WorldWideScience

Sample records for ground state theory

  1. Is the ground state of Yang-Mills theory Coulombic?

    OpenAIRE

    Heinzl, Thomas; Ilderton, Anton; Langfeld, Kurt; Lavelle, Martin; Lutz, Wolfgang; McMullan, David

    2008-01-01

    We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-abelian Coulomb fields is found to have a good overlap with the ground state for all ch...

  2. Is the ground state of Yang-Mills theory Coulombic?

    Science.gov (United States)

    Heinzl, T.; Ilderton, A.; Langfeld, K.; Lavelle, M.; Lutz, W.; McMullan, D.

    2008-08-01

    We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-Abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true ground state in the continuum limit.

  3. Multiconfiguration Pair-Density Functional Theory Outperforms Kohn-Sham Density Functional Theory and Multireference Perturbation Theory for Ground-State and Excited-State Charge Transfer.

    Science.gov (United States)

    Ghosh, Soumen; Sonnenberger, Andrew L; Hoyer, Chad E; Truhlar, Donald G; Gagliardi, Laura

    2015-08-11

    The correct description of charge transfer in ground and excited states is very important for molecular interactions, photochemistry, electrochemistry, and charge transport, but it is very challenging for Kohn-Sham (KS) density functional theory (DFT). KS-DFT exchange-correlation functionals without nonlocal exchange fail to describe both ground- and excited-state charge transfer properly. We have recently proposed a theory called multiconfiguration pair-density functional theory (MC-PDFT), which is based on a combination of multiconfiguration wave function theory with a new type of density functional called an on-top density functional. Here we have used MC-PDFT to study challenging ground- and excited-state charge-transfer processes by using on-top density functionals obtained by translating KS exchange-correlation functionals. For ground-state charge transfer, MC-PDFT performs better than either the PBE exchange-correlation functional or CASPT2 wave function theory. For excited-state charge transfer, MC-PDFT (unlike KS-DFT) shows qualitatively correct behavior at long-range with great improvement in predicted excitation energies.

  4. Theory of ground state factorization in quantum cooperative systems.

    Science.gov (United States)

    Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio

    2008-05-16

    We introduce a general analytic approach to the study of factorization points and factorized ground states in quantum cooperative systems. The method allows us to determine rigorously the existence, location, and exact form of separable ground states in a large variety of, generally nonexactly solvable, spin models belonging to different universality classes. The theory applies to translationally invariant systems, irrespective of spatial dimensionality, and for spin-spin interactions of arbitrary range.

  5. Theory of Nonlinear Dispersive Waves and Selection of the Ground State

    International Nuclear Information System (INIS)

    Soffer, A.; Weinstein, M.I.

    2005-01-01

    A theory of time-dependent nonlinear dispersive equations of the Schroedinger or Gross-Pitaevskii and Hartree type is developed. The short, intermediate and large time behavior is found, by deriving nonlinear master equations (NLME), governing the evolution of the mode powers, and by a novel multitime scale analysis of these equations. The scattering theory is developed and coherent resonance phenomena and associated lifetimes are derived. Applications include Bose-Einstein condensate large time dynamics and nonlinear optical systems. The theory reveals a nonlinear transition phenomenon, 'selection of the ground state', and NLME predicts the decay of excited state, with half its energy transferred to the ground state and half to radiation modes. Our results predict the recent experimental observations of Mandelik et al. in nonlinear optical waveguides

  6. Derivation of the RPA (Random Phase Approximation) Equation of ATDDFT (Adiabatic Time Dependent Density Functional Ground State Response Theory) from an Excited State Variational Approach Based on the Ground State Functional.

    Science.gov (United States)

    Ziegler, Tom; Krykunov, Mykhaylo; Autschbach, Jochen

    2014-09-09

    The random phase approximation (RPA) equation of adiabatic time dependent density functional ground state response theory (ATDDFT) has been used extensively in studies of excited states. It extracts information about excited states from frequency dependent ground state response properties and avoids, thus, in an elegant way, direct Kohn-Sham calculations on excited states in accordance with the status of DFT as a ground state theory. Thus, excitation energies can be found as resonance poles of frequency dependent ground state polarizability from the eigenvalues of the RPA equation. ATDDFT is approximate in that it makes use of a frequency independent energy kernel derived from the ground state functional. It is shown in this study that one can derive the RPA equation of ATDDFT from a purely variational approach in which stationary states above the ground state are located using our constricted variational DFT (CV-DFT) method and the ground state functional. Thus, locating stationary states above the ground state due to one-electron excitations with a ground state functional is completely equivalent to solving the RPA equation of TDDFT employing the same functional. The present study is an extension of a previous work in which we demonstrated the equivalence between ATDDFT and CV-DFT within the Tamm-Dancoff approximation.

  7. Adding Theoretical Grounding to Grounded Theory: Toward Multi-Grounded Theory

    OpenAIRE

    Göran Goldkuhl; Stefan Cronholm

    2010-01-01

    The purpose of this paper is to challenge some of the cornerstones of the grounded theory approach and propose an extended and alternative approach for data analysis and theory development, which the authors call multi-grounded theory (MGT). A multi-grounded theory is not only empirically grounded; it is also grounded in other ways. Three different grounding processes are acknowledged: theoretical, empirical, and internal grounding. The authors go beyond the pure inductivist approach in GT an...

  8. Ground-state densities from the Rayleigh-Ritz variation principle and from density-functional theory.

    Science.gov (United States)

    Kvaal, Simen; Helgaker, Trygve

    2015-11-14

    The relationship between the densities of ground-state wave functions (i.e., the minimizers of the Rayleigh-Ritz variation principle) and the ground-state densities in density-functional theory (i.e., the minimizers of the Hohenberg-Kohn variation principle) is studied within the framework of convex conjugation, in a generic setting covering molecular systems, solid-state systems, and more. Having introduced admissible density functionals as functionals that produce the exact ground-state energy for a given external potential by minimizing over densities in the Hohenberg-Kohn variation principle, necessary and sufficient conditions on such functionals are established to ensure that the Rayleigh-Ritz ground-state densities and the Hohenberg-Kohn ground-state densities are identical. We apply the results to molecular systems in the Born-Oppenheimer approximation. For any given potential v ∈ L(3/2)(ℝ(3)) + L(∞)(ℝ(3)), we establish a one-to-one correspondence between the mixed ground-state densities of the Rayleigh-Ritz variation principle and the mixed ground-state densities of the Hohenberg-Kohn variation principle when the Lieb density-matrix constrained-search universal density functional is taken as the admissible functional. A similar one-to-one correspondence is established between the pure ground-state densities of the Rayleigh-Ritz variation principle and the pure ground-state densities obtained using the Hohenberg-Kohn variation principle with the Levy-Lieb pure-state constrained-search functional. In other words, all physical ground-state densities (pure or mixed) are recovered with these functionals and no false densities (i.e., minimizing densities that are not physical) exist. The importance of topology (i.e., choice of Banach space of densities and potentials) is emphasized and illustrated. The relevance of these results for current-density-functional theory is examined.

  9. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  10. Cluster expansion of the wavefunction. Calculation of electron correlations in ground and excited states by SAC and SAC CI theories

    International Nuclear Information System (INIS)

    Nakatsuji, H.

    1979-01-01

    The SAC and SAC CI theories are formulated for actual calculations of singlet ground states and their excited states of arbitrary spin multiplicity. Approximations are considered for the variational methods since time-consuming terms are involved. The results of test calculations for singlet states have shown, with much smaller numbers of variables (sizes of the matrices involved), excellent agreement with the full CI and close-to-full CI results. This shows the utility of the SAC theory for ground states and especially of the SAC CI theory for excited states, since the slow convergence of the CI theory is much more critical for excited states than for ground states. (Auth.)

  11. On the ground state of Yang-Mills theory

    International Nuclear Information System (INIS)

    Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

    2011-01-01

    Highlights: → The ground state overlap for sets of meson potential trial states is measured. → Non-uniform gluonic distributions are probed via Wilson loop operator. → The locally UV-regulated flux-tube operators can optimize the ground state overlap. - Abstract: We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

  12. GROUNDED THEORY METHODOLOGY and GROUNDED THEORY RESEARCH in TURKEY

    OpenAIRE

    ARIK, Ferhat; ARIK, Işıl Avşar

    2016-01-01

    This research discusses the historical development of the Grounded Theory Methodology, which is one of the qualitative research method, its transformation over time and how it is used as a methodology in Turkey. The Grounded Theory which was founded by Strauss and Glaser, is a qualitative methodology based on inductive logic to discover theories in contrast with the deductive understanding which is based on testing an existing theory in sociology. It is possible to examine the Grounded Theory...

  13. Hartree–Fock many-body perturbation theory for nuclear ground-states

    Directory of Open Access Journals (Sweden)

    Alexander Tichai

    2016-05-01

    Full Text Available We investigate the order-by-order convergence behavior of many-body perturbation theory (MBPT as a simple and efficient tool to approximate the ground-state energy of closed-shell nuclei. To address the convergence properties directly, we explore perturbative corrections up to 30th order and highlight the role of the partitioning for convergence. The use of a simple Hartree–Fock solution for the unperturbed basis leads to a convergent MBPT series for soft interactions, in contrast to the divergent MBPT series obtained with a harmonic oscillator basis. For larger model spaces and heavier nuclei, where a direct high-order MBPT calculation is not feasible, we perform third-order calculations and compare to advanced ab initio coupled-cluster results for the same interactions and model spaces. We demonstrate that third-order MBPT provides ground-state energies for nuclei up into the tin isotopic chain in excellent agreement with the best available coupled-cluster calculations at a fraction of the computational cost.

  14. Hartree–Fock many-body perturbation theory for nuclear ground-states

    Energy Technology Data Exchange (ETDEWEB)

    Tichai, Alexander, E-mail: alexander.tichai@physik.tu-darmstadt.de [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Langhammer, Joachim [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Binder, Sven [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Roth, Robert, E-mail: robert.roth@physik.tu-darmstadt.de [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2016-05-10

    We investigate the order-by-order convergence behavior of many-body perturbation theory (MBPT) as a simple and efficient tool to approximate the ground-state energy of closed-shell nuclei. To address the convergence properties directly, we explore perturbative corrections up to 30th order and highlight the role of the partitioning for convergence. The use of a simple Hartree–Fock solution for the unperturbed basis leads to a convergent MBPT series for soft interactions, in contrast to the divergent MBPT series obtained with a harmonic oscillator basis. For larger model spaces and heavier nuclei, where a direct high-order MBPT calculation is not feasible, we perform third-order calculations and compare to advanced ab initio coupled-cluster results for the same interactions and model spaces. We demonstrate that third-order MBPT provides ground-state energies for nuclei up into the tin isotopic chain in excellent agreement with the best available coupled-cluster calculations at a fraction of the computational cost.

  15. On the ground state of Yang-Mills theory

    OpenAIRE

    Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

    2011-01-01

    We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state ...

  16. On the ground state of Yang-Mills theory

    Science.gov (United States)

    Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

    2011-08-01

    We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

  17. Accurate Ground-State Energies of Solids and Molecules from Time-Dependent Density-Functional Theory

    DEFF Research Database (Denmark)

    Olsen, Thomas; Thygesen, Kristian Sommer

    2014-01-01

    We demonstrate that ground-state energies approaching chemical accuracy can be obtained by combining the adiabatic-connection fluctuation-dissipation theorem with time-dependent densityfunctional theory. The key ingredient is a renormalization scheme, which eliminates the divergence...

  18. Rigour and grounded theory.

    Science.gov (United States)

    Cooney, Adeline

    2011-01-01

    This paper explores ways to enhance and demonstrate rigour in a grounded theory study. Grounded theory is sometimes criticised for a lack of rigour. Beck (1993) identified credibility, auditability and fittingness as the main standards of rigour for qualitative research methods. These criteria were evaluated for applicability to a Straussian grounded theory study and expanded or refocused where necessary. The author uses a Straussian grounded theory study (Cooney, In press) to examine how the revised criteria can be applied when conducting a grounded theory study. Strauss and Corbin (1998b) criteria for judging the adequacy of a grounded theory were examined in the context of the wider literature examining rigour in qualitative research studies in general and grounded theory studies in particular. A literature search for 'rigour' and 'grounded theory' was carried out to support this analysis. Criteria are suggested for enhancing and demonstrating the rigour of a Straussian grounded theory study. These include: cross-checking emerging concepts against participants' meanings, asking experts if the theory 'fit' their experiences, and recording detailed memos outlining all analytical and sampling decisions. IMPLICATIONS FOR RESEARCH PRACTICE: The criteria identified have been expressed as questions to enable novice researchers to audit the extent to which they are demonstrating rigour when writing up their studies. However, it should not be forgotten that rigour is built into the grounded theory method through the inductive-deductive cycle of theory generation. Care in applying the grounded theory methodology correctly is the single most important factor in ensuring rigour.

  19. Constructivist Grounded Theory?

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, PhD, Hon. PhD

    2012-06-01

    Full Text Available AbstractI refer to and use as scholarly inspiration Charmaz’s excellent article on constructivist grounded theory as a tool of getting to the fundamental issues on why grounded theory is not constructivist. I show that constructivist data, if it exists at all, is a very, very small part of the data that grounded theory uses.

  20. [Introduction to grounded theory].

    Science.gov (United States)

    Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

    2012-02-01

    Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

  1. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Dr. Alvita Nathaniel, DSN, APRN, BC

    2005-06-01

    Full Text Available The Grounded Theory Perspective III: Theoretical Coding, Barney G. Glaser (Sociology Press, 2005. Not intended for a beginner, this book further defi nes, describes, and explicates the classic grounded theory (GT method. Perspective III lays out various facets of theoretical coding as Glaser meticulously distinguishes classic GT from other subsequent methods. Developed many years after Glaser’s classic GT, these methods, particularly as described by Strauss and Corbin, adopt the grounded theory name and engender ongoing confusion about the very premises of grounded theory. Glaser distinguishes between classic GT and the adscititious methods in his writings, referring to remodeled grounded theory and its offshoots as Qualitative Data Analysis (QDA models.

  2. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2005-03-01

    Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

  3. Quantifying confidence in density functional theory predictions of magnetic ground states

    Science.gov (United States)

    Houchins, Gregory; Viswanathan, Venkatasubramanian

    2017-10-01

    Density functional theory (DFT) simulations, at the generalized gradient approximation (GGA) level, are being routinely used for material discovery based on high-throughput descriptor-based searches. The success of descriptor-based material design relies on eliminating bad candidates and keeping good candidates for further investigation. While DFT has been widely successfully for the former, oftentimes good candidates are lost due to the uncertainty associated with the DFT-predicted material properties. Uncertainty associated with DFT predictions has gained prominence and has led to the development of exchange correlation functionals that have built-in error estimation capability. In this work, we demonstrate the use of built-in error estimation capabilities within the BEEF-vdW exchange correlation functional for quantifying the uncertainty associated with the magnetic ground state of solids. We demonstrate this approach by calculating the uncertainty estimate for the energy difference between the different magnetic states of solids and compare them against a range of GGA exchange correlation functionals as is done in many first-principles calculations of materials. We show that this estimate reasonably bounds the range of values obtained with the different GGA functionals. The estimate is determined as a postprocessing step and thus provides a computationally robust and systematic approach to estimating uncertainty associated with predictions of magnetic ground states. We define a confidence value (c-value) that incorporates all calculated magnetic states in order to quantify the concurrence of the prediction at the GGA level and argue that predictions of magnetic ground states from GGA level DFT is incomplete without an accompanying c-value. We demonstrate the utility of this method using a case study of Li-ion and Na-ion cathode materials and the c-value metric correctly identifies that GGA-level DFT will have low predictability for NaFePO4F . Further, there

  4. Nuclear ground state

    International Nuclear Information System (INIS)

    Negele, J.W.

    1975-01-01

    The nuclear ground state is surveyed theoretically, and specific suggestions are given on how to critically test the theory experimentally. Detailed results on 208 Pb are discussed, isolating several features of the charge density distributions. Analyses of 208 Pb electron scattering and muonic data are also considered. 14 figures

  5. Grounded theory in music therapy research.

    Science.gov (United States)

    O'Callaghan, Clare

    2012-01-01

    Grounded theory is one of the most common methodologies used in constructivist (qualitative) music therapy research. Researchers use the term "grounded theory" when denoting varying research designs and theoretical outcomes. This may be challenging for novice researchers when considering whether grounded theory is appropriate for their research phenomena. This paper examines grounded theory within music therapy research. Grounded theory is briefly described, including some of its "contested" ideas. A literature search was conducted using the descriptor "music therapy and grounded theory" in Pubmed, CINAHL PsychlNFO, SCOPUS, ERIC (CSA), Web of Science databases, and a music therapy monograph series. A descriptive analysis was performed on the uncovered studies to examine researched phenomena, grounded theory methods used, and how findings were presented, Thirty music therapy research projects were found in refereed journals and monographs from 1993 to "in press." The Strauss and Corbin approach to grounded theory dominates the field. Descriptors to signify grounded theory components in the studies greatly varied. Researchers have used partial or complete grounded theory methods to examine clients', family members', staff, music therapy "overhearers," music therapists', and students' experiences, as well as music therapy creative products and professional views, issues, and literature. Seven grounded theories were offered. It is suggested that grounded theory researchers clarify what and who inspired their design, why partial grounded theory methods were used (when relevant), and their ontology. By elucidating assumptions underpinning the data collection, analysis, and findings' contribution, researchers will continue to improve music therapy research using grounded theory methods.

  6. General study of ground states in gauged N=2 supergravity theories with symmetric scalar manifolds in 5 dimensions

    International Nuclear Information System (INIS)

    Oegetbil, O.

    2007-01-01

    After reviewing the existing results we give an extensive analysis of the critical points of the potentials of the gauged N=2 Yang-Mills/Einstein supergravity theories coupled to tensor multiplets and hypermultiplets. Our analysis includes all the possible gaugings of all N=2 Maxwell-Einstein supergravity theories whose scalar manifolds are symmetric spaces. In general, the scalar potential gets contributions from R-symmetry gauging, tensor couplings, and hypercouplings. We show that the coupling of a hypermultiplet into a theory whose potential has a nonzero value at its critical point, and gauging a compact subgroup of the hyperscalar isometry group will only rescale the value of the potential at the critical point by a positive factor, and therefore will not change the nature of an existing critical point. However this is not the case for noncompact SO(1,1) gaugings. An SO(1,1) gauging of the hyperisometry will generally lead to de Sitter vacua, which is analogous to the ground states found by simultaneously gauging SO(1,1) symmetry of the real scalar manifold with U(1) R in earlier literature. SO(m,1) gaugings with m>1, which give contributions to the scalar potential only in the magical Jordan family theories, on the other hand, do not lead to de Sitter vacua. Anti-de Sitter vacua are generically obtained when the U(1) R symmetry is gauged. We also show that it is possible to embed certain generic Jordan family theories into the magical Jordan family preserving the nature of the ground states. However the magical Jordan family theories have additional ground states which are not found in the generic Jordan family theories

  7. Evaluation of upper and lower bounds to energy eigenvalues in Shoenberg's perturbation-theory ground state by means of partitioning technique

    International Nuclear Information System (INIS)

    Logrado, P.G.; Vianna, J.D.M.

    Upper and lower bounds for the energy eigenvalues is Schoenberg's perturbation-theory ground state are studied. After a review of the characteristic features of the partitioning techniques the perturbative expansion proposed by Schoenberg is generated from an exact operator equation. The upper and lower bounds for the ground state eigenvalue are derived by using reaction and wave operators concepts, the bracketing function and operator inequalities. (Author) [pt

  8. Dynasting Theory: Lessons in learning grounded theory

    Directory of Open Access Journals (Sweden)

    Johnben Teik-Cheok Loy, MBA, MTS, Ph.D.

    2011-06-01

    Full Text Available This article captures the key learning lessons gleaned from the author’s experience learning and developing a grounded theory for his doctoral dissertation using the classic methodology as conceived by Barney Glaser. The theory was developed through data gathered on founders and successors of Malaysian Chinese family-own businesses. The main concern for Malaysian Chinese family businesses emerged as dynasting . the building, maintaining, and growing the power and resources of the business within the family lineage. The core category emerged as dynasting across cultures, where founders and successors struggle to transition from traditional Chinese to hybrid cultural and modernized forms of family business from one generation to the next. The key learning lessons were categorized under five headings: (a sorting through different versions of grounded theory, (b educating and managing research stakeholders, (c embracing experiential learning, (d discovering the core category: grounded intuition, and (e recognizing limitations and possibilities.Keywords: grounded theory, learning, dynasting, family business, Chinese

  9. Scattering Properties of Ground-State 23Na Vapor Using Generalized Scattering Theory

    Science.gov (United States)

    Al-Harazneh, A. A.; Sandouqa, A. S.; Joudeh, B. R.; Ghassib, H. B.

    2018-04-01

    The scattering properties of ground-state 23Na vapor are investigated within the framework of the Galitskii-Migdal-Feynman formalism. Viewed as a generalized scattering theory, this formalism is used to calculate the medium phase shifts. The scattering properties of the system—the total, viscosity, spin-exchange, and average cross sections—are then computed using these phase shifts according to standard recipes. The total cross section is found to exhibit the Ramsauer-Townsend effect as well as resonance peaks. These peaks are caused by the large difference between the potentials for electronic spin-singlet and spin-triplet states. They represent quasi-bound states in the system. The results obtained for the complex spin-exchange cross sections are particularly highlighted because of their importance in the spectroscopy of the Na2 dimer. So are the results for the scattering lengths pertaining to both singlet and triplet states. Wherever possible, comparison is made with other published results.

  10. The Development of Constructivist Grounded Theory

    OpenAIRE

    Jane Mills; Ann Bonner; Karen Francis

    2006-01-01

    Constructivist grounded theory is a popular method for research studies primarily in the disciplines of psychology, education, and nursing. In this article, the authors aim to locate the roots of constructivist grounded theory and then trace its development. They examine key grounded theory texts to discern their ontological and epistemological orientation. They find Strauss and Corbin's texts on grounded theory to possess a discernable thread of constructivism in their approach to inquiry. T...

  11. Grounded Theory in Medical Education Research.

    Science.gov (United States)

    Tavakol, Mohsen; Torabi, Sima; Akbar Zeinaloo, Ali

    2006-12-01

    The grounded theory method provides a systematic way to generate theoretical constructs or concepts that illuminate psychosocial processes common to individual who have a similar experience of the phenomenon under investigation. There has been an increase in the number of published research reports that use the grounded theory method. However, there has been less medical education research, which is based on the grounded theory tradition. The purpose of this paper is to introduce basic tenants of qualitative research paradigm with specific reference to ground theory. The paper aims to encourage readers to think how they might possibly use the grounded theory method in medical education research and to apply such a method to their own areas of interest. The important features of a grounded theory as well as its implications for medical education research are explored. Data collection and analysis are also discussed. It seems to be reasonable to incorporate knowledge of this kind in medical education research.

  12. The electromagnetic virtual cloud of the ground-state hydrogen atom - a quantum field theory approach

    International Nuclear Information System (INIS)

    Radozycki, T.

    1990-01-01

    The properties of the virtual cloud around the hydrogen atom in the ground state are studied with the use of quantum field theory methods. The relativistic expression for the electromagnetic energy density around the atom, with the electron spin taken into account, is obtained. The distribution of the angular momentum contained in the cloud and the self-interaction kernel for the electrons bound in atom are also investigated. (author)

  13. Kohn-Sham Theory for Ground-State Ensembles

    International Nuclear Information System (INIS)

    Ullrich, C. A.; Kohn, W.

    2001-01-01

    An electron density distribution n(r) which can be represented by that of a single-determinant ground state of noninteracting electrons in an external potential v(r) is called pure-state v -representable (P-VR). Most physical electronic systems are P-VR. Systems which require a weighted sum of several such determinants to represent their density are called ensemble v -representable (E-VR). This paper develops formal Kohn-Sham equations for E-VR physical systems, using the appropriate coupling constant integration. It also derives local density- and generalized gradient approximations, and conditions and corrections specific to ensembles

  14. Navigating the grounded theory terrain. Part 1.

    Science.gov (United States)

    Hunter, Andrew; Murphy, Kathy; Grealish, Annmarie; Casey, Dympna; Keady, John

    2011-01-01

    The decision to use grounded theory is not an easy one and this article aims to illustrate and explore the methodological complexity and decision-making process. It explores the decision making of one researcher in the first two years of a grounded theory PhD study looking at the psychosocial training needs of nurses and healthcare assistants working with people with dementia in residential care. It aims to map out three different approaches to grounded theory: classic, Straussian and constructivist. In nursing research, grounded theory is often referred to but it is not always well understood. This confusion is due in part to the history of grounded theory methodology, which is one of development and divergent approaches. Common elements across grounded theory approaches are briefly outlined, along with the key differences of the divergent approaches. Methodological literature pertaining to the three chosen grounded theory approaches is considered and presented to illustrate the options and support the choice made. The process of deciding on classical grounded theory as the version best suited to this research is presented. The methodological and personal factors that directed the decision are outlined. The relative strengths of Straussian and constructivist grounded theories are reviewed. All three grounded theory approaches considered offer the researcher a structured, rigorous methodology, but researchers need to understand their choices and make those choices based on a range of methodological and personal factors. In the second article, the final methodological decision will be outlined and its research application described.

  15. Ground state hydrogen conformations and vibrational analysis of 1,2-dihdroxyanthraquinone (alizarin) molecule by AB initio Hartree-Fock and density functional theory calculations

    International Nuclear Information System (INIS)

    Delta, E.; Ucun, F.; Saglam, A.

    2010-01-01

    The ground state hydrogen conformations of 1,2-dihydroxyanthraquinone (alizarin) molecule have been investigated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-31G(d,p) basis set. The calculations indicate that the compound in the ground state exist with the doubly bonded O atom linked intra molecularly by the two hydrogen bonds. The vibrational analyses of the ground state conformation of the compound were also made and its optimized geometry parameters were given.

  16. Correlations of zero-entropy critical states in the XXZ model: integrability and Luttinger theory far from the ground state

    Directory of Open Access Journals (Sweden)

    R. Vlijm, I. S. Eliëns, J. -S. Caux

    2016-10-01

    Full Text Available Pumping a finite energy density into a quantum system typically leads to `melted' states characterized by exponentially-decaying correlations, as is the case for finite-temperature equilibrium situations. An important exception to this rule are states which, while being at high energy, maintain a low entropy. Such states can interestingly still display features of quantum criticality, especially in one dimension. Here, we consider high-energy states in anisotropic Heisenberg quantum spin chains obtained by splitting the ground state's magnon Fermi sea into separate pieces. Using methods based on integrability, we provide a detailed study of static and dynamical spin-spin correlations. These carry distinctive signatures of the Fermi sea splittings, which would be observable in eventual experimental realizations. Going further, we employ a multi-component Tomonaga-Luttinger model in order to predict the asymptotics of static correlations. For this effective field theory, we fix all universal exponents from energetics, and all non-universal correlation prefactors using finite-size scaling of matrix elements. The correlations obtained directly from integrability and those emerging from the Luttinger field theory description are shown to be in extremely good correspondence, as expected, for the large distance asymptotics, but surprisingly also for the short distance behavior. Finally, we discuss the description of dynamical correlations from a mobile impurity model, and clarify the relation of the effective field theory parameters to the Bethe Ansatz solution.

  17. Building Grounded Theory in Entrepreneurship Research

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    2007-01-01

    In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field....... The chapter has two goals. First, we wish to provide an explicit paradigmatic positioning of the grounded theory methodology, discussing the most relevant views of ontology and epistemology that can be used as alternative starting points for conducting grounded theory research. While the chapter introduces...... our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our...

  18. Essential methodological considerations when using grounded theory.

    Science.gov (United States)

    Achora, Susan; Matua, Gerald Amandu

    2016-07-01

    To suggest important methodological considerations when using grounded theory. A research method widely used in nursing research is grounded theory, at the centre of which is theory construction. However, researchers still struggle with some of its methodological issues. Although grounded theory is widely used to study and explain issues in nursing practice, many researchers are still failing to adhere to its rigorous standards. Researchers should articulate the focus of their investigations - the substantive area of interest as well as the focal population. This should be followed by a succinct explanation of the strategies used to collect and analyse data, supported by clear coding processes. Finally, the resolution of the core issues, including the core category and related categories, should be explained to advance readers' understanding. Researchers should endeavour to understand the tenets of grounded theory. This enables 'neophytes' in particular to make methodological decisions that will improve their studies' rigour and fit with grounded theory. This paper complements the current dialogue on improving the understanding of grounded theory methodology in nursing research. The paper also suggests important procedural decisions researchers need to make to preserve their studies' scientific merit and fit with grounded theory.

  19. Making sense of grounded theory in medical education.

    Science.gov (United States)

    Kennedy, Tara J T; Lingard, Lorelei A

    2006-02-01

    Grounded theory is a research methodology designed to develop, through collection and analysis of data that is primarily (but not exclusively) qualitative, a well-integrated set of concepts that provide a theoretical explanation of a social phenomenon. This paper aims to provide an introduction to key features of grounded theory methodology within the context of medical education research. In this paper we include a discussion of the origins of grounded theory, a description of key methodological processes, a comment on pitfalls encountered commonly in the application of grounded theory research, and a summary of the strengths of grounded theory methodology with illustrations from the medical education domain. The significant strengths of grounded theory that have resulted in its enduring prominence in qualitative research include its clearly articulated analytical process and its emphasis on the generation of pragmatic theory that is grounded in the data of experience. When applied properly and thoughtfully, grounded theory can address research questions of significant relevance to the domain of medical education.

  20. Grounded Theory in Medical Education Research

    OpenAIRE

    Tavakol, Mohsen; Torabi, Sima; Akbar Zeinaloo, Ali

    2009-01-01

    The grounded theory method provides a systematic way to generate theoretical constructs or concepts that illuminate psychosocial processes common to individual who have a similar expe­rience of the phenomenon under investigation. There has been an increase in the number of pub­lished research reports that use the grounded theory method. However, there has been less medical education research, which is based on the grounded theory tradition. The purpose of this paper is to introduce basic tena...

  1. Review: Günter Mey & Katja Mruck (Eds. (2007. Grounded Theory Reader

    Directory of Open Access Journals (Sweden)

    Adrian Schmidtke

    2009-07-01

    Full Text Available The volume was published to mark the 40th anniversary of the publication of "The Discovery of Grounded Theory." The first part describes the emergence and fundamental positions of grounded theory methodology (GTM in methodological and theoretical terms; the second part focuses on research practices. The "Grounded Theory Reader" is an excellent compilation that doesn’t claim to be a standard textbook for newcomers to GTM. Rather, it is a reflection of the state of the art in GTM and enables insights in complex research practices. A basic understanding of GTM is recommended in order to get the most from the book. URN: urn:nbn:de:0114-fqs0903286

  2. Puzzling the Picture Using Grounded Theory

    Science.gov (United States)

    Bennett, Elisabeth E.

    2016-01-01

    Since the first publication by Glaser and Strauss in 1967, Grounded Theory has become a highly influential research approach in the social sciences. The approach provides techniques and coding strategies for building theory inductively from the "ground up" as concepts within the data earn relevance into an evolving substantive theory.…

  3. Navigating the grounded theory terrain. Part 2.

    Science.gov (United States)

    Hunter, Andrew; Murphy, Kathy; Grealish, Annmarie; Casey, Dympna; Keady, John

    2011-01-01

    In this paper, the choice of classic grounded theory will be discussed and justified in the context of the first author's PhD research. The methodological discussion takes place within the context of PhD research entitled: Development of a stakeholder-led framework for a structured education programme that will prepare nurses and healthcare assistants to deliver a psychosocial intervention for people with dementia. There is a lack of research and limited understanding of the effect of psychosocial interventions on people with dementia. The first author thought classic grounded theory a suitable research methodology to investigate as it is held to be ideal for areas of research where there is little understanding of the social processes at work. The literature relating to the practical application of classic grounded theory is illustrated using examples relating to four key grounded theory components: Theory development: using constant comparison and memoing, Methodological rigour, Emergence of a core category, Inclusion of self and engagement with participants. Following discussion of the choice and application of classic grounded theory, this paper explores the need for researchers to visit and understand the various grounded theory options. This paper argues that researchers new to grounded theory must be familiar with and understand the various options. The researchers will then be able to apply the methodologies they choose consistently and critically. Doing so will allow them to develop theory rigorously and they will ultimately be able to better defend their final methodological destinations.

  4. Theory of singlet-ground-state magnetism. Application to field-induced transitions in CsFeCl3 and CsFeBr3

    DEFF Research Database (Denmark)

    Lindgård, P.-A.; Schmid, B.

    1993-01-01

    In the singlet ground-state systems CsFeCl3 and CsFeBr3 a large single-ion anisotropy causes a singlet ground state and a doubly degenerate doublet as the first excited states of the Fe2+ ion. In addition the magneteic interaction is anisotropic being much larger along the z axis than perpendicular...... to it. Therefore, these quasi-one-dimensional magnetic model systems are ideal to demonstrate unique correlation effects. Within the framework of the correlation theory we derive the expressions for the excitation spectrum. When a magnetic field is applied parallel to the z axis both substances have...

  5. Ground state of charged Base and Fermi fluids in strong coupling

    International Nuclear Information System (INIS)

    Mazighi, R.

    1982-03-01

    The ground state and excited states of the charged Bose gas were studied (wave function, equation of state, thermodynamics, application of Feynman theory). The ground state of the charged Fermi gas was also investigated together with the miscibility of charged Bose and Fermi gases at 0 deg K (bosons-bosons, fermions-bosons and fermions-fermions) [fr

  6. Multireference Density Functional Theory with Generalized Auxiliary Systems for Ground and Excited States.

    Science.gov (United States)

    Chen, Zehua; Zhang, Du; Jin, Ye; Yang, Yang; Su, Neil Qiang; Yang, Weitao

    2017-09-21

    To describe static correlation, we develop a new approach to density functional theory (DFT), which uses a generalized auxiliary system that is of a different symmetry, such as particle number or spin, from that of the physical system. The total energy of the physical system consists of two parts: the energy of the auxiliary system, which is determined with a chosen density functional approximation (DFA), and the excitation energy from an approximate linear response theory that restores the symmetry to that of the physical system, thus rigorously leading to a multideterminant description of the physical system. The electron density of the physical system is different from that of the auxiliary system and is uniquely determined from the functional derivative of the total energy with respect to the external potential. Our energy functional is thus an implicit functional of the physical system density, but an explicit functional of the auxiliary system density. We show that the total energy minimum and stationary states, describing the ground and excited states of the physical system, can be obtained by a self-consistent optimization with respect to the explicit variable, the generalized Kohn-Sham noninteracting density matrix. We have developed the generalized optimized effective potential method for the self-consistent optimization. Among options of the auxiliary system and the associated linear response theory, reformulated versions of the particle-particle random phase approximation (pp-RPA) and the spin-flip time-dependent density functional theory (SF-TDDFT) are selected for illustration of principle. Numerical results show that our multireference DFT successfully describes static correlation in bond dissociation and double bond rotation.

  7. Demystifying Theoretical Sampling in Grounded Theory Research

    Directory of Open Access Journals (Sweden)

    Jenna Breckenridge BSc(Hons,Ph.D.Candidate

    2009-06-01

    Full Text Available Theoretical sampling is a central tenet of classic grounded theory and is essential to the development and refinement of a theory that is ‘grounded’ in data. While many authors appear to share concurrent definitions of theoretical sampling, the ways in which the process is actually executed remain largely elusive and inconsistent. As such, employing and describing the theoretical sampling process can present a particular challenge to novice researchers embarking upon their first grounded theory study. This article has been written in response to the challenges faced by the first author whilst writing a grounded theory proposal. It is intended to clarify theoretical sampling for new grounded theory researchers, offering some insight into the practicalities of selecting and employing a theoretical sampling strategy. It demonstrates that the credibility of a theory cannot be dissociated from the process by which it has been generated and seeks to encourage and challenge researchers to approach theoretical sampling in a way that is apposite to the core principles of the classic grounded theory methodology.

  8. Navigating Grounded Theory:A critical and reflective response to the challenges of using grounded theory in an education PhD

    OpenAIRE

    Nelson, James

    2015-01-01

    This paper offers a critical reflection upon the use of a grounded theory approach within a doctoral study. As well as providing an outline of grounded theory, it begins by noting the existence of some powerful critiques of a grounded theory approach, in particular around the key concepts of ‘theory’, ‘discovery’ and ‘ground’. It is argued that, in some cases, grounded theory struggles to counter these challenges, especially in its ‘purist’ forms. However, with reference to research carried o...

  9. Doing Quantitative Grounded Theory: A theory of trapped travel consumption

    Directory of Open Access Journals (Sweden)

    Mark S. Rosenbaum, Ph.D.

    2008-11-01

    Full Text Available All is data. Grounded theorists employ this sentence in their quest to create original theoretical frameworks. Yet researchers typically interpret the word gdatah to mean qualitative data or, more specifically, interview data collected from respondents. This is not to say that qualitative data is deficient; however, grounded theorists may be missing vast opportunities to create pioneering theories from quantitative data. Indeed, Glaser and Strauss (1967 argued that researchers would use qualitative and/or quantitative data to fashion original frameworks and related hypotheses, and Glaserfs (2008 recently published book, titledDoing Quantitative Grounded Theory, is an attempt to help researchers understand how to use quantitative data for grounded theory (GT.

  10. Grounded theory methodology - has it become a movement?

    OpenAIRE

    Berterö, Carina

    2012-01-01

    There is an ongoing debate regarding the nature of grounded theory, and an examination of many studies claiming to follow grounded theory indicates a wide range of approaches. In 1967 Glaser and Strauss’s ‘‘The Discovery of Grounded Theory; Strategies for Qualitative Research’’ was published and represented a breakthrough in qualitative research; it offered methodological consensus and systematic strategies for qualitative research practice. The defining characteristics of grounded theory inc...

  11. The use of grounded theory in studies of nurses and midwives' coping processes: a systematic literature search.

    Science.gov (United States)

    Cheer, Karen; MacLaren, David; Tsey, Komla

    2015-01-01

    Researchers are increasingly using grounded theory methodologies to study the professional experience of nurses and midwives. To review common grounded theory characteristics and research design quality as described in grounded theory studies of coping strategies used by nurses and midwives. A systematic database search for 2005-2015 identified and assessed grounded theory characteristics from 16 studies. Study quality was assessed using a modified Critical Appraisal Skills Programme tool. Grounded theory was considered a methodology or a set of methods, able to be used within different nursing and midwifery contexts. Specific research requirements determined the common grounded theory characteristics used in different studies. Most researchers did not clarify their epistemological and theoretical perspectives. To improve research design and trustworthiness of grounded theory studies in nursing and midwifery, researchers need to state their theoretical stance and clearly articulate their use of grounded theory methodology and characteristics in research reporting.

  12. Grounded theory research: literature reviewing and reflexivity.

    Science.gov (United States)

    McGhee, Gerry; Marland, Glenn R; Atkinson, Jacqueline

    2007-11-01

    This paper is a report of a discussion of the arguments surrounding the role of the initial literature review in grounded theory. Researchers new to grounded theory may find themselves confused about the literature review, something we ourselves experienced, pointing to the need for clarity about use of the literature in grounded theory to help guide others about to embark on similar research journeys. The arguments for and against the use of a substantial topic-related initial literature review in a grounded theory study are discussed, giving examples from our own studies. The use of theoretically sampled literature and the necessity for reflexivity are also discussed. Reflexivity is viewed as the explicit quest to limit researcher effects on the data by awareness of self, something seen as integral both to the process of data collection and the constant comparison method essential to grounded theory. A researcher who is close to the field may already be theoretically sensitized and familiar with the literature on the study topic. Use of literature or any other preknowledge should not prevent a grounded theory arising from the inductive-deductive interplay which is at the heart of this method. Reflexivity is needed to prevent prior knowledge distorting the researcher's perceptions of the data.

  13. Current density functional theory in a continuum and lattice Lagrangians: Application to spontaneously broken chiral ground states

    International Nuclear Information System (INIS)

    Rasolt, M.; Vignale, G.

    1992-03-01

    We formulate the current-density functional theory for systems in arbitrarily strong magnetic fields. A set of self-consistent equations comparable to the Kohn-Sham equations for ordinary density functional theory is derived, and proved to be gauge-invariant and to satisfy the continuity equation. These equations of Vignale and Rasolt involve the gauge field corresponding to the external magnetic field as well as a new gauge field generated entirely from the many-body interactions. We next extend this gauge theory (following Rasolt and Vignale) to a lattice Lagrangian believed to be appropriate to a tight-binding Hamiltonian in the presence of an external magnetic field. We finally examine the nature of the ground state of a strongly nonuniform electron gas in the presence of this many-body self-induced gauge field

  14. Empirical and pragmatic adequacy of grounded theory: Advancing nurse empowerment theory for nurses' practice.

    Science.gov (United States)

    Udod, Sonia A; Racine, Louise

    2017-12-01

    To draw on the findings of a grounded theory study aimed at exploring how power is exercised in nurse-manager relationships in the hospital setting, this paper examines the empirical and pragmatic adequacy of grounded theory as a methodology to advance the concept of empowerment in the area of nursing leadership and management. The evidence on staff nurse empowerment has highlighted the magnitude of individual and organisational outcomes, but has not fully explicated the micro-level processes underlying how power is exercised, shared or created within the nurse-manager relationship. Although grounded theory is a widely adopted nursing research methodology, it remains less used in nursing leadership because of the dominance of quantitative approaches to research. Grounded theory methodology provides the empirical and pragmatic relevance to inform nursing practice and policy. Grounded theory is a relevant qualitative approach to use in leadership research as it provides a fine and detailed analysis of the process underlying complexity and bureaucracy. Discursive paper. A critical examination of the empirical and pragmatic relevance of grounded theory by (Corbin & Strauss, , ) as a method for analysing and solving problems in nurses' practice is provided. This paper provides evidence to support the empirical and pragmatic adequacy of grounded theory methodology. Although the application of the ontological, epistemological and methodological assumptions of grounded theory is challenging, this methodology is useful to address real-life problems in nursing practice by developing theoretical explanations of nurse empowerment, or lack thereof, in the workplace. Grounded theory represents a relevant methodology to inform nursing leadership research. Grounded theory is anchored in the reality of practice. The strength of grounded theory is to provide results that can be readily applied to clinical practice and policy as they arise from problems that affect practice and that

  15. Ground-state properties of exotic nuclei near Z=40 in the relativistic mean-field theory

    International Nuclear Information System (INIS)

    Lalazissis, G.A.

    1995-01-01

    Study of the ground-state properties of Kr, Sr and Zr isotopes has been performed in the framework of the relativistic mean-field (RMF) theory using the recently proposed relativistic parameter set NL-SH. It is shown that the RMF theory provides an unified and excellent description of the binding energies, isotope shifts and deformation properties of nuclei over a large range of isospin in the Z=40 region. It is observed that the RMF theory with the force NL-SH is able to describe the anomalous kinks in isotope shifts in Kr and Sr nuclei, the problem which has hitherto remained unresolved. This is in contrast with the density-dependent Skyrme-Hartree-Fock approach which does not reproduce the behaviour of the isotope shifts about shell closure. On the Zr chain we predict that the isotope shifts exhibit a trend similar to that of the Kr and Sr nuclei. The RMF theory also predicts shape coexistence in heavy Sr isotopes. Several dramatic shape transitions in the isotopic chains are shown to be a general feature of nuclei in this region. A comparison of the properties with the available mass models shows that the results of the RMF theory are generally in accord with the predictions of the finite-range droplet model. ((orig.))

  16. Examining the Nexus between Grounded Theory and Symbolic Interactionism

    Directory of Open Access Journals (Sweden)

    P. Jane Milliken RN, PhD

    2012-12-01

    Full Text Available Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interactionism to grounded theory research. In this article we discuss the symbolic interactionist concepts of mind, self, and society, and their applicability in grounded theorizing. Our purpose is to highlight foundational concepts of symbolic interactionism and their centrality in the processes of conducting grounded theory research.

  17. Review Essay: A Journey through Grounded Theory

    Directory of Open Access Journals (Sweden)

    Paula Krüger

    2007-01-01

    Full Text Available In "Constructing Grounded Theory", Kathy CHARMAZ guides the reader through the research process. Starting with a look back at the history of grounded theory, she explains how to gather rich data, code it, write memos, and compose the first draft. Through various examples from her own research CHARMAZ provides the reader not only with a theoretical description of how to construct a grounded theory but also with a way of seeing how new questions emerge from the data and new theory is built from it. She highlights central concepts, definitions, and useful questions, and offers the reader flexible guidelines to design and conduct a research project. Because of this, the book will be very useful for novices as well as for experts and (PhD- students in the late stages of their theses; it is a must-have for everyone who works with/on (constructivist grounded theory. URN: urn:nbn:de:0114-fqs0701256

  18. Supervision of Special Education Instruction in Rural Public School Districts: A Grounded Theory

    OpenAIRE

    Bays, Debora Ann

    2001-01-01

    The grounded theory presented in this study describes how the supervision of special education instruction occurs in public elementary schools in rural settings. Grounded theory methodology (Strauss & Corbin, 1998) was employed in this study. Nine elementary schools in three rural districts in the state of Virginia participated in the study. Interview data were collected from 34 participants, including special and general education teachers, principals, and directors of special education. Obs...

  19. Variational transition state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.

    1986-01-01

    This project is concerned with the development and applications of generalized transition state theory and multidimensional tunneling approximations to chemical reaction rates. They have developed and implemented several practical versions of variational transition state theory (VTST), namely canonical variational theory (CVT), improved canonical variational theory (ICVT), and microcanonical variational theory (μVT). They have also developed and implemented several accurate multidimensional semiclassical tunneling approximations, the most accurate of which are the small-curvature semiclassical adiabatic (SCSA), large-curvature version-3 (LC3), and least-action (LA) approximations. They have applied the methods to thermal rate constants, using transmission coefficients based on ground-state tunneling, and they have also presented and applied adiabatic and diabatic extensions to calculated rate constants for vibrationally excited reactants. Their general goal is to develop accurate methods for calculating chemical reaction rate constants that remain practical even for reasonably complicated molecules. The approximations mentioned above yield rate constants for systems whose potential energy surface is known or assumed. Thus a second, equally important aspect of their work is the determination or modeling, semi-empirically and/or from electronic structure calculations, of potential energy surfaces

  20. The application of grounded theory and symbolic interactionism.

    Science.gov (United States)

    Jeon, Yun-Hee

    2004-09-01

    This paper describes the methodological and theoretical context and underpinnings of a study that examined community psychiatric nurses' work with family caregivers of older people with depression. The study used grounded theory research methods, with its theoretical foundations drawn from symbolic interactionism. The aims of the study were to describe and conceptualize the processes involved when community nurses work and interact with family caregivers and to develop an explanatory theory of these processes. This paper begins with an explanation of the rationale for using grounded theory as the method of choice, followed by a discussion of the theoretical underpinnings of the study, including a brief summary of the nature and origins of symbolic interactionism. Key premises of symbolic interactionism regarded as central to the study are outlined and an analytical overview of the grounded theory method is provided. The paper concludes with a commentary on some of the issues and debates in the use of grounded theory in nursing research. The main purpose of this paper is to provide a methodical and critical review of symbolic interactionism and grounded theory that can help readers, particularly those who are intending to use grounded theory, better understand the processes involved in applying this method to their research.

  1. Ground-state energies and highest occupied eigenvalues of atoms in exchange-only density-functional theory

    Science.gov (United States)

    Li, Yan; Harbola, Manoj K.; Krieger, J. B.; Sahni, Viraht

    1989-11-01

    The exchange-correlation potential of the Kohn-Sham density-functional theory has recently been interpreted as the work required to move an electron against the electric field of its Fermi-Coulomb hole charge distribution. In this paper we present self-consistent results for ground-state total energies and highest occupied eigenvalues of closed subshell atoms as obtained by this formalism in the exchange-only approximation. The total energies, which are an upper bound, lie within 50 ppm of Hartree-Fock theory for atoms heavier than Be. The highest occupied eigenvalues, as a consequence of this interpretation, approximate well the experimental ionization potentials. In addition, the self-consistently calculated exchange potentials are very close to those of Talman and co-workers [J. D. Talman and W. F. Shadwick, Phys. Rev. A 14, 36 (1976); K. Aashamar, T. M. Luke, and J. D. Talman, At. Data Nucl. Data Tables 22, 443 (1978)].

  2. Grounded theory in medical education research: AMEE Guide No. 70.

    Science.gov (United States)

    Watling, Christopher J; Lingard, Lorelei

    2012-01-01

    Qualitative research in general and the grounded theory approach in particular, have become increasingly prominent in medical education research in recent years. In this Guide, we first provide a historical perspective on the origin and evolution of grounded theory. We then outline the principles underlying the grounded theory approach and the procedures for doing a grounded theory study, illustrating these elements with real examples. Next, we address key critiques of grounded theory, which continue to shape how the method is perceived and used. Finally, pitfalls and controversies in grounded theory research are examined to provide a balanced view of both the potential and the challenges of this approach. This Guide aims to assist researchers new to grounded theory to approach their studies in a disciplined and rigorous fashion, to challenge experienced researchers to reflect on their assumptions, and to arm readers of medical education research with an approach to critically appraising the quality of grounded theory studies.

  3. Family, state, class and solidarity: re-conceptualising intergenerational solidarity through the grounded theory approach.

    Science.gov (United States)

    Timonen, Virpi; Conlon, Catherine; Scharf, Thomas; Carney, Gemma

    2013-09-01

    The relationship between class and intergenerational solidarities in the public and private spheres calls for further conceptual and theoretical development. This article discusses the findings from the first wave of a qualitative longitudinal study entitled Changing Generations , conducted in Ireland in 2011-2012, comprising 100 in-depth interviews with men and women across the age and socioeconomic spectrums. Constructivist grounded theory analysis of the data gives rise to the following postulates: (1) intergenerational solidarity at the family level is strongly contoured by socioeconomic status (SES); (2) intergenerational solidarity evolves as family generations observe each others' practices and adjust their expectations accordingly; (3) intergenerational solidarity within families is also shaped by the public sphere (the welfare state) that generates varying expectations and levels of solidarity regarding State supports for different age groups, again largely dependent on SES; (4) the liberal welfare state context, especially at a time of economic crisis, enhances the significance of intergenerational solidarity within families. We conclude by calling for research that is attuned to age/generation, gender and class, and how these operate across the family and societal levels.

  4. Alteration of the ground state by external magnetic fields. [External field, coupling constant ratio, static tree level approximation

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, B J; Shepard, H K [New Hampshire Univ., Durham (USA). Dept. of Physics

    1976-03-22

    By fully exploiting the mathematical and physical analogy to the Ginzburg-Landau theory of superconductivity, a complete discussion of the ground state behavior of the four-dimensional Abelian Higgs model in the static tree level approximation is presented. It is shown that a sufficiently strong external magnetic field can alter the ground state of the theory by restoring a spontaneously broken symmetry, or by creating a qualitatively different 'vortex' state. The energetically favored ground state is explicitly determined as a function of the external field and the ratio between coupling constants of the theory.

  5. Grounded Theory Methodology: Positivism, Hermeneutics, and Pragmatism

    Science.gov (United States)

    Age, Lars-Johan

    2011-01-01

    Glaserian grounded theory methodology, which has been widely adopted as a scientific methodology in recent decades, has been variously characterised as "hermeneutic" and "positivist." This commentary therefore takes a different approach to characterising grounded theory by undertaking a comprehensive analysis of: (a) the philosophical paradigms of…

  6. How to Develop a Multi-Grounded Theory: the evolution of a business process theory

    Directory of Open Access Journals (Sweden)

    Mikael Lind

    2006-05-01

    Full Text Available In the information systems field there is a great need for different theories. Theory development can be performed in different ways – deductively and/or inductively. Different approaches with their pros and cons for theory development exists. A combined approach, which builds on inductive as well as deductive thinking, has been put forward – a Multi-Grounded Theory approach. In this paper the evolution of a business process theory is regarded as the development of a multi-grounded theory. This evolution is based on empirical studies, theory-informed conceptual development and the creation of conceptual cohesion. The theoretical development has involved a dialectic approach aiming at a theoretical synthesis based on antagonistic theories. The result of this research process was a multi-grounded business process theory. Multi-grounded means that the theory is empirically, internally and theoretically founded. This business process theory can be used as an aid for business modellers to direct attention towards relevant aspects when business process determination is performed.

  7. Excited-state density functional theory

    International Nuclear Information System (INIS)

    Harbola, Manoj K; Hemanadhan, M; Shamim, Md; Samal, P

    2012-01-01

    Starting with a brief introduction to excited-state density functional theory, we present our method of constructing modified local density approximated (MLDA) energy functionals for the excited states. We show that these functionals give accurate results for kinetic energy and exchange energy compared to the ground state LDA functionals. Further, with the inclusion of GGA correction, highly accurate total energies for excited states are obtained. We conclude with a brief discussion on the further direction of research that include the construction of correlation energy functional and exchange potential for excited states.

  8. Building International Business Theory: A Grounded Theory Approach

    OpenAIRE

    Gligor, David; Esmark, Carol; Golgeci, Ismail

    2016-01-01

    The field of international business (IB) is in need of more theory development (Morck & Yeung, 2007). As such, the main focus of our manuscript was to provide guidance on how to build IB specific theory using grounded theory (GT). Moreover, we contribute to future theory development by identifying areas within IB where GT can be applied and the type of research issues that can be addressed using this methodology. Finally, we make a noteworthy contribution by discussing some of GT’s caveats an...

  9. Constructing New Theory for Identifying Students with Emotional Disturbance: A Constructivist Approach to Grounded Theory

    OpenAIRE

    Dori Barnett

    2012-01-01

    A grounded theory study that examined how practitioners in a county alternative and correctional education setting identify youth with emotional and behavioral difficulties for special education services provides an exemplar for a constructivist approach to grounded theory methodology. Discussion focuses on how a constructivist orientation to grounded theory methodology informed research decisions, shaped the development of the emergent grounded theory, and prompted a way of thinking about da...

  10. Fission barriers and asymmetric ground states in the relativistic mean-field theory

    International Nuclear Information System (INIS)

    Rutz, K.; Reinhard, P.G.; Greiner, W.

    1995-01-01

    The symmetric and asymmetric fission path for 240 Pu, 232 Th and 226 Ra is investigated within the relativistic mean-field model. Standard parametrizations which are well fitted to nuclear ground-state properties are found to deliver reasonable qualitative and quantitative features of fission, comparable to similar nonrelativistic calculations. Furthermore, stable octupole deformations in the ground states of radium isotopes are investigated. They are found in a series of isotopes, qualitatively in agreement with nonrelativistic models. But the quantitative details differ amongst the models and between the various relativistic parametrizations. (orig.)

  11. Coexisting Kondo singlet state with antiferromagnetic long-range order: A possible ground state for Kondo insulators

    International Nuclear Information System (INIS)

    Zhang Guangming; Yu Lu

    2000-04-01

    The ground-state phase diagram of a half-filled anisotropic Kondo lattice model is calculated within a mean-field theory. For small transverse exchange coupling J perpendicular perpendicular c1 , the ground state shows an antiferromagnetic long-range order with finite staggered magnetizations of both localized spins and conduction electrons. When J perpendicular > J perpendicular c2 , the long-range order is destroyed and the system is in a disordered Kondo singlet state with a hybridization gap. Both ground states can describe the low-temperature phases of Kondo insulating compounds. Between these two distinct phases, there may be a coexistent regime as a result of the balance between local Kondo screening and magnetic interactions. (author)

  12. From Darwin to constructivism: the evolution of grounded theory.

    Science.gov (United States)

    Hall, Helen; Griffiths, Debra; McKenna, Lisa

    2013-01-01

    To explore the evolution of grounded theory and equip the reader with a greater understanding of the diverse conceptual positioning that is evident in the methodology. Grounded theory was developed during the modernist phase of research to develop theories that are derived from data and explain human interaction. Its philosophical foundations derive from symbolic interactionism and were influenced by a range of scholars including Charles Darwin and George Mead. Rather than a rigid set of rules and procedures, grounded theory is a way of conceptualising data. Researchers demonstrate a range of perspectives and there is significant variation in the way the methodology is interpreted and executed. Some grounded theorists continue to align closely with the original post-positivist view, while others take a more constructivist approach. Although the diverse interpretations accommodate flexibility, they may also result in confusion. The grounded theory approach enables researchers to align to their own particular world view and use methods that are flexible and practical. With an appreciation of the diverse philosophical approaches to grounded theory, researchers are enabled to use and appraise the methodology more effectively.

  13. Informed Grounded Theory

    Science.gov (United States)

    Thornberg, Robert

    2012-01-01

    There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

  14. Fast Preparation of Critical Ground States Using Superluminal Fronts

    Science.gov (United States)

    Agarwal, Kartiek; Bhatt, R. N.; Sondhi, S. L.

    2018-05-01

    We propose a spatiotemporal quench protocol that allows for the fast preparation of ground states of gapless models with Lorentz invariance. Assuming the system initially resides in the ground state of a corresponding massive model, we show that a superluminally moving "front" that locally quenches the mass, leaves behind it (in space) a state arbitrarily close to the ground state of the gapless model. Importantly, our protocol takes time O (L ) to produce the ground state of a system of size ˜Ld (d spatial dimensions), while a fully adiabatic protocol requires time ˜O (L2) to produce a state with exponential accuracy in L . The physics of the dynamical problem can be understood in terms of relativistic rarefaction of excitations generated by the mass front. We provide proof of concept by solving the proposed quench exactly for a system of free bosons in arbitrary dimensions, and for free fermions in d =1 . We discuss the role of interactions and UV effects on the free-theory idealization, before numerically illustrating the usefulness of the approach via simulations on the quantum Heisenberg spin chain.

  15. RPA ground state correlations in nuclei

    International Nuclear Information System (INIS)

    Lenske, H.

    1990-01-01

    Overcounting in the RPA theory of ground state correlations is shown to be avoided if exact rather than quasiboson commutators are used. Single particle occupation probabilities are formulated in a compact way by the RPA Green function. Calculations with large configuration spaces and realistic interactions are performed with 1p1h RPA and second RPA (SRPA) including 2p2h mixing in excited states. In 41 Ca valence hole states are found to be quenched by about 10% in RPA and up to 18% in SRPA. Contributions from low and high lying excitations and their relation to long and short range correlations in finite nuclei are investigated. (orig.)

  16. Using grounded theory to create a substantive theory of promoting schoolchildren's mental health.

    Science.gov (United States)

    Puolakka, Kristiina; Haapasalo-Pesu, Kirsi-Maria; Kiikkala, Irma; Astedt-Kurki, Päivi; Paavilainen, Eija

    2013-01-01

    To discuss the creation of a substantive theory using grounded theory. This article provides an example of generating theory from a study of mental health promotion at a high school in Finland. Grounded theory is a method for creating explanatory theory. It is a valuable tool for health professionals when studying phenomena that affect patients' health, offering a deeper understanding of nursing methods and knowledge. Interviews with school employees, students and parents, and verbal responses to the 'school wellbeing profile survey', as well as working group memos related to the development activities. Participating children were aged between 12 and 15. The analysis was conducted by applying the grounded theory method and involved open coding of the material, constant comparison, axial coding and selective coding after identifying the core category. The analysis produced concepts about mental health promotion in school and assumptions about relationships. Grounded theory proved to be an effective means of eliciting people's viewpoints on mental health promotion. The personal views of different parties make it easier to identify an action applicable to practice.

  17. Grounded theory: building a middle-range theory in nursing

    Directory of Open Access Journals (Sweden)

    Maria João Fernandes

    2015-03-01

    Full Text Available The development of nursing as a discipline results from a boom of investigations underway for nearly a century, and of the construction of theories that have arisen during the 1950’s, with greater relevance since the 1960’s. Giving continuation to the production of knowledge in nursing and seeking to contribute to the increase in the number of explanatory theories of the functional content of nurses, there is interest in answering the question: how can a middle-range theory in nursing be built that explains the nurse-elderly interaction in a successful aging process? As well, we address the goal of describing the process of building a middle-range theory in nursing. Middle-range theory refers to a qualitative paradigm study of inductive thinking, developed in the context of primary health care. The information was collected through participant observation and interviews. Method of analysis grounded theory by Corbin and Strauss(1 was followed, utilizing the triangulation of data and theoretical sampling. Grounded theory has become a method of analysis which facilitates the understanding and explanation of the phenomenon under study. By making clear the nature and process of the nurse-elderly interaction in the selected context and within the context of successful aging, a middle-range theory proposal emerged.

  18. Examining the Nexus between Grounded Theory and Symbolic Interactionism

    OpenAIRE

    P. Jane Milliken RN, PhD; Rita Schreiber RN, DNS

    2012-01-01

    Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interac...

  19. Linking Symbolic Interactionism and Grounded Theory Methods in a Research Design

    Directory of Open Access Journals (Sweden)

    Jennifer Chamberlain-Salaun

    2013-09-01

    Full Text Available This article focuses on Corbin and Strauss’ evolved version of grounded theory. In the third edition of their seminal text, Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory, the authors present 16 assumptions that underpin their conception of grounded theory methodology. The assumptions stem from a symbolic interactionism perspective of social life, including the themes of meaning, action and interaction, self and perspectives. As research design incorporates both methodology and methods, the authors aim to expose the linkages between the 16 assumptions and essential grounded theory methods, highlighting the application of the latter in light of the former. Analyzing the links between symbolic interactionism and essential grounded theory methods provides novice researchers and researchers new to grounded theory with a foundation from which to design an evolved grounded theory research study.

  20. Constructing New Theory for Identifying Students with Emotional Disturbance: A Constructivist Approach to Grounded Theory

    Directory of Open Access Journals (Sweden)

    Dori Barnett

    2012-06-01

    Full Text Available A grounded theory study that examined how practitioners in a county alternative and correctional education setting identify youth with emotional and behavioral difficulties for special education services provides an exemplar for a constructivist approach to grounded theory methodology. Discussion focuses on how a constructivist orientation to grounded theory methodology informed research decisions, shaped the development of the emergent grounded theory, and prompted a way of thinking about data collection and analysis. Implications for future research directions and policy and practice in the field of special and alternative education are discussed.

  1. Rydberg energies using excited state density functional theory

    International Nuclear Information System (INIS)

    Cheng, C.-L.; Wu Qin; Van Voorhis, Troy

    2008-01-01

    We utilize excited state density functional theory (eDFT) to study Rydberg states in atoms. We show both analytically and numerically that semilocal functionals can give quite reasonable Rydberg energies from eDFT, even in cases where time dependent density functional theory (TDDFT) fails catastrophically. We trace these findings to the fact that in eDFT the Kohn-Sham potential for each state is computed using the appropriate excited state density. Unlike the ground state potential, which typically falls off exponentially, the sequence of excited state potentials has a component that falls off polynomially with distance, leading to a Rydberg-type series. We also address the rigorous basis of eDFT for these systems. Perdew and Levy have shown using the constrained search formalism that every stationary density corresponds, in principle, to an exact stationary state of the full many-body Hamiltonian. In the present context, this means that the excited state DFT solutions are rigorous as long as they deliver the minimum noninteracting kinetic energy for the given density. We use optimized effective potential techniques to show that, in some cases, the eDFT Rydberg solutions appear to deliver the minimum kinetic energy because the associated density is not pure state v-representable. We thus find that eDFT plays a complementary role to constrained DFT: The former works only if the excited state density is not the ground state of some potential while the latter applies only when the density is a ground state density.

  2. Are There Two Methods of Grounded Theory? Demystifying the Methodological Debate

    Directory of Open Access Journals (Sweden)

    Cheri Ann Hernandez, RN, Ph.D., CDE

    2008-06-01

    Full Text Available Grounded theory is an inductive research method for the generation of substantive or formal theory, using qualitative or quantitative data generated from research interviews, observation, or written sources, or some combination thereof (Glaser & Strauss, 1967. In recent years there has been much controversy over the etiology of its discovery, as well as, the exact way in which grounded theory research is to be operationalized. Unfortunately, this situation has resulted in much confusion, particularly among novice researchers who wish to utilize this research method. In this article, the historical, methodological and philosophical roots of grounded theory are delineated in a beginning effort to demystify this methodological debate. Grounded theory variants such as feminist grounded theory (Wuest, 1995 or constructivist grounded theory (Charmaz, 1990 are beyond the scope of this discussion.

  3. Year 7 Students, Information Literacy, and Transfer: A Grounded Theory

    Science.gov (United States)

    Herring, James E.

    2011-01-01

    This study examined the views of year 7 students, teacher librarians, and teachers in three state secondary schools in rural New South Wales, Australia, on information literacy and transfer. The aims of the study included the development of a grounded theory in relation to information literacy and transfer in these schools. The study's perspective…

  4. Ground-state structures of Hafnium clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Wei Chun; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technoloty, Multimedia University, Melaca Campus, 75450 Melaka (Malaysia)

    2015-04-24

    Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.

  5. Perturbing the ground ring of 2D string theory

    International Nuclear Information System (INIS)

    Barbon, J.L.F.

    1992-01-01

    In this paper, the authors use free field techniques in D = 2 string theory t calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, the authors find that the 'ground cone' preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. The authors also quote some facts concerning the Liouville matrix a model dictionary in this class of theories

  6. Grounded theory, a kvalitatív kutatás klasszikus mérföldköve (Grounded theory, the classic milestone of qualitative research)

    OpenAIRE

    Mitev, Ariel Zoltán

    2012-01-01

    A grounded theory olyan kutatási módszer, ahol az elmélet az empirikus adatokból fejlődik ki és abban gyökerezik (Glaser - Strauss, 1967). Annak ellenére, hogy a módszer nemzetközileg rendkívül népszerű, a grounded theory nem igazán vert gyökeret a hazai menedzsment- és marketingkutatás talajában. A cikk célja a grounded theory kulcsfontosságú mozzanatainak bemutatása és a módszer népszerűsítése. / === / Grounded theory is a research method in which theory emerges from the data and is grounde...

  7. Elaborations of grounded theory in information research: arenas/social worlds theory, discourse and situational analysis

    OpenAIRE

    Vasconcelos, A.C.; Sen, B.A.; Rosa, A.; Ellis, D.

    2012-01-01

    This paper explores elaborations of Grounded Theory in relation to Arenas/Social Worlds Theory. The notions of arenas and social worlds were present in early applications of Grounded Theory but have not been as much used or recognised as the general Grounded Theory approach, particularly in the information studies field. The studies discussed here are therefore very unusual in information research. The empirical contexts of these studies are those of (1) the role of discourse in the organisat...

  8. Unambiguous assignment of the ground state of a nearly degenerate cluster

    International Nuclear Information System (INIS)

    Gutsev, G. L.; Khanna, S. N.; Jena, P.

    2000-01-01

    A synergistic approach that combines first-principles theory and electron photodetachment experiment is shown to be able to uniquely identify the ground state of a nearly degenerate cluster in the gas phase. Additionally, this approach can complement the Stern-Gerlach technique in determining the magnetic moment of small clusters unambiguously. The method, applied to a Fe 3 cluster, reveals its ground state to have a magnetic moment of 10μ B --in contrast with earlier predictions. (c) 2000 The American Physical Society

  9. A Grounded Theory of the Process of Spiritual Change Among Homicide Survivors.

    Science.gov (United States)

    Johnson, Shannon K; Zitzmann, Brooks

    2018-01-01

    Grounded theory was used to generate a mid-range theory of the process of spiritual change in the lives of survivors of homicide victims. Theoretical sampling guided the selection of 30 participants from a larger study of spiritual change after homicide ( N = 112). Individual interviews were analyzed using a four-step sequence of line-by-line, focused, axial, and selective coding. Analysis generated a closed theory consisting of three fluids, consecutive but nonlinear stages. Each stage consisted of an overarching process and a state of being in the world: (a) Disintegrating: living in a state of shock; (b) Reckoning: living in a state of stagnation; (c) Recreating and reintegrating the self: living in a state of renewal. Movement through the stages was fueled by processes of spiritual connection that yielded changes that permeated the theory. Findings can be used to help practitioners address the processes that drive spiritual change in the lives of homicide survivors.

  10. How to Develop a Multi-Grounded Theory: the evolution of a business process theory

    OpenAIRE

    Mikael Lind; Goran Goldkuhl

    2006-01-01

    In the information systems field there is a great need for different theories. Theory development can be performed in different ways – deductively and/or inductively. Different approaches with their pros and cons for theory development exists. A combined approach, which builds on inductive as well as deductive thinking, has been put forward – a Multi-Grounded Theory approach. In this paper the evolution of a business process theory is regarded as the development of a multi-grounded theory. Th...

  11. Vaccination learning experiences of nursing students: a grounded theory study.

    Science.gov (United States)

    Ildarabadi, Eshagh; Karimi Moonaghi, Hossein; Heydari, Abbas; Taghipour, Ali; Abdollahimohammad, Abdolghani

    2015-01-01

    This study aimed to explore the experiences of nursing students being trained to perform vaccinations. The grounded theory method was applied to gather information through semi-structured interviews. The participants included 14 undergraduate nursing students in their fifth and eighth semesters of study in a nursing school in Iran. The information was analyzed according to Strauss and Corbin's method of grounded theory. A core category of experiential learning was identified, and the following eight subcategories were extracted: students' enthusiasm, vaccination sensitivity, stress, proper educational environment, absence of prerequisites, students' responsibility for learning, providing services, and learning outcomes. The vaccination training of nursing students was found to be in an acceptable state. However, some barriers to effective learning were identified. As such, the results of this study may provide empirical support for attempts to reform vaccination education by removing these barriers.

  12. Reflecting on the challenges of choosing and using a grounded theory approach.

    Science.gov (United States)

    Markey, Kathleen; Tilki, Mary; Taylor, Georgina

    2014-11-01

    To explore three different approaches to grounded theory and consider some of the possible philosophical assumptions underpinning them. Grounded theory is a comprehensive yet complex methodology that offers a procedural structure that guides the researcher. However, divergent approaches to grounded theory present dilemmas for novice researchers seeking to choose a suitable research method. This is a methodology paper. This is a reflexive paper that explores some of the challenges experienced by a PhD student when choosing and operationalising a grounded theory approach. Before embarking on a study, novice grounded theory researchers should examine their research beliefs to assist them in selecting the most suitable approach. This requires an insight into the approaches' philosophical assumptions, such as those pertaining to ontology and epistemology. Researchers need to be clear about the philosophical assumptions underpinning their studies and the effects that different approaches will have on the research results. This paper presents a personal account of the journey of a novice grounded theory researcher who chose a grounded theory approach and worked within its theoretical parameters. Novice grounded theory researchers need to understand the different philosophical assumptions that influence the various grounded theory approaches, before choosing one particular approach.

  13. A Grounded Theory Study on Journeying through the Shield to Sacredness: "Ni'hokaa' Diyin Dine'e Idliini Dolzin"

    Science.gov (United States)

    Garrity, Geraldine

    2013-01-01

    In doing a grounded theory study, the researcher does not identify a hypothesis, formulate research questions, or state a specific problem at the beginning of the research. Grounded theory research begins with data collection, minimizing preconceptions about outcomes to the greatest extent possible. I began my research with this attitude of not…

  14. Perturbing the ground ring of 2D string theory

    CERN Document Server

    Barbón, José L F

    1992-01-01

    We use free field techniques in D=2 string theory to calculate the perturbation of the special state algebras when the cosmologi- cal constant is turned on. In particular, we find that the "ground cone" preserved by the ring structure is promoted to a three dimen- sional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) a three dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical inter- pretation is found. We also quote some facts concerning the Liouville/matrix model dictio- nary in this class of theories.

  15. Constructing a Grounded Theory of E-Learning Assessment

    Science.gov (United States)

    Alonso-Díaz, Laura; Yuste-Tosina, Rocío

    2015-01-01

    This study traces the development of a grounded theory of assessment in e-learning environments, a field in need of research to establish the parameters of an assessment that is both reliable and worthy of higher learning accreditation. Using grounded theory as a research method, we studied an e-assessment model that does not require physical…

  16. Safranin-O dye in the ground state. A study by density functional theory, Raman, SERS and infrared spectroscopy

    Science.gov (United States)

    Lofrumento, C.; Arci, F.; Carlesi, S.; Ricci, M.; Castellucci, E.; Becucci, M.

    2015-02-01

    The analysis of ground state structural and vibrational properties of Safranin-O is presented. The experimental results, obtained by FTIR, Raman and SERS spectroscopy, are discussed in comparison to the results of DFT calculations carried out at the B3LYP/6-311 + G(d,p) level of theory. The calculated spectra reproduce quite satisfactorily the experimental data. The calculated Safranin-O equilibrium structure and the assignment of the vibrational spectra are reported as well. From the changes between Raman and SERS spectra a model is presented for the interaction of Safranin-O with silver nanoparticles.

  17. Ground state energies from converging and diverging power series expansions

    International Nuclear Information System (INIS)

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E.; Su, Q.; Grobe, R.

    2016-01-01

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh–Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state’s spatial extension is comparable to L. Once the binding strength is so strong that the ground state’s extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  18. Ground state energies from converging and diverging power series expansions

    Energy Technology Data Exchange (ETDEWEB)

    Lisowski, C.; Norris, S.; Pelphrey, R.; Stefanovich, E., E-mail: eugene-stefanovich@usa.net; Su, Q.; Grobe, R.

    2016-10-15

    It is often assumed that bound states of quantum mechanical systems are intrinsically non-perturbative in nature and therefore any power series expansion methods should be inapplicable to predict the energies for attractive potentials. However, if the spatial domain of the Schrödinger Hamiltonian for attractive one-dimensional potentials is confined to a finite length L, the usual Rayleigh–Schrödinger perturbation theory can converge rapidly and is perfectly accurate in the weak-binding region where the ground state’s spatial extension is comparable to L. Once the binding strength is so strong that the ground state’s extension is less than L, the power expansion becomes divergent, consistent with the expectation that bound states are non-perturbative. However, we propose a new truncated Borel-like summation technique that can recover the bound state energy from the diverging sum. We also show that perturbation theory becomes divergent in the vicinity of an avoided-level crossing. Here the same numerical summation technique can be applied to reproduce the energies from the diverging perturbative sums.

  19. Straussian Grounded-Theory Method: An Illustration

    Science.gov (United States)

    Thai, Mai Thi Thanh; Chong, Li Choy; Agrawal, Narendra M.

    2012-01-01

    This paper demonstrates the benefits and application of Straussian Grounded Theory method in conducting research in complex settings where parameters are poorly defined. It provides a detailed illustration on how this method can be used to build an internationalization theory. To be specific, this paper exposes readers to the behind-the-scene work…

  20. Management Research and Grounded Theory: A review of grounded theorybuilding approach in organisational and management research.

    Directory of Open Access Journals (Sweden)

    Graham J.J. Kenealy, Ph.D.

    2008-06-01

    Full Text Available Grounded theory is a systematic methodology for the collection and analysis of data which was discovered by Glaser and Strauss in the 1960’s. The discovery of this method was first presented to the academic community in their book ‘The Discovery of Grounded Theory’ (1967 which still remains a primary point of reference for those undertaking qualitative research and grounded theory in particular. This powerful research method has become very popular in some research domains; whilst increasing in popularity it is still less prevalent in the field of organisational and management research particularly in its original form. This self reflexive paper sets out to explore the possibilities for this imbalance which takes the discussion onto the areas of methodological adaptation and training. It also enters the debate about access to research subjects and provides a succinct argument supporting the notion that grounded theory should simply be viewed as a method that develops empirically grounded conceptual theory.

  1. Search for C+ C clustering in Mg ground state

    Indian Academy of Sciences (India)

    2017-01-04

    Jan 4, 2017 ... Finite-range knockout theory predictions were much larger for (12C,212C) reaction, indicating a very small 12C−12C clustering in 24Mg. (g.s.) . Our present results contradict most of the proposed heavy cluster (12C+12C) structure models for the ground state of 24Mg. Keywords. Direct nuclear reactions ...

  2. Celebrating 50 Years of Grounded Theory: Onward and Forward Editorial

    OpenAIRE

    Astrid Gynnild

    2017-01-01

    Welcome to this very special issue of the Grounded Theory Review. In this issue we celebrate 50 amazing years of grounded theory during which it has become one of the fastest growing methods in the global research world. Five decades after The Discovery of Grounded Theory was first published, the seminal work of founders Barney G. Glaser and Anselm Strauss is cited more than 94,000 times on Google Scholar alone. We celebrate that after 50 years of researching, teaching, defending, explic...

  3. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    Science.gov (United States)

    Borges, L. H. C.; Barone, F. A.

    2016-02-01

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schrödinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector.

  4. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    Energy Technology Data Exchange (ETDEWEB)

    Borges, L.H.C. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil); Barone, F.A. [IFQ-Universidade Federal de Itajuba, Itajuba, MG (Brazil)

    2016-02-15

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schroedinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector. (orig.)

  5. Traces of Lorentz symmetry breaking in a hydrogen atom at ground state

    International Nuclear Information System (INIS)

    Borges, L.H.C.; Barone, F.A.

    2016-01-01

    Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the hydrogen atom are investigated. We use standard Rayleigh-Schroedinger perturbation theory in order to obtain the corrections to the ground state energy and the wave function. It is shown that an induced four-pole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in Borges et al. (Eur Phys J C 74:2937, 2014), where the Lorentz symmetry is broken in the electromagnetic sector. (orig.)

  6. Linking Symbolic Interactionism and Grounded Theory Methods in a Research Design

    OpenAIRE

    Jennifer Chamberlain-Salaun; Jane Mills; Kim Usher

    2013-01-01

    This article focuses on Corbin and Strauss’ evolved version of grounded theory. In the third edition of their seminal text, Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory, the authors present 16 assumptions that underpin their conception of grounded theory methodology. The assumptions stem from a symbolic interactionism perspective of social life, including the themes of meanin...

  7. Graphene ground states

    Science.gov (United States)

    Friedrich, Manuel; Stefanelli, Ulisse

    2018-06-01

    Graphene is locally two-dimensional but not flat. Nanoscale ripples appear in suspended samples and rolling up often occurs when boundaries are not fixed. We address this variety of graphene geometries by classifying all ground-state deformations of the hexagonal lattice with respect to configurational energies including two- and three-body terms. As a consequence, we prove that all ground-state deformations are either periodic in one direction, as in the case of ripples, or rolled up, as in the case of nanotubes.

  8. Making Sense of Grounded Theory Approach: Implications for Medial Education Research

    OpenAIRE

    Mohsen Tavokol; S Torabi; AA Zeialoo

    2009-01-01

    This article first gives a definition of grounded theory and its development and use in medicine and medical education. The fundamental differences of grounded theory with quantitative methods are discussed along a full discussion of the steps required to use a grounded theory approach. At the end the questions in the area of medical education which can best addressed with this approach are provided. 

  9. "Naturalist Inquiry" and Grounded Theory

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser

    2004-01-01

    Full Text Available The world of Qualitative Data Analysis (QDA methodology became quite taken with LINCOLN and GUBA's book "Naturalist Inquiry" (1985. I have no issue with it with respect to its application to QDA; it helped clarify and advance so many QDA issues. However, its application to Grounded Theory (GT has been a major block on GT, as originated, by its cooptation and corruption hence remodeling of GT by default. LINCOLN and GUBA have simply assumed GT is just another QDA method, which it is not. In "The Grounded Theory Perspective II" (GLASER 2002a, Chapter 9 on credibility, I have discussed "Naturalist In­quiry" (NI thought regarding how LINCOLN and GUBA's notion of "trustworthy" data (or worrisome data orientation and how their view of constant comparison can and has remodeled and eroded GT. In this paper I will consider other aspects of NI that remodel GT. URN: urn:nbn:de:0114-fqs040170

  10. Challenges in combining different data sets during analysis when using grounded theory.

    Science.gov (United States)

    Rintala, Tuula-Maria; Paavilainen, Eija; Astedt-Kurki, Päivi

    2014-05-01

    To describe the challenges in combining two data sets during grounded theory analysis. The use of grounded theory in nursing research is common. It is a suitable method for studying human action and interaction. It is recommended that many alternative sources of data are collected to create as rich a dataset as possible. Data from interviews with people with diabetes (n=19) and their family members (n=19). Combining two data sets. When using grounded theory, there are numerous challenges in collecting and managing data, especially for the novice researcher. One challenge is to combine different data sets during the analysis. There are many methodological textbooks about grounded theory but there is little written in the literature about combining different data sets. Discussion is needed on the management of data and the challenges of grounded theory. This article provides a means for combining different data sets in the grounded theory analysis process.

  11. Indolo[2,3-b]carbazoles with tunable ground states: How Clar's aromatic sextet determines the singlet biradical character

    KAUST Repository

    Luo, Ding; Lee, Sangsu; Zheng, Bin; Sun, Zhe; Zeng, Wangdong; Huang, Kuo-Wei; Furukawa, Ko; Kim, Dongho; Webster, Richard D.; Wu, Jishan

    2014-01-01

    and showed different ground states. Based on variable-temperature NMR/ESR measurements and density functional theory calculations, it was found that the indolo[2,3-b]carbazole derivative 1 is a persistent singlet biradical in the ground state with a moderate

  12. Cluster expansion for ground states of local Hamiltonians

    Directory of Open Access Journals (Sweden)

    Alvise Bastianello

    2016-08-01

    Full Text Available A central problem in many-body quantum physics is the determination of the ground state of a thermodynamically large physical system. We construct a cluster expansion for ground states of local Hamiltonians, which naturally incorporates physical requirements inherited by locality as conditions on its cluster amplitudes. Applying a diagrammatic technique we derive the relation of these amplitudes to thermodynamic quantities and local observables. Moreover we derive a set of functional equations that determine the cluster amplitudes for a general Hamiltonian, verify the consistency with perturbation theory and discuss non-perturbative approaches. Lastly we verify the persistence of locality features of the cluster expansion under unitary evolution with a local Hamiltonian and provide applications to out-of-equilibrium problems: a simplified proof of equilibration to the GGE and a cumulant expansion for the statistics of work, for an interacting-to-free quantum quench.

  13. Making Sense of Grounded Theory Approach: Implications for Medial Education Research

    Directory of Open Access Journals (Sweden)

    Mohsen Tavokol

    2009-02-01

    Full Text Available This article first gives a definition of grounded theory and its development and use in medicine and medical education. The fundamental differences of grounded theory with quantitative methods are discussed along a full discussion of the steps required to use a grounded theory approach. At the end the questions in the area of medical education which can best addressed with this approach are provided. 

  14. Ground states of a spin-boson model

    International Nuclear Information System (INIS)

    Amann, A.

    1991-01-01

    Phase transition with respect to ground states of a spin-boson Hamiltonian are investigated. The spin-boson model under discussion consists of one spin and infinitely many bosons with a dipole-type coupling. It is shown that the order parameter of the model vanishes with respect to arbitrary ground states if it vanishes with respect to ground states obtained as (biased) temperature to zero limits of thermic equilibrium states. The ground states of the latter special type have been investigated by H. Spohn. Spohn's respective phase diagrams are therefore valid for arbitrary ground states. Furthermore, disjointness of ground states in the broken symmetry regime is examined

  15. Qualitative research in healthcare: an introduction to grounded theory using thematic analysis.

    Science.gov (United States)

    Chapman, A L; Hadfield, M; Chapman, C J

    2015-01-01

    In today's NHS, qualitative research is increasingly important as a method of assessing and improving quality of care. Grounded theory has developed as an analytical approach to qualitative data over the last 40 years. It is primarily an inductive process whereby theoretical insights are generated from data, in contrast to deductive research where theoretical hypotheses are tested via data collection. Grounded theory has been one of the main contributors to the acceptance of qualitative methods in a wide range of applied social sciences. The influence of grounded theory as an approach is, in part, based on its provision of an explicit framework for analysis and theory generation. Furthermore the stress upon grounding research in the reality of participants has also given it credence in healthcare research. As with all analytical approaches, grounded theory has drawbacks and limitations. It is important to have an understanding of these in order to assess the applicability of this approach to healthcare research. In this review we outline the principles of grounded theory, and focus on thematic analysis as the analytical approach used most frequently in grounded theory studies, with the aim of providing clinicians with the skills to critically review studies using this methodology.

  16. Triplet and ground state potential energy surfaces of 1,4-diphenyl-1,3-butadiene: theory and experiment.

    Science.gov (United States)

    Saltiel, J; Dmitrenko, O; Pillai, Z S; Klima, R; Wang, S; Wharton, T; Huang, Z-N; van de Burgt, L J; Arranz, J

    2008-05-01

    Relative energies of the ground state isomers of 1,4-diphenyl-1,3-butadiene (DPB) are determined from the temperature dependence of equilibrium isomer compositions obtained with the use of diphenyl diselenide as catalyst. Temperature and concentration effects on photostationary states and isomerization quantum yields with biacetyl or fluorenone as triplet sensitizers with or without the presence of O(2), lead to significant modification of the proposed DPB triplet potential energy surface. Quantum yields for ct-DPB formation from tt-DPB increase with [tt-DPB] revealing a quantum chain process in the tt --> ct direction, as had been observed for the ct --> tt direction, and suggesting an energy minimum at the (3)ct* geometry. They confirm the presence of planar and twisted isomeric triplets in equilibrium (K), with energy transfer from planar or quasi-planar geometries (quantum chain events from tt and ct triplets) and unimolecular decay (k(d)) from twisted geometries. Starting from cc-DPB, varphi(cc-->tt) increases with increasing [cc-DPB] whereas varphi(cc-->ct) is relatively insensitive to concentration changes. The concentration and temperature dependencies of the decay rate constants of DPB triplets in cyclohexane are consistent with the mechanism deduced from the photoisomerization quantum yields. The experimental DeltaH between (3)tt-DPB* and (3)tp-DPB*, 2.7 kcal mol(-1), is compared with the calculated energy difference [DFT with B3LYP/6-31+G(d,p) basis set]. Use of the calculated DeltaS = 4.04 eu between the two triplets gives k(d) = (2.4-6.4) x 10(7) s(-1), close to 1.70 x 10(7) s(-1), the value for twisted stilbene triplet decay. Experimental and calculated relative energies of DPB isomers on the ground and triplet state surfaces agree and theory is relied upon to deduce structural characteristics of the equilibrated conformers in the DPB triplet state.

  17. Midwifery students learning experiences in labor wards: a grounded theory.

    Science.gov (United States)

    Brunstad, Anne; Hjälmhult, Esther

    2014-12-01

    The labor ward is an important and challenging learning area for midwifery students. It is there the students learn in authentic complex situations, in intimate situations, with potential risk for the life and health of mothers and their babies. The aim of this study was to explore the main concern expressed by midwifery students in labor wards and how they handled this concern. A longitudinal study based on grounded theory methodology was used. The participants were 10 postgraduate midwifery students, from a University College in Norway. Data were gathered and analyzed throughout the 2-year postgraduate program, in the students first, third and fourth semesters. Every student was interviewed three times in a total of 15 single and three focus-group sessions. The grounded theory of "building relationships" explains how students dealt with their main concern: "how to gain access to learning experiences". This theory consisted of three strategies; a) controlling vulnerability, b) cultivating trust and c) obtaining acceptance. Clarifying discussions involving midwives and students may facilitate the process of building relationships and contribute to confident learning. Students appreciate it when the midwives initiate discussions about acute situations and state that a novice may perceive labor and childbirth as more frightening than an experienced midwife would. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. The First-Year University Experience for Sexual Minority Students: A Grounded Theory Exploration

    Science.gov (United States)

    Alessi, Edward J.; Sapiro, Beth; Kahn, Sarilee; Craig, Shelley L.

    2017-01-01

    This exploratory study used grounded theory to understand the role of minority stress on the first-year experience of lesbian, gay, bisexual, queer, and questioning emerging adults attending a university in the Northeastern part of the United States. Twenty-one lesbian, gay, bisexual, queer, and questioning sophomores participated in focus groups…

  19. Classroom research in religious education: The potential of grounded theory

    OpenAIRE

    Rothgangel, Martin; Saup, Judith

    2017-01-01

    Grounded theory is one of the most common qualitative research strategies in social sciences. Currently, many applications of this theory are being developed for religious education. In the article it is argued that grounded theory deserves special attention for classroom research in religious education. For this reason, the basic features (fundamental openness and concurrence of data collection and analysis; constant comparison and asking analytical questions) as well as the coding strategie...

  20. Using extant literature in a grounded theory study: a personal account.

    Science.gov (United States)

    Yarwood-Ross, Lee; Jack, Kirsten

    2015-03-01

    To provide a personal account of the factors in a doctoral study that led to the adoption of classic grounded theory principles relating to the use of literature. Novice researchers considering grounded theory methodology will become aware of the contentious issue of how and when extant literature should be incorporated into a study. The three main grounded theory approaches are classic, Straussian and constructivist, and the seminal texts provide conflicting beliefs surrounding the use of literature. A classic approach avoids a pre-study literature review to minimise preconceptions and emphasises the constant comparison method, while the Straussian and constructivist approaches focus more on the beneficial aspects of an initial literature review and researcher reflexivity. The debate also extends into the wider academic community, where no consensus exists. This is a methodological paper detailing the authors' engagement in the debate surrounding the role of the literature in a grounded theory study. In the authors' experience, researchers can best understand the use of literature in grounded theory through immersion in the seminal texts, engaging with wider academic literature, and examining their preconceptions of the substantive area. The authors concluded that classic grounded theory principles were appropriate in the context of their doctoral study. Novice researchers will have their own sets of circumstances when preparing their studies and should become aware of the different perspectives to make decisions that they can ultimately justify. This paper can be used by other novice researchers as an example of the decision-making process that led to delaying a pre-study literature review and identifies the resources used to write a research proposal when using a classic grounded theory approach.

  1. On the ground state of the two-dimensional non-ideal Bose gas

    International Nuclear Information System (INIS)

    Lozovik, Yu.E.; Yudson, V.I.

    1978-01-01

    The theory of the ground state of the two-dimensional non-ideal Bose gas is presented. The conditions for the validity of the ladder and the Bogolubov approximations are derived. These conditions ensure the existence of a Bose condensate in the ground state of two-dimensional systems. These conditions are different from the corresponding conditions for the three-dimensional case. The connection between the effective interaction and the two-dimensional scattering amplitude at some characteristic energy kappa 2 /2m (not equal to 0) is obtained (f(kappa = 0) = infinity in the two-dimensional case). (Auth.)

  2. A Leadership Identity Development Model: Applications from a Grounded Theory

    Science.gov (United States)

    Komives, Susan R.; Mainella, Felicia C.; Longerbeam, Susan D.; Osteen, Laura; Owen, Julie E.

    2006-01-01

    This article describes a stage-based model of leadership identity development (LID) that resulted from a grounded theory study on developing a leadership identity (Komives, Owen, Longerbeam, Mainella, & Osteen, 2005). The LID model expands on the leadership identity stages, integrates the categories of the grounded theory into the LID model, and…

  3. The grounded theory of "trust building".

    Science.gov (United States)

    Ramezani, Monir; Ahmadi, Fazlollah; Mohammadi, Eesa; Kazemnejad, Anoshirvan

    2017-01-01

    Despite the growing importance of spiritual care, the delivery of spiritual care is still an area of disagreement among healthcare providers. To develop a grounded theory about spiritual care delivery based on Iranian nurses' perceptions and experiences. A grounded theory approach: A qualitative study using the grounded theory approach. Participants and research context: Data were collected through holding 27 interviews with 25 participants (17 staff nurses, 3 physicians, 3 patients, 1 family member, and 1 nurse assistant). The study setting was the Imam Khomeini Hospital Complex. Sampling was started purposively and continued theoretically. Data analysis was performed by the method proposed by Strauss and Corbin. Ethical consideration: The study was approved by the Ethics Committee of Tarbiat Modares University and the agreement of the administrators of the study setting was got before starting the study. The core category of the study was "Trust building" which reflected the nature of spiritual care delivery by nurses. Trust building was the result of eight main categories or strategies including creating a positive mentality at hospital admission, understanding patients in care circumstances, having a caring presence, adhering to care ethics, developing meaningful relationships, promoting positive thinking and energy, establishing effective communication with patients, and attempting to create a safe therapeutic environment. Poor interprofessional coordination negatively affected this process while living toward developing greater cognizance of divinity and adhering to the principles of professional ethics facilitated it. The outcome of the process was to gain a sense of partial psychological security. The "Trust building" theory can be used as a guide for describing and expanding nurses' roles in spiritual care delivery, developing care documentation systems and clinical guidelines, and planning educational programs for nursing students and staff nurses.

  4. Using grounded theory as a method for rigorously reviewing literature

    NARCIS (Netherlands)

    Wolfswinkel, J.; Furtmueller-Ettinger, Elfriede; Wilderom, Celeste P.M.

    2013-01-01

    This paper offers guidance to conducting a rigorous literature review. We present this in the form of a five-stage process in which we use Grounded Theory as a method. We first probe the guidelines explicated by Webster and Watson, and then we show the added value of Grounded Theory for rigorously

  5. Ground-State Structures of Ice at High-Pressures

    OpenAIRE

    McMahon, Jeffrey M.

    2011-01-01

    \\textit{Ab initio} random structure searching based on density functional theory is used to determine the ground-state structures of ice at high pressures. Including estimates of lattice zero-point energies, ice is found to adopt three novel crystal phases. The underlying sub-lattice of O atoms remains similar among them, and the transitions can be characterized by reorganizations of the hydrogen bonds. The symmetric hydrogen bonds of ice X and $Pbcm$ are initially lost as ice transforms to s...

  6. The significant role of covalency in determining the ground state of cobalt phthalocyanines molecule

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2016-03-01

    Full Text Available To shed some light on the metal 3d ground state configuration of cobalt phthalocyanines system, so far in debate, we present an investigation by X-ray absorption spectroscopy (XAS at Co L2,3 edge and theoretical calculation. The density functional theory calculations reveal highly anisotropic covalent bond between central cobalt ion and nitrogen ligands, with the dominant σ donor accompanied by weak π-back acceptor interaction. Our combined experimental and theoretical study on the Co-L2,3 XAS spectra demonstrate a robust ground state of 2A1g symmetry that is built from 73% 3d7 character and 27% 3 d 8 L ¯ ( L ¯ denotes a ligand hole components, as the first excited-state with 2Eg symmetry lies about 158 meV higher in energy. The effect of anisotropic and isotropic covalency on the ground state was also calculated and the results indicate that the ground state with 2A1g symmetry is robust in a large range of anisotropic covalent strength while a transition of ground state from 2A1g to 2Eg configuration when isotropic covalent strength increases to a certain extent. Here, we address a significant anisotropic covalent effect of short Co(II-N bond on the ground state and suggest that it should be taken into account in determining the ground state of analogous cobalt complexes.

  7. The ground state hydrogen conformations and vibrational analysis of 2-, 3-, 4- and 5- dihydroxybenzaldehyde: A DFT study

    International Nuclear Information System (INIS)

    Cirak, C.; Saglam, A.; Ucun, F.

    2010-01-01

    The ground state hydrogen conformations of 2-, 3-, 4- and 5-dihydroxybenzaldehyde have been investigated using density functional theory (B3LYP) methods with 6-31G (d,p) basis set. The calculations have indicated that the compounds in the ground state exist with the carbonyl group O atom linked intra molecularly by the two hydrogen bonds of the two hydroxyl groups. The vibrational analyses of the ground state conformers of all the compounds were done and their optimized geometry parameters were given.

  8. Kleinian singularities and the ground ring of c=1 string theory

    International Nuclear Information System (INIS)

    Ghoshal, D.; Jatkar, D.P.; Mukhi, S.

    1993-01-01

    We investigate the nature of the ground ring of c=1 string theory at the special ADE points in the c=1 moduli space associated to discrete subgroups of SU(2). The chiral ground rings at these points are shown to define the ADE series of singular varieties introduced by Klein. The non-chiral ground rings relevant to closed-string theory are 3 real dimensional singular varieties obtained as U(1) quotients of the kleinian varieties. The unbroken symmetries of the theory at these points are the volume-preserving diffeomorphisms of these varieties. The theory of kleinian singularities has a close relation to that of complex hyperKaehler surfaces, or gravitational instantons. We speculate on the relevance of these instantons and of self-dual gravity in c=1 string theory. (orig.)

  9. Developing a Guideline for Reporting and Evaluating Grounded Theory Research Studies (GUREGT)

    DEFF Research Database (Denmark)

    Berthelsen, Connie Bøttcher; Grimshaw-Aagaard, Søsserr Lone Smilla; Hansen, Carrinna

    2018-01-01

    theory research studies. The study was conducted in three phases. Phase 1: A structured literature review in PubMed, CINAHL, Cochrane Libraries, PsycInfo and SCOPUS to identify recommendations for reporting and evaluating grounded theory. Phase 2: A selective review of the methodological grounded theory...

  10. 2D XXZ model ground state properties using an analytic Lanczos expansion

    International Nuclear Information System (INIS)

    Witte, N.S.; Hollenberg, L.C.L.; Weihong Zheng

    1997-01-01

    A formalism was developed for calculating arbitrary expectation values for any extensive lattice Hamiltonian system using a new analytic Lanczos expansion, or plaquette expansion, and a recently proved exact theorem for ground state energies. The ground state energy, staggered magnetisation and the excited state gap of the 2D anisotropic antiferromagnetic Heisenberg Model are then calculated using this expansion for a range of anisotropy parameters and compared to other moment based techniques, such as the t-expansion, and spin-wave theory and series expansion methods. It was found that far from the isotropic point all moment methods give essentially very similar results, but near the isotopic point the plaquette expansion is generally better than the others. 20 refs., 6 tabs

  11. Force-balance and differential equation for the ground-state electron density in atoms and molecules

    International Nuclear Information System (INIS)

    Amovilli, C.; March, N.H.; Gal, T.; Nagy, A.

    2000-01-01

    Holas and March (1995) established a force-balance equation from the many-electron Schroedinger equation. Here, the authors propose this as a basis for the construction of a (usually approximate) differential equation for the ground-state electron density. By way of example they present the simple case of two-electron systems with different external potentials but with weak electron-electron Coulomb repulsion λe 2 /r 12 . In this case first-order Rayleigh-Schroedinger (RS) perturbation theory of the ground-state wave function is known to lead to a compact expression for the first-order density matrix γ(r,rprime) in terms of its diagonal density ρ(r) and the density corresponding to λ = 0. This result allows the force-balance equation to be written as a third-order linear, differential homogeneous equation for the ground-state electron density ρ(r). The example of the two-electron Hookean atom is treated: For this case one can also transcend the first-order RS perturbation theory and get exact results for discrete choices of force constants (external potential)

  12. Non-Gaussian ground-state deformations near a black-hole singularity

    Science.gov (United States)

    Hofmann, Stefan; Schneider, Marc

    2017-03-01

    The singularity theorem by Hawking and Penrose qualifies Schwarzschild black holes as geodesic incomplete space-times. Albeit this is a mathematically rigorous statement, it requires an operational framework that allows us to probe the spacelike singularity via a measurement process. Any such framework necessarily has to be based on quantum theory. As a consequence, the notion of classical completeness needs to be adapted to situations where the only adequate description is in terms of quantum fields in dynamical space-times. It is shown that Schwarzschild black holes turn out to be complete when probed by self-interacting quantum fields in the ground state and in excited states. The measure for populating quantum fields on hypersurfaces in the vicinity of the black-hole singularity goes to zero towards the singularity. This statement is robust under non-Gaussian deformations of and excitations relative to the ground state. The physical relevance of different completeness concepts for black holes is discussed.

  13. Living on the edge of asthma: A grounded theory exploration.

    Science.gov (United States)

    Shaw, Michele R; Oneal, Gail

    2014-10-01

    Most asthma-related emergency department (ED) visits and hospitalizations for asthma are preventable. Our purpose was to develop a grounded theory to guide interventions to reduce unnecessary hospitalizations and ED visits. Grounded theory inquiry guided interviews of 20 participants, including 13 parents and 7 children. Living on the edge of asthma was the emergent theory. Categories included: balancing, losing control, seeking control, and transforming. The theory provides the means for nurses to understand the dynamic process that families undergo in trying to prevent and then deal with and learn from an acute asthma attack requiring hospitalization or an ED visit. © 2014, Wiley Periodicals, Inc.

  14. Participants' views of telephone interviews within a grounded theory study.

    Science.gov (United States)

    Ward, Kim; Gott, Merryn; Hoare, Karen

    2015-12-01

    To offer a unique contribution to the evolving debate around the use of the telephone during semistructured interview by drawing on interviewees' reflections on telephone interview during a grounded theory study. The accepted norm for qualitative interviews is to conduct them face-to-face. It is typical to consider collecting qualitative data via telephone only when face-to-face interview is not possible. During a grounded theory study, exploring users' experiences with overnight mask ventilation for sleep apnoea, the authors selected the telephone to conduct interviews. This article reports participants' views on semistructured interview by telephone. An inductive thematic analysis was conducted on data pertaining to the use of the telephone interview in a grounded theory study. The data were collected during 4 months of 2011 and 6 months in 2014. The article presents an inductive thematic analysis of sixteen participants' opinions about telephone interviewing and discusses these in relation to existing literature reporting the use of telephone interviews in grounded theory studies. Overall, participants reported a positive experience of telephone interviewing. From each participants reports we identified four themes from the data: being 'phone savvy; concentrating on voice instead of your face; easy rapport; and not being judged or feeling inhibited. By drawing on these data, we argue that the telephone as a data collection tool in grounded theory research and other qualitative methodologies need not be relegated to second best status. Rather, researchers can consider telephone interview a valuable first choice option. © 2015 John Wiley & Sons Ltd.

  15. Photoionization of furan from the ground and excited electronic states.

    Science.gov (United States)

    Ponzi, Aurora; Sapunar, Marin; Angeli, Celestino; Cimiraglia, Renzo; Došlić, Nađa; Decleva, Piero

    2016-02-28

    Here we present a comparative computational study of the photoionization of furan from the ground and the two lowest-lying excited electronic states. The study aims to assess the quality of the computational methods currently employed for treating bound and continuum states in photoionization. For the ionization from the ground electronic state, we show that the Dyson orbital approach combined with an accurate solution of the continuum one particle wave functions in a multicenter B-spline basis, at the density functional theory (DFT) level, provides cross sections and asymmetry parameters in excellent agreement with experimental data. On the contrary, when the Dyson orbitals approach is combined with the Coulomb and orthogonalized Coulomb treatments of the continuum, the results are qualitatively different. In excited electronic states, three electronic structure methods, TDDFT, ADC(2), and CASSCF, have been used for the computation of the Dyson orbitals, while the continuum was treated at the B-spline/DFT level. We show that photoionization observables are sensitive probes of the nature of the excited states as well as of the quality of excited state wave functions. This paves the way for applications in more complex situations such as time resolved photoionization spectroscopy.

  16. Classic Grounded Theory to Analyse Secondary Data: Reality and Reflections

    Directory of Open Access Journals (Sweden)

    Lorraine Andrews

    2012-06-01

    Full Text Available This paper draws on the experiences of two researchers and discusses how they conducted a secondary data analysis using classic grounded theory. The aim of the primary study was to explore first-time parents’ postnatal educational needs. A subset of the data from the primary study (eight transcripts from interviews with fathers was used for the secondary data analysis. The objectives of the secondary data analysis were to identify the challenges of using classic grounded theory with secondary data and to explore whether the re-analysis of primary data using a different methodology would yield a different outcome. Through the process of re-analysis a tentative theory emerged on ‘developing competency as a father’. Challenges encountered during this re-analysis included the small dataset, the pre-framed data, and limited ability for theoretical sampling. This re-analysis proved to be a very useful learning tool for author 1(LA, who was a novice with classic grounded theory.

  17. Grounded Theory for Creating Adolescent Readers

    Science.gov (United States)

    Tacy, Cheryl Melissa

    2017-01-01

    The purpose of this qualitative grounded theory study was to discover the impact on adolescent reading motivation as students were given an opportunity to select recreational reading material and read consistently during class time. This study also explored the motivational impact of student engagement from dialogue with peers about their reading…

  18. Linking the Intercultural and Grounded Theory: Methodological Issues in Migration Research

    Directory of Open Access Journals (Sweden)

    Vera Sheridan

    2009-01-01

    Full Text Available Connecting intercultural research with Grounded Theory was advocated in the early history of intercultural theorising and includes the development of researchers' intercultural competencies. Such competency comes to the fore where intercultural theory places an equal emphasis on home and host cultures in migration research. In this context we have found a Grounded Theory approach particularly suitable for disentangling complex interlinkings within migration experiences and their individual outcomes. Grounded Theory allows for the exploration of various theories in different fields and the emergence of new or deeper interpretations of intercultural experiences, including where research has not engaged deeply with or avoided intercultural contexts. The use of software, based on Grounded Theory, provides the resource for systematically exploring the inter-related nature of data. In addition, engaging in intercultural research, in particular, raises questions around our practice as social science researchers: adherence to ethics guidelines, for instance, can be in some conflict with the relations we build with members of communities whose cultural values, for instance around friendship or trust, impact on the norms of both our own and institutional expectations. This leads to reflection on the relationship with research participants in terms of our own intercultural experiences and position. URN: urn:nbn:de:0114-fqs0901363

  19. Gifted Students in Transition: A Grounded Theory Study

    Science.gov (United States)

    Meadows, Jodi J.

    2017-01-01

    Gifted students in transition to college may be at risk for underachievement, difficult transition, or even attrition. Giftedness by itself is not always sufficient for academic success in college. The purpose of this grounded theory study was to construct a theory regarding the process of transition to college for high-achieving gifted high…

  20. Search for the weak non-analog Fermi branch in the 42Sc ground state beta decay

    International Nuclear Information System (INIS)

    DelVecchio, R.M.; Daehnick, W.W.

    1978-01-01

    We have searched for the β-decay branch from the 4 2Sc ground state to the 1.837 MeV level in 4 2Ca. Since both states are J/sup π/ = 0 + , T = 1, this decay is an example of a non-analog Fermi decay which could occur by reason of some mixing of the analog ground states into the lowest excited 0 + state in both 4 2Sc and 4 2Ca. As a signal for this branch, we looked for a subsequent cascade γ ray with a Ge(Li) detector-rabbit arrangement. We found a branching ratio of (2.2 +- 1.7) x 10 - 5 relative to the superallowed ground state to ground state decay. Interpreted as an upper limit, this corresponds to a branching ratio - 5 at the 68% confidence level. This result is at the lower bound of what present theory can predict with a Coulomb force mixing calculation

  1. Ground states of quantum spin systems

    International Nuclear Information System (INIS)

    Bratteli, Ola; Kishimoto, Akitaka; Robinson, D.W.

    1978-07-01

    The authors prove that ground states of quantum spin systems are characterized by a principle of minimum local energy and that translationally invariant ground states are characterized by the principle of minimum energy per unit volume

  2. The ground state energy of 3He droplet in the LOCV framework

    International Nuclear Information System (INIS)

    Modarres, M.; Motahari, S.; Rajabi, A.

    2012-01-01

    The (extended) lowest order constrained variational method was used to calculate the ground state energy of liquid helium 3 ( 3 He) droplets at zero temperature. Different types of density distribution profiles, such as the Gaussian, the Quasi-Gaussian and the Woods-Saxon were used. It was shown that at least, on average, near 20 3 He atoms are needed to get the bound state for 3 He liquid droplet. Depending on the choice of the density profiles and the atomic radius of 3 He, the above estimate can increase to 300. Our calculated ground state energy and the number of atoms in liquid 3 He droplet were compared with those of Variational Monte Carlo method, Diffusion Monte Carlo method and Density Functional Theory, for which a reasonable agreement was found.

  3. A Novel Method of Enhancing Grounded Theory Memos with Voice Recording

    Science.gov (United States)

    Stocker, Rachel; Close, Helen

    2013-01-01

    In this article the authors present the recent discovery of a novel method of supplementing written grounded theory memos with voice recording, the combination of which may provide significant analytical advantages over solely the traditional written method. Memo writing is an essential component of a grounded theory study, however it is often…

  4. A Brush with Research: Teaching Grounded Theory in the Art and Design Classroom

    Science.gov (United States)

    Compton, Mike; Barrett, Sean

    2016-01-01

    Grounded Theory is a systematic approach to social research that allows for new concepts and theories to emerge from gathered data, as opposed to relying on either established theory or personal conjecture to interpret social processes. Although Grounded Theory is a well-known method within social science literature, it is relatively unknown in…

  5. Method development at Nordic School of Public Health NHV: Phenomenology and Grounded Theory.

    Science.gov (United States)

    Strandmark, Margaretha

    2015-08-01

    Qualitative methods such as phenomenology and grounded theory have been valuable tools in studying public health problems. A description and comparison of these methods. Phenomenology emphasises an inside perspective in form of consciousness and subjectively lived experiences, whereas grounded theory emanates from the idea that interactions between people create new insights and knowledge. Fundamental aspects of phenomenology include life world, consciousness, phenomenological reduction and essence. Significant elements in grounded theory are coding, categories and core categories, which develop a theory. There are differences in the philosophical approach, the name of the concept and the systematic tools between the methods. Thus, the phenomenological method is appropriate when studying emotional and existential research problems, and grounded theory is a method more suited to investigate processes. © 2015 the Nordic Societies of Public Health.

  6. On the topological ground state of E-infinity spacetime and the super string connection

    International Nuclear Information System (INIS)

    El Naschie, M.S.

    2007-01-01

    There are at present a huge number of valid super string ground states, making the one corresponding to our own universe extremely hard to determine. Therefore it may come as quite a surprise that it is a rather simple undertaking to determine the exact topological ground state of E-infinity Cantorian spacetime theory. Similar to the ground state of the Higgs for E-infinity, the expectation value of the topological ground state is non-zero and negative. Its value is given exactly by -bar o -∼ n(1/φ) n =-(4+φ 3 ) where φ=(5-1)/2 and n represents an integer Menger-Uhryson dimension running from n=0 to n=-∼. Recalling that the average dimension of ε (∼) is given by ∼ =4+φ 3 , one could interpret this result as saying that our E-infinity spacetime may be viewed as an in itself closed manifold given by the remarkable equation: + =zeroThus in a manner of speaking, the universe could have spontaneously tunnelled into existence from virtual nothingness

  7. The importance of symbolic interaction in grounded theory research on women's health.

    Science.gov (United States)

    Crooks, D L

    2001-01-01

    A variety of grounded theory studies are presented in this issue of Health Care for Women International that attend to different factors and situations impacting women's health. In this paper I will provide the basic principles of symbolic interactionism (SI) for the reader unfamiliar with the conceptual underpinnings of the grounded theory research method. I will discuss why SI is a fitting perspective for use in the study of women, women's perspectives, and women's health. I will conclude with a brief discussion of challenges to researchers maintaining the symbolic interaction perspective in grounded theory research.

  8. [The grounded theory as a methodological alternative for nursing research].

    Science.gov (United States)

    dos Santos, Sérgio Ribeiro; da Nóbrega, Maria Miriam

    2002-01-01

    This study presents a method of interpretative and systematic research with appliance to the development of studies in nursing called "the grounded theory", whose theoretical support is the symbolic interactionism. The purpose of the paper is to describe the grounded theory as an alternative methodology for the construction of knowledge in nursing. The study highlights four topics: the basic principle, the basic concepts, the trajectory of the method and the process of analysis of the data. We conclude that the systematization of data and its interpretation, based on social actors' experience, constitute strong subsidies to generate theories through this research tool.

  9. Stability of the electroweak ground state in the Standard Model and its extensions

    International Nuclear Information System (INIS)

    Di Luzio, Luca; Isidori, Gino; Ridolfi, Giovanni

    2016-01-01

    We review the formalism by which the tunnelling probability of an unstable ground state can be computed in quantum field theory, with special reference to the Standard Model of electroweak interactions. We describe in some detail the approximations implicitly adopted in such calculation. Particular attention is devoted to the role of scale invariance, and to the different implications of scale-invariance violations due to quantum effects and possible new degrees of freedom. We show that new interactions characterized by a new energy scale, close to the Planck mass, do not invalidate the main conclusions about the stability of the Standard Model ground state derived in absence of such terms.

  10. Stability of the electroweak ground state in the Standard Model and its extensions

    Energy Technology Data Exchange (ETDEWEB)

    Di Luzio, Luca, E-mail: diluzio@ge.infn.it [Dipartimento di Fisica, Università di Genova and INFN, Sezione di Genova, Via Dodecaneso 33, I-16146 Genova (Italy); Isidori, Gino [Department of Physics, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Ridolfi, Giovanni [Dipartimento di Fisica, Università di Genova and INFN, Sezione di Genova, Via Dodecaneso 33, I-16146 Genova (Italy)

    2016-02-10

    We review the formalism by which the tunnelling probability of an unstable ground state can be computed in quantum field theory, with special reference to the Standard Model of electroweak interactions. We describe in some detail the approximations implicitly adopted in such calculation. Particular attention is devoted to the role of scale invariance, and to the different implications of scale-invariance violations due to quantum effects and possible new degrees of freedom. We show that new interactions characterized by a new energy scale, close to the Planck mass, do not invalidate the main conclusions about the stability of the Standard Model ground state derived in absence of such terms.

  11. Study of some electronics properties of new superconductor Sr2VO3FeAs in ground state

    Directory of Open Access Journals (Sweden)

    M Majidiyan

    2010-09-01

    Full Text Available In this paper, some electronics properties of new superconductor Sr2VO3FeAs, such as density of states, band structure, density of electron cloud and bound lengths in the ground state have been calculated. According to N(Ef in ground state CV/T value has been estimated. The calculations were performed in the framework of density functional theory (DFT, using the full potential linearized augmented plane wave (FP-LAPW method with the general gradient approximation (GGA.

  12. A Personal Journey with Grounded Theory Methodology. Kathy Charmaz in Conversation With Reiner Keller

    Directory of Open Access Journals (Sweden)

    Kathy Charmaz

    2016-01-01

    Full Text Available Kathy CHARMAZ is one of the most important thinkers in grounded theory methodology today. Her trailblazing work on constructivist grounded theory continues to inspire research across many disciplines and around the world. In this interview, she reflects on the aura surrounding qualitative inquiry that existed in California in the late 1960s to early 1970s and the lessons she learned from her first forays into empirical research. She comments on the trajectory that grounded theory research has followed since then and gives an account of her own perspective on constructivist grounded theory. In doing so, she underlines the importance of the Chicago School and symbolic interactionist tradition for grounded theory research work today and shows where the latter is positioned in the current field of qualitative fieldwork. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1601165

  13. Theory- Building for Iranian Underground Music Using Grounded Theory

    Directory of Open Access Journals (Sweden)

    Masoud Kowsari

    2013-03-01

    Full Text Available Different genres of underground music are important issues in Iranian youth culture. The purpose of this research was to study masculinity in Iranian- Persian rap music. Therefore, Persian rap music as a part of Iranian popular culture, between 2001 and 2011 was analyzed. We used qualitative research approach. The main method used in this study, was "Constructive Grounded Theory ". So instead of using existing theories as a theoretical framework, the researcher sought to generate local theory from research field. Thus, using theoretical sampling, data compiled from various sources. The multiple data collection techniques such as interviews, observation, online observation, collecting documents and texts were used. Then all the data was coded with using open, axial and selective coding methods. Finally, 62 concepts and 16 categories derived from data and "plural form of masculinity in Iranian-Persian rap music" was defined as the core category. Then according to paradigmatic model, "Substantive Theory" emerged from the data, was presented as "story" and "visual model". Finally seven questions of Strauss and Corbin about the experience in research has been assessed to evaluating research.

  14. Many-body Green’s function theory for electron-phonon interactions: Ground state properties of the Holstein dimer

    International Nuclear Information System (INIS)

    Säkkinen, Niko; Leeuwen, Robert van; Peng, Yang; Appel, Heiko

    2015-01-01

    We study ground-state properties of a two-site, two-electron Holstein model describing two molecules coupled indirectly via electron-phonon interaction by using both exact diagonalization and self-consistent diagrammatic many-body perturbation theory. The Hartree and self-consistent Born approximations used in the present work are studied at different levels of self-consistency. The governing equations are shown to exhibit multiple solutions when the electron-phonon interaction is sufficiently strong, whereas at smaller interactions, only a single solution is found. The additional solutions at larger electron-phonon couplings correspond to symmetry-broken states with inhomogeneous electron densities. A comparison to exact results indicates that this symmetry breaking is strongly correlated with the formation of a bipolaron state in which the two electrons prefer to reside on the same molecule. The results further show that the Hartree and partially self-consistent Born solutions obtained by enforcing symmetry do not compare well with exact energetics, while the fully self-consistent Born approximation improves the qualitative and quantitative agreement with exact results in the same symmetric case. This together with a presented natural occupation number analysis supports the conclusion that the fully self-consistent approximation describes partially the bipolaron crossover. These results contribute to better understanding how these approximations cope with the strong localizing effect of the electron-phonon interaction

  15. Symbolic interactionism in grounded theory studies: women surviving with HIV/AIDS in rural northern Thailand.

    Science.gov (United States)

    Klunklin, Areewan; Greenwood, Jennifer

    2006-01-01

    Although it is generally acknowledged that symbolic interactionism and grounded theory are connected, the precise nature of their connection remains implicit and unexplained. As a result, many grounded theory studies are undertaken without an explanatory framework. This in turn results in the description rather than the explanation of data determined. In this report, the authors make explicit and explain the nature of the connections between symbolic interactionism and grounded theory research. Specifically, they make explicit the connection between Blumer's methodological principles and processes and grounded theory methodology. In addition, the authors illustrate the explanatory power of symbolic interactionism in grounded theory using data from a study of the HIV/AIDS experiences of married and widowed Thai women.

  16. How to do a grounded theory study: a worked example of a study of dental practices.

    Science.gov (United States)

    Sbaraini, Alexandra; Carter, Stacy M; Evans, R Wendell; Blinkhorn, Anthony

    2011-09-09

    Qualitative methodologies are increasingly popular in medical research. Grounded theory is the methodology most-often cited by authors of qualitative studies in medicine, but it has been suggested that many 'grounded theory' studies are not concordant with the methodology. In this paper we provide a worked example of a grounded theory project. Our aim is to provide a model for practice, to connect medical researchers with a useful methodology, and to increase the quality of 'grounded theory' research published in the medical literature. We documented a worked example of using grounded theory methodology in practice. We describe our sampling, data collection, data analysis and interpretation. We explain how these steps were consistent with grounded theory methodology, and show how they related to one another. Grounded theory methodology assisted us to develop a detailed model of the process of adapting preventive protocols into dental practice, and to analyse variation in this process in different dental practices. By employing grounded theory methodology rigorously, medical researchers can better design and justify their methods, and produce high-quality findings that will be more useful to patients, professionals and the research community.

  17. How to do a grounded theory study: a worked example of a study of dental practices

    Directory of Open Access Journals (Sweden)

    Evans R

    2011-09-01

    Full Text Available Abstract Background Qualitative methodologies are increasingly popular in medical research. Grounded theory is the methodology most-often cited by authors of qualitative studies in medicine, but it has been suggested that many 'grounded theory' studies are not concordant with the methodology. In this paper we provide a worked example of a grounded theory project. Our aim is to provide a model for practice, to connect medical researchers with a useful methodology, and to increase the quality of 'grounded theory' research published in the medical literature. Methods We documented a worked example of using grounded theory methodology in practice. Results We describe our sampling, data collection, data analysis and interpretation. We explain how these steps were consistent with grounded theory methodology, and show how they related to one another. Grounded theory methodology assisted us to develop a detailed model of the process of adapting preventive protocols into dental practice, and to analyse variation in this process in different dental practices. Conclusions By employing grounded theory methodology rigorously, medical researchers can better design and justify their methods, and produce high-quality findings that will be more useful to patients, professionals and the research community.

  18. Grounded Theory as a "Family of Methods": A Genealogical Analysis to Guide Research

    Science.gov (United States)

    Babchuk, Wayne A.

    2011-01-01

    This study traces the evolution of grounded theory from a nuclear to an extended family of methods and considers the implications that decision-making based on informed choices throughout all phases of the research process has for realizing the potential of grounded theory for advancing adult education theory and practice. [This paper was…

  19. Stability of the electroweak ground state in the Standard Model and its extensions

    Directory of Open Access Journals (Sweden)

    Luca Di Luzio

    2016-02-01

    Full Text Available We review the formalism by which the tunnelling probability of an unstable ground state can be computed in quantum field theory, with special reference to the Standard Model of electroweak interactions. We describe in some detail the approximations implicitly adopted in such calculation. Particular attention is devoted to the role of scale invariance, and to the different implications of scale-invariance violations due to quantum effects and possible new degrees of freedom. We show that new interactions characterized by a new energy scale, close to the Planck mass, do not invalidate the main conclusions about the stability of the Standard Model ground state derived in absence of such terms.

  20. Introducing Grounded Theory into translation studies | Wehrmeyer ...

    African Journals Online (AJOL)

    This article introduces tenets of Grounded Theory into a reception-oriented model for translation studies, in which the basis of comparison (tertium comparationis) between source and target texts is constructed from target audience expectancy norms. The model is primarily designed for projects where conformity to target ...

  1. Search for the QCD ground state

    International Nuclear Information System (INIS)

    Reuter, M.; Wetterich, C.

    1994-05-01

    Within the Euclidean effective action approach we propose criteria for the ground state of QCD. Despite a nonvanishing field strength the ground state should be invariant with respect to modified Poincare transformations consisting of a combination of translations and rotations with suitable gauge transformations. We have found candidate states for QCD with four or more colours. The formation of gluon condensates shows similarities with the Higgs phenomenon. (orig.)

  2. A systematic review of grounded theory studies in physiotherapy.

    Science.gov (United States)

    Ali, Nancy; May, Stephen; Grafton, Kate

    2018-05-23

    This systematic review aimed at appraising the methodological rigor of grounded theory research published in the field of physiotherapy to assess how the methodology is understood and applied. A secondary aim was to provide research implications drawn from the findings to guide future grounded theory methodology (GTM) research. A systematic search was conducted in MEDLINE, CINHAL, SPORT Discus, Science Direct, PubMed, Scopus, and Web of Science to identify studies in the field of physiotherapy that reported using GTM and/or methods in the study title and/or abstract. The descriptive characteristics and methodological quality of eligible studies were examined using grounded theory methodology assessment guidelines. The review included 68 studies conducted between 1998 and 2017. The findings showed that GTM is becoming increasingly used by physiotherapy researchers. Thirty-six studies (53%) demonstrated a good understanding and appropriate application of GTM. Thirty-two studies (47%) presented descriptive findings and were considered to be of poor methodological quality. There are several key tenets of GTM that are integral to the iterative process of qualitative theorizing and need to be applied throughout all research practices including sampling, data collection, and analysis.

  3. Toward a Definition of Complexity for Quantum Field Theory States.

    Science.gov (United States)

    Chapman, Shira; Heller, Michal P; Marrochio, Hugo; Pastawski, Fernando

    2018-03-23

    We investigate notions of complexity of states in continuous many-body quantum systems. We focus on Gaussian states which include ground states of free quantum field theories and their approximations encountered in the context of the continuous version of the multiscale entanglement renormalization ansatz. Our proposal for quantifying state complexity is based on the Fubini-Study metric. It leads to counting the number of applications of each gate (infinitesimal generator) in the transformation, subject to a state-dependent metric. We minimize the defined complexity with respect to momentum-preserving quadratic generators which form su(1,1) algebras. On the manifold of Gaussian states generated by these operations, the Fubini-Study metric factorizes into hyperbolic planes with minimal complexity circuits reducing to known geodesics. Despite working with quantum field theories far outside the regime where Einstein gravity duals exist, we find striking similarities between our results and those of holographic complexity proposals.

  4. A Grounded Theory of Master's-Level Counselor Research Identity

    Science.gov (United States)

    Jorgensen, Maribeth F.; Duncan, Kelly

    2015-01-01

    A grounded theory approach was used to examine the research identity of 17 master's-level counseling trainees and practitioners. The emergent theory gave an understanding to sources of variation in the process and outcome of research identity. The authors provide recommendations for counselor educators to use with current and former students.

  5. Empowerment in School Nursing Practice: A Grounded Theory Approach

    Science.gov (United States)

    Broussard, Lisa

    2007-01-01

    Professional empowerment is vital to nurses' productivity and job satisfaction. A grounded theory study was conducted to describe the basic social process experienced by school nurses in relation to professional empowerment. Interviews with 10 school nurses led to the development of a situation-specific theory of school nurse empowerment,…

  6. The Development of the TPR-DB as Grounded Theory Method

    DEFF Research Database (Denmark)

    Carl, Michael; Schaeffer, Moritz

    2018-01-01

    and refine the emerging concepts and categories and to validate the developing theories, the TPR-DB has been extended with further translation studies in different languages and translation modes. In this respect, it shares many features with Grounded Theory Method. This method was discovered in 1967...... and used in qualitative research in social science ad many other research areas. We analyze the TPR-DB development as a Grounded Theory Method....... on quantitative assessment of well-defined research questions on cognitive processes in human translation production, the integration of the data into the TPR-DB allowed for broader qualitative and exploratory research which has led to new codes, categories and research themes. In a constant effort to develop...

  7. Bulk Renormalization Group Flows and Boundary States in Conformal Field Theories

    Directory of Open Access Journals (Sweden)

    John Cardy

    2017-08-01

    Full Text Available We propose using smeared boundary states $e^{-\\tau H}|\\cal B\\rangle$ as variational approximations to the ground state of a conformal field theory deformed by relevant bulk operators. This is motivated by recent studies of quantum quenches in CFTs and of the entanglement spectrum in massive theories. It gives a simple criterion for choosing which boundary state should correspond to which combination of bulk operators, and leads to a rudimentary phase diagram of the theory in the vicinity of the RG fixed point corresponding to the CFT, as well as rigorous upper bounds on the universal amplitude of the free energy. In the case of the 2d minimal models explicit formulae are available. As a side result we show that the matrix elements of bulk operators between smeared Ishibashi states are simply given by the fusion rules of the CFT.

  8. Knot theory and a physical state of quantum gravity

    International Nuclear Information System (INIS)

    Liko, Tomas; Kauffman, Louis H

    2006-01-01

    We discuss the theory of knots, and describe how knot invariants arise naturally in gravitational physics. The focus of this review is to delineate the relationship between knot theory and the loop representation of non-perturbative canonical quantum general relativity (loop quantum gravity). This leads naturally to a discussion of the Kodama wavefunction, a state which is conjectured to be the ground state of the gravitational field with positive cosmological constant. This review can serve as a self-contained introduction to loop quantum gravity and related areas. Our intent is to make the paper accessible to a wider audience that may include topologists, knot theorists, and other persons innocent of the physical background to this approach to quantum gravity. (topical review)

  9. "Emergence" vs. "Forcing" of Empirical Data? A Crucial Problem of "Grounded Theory" Reconsidered

    Directory of Open Access Journals (Sweden)

    Udo Kelle

    2005-05-01

    Full Text Available Since the late 1960s Barney GLASER and Anselm STRAUSS, developers of the methodology of "Grounded Theory" have made several attempts to explicate, clarify and reconceptualise some of the basic tenets of their methodological approach. Diverging concepts and understandings of Grounded Theory have arisen from these attempts which have led to a split between its founders. Much of the explication and reworking of Grounded Theory surrounds the relation between data and theory and the role of previous theoretical assumptions. The book which initially established the popularity of GLASER's and STRAUSS' methodological ideas, "The Discovery of Grounded Theory", contains two conflicting understandings of the relation between data and theory—the concept of "emergence" on the one hand and the concept of "theoretical sensitivity" on the other hand. Much of the later developments of Grounded Theory can be seen as attempts to reconcile these prima facie diverging concepts. Thereby GLASER recommends to draw on a variety of "coding families" while STRAUSS proposes the use of a general theory of action to build an axis for an emerging theory. This paper first summarises the most important developments within "Grounded Theory" concerning the understanding of the relation between empirical data and theoretical statements. Thereby special emphasis will be laid on differences between GLASER's and STRAUSS' concepts and on GLASER's current critique that the concepts of "coding paradigm" and "axial coding" described by STRAUSS and Juliet CORBIN lead to the "forcing" of data. It will be argued that GLASER's critique points out some existing weaknesses of STRAUSS' concepts but vastly exaggerates the risks of the STRAUSSian approach. A main argument of this paper is that basic problems of empirically grounded theory construction can be treated much more effectively if one draws on certain results of contemporary philosophical and epistemological discussions and on widely

  10. Where Are the Grounds for Grounded Theory? A Troubled Empirical Methodology Meets Wittgenstein

    Science.gov (United States)

    James, Fiona

    2018-01-01

    This article provides a critical exposition of the epistemological underpinnings of a recent redevelopment of Grounded Theory (GT) methodology, "Constructivist" GT. Although proffered as freed from the "objectivist" tenets of the original version, critical examination exposes the essentialism threaded through its integral…

  11. Exact ground state of finite Bose-Einstein condensates on a ring

    International Nuclear Information System (INIS)

    Sakmann, Kaspar; Streltsov, Alexej I.; Alon, Ofir E.; Cederbaum, Lorenz S.

    2005-01-01

    The exact ground state of the many-body Schroedinger equation for N bosons on a one-dimensional ring interacting via a pairwise δ-function interaction is presented for up to 50 particles. The solutions are obtained by solving Lieb and Liniger's system of coupled transcendental equations numerically for finite N. The ground-state energies for repulsive and attractive interactions are shown to be smoothly connected at the point of zero interaction strength, implying that the Bethe ansatz can be used also for attractive interactions for all cases studied. For repulsive interactions the exact energies are compared to (i) Lieb and Liniger's thermodynamic limit solution and (ii) the Tonks-Girardeau gas limit. It is found that the energy of the thermodynamic limit solution can differ substantially from that of the exact solution for finite N when the interaction is weak or when N is small. A simple relation between the Tonks-Girardeau gas limit and the solution for finite interaction strength is revealed. For attractive interactions we find that the true ground-state energy is given to a good approximation by the energy of the system of N attractive bosons on an infinite line, provided the interaction is stronger than the critical interaction strength of mean-field theory

  12. grounded theory approach in sermon analysis of sermons

    African Journals Online (AJOL)

    The grounded theory approach is implemented in analysing sermons on poverty and directed at ... poverty situation in South Africa, especially in the black community (Pieterse ..... The activity of open coding discovers gaps or holes of needed.

  13. Developing a Leadership Identity: A Grounded Theory

    Science.gov (United States)

    Komives, Susan R.; Owen, Julie E; Longerbeam, Susan D.; Mainella, Felicia C.; Osteen, Laura

    2005-01-01

    This grounded theory study on developing a leadership identity revealed a 6-stage developmental process. The thirteen diverse students in this study described their leadership identity as moving from a leader-centric view to one that embraced leadership as a collaborative, relational process. Developing a leadership identity was connected to the…

  14. Crystalline beam ground state

    International Nuclear Information System (INIS)

    Wei, Jie; Li, Xiao-Ping; Sessler, A.M.

    1993-01-01

    In order to employ Molecular Dynamics method, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations has been performed to obtain the equilibrium structure. The effects of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time-dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Rahman and Schiffer, depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

  15. Crystalline beam ground state

    International Nuclear Information System (INIS)

    Wei, Jie; Li, Xiao-Ping

    1993-01-01

    In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Schiffer et al. depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

  16. Crystalline beam ground state

    International Nuclear Information System (INIS)

    Wei, J.; Li, X.P.

    1993-01-01

    In order to employ the Molecular Dynamics method, commonly used in condensed matter physics, the authors have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. They include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations has been performed to obtain the equilibrium structure. The effects of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time-dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Rahman and Schiffer, depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

  17. A Grounded Theory Analysis of Introductory Computer Science Pedagogy

    Directory of Open Access Journals (Sweden)

    Jonathan Wellons

    2011-12-01

    Full Text Available Planning is a critical, early step on the path to successful program writing and a skill that is often lacking in novice programmers. As practitioners we are continually searching for or creating interventions to help our students, particularly those who struggle in the early stages of their computer science education. In this paper we report on our ongoing research of novice programming skills that utilizes the qualitative research method of grounded theory to develop theories and inform the construction of these interventions. We describe how grounded theory, a popular research method in the social sciences since the 1960’s, can lend formality and structure to the common practice of simply asking students what they did and why they did it. Further, we aim to inform the reader not only about our emerging theories on interventions for planning but also how they might collect and analyze their own data in this and other areas that trouble novice programmers. In this way those who lecture and design CS1 interventions can do so from a more informed perspective.

  18. Teaching Theory Construction With Initial Grounded Theory Tools: A Reflection on Lessons and Learning.

    Science.gov (United States)

    Charmaz, Kathy

    2015-12-01

    This article addresses criticisms of qualitative research for spawning studies that lack analytic development and theoretical import. It focuses on teaching initial grounded theory tools while interviewing, coding, and writing memos for the purpose of scaling up the analytic level of students' research and advancing theory construction. Adopting these tools can improve teaching qualitative methods at all levels although doctoral education is emphasized here. What teachers cover in qualitative methods courses matters. The pedagogy presented here requires a supportive environment and relies on demonstration, collective participation, measured tasks, progressive analytic complexity, and accountability. Lessons learned from using initial grounded theory tools are exemplified in a doctoral student's coding and memo-writing excerpts that demonstrate progressive analytic development. The conclusion calls for increasing the number and depth of qualitative methods courses and for creating a cadre of expert qualitative methodologists. © The Author(s) 2015.

  19. α-decay half-lives of some nuclei from ground state to ground state using different nuclear potential

    Directory of Open Access Journals (Sweden)

    Akrawy Dashty T.

    2018-01-01

    Full Text Available Theoretical α-decay half-lives of some nuclei from ground state to ground state are calculated using different nuclear potential model including Coulomb proximity potential (CPPM, Royer proximity potential and Broglia and Winther 1991. The calculated values comparing with experimental data, it is observed that the CPPM model is in good agreement with the experimental data.

  20. Stop. Write! Writing Grounded Theory

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, PhD, Hon. PhD

    2012-06-01

    Full Text Available The message in this book, the dictum in this book, is to stop and write when the Grounded Theory (GT methodology puts you in that ready position. Stop unending conceptualization, unending data coverage, and unending listening to others who would egg you on with additional data, ideas and/or requirements or simply wait too long. I will discuss these ideas in detail. My experience with PhD candidates is that for the few who write when ready, many do not and SHOULD. Simply put, many write-up, but many more should.

  1. Toward a Definition of Complexity for Quantum Field Theory States

    Science.gov (United States)

    Chapman, Shira; Heller, Michal P.; Marrochio, Hugo; Pastawski, Fernando

    2018-03-01

    We investigate notions of complexity of states in continuous many-body quantum systems. We focus on Gaussian states which include ground states of free quantum field theories and their approximations encountered in the context of the continuous version of the multiscale entanglement renormalization ansatz. Our proposal for quantifying state complexity is based on the Fubini-Study metric. It leads to counting the number of applications of each gate (infinitesimal generator) in the transformation, subject to a state-dependent metric. We minimize the defined complexity with respect to momentum-preserving quadratic generators which form s u (1 ,1 ) algebras. On the manifold of Gaussian states generated by these operations, the Fubini-Study metric factorizes into hyperbolic planes with minimal complexity circuits reducing to known geodesics. Despite working with quantum field theories far outside the regime where Einstein gravity duals exist, we find striking similarities between our results and those of holographic complexity proposals.

  2. Reconceptualising Moderation in Asynchronous Online Discussions Using Grounded Theory

    Science.gov (United States)

    Vlachopoulos, Panos; Cowan, John

    2010-01-01

    This article reports a grounded theory study of the moderation of asynchronous online discussions, to explore the processes by which tutors in higher education decide when and how to moderate. It aims to construct a theory of e-moderation based on some key factors which appear to influence e-moderation. It discusses previous research on the…

  3. Sideband cooling of micromechanical motion to the quantum ground state.

    Science.gov (United States)

    Teufel, J D; Donner, T; Li, Dale; Harlow, J W; Allman, M S; Cicak, K; Sirois, A J; Whittaker, J D; Lehnert, K W; Simmonds, R W

    2011-07-06

    The advent of laser cooling techniques revolutionized the study of many atomic-scale systems, fuelling progress towards quantum computing with trapped ions and generating new states of matter with Bose-Einstein condensates. Analogous cooling techniques can provide a general and flexible method of preparing macroscopic objects in their motional ground state. Cavity optomechanical or electromechanical systems achieve sideband cooling through the strong interaction between light and motion. However, entering the quantum regime--in which a system has less than a single quantum of motion--has been difficult because sideband cooling has not sufficiently overwhelmed the coupling of low-frequency mechanical systems to their hot environments. Here we demonstrate sideband cooling of an approximately 10-MHz micromechanical oscillator to the quantum ground state. This achievement required a large electromechanical interaction, which was obtained by embedding a micromechanical membrane into a superconducting microwave resonant circuit. To verify the cooling of the membrane motion to a phonon occupation of 0.34 ± 0.05 phonons, we perform a near-Heisenberg-limited position measurement within (5.1 ± 0.4)h/2π, where h is Planck's constant. Furthermore, our device exhibits strong coupling, allowing coherent exchange of microwave photons and mechanical phonons. Simultaneously achieving strong coupling, ground state preparation and efficient measurement sets the stage for rapid advances in the control and detection of non-classical states of motion, possibly even testing quantum theory itself in the unexplored region of larger size and mass. Because mechanical oscillators can couple to light of any frequency, they could also serve as a unique intermediary for transferring quantum information between microwave and optical domains.

  4. A discussion of differences in preparation, performance and postreflections in participant observations within two grounded theory approaches.

    Science.gov (United States)

    Berthelsen, Connie Bøttcher; Lindhardt, Tove; Frederiksen, Kirsten

    2017-06-01

    This paper presents a discussion of the differences in using participant observation as a data collection method by comparing the classic grounded theory methodology of Barney Glaser with the constructivist grounded theory methodology by Kathy Charmaz. Participant observations allow nursing researchers to experience activities and interactions directly in situ. However, using participant observations as a data collection method can be done in many ways, depending on the chosen grounded theory methodology, and may produce different results. This discussion shows that how the differences between using participant observations in classic and constructivist grounded theory can be considerable and that grounded theory researchers should adhere to the method descriptions of performing participant observations according to the selected grounded theory methodology to enhance the quality of research. © 2016 Nordic College of Caring Science.

  5. Variational theory of valence fluctuations: Ground states and quasiparticle excitations of the Anderson lattice model

    Science.gov (United States)

    Brandow, B. H.

    1986-01-01

    A variational study of ground states of the orbitally nondegenerate Anderson lattice model, using a wave function with one variational parameter per Bloch state k, has been extended to deal with essentially metallic systems having a nonintegral number of electrons per site. Quasiparticle excitations are obtained by direct appeal to Landau's original definition for interacting Fermi liquids, scrEqp(k,σ)=δEtotal/δn qp(k,σ). This approach provides a simple and explicit realization of the Luttinger picture of a periodic Fermi liquid. A close correspondence is maintained between the ``interacting'' (U=∞) system and the corresponding ``noninteracting'' (U=0) case, i.e., ordinary band theory; the result can be described as a renormalized band or renormalized hybridization theory. The occupation-number distribution for the conduction orbitals displays a finite discontinuity at the Fermi surface. If the d-f hybridization is nonzero throughout the Brillouin zone, the quasiparticle spectrum will always exhibit a gap, although this gap becomes exponentially small (i.e., of order TK) in the Kondo-lattice regime. In the ``ionic'' case with precisely two electrons per site, such a system may therefore exhibit an insulating (semiconducting) gap. The quasiparticle state density exhibits a prominent spike on each side of the spectral gap, just as in the elementary hybridization model (the U=0 case). For the metallic case, with a nonintegral number of electrons per site, the Fermi level falls within one of the two sharp density peaks. The effective mass at the Fermi surface tends to be very large; enhancements by a factor >~102 are quite feasible. The foregoing variational theory has also been refined by means of a trial wave function having two variational parameters per Bloch state k. The above qualitative features are all retained, with some quantitative differences, but there are also some qualitatively new features. The most interesting of these is the appearance, within

  6. Variational transition-state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.; Garrett, B.C.

    1980-01-01

    A general introduction to and some results from studies of a procedure called variational transition-state theory are presented. A fundamental assumption of this theory is that the net rate of forward reaction at equilibrium equals the equilibrium flux in the product direction through the transition state where the transition state is a surface in phase space dividing reactants from products. Classical generalized-transition-state-theory calculations for nine collinear systems are compared to classical trajectory calculations. This new technique should provide useful insight into the successes and failures of the conventional theory and useful quantitative estimates of possible errors on the predictions of conventional transition-state theory. This should also contribute to a more accurate theory now available for the practical calculations of chemical reaction rates and thermochemical and structural interpretations of rate processes

  7. A Grounded Theory of Counseling Students Who Report Problematic Peers

    Science.gov (United States)

    Parker, Lindy K.; Chang, Catherine Y.; Corthell, Kimere K.; Walsh, Maggie E.; Brack, Greg; Grubbs, Natalie K.

    2014-01-01

    All counselors, including students, are responsible for intervening when a colleague shows signs of impairment. This grounded theory study investigated experiences of 12 counseling students who reported problematic peers. An emergent theory of the peer reporting process is presented, along with implications for counselor educators and suggestions…

  8. A grounded theory como abordagem metodológica: relatos de uma experiência de campo

    Directory of Open Access Journals (Sweden)

    Marcelo de Rezende Pinto

    2012-09-01

    Full Text Available Uma vez que já é possível encontrar no Brasil alguns artigos que contemplam questões atinentes ao histórico, tipologias e principais características da grounded theory, este trabalho tem por finalidade contribuir para uma maior discussão dessa abordagem metodológica enquanto estilo de fazer pesquisa. De maneira específi ca, o trabalho tenta descrever uma experiência de campo e, principalmente, contar a saga de um pesquisador envolvido com o desafio de colocar a grounded theory em prática. Para isso, buscou-se dividir o trabalho em três partes distintas. Na primeira parte, apresentamos a grounded theory de uma maneira ampla, introduzindo alguns dos seus princípios fundamentais. Na segunda parte, descreve-se o trabalho de campo que foi realizado - nos moldes da grounded theory - com o objetivo de investigar a forma como os consumidores brasileiros oriundos das classes mais populares vivenciam suas experiências de consumo de produtos eletrônicos. Na terceira e última parte, são apresentadas algumas reflexões sobre as exigências práticas para a “operacionalização” de pesquisas comprometidas com o “espírito” da grounded theory, bem como as dúvidas, os dilemas, as difi culdades e as angústias vivenciadas ao longo de todo o processo de pesquisa contadas por quem passou por elas. ----- The Grounded Theory as Methodological Approach: reports of a field experience ----- ABSTRACT ----- As there are few articles that address issues relating to the history, types and main characteristics of grounded theory in Brazil, this paper aims to further the discussion of this methodological approach as a way of doing research. More specifically, the paper describes a field experience, and in particular the history of a researcher involved with the challenge of putting grounded theory into practice. The work is divided into three distinct parts. First we present grounded theory broadly, introducing some of its fundamental

  9. Excited-state properties from ground-state DFT descriptors: A QSPR approach for dyes.

    Science.gov (United States)

    Fayet, Guillaume; Jacquemin, Denis; Wathelet, Valérie; Perpète, Eric A; Rotureau, Patricia; Adamo, Carlo

    2010-02-26

    This work presents a quantitative structure-property relationship (QSPR)-based approach allowing an accurate prediction of the excited-state properties of organic dyes (anthraquinones and azobenzenes) from ground-state molecular descriptors, obtained within the (conceptual) density functional theory (DFT) framework. The ab initio computation of the descriptors was achieved at several levels of theory, so that the influence of the basis set size as well as of the modeling of environmental effects could be statistically quantified. It turns out that, for the entire data set, a statistically-robust four-variable multiple linear regression based on PCM-PBE0/6-31G calculations delivers a R(adj)(2) of 0.93 associated to predictive errors allowing for rapid and efficient dye design. All the selected descriptors are independent of the dye's family, an advantage over previously designed QSPR schemes. On top of that, the obtained accuracy is comparable to the one of the today's reference methods while exceeding the one of hardness-based fittings. QSPR relationships specific to both families of dyes have also been built up. This work paves the way towards reliable and computationally affordable color design for organic dyes. Copyright 2009 Elsevier Inc. All rights reserved.

  10. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  11. Density-matrix-functional calculations for matter in strong magnetic fields: Ground states of heavy atoms

    DEFF Research Database (Denmark)

    Johnsen, Kristinn; Yngvason, Jakob

    1996-01-01

    We report on a numerical study of the density matrix functional introduced by Lieb, Solovej, and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes exactly the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge Z...... and the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained...... by other methods. For iron at B=1012 G the ground-state energy differs by less than 2% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative charge...

  12. Matrix product states for lattice field theories

    Energy Technology Data Exchange (ETDEWEB)

    Banuls, M.C.; Cirac, J.I. [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Saito, H. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Tsukuba Univ., Ibaraki (Japan). Graduate School of Pure and Applied Sciences

    2013-10-15

    The term Tensor Network States (TNS) refers to a number of families of states that represent different ansaetze for the efficient description of the state of a quantum many-body system. Matrix Product States (MPS) are one particular case of TNS, and have become the most precise tool for the numerical study of one dimensional quantum many-body systems, as the basis of the Density Matrix Renormalization Group method. Lattice Gauge Theories (LGT), in their Hamiltonian version, offer a challenging scenario for these techniques. While the dimensions and sizes of the systems amenable to TNS studies are still far from those achievable by 4-dimensional LGT tools, Tensor Networks can be readily used for problems which more standard techniques, such as Markov chain Monte Carlo simulations, cannot easily tackle. Examples of such problems are the presence of a chemical potential or out-of-equilibrium dynamics. We have explored the performance of Matrix Product States in the case of the Schwinger model, as a widely used testbench for lattice techniques. Using finite-size, open boundary MPS, we are able to determine the low energy states of the model in a fully non-perturbativemanner. The precision achieved by the method allows for accurate finite size and continuum limit extrapolations of the ground state energy, but also of the chiral condensate and the mass gaps, thus showing the feasibility of these techniques for gauge theory problems.

  13. Classical many-particle systems with unique disordered ground states

    Science.gov (United States)

    Zhang, G.; Stillinger, F. H.; Torquato, S.

    2017-10-01

    Classical ground states (global energy-minimizing configurations) of many-particle systems are typically unique crystalline structures, implying zero enumeration entropy of distinct patterns (aside from trivial symmetry operations). By contrast, the few previously known disordered classical ground states of many-particle systems are all high-entropy (highly degenerate) states. Here we show computationally that our recently proposed "perfect-glass" many-particle model [Sci. Rep. 6, 36963 (2016), 10.1038/srep36963] possesses disordered classical ground states with a zero entropy: a highly counterintuitive situation . For all of the system sizes, parameters, and space dimensions that we have numerically investigated, the disordered ground states are unique such that they can always be superposed onto each other or their mirror image. At low energies, the density of states obtained from simulations matches those calculated from the harmonic approximation near a single ground state, further confirming ground-state uniqueness. Our discovery provides singular examples in which entropy and disorder are at odds with one another. The zero-entropy ground states provide a unique perspective on the celebrated Kauzmann-entropy crisis in which the extrapolated entropy of a supercooled liquid drops below that of the crystal. We expect that our disordered unique patterns to be of value in fields beyond glass physics, including applications in cryptography as pseudorandom functions with tunable computational complexity.

  14. Victimising of School Bullying: A Grounded Theory

    Science.gov (United States)

    Thornberg, Robert; Halldin, Karolina; Bolmsjo, Natalie; Petersson, Annelie

    2013-01-01

    The aim of this study was to investigate how individuals;who had been victims of school bullying; perceived their bullying experiences and how these had affected them; and to generate a grounded theory of being a victim of bullying at school. Twenty-one individuals, who all had prior experiences of being bullied in school for more than one year,…

  15. Emergent Ising degrees of freedom above a double-stripe magnetic ground state

    Science.gov (United States)

    Zhang, Guanghua; Flint, Rebecca

    2017-12-01

    Double-stripe magnetism [Q =(π /2 ,π /2 )] has been proposed as the magnetic ground state for both the iron-telluride and BaTi2Sb2O families of superconductors. Double-stripe order is captured within a J1-J2-J3 Heisenberg model in the regime J3≫J2≫J1 . Intriguingly, besides breaking spin-rotational symmetry, the ground-state manifold has three additional Ising degrees of freedom associated with bond ordering. Via their coupling to the lattice, they give rise to an orthorhombic distortion and to two nonuniform lattice distortions with wave vector (π ,π ) . Because the ground state is fourfold degenerate, modulo rotations in spin space, only two of these Ising bond order parameters are independent. Here, we introduce an effective field theory to treat all Ising order parameters, as well as magnetic order, and solve it within a large-N limit. All three transitions, corresponding to the condensations of two Ising bond order parameters and one magnetic order parameter are simultaneous and first order in three dimensions, but lower dimensionality, or equivalently weaker interlayer coupling, and weaker magnetoelastic coupling can split the three transitions, and in some cases allows for two separate Ising phase transitions above the magnetic one.

  16. Cavity optomechanics -- beyond the ground state

    Science.gov (United States)

    Meystre, Pierre

    2011-05-01

    The coupling of coherent optical systems to micromechanical devices, combined with breakthroughs in nanofabrication and in ultracold science, has opened up the exciting new field of cavity optomechanics. Cooling of the vibrational motion of a broad range on oscillating cantilevers and mirrors near their ground state has been demonstrated, and the ground state of at least one such system has now been reached. Cavity optomechanics offers much promise in addressing fundamental physics questions and in applications such as the detection of feeble forces and fields, or the coherent control of AMO systems and of nanoscale electromechanical devices. However, these applications require taking cavity optomechanics ``beyond the ground state.'' This includes the generation and detection of squeezed and other non-classical states, the transfer of squeezing between electromagnetic fields and motional quadratures, and the development of measurement schemes for the characterization of nanomechanical structures. The talk will present recent ``beyond ground state'' developments in cavity optomechanics. We will show how the magnetic coupling between a mechanical membrane and a BEC - or between a mechanical tuning fork and a nanoscale cantilever - permits to control and monitor the center-of-mass position of the mechanical system, and will comment on the measurement back-action on the membrane motion. We will also discuss of state transfer between optical and microwave fields and micromechanical devices. Work done in collaboration with Dan Goldbaum, Greg Phelps, Keith Schwab, Swati Singh, Steve Steinke, Mehmet Tesgin, and Mukund Vengallatore and supported by ARO, DARPA, NSF, and ONR.

  17. Reflecting on e-Recruiting Research Using Grounded Theory

    NARCIS (Netherlands)

    Wolfswinkel, Joost; Furtmueller-Ettinger, Elfriede; Wilderom, Celeste P.M.

    2010-01-01

    This paper presents a systematic review of the e-Recruiting literature through a grounded theory lens. The large number of publications and the increasing diversity of publications on e-Recruiting research, as the most studied area within e-HRM (Electronic Human Resource Management), calls for a

  18. Adjoint sensitivity theory for steady-state ground-water flow

    International Nuclear Information System (INIS)

    1983-11-01

    In this study, adjoint sensitivity theory is developed for equations of two-dimensional steady-state flow in a confined aquifer. Both the primary flow equation and the adjoint sensitivity equation are solved using the Galerkin finite element method. The developed computer code is used to investigate the regional flow parameters of the Leadville Formation of the Paradox Basin in Utah and the Wolcamp carbonate/sandstone aquifer of the Palo Duro Basin in the Texas Panhandle. Two performance measures are evaluated, local heads and velocity in the vicinity of potential high-level nuclear waste repositories. The results illustrate the sensitivity of calculated local heads to the boundary conditions. Local velocity-related performance measures are more sensitive to hydraulic conductivities. The uncertainty in the performance measure is a function of the parameter sensitivity, parameter variance and the correlation between parameters. Given a parameter covariance matrix, the uncertainty of the performance measure can be calculated. Although no results are presented here, the implications of uncertainty calculations for the two studies are discussed. 18 references, 25 figures

  19. The Relationship between an Emerging Grounded Theory and the Existing Literature: Four phases for consideration

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2006-06-01

    Full Text Available The relationship between grounded theory researchers and the existing literature has become a red herring that even confuses some grounded theorists who have completed a study. Antoinette McCallin’s essay does a commendable job outlining the realities of the research terrain that make proceeding without some exposure to the literature unlikely and ill-advised in most situations. When embarking on my dissertation, I needed to know enough about the literature, both substantive and methodological, to argue for the use of classic grounded theory as opposed to many other choices within my field; yet my study benefited from the necessary tensions between the emerging grounded theory and the existing literature. In this brief essay I propose that the relationship between the existing literature and a developing grounded theory project goes through four discernible phases:noncommittal, comparative, integrative, and, if the analyst can push, a transcendent phase in which the theory is not simply one of a number of theories of a kind within the discipline’s literature. I explain the phases to make more explicit the under-recognized subversive potential of grounded theory to push pass disciplinary boundaries by broadening the ‘relevant’ literature. Barney Glaser has often admonished grounded theory researchers to put off the literature to avoid wasting time and energy with literature that may prove irrelevant. I have not found such literature to be irrelevant as much as limited, and in some cases restricted by what a particular discipline defines as the appropriate literature. Therefore, the question of what literature offers possibilities for literature review and comparisons that would allow for richer knowledge generation. I return to this matter toward the end of the essay.

  20. Challenging convention: symbolic interactionism and grounded theory.

    Science.gov (United States)

    Newman, Barbara

    2008-01-01

    Not very much is written in the literature about decisions made by researchers and the justifications on method as a result of a particular clinical problem, together with an appropriate and congruent theoretical perspective, particularly for Glaserian grounded theory. I contend the utilisation of symbolic interactionism as a theoretical perspective to inform and guide the evolving research process and analysis of data when using classic or Glaserian grounded theory (GT) method, is not always appropriate. Within this article I offer an analysis of the key issues to be addressed when contemplating the use of Glaserian GT and the utilisation of an appropriate theoretical perspective, rather than accepting convention of symbolic interactionism (SI). The analysis became imperative in a study I conducted that sought to explore the concerns, adaptive behaviours, psychosocial processes and relevant interactions over a 12-month period, among newly diagnosed persons with end stage renal disease, dependent on haemodialysis in the home environment for survival. The reality of perception was central to the end product in the study. Human ethics approval was granted by six committees within New South Wales Health Department and one from a university.

  1. On the ground state and infrared divergences of Goldstone bosons in two dimensions

    International Nuclear Information System (INIS)

    Jevicki, A.

    1977-01-01

    The O(N) invariant Goldstone field theory is studied in two dimensions where rigorous theorems forbid the occurrence of spontaneous symmetry breaking. It is agreed that for computation of the ground state energy at weak coupling it is still the standard Goldstone perturbation expansion that is applicable. This happens due to cancellation of infrared divergences and this fact is demonstrated explicitly at the two-loop level. (Auth.)

  2. Ground-state projection multigrid for propagators in 4-dimensional SU(2) gauge fields

    International Nuclear Information System (INIS)

    Kalkreuter, T.

    1991-09-01

    The ground-state projection multigrid method is studied for computations of slowly decaying bosonic propagators in 4-dimensional SU(2) lattice gauge theory. The defining eigenvalue equation for the restriction operator is solved exactly. Although the critical exponent z is not reduced in nontrivial gauge fields, multigrid still yields considerable speedup compared with conventional relaxation. Multigrid is also able to outperform the conjugate gradient algorithm. (orig.)

  3. A Grounded Theory of School of Education Futures

    Science.gov (United States)

    Doiron, Joseph A.

    2017-01-01

    The purpose of this grounded theory study was to explore the futures that school of education leaders envision for their institutions. American higher education institutions broadly, and schools of education specifically, face a complex of challenges to their traditional structures, processes, practices, value, and values. These challenges create…

  4. A Grounded Theory on Helping Behavior and Its Shaping Factors

    Directory of Open Access Journals (Sweden)

    A Grounded Theory on Helping Behavior and Its Shaping Factors

    2006-06-01

    Full Text Available In social psychology, the attribution model of helping behavior suggests that beliefs of the helping target’s responsibility for the need for help evoke affective motivators such as feelings of pity, sympathy, or anger. The affective motivation leads to helping or not helping the target. The current emergent theory is an enhancement of this theory by incorporating other personal and situational variables.Through the use of classic grounded theory, I interviewed 80 participants from different De La Salle Schools in the Philippines. This yielded over 1300 individual incidents that were compared and contrasted to form codes, categories and subcategories. A theory on the decision making process of helping emerged that incorporates the helper’s personal conviction, and rational deliberations of the situation. The desire to help is based on the helper’s rationalemotive beliefs (philosophical ideals and values that nurture helping and the knowledge of the nature of risk/problem and relational-emotive ties (with the one who needs help and with a social group that nurtures helping. The desire to help undergoes a process of rationalpragmatic-deliberations on the appropriateness of the recipients need of help, the cost of helping, the helper’s capability of helping, and the logistics of helping before the actual helping occurs. The theory has implications for current social psychological theories of helping, and the use of classic grounded theory research.

  5. Bound-state perturbation theory and annihilation effects in positronium

    International Nuclear Information System (INIS)

    Abbasabadi, A.; Repko, W.W.

    1987-01-01

    Working in Coulomb gauge and using the lowest-order equation proposed by Barbieri and Remiddi it is calculated, in the one-loop order of perturbation theory, the decay rate and the energy shift of the ground states of parapositronium and orthopositronium, respectively. Our result for the decay rate agrees with that of Harris and Brown. For contribution of one-photon-annihilation channel to the energy shift, it is confirmed the result of Karplus and Klein. These results are derived completely within the bound-state formalism and avoid the necessity of performing on-mass-shell wave function and vertex renormalization subtractions

  6. Living with the Choice: A Grounded Theory of Iraqi Refugee Resettlement to the U.S.

    Science.gov (United States)

    Davenport, Lisa A

    2017-04-01

    Though the United States has become a place of increasing resettlement for refugees, particularly Iraqi refugees who have been forced to flee their homeland due to violence, persecution and civil unrest, little is known about Iraqi refugee resettlement in the United States, or the way in which resettlement impacts health and adjustment. A grounded theory study was conducted to develop a substantive theory of Iraqi refugee resettlement. Participants in the qualitative study included 29 Iraqi refugees and 2 community partners who participated in face-to face interviews. Data analysis and interpretation revealed fundamental concepts related to Iraqi refugee resettlement. Results of analysis showed that for Iraqis choosing to resettle here, the outcome is dichotomous: satisfaction or regret. The outcome is influenced by contextual factors as well as facilitating and hindering intervening conditions during the basic social process of resettlement transition. Each refugee's story is unique, yet all share common threads. This study allowed Iraqi refugees the opportunity to voice their personal experiences of resettling in America, and revealed life stories that inspire and illuminate a process that can guide health care delivery as they cope with the stresses of their journey. As a result, an in-depth storyline was established to explain the process of resettlement for Iraqi refugees. The development of this resettlement theory, grounded in Iraqi refugee experience, has the potential to guide nursing education, enhance the efficacy of practice, inform policy development and form the basis for research.

  7. Ground state searches in fcc intermetallics

    International Nuclear Information System (INIS)

    Wolverton, C.; de Fontaine, D.; Ceder, G.; Dreysse, H.

    1991-12-01

    A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration

  8. Racial and Ethnic Diversity in Grounded Theory Research

    Science.gov (United States)

    Draucker, Claire Burke; Al-Khattab, Halima; Hines, Dana D.; Mazurczyk, Jill; Russell, Anne C.; Stephenson, Pam Shockey; Draucker, Shannon

    2014-01-01

    National initiatives in the United States call for health research that addresses racial/ethnic disparities. Although grounded theory (GT) research has the potential to contribute much to the understanding of the health experiences of people of color, the extent to which it has contributed to health disparities research is unclear. In this article we describe a project in which we reviewed 44 GT studies published in Qualitative Health Research within the last five years. Using a framework proposed by Green, Creswell, Shope, and Clark (2007), we categorized the studies at one of four levels based on the status and significance afforded racial/ethnic diversity. Our results indicate that racial/ethnic diversity played a primary role in five studies, a complementary role in one study, a peripheral role in five studies, and an absent role in 33 studies. We suggest that GT research could contribute more to health disparities research if techniques were developed to better analyze the influence of race/ethnicity on health-related phenomena. PMID:26401523

  9. Racial and Ethnic Diversity in Grounded Theory Research.

    Science.gov (United States)

    Draucker, Claire Burke; Al-Khattab, Halima; Hines, Dana D; Mazurczyk, Jill; Russell, Anne C; Stephenson, Pam Shockey; Draucker, Shannon

    2014-04-28

    National initiatives in the United States call for health research that addresses racial/ethnic disparities. Although grounded theory (GT) research has the potential to contribute much to the understanding of the health experiences of people of color, the extent to which it has contributed to health disparities research is unclear. In this article we describe a project in which we reviewed 44 GT studies published in Qualitative Health Research within the last five years. Using a framework proposed by Green, Creswell, Shope, and Clark (2007), we categorized the studies at one of four levels based on the status and significance afforded racial/ethnic diversity. Our results indicate that racial/ethnic diversity played a primary role in five studies, a complementary role in one study, a peripheral role in five studies, and an absent role in 33 studies. We suggest that GT research could contribute more to health disparities research if techniques were developed to better analyze the influence of race/ethnicity on health-related phenomena.

  10. Ground-state triply and doubly heavy baryons in a relativistic three-quark model

    International Nuclear Information System (INIS)

    Martynenko, A.P.

    2008-01-01

    Mass spectra of the ground-state baryons consisting of three or two heavy (b or c) and one light (u,d,s) quarks are calculated in the framework of the relativistic quark model and the hyperspherical expansion. The predictions of masses of the triply and doubly heavy baryons are obtained by employing the perturbation theory for the spin-independent and spin-dependent parts of the three-quark Hamiltonian

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

    Science.gov (United States)

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

    2013-12-01

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

  12. Singlet Ground State Magnetism:

    DEFF Research Database (Denmark)

    Loidl, A.; Knorr, K.; Kjems, Jørgen

    1979-01-01

    The magneticGamma 1 –Gamma 4 exciton of the singlet ground state system TbP has been studied by inelastic neutron scattering above the antiferromagnetic ordering temperature. Considerable dispersion and a pronounced splitting was found in the [100] and [110] directions. Both the band width...

  13. Understanding the Conceptual Development Phase of Applied Theory-Building Research: A Grounded Approach

    Science.gov (United States)

    Storberg-Walker, Julia

    2007-01-01

    This article presents a provisional grounded theory of conceptual development for applied theory-building research. The theory described here extends the understanding of the components of conceptual development and provides generalized relations among the components. The conceptual development phase of theory-building research has been widely…

  14. A grounded theory of young tennis players use of music to manipulate emotional state.

    Science.gov (United States)

    Bishop, Daniel T; Karageorghis, Costas I; Loizou, Georgios

    2007-10-01

    The main objectives of this study were (a) to elucidate young tennis players' use of music to manipulate emotional states, and (b) to present a model grounded in present data to illustrate this phenomenon and to stimulate further research. Anecdotal evidence suggests that music listening is used regularly by elite athletes as a preperformance strategy, but only limited empirical evidence corroborates such use. Young tennis players (N = 14) were selected purposively for interview and diary data collection. Results indicated that participants consciously selected music to elicit various emotional states; frequently reported consequences of music listening included improved mood, increased arousal, and visual and auditory imagery. The choice of music tracks and the impact of music listening were mediated by a number of factors, including extramusical associations, inspirational lyrics, music properties, and desired emotional state. Implications for the future investigation of preperformance music are discussed.

  15. Effect of the ground state correlations in the density distribution and zero point fluctuations

    International Nuclear Information System (INIS)

    Barranco, F.; Broglia, R.A.

    1985-01-01

    The existence of collective vibrations in the spectrum implies that the description of the ground state in an independent particle model must be corrected. This is because of the zero point fluctuations induced by the collective vibrations, so that ground state correlations have to be included. These are taken into account via the diagrammatic expansion of the Nuclear Field Theory, giving place to a renormalization in the different properties of the ground state. As far as the density distribution is concerned, in a NFT consistent calculation, the largest contributions arise from diagrams that cannot be expressed in terms of backward going amplitudes of the phonon RPA wave function. For a given multipolarity the main correction comes from the low lying state. The giant resonance is of smaller relevance since it lies at larger energies in the response function. The octupole modes give the dominant contribution, and the effect in average becomes smaller as the multipolarity increases. These results agree quite well with those obtained taking into account the zero point fluctuations of the nuclear surface in the collective model with the Esbensen and Bertsch prescription, which the authors use to explain the anomalous behaviour of the mean square radii of the Calcium isotopes

  16. Staying theoretically sensitive when conducting grounded theory research.

    Science.gov (United States)

    Reay, Gudrun; Bouchal, Shelley Raffin; A Rankin, James

    2016-09-01

    Background Grounded theory (GT) is founded on the premise that underlying social patterns can be discovered and conceptualised into theories. The method and need for theoretical sensitivity are best understood in the historical context in which GT was developed. Theoretical sensitivity entails entering the field with no preconceptions, so as to remain open to the data and the emerging theory. Investigators also read literature from other fields to understand various ways to construct theories. Aim To explore the concept of theoretical sensitivity from a classical GT perspective, and discuss the ontological and epistemological foundations of GT. Discussion Difficulties in remaining theoretically sensitive throughout research are discussed and illustrated with examples. Emergence - the idea that theory and substance will emerge from the process of comparing data - and staying open to the data are emphasised. Conclusion Understanding theoretical sensitivity as an underlying guiding principle of GT helps the researcher make sense of important concepts, such as delaying the literature review, emergence and the constant comparative method (simultaneous collection, coding and analysis of data). Implications for practice Theoretical sensitivity and adherence to the GT research method allow researchers to discover theories that can bridge the gap between theory and practice.

  17. Grounded theory for radiotherapy practitioners: Informing clinical practice

    International Nuclear Information System (INIS)

    Walsh, N.A.

    2010-01-01

    Radiotherapy practitioners may be best placed to undertake qualitative research within the context of cancer, due to specialist knowledge of radiation treatment and sensitivity to radiotherapy patient's needs. The grounded theory approach to data collection and analysis is a unique method of identifying a theory directly based on data collected within a clinical context. Research for radiotherapy practitioners is integral to role expansion within the government's directive for evidence-based practice. Due to the paucity of information on qualitative research undertaken by radiotherapy radiographers, this article aims to assess the potential impact of qualitative research on radiotherapy patient and service outcomes.

  18. Exploring Attitude Transformation: A Grounded Theory Study of Romanian Teachers of Roma Students

    Science.gov (United States)

    Jones, Laura Estella

    2016-01-01

    The purpose of this systematic grounded theory study was to explore the process of change in teacher attitudes toward including Roma ("Gypsy") students in non-segregated schools in Romania. The theories guiding this study included Mezirow's (1991, 2000) theory of transformation, Gay's (2002, 2013) theory of culturally responsive…

  19. 66Ga ground state β spectrum

    DEFF Research Database (Denmark)

    Severin, Gregory; Knutson, L. D.; Voytas, P. A.

    2014-01-01

    The ground state branch of the β decay of 66Ga is an allowed Fermi (0+ → 0+) transition with a relatively high f t value. The large f t and the isospin-forbidden nature of the transition indicates that the shape of the β spectrum of this branch may be sensitive to higher order contributions...... to the decay. Two previous measurements of the shape have revealed deviations from an allowed spectrum but disagree about whether the shape factor has a positive or negative slope. As a test of a new iron-free superconducting β spectrometer, we have measured the shape of the ground state branch of the 66Ga β...... spectrum above a positron energy of 1.9 MeV. The spectrum is consistent with an allowed shape, with the slope of the shape factor being zero to within ±3 × 10−3 per MeV. We have also determined the endpoint energy for the ground state branch to be 4.1535 ± 0.0003 (stat.) ±0.0007 (syst.) MeV, in good...

  20. The Experiential Model of the Person-Centred Record: a social constructionist grounded theory

    OpenAIRE

    Mihelcic, Joanne

    2017-01-01

    The objective of this research was to explore the co-creation of person-centred records, to support memory, identity and personhood, with the person diagnosed with early stage dementia. This thesis describes the design of a second generation grounded theory methodology and applied archival research. With its postmodern, continuum and social constructionist influences second generation grounded theory sees a shift in how we understand the researcher’s interaction with participants in a study...

  1. Ground state analysis of magnetic nanographene molecules with modified edge

    International Nuclear Information System (INIS)

    Gorjizadeh, Narjes; Ota, Norio; Kawazoe, Yoshiyuki

    2013-01-01

    Highlights: ► Graphene molecules can become ferromagnetic by edge modifications. ► Dihydrogenation of one zigzag edge of rectangular flakes make them ferromagnetic. ► Triangular flakes become high-spin state by dehydrogenization of one zigzag edge. - Abstract: We study spin states of edge modified nanographene molecules with rectangular and triangular shapes by first principle calculations using density functional theory (DFT) and Hartree–Fock (HF) methods with Møller–Plesset (MP) correlation energy correction at different levels. Anthracene (C 14 H 10 ) and phenalenyl (C 13 H 9 ), which contain three benzene rings combined in two different ways, can be considered as fragments of a graphene sheet. Carbon-based ferromagnetic materials are of great interest both in fundamental science and technological potential in organic spintronics devices. We show that non-magnetic rectangular molecules such as C 14 H 10 can become ferromagnetic with high-spin state as the ground state by dihydrogenization of one of the zigzag edges, while triangular molecules such as C 13 H 9 become ferromagnetic with high-spin state by dehydrogenization of one of the zigzag edges

  2. Usos e Aplicações da Grounded Theory em Administração

    Directory of Open Access Journals (Sweden)

    Eliane Maria Pires Giavina Bianchi

    2008-01-01

    Full Text Available This paper discusses the usage and application of grounded theory in the administration area.Grounded theory is a research tool under the qualitative paradigm that, since its beginning in 1967raised some debates in the academic arena. Its original authors, Barney Glaser & Anselm Strauss,developed, throughout their academic trajectories,distinct thoughts regarding the process of datacollection and data analysis, the researcher attitude and the way of attainment the researchresults: theory grounded on empirical data. In spite of that, the history on the evolution of theresearch method, the research method working process clarification and an analysis of someapplications in the administrative area are discussed in this paper to support reflections ongrounded theory applicability and potentiality in administration. The purpose of this paper is tocontribute with researchers by bringing relevant information to support the processes of choice ofthis research method and its proper execution in their research. The conclusion is that groundedtheory is complex, rich, and powerful being applicable in administration as part of the social science

  3. Exact ground-state correlation functions of one-dimenisonal strongly correlated electron models with resonating-valence-bond ground state

    International Nuclear Information System (INIS)

    Yamanaka, Masanori; Honjo, Shinsuke; Kohmoto, Mahito

    1996-01-01

    We investigate one-dimensional strongly correlated electron models which have the resonating-valence-bond state as the exact ground state. The correlation functions are evaluated exactly using the transfer matrix method for the geometric representations of the valence-bond states. In this method, we only treat matrices with small dimensions. This enables us to give analytical results. It is shown that the correlation functions decay exponentially with distance. The result suggests that there is a finite excitation gap, and that the ground state is insulating. Since the corresponding noninteracting systems may be insulating or metallic, we can say that the gap originates from strong correlation. The persistent currents of the present models are also investigated and found to be exactly vanishing

  4. The ground state tunneling splitting and the zero point energy of malonaldehyde: a quantum Monte Carlo determination.

    Science.gov (United States)

    Viel, Alexandra; Coutinho-Neto, Maurício D; Manthe, Uwe

    2007-01-14

    Quantum dynamics calculations of the ground state tunneling splitting and of the zero point energy of malonaldehyde on the full dimensional potential energy surface proposed by Yagi et al. [J. Chem. Phys. 1154, 10647 (2001)] are reported. The exact diffusion Monte Carlo and the projection operator imaginary time spectral evolution methods are used to compute accurate benchmark results for this 21-dimensional ab initio potential energy surface. A tunneling splitting of 25.7+/-0.3 cm-1 is obtained, and the vibrational ground state energy is found to be 15 122+/-4 cm-1. Isotopic substitution of the tunneling hydrogen modifies the tunneling splitting down to 3.21+/-0.09 cm-1 and the vibrational ground state energy to 14 385+/-2 cm-1. The computed tunneling splittings are slightly higher than the experimental values as expected from the potential energy surface which slightly underestimates the barrier height, and they are slightly lower than the results from the instanton theory obtained using the same potential energy surface.

  5. Using Grounded Theory to Analyze Qualitative Observational Data that is Obtained by Video Recording

    Directory of Open Access Journals (Sweden)

    Colin Griffiths

    2013-06-01

    Full Text Available This paper presents a method for the collection and analysis of qualitative data that is derived by observation and that may be used to generate a grounded theory. Video recordings were made of the verbal and non-verbal interactions of people with severe and complex disabilities and the staff who work with them. Three dyads composed of a student/teacher or carer and a person with a severe or profound intellectual disability were observed in a variety of different activities that took place in a school. Two of these recordings yielded 25 minutes of video, which was transcribed into narrative format. The nature of the qualitative micro data that was captured is described and the fit between such data and classic grounded theory is discussed. The strengths and weaknesses of the use of video as a tool to collect data that is amenable to analysis using grounded theory are considered. The paper concludes by suggesting that using classic grounded theory to analyze qualitative data that is collected using video offers a method that has the potential to uncover and explain patterns of non-verbal interactions that were not previously evident.

  6. Maintaining the balance: New Zealand secondary school nurses' perceptions of skin infections in young people--a grounded theory.

    Science.gov (United States)

    Lambe, Catherine I; Hoare, Karen J

    2016-01-01

    The objective of this study was to explore the perceptions of New Zealand secondary school nurses regarding skin infections in young people aged 14-18 years. A constructivist grounded theory method was adopted. Ten non-structured interviews were conducted with secondary school nurses working in Auckland, New Zealand, between January and July 2013. Interviews were audiotaped, transcribed and analysed using all tenets of grounded theory that included writing memos, theoretical sampling and the constant comparative method. Analysis revealed the core category Maintaining the balance, which is presented as a grounded theory model. It represents the constant state of balancing the school nurse undergoes in trying to counter the risk to the student. The nurse attempts to tip the balance in favour of action, by reducing barriers to healthcare, providing youth-friendly, affordable and accessible healthcare, and following up until resolution is achieved. The nurse is aware that failing to monitor until resolution can again tip the fulcrum back to inaction, placing the young person at risk again. It is concluded that nurses are knowledgeable about the risks present in the communities they serve and are innovative in the methods they employ to ensure satisfactory outcomes for young people experiencing skin infections. School nursing is an evolving model for delivering primary healthcare to young people in New Zealand. The grounded theory model 'Maintaining the balance' describes a model of care where nursing services are delivered where young people spend time, and the nurse is immersed in the community. This model of care may be transferable to other healthcare situations. © 2015 John Wiley & Sons Ltd.

  7. Resisting Coherence: Trans Men's Experiences and the Use of Grounded Theory Methods

    Science.gov (United States)

    Catalano, D. Chase J.

    2017-01-01

    In this methodological reflective manuscript, I explore my decision to use a grounded theoretical approach to my dissertation study on trans* men in higher education. Specifically, I question whether grounded theory as a methodology is capable of capturing the complexity and capaciousness of trans*-masculine experiences. Through the lenses of…

  8. Estimation of ground and excited-state dipole moments of 1, 2-diazines by solvatochromic method and quantum-chemical calculation

    DEFF Research Database (Denmark)

    Manohara, S.R.; Kumar, V. Udaya; Shivakumaraiah

    2013-01-01

    chemical calculations using the DFT method by adopting B3LYP/6-31G* level of theory (Gaussian 03) and using the AM1 method (Chem3D Ultra 8.0). It was observed that, dipole moments of diazines in the excited-state (μe) were greater than the corresponding ground-state values (μg), indicating a substantial...

  9. Methodological tools for the collection and analysis of participant observation data using grounded theory.

    Science.gov (United States)

    Laitinen, Heleena; Kaunonen, Marja; Astedt-Kurki, Päivi

    2014-11-01

    To give clarity to the analysis of participant observation in nursing when implementing the grounded theory method. Participant observation (PO) is a method of collecting data that reveals the reality of daily life in a specific context. In grounded theory, interviews are the primary method of collecting data but PO gives a distinctive insight, revealing what people are really doing, instead of what they say they are doing. However, more focus is needed on the analysis of PO. An observational study carried out to gain awareness of nursing care and its electronic documentation in four acute care wards in hospitals in Finland. Discussion of using the grounded theory method and PO as a data collection tool. The following methodological tools are discussed: an observational protocol, jotting of notes, microanalysis, the use of questioning, constant comparison, and writing and illustrating. Each tool has specific significance in collecting and analysing data, working in constant interaction. Grounded theory and participant observation supplied rich data and revealed the complexity of the daily reality of acute care. In this study, the methodological tools provided a base for the study at the research sites and outside. The process as a whole was challenging. It was time-consuming and it required rigorous and simultaneous data collection and analysis, including reflective writing. Using these methodological tools helped the researcher stay focused from data collection and analysis to building theory. Using PO as a data collection method in qualitative nursing research provides insights. It is not commonly discussed in nursing research and therefore this study can provide insight, which cannot be seen or revealed by using other data collection methods. Therefore, this paper can produce a useful tool for those who intend to use PO and grounded theory in their nursing research.

  10. Kinetically blocked stable heptazethrene and octazethrene: Closed-shell or open-shell in the ground state?

    KAUST Repository

    Li, Yuan

    2012-09-12

    Polycyclic aromatic hydrocarbons with an open-shell singlet biradical ground state are of fundamental interest and have potential applications in materials science. However, the inherent high reactivity makes their synthesis and characterization very challenging. In this work, a convenient synthetic route was developed to synthesize two kinetically blocked heptazethrene (HZ-TIPS) and octazethrene (OZ-TIPS) compounds with good stability. Their ground-state electronic structures were systematically investigated by a combination of different experimental methods, including steady-state and transient absorption spectroscopy, variable temperature NMR, electron spin resonance (ESR), superconducting quantum interfering device (SQUID), FT Raman, and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. All these demonstrated that the heptazethrene derivative HZ-TIPS has a closed-shell ground state while its octazethrene analogue OZ-TIPS with a smaller energy gap exists as an open-shell singlet biradical with a large measured biradical character (y = 0.56). Large two-photon absorption (TPA) cross sections (σ(2)) were determined for HZ-TIPS (σ(2)max = 920 GM at 1250 nm) and OZ-TIPS (σ(2)max = 1200 GM at 1250 nm). In addition, HZ-TIPS and OZ-TIPS show a closely stacked 1D polymer chain in single crystals. © 2012 American Chemical Society.

  11. High-speed ground transportation development outside United States

    Energy Technology Data Exchange (ETDEWEB)

    Eastham, T.R. [Queen`s Univ., Kingston, Ontario (United Kingdom)

    1995-09-01

    This paper surveys the state of high-speed (in excess of 200 km/h) ground-transportation developments outside the United States. Both high-speed rail and Maglev systems are covered. Many vehicle systems capable of providing intercity service in the speed range 200--500 km/h are or will soon be available. The current state of various technologies, their implementation, and the near-term plans of countries that are most active in high-speed ground transportation development are reported.

  12. Protocol: A grounded theory of 'recovery'-perspectives of adolescent users of mental health services.

    Science.gov (United States)

    Palmquist, Lucianne; Patterson, Sue; O'Donovan, Analise; Bradley, Graham

    2017-07-20

    Policies internationally endorse the recovery paradigm as the appropriate foundation for youth mental health services. However, given that this paradigm is grounded in the views of adults with severe mental illness, applicability to youth services and relevance to young people is uncertain, particularly as little is known about young people's views. A comprehensive understanding of the experiences and expectations of young people is critical to developing youth mental health services that are acceptable, accessible, effective and relevant. To inform development of policy and youth services, the study described in this protocol aims to develop a comprehensive account of the experiences and expectations of 12-17 year olds as they encounter mental disorders and transition through specialist mental health services. Data will be analysed to model recovery from the adolescents' perspective. This grounded theory study will use quantitative and qualitative data collected in interviews with 12-17 year olds engaged with specialist Child/Youth Mental Health Service in Queensland, Australia. Interviews will explore adolescents' expectations and experiences of mental disorder, and of services, as they transition through specialist mental health services, including the meaning of their experiences and ideas of 'recovery' and how their experiences and expectations are shaped. Data collection and analysis will use grounded theory methods. Adolescents' experiences will be presented as a mid-range theory. The research will provide tangible recommendations for youth-focused mental health policy and practice. Findings will be disseminated within academic literature and beyond to participants, health professionals, mental health advocacy groups and policy and decision makers via publications, research summaries, conferences and workshops targeting different audiences. Ethical and research governance approvals have been obtained from relevant Human Research Ethics committees and all

  13. Use of empathy in psychiatric practice: constructivist grounded theory study

    Science.gov (United States)

    Watling, Chris

    2017-01-01

    Background Psychiatry has faced significant criticism for overreliance on the Diagnostic and Statistical Manual of Mental Disorders (DSM) and medications with purported disregard for empathetic, humanistic interventions. Aims To develop an empirically based qualitative theory explaining how psychiatrists use empathy in day-to-day practice, to inform practice and teaching approaches. Method This study used constructivist grounded theory methodology to ask (a) ‘How do psychiatrists understand and use empathetic engagement in the day-to-day practice of psychiatry?’ and (b) ‘How do psychiatrists learn and teach the skills of empathetic engagement?’ The authors interviewed 17 academic psychiatrists and 4 residents and developed a theory by iterative coding of the collected data. Results This constructivist grounded theory of empathetic engagement in psychiatric practice considered three major elements: relational empathy, transactional empathy and instrumental empathy. As one moves from relational empathy through transactional empathy to instrumental empathy, the actions of the psychiatrist become more deliberate and interventional. Conclusions Participants were described by empathy-based interventions which are presented in a theory of ’empathetic engagement’. This is in contrast to a paradigm that sees psychiatry as purely based on neurobiological interventions, with psychotherapy and interpersonal interventions as completely separate activities from day-to-day psychiatric practice. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:28243463

  14. The Constant Comparative Analysis Method Outside of Grounded Theory

    Science.gov (United States)

    Fram, Sheila M.

    2013-01-01

    This commentary addresses the gap in the literature regarding discussion of the legitimate use of Constant Comparative Analysis Method (CCA) outside of Grounded Theory. The purpose is to show the strength of using CCA to maintain the emic perspective and how theoretical frameworks can maintain the etic perspective throughout the analysis. My…

  15. The Rediscovery and Resurrection of Bunk Johnson – a Grounded Theory Approach: A case study in jazz historiography

    Directory of Open Access Journals (Sweden)

    Richard Ekins, Ph.D., FRSA

    2011-12-01

    Full Text Available This paper was written in the beginning phase of my transitioning from grounded theory sociologist (Ekins, 19971 to grounded theory musicologist (Ekins, 20102. In particular, it provides preliminary data for a grounded theory of ‘managing authenticity’, the core category/basic social process (Glaser, 1978 that has emerged from my ongoing grounded theory work in jazz historiography. It was written whilst I was ‘credentialising’ (Glaser, 2010 my transition to popular music studies and popular musicology. In consequence, it incorporates many aspects that are inimical to classic grounded theory. As with so much of Straussian and so-called constructivist grounded theory (Bryant and Charmaz, 2007, it roots itself in G.H. Mead and a social constructivist symbolic interactionism – inter alia, a legitimising (authenticating strategy. Moreover, as is typical of this mode of conceptualising, the paper fills the void of inadequate classic grounded theorising with less conceptual theorising and more conceptual description. Nevertheless, the article does introduce a number of categories that ‘fit and work’, and have ‘conceptual grab’ (Glaser, 1978; Glaser, 1992. In particular, in terms of my own continuing credentialising as a classic grounded theorist, it sets forth important categories to be integrated into my ongoing work on managing authenticity in New Orleans revivalist jazz, namely, ‘trailblazing’, ‘mythologizing’, ‘debunking’, and ‘marginalising’, in the context of the ‘rediscovering’ and ‘resurrecting’ of a jazz pioneer. More specifically, the paper is offered to classic grounded theorists as a contribution to preliminary generic social process analysis in the substantive area of jazz historiography.

  16. Exact many-electron ground states on diamond and triangle Hubbard chains

    International Nuclear Information System (INIS)

    Gulacsi, Zsolt; Kampf, Arno; Vollhardt, Dieter

    2009-01-01

    We construct exact ground states of interacting electrons on triangle and diamond Hubbard chains. The construction requires (1) a rewriting of the Hamiltonian into positive semidefinite form, (2) the construction of a many-electron ground state of this Hamiltonian, and (3) the proof of the uniqueness of the ground state. This approach works in any dimension, requires no integrability of the model, and only demands sufficiently many microscopic parameters in the Hamiltonian which have to fulfill certain relations. The scheme is first employed to construct exact ground state for the diamond Hubbard chain in a magnetic field. These ground states are found to exhibit a wide range of properties such as flat-band ferromagnetism and correlation induced metallic, half-metallic or insulating behavior, which can be tuned by changing the magnetic flux, local potentials, or electron density. Detailed proofs of the uniqueness of the ground states are presented. By the same technique exact ground states are constructed for triangle Hubbard chains and a one-dimensional periodic Anderson model with nearest-neighbor hybridization. They permit direct comparison with results obtained by variational techniques for f-electron ferromagnetism due to a flat band in CeRh 3 B 2 . (author)

  17. Approximating the ground state of gapped quantum spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Michalakis, Spyridon [Los Alamos National Laboratory; Hamza, Eman [NON LANL; Nachtergaele, Bruno [NON LANL; Sims, Robert [NON LANL

    2009-01-01

    We consider quantum spin systems defined on finite sets V equipped with a metric. In typical examples, V is a large, but finite subset of Z{sup d}. For finite range Hamiltonians with uniformly bounded interaction terms and a unique, gapped ground state, we demonstrate a locality property of the corresponding ground state projector. In such systems, this ground state projector can be approximated by the product of observables with quantifiable supports. In fact, given any subset {chi} {contained_in} V the ground state projector can be approximated by the product of two projections, one supported on {chi} and one supported on {chi}{sup c}, and a bounded observable supported on a boundary region in such a way that as the boundary region increases, the approximation becomes better. Such an approximation was useful in proving an area law in one dimension, and this result corresponds to a multi-dimensional analogue.

  18. Seeking Humanizing Care in Patient-Centered Care Process: A Grounded Theory Study.

    Science.gov (United States)

    Cheraghi, Mohammad Ali; Esmaeili, Maryam; Salsali, Mahvash

    Patient-centered care is both a goal in itself and a tool for enhancing health outcomes. The application of patient-centered care in health care services globally however is diverse. This article reports on a study that sought to introduce patient-centered care. The aim of this study is to explore the process of providing patient-centered care in critical care units. The study used a grounded theory method. Data were collected on 5 critical care units in Tehran University of Medical Sciences. Purposive and theoretical sampling directed the collection of data using 29 semistructured interviews with 27 participants (nurses, patients, and physician). Data obtained were analyzed according to the analysis stages of grounded theory and constant comparison to identify the concepts, context, and process of the study. The core category of this grounded theory is "humanizing care," which consisted of 4 interrelated phases, including patient acceptance, purposeful patient assessment and identification, understanding patients, and patient empowerment. A core category of humanizing care integrated the theory. Humanizing care was an outcome and process. Patient-centered care is a dynamic and multifaceted process provided according to the nurses' understanding of the concept. Patient-centered care does not involve repeating routine tasks; rather, it requires an all-embracing understanding of the patients and showing respect for their values, needs, and preferences.

  19. Grounded theory: a methodological spiral from positivism to postmodernism.

    Science.gov (United States)

    Mills, Jane; Chapman, Ysanne; Bonner, Ann; Francis, Karen

    2007-04-01

    Our aim in this paper is to explain a methodological/methods package devised to incorporate situational and social world mapping with frame analysis, based on a grounded theory study of Australian rural nurses' experiences of mentoring. Situational analysis, as conceived by Adele Clarke, shifts the research methodology of grounded theory from being located within a postpositivist paradigm to a postmodern paradigm. Clarke uses three types of maps during this process: situational, social world and positional, in combination with discourse analysis. During our grounded theory study, the process of concurrent interview data generation and analysis incorporated situational and social world mapping techniques. An outcome of this was our increased awareness of how outside actors influenced participants in their constructions of mentoring. In our attempts to use Clarke's methodological package, however, it became apparent that our constructivist beliefs about human agency could not be reconciled with the postmodern project of discourse analysis. We then turned to the literature on symbolic interactionism and adopted frame analysis as a method to examine the literature on rural nursing and mentoring as secondary form of data. While we found situational and social world mapping very useful, we were less successful in using positional maps. In retrospect, we would argue that collective action framing provides an alternative to analysing such positions in the literature. This is particularly so for researchers who locate themselves within a constructivist paradigm, and who are therefore unwilling to reject the notion of human agency and the ability of individuals to shape their world in some way. Our example of using this package of situational and social worlds mapping with frame analysis is intended to assist other researchers to locate participants more transparently in the social worlds that they negotiate in their everyday practice.

  20. A discussion of differences in preparation, performance and postreflections in participant observations within two grounded theory approaches

    DEFF Research Database (Denmark)

    Bøttcher Berthelsen, Connie; Damsgaard, Tove Lindhardt; Frederiksen, Kirsten

    2017-01-01

    This paper presents a discussion of the differences in using participant observation as a data collection method by comparing the classic grounded theory methodology of Barney Glaser with the constructivist grounded theory methodology by Kathy Charmaz. Participant observations allow nursing...... researchers to experience activities and interactions directly in situ. However, using participant observations as a data collection method can be done in many ways, depending on the chosen grounded theory methodology, and may produce different results. This discussion shows that how the differences between...

  1. PENGALAMAN MAHASISWA DALAM MELAKUKAN WIRAUSAHA INFORMASI: SEBUAH PENELITIAN GROUNDED THEORY

    Directory of Open Access Journals (Sweden)

    Afdini Rihlatul Mahmudah

    2016-11-01

    Full Text Available The main focus of this paper is to explore students’ understanding of information entrepreneurship. This is a qualitative study using grounded theory. Selection of the method is based on research conducted purpose, namely to build a theory based on the views of respondents. The steps taken to obtain the data are interviews, observation, and document review. The data is analyzed based on data analysis model constructivism form of transcription of data and interpretation of data through open coding, axial coding, and selective coding. Because that’s grounded theory meant to know in depth understanding of information entrepreneurship is mainly done by the students. The study also covers entrepreneurship and entrepreneurial activity information extracted information from the perspective of students. The conclusion of this study is an entrepreneur information definition. That defi nition is work in the fi eld of information that can be done independently or in groups, with flexibility in the time and place of the work, in the form of search activity information, creating web and library systems, consulting libraries, teachers, and librarians to make money, add experience and knowledge, as well as develop social activities.

  2. Ground state energy of a polaron in a superlattice

    International Nuclear Information System (INIS)

    Mensah, S.Y.; Allotey, F.K.A.; Nkrumah, G.; Mensah, N.G.

    2000-10-01

    The ground state energy of a polaron in a superlattice was calculated using the double-time Green functions. The effective mass of the polaron along the planes perpendicular to the superlattice axis was also calculated. The dependence of the ground state energy and the effective mass along the planes perpendicular to the superlattice axis on the electron-phonon coupling constant α and on the superlattice parameters (i.e. the superlattice period d and the bandwidth Δ) were studied. It was observed that if an infinite square well potential is assumed, the ground state energy of the polaron decreases (i.e. becomes more negative) with increasing α and d, but increases with increasing Δ. For small values of α, the polaron ground state energy varies slowly with Δ, becoming approximately constant for large Δ. The effective mass along the planes perpendicular to the superlattice axis was found to be approximately equal to the mass of an electron for all typical values of α, d and Δ. (author)

  3. Trapping cold ground state argon atoms.

    Science.gov (United States)

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  4. Correlated ground state and E2 giant resonance built on it

    International Nuclear Information System (INIS)

    Tohyama, Mitsuru

    1995-01-01

    Taking 16 O as an example of realistic nuclei, we demonstrate that a correlated ground state can be obtained as a long time solution of a time-dependent density-matrix formalism (TDDM) when the residual interaction is adiabatically treated. We also study in TDDM the E2 giant resonance of 16 O built on the correlated ground state and compare it with that built on the Hartree-Fock ground state. It is found that a spurious mixing of low frequency components seen in the latter is eliminated by using the correlated ground state. (author)

  5. Thermal instability in a gravity-like scalar theory

    International Nuclear Information System (INIS)

    Brandt, F. T.; Frenkel, J.; Das, Ashok

    2008-01-01

    We study the question of stability of the ground state of a scalar theory which is a generalization of the φ 3 theory and has some similarity to gravity with a cosmological constant. We show that the ground state of the theory at zero temperature becomes unstable above a certain critical temperature, which is evaluated in closed form at high temperature.

  6. Culturally Responsive Teaching in the Context of Mathematics: A Grounded Theory Case Study

    Science.gov (United States)

    Bonner, Emily P.; Adams, Thomasenia L.

    2012-01-01

    In this grounded theory case study, four interconnected, foundational cornerstones of culturally responsive mathematics teaching (CRMT), communication, knowledge, trust/relationships, and constant reflection/revision, were systematically unearthed to develop an initial working theory of CRMT that directly informs classroom practice. These…

  7. Ground-Water Availability in the United States

    Science.gov (United States)

    Reilly, Thomas E.; Dennehy, Kevin F.; Alley, William M.; Cunningham, William L.

    2008-01-01

    Ground water is among the Nation's most important natural resources. It provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. Large-scale development of ground-water resources with accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. The challenges in determining ground-water availability are many. This report examines what is known about the Nation's ground-water availability and outlines a program of study by the U.S. Geological Survey Ground-Water Resources Program to improve our understanding of ground-water availability in major aquifers across the Nation. The approach is designed to provide useful regional information for State and local agencies who manage ground-water resources, while providing the building blocks for a national assessment. The report is written for a wide audience interested or involved in the management, protection, and sustainable use of the Nation's water resources.

  8. Is That a Real Theory or Did You Just Make It Up? Teaching Classic Grounded Theory

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, Ph.D.

    2010-06-01

    Full Text Available The title of this paper was derived from an incident I observed some years ago while accompanying a highly talented musician-songwriter friend to a performance. During a break, an audience member approached him to compliment the last song he had performed. He had written both the music and the lyrics to the song, one of many he had written. The audience member queried, “Is that a real song, or did you just make it up?” A touch amused, and not knowing whether he should be flattered or insulted, he politely replied, “It is a real song and I made it up.”This episode puts in mind a similar attitude in the social sciences that Glaser and Strauss (1967 noted, in which a small number of ’theoretical capitalists’ originate what are considered to be “real” theories and others are relegated to the role of “proletariat” testers. The means by which these theorists derived their theories remained largely mysterious. Unleashing proletariat testers was one of the chief rationales behind Glaser and Strauss’ development of grounded theory. It brought a democratic option into the social sciences that enabled anyone who learned the methodology to generate theory. The democratic ethos of the methodology may also have inadvertently unleashed an abundance of aspiring remodelers of the methodology, who unfortunately have eroded its primary purpose—to generate theories that are fully grounded in data rather than speculation or ideology.

  9. The ground state energy of a classical gas

    International Nuclear Information System (INIS)

    Conlon, J.G.

    1983-01-01

    The ground state energy of a classical gas is treated using a probability function for the position of the particles and a potential function. The lower boundary for the energy when the particle number is large is defined as ground state energy. The coulomb gas consisting of positive and negative particles is also treated (fixed and variable density case) the stability of the relativistic system is investigated as well. (H.B.)

  10. Anomalous Ground State of the Electrons in Nano-confined Water

    Science.gov (United States)

    2016-06-13

    Anomalous ground state of the electrons in nano -confined water G. F. Reiter1*, Aniruddha Deb2*, Y. Sakurai3, M. Itou3, V. G. Krishnan4, S. J...electronic ground state of nano -confined water must be responsible for these anomalies but has so far not been investigated. We show here for the first time...using x-ray Compton scattering and a computational model, that the ground state configuration of the valence electrons in a particular nano

  11. Theories of the nuclear ground state beyond Hartree-Fock

    International Nuclear Information System (INIS)

    Gogny, D.

    1979-01-01

    Intensive efforts have been invested toward defining a microscopic approach, simple enough to render feasible systematic calculations of nuclear structure and of the some time sufficiently rich in information as to serve for updating traditional microscopic approaches to the collective excitations. Our starting point is the mean field approximation with density dependent effective forces. To describe the collective excitations we use the two well known extensions based on the H.F. theory namely the random phase approximation and the adiabatic approximation to the time dependent Hartree-Fock theory. The purpose of this paper is to show what sort of calculations can be effectively carried out in the frame of such fully self consistent approaches. (KBE) 891 KBE/KBE 892 ARA

  12. Building bridges to observational perspectives: a grounded theory of therapy processes in psychosis.

    Science.gov (United States)

    Dilks, Sarah; Tasker, Fiona; Wren, Bernadette

    2008-06-01

    This study set out to explore therapy processes in psychosis with an initial focus on reflexivity and how this might be expressed in therapy conversations. Leiman's (2000) definition of reflexivity was used as a starting-point for an exploratory investigation of the use of language as reflective activity. Grounded theory was chosen as an appropriate methodology to distil an explanatory account across the qualitative data collected. Six psychologist-client pairs supplied three tapes of therapy sessions spread out across the course of therapy. Each participant was separately interviewed on two occasions to ascertain their views of therapy and of the emerging grounded theory. A grounded theory was developed conceptualizing the processes and activities in psychological therapy in psychosis. Building bridges to observational perspectives summarizes the core process in psychological therapy in psychosis. Therapy in psychosis is understood as intimately linking the social and internal world in a dialogical process aimed at enhancing the client's functioning in the social world rather than at specifically developing the private mental experience of reflexivity or mentalizing.

  13. The process of accepting breast cancer among Chinese women: A grounded theory study.

    Science.gov (United States)

    Chen, Shuang-Qin; Liu, Jun-E; Li, Zhi; Su, Ya-Li

    2017-06-01

    To describe the process by which Chinese women accept living with breast cancer. Individual interviews were conducted with 18 Chinese women who completed breast cancer treatment. Data were collected from September 2014 to January 2015 at a large tertiary teaching hospital in Beijing, China. In this grounded theory study, data were analyzed using constant comparative and coding analysis methods. In order to explain the process of accepting having breast cancer among women in China through the grounded theory study, a model that includes 5 axial categories was developed. Cognitive reconstruction emerged as the core category. The extent to which the women with breast cancer accepted having the disease was found to increase with the treatment stage and as their treatment stage progressed with time. The accepting process included five stages: non-acceptance, passive acceptance, willingness to accept, behavioral acceptance, and transcendence of acceptance. Our study using grounded theory study develops a model describing the process by which women accept having breast cancer. The model provides some intervention opportunities at every point of the process. Copyright © 2017. Published by Elsevier Ltd.

  14. A grounded theory of how social support influences physical activity in adolescent girls

    Science.gov (United States)

    Fawkner, Samantha

    2018-01-01

    ABSTRACT Purpose: Adolescent girls are not sufficiently active to achieve health benefits. Social support from friends and family has been positively associated with physical activity in adolescent girls; however it is unclear how social support influences physical activity behaviour. This study aimed to develop a grounded theory of how social support influences physical activity in adolescent girls. Methods: A qualitative, constructivist grounded theory approach was adopted. Individual interviews explored adolescent girls’ perspectives of how significant others’ influenced their physical activity through providing social support, and through modelling physical activity. Results: Participants perceived social support to influence physical activity behaviour through performance improvements, self-efficacy, enjoyment, motivation and by enabling physical activity. Improvements in performance and self-efficacy were also linked to motivation to be active. Girls perceived modelling to influence behaviour through providing opportunities for them to be physically active, and by inspiring them to be active. Conclusion: The grounded theory outlines adolescent girls’ perceptions of how significant others influence their physical activity and provides a framework for future research examining the role of social support on physical activity. PMID:29405881

  15. A grounded theory of how social support influences physical activity in adolescent girls.

    Science.gov (United States)

    Laird, Yvonne; Fawkner, Samantha; Niven, Ailsa

    2018-12-01

    Adolescent girls are not sufficiently active to achieve health benefits. Social support from friends and family has been positively associated with physical activity in adolescent girls; however it is unclear how social support influences physical activity behaviour. This study aimed to develop a grounded theory of how social support influences physical activity in adolescent girls. A qualitative, constructivist grounded theory approach was adopted. Individual interviews explored adolescent girls' perspectives of how significant others' influenced their physical activity through providing social support, and through modelling physical activity. Participants perceived social support to influence physical activity behaviour through performance improvements, self-efficacy, enjoyment, motivation and by enabling physical activity. Improvements in performance and self-efficacy were also linked to motivation to be active. Girls perceived modelling to influence behaviour through providing opportunities for them to be physically active, and by inspiring them to be active. The grounded theory outlines adolescent girls' perceptions of how significant others influence their physical activity and provides a framework for future research examining the role of social support on physical activity.

  16. Solving satisfiability problems by the ground-state quantum computer

    International Nuclear Information System (INIS)

    Mao Wenjin

    2005-01-01

    A quantum algorithm is proposed to solve the satisfiability (SAT) problems by the ground-state quantum computer. The scale of the energy gap of the ground-state quantum computer is analyzed for the 3-bit exact cover problem. The time cost of this algorithm on the general SAT problems is discussed

  17. Is Birth Order Really Important in Peer Relationship? A Grounded Theory Approach

    Science.gov (United States)

    Coskun, Kerem; Çikrikci, Özkan; Topkaya, Yavuz

    2017-01-01

    This article seeks to develop a theory about the importance of peer relationship among the oldest of the youngest children who have finished preschool education and already started primary school. In the study, observation was employed to collect data from 22 children. The data were analysed through the grounded theory approach, in which data are…

  18. Solid state theory

    CERN Document Server

    Harrison, Walter A

    2011-01-01

    ""A well-written text . . . should find a wide readership, especially among graduate students."" - Dr. J. I. Pankove, RCA.The field of solid state theory, including crystallography, semi-conductor physics, and various applications in chemistry and electrical engineering, is highly relevant to many areas of modern science and industry. Professor Harrison's well-known text offers an excellent one-year graduate course in this active and important area of research. While presenting a broad overview of the fundamental concepts and methods of solid state physics, including the basic quantum theory o

  19. Comfort vs risk: a grounded theory about female adolescent behaviour in the sun.

    Science.gov (United States)

    Norton, Elizabeth; Holloway, Immy; Galvin, Kathleen

    2014-07-01

    To generate a grounded theory about female adolescent behaviour in the sun. Nurses have key roles in health promotion and skin cancer prevention. Adolescents' resistance to sun safety messages and their vulnerability to sunburn are of concern internationally. Understanding why young women do as they do in the sun may enhance skin cancer prevention, but their behaviour has not been explained before in the UK. The study incorporated a qualitative grounded theory design using the approach of Glaser. Qualitative data were gleaned from group and one-to-one, semi-structured interviews with 20 female participants aged 14-17, research memos and literature. Sampling was purposive and theoretical. Data collection, analysis and theory generation occurred concurrently. Data were analysed using the constant comparative method. Data collection ended when a substantive theory had been generated. Data analysis revealed five categories of findings: fitting in, being myself, being physically comfortable, slipping up and being comfortable (the core category). The theory generated around the core explains how young women direct their sun-related activities towards meeting their physical and psychosocial comfort needs. A contribution of this research is the grounded theory explaining the behaviour of young women in the sun. Further, the theory challenges assumptions that female adolescents necessarily take risks; it explains their sun-related activities in terms of comfort. The theory extends findings from other researchers' descriptive qualitative studies and also appears to apply to young people in countries other than the UK. Understanding the sun-related activity of young women in terms of physical and psychosocial comfort may help nurses to develop new approaches to skin cancer prevention. These could complement existing messages and humanise health promotion. © 2013 John Wiley & Sons Ltd.

  20. Calculations of the ground state of 16O

    International Nuclear Information System (INIS)

    Pieper, S.C.

    1989-01-01

    One of the central problems in nuclear physics is the description of nuclei as systems of nucleons interacting via realistic potentials. There are two main aspects of this problem: specification of the Hamiltonian, and calculation of the ground states of nuclei with the given interaction. Realistic interactions must contain both two- and three-nucleon potentials and these potentials have a complicated non-central operator structure consisting, for example, of spin, isospin and tensor dependences. This structure results in formidable many-body problems in the computation of the ground states of nuclei. At present, reliable solutions of the Faddeev equations for the A = 3 nuclei with such interactions are routine. Recently, Carlson has made an essentially exact GFMC calculation of the He ground state using just a two-nucleon interaction, and there are reliable variational calculations for more complete potential models. Nuclear matter calculations can also be made with reasonable reliability. However, there have been very few calculations of nuclei with A > 5 using realistic interactions, and none with a modern three-nucleon interaction. In the present paper I present a new technique for variational calculations for such nuclei and apply it to the ground state of 16 O. 15 refs., 2 figs., 3 tabs

  1. Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity.

    Science.gov (United States)

    Engward, Hilary; Davis, Geraldine

    2015-07-01

    A discussion of the meaning of reflexivity in research with the presentation of examples of how a model of reflexivity was used in a grounded theory research project. Reflexivity requires the researcher to make transparent the decisions they make in the research process and is therefore important in developing quality in nursing research. The importance of being reflexive is highlighted in the literature in relation to nursing research, however, practical guidance as to how to go about doing research reflexively is not always clearly articulated. This is a discussion paper. The concept of reflexivity in research is explored using the Alvesson and Skoldberg model of reflexivity and practical examples of how a researcher developed reflexivity in a grounded theory project are presented. Nurse researchers are encouraged to explore and apply the concept of reflexivity in their research practices to develop transparency in the research process and to increase robustness in their research. The Alvesson and Skoldberg model is of value in applying reflexivity in qualitative nursing research, particularly in grounded theory research. Being reflexive requires the researcher to be completely open about decisions that are made in the research process. The Alvesson and Skolberg model of reflexivity is a useful model that can enhance reflexivity in the research process. It can be a useful practical tool to develop reflexivity in grounded theory research. © 2015 John Wiley & Sons Ltd.

  2. Working Together Toward a Common Goal: A Grounded Theory of Nurse-Physician Collaboration.

    Science.gov (United States)

    Fewster-Thuente, Lori

    2015-01-01

    Working together toward a common goal is an empirically derived theory that can guide education and practice to improve patient outcomes while saving money and lives. Grounded theory was used to explore nurses' and physicians' experiences with collaboration in order to understand the process intrinsically.

  3. The Frustrations of Reader Generalizability and Grounded Theory: Alternative Considerations for Transferability

    Directory of Open Access Journals (Sweden)

    Thomas Misco

    2007-01-01

    Full Text Available In this paper I convey a recurring problem and possible solution that arose during my doctoral research on the topic of cross-cultural Holocaust curriculum development for Latvian schools. Specifically, as I devised the methodology for my research, I experienced a number of frustrations concerning the issue of transferability and the limitations of both reader generalizability and grounded theory. Ultimately, I found a more appropriate goal for the external applicability of this and other highly contextual research studies in the form of "grounded understandings," which are tentative apprehensions of the importance or significance of phenomena and conceptualizations that hold meaning and explanatory power, but are only embryonic in their potential to generate theory.

  4. Selection of Grounded Theory as an Appropriate Research Methodology for a Dissertation: One Student’s Perspective

    Directory of Open Access Journals (Sweden)

    James W. Jones, Ed.D.

    2009-06-01

    Full Text Available Doctoral students wanting to use grounded theory as a methodological approach for their dissertation often face multiple challenges gaining acceptance of their approach by their committee. This paper presents the case that the author used to overcome these challenges through the process of eliminating other methodologies, leaving grounded theory as the preferred method for the desired research issue. Through examining the approach used successfully by the author, other doctoral students will be able to frame similar arguments justifying the use of grounded theory in their dissertations and seeing the use of the method continue to spread into new fields and applications. This paper examines the case built for selecting grounded theory as a defensible dissertation approach. The basic research issue that I wanted to investigate was how practitioners in an applied field sought information in their work; in other words, how they researched. I further narrowed the investigation down to a more specific field, but the paper presented here is left in broader form so that other students can see the approach in more general terms.

  5. A theoretical study on the geometry and spectroscopic properties of ground-state and local minima isomers of (CuS)n=2-6 clusters

    Science.gov (United States)

    Luque-Ceballos, Jonathan C.; Posada-Borbón, Alvaro; Herrera-Urbina, Ronaldo; Aceves, R.; Juárez-Sánchez, J. Octavio; Posada-Amarillas, Alvaro

    2018-03-01

    Spectroscopic properties of gas-phase copper sulfide clusters (CuS)n (n = 2-6) are calculated using Density Functional Theory (DFT) and time-dependent (TD) DFT approaches. The energy landscape of the potential energy surface is explored through a basin-hopping DFT methodology. Ground-state and low-lying isomer structures are obtained. The global search was performed at the B3PW91/SDD level of theory. Normal modes are calculated to validate the existence of optimal cluster structures. Energetic properties are obtained for the ground-state and isomer clusters and their relative energies are evaluated for probing isomerization. This is a few tenths of an eV, except for (CuS)2 cluster, which presents energy differences of ∼1 eV. Notable differences in the infrared spectra exist between the ground-state and first isomer structures, even for the (CuS)5 cluster, which has in both configurations a core copper pyramid. TDDFT provides the simulated absorption spectrum, presenting a theoretical description of optical absorption bands in terms of electronic excitations in the UV and visible regions. Results exhibit a significant dependence of the calculated UV/vis spectra on clusters size and shape regarding the ground state structures. Optical absorption is strong in the UV region, and weak or forbidden in the visible region of the spectrum.

  6. Quinoidal Oligo(9,10-anthryl)s with Chain-Length-Dependent Ground States: A Balance between Aromatic Stabilization and Steric Strain Release

    KAUST Repository

    Lim, Zhenglong

    2015-11-12

    Quinoidal π-conjugated polycyclic hydrocarbons have attracted intensive research interest due to their unique optical/electronic properties and possible magnetic activity, which arises from a thermally excited triplet state. However, there is still lack of fundamental understanding on the factors that determine the electronic ground states. Herein, by using quinoidal oligo(9,10-anthryl)s, it is demonstrated that both aromatic stabilisation and steric strain release play balanced roles in determining the ground states. Oligomers with up to four anthryl units were synthesised and their ground states were investigated by electronic absorption and electron spin resonance (ESR) spectroscopy, assisted by density functional theory (DFT) calculations. The quinoidal 9,10-anthryl dimer 1 has a closed-shell ground state, whereas the tri- (2) and tetramers (3) both have an open-shell diradical ground state with a small singlet-triplet gap. Such a difference results from competition between two driving forces: the large steric repulsion between the anthryl/phenyl units in the closed-shell quinoidal form that drives the molecule to a flexible open-shell diradical structure, and aromatic stabilisation due to the gain of more aromatic sextet rings in the closed-shell form, which drives the molecule towards a contorted quinoidal structure. The ground states of these oligomers thus depend on the overall balance between these two driving forces and show chain-length dependence. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The 'realities' of part-time nursing: a grounded theory study.

    Science.gov (United States)

    Jamieson, Lynn N; Williams, Leonie Mosel; Lauder, William; Dwyer, Trudy

    2008-10-01

    To develop a theory that explains the 'realities' of part-time nursing. While little is known about the phenomenon of part-time nursing, increasing numbers of nurses work in part-time employment. Grounded theory. The problem that part-time nurses shared was an inability to achieve their personal optimal nursing potential. Motivators to work part-time, employment hours, specialty, individual and organizational factors formed contextual conditions that led to this problem. Part-time nurses responded to the challenges through a process of adaptation and adjustment. Harnessing the full productive potential of part-time nurses requires support to limit the difficulties that they encounter. The developed theory provides a valuable guide to managerial action. Nurse Managers need to consider the developed substantive theory when planning and managing nursing workforces.

  8. Isospin mixing in the ground state of sup 5 sup 2 Mn

    CERN Document Server

    Schuurmans, P; Phalet, T; Severijns, N; Vereecke, B; Versyck, S

    2000-01-01

    The presence of isospin mixing into the ground state of sup 5 sup 2 Mn was studied via anisotropic positron emission from nuclei. With this method the isospin forbidden Fermi-component in the Gamow-Teller dominated beta decay was determined. It is shown that sample purity and the control of positron scattering is of vital importance. Comparison between theory and experiment shows that shell model calculations of the isospin mixing probability deviate by a factor three to seven from experiment. For more recent Hartree-Fock-RPA based calculations the difference is over two orders of magnitude.

  9. Ground-state properties of trapped Bose-Fermi mixtures: Role of exchange correlation

    International Nuclear Information System (INIS)

    Albus, Alexander P.; Wilkens, Martin; Illuminati, Fabrizio

    2003-01-01

    We introduce density-functional theory for inhomogeneous Bose-Fermi mixtures, derive the associated Kohn-Sham equations, and determine the exchange-correlation energy in local-density approximation. We solve numerically the Kohn-Sham system, and determine the boson and fermion density distributions and the ground-state energy of a trapped, dilute mixture beyond mean-field approximation. The importance of the corrections due to exchange correlation is discussed by a comparison with current experiments; in particular, we investigate the effect of the repulsive potential-energy contribution due to exchange correlation on the stability of the mixture against collapse

  10. Ground state energy fluctuations in the nuclear shell model

    International Nuclear Information System (INIS)

    Velazquez, Victor; Hirsch, Jorge G.; Frank, Alejandro; Barea, Jose; Zuker, Andres P.

    2005-01-01

    Statistical fluctuations of the nuclear ground state energies are estimated using shell model calculations in which particles in the valence shells interact through well-defined forces, and are coupled to an upper shell governed by random 2-body interactions. Induced ground-state energy fluctuations are found to be one order of magnitude smaller than those previously associated with chaotic components, in close agreement with independent perturbative estimates based on the spreading widths of excited states

  11. A Grounded Theory for Identifying Students with Emotional Disturbance: Promising Practices for Assessment, Intervention, and Service Delivery

    Science.gov (United States)

    Barnett, Dori

    2012-01-01

    A qualitative grounded theory study examined how practicing professionals involved in the ED identification process reconstructed the category of "emotional disturbance" as it applied to students in an alternative educational setting. A grounded theory integrates six emergent themes and essentially reframes the existing ED criteria in contemporary…

  12. Grounded Theory: A practical guide for management, business and market researchers Christina Goulding Grounded Theory: A practical guide for management, business and market researchers Sage Publications No of pages: 186 £18.99 0761966838 0761966838 [Formula: see text].

    Science.gov (United States)

    Woods, Leslie

    2003-10-01

    Much has been written about the grounded theory approach to qualitative research, however the number of books devoted solely to this methodology remains relatively few. Therefore, any new book dedicated to the subject is always likely to attract attention - especially given the increasing popularity of grounded theory in healthcare research.

  13. Ground state phase diagram of extended attractive Hubbard model

    International Nuclear Information System (INIS)

    Robaszkiewicz, S.; Chao, K.A.; Micnas, R.

    1980-08-01

    The ground state phase diagram of the extended Hubbard model with intraatomic attraction has been derived in the Hartree-Fock approximation formulated in terms of the Bogoliubov variational approach. For a given value of electron density, the nature of the ordered ground state depends essentially on the sign and the strength of the nearest neighbor coupling. (author)

  14. Exact ground and excited states of an antiferromagnetic quantum spin model

    International Nuclear Information System (INIS)

    Bose, I.

    1989-08-01

    A quasi-one-dimensional spin model which consists of a chain of octahedra of spins has been suggested for which a certain parameter regime of the Hamiltonian, the ground state, can be written down exactly. The ground state is highly degenerate and can be other than a singlet. Also, several excited states can be constructed exactly. The ground state is a local RVB state for which resonance is confined to rings of spins. Some exact numerical results for an octahedron of spins have also been reported. (author). 16 refs, 2 figs, 1 tab

  15. Extended random-phase approximation with three-body ground-state correlations

    International Nuclear Information System (INIS)

    Tohyama, M.; Schuck, P.

    2008-01-01

    An extended random-phase approximation (ERPA) which contains the effects of ground-state correlations up to a three-body level is applied to an extended Lipkin model which contains an additional particle-scattering term. Three-body correlations in the ground state are necessary to preserve the hermiticity of the Hamiltonian matrix of ERPA. Two approximate forms of ERPA which neglect the three-body correlations are also applied to investigate the importance of three-body correlations. It is found that the ground-state energy is little affected by the inclusion of the three-body correlations. On the contrary, three-body correlations for the excited states can become quite important. (orig.)

  16. Understanding College Students' Civic Identity Development: A Grounded Theory

    Science.gov (United States)

    Johnson, Matthew R.

    2017-01-01

    This article presents the results of a study designed to understand the development of college students' civic identity--that is, an identity encompassing their knowledge, attitudes, values, and actions regarding civic engagement. Grounded theory was used to examine the experiences and attitudes of 19 college seniors who manifested strong civic…

  17. Infusing Participants' Voices into Grounded Theory Research: A Poetic Anthology

    Science.gov (United States)

    Kennedy, Brianna L.

    2009-01-01

    This article augments the author's grounded theory study of student and teacher interactions in alternative education classrooms by presenting poetic transcription as a way to portray the essences and experiences of the participants. The author builds on the experimental writing traditions of other researchers to embrace her own experiences as a…

  18. Endeavoring to Contextualize Curricula Within an EBP Framework: A Grounded Theory Study.

    Science.gov (United States)

    Malik, Gulzar; McKenna, Lisa; Griffiths, Debra

    2018-01-01

    Adopting evidence-based practice (EBP) principles in undergraduate education can facilitate nursing students' appreciation of EBP. Using grounded theory method, this study aimed to explore processes used by nurse academics while integrating EBP concepts in undergraduate nursing curricula across Australian universities. Twenty-three nurse academics were interviewed and nine were observed during teaching of undergraduate students. In addition, 20 unit/subject guides were analyzed using grounded theory approach of data analysis. The theory " On a path to success: Endeavoring to contextualize curricula within an EBP framework" reflects academics' endeavors toward linking EBP concepts to practice, aiming to contextualize curricula in a manner that engages students within an EBP framework. However, academics' journeys were influenced by several contextual factors which require strategies to accomplish their endeavors. In conclusion, initiatives to minimize barriers, faculty development, and provision of resources across educational and clinical settings are fundamental to achieving undergraduate curricula underpinned by EBP concepts.

  19. Examining Philosophy of Technology Using Grounded Theory Methods

    Directory of Open Access Journals (Sweden)

    Mark David Webster

    2016-03-01

    Full Text Available A qualitative study was conducted to examine the philosophy of technology of K-12 technology leaders, and explore the influence of their thinking on technology decision making. The research design aligned with CORBIN and STRAUSS grounded theory methods, and I proceeded from a research paradigm of critical realism. The subjects were school technology directors and instructional technology specialists, and data collection consisted of interviews and a written questionnaire. Data analysis involved the use of grounded theory methods including memo writing, open and axial coding, constant comparison, the use of purposive and theoretical sampling, and theoretical saturation of categories. Three broad philosophy of technology views were widely held by participants: an instrumental view of technology, technological optimism, and a technological determinist perspective that saw technological change as inevitable. Technology leaders were guided by two main approaches to technology decision making, represented by the categories Educational goals and curriculum should drive technology, and Keep up with technology (or be left behind. The core category and central phenomenon that emerged was that technology leaders approached technology leadership by placing greater emphasis on keeping up with technology, being influenced by an ideological orientation to technological change, and being concerned about preparing students for a technological future. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs160252

  20. Electrical-field-induced magnetic Skyrmion ground state in a two-dimensional chromium tri-iodide ferromagnetic monolayer

    Science.gov (United States)

    Liu, Jie; Shi, Mengchao; Mo, Pinghui; Lu, Jiwu

    2018-05-01

    Using fully first-principles non-collinear self-consistent field density functional theory (DFT) calculations with relativistic spin-orbital coupling effects, we show that, by applying an out-of-plane electrical field on a free-standing two-dimensional chromium tri-iodide (CrI3) ferromagnetic monolayer, the Néel-type magnetic Skyrmion spin configurations become more energetically-favorable than the ferromagnetic spin configurations. It is revealed that the topologically-protected Skyrmion ground state is caused by the breaking of inversion symmetry, which induces the non-trivial Dzyaloshinskii-Moriya interaction (DMI) and the energetically-favorable spin-canting configuration. Combining the ferromagnetic and the magnetic Skyrmion ground states, it is shown that 4-level data can be stored in a single monolayer-based spintronic device, which is of practical interests to realize the next-generation energy-efficient quaternary logic devices and multilevel memory devices.

  1. Common Ground of Two Paradigms: Incorporating Critical Theory into Current Art Therapy Practices

    Science.gov (United States)

    Nolan, Emily

    2013-01-01

    Clinical art therapy and studio-based community art therapy represent two major paradigms in art therapy practice. This viewpoint explores how critical theory can be incorporated into both paradigms and result in common ground between them. Critical theory encompasses an understanding of oppression in psychological, social, and cultural contexts…

  2. Identifying Barriers in Implementing Outcomes-Based Assessment Program Review: A Grounded Theory Analysis

    Science.gov (United States)

    Bresciani, Marilee J.

    2011-01-01

    The purpose of this grounded theory study was to identify the typical barriers encountered by faculty and administrators when implementing outcomes-based assessment program review. An analysis of interviews with faculty and administrators at nine institutions revealed a theory that faculty and administrators' promotion, tenure (if applicable),…

  3. Action Learning and Constructivist Grounded Theory: Powerfully Overlapping Fields of Practice

    Science.gov (United States)

    Rand, Jane

    2013-01-01

    This paper considers the shared characteristics between action learning (AL) and the research methodology constructivist grounded theory (CGT). Mirroring Edmonstone's [2011. "Action Learning and Organisation Development: Overlapping Fields of Practice." "Action Learning: Research and Practice" 8 (2): 93-102] article, which…

  4. A Grounded Theory of Western-Trained Asian Group Leaders Leading Groups in Asia

    Science.gov (United States)

    Taephant, Nattasuda; Rubel, Deborah; Champe, Julia

    2015-01-01

    This grounded theory research explored the experiences of Western-trained Asian group leaders leading groups in Asia. A total of 6 participants from Japan, Taiwan, and Thailand were interviewed 3 times over 9 months. The recursive process of data collection and analysis yielded substantive theory describing the participants' process of reconciling…

  5. Magnetostriction-driven ground-state stabilization in 2H perovskites

    International Nuclear Information System (INIS)

    Porter, D. G.; Senn, M. S.; University of Oxford; Khalyavin, D. D.; Cortese, A.

    2016-01-01

    In this paper, the magnetic ground state of Sr_3ARuO_6, with A =(Li,Na), is studied using neutron diffraction, resonant x-ray scattering, and laboratory characterization measurements of high-quality crystals. Combining these results allows us to observe the onset of long-range magnetic order and distinguish the symmetrically allowed magnetic models, identifying in-plane antiferromagnetic moments and a small ferromagnetic component along the c axis. While the existence of magnetic domains masks the particular in-plane direction of the moments, it has been possible to elucidate the ground state using symmetry considerations. We find that due to the lack of local anisotropy, antisymmetric exchange interactions control the magnetic order, first through structural distortions that couple to in-plane antiferromagnetic moments and second through a high-order magnetoelastic coupling that lifts the degeneracy of the in-plane moments. Finally, the symmetry considerations used to rationalize the magnetic ground state are very general and will apply to many systems in this family, such as Ca_3ARuO_6, with A = (Li,Na), and Ca_3LiOsO_6 whose magnetic ground states are still not completely understood.

  6. The relation between the (N) and (N-1) electrons atomic ground state

    International Nuclear Information System (INIS)

    Briet, P.

    1984-05-01

    The relation between the ground state of an N and (N-1) electrons atomic system are studied. We show that in some directions of the configuration space, the ratio of the N electrons atomic ground state to the one particle density is asymptotically equivalent to the (N-1) electrons atomic ground state

  7. Degenerate ground states and multiple bifurcations in a two-dimensional q-state quantum Potts model.

    Science.gov (United States)

    Dai, Yan-Wei; Cho, Sam Young; Batchelor, Murray T; Zhou, Huan-Qiang

    2014-06-01

    We numerically investigate the two-dimensional q-state quantum Potts model on the infinite square lattice by using the infinite projected entangled-pair state (iPEPS) algorithm. We show that the quantum fidelity, defined as an overlap measurement between an arbitrary reference state and the iPEPS ground state of the system, can detect q-fold degenerate ground states for the Z_{q} broken-symmetry phase. Accordingly, a multiple bifurcation of the quantum ground-state fidelity is shown to occur as the transverse magnetic field varies from the symmetry phase to the broken-symmetry phase, which means that a multiple-bifurcation point corresponds to a critical point. A (dis)continuous behavior of quantum fidelity at phase transition points characterizes a (dis)continuous phase transition. Similar to the characteristic behavior of the quantum fidelity, the magnetizations, as order parameters, obtained from the degenerate ground states exhibit multiple bifurcation at critical points. Each order parameter is also explicitly demonstrated to transform under the Z_{q} subgroup of the symmetry group of the Hamiltonian. We find that the q-state quantum Potts model on the square lattice undergoes a discontinuous (first-order) phase transition for q=3 and q=4 and a continuous phase transition for q=2 (the two-dimensional quantum transverse Ising model).

  8. Coherent Control of Ground State NaK Molecules

    Science.gov (United States)

    Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin

    2016-05-01

    Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE

  9. An experiential perspective on persecutory paranoia: a grounded theory construction.

    Science.gov (United States)

    Boyd, Tom; Gumley, Andrew

    2007-03-01

    Recently there has been a large volume of research on persecutory paranoia. Evidence has emerged for the role of social factors in the development of paranoia. There have, however, been no studies that have collaborated with users to develop an experiential perspective on paranoia. This study used a social constructionist version of grounded theory to develop an experiential perspective on persecutory paranoia. Ten individuals who had experience of persecutory paranoia were interviewed. The interviews were transcribed and analysed using the grounded theory method. A core process of fear and vulnerability was constructed. Subcategories of confusion and uncertainty, and self under attack contributed to the core process. These processes led to an engaging of the safety systems. Subthemes of these categories were identified. Many of these factors interacted to create the complex and dynamic experience of paranoia. Participants were often responding to genuinely frightening experiences but were also attacking themselves. Paranoia evolved as a mechanism of keeping oneself safe in dangerous situations. The need to negotiate a shared meaning of paranoia with users is emphasized. Direction for future research was discussed.

  10. Qualitative Research: A Grounded Theory Example and Evaluation Criteria

    OpenAIRE

    Bitsch, Vera

    2005-01-01

    The qualitative research paradigm, although occasionally applied, is not widely discussed in agribusiness and agricultural economics literature. The primary goals of this paper are (a) to present insights into qualitative research approaches and processes by outlining grounded theory as an example of a systematic and rigorous qualitative approach, and (b) to discuss criteria for scientific rigor applicable to qualitative research. In addition, assessing qualitative research is demonstrated by...

  11. Theory and computation of triply excited resonances: Application to states of He-

    International Nuclear Information System (INIS)

    Nicolaides, C.A.; Piangos, N.A.; Komninos, Y.

    1993-01-01

    Autoionizing multiply excited states offer unusual challenges to the theory of electronic structure and spectra because of the presence of strong electron correlations, of their occasional weak binding, of their proximity to more than one threshold, and of their degeneracy with many continua. Here we discuss a theory that addresses these difficulties in conjunction with the computation of their wave functions and intrinsic properties. Emphasis is given on the justification of the possible presence of self-consistently obtained open-channel-like (OCL) correlating configurations in the square-integrable representation of such states and on their effect on the energy E and the width Γ. Application of the theory has allowed the prediction of two hitherto unknown He - triply excited resonances, the 2s2p 2 2 P (E=59.71 eV, above the He ground state, Γ=79 meV) and the 2p 3 2 Do (E=59.46 eV, Γ=282 meV) (1 a.u.=27.2116 eV). These resonances are above the singly excited states of He and are embedded in its doubly excited spectrum. The relatively broad 2p 3 2 Do state interacts strongly with the He 2s2p 3 Po εd continuum. The effect of this interaction has been studied in terms of the coupling with fixed core scattering states as well as with a self-consistently computed OCL bound configuration

  12. Experimental Insights into Ground-State Selection of Quantum XY Pyrochlores

    Science.gov (United States)

    Hallas, Alannah M.; Gaudet, Jonathan; Gaulin, Bruce D.

    2018-03-01

    Extensive experimental investigations of the magnetic structures and excitations in the XY pyrochlores have been carried out over the past decade. Three families of XY pyrochlores have emerged: Yb2B2O7, Er2B2O7, and, most recently, [Formula: see text]Co2F7. In each case, the magnetic cation (either Yb, Er, or Co) exhibits XY anisotropy within the local pyrochlore coordinates, a consequence of crystal field effects. Materials in these families display rich phase behavior and are candidates for exotic ground states, such as quantum spin ice, and exotic ground-state selection via order-by-disorder mechanisms. In this review, we present an experimental summary of the ground-state properties of the XY pyrochlores, including evidence that they are strongly influenced by phase competition. We empirically demonstrate the signatures for phase competition in a frustrated magnet: multiple heat capacity anomalies, suppressed TN or TC, sample- and pressure-dependent ground states, and unconventional spin dynamics.

  13. Student Affairs Professionals Supporting Students with Disabilities: A Grounded Theory Model

    Science.gov (United States)

    Kimball, Ezekiel; Vaccaro, Annemarie; Vargas, Nadia

    2016-01-01

    In an action-based grounded theory project, the authors collected data from 31 student affairs professionals. During seven focus groups, practitioners described feeling unknowledgeable about disability law, accommodations, and diagnoses. However, they drew upon their core values and transferrable skills to support individual students. Participants…

  14. The San Miguel Artist Project: A Grounded Theory of "The Emergence of Wonder"

    Directory of Open Access Journals (Sweden)

    Gordon Medlock

    2015-03-01

    Full Text Available This article employs classical grounded theory methodology to explain the creative process of artists. Two integrally connected core variables are identified: emergence and wonder. Wonder represents the experience that motivates and sustains the creation of works of art, and emergence the process by which the sense of wonder is progressively embodied in the content and form of the work. The theory describes a number of distinct phases, including the experience of wonder, immersion in artistic practice, conceiving a specific work or project, composing the work, presenting the work for an actual or potential audience, and finally moving-on. These phases involve a dynamic stream of recursive processes—sketching, refining, connecting, channeling, and assessing—that ultimately facilitate the emergence of wonder in artistic works. The theory of the emergence of wonder also appears to apply to the research processes of both grounded theory methodology and phenomenology, suggesting that these two research methodologies are more similar and have more in common with the artistic creative process than is commonly acknowledged. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150256

  15. A grounded theory como alternativa metodológica para pesquisa em enfermagem

    Directory of Open Access Journals (Sweden)

    Sérgio Ribeiro dos Santos

    2002-10-01

    Full Text Available O presente estudo apresenta um método de pesquisa interpretativo e sistemático para desenvolvimento de pesquisa em enfermagem chamado grounded theory, cujo suporte teórico é o interacionismo simbólico. O propósito é descrever a grounded theory como alternativa metodológica para construção do conhecimento em enfermagem. O estudo destaca: princípio fundamental, conceitos básicos, trajetória do método e processo de análise dos dados. Concluímos que a sistematização dos dados e sua interpretação, a partir da experiência vivenciada pelos atores sociais, constituem ricos subsídios para gerar teorias através desta ferramenta de pesquisa.

  16. Making Things Right: Nurses' Experiences with Workplace Bullying—A Grounded Theory

    Science.gov (United States)

    Gaffney, Donna A.; DeMarco, Rosanna F.; Hofmeyer, Anne; Vessey, Judith A.; Budin, Wendy C.

    2012-01-01

    While bullying in the healthcare workplace has been recognized internationally, there is still a culture of silence in many institutions in the United States, perpetuating underreporting and insufficient and unproven interventions. The deliberate, repetitive, and aggressive behaviors of bullying can cause psychological and/or physical harm among professionals, disrupt nursing care, and threaten patient safety and quality outcomes. Much of the literature focuses on categories of bullying behaviors and nurse responses. This qualitative study reports on the experiences of nurses confronting workplace bullying. We collected data from the narratives of 99 nurses who completed an open-ended question embedded in an online survey in 2007. A constructivist grounded theory approach was used to analyze the data and shape a theory of how nurses make things right when confronted with bullying. In a four-step process, nurses place bullying in context, assess the situation, take action, and judge the outcomes of their actions. While many nurses do engage in a number of effective yet untested strategies, two additional concerns remain: inadequate support among nursing colleagues and silence and inaction by nurse administrators. Qualitative inquiry has the potential to guide researchers to a greater understanding of the complexities of bullying in the workplace. PMID:22567223

  17. Making Things Right: Nurses' Experiences with Workplace Bullying—A Grounded Theory

    Directory of Open Access Journals (Sweden)

    Donna A. Gaffney

    2012-01-01

    Full Text Available While bullying in the healthcare workplace has been recognized internationally, there is still a culture of silence in many institutions in the United States, perpetuating underreporting and insufficient and unproven interventions. The deliberate, repetitive, and aggressive behaviors of bullying can cause psychological and/or physical harm among professionals, disrupt nursing care, and threaten patient safety and quality outcomes. Much of the literature focuses on categories of bullying behaviors and nurse responses. This qualitative study reports on the experiences of nurses confronting workplace bullying. We collected data from the narratives of 99 nurses who completed an open-ended question embedded in an online survey in 2007. A constructivist grounded theory approach was used to analyze the data and shape a theory of how nurses make things right when confronted with bullying. In a four-step process, nurses place bullying in context, assess the situation, take action, and judge the outcomes of their actions. While many nurses do engage in a number of effective yet untested strategies, two additional concerns remain: inadequate support among nursing colleagues and silence and inaction by nurse administrators. Qualitative inquiry has the potential to guide researchers to a greater understanding of the complexities of bullying in the workplace.

  18. Ground-state and dynamical properties of two-dimensional dipolar Fermi liquids

    International Nuclear Information System (INIS)

    Abedinpour, Saeed H.; Asgari, Reza; Tanatar, B.; Polini, Marco

    2014-01-01

    We study the ground-state properties of a two-dimensional spin-polarized fluid of dipolar fermions within the Euler–Lagrange Fermi-hypernetted-chain approximation. Our method is based on the solution of a scattering Schrödinger equation for the “pair amplitude” √(g(r)), where g(r) is the pair distribution function. A key ingredient in our theory is the effective pair potential, which includes a bosonic term from Jastrow–Feenberg correlations and a fermionic contribution from kinetic energy and exchange, which is tailored to reproduce the Hartree–Fock limit at weak coupling. Very good agreement with recent results based on quantum Monte Carlo simulations is achieved over a wide range of coupling constants up to the liquid-to-crystal quantum phase transition. Using the fluctuation–dissipation theorem and a static approximation for the effective inter-particle interactions, we calculate the dynamical density–density response function, and furthermore demonstrate that an undamped zero-sound mode exists for any value of the interaction strength, down to infinitesimally weak couplings. -- Highlights: •We have studied the ground state properties of a strongly correlated two-dimensional fluid of dipolar fermions. •We have calculated the effective inter-particle interaction and the dynamical density–density response function. •We have shown that an undamped zero sound mode exists at any value of the interaction strength

  19. Antibonding hole ground state in InAs quantum dot molecules

    Energy Technology Data Exchange (ETDEWEB)

    Planelles, Josep [Departament de Química Física i Analítica, Universitat Jaume I, E-12080, Castelló (Spain)

    2015-01-22

    Using four-band k⋅p Hamiltonians, we study how strain and position-dependent effective masses influence hole tunneling in vertically coupled InAs/GaAs quantum dots. Strain reduces the tunneling and hence the critical interdot distance required for the ground state to change from bonding to antibonding. Variable mass has the opposite effect and a rough compensation leaves little affected the critical bonding-to-antibonding ground state crossover. An alternative implementation of the magnetic field in the envelope function Hamiltonian is given which retrieves the experimental denial of possible after growth reversible magnetically induced bonding-to-antibonding ground state transition, predicted by the widely used Luttinger-Kohn Hamiltonian.

  20. Full-potential multiple scattering theory with space-filling cells for bound and continuum states.

    Science.gov (United States)

    Hatada, Keisuke; Hayakawa, Kuniko; Benfatto, Maurizio; Natoli, Calogero R

    2010-05-12

    We present a rigorous derivation of a real-space full-potential multiple scattering theory (FP-MST) that is free from the drawbacks that up to now have impaired its development (in particular the need to expand cell shape functions in spherical harmonics and rectangular matrices), valid both for continuum and bound states, under conditions for space partitioning that are not excessively restrictive and easily implemented. In this connection we give a new scheme to generate local basis functions for the truncated potential cells that is simple, fast, efficient, valid for any shape of the cell and reduces to the minimum the number of spherical harmonics in the expansion of the scattering wavefunction. The method also avoids the need for saturating 'internal sums' due to the re-expansion of the spherical Hankel functions around another point in space (usually another cell center). Thus this approach provides a straightforward extension of MST in the muffin-tin (MT) approximation, with only one truncation parameter given by the classical relation l(max) = kR(b), where k is the electron wavevector (either in the excited or ground state of the system under consideration) and R(b) is the radius of the bounding sphere of the scattering cell. Moreover, the scattering path operator of the theory can be found in terms of an absolutely convergent procedure in the l(max) --> ∞ limit. Consequently, this feature provides a firm ground for the use of FP-MST as a viable method for electronic structure calculations and makes possible the computation of x-ray spectroscopies, notably photo-electron diffraction, absorption and anomalous scattering among others, with the ease and versatility of the corresponding MT theory. Some numerical applications of the theory are presented, both for continuum and bound states.

  1. A Model Ground State of Polyampholytes

    International Nuclear Information System (INIS)

    Wofling, S.; Kantor, Y.

    1998-01-01

    The ground state of randomly charged polyampholytes (polymers with positive and negatively charged groups along their backbone) is conjectured to have a structure similar to a necklace, made of weakly charged parts of the chain, compacting into globules, connected by highly charged stretched 'strings' attempted to quantify the qualitative necklace model, by suggesting a zero approximation model, in which the longest neutral segment of the polyampholyte forms a globule, while the remaining part will form a tail. Expanding this approximation, we suggest a specific necklace-type structure for the ground state of randomly charged polyampholyte's, where all the neutral parts of the chain compact into globules: The longest neutral segment compacts into a globule; in the remaining part of the chain, the longest neutral segment (the second longest neutral segment) compacts into a globule, then the third, and so on. A random sequence of charges is equivalent to a random walk, and a neutral segment is equivalent to a loop inside the random walk. We use analytical and Monte Carlo methods to investigate the size distribution of loops in a one-dimensional random walk. We show that the length of the nth longest neutral segment in a sequence of N monomers (or equivalently, the nth longest loop in a random walk of N steps) is proportional to N/n 2 , while the mean number of neutral segments increases as √N. The polyampholytes in the ground state within our model is found to have an average linear size proportional to dN, and an average surface area proportional to N 2/3

  2. Three-body problem in the ground-state representation

    International Nuclear Information System (INIS)

    Gonzalez, A.

    1993-01-01

    The ground-state probability density of a three-body system is used to construct a classical potential U whose minimum coincides exactly with the ground-state energy. The spectrum of excited states may approximately be obtained by imposing quasiclassical quantization conditions over the classical motion in U. We show nontrivial one-dimensional models in which either this quantization condition is exact or considerably improves the usual semiclassical quantization. For three-dimensional problems, the small-oscillation frequencies in states with total angular momentum L = 0 are computed. These frequencies could represent an improvement over the frequencies of triatomic molecules computed with the use of ordinary quasiclassics for the motion of the nuclei in the molecular term. By providing a semiclassical description of the first excited quantum states, the sketched approach rises some interesting questions such as, for example, the relevance (once again) of classical chaos to quantum mechanics

  3. Variational estimate of the vacuum state of the SU(2) lattice gauge theory with a disordered trial wave function

    International Nuclear Information System (INIS)

    Heys, D.W.; Stump, D.R.

    1984-01-01

    The variational principle is used to estimate the ground state of the Kogut-Susskind Hamiltonian of the SU(2) lattice gauge theory, with a trial wave function for which the magnetic fields on different plaquettes are uncorrelated. This trial function describes a disordered state. The energy expectation value is evaluated by a Monte Carlo method. The variational results are compared to similar results for a related Abelian gauge theory. Also, the expectation value of the Wilson loop operator is computed for the trial state, and the resulting estimate of the string tension is compared to the prediction of asymptotic freedom

  4. Fathers' Orientation to Their Children's Autism Diagnosis: A Grounded Theory Study

    Science.gov (United States)

    Hannon, Michael D.; Hannon, LaChan V.

    2017-01-01

    Sixteen fathers of individuals with autism were interviewed to develop a grounded theory explaining how they learned about their children's autism diagnosis. Results suggest the orientation process entails at least two phases: orienting oneself and orienting others. The orienting oneself phase entailed fathers having suspicion of developmental…

  5. Conducting a Grounded Theory Study in a Language Other Than English

    Directory of Open Access Journals (Sweden)

    Intansari Nurjannah

    2014-03-01

    Full Text Available Translation can be a problem area for researchers conducting qualitative studies in languages other than English who intend to publish the results in an English-language journal. Analyzing the data is also complex when the research team consists of people from different language backgrounds. Translation must be considered as an issue in its own right to maintain the integrity of the research, especially in a grounded theory study. In this article, we offer guidelines for the process of translation for data analysis in a grounded theory study in which the research was conducted in a language other than English (Indonesian. We make recommendations about procedures to choose when, who, and how to translate data. The translation procedure is divided into four steps which are as follows: translation in the process of coding, translation in the process of team discussion, translation in the process of advanced coding, and ensuring the accuracy of translation.

  6. Building Theory from Data in the Field of Entrepreneurship

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    In this paper, we describe the process of building of grounded theory. We have an emphasis on the field of entrepreneurship: we describe and analyse current grounded theory research in entrepreneurship and point out directions and potential improvements for future research. A basis for our...... assessment of the current state of grounded theory research in entrepreneurship and for our suggestions for the future is provided by an analysis that we have conducted of recent grounded theory-based entrepreneurship research that has been published in top-tier research journals. Our paper has two goals....... First, we wish to provide an explicit paradigmatic positioning of the grounded theory methodology, discussing the most relevant views of ontologies and epistemologies that can be used as alternative starting points on conducting grounded theory research. Currently, different paradigms are used...

  7. Becoming Selfless: A Grounded Theory of Commitment to Service

    Directory of Open Access Journals (Sweden)

    Roland Nino L. Agoncillo

    2014-05-01

    Full Text Available This study focuses on the substantive area of commitment to service in the community of educational partners in the Philippines. Educational partners are lay people who assist religious organizations in the field of education, and in the Philippines, about 96 percent of educational partners are in Lasallian schools and organizations. Educational partners are young professionals, volunteers between the ages of 24-39 who strive to live the teachings of St. John Baptist De La Salle. The volunteers aim to generate a spirit of service, a sense of mission to the youth. By using a classic Grounded Theory approach, the theory of becoming selfless was generated. The theory explains the stages educational partners undergo when resolving their organizational commitment to service. Organizational commitment is the psychological attachment, involvement and identification of the individual to the organization. Becoming selfless provides a theoretical focal point to better understand the complexity of commitment.

  8. Stability of quantum-dot excited-state laser emission under simultaneous ground-state perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Kaptan, Y., E-mail: yuecel.kaptan@physik.tu-berlin.de; Herzog, B.; Schöps, O.; Kolarczik, M.; Woggon, U.; Owschimikow, N. [Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin (Germany); Röhm, A.; Lingnau, B.; Lüdge, K. [Institut für Theoretische Physik, Technische Universität Berlin, Berlin (Germany); Schmeckebier, H.; Arsenijević, D.; Bimberg, D. [Institut für Festkörperphysik, Technische Universität Berlin, Berlin (Germany); Mikhelashvili, V.; Eisenstein, G. [Technion Institute of Technology, Faculty of Electrical Engineering, Haifa (Israel)

    2014-11-10

    The impact of ground state amplification on the laser emission of In(Ga)As quantum dot excited state lasers is studied in time-resolved experiments. We find that a depopulation of the quantum dot ground state is followed by a drop in excited state lasing intensity. The magnitude of the drop is strongly dependent on the wavelength of the depletion pulse and the applied injection current. Numerical simulations based on laser rate equations reproduce the experimental results and explain the wavelength dependence by the different dynamics in lasing and non-lasing sub-ensembles within the inhomogeneously broadened quantum dots. At high injection levels, the observed response even upon perturbation of the lasing sub-ensemble is small and followed by a fast recovery, thus supporting the capacity of fast modulation in dual-state devices.

  9. The persistence of women in STEM: A constructivist grounded theory study

    Science.gov (United States)

    Gamm, Ryan

    Men and women have reached relative parity in most sectors of the United States workforce. Yet women remain underrepresented in science, technology, engineering, and mathematics (STEM) fields (AAUW, 2010). Underrepresentation persists despite several decades of research, legislation, and intervention focused on gender equality in STEM fields (Clewell, 2002). The underrepresentation or shortage of women in STEM fields is identifiable primarily in degree attainment, in workforce demographics, and in a gender wage gap. Situated in constructivist grounded theory, this study asks how do women in science, technology, engineering, and mathematics (STEM) fields, particularly those in established career positions, persist when encountering personal and institutional barriers, resistance, and hostility? I use an interpretive-constructivist lens to conduct a grounded theory study exploring the experiences of women who persist in STEM fields, their relation to extant literature on this topic, and the connections to K-12 education practices, specifically curriculum. To understand the connections to curriculum I employ Pinar's (2012) method of currere. Pinar (2012) contends currere "provides a strategy for students of curriculum to study the relations between academic knowledge and life history in the interests of self-understanding and social reconstruction" (p.44). This qualitative study explored nine female STEM workers stories of persistence as each respondent works in STEM fields were gender parity has yet to be established. This study presents a substantive theory: As women persist in STEM fields they reframe themselves to be situated in the overlapping intersection of the social processes that correspond to "engagement" and "persistence." This reframing is possible by interpreting one's present day circumstances by independently removing oneself from current circumstances to understand the cumulative effect of both past and present. The findings highlight the importance

  10. Differential cross sections for elastic and inelastic n=2 excitation of ground-state helium at 29.6 and 40.1 eV

    International Nuclear Information System (INIS)

    Brunger, M.J.

    1989-11-01

    Differential cross sections have been measured for elastic and inelastic scattering of electrons by ground-state helium at 29.6 and 40.1eV. The normalisation of the cross sections is discussed. Theoretical cross sections have been obtained using a 10-state coupled-channels-optical calculation. In general, there is good agreement between theory and experiment for singlet states but not for triplet. 20 refs., 5 tabs., 6 figs

  11. Study of structure and potential energy curve for ground state X1Σ+ of LaF

    International Nuclear Information System (INIS)

    Chen Linhong; Shang Rencheng

    2002-01-01

    The equilibrium geometry, harmonic frequency and dissociation energy of the molecule LaF have been calculated on several kinds of computation levels with energy-consistent relativistic effective core potentials and valence basis sets including polarization functions 4f2g and diffuse functions 1s1p1d. The possible electronic state and its reasonable dissociation limit for the ground state of LaF are determined based on Atomic and Molecular Reaction Statics (AMRS). The potential energy curve scan for the ground state X 1 Σ + has been carried out with B3LYP method of density functional theory. Murrell-Sorbie analytic potential energy function and its Dunham expansion around equilibrium position have been also derived with a nonlinear least-square fit. The calculated spectroscopic constants are in good agreement with the experimental results of vibrational spectra. The analytical function obtained here is of great realistic importance due to its use in calculating fine transitional structure of vibrational spectra and the reaction dynamic process between atoms and molecules

  12. Saudi Deaf Students Post-Secondary Transitioning Experience: A Grounded Theory Study

    Science.gov (United States)

    Almotiri, Abdullah

    2017-01-01

    Understanding how deaf and hard-of-hearing (DHH) international students transition to post-secondary institutions is important for ensuring their academic and personal success. In this grounded theory study, five Saudi Arabian students who are DHH and enrolled at Gallaudet University were interviewed about their transition experience. Participants…

  13. A Grounded Theory of Collaborative Synchronizing in Relation to Challenging Students

    Science.gov (United States)

    Thornberg, Robert

    2012-01-01

    The aim of this study was to investigate multiprofessional collaboration as well as collaboration between professionals and challenging students and their parents in which the focus for these collaborations was on handling the challenging students' academic and social behavior. A grounded theory study of collaboration between a prereferral…

  14. Philosophical Roots of Classical Grounded Theory: Its Foundations in Symbolic Interactionism

    Science.gov (United States)

    Aldiabat, Khaldoun M.; Le Navenec, Carole-Lynne

    2011-01-01

    Although many researchers have discussed the historical relationship between the Grounded Theory methodology and Symbolic Interactionism, they have not clearly articulated the congruency of their salient concepts and assumptions. The purpose of this paper is to provide a thorough discussion of this congruency. A hypothetical example about smoking…

  15. On calculations of the ground state energy in quantum mechanics

    International Nuclear Information System (INIS)

    Efimov, G.V.

    1991-02-01

    In nonrelativistic quantum mechanics the Wick-ordering method called the oscillator representation suggested to calculate the ground-state energy for a wide class of potentials allowing the existence of a bound state. The following examples are considered: the orbital excitations of the ground-state in the Coulomb plus linear potential, the Schroedinger equation with a ''relativistic'' kinetic energy √p 2 +m 2 , the Coulomb three-body problem. (author). 22 refs, 2 tabs

  16. Antidiabetic Theory of Superconducting State Transition: Phonons and Strong Electron Correlations the Old Physics and New Aspects

    International Nuclear Information System (INIS)

    Banacky, P.

    2010-01-01

    Complex electronic ground state of molecular and solid state system is analyzed on the ab initio level beyond the adiabatic Born-Oppenheimer approximation (BOA). The attention is focused on the band structure fluctuation (BSF) at Fermi level, which is induced by electron-phonon coupling in superconductors, and which is absent in the non-superconducting analogues. The BSF in superconductors results in breakdown of the adiabatic BOA. At these circumstances, chemical potential is substantially reduced and system is stabilized (effect of nuclear dynamics) in the anti adiabatic state at broken symmetry with a gap(s) in one-particle spectrum. Distorted nuclear structure has fluxional character and geometric degeneracy of the anti adiabatic ground state enables formation of mobile bipolarons in real space. It has been shown that an effective attractive e-e interaction (Cooper-pair formation) is in fact correction to electron correlation energy at transition from adiabatic into anti adiabatic ground electronic state. In this respect, Cooper-pair formation is not the primary reason for transition into superconducting state, but it is a consequence of anti adiabatic state formation. It has been shown that thermodynamic properties of system in anti adiabatic state correspond to thermodynamics of superconducting state. Illustrative application of the theory for different types of superconductors is presented.

  17. Probing quantum frustrated systems via factorization of the ground state.

    Science.gov (United States)

    Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio

    2010-05-21

    The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized ground states below a threshold value of the frustration. Ground-state separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized ground states and the critical frustration are determined for various classes of nonexactly solvable spin models with different spatial ranges of the interactions. For weak frustration, the existence of disentangling transitions determines the range of applicability of mean-field descriptions in biological and physical problems such as stochastic gene expression and the stability of long-period modulated structures.

  18. Ground-state fidelity in the BCS-BEC crossover

    International Nuclear Information System (INIS)

    Khan, Ayan; Pieri, Pierbiagio

    2009-01-01

    The ground-state fidelity has been introduced recently as a tool to investigate quantum phase transitions. Here, we apply this concept in the context of a crossover problem. Specifically, we calculate the fidelity susceptibility for the BCS ground-state wave function, when the intensity of the fermionic attraction is varied from weak to strong in an interacting Fermi system, through the BCS-Bose-Einstein Condensation crossover. Results are presented for contact and finite-range attractive potentials and for both continuum and lattice models. We conclude that the fidelity susceptibility can be useful also in the context of crossover problems.

  19. Implications of male circumcision for women in Papua New Guinea: a transformational grounded theory study.

    Science.gov (United States)

    Redman-MacLaren, Michelle; Mills, Jane; Tommbe, Rachael; MacLaren, David; Speare, Rick; McBride, William J H

    2017-07-27

    Male circumcision reduces the risk of female-to-male transmission of human immunodeficiency virus (HIV) and is being explored for HIV prevention in Papua New Guinea (PNG). PNG has a concentrated HIV epidemic which is largely heterosexually transmitted. There are a diverse range of male circumcision and penile modification practices across PNG. Exploring the implications of male circumcision for women in PNG is important to inform evidence-based health policy that will result in positive, intended consequences. The transformational grounded theory study incorporated participatory action research and decolonizing methodologies. In Phase One, an existing data set from a male circumcision study of 861 male and 519 female participants was theoretically sampled and analyzed for women's understanding and experience of male circumcision. In Phase Two of the study, primary data were co-generated with 64 women in seven interpretive focus group discussions and 11 semi-structured interviews to develop a theoretical model of the processes used by women to manage the outcomes of male circumcision. In Phase Three participants assisted to refine the developing transformational grounded theory and identify actions required to improve health. Many women know a lot about male circumcision and penile modification and the consequences for themselves, their families and communities. Their ability to act on this knowledge is determined by numerous social, cultural and economic factors. A transformational grounded theory was developed with connecting categories of: Women Know a Lot, Increasing Knowledge; Increasing Options; and Acting on Choices. Properties and dimensions of each category are represented in the model, along with the intervening condition of Safety. The condition of Safety contextualises the overarching lived realty for women in PNG, enables the inclusion of men in the transformational grounded theory model, and helps to explain relationships between men and women. The

  20. Antiferrodistortive phase transitions and ground state of PZT ceramics

    International Nuclear Information System (INIS)

    Pandey, Dhananjai

    2013-01-01

    The ground state of the technologically important Pb(Zr x Ti (1-x) )O 3 , commonly known as PZT, ceramics is currently under intense debate. The phase diagram of this material shows a morphotropic phase boundary (MPB) for x∼0.52 at 300K, across which a composition induced structural phase transition occurs leading to maximization of the piezoelectric properties. In search for the true ground state of the PZT in the MPB region, Beatrix Noheda and coworkers first discovered a phase transition from tetragonal (space group P4mm) to an M A type monoclinic phase (space group Cm) at low temperatures for x=0.52. Soon afterwards, we discovered yet another low temperature phase transition for the same composition in which the M A type (Cm) monoclinic phase transforms to another monoclinic phase with Cc space group. We have shown that the Cm to Cc phase transition is an antiferrodistortive (AFD) transition involving tilting of oxygen octahedra leading to unit cell doubling and causing appearance of superlattice reflections which are observable in the electron and neutron diffraction patterns only and not in the XRD patterns, as a result of which Noheda and coworkers missed the Cc phase in their synchrotron XRD studies at low temperatures. Our findings were confirmed by leading groups using neutron, TEM, Raman and high pressure diffraction studies. The first principles calculations also confirmed that the true ground state of PZT in the MPB region has Cc space group. However, in the last couple of years, the Cc space group of the ground state has become controversial with an alternative proposal of R3c as the space group of the ground state phase which is proposed to coexist with the metastable Cm phase. In order to resolve this controversy, we recently revisited the issue using pure PZT and 6% Sr 2+ substituted PZT, the latter samples show larger tilt angle on account of the reduction in the average cationic radius at the Pb 2+ site. Using high wavelength neutrons and high

  1. Extended Lagrangian Excited State Molecular Dynamics.

    Science.gov (United States)

    Bjorgaard, J A; Sheppard, D; Tretiak, S; Niklasson, A M N

    2018-02-13

    An extended Lagrangian framework for excited state molecular dynamics (XL-ESMD) using time-dependent self-consistent field theory is proposed. The formulation is a generalization of the extended Lagrangian formulations for ground state Born-Oppenheimer molecular dynamics [Phys. Rev. Lett. 2008 100, 123004]. The theory is implemented, demonstrated, and evaluated using a time-dependent semiempirical model, though it should be generally applicable to ab initio theory. The simulations show enhanced energy stability and a significantly reduced computational cost associated with the iterative solutions of both the ground state and the electronically excited states. Relaxed convergence criteria can therefore be used both for the self-consistent ground state optimization and for the iterative subspace diagonalization of the random phase approximation matrix used to calculate the excited state transitions. The XL-ESMD approach is expected to enable numerically efficient excited state molecular dynamics for such methods as time-dependent Hartree-Fock (TD-HF), Configuration Interactions Singles (CIS), and time-dependent density functional theory (TD-DFT).

  2. Ground state correlations and structure of odd spherical nuclei

    International Nuclear Information System (INIS)

    Mishev, S.; Voronov, V. V.

    2006-01-01

    It is well known that the Pauli principle plays a substantial role at low energies because the phonon operators are not ideal boson operators. Calculating the exact commutators between the quasiparticle and phonon operators one can take into account the Pauli principle corrections. Besides the ground state correlations due to the quasiparticle interaction in the ground state influence the single particle fragmentation as well. In this paper, we generalize the basic QPM equations to account for both mentioned effects. As an illustration of our approach, calculations on the structure of the low-lying states in "1"3"1Ba have been performed.

  3. BCS wave function, matrix product states, and the Ising conformal field theory

    Science.gov (United States)

    Montes, Sebastián; Rodríguez-Laguna, Javier; Sierra, Germán

    2017-11-01

    We present a characterization of the many-body lattice wave functions obtained from the conformal blocks (CBs) of the Ising conformal field theory (CFT). The formalism is interpreted as a matrix product state using continuous ancillary degrees of freedom. We provide analytic and numerical evidence that the resulting states can be written as BCS states. We give a complete proof that the translationally invariant 1D configurations have a BCS form and we find suitable parent Hamiltonians. In particular, we prove that the ground state of the finite-size critical Ising transverse field (ITF) Hamiltonian can be obtained with this construction. Finally, we study 2D configurations using an operator product expansion (OPE) approximation. We associate these states to the weak pairing phase of the p +i p superconductor via the scaling of the pairing function and the entanglement spectrum.

  4. Ground-state splitting of ultrashallow thermal donors with negative central-cell corrections in silicon

    Science.gov (United States)

    Hara, Akito; Awano, Teruyoshi

    2017-06-01

    Ultrashallow thermal donors (USTDs), which consist of light element impurities such as carbon, hydrogen, and oxygen, have been found in Czochralski silicon (CZ Si) crystals. To the best of our knowledge, these are the shallowest hydrogen-like donors with negative central-cell corrections in Si. We observed the ground-state splitting of USTDs by far-infrared optical absorption at different temperatures. The upper ground-state levels are approximately 4 meV higher than the ground-state levels. This energy level splitting is also consistent with that obtained by thermal excitation from the ground state to the upper ground state. This is direct evidence that the wave function of the USTD ground state is made up of a linear combination of conduction band minimums.

  5. Doing the Things We Do: A Grounded Theory of Academic Procrastination

    Science.gov (United States)

    Schraw, Gregory; Wadkins, Theresa; Olafson, Lori

    2007-01-01

    The authors conducted a grounded theory study of academic procrastination to explore adaptive and maladaptive aspects of procrastination and to help guide future empirical research. They discuss previous research on the definition and dimensionality of procrastination and describe the study in which interview data were collected in 4 stages,…

  6. Combining symmetry collective states with coupled-cluster theory: Lessons from the Agassi model Hamiltonian

    Science.gov (United States)

    Hermes, Matthew R.; Dukelsky, Jorge; Scuseria, Gustavo E.

    2017-06-01

    The failures of single-reference coupled-cluster theory for strongly correlated many-body systems is flagged at the mean-field level by the spontaneous breaking of one or more physical symmetries of the Hamiltonian. Restoring the symmetry of the mean-field determinant by projection reveals that coupled-cluster theory fails because it factorizes high-order excitation amplitudes incorrectly. However, symmetry-projected mean-field wave functions do not account sufficiently for dynamic (or weak) correlation. Here we pursue a merger of symmetry projection and coupled-cluster theory, following previous work along these lines that utilized the simple Lipkin model system as a test bed [J. Chem. Phys. 146, 054110 (2017), 10.1063/1.4974989]. We generalize the concept of a symmetry-projected mean-field wave function to the concept of a symmetry projected state, in which the factorization of high-order excitation amplitudes in terms of low-order ones is guided by symmetry projection and is not exponential, and combine them with coupled-cluster theory in order to model the ground state of the Agassi Hamiltonian. This model has two separate channels of correlation and two separate physical symmetries which are broken under strong correlation. We show how the combination of symmetry collective states and coupled-cluster theory is effective in obtaining correlation energies and order parameters of the Agassi model throughout its phase diagram.

  7. Rearrangements in ground and excited states

    CERN Document Server

    de Mayo, Paul

    1980-01-01

    Rearrangements in Ground and Excited States, Volume 3 presents essays on the chemical generation of excited states; the cis-trans isomerization of olefins; and the photochemical rearrangements in trienes. The book also includes essays on the zimmerman rearrangements; the photochemical rearrangements of enones; the photochemical rearrangements of conjugated cyclic dienones; and the rearrangements of the benzene ring. Essays on the photo rearrangements via biradicals of simple carbonyl compounds; the photochemical rearrangements involving three-membered rings or five-membered ring heterocycles;

  8. Assessing the optimism-pessimism debate: Nuclear proliferation, nuclear risks, and theories of state action

    International Nuclear Information System (INIS)

    Busch, Nathan Edward

    2001-01-01

    This dissertation focuses on the current debate in international relations literature over the risks associated with the proliferation of nuclear weapons. On this subject, IR scholars are divided into roughly two schools: proliferation 'optimists,' who argue that proliferation can be beneficial and that its associated hazards are at least surmountable, and proliferation 'pessimists,' who believe the opposite. This debate centers upon a theoretical disagreement about how best to explain and predict the behavior of states. Optimists generally ground their arguments on rational deterrence theory and maintain that nuclear weapons can actually increase stability among states, while pessimists often ground their arguments on 'organization theory,' which contends that organizational, bureaucratic, and other factors prevent states from acting rationally. A major difficulty with the proliferation debate, however, is that both sides tend to advance their respective theoretical positions without adequately supporting them with solid empirical evidence. This dissertation detailed analyses of the nuclear programs in the United States, Russia, China, India, and Pakistan to determine whether countries with nuclear weapons have adequate controls over their nuclear arsenals and tissue material stockpiles (such as highly enriched uranium and plutonium). These case studies identify the strengths and weaknesses of different systems of nuclear controls and help predict what types of controls proliferating states are likely to employ. On the basis of the evidence gathered from these cases, this dissertation concludes that a further spread of nuclear weapons would tend to have seriously negative effects on international stability by increasing risks of accidental, unauthorized, or inadvertent use of nuclear weapons and risks of thefts of fissile materials for use in nuclear or radiological devices by aspiring nuclear states or terrorist groups. (author)

  9. Application of the random phase approximation to some atoms with ns2 ground state configurations

    International Nuclear Information System (INIS)

    Wright, L.A.

    1975-01-01

    Atomic bound state properties such as excitation energies and oscillator strengths were calculated by the Random Phase Approximation (RPA), also known as the Time Dependent Hartree-Fock Approximation (TDHFA). The RPA is equivalent to describing excited states as the creation of particle-hole pairs and the application to atoms is important for two reasons: the wide range of densities in an atom will cause the physical interpretation and mathematical approximations to be much different than with a uniform density system, such as an electron gas; this method could detect the existence of collective states in atoms similar to those responsible for the giant dipole resonances in nuclei. The method is shown to be superior to the H-F method in three basic ways: (1) The RPA contains explicit correlations between the excited and ground states. These are not included in the H-F theory. One can apply this method to large atoms since only these correlations are explicitly included. (2) The RPA calculates excitation energies directly without recourse to highly correlated ground state wavefunctions. This is in contrast to the method of configuration mixing which is known to have slow convergence properties. (3) Oscillator strengths and photoionization cross sections can be calculated by finding the eigenvectors corresponding excitation energy eigenvalues. The strength of the RPA is that the excitation energies and oscillator strengths, which are relative quantities, are calculated directly. The results for the oscillator strengths show an improvement of up to 45 percent over the H-F values and an improvement over the RPA done with Hartree wavefunctions by as much as 65 percent. The work was limited to atoms with an ns 2 ground state configuration. These atoms were He, Be, Mg and Ca

  10. "Putting My Man Face on": A Grounded Theory of College Men's Gender Identity Development

    Science.gov (United States)

    Edwards, Keith E.; Jones, Susan R.

    2009-01-01

    The theory that emerged from this constructivist grounded theory study of 10 college men's experiences depicts their gender identity as developed through constant interaction with society's expectations of them as men. In order to try to meet these perceived expectations, participants described putting on a performance that was like wearing a mask…

  11. Ground-state properties of rare-earth metals: an evaluation of density-functional theory

    International Nuclear Information System (INIS)

    Söderlind, Per; Turchi, P E A; Landa, A; Lordi, V

    2014-01-01

    The rare-earth metals have important technological applications due to their magnetic properties, but are scarce and expensive. Development of high-performance magnetic materials with less rare-earth content is desired, but theoretical modeling is hampered by complexities of the rare earths electronic structure. The existence of correlated (atomic-like) 4f electrons in the vicinity of the valence band makes any first-principles theory challenging. Here, we apply and evaluate the efficacy of density-functional theory for the series of lanthanides (rare earths), investigating the influence of the electron exchange and correlation functional, spin-orbit interaction, and orbital polarization. As a reference, the results are compared with those of the so-called ‘standard model’ of the lanthanides in which electrons are constrained to occupy 4f core states with no hybridization with the valence electrons. Some comparisons are also made with models designed for strong electron correlations. Our results suggest that spin–orbit coupling and orbital polarization are important, particularly for the magnitude of the magnetic moments, and that calculated equilibrium volumes, bulk moduli, and magnetic moments show correct trends overall. However, the precision of the calculated properties is not at the level of that found for simpler metals in the Periodic Table of Elements, and the electronic structures do not accurately reproduce x-ray photoemission spectra. (paper)

  12. Variational minimization of atomic and molecular ground-state energies via the two-particle reduced density matrix

    International Nuclear Information System (INIS)

    Mazziotti, David A.

    2002-01-01

    Atomic and molecular ground-state energies are variationally determined by constraining the two-particle reduced density matrix (2-RDM) to satisfy positivity conditions. Because each positivity condition corresponds to correcting the ground-state energies for a class of Hamiltonians with two-particle interactions, these conditions collectively provide a new approach to many-body theory that, unlike perturbation theory, can capture significantly correlated phenomena including the multireference effects of potential-energy surfaces. The D, Q, and G conditions for the 2-RDM are extended through generalized lifting operators inspired from the formal solution of N-representability. These lifted conditions agree with the hierarchy of positivity conditions presented by Mazziotti and Erdahl [Phys. Rev. A 63, 042113 (2001)]. The connection between positivity and the formal solution explains how constraining higher RDMs to be positive semidefinite improves the N representability of the 2-RDM and suggests using pieces of higher positivity conditions that computationally scale like the D condition. With the D, Q, and G conditions as well as pieces of higher positivity the electronic energies for Be, LiH, H 2 O, and BH are computed through a primal-dual interior-point algorithm for positive semidefinite programming. The variational method produces potential-energy surfaces that are highly accurate even far from the equilibrium geometry where single-reference perturbation-based methods often fail to produce realistic energies

  13. Ab Initio Optimized Effective Potentials for Real Molecules in Optical Cavities: Photon Contributions to the Molecular Ground State

    Science.gov (United States)

    2018-01-01

    We introduce a simple scheme to efficiently compute photon exchange-correlation contributions due to the coupling to transversal photons as formulated in the newly developed quantum-electrodynamical density-functional theory (QEDFT).1−5 Our construction employs the optimized-effective potential (OEP) approach by means of the Sternheimer equation to avoid the explicit calculation of unoccupied states. We demonstrate the efficiency of the scheme by applying it to an exactly solvable GaAs quantum ring model system, a single azulene molecule, and chains of sodium dimers, all located in optical cavities and described in full real space. While the first example is a two-dimensional system and allows to benchmark the employed approximations, the latter two examples demonstrate that the correlated electron-photon interaction appreciably distorts the ground-state electronic structure of a real molecule. By using this scheme, we not only construct typical electronic observables, such as the electronic ground-state density, but also illustrate how photon observables, such as the photon number, and mixed electron-photon observables, for example, electron–photon correlation functions, become accessible in a density-functional theory (DFT) framework. This work constitutes the first three-dimensional ab initio calculation within the new QEDFT formalism and thus opens up a new computational route for the ab initio study of correlated electron–photon systems in quantum cavities. PMID:29594185

  14. Ground state correlations and structure of odd spherical nuclei

    International Nuclear Information System (INIS)

    Mishev, S.; Voronov, V.V.

    2008-01-01

    It is well known that the Pauli principle plays a substantial role at low energies because the phonon operators are not ideal boson operators. Calculating the exact commutators between the quasiparticle and phonon operators one can take into account the Pauli principle corrections. Besides, the ground state correlations due to the quasiparticle interaction in the ground state influence the single-particle fragmentation as well. In this paper, we generalize the basic equations of the quasiparticle-phonon nuclear model to account for both effects mentioned. As an illustration of our approach, calculations on the structure of the low-lying states in 133 Ba have been performed

  15. Psychosocial Intervention Use in Long-Stay Dementia Care: A Classic Grounded Theory.

    Science.gov (United States)

    Hunter, Andrew; Keady, John; Casey, Dympna; Grealish, Annmarie; Murphy, Kathy

    2016-12-01

    The objective of this study was to develop a substantive grounded theory of staff psychosocial intervention use with residents with dementia in long-stay care. "Becoming a person again" emerged as the core category accounting for staffs' psychosocial intervention use within long-stay care. Interview data were collected from participants in nine Irish long-stay settings: 14 residents with dementia, 19 staff nurses, one clinical facilitator, seven nurse managers, 21 nursing assistants, and five relatives. Constant comparative method guided the data collection and analysis. The researcher's theoretical memos, based on unstructured observation, and applicable extant literature were also included as data. By identifying the mutuality of the participants' experiences, this classic grounded theory explains staff motivation toward psychosocial intervention use within long-stay care. It also explains how institutional factors interact with those personal factors that incline individuals toward psychosocial intervention use. © The Author(s) 2016.

  16. Ground state of the parallel double quantum dot system.

    Science.gov (United States)

    Zitko, Rok; Mravlje, Jernej; Haule, Kristjan

    2012-02-10

    We resolve the controversy regarding the ground state of the parallel double quantum dot system near half filling. The numerical renormalization group predicts an underscreened Kondo state with residual spin-1/2 magnetic moment, ln2 residual impurity entropy, and unitary conductance, while the Bethe ansatz solution predicts a fully screened impurity, regular Fermi-liquid ground state, and zero conductance. We calculate the impurity entropy of the system as a function of the temperature using the hybridization-expansion continuous-time quantum Monte Carlo technique, which is a numerically exact stochastic method, and find excellent agreement with the numerical renormalization group results. We show that the origin of the unconventional behavior in this model is the odd-symmetry "dark state" on the dots.

  17. Patients' experiences with home parenteral nutrition: A grounded theory study.

    Science.gov (United States)

    Wong, Christina; Lucas, Beverley; Wood, Diana

    2018-04-01

    Parenteral nutrition (PN) provides nourishment and hydration as an intravenous infusion to patients with intestinal failure (IF). The aim of the study is to generate theory that explains the experiences of adult patients living with home parenteral nutrition (HPN) and complex medication regimens. A grounded theory methodology was used to explore the experiences of twelve patients receiving HPN. A semi-structured interview was conducted and recorded in each participant's home setting. Each interview was transcribed verbatim. The simultaneous process of data collection and analysis was followed reflecting the principles of the constant comparative approach. A total of 15 patients gave written consent, with 12 of them agreeing to be interviewed. All the participants had previously undergone surgery as a result of chronic ill health or sudden illness. Analysis revealed two core categories: stoma and HPN, and these were supported by the subcategories: maintaining stoma output, access to toilets, managing dietary changes, maintaining the HPN infusion routine, access to technical help to set up an HPN infusion, mobility with HPN equipment and general health changes. The strategy of living with loss was demonstrated by all the participants, and this was supported by the action strategies of maintaining daily activities and social interactions. This study generates new understanding and insight into the views and experiences of patients receiving HPN in the UK. The findings from these participants have been shown to resonate with the Kubler-Ross Model [1] of the five stages of grief. The theory of living with loss was generated by the use of a grounded theory methodology. This small scale exploratory study reveals opportunities for improvements in practice to be considered by the nutrition support team (NST) and other healthcare professionals involved in the patient's hospital stay prior to discharge on HPN. Copyright © 2018 European Society for Clinical Nutrition and

  18. Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: Application to SSSH

    Science.gov (United States)

    Kolmann, Stephen J.; Jordan, Meredith J. T.

    2010-02-01

    One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol-1 at the CCSD(T)/6-31G∗ level of theory, has a 4 kJ mol-1 dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol-1 lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol-1 lower in energy at the CCSD(T)/6-31G∗ level of theory. Ideally, for sub-kJ mol-1 thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented.

  19. Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: application to SSSH.

    Science.gov (United States)

    Kolmann, Stephen J; Jordan, Meredith J T

    2010-02-07

    One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol(-1) at the CCSD(T)/6-31G* level of theory, has a 4 kJ mol(-1) dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol(-1) lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol(-1) lower in energy at the CCSD(T)/6-31G* level of theory. Ideally, for sub-kJ mol(-1) thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented.

  20. Marshaling Resources: A Classic Grounded Theory Study of Online Learners

    Directory of Open Access Journals (Sweden)

    Barbara Yalof

    2014-06-01

    Full Text Available Classic grounded theory (CGT was used to identify a main concern of online students in higher education. One of the main impediments to studying online is a sense of isolation and lack of access to support systems as students navigate through complex requirements of their online programs. Hypothetical probability statements illustrate the imbalance between heightened needs of virtual learners and perceived inadequate support provided by educational institutions. The core variable, marshaling resources, explains how peer supports sustain motivation toward successful program completion. Understanding the critical contribution virtual interpersonal networks make towards maximizing resources by group problem solving is a significant aspect of this theory. Keywords: Online learning, e-learning, personal learning networks, peer networks

  1. Splitting of ISGMR strength in the light-mass nucleus 24Mg due to ground-state deformation

    Directory of Open Access Journals (Sweden)

    Y.K. Gupta

    2015-09-01

    Full Text Available The isoscalar giant monopole resonance (ISGMR strength distribution in 24Mg has been determined from background-free inelastic scattering of 386-MeV α particles at extreme forward angles, including 0∘. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of 24Mg.

  2. Business analysis methodology in telecommunication industry – the research based on the grounded theory

    Directory of Open Access Journals (Sweden)

    Hana Nenickova

    2013-10-01

    Full Text Available The objective of this article is to present the grounded theory using in the qualitative research as a basis to build a business analysis methodology for the implementation of information systems in telecommunication enterprises in Czech Republic. In the preparation of the methodology I have used the current needs of telecommunications companies, which are characterized mainly by high dependence on information systems. Besides that, this industry is characterized by high flexibility and competition and compressing of the corporate strategy timeline. The grounded theory of business analysis defines the specifics of the telecommunications industry, focusing on the very specific description of the procedure for collecting the business requirements and following the business strategy.

  3. Ab initio optimization principle for the ground states of translationally invariant strongly correlated quantum lattice models.

    Science.gov (United States)

    Ran, Shi-Ju

    2016-05-01

    In this work, a simple and fundamental numeric scheme dubbed as ab initio optimization principle (AOP) is proposed for the ground states of translational invariant strongly correlated quantum lattice models. The idea is to transform a nondeterministic-polynomial-hard ground-state simulation with infinite degrees of freedom into a single optimization problem of a local function with finite number of physical and ancillary degrees of freedom. This work contributes mainly in the following aspects: (1) AOP provides a simple and efficient scheme to simulate the ground state by solving a local optimization problem. Its solution contains two kinds of boundary states, one of which play the role of the entanglement bath that mimics the interactions between a supercell and the infinite environment, and the other gives the ground state in a tensor network (TN) form. (2) In the sense of TN, a novel decomposition named as tensor ring decomposition (TRD) is proposed to implement AOP. Instead of following the contraction-truncation scheme used by many existing TN-based algorithms, TRD solves the contraction of a uniform TN in an opposite way by encoding the contraction in a set of self-consistent equations that automatically reconstruct the whole TN, making the simulation simple and unified; (3) AOP inherits and develops the ideas of different well-established methods, including the density matrix renormalization group (DMRG), infinite time-evolving block decimation (iTEBD), network contractor dynamics, density matrix embedding theory, etc., providing a unified perspective that is previously missing in this fields. (4) AOP as well as TRD give novel implications to existing TN-based algorithms: A modified iTEBD is suggested and the two-dimensional (2D) AOP is argued to be an intrinsic 2D extension of DMRG that is based on infinite projected entangled pair state. This paper is focused on one-dimensional quantum models to present AOP. The benchmark is given on a transverse Ising

  4. Time dependent density matrix theory and effective interaction

    Energy Technology Data Exchange (ETDEWEB)

    Tohyama, Mitsuru [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1998-07-01

    A correlated ground state of {sup 16}O and an E2 giant resonance built on it are calculated using an extended version of the time-dependent Hartree-Fock theory called the time-dependent density-matrix theory (TDDM). The Skyrme force is used in the calculation of both a mean field and two-body correlations. It is found that TDDM gives reasonable ground-state correlations and a large spreading width of the E2 giant resonance when single-particle states in the continuum are treated appropriately. (author)

  5. Bateman's dual system revisited: quantization, geometric phase and relation with the ground-state energy of the linear harmonic oscillator

    International Nuclear Information System (INIS)

    Blasone, Massimo; Jizba, Petr

    2004-01-01

    By using the Feynman-Hibbs prescription for the evolution amplitude, we quantize the system of a damped harmonic oscillator coupled to its time-reversed image, known as Bateman's dual system. The time-dependent quantum states of such a system are constructed and discussed entirely in the framework of the classical theory. The corresponding geometric (Pancharatnam) phase is calculated and found to be directly related to the ground-state energy of the 1D linear harmonic oscillator to which the 2D system reduces under appropriate constraint

  6. Review: Franz Breuer with Assistance of Barbara Dieris and Antje Lettau (2009. Reflexive Grounded Theory. Eine Einführung für die Forschungspraxis [Reflexive Grounded Theory: An Introduction to Research Praxis

    Directory of Open Access Journals (Sweden)

    Sandra Da Rin

    2010-03-01

    Full Text Available This textbook by Franz BREUER, produced with the assistance of Barbara DIERIS and Antje LETTAU, is of interest more for the introduction it provides to reflexive research praxis than to grounded theory methodology. This means the subjectivity of the researcher is included in the research process as a decisive source of cognition. Reflexive grounded theory methodology is characterized by three elements that also structure the textbook. In the present review, I focus on two of these in detail: the approach to the research field based on ethnography, particular its epistemological prerequisites, and the inclusion of (self- reflexivity. The latter points to questions that are addressed at the end of this review. URN: urn:nbn:de:0114-fqs1002140

  7. Processo Orçamentário: uma aplicação da análise substantiva com utilização da grounded theory [Budgeting: substantive analysis using grounded theory

    Directory of Open Access Journals (Sweden)

    Tânia Regina Sordi Relvas

    2011-09-01

    Full Text Available Diante da constatação de que os estudos sobre o orçamento exploram o fenômeno de forma reducionista, este artigo tem por objetivo propor uma teoria substantiva abrangente e fundamentada em dados empíricos para a análise do orçamento. Essa abordagem considera seus elementos constituintes e suas interdependências. Isso foi feito por meio da aplicação da abordagem indutiva fundamentada nos dados empíricos (grounded theory, sob o paradigma qualitativo. O foco de análise foi uma instituição financeira de grande porte e o trabalho de campo foi desenvolvido ao longo de dois anos, envolvendo vários níveis gerenciais. A contribuição do trabalho advém da disponibilização de framework para o tratamento do tema em um contexto amplo, o que permitiu entender aspectos que deixariam de ser considerados com uma abordagem de análise mais restrita e menos abrangente. Como produto da teoria substantiva, cinco proposições foram desenvolvidas com a perspectiva de serem aplicadas nas organizações. --- Budgeting: substantive analysis using grounded theory --- Abstract --- Considering the fact that studies into budgeting basically use a reductionist approach, this paper proposes a comprehensive substantive theory based on empirical data to be used in budget analysis. This approach takes into consideration its elements and interdependence by applying the inductive approach based on empirical data (grounded theory on a qualitative paradigm. The focus was an in-depth two-year study of a large Brazilian financial institution involving several management levels. The main contribution of the study is as a framework that treats all elements of the budget process in a comprehensive and coherent fashion, otherwise impossible using a reductionist approach. As products of the substantive theory, five propositions were developed to be applied in organizations.

  8. Perspectives on the Aetiology of ODD and CD: A Grounded Theory Approach

    Science.gov (United States)

    McFarland, Patrick; Sanders, James; Hagen, Bradley

    2016-01-01

    Antisocial disorders, such as oppositional defiant disorder (ODD) and conduct disorder (CD), are common reasons for youth to be seen for clinical intervention. The intent of this constructivist grounded theory study was to evaluate clinicians' perspectives on the aetiology of antisocial disorders. Six professionals from various professional…

  9. Leading Effective Educational Technology in K-12 School Districts: A Grounded Theory

    Science.gov (United States)

    Hill, Lara Gillian C.

    2011-01-01

    A systematic grounded theory qualitative study was conducted investigating the process of effectively leading educational technology in New Jersey public K-12 school districts. Data were collected from educational technology district leaders (whether formal or non-formal administrators) and central administrators through a semi-structured online…

  10. Revisiting Symbolic Interactionism as a Theoretical Framework Beyond the Grounded Theory Tradition

    DEFF Research Database (Denmark)

    Handberg, Charlotte; Thorne, Sally; Midtgaard, Julie

    2015-01-01

    The tight bond between grounded theory (GT) and symbolic interactionism (SI) is well known within the qualitative health research field. We aimed to disentangle this connection through critical reflection on the conditions under which it might add value as an underpinning to studies outside the GT...

  11. Cluster decay of Ba isotopes from ground state and as an excited ...

    Indian Academy of Sciences (India)

    otherwise, inclusion of excitation energy decreases the T1/2 values. ... penetrates the nuclear barrier and reaches scission configuration after running .... between the ground-state energy levels of the parent nuclei and the ground-state energy.

  12. Magnetic properties of singlet ground state systems

    International Nuclear Information System (INIS)

    Diederix, K.M.

    1979-01-01

    Experiments are described determining the properties of a magnetic system consisting of a singlet ground state. Cu(NO 3 ) 2 .2 1/2H 2 O has been studied which is a system of S = 1/2 alternating antiferromagnetic Heisenberg chains. The static properties, spin lattice relaxation time and field-induced antiferromagnetically ordered state measurements are presented. Susceptibility and magnetic cooling measurements of other compounds are summarised. (Auth.)

  13. GP and pharmacist inter-professional learning - a grounded theory study.

    Science.gov (United States)

    Cunningham, David E; Ferguson, Julie; Wakeling, Judy; Zlotos, Leon; Power, Ailsa

    2016-05-01

    Practice Based Small Group Learning (PBSGL) is an established learning resource for primary care clinicians in Scotland and is used by one-third of general practitioners (GPs). Scottish Government and UK professional bodies have called for GPs and pharmacists to work more closely together to improve care. To gain GPs' and pharmacists' perceptions and experiences of learning together in an inter-professional PBSGL pilot. Qualitative research methods involving established GP PBSGL groups in NHS Scotland recruiting one or two pharmacists to join them. A grounded theory method was used. GPs were interviewed in focus groups by a fellow GP, and pharmacists were interviewed individually by two researchers, neither being a GP or a pharmacist. Interviews were audio-recorded, transcribed and analysed using grounded theory methods. Data saturation was achieved and confirmed. Three themes were identified: GPs' and pharmacists' perceptions and experiences of inter-professional learning; Inter-professional relationships and team-working; Group identity and purpose of existing GP groups. Pharmacists were welcomed into GP groups and both professions valued inter-professional PBSGL learning. Participants learned from each other and both professions gained a wider perspective of the NHS and of each others' roles in the organisation. Inter-professional relationships, communication and team-working were strengthened and professionals regarded each other as peers and friends.

  14. Gapless Spin-Liquid Ground State in the S =1 /2 Kagome Antiferromagnet

    Science.gov (United States)

    Liao, H. J.; Xie, Z. Y.; Chen, J.; Liu, Z. Y.; Xie, H. D.; Huang, R. Z.; Normand, B.; Xiang, T.

    2017-03-01

    The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S =1 /2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid. We discuss the comparison with other numerical studies and the physical interpretation of this result.

  15. Long range order in the ground state of two-dimensional antiferromagnets

    International Nuclear Information System (INIS)

    Neves, E.J.; Perez, J.F.

    1985-01-01

    The existence of long range order is shown in the ground state of the two-dimensional isotropic Heisenberg antiferromagnet for S >= 3/2. The method yields also long range order for the ground state of a larger class of anisotropic quantum antiferromagnetic spin systems with or without transverse magnetic fields. (Author) [pt

  16. Ground and excited state properties of high performance anthocyanidin dyes-sensitized solar cells in the basic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Prima, Eka Cahya [Advanced Functional Material Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); Computational Material Design and Quantum Engineering Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); International Program on Science Education, Universitas Pendidikan Indonesia (Indonesia); Yuliarto, Brian; Suyatman, E-mail: yatman@tf.itb.ac.id [Advanced Functional Material Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia); Dipojono, Hermawan Kresno [Computational Material Design and Quantum Engineering Laboratory, Engineering Physics, Institut Teknologi Bandung (Indonesia)

    2015-09-30

    The aglycones of anthocyanidin dyes were previously reported to form carbinol pseudobase, cis-chalcone, and trans-chalcone due to the basic levels. The further investigations of ground and excited state properties of the dyes were characterized using density functional theory with PCM(UFF)/B3LYP/6-31+G(d,p) level in the basic solutions. However, to the best of our knowledge, the theoretical investigation of their potential photosensitizers has never been reported before. In this paper, the theoretical photovoltaic properties sensitized by dyes have been successfully investigated including the electron injections, the ground and excited state oxidation potentials, the estimated open circuit voltages, and the light harvesting efficiencies. The results prove that the electronic properties represented by dyes’ LUMO-HOMO levels will affect to the photovoltaic performances. Cis-chalcone dye is the best anthocyanidin aglycone dye with the electron injection spontaneity of −1.208 eV, the theoretical open circuit voltage of 1.781 V, and light harvesting efficiency of 56.55% due to the best HOMO-LUMO levels. Moreover, the ethanol solvent slightly contributes to the better cell performance than the water solvent dye because of the better oxidation potential stabilization in the ground state as well as in the excited state. These results are in good agreement with the known experimental report that the aglycones of anthocyanidin dyes in basic solvent are the high potential photosensitizers for dye-sensitized solar cell.

  17. Learning Approach on the Ground State Energy Calculation of Helium Atom

    International Nuclear Information System (INIS)

    Shah, Syed Naseem Hussain

    2010-01-01

    This research investigated the role of learning approach on the ground state energy calculation of Helium atom in improving the concepts of science teachers at university level. As the exact solution of several particles is not possible here we used approximation methods. Using this method one can understand easily the calculation of ground state energy of any given function. Variation Method is one of the most useful approximation methods in estimating the energy eigen values of the ground state and the first few excited states of a system, which we only have a qualitative idea about the wave function.The objective of this approach is to introduce and involve university teacher in new research, to improve their class room practices and to enable teachers to foster critical thinking in students.

  18. Men in Nursing: Intention, Intentionality, Caring, and Healing: Emphasis on the Results of a Grounded Theory Study.

    Science.gov (United States)

    Zahourek, Rothlyn P

    2016-01-01

    The purpose of this article is to amplify the results section of a grounded theory study on how men in nursing view and experience intention, intentionality, caring, and healing. This is the second grounded theory study addressing intentionality in healing. The first study included a female population. The theory that was generated-Intentionality: The Matrix of Healing (IMH)-is examined with these new data. The results are compared with issues generally faced by men in nursing and how they described their beliefs and experiences with intentionality and healing. The theory (IMH) is supported; the importance of action in this cohort was an additional emphasis. This article provides an expanded view of men in nursing and their experiences as nurses and with intentionality, caring, and healing and has implications for the development of holistic nursing theory as well.

  19. Thermodynamic Ground States of Complex Oxide Heterointerfaces

    DEFF Research Database (Denmark)

    Gunkel, F.; Hoffmann-Eifert, S.; Heinen, R. A.

    2017-01-01

    The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature...

  20. Leading Critically: A Grounded Theory of Applied Critical Thinking in Leadership Studies

    Science.gov (United States)

    Jekins, Daniel M.; Cutchens, Amanda B.

    2011-01-01

    This study describes the development of a grounded theory of applied critical thinking in leadership studies and examines how student-centered experiential learning in leadership education bridged critical thinking with action. Over three semester undergraduate students in an upper level leadership studies course at a large four-year public…

  1. Factors Affecting Christian Parents' School Choice Decision Processes: A Grounded Theory Study

    Science.gov (United States)

    Prichard, Tami G.; Swezey, James A.

    2016-01-01

    This study identifies factors affecting the decision processes for school choice by Christian parents. Grounded theory design incorporated interview transcripts, field notes, and a reflective journal to analyze themes. Comparative analysis, including open, axial, and selective coding, was used to reduce the coded statements to five code families:…

  2. On the ground state for fractional quantum hall effect

    International Nuclear Information System (INIS)

    Jellal, A.

    1998-09-01

    In the present letter, we investigate the ground state wave function for an explicit model of electrons in an external magnetic field with specific inter-particle interactions. The excitation states of this model are also given. (author)

  3. Reading Fluency Techniques from the Bottom-up: A Grounded Theory

    Directory of Open Access Journals (Sweden)

    Seyyed Ali Ostovar-Namaghi

    2015-09-01

    Full Text Available In many EFL contexts, including language education milieu in Iran, reading fluency is usually taken for granted since language education in public high schools mainly focuses on reading comprehension. Taking the detrimental effect of fluency deficiency into account, some practitioners foreground reading fluency and try to develop it early on. To give voice to their theories of practice, this qualitative study interviewed teachers who were willing to share their experience with the researchers. In line with grounded theory, the iterative process of data collection and analysis continued until the conceptualization of fluency development techniques was saturated. The techniques emerged are conducive to fluency development and as such the findings have clear implications for practitioners and policy makers nation-wide.

  4. The Methodological Dynamism of Grounded Theory

    Directory of Open Access Journals (Sweden)

    Nicholas Ralph

    2015-11-01

    Full Text Available Variations in grounded theory (GT interpretation are the subject of ongoing debate. Divergences of opinion, genres, approaches, methodologies, and methods exist, resulting in disagreement on what GT methodology is and how it comes to be. From the postpositivism of Glaser and Strauss, to the symbolic interactionist roots of Strauss and Corbin, through to the constructivism of Charmaz, the field of GT methodology is distinctive in the sense that those using it offer new ontological, epistemological, and methodological perspectives at specific moments in time. We explore the unusual dynamism attached to GT’s underpinnings. Our view is that through a process of symbolic interactionism, in which generations of researchers interact with their context, moments are formed and philosophical perspectives are interpreted in a manner congruent with GT’s essential methods. We call this methodological dynamism, a process characterized by contextual awareness and moment formation, contemporaneous translation, generational methodology, and methodological consumerism.

  5. Being There: A Grounded-Theory Study of Student Perceptions of Instructor Presence in Online Classes

    Science.gov (United States)

    Feeler, William

    2012-01-01

    The purpose of this study was to explore the perceptions of experienced individual online students at a community college in Texas in order to generate a substantive theory of community college student perceptions of online instructor presence. This qualitative study used Active Interviewing and followed a Straussian grounded-theory design to…

  6. Classification of matrix-product ground states corresponding to one-dimensional chains of two-state sites of nearest neighbor interactions

    International Nuclear Information System (INIS)

    Fatollahi, Amir H.; Khorrami, Mohammad; Shariati, Ahmad; Aghamohammadi, Amir

    2011-01-01

    A complete classification is given for one-dimensional chains with nearest-neighbor interactions having two states in each site, for which a matrix product ground state exists. The Hamiltonians and their corresponding matrix product ground states are explicitly obtained.

  7. Exploring the use of grounded theory as a methodological approach to examine the 'black box' of network leadership in the national quality forum.

    Science.gov (United States)

    Hoflund, A Bryce

    2013-01-01

    This paper describes how grounded theory was used to investigate the "black box" of network leadership in the creation of the National Quality Forum. Scholars are beginning to recognize the importance of network organizations and are in the embryonic stages of collecting and analyzing data about network leadership processes. Grounded theory, with its focus on deriving theory from empirical data, offers researchers a distinctive way of studying little-known phenomena and is therefore well suited to exploring network leadership processes. Specifically, this paper provides an overview of grounded theory, a discussion of the appropriateness of grounded theory to investigating network phenomena, a description of how the research was conducted, and a discussion of the limitations and lessons learned from using this approach.

  8. Ground motion effects

    Energy Technology Data Exchange (ETDEWEB)

    Blume, J A [John A. Blume and Associates, San Francisco, CA (United States)

    1969-07-01

    Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

  9. Ground motion effects

    International Nuclear Information System (INIS)

    Blume, J.A.

    1969-01-01

    Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

  10. Taking Root: a grounded theory on evidence-based nursing implementation in China.

    Science.gov (United States)

    Cheng, L; Broome, M E; Feng, S; Hu, Y

    2018-06-01

    Evidence-based nursing is widely recognized as the critical foundation for quality care. To develop a middle-range theory on the process of evidence-based nursing implementation in Chinese context. A grounded theory study using unstructured in-depth individual interviews was conducted with 56 participants who were involved in 24 evidence-based nursing implementation projects in Mainland China from September 2015 to September 2016. A middle-range grounded theory of 'Taking Root' was developed. The theory describes the evidence implementation process consisting of four components (driving forces, process, outcome, sustainment/regression), three approaches (top-down, bottom-up and outside-in), four implementation strategies (patient-centred, nurses at the heart of change, reaching agreement, collaboration) and two patterns (transformational and adaptive implementation). Certain perspectives may have not been captured, as the retrospective nature of the interviewing technique did not allow for 'real-time' assessment of the actual implementation process. The transferability of the findings requires further exploration as few participants with negative experiences were recruited. This is the first study that explored evidence-based implementation process, strategies, approaches and patterns in the Chinese nursing practice context to inform international nursing and health policymaking. The theory of Taking Root described various approaches to evidence implementation and how the implementation can be transformational for the nurses and the setting in which they work. Nursing educators, managers and researchers should work together to improve nurses' readiness for evidence implementation. Healthcare systems need to optimize internal mechanisms and external collaborations to promote nursing practice in line with evidence and achieve clinical outcomes and sustainability. © 2017 International Council of Nurses.

  11. Stable tetrabenzo-Chichibabin's hydrocarbons: Tunable ground state and unusual transition between their closed-shell and open-shell resonance forms

    KAUST Repository

    Zeng, Zebing

    2012-09-05

    Stable open-shell polycyclic aromatic hydrocarbons (PAHs) are of fundamental interest due to their unique electronic, optical, and magnetic properties and promising applications in materials sciences. Chichibabin\\'s hydrocarbon as a classical open-shell PAH has been investigated for a long time. However, most of the studies are complicated by their inherent high reactivity. In this work, two new stable benzannulated Chichibabin\\'s hydrocarbons 1-CS and 2-OS were prepared, and their electronic structure and geometry in the ground state were studied by various experiments (steady-state and transient absorption spectra, NMR, electron spin resonance (ESR), superconducting quantum interference device (SQUID), FT Raman, X-ray crystallographic etc.) and density function theory (DFT) calculations. 1-CS and 2-OS exhibited tunable ground states, with a closed-shell quinoidal structure for 1-CS and an open-shell biradical form for 2-OS. Their corresponding excited-state forms 1-OS and 2-CS were also chemically approached and showed different decay processes. The biradical 1-OS displayed an unusually slow decay to the ground state (1-CS) due to a large energy barrier (95 ± 2.5 kJ/mol) arising from severe steric hindrance during the transition from an orthogonal biradical form to a butterfly-like quinoidal form. The quick transition from the quinoidal 2-CS (excited state) to the orthogonal biradicaloid 2-OS (ground state) happened during the attempted synthesis of 2-CS. Compounds 1-CS and 2-OS can be oxidized into stable dications by FeCl 3 and/or concentrated H 2SO 4. The open-shell 2-OS also exhibited a large two-photon absorption (TPA) cross section (760 GM at 1200 nm). © 2012 American Chemical Society.

  12. Dissociation energy of the ground state of NaH

    International Nuclear Information System (INIS)

    Huang, Hsien-Yu; Lu, Tsai-Lien; Whang, Thou-Jen; Chang, Yung-Yung; Tsai, Chin-Chun

    2010-01-01

    The dissociation energy of the ground state of NaH was determined by analyzing the observed near dissociation rovibrational levels. These levels were reached by stimulated emission pumping and fluorescence depletion spectroscopy. A total of 114 rovibrational levels in the ranges 9≤v '' ≤21 and 1≤J '' ≤14 were assigned to the X 1 Σ + state of NaH. The highest vibrational level observed was only about 40 cm -1 from the dissociation limit in the ground state. One quasibound state, above the dissociation limit and confined by the centrifugal barrier, was observed. Determining the vibrational quantum number at dissociation v D from the highest four vibrational levels yielded the dissociation energy D e =15 815±5 cm -1 . Based on new observations and available data, a set of Dunham coefficients and the rotationless Rydberg-Klein-Rees curve were constructed. The effective potential curve and the quasibound states were discussed.

  13. Parochial Dissonance: A Grounded Theory of Wisconsin's New North Response to the Employability Skills Gap

    Science.gov (United States)

    Baneck, Timothy M.

    2012-01-01

    The purpose of this study was to generate a theory that explained the beliefs and behaviors of participants from business, not-for-profit business, education, and government sectors when resolving the employability skills gap. Classical grounded theory was the inductive methodology applied to this study. The New North, an 18 county region located…

  14. Ground-state magnetization of the Ising spin glass: A recursive numerical method and Chen-Ma scaling

    Science.gov (United States)

    Sepehrinia, Reza; Chalangari, Fartash

    2018-03-01

    The ground-state properties of quasi-one-dimensional (Q1D) Ising spin glass are investigated using an exact numerical approach and analytical arguments. A set of coupled recursive equations for the ground-state energy are introduced and solved numerically. For various types of coupling distribution, we obtain accurate results for magnetization, particularly in the presence of a weak external magnetic field. We show that in the weak magnetic field limit, similar to the 1D model, magnetization exhibits a singular power-law behavior with divergent susceptibility. Remarkably, the spectrum of magnetic exponents is markedly different from that of the 1D system even in the case of two coupled chains. The magnetic exponent makes a crossover from being dependent on a distribution function to a constant value independent of distribution. We provide an analytic theory for these observations by extending the Chen-Ma argument to the Q1D case. We derive an analytical formula for the exponent which is in perfect agreement with the numerical results.

  15. Regionalization of ground motion attenuation in the conterminous United States

    International Nuclear Information System (INIS)

    Chung, D.H.; Bernreuter, D.L.

    1979-01-01

    Attenuation results from geometric spreading and from absorption. The former is almost independent of crustal geology or physiographic region. The latter depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high-frequency waves, absorption does not affect ground motion at distances less than 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States will be similar to that in the western United States. Most of the differences in ground motion can be accounted for by differences in attenuation caused by differences in absorption. The other important factor is that for some Western earthquakes the fault breaks the earth's surface, resulting in larger ground motion. No Eastern earthquakes are known to have broken the earth's surface by faulting. The stress drop of Eastern earthquakes may be higher than for Western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. This factor is believed to be of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. 6 figures

  16. The role of community mental health nurses caring for people with schizophrenia in Taiwan: a substantive grounded theory.

    Science.gov (United States)

    Huang, Xuan-Yi; Yen, Wen-Jiuan; Liu, Shwu-Jiuan; Lin, Chouh-Jiuan

    2008-03-01

    The aim was to develop a practice theory that can be used to guide the direction of community nursing practice to help clients with schizophrenia and those who care for them. Substantive grounded theory was developed through use of grounded theory method of Strauss and Corbin. Two groups of participants in Taiwan were selected using theoretical sampling: one group consisted of community mental health nurses and the other group was clients with schizophrenia and those who cared for them. The number of participants in each group was determined by theoretical saturation. Semi-structured one-to-one in-depth interviews and unstructured non-participant observation were utilized for data collection. Data analysis involved three stages: open, axial and selective coding. During the process of coding and analysis, both inductive and deductive thinking were utilized and the constant comparative analysis process continued until data saturation occurred. To establish trustworthiness, the four criteria of credibility, transferability, dependability and confirmability were followed along with field trial, audit trial, member check and peer debriefing for reliability and validity. A substantive grounded theory, the role of community mental health nurses caring for people with schizophrenia in Taiwan, was developed through utilization of grounded theory method of Strauss and Corbin. In this paper, results and discussion focus on causal conditions, context, intervening conditions, consequences and phenomenon. The theory is the first to contribute knowledge about the field of mental health home visiting services in Taiwan to provide guidance for the delivery of quality care to assist people in the community with schizophrenia and their carers.

  17. Magnetic excitons in singlet-ground-state ferromagnets

    DEFF Research Database (Denmark)

    Birgeneau, R.J.; Als-Nielsen, Jens Aage; Bucher, E.

    1971-01-01

    The authors report measurements of the dispersion of singlet-triplet magnetic excitons as a function of temperature in the singlet-ground-state ferromagnets fcc Pr and Pr3Tl. Well-defined excitons are observed in both the ferromagnetic and paramagnetic regions, but with energies which are nearly...

  18. Ab initio calculation atomics ground state wave function for interactions Ion- Atom

    International Nuclear Information System (INIS)

    Shojaee, F.; Bolori zadeh, M. A.

    2007-01-01

    Ab initio calculation atomics ground state wave function for interactions Ion- Atom Atomic wave function expressed in a Slater - type basis obtained within Roothaan- Hartree - Fock for the ground state of the atoms He through B. The total energy is given for each atom.

  19. Relativistic configuration interaction calculation on the ground and excited states of iridium monoxide

    International Nuclear Information System (INIS)

    Suo, Bingbing; Yu, Yan-Mei; Han, Huixian

    2015-01-01

    We present the fully relativistic multi-reference configuration interaction calculations of the ground and low-lying excited electronic states of IrO for individual spin-orbit component. The lowest-lying state is calculated for Ω = 1/2, 3/2, 5/2, and 7/2 in order to clarify the ground state of IrO. Our calculation suggests that the ground state is of Ω = 1/2, which is highly mixed with 4 Σ − and 2 Π states in Λ − S notation. The two low-lying states 5/2 and 7/2 are nearly degenerate with the ground state and locate only 234 and 260 cm −1 above, respectively. The equilibrium bond length 1.712 Å and the harmonic vibrational frequency 903 cm −1 of the 5/2 state are close to the experimental measurement of 1.724 Å and 909 cm −1 , which suggests that the 5/2 state should be the low-lying state that contributes to the experimental spectra. Moreover, the electronic states that give rise to the observed transition bands are assigned for Ω = 5/2 and 7/2 in terms of the obtained excited energies and oscillator strengths

  20. Tailoring reablement: A grounded theory study of establishing reablement in a community setting in Norway.

    Science.gov (United States)

    Moe, Cathrine; Brinchmann, Berit Støre

    2018-01-01

    Reablement is an interprofessional, home-based rehabilitation service that aims to enable senior residents to cope with everyday life and to prevent functional impairments. Systematic accounts of what practitioners actually do when establishing reablement are lacking. This study aims to generate a grounded theory of practitioners' patterns of action when establishing reablement. The study is located in Norway, and grounded theory is the methodological approach. Data were collected from January 2014 to August 2016 through participant observations, focus group interviews and individual interviews. Informants are municipal healthcare employees in different organisational areas associated with the process of establishing reablement services (managers of conventional home care and representatives from the administration and service-provider offices). Altogether, 17 individuals are interviewed. The empirical data are analysed several times using open, selective and theoretical coding. The grounded theory, "tailoring reablement," includes three phases-replicating, adapting and establishing-and the strategies of collaborating, developing knowledge, habituating and filtering. The theory of tailoring reablement also includes the impact of the contextual factors. The study seeks to bridge the gap between research and practice. The theory of tailoring reablement emerges from an inductive approach and theorises participants' actions. The theory focuses on the phases from innovation to implementation. Establishing a new service model in a complex welfare setting requires a wide range of actors and agencies. Tailoring reablement also requires flexibility and professional autonomy. It is important to create terms and conditions for this within a stringent health and care service. The insights of this study have implications for practice development of reablement and can fit other public sector fields. © 2017 The Authors. Health and Social Care in the Community Published by John

  1. Phenomenography and Grounded Theory as Research Methods in Computing Education Research Field

    Science.gov (United States)

    Kinnunen, Paivi; Simon, Beth

    2012-01-01

    This paper discusses two qualitative research methods, phenomenography and grounded theory. We introduce both methods' data collection and analysis processes and the type or results you may get at the end by using examples from computing education research. We highlight some of the similarities and differences between the aim, data collection and…

  2. Rearrangements in ground and excited states

    CERN Document Server

    de Mayo, Paul

    1980-01-01

    Rearrangements in Ground and Excited States, Volume 2 covers essays on the theoretical approach of rearrangements; the rearrangements involving boron; and the molecular rearrangements of organosilicon compounds. The book also includes essays on the polytopal rearrangement at phosphorus; the rearrangement in coordination complexes; and the reversible thermal intramolecular rearrangements of metal carbonyls. Chemists and people involved in the study of rearrangements will find the book invaluable.

  3. The ground state energy of a bound polaron in the presence of a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Zorkani, I [International Centre for Theoretical Physics, Trieste (Italy); Belhissi, R [Faculte des Sciences Dhar Mahraz, Fes (Morocco). Dept. de Physique

    1995-09-01

    A theoretical calculation for the ground state energy of a bound polaron as a function of the magnetic field is presented. The theory is based on a variational approach using a trial wave function proposed by Devreese et al. in the absence of the magnetic field. It was shown that his function is adequate for all electron - phonon coupling {alpha} and all parameter {gamma}{sub 0} which is the ratio between the L.O. phonon energy and the Colombian one. Analytical results are obtained in the weak coupling limit. (author). 27 refs, 4 figs, 1 tab.

  4. A Rigorous Investigation on the Ground State of the Penson-Kolb Model

    Science.gov (United States)

    Yang, Kai-Hua; Tian, Guang-Shan; Han, Ru-Qi

    2003-05-01

    By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard model. However, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson-Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q = 0. Our results support the equivalence between these models. The project partially supported by the Special Funds for Major State Basic Research Projects (G20000365) and National Natural Science Foundation of China under Grant No. 10174002

  5. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians.

    Science.gov (United States)

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G

    2017-02-17

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)NJOPFM1367-263010.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  6. The Youth and Experience of Traffic Accidents (Grounded Theory

    Directory of Open Access Journals (Sweden)

    Sayyed-Muhammad-Hossein Javadi

    2017-01-01

    Full Text Available Background: Traffic accidents are among major causes of death all over the world. In Iran, it has become a social problem, with lots of people involved in; and the youth include the most victims of traffic accidents. Objectives: The main objective of this research is to review the experience of the youth (18–24 years old in Tehran, Iran with traffic accidents, and to develop a model to specify the factors. Methods: This study is based on Grounded Theory, in which a sample group of 50 young people, 18–24 years old, in Tehran, Iran, were selected and interviewed, using stratified purposive and snowball sampling method. Data is mainly collected by interviewing the youth in 7 key topics. To analyze the data, Grounded Theory is used through production of themes, components and concepts. Results: There are 11 general components for traffic accidents according to the ideas of the youth which will come in 3 categories including: individual factors (emotions, sensory-motor skills, and physical-mental health; environmental factors (road and traffic problems, a companion, using cellphone, or front individual, including carless drivers or passersby; and underlying factors (gender, legal and cultural infrastructures. And finally, the core category of carelessness, which is the leading cause in traffic accidents.    Conclusion: The findings indicate that a chain of various factors may cause traffic accidents with lots of devastating consequences. It is therefore necessary to modify driving culture, to internalize the attitude of caution, to use polyhedral strategies, and to apply them all correctly.

  7. Nuclear quadrupole moment of the 99Tc ground state

    International Nuclear Information System (INIS)

    Errico, Leonardo; Darriba, German; Renteria, Mario; Tang Zhengning; Emmerich, Heike; Cottenier, Stefaan

    2008-01-01

    By combining first-principles calculations and existing nuclear magnetic resonance (NMR) experiments, we determine the quadrupole moment of the 9/2 + ground state of 99 Tc to be (-)0.14(3)b. This confirms the value of -0.129(20)b, which is currently believed to be the most reliable experimental determination, and disagrees with two earlier experimental values. We supply ab initio calculated electric-field gradients for Tc in YTc 2 and ZrTc 2 . If this calculated information would be combined with yet to be performed Tc-NMR experiments in these compounds, the error bar on the 99 Tc ground state quadrupole moment could be further reduced

  8. Measurement of the ground-state hyperfine splitting of antihydrogen

    CERN Document Server

    Juhász, B; Federmann, S

    2011-01-01

    The ASACUSA collaboration at the Antiproton Decelerator of CERN is planning to measure the ground-state hyperfine splitting of antihydrogen using an atomic beam line, consisting of a cusp trap as a source of partially polarized antihydrogen atoms, a radiofrequency spin-flip cavity, a superconducting sextupole magnet as spin analyser, and an antihydrogen detector. This will be a measurement of the antiproton magnetic moment, and also a test of the CPT invariance. Monte Carlo simulations predict that the antihydrogen ground-state hyperfine splitting can be determined with a relative precision of ~10−7. The first preliminary measurements of the hyperfine transitions will start in 2011.

  9. Effective field theory for triaxially deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.B. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Kaiser, N. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Institute for Advanced Simulation, Institut fuer Kernphysik, Juelich Center for Hadron Physics and JARA-HPC, Forschungszentrum Juelich, Juelich (Germany); Meng, J. [Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); University of Stellenbosch, Department of Physics, Stellenbosch (South Africa)

    2017-10-15

    Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation. (orig.)

  10. Efficient basis formulation for 1+1 dimensional SU(2) lattice gauge theory. Spectral calculations with matrix product states

    Energy Technology Data Exchange (ETDEWEB)

    Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, Krzysztof [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2017-07-20

    We propose an explicit formulation of the physical subspace for a 1+1 dimensional SU(2) lattice gauge theory, where the gauge degrees of freedom are integrated out. Our formulation is completely general, and might be potentially suited for the design of future quantum simulators. Additionally, it allows for addressing the theory numerically with matrix product states. We apply this technique to explore the spectral properties of the model and the effect of truncating the gauge degrees of freedom to a small finite dimension. In particular, we determine the scaling exponents for the vector mass. Furthermore, we also compute the entanglement entropy in the ground state and study its scaling towards the continuum limit.

  11. Efficient Basis Formulation for (1+1-Dimensional SU(2 Lattice Gauge Theory: Spectral Calculations with Matrix Product States

    Directory of Open Access Journals (Sweden)

    Mari Carmen Bañuls

    2017-11-01

    Full Text Available We propose an explicit formulation of the physical subspace for a (1+1-dimensional SU(2 lattice gauge theory, where the gauge degrees of freedom are integrated out. Our formulation is completely general, and might be potentially suited for the design of future quantum simulators. Additionally, it allows for addressing the theory numerically with matrix product states. We apply this technique to explore the spectral properties of the model and the effect of truncating the gauge degrees of freedom to a small finite dimension. In particular, we determine the scaling exponents for the vector mass. Furthermore, we also compute the entanglement entropy in the ground state and study its scaling towards the continuum limit.

  12. Efficient Basis Formulation for (1 +1 )-Dimensional SU(2) Lattice Gauge Theory: Spectral Calculations with Matrix Product States

    Science.gov (United States)

    Bañuls, Mari Carmen; Cichy, Krzysztof; Cirac, J. Ignacio; Jansen, Karl; Kühn, Stefan

    2017-10-01

    We propose an explicit formulation of the physical subspace for a (1 +1 )-dimensional SU(2) lattice gauge theory, where the gauge degrees of freedom are integrated out. Our formulation is completely general, and might be potentially suited for the design of future quantum simulators. Additionally, it allows for addressing the theory numerically with matrix product states. We apply this technique to explore the spectral properties of the model and the effect of truncating the gauge degrees of freedom to a small finite dimension. In particular, we determine the scaling exponents for the vector mass. Furthermore, we also compute the entanglement entropy in the ground state and study its scaling towards the continuum limit.

  13. Efficient basis formulation for 1+1 dimensional SU(2) lattice gauge theory. Spectral calculations with matrix product states

    International Nuclear Information System (INIS)

    Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan; Cichy, Krzysztof; Adam Mickiewicz Univ., Poznan; Jansen, Karl

    2017-01-01

    We propose an explicit formulation of the physical subspace for a 1+1 dimensional SU(2) lattice gauge theory, where the gauge degrees of freedom are integrated out. Our formulation is completely general, and might be potentially suited for the design of future quantum simulators. Additionally, it allows for addressing the theory numerically with matrix product states. We apply this technique to explore the spectral properties of the model and the effect of truncating the gauge degrees of freedom to a small finite dimension. In particular, we determine the scaling exponents for the vector mass. Furthermore, we also compute the entanglement entropy in the ground state and study its scaling towards the continuum limit.

  14. A grounded theory of Internet and social media use by young people who use augmentative and alternative communication (AAC).

    Science.gov (United States)

    Hynan, Amanda; Goldbart, Juliet; Murray, Janice

    2015-01-01

    This paper presents a conceptual grounded theory for how young people with a diagnosis of cerebral palsy who use augmentative and alternative communication (AAC), perceive using the Internet and social media. The aims of the research were to understand and contextualise their perceptions of access and use and explore implications for self-representation and social participation; to date literature on this topic is limited. A constructivist grounded theory research approach concurrently collected and analysed interview data from 25 participants (aged 14-24 years) who use AAC and additional sources. A conceptual grounded theory was developed around an emergent core category that showed young people who use AAC have a clear desire to use the Internet and social media. This was underpinned by eight supporting categories: reported use, described support, online challenges, access technology, speech generating device (SGD) issues, self-determination, self-representation and online social ties. The conceptual grounded theory supports understanding of facilitators and challenges to use of the Internet and social media by young people with a diagnosis of cerebral palsy who use AAC. The grounded theory illustrates how the desire to use the Internet and social media is based upon perceived benefits for enriching social relationships and enhancing opportunities for self-representation and self-determination that are synonymous with identified antecedents for community-based social inclusion. Some of the participants are engaging with the Internet and social media through collaborative practice and the implications for how this phenomenon may impact on orthographic literacy and the personal care workforce are raised.

  15. Electron scattering from the ground state of mercury

    International Nuclear Information System (INIS)

    Fursa, D.; Bray, I.

    2000-01-01

    Full text: Close-coupling calculations have been performed for electron scattering from the ground state of mercury. We have used non-relativistic convergent close-coupling computer code with only minor modifications in order to account for the most prominent relativistic effects. These are the relativistic shift effect and singlet-triplet mixing. Very good agreement with measurements of differential cross sections for elastic scattering and excitation of 6s6p 1 P state at all energies is obtained. It is well recognised that a consistent approach to electron scattering from heavy atoms (like mercury, with nuclear charge Z=80) must be based on a fully relativistic Dirac equations based technique. While development of such technique is under progress in our group, the complexity of the problem ensures that results will not be available in the near future. On other hand, there is considerable interest in reliable theoretical results for electron scattering from heavy atoms from both applications and the need to interpret existing experimental data. This is particularly the case for mercury, which is the major component in fluorescent lighting devices and has been the subject of intense experimental study since nineteen thirties. Similarly to our approach for alkaline-earth atoms we use a model of two valence electrons above an inert Hartree-Fock core to describe the mercury atom. Note that this model does not account for any core excited states which are present in the mercury discrete spectrum. The major effect of missing core-excited states is substantial underestimation of the static dipole polarizability of the mercury ground state (34 a.u.) and consequent underestimation of the forward scattering elastic cross sections. We correct for this by adding in the scattering calculations a phenomenological polarization potential. In order to obtain correct ground state ionization energy for mercury one has to account for the relativistic shift effect. We model this

  16. Yet Another Puzzle of Ground

    NARCIS (Netherlands)

    Korbmacher, J.

    2015-01-01

    We show that any predicational theory of partial ground that extends a standard theory of syntax and that proves some commonly accepted principles for partial ground is inconsistent. We suggest a way to obtain a consistent predicational theory of ground.

  17. iPads in K-12 Schools: A Grounded Theory Study of Value

    Science.gov (United States)

    Townsend, Mary Beth

    2017-01-01

    This qualitative grounded theory study investigated the value of iPads in K-12 schools when used in one-to-one ratios. The purpose of the study was to understand the perspectives of teachers using iPads in one-to-one ratios for teaching and learning in the classroom and administrators responsible for the implementation of these devices. The…

  18. Reactive ground-state pathways are not ubiquitous in red/green cyanobacteriochromes.

    Science.gov (United States)

    Chang, Che-Wei; Gottlieb, Sean M; Kim, Peter W; Rockwell, Nathan C; Lagarias, J Clark; Larsen, Delmar S

    2013-09-26

    Recent characterization of the red/green cyanobacteriochrome (CBCR) NpR6012g4 revealed a high quantum yield for its forward photoreaction [J. Am. Chem. Soc. 2012, 134, 130-133] that was ascribed to the activity of hidden, productive ground-state intermediates. The dynamics of the pathways involving these ground-state intermediates was resolved with femtosecond dispersed pump-dump-probe spectroscopy, the first such study reported for any CBCR. To address the ubiquity of such second-chance initiation dynamics (SCID) in CBCRs, we examined the closely related red/green CBCR NpF2164g6 from Nostoc punctiforme. Both NpF2164g6 and NpR6012g4 use phycocyanobilin as the chromophore precursor and exhibit similar excited-state dynamics. However, NpF2164g6 exhibits a lower quantum yield of 32% for the generation of the isomerized Lumi-R primary photoproduct, compared to 40% for NpR6012g4. This difference arises from significantly different ground-state dynamics between the two proteins, with the SCID mechanism deactivated in NpF2164g6. We present an integrated inhomogeneous target model that self-consistently fits the pump-probe and pump-dump-probe signals for both forward and reverse photoreactions in both proteins. This work demonstrates that reactive ground-state intermediates are not ubiquitous phenomena in CBCRs.

  19. Quantum ground state and single-phonon control of a mechanical resonator.

    Science.gov (United States)

    O'Connell, A D; Hofheinz, M; Ansmann, M; Bialczak, Radoslaw C; Lenander, M; Lucero, Erik; Neeley, M; Sank, D; Wang, H; Weides, M; Wenner, J; Martinis, John M; Cleland, A N

    2010-04-01

    Quantum mechanics provides a highly accurate description of a wide variety of physical systems. However, a demonstration that quantum mechanics applies equally to macroscopic mechanical systems has been a long-standing challenge, hindered by the difficulty of cooling a mechanical mode to its quantum ground state. The temperatures required are typically far below those attainable with standard cryogenic methods, so significant effort has been devoted to developing alternative cooling techniques. Once in the ground state, quantum-limited measurements must then be demonstrated. Here, using conventional cryogenic refrigeration, we show that we can cool a mechanical mode to its quantum ground state by using a microwave-frequency mechanical oscillator-a 'quantum drum'-coupled to a quantum bit, which is used to measure the quantum state of the resonator. We further show that we can controllably create single quantum excitations (phonons) in the resonator, thus taking the first steps to complete quantum control of a mechanical system.

  20. A Ground State Tri-pí-Methane Rearrangement

    Czech Academy of Sciences Publication Activity Database

    Zimmerman, H. E.; Církva, Vladimír; Jiang, L.

    2000-01-01

    Roč. 41, č. 49 (2000), s. 9585-9587 ISSN 0040-4039 Institutional research plan: CEZ:AV0Z4072921 Keywords : tri-pi-methane * ground state Subject RIV: CC - Organic Chemistry Impact factor: 2.558, year: 2000

  1. Perceived changes associated with autogenic training for anxiety: a grounded theory study.

    Science.gov (United States)

    Yurdakul, Levent; Holttum, Sue; Bowden, Ann

    2009-12-01

    Autogenic training (AT) is a behaviourally orientated intervention usually taught in eight or nine sessions in the United Kingdom: clients are taught six simple mental formulae designed to induce a calm state of mind and body, five additional emotional expression exercises, and individually tailored 'personal formulae' for supporting positive change. In the absence of existing psychological (as opposed to neuro-physiological) models of AT's mechanisms, this study aimed to produce the first such model, drawing on the perceptions of recent AT clients. An abbreviated form of grounded theory was used to explore retrospectively and in detail the experiences of a small sample of people of the process of change. Forty people were approached and 12 women participated who had completed AT in group form after referral for anxiety. Each was interviewed individually. A preliminary model of change was produced, grounded in the interview data. Factors reported to be salient were learning in a group, the core AT experience (the six standard exercises), difficulties with practice, the importance of regular practice integrated into daily life, and enhanced well-being and coping, which incorporated reduced worrying and clearer thinking. Limitations of the study are discussed, as are areas for further research and implications for anxiety treatment. This was a small study with a self-selected sample. However, theoretical generalizations can be made about the process of change. Since AT does not specifically focus on challenging negative cognitions, the cognitive changes reported have implications for anxiety treatments.

  2. Many electron variational ground state of the two dimensional Anderson lattice

    International Nuclear Information System (INIS)

    Zhou, Y.; Bowen, S.P.; Mancini, J.D.

    1991-02-01

    A variational upper bound of the ground state energy of two dimensional finite Anderson lattices is determined as a function of lattice size (up to 16 x 16). Two different sets of many-electron basis vectors are used to determine the ground state for all values of the coulomb integral U. This variational scheme has been successfully tested for one dimensional models and should give good estimates in two dimensions

  3. Information Theoretic Characterization of Physical Theories with Projective State Space

    Science.gov (United States)

    Zaopo, Marco

    2015-08-01

    Probabilistic theories are a natural framework to investigate the foundations of quantum theory and possible alternative or deeper theories. In a generic probabilistic theory, states of a physical system are represented as vectors of outcomes probabilities and state spaces are convex cones. In this picture the physics of a given theory is related to the geometric shape of the cone of states. In quantum theory, for instance, the shape of the cone of states corresponds to a projective space over complex numbers. In this paper we investigate geometric constraints on the state space of a generic theory imposed by the following information theoretic requirements: every non completely mixed state of a system is perfectly distinguishable from some other state in a single shot measurement; information capacity of physical systems is conserved under making mixtures of states. These assumptions guarantee that a generic physical system satisfies a natural principle asserting that the more a state of the system is mixed the less information can be stored in the system using that state as logical value. We show that all theories satisfying the above assumptions are such that the shape of their cones of states is that of a projective space over a generic field of numbers. Remarkably, these theories constitute generalizations of quantum theory where superposition principle holds with coefficients pertaining to a generic field of numbers in place of complex numbers. If the field of numbers is trivial and contains only one element we obtain classical theory. This result tells that superposition principle is quite common among probabilistic theories while its absence gives evidence of either classical theory or an implausible theory.

  4. Entanglement entropy for 2D gauge theories with matters

    Science.gov (United States)

    Aoki, Sinya; Iizuka, Norihiro; Tamaoka, Kotaro; Yokoya, Tsuyoshi

    2017-08-01

    We investigate the entanglement entropy in 1 +1 -dimensional S U (N ) gauge theories with various matter fields using the lattice regularization. Here we use extended Hilbert space definition for entanglement entropy, which contains three contributions; (1) classical Shannon entropy associated with superselection sector distribution, where sectors are labeled by irreducible representations of boundary penetrating fluxes, (2) logarithm of the dimensions of their representations, which is associated with "color entanglement," and (3) EPR Bell pairs, which give "genuine" entanglement. We explicitly show that entanglement entropies (1) and (2) above indeed appear for various multiple "meson" states in gauge theories with matter fields. Furthermore, we employ transfer matrix formalism for gauge theory with fundamental matter field and analyze its ground state using hopping parameter expansion (HPE), where the hopping parameter K is roughly the inverse square of the mass for the matter. We evaluate the entanglement entropy for the ground state and show that all (1), (2), (3) above appear in the HPE, though the Bell pair part (3) appears in higher order than (1) and (2) do. With these results, we discuss how the ground state entanglement entropy in the continuum limit can be understood from the lattice ground state obtained in the HPE.

  5. Sub-Doppler spectroscopy of thioformaldehyde: Excited state perturbations and evidence for rotation-induced vibrational mixing in the ground state

    International Nuclear Information System (INIS)

    Clouthier, D.J.; Huang, G.; Adam, A.G.; Merer, A.J.

    1994-01-01

    High-resolution intracavity dye laser spectroscopy has been used to obtain sub-Doppler spectra of transitions to 350 rotational levels in the 4 1 0 band of the A 1 A 2 --X 1 A 1 electronic transition of thioformaldehyde. Ground state combination differences from the sub-Doppler spectra, combined with microwave and infrared data, have been used to improve the ground state rotational and centrifugal distortion constants of H 2 CS. The upper state shows a remarkable number of perturbations. The largest of these are caused by nearby triplet levels, with matrix elements of 0.05--0.15 cm -1 . A particularly clear singlet--triplet avoided crossing in K a ' = 7 has been shown to be caused by interaction with the F 1 component of the 3 1 6 2 vibrational level of the a 3 A 2 state. At least 53% of the S 1 levels show evidence of very small perturbations by high rovibronic levels of the ground state. The number of such perturbations is small at low J, but increases rapidly beyond J=5 such that 40%--80% of the observed S 1 levels of any given J are perturbed by ground state levels. Model calculations show that the density and J dependence of the number of perturbed levels can be explained if there is extensive rotation-induced mixing of the vibrational levels in the ground state

  6. Opting in and opting out: a grounded theory of nursing's contribution to inpatient rehabilitation.

    Science.gov (United States)

    Pryor, Julie; Walker, Annette; O'Connell, Beverly; Worrall-Carter, Linda

    2009-12-01

    To develop a grounded theory of nursing's contribution to patient rehabilitation from the perspective of nurses working in inpatient rehabilitation. Grounded theory method, informed by the theoretical perspective of symbolic interactionism, was used to guide data collection and analysis, and the development of a grounded theory. Five inpatient rehabilitation units in Australia. Thirty-five registered and 18 enrolled nurses participated in audio-taped interviews and/or were observed during periods of their everyday practice. The analysis revealed a situation whereby nurses made decisions about when to 'opt in' and when to 'opt out' of inpatient rehabilitation. This occurred on two levels: with their interaction with patients and allied health professionals, and when faced with negative system issues that impacted on their ability to contribute to patient rehabilitation. The primary contribution nurses made to inpatient rehabilitation was working directly with patients, enabling them to self-care. Nurses coached patients when their decisions about 'opting in' and 'opting out' were based on assessment of the person in their particular context. In contrast, the nurses mostly distanced themselves from system-based problems, 'opting out' of addressing them. They did this not to make their working lives easier, but more manageable. System-based problems impacted negatively on the nurses' ability to deliver comprehensive rehabilitation care. As a consequence, some nurses felt unable to influence the care and they withdrew professionally to make their work lives more manageable.

  7. Ground-state properties of a supersymmetric fermion chain

    International Nuclear Information System (INIS)

    Fendley, Paul; Hagendorf, Christian

    2011-01-01

    We analyze the ground state of a strongly interacting fermion chain with a supersymmetry. We conjecture a number of exact results, such as a hidden duality between weak and strong couplings. By exploiting a scale-free property of the perturbative expansions, we find exact expressions for the order parameters, yielding the critical exponents. We show that the ground state of this fermion chain and another model in the same universality class, the XYZ chain along a line of couplings, are both written in terms of the same polynomials. We demonstrate this explicitly for up to N = 24 sites and provide consistency checks for large N. These polynomials satisfy a recursion relation related to the Painlevé VI differential equation and, using a scale-free property of these polynomials, we derive a simple and exact formula for their N→∞ limit

  8. On negative norm states in supersymmetric theories

    International Nuclear Information System (INIS)

    Ellwanger, U.

    1983-01-01

    We study the effective kinetic energy of scalar fields for two classes of supersymmetric theories. In theories with very large VEVs of scalar fields, as proposed by Witten, the use of the renormalization group improved effective action prevents the appearance of negative norm states. For simpler theories a general criterium for the absence of negative norm states is given, which is violated in a model with O(N)-symmetry proposed recently. (orig.)

  9. Non-degenerated Ground States and Low-degenerated Excited States in the Antiferromagnetic Ising Model on Triangulations

    Science.gov (United States)

    Jiménez, Andrea

    2014-02-01

    We study the unexpected asymptotic behavior of the degeneracy of the first few energy levels in the antiferromagnetic Ising model on triangulations of closed Riemann surfaces. There are strong mathematical and physical reasons to expect that the number of ground states (i.e., degeneracy) of the antiferromagnetic Ising model on the triangulations of a fixed closed Riemann surface is exponential in the number of vertices. In the set of plane triangulations, the degeneracy equals the number of perfect matchings of the geometric duals, and thus it is exponential by a recent result of Chudnovsky and Seymour. From the physics point of view, antiferromagnetic triangulations are geometrically frustrated systems, and in such systems exponential degeneracy is predicted. We present results that contradict these predictions. We prove that for each closed Riemann surface S of positive genus, there are sequences of triangulations of S with exactly one ground state. One possible explanation of this phenomenon is that exponential degeneracy would be found in the excited states with energy close to the ground state energy. However, as our second result, we show the existence of a sequence of triangulations of a closed Riemann surface of genus 10 with exactly one ground state such that the degeneracy of each of the 1st, 2nd, 3rd and 4th excited energy levels belongs to O( n), O( n 2), O( n 3) and O( n 4), respectively.

  10. Nurses experience of using scientific knowledge in clinical practice: a grounded theory study.

    Science.gov (United States)

    Renolen, Åste; Hjälmhult, Esther

    2015-12-01

    Guidelines recommend the use of evidence-based practice in nursing. Nurses are expected to give patients care and treatment based on the best knowledge available. They may have knowledge and positive attitudes, but this does not mean that they are basing their work on evidence-based practice. Knowledge is still lacking about what is needed to successfully implement evidence-based practice. The aim of this study was to gain more knowledge about what nurses perceive as the most important challenge in implementing evidence-based practice and to explain how they act to face and overcome this challenge. We used classical grounded theory methodology and collected data through four focus groups and one individual interview in different geographical locations in one large hospital trust in Norway. Fourteen registered clinical practice nurses participated. We analysed the data in accordance with grounded theory, using the constant comparative method. Contextual balancing of knowledge emerged as the core category and explains how the nurses dealt with their main concern, how to determine what types of knowledge they could trust. The nurses' main strategies were an inquiring approach, examining knowledge and maintaining control while taking care of patients. They combined their own experienced-based knowledge and the guidelines of evidence-based practice with a sense of control in the actual situation. The grounded theory contextual balancing of knowledge may help us to understand how nurses detect what types of knowledge they can trust in clinical practice. The nurses needed to rely on what they did, and they seemed to rely on their own experience rather than on research. © 2015 Nordic College of Caring Science.

  11. Correlation induced paramagnetic ground state in FeAl

    Czech Academy of Sciences Publication Activity Database

    Mohn, P.; Persson, C.; Blaha, P.; Schwarz, K.; Novák, Pavel; Eschrig, H.

    2001-01-01

    Roč. 87, č. 19 (2001), s. 196401-1-196401-4 ISSN 0031-9007 Institutional research plan: CEZ:AV0Z1010914 Keywords : FeAl * paramagnetic ground state Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 6.668, year: 2001

  12. A Social Accountable Model for Medical Education System in Iran: A Grounded-Theory

    Directory of Open Access Journals (Sweden)

    Mohammadreza Abdolmaleki

    2017-10-01

    Full Text Available Social accountability has been increasingly discussed over the past three decades in various fields providing service to the community and has been expressed as a goal for various areas. In medical education system, like other social accountability areas, it is considered as one of the main objectives globally. The aim of this study was to seek a social accountability theory in the medical education system that is capable of identifying all the standards, norms, and conditions within the country related to the study subject and recognize their relationship. In this study, a total of eight experts in the field of social accountability in medical education system with executive or study experience were interviewedpersonally. After analysis of interviews, 379 codes, 59 secondary categories, 16 subcategories, and 9 main categories were obtained. The resulting data was collected and analyzed at three levels of open coding, axial coding, and selective coding in the form of grounded theory study of “Accountability model of medical education in Iran”, which can be used in education system’s policies and planning for social accountability, given that almost all effective components of social accountability in highereducation health system with causal and facilitator associations were determined.Keywords: SOCIAL ACCOUNTABILITY, COMMUNITY–ORIENTED MEDICINE, COMMUNITY MEDICINE, EDUCATION SYSTEM, GROUNDED THEORY

  13. The ground state magnetic moment and susceptibility of a two electron Gaussian quantum dot

    Science.gov (United States)

    Boda, Aalu; Chatterjee, Ashok

    2018-04-01

    The problem of two interacting electrons moving in a two-dimensional semiconductor quantum dot with Gaussian confinement under the influence of an external magnetic field is studied by using a method of numerical diagonalization of the Hamiltonian matrix with in the effective-mass approximation. The energy spectrum is calculated as a function of the magnetic field. We find the ground state magnetic moment and the magnetic susceptibility show zero temperature diamagnetic peaks due to exchange induced singlet-triplet oscillations. The position and the number of these peaks depend on the size of the quantum dot and also strength of the electro-electron interaction. The theory is applied to a GaAs quantum dot.

  14. Intentionality: evolutionary development in healing: a grounded theory study for holistic nursing.

    Science.gov (United States)

    Zahourek, Rothlyn P

    2005-03-01

    Although intentionality has been implicated as a causal variable in healing research, its definition has been inconsistent and vague. The objective of this grounded theory study is to develop a substantive theory of intentionality in a naturalistic encounter between nurse-healers and their healee-clients, and to consider the implications for practice and research. Six expert nurse-healers and six healee-clients were interviewed as individuals and in dyads before and after treatments. Interviews and observational data were analyzed using the constant comparative method and synthesized analysis. Participants described their experience of intentionality in healing as an evolutionary process characterized by distinctive shifts. The theory of intentionality: the matrix for healing (IMH) includes definitions of intentionality and a conceptual framework of three developmental phases of intentionality (generic, healing, and transforming intentionalities). The predominant attribute, development, is described. The theory contributes to knowledge about healing and intentionality and has implications for practice and future research.

  15. Park Planning for Ageing Adults Using Grounded Theory Methodology

    Directory of Open Access Journals (Sweden)

    Bernie Dahl

    2004-06-01

    Full Text Available The importance of understanding park planning issues and implementing planning strategies for ageing adults was the driving force for this study. Literature reviews have identified a variety of scholarly work from fields such as gerontology, psychology, sociology and economics, all of which provide valuable information regarding the special needs of ageing adults. Very few researchers, however, have investigated the leisure behaviours of older adults in outdoor recreation (Croskeys, Tinsley and Tinsley, 2002 and the use of grounded theory methodology has essentially been unexplored in this area. Ageing adults are projected to live more than 20 percent of their life in retirement (MRP, 1998, cited in Croskeys, Tinsley and Tinsley, 2002, allowing for an increased amount of discretionary time. This offers opportunities for ageing adults to participate in outdoor recreational activities and will undoubtedly increase their leisure time. However, with limited research in recreational needs and inclusion for older adults, it is difficult for park planners and administrators to meet the growing needs of this population. Therefore, this research is necessary in order to determine whether ageing adults are being accounted for in park and outdoor recreational planning. The objective of this study was to use grounded theory research methodology to identify and examine ageing adult needs in relation to outdoor leisure activities in a regional park setting. Ten Midwestern regional park visitors (aged 65-75 years old and four park employees were interviewed. Our research attempts to fill in the gaps between the perceptions of ageing park users and those of park planners, using a methodology that relies primarily on direct contact with park visitors.

  16. Tight-binding approximations to time-dependent density functional theory — A fast approach for the calculation of electronically excited states

    Energy Technology Data Exchange (ETDEWEB)

    Rüger, Robert, E-mail: rueger@scm.com [Scientific Computing & Modelling NV, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Department of Theoretical Chemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Linnéstr. 2, 04103 Leipzig (Germany); Lenthe, Erik van [Scientific Computing & Modelling NV, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Heine, Thomas [Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Linnéstr. 2, 04103 Leipzig (Germany); Visscher, Lucas [Department of Theoretical Chemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands)

    2016-05-14

    We propose a new method of calculating electronically excited states that combines a density functional theory based ground state calculation with a linear response treatment that employs approximations used in the time-dependent density functional based tight binding (TD-DFTB) approach. The new method termed time-dependent density functional theory TD-DFT+TB does not rely on the DFTB parametrization and is therefore applicable to systems involving all combinations of elements. We show that the new method yields UV/Vis absorption spectra that are in excellent agreement with computationally much more expensive TD-DFT calculations. Errors in vertical excitation energies are reduced by a factor of two compared to TD-DFTB.

  17. The role of pride in women with anorexia nervosa: A grounded theory study.

    Science.gov (United States)

    Faija, Cintia L; Tierney, Stephanie; Gooding, Patricia A; Peters, Sarah; Fox, John R E

    2017-12-01

    Theory and clinical literature suggest that pride may play an important role in the maintenance of restrictive eating disorders. A grounded theory study explored experiences of, and reflections on, pride among women with a current or past diagnosis of anorexia nervosa. This is a qualitative study using grounded theory. Semistructured interviews were conducted with 21 women recruited from an eating disorder unit in England, and from a UK self-help organization. Grounded theory from a constructivist lens was used. Analysis involved coding, constant comparison, and memo-writing. Pride evolves over the course of anorexia nervosa. Two overarching conceptual categories were identified: 'pride becoming intertwined with anorexia' and 'pride during the journey towards recovery'. These categories encompassed different forms of pride: 'alluring pride', 'toxic pride', 'pathological pride', 'anorexia pride', 'shameful pride', 'recovery pride', and 'resilient pride'. Initially, pride contributed to self-enhancement and buffered negative emotions. As the condition progressed, pride became a challenge to health and interfered with motivation to change. During recovery, perceptions of pride altered as a healthy approach to living ensued. The evolving nature of pride plays a central role in development, maintenance, and treatment of anorexia nervosa. Understanding of pride and its role in psychotherapeutic work with this client group may increase motivation to change and promote recovery. Future work should investigate whether tackling pride in eating disorders increases treatment efficacy and reduces the risk of relapsing. Pride associated with anorexia appeared to evolve in nature. During early stages of the eating disorder, it stopped people from seeking help. Later on, it prevented them from seeing pride in healthy domains of life (outside anorexia). Over time, pride in anorexia became an overwhelming emotion that interfered with motivation to change. It is important for

  18. Professional Socialization of Iranian BSN Students: A Grounded Theory Study.

    Science.gov (United States)

    Dinmohammadi, Mohammad Reza; Peyrovi, Hamid; Mehrdad, Neda

    2017-12-01

    Introduction: Professional socialization is a critical aspect of nursing students' development, which begins with entry into the nursing program and continues when their professional practice begins. The aim of this study was to explore the socialization of Iranian BSN students in the nursing profession. Methods: An exploratory qualitative approach utilizing Straussian version of the grounded theory (1998) method was used. Individual in-depth semi-structured interviews were undertaken with 14 participants chosen from two large nursing schools in an urban area through purposive and theoretical sampling. The data were analyzed, using the constant comparative method. Results: Five main categories and eleven subcategories emerged and integrated around one core category. Professional metamorphosis as the core variable was a complex and interrelated process (consisting of three stages: dependence, disintegration, and integration) with dynamic, ongoing, and personal features influenced by professional and extra-professional context. The students assumed a passive role in the initial of their studies. However, during the last year of the educational program, they gradually involved actively in dealing with own personal and professional issues. Conclusion: This study introduced "professional metamorphosis of BSN students" as a substantive grounded theory in the socio-cultural context of the health care system in Iran. During this process, students move from outsider personal position to insider professional position. The nurse educators and administrators may develop effective educational interventions to promote professional socialization of students with an understanding of the promoting and driving forces influencing socialization.

  19. Entrepreneurial Orientation of Community College Workforce Divisions and the Impact of Organizational Structure: A Grounded Theory Study

    Science.gov (United States)

    Schiefen, Kathleen M.

    2010-01-01

    This research focused on how organizational structure of community colleges influenced the entrepreneurial orientation of deans, directors, vice presidents, and vice chancellors of workforce units. Using grounded theory methodology, the researcher identified three emergent theories applicable to both integrated and separate workforce units. These…

  20. Nonspherical atomic ground-state densities and chemical deformation densities from x-ray scattering

    International Nuclear Information System (INIS)

    Ruedenberg, K.; Schwarz, W.H.E.

    1990-01-01

    Presuming that chemical insight can be gained from the difference between the molecular electron density and the superposition of the ground-state densities of the atoms in a molecule, it is pointed out that, for atoms with degenerate ground states, an unpromoted ''atom in a molecule'' is represented by a specific ensemble of the degenerate atomic ground-state wave functions and that this ensemble is determined by the anisotropic local surroundings. The resulting atomic density contributions are termed oriented ground state densities, and the corresponding density difference is called the chemical deformation density. The constraints implied by this conceptual approach for the atomic density contributions are formulated and a method is developed for determining them from x-ray scattering data. The electron density of the appropriate promolecule and its x-ray scattering are derived, the determination of the parameters of the promolecule is outlined, and the chemical deformation density is formulated

  1. Construction of ground-state preserving sparse lattice models for predictive materials simulations

    Science.gov (United States)

    Huang, Wenxuan; Urban, Alexander; Rong, Ziqin; Ding, Zhiwei; Luo, Chuan; Ceder, Gerbrand

    2017-08-01

    First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground states. However, despite recent advances, the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation, since this property is not guaranteed by default. In this paper, we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference data. The method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model parameters. The robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes, i.e., Li2xFe2(1-x)O2 and Li2xTi2(1-x)O2, for which the construction of cluster expansion models with compressive sensing alone has proven to be challenging. We demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction, but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative refinement. This method provides a general tool for building robust, compressed and constrained physical models with predictive power.

  2. Grounded Theory sebagai Metode Riset “Realitas Tertambah” di Museum Fatahillah

    Directory of Open Access Journals (Sweden)

    Leonardo Widya

    2014-03-01

    Full Text Available Augmented Reality (AR is part of the science of visual communication design/graphic design through theaddition of images on the real world with virtual information to enhance one’s senses with the help of “smart glasses”with three general characteristics: 1. The combination of real environment with virtual objects, 2. Interactivedisplay, 3. Display in 3D. Qualitative research methods and grounded theory approach in the real environmentin the area of Jakarta Fatahillah museum, discovered a new theory as a basis the idea that Visual PrototypingAugmented Reality technique with image manipulation-image nuanced Kota Tua as Jakarta Icon. The idea ofexploiting foreign tourists enriching way to learn more about Indonesia through social networking in a virtual worldstrategies to increase tourism.

  3. Trust Development With the Spanish-Speaking Mexican American Patient: A Grounded Theory Study.

    Science.gov (United States)

    Jones, Sharon M

    2018-06-01

    Interpersonal trust between patient and nurse is important in patient-centered care. Trust development may be more difficult if the patient and nurse do not speak the same language. In this grounded theory study, Spanish-speaking Mexican American adults ( n = 20) hospitalized on a medical-surgical or obstetric unit in the Midwestern United States were interviewed. Through data analysis, a model of how trust develops between nurse and patient revealed eight categories and the core category Caring for Me Well Even When Not Understanding Me. The beginning phase had four categories: Asking for Help, Bothering, Communicating, and Understanding. The middle phase had two categories: Platicando (chatting) and Being Available. The end point category was Having Trust, and outcomes were Feeling Comfortable and Feeling Supported. The language barrier was a hindrance to trust development but the nurse's way of being (personality) was more important. Therefore, the patient did develop trust with nurses who did not speak Spanish.

  4. Black holes, parallelizable horizons, and half-BPS states for the Einstein-Gauss-Bonnet theory in five dimensions

    International Nuclear Information System (INIS)

    Canfora, Fabrizio; Giacomini, Alex; Troncoso, Ricardo

    2008-01-01

    Exact vacuum solutions with a nontrivial torsion for the Einstein-Gauss-Bonnet theory in five dimensions are constructed. We consider a class of static metrics whose spacelike section is a warped product of the real line with a nontrivial base manifold endowed with a fully antisymmetric torsion. It is shown that requiring solutions of this sort to exist, fixes the Gauss-Bonnet coupling such that the Lagrangian can be written as a Chern-Simons form. The metric describes black holes with an arbitrary, but fixed, base manifold. It is shown that requiring its ground state to possess unbroken supersymmetries fixes the base manifold to be locally a parallelized three-sphere. The ground state turns out to be half-BPS, which could not be achieved in the absence of torsion in vacuum. The Killing spinors are explicitly found

  5. Stable π-Extended p -Quinodimethanes: Synthesis and Tunable Ground States

    KAUST Repository

    Zeng, Zebing

    2014-12-18

    © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. p-Quinodimethane (p-QDM) is a highly reactive hydrocarbon showing large biradical character in the ground state. It has been demonstrated that incorporation of the p-QDM moiety into an aromatic hydrocarbon framework could lead to new π-conjugated systems with significant biradical character and unique optical, electronic and magnetic properties. On the other hand, the extension of p-QDM is expected to result in molecules with even larger biradical character and higher reactivity. Therefore, the synthesis of stable π-extended p-QDMs is very challenging. In this Personal Account we will briefly discuss different stabilizing strategies and synthetic methods towards stable π-extended p-QDMs with tunable ground states and physical properties, including two types of polycyclic hydrocarbons: (1) tetrabenzo-Tschitschibabin\\'s hydrocarbons, and (2) tetracyano-rylenequinodimethanes. We will discuss how the aromaticity, substituents and steric hindrance play important roles in determining their ground states and properties. Incorporation of the p-quinodimethane moiety into aromatic hydrocarbon frameworks can lead to new π-conjugated systems with significant biradical character and unique optical, electronic and magnetic properties. Furthermore, the extension of p-QDM is expected to result in molecules with even larger biradical character and higher reactivity. In this Personal Account, different stabilizing strategies and synthetic methods towards stable π-extended p-QDMs with tunable ground states and physical properties are briefly discussed, including the roles of aromaticity, substituents and steric hindrance.

  6. Desarrollo cultural en las organizaciones. Un modelo de estudio basado en la Grounded Theory Cultural development in organizations. A model study based on the Grounded Theory

    Directory of Open Access Journals (Sweden)

    Manuel SÁNCHEZ-SANVICENTE

    2012-08-01

    Full Text Available La cultura organizacional se configura a partir de la interrelación de los procesos de apropiación de la filosofía, la pertenencia, la adaptación, la satisfacción y el liderazgo compartidos por un grupo. Este conjunto de categorías puede ser reconocido mediante el uso de una matriz que incluye en su estructura subcategorías o conceptos y un conjunto de propiedades observables en el público interno. El presente artículo tiene por objetivo describir un modelo de estudio construido a partir de la Grounded Theory o Teoría Fundamentada que nos permita comprender el desarrollo cultural de las organizaciones. El estudio de caso se realizó en una compañía líder en Europa del sector de la distribución.AbstractThe organizational culture is set from the interplay of the processes of appropriation of philosophy, membership, adaptation, satisfaction and leadership shared by a group. This set of categories can be recognized by using a matrix that includes in its structure or sub-concepts and a set of observable properties in the workforce. This article aims to describe a study model built from the Grounded Theory that allows us to understand the cultural development of organizations. The case study was conducted in a European leader in the distribution sector.

  7. Investigating the Perceptions of Care Coordinators on Using Behavior Theory-Based Mobile Health Technology With Medicaid Populations: A Grounded Theory Study.

    Science.gov (United States)

    Sigler, Brittany Erika

    2017-03-21

    Medicaid populations are less engaged in their health care than the rest of the population, translating to worse health outcomes and increased health care costs. Since theory-based mobile health (mHealth) interventions have been shown to increase patient engagement, mobile phones may be an optimal strategy to reach this population. With increased development of theory-based mHealth technology, these interventions must now be evaluated with these medically underserved populations in a real-world setting. The aim of our study was to investigate care coordinators' perceived value of using a health behavior theory-based mHealth platform with Medicaid clients. In particular, attention was paid to the perceived impact on patient engagement. This research was conducted using the patient-provider text messaging (short message service, SMS) platform, Sense Health (now Wellpass), which integrates the transtheoretical model (TTM), also called the stages of change model; social cognitive theory (SCT); supportive accountability; and motivational interviewing (MI). Interviews based in grounded theory methodology were conducted with 10 care managers to understand perceptions of the relationship between mHealth and patient engagement. The interviews with care managers yielded a foundation for a grounded theory model, presenting themes that suggested 4 intertwined correlative relationships revolving around patient engagement: (1) A text messaging (short message service, SMS) platform supplements the client-care manager dynamic, which is grounded in high quality, reciprocal-communication to increase patient engagement; (2) Texting enhances the relationship between literacy and access to care for Medicaid patients, increasing low-literacy patients' agency to access services; (3) Texting enhances communication, providing care managers with a new means to support their clients; and (4) Reminders augment client accountability, leading to both increased motivation and readiness to change

  8. Ground states of the massless Derezinski-Gerard model

    International Nuclear Information System (INIS)

    Ohkubo, Atsushi

    2009-01-01

    We consider the massless Derezinski-Gerard model introduced by Derezinski and Gerard in 1999. We give a sufficient condition for the existence of a ground state of the massless Derezinski-Gerard model without the assumption that the Hamiltonian of particles has compact resolvent.

  9. Ground State Structure of a Coupled 2-Fermion System in Supersymmetric Quantum Mechanics

    Science.gov (United States)

    Finster, Felix

    1997-05-01

    We prove the uniqueness of the ground state for a supersymmetric quantum mechanical system of two fermions and two bosons, which is closely related to theN=1 WZ-model. The proof is constructive and gives detailed information on what the ground state looks like

  10. High-field magnetoconductance in La-Sr manganites of FM and AFM ground states

    Science.gov (United States)

    Jirák, Zdeněk; Kaman, Ondřej; Knížek, Karel; Levinský, Petr; Míšek, Martin; Veverka, Pavel; Hejtmánek, Jiří

    2018-06-01

    Large-grain La1-xSrxMnO3 ceramic samples of compositions x = 0.45 and 0.55, representing the ferromagnetic (FM) and A-type antiferromagnetic (AFM) ground states, were produced via classical sintering at 1500 °C of cold-pressed sol-gel prepared single-phase nanoparticles. Using the same precursors, nanogranular forms of both manganite ceramics were prepared by fast spark plasma sintering at low temperature of 900 °C, which limits the growth of crystal grains. The magnetotransport of both the bulk and nanogranular forms was investigated in a broad range of magnetic fields up to 130 kOe and analyzed on the basis of detailed magnetic measurements. Both the large-grain and nanogranular systems with x = 0.45, possessing a pure FM state with similar Curie tempereature TC ≈ 345 K), show nearly the same conductivity enhancement in external fields when expressed relatively to the zero-field values. This positive magnetoconductance (MC) can be separated into two terms: (i) the hysteretic low-field MC that reflects the field-induced orientation of magnetic moments of individual grains, and (ii) the high-field MC that depends linearly on external field. In the case of large-grain ceramics with x = 0.55, a partially ordered FM state formed below TC = 264 K is replaced by pure A-type AFM ground state below 204 K. This A-type AFM state is characterized by positive magnetoconductance that is essentially of quadratic dependence on external field in the investigated range up to 130 kOe. On contrary, the nanogranular product with x = 0.55 exhibits a mixed FM/AFM state at low temperatures, and, as a consequence, its magnetotransport combines the features of FM and A-type AFM systems, in which the quadratic term is much enhanced and clearly dominates at high fields. For interpretation of observed behaviors, the theory of grain-boundary tunneling is revisited.

  11. Matrix effective theories of the fractional quantum Hall effect

    International Nuclear Information System (INIS)

    Cappelli, Andrea; Rodriguez, Ivan D

    2009-01-01

    The present understanding of nonperturbative ground states in the fractional quantum Hall effect is based on effective theories of the Jain 'composite fermion' excitations. We review the approach based on matrix variables, i.e. D0 branes, originally introduced by Susskind and Polychronakos. We show that the Maxwell-Chern-Simons matrix gauge theory provides a matrix generalization of the quantum Hall effect, where the composite-fermion construction naturally follows from gauge invariance. The matrix ground states obtained by suitable projections of higher Landau levels are found to be in one-to-one correspondence with the Laughlin and Jain hierarchical states. The matrix theory possesses a physical limit for commuting matrices that could be reachable while staying in the same phase.

  12. Reconciling the good patient persona with problematic and non-problematic humour: a grounded theory.

    Science.gov (United States)

    McCreaddie, May; Wiggins, Sally

    2009-08-01

    Humour is a complex phenomenon, incorporating cognitive, emotional, behavioural, physiological and social aspects. Research to date has concentrated on reviewing (rehearsed) humour and 'healthy' individuals via correlation studies using personality-trait based measurements, principally on psychology students in laboratory conditions. Nurses are key participants in modern healthcare interactions however, little is known about their (spontaneous) humour use. A middle-range theory that accounted for humour use in CNS-patient interactions was the aim of the study. The study reviewed the antecedents of humour exploring the use of humour in relation to (motivational) humour theories. Twenty Clinical Nurse Specialist-patient interactions and their respective peer groups in a country of the United Kingdom. An evolved constructivist grounded theory approach investigated a complex and dynamic phenomenon in situated contexts. Naturally occurring interactions provided the basis of the data corpus with follow-up interviews, focus groups, observation and field notes. A constant comparative approach to data collection and analysis was applied until theoretical sufficiency incorporating an innovative interpretative and illustrative framework. This paper reports the grounded theory and is principally based upon 20 CNS-patient interactions and follow-up data. The negative case analysis and peer group interactions will be reported in separate publications. The theory purports that patients' use humour to reconcile a good patient persona. The core category of the good patient persona, two of its constituent elements (compliance, sycophancy), conditions under which it emerges and how this relates to the use of humour are outlined and discussed. In seeking to establish and maintain a meaningful and therapeutic interaction with the CNS, patients enact a good patient persona to varying degrees depending upon the situated context. The good patient persona needs to be maintained within the

  13. Learning to live with a hand nerve disorder: A constructed grounded theory.

    Science.gov (United States)

    Ashwood, Mark; Jerosch-Herold, Christina; Shepstone, Lee

    2017-11-29

    Grounded theory. The broader perspective of health offered by the World Health Organization's International Classification of Functioning, Disability and Health has had a significant bearing on how we view the measurement of health outcomes after surgical or therapy interventions for peripheral nerve disorders affecting the hand. The value of the patient's perspective is now recognized and outcomes which reflect this are being advocated in the clinical management and support of this population. This qualitative study sought to explore the lived experience of a hand nerve disorder and in particular the impact on body structure/function, activities, and participation. In depth, one-to-one interviews with 14 people with a range of hand nerve disorders were conducted. Constructivist grounded theory methods were used to collect and analyze the data. Patients were also given the option of taking photographs to visually represent what it is like to live with a nerve disorder, to bring with them for discussion during the interview. The impact of hand nerve disorders forms part of a wider narrative on adaptation. A process of "struggling" and then "overcoming" was experienced. This was followed by an interior aspect of adaptation described as "accepting." This gave rise to participants "transforming," being changed as a result of the journey that they had been on. This study provides an explanatory theory on the adaptive process following a hand nerve disorder which may inform future patient-therapist interactions. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  14. Entanglement of two ground state neutral atoms using Rydberg blockade

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; Browaeys, Antoine; Evellin, Charles

    2011-01-01

    We report on our recent progress in trapping and manipulation of internal states of single neutral rubidium atoms in optical tweezers. We demonstrate the creation of an entangled state between two ground state atoms trapped in separate tweezers using the effect of Rydberg blockade. The quality...... of the entanglement is measured using global rotations of the internal states of both atoms....

  15. Enterprise Factors Contributing to The Success of Malaysian Biotechnology SMEs: A Grounded Theory Approach

    Directory of Open Access Journals (Sweden)

    Saridan Abu Bakar

    2013-07-01

    Full Text Available While numerous empirical studies have been conducted in Western countries on biotechnology enterprises, little empirical research has been done in Malaysia especially in respect to the factors that contribute to the success of biotechnology small and medium enterprises (SMEs. In view of this, a study was undertaken recently in Malaysia to address this gap in the existing body of biotechnology knowledge. Using a grounded theory approach, this qualitative study managed to develop a conceptual framework that sheds useful information on the enterprise factors that significantly impact the success of Malaysian biotechnology SMEs. Specifically, this study found that organizational structure, innovation activities, linkages with academic research institutions, linkages with other private enterprises, personal linkages with academic researchers, access to financial capital, the procuring of government assistances, vertical integration, enterprise image, GMP compliance and halal certification, strongly influence enterprise success.Keywords: biotechnology, SMEs, Malaysia, success, qualitative study, grounded theory

  16. Clarification of the Blurred Boundaries between Grounded Theory and Ethnography: Differences and Similarities

    Science.gov (United States)

    Aldiabat, Khaldoun; Le Navenec, Carol-Lynne

    2011-01-01

    There is confusion among graduate students about how to select the qualitative methodology that best fits their research question. Often this confusion arises in regard to making a choice between a grounded theory methodology and an ethnographic methodology. This difficulty may stem from the fact that these students do not have a clear…

  17. Discovering Shared Experiences of Second Generation Community College Employees: A Grounded Theory Study

    Science.gov (United States)

    Studebaker, Eric J.

    2012-01-01

    The second generation community college employee had not been a target population of any previous research in the field of higher education. This study added to a broader understanding of employees, their various characteristics, and the implications of those characteristics. The purpose of this study was to develop a grounded theory defining the…

  18. Ground State Energy of the Modified Nambu-Goto String

    Science.gov (United States)

    Hadasz, Leszek

    We calculate, using zeta function regularization method, semiclassical energy of the Nambu-Goto string supplemented with the boundary, Gauss-Bonnet term in the action and discuss the tachyonic ground state problem.

  19. Ground state energy of the modified Nambu-Goto string

    OpenAIRE

    Hadasz, Leszek

    1997-01-01

    We calculate, using zeta function regularization method, semiclassical energy of the Nambu-Goto string supplemented with the boundary, Gauss-Bonnet term in the action and discuss the tachyonic ground state problem.

  20. Non-local ground-state functional for quantum spin chains with translational broken symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Libero, Valter L.; Penteado, Poliana H.; Veiga, Rodrigo S. [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica

    2011-07-01

    Full text. Thanks to the development and use of new materials with special doping, it becomes relevant the study of Heisenberg spin-chains with broken translational symmetry, induced for instance by finite-size effects, bond defects or by impurity spin in the chain. The exact numerical results demands huge computational efforts, due to the size of the Hilbert space involved and the lack of symmetry to exploit. Density Functional Theory (DFT) has been considered a simple alternative to obtain ground-state properties for such systems. Usually, DFT starts with a uniform system to build the correlation energy and after implement a local approximation to construct local functionals. Based on our prove of the Hohenberg-Kohn theorem for Heisenberg models, and in order to describe more realistic models, we have recently developed a non-local exchange functional for the ground-state energy of quantum-spin chains. A alternating-bond chain is used to obtain the correlation energy and a local unit-cell approximation - LUCA, is defined in the context of DFT. The alternating chain is a good starting point to construct functionals since it is intrinsically non-homogeneous, therefore instead of the usual local approximation (like LDA for electronic systems) we need to introduce an approximation based upon a unit cell concept, that renders a non-local functional in the bond exchange interaction. The agreement with exact numerical data (obtained only for small chains, although the functional can be applied for chains with arbitrary size) is significantly better than in our previous local formulation, even for chains with several ferromagnetic or antiferromagnetic bond defects. These results encourage us to extend the concept of LUCA for chains with alternating-spin magnitudes. We also have constructed a non-local functional based on an alternating-spin chain, instead of a local alternating-bond, using spin-wave-theory. Because of its non-local nature, this functional is expected to

  1. Non-local ground-state functional for quantum spin chains with translational broken symmetry

    International Nuclear Information System (INIS)

    Libero, Valter L.; Penteado, Poliana H.; Veiga, Rodrigo S.

    2011-01-01

    Full text. Thanks to the development and use of new materials with special doping, it becomes relevant the study of Heisenberg spin-chains with broken translational symmetry, induced for instance by finite-size effects, bond defects or by impurity spin in the chain. The exact numerical results demands huge computational efforts, due to the size of the Hilbert space involved and the lack of symmetry to exploit. Density Functional Theory (DFT) has been considered a simple alternative to obtain ground-state properties for such systems. Usually, DFT starts with a uniform system to build the correlation energy and after implement a local approximation to construct local functionals. Based on our prove of the Hohenberg-Kohn theorem for Heisenberg models, and in order to describe more realistic models, we have recently developed a non-local exchange functional for the ground-state energy of quantum-spin chains. A alternating-bond chain is used to obtain the correlation energy and a local unit-cell approximation - LUCA, is defined in the context of DFT. The alternating chain is a good starting point to construct functionals since it is intrinsically non-homogeneous, therefore instead of the usual local approximation (like LDA for electronic systems) we need to introduce an approximation based upon a unit cell concept, that renders a non-local functional in the bond exchange interaction. The agreement with exact numerical data (obtained only for small chains, although the functional can be applied for chains with arbitrary size) is significantly better than in our previous local formulation, even for chains with several ferromagnetic or antiferromagnetic bond defects. These results encourage us to extend the concept of LUCA for chains with alternating-spin magnitudes. We also have constructed a non-local functional based on an alternating-spin chain, instead of a local alternating-bond, using spin-wave-theory. Because of its non-local nature, this functional is expected to

  2. Accommodating interruptions: A grounded theory of young people with asthma.

    Science.gov (United States)

    Hughes, Mary; Savage, Eileen; Andrews, Tom

    2018-01-01

    The aim of this study was to develop an explanatory theory on the lives of young people with asthma, issues affecting them and the impact of asthma on their day-to-day lives. Accommodating Interruptions is a theory that explains young people's concerns about living with asthma. Although national and international asthma management guidelines exist, it is accepted that the symptom control of asthma among the young people population is poor. This study was undertaken using Classic Grounded Theory. Data were collected through in-depth interviews and clinic consultations with young people aged 11-16 years who had asthma for over 1 year. Data were also collected from participant diaries. Constant comparative analysis, theoretical coding and memo writing were used to develop the substantive theory. The theory explains how young people resolve their main concern of being restricted by Accommodating Interruptions in their lives. They do this by assimilating behaviours in balance finding, moderating influence, fitting in and assuming control minimising the effects of asthma on their everyday lives. The theory of Accommodating Interruptions explains young people's asthma management behaviours in a new way. It allows us to understand how and why young people behave the way they do because they want to participate and be included in everyday activities, events and relationships. The theory adds to the body of knowledge on how young people with asthma live their day-to-day lives and it challenges some existing viewpoints in the literature regarding their behaviours. The findings have implications for developing services to support young people in a more meaningful way as they accommodate the interruptions associated with asthma in their lives. © 2017 John Wiley & Sons Ltd.

  3. Singlet Ground State Magnetism: III Magnetic Excitons in Antiferromagnetic TbP

    DEFF Research Database (Denmark)

    Knorr, K.; Loidl, A.; Kjems, Jørgen

    1981-01-01

    The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined.......The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined....

  4. Ground and excited state behavior of 1,4-dimethoxy-3-methyl-anthracene-9,10-dione in silver nanoparticles: Spectral and computational investigations

    Energy Technology Data Exchange (ETDEWEB)

    Umadevi, M., E-mail: ums10@yahoo.com [Department of Physics, Mother Teresa Women' s University, Kodaikanal 624101, Tamil Nadu (India); Kavitha, S.R. [Department of Physics, Mother Teresa Women' s University, Kodaikanal 624101, Tamil Nadu (India); Vanelle, P.; Terme, T.; Khoumeri, O. [Laboratoire de Pharmaco-Chimie Radicalaire, Faculté de Pharmacie, Aix-Marseille Univ, CNRS, Institut de Chimie Radicalaire ICR, UMR 7273, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05 (France)

    2013-10-15

    Silver nanoparticles (Ag NPs) of various sizes have been successfully synthesized by the simple and convenient Creighton method using sodium borohydride as the reducing agent under microwave irradiation. Optical absorption and fluorescence emission spectroscopic techniques were employed to investigate the effect of silver nanoparticles on the ground and excited state of 1,4-dimethoxy-3-methylanthracene-9,10-dione (DMMAD). The surface plasmon resonance (SPR) peak of the prepared silver colloidal solution was observed at 400 nm. Fluorescence quenching of DMMAD by silver nanoparticles has been found to increase with increase in the size of Ag. The fluorescence quenching has been explained by Forster Resonance Energy Transfer (FRET) theory between DMMAD and silver nanoparticles. The Stern–Volmer quenching constant and Benesi–Hildebrand association constant for the above system were calculated. DFT calculations were also performed to study the charge distribution of DMMAD in Ag both in ground and excited states. -- Highlights: • Silver nanoparticles (Ag NPs) have been synthesized using the Creighton method. • Effect of Ag NPs on the ground state of DMMAD was studied. • Influence of Ag NPs on the excited state of DMMAD was investigated. • Fluorescence quenching has been explained by Forster Resonance Energy Transfer. • Quenching and binding constants were also calculated.

  5. Scaling behavior of ground-state energy cluster expansion for linear polyenes

    Science.gov (United States)

    Griffin, L. L.; Wu, Jian; Klein, D. J.; Schmalz, T. G.; Bytautas, L.

    Ground-state energies for linear-chain polyenes are additively expanded in a sequence of terms for chemically relevant conjugated substructures of increasing size. The asymptotic behavior of the large-substructure limit (i.e., high-polymer limit) is investigated as a means of characterizing the rapidity of convergence and consequent utility of this energy cluster expansion. Consideration is directed to computations via: simple Hückel theory, a refined Hückel scheme with geometry optimization, restricted Hartree-Fock self-consistent field (RHF-SCF) solutions of fixed bond-length Parisier-Parr-Pople (PPP)/Hubbard models, and ab initio SCF approaches with and without geometry optimization. The cluster expansion in what might be described as the more "refined" approaches appears to lead to qualitatively more rapid convergence: exponentially fast as opposed to an inverse power at the simple Hückel or SCF-Hubbard levels. The substructural energy cluster expansion then seems to merit special attention. Its possible utility in making accurate extrapolations from finite systems to extended polymers is noted.

  6. A Continuous Family of Equilibria in Ferromagnetic Media are Ground States

    Science.gov (United States)

    Su, Xifeng; de la Llave, Rafael

    2017-09-01

    We show that a foliation of equilibria (a continuous family of equilibria whose graph covers all the configuration space) in ferromagnetic transitive models are ground states. The result we prove is very general, and it applies to models with long range and many-body interactions. As an application, we consider several models of networks of interacting particles including models of Frenkel-Kontorova type on Z^d and one-dimensional quasi-periodic media. The result above is an analogue of several results in the calculus of variations (fields of extremals) and in PDE's. Since the models we consider are discrete and long range, new proofs need to be given. We also note that the main hypothesis of our result (the existence of foliations of equilibria) is the conclusion (using KAM theory) of several recent papers. Hence, we obtain that the KAM solutions recently established are minimizers when the interaction is ferromagnetic and transitive (these concepts are defined later).

  7. Virtual patient design: exploring what works and why. A grounded theory study.

    Science.gov (United States)

    Bateman, James; Allen, Maggie; Samani, Dipti; Kidd, Jane; Davies, David

    2013-06-01

    Virtual patients (VPs) are online representations of clinical cases used in medical education. Widely adopted, they are well placed to teach clinical reasoning skills. International technology standards mean VPs can be created, shared and repurposed between institutions. A systematic review has highlighted the lack of evidence to support which of the numerous VP designs may be effective, and why. We set out to research the influence of VP design on medical undergraduates. This is a grounded theory study into the influence of VP design on undergraduate medical students. Following a review of the literature and publicly available VP cases, we identified important design properties. We integrated them into two substantial VPs produced for this research. Using purposeful iterative sampling, 46 medical undergraduates were recruited to participate in six focus groups. Participants completed both VPs, an evaluation and a 1-hour focus group discussion. These were digitally recorded, transcribed and analysed using grounded theory, supported by computer-assisted analysis. Following open, axial and selective coding, we produced a theoretical model describing how students learn from VPs. We identified a central core phenomenon designated 'learning from the VP'. This had four categories: VP Construction; External Preconditions; Student-VP Interaction, and Consequences. From these, we constructed a three-layer model describing the interactions of students with VPs. The inner layer consists of the student's cognitive and behavioural preconditions prior to sitting a case. The middle layer considers the VP as an 'encoded object', an e-learning artefact and as a 'constructed activity', with associated pedagogic and organisational elements. The outer layer describes cognitive and behavioural change. This is the first grounded theory study to explore VP design. This original research has produced a model which enhances understanding of how and why the delivery and design of VPs

  8. Rayleigh approximation to ground state of the Bose and Coulomb glasses

    Science.gov (United States)

    Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.

    2015-01-01

    Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties. PMID:25592417

  9. Zethrenes, Extended p -Quinodimethanes, and Periacenes with a Singlet Biradical Ground State

    KAUST Repository

    Sun, Zhe

    2014-08-19

    ConspectusResearchers have studied polycyclic aromatic hydrocarbons (PAHs) for more than 100 years, and most PAHs in the neutral state reported so far have a closed-shell electronic configuration in the ground state. However, recent studies have revealed that specific types of polycyclic hydrocarbons (PHs) could have a singlet biradical ground state and exhibit unique electronic, optical, and magnetic activities. With the appropriate stabilization, these new compounds could prove useful as molecular materials for organic electronics, nonlinear optics, organic spintronics, organic photovoltaics, and energy storage devices. However, before researchers can use these materials to design new devices, they need better methods to synthesize these molecules and a better understanding of the fundamental relationship between the structure and biradical character of these compounds and their physical properties. Their biradical character makes these compounds difficult to synthesize. These compounds are also challenging to physically characterize and require the use of various experimental techniques and theoretic methods to comprehensively describe their unique properties.In this Account, we will discuss the chemistry and physics of three types of PHs with a significant singlet biradical character, primarily developed in our group. These structures are zethrenes, Z-shaped quinoidal hydrocarbons; hydrocarbons that include a proaromatic extended p-quinodimethane unit; and periacenes, acenes fused in a peri-Arrangement. We used a variety of synthetic methods to prepare these compounds and stabilized them using both thermodynamic and kinetic approaches. We probed their ground-state structures by electronic absorption, NMR, ESR, SQUID, Raman spectroscopy, and X-ray crystallography and also performed density functional theory calculations. We investigated the physical properties of these PHs using various experimental methods such as one-photon absorption, two-photon absorption

  10. Modeling of the stress-strain state of the ground mass contaminated with peracetic acid

    Directory of Open Access Journals (Sweden)

    Levenko Anna

    2017-01-01

    Full Text Available None of the methods described previously provides a solution to the problem that deals with the SSS evaluation of the ground mass which is under the influence of chemically active substances and, in particular, under the influence of peracetic acid. The stress-strain state of the ground mass contaminated with peracetic acid was estimated. Stresses occurring in the ground mass in the natural state were determined after the entry of acid into it and after the chemical fixation of it with sodium silicate. All the parameters of the stress-strain state of the ground mass were obtained under a number of physical and mechanical conditions. It was determined that following the work on the silicatization of the ground mass contaminated with peracetic acid the quantity of strain decreased by 26.11 to 48.9%. The comparison of the results of stress calculations indicates the stress reduction in the ground mass in 1.8 – 2.6 times after its fixing.

  11. Ground state structure of a coupled 2-fermion system in supersymmetric quantum mechanics

    International Nuclear Information System (INIS)

    Finster, F.

    1997-01-01

    We prove the uniqueness of the ground state for a supersymmetric quantum mechanical system of two fermions and two bosons, which is closely related to the N=1 WZ-model. The proof is constructive and gives detailed information on what the ground state looks like. copyright 1997 Academic Press, Inc

  12. Adolescent Perspectives Following Ostomy Surgery: A Grounded Theory Study.

    Science.gov (United States)

    Mohr, Lynn D; Hamilton, Rebekah J

    2016-01-01

    This purpose of this study was to provide a theoretical account of how adolescents aged 13 to 18 years process the experience of having an ostomy. Qualitative study using grounded theory design. The sample comprised of 12 English-speaking adolescents aged 13-18 years: 10 with an ostomy and 2 with medical management of their disease. Respondents completed audio-recorded interviews that were transcribed verbatim. Data were analyzed using the constant comparative method until data saturation occurred. Dedoose, a Web-based qualitative methods management tool, was used to capture major themes arising from the data. Study results indicate that for adolescents between 13 and 18 years of age, processing the experience of having an ostomy includes concepts of the "physical self" and "social self" with the goal of "normalizing." Subcategories of physical self include (a) changing reality, (b) learning, and (c) adapting. Subcategories of social self include (a) reentering and (b) disclosing. This study sheds light on how adolescents process the experience of having an ostomy and how health care providers can assist adolescents to move through the process to get back to their desired "normal" state. Health care providers can facilitate the adolescent through the ostomy experience by being proactive in conversations not only about care issues but also about school and family concerns and spirituality. Further research is needed in understanding how parents process their adolescents' ostomy surgery experience and how spirituality assists adolescents in coping and adjustment with body-altering events.

  13. A simple parameter-free wavefunction for the ground state of two-electron atoms

    International Nuclear Information System (INIS)

    Ancarani, L U; Rodriguez, K V; Gasaneo, G

    2007-01-01

    We propose a simple and pedagogical wavefunction for the ground state of two-electron atoms which (i) is parameter free (ii) satisfies all two-particle cusp conditions (iii) yields reasonable ground-state energies, including the prediction of a bound state for H - . The mean energy, and other mean physical quantities, is evaluated analytically. The simplicity of the result can be useful as an easy-to-use wavefunction when testing collision models

  14. Uses of solid state analogies in elementary particle theory

    International Nuclear Information System (INIS)

    Anderson, P.W.

    1976-01-01

    The solid state background of some of the modern ideas of field theory is reviewed, and additional examples of model situations in solid state or many-body theory which may have relevance to fundamental theories of elementary particles are adduced

  15. Trapping cold ground state argon atoms for sympathetic cooling of molecules

    OpenAIRE

    Edmunds, P. D.; Barker, P. F.

    2014-01-01

    We trap cold, ground-state, argon atoms in a deep optical dipole trap produced by a build-up cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of co-trapped metastable argon atoms using a new type of parametric loss spectroscopy. Using this technique we als...

  16. Quasi-degenerate perturbation theory using matrix product states

    International Nuclear Information System (INIS)

    Sharma, Sandeep; Jeanmairet, Guillaume; Alavi, Ali

    2016-01-01

    In this work, we generalize the recently proposed matrix product state perturbation theory (MPSPT) for calculating energies of excited states using quasi-degenerate (QD) perturbation theory. Our formulation uses the Kirtman-Certain-Hirschfelder canonical Van Vleck perturbation theory, which gives Hermitian effective Hamiltonians at each order, and also allows one to make use of Wigner’s 2n + 1 rule. Further, our formulation satisfies Granovsky’s requirement of model space invariance which is important for obtaining smooth potential energy curves. Thus, when we use MPSPT with the Dyall Hamiltonian, we obtain a model space invariant version of quasi-degenerate n-electron valence state perturbation theory (NEVPT), a property that the usual formulation of QD-NEVPT2 based on a multipartitioning technique lacked. We use our method on the benchmark problems of bond breaking of LiF which shows ionic to covalent curve crossing and the twist around the double bond of ethylene where significant valence-Rydberg mixing occurs in the excited states. In accordance with our previous work, we find that multi-reference linearized coupled cluster theory is more accurate than other multi-reference theories of similar cost

  17. Quasi-degenerate perturbation theory using matrix product states

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Sandeep, E-mail: sanshar@gmail.com; Jeanmairet, Guillaume [Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart (Germany); Alavi, Ali, E-mail: a.alavi@fkf.mpg.de [Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart (Germany); Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2016-01-21

    In this work, we generalize the recently proposed matrix product state perturbation theory (MPSPT) for calculating energies of excited states using quasi-degenerate (QD) perturbation theory. Our formulation uses the Kirtman-Certain-Hirschfelder canonical Van Vleck perturbation theory, which gives Hermitian effective Hamiltonians at each order, and also allows one to make use of Wigner’s 2n + 1 rule. Further, our formulation satisfies Granovsky’s requirement of model space invariance which is important for obtaining smooth potential energy curves. Thus, when we use MPSPT with the Dyall Hamiltonian, we obtain a model space invariant version of quasi-degenerate n-electron valence state perturbation theory (NEVPT), a property that the usual formulation of QD-NEVPT2 based on a multipartitioning technique lacked. We use our method on the benchmark problems of bond breaking of LiF which shows ionic to covalent curve crossing and the twist around the double bond of ethylene where significant valence-Rydberg mixing occurs in the excited states. In accordance with our previous work, we find that multi-reference linearized coupled cluster theory is more accurate than other multi-reference theories of similar cost.

  18. Quasi-degenerate perturbation theory using matrix product states

    Science.gov (United States)

    Sharma, Sandeep; Jeanmairet, Guillaume; Alavi, Ali

    2016-01-01

    In this work, we generalize the recently proposed matrix product state perturbation theory (MPSPT) for calculating energies of excited states using quasi-degenerate (QD) perturbation theory. Our formulation uses the Kirtman-Certain-Hirschfelder canonical Van Vleck perturbation theory, which gives Hermitian effective Hamiltonians at each order, and also allows one to make use of Wigner's 2n + 1 rule. Further, our formulation satisfies Granovsky's requirement of model space invariance which is important for obtaining smooth potential energy curves. Thus, when we use MPSPT with the Dyall Hamiltonian, we obtain a model space invariant version of quasi-degenerate n-electron valence state perturbation theory (NEVPT), a property that the usual formulation of QD-NEVPT2 based on a multipartitioning technique lacked. We use our method on the benchmark problems of bond breaking of LiF which shows ionic to covalent curve crossing and the twist around the double bond of ethylene where significant valence-Rydberg mixing occurs in the excited states. In accordance with our previous work, we find that multi-reference linearized coupled cluster theory is more accurate than other multi-reference theories of similar cost.

  19. Nursing communication in nursing care to mastectomized women: a grounded theory study.

    Science.gov (United States)

    de Almeida Araújo, Iliana Maria; da Silva, Raimunda Magalhães; Bonfim, Isabela Melo; Fernandes, Ana Fátima Carvalho

    2010-01-01

    The goal was to understand the nurse/patient communication process, emphasizing nursing care to mastectomized women. Symbolic Interactionism and Grounded Theory were used to interview eight nurses from a referral institution in cancer treatment, using the guiding question: how do nurses perceive their communication process with mastectomized women? Data analysis allowed for the creation of a central theory: the meaning of communication in nursing care to women, constituted by three distinct but inter-related phenomena: perceiving communication, the relationship nurse/mastectomized woman and rethinking the communication nurse/mastectomized woman. With a view to satisfactory communication, professionals need to get involved and believe that their presence is as important as the performance of technical procedures that relieve situations of stress.

  20. The Factors That Influence Bureaucracy and Professionalism in Schools: A Grounded Theory Study

    Science.gov (United States)

    Koybasi, Fatma; Ugurlu, Celal Teyyar

    2017-01-01

    The aim of this study is to identify the factors that influence the interaction between bureaucracy and professionalism in schools and to develop a model of bureaucracy-professionalism interaction. This is a qualitative study carried out in grounded theory model. The study group consisted of 10 male and 10 female teachers who were working in Sivas…

  1. A model to explain suicide by self-immolation among Iranian women: A grounded theory study.

    Science.gov (United States)

    Khankeh, Hamid Reza; Hosseini, Seyed Ali; Rezaie, Leeba; Shakeri, Jalal; Schwebel, David C

    2015-11-01

    Self-immolation is a common method of suicide among Iranian women. There are several contributing motives for attempting self-immolation, and exploration of the process of self-immolation incidents will help interventionists and clinicians develop prevention programs. A grounded theory study using face-to-face, recorded interviews was conducted with surviving self-immolated patients (n=14), their close relatives (n=5), and medical staff (n=8) in Kermanshah, Iran. Data were analyzed using constant comparison in open, axial, and selective coding stages. A conceptual model was developed to explain the relationships among the main categories extracted through the grounded theory study. Family conflicts emerged as the core category. Cultural context of self-immolated patients offered a contextual condition. Other important categories linked to the core category were mental health problems, distinct characteristics of the suicidal method, and self-immolation as a threat. The role of mental health problems as a causal condition was detected in different levels of the self-immolation process. Finally, adverse consequences of self-immolation emerged as having important impact. The conceptual model, derived through grounded theory study, can guide design of prevention programs. The pivotal role of family conflicts should be emphasized in mental health interventions. The impact of adverse consequences of self-immolation on further suicidal processes necessitates post-suicide prevention programs. Further research to design specific interventions is recommended. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  2. Bimetric Theory of Fractional Quantum Hall States

    Science.gov (United States)

    Gromov, Andrey; Son, Dam Thanh

    2017-10-01

    We present a bimetric low-energy effective theory of fractional quantum Hall (FQH) states that describes the topological properties and a gapped collective excitation, known as the Girvin-Macdonald-Platzman (GMP) mode. The theory consists of a topological Chern-Simons action, coupled to a symmetric rank-2 tensor, and an action à la bimetric gravity, describing the gapped dynamics of a spin-2 mode. The theory is formulated in curved ambient space and is spatially covariant, which allows us to restrict the form of the effective action and the values of phenomenological coefficients. Using bimetric theory, we calculate the projected static structure factor up to the k6 order in the momentum expansion. To provide further support for the theory, we derive the long-wave limit of the GMP algebra, the dispersion relation of the GMP mode, and the Hall viscosity of FQH states. The particle-hole (PH) transformation of the theory takes a very simple form, making the duality between FQH states and their PH conjugates manifest. We also comment on the possible applications to fractional Chern insulators, where closely related structures arise. It is shown that the familiar FQH observables acquire a curious geometric interpretation within the bimetric formalism.

  3. Bimetric Theory of Fractional Quantum Hall States

    Directory of Open Access Journals (Sweden)

    Andrey Gromov

    2017-11-01

    Full Text Available We present a bimetric low-energy effective theory of fractional quantum Hall (FQH states that describes the topological properties and a gapped collective excitation, known as the Girvin-Macdonald-Platzman (GMP mode. The theory consists of a topological Chern-Simons action, coupled to a symmetric rank-2 tensor, and an action à la bimetric gravity, describing the gapped dynamics of a spin-2 mode. The theory is formulated in curved ambient space and is spatially covariant, which allows us to restrict the form of the effective action and the values of phenomenological coefficients. Using bimetric theory, we calculate the projected static structure factor up to the k^{6} order in the momentum expansion. To provide further support for the theory, we derive the long-wave limit of the GMP algebra, the dispersion relation of the GMP mode, and the Hall viscosity of FQH states. The particle-hole (PH transformation of the theory takes a very simple form, making the duality between FQH states and their PH conjugates manifest. We also comment on the possible applications to fractional Chern insulators, where closely related structures arise. It is shown that the familiar FQH observables acquire a curious geometric interpretation within the bimetric formalism.

  4. Guidelines for ground motion definition for the eastern United States

    International Nuclear Information System (INIS)

    Gwaltney, R.C.; Aramayo, G.A.; Williams, R.T.

    1985-06-01

    Guidelines for the determination of earthquake ground motion definition for the eastern United States are established here. Both far-field and near-field guidelines are given. The guidelines were based on an extensive review of the current procedures for specifying ground motion in the United States. Both empirical and theoretical procedures were used in establishing the guidelines because of the low seismicity in the eastern United States. Only a few large- to great-sized earthquakes (M/sub s/ > 7.5) have occurred in this region, no evidence of tectonic surface ruptures related to historic or Holocene earthquakes has been found, and no currently active plate boundaries of any kind are known in this region. Very little instrumented data have been gathered in the East. Theoretical procedures are proposed so that in regions of almost no data, a reasonable level of seismic ground motion activity can be assumed. The guidelines are to be used to develop the safe shutdown earthquake (SSE). A new procedure for establishing the operating basis earthquake (OBE) is proposed, in particular for the eastern United States. The OBE would be developed using a probabilistic assessment of the geological conditions and the recurrence of seismic events at a site. These guidelines should be useful in development of seismic design requirements for future reactors. 17 refs., figs., tabs

  5. Assertiveness process of Iranian nurse leaders: a grounded theory study.

    Science.gov (United States)

    Mahmoudirad, Gholamhossein; Ahmadi, Fazlollah; Vanaki, Zohreh; Hajizadeh, Ebrahim

    2009-06-01

    The purpose of this study was to explore the assertiveness process in Iranian nursing leaders. A qualitative design based on the grounded theory approach was used to collect and analyze the assertiveness experiences of 12 nurse managers working in four hospitals in Iran. Purposeful and theoretical sampling methods were employed for the data collection and selection of the participants, and semistructured interviews were held. During the data analysis, 17 categories emerged and these were categorized into three themes: "task generation", "assertiveness behavior", and "executive agents". From the participants' experiences, assertiveness theory emerged as being fundamental to the development of a schematic model describing nursing leadership behaviors. From another aspect, religious beliefs also played a fundamental role in Iranian nursing leadership assertiveness. It was concluded that bringing a change in the current support from top managers and improving self-learning are required in order to enhance the assertiveness of the nursing leaders in Iran.

  6. Construction and study of exact ground states for a class of quantum antiferromagnets

    International Nuclear Information System (INIS)

    Fannes, M.

    1989-01-01

    Techniques of quantum probability are used to construct the exact ground states for a class of quantum spin systems in one dimension. This class in particular contains the antiferromagnetic models introduced by various authors under the name of VBS-models. The construction permits a detailed study of these ground states. (A.C.A.S.) [pt

  7. Ground state properties of the bond alternating spin-1/2 anisotropic Heisenberg chain

    Directory of Open Access Journals (Sweden)

    S. Paul

    2017-06-01

    Full Text Available Ground state properties, dispersion relations and scaling behaviour of spin gap of a bond alternating spin-1/2 anisotropic Heisenberg chain have been studied where the exchange interactions on alternate bonds are ferromagnetic (FM and antiferromagnetic (AFM in two separate cases. The resulting models separately represent nearest neighbour (NN AFM-AFM and AFM-FM bond alternating chains. Ground state energy has been estimated analytically by using both bond operator and Jordan-Wigner representations and numerically by using exact diagonalization. Dispersion relations, spin gap and several ground state orders have been obtained. Dimer order and string orders are found to coexist in the ground state. Spin gap is found to develop as soon as the non-uniformity in alternating bond strength is introduced in the AFM-AFM chain which further remains non-zero for the AFM-FM chain. This spin gap along with the string orders attribute to the Haldane phase. The Haldane phase is found to exist in most of the anisotropic region similar to the isotropic point.

  8. Density-functional theory for internal magnetic fields

    Science.gov (United States)

    Tellgren, Erik I.

    2018-01-01

    A density-functional theory is developed based on the Maxwell-Schrödinger equation with an internal magnetic field in addition to the external electromagnetic potentials. The basic variables of this theory are the electron density and the total magnetic field, which can equivalently be represented as a physical current density. Hence, the theory can be regarded as a physical current density-functional theory and an alternative to the paramagnetic current density-functional theory due to Vignale and Rasolt. The energy functional has strong enough convexity properties to allow a formulation that generalizes Lieb's convex analysis formulation of standard density-functional theory. Several variational principles as well as a Hohenberg-Kohn-like mapping between potentials and ground-state densities follow from the underlying convex structure. Moreover, the energy functional can be regarded as the result of a standard approximation technique (Moreau-Yosida regularization) applied to the conventional Schrödinger ground-state energy, which imposes limits on the maximum curvature of the energy (with respect to the magnetic field) and enables construction of a (Fréchet) differentiable universal density functional.

  9. Perturbation theory in large order

    International Nuclear Information System (INIS)

    Bender, C.M.

    1978-01-01

    For many quantum mechanical models, the behavior of perturbation theory in large order is strikingly simple. For example, in the quantum anharmonic oscillator, which is defined by -y'' + (x 2 /4 + ex 4 /4 - E) y = 0, y ( +- infinity) = 0, the perturbation coefficients, A/sub n/, in the expansion for the ground-state energy, E(ground state) approx. EPSILON/sub n = 0//sup infinity/ A/sub n/epsilon/sup n/, simplify dramatically as n → infinity: A/sub n/ approx. (6/π 3 )/sup 1/2/(-3)/sup n/GAMMA(n + 1/2). Methods of applied mathematics are used to investigate the nature of perturbation theory in quantum mechanics and show that its large-order behavior is determined by the semiclassical content of the theory. In quantum field theory the perturbation coefficients are computed by summing Feynman graphs. A statistical procedure in a simple lambda phi 4 model for summing the set of all graphs as the number of vertices → infinity is presented. Finally, the connection between the large-order behavior of perturbation theory in quantum electrodynamics and the value of α, the charge on the electron, is discussed. 7 figures

  10. Using Grounded Theory to Understand Resiliency in Pre-Teen Children of High-Conflict Families

    Science.gov (United States)

    Pomrenke, Marlene

    2007-01-01

    Using grounded theory, this study identified factors that contributed to children's ability to utilize their resilient attributes. Children between the ages of 9 and 12 from high-conflict separated or divorced families participated in a study that examined how family and community interactions promote resilient behaviour. Substantive-level theory…

  11. Generating or developing grounded theory: methods to understand health and illness.

    Science.gov (United States)

    Woods, Phillip; Gapp, Rod; King, Michelle A

    2016-06-01

    Grounded theory is a qualitative research methodology that aims to explain social phenomena, e.g. why particular motivations or patterns of behaviour occur, at a conceptual level. Developed in the 1960s by Glaser and Strauss, the methodology has been reinterpreted by Strauss and Corbin in more recent times, resulting in different schools of thought. Differences arise from different philosophical perspectives concerning knowledge (epistemology) and the nature of reality (ontology), demanding that researchers make clear theoretical choices at the commencement of their research when choosing this methodology. Compared to other qualitative methods it has ability to achieve understanding of, rather than simply describing, a social phenomenon. Achieving understanding however, requires theoretical sampling to choose interviewees that can contribute most to the research and understanding of the phenomenon, and constant comparison of interviews to evaluate the same event or process in different settings or situations. Sampling continues until conceptual saturation is reached, i.e. when no new concepts emerge from the data. Data analysis focusses on categorising data (finding the main elements of what is occurring and why), and describing those categories in terms of properties (conceptual characteristics that define the category and give meaning) and dimensions (the variations within properties which produce specificity and range). Ultimately a core category which theoretically explains how all other categories are linked together is developed from the data. While achieving theoretical abstraction in the core category, it should be logical and capture all of the variation within the data. Theory development requires understanding of the methodology not just working through a set of procedures. This article provides a basic overview, set in the literature surrounding grounded theory, for those wanting to increase their understanding and quality of research output.

  12. Magnetic ground state of Ti{sub 1-x}Sc{sub x}Fe{sub 2} system

    Energy Technology Data Exchange (ETDEWEB)

    Saoudi, M.; Deportes, J.; Ouladdiaf, B. E-mail: ouladdiaf@ill.fr

    2001-06-01

    The magnetic ground states of the Laves phases Ti{sub 1-x}Sc{sub x}Fe{sub 2} system have been investigated by means of powder neutron diffraction and magnetisation techniques. For x=0.23, a transition is observed from a collinear ferromagnet along the c-axis to a canted one at T{sub f}=200 K. For x=0.27, 0.3, 0.33, an additional first-order transition is observed at T{sub t1}{approx}120 K accompanied by a large magnetovolume anomaly associated to a jump of the magnetic moment of the Fe atoms at the 2a site. The magnetic moment instability in a frustrated lattice should be considered to interpret this transition, although most of the other magnetic states can be discussed within Moriya's theory for itinerant electron systems with competing ferromagnetic and antiferromagnetic spin fluctuations.

  13. A unified theory of quasibound states

    Directory of Open Access Journals (Sweden)

    Curt A. Moyer

    2014-02-01

    Full Text Available We report a formalism for the study of quasibound states, defined here broadly as those states having a connectedness to true bound states through the variation of some physical parameter. The theory admits quasibound states with real energies (stationary quasibound states and quantum resonances within the same framework, and makes a clean distinction between these states and those of the associated continuum. The approach taken here builds on our earlier work by clarifying several crucial points and extending the formalism to encompass a variety of continuous spectra, including those with degeneracies. The theory is illustrated by examining several cases pertinent to applications widely discussed in the literature. The related issue of observing stationary quasibound states also is addressed. We argue that the Adiabatic Theorem of quantum mechanics not only establishes the criteria necessary for their detection, but also engenders a method for assigning to them a level width that is sufficiently distinct from that of quantum resonances so as to allow the two to be differentiated experimentally.

  14. Numerical simulations of oscillating soliton stars: Excited states in spherical symmetry and ground state evolutions in 3D

    International Nuclear Information System (INIS)

    Balakrishna, Jayashree; Bondarescu, Ruxandra; Daues, Gregory; Bondarescu, Mihai

    2008-01-01

    Excited state soliton stars are studied numerically for the first time. The stability of spherically symmetric S-branch excited state oscillatons under radial perturbations is investigated using a 1D code. We find that these stars are inherently unstable either migrating to the ground state or collapsing to black holes. Higher excited state configurations are observed to cascade through intermediate excited states during their migration to the ground state. This is similar to excited state boson stars [J. Balakrishna, E. Seidel, and W.-M. Suen, Phys. Rev. D 58, 104004 (1998).]. Ground state oscillatons are then studied in full 3D numerical relativity. Finding the appropriate gauge condition for the dynamic oscillatons is much more challenging than in the case of boson stars. Different slicing conditions are explored, and a customized gauge condition that approximates polar slicing in spherical symmetry is implemented. Comparisons with 1D results and convergence tests are performed. The behavior of these stars under small axisymmetric perturbations is studied and gravitational waveforms are extracted. We find that the gravitational waves damp out on a short time scale, enabling us to obtain the complete waveform. This work is a starting point for the evolution of real scalar field systems with arbitrary symmetries

  15. Becoming an Older Volunteer: A Grounded Theory Study

    Science.gov (United States)

    Witucki Brown, Janet; Chen, Shu-li; Mefford, Linda; Brown, Allie; Callen, Bonnie; McArthur, Polly

    2011-01-01

    This Grounded Theory study describes the process by which older persons “become” volunteers. Forty interviews of older persons who volunteered for Habitat for Humanity were subjected to secondary content analysis to uncover the process of “becoming” a volunteer. “Helping out” (core category) for older volunteers occurs within the context of “continuity”, “commitment” and “connection” which provide motivation for volunteering. When a need arises, older volunteers “help out” physically and financially as health and resources permit. Benefits described as “blessings” of volunteering become motivators for future volunteering. Findings suggest that older volunteering is a developmental process and learned behavior which should be fostered in older persons by personally inviting them to volunteer. Intergenerational volunteering projects will allow older persons to pass on knowledge and skills and provide positive role modeling for younger volunteers. PMID:21994824

  16. Becoming an Older Volunteer: A Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Janet Witucki Brown

    2011-01-01

    Full Text Available This Grounded Theory study describes the process by which older persons “become” volunteers. Forty interviews of older persons who volunteered for Habitat for Humanity were subjected to secondary content analysis to uncover the process of “becoming” a volunteer. “Helping out” (core category for older volunteers occurs within the context of “continuity”, “commitment” and “connection” which provide motivation for volunteering. When a need arises, older volunteers “help out” physically and financially as health and resources permit. Benefits described as “blessings” of volunteering become motivators for future volunteering. Findings suggest that older volunteering is a developmental process and learned behavior which should be fostered in older persons by personally inviting them to volunteer. Intergenerational volunteering projects will allow older persons to pass on knowledge and skills and provide positive role modeling for younger volunteers.

  17. Induced quadrupolar singlet ground state of praseodymium in a modulated pyrochlore

    Science.gov (United States)

    van Duijn, J.; Kim, K. H.; Hur, N.; Ruiz-Bustos, R.; Adroja, D. T.; Bridges, F.; Daoud-Aladine, A.; Fernandez-Alonso, F.; Wen, J. J.; Kearney, V.; Huang, Q. Z.; Cheong, S.-W.; Perring, T. G.; Broholm, C.

    2017-09-01

    The complex structure and magnetism of Pr2 -xBixRu2O7 was investigated by neutron scattering and extended x-ray absorption fine structure. Pr has an approximate doublet ground state and the first excited state is a singlet. While the B -site (Ru) is well ordered throughout, this is not the case for the A -site (Pr/Bi). A broadened distribution for the Pr-O2 bond length at low temperature indicates the Pr environment varies from site to site even for x =0 . The environment about the Bi site is highly disordered ostensibly due to the 6 s lone pairs on Bi3 +. Correspondingly, we find that the non-Kramers doublet ground-state degeneracy, otherwise anticipated for Pr in the pyrochlore structure, is lifted so as to produce a quadrupolar singlet ground state with a spatially varying energy gap. For x =0 , below TN, the Ru sublattice orders antiferromagnetically, with propagation vector k =(0 ,0 ,0 ) as for Y2Ru2O7 . No ordering associated with the Pr sublattice is observed down to 100 mK. The low-energy magnetic response of Pr2 -xBixRu2O7 features a broad spectrum of magnetic excitations associated with inhomogeneous splitting of the Pr quasidoublet ground state. For x =0 (x =0.97 ), the spectrum is temperature dependent (independent). It appears disorder associated with Bi alloying enhances the inhomogeneous Pr crystal-field level splitting so that intersite interactions become irrelevant for x =0.97 . The structural complexity for the A -site may be reflected in the hysteretic uniform magnetization of B -site ruthenium in the Néel phase.

  18. Exact ground-state phase diagrams for the spin-3/2 Blume-Emery-Griffiths model

    Energy Technology Data Exchange (ETDEWEB)

    Canko, Osman; Keskin, Mustafa [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Deviren, Bayram [Institute of Science, Erciyes University, 38039 Kayseri (Turkey)], E-mail: keskin@erciyes.edu.tr

    2008-05-15

    We have calculated the exact ground-state phase diagrams of the spin-3/2 Ising model using the method that was proposed and applied to the spin-1 Ising model by Dublenych (2005 Phys. Rev. B 71 012411). The calculated, exact ground-state phase diagrams on the diatomic and triangular lattices with the nearest-neighbor (NN) interaction have been presented in this paper. We have obtained seven and 15 topologically different ground-state phase diagrams for J>0 and J<0, respectively, on the diatomic lattice and have found the conditions for the existence of uniform and intermediate or non-uniform phases. We have also constructed the exact ground-state phase diagrams of the model on the triangular lattice and found 20 and 59 fundamental phase diagrams for J>0 and J<0, respectively, the conditions for the existence of uniform and intermediate phases have also been found.

  19. This too shall pass: a grounded theory study of Filipino cancer survivorship.

    Science.gov (United States)

    de Guzman, Allan B; Jimenez, Benito Christian B; Jocson, Kathlyn P; Junio, Aileen R; Junio, Drazen E; Jurado, Jasper Benjamin N; Justiniano, Angela Bianca F

    2013-03-01

    Considering the paucity of studies dealing with the holistic aspect of the cancer experience, this grounded theory study seeks to conceptualize the process of cancer survivorship among Filipinos. Twenty-seven Filipino cancer survivors were purposively selected, and a two-part instrument, specifically robotfoto and focus group interviews, was used to gather data. The Glaserian method of grounded theory analysis was used, and extended texts were analyzed inductively via a dendrogram. Member checking and correspondence were observed to validate the surfacing stages, leading to the conceptualization of a theoretical model termed as the Ribbon of Cancer Survivorship. The said model describes the trifling (living before), transfusing (accepting the reality), transforming (being strong), and transcending (living beyond) phases of cancer survivorship. Ten interesting substages were also identified, namely: tainting, desolating, disrupting, and embracing for the transfusing phase; tormenting, distressing, awakening, and transfiguring for the transforming phase, and trembling and enlivening for the transcending phase. The resulting theoretical model has clearly and successfully described the entire process of cancer survivorship among Filipinos. It is hoped that the model be used as a reference for future studies about cancer survivorship and as a guide for nurses in providing a more empathetic care among cancer patients.

  20. Balancing power: A grounded theory study on partnership of academic service institutes.

    Science.gov (United States)

    Heshmati Nabavi, Fatemeh; Vanaki, Zohreh; Mohammadi, Eesa; Yazdani, Shahram

    2017-07-01

    Governments and professional organizations have called for new partnerships between health care providers and academics to improve clinical education for the benefit of both students and patients. To develop a substantive grounded theory on the process of forming academic-service partnerships in implementing clinical education, from the perspective of academic and clinical nursing staff members and managers working in Iranian settings. The participants included 15 hospital nurses, nurse managers, nurse educators, and educational managers from two central universities and clinical settings from 2009 to 2012. Data were collected through 30 in-depth, semi-structure interviews with the individual participants and then analyzed using the methodology of Strauss and Corbin's grounded theory. Utilizing "balancing power" as the core variable enabled us to integrate the concepts concerning the partnership processes between clinical and educational institutes. Three distinct and significant categories emerged to explain the process of partnership: 1) divergence, 2) conflict between educational and caring functions, and 3) creation of balance between educational and caring functions. In implementing clinical education, partnerships have been formed within a challenging context in Iran. Conflict between clinical and educational functions was the main concern of both sides of the partnership in forming a collaborative relationship, with our findings emphasizing the importance of nursing educators' role in the establishment of partnership programs.

  1. Evaluating the Performance of DFT Functionals in Assessing the Interaction Energy and Ground-State Charge Transfer of Donor/Acceptor Complexes: Tetrathiafulvalene−Tetracyanoquinodimethane (TTF−TCNQ) as a Model Case

    KAUST Repository

    Sini, Gjergji

    2011-03-08

    We have evaluated the performance of several density functional theory (DFT) functionals for the description of the ground-state electronic structure and charge transfer in donor/acceptor complexes. The tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) complex has been considered as a model test case. Hybrid functionals have been chosen together with recently proposed long-range corrected functionals (ωB97X, ωB97X-D, LRC-ωPBEh, and LC-ωPBE) in order to assess the sensitivity of the results to the treatment and magnitude of exact exchange. The results show an approximately linear dependence of the ground-state charge transfer with the HOMO TTF-LUMOTCNQ energy gap, which in turn depends linearly on the percentage of exact exchange in the functional. The reliability of ground-state charge transfer values calculated in the framework of a monodeterminantal DFT approach was also examined. © 2011 American Chemical Society.

  2. Evaluating the Performance of DFT Functionals in Assessing the Interaction Energy and Ground-State Charge Transfer of Donor/Acceptor Complexes: Tetrathiafulvalene−Tetracyanoquinodimethane (TTF−TCNQ) as a Model Case

    KAUST Repository

    Sini, Gjergji; Sears, John S.; Brédas, Jean-Luc

    2011-01-01

    We have evaluated the performance of several density functional theory (DFT) functionals for the description of the ground-state electronic structure and charge transfer in donor/acceptor complexes. The tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) complex has been considered as a model test case. Hybrid functionals have been chosen together with recently proposed long-range corrected functionals (ωB97X, ωB97X-D, LRC-ωPBEh, and LC-ωPBE) in order to assess the sensitivity of the results to the treatment and magnitude of exact exchange. The results show an approximately linear dependence of the ground-state charge transfer with the HOMO TTF-LUMOTCNQ energy gap, which in turn depends linearly on the percentage of exact exchange in the functional. The reliability of ground-state charge transfer values calculated in the framework of a monodeterminantal DFT approach was also examined. © 2011 American Chemical Society.

  3. Mid-infrared picosecond pump-dump-probe and pump-repump-probe experiments to resolve a ground-state intermediate in cyanobacterial phytochrome Cph1.

    Science.gov (United States)

    van Wilderen, Luuk J G W; Clark, Ian P; Towrie, Michael; van Thor, Jasper J

    2009-12-24

    Multipulse picosecond mid-infrared spectroscopy has been used to study photochemical reactions of the cyanobacterial phytochrome photoreceptor Cph1. Different photophysical schemes have been discussed in the literature to describe the pathways after photoexcitation, particularly, to identify reaction phases that are linked to photoisomerisation and electronic decay in the 1566-1772 cm(-1) region that probes C=C and C=O stretching modes of the tetrapyrrole chromophore. Here, multipulse spectroscopy is employed, where, compared to conventional visible pump-mid-infrared probe spectroscopy, an additional visible pulse is incorporated that interacts with populations that are evolving on the excited- and ground-state potential energy surfaces. The time delays between the pump and the dump pulse are chosen such that the dump pulse interacts with different phases in the reaction process. The pump and dump pulses are at the same wavelength, 640 nm, and are resonant with the Pr ground state as well as with the excited state and intermediates. Because the dump pulse additionally pumps the remaining, partially recovered, and partially oriented ground-state population, theory is developed for estimating the fraction of excited-state molecules. The calculations take into account the model-dependent ground-state recovery fraction, the angular dependence of the population transfer resulting from the finite bleach that occurs with linearly polarized intense femtosecond optical excitation, and the partially oriented population for the dump field. Distinct differences between the results from the experiments that use a 1 or a 14 ps dump time favor a branching evolution from S1 to an excited state or reconfigured chromophore and to a newly identified ground-state intermediate (GSI). Optical dumping at 1 ps shows the instantaneous induced absorption of a delocalized C=C stretching mode at 1608 cm(-1), where the increased cross section is associated with the electronic ground-state

  4. Ground-state correlations within a nonperturbative approach

    Czech Academy of Sciences Publication Activity Database

    De Gregorio, G.; Herko, J.; Knapp, F.; Lo Iudice, N.; Veselý, Petr

    2017-01-01

    Roč. 95, č. 2 (2017), č. článku 024306. ISSN 2469-9985 R&D Projects: GA ČR GA13-07117S Institutional support: RVO:61389005 Keywords : ground state * harmonic oscillator frequency * space dimensions Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 3.820, year: 2016

  5. Regular perturbation theory for two-electron atoms

    International Nuclear Information System (INIS)

    Feranchuk, I.D.; Triguk, V.V.

    2011-01-01

    Regular perturbation theory (RPT) for the ground and excited states of two-electron atoms or ions is developed. It is shown for the first time that summation of the matrix elements from the electron-electron interaction operator over all intermediate states can be calculated in a closed form by means of the two-particle Coulomb Green's function constructed in the Letter. It is shown that the second order approximation of RPT includes the main part of the correlation energy both for the ground and excited states. This approach can be also useful for description of two-electron atoms in external fields. -- Highlights: → We develop regular perturbation theory for the two-electron atoms or ions. → We calculate the sum of the matrix elements over all intermediate states. → We construct the two-particle Coulomb Green's function.

  6. Exact ground-state phase diagrams for the spin-3/2 Blume-Emery-Griffiths model

    International Nuclear Information System (INIS)

    Canko, Osman; Keskin, Mustafa; Deviren, Bayram

    2008-01-01

    We have calculated the exact ground-state phase diagrams of the spin-3/2 Ising model using the method that was proposed and applied to the spin-1 Ising model by Dublenych (2005 Phys. Rev. B 71 012411). The calculated, exact ground-state phase diagrams on the diatomic and triangular lattices with the nearest-neighbor (NN) interaction have been presented in this paper. We have obtained seven and 15 topologically different ground-state phase diagrams for J>0 and J 0 and J<0, respectively, the conditions for the existence of uniform and intermediate phases have also been found

  7. Recognizing and responding to uncertainty: a grounded theory of nurses' uncertainty.

    Science.gov (United States)

    Cranley, Lisa A; Doran, Diane M; Tourangeau, Ann E; Kushniruk, Andre; Nagle, Lynn

    2012-08-01

    There has been little research to date exploring nurses' uncertainty in their practice. Understanding nurses' uncertainty is important because it has potential implications for how care is delivered. The purpose of this study is to develop a substantive theory to explain how staff nurses experience and respond to uncertainty in their practice. Between 2006 and 2008, a grounded theory study was conducted that included in-depth semi-structured interviews. Fourteen staff nurses working in adult medical-surgical intensive care units at two teaching hospitals in Ontario, Canada, participated in the study. The theory recognizing and responding to uncertainty characterizes the processes through which nurses' uncertainty manifested and how it was managed. Recognizing uncertainty involved the processes of assessing, reflecting, questioning, and/or being unable to predict aspects of the patient situation. Nurses' responses to uncertainty highlighted the cognitive-affective strategies used to manage uncertainty. Study findings highlight the importance of acknowledging uncertainty and having collegial support to manage uncertainty. The theory adds to our understanding the processes involved in recognizing uncertainty, strategies and outcomes of managing uncertainty, and influencing factors. Tailored nursing education programs should be developed to assist nurses in developing skills in articulating and managing their uncertainty. Further research is needed to extend, test and refine the theory of recognizing and responding to uncertainty to develop strategies for managing uncertainty. This theory advances the nursing perspective of uncertainty in clinical practice. The theory is relevant to nurses who are faced with uncertainty and complex clinical decisions, to managers who support nurses in their clinical decision-making, and to researchers who investigate ways to improve decision-making and care delivery. ©2012 Sigma Theta Tau International.

  8. The spectra of supersymmetric states in string theory

    NARCIS (Netherlands)

    Cheng, M.C.N.

    2008-01-01

    In this thesis we study the spectra of supersymmetric states in string theory compactifications with eight and sixteen supercharges, with special focus placed on the quantum states of black holes and the phenomenon of wall-crossing in these theories. A self-contained introduction to the relevant

  9. Communication: Orbital instabilities and triplet states from time-dependent density functional theory and long-range corrected functionals

    Science.gov (United States)

    Sears, John S.; Koerzdoerfer, Thomas; Zhang, Cai-Rong; Brédas, Jean-Luc

    2011-10-01

    Long-range corrected hybrids represent an increasingly popular class of functionals for density functional theory (DFT) that have proven to be very successful for a wide range of chemical applications. In this Communication, we examine the performance of these functionals for time-dependent (TD)DFT descriptions of triplet excited states. Our results reveal that the triplet energies are particularly sensitive to the range-separation parameter; this sensitivity can be traced back to triplet instabilities in the ground state coming from the large effective amounts of Hartree-Fock exchange included in these functionals. As such, the use of standard long-range corrected functionals for the description of triplet states at the TDDFT level is not recommended.

  10. A projection gradient method for computing ground state of spin-2 Bose–Einstein condensates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hanquan, E-mail: hanquan.wang@gmail.com [School of Statistics and Mathematics, Yunnan University of Finance and Economics, Kunming, Yunnan Province, 650221 (China); Yunnan Tongchang Scientific Computing and Data Mining Research Center, Kunming, Yunnan Province, 650221 (China)

    2014-10-01

    In this paper, a projection gradient method is presented for computing ground state of spin-2 Bose–Einstein condensates (BEC). We first propose the general projection gradient method for solving energy functional minimization problem under multiple constraints, in which the energy functional takes real functions as independent variables. We next extend the method to solve a similar problem, where the energy functional now takes complex functions as independent variables. We finally employ the method into finding the ground state of spin-2 BEC. The key of our method is: by constructing continuous gradient flows (CGFs), the ground state of spin-2 BEC can be computed as the steady state solution of such CGFs. We discretized the CGFs by a conservative finite difference method along with a proper way to deal with the nonlinear terms. We show that the numerical discretization is normalization and magnetization conservative and energy diminishing. Numerical results of the ground state and their energy of spin-2 BEC are reported to demonstrate the effectiveness of the numerical method.

  11. A projection gradient method for computing ground state of spin-2 Bose–Einstein condensates

    International Nuclear Information System (INIS)

    Wang, Hanquan

    2014-01-01

    In this paper, a projection gradient method is presented for computing ground state of spin-2 Bose–Einstein condensates (BEC). We first propose the general projection gradient method for solving energy functional minimization problem under multiple constraints, in which the energy functional takes real functions as independent variables. We next extend the method to solve a similar problem, where the energy functional now takes complex functions as independent variables. We finally employ the method into finding the ground state of spin-2 BEC. The key of our method is: by constructing continuous gradient flows (CGFs), the ground state of spin-2 BEC can be computed as the steady state solution of such CGFs. We discretized the CGFs by a conservative finite difference method along with a proper way to deal with the nonlinear terms. We show that the numerical discretization is normalization and magnetization conservative and energy diminishing. Numerical results of the ground state and their energy of spin-2 BEC are reported to demonstrate the effectiveness of the numerical method

  12. Normal ground state of dense relativistic matter in a magnetic field

    International Nuclear Information System (INIS)

    Gorbar, E. V.; Miransky, V. A.; Shovkovy, I. A.

    2011-01-01

    The properties of the ground state of relativistic matter in a magnetic field are examined within the framework of a Nambu-Jona-Lasinio model. The main emphasis of this study is the normal ground state, which is realized at sufficiently high temperatures and/or sufficiently large chemical potentials. In contrast to the vacuum state, which is characterized by the magnetic catalysis of chiral symmetry breaking, the normal state is accompanied by the dynamical generation of the chiral shift parameter Δ. In the chiral limit, the value of Δ determines a relative shift of the longitudinal momenta (along the direction of the magnetic field) in the dispersion relations of opposite chirality fermions. We argue that the chirality remains a good approximate quantum number even for massive fermions in the vicinity of the Fermi surface and, therefore, the chiral shift is expected to play an important role in many types of cold dense relativistic matter, relevant for applications in compact stars. The qualitative implications of the revealed structure of the normal ground state on the physics of protoneutron stars are discussed. A noticeable feature of the Δ parameter is that it is insensitive to temperature when T 0 , where μ 0 is the chemical potential, and increases with temperature for T>μ 0 . The latter implies that the chiral shift parameter is also generated in the regime relevant for heavy ion collisions.

  13. Psychotherapists' spiritual, religious, atheist or agnostic identity and their practice of psychotherapy: a grounded theory study.

    Science.gov (United States)

    Magaldi-Dopman, Danielle; Park-Taylor, Jennie; Ponterotto, Joseph G

    2011-05-01

    In this present grounded theory study, 16 experienced psychologists, who practiced from varied theoretical orientations and came from diverse religious/spiritual/nonreligious backgrounds, explored their personal religious/spiritual/nonreligious identity development journeys, their experiences with clients' religious/spiritual content in psychotherapy sessions, and how their identity may have influenced the way they interacted with religious/spiritual material during sessions. Results revealed that psychologists' spiritual/religious/nonreligious identity is conflicted and complex and that their academic and clinical training did not provide sufficient opportunity to examine how this may affect their therapeutic work. A tentative grounded theory emerged suggesting that psychologists both identified with and were activated by clients' spiritual/religious conflicts and their internal experiences about the spiritual/religious content, both of which presented significant challenges to therapeutic work.

  14. Pade approximants for the ground-state energy of closed-shell quantum dots

    International Nuclear Information System (INIS)

    Gonzalez, A.; Partoens, B.; Peeters, F.M.

    1997-08-01

    Analytic approximations to the ground-state energy of closed-shell quantum dots (number of electrons from 2 to 210) are presented in the form of two-point Pade approximants. These Pade approximants are constructed from the small- and large-density limits of the energy. We estimated that the maximum error, reached for intermediate densities, is less than ≤ 3%. Within that present approximation the ground-state is found to be unpolarized. (author). 21 refs, 3 figs, 2 tabs

  15. Exact ground-state correlation functions of an atomic-molecular Bose–Einstein condensate model

    Science.gov (United States)

    Links, Jon; Shen, Yibing

    2018-05-01

    We study the ground-state properties of an atomic-molecular Bose–Einstein condensate model through an exact Bethe Ansatz solution. For a certain range of parameter choices, we prove that the ground-state Bethe roots lie on the positive real-axis. We then use a continuum limit approach to obtain a singular integral equation characterising the distribution of these Bethe roots. Solving this equation leads to an analytic expression for the ground-state energy. The form of the expression is consistent with the existence of a line of quantum phase transitions, which has been identified in earlier studies. This line demarcates a molecular phase from a mixed phase. Certain correlation functions, which characterise these phases, are then obtained through the Hellmann–Feynman theorem.

  16. A taxonomy of dignity: a grounded theory study

    Directory of Open Access Journals (Sweden)

    Jacobson Nora

    2009-02-01

    Full Text Available Abstract Background This paper has its origins in Jonathan Mann's insight that the experience of dignity may explain the reciprocal relationships between health and human rights. It follows his call for a taxonomy of dignity: "a coherent vocabulary and framework to characterize dignity." Methods Grounded theory procedures were use to analyze literature pertaining to dignity and to conduct and analyze 64 semi-structured interviews with persons marginalized by their health or social status, individuals who provide health or social services to these populations, and people working in the field of health and human rights. Results The taxonomy presented identifies two main forms of dignity–human dignity and social dignity–and describes several elements of these forms, including the social processes that violate or promote them, the conditions under which such violations and promotions occur, the objects of violation and promotion, and the consequences of dignity violation. Together, these forms and elements point to a theory of dignity as a quality of individuals and collectives that is constituted through interaction and interpretation and structured by conditions pertaining to actors, relationships, settings, and the broader social order. Conclusion The taxonomy has several implications for work in health and human rights. It suggests a map to possible points of intervention and provides a language in which to talk about dignity.

  17. A Quantum Version of Wigner's Transition State Theory

    NARCIS (Netherlands)

    Schubert, R.; Waalkens, H.; Wiggins, S.

    A quantum version of a recent realization of Wigner's transition state theory in phase space is presented. The theory developed builds on a quantum normal form which locally decouples the quantum dynamics near the transition state to any desired order in (h) over bar. This leads to an explicit

  18. Sifting for Success: A Grounded Theory Approach to Sponsorship of Black Student Academic Success

    Science.gov (United States)

    Powell, Shameka N.

    2015-01-01

    Numerous findings and theories have been used to make sense of African Americans students' educational successes and experiences. Along those lines, the purpose of this study is to generate a theoretical framework of sponsorship that is grounded in Black students' educational experiences. Sponsorship is taken to be the process through which agents…

  19. Reading Comprehension Profiles of High-Functioning Students on the Autism Spectrum: A Grounded Theory

    Science.gov (United States)

    Williamson, Pamela; Carnahan, Christina R.; Jacobs, Jennifer A.

    2012-01-01

    Using a constructivist grounded theory approach, this study sought to understand what influences reading comprehension and how meaning is made from text among high-functioning individuals with autism spectrum disorder (ASD). Using a think-aloud procedure, 13 individuals ages 7-13 with ASD read 16 passages at their instructional reading level.…

  20. Ground state structure of U2Mo: static and lattice dynamics study

    International Nuclear Information System (INIS)

    Mukherjee, D.; Sahoo, B.D.; Joshi, K.D.; Kaushik, T.C.

    2016-01-01

    According to experimental reports, the ground state stable structure of U 2 Mo is tetragonal. However, various theoretical studies performed in past do not get tetragonal phase as the stable structure at ambient conditions. Therefore, the ground state structure of U 2 Mo is still unresolved. In an attempt to understand the ground state properties of this system, we have carried out first principle electronic band structure calculations. The structural stability analysis carried out using evolutionary structure search algorithm in conjunction with ab-inito method shows that a hexagonal structure (space group P6/mmm) is the lowest enthalpy structure at ambient condition and remains stable upto 200 GPa. The elastic and lattice dynamical stability further supports the stability of this phase at ambient condition. Further, using the 0 K calculations in conjunction with finite temperature corrections, we have derived the isotherm and shock adiabat (Hugoniot) of this material. Various equilibrium properties such as ambient pressure volume, bulk modulus, pressure derivative of bulk modulus etc. are derived from equation of state. (author)