2,922 research outputs found

    Criticality and superfluidity in liquid ^4He under nonequilibrium conditions

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    We review a striking array of recent experiments and their theoretical interpretations on the superfluid transition in ^4He in the presence of a heat flux Q. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If Q is in the same direction as gravity, a self-organized state can arise, in which the entire sample has a uniform reduced temperature, on either the normal or superfluid side of the transition. Finally, we review recent theory and experiment regarding the heat capacity at constant Q. The excitement that surrounds this field arises from the fact that advanced thermometry and the future availability of a microgravity experimental platform aboard the International Space Station will soon open to experimental exploration decades of reduced temperature that were previously inaccessible

    The me in memory:the role of the self in autobiographical memory development

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    This paper tests the hypothesis that self development plays a role in the offset of childhood amnesia; assessing the importance of both the capacity to anchor a memory to the self-concept, and the strength of the self-concept as an anchor. We demonstrate for the first time that the volume of 3- to 6-year-old’s specific autobiographical memories is predicted by both the volume of their self-knowledge, and their capacity for self-source monitoring within self-referencing paradigms (N =186). Moreover, there is a bidirectional relationship between self and memory, such that autobiographical memory mediates the link between self-source monitoring and self-knowledge. These predictive relationships suggests that the self memory system is active in early childhood

    Solute transport in a heterogeneous aquifer: a search for nonlinear deterministic dynamics

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    International audienceThe potential use of a nonlinear deterministic framework for understanding the dynamic nature of solute transport processes in subsurface formations is investigated. Time series of solute particle transport in a heterogeneous aquifer medium, simulated using an integrated probability/Markov chain (TP/MC) model, groundwater flow model, and particle transport model, are studied. The correlation dimension method, a popular nonlinear time series analysis technique, is used to identify nonlinear determinism. Sensitivity of the solute transport dynamics to the four hydrostratigraphic parameters involved in the TP/MC model: (1) number of facies; (2) volume proportions of facies; (3) mean lengths (and thereby anisotropy ratio of mean length) of facies; and (4) juxtapositional tendencies (i.e. degree of entropy) among the facies is also studied. The western San Joaquin Valley aquifer system in California is considered as a reference system. The results indicate, in general, the nonlinear deterministic nature of solute transport dynamics (dominantly governed by only a very few variables, on the order of 3), even though more complex behavior is possible under certain (extreme) hydrostratigraphic conditions. The sensitivity analysis reveals: (1) the importance of the hydrostratigraphic parameters (in particular, volume proportions of facies and mean lengths) in representing aquifer heterogeneity; and (2) the ability of the correlation dimension method in capturing the (extent of) complexity of the underlying dynamics. Verification and confirmation of the present results through use of other nonlinear deterministic techniques and assessment of their reliability for a wide range of solute transport scenarios are recommended

    Antiferromagnetic correlations and impurity broadening of NMR linewidths in cuprate superconductors

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    We study a model of a d-wave superconductor with strong potential scatterers in the presence of antiferromagnetic correlations and apply it to experimental nuclear magnetic resonance (NMR) results on Zn impurities in the superconducting state of YBCO. We then focus on the contribution of impurity-induced paramagnetic moments, with Hubbard correlations in the host system accounted for in Hartree approximation. We show that local magnetism around individual impurities broadens the line, but quasiparticle interference between impurity states plays an important role in smearing out impurity satellite peaks. The model, together with estimates of vortex lattice effects, provides a semi-quantitative description of the impurity concentration dependence of the NMR line shape in the superconducting state, and gives a qualitative description of the temperature dependence of the line asymmetry. We argue that impurity-induced paramagnetism and resonant local density of states effects are both necessary to explain existing experiments.Comment: 15 pages, 23 figures, submitted to Phys. Rev.

    ‘My favourite things to do’ and ‘my favourite people’: Exploring salient aspects of children’s self-concept

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    This study explores the potential of the ‘draw-and-write’ method for inviting children to communicate salient aspects of their self-concept. Irish primary school children aged 10–13 years drew and wrote about their favourite people and things to do (social and active self). Children drew and described many salient activities (39 in total) and people – including pets. Results suggest that widely used, adult-constructed self-esteem scales for children, while multidimensional, are limited, and that ‘draw-and-write’ is an effective multimodal method with which children can express their social and active self-concepts

    The Ursinus Weekly, November 20, 1944

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    Campus heads plan full calendar for student activities • \u27Players\u27 are chosen by Curtain Club \u27stars\u27 under revised system • Three more students receive recognition in Who\u27s Who • Len Mayfair is scheduled for senior ball with Miles of Melody orchestra, Dec. 8 • Sororities accept 18 pledges Friday • Brass quartet plays at Thanksgiving service • Fleet men interviewed represent land, sea, air phases of U.S. Navy • WSSF send relief to allied students • No nails, no tape -- rooms are decorated • Prospective debaters to meet with Betsy Shumaker tonight • WAA plans hockey play day to precede traditional banquet • Six new practice teachers start at Norristown, C-T High Schools • Navy forecast: cloudy this week • German soldier • Snell\u27s Belles triumph over Drexel 7-0 for second win of hockey season • Three Ursinus girls win recognition at all-college hockey tryouts Saturday • Ursinus JV\u27s play in shades of evening to down Drexel, 3-0 • Hungry civilians see fowl Thanksgiving • Students may see ballet at half pricehttps://digitalcommons.ursinus.edu/weekly/1690/thumbnail.jp

    Who I Am: The Meaning of Early Adolescents’ Most Valued Activities and Relationships, and Implications for Self-Concept Research

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    Self-concept research in early adolescence typically measures young people’s self-perceptions of competence in specific, adult-defined domains. However, studies have rarely explored young people’s own views of valued self-concept factors and their meanings. For two major self domains, the active and the social self, this mixed-methods study identified factors valued most by 526 young people from socioeconomically diverse backgrounds in Ireland (10-12 years), and explored the meanings associated with these in a stratified subsample (n = 99). Findings indicate that self-concept scales for early adolescence omit active and social self factors and meanings valued by young people, raising questions about content validity of scales in these domains. Findings also suggest scales may under-represent girls’ active and social selves; focus too much on some school-based competencies; and, in omitting intrinsically salient self domains and meanings, may focus more on contingent (extrinsic) rather than true (intrinsic) self-esteem

    The Ursinus Weekly, June 26, 1944

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    Fifty-eight sailors get transfer orders to premidshipman school and colleges • Graduates hear Dr. George W. McClelland; Schonfeld, Snyder take top scholastic honors • Two new prizes given at graduation today • Alumni re-elect Johnson as head • Baccalaureate sermon explains war words • Directors announce loyalty fund boost • Phys-edders choose Peg Hudson to lead activities next year • Marion is awarded first prize in nation-wide church contest • Miss Eleanor Norris married to Clark Moore in Ambler church • Betty Bradway receives award as outstanding junior athlete • Alumni of Cub and Key meet • Rosicrucians add 21 to club membership • Girls undefeated in hockey and softball in all-round successful \u2743-\u2744 season • Ball team wins nine to close good season • Teddy leaves record as faithful phys-edder • Dr. McClure speaks at Baldwin • Salute to the phys-edders: bless \u27em • Will and testament • Thru the crystal ball • Majority of graduates accept positions in field of teachinghttps://digitalcommons.ursinus.edu/weekly/1738/thumbnail.jp

    Implications of non-feasible transformations among icosahedral hh orbitals

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    The symmetric group S6S_6 that permutes the six five-fold axes of an icosahedron is introduced to go beyond the simple rotations that constitute the icosahedral group II. Owing to the correspondence h↔dh\leftrightarrow d, the calculation of the Coulomb energies for the icosahedral configurations hNh^N based on the sequence O(5)⊃S6⊃S5⊃IO(5) \supset S_6 \supset S_5 \supset I can be brought to bear on Racah's classic theory for the atomic d shell based on SO(5)⊃SOL(3)⊃ISO(5) \supset SO_L(3) \supset I. Among the elements of S6S_6 is the kaleidoscope operator K{\cal K} that rotates the weight space of SO(5) by π/2\pi/2. Its use explains some puzzling degeneracies in d^3 involving the spectroscopic terms ^2P, ^2F, ^2G and ^2H.Comment: Tentatively scheduled to appear in Physical Preview Letters Apr 5, 99. Revtex, 1 ps figur
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