syndrome.

PubMed

Walby, A P; Schuknecht, H F

1984-07-01

Inherited cochleosaccular dysplasia occurred in a woman coincidentally with Down's syndrome. Study of the right temporal bone revealed abnormalities of the cochlea and saccule consistent with Scheibe 's original description. There was also a short cochlea and small lateral semicircular canal consistent with previous descriptions of Down's syndrome.

A Theoretically Consistent Framework for Modelling Lagrangian Particle Deposition in Plant Canopies

NASA Astrophysics Data System (ADS)

Bailey, Brian N.; Stoll, Rob; Pardyjak, Eric R.

2018-06-01

We present a theoretically consistent framework for modelling Lagrangian particle deposition in plant canopies. The primary focus is on describing the probability of particles encountering canopy elements (i.e., potential deposition), and provides a consistent means for including the effects of imperfect deposition through any appropriate sub-model for deposition efficiency. Some aspects of the framework draw upon an analogy to radiation propagation through a turbid medium with which to develop model theory. The present method is compared against one of the most commonly used heuristic Lagrangian frameworks, namely that originally developed by Legg and Powell (Agricultural Meteorology, 1979, Vol. 20, 47-67), which is shown to be theoretically inconsistent. A recommendation is made to discontinue the use of this heuristic approach in favour of the theoretically consistent framework developed herein, which is no more difficult to apply under equivalent assumptions. The proposed framework has the additional advantage that it can be applied to arbitrary canopy geometries given readily measurable parameters describing vegetation structure.

Group theoretical formulation of free fall and projectile motion

NASA Astrophysics Data System (ADS)

Düztaş, Koray

2018-07-01

In this work we formulate the group theoretical description of free fall and projectile motion. We show that the kinematic equations for constant acceleration form a one parameter group acting on a phase space. We define the group elements ϕ t by their action on the points in the phase space. We also generalize this approach to projectile motion. We evaluate the group orbits regarding their relations to the physical orbits of particles and unphysical solutions. We note that the group theoretical formulation does not apply to more general cases involving a time-dependent acceleration. This method improves our understanding of the constant acceleration problem with its global approach. It is especially beneficial for students who want to pursue a career in theoretical physics.

Characterization of B-H agostic compounds involved in the dehydrogenation of amine-boranes by group 4 metallocenes.

PubMed

Zhu, Jingwen; Zins, Emilie-Laure; Alikhani, Mohammad Esmaïl

2016-12-01

For over a decade, amine-borane has been considered as a potential chemical hydrogen vector in the context of a search for cleaner energy sources. When catalyzed by organometallic complexes, the reaction mechanisms currently considered involve the formation of β-BH agostic intermediates. A thorough understanding of these intermediates may constitute a crucial step toward the identification of ideal catalysts. Topological approaches such as QTAIM and ELF revealed to be particularly suitable for the description of β-agostic interactions. When studying model catalysts, accurate theoretical calculations may be carried out. However, for a comparison with experimental data, calculations should also be carried out on large organo-metallic species, often including transition metals belonging to the second or the third row. In such a case, DFT methods are particularly attractive. Unfortunately, triple-ζ all electrons basis sets are not easily available for heavy transition metal elements. Thus, a subtle balance should be reached between the affordable level of calculations and the required accuracy of the electronic description of the systems. Herein we propose the use of B3LYP functional in combination with the LanL2DZ pseudopotential for the metal atom and 6-311++G(2d,2p) basis set for the other atoms, followed by a single point using the DKH2 relativistic Hamiltonian in combination with the B3LYP/DZP-DKH level, as a "minimum level of theory" leading to a consistent topological description of the interaction within the ELF and QTAIM framework, in the context of isolated (gas-phase) group 4 metallocene catalysts.

Fundamental Neutron Physics: Theory and Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gudkov, Vladimir

The goal of the proposal was to study the possibility of searching for manifestations of new physics beyond the Standard model in fundamental neutron physics experiments. This involves detailed theoretical analyses of parity- and time reversal invariance-violating processes in neutron-induced reactions, properties of neutron β-decay, and the precise description of properties of neutron interactions with nuclei. To describe neutron-nuclear interactions, we use both the effective field theory approach and the theory of nuclear reaction with phenomenological nucleon potentials for the systematic description of parity- and time reversal-violating effects in the consistent way. A major emphasis of our research during themore » funding period has been the study of parity violation (PV) and time reversal invariance violation (TRIV) in few-body systems. We studied PV effects in non-elastic processes in three-nucleon system using both ”DDH-like” and effective field theory (EFT) approaches. The wave functions were obtained by solving three-body Faddeev equations in configuration space for a number of realistic strong potentials. The observed model dependence for the DDH approach indicates intrinsic difficulty in the description of nuclear PV effects, and it could be the reason for the observed discrepancies in the nuclear PV data analysis. It shows that the DDH approach could be a reasonable approach for analysis of PV effects only if exactly the same strong and weak potentials are used in calculating all PV observables in all nuclei. However, the existing calculations of nuclear PV effects were performed using different potentials; therefore, strictly speaking, one cannot compare the existing results of these calculations among themselves.« less

Quality of randomised controlled trials in medical education reported between 2012 and 2013: a systematic review protocol.

PubMed

Tolsgaard, Martin G; Ku, Cheryl; Woods, Nicole N; Kulasegaram, Kulamakan Mahan; Brydges, Ryan; Ringsted, Charlotte

2014-07-30

Research in medical education has increased in volume over the past decades but concerns have been raised regarding the quality of trials conducted within this field. Randomised controlled trials (RCTs) involving educational interventions that are reported in biomedical journals have been criticised for their insufficient conceptual, theoretical framework. RCTs published in journals dedicated to medical education, on the other hand, have been questioned regarding their methodological rigour. The aim of this study is therefore to assess the quality of RCTs of educational interventions reported in 2012 and 2013 in journals dedicated to medical education compared to biomedical journals with respect to objective quality criteria. RCTs published between 1 January 2012 and 31 December 2013 in English are included. The search strategy is developed with the help of experienced librarians to search online databases for key terms. All of the identified RCTs are screened based on their titles and abstracts individually by the authors and then compared in pairs to assess agreement. Data are extracted from the included RCTs by independently scoring each RCT using a data collection form. The data collection form consists of four steps. Step 1 includes confirmation of RCT eligibility; step 2 consists of the CONSORT checklist; step 3 consists of the Medical Education Research Study Quality Instrument framework; step 4 consists of a Medical Education Extension (MEdEx) to the CONSORT checklist. The MEdEx includes the following elements: Description of scientific background, explanation of rationale, quality of research questions and hypotheses, clarity in the description of the use of the intervention and control as well as interpretation of results. This review is the first to systematically examine the quality of RCTs conducted in medical education. We plan to disseminate the results through publications and presentation at relevant conferences. Ethical approval is not sought for this review. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The Persistence and Importance of Patriotism in the All-Volunteer Force

DTIC Science & Technology

1982-12-13

The description is cast in a theoretical framework which challenges the wisdom of focusing primarily on levels of pay and other market oriented conditions of work when establishing military manpower policy.

Notes on Barkas-Andersen effect

NASA Astrophysics Data System (ADS)

Sigmund, Peter; Schinner, Andreas

2014-10-01

Stimulated by recent statements in the literature on electronic stopping of heavy ions in matter, we try to clarify some central theoretical aspects of the Barkas-Andersen effect, about which there does not seem to be unanimous agreement in the community. We address the role of inner versus outer target shells, of projectile screening by bound electrons, the interference between Lindhard's description and perturbation theory, as well as the equivalence between a single-electron versus Fermi-gas description of the effect.

Emotions while awaiting lung transplantation: A comprehensive qualitative analysis

PubMed Central

Brügger, Aurelia; Aubert, John-David

2014-01-01

Patients awaiting lung transplantation are at risk of negative emotional and physical experiences. How do they talk about emotions? Semi-structured interviews were performed (15 patients). Categorical analysis focusing on emotion-related descriptions was organized into positive–negative–neutral descriptions: for primary and secondary emotions, evaluation processes, coping strategies, personal characteristics, emotion descriptions associated with physical states, (and) contexts were listed. Patients develop different strategies to maintain positive identity and attitude, while preserving significant others from extra emotional load. Results are discussed within various theoretical and research backgrounds, in emphasizing their importance in the definition of emotional support starting from the patient’s perspective. PMID:28070345

Emotions while awaiting lung transplantation: A comprehensive qualitative analysis.

PubMed

Brügger, Aurelia; Aubert, John-David; Piot-Ziegler, Chantal

2014-07-01

Patients awaiting lung transplantation are at risk of negative emotional and physical experiences. How do they talk about emotions? Semi-structured interviews were performed (15 patients). Categorical analysis focusing on emotion-related descriptions was organized into positive-negative-neutral descriptions: for primary and secondary emotions, evaluation processes, coping strategies, personal characteristics, emotion descriptions associated with physical states, (and) contexts were listed. Patients develop different strategies to maintain positive identity and attitude, while preserving significant others from extra emotional load. Results are discussed within various theoretical and research backgrounds, in emphasizing their importance in the definition of emotional support starting from the patient's perspective.

Verification of Gyrokinetic codes: theoretical background and applications

NASA Astrophysics Data System (ADS)

Tronko, Natalia

2016-10-01

In fusion plasmas the strong magnetic field allows the fast gyro motion to be systematically removed from the description of the dynamics, resulting in a considerable model simplification and gain of computational time. Nowadays, the gyrokinetic (GK) codes play a major role in the understanding of the development and the saturation of turbulence and in the prediction of the consequent transport. We present a new and generic theoretical framework and specific numerical applications to test the validity and the domain of applicability of existing GK codes. For a sound verification process, the underlying theoretical GK model and the numerical scheme must be considered at the same time, which makes this approach pioneering. At the analytical level, the main novelty consists in using advanced mathematical tools such as variational formulation of dynamics for systematization of basic GK code's equations to access the limits of their applicability. The indirect verification of numerical scheme is proposed via the Benchmark process. In this work, specific examples of code verification are presented for two GK codes: the multi-species electromagnetic ORB5 (PIC), and the radially global version of GENE (Eulerian). The proposed methodology can be applied to any existing GK code. We establish a hierarchy of reduced GK Vlasov-Maxwell equations using the generic variational formulation. Then, we derive and include the models implemented in ORB5 and GENE inside this hierarchy. At the computational level, detailed verification of global electromagnetic test cases based on the CYCLONE are considered, including a parametric β-scan covering the transition between the ITG to KBM and the spectral properties at the nominal β value.

Spin Triplet Nematic Pairing Symmetry and Superconducting Double Transition in U1-xThxBe13

NASA Astrophysics Data System (ADS)

Machida, Kazushige

2018-03-01

Motivated by a recent experiment on U1-xThxBe13 with x = 3%, we develop a theory to narrow down the possible pair symmetry to consistently describe the double transition utilizing various theoretical tools, including group theory and Ginzburg-Landau theory. It is explained in terms of the two-dimensional representation Eu with spin triplet. Symmetry breaking causes the degenerate Tc to split into two. The low-temperature phase is identified as the cyclic p wave: d(k) = \\hat{x}kx + ɛ \\hat{y}ky + ɛ 2\\hat{z}kz with ɛ3 = 1, whereas the biaxial nematic phase: d(k) = √{3} (\\hat{x}kx - \\hat{y}ky) is the high-temperature one. This allows us to simultaneously identify the uniaxial nematic phase: d(k) = 2\\hat{z}kz - \\hat{x}kx - \\hat{y}ky for UBe13, which spontaneously breaks the cubic symmetry of the system. Those pair functions are fully consistent with this description and existing data. We comment on the accidental scenario in addition to this degeneracy scenario and the intriguing topological nature hidden in this long-known material.

Sparse Coding of Natural Human Motion Yields Eigenmotions Consistent Across People

NASA Astrophysics Data System (ADS)

Thomik, Andreas; Faisal, A. Aldo

2015-03-01

Providing a precise mathematical description of the structure of natural human movement is a challenging problem. We use a data-driven approach to seek a generative model of movement capturing the underlying simplicity of spatial and temporal structure of behaviour observed in daily life. In perception, the analysis of natural scenes has shown that sparse codes of such scenes are information theoretic efficient descriptors with direct neuronal correlates. Translating from perception to action, we identify a generative model of movement generation by the human motor system. Using wearable full-hand motion capture, we measure the digit movement of the human hand in daily life. We learn a dictionary of ``eigenmotions'' which we use for sparse encoding of the movement data. We show that the dictionaries are generally well preserved across subjects with small deviations accounting for individuality of the person and variability in tasks. Further, the dictionary elements represent motions which can naturally describe hand movements. Our findings suggest the motor system can compose complex movement behaviours out of the spatially and temporally sparse activation of ``eigenmotion'' neurons, and is consistent with data on grasp-type specificity of specialised neurons in the premotor cortex. Andreas is supported by the Luxemburg Research Fund (1229297).

Refeeding syndrome or refeeding hypophosphatemia: a systematic review of cases.

PubMed

Skipper, Annalynn

2012-02-01

Nutrition support clinicians refer to the abnormalities in laboratory data and changes in clinical signs and symptoms that follow refeeding of starved or malnourished patients as refeeding syndrome. Theoretical descriptions of refeeding syndrome include a complex and extensive list of changes, such as hypophosphatemia, hypomagnesemia, hypokalemia, hyponatremia, hypocalcemia, hyperglycemia, and vitamin deficiency--all of which are accompanied by clinical signs and symptoms. In practice, clinicians see asymptomatic refeeding hypophosphatemia more often than a full-blown syndrome with multiple laboratory and clinical abnormalities. Confusion results because there is no widely accepted or uniformly applied set of defining characteristics for diagnosing refeeding syndrome. To gain insight into the clinical characteristics of refeeding syndrome described in the literature, a systematic review of reported cases and case series was conducted. Since 2000, 20 authors described 27 cases that contained sufficient data for review. Hypophosphatemia occurred in 26 patients (96%). While 19 patients (71%) experienced at least 1 other laboratory abnormality, only 14 (51%) exhibited a consistent pattern of abnormally low phosphorus and magnesium levels. Seven patients had hypocalcemia (26%), and hyponatremia was reported in 3 patients (11%). There were no reports of hyperglycemia. Mean data reported in case series containing data from 63 patients showed that hypophosphatemia was a consistent finding but that other abnormalities were not consistently identified. Findings suggest that refeeding hypophosphatemia is not accompanied by a consistent pattern of biochemical or clinical abnormalities among case reports or case series of patients reported to have refeeding syndrome.

Self-Consistent Model of Magnetospheric Ring Current and Electromagnetic Ion Cyclotron Waves: The 2-7 May 1998 Storm

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Gamayunov, K. V.; Jordanova, V. K.

2003-01-01

A complete description of a self-consistent model of magnetospheric ring current interacting with electromagnetic ion cyclotron waves is presented. The model is based on the system of two kinetic equations; one equation describes the ring current ion dynamics, and another equation describes the wave evolution. The effects on ring current ions interacting with electromagnetic ion cyclotron waves and back on waves are considered self-consistently by solving both equations on a global magnetospheric scale under nonsteady state conditions. The developed model is employed to simulate the entire 2-7 May 1998 storm period. First, the trapped number fluxes of the ring current protons are calculated and presented along with comparison with the data measured by the three- dimensional hot plasma instrument Polar/HYDRA. Incorporating in the model the wave-particle interaction leads to much better agreement between the experimental data and the model results. Second, examining of the wave (MLT, L shell) distributions produced by the model during the storm progress reveals an essential intensification of the wave emission about 2 days after the main phase of the storm. This result is well consistent with the earlier ground-based observations. Finally, the theoretical shapes and the occurrence rates of the wave power spectral densities are studied. It is found that about 2 days after the storm s main phase on 4 May, mainly non-Gaussian shapes of power spectral densities are produced.

Self-Consistent Ring Current Modeling with Propagating Electromagnetic Ion Cyclotron Waves in the Presence of Heavy Ions

NASA Technical Reports Server (NTRS)

Khazanov, George V.

2006-01-01

The self-consistent treatment of the RC ion dynamics and EMIC waves, which are thought to exert important influences on the ion dynamical evolution, is an important missing element in our understanding of the storm-and recovery-time ring current evolution. Under certain conditions, relativistic electrons, with energies 21 MeV, can be removed from the outer radiation belt by EMIC wave scattering during a magnetic storm. That is why the modeling of EMIC waves is critical and timely issue in magnetospheric physics. To describe the RC evolution itself this study uses the ring current-atmosphere interaction model (RAM). RAM solves the gyration and bounce-averaged Boltzmann-Landau equation inside of geosynchronous orbit. Originally developed at the University of Michigan, there are now several branches of this model currently in use as describe by Liemohn namely those at NASA Goddard Space Flight Center This study will generalize the self-consistent theoretical description of RC ions and EMIC waves that has been developed by Khazanov and include the heavy ions and propagation effects of EMIC waves in the global dynamic of self-consistent RC - EMIC waves coupling. The results of our newly developed model that will be presented at GEM meeting, focusing mainly on the dynamic of EMIC waves and comparison of these results with the previous global RC modeling studies devoted to EMIC waves formation. We also discuss RC ion precipitations and wave induced thermal electron fluxes into the ionosphere.

Self-Consistent Ring Current/Electromagnetic Ion Cyclotron Waves Modeling

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Gamayunov, K. V.; Gallagher, D. L.

2006-01-01

The self-consistent treatment of the RC ion dynamics and EMIC waves, which are thought to exert important influences on the ion dynamical evolution, is an important missing element in our understanding of the storm-and recovery-time ring current evolution. For example, the EMlC waves cause the RC decay on a time scale of about one hour or less during the main phase of storms. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Under certain conditions, relativistic electrons, with energies 21 MeV, can be removed from the outer radiation belt by EMIC wave scattering during a magnetic storm. That is why the modeling of EMIC waves is critical and timely issue in magnetospheric physics. This study will generalize the self-consistent theoretical description of RC ions and EMIC waves that has been developed by Khazanov et al. [2002, 2003] and include the heavy ions and propagation effects of EMIC waves in the global dynamic of self-consistent RC - EMIC waves coupling. The results of our newly developed model that will be presented at the meeting, focusing mainly on the dynamic of EMIC waves and comparison of these results with the previous global RC modeling studies devoted to EMIC waves formation. We also discuss RC ion precipitations and wave induced thermal electron fluxes into the ionosphere.

Open charm meson production at BNL RHIC within kt-factorization approach and revision of their semileptonic decays

NASA Astrophysics Data System (ADS)

Maciuła, Rafał; Szczurek, Antoni; Łuszczak, Marta

2015-09-01

We discuss inclusive production of open charm mesons in proton-proton scattering at the BNL RHIC. The calculation is performed in the framework of kt-factorization approach which effectively includes higher-order pQCD corrections. Different models of unintegrated gluon distributions (UGDF) from the literature are used. We focus on UGDF models favored by the LHC data and on a new up-to-date parametrizations based on the HERA collider deep-inelastic scattering high-precision data. Results of the kt-factorization approach are compared to next-to-leading order collinear predictions. The hadronization of heavy quarks is done by means of fragmentation function technique. The theoretical transverse momentum distributions of charmed mesons are compared with recent experimental data of the STAR collaboration at √{s }=200 and 500 GeV. Theoretical uncertainties related to the choice of renormalization and factorization scales as well as due to the quark mass are discussed. A very good description of the measured integrated cross sections and differential distributions is obtained for the Jung setB0 CCFM UGDF. Revised charm and bottom theoretical cross sections corresponding to those measured recently by the STAR and PHENIX collaborations for semileptonic decays of D and B mesons are presented. Significant improvement in theoretical description of the nonphotonic electrons measurements is clearly obtained with respect to the previous studies within the kt-factorization.

Commercial Aircraft Protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehst, David A.

This report summarizes the results of theoretical research performed during 3 years of P371 Project implementation. In results of such research a new scientific conceptual technology of quasi-passive individual infrared protection of heat-generating objects – Spatial Displacement of Thermal Image (SDTI technology) was developed. Theoretical substantiation and description of working processes of civil aircraft individual IR-protection system were conducted. The mathematical models and methodology were presented, there were obtained the analytical dependencies which allow performing theoretical research of the affect of intentionally arranged dynamic field of the artificial thermal interferences with variable contrast onto main parameters of optic-electronic tracking andmore » homing systems.« less

A review of carrier thermoelectric-transport theory in organic semiconductors.

PubMed

Lu, Nianduan; Li, Ling; Liu, Ming

2016-07-20

Carrier thermoelectric-transport theory has recently become of growing interest and numerous thermoelectric-transport models have been proposed for organic semiconductors, due to pressing current issues involving energy production and the environment. The purpose of this review is to provide a theoretical description of the thermoelectric Seebeck effect in organic semiconductors. Special attention is devoted to the carrier concentration, temperature, polaron effect and dipole effect dependence of the Seebeck effect and its relationship to hopping transport theory. Furthermore, various theoretical methods are used to discuss carrier thermoelectric transport. Finally, an outlook of the remaining challenges ahead for future theoretical research is provided.

COSMOS-e'-soft Higgsotic attractors

NASA Astrophysics Data System (ADS)

Choudhury, Sayantan

2017-07-01

In this work, we have developed an elegant algorithm to study the cosmological consequences from a huge class of quantum field theories (i.e. superstring theory, supergravity, extra dimensional theory, modified gravity, etc.), which are equivalently described by soft attractors in the effective field theory framework. In this description we have restricted our analysis for two scalar fields - dilaton and Higgsotic fields minimally coupled with Einstein gravity, which can be generalized for any arbitrary number of scalar field contents with generalized non-canonical and non-minimal interactions. We have explicitly used R^2 gravity, from which we have studied the attractor and non-attractor phases by exactly computing two point, three point and four point correlation functions from scalar fluctuations using the In-In (Schwinger-Keldysh) and the δ N formalisms. We have also presented theoretical bounds on the amplitude, tilt and running of the primordial power spectrum, various shapes (equilateral, squeezed, folded kite or counter-collinear) of the amplitude as obtained from three and four point scalar functions, which are consistent with observed data. Also the results from two point tensor fluctuations and the field excursion formula are explicitly presented for the attractor and non-attractor phase. Further, reheating constraints, scale dependent behavior of the couplings and the dynamical solution for the dilaton and Higgsotic fields are also presented. New sets of consistency relations between two, three and four point observables are also presented, which shows significant deviation from canonical slow-roll models. Additionally, three possible theoretical proposals have presented to overcome the tachyonic instability at the time of late time acceleration. Finally, we have also provided the bulk interpretation from the three and four point scalar correlation functions for completeness.

TAD- THEORETICAL AERODYNAMICS PROGRAM

NASA Technical Reports Server (NTRS)

Barrowman, J.

1994-01-01

This theoretical aerodynamics program, TAD, was developed to predict the aerodynamic characteristics of vehicles with sounding rocket configurations. These slender, axisymmetric finned vehicle configurations have a wide range of aeronautical applications from rockets to high speed armament. Over a given range of Mach numbers, TAD will compute the normal force coefficient derivative, the center-of-pressure, the roll forcing moment coefficient derivative, the roll damping moment coefficient derivative, and the pitch damping moment coefficient derivative of a sounding rocket configured vehicle. The vehicle may consist of a sharp pointed nose of cone or tangent ogive shape, up to nine other body divisions of conical shoulder, conical boattail, or circular cylinder shape, and fins of trapezoid planform shape with constant cross section and either three or four fins per fin set. The characteristics computed by TAD have been shown to be accurate to within ten percent of experimental data in the supersonic region. The TAD program calculates the characteristics of separate portions of the vehicle, calculates the interference between separate portions of the vehicle, and then combines the results to form a total vehicle solution. Also, TAD can be used to calculate the characteristics of the body or fins separately as an aid in the design process. Input to the TAD program consists of simple descriptions of the body and fin geometries and the Mach range of interest. Output includes the aerodynamic characteristics of the total vehicle, or user-selected portions, at specified points over the mach range. The TAD program is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 computer with a central memory requirement of approximately 123K of 8 bit bytes. The TAD program was originally developed in 1967 and last updated in 1972.

Systematics of intermediate-energy single-nucleon removal cross sections

NASA Astrophysics Data System (ADS)

Tostevin, J. A.; Gade, A.

2014-11-01

There is now a large and increasing body of experimental data and theoretical analyses for reactions that remove a single nucleon from an intermediate-energy beam of neutron- or proton-rich nuclei. In each such measurement, one obtains the inclusive cross section for the population of all bound final states of the mass A -1 reaction residue. These data, from different regions of the nuclear chart, and that involve weakly and strongly bound nucleons, are compared with theoretical expectations. These calculations include an approximate treatment of the reaction dynamics and shell-model descriptions of the projectile initial state, the bound final states of the residues, and the single-particle strengths computed from their overlap functions. The results are discussed in the light of recent data, more exclusive tests of the eikonal dynamical description, and calculations that take input from more microscopic nuclear structure models.

Teaching Computer Languages and Elementary Theory for Mixed Audiences at University Level

NASA Astrophysics Data System (ADS)

Christiansen, Henning

2004-09-01

Theoretical issues of computer science are traditionally taught in a way that presupposes a solid mathematical background and are usually considered more or less inaccessible for students without this. An effective methodology is described which has been developed for a target group of university students with different backgrounds such as natural science or humanities. It has been developed for a course that integrates theoretical material on computer languages and abstract machines with practical programming techniques. Prolog used as meta-language for describing language issues is the central instrument in the approach: Formal descriptions become running prototypes that are easy and appealing to test and modify, and can be extended into analyzers, interpreters, and tools such as tracers and debuggers. Experience shows a high learning curve, especially when the principles are extended into a learning-by-doing approach having the students to develop such descriptions themselves from an informal introduction.

Theoretical description of the mixed-field orientation of asymmetric-top molecules: A time-dependent study

NASA Astrophysics Data System (ADS)

Omiste, Juan J.; González-Férez, Rosario

2016-12-01

We present a theoretical study of the mixed-field-orientation of asymmetric-top molecules in tilted static electric field and nonresonant linearly polarized laser pulse by solving the time-dependent Schrödinger equation. Within this framework, we compute the mixed-field orientation of a state-selected molecular beam of benzonitrile (C7H5N ) and compare with the experimental observations [J. L. Hansen et al., Phys. Rev. A 83, 023406 (2011), 10.1103/PhysRevA.83.023406] and with our previous time-independent descriptions [J. J. Omiste et al., Phys. Chem. Chem. Phys. 13, 18815 (2011), 10.1039/c1cp21195a]. For an excited rotational state, we investigate the field-dressed dynamics for several field configurations as those used in the mixed-field experiments. The nonadiabatic phenomena and their consequences on the rotational dynamics are analyzed in detail.

Photonics and spectroscopy in nanojunctions: a theoretical insight

DOE PAGES

Galperin, Michael

2017-04-11

The progress of experimental techniques at the nanoscale in the last decade made optical measurements in current-carrying nanojunctions a reality, thus indicating the emergence of a new field of research coined optoelectronics. Optical spectroscopy of open nonequilibrium systems is a natural meeting point for (at least) two research areas: nonlinear optical spectroscopy and quantum transport, each with its own theoretical toolbox. We review recent progress in the field comparing theoretical treatments of optical response in nanojunctions as is accepted in nonlinear spectroscopy and quantum transport communities. A unified theoretical description of spectroscopy in nanojunctions is presented. Here, we argue thatmore » theoretical approaches of the quantum transport community (and in particular, the Green function based considerations) yield a convenient tool for optoelectronics when the radiation field is treated classically, and that differences between the toolboxes may become critical when studying the quantum radiation field in junctions.« less

Estimation of M 1 scissors mode strength for deformed nuclei in the medium- to heavy-mass region by statistical Hauser-Feshbach model calculations

NASA Astrophysics Data System (ADS)

Mumpower, M. R.; Kawano, T.; Ullmann, J. L.; Krtička, M.; Sprouse, T. M.

2017-08-01

Radiative neutron capture is an important nuclear reaction whose accurate description is needed for many applications ranging from nuclear technology to nuclear astrophysics. The description of such a process relies on the Hauser-Feshbach theory which requires the nuclear optical potential, level density, and γ -strength function as model inputs. It has recently been suggested that the M 1 scissors mode may explain discrepancies between theoretical calculations and evaluated data. We explore statistical model calculations with the strength of the M 1 scissors mode estimated to be dependent on the nuclear deformation of the compound system. We show that the form of the M 1 scissors mode improves the theoretical description of evaluated data and the match to experiment in both the fission product and actinide regions. Since the scissors mode occurs in the range of a few keV to a few MeV, it may also impact the neutron capture cross sections of neutron-rich nuclei that participate in the rapid neutron capture process of nucleosynthesis. We comment on the possible impact to nucleosynthesis by evaluating neutron capture rates for neutron-rich nuclei with the M 1 scissors mode active.

A Game Theoretical Approach to Hacktivism: Is Attack Likelihood a Product of Risks and Payoffs?

PubMed

Bodford, Jessica E; Kwan, Virginia S Y

2018-02-01

The current study examines hacktivism (i.e., hacking to convey a moral, ethical, or social justice message) through a general game theoretic framework-that is, as a product of costs and benefits. Given the inherent risk of carrying out a hacktivist attack (e.g., legal action, imprisonment), it would be rational for the user to weigh these risks against perceived benefits of carrying out the attack. As such, we examined computer science students' estimations of risks, payoffs, and attack likelihood through a game theoretic design. Furthermore, this study aims at constructing a descriptive profile of potential hacktivists, exploring two predicted covariates of attack decision making, namely, peer prevalence of hacking and sex differences. Contrary to expectations, results suggest that participants' estimations of attack likelihood stemmed solely from expected payoffs, rather than subjective risks. Peer prevalence significantly predicted increased payoffs and attack likelihood, suggesting an underlying descriptive norm in social networks. Notably, we observed no sex differences in the decision to attack, nor in the factors predicting attack likelihood. Implications for policymakers and the understanding and prevention of hacktivism are discussed, as are the possible ramifications of widely communicated payoffs over potential risks in hacking communities.

A gauge-theoretic approach to gravity.

PubMed

Krasnov, Kirill

2012-08-08

Einstein's general relativity (GR) is a dynamical theory of the space-time metric. We describe an approach in which GR becomes an SU(2) gauge theory. We start at the linearized level and show how a gauge-theoretic Lagrangian for non-interacting massless spin two particles (gravitons) takes a much more simple and compact form than in the standard metric description. Moreover, in contrast to the GR situation, the gauge theory Lagrangian is convex. We then proceed with a formulation of the full nonlinear theory. The equivalence to the metric-based GR holds only at the level of solutions of the field equations, that is, on-shell. The gauge-theoretic approach also makes it clear that GR is not the only interacting theory of massless spin two particles, in spite of the GR uniqueness theorems available in the metric description. Thus, there is an infinite-parameter class of gravity theories all describing just two propagating polarizations of the graviton. We describe how matter can be coupled to gravity in this formulation and, in particular, how both the gravity and Yang-Mills arise as sectors of a general diffeomorphism-invariant gauge theory. We finish by outlining a possible scenario of the ultraviolet completion of quantum gravity within this approach.

Theoretical ecology without species

NASA Astrophysics Data System (ADS)

Tikhonov, Mikhail

The sequencing-driven revolution in microbial ecology demonstrated that discrete ``species'' are an inadequate description of the vast majority of life on our planet. Developing a novel theoretical language that, unlike classical ecology, would not require postulating the existence of species, is a challenge of tremendous medical and environmental significance, and an exciting direction for theoretical physics. Here, it is proposed that community dynamics can be described in a naturally hierarchical way in terms of population fluctuation eigenmodes. The approach is applied to a simple model of division of labor in a multi-species community. In one regime, effective species with a core and accessory genome are shown to naturally appear as emergent concepts. However, the same model allows a transition into a regime where the species formalism becomes inadequate, but the eigenmode description remains well-defined. Treating a community as a black box that expresses enzymes in response to resources reveals mathematically exact parallels between a community and a single coherent organism with its own fitness function. This coherence is a generic consequence of division of labor, requires no cooperative interactions, and can be expected to be widespread in microbial ecosystems. Harvard Center of Mathematical Sciences and Applications;John A. Paulson School of Engineering and Applied Sciences.

Coherence in the Visual Imagination.

PubMed

Vertolli, Michael O; Kelly, Matthew A; Davies, Jim

2018-04-01

An incoherent visualization is when aspects of different senses of a word (e.g., the biological "mouse" vs. the computer "mouse") are present in the same visualization (e.g., a visualization of a biological mouse in the same image with a computer tower). We describe and implement a new model of creating contextual coherence in the visual imagination called Coherencer, based on the SOILIE model of imagination. We show that Coherencer is able to generate scene descriptions that are more coherent than SOILIE's original approach as well as a parallel connectionist algorithm that is considered competitive in the literature on general coherence. We also show that co-occurrence probabilities are a better association representation than holographic vectors and that better models of coherence improve the resulting output independent of the association type that is used. Theoretically, we show that Coherencer is consistent with other models of cognitive generation. In particular, Coherencer is a similar, but more cognitively plausible model than the C 3 model of concept combination created by Costello and Keane (2000). We show that Coherencer is also consistent with both the modal schematic indices of perceptual symbol systems theory (Barsalou, 1999) and the amodal contextual constraints of Thagard's (2002) theory of coherence. Finally, we describe how Coherencer is consistent with contemporary research on the hippocampus, and we show evidence that the process of making a visualization coherent is serial. Copyright © 2017 Cognitive Science Society, Inc.

Qualitative Descriptive Methods in Health Science Research.

PubMed

Colorafi, Karen Jiggins; Evans, Bronwynne

2016-07-01

The purpose of this methodology paper is to describe an approach to qualitative design known as qualitative descriptive that is well suited to junior health sciences researchers because it can be used with a variety of theoretical approaches, sampling techniques, and data collection strategies. It is often difficult for junior qualitative researchers to pull together the tools and resources they need to embark on a high-quality qualitative research study and to manage the volumes of data they collect during qualitative studies. This paper seeks to pull together much needed resources and provide an overview of methods. A step-by-step guide to planning a qualitative descriptive study and analyzing the data is provided, utilizing exemplars from the authors' research. This paper presents steps to conducting a qualitative descriptive study under the following headings: describing the qualitative descriptive approach, designing a qualitative descriptive study, steps to data analysis, and ensuring rigor of findings. The qualitative descriptive approach results in a summary in everyday, factual language that facilitates understanding of a selected phenomenon across disciplines of health science researchers. © The Author(s) 2016.

Methods of feminist family therapy supervision.

PubMed

Prouty, A M; Thomas, V; Johnson, S; Long, J K

2001-01-01

Although feminist family therapy has been studied and practiced for more than 20 years, writing about feminist supervision in family therapy has been limited. Three supervision methods emerged from a qualitative study of the experiences of feminist family therapy supervisors and the therapists they supervised: The supervision contract, collaborative methods, and hierarchical methods. In addition to a description of the participants' experiences of these methods, we discuss their fit with previous theoretical descriptions of feminist supervision and offer suggestions for future research.

Alternating-Offers Protocol for Multi-issue Bilateral Negotiation in Semantic-Enabled Marketplaces

NASA Astrophysics Data System (ADS)

Ragone, Azzurra; di Noia, Tommaso; di Sciascio, Eugenio; Donini, Francesco M.

We present a semantic-based approach to multi-issue bilateral negotiation for e-commerce. We use Description Logics to model advertisements, and relations among issues as axioms in a TBox. We then introduce a logic-based alternating-offers protocol, able to handle conflicting information, that merges non-standard reasoning services in Description Logics with utility thoery to find the most suitable agreements. We illustrate and motivate the theoretical framework, the logical language, and the negotiation protocol.

The impact of galaxy formation on satellite kinematics and redshift-space distortions

NASA Astrophysics Data System (ADS)

Orsi, Álvaro A.; Angulo, Raúl E.

2018-04-01

Galaxy surveys aim to map the large-scale structure of the Universe and use redshift-space distortions to constrain deviations from general relativity and probe the existence of massive neutrinos. However, the amount of information that can be extracted is limited by the accuracy of theoretical models used to analyse the data. Here, by using the L-Galaxies semi-analytical model run over the Millennium-XXL N-body simulation, we assess the impact of galaxy formation on satellite kinematics and the theoretical modelling of redshift-space distortions. We show that different galaxy selection criteria lead to noticeable differences in the radial distributions and velocity structure of satellite galaxies. Specifically, whereas samples of stellar mass selected galaxies feature satellites that roughly follow the dark matter, emission line satellite galaxies are located preferentially in the outskirts of haloes and display net infall velocities. We demonstrate that capturing these differences is crucial for modelling the multipoles of the correlation function in redshift space, even on large scales. In particular, we show how modelling small-scale velocities with a single Gaussian distribution leads to a poor description of the measured clustering. In contrast, we propose a parametrization that is flexible enough to model the satellite kinematics and that leads to an accurate description of the correlation function down to sub-Mpc scales. We anticipate that our model will be a necessary ingredient in improved theoretical descriptions of redshift-space distortions, which together could result in significantly tighter cosmological constraints and a more optimal exploitation of future large data sets.

Fundamental principles of absolute radiometry and the philosophy of this NBS program (1968 to 1971)

NASA Technical Reports Server (NTRS)

Geist, J.

1972-01-01

A description is given work performed on a program to develop an electrically calibrated detector (also called absolute radiometer, absolute detector, and electrically calibrated radiometer) that could be used to realize, maintain, and transfer a scale of total irradiance. The program includes a comprehensive investigation of the theoretical basis of absolute detector radiometry, as well as the design and construction of a number of detectors. A theoretical analysis of the sources of error is also included.

Theoretical Modeling of Molecular and Electron Kinetic Processes. Volume I. Theoretical Formulation of Analysis and Description of Computer Program.

DTIC Science & Technology

1979-01-01

syn- thesis proceed s by ignoring unacceptable syntax or other errors , pro- tection against subsequent execution of a faulty reaction scheme can be...resulting TAPE9 . During subroutine syn thesis and reaction processing, a search is made (fo r each secondary electron collision encountered) to...program library, which can be cat- alogued and saved if any future specialized modifications (beyond the scope of the syn thesis capability of LASER

Measurement of strains at high temperatures by means of electro-optics holography

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Bhat, G.; Vaitekunas, Jeffrey

Electro-optics holographic-moire interferometry is used to measure strains at temperatures up to 1000 C. A description of the instrumentation developed to carry out the measurements is given. The data processing technique is also explained. Main problems encountered in recording patterns at high temperatures are analyzed and possible solutions are outlined. Optical results are compared with strain gage values obtained with instrumented specimens and with theoretical results. Very good agreement is found between optical, strain gage and theoretical results.

Measurement of strains at high temperatures by means of electro-optics holography

NASA Technical Reports Server (NTRS)

Sciammarella, Cesar A.; Bhat, G.; Vaitekunas, Jeffrey

1991-01-01

Electro-optics holographic-moire interferometry is used to measure strains at temperatures up to 1000 C. A description of the instrumentation developed to carry out the measurements is given. The data processing technique is also explained. Main problems encountered in recording patterns at high temperatures are analyzed and possible solutions are outlined. Optical results are compared with strain gage values obtained with instrumented specimens and with theoretical results. Very good agreement is found between optical, strain gage and theoretical results.

Analysis of multimode fiber bundles for endoscopic spectral-domain optical coherence tomography

PubMed Central

Risi, Matthew D.; Makhlouf, Houssine; Rouse, Andrew R.; Gmitro, Arthur F.

2016-01-01

A theoretical analysis of the use of a fiber bundle in spectral-domain optical coherence tomography (OCT) systems is presented. The fiber bundle enables a flexible endoscopic design and provides fast, parallelized acquisition of the OCT data. However, the multimode characteristic of the fibers in the fiber bundle affects the depth sensitivity of the imaging system. A description of light interference in a multimode fiber is presented along with numerical simulations and experimental studies to illustrate the theoretical analysis. PMID:25967012

Uncertainties on exclusive diffractive Higgs boson and jet production at the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dechambre, A.; CEA/IRFU/Service de physique des particules, CEA/Saclay; Kepka, O.

2011-03-01

Two theoretical descriptions of exclusive diffractive jets and Higgs production at the LHC were implemented into the FPMC generator: the Khoze, Martin, Ryskin model and the Cudell, Hernandez, Ivanov, Dechambre exclusive model. We then study the uncertainties. We compare their predictions to the CDF measurement and discuss the possibility of constraining the exclusive Higgs production at the LHC with early measurements of exclusive jets. We show that the present theoretical uncertainties can be reduced with such data by a factor of 5.

Perceptions of barriers, facilitators and motivators related to use of prenatal care: A qualitative descriptive study of inner-city women in Winnipeg, Canada.

PubMed

Heaman, Maureen I; Sword, Wendy; Elliott, Lawrence; Moffatt, Michael; Helewa, Michael E; Morris, Heather; Tjaden, Lynda; Gregory, Patricia; Cook, Catherine

2015-01-01

The objective of this qualitative descriptive study was to explore the perceptions of women living in inner-city Winnipeg, Canada, about barriers, facilitators, and motivators related to their use of prenatal care. Individual, semi-structured interviews were conducted in person with 26 pregnant or postpartum women living in inner-city neighborhoods with high rates of inadequate prenatal care. Interviews averaged 67 min in length. Recruitment of participants continued until data saturation was achieved. Inductive content analysis was used to identify themes and subthemes under four broad topics of interest (barriers, facilitators, motivators, and suggestions). Sword's socio-ecological model of health services use provided the theoretical framework for the research. This model conceptualizes service use as a product of two interacting systems: the personal and situational attributes of potential users and the characteristics of health services. Half of the women in our sample were single and half self-identified as Aboriginal. Participants discussed several personal and system-related barriers affecting use of prenatal care, such as problems with transportation and child care, lack of prenatal care providers, and inaccessible services. Facilitating factors included transportation assistance, convenient location of services, positive care provider qualities, and tangible rewards. Women were motivated to attend prenatal care to gain knowledge and skills and to have a healthy baby. Consistent with the theoretical framework, women's utilization of prenatal care was a product of two interacting systems, with several barriers related to personal and situational factors affecting women's lives, while other barriers were related to problems with service delivery and the broader healthcare system. Overcoming barriers to prenatal care and capitalizing on factors that motivate women to seek prenatal care despite difficult living circumstances may help improve use of prenatal care by inner-city women.

Perceptions of barriers, facilitators and motivators related to use of prenatal care: A qualitative descriptive study of inner-city women in Winnipeg, Canada

PubMed Central

Heaman, Maureen I; Sword, Wendy; Elliott, Lawrence; Moffatt, Michael; Helewa, Michael E; Morris, Heather; Tjaden, Lynda; Gregory, Patricia; Cook, Catherine

2015-01-01

Objective: The objective of this qualitative descriptive study was to explore the perceptions of women living in inner-city Winnipeg, Canada, about barriers, facilitators, and motivators related to their use of prenatal care. Methods: Individual, semi-structured interviews were conducted in person with 26 pregnant or postpartum women living in inner-city neighborhoods with high rates of inadequate prenatal care. Interviews averaged 67 min in length. Recruitment of participants continued until data saturation was achieved. Inductive content analysis was used to identify themes and subthemes under four broad topics of interest (barriers, facilitators, motivators, and suggestions). Sword’s socio-ecological model of health services use provided the theoretical framework for the research. This model conceptualizes service use as a product of two interacting systems: the personal and situational attributes of potential users and the characteristics of health services. Results: Half of the women in our sample were single and half self-identified as Aboriginal. Participants discussed several personal and system-related barriers affecting use of prenatal care, such as problems with transportation and child care, lack of prenatal care providers, and inaccessible services. Facilitating factors included transportation assistance, convenient location of services, positive care provider qualities, and tangible rewards. Women were motivated to attend prenatal care to gain knowledge and skills and to have a healthy baby. Conclusion: Consistent with the theoretical framework, women’s utilization of prenatal care was a product of two interacting systems, with several barriers related to personal and situational factors affecting women’s lives, while other barriers were related to problems with service delivery and the broader healthcare system. Overcoming barriers to prenatal care and capitalizing on factors that motivate women to seek prenatal care despite difficult living circumstances may help improve use of prenatal care by inner-city women. PMID:27092262

Slave finite elements for nonlinear analysis of engine structures, volume 1

NASA Technical Reports Server (NTRS)

Gellin, S.

1991-01-01

A 336 degrees of freedom slave finite element processing capability to analyze engine structures under severe thermomechanical loading is presented. Description of the theoretical development and demonstration of that element is presented in this volume.

Investigating Music Information Objects

ERIC Educational Resources Information Center

Weissenberger, Lynnsey K.

2016-01-01

This dissertation, titled "Investigating Music Information Objects," is a study of the nature, description, representations, and ideas related to music information objects (MIOs). This research study investigates how music practitioners from various traditions describe and conceptualize MIOs, using a theoretical framework to classify…

Somaesthetics of Music

ERIC Educational Resources Information Center

Maus, Fred Everett

2010-01-01

Philosopher Richard Shusterman's book "Body Consciousness" is the most recent and most extensive addition to Shusterman's project of "somaesthetics," an area of philosophy dealing with experiences of embodiment. Shusterman distinguishes three aspects of somaesthetics. Analytic somaesthetics is a "descriptive and theoretical enterprise"; pragmatic…

Quantum epistemology from subquantum ontology: Quantum mechanics from theory of classical random fields

NASA Astrophysics Data System (ADS)

Khrennikov, Andrei

2017-02-01

The scientific methodology based on two descriptive levels, ontic (reality as it is) and epistemic (observational), is briefly presented. Following Schrödinger, we point to the possible gap between these two descriptions. Our main aim is to show that, although ontic entities may be unaccessible for observations, they can be useful for clarification of the physical nature of operational epistemic entities. We illustrate this thesis by the concrete example: starting with the concrete ontic model preceding quantum mechanics (the latter is treated as an epistemic model), namely, prequantum classical statistical field theory (PCSFT), we propose the natural physical interpretation for the basic quantum mechanical entity-the quantum state ("wave function"). The correspondence PCSFT ↦ QM is not straightforward, it couples the covariance operators of classical (prequantum) random fields with the quantum density operators. We use this correspondence to clarify the physical meaning of the pure quantum state and the superposition principle-by using the formalism of classical field correlations. In classical mechanics the phase space description can be considered as the ontic description, here states are given by points λ =(x , p) of phase space. The dynamics of the ontic state is given by the system of Hamiltonian equations.We can also consider probability distributions on the phase space (or equivalently random variables valued in it). We call them probabilistic ontic states. Dynamics of probabilistic ontic states is given by the Liouville equation.In classical physics we can (at least in principle) measure both the coordinate and momentum and hence ontic states can be treated as epistemic states as well (or it is better to say that here epistemic states can be treated as ontic states). Probabilistic ontic states represent probabilities for outcomes of joint measurement of position and momentum.However, this was a very special, although very important, example of description of physical phenomena. In general there are no reasons to expect that properties of ontic states are approachable through our measurements. There is a gap between ontic and epistemic descriptions, cf. also with 't Hooft [49,50] and G G. Groessing et al. [51]. In general the presence of such a gap also implies unapproachability of the probabilistic ontic states, i.e., probability distributions on the space of ontic states. De Broglie [28] called such probability distributions hidden probabilities and distinguished them sharply from probability distributions of measurements outcomes, see also Lochak [29]. (The latter distributions are described by the quantum formalism.)This ontic-epistemic approach based on the combination of two descriptive levels for natural phenomena is closely related to the old Bild conception which was originated in the works of Hertz. Later it was heavily explored by Schrödinger in the quantum domain, see, e.g., [8,11] for detailed analysis. According to Hertz one cannot expect to construct a complete theoretical model based explicitly on observable quantities. The complete theoretical model can contain quantities which are unapproachable for external measurement inspection. For example, Hertz by trying to create a mechanical model for Maxwell's electromagnetism invented hidden masses. The main distinguishing property of a theoretical model (in contrast to an observational model) is the continuity of description, i.e., the absence of gaps in description. From this viewpoint, the quantum mechanical description is not continuous: there is a gap between premeasurement dynamics and the measurement outcome. QM cannot say anything what happens in the process of measurement, this is the well known measurement problem of QM [32], cf. [52,53]. Continuity of description is closely related to causality. However, here we cannot go in more detail, see [8,11].The important question is about interrelation between two levels of description, ontic-epistemic (or theoretical-observational). In the introduction we have already cited Schrödinger who emphasized the possible complexity of this interrelation. In particular, in general there is no reason to expect a straightforward coupling of the form, cf. [9,10]:

Microscopic description of production cross sections including deexcitation effects

NASA Astrophysics Data System (ADS)

Sekizawa, Kazuyuki

2017-07-01

Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable. Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compound-nucleus deexcitation model, GEMINI++. Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using the particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wave function after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely used grazing calculations. Results: The method is applied to describe cross sections for multinucleon transfer processes in 40Ca+124Sn (Ec .m .≃128.54 MeV ), 48Ca+124Sn (Ec .m .≃125.44 MeV ), 40Ca+208Pb (Ec .m .≃208.84 MeV ), 58Ni+208Pb (Ec .m .≃256.79 MeV ), 64Ni+238U (Ec .m .≃307.35 MeV ), and 136Xe+198Pt (Ec .m .≃644.98 MeV ) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in grazing calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one proton, compared to the grazing results. However, there remain discrepancies between the measurements and the calculated cross sections, indicating a limit of the theoretical framework that works with a single mean-field potential. Possible causes of the discrepancies are discussed. Conclusions: To perfectly reproduce experimental cross sections for multinucleon transfer processes, one should go beyond the standard self-consistent mean-field description. Nevertheless, the proposed method will provide valuable information to optimize production mechanisms of new neutron-rich nuclei through its microscopic, nonempirical predictions.

A pedestrian approach to the measurement problem in quantum mechanics

NASA Astrophysics Data System (ADS)

Boughn, Stephen; Reginatto, Marcel

2013-09-01

The quantum theory of measurement has been a matter of debate for over eighty years. Most of the discussion has focused on theoretical issues with the consequence that other aspects (such as the operational prescriptions that are an integral part of experimental physics) have been largely ignored. This has undoubtedly exacerbated attempts to find a solution to the "measurement problem". How the measurement problem is defined depends to some extent on how the theoretical concepts introduced by the theory are interpreted. In this paper, we fully embrace the minimalist statistical (ensemble) interpretation of quantum mechanics espoused by Einstein, Ballentine, and others. According to this interpretation, the quantum state description applies only to a statistical ensemble of similarly prepared systems rather than representing an individual system. Thus, the statistical interpretation obviates the need to entertain reduction of the state vector, one of the primary dilemmas of the measurement problem. The other major aspect of the measurement problem, the necessity of describing measurements in terms of classical concepts that lay outside of quantum theory, remains. A consistent formalism for interacting quantum and classical systems, like the one based on ensembles on configuration space that we refer to in this paper, might seem to eliminate this facet of the measurement problem; however, we argue that the ultimate interface with experiments is described by operational prescriptions and not in terms of the concepts of classical theory. There is no doubt that attempts to address the measurement problem have yielded important advances in fundamental physics; however, it is also very clear that the measurement problem is still far from being resolved. The pedestrian approach presented here suggests that this state of affairs is in part the result of searching for a theoretical/mathematical solution to what is fundamentally an experimental/observational question. It suggests also that the measurement problem is, in some sense, ill-posed and might never be resolved. This point of view is tenable so long as one is willing to view physical theories as providing models of nature rather than complete descriptions of reality. Among other things, these considerations lead us to suggest that the Copenhagen interpretation's insistence on the classicality of the measurement apparatus should be replaced by the requirement that a measurement, which is specified operationally, should simply be of sufficient precision.

Compaction Behavior of Granular Materials

NASA Astrophysics Data System (ADS)

Endicott, Mark R.; Kenkre, V. M.; Glass, S. Jill; Hurd, Alan J.

1996-03-01

We report the results of our recent study of compaction of granular materials. A theoretical model is developed for the description of the compaction of granular materials exemplified by granulated ceramic powders. Its predictions are compared to observations of uniaxial compaction tests of ceramic granules of PMN-PT, spray dried alumina and rutile. The theoretical model employs a volume-based statistical mechanics treatment and an activation analogy. Results of a computer simulation of random packing of discs in two dimensions are also reported. The effect of type of particle size distribution and other parameters of that distribution on the calculated quantities are discussed. We examine the implications of the results of the simulation for the theoretical model.

Striking a Balance: Experiment and Concept in Undergraduate Inorganic Chemistry.

ERIC Educational Resources Information Center

Frey, John E.

1990-01-01

Described is an inorganic chemistry course based on the premise that a balanced understanding of inorganic chemistry requires knowledge of the experimental, theoretical, and technological aspects of the subject. A detailed description of lectures and laboratories is included. (KR)

Understanding and Validity in Qualitative Research.

ERIC Educational Resources Information Center

Maxwell, Joseph A.

1992-01-01

Details the philosophical and practical dimensions of five types of validity used in qualitative research: descriptive, interpretive, theoretical, generalizable, and evaluative, with corresponding issues of understanding. Presents this typology as a checklist of the kinds of threats to validity that may arise. (SK)

Reconciling Verbal and Nonverbal Models of Dyadic Communication

ERIC Educational Resources Information Center

Firestone, Ira J.

1977-01-01

This paper examines two distinct theoretical descriptions of dyadic communication, the distance-equilibrium and reciprocity formulations, and shows that they carry divergent implications for changes that can occur in interpersonal relations. Presented at the Western Psychological Association meeting, April 1975. (Author)

Student Centered WebCT Instruction for African Language.

ERIC Educational Resources Information Center

Moshi, Lioba; Ojo, Akinloye

2000-01-01

Explores theoretical issues concerning instructional technology for African language instruction, gives a brief description of WebCT (a web-based instruction framework), and describes its practicality in the instruction of African languages with special focus on Swahili and Yoruba. (Author/VWL)

World Englishes and English-Using Communities.

ERIC Educational Resources Information Center

Kachru, Braj B.

1997-01-01

A review of literature since 1990 on world English focuses on theoretical, conceptual, descriptive, ideological, and power-related issues, including: types of diaspora; English-using communities; dynamics of those communities; monolingual paradigms and heteroglossic English forms; transcultural literary creativity; codification and authentication…

The Clinician's "World of Action" as an Approach to Teaching Abnormal Psychology.

ERIC Educational Resources Information Center

Bibace, Roger; And Others

1979-01-01

Presents a description of an undergraduate abnormal psychology course developed from a theory of instruction and active student participation, the theoretical basis for the course, student course evaluation, and an interpretation of the students' performances. (Author/CK)

Analysis of the DFP/AFCS Systems for Compensating Gravity Distortions on the 70-Meter Antenna

NASA Technical Reports Server (NTRS)

Imbriale, William A.; Hoppe, Daniel J.; Rochblatt, David

2000-01-01

This paper presents the theoretical computations showing the expected performances for both systems. The basic analysis tool is a Physical Optics reflector analysis code that was ported to a parallel computer for faster execution times. There are several steps involved in computing the RF performance of the various systems. 1 . A model of the RF distortions of the main reflector is required. This model is based upon measured holography maps of the 70-meter antenna obtained at 3 elevation angles. The holography maps are then processed (using an appropriate gravity mechanical model of the dish) to provide surface distortion maps at all elevation angles. 2. From the surface distortion maps, ray optics is used to determine the theoretical shape of the DFP that will exactly phase compensate the distortions. 3. From the theoretical shape and a NASTRAN mechanical model of the plate, the actuator positions that generate a surface that provides the best RMS fit to the theoretical model are selected. Using the actuator positions and the NASTRAN model provides an accurate description of the actual mirror shape. 4. Starting from the mechanical drawings of the feed, a computed RF feed pattern is generated. This pattern is expanded into a set of spherical wave modes so that a complete near field analysis of the reflector system can be obtained. 5. For the array feed, the excitation coefficients that provide the maximum gain are computed using a phase conjugate technique. The basic experimental geometry consisted of a dual shaped 70-meter antenna system; a refocusing ellipse, a DFP and an array feed system. To provide physical insight to the systems performance, focal plane field plots are presented at several elevations. Curves of predicted performance are shown for the DFP system, monopulse tracking system, AFCS and combined DFP/AFCS system. The calculated results show that the combined DFP/AFCS system is capable of recovering the majority of the gain lost due to gravity distortion.

Are we ready to accept the challenge? Addressing the shortcomings of contemporary qualitative health research.

PubMed

Lau, Sofie Rosenlund; Traulsen, Janine M

Qualitative approaches represent an important contributor to health care research. However, several researchers argue that contemporary qualitative research does not live up to its full potential. By presenting a snapshot of contemporary qualitative research in the field of social and administrative pharmacy, this study challenges contributors to the field by asking: Are we ready to accept the challenge and take qualitative research one step further? The purpose of this study was to initiate a constructive dialogue on the need for increased transparency in qualitative data analysis, including explicitly reflecting upon theoretical perspectives affecting the research process. Content analysis was used to evaluate levels of theoretical visibility and analysis transparency in selected qualitative research articles published in Research in Social and Administrative Pharmacy between January 2014 and January 2015. In 14 out of 21 assessed papers, the use of theory was found to be Seemingly Absent (lowest level of theory use), and the data analyses did not include any interpretive endeavors. Only two papers consistently applied theory throughout the entire study and clearly took the data analyses from a descriptive to an interpretive level. It was found that the aim of the majority of assessed papers was to change or modify a given practice, which however, resulted in a lack of both theoretical underpinnings and analysis transparency. This study takes the standpoint that theory and high-quality analysis go hand-in-hand. Based on the content analysis, articles that were deemed to be high in quality were explicit about the theoretical framework of their study and transparent in how they analyzed their data. It was found that theory contributed to the transparency of how the data were analyzed and interpreted. Two ways of improving contemporary qualitative research in the field of social and administrative pharmacy are discussed: engaging with social theory and establishing close collaboration with social scientists. Copyright © 2016 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galperin, Michael

The progress of experimental techniques at the nanoscale in the last decade made optical measurements in current-carrying nanojunctions a reality, thus indicating the emergence of a new field of research coined optoelectronics. Optical spectroscopy of open nonequilibrium systems is a natural meeting point for (at least) two research areas: nonlinear optical spectroscopy and quantum transport, each with its own theoretical toolbox. We review recent progress in the field comparing theoretical treatments of optical response in nanojunctions as is accepted in nonlinear spectroscopy and quantum transport communities. A unified theoretical description of spectroscopy in nanojunctions is presented. Here, we argue thatmore » theoretical approaches of the quantum transport community (and in particular, the Green function based considerations) yield a convenient tool for optoelectronics when the radiation field is treated classically, and that differences between the toolboxes may become critical when studying the quantum radiation field in junctions.« less

Full-dimensional analytical potential energy surface describing the gas-phase Cl + C2H6 reaction and kinetics study of rate constants and kinetic isotope effects.

PubMed

Rangel, Cipriano; Espinosa-Garcia, Joaquin

2018-02-07

Within the Born-Oppenheimer approximation a full-dimensional analytical potential energy surface, PES-2017, was developed for the gas-phase hydrogen abstraction reaction between the chlorine atom and ethane, which is a nine body system. This surface presents a valence-bond/molecular mechanics functional form dependent on 60 parameters and is fitted to high-level ab initio calculations. This reaction presents little exothermicity, -2.30 kcal mol -1 , with a low height barrier, 2.44 kcal mol -1 , and intermediate complexes in the entrance and exit channels. We found that the energetic description was strongly dependent on the ab initio level used and it presented a very flat topology in the entrance channel, which represents a theoretical challenge in the fitting process. In general, PES-2017 reproduces the ab initio information used as input, which is merely a test of self-consistency. As a first test of the quality of the PES-2017, a theoretical kinetics study was performed in the temperature range 200-1400 K using two approaches, i.e. the variational transition-state theory and quasi-classical trajectory calculations, with spin-orbit effects. The rate constants show reasonable agreement with experiments in the whole temperature range, with the largest differences at the lowest temperatures, and this behaviour agrees with previous theoretical studies, thus indicating the inherent difficulties in the theoretical simulation of the kinetics of the title reaction. Different sources of error were analysed, such as the limitations of the PES and theoretical methods, recrossing effects, and the tunnelling effect, which is negligible in this reaction, and the manner in which the spin-orbit effects were included in this non-relativistic study. We found that the variation of spin-orbit coupling along the reaction path, and the influence of the reactivity of the excited Cl( 2 P 1/2 ) state, have relative importance, but do not explain the whole discrepancy. Finally, the activation energy and the kinetics isotope effects reproduce the experimental information.

Leadership research in business and health care.

PubMed

Vance, Connie; Larson, Elaine

2002-01-01

To summarize research on leadership in the health care and business literature and to identify the outcomes of leadership on individuals, groups, and organizations. A computerized search and review of research studies was conducted in the health care and business literature from 1970-1999. Studies were categorized and analyzed according to participants, design, primary topic area, and effects or outcomes of leadership. Most of the health care and business literature on leadership consisted of anecdotal or theoretical discussion. Only 4.4% (n = 290) of 6,628 articles reviewed were data-based. Further, the largest proportion of the research (120/290, 41.4%) was purely descriptive of the demographic characteristics or personality traits of leaders. Other studies showed the influence of leadership on subordinates (27.9%). Only 15 (5.2%) of 290 research articles include correlations of qualities or styles of leadership with measurable outcomes on the recipients of services or positive changes in organizations. Research on leadership in the health care and business literature to date has been primarily descriptive. Although work in the social sciences indicates that leadership styles can have a major influence on performance and outcomes, minimal transfer of this work to the health care system is evident. Limited research on leadership and health care outcomes exists, such as changes in patient care or improvements in organizational outputs. In this era of evidence-based practice, such research, although difficult to conduct, is urgently needed.

Application of the compensated Arrhenius formalism to fluidity data of polar organic liquids.

PubMed

Petrowsky, Matt; Fleshman, Allison M; Frech, Roger

2013-03-14

The temperature dependence of viscosity (the reciprocal of fluidity) in polar liquids has been studied for over a century, but the available theoretical models have serious limitations. Consequently, the viscosity is often described with empirical equations using adjustable fitting parameters that offer no insight into the molecular mechanism of transport. We have previously reported a novel approach called the compensated Arrhenius formalism (CAF) to describe ionic conductivity, self-diffusion, and dielectric relaxation in terms of molecular and system properties. Here the CAF is applied to fluidity data of pure n-acetates, 2-ketones, n-nitriles, and n-alcohols over the temperature range 5-85 °C. The fluidity is represented as an Arrhenius-like expression that includes a static dielectric constant dependence in the exponential prefactor. The dielectric constant dependence results from the dependence of mass and charge transport on the molecular dipole moment and the solvent dipole density. The CAF is the only self-consistent description of fluid transport in polar liquids written solely in terms of molecular and system parameters. A scaling procedure is used to calculate the activation energy for transport. We find that the activation energies for fluidity of the aprotic liquids are comparable in value, whereas a higher average E(a) value is observed for the n-alcohol data. Finally, we contrast the molecular description of transport presented here with the conventional hydrodynamic model.

Ultrafast absorption of intense x rays by nitrogen molecules

NASA Astrophysics Data System (ADS)

Buth, Christian; Liu, Ji-Cai; Chen, Mau Hsiung; Cryan, James P.; Fang, Li; Glownia, James M.; Hoener, Matthias; Coffee, Ryan N.; Berrah, Nora

2012-06-01

We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser Linac Coherent Light Source (LCLS). We set out from a rate-equation description for the x-ray absorption by a nitrogen atom. The equations are formulated using all one-x-ray-photon absorption cross sections and the Auger and radiative decay widths of multiply-ionized nitrogen atoms. Cross sections are obtained with a one-electron theory and decay widths are determined from ab initio computations using the Dirac-Hartree-Slater (DHS) method. We also calculate all binding and transition energies of nitrogen atoms in all charge states with the DHS method as the difference of two self-consistent field (SCF) calculations (ΔSCF method). To describe the interaction with N2, a detailed investigation of intense x-ray-induced ionization and molecular fragmentation are carried out. As a figure of merit, we calculate ion yields and the average charge state measured in recent experiments at the LCLS. We use a series of phenomenological models of increasing sophistication to unravel the mechanisms of the interaction of x rays with N2: a single atom, a symmetric-sharing model, and a fragmentation-matrix model are developed. The role of the formation and decay of single and double core holes, the metastable states of N_2^{2+}, and molecular fragmentation are explained.

Relevance of the DFT method to study expanded porphyrins with different topologies.

PubMed

Torrent-Sucarrat, Miquel; Navarro, Sara; Cossío, Fernando P; Anglada, Josep M; Luis, Josep M

2017-12-15

Meso-aryl expanded porphyrins present a structural versatility that allows them to achieve different topologies with distinct aromaticities. Several studies appeared in the literature studying these topological switches from an experimental and theoretical point of view. Most of these publications include density functional theory calculations, being the B3LYP the most used methodology. In this work, we show that the selection of the functional has a critical role on the geometric, energetic, and magnetic results of these expanded porphyrins, and that the use of an inadequate methodology can even generate spurious stationary points on the potential energy surface. To illustrate these aspects, in this article we have studied different molecular distortions of two expanded porphyrins, [32]-heptaphyrin and [26]-hexaphyrin using 11 DFT functionals and performing single point energy calculations at the local pair natural orbital coupled cluster DLPNO-CCSD(T) method, which have been carried out for benchmarking purposes. For some selected functionals, the dispersion effects have also been evaluated using the D3-Grimme's dispersion correction with Becke-Johnson damping. Our results let us to conclude that the CAM-B3LYP, M05-2X, and M06-2X functionals are the methodologies that provide a more consistent description of these topological switches, while other methods, such as B3LYP, BPE, and BP86, show a biased description. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

An effective description of dark matter and dark energy in the mildly non-linear regime

DOE PAGES

Lewandowski, Matthew; Maleknejad, Azadeh; Senatore, Leonardo

2017-05-18

In the next few years, we are going to probe the low-redshift universe with unprecedented accuracy. Among the various fruits that this will bear, it will greatly improve our knowledge of the dynamics of dark energy, though for this there is a strong theoretical preference for a cosmological constant. We assume that dark energy is described by the so-called Effective Field Theory of Dark Energy, which assumes that dark energy is the Goldstone boson of time translations. Such a formalism makes it easy to ensure that our signatures are consistent with well-established principles of physics. Since most of the informationmore » resides at high wavenumbers, it is important to be able to make predictions at the highest wavenumber that is possible. Furthermore, the Effective Field Theory of Large-Scale Structure (EFTofLSS) is a theoretical framework that has allowed us to make accurate predictions in the mildly non-linear regime. In this paper, we derive the non-linear equations that extend the EFTofLSS to include the effect of dark energy both on the matter fields and on the biased tracers. For the specific case of clustering quintessence, we then perturbatively solve to cubic order the resulting non-linear equations and construct the one-loop power spectrum of the total density contrast.« less

Dynamics of relaxation to a stationary state for interacting molecular motors

NASA Astrophysics Data System (ADS)

Gomes, Luiza V. F.; Kolomeisky, Anatoly B.

2018-01-01

Motor proteins are active enzymatic molecules that drive a variety of biological processes, including transfer of genetic information, cellular transport, cell motility and muscle contraction. It is known that these biological molecular motors usually perform their cellular tasks by acting collectively, and there are interactions between individual motors that specify the overall collective behavior. One of the fundamental issues related to the collective dynamics of motor proteins is the question if they function at stationary-state conditions. To investigate this problem, we analyze a relaxation to the stationary state for the system of interacting molecular motors. Our approach utilizes a recently developed theoretical framework, which views the collective dynamics of motor proteins as a totally asymmetric simple exclusion process of interacting particles, where interactions are taken into account via a thermodynamically consistent approach. The dynamics of relaxation to the stationary state is analyzed using a domain-wall method that relies on a mean-field description, which takes into account some correlations. It is found that the system quickly relaxes for repulsive interactions, while attractive interactions always slow down reaching the stationary state. It is also predicted that for some range of parameters the fastest relaxation might be achieved for a weak repulsive interaction. Our theoretical predictions are tested with Monte Carlo computer simulations. The implications of our findings for biological systems are briefly discussed.

Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

DOE PAGES

Ackermann, M.

2015-09-02

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former onmore » the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. As a result, we quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.« less

Beyond Classical Information Theory: Advancing the Fundamentals for Improved Geophysical Prediction

NASA Astrophysics Data System (ADS)

Perdigão, R. A. P.; Pires, C. L.; Hall, J.; Bloeschl, G.

2016-12-01

Information Theory, in its original and quantum forms, has gradually made its way into various fields of science and engineering. From the very basic concepts of Information Entropy and Mutual Information to Transit Information, Interaction Information and respective partitioning into statistical synergy, redundancy and exclusivity, the overall theoretical foundations have matured as early as the mid XX century. In the Earth Sciences various interesting applications have been devised over the last few decades, such as the design of complex process networks of descriptive and/or inferential nature, wherein earth system processes are "nodes" and statistical relationships between them designed as information-theoretical "interactions". However, most applications still take the very early concepts along with their many caveats, especially in heavily non-Normal, non-linear and structurally changing scenarios. In order to overcome the traditional limitations of information theory and tackle elusive Earth System phenomena, we introduce a new suite of information dynamic methodologies towards a more physically consistent and information comprehensive framework. The methodological developments are then illustrated on a set of practical examples from geophysical fluid dynamics, where high-order nonlinear relationships elusive to the current non-linear information measures are aptly captured. In doing so, these advances increase the predictability of critical events such as the emergence of hyper-chaotic regimes in ocean-atmospheric dynamics and the occurrence of hydro-meteorological extremes.

Correlation, temperature and disorder: Recent developments in the one-step description of angle-resolved photoemission

NASA Astrophysics Data System (ADS)

Braun, Jürgen; Minár, Ján; Ebert, Hubert

2018-04-01

Various apparative developments extended the potential of angle-resolved photoemission spectroscopy tremendously during the last two decades. Modern experimental arrangements consisting of new photon sources, analyzers and detectors supply not only extremely high angle and energy resolution but also spin resolution. This provides an adequate platform to study in detail new materials like low-dimensional magnetic structures, Rashba systems, topological insulator materials or high TC superconductors. The interest in such systems has grown enormously not only because of their technological relevance but even more because of exciting new physics. Furthermore, the use of photon energies from few eV up to several keV makes this experimental technique a rather unique tool to investigate the electronic properties of solids and surfaces. The following article reviews the corresponding recent theoretical developments in the field of angle-resolved photoemission with a special emphasis on correlation effects, temperature and relativistic aspects. The most successful theoretical approach to deal with angle-resolved photoemission is the so-called spectral function or one-step formulation of the photoemission process. Nowadays, the one-step model allows for photocurrent calculations for photon energies ranging from a few eV to more than 10 keV, to deal with arbitrarily ordered and disordered systems, to account for finite temperatures, and considering in addition strong correlation effects within the dynamical mean-field theory or similar advanced approaches.

An effective description of dark matter and dark energy in the mildly non-linear regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewandowski, Matthew; Maleknejad, Azadeh; Senatore, Leonardo

In the next few years, we are going to probe the low-redshift universe with unprecedented accuracy. Among the various fruits that this will bear, it will greatly improve our knowledge of the dynamics of dark energy, though for this there is a strong theoretical preference for a cosmological constant. We assume that dark energy is described by the so-called Effective Field Theory of Dark Energy, which assumes that dark energy is the Goldstone boson of time translations. Such a formalism makes it easy to ensure that our signatures are consistent with well-established principles of physics. Since most of the informationmore » resides at high wavenumbers, it is important to be able to make predictions at the highest wavenumber that is possible. Furthermore, the Effective Field Theory of Large-Scale Structure (EFTofLSS) is a theoretical framework that has allowed us to make accurate predictions in the mildly non-linear regime. In this paper, we derive the non-linear equations that extend the EFTofLSS to include the effect of dark energy both on the matter fields and on the biased tracers. For the specific case of clustering quintessence, we then perturbatively solve to cubic order the resulting non-linear equations and construct the one-loop power spectrum of the total density contrast.« less

An effective description of dark matter and dark energy in the mildly non-linear regime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewandowski, Matthew; Senatore, Leonardo; Maleknejad, Azadeh, E-mail: matthew.lewandowski@cea.fr, E-mail: azade@ipm.ir, E-mail: senatore@stanford.edu

In the next few years, we are going to probe the low-redshift universe with unprecedented accuracy. Among the various fruits that this will bear, it will greatly improve our knowledge of the dynamics of dark energy, though for this there is a strong theoretical preference for a cosmological constant. We assume that dark energy is described by the so-called Effective Field Theory of Dark Energy, which assumes that dark energy is the Goldstone boson of time translations. Such a formalism makes it easy to ensure that our signatures are consistent with well-established principles of physics. Since most of the informationmore » resides at high wavenumbers, it is important to be able to make predictions at the highest wavenumber that is possible. The Effective Field Theory of Large-Scale Structure (EFTofLSS) is a theoretical framework that has allowed us to make accurate predictions in the mildly non-linear regime. In this paper, we derive the non-linear equations that extend the EFTofLSS to include the effect of dark energy both on the matter fields and on the biased tracers. For the specific case of clustering quintessence, we then perturbatively solve to cubic order the resulting non-linear equations and construct the one-loop power spectrum of the total density contrast.« less

Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collaboration: Fermi LAT Collaboration

2015-09-01

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ∼ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on themore » IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.« less

Distance Education in Taiwan: A Model Validated.

ERIC Educational Resources Information Center

Shih, Mei-Yau; Zvacek, Susan M.

The Triad Perspective Model of Distance Education (TPMDE) guides researchers in developing research questions, gathering data, and producing a comprehensive description of a distance education program. It was developed around three theoretical perspectives: (1) curriculum development theory (Tyler's four questions, 1949); (2) systems theory…

Cognitive Architectures for Multimedia Learning

ERIC Educational Resources Information Center

Reed, Stephen K.

2006-01-01

This article provides a tutorial overview of cognitive architectures that can form a theoretical foundation for designing multimedia instruction. Cognitive architectures include a description of memory stores, memory codes, and cognitive operations. Architectures that are relevant to multimedia learning include Paivio's dual coding theory,…

Planetary rings - Theory

NASA Technical Reports Server (NTRS)

Borderies, Nicole

1989-01-01

Theoretical models of planetary-ring dynamics are examined in a brief analytical review. The mathematical description of streamlines and streamline interactions is outlined; the redistribution of angular momentum due to collisions between particles is explained; and problems in the modeling of broad, narrow, and arc rings are discussed.

Desorption kinetics of hydrophobic organic chemicals from sediment to water: a review of data and models.

PubMed

Birdwell, Justin; Cook, Robert L; Thibodeaux, Louis J

2007-03-01

Resuspension of contaminated sediment can lead to the release of toxic compounds to surface waters where they are more bioavailable and mobile. Because the timeframe of particle resettling during such events is shorter than that needed to reach equilibrium, a kinetic approach is required for modeling the release process. Due to the current inability of common theoretical approaches to predict site-specific release rates, empirical algorithms incorporating the phenomenological assumption of biphasic, or fast and slow, release dominate the descriptions of nonpolar organic chemical release in the literature. Two first-order rate constants and one fraction are sufficient to characterize practically all of the data sets studied. These rate constants were compared to theoretical model parameters and functionalities, including chemical properties of the contaminants and physical properties of the sorbents, to determine if the trends incorporated into the hindered diffusion model are consistent with the parameters used in curve fitting. The results did not correspond to the parameter dependence of the hindered diffusion model. No trend in desorption rate constants, for either fast or slow release, was observed to be dependent on K(OC) or aqueous solubility for six and seven orders of magnitude, respectively. The same was observed for aqueous diffusivity and sediment fraction organic carbon. The distribution of kinetic rate constant values was approximately log-normal, ranging from 0.1 to 50 d(-1) for the fast release (average approximately 5 d(-1)) and 0.0001 to 0.1 d(-1) for the slow release (average approximately 0.03 d(-1)). The implications of these findings with regard to laboratory studies, theoretical desorption process mechanisms, and water quality modeling needs are presented and discussed.

Field theoretical prediction of a property of the tropical cyclone

NASA Astrophysics Data System (ADS)

Spineanu, F.; Vlad, M.

2014-01-01

The large scale atmospheric vortices (tropical cyclones, tornadoes) are complex physical systems combining thermodynamics and fluid-mechanical processes. The late phase of the evolution towards stationarity consists of the vorticity concentration, a well known tendency to self-organization , an universal property of the two-dimensional fluids. It may then be expected that the stationary state of the tropical cyclone has the same nature as the vortices of many other systems in nature: ideal (Euler) fluids, superconductors, Bose-Einsetin condensate, cosmic strings, etc. Indeed it was found that there is a description of the atmospheric vortex in terms of a classical field theory. It is compatible with the more conventional treatment based on conservation laws, but the field theoretical model reveals properties that are almost inaccessible to the conventional formulation: it identifies the stationary states as being close to self-duality. This is of highest importance: the self-duality is known to be the origin of all coherent structures known in natural systems. Therefore the field theoretical (FT) formulation finds that the cuasi-coherent form of the atmospheric vortex (tropical cyclone) at stationarity is an expression of this particular property. In the present work we examine a strong property of the tropical cyclone, which arises in the FT formulation in a natural way: the equality of the masses of the particles associated to the matter field and respectively to the gauge field in the FT model is translated into the equality between the maximum radial extension of the tropical cyclone and the Rossby radius. For the cases where the FT model is a good approximation we calculate characteristic quantities of the tropical cyclone and find good comparison with observational data.

Verification of Gyrokinetic codes: Theoretical background and applications

NASA Astrophysics Data System (ADS)

Tronko, Natalia; Bottino, Alberto; Görler, Tobias; Sonnendrücker, Eric; Told, Daniel; Villard, Laurent

2017-05-01

In fusion plasmas, the strong magnetic field allows the fast gyro-motion to be systematically removed from the description of the dynamics, resulting in a considerable model simplification and gain of computational time. Nowadays, the gyrokinetic (GK) codes play a major role in the understanding of the development and the saturation of turbulence and in the prediction of the subsequent transport. Naturally, these codes require thorough verification and validation. Here, we present a new and generic theoretical framework and specific numerical applications to test the faithfulness of the implemented models to theory and to verify the domain of applicability of existing GK codes. For a sound verification process, the underlying theoretical GK model and the numerical scheme must be considered at the same time, which has rarely been done and therefore makes this approach pioneering. At the analytical level, the main novelty consists in using advanced mathematical tools such as variational formulation of dynamics for systematization of basic GK code's equations to access the limits of their applicability. The verification of the numerical scheme is proposed via the benchmark effort. In this work, specific examples of code verification are presented for two GK codes: the multi-species electromagnetic ORB5 (PIC) and the radially global version of GENE (Eulerian). The proposed methodology can be applied to any existing GK code. We establish a hierarchy of reduced GK Vlasov-Maxwell equations implemented in the ORB5 and GENE codes using the Lagrangian variational formulation. At the computational level, detailed verifications of global electromagnetic test cases developed from the CYCLONE Base Case are considered, including a parametric β-scan covering the transition from ITG to KBM and the spectral properties at the nominal β value.

Culturally Embedded Risk Factors for Cambodian Husband-Wife HIV Transmission: From Women's Point of View.

PubMed

Yang, Youngran; Lewis, Frances Marcus; Wojnar, Danuta

2016-03-01

The purpose of this study was to use interview data to examine the validity of a recently published theoretical model of HIV transmission between husband and virginal wives in rural Cambodia. This study used a qualitative description method with a sample of women diagnosed with HIV/AIDS in Phnom Penh, Cambodia. Data were collected through in-depth interviews conducted with 15 women who self-identified as having contracted HIV from their HIV-positive husbands. Interviews were conducted in Khmer, translated and back-translated for accuracy, and then coded using deductive content analysis. Trustworthiness of study results was protected through peer debriefing, coding to consensus, and maintaining an audit trail. Each conceptual domain of the prior published theoretical model of HIV transmission was validated and further elaborated by current study data: wives' acceptance of their husbands' involvement with commercial sex workers, the common practice of unprotected sex between HIV-infected spouses and uninfected wives, and wives' beliefs about the value of the ideal Khmer woman. In addition, the current study findings identified a new domain that substantially distinguished between the beliefs and attitudes held about marriage and sex by wives and spouses. Women were not passive recipients of HIV transmission; they reciprocated with behaviors that were consistent with being a good Khmer woman in rural Cambodia, all of which increased their vulnerability to HIV transmission from their HIV-infected spouses. Future interventions or programs should consider all these factors and not overly rely on simplistic educational messages about wearing barriers for HIV transmission during sex. The refined theoretical model of HIV transmission from this qualitative research can be used to formulate culturally sensitive and embedded programs for curbing intramarital HIV transmission in Cambodia among the rural poor. © 2016 Sigma Theta Tau International.

Selecting foils for identification lineups: matching suspects or descriptions?

PubMed

Tunnicliff, J L; Clark, S E

2000-04-01

Two experiments directly compare two methods of selecting foils for identification lineups. The suspect-matched method selects foils based on their match to the suspect, whereas the description-matched method selects foils based on their match to the witness's description of the perpetrator. Theoretical analyses and previous results predict an advantage for description-matched lineups both in terms of correctly identifying the perpetrator and minimizing false identification of innocent suspects. The advantage for description-matched lineups should be particularly pronounced if the foils selected in suspect-matched lineups are too similar to the suspect. In Experiment 1, the lineups were created by trained police officers, and in Experiment 2, the lineups were constructed by undergraduate college students. The results of both experiments showed higher suspect-to-foil similarity for suspect-matched lineups than for description-matched lineups. However, neither experiment showed a difference in correct or false identification rates. Both experiments did, however, show that there may be an advantage for suspect-matched lineups in terms of no-pick and rejection responses. From these results, the endorsement of one method over the other seems premature.

Estimation of M 1 scissors mode strength for deformed nuclei in the medium- to heavy-mass region by statistical Hauser-Feshbach model calculations

DOE PAGES

Mumpower, Matthew Ryan; Kawano, Toshihiko; Ullmann, John Leonard; ...

2017-08-17

Radiative neutron capture is an important nuclear reaction whose accurate description is needed for many applications ranging from nuclear technology to nuclear astrophysics. The description of such a process relies on the Hauser-Feshbach theory which requires the nuclear optical potential, level density, and γ-strength function as model inputs. It has recently been suggested that the M1 scissors mode may explain discrepancies between theoretical calculations and evaluated data. We explore statistical model calculations with the strength of the M1 scissors mode estimated to be dependent on the nuclear deformation of the compound system. We show that the form of the M1more » scissors mode improves the theoretical description of evaluated data and the match to experiment in both the fission product and actinide regions. Since the scissors mode occurs in the range of a few keV to a few MeV, it may also impact the neutron capture cross sections of neutron-rich nuclei that participate in the rapid neutron capture process of nucleosynthesis. As a result, we comment on the possible impact to nucleosynthesis by evaluating neutron capture rates for neutron-rich nuclei with the M1 scissors mode active.« less

Diminish electrostatic in piezoresponse force microscopy through longer or ultra-stiff tips

NASA Astrophysics Data System (ADS)

Gomez, A.; Puig, T.; Obradors, X.

2018-05-01

Piezoresponse Force Microscopy is a powerful but delicate nanoscale technique that measures the electromechanical response resulting from the application of a highly localized electric field. Though mechanical response is normally due to piezoelectricity, other physical phenomena, especially electrostatic interaction, can contribute to the signal read. We address this problematic through the use of longer ultra-stiff probes providing state of the art sensitivity, with the lowest electrostatic interaction and avoiding working in high frequency regime. In order to find this solution we develop a theoretical description addressing the effects of electrostatic contributions in the total cantilever vibration and its quantification for different setups. The theory is subsequently tested in a Periodically Poled Lithium Niobate (PPLN) crystal, a sample with well-defined 0° and 180° domains, using different commercial available conductive tips. We employ the theoretical description to compare the electrostatic contribution effects into the total phase recorded. Through experimental data our description is corroborated for each of the tested commercially available probes. We propose that a larger probe length can be a solution to avoid electrostatic forces, so the cantilever-sample electrostatic interaction is reduced. Our proposed solution has great implications into avoiding artifacts while studying soft biological samples, multiferroic oxides, and thin film ferroelectric materials.

Frequency-Domain Identification Of Aeroelastic Modes

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.; Tischler, Mark B.

1991-01-01

Report describes flight measurements and frequency-domain analyses of aeroelastic vibrational modes of wings of XV-15 tilt-rotor aircraft. Begins with description of flight-test methods. Followed by brief discussion of methods of analysis, which include Fourier-transform computations using chirp z transformers, use of coherence and other spectral functions, and methods and computer programs to obtain frequencies and damping coefficients from measurements. Includes brief description of results of flight tests and comparisions among various experimental and theoretical results. Ends with section on conclusions and recommended improvements in techniques.

Operational manual for two-dimensional transonic code TSFOIL

NASA Technical Reports Server (NTRS)

Stahara, S. S.

1978-01-01

This code solves the two-dimensional, transonic, small-disturbance equations for flow past lifting airfoils in both free air and various wind-tunnel environments by using a variant of the finite-difference method. A description of the theoretical and numerical basis of the code is provided, together with complete operating instructions and sample cases for the general user. In addition, a programmer's manual is also presented to assist the user interested in modifying the code. Included in the programmer's manual are a dictionary of subroutine variables in common and a detailed description of each subroutine.

Intra- and inter-observer agreement when using a descriptive classification scale for clinical assessment of faecal consistency in growing pigs.

PubMed

Pedersen, Ken Steen; Toft, Nils

2011-03-01

The objective of the current study was to evaluate intra- and inter-observer agreement using a descriptive classification scale with four categories, descriptive text and pictures for assessment of consistency in faecal samples from pigs post weaning. The four consistency categories were score one=firm and shaped, score two=soft and shaped, score three=loose and score four=watery. Five observers from the same veterinary practice examined 100 faecal samples using the scale with four categories. Four of the observers examined the 100 faecal samples twice within the same day. Within observers the difference in proportions for the individual consistency categories between two examinations was on average 0.04 (range: 0-0.10). The mean intra-observer agreement was 0.82 (range: 0.72-0.91) with a mean kappa value of 0.76 (range: 0.61-0.88). For inter-observer agreement overall kappa was 0.64. For the 10 pair-wise comparisons the mean inter-observer agreement was 0.73 (range: 0.61-0.90) with a mean kappa value of 0.64 (range: 0.48-0.87). The difference in proportions for the individual consistency categories was on average 0.08 (range: 0-0.17). In conclusion, the agreement observed for the descriptive classification scale with four categories, descriptive text and pictures may be categorized as a substantial to almost perfect intra-observer agreement and a moderate to almost perfect inter-observer agreement. However, more objective measures than clinical scales may still be needed to improve intra- and inter-observer agreement in research studies. Copyright © 2010 Elsevier B.V. All rights reserved.

Case report and theoretical description of accelerated resolution therapy (ART) for military-related post-traumatic stress disorder.

PubMed

Kip, Kevin E; Shuman, Amy; Hernandez, Diego F; Diamond, David M; Rosenzweig, Laney

2014-01-01

This article describes a new, brief exposure-based psychotherapy known as Accelerated Resolution Therapy (ART) that is currently being evaluated as a treatment for combat-related post-traumatic stress disorder (PTSD). We describe a case report of an Army veteran with combat-related PTSD who was treated with 2 sessions of ART and experienced significant clinical improvement. We then discuss the theoretical basis and major components of the ART protocol, including use of lateral left-right eye movements, and differentiate ART with evidence-based psychotherapies currently endorsed by the Department of Defense and Veterans Administration. The number of military personnel who have served in the wars in Iraq and Afghanistan and are afflicted with PTSD is likely in the hundreds of thousands. The ART protocol, which is delivered in 2 to 5 sessions and without homework, uses the psychotherapeutic practices of imaginal exposure and imagery rescripting (IR) facilitated through sets of eye movements. In addition to its brevity, a novel component of ART is use of IR to "replace" negative imagery (and other sensations) with positive imagery. This theoretical description of ART and single case report provide a rationale for future formal evaluation of ART for treatment of military-related PTSD. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

A gauge-theoretic approach to gravity

PubMed Central

Krasnov, Kirill

2012-01-01

Einstein's general relativity (GR) is a dynamical theory of the space–time metric. We describe an approach in which GR becomes an SU(2) gauge theory. We start at the linearized level and show how a gauge-theoretic Lagrangian for non-interacting massless spin two particles (gravitons) takes a much more simple and compact form than in the standard metric description. Moreover, in contrast to the GR situation, the gauge theory Lagrangian is convex. We then proceed with a formulation of the full nonlinear theory. The equivalence to the metric-based GR holds only at the level of solutions of the field equations, that is, on-shell. The gauge-theoretic approach also makes it clear that GR is not the only interacting theory of massless spin two particles, in spite of the GR uniqueness theorems available in the metric description. Thus, there is an infinite-parameter class of gravity theories all describing just two propagating polarizations of the graviton. We describe how matter can be coupled to gravity in this formulation and, in particular, how both the gravity and Yang–Mills arise as sectors of a general diffeomorphism-invariant gauge theory. We finish by outlining a possible scenario of the ultraviolet completion of quantum gravity within this approach. PMID:22792040

The measurement of patient attitudes regarding prenatal and preconception genetic carrier screening and translational behavioral medicine: an integrative review.

PubMed

Shiroff, Jennifer J; Gregoski, Mathew J

2017-06-01

Measurement of recessive carrier screening attitudes related to conception and pregnancy is necessary to determine current acceptance, and whether behavioral intervention strategies are needed in clinical practice. To evaluate quantitative survey instruments to measure patient attitudes regarding genetic carrier testing prior to conception and pregnancy databases examining patient attitudes regarding genetic screening prior to conception and pregnancy from 2003-2013 were searched yielding 344 articles; eight studies with eight instruments met criteria for inclusion. Data abstraction on theoretical framework, subjects, instrument description, scoring, method of measurement, reliability, validity, feasibility, level of evidence, and outcomes was completed. Reliability information was provided in five studies with an internal consistency of Cronbach's α >0.70. Information pertaining to validity was presented in three studies and included construct validity via factor analysis. Despite limited psychometric information, these questionnaires are self-administered and can be briefly completed, making them a feasible method of evaluation.

Antiferromagnetic Interlayer Exchange Coupling in All-Semiconducting EuS/PbS/EuS Trilayers

NASA Technical Reports Server (NTRS)

Smits, C. J. P.; Filip, A. T.; Swagten, H. J. M.; Koopmans, B.; deJonge, W. J. M.; Chernyshova, M.; Kowalczyk, L.; Grasza, K.; Szczerbakow, A.; Story, T.

2003-01-01

A comprehensive experimental study on the antiferromagnetic interlayer exchange coupling in high quality epitaxial all-semiconducting EuSPbSEuS trilayers is reported. The influence of substrates, the thickness of the non-magnetic PbS spacer layer, and of temperature, was investigated by means of SQUID magnetometry. In trilayers with a PbS thickness between 4 and 12 deg A the low temperature hysteresis loops showed the signature of antiferromagnetic coupling. The value of the interlayer exchange coupling energy was determined by simulating the data with a modified Stoner model, including Zeeman, anisotropy, and exchange coupling energies. An important observation was of a strong dependence of the interlayer exchange coupling energy on temperature, consistent with a power law dependence of the exchange coupling constant on the saturation magnetization of the EuS layers. While no theoretical description is readily available, we conjecture that the observed behavior is due to a dependence of the interlayer exchange coupling energy on the exchange splitting of the EuS conduction band.

[Nursing knowledge production: transposition and repercussions on the graduation teaching].

PubMed

Pereira, Wilza Rocha

2013-09-01

The research aimed to analyze the production of knowledge in nursing at a public university, in order to evaluate the impact of that production during the Nursing Graduation. An exploratory and descriptive research has been done in two stages. The first one consisted of gathering the reports of researches executed by the teachers who coordinated them from 2000 to 2009. As a result of this stage, it was mapped the type of studies performed, the themes and the theoretical and methodological references most utilized. During the second stage we studied the current pedagogical project used in the Graduation course, and crossed the data with the previously, to create a dimension to some of the transpositions and applications of the knowledge produced by the researches to the Nursing Graduation course. We concluded that, in different ways, not only the application of the studies has been occurring but also the transposition of ideals that cross through the research groups to which they belong, being able to bring change to nursing education.

Active Plasmonics: Principles, Structures, and Applications.

PubMed

Jiang, Nina; Zhuo, Xiaolu; Wang, Jianfang

2018-03-28

Active plasmonics is a burgeoning and challenging subfield of plasmonics. It exploits the active control of surface plasmon resonance. In this review, a first-ever in-depth description of the theoretical relationship between surface plasmon resonance and its affecting factors, which forms the basis for active plasmon control, will be presented. Three categories of active plasmonic structures, consisting of plasmonic structures in tunable dielectric surroundings, plasmonic structures with tunable gap distances, and self-tunable plasmonic structures, will be proposed in terms of the modulation mechanism. The recent advances and current challenges for these three categories of active plasmonic structures will be discussed in detail. The flourishing development of active plasmonic structures opens access to new application fields. A significant part of this review will be devoted to the applications of active plasmonic structures in plasmonic sensing, tunable surface-enhanced Raman scattering, active plasmonic components, and electrochromic smart windows. This review will be concluded with a section on the future challenges and prospects for active plasmonics.

Multipulse technique exploiting the intermodulation of ultrasound waves in a nonlinear medium.

PubMed

Biagi, Elena; Breschi, Luca; Vannacci, Enrico; Masotti, Leonardo

2009-03-01

In recent years, the nonlinear properties of materials have attracted much interest in nondestructive testing and in ultrasound diagnostic applications. Acoustic nonlinear parameters represent an opportunity to improve the information that can be extracted from a medium such as structural organization and pathologic status of tissue. In this paper, a method called pulse subtraction intermodulation (PSI), based on a multipulse technique, is presented and investigated both theoretically and experimentally. This method allows separation of the intermodulation products, which arise when 2 separate frequencies are transmitted in a nonlinear medium, from fundamental and second harmonic components, making them available for improved imaging techniques or signal processing algorithms devoted to tissue characterization. The theory of intermodulation product generation was developed according the Khokhlov-Zabolotskaya-Kuznetsov (KZK) nonlinear propagation equation, which is consistent with experimental results. The description of the proposed method, characterization of the intermodulation spectral contents, and quantitative results coming from in vitro experimentation are reported and discussed in this paper.

Direct determination of three-phase contact line properties on nearly molecular scale

DOE PAGES

Winkler, P. M.; McGraw, R. L.; Bauer, P. S.; ...

2016-05-17

Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopicallymore » measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of –10 –10 J/m that becomes increasingly dominant with increasing curvature of the contact line. Furthermore, these results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.« less

Off-axis holographic laser speckle contrast imaging of blood vessels in tissues

NASA Astrophysics Data System (ADS)

Abdurashitov, Arkady; Bragina, Olga; Sindeeva, Olga; Sergey, Sindeev; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.

2017-09-01

Laser speckle contrast imaging (LSCI) has become one of the most common tools for functional imaging in tissues. Incomplete theoretical description and sophisticated interpretation of measurement results are completely sidelined by a low-cost and simple hardware, fastness, consistent results, and repeatability. In addition to the relatively low measuring volume with around 700 μm of the probing depth for the visible spectral range of illumination, there is no depth selectivity in conventional LSCI configuration; furthermore, in a case of high NA objective, the actual penetration depth of light in tissues is greater than depth of field (DOF) of an imaging system. Thus, the information about these out-of-focus regions persists in the recorded frames but cannot be retrieved due to intensity-based registration method. We propose a simple modification of LSCI system based on the off-axis holography to introduce after-registration refocusing ability to overcome both depth-selectivity and DOF problems as well as to get the potential possibility of producing a cross-section view of the specimen.

The model of the optical-electronic control system of vehicles location at level crossing

NASA Astrophysics Data System (ADS)

Verezhinskaia, Ekaterina A.; Gorbachev, Aleksei A.; Maruev, Ivan A.; Shavrygina, Margarita A.

2016-04-01

Level crossing - one of the most dangerous sections of the road network, where railway line crosses motor road at the same level. The collision of trains with vehicles at a level crossing is a serious type of road traffic accidents. The purpose of this research is to develop complex optical electronic control system of vehicles location in the dangerous zone of level crossing. The system consists of registration blocks (including photodetector, lens, infrared emitting diode), determinant devices and camera installed within the boundaries of level crossing. The system performs detection of objects (vehicles) by analysing the time of the object movement opposite to the registration block and level of the reflected signal from the object. The paper presents theoretical description and experimental research of main principles of the system operation. Experimental research of the system model with selected optical-electronic components have confirmed the possibility of metal objects detection at the required distance (0.5 - 2 m) with different values of background illuminance.

Experimental and theoretical investigations on the warm-up of a high-pressure mercury discharge lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zalach, J.; Franke, St.; Schoepp, H.

2011-03-15

Modern high-pressure discharge lamps are forced to provide instant light and hot relight capabilities - if possible at lower power units. A detailed understanding of the warm-up of high-pressure discharge lamps is therefore required. Complex fluid model codes were developed for the past years including more and more processes like two-dimensional treatment of convection trying to provide a more comprehensive and consistent description of high-pressure discharge lamps. However, there is a lack of experimental data to examine the performance of these models. This work provides a very complete set of geometrical, electrical, spectroscopic, and thermographic data according to the warm-upmore » of a high-pressure mercury discharge lamp that is compared to the results of a state of the art fluid code. Quantitative agreement is achieved for single parameters like wall temperatures. But the paper also reveals the need for further investigations and improvements of the code.« less

REVIEWS OF TOPICAL PROBLEMS: Concept of consciousness in the context of quantum mechanics

NASA Astrophysics Data System (ADS)

Menskii, Mikhail B.

2005-04-01

Conceptual problems of the quantum theory of measurement are considered, which are embodied in well-known paradoxes and in Bell's inequalities. Arguments are advanced in favor of the viewpoint that these problems may hardly be solved without direct inclusion of the observer's consciousness in the theoretical description of a quantum measurement. Discussed in this connection is the so-called many-worlds interpretation of quantum mechanics proposed by Everett, as is the extension of Everett's concept, which consists in the assumption that separating the quantum state components corresponding to alternative measurements is not only associated with the observer's consciousness but is completely identified with it. This approach is shown to open up qualitatively new avenues for the unification of physics and psychology and, more broadly, of the sciences and the humanities. This may lead to an extension of the theory of consciousness and shed light on significant and previously misunderstood phenomena in the sphere of consciousness.

A systemic investigation of hydrogen peroxide clusters (H2O2)n (n = 1-6) and liquid-state hydrogen peroxide: based on atom-bond electronegativity equalization method fused into molecular mechanics and molecular dynamics.

PubMed

Yu, Chun-Yang; Yang, Zhong-Zhi

2011-03-31

Hydrogen peroxide (HP) clusters (H(2)O(2))(n) (n = 1-6) and liquid-state HP have been systemically investigated by the newly constructed ABEEM/MM fluctuating charge model. Because of the explicit description of charge distribution and special treatment of the hydrogen-bond interaction region, the ABEEM/MM potential model gives reasonable properties of HP clusters, including geometries, interaction energies, and dipole moments, when comparing with the present ab initio results. Meanwhile, the average dipole moment, static dielectric constant, heats of vaporization, radial distribution function, and diffusion constant for the dynamic properties of liquid HP at 273 K and 1 atm are fairly consistent with the available experimental data. To the best of our knowledge, this is the first theoretical investigation of condensed HP. The properties of HP monomer are studied in detail involving the structure, torsion potentials, molecular orbital analysis, charge distribution, dipole moment, and vibrational frequency.

A new Lagrangian method for real gases at supersonic speed

NASA Technical Reports Server (NTRS)

Loh, C. Y.; Liou, Meng-Sing

1992-01-01

With the renewed interest in high speed flights, the real gas effect is of theoretical as well as practical importance. In the past decade, upwind splittings or Godunov-type Riemann solutions have received tremendous attention and as a result significant progress has been made both in the ideal and non-ideal gas. In this paper, we propose a new approach that is formulated using the Lagrangian description, for the calculation of supersonic/hypersonic real gas inviscid flows. This new formulation avoids the grid generation step which is automatically obtained as the solution procedure marches in the 'time-like' direction. As a result, no remapping is required and the accuracy is faithfully maintained in the Lagrangian level. In this paper, we give numerical results for a variety of real gas problems consisting of essential elements in high speed flows, such as shock waves, expansion waves, slip surfaces and their interactions. Finally, calculations for flows in a generic inlet and nozzle are presented.

Assessing treatment motivation among patients receiving antiretroviral therapy: A multidimensional approach

PubMed Central

Houston, Eric; McKirnan, David J.; Cervone, Daniel; Johnson, Matthew S.; Sandfort, Theo G.M.

2011-01-01

Using multidimensional scaling analysis (MDS), this study examined how patient conceptualisations of treatment motivation compare with theoretically-based assumptions used in current assessment approaches. Patients undergoing antiretroviral therapy for HIV/AIDS (n = 39) rated for similarity all possible pairings of 23 treatment descriptions, including descriptors of intrinsic, extrinsic, approach, and avoidance motivation. MDS analyses revealed that patient perceptions of intrinsic and extrinsic motivation often differ from those based on definitions derived from common interpretations of self-determination theory. Findings also showed that patients reported motivation for avoiding treatment when they associated their medication regimens with side effects and other negatively-valenced outcomes. The study describes new applications of MDS in assessing how patients perceive the relationship between treatment behaviours and specific forms of motivation, such as intrinsic and extrinsic motivation. In addition, the study suggests how MDS may be used to develop behavioural strategies aimed at helping patients follow their regimens consistently by identifying treatment conceptualisations and contexts that facilitate or impede adherence. PMID:21942538

Assessing treatment motivation among patients receiving antiretroviral therapy: a multidimensional approach.

PubMed

Houston, Eric; McKirnan, David J; Cervone, Daniel; Johnson, Matthew S; Sandfort, Theo G M

2012-01-01

Using multidimensional scaling (MDS) analysis, this study examined how patient conceptualisations of treatment motivation compare with theoretically based assumptions used in current assessment approaches. Patients undergoing antiretroviral therapy for HIV/AIDS (n=39) rated for similarity between all possible pairings of 23 treatment descriptions, including descriptors of intrinsic, extrinsic, approach and avoidance motivation. MDS analyses revealed that patient perceptions of intrinsic and extrinsic motivations often differ from those based on definitions derived from common interpretations of self-determination theory. Findings also showed that patients reported motivation for avoiding treatment when they associated their medication regimens with side effects and other negatively valenced outcomes. The study describes new applications of MDS in assessing how patients perceive the relationship between treatment behaviours and specific forms of motivation, such as intrinsic and extrinsic motivations. In addition, the study suggests how MDS may be used to develop behavioural strategies aimed at helping patients follow their regimens consistently by identifying treatment conceptualisations and contexts that facilitate or impede adherence.

Transformational Play as a Curricular Scaffold: Using Videogames to Support Science Education

NASA Astrophysics Data System (ADS)

Barab, Sasha A.; Scott, Brianna; Siyahhan, Sinem; Goldstone, Robert; Ingram-Goble, Adam; Zuiker, Steven J.; Warren, Scott

2009-08-01

Drawing on game-design principles and an underlying situated theoretical perspective, we developed and researched a 3D game-based curriculum designed to teach water quality concepts. We compared undergraduate student dyads assigned randomly to four different instructional design conditions where the content had increasingly level of contextualization: (a) expository textbook condition, (b) simplistic framing condition, (c) immersive world condition, and (d) a single-user immersive world condition. Results indicated that the immersive-world dyad and immersive-world single user conditions performed significantly better than the electronic textbook group on standardized items. The immersive-world dyad condition also performed significantly better than either the expository textbook or the descriptive framing condition on a performance-based transfer task, and performed significantly better than the expository textbook condition on standardized test items. Implications for science education, and consistent with the goals of this special issue, are that immersive game-based learning environments provide a powerful new form of curriculum for teaching and learning science.

Quantum Monte Carlo calculations of neutron matter with chiral three-body forces

DOE PAGES

Tews, I.; Gandolfi, Stefano; Gezerlis, A.; ...

2016-02-02

Chiral effective field theory (EFT) enables a systematic description of low-energy hadronic interactions with controlled theoretical uncertainties. For strongly interacting systems, quantum Monte Carlo (QMC) methods provide some of the most accurate solutions, but they require as input local potentials. We have recently constructed local chiral nucleon-nucleon (NN) interactions up to next-to-next-to-leading order (N 2LO). Chiral EFT naturally predicts consistent many-body forces. In this paper, we consider the leading chiral three-nucleon (3N) interactions in local form. These are included in auxiliary field diffusion Monte Carlo (AFDMC) simulations. We present results for the equation of state of neutron matter and formore » the energies and radii of neutron drops. Specifically, we study the regulator dependence at the Hartree-Fock level and in AFDMC and find that present local regulators lead to less repulsion from 3N forces compared to the usual nonlocal regulators.« less

Optical Air Flow Measurements in Flight

NASA Technical Reports Server (NTRS)

Bogue, Rodney K.; Jentink, Henk W.

2004-01-01

This document has been written to assist the flight-test engineer and researcher in using optical flow measurements in flight applications. The emphasis is on describing tradeoffs in system design to provide desired measurement performance as currently understood. Optical system components are discussed with examples that illustrate the issues. The document concludes with descriptions of optical measurement systems designed for a variety of applications including aeronautics research, airspeed measurement, and turbulence hazard detection. Theoretical discussion is minimized, but numerous references are provided to supply ample opportunity for the reader to understand the theoretical underpinning of optical concepts.

Polarization characteristics of an altazimuth sky scanner

NASA Technical Reports Server (NTRS)

Garrison, L. M.; Blaszczak, Z.; Green, A. E. S.

1980-01-01

A theoretical description of the polarization characteristics of an altazimuth sky scanner optical system based on Mueller-Stokes calculus is presented. This computer-driven optical system was designed to perform laboratory studies of skylight and of celestial objects during day or night, and has no space limitations; however, the two parallel 45 deg tilt mirrors introduce some intrinsic polarization. Therefore, proper data interpretation requires a theoretical understanding of the polarization features of the instrument and accurate experimental determination of the Mueller-Stokes matrix elements describing the polarizing and depolarizing action of the system.

Structural properties of lead-lithium alloys

NASA Astrophysics Data System (ADS)

Khambholja, S. G.; Satikunvar, D. D.; Abhishek, Agraj; Thakore, B. Y.

2018-05-01

Lead-Lihtium alloys have found large number of applications as liquid metal coolants in nuclear reactors. Large number of experimental work is reported for this system. However, complete theoretical description is still rare. In this scenario, we in the present work report the study of ground state properties of Lead-Lithium system. The present study is performed using plane wave pseudopotential density functional theory as implemented in Quantum ESPRESSO package. The theoretical findings are in agreement with previously reported experimental data. Some conclusions are drawn based on present study, which will be helpful for a comprehensive study.

Parsimonious description for predicting high-dimensional dynamics

PubMed Central

Hirata, Yoshito; Takeuchi, Tomoya; Horai, Shunsuke; Suzuki, Hideyuki; Aihara, Kazuyuki

2015-01-01

When we observe a system, we often cannot observe all its variables and may have some of its limited measurements. Under such a circumstance, delay coordinates, vectors made of successive measurements, are useful to reconstruct the states of the whole system. Although the method of delay coordinates is theoretically supported for high-dimensional dynamical systems, practically there is a limitation because the calculation for higher-dimensional delay coordinates becomes more expensive. Here, we propose a parsimonious description of virtually infinite-dimensional delay coordinates by evaluating their distances with exponentially decaying weights. This description enables us to predict the future values of the measurements faster because we can reuse the calculated distances, and more accurately because the description naturally reduces the bias of the classical delay coordinates toward the stable directions. We demonstrate the proposed method with toy models of the atmosphere and real datasets related to renewable energy. PMID:26510518

Interdisciplinary Research Boosted by Serendipity

ERIC Educational Resources Information Center

Darbellay, Frédéric; Moody, Zoe; Sedooka, Ayuko; Steffen, Gabriela

2014-01-01

Interdisciplinary research can be defined as the practice of discovering new objects of knowledge beyond disciplinary borders. It often operates through the cross-fertilization and hybridization of concepts, theoretical frameworks, and methodological tools to enable the description, analysis, and understanding of the complexity of objects of study…

An Educational Response to Aging.

ERIC Educational Resources Information Center

McLain, Rosemary

1978-01-01

The emphasis of this article is on aging and the needs of the elderly as a basis for developing educational content in the curriculum. It includes a description of a theoretical framework developed by Abraham Maslow for a holistic approach to needs of the aged. (Editor/RK)

Rational and Mechanistic Perspectives on Reinforcement Learning

ERIC Educational Resources Information Center

Chater, Nick

2009-01-01

This special issue describes important recent developments in applying reinforcement learning models to capture neural and cognitive function. But reinforcement learning, as a theoretical framework, can apply at two very different levels of description: "mechanistic" and "rational." Reinforcement learning is often viewed in mechanistic terms--as…

Evolutionary Design in Biological Physics and Materials Science

NASA Astrophysics Data System (ADS)

Yang, M.; Park, J.-M.; Deem, M. W.

In this chapter we provide a thorough discussion of the theoretical description of the multi-site approach to cancer vaccination. The discussion is somewhat demanding from a biological point of view. References to primary biological publications are given. A general reference on immunology is [1].

DRI Model of the U.S. Economy -- Model Documentation

EIA Publications

1993-01-01

Provides documentation on Data Resources, Inc., DRI Model of the U.S. Economy and the DRI Personal Computer Input/Output Model. It also describes the theoretical basis, structure and functions of both DRI models; and contains brief descriptions of the models and their equations.

Holopoetry.

ERIC Educational Resources Information Center

Kac, Eduardo

1996-01-01

Discusses a new poetic language invented in 1983 based on innovative use of the holographic medium. Defines what a holopoem is and explains the fundamental concepts of holopoetics. Introduces theoretical principles that address the new readerly experience created by the holotext. Provides a descriptive list of all holopoems created to date. (PA)

Introducing the "Cybercounseling and Cyberlearning" Web Site (cybercounsel.uncg.edu).

ERIC Educational Resources Information Center

Walz, Garry R.; Bloom, John W.

This chapter introduces the "Cybercounseling and Cyberlearning" Web site. It includes a brief description of the following chapters contained in the Web site: (1) "Cybersupervision: Close Encounters in the New Millennium" (D. Coursol and J. Lewis); (2) "Theoretical Tenets of Cybersupervision: Implications and…

Estimating Large Numbers

ERIC Educational Resources Information Center

Landy, David; Silbert, Noah; Goldin, Aleah

2013-01-01

Despite their importance in public discourse, numbers in the range of 1 million to 1 trillion are notoriously difficult to understand. We examine magnitude estimation by adult Americans when placing large numbers on a number line and when qualitatively evaluating descriptions of imaginary geopolitical scenarios. Prior theoretical conceptions…

Wife Abuse and the Wife Abuser: Review and Recommendations.

ERIC Educational Resources Information Center

Carden, Ann D.

1994-01-01

Reviews clinical, theoretical, and empirical literature on wife abuse/abusers. Presents historical and contextual information, overview of domestic violence, prevalence data, and descriptions of evolution and current status of public and professional awareness and response. Proposes integrative model for understanding etiologic, dynamic, and…

Generative Inferences Based on Learned Relations

ERIC Educational Resources Information Center

Chen, Dawn; Lu, Hongjing; Holyoak, Keith J.

2017-01-01

A key property of relational representations is their "generativity": From partial descriptions of relations between entities, additional inferences can be drawn about other entities. A major theoretical challenge is to demonstrate how the capacity to make generative inferences could arise as a result of learning relations from…

Improving Student Performance Outcomes and Graduation Rates through Institutional Partnerships

ERIC Educational Resources Information Center

Roggow, Michael J.

2014-01-01

This chapter explores a grant-sponsored program and examines the role of departmental and institutional collaborations in advancing student performance outcomes. It provides a theoretical framework and a description of best practices for ensuring the success of first-generation urban community college students.

Surface stress induced by interactions of adsorbates and its effect on deformation and frequency of microcantilever sensors

NASA Astrophysics Data System (ADS)

Yi, X.; Duan, H. L.

2009-08-01

Surface stress is widely used to characterize the adsorption effect on the mechanical response of nanomaterials and nanodevices. However, quantitative relations between continuum-level descriptions of surface stress and molecular-level descriptions of adsorbate interactions are not well established. In this paper, we first obtain the relations between the adsorption-induced surface stress and the van der Waals and Coulomb interactions in terms of the physical and chemical interactions between adsorbates and solid surfaces. Then, we present a theoretical framework to predict the deflection and resonance frequencies of microcantilevers with the simultaneous effects of the eigenstrain, surface stress and adsorption mass. Finally, the adsorption-induced deflection and resonance frequency shift of microcantilevers are numerically analyzed for the van der Waals and Coulomb interactions. The present theoretical framework quantifies the mechanisms of the adsorption-induced surface stress, and thus provides guidelines to the analysis of the sensitivities, and the identification of the detected substance in the design and application of micro- and nanocantilever sensors.

Josephson flux-flow oscillator: The microscopic tunneling approach

NASA Astrophysics Data System (ADS)

Gulevich, D. R.; Koshelets, V. P.; Kusmartsev, F. V.

2017-07-01

We elaborate a theoretical description of large Josephson junctions which is based on Werthamer's microscopic tunneling theory. The model naturally incorporates coupling of electromagnetic radiation to the tunnel currents and, therefore, is particularly suitable for description of the self-coupling effect in Josephson junction. In our numerical calculations we treat the arising integro-differential equation, which describes temporal evolution of the superconducting phase difference coupled to the electromagnetic field, by the Odintsov-Semenov-Zorin algorithm. This allows us to avoid evaluation of the time integrals at each time step while taking into account all the memory effects. To validate the obtained microscopic model of large Josephson junction we focus our attention on the Josephson flux-flow oscillator. The proposed microscopic model of flux-flow oscillator does not involve the phenomenological damping parameter, rather the damping is taken into account naturally in the tunnel current amplitudes calculated at a given temperature. The theoretically calculated current-voltage characteristics is compared to our experimental results obtained for a set of fabricated flux-flow oscillators of different lengths.

The Definition, Rationale, and Effects of Thresholding in OCT Angiography.

PubMed

Cole, Emily D; Moult, Eric M; Dang, Sabin; Choi, WooJhon; Ploner, Stefan B; Lee, ByungKun; Louzada, Ricardo; Novais, Eduardo; Schottenhamml, Julia; Husvogt, Lennart; Maier, Andreas; Fujimoto, James G; Waheed, Nadia K; Duker, Jay S

2017-01-01

To examine the definition, rationale, and effects of thresholding in OCT angiography (OCTA). A theoretical description of OCTA thresholding in combination with qualitative and quantitative analysis of the effects of OCTA thresholding in eyes from a retrospective case series. Four eyes were qualitatively examined: 1 from a 27-year-old control, 1 from a 78-year-old exudative age-related macular degeneration (AMD) patient, 1 from a 58-year-old myopic patient, and 1 from a 77-year-old nonexudative AMD patient with geographic atrophy (GA). One eye from a 75-year-old nonexudative AMD patient with GA was quantitatively analyzed. A theoretical thresholding model and a qualitative and quantitative description of the dependency of OCTA on thresholding level. Due to the presence of system noise, OCTA thresholding is a necessary step in forming OCTA images; however, thresholding can complicate the relationship between blood flow and OCTA signal. Thresholding in OCTA can cause significant artifacts, which should be considered when interpreting and quantifying OCTA images.

Epidemiology as discourse: the politics of development institutions in the Epidemiological Profile of El Salvador

PubMed Central

Aviles, L

2001-01-01

STUDY OBJECTIVE—To determine the ways in which institutions devoted to international development influence epidemiological studies.
DESIGN—This article takes a descriptive epidemiological study of El Salvador, Epidemiological Profile, conducted in 1994 by the US Agency for International Development, as a case study. The methods include discourse analysis in order to uncover the ideological basis of the report and its characteristics as a discourse of development.
SETTING—El Salvador.
RESULTS—The Epidemiological Profile theoretical basis, the epidemiological transition theory, embodies the ethnocentrism of a "colonizer's model of the world." This report follows the logic of a discourse of development by depoliticising development, creating abnormalities, and relying on the development consulting industry. The epidemiological transition theory serves as an ideology that legitimises and dissimulates the international order.
CONCLUSIONS—Even descriptive epidemiological assessments or epidemiological profiles are imbued with theoretical assumptions shaped by the institutional setting under which epidemiological investigations are conducted.


Keywords: El Salvador; politics PMID:11160170

Significance of out-of-plane electronic contributions in Bi-cuprates studied by resonant photoelectron spectroscopy at the Cu2p edge

NASA Astrophysics Data System (ADS)

Janowitz, Christoph; Schmeißer, Dieter

2018-04-01

In high-temperature superconductors with a layered crystal structure, the copper-oxygen planes are commonly considered to dominate the electronic properties around the Fermi energy. As a consequence, out-of-plane contributions are often neglected in the description of these materials. Here we report on a resonant photoemission study of Pb0,4Bi1,6Sr2,0CaCu2O8 ((Pb, Bi)-2212) and Pb0,6Bi1,4Sr1.5La0.5CuO6 ((Pb, Bi)-2201)) single crystals to unravel the resonant decay mechanisms at the Cu2p absorption edge. We find evidence for a pronounced polarization dependence caused by two different Auger processes for in-plane and out-of-plane orientations. We deduce that the lowest energy valence state—which is involved in the two Auger processes—consists of three-dimensional contributions by admixed out-of-plane Sr, Bi, and O2p states. It also suggests that the doping-induced charge density is dynamic, fluctuating within the Cu-O plane, and spills out perpendicular to it. This suggests that out-of-plane electronic degrees of freedom should be included in future consistent theoretical models of these materials.

Optical response of the sodium alanate system: GW0-BSE calculations and thin film measurements

NASA Astrophysics Data System (ADS)

van Setten, M. J.; Gremaud, R.; Brocks, G.; Dam, B.; Kresse, G.; de Wijs, G. A.

2011-01-01

We calculate from first principles the optical spectra of the hydrides in the sodium alanate hydrogen storage system: NaH, NaAlH4, and Na3AlH6. In particular we study the effects of systematic improvements of the theoretical description. To benchmark the calculations we also measure the optical response of a thin film of NaH. The simplest calculated dielectric functions are based upon independent electrons and holes, whose spectrum is obtained at the G0W0 level. Successive improvements consist of including partial self-consistency (so-called GW0) and account for excitonic effects, using the Bethe-Salpeter equation (BSE). Each improvement gives a sizable blue shift or red shift of the dielectric functions, but conserves the trend in the optical gap among different materials. Whereas these shifts partially cancel at the highest (GW0-BSE) level of approximation, the shape of the dielectric functions is strongly modified by excitonic effects. Calculations at the GW0-BSE level give a good agreement with the dielectric function of NaH extracted from the measurements. It demonstrates that the approach can be used for a quantitative interpretation of spectra in novel hydrogen storage materials obtained via, e.g., hydrogenography.

Coupling continuum dislocation transport with crystal plasticity for application to shock loading conditions

DOE PAGES

Luscher, Darby Jon; Mayeur, Jason Rhea; Mourad, Hashem Mohamed; ...

2015-08-05

Here, we have developed a multi-physics modeling approach that couples continuum dislocation transport, nonlinear thermoelasticity, crystal plasticity, and consistent internal stress and deformation fields to simulate the single-crystal response of materials under extreme dynamic conditions. Dislocation transport is modeled by enforcing dislocation conservation at a slip-system level through the solution of advection-diffusion equations. Nonlinear thermoelasticity provides a thermodynamically consistent equation of state to relate stress (including pressure), temperature, energy densities, and dissipation. Crystal plasticity is coupled to dislocation transport via Orowan's expression where the constitutive description makes use of recent advances in dislocation velocity theories applicable under extreme loading conditions.more » The configuration of geometrically necessary dislocation density gives rise to an internal stress field that can either inhibit or accentuate the flow of dislocations. An internal strain field associated with the internal stress field contributes to the kinematic decomposition of the overall deformation. The paper describes each theoretical component of the framework, key aspects of the constitutive theory, and some details of a one-dimensional implementation. Results from single-crystal copper plate impact simulations are discussed in order to highlight the role of dislocation transport and pile-up in shock loading regimes. The main conclusions of the paper reinforce the utility of the modeling approach to shock problems.« less

The cosmological lithium problem revisited

NASA Astrophysics Data System (ADS)

Bertulani, C. A.; Mukhamedzhanov, A. M.; Shubhchintak

2016-07-01

After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

The hydrodynamic description of pseudorapidity distributions at lower energies at BNL-RHIC

NASA Astrophysics Data System (ADS)

Jiang, Zhi-Jin; Huang, Yan; Zhang, Hai-Li; Zhang, Yu

2017-04-01

The hot and dense matter produced in nucleus-nucleus collisions is supposed to expand according to unified hydrodynamics, one of the few theoretical models that can be worked out exactly. The solution is then used to formulate the rapidity distribution of charged particles frozen out from the fluid on the space-like hypersurface with a fixed temperature, T FO. A comparison is made between the theoretical predictions and the experimental measurements carried out by PHOBOS Collaboration in the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) in different centrality Au-Au and Cu-Cu collisions at √ {s_{ {NN}}} = 19.6 and 22.4 GeV, respectively. The theoretical results are in good accordance with experimental data.

Acoustic solitons in waveguides with Helmholtz resonators: transmission line approach.

PubMed

Achilleos, V; Richoux, O; Theocharis, G; Frantzeskakis, D J

2015-02-01

We report experimental results and study theoretically soliton formation and propagation in an air-filled acoustic waveguide side loaded with Helmholtz resonators. We propose a theoretical modeling of the system, which relies on a transmission-line approach, leading to a nonlinear dynamical lattice model. The latter allows for an analytical description of the various soliton solutions for the pressure, which are found by means of dynamical systems and multiscale expansion techniques. These solutions include Boussinesq-like and Korteweg-de Vries pulse-shaped solitons that are observed in the experiment, as well as nonlinear Schrödinger envelope solitons, that are predicted theoretically. The analytical predictions are in excellent agreement with direct numerical simulations and in qualitative agreement with the experimental observations.

Theoretical and empirical bases for dialect-neutral language assessment: contributions from theoretical and applied linguistics to communication disorders.

PubMed

Pearson, Barbara Zurer

2004-02-01

Three avenues of theoretical research provide insights for discovering abstract properties of language that are subject to disorder and amenable to assessment: (1) the study of universal grammar and its acquisition; (2) descriptions of African American English (AAE) Syntax, Semantics, and Phonology within theoretical linguistics; and (3) the study of specific language impairment (SLI) cross-linguistically. Abstract linguistic concepts were translated into a set of assessment protocols that were used to establish normative data on language acquisition (developmental milestones) in typically developing AAE children ages 4 to 9 years. Testing AAE-speaking language impaired (LI) children and both typically developing (TD) and LI Mainstream American English (MAE)-learning children on these same measures provided the data to select assessments for which (1) TD MAE and AAE children performed the same, and (2) TD performance was reliably different from LI performance in both dialect groups.

Theoretical predictor for candidate structure assignment from IMS data of biomolecule-related conformational space.

PubMed

Schenk, Emily R; Nau, Frederic; Fernandez-Lima, Francisco

2015-06-01

The ability to correlate experimental ion mobility data with candidate structures from theoretical modeling provides a powerful analytical and structural tool for the characterization of biomolecules. In the present paper, a theoretical workflow is described to generate and assign candidate structures for experimental trapped ion mobility and H/D exchange (HDX-TIMS-MS) data following molecular dynamics simulations and statistical filtering. The applicability of the theoretical predictor is illustrated for a peptide and protein example with multiple conformations and kinetic intermediates. The described methodology yields a low computational cost and a simple workflow by incorporating statistical filtering and molecular dynamics simulations. The workflow can be adapted to different IMS scenarios and CCS calculators for a more accurate description of the IMS experimental conditions. For the case of the HDX-TIMS-MS experiments, molecular dynamics in the "TIMS box" accounts for a better sampling of the molecular intermediates and local energy minima.

Programmer's manual for the Mission Analysis Evaluation and Space Trajectory Operations program (MAESTRO)

NASA Technical Reports Server (NTRS)

Lutzky, D.; Bjorkman, W. S.

1973-01-01

The Mission Analysis Evaluation and Space Trajectory Operations program known as MAESTRO is described. MAESTRO is an all FORTRAN, block style, computer program designed to perform various mission control tasks. This manual is a guide to MAESTRO, providing individuals the capability of modifying the program to suit their needs. Descriptions are presented of each of the subroutines descriptions consist of input/output description, theory, subroutine description, and a flow chart where applicable. The programmer's manual also contains a detailed description of the common blocks, a subroutine cross reference map, and a general description of the program structure.

THE EFFECT OF TWO-MAGNON SCATTERING ON PARALLEL-PUMP INSTABILITY THRESHOLDS.

DTIC Science & Technology

Following a general description of the important properties and symmetries of the parallel-pump coupling and of two- magnon scattering, several...theoretical approaches to the problem of the effect of two- magnon scattering on the parallel-pump instability threshold are explored. A successful approach

Pathophysiology 220.

ERIC Educational Resources Information Center

Smith, Lori

A description is provided of a course, "Pathophysiology 220," designed to provide junior nursing students at the University of Michigan's School of Nursing with theoretical knowledge of a broad range of pathophysiological conditions. Section I discusses the place of the course in the curriculum, the allotment of class time, course requirements,…

Contribution to the Performance Determination of Microjets. Ph.D. Thesis - Technical Univ., Feb. 1983

NASA Technical Reports Server (NTRS)

Hayn, D.

1984-01-01

Theoretical investigations are made on the performance of microjets. A description is given of experiments with micropropulsion units to correlate the results obtained in the first part of the report. Execution of performance measurements is discussed, and error calculations are presented.

Senseless Extravagance, Shocking Gaps

ERIC Educational Resources Information Center

Weissbourd, Richard; Dodge, Trevor

2012-01-01

Although most people in the United States believe, at least theoretically, in educational equality, fewer and fewer appear to care about the resource gaps between affluent and poor schools, says Weissbourd. He illustrates these gaps with vivid descriptions of what he calls an "opulence arms race" among affluent independent schools, but…

Research on Educational Innovations. Third Edition.

ERIC Educational Resources Information Center

Ellis, Arthur K.

The focus of this book is major educational innovations, that is, programs and curricula that have achieved widespread influence. It presents such fundamentals as definitions, descriptions, theoretical and empirical bases, critical analyses, and conclusions from published research. (The book discusses only published research.) Titles of the 15…

Harmonic generation with multiple wiggler schemes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonifacio, R.; De Salvo, L.; Pierini, P.

1995-02-01

In this paper the authors give a simple theoretical description of the basic physics of the single pass high gain free electron laser (FEL), describing in some detail the FEL bunching properties and the harmonic generation technique with a multiple-wiggler scheme or a high gain optical klystron configuration.

STRATEGIES FOR INSTRUCTIONAL CHANGE--PROMISING IDEAS AND PERPLEXING PROBLEMS.

ERIC Educational Resources Information Center

HARRIS, BEN M.

SUPERVISION, BECAUSE IT COVERS A MULTIPLICITY OF TASKS PERFORMED IN NO FIXED LOCUS, ITS ALMOST IMMUNE TO SYSTEMATIC EVALUATION. ELABORATE DESCRIPTIVE STUDIES ARE NEEDED (POSSIBLY REPLICATIONS OF EDUCATIONAL ADMINISTRATION STUDIES) ON SUCH TOPICS AS RESISTANCE TO CHANGE AND SUPERVISOR-SUPERVISOR RELATIONSHIPS. THEORETICAL MODELS AND CONCEPTS WHICH…

Theoretical study of the noble metals on semiconductor surfaces and Ti-base shape memory alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Yungui

1994-07-27

The electronic and structural properties of the (√3 x√3) R30° Ag/Si(111) and (√3 x √3) R30° Au/Si(111) surfaces are investigated using first principles total energy calculations. We have tested almost all experimentally proposed structural models for both surfaces and found the energetically most favorable model for each of them. The lowest energy model structure of the (√3 x √3) R30° Ag/Si(111) surface consists of a top layer of Ag atoms arranged as ``honeycomb-chained-trimers`` lying above a distorted ``missing top layer`` Si(111) substrate. The coverage of Ag is 1 monolayer (ML). We find that the honeycomb structure observed in STM imagesmore » arise from the electronic charge densities of an empty surface band near the Fermi level. The electronic density of states of this model gives a ``pseudo-gap`` around the Fermi level, which is consistent with experimental results. The lowest energy model for the (√3 x √3) R30° Au/Si(111) surface is a conjugate honeycomb-chained-trimer (CHCT-1) configuration which consists of a top layer of trimers formed by 1 ML Au atoms lying above a ``missing top layer`` Si(111) substrate with a honeycomb-chained-trimer structure for its first layer. The structures of Au and Ag are in fact quite similar and belong to the same class of structural models. However, small variation in the structural details gives rise to quite different observed STM images, as revealed in the theoretical calculations. The electronic charge density from bands around the Fermi level for the (√3 x √3) R30°, Au/Si(111) surface also gives a good description of the images observed in STM experiments. First principles calculations are performed to study the electronic and structural properties of a series of Ti-base binary alloys TiFe, TiNi, TiPd, TiMo, and TiAu in the B2 structure.« less

Ethnomathematics in Perspective of Sundanese Culture

ERIC Educational Resources Information Center

Abdullah, Atje Setiawan

2017-01-01

This study is an exploratory research aims to find and know about a phenomenon by exploration. Therefore, the approach used in this study is ethnographic approach, an empirical and theoretical approach to get description and deep analysis about a culture based on field study. From the sustainable interviews and confirmation about field research…

Connecting through Comics: Expanding Opportunities for Teaching and Learning

ERIC Educational Resources Information Center

Bolton-Gary, Cynthia

2012-01-01

When students are faced with learning abstract contents, creating meaningful teaching and learning opportunities is a challenge for many educators. Concerns for how to get students to connect theoretical constructs and apply them to the "real world" is especially critical for those students studying to be teachers. This descriptive study…

MODEL FOR HYSTERETIC CONSTITUTIVE RELATIONS GOVERNING MULTIPHASE FLOW. 1. SATURATION-PRESSURE RELATIONS

EPA Science Inventory

In these companion papers, a general theoretical model is presented for the description of functional relationships between relative permeability k, fluid saturation S, and pressure P in two- or three-phase (e.g., air-water or air-oil-water) porous media systems subject to arbitr...

Derivation of the Freundlich Adsorption Isotherm from Kinetics

ERIC Educational Resources Information Center

Skopp, Joseph

2009-01-01

The Freundlich adsorption isotherm is a useful description of adsorption phenomena. It is frequently presented as an empirical equation with little theoretical basis. In fact, a variety of derivations exist. Here a new derivation is presented using the concepts of fractal reaction kinetics. This derivation provides an alternative basis for…

Critical Care Specialty Elective: Nursing 401A.

ERIC Educational Resources Information Center

Jepson, Cheri A.

This course guide describes an elective speciality course on critical/intensive care nursing. A rationale for the course is followed by general information, including a description of the theoretical and clinical course components, an enumeration of major goals and objectives, a detailed outline of the units of instruction, a calendar of…

A Descriptive Correlational Study of Teacher Participation in Professional Development and Teacher Efficacy

ERIC Educational Resources Information Center

Tupou, Samuel F.

2013-01-01

This study examines teacher efficacy within the context of professional development to understand the relationship between teacher efficacy and teacher collaboration. Two theoretical frameworks framed this teacher efficacy study based on "locus of control" and "social cognitive theory." A 29-item questionnaire was e-mailed to…

Child Language Research: Building on the Past, Looking to the Future.

ERIC Educational Resources Information Center

Perera, Katharine

1994-01-01

Outlines descriptive, theoretical, and methodological advances in child language research since the first volume of the "Journal of Child Language" was published. Papers in this volume build on earlier research, point the way to new research avenues, and open new lines of inquiry. (Contains 36 references.) (JP)

Voicing Solidarity: Linguistic Hospitality and Poststructuralism in the Real World

ERIC Educational Resources Information Center

Phipps, Alison

2012-01-01

Structuralism has dominated the field of applied linguistics, which has consequences for the positioning of applied linguistics "vis-a-vis" policy makers, educational practice, and also theoretical and methodological innovations. These consequences pertain to how the field advocates, takes sides, balances its descriptive modes with its discursive…

The ecology and evolution of gall-forming insects.

Treesearch

Peter W. Price; William J. Mattson; Yuri N. Baranchikov

1994-01-01

This international proceedings focuses on the biology, ecology, and evolution of gall-forming insects and their uniquely specialized relationships with their host plants. The individual contributions range in scope from detailed descriptive to profoundly theoretical, synthetic studies. One underlying theme of the proceedings is the important contribution of knowledge...

The Ability of Indonesian EFL Learners in Writing Academic Papers

ERIC Educational Resources Information Center

Husin, M. Said; Nurbayani, Etty

2017-01-01

This study is meant to examine the thesis quality of students of English Department at IAIN Samarinda. Through the descriptive-quantitative research, the thesis quality of students of English Department at IAIN Samarinda is reviewed from the aspects of language, structure, concepts understanding, theoretical framework, methodology, content,…

Overview of Mediated Courseware in Learning Centers.

ERIC Educational Resources Information Center

Spangenberg, Ronald W.

A limited overview of some media related factors, this document should be helpful to the learning center manager who lacks extensive experience with media. It discusses important theoretical factors associated with media selection and summarizes research concerning the use of color and of motion in learning. Descriptive information concerning…

Looking into a Deaf Child's Future: A Brief Treatment Approach.

ERIC Educational Resources Information Center

Harvey, Michael A.; Green, Christine L.

1990-01-01

A hearing mother who reported obsessional thoughts about her deaf child's future underwent brief psychotherapy. Clinical hypnosis modified the mother's negative images of her child's future, and meetings attended by the mother, a vocational counselor, and deaf adults affirmed the more positive images. Theoretical descriptions and personal…

Antecedents to Organizational Performance: Theoretical and Practical Implications for Aircraft Maintenance Officer Force Development

DTIC Science & Technology

2015-03-26

to my reader, Lieutenant Colonel Robert Overstreet, for helping solidify my research, coaching me through the statistical analysis, and positive...61  Descriptive Statistics .............................................................................................................. 61...common-method bias requires careful assessment of potential sources of bias and implementing procedural and statistical control methods. Podsakoff

Developmental Designs: A Description of the Approach and Implementation in Schools

ERIC Educational Resources Information Center

Kwame-Ross, Terrance; Crawford, Linda; Klug, Erin

2011-01-01

This article describes the theoretical and conceptual framework upon which the Developmental Designs (DD) approach is based and four fundamental human needs especially compelling for adolescents. These are used as the foreground to explain and contextualize the Developmental Designs' 10 classroom practices and professional development…

An Experiment on the Dispersion of Light

ERIC Educational Resources Information Center

Thompson, Frank

2012-01-01

A simplified theoretical explanation of dispersion in dielectric materials has been given and experiments have been carried out on two liquids, namely, distilled water and sunflower oil. The appendix contains a detailed description of the construction of a homemade spectrometer and hollow prism and an assessment of its suitability for the above…

Storytelling as an Instructional Method: Definitions and Research Questions

ERIC Educational Resources Information Center

Andrews, Dee H.; Hull, Thomas D.; Donahue, Jennifer A.

2009-01-01

This paper discusses the theoretical and empirical foundations of the use of storytelling in instruction. The definition of "story" is given and four instructional methods are identified related to storytelling: case-based, narrative-based, scenario-based, and problem-based instruction. The article provides descriptions of the four…

Transient flow thrust prediction for an ejector propulsion concept

NASA Technical Reports Server (NTRS)

Drummond, Colin K.

1989-01-01

A method for predicting transient thrust augmenting ejector characteristics is introduced. The analysis blends classic self-similar turbulent jet descriptions with a mixing region control volume analysis to predict transient effects in a new way. Details of the theoretical foundation, the solution algorithm, and sample calculations are given.

Strategies for Implementation: The El Camino College Total Quality Management Story.

ERIC Educational Resources Information Center

Schauerman, Sam; Peachy, Burt

1994-01-01

Traces the development of the principles and practices of Total Quality Management (TQM) at El Camino College, in California. Discusses institutional resistance to change and the need for careful implementation analysis and constituent group involvement. Includes a nine-item bibliography of theoretical and descriptive works. (MAB)

INTERPERSONAL RELATIONSHIPS--A REVIEW. UTAH STUDIES IN VOCATIONAL REHABILITATION.

ERIC Educational Resources Information Center

JORGENSEN, GARY Q.; RUSHLAU, PERRY J.

THIS MONOGRAPH IS A REVIEW OF SELECTED LITERATURE IN THE AREA OF INTERPERSONAL RELATIONSHIPS, WHICH HAS RELEVANCE TO THE CLIENT-COUNSELOR INTERACTION. THE STUDIES HAVE BEEN TREATED WITHIN THE FRAMEWORK OF MCGRATH'S DESCRIPTIVE MODEL FOR INTERPERSONAL RELATIONSHIPS. COMPARATIVE ANALYSIS OF THEORETICAL APPROACHES HAS YIELDED TWO LINES OF EVIDENCE…

"The Theory behind How Students Learn": Applying Developmental Theory to Research on Children's Historical Thinking

ERIC Educational Resources Information Center

Dulberg, Nancy

2005-01-01

Recent research on children's historical thinking has produced rich descriptions of instruction. However, the research literature is largely lacking a theoretical model of learning. This article asserts that developmental constructivist theory informs research design and interpretation, provides explanatory power, and promises more useful…

A Unified Framework for Monetary Theory and Policy Analysis.

ERIC Educational Resources Information Center

Lagos, Ricardo; Wright, Randall

2005-01-01

Search-theoretic models of monetary exchange are based on explicit descriptions of the frictions that make money essential. However, tractable versions of these models typically make strong assumptions that render them ill suited for monetary policy analysis. We propose a new framework, based on explicit micro foundations, within which macro…

Learning Processes and Approaches: Examining Their Interrelationships to Understand Student Learning

ERIC Educational Resources Information Center

Chennamsetti, Prashanti

2008-01-01

The purpose of this paper is to explore the relationship between two contrasting research paradigms, namely, cognitive and experiential research, a significant literature review previously unaddressed. To achieve this objective, a conceptual description of three theoretical frameworks, Dual-Store model, Levels of Processing (LOP; drawn from…

Functional Contextualism: An Ideal Framework for Theory in Instructional Design and Technology

ERIC Educational Resources Information Center

Reigeluth, Charles M.; An, Yun-Jo

2006-01-01

In this article, the authors comment on Eric Fox's description of functional contextualism which makes several contributions to instructional design and technology (IDT). They agree that functional contextualism does indeed provide some "theoretical clarity and philosophical cohesion," not just for constructivism, but also for understanding…

A New Typology of Home-Care Helpers

ERIC Educational Resources Information Center

Porter, Eileen J.; Ganong, Lawrence H.; Drew, Nancy; Lanes, Tracy I.

2004-01-01

Purpose: The formal-informal dichotomy of home care, which has been a theoretical framework in quantitative and qualitative research, might not be descriptive of older persons' views about their home-care providers. This qualitative study explores the perspectives of older women about the characteristics of their home-care providers. Design and…

A Survey of Model Evaluation Approaches with a Tutorial on Hierarchical Bayesian Methods

ERIC Educational Resources Information Center

Shiffrin, Richard M.; Lee, Michael D.; Kim, Woojae; Wagenmakers, Eric-Jan

2008-01-01

This article reviews current methods for evaluating models in the cognitive sciences, including theoretically based approaches, such as Bayes factors and minimum description length measures; simulation approaches, including model mimicry evaluations; and practical approaches, such as validation and generalization measures. This article argues…

A Model of Economics Learning in the High Schools.

ERIC Educational Resources Information Center

Walstad, William B.; Soper, John C.

1982-01-01

Reports the results of a study that evaluated the impact of the Developmental Economic Education Project (DEEP) and the International Paper Company (IPCF) awards program for teaching economics on high school student cognitive and affective outcomes. A description of the theoretical model used for the analysis is included. (AM)

Truth and Consequences: Believing as Adaptive Behavior.

ERIC Educational Resources Information Center

Sawyer, Llewlee L.

A theoretical cornerstone of cognitive therapy is the idea that the relationship between experience and cognition, the interpretation of experience, is recursive. Human beings can respond to a given experience with more than one description and/or explanation of the experience and these alternative interpretations can have different experiential…

Phoretic self-propulsion: a mesoscopic description of reaction dynamics that powers motion.

PubMed

de Buyl, Pierre; Kapral, Raymond

2013-02-21

The fabrication of synthetic self-propelled particles and the experimental investigations of their dynamics have stimulated interest in self-generated phoretic effects that propel nano- and micron-scale objects. Theoretical modeling of these phenomena is often based on a continuum description of the solvent for different phoretic propulsion mechanisms, including, self-electrophoresis, self-diffusiophoresis and self-thermophoresis. The work in this paper considers various types of catalytic chemical reaction at the motor surface and in the bulk fluid that come into play in mesoscopic descriptions of the dynamics. The formulation is illustrated by developing the mesoscopic reaction dynamics for exothermic and dissociation reactions that are used to power motor motion. The results of simulations of the self-propelled dynamics of composite Janus particles by these mechanisms are presented.

Impact of Beads and Drops on a Repellent Solid Surface: A Unified Description

NASA Astrophysics Data System (ADS)

Arora, S.; Fromental, J.-M.; Mora, S.; Phou, Ty; Ramos, L.; Ligoure, C.

2018-04-01

We investigate freely expanding sheets formed by ultrasoft gel beads, and liquid and viscoelastic drops, produced by the impact of the bead or drop on a silicon wafer covered with a thin layer of liquid nitrogen that suppresses viscous dissipation thanks to an inverse Leidenfrost effect. Our experiments show a unified behavior for the impact dynamics that holds for solids, liquids, and viscoelastic fluids and that we rationalize by properly taking into account elastocapillary effects. In this framework, the classical impact dynamics of solids and liquids, as far as viscous dissipation is negligible, appears as the asymptotic limits of a universal theoretical description. A novel material-dependent characteristic velocity that includes both capillary and bulk elasticity emerges from this unified description of the physics of impact.

Gender differences in human interpersonal conflicts: A reply to Ingram et al. (2012).

PubMed

Trnka, Radek

2013-07-27

In the article, I comment on the study results of Ingram et al. (2012). Feelings of anger were hypothesized to be reported more often in the descriptions of past conflicts of boys than in the descriptions of past conflicts of girls. However, the authors found that boys were no more likely than girls to describe feelings of anger ensuing from a conflict. An explanation of this interesting finding is not provided in the discussion section. The present study provides possible theoretical explanations for this finding, also using the results of our studies published in the past.

Thermodynamics of a time-dependent and dissipative oval billiard: A heat transfer and billiard approach.

PubMed

Leonel, Edson D; Galia, Marcus Vinícius Camillo; Barreiro, Luiz Antonio; Oliveira, Diego F M

2016-12-01

We study some statistical properties for the behavior of the average squared velocity-hence the temperature-for an ensemble of classical particles moving in a billiard whose boundary is time dependent. We assume the collisions of the particles with the boundary of the billiard are inelastic, leading the average squared velocity to reach a steady-state dynamics for large enough time. The description of the stationary state is made by using two different approaches: (i) heat transfer motivated by the Fourier law and (ii) billiard dynamics using either numerical simulations and theoretical description.

Theoretical description of magnetocaloric effect in the shape memory alloy exhibiting metamagnetic behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

L'vov, Victor A.; Taras Shevchenko National University, Kyiv 01601; Kosogor, Anna, E-mail: annakosogor@gmail.com

2016-01-07

A simple thermodynamic theory is proposed for the quantitative description of giant magnetocaloric effect observed in metamagnetic shape memory alloys. Both the conventional magnetocaloric effect at the Curie temperature and the inverse magnetocaloric effect at the transition from the ferromagnetic austenite to a weakly magnetic martensite are considered. These effects are evaluated from the Landau-type free energy expression involving exchange interactions in a system of a two magnetic sublattices. The findings of the thermodynamic theory agree with first-principles calculations and experimental results from Ni-Mn-In-Co and Ni-Mn-Sn alloys, respectively.

Real-time value-driven diagnosis

NASA Technical Reports Server (NTRS)

Dambrosio, Bruce

1995-01-01

Diagnosis is often thought of as an isolated task in theoretical reasoning (reasoning with the goal of updating our beliefs about the world). We present a decision-theoretic interpretation of diagnosis as a task in practical reasoning (reasoning with the goal of acting in the world), and sketch components of our approach to this task. These components include an abstract problem description, a decision-theoretic model of the basic task, a set of inference methods suitable for evaluating the decision representation in real-time, and a control architecture to provide the needed continuing coordination between the agent and its environment. A principal contribution of this work is the representation and inference methods we have developed, which extend previously available probabilistic inference methods and narrow, somewhat, the gap between probabilistic and logical models of diagnosis.

The cosmological lithium problem revisited

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertulani, C. A., E-mail: carlos.bertulani@tamuc.edu; Department of Physics and Astronomy, Texas A&M University, College Station, TX 75429; Mukhamedzhanov, A. M., E-mail: akram@comp.tamu.edu

After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although ourmore » attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.« less

Professional failure to thrive: a threat to high-quality care?

PubMed

Stamler, Lynnette Leeseberg; Gabriel, Aaron M

2010-03-01

The term professional failure to thrive arose from descriptions of non-organic failure to thrive in infants and observations of nurses' behaviours. First coined by Stamler in 1997, subsequent unrelated research results have supported the theoretical construct. In an era when patient safety and high-quality care have never been more important, and nursing retention has reached heretofore unknown levels of global concern, critical examination of factors that may alleviate professional issues and support high-quality healthcare is especially useful. In this paper, we suggest theoretical causes for professional failure to thrive (PFTT) and associated behaviours exhibited by nurses, and draw links to current research to support the theory. Given the theoretical support, PFTT represents an additional avenue that should be considered and explored through research studies.

49 CFR 587.6 - General description.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) DEFORMABLE BARRIERS Side Impact Moving Deformable Barrier § 587.6 General description. (a) The moving deformable barrier consists of component parts and...

A theoretical study of microwave beam absorption by a rectenna

NASA Technical Reports Server (NTRS)

Ott, J. H.; Rice, J. S.; Thorn, D. C.

1980-01-01

The rectenna's microwave power beam absorption limit was theoretically confirmed by two mathematical models descriptive of the microwave absorption process; first one model was based on the current sheet equivalency of a large planar array above a reflector and the second model, which was based on the properties of a waveguide with special imaging characteristics, quantified the electromagnetic modes (field configurations) in the immediate vicinity of a Rectenna element spacing which permit total power beam absorption by preventing unwanted modes from propagating (scattering) were derived using these models. Several factors causing unwanted scattering are discussed.

Les Houches 2015: Physics at TeV Colliders Standard Model Working Group Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, J.R.; et al.

This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phenomenological studies essential for comparing LHC data from Run I with theoretical predictions and projections for future measurements in Run II, and (V) new developments in Monte Carlo event generators.

Safety belt promotion: theory and practice.

PubMed

Nelson, G D; Moffit, P B

1988-02-01

The purpose of this paper is to provide practitioners a rationale and description of selected theoretically based approaches to safety belt promotion. Theory failure is a threat to the integrity and effectiveness of safety belt promotion. The absence of theory driven programs designed to promote safety belt use is a concern of this paper. Six theoretical models from the social and behavioral sciences are reviewed with suggestions for application to promoting safety belt use and include Theory of Reasoned Action, the Health Belief Model, Fear Arousal, Operant Learning, Social Learning Theory, and Diffusion of Innovations. Guidelines for the selection and utilization of theory are discussed.

A structural and theoretical study of the alkylammonium nitrates forefather: Liquid methylammonium nitrate

NASA Astrophysics Data System (ADS)

Gontrani, Lorenzo; Caminiti, Ruggero; Salma, Umme; Campetella, Marco

2017-09-01

We present here a structural and vibrational analysis of melted methylammonium nitrate, the simplest compound of the family of alkylammonium nitrates. The static and dynamical features calculated were endorsed by comparing the experimental X-ray data with the theoretical ones. A reliable description cannot be obtained with classical molecular dynamics owing to polarization effects. Contrariwise, the structure factor and the vibrational frequencies obtained from ab initio molecular dynamics trajectories are in very good agreement with the experiment. A careful analysis has provided additional information on the complex hydrogen bonding network that exists in this liquid.

Theory of the Trojan-Horse Method - From the Original Idea to Actual Applications

NASA Astrophysics Data System (ADS)

Typel, Stefan

2018-01-01

The origin and the main features of the Trojan-horse (TH) method are delineated starting with the original idea of Gerhard Baur. Basic theoretical considerations, general experimental conditions and possible problems are discussed. Significant steps in experimental studies towards the implementation of the TH method and the development of the theoretical description are presented. This lead to the successful application of the TH approach by Claudio Spitaleri and his group to determine low-energy cross section that are relevant for astrophysics. An outlook with possible developments in the future are given.

Modeling Theory of Mind and Cognitive Appraisal with Decision-Theoretic Agents

DTIC Science & Technology

2011-04-07

following key factors: Consistency: People expect, prefer, and are driven to maintain consistency, and avoid cognitive dissonance , be- tween beliefs...Modeling Theory of Mind and Cognitive Appraisal with Decision-Theoretic Agents David V. Pynadath1, Mei Si2, and Stacy C. Marsella1 1Institute for...capacity in appraisal and social emotions, as well as arguing for a uniform process for emotion and cognition . 1 Report Documentation Page Form

Single, Complete, Probability Spaces Consistent With EPR-Bohm-Bell Experimental Data

NASA Astrophysics Data System (ADS)

Avis, David; Fischer, Paul; Hilbert, Astrid; Khrennikov, Andrei

2009-03-01

We show that paradoxical consequences of violations of Bell's inequality are induced by the use of an unsuitable probabilistic description for the EPR-Bohm-Bell experiment. The conventional description (due to Bell) is based on a combination of statistical data collected for different settings of polarization beam splitters (PBSs). In fact, such data consists of some conditional probabilities which only partially define a probability space. Ignoring this conditioning leads to apparent contradictions in the classical probabilistic model (due to Kolmogorov). We show how to make a completely consistent probabilistic model by taking into account the probabilities of selecting the settings of the PBSs. Our model matches both the experimental data and is consistent with classical probability theory.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirojsirikul, Teerapong; Götz, Andreas W.; Weare, John

Green Fluorescent Protein (GFP) is a widely used fluorescent biomarker for the study of biological systems. Our investigation is focused on providing a reliable theoretical description of the GFP chromophore, the photochemical properties of which can be influenced through both the surrounding protein environment and pH levels. In this work we are specifically addressing the effect of an aqueous solvation environment , where a number of experimental measurements have been performed. Our approach is based on a combined quantum mechanics molecular mechanics (QM/MM) methodology, which incorporates high level coupled cluster theory for the analysis of excited states. It also presentsmore » the first application of the newly developed NWChem/AMBER QM/MM interface. Using a systematic approach, which involves comparison of gas phase and aqueous results for different protonation states and conformations, we have resolved existing uncertainties regarding theoretical interpretation of the experimental data. We observe that the impact of aqueous environment on charged states generally results in blue shifts, but the magnitude of the effect is sensitive to charge state and conformation and can be rationalized based on charge movement into the area of higher/lower external electrostatic potentials. At neutral pH levels the experimentally observed absorption signal is most likely coming from the phenol protonated form. Our results also show that the high level coupled description is essential for proper description of excited states of GFP.« less

Edgar Allan Poe: a case description of the Marfan syndrome in an obscure short story.

PubMed

Battle, Robert W

2011-07-01

In the obscure short story “A Tale of the Ragged Mountains,” Edgar Allen Poe meticulously described a character with features remarkably consistent with the Marfan syndrome. This description appeared in fiction >50 years before the celebrated index description in the published medical research by Professor Antoine Marfan in Paris in 1896.

Chunking dynamics: heteroclinics in mind

PubMed Central

Rabinovich, Mikhail I.; Varona, Pablo; Tristan, Irma; Afraimovich, Valentin S.

2014-01-01

Recent results of imaging technologies and non-linear dynamics make possible to relate the structure and dynamics of functional brain networks to different mental tasks and to build theoretical models for the description and prediction of cognitive activity. Such models are non-linear dynamical descriptions of the interaction of the core components—brain modes—participating in a specific mental function. The dynamical images of different mental processes depend on their temporal features. The dynamics of many cognitive functions are transient. They are often observed as a chain of sequentially changing metastable states. A stable heteroclinic channel (SHC) consisting of a chain of saddles—metastable states—connected by unstable separatrices is a mathematical image for robust transients. In this paper we focus on hierarchical chunking dynamics that can represent several forms of transient cognitive activity. Chunking is a dynamical phenomenon that nature uses to perform information processing of long sequences by dividing them in shorter information items. Chunking, for example, makes more efficient the use of short-term memory by breaking up long strings of information (like in language where one can see the separation of a novel on chapters, paragraphs, sentences, and finally words). Chunking is important in many processes of perception, learning, and cognition in humans and animals. Based on anatomical information about the hierarchical organization of functional brain networks, we propose a cognitive network architecture that hierarchically chunks and super-chunks switching sequences of metastable states produced by winnerless competitive heteroclinic dynamics. PMID:24672469

Chunking dynamics: heteroclinics in mind.

PubMed

Rabinovich, Mikhail I; Varona, Pablo; Tristan, Irma; Afraimovich, Valentin S

2014-01-01

Recent results of imaging technologies and non-linear dynamics make possible to relate the structure and dynamics of functional brain networks to different mental tasks and to build theoretical models for the description and prediction of cognitive activity. Such models are non-linear dynamical descriptions of the interaction of the core components-brain modes-participating in a specific mental function. The dynamical images of different mental processes depend on their temporal features. The dynamics of many cognitive functions are transient. They are often observed as a chain of sequentially changing metastable states. A stable heteroclinic channel (SHC) consisting of a chain of saddles-metastable states-connected by unstable separatrices is a mathematical image for robust transients. In this paper we focus on hierarchical chunking dynamics that can represent several forms of transient cognitive activity. Chunking is a dynamical phenomenon that nature uses to perform information processing of long sequences by dividing them in shorter information items. Chunking, for example, makes more efficient the use of short-term memory by breaking up long strings of information (like in language where one can see the separation of a novel on chapters, paragraphs, sentences, and finally words). Chunking is important in many processes of perception, learning, and cognition in humans and animals. Based on anatomical information about the hierarchical organization of functional brain networks, we propose a cognitive network architecture that hierarchically chunks and super-chunks switching sequences of metastable states produced by winnerless competitive heteroclinic dynamics.

PROCEEDINGS OF RIKEN/BNL RESEARCH CENTER WORKSHOP, EQUILIBRIUM AND NON-EQUILIBRIM ASPECTTS OF HOT, DENSE QCD, VOLUME 28.

DOE Office of Scientific and Technical Information (OSTI.GOV)

DE VEGA,H.J.; BOYANOVSKY,D.

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven, beginning operation this year, and the Large Hadron Collider (LHC) at CERN, beginning operation {approximately}2005, will provide an unprecedented range of energies and luminosities that will allow us to probe the Gluon-Quark plasma. At RHIC and LHC, at central rapidity typical estimates of energy densities and temperatures are e * 1-10 GeV/fm3 and T0 * 300 - 900 MeV. Such energies are well above current estimates for the GQ plasma. Initially, this hot, dense plasma is far from local thermal equilibrium, making the theoretical study of transport phenomena, kinetic and chemical equilibrationmore » in dense and hot plasmas, and related issues a matter of fundamental importance. During the last few years a consistent framework to study collective effects in the Gluon-Quark plasma, and a microscopic description of transport in terms of the hard thermal (and dense) loops resummation program has emerged. This approach has the potential of providing a microscopic formulation of transport, in the regime of temperatures and densities to be achieved at RHIC and LHC. A parallel development over the last few years has provided a consistent formulation of non-equilibrium quantum field theory that provides a real-time description of phenomena out of equilibrium. Novel techniques including non-perturbative approaches and the dynamical renormalization group techniques lead to new insights into transport and relaxation. A deeper understanding of collective.excitations and transport phenomena in the GQ plasma could lead to recognize novel potential experimental signatures. New insights into small-c physics reveals a striking similarity between small-c and hard thermal loops, and novel real-time numerical simulations have recently studied the parton distributions and their thermalizations in the initial stages of a heavy ion collision.« less

PROCEEDINGS OF RIKEN/BNL RESEARCH CENTER WORKSHOP, EQUILIBRIUM AND NON-EQUILIBRIM ASPECTS OF HOT, DENSE QCD, VOLUME 28.

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Vega, H.J.; Boyanovsky, D.

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven, beginning operation this year, and the Large Hadron Collider (LHC) at CERN, beginning operation {approximately}2005, will provide an unprecedented range of energies and luminosities that will allow us to probe the Gluon-Quark plasma. At RHIC and LHC, at central rapidity typical estimates of energy densities and temperatures are e * 1-10 GeV/fm3 and T0 * 300 - 900 MeV. Such energies are well above current estimates for the GQ plasma. Initially, this hot, dense plasma is far from local thermal equilibrium, making the theoretical study of transport phenomena, kinetic and chemical equilibrationmore » in dense and hot plasmas, and related issues a matter of fundamental importance. During the last few years a consistent framework to study collective effects in the Gluon-Quark plasma, and a microscopic description of transport in terms of the hard thermal (and dense) loops resummation program has emerged. This approach has the potential of providing a microscopic formulation of transport, in the regime of temperatures and densities to be achieved at RHIC and LHC. A parallel development over the last few years has provided a consistent formulation of non-equilibrium quantum field theory that provides a real-time description of phenomena out of equilibrium. Novel techniques including non-perturbative approaches and the dynamical renormalization group techniques lead to new insights into transport and relaxation. A deeper understanding of collective.excitations and transport phenomena in the GQ plasma could lead to recognize novel potential experimental signatures. New insights into small-c physics reveals a striking similarity between small-c and hard thermal loops, and novel real-time numerical simulations have recently studied the parton distributions and their thermalizations in the initial stages of a heavy ion collision.« less

Nursing management of sensory overload in psychiatry – Theoretical densification and modification of the framework model

PubMed

Scheydt, Stefan; Needham, Ian; Behrens, Johann

2017-01-01

Background: Within the scope of the research project on the subjects of sensory overload and stimulus regulation, a theoretical framework model of the nursing care of patients with sensory overload in psychiatry was developed. In a second step, this theoretical model should now be theoretically compressed and, if necessary, modified. Aim: Empirical verification as well as modification, enhancement and theoretical densification of the framework model of nursing care of patients with sensory overload in psychiatry. Method: Analysis of 8 expert interviews by summarizing and structuring content analysis methods based on Meuser and Nagel (2009) as well as Mayring (2010). Results: The developed framework model (Scheydt et al., 2016b) could be empirically verified, theoretically densificated and extended by one category (perception modulation). Thus, four categories of nursing care of patients with sensory overload can be described in inpatient psychiatry: removal from stimuli, modulation of environmental factors, perceptual modulation as well as help somebody to help him- or herself / coping support. Conclusions: Based on the methodological approach, a relatively well-saturated, credible conceptualization of a theoretical model for the description of the nursing care of patients with sensory overload in stationary psychiatry could be worked out. In further steps, these measures have to be further developed, implemented and evaluated regarding to their efficacy.

An inconclusive study comparing the effect of concrete and abstract descriptions of belief-inconsistent information.

PubMed

Collins, Katherine A; Clément, Richard

2018-01-01

Linguistic bias is the differential use of linguistic abstraction (as defined by the Linguistic Category Model) to describe the same behaviour for members of different groups. Essentially, it is the tendency to use concrete language for belief-inconsistent behaviours and abstract language for belief-consistent behaviours. Having found that linguistic bias is produced without intention or awareness in many contexts, researchers argue that linguistic bias reflects, reinforces, and transmits pre-existing beliefs, thus playing a role in belief maintenance. Based on the Linguistic Category Model, this assumes that concrete descriptions reduce the impact of belief-inconsistent behaviours while abstract descriptions maximize the impact of belief-consistent behaviours. However, a key study by Geschke, Sassenberg, Ruhrmann, and Sommer [2007] found that concrete descriptions of belief-inconsistent behaviours actually had a greater impact than abstract descriptions, a finding that does not fit easily within the linguistic bias paradigm. Abstract descriptions (e.g. the elderly woman is athletic) are, by definition, more open to interpretation than concrete descriptions (e.g. the elderly woman works out regularly). It is thus possible that abstract descriptions are (1) perceived as having less evidentiary strength than concrete descriptions, and (2) understood in context (i.e. athletic for an elderly woman). In this study, the design of Geschke et al. [2007] was modified to address this possibility. We expected that the differences in the impact of concrete and abstract descriptions would be reduced or reversed, but instead we found that differences were largely absent. This study did not support the findings of Geschke et al. [2007] or the linguistic bias paradigm. We encourage further attempts to understand the strong effect of concrete descriptions for belief-inconsistent behaviour.

Neuroimaging Craving: Urge Intensity Matters

PubMed Central

Wilson, Stephen J.; Sayette, Michael A.

2015-01-01

Functional neuroimaging has become an increasingly common tool for studying drug craving. Furthermore, functional neuroimaging studies, which have addressed an incredibly diverse array of questions regarding the nature and treatment of craving, have had a substantial impact on theoretical models of addiction. Here, we offer three points related to this sizeable and influential body of research. First, we assert that the craving most investigators seek to study represents not just a desire but a strong desire to use drugs, consistent with prominent theoretical and clinical descriptions of craving. Second, we highlight that, despite the clear conceptual and clinical emphasis on craving as an intense desire, brain imaging studies often have been explicitly designed in a way that reduces the ability to generate powerful cravings. We illustrate this point by reviewing the peak urge levels endorsed by participants in functional magnetic resonance imaging (fMRI) studies of cigarette craving in nicotine-deprived versus nondeprived smokers. Third, we suggest that brain responses measured during mild states of desire (such as following satiety) differ in fundamental ways from those measured during states of overpowering desire (i.e., craving) to use drugs. We support this position by way of a meta-analysis revealing that fMRI cue exposure studies using nicotine-deprived smokers have produced different patterns of brain activation than those using nondeprived smokers. Regarding brain imaging studies of craving, intensity of the urges matter, and more explicit attention to urge intensity in future work has the potential to yield valuable information about the nature of craving. PMID:25073979

Coevolutionary dynamics in large, but finite populations

NASA Astrophysics Data System (ADS)

Traulsen, Arne; Claussen, Jens Christian; Hauert, Christoph

2006-07-01

Coevolving and competing species or game-theoretic strategies exhibit rich and complex dynamics for which a general theoretical framework based on finite populations is still lacking. Recently, an explicit mean-field description in the form of a Fokker-Planck equation was derived for frequency-dependent selection with two strategies in finite populations based on microscopic processes [A. Traulsen, J. C. Claussen, and C. Hauert, Phys. Rev. Lett. 95, 238701 (2005)]. Here we generalize this approach in a twofold way: First, we extend the framework to an arbitrary number of strategies and second, we allow for mutations in the evolutionary process. The deterministic limit of infinite population size of the frequency-dependent Moran process yields the adjusted replicator-mutator equation, which describes the combined effect of selection and mutation. For finite populations, we provide an extension taking random drift into account. In the limit of neutral selection, i.e., whenever the process is determined by random drift and mutations, the stationary strategy distribution is derived. This distribution forms the background for the coevolutionary process. In particular, a critical mutation rate uc is obtained separating two scenarios: above uc the population predominantly consists of a mixture of strategies whereas below uc the population tends to be in homogeneous states. For one of the fundamental problems in evolutionary biology, the evolution of cooperation under Darwinian selection, we demonstrate that the analytical framework provides excellent approximations to individual based simulations even for rather small population sizes. This approach complements simulation results and provides a deeper, systematic understanding of coevolutionary dynamics.

Promoting physical therapists' of research evidence to inform clinical practice: part 1--theoretical foundation, evidence, and description of the PEAK program.

PubMed

Tilson, Julie K; Mickan, Sharon

2014-06-25

There is a need for theoretically grounded and evidence-based interventions that enhance the use of research evidence in physical therapist practice. This paper and its companion paper introduce the Physical therapist-driven Education for Actionable Knowledge translation (PEAK) program, an educational program designed to promote physical therapists' integration of research evidence into clinical decision-making. The pedagogical foundations for the PEAK educational program include Albert Bandura's social cognitive theory and Malcolm Knowles's adult learning theory. Additionally, two complementary frameworks of knowledge translation, the Promoting Action on Research Implementation in Health Services (PARiHS) and Knowledge to Action (KTA) Cycle, were used to inform the organizational elements of the program. Finally, the program design was influenced by evidence from previous attempts to facilitate the use of research in practice at the individual and organizational levels. The 6-month PEAK program consisted of four consecutive and interdependent components. First, leadership support was secured and electronic resources were acquired and distributed to participants. Next, a two-day training workshop consisting of didactic and small group activities was conducted that addressed the five steps of evidence based practice. For five months following the workshop, participants worked in small groups to review and synthesize literature around a group-selected area of common clinical interest. Each group contributed to the generation of a "Best Practices List" - a list of locally generated, evidence-based, actionable behaviors relevant to the groups' clinical practice. Ultimately, participants agreed to implement the Best Practices List in their clinical practice. This, first of two companion papers, describes the underlying pedagogical theories, knowledge translation frameworks, and research evidence used to derive the PEAK program - an educational program designed to promote the use of research evidence to inform physical therapist practice. The four components of the program are described in detail. The companion paper reports the results of a mixed methods feasibility analysis of this complex educational intervention.

Non-equilibrium dynamics of artificial quantum matter

NASA Astrophysics Data System (ADS)

Babadi, Mehrtash

The rapid progress of the field of ultracold atoms during the past two decades has set new milestones in our control over matter. By cooling dilute atomic gases and molecules to nano-Kelvin temperatures, novel quantum mechanical states of matter can be realized and studied on a table-top experimental setup while bulk matter can be tailored to faithfully simulate abstract theoretical models. Two of such models which have witnessed significant experimental and theoretical attention are (1) the two-component Fermi gas with resonant s-wave interactions, and (2) the single-component Fermi gas with dipole-dipole interactions. This thesis is devoted to studying the non-equilibrium collective dynamics of these systems using the general framework of quantum kinetic theory. We present a concise review of the utilized mathematical methods in the first two chapters, including the Schwinger-Keldysh formalism of non-equilibrium quantum fields, two-particle irreducible (2PI) effective actions and the framework of quantum kinetic theory. We study the collective dynamics of the dipolar Fermi gas in a quasi-two-dimensional optical trap in chapter 3 and provide a detailed account of its dynamical crossover from the collisionless to the hydrodynamical regime. Chapter 4 is devoted to studying the dynamics of the attractive Fermi gas in the normal phase. Starting from the self-consistent T-matrix (pairing fluctuation) approximation, we systematically derive a set of quantum kinetic equations and show that they provide a globally valid description of the dynamics of the attractive Fermi gas, ranging from the weak-coupling Fermi liquid phase to the intermediate non-Fermi liquid pairing pseudogap regime and finally the strong-coupling Bose liquid phase. The shortcomings of the self-consistent T-matrix approximation in two spatial dimensions are discussed along with a proposal to overcome its unphysical behaviors. The developed kinetic formalism is finally utilized to reproduce and interpret the findings of a recent experiment done on the collective dynamics of trapped two-dimensional ultracold gases.

Decomposing associations between acculturation and drinking in Mexican Americans

PubMed Central

Mills, Britain A.; Caetano, Raul

2011-01-01

Background Acculturation to life in the United States is a known predictor of Hispanic drinking behavior. We compare the ability of 2 theoretical models of this effect – sociocultural theory and general stress theory – to account for associations between acculturation and drinking in a sample of Mexican Americans. Limitations of previous evaluations of these theoretical models are addressed by using a broader range of hypothesized cognitive mediators and a more direct measure of acculturative stress. In addition, we explore nonlinearities as possible underpinnings of attenuated acculturation effects among males. Methods Respondents (N = 2,595, current drinker N = 1,351) were interviewed as part of 2 recent multistage probability samples in a study of drinking behavior among Mexican Americans in the United States. The ability of norms, drinking motives, alcohol expectancies, and acculturation stress to account for relations between acculturation and drinking outcomes (volume and heavy drinking days) were assessed with a hierarchical linear regression strategy. Nonlinear trends were assessed by modeling quadratic effects of acculturation and acculturation stress on cognitive mediators and drinking outcomes. Results Consistent with previous findings, acculturation effects on drinking outcomes were stronger for females than males. Among females, only drinking motives explained acculturation associations with volume or heavy drinking days. Among males, acculturation was linked to increases in norms, and norms were positive predictors of drinking outcomes. However, adjusted effects of acculturation were non-existent or trending in a negative direction, which counter-acted this indirect normative influence. Acculturation stress did not explain positive associations between acculturation and drinking. Conclusions Stress and alcohol outcome expectancies play little role in the positive linear association between acculturation and drinking outcomes, but drinking motives appears to at least partially account for this effect. Consistent with recent reports, these results challenge stress models of linear acculturation effects on drinking outcomes and provide (partial) support for sociocultural models. Inconsistent mediation patterns – rather than nonlinearities – represented a more plausible statistical description of why acculturation-drinking associations are weakened among males. PMID:22316139

Decomposing associations between acculturation and drinking in Mexican Americans.

PubMed

Mills, Britain A; Caetano, Raul

2012-07-01

Acculturation to life in the United States is a known predictor of Hispanic drinking behavior. We compare the ability of 2 theoretical models of this effect-sociocultural theory and general stress theory-to account for associations between acculturation and drinking in a sample of Mexican Americans. Limitations of previous evaluations of these theoretical models are addressed using a broader range of hypothesized cognitive mediators and a more direct measure of acculturative stress. In addition, we explore nonlinearities as possible underpinnings of attenuated acculturation effects among men. Respondents (N = 2,595, current drinker N = 1,351) were interviewed as part of 2 recent multistage probability samples in a study of drinking behavior among Mexican Americans in the United States. The ability of norms, drinking motives, alcohol expectancies, and acculturation stress to account for relations between acculturation and drinking outcomes (volume and heavy drinking days) were assessed with a hierarchical linear regression strategy. Nonlinear trends were assessed by modeling quadratic effects of acculturation and acculturation stress on cognitive mediators and drinking outcomes. Consistent with previous findings, acculturation effects on drinking outcomes were stronger for women than men. Among women, only drinking motives explained acculturation associations with volume or heavy drinking days. Among men, acculturation was linked to increases in norms, and norms were positive predictors of drinking outcomes. However, adjusted effects of acculturation were nonexistent or trending in a negative direction, which counteracted this indirect normative influence. Acculturation stress did not explain the positive associations between acculturation and drinking. Stress and alcohol outcome expectancies play little role in the positive linear association between acculturation and drinking outcomes, but drinking motives appear to at least partially account for this effect. Consistent with recent reports, these results challenge stress models of linear acculturation effects on drinking outcomes and provide (partial) support for sociocultural models. Inconsistent mediation patterns-rather than nonlinearities-represented a more plausible statistical description of why acculturation-drinking associations are weakened among men. Copyright © 2012 by the Research Society on Alcoholism.

Thermal APU/hydraulics analysis program. User's guide and programmer's manual

NASA Technical Reports Server (NTRS)

Deluna, T. A.

1976-01-01

The User's Guide information plus program description necessary to run and have a general understanding of the Thermal APU/Hydraulics Analysis Program (TAHAP) is described. This information consists of general descriptions of the APU/hydraulic system and the TAHAP model, input and output data descriptions, and specific subroutine requirements. Deck setups and input data formats are included and other necessary and/or helpful information for using TAHAP is given. The math model descriptions for the driver program and each of its supporting subroutines are outlined.

7 CFR 621.10 - Description.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AGRICULTURE WATER RESOURCES RIVER BASIN INVESTIGATIONS AND SURVEYS USDA Cooperative Studies § 621.10 Description. Cooperative river basin studies provide USDA planning assistance to Federal, State, and local... the requesting agencies and citizen groups that are consistent with USDA authorities and...

7 CFR 621.10 - Description.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AGRICULTURE WATER RESOURCES RIVER BASIN INVESTIGATIONS AND SURVEYS USDA Cooperative Studies § 621.10 Description. Cooperative river basin studies provide USDA planning assistance to Federal, State, and local... the requesting agencies and citizen groups that are consistent with USDA authorities and...

Generalised Central Limit Theorems for Growth Rate Distribution of Complex Systems

NASA Astrophysics Data System (ADS)

Takayasu, Misako; Watanabe, Hayafumi; Takayasu, Hideki

2014-04-01

We introduce a solvable model of randomly growing systems consisting of many independent subunits. Scaling relations and growth rate distributions in the limit of infinite subunits are analysed theoretically. Various types of scaling properties and distributions reported for growth rates of complex systems in a variety of fields can be derived from this basic physical model. Statistical data of growth rates for about 1 million business firms are analysed as a real-world example of randomly growing systems. Not only are the scaling relations consistent with the theoretical solution, but the entire functional form of the growth rate distribution is fitted with a theoretical distribution that has a power-law tail.

From the Immoral to the Incorruptible: How Prescriptive Expectations Turn the Powerful Into Paragons of Virtue.

PubMed

Hu, Miao; Rucker, Derek D; Galinsky, Adam D

2016-06-01

Ample evidence documents that power increases unethical behavior. This article introduces a new theoretical framework for understanding when power leads to more versus less unethical behavior. Our key proposition is that people hold expectations about power that are both descriptive (how the powerful do behave) and prescriptive (how the powerful should behave). People hold descriptive beliefs that the powerful do behave more unethically than the powerless, but they hold prescriptive beliefs that the powerful should behave more ethically than the powerless. Whichever expectation-descriptive or prescriptive-is salient affects how power influences one's behavior. Three experiments demonstrate that activating descriptive expectations for power leads the powerful to cheat more than the powerless, whereas activating prescriptive expectations leads the powerful to cheat less than the powerless. The current work offers new ideas for curbing unethical behavior by those with power: focus their attention on prescriptive expectations for power. © 2016 by the Society for Personality and Social Psychology, Inc.

Motion Law Analysis and Structural Optimization of the Ejection Device of Tray Seeder

NASA Astrophysics Data System (ADS)

Luo, Xin; Hu, Bin; Dong, Chunwang; Huang, Lili

An ejection mechanism consisting four reset springs, an electromagnet and a seed disk was designed for tray seeder. The motion conditions of seeds in the seed disk were theoretical analyzed and intensity and height of seed ejection were calculated. The motions of the seeds and seed disk were multi-body dynamic simulated using Cosmos modules plug-in SolidWorks software package. The simulation results showed the consistence with the theoretical analysis.

Pressure Mapping in Elderly Care: A Tool to Increase Pressure Injury Knowledge and Awareness Among Staff.

PubMed

Hultin, Lisa; Olsson, Estrid; Carli, Cheryl; Gunningberg, Lena

The purpose of this study was to evaluate the use of a pressure mapping system with real-time feedback of pressure points in elderly care, with specific focus on pressure injury (PI) knowledge/attitudes (staff), interface pressure, and PI prevention activities (residents). Descriptive, 1-group pretest/posttest study. A convenience sample of 40 assistant nurses and aides participated in the study; staff members were recruited at daytime, and 1 nighttime meeting was held at the facility. A convenience sample of 12 residents with risk for PI were recruited, 4 from each ward. Inclusion criteria were participants older than 65 years, Modified Norton Scale score 20 or less, and in need of help with turning in order to prevent PI. The study setting was a care facility for the elderly in Uppsala, Sweden. A descriptive, comparative pretest/posttest study design was used. The intervention consisted of the use of a pressure mapping system, combined with theoretical and practical teaching. Theoretical and practical information related to PI prevention and the pressure mapping system was presented to the staff. The staff (n = 40) completed the Pressure Ulcer Knowledge and Assessment Tool (PUKAT) and Attitudes towards Pressure Ulcer (APuP) before and following study intervention. Residents' beds were equipped with a pressure mapping system during 7 consecutive days. Peak pressures and preventive interventions were registered 3 times a day by trained study nurses, assistant nurses, and aides. Staff members' PUKAT scores increased significantly (P = .002), while their attitude scores, which were high pretest, remained unchanged. Peak interface pressures were significantly reduced (P = .016), and more preventive interventions (n = 0.012) were implemented when the staff repositioned residents after feedback from the pressure mapping system. A limited educational intervention, combined with the use of a pressure mapping system, was successful as it improved staff members' knowledge about PI prevention, reduced interface pressure, and increased PI prevention activities. As many of the staff members lacked formal education in PI prevention and management, opportunities for teaching sessions and reflection upon PI prevention should be incorporated into the workplace. More research is needed to evaluate the effect of continuous pressure mapping on the incidence of PI.

Theory and interpretation in qualitative studies from general practice: Why and how?

PubMed

Malterud, Kirsti

2016-03-01

In this article, I want to promote theoretical awareness and commitment among qualitative researchers in general practice and suggest adequate and feasible theoretical approaches. I discuss different theoretical aspects of qualitative research and present the basic foundations of the interpretative paradigm. Associations between paradigms, philosophies, methodologies and methods are examined and different strategies for theoretical commitment presented. Finally, I discuss the impact of theory for interpretation and the development of general practice knowledge. A scientific theory is a consistent and soundly based set of assumptions about a specific aspect of the world, predicting or explaining a phenomenon. Qualitative research is situated in an interpretative paradigm where notions about particular human experiences in context are recognized from different subject positions. Basic theoretical features from the philosophy of science explain why and how this is different from positivism. Reflexivity, including theoretical awareness and consistency, demonstrates interpretative assumptions, accounting for situated knowledge. Different types of theoretical commitment in qualitative analysis are presented, emphasizing substantive theories to sharpen the interpretative focus. Such approaches are clearly within reach for a general practice researcher contributing to clinical practice by doing more than summarizing what the participants talked about, without trying to become a philosopher. Qualitative studies from general practice deserve stronger theoretical awareness and commitment than what is currently established. Persistent attention to and respect for the distinctive domain of knowledge and practice where the research deliveries are targeted is necessary to choose adequate theoretical endeavours. © 2015 the Nordic Societies of Public Health.

15 CFR 930.39 - Content of a consistency determination.

Code of Federal Regulations, 2013 CFR

2013-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Consistency for Federal... include a detailed description of the activity, its associated facilities, and their coastal effects, and...

15 CFR 930.39 - Content of a consistency determination.

Code of Federal Regulations, 2012 CFR

2012-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Consistency for Federal... include a detailed description of the activity, its associated facilities, and their coastal effects, and...

15 CFR 930.39 - Content of a consistency determination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Consistency for Federal... include a detailed description of the activity, its associated facilities, and their coastal effects, and...

15 CFR 930.39 - Content of a consistency determination.

Code of Federal Regulations, 2014 CFR

2014-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Consistency for Federal... include a detailed description of the activity, its associated facilities, and their coastal effects, and...

Level crossing analysis of chemically induced dynamic nuclear polarization: Towards a common description of liquid-state and solid-state cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sosnovsky, Denis V.; Ivanov, Konstantin L., E-mail: ivanov@tomo.nsc.ru; Novosibirsk State University, Pirogova 2, 630090, Novosibirsk

Chemically Induced Dynamic Nuclear Polarization (CIDNP) is an efficient method of creating non-equilibrium polarization of nuclear spins by using chemical reactions, which have radical pairs as intermediates. The CIDNP effect originates from (i) electron spin-selective recombination of radical pairs and (ii) the dependence of the inter-system crossing rate in radical pairs on the state of magnetic nuclei. The CIDNP effect can be investigated by using Nuclear Magnetic Resonance (NMR) methods. The gain from CIDNP is then two-fold: it allows one to obtain considerable amplification of NMR signals; in addition, it provides a very useful tool for investigating elusive radicals andmore » radical pairs. While the mechanisms of the CIDNP effect in liquids are well established and understood, detailed analysis of solid-state CIDNP mechanisms still remains challenging; likewise a common theoretical frame for the description of CIDNP in both solids and liquids is missing. Difficulties in understanding the spin dynamics that lead to the CIDNP effect in the solid-state case are caused by the anisotropy of spin interactions, which increase the complexity of spin evolution. In this work, we propose to analyze CIDNP in terms of level crossing phenomena, namely, to attribute features in the CIDNP magnetic field dependence to Level Crossings (LCs) and Level Anti-Crossings (LACs) in a radical pair. This approach allows one to describe liquid-state CIDNP; the same holds for the solid-state case where anisotropic interactions play a significant role in CIDNP formation. In solids, features arise predominantly from LACs, since in most cases anisotropic couplings result in perturbations, which turn LCs into LACs. We have interpreted the CIDNP mechanisms in terms of the LC/LAC concept. This consideration allows one to find analytical expressions for a wide magnetic field range, where several different mechanisms are operative; furthermore, the LAC description gives a way to determine CIDNP sign rules. Thus, LCs/LACs provide a consistent description of CIDNP in both liquids and solids with the prospect of exploiting it for the analysis of short-lived radicals and for optimizing the polarization level.« less

Aggregate Timber Supply: From the Forest to the Market

Treesearch

David N. Wear; Subhrendu K. Pattanayak

2003-01-01

Timber supply modeling is a means of formalizing the production behavior of heterogeneous landowners managing a wide variety of forest types and vintages within a region. The critical challenge of timber supply modeling is constructing theoretically valid and empirically practical aggregate descriptions of harvest behavior. Understanding timber supply is essential for...

Acceptance and Commitment Therapy (ACT) as a Career Counselling Strategy

ERIC Educational Resources Information Center

Hoare, P. Nancey; McIlveen, Peter; Hamilton, Nadine

2012-01-01

Acceptance and commitment therapy (ACT) has potential to contribute to career counselling. In this paper, the theoretical tenets of ACT and a selection of its counselling techniques are overviewed along with a descriptive case vignette. There is limited empirical research into ACT's application in career counselling. Accordingly, a research agenda…

The Monterey Model for Micro Business Special Education

ERIC Educational Resources Information Center

Moberg, Eric M.

2009-01-01

The following program description, literature review, and theoretical bases demonstrate the andragogical soundness of the two projects and a club of the Monterey Adult Transitions Program. The Bistro Project began as a suggestion of an Associate Superintendent, who ran a similar project in the Boston area. The Greenhouse Project began as a…

Research in Foreign Language Education in Portugal (2006-2011): Its Transformative Potential

ERIC Educational Resources Information Center

Vieira, Flávia; Moreira, Maria Alfredo; Peralta, Helena

2014-01-01

This article reviews a selective corpus of empirical and theoretical texts on foreign language pedagogy and teacher education, produced in Portugal between 2006 and 2011. A descriptive and interpretative approach is adopted to inquire into the transformative potential of research, with a focus on its scope, purposes, conceptual and methodological…

Cultural Accommodation as Method and Metaphor

ERIC Educational Resources Information Center

Leong, Frederick T. L.

2007-01-01

The author summarizes the cultural accommodation model (CAM) of cross-cultural psychotherapy (F. T. L. Leong & S. H. Lee, 2006). This summary is divided into 2 parts, with the 1st part describing the theoretical development of the CAM as a method of psychotherapy and the research approach underlying it. This section includes a description of the…

Three Cases of Adolescent Childbearing Decision-Making: The Importance of Ambivalence

ERIC Educational Resources Information Center

Bender, Soley S.

2008-01-01

Limited information is available about the childbearing decision-making experience by the pregnant adolescent. The purpose of this case study was to explore this experience with three pregnant teenagers. The study is based on nine qualitative interviews. Within-case descriptions applying the theoretical model of decision-making regarding unwanted…

A Phenomenological Study on International Doctoral Students' Acculturation Experiences at a U.S. University

ERIC Educational Resources Information Center

Campbell, Throy A.

2015-01-01

A phenomenological method was used to analyze ten international doctoral students' description of their lived experiences at a United States (U.S.) university. The analysis was based on the theoretical premise of how students acculturate to their new educational settings. Three broad overlapping themes emerged: (1) participants' past experiences…

Engineman 3 & 2. Rate Training Manual and Nonresident Career Course.

ERIC Educational Resources Information Center

Thayer, C. B.; Farris, C. L.

This Navy training and self-study manual is designed to provide a basic theoretical and practical understanding of primarily diesel engines and associated equipment, the main emphasis being on shipboard types and operations. Each chapter offers verbal and pictorial description of machinery, with both schematic and equipment-specific depiction of…

The slab geometry laser. I - Theory

NASA Technical Reports Server (NTRS)

Eggleston, J. M.; Kane, T. J.; Kuhn, K.; Byer, R. L.; Unternahrer, J.

1984-01-01

Slab geometry solid-state lasers offer significant performance improvements over conventional rod-geometry lasers. A detailed theoretical description of the thermal, stress, and beam-propagation characteristics of a slab laser is presented. The analysis includes consideration of the effects of the zig-zag optical path, which eliminates thermal and stress focusing and reduces residual birefringence.

Eleventh-Grade High School Students' Accounts of Mathematical Metacognitive Knowledge: Explicitness and Systematicity

ERIC Educational Resources Information Center

van Velzen, Joke H.

2016-01-01

Theoretically, it has been argued that a conscious understanding of metacognitive knowledge requires that this knowledge is explicit and systematic. The purpose of this descriptive study was to obtain a better understanding of explicitness and systematicity in knowledge of the mathematical problem-solving process. Eighteen 11th-grade…

Oh Darn! I'd Love to Come, but I Already Have Plans: Television Invitations as Conversational Models.

ERIC Educational Resources Information Center

Salzman, Ann

1989-01-01

The degree to which television conversations follow the rules of naturally occurring conversation is investigated. The occurrences of 1 type of pragmatic behavior (the dispreferred behavior of refusing social invitations) in 25 television conversations are compared with a theoretical description of such conversational strategies. (seven…

Mathematical modeling of forest fire initiation in three dimensional setting

Treesearch

Valeriy Perminov

2007-01-01

In this study, the assignment and theoretical investigations of the problems of forest fire initiation were carried out, including development of a mathematical model for description of heat and mass transfer processes in overterrestrial layer of atmosphere at crown forest fire initiation, taking into account their mutual influence. Mathematical model of forest fire...

Barriers to College Access for Latino/a Adolescents: A Comparison of Theoretical Frameworks

ERIC Educational Resources Information Center

Gonzalez, Laura M.

2015-01-01

A comprehensive description of barriers to college access for Latino/a adolescents is an important step toward improving educational outcomes. However, relevant scholarship on barriers has not been synthesized in a way that promotes coherent formulation of intervention strategies or constructive scholarly discussion. The goal of this article is to…

Business Student Attitudes, Experience, and Satisfaction with Online Courses

ERIC Educational Resources Information Center

Kuzma, Ann; Kuzma, John; Thiewes, Harold

2015-01-01

The purpose of our study is to examine business students' perceptions of their online class experience relative to the traditional in-class experience; specifically, whether a descriptive, theoretical or analytical course would be preferred as an online or traditional course. Two hundred and ninety students enrolled in upper-level business courses…

Method for Analyzing Students' Utilization of Prior Physics Learning in New Contexts

ERIC Educational Resources Information Center

McBride, Dyan L.; Zollman, Dean; Rebello, N. Sanjay

2010-01-01

In prior research, the classification of concepts into three types--descriptive, hypothetical and theoretical--has allowed for the association of students' use of different concept types with their level of understanding. Previous studies have also examined the ways in which students link concepts to determine whether students have a meaningful…

The Ethical Behavior of Counselors: New Directions in Ethical Behavior Research.

ERIC Educational Resources Information Center

Paradise, Louis V.

The ethical behavior of counselors is an issue of current importance to those in the profession. This paper briefly examines the literature in this area. While considerable descriptive research on ethical behavior exists, the conspicuous absence of any experimental methodologies and theoretically-based investigations were noted. The need for new…

How Not to Prepare School Principals

ERIC Educational Resources Information Center

Davis, Stephen H.; Leon, Ronald J.

2011-01-01

Instead of focusing on how principals should be trained, an contrarian view is offered, grounded upon theoretical perspectives of experiential learning, and in particular, upon the theory of andragogy. A brief parable of the DoNoHarm School of Medicine is used as a descriptive analog for many principal preparation programs in America. The…

The Use of Descriptive Data from Bilingual Children to Inform Theories of Specific Language Impairment

ERIC Educational Resources Information Center

Weismer, Susan Ellis; Kaushanskaya, Margarita

2010-01-01

In her Keynote Article, Paradis reviews evidence from bilingual language development to assess the claims of two opposing theoretical views of language disorders. Specifically, she examines the evidence for similarities in language profiles of typically developing (TD) sequential bilingual (second language [L2]) children and monolingual children…

My Hero, My Friend: Exploring Honduran Youths' Lived Experience of the God-Individual Relationship

ERIC Educational Resources Information Center

Mitchell, Monique B.; Silver, Christopher F.; Ross, Christopher F. J.

2012-01-01

Extensive social science research has focused on God image and God concept through the lens of attachment theory and the parental relationship. While vast theoretical frameworks exist, the authors suggest that more focused phenomenological research would shed light on adolescent lived experience within experiential descriptive language and…

Geometric Reasoning in an Active-Engagement Upper-Division E&M Classroom

ERIC Educational Resources Information Center

Cerny, Leonard Thomas

2012-01-01

A combination of theoretical perspectives is used to create a rich description of student reasoning when facing a highly-geometric electricity and magnetism problem in an upper-division active-engagement physics classroom at Oregon State University. Geometric reasoning as students encounter problem situations ranging from familiar to novel is…

Changes in Teaching Efficacy during a Professional Development School-Based Science Methods Course

ERIC Educational Resources Information Center

Swars, Susan L.; Dooley, Caitlin McMunn

2010-01-01

This mixed methods study offers a theoretically grounded description of a field-based science methods course within a Professional Development School (PDS) model (i.e., PDS-based course). The preservice teachers' (n = 21) experiences within the PDS-based course prompted significant changes in their personal teaching efficacy, with the…

Accessing technical data bases using STDS: A collection of scenarios

NASA Technical Reports Server (NTRS)

Hardgrave, W. T.

1975-01-01

A line by line description is given of sessions using the set-theoretic data system (STDS) to interact with technical data bases. The data bases contain data from actual applications at NASA Langley Research Center. The report is meant to be a tutorial document that accompanies set processing in a network environment.

Critical Pedagogy(ies) for ELT in Indonesia

ERIC Educational Resources Information Center

Larson, Kasey R.

2014-01-01

This paper will explore the theoretical underpinnings that present a rationale for the use of critical pedagogy as an English Language Teaching (ELT) approach in Indonesia. A brief description of critical pedagogy is given, followed by a detailed rationale for its use including an overview of critical pedagogy studies done in Asia, an exploration…

Globalization and Higher Education Organizational Change: A Framework for Analysis

ERIC Educational Resources Information Center

Vaira, Massimiliano

2004-01-01

The aim of this article is to outline a theoretical framework to address Higher Education organizational change in a globalized and globalizing age. The paper will start with a brief description of trends characterizing the global landscape and their relationships with Higher Education policies and institutions. Although these trends are well…

The Syntactic Structure of K'ichee' Mayan

ERIC Educational Resources Information Center

Duncan, Lachlan

2010-01-01

Linguistic research on the Mayan languages up to the mid 1980s was almost exclusively descriptive in nature. At best, analyses were speculative and pre-theoretical. Since then, research based on contemporary theories of syntax have begun to emerge. In adopting the formal architecture of OT-LFG, I argue that my dissertation can be included amongst…

Management Ethics: Integrity at Work. Sage Series on Business Ethics.

ERIC Educational Resources Information Center

Petrick, Joseph A.; Quinn, John F.

This book tries to redefine what it means for a manager to function with integrity and competence in the private and public sectors domestically and globally. It integrates theoretical work in both descriptive and normative ethics and incorporates legal, communication, quality, and organizational theories into a conceptual framework designed to…

Promoting Community Renewal through Civic Literacy and Service Learning. New Directions for Community Colleges, Number 93.

ERIC Educational Resources Information Center

Parsons, Michael H., Ed.; Lisman, C. David, Ed.

1996-01-01

Based on the idea that community colleges have a critical role in enhancing civic literacy through community-based programming and service learning, this volume provides descriptions of theoretical frameworks and practical models for incorporating community renewal into the college mission. The following articles are provided: (1) "Service…

Sentence-Based Metadata: An Approach and Tool for Viewing Database Designs.

ERIC Educational Resources Information Center

Boyle, John M.; Gunge, Jakob; Bryden, John; Librowski, Kaz; Hanna, Hsin-Yi

2002-01-01

Describes MARS (Museum Archive Retrieval System), a research tool which enables organizations to exchange digital images and documents by means of a common thesaurus structure, and merge the descriptive data and metadata of their collections. Highlights include theoretical basis; searching the MARS database; and examples in European museums.…

Spectroscopy and Direct Products: Simpler yet Deeper

ERIC Educational Resources Information Center

Kettle, Sidney F. A.

2010-01-01

When irreducible representations are given in diagrammatic form, it is possible to show direct products pictorially. By giving a similar description of the electric vector associated with a light wave, group-theoretical selection rules (the requirement of a totally symmetric direct product) can also be shown in pictorial form. The [upsilon](CO)…

Structural Analysis of Treatment Cycles Representing Transitions between Nursing Organizational Units Inferred from Diabetes

PubMed Central

Dehmer, Matthias; Kurt, Zeyneb; Emmert-Streib, Frank; Them, Christa; Schulc, Eva; Hofer, Sabine

2015-01-01

In this paper, we investigate treatment cycles inferred from diabetes data by means of graph theory. We define the term treatment cycles graph-theoretically and perform a descriptive as well as quantitative analysis thereof. Also, we interpret our findings in terms of nursing and clinical management. PMID:26030296

Audience and Witnessing: Research into Dramatherapy using Vignettes and aMSN Messenger

ERIC Educational Resources Information Center

Jones, Phil

2008-01-01

This article describes the process of research undertaken to examine therapists' responses to the concept of the core processes of change in dramatherapy. The research uses a combination of vignette description and analysis using aMSN messenger. The article describes the theoretical underpinning and rationale to the approach, and the…

Reliability and Validity of the "Achievement Emotions Questionnaire": A Study of Argentinean University Students

ERIC Educational Resources Information Center

Paoloni, Paola Verónica; Vaja, Arabela Beatriz; Muñoz, Verónica Lilian

2014-01-01

Introduction: This paper aims at describing the psychometric features of the Achievement Emotions Questionnaire (AEQ), focusing specifically on the section that measures class emotions. From a theoretical perspective, this instrument was designed based on the control-value theory of achievement emotions. Therefore, a description of the…