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Hempel's Dilemma is a challenge that has to be met by any formulation of physicalism that specifies the physical by reference to a particular physical theory. It poses the problem that if one's specification of the physical is ‘current’ physical theory, then the physicalism which depends on it is false because current physics is false; and if the specification of the physical is a future or an ideal physics, the physicalism based on it would be trivial as it would be tautologously true, or because very little (if anything at all) can be inferred from or about a physics that does not yet exist. I review the reasons for thinking that the dilemma is a perpetual problem for currentist specifications of the physical, then introduce the argument that the standard positions on the specification question are wanting because they lack a generality which physicalism is generally accepted to have. I end with a suggestion for a way forward for physicalism. [ABSTRACT FROM PUBLISHER]

This investigation-based lesson is geared toward third through fifth grade students. The lesson presented in this article was the first of three lessons designed and taught by us for our first preservice teaching course. UTeach is a teacher preparation program for undergraduate STEM majors, which originated at the University of Austin, Texas. The first course taken by UTeach interns is STEP 1—Inquiry Approaches to Teaching. All UTeach courses promote the use of the 5E (Engage, Explore, Explain, Elaborate, and Evaluate) instructional model. We planned this first lesson by incorporating only Exploration, Explanation, and Elaboration and addressed the most basic principle of sound, which is that sounds are caused by vibrations that travel through some materials (mediums) better than others. [ABSTRACT FROM PUBLISHER]

The article investigates the potential and challenges of integrating geography with other school subjects. The analysis is based on the outcomes of a course that introduced the principles of discipline-based integration. The course was included in multicultural-class teacher education programme at the University of Helsinki. For a project within the course, the students worked in small groups and made short films that integrated three subjects – geography, physics, and visual arts – in order to evoke questions of space in children's minds. The students were asked to write essays in which they analysed their understanding of space from the three subjects’ viewpoints, describe the aims and contents of their short films, and lastly reflect on their experiences of the potential and possible problems in discipline integration. In this article, the authors analyse the students’ experience of the integration between the geography, physics, and visual arts. In general, the students experienced discipline-based integration as an interesting way of working. Moreover, the project seemed to deepen their understanding of different grounds for integrative pedagogy. Although the students reported some difficulties regarding the subject knowledge required for fruitful integration, the process enabled them to construct a better understanding of the identity of each discipline. [ABSTRACT FROM PUBLISHER]

We present a time-dependent method for determining several approximate excited-state energies and wave functions using a vectorial approach to multidimensional supersymmetric quantum mechanics. First, a vectorial approach is used to generate the tensor sector two Hamiltonian, which is isospectral with the original scalar sector one Hamiltonian above the ground state of the sector one Hamiltonian. We construct a time-dependent Hamiltonian interpolating between the scalar sector one Hamiltonian and the tensor sector two Hamiltonian. Then, we can adiabatically switch from the ground state of the sector one Hamiltonian to the ground state of the sector two Hamiltonian by solving the time-dependent Schrödinger equation. In addition, by employing an initial wave packet orthogonal to that leading to the ground state of sector two, we also obtain the first-excited state of sector two. Construction of the orthogonal sector one states is trivial due to the tensor nature of sector two. The ground and first-excited states of the sector two Hamiltonian can be used with the charge operator to obtain the first two excited state wave functions of the sector one Hamiltonian. Excellent computational results are obtained for two-dimensional nonseparable degenerate and nondegenerate systems. [ABSTRACT FROM AUTHOR]

This paper assesses the utility of momentum space in the density-based quantification of the steric effect proposed by Liu [J. Chem. Phys. 126, 244103 (2007)], which is based on a new energy partition scheme where the total electronic energy is decomposed into contributions from three independent effects: steric, electrostatic, and the fermionic quantum. The steric energy defined in this way is repulsive, exclusive, and extensive and intrinsically linked to Bader's quantum theory of atoms in molecules. In this work, the plausibility of defining and computing steric energies using momentum densities according to this scheme is confirmed from numerical tests. Moreover, we found that the correlation between the experimental scales of the steric energies and theoretical values computed from momentum densities is even better than the same correlation with theoretical estimations obtained from position densities. [ABSTRACT FROM AUTHOR]

In this paper, a compact and sharp-rejection low-pass filter is proposed and analyzed. By combining a stepped-impedance shunt open stub and two additional shunt open stubs, a compact low-pass filter with wide upper stopband and very high passband selectivity is realized. Wide stopband and sharp rejection characteristics are achieved by realizing three transmission zeros near the passband edges. This filter demonstrated very good measured characteristics at cut-off frequency (ƒc) of 2.49 GHz, including a low insertion loss of 0.21 ± 0.05 dB, a wide stopband from 2.8 to 7 GHz and an attenuation slope of 49 dB/GHz. Experimental results also show a good agreement with the predicted results. [ABSTRACT FROM AUTHOR]

Today, much of psychoanalysis has moved beyond Freud, both methodologically and theoretically. I understand Freud to have been always either explicitly or implicitly committed to the view that psychoanalysis is a science, if only at times as an aspirational goal. The question I intend to raise in this article is not whether psychoanalysis is scientific, but rather whether it should still consider itself so in the light of contemporary theoretical physics' ever greater dependence on mathematical assertions that have not to date been validated by experimental conformation. Bestowing the appellation of science to superstring theory, “the theory of everything,” is at present a self-crowing by its adherents taken as a hereditary birthright. I view the relation between psychoanalytic theory and contemporary theoretical physics as a parallelism – a parallelism between approaches to conceptualisation rather than a reduction of disciplines. [ABSTRACT FROM AUTHOR]

This article explores what it can mean to be a woman physics student. A case study approach is used to explore how five women who are studying physics at a Swedish university simultaneously negotiate their doing of physics and their doing of gender. By conceptualising both gender and learning as aspects of identity formation, the analysis of the interviews with the five women offers insights into the nuances and complexities of how women relate to the gendered disciplinary culture of physics. This contrasts how research on gender and physics education has been predominantly concerned with comparisons of female and male students' attitudes and/or achievements. Furthermore, the analysis brings to the fore how it is not just the masculine connotations of physics that shape the experiences of the five women, but also the expectations on female physics students. [ABSTRACT FROM AUTHOR]

Background: Although research on epistemological beliefs has expanded over the past two decades, there are still some issues that need to be explored, such as whether epistemological beliefs are domain general or domain specific. Purpose: One of the purposes of this research was to determine if high school students' general epistemological beliefs were different from their epistemological beliefs in the domain of physics. Sample: The research was conducted with 15 grade nine students studying in an urban all-boys school. Their average age was 16. Their previous school experiences were traditional oriented. Design and methods: A case study design with qualitative methods was used for the research. Two questionnaires were developed and used in semi-structured interview protocols two times, within an interval of one semester. The students' epistemological beliefs were categorized as low, medium, high, and very high for each dimension. Conclusions: The following conclusions can be drawn from the study. First, high school students do not have sophisticated general epistemological beliefs in a traditional environment. Second, similarly, high school students' epistemological beliefs in the domain of physics are not sophisticated in a traditional environment. Third, both students' general and physics epistemological beliefs can change and improve to higher levels. However, since beliefs are multidimensional, changes or improvements in one dimension of beliefs do not have to occur in other dimensions. Fourth, the levels of students' beliefs about nature of knowledge in general increase easier than the levels of their beliefs about nature of knowledge in physics. Finally, students' general epistemological beliefs are correlated with their epistemological beliefs in the domain of physics in all dimensions in traditional-oriented approach. However, the correlation decreases in time and it is not possible to mention a domain generality of beliefs when students have constructivist teaching and learning experiences. [ABSTRACT FROM AUTHOR]

In the 1950s, Terman summarized the results of his longitudinal study of the gifted and compared the 'life success' of the 150 most successful men (Group A) with the 150 least successful men (Group C) at the midpoint of their careers (age 30). The objective of this article is to replicate the original Terman work with a modern sample of the most successful (Group A) and least successful (Group C) American Academic Olympians (N = 190). The most successful adult Olympians were not hampered by a lack of motivation because they had parents who supplied a conducive home atmosphere when they were growing up. We present implications of this study for today's schools and for parents of the gifted. [ABSTRACT FROM AUTHOR]

When the above title was proposed to me, my first thought was, “Well, in this title surely some popular misconceptions about particle physics are condensed.” My second thought was “This provocative title may provide an opportunity to reflect upon what particle physics, and in particular neutron-particle physics, can give us and what not.” So the title was left unchanged. [ABSTRACT FROM AUTHOR]

In line with the cognitive theory of multimedia learning by Moreno and Mayer (2007), an interactive, multimodal learning environment was designed for the pretraining of science concepts in the joint area of physics, chemistry, biology, applied mathematics, and computer sciences. In the experimental set up, a pretest was embedded in order to increase the effect of the treatment. The pretest consisted of short-answer and multiple-choice questions. The results show a high learning gain, especially after applying a pretest. The learning gain was insignificant if no treatment followed the pretest. The pretest effect did not depend on the question type. Time on task was not a significant variable. [ABSTRACT FROM AUTHOR]

A higher-order numerical method is presented for the axisymmetric swirling flows of Boussinesq fluid in arbitrary-shaped containers with rotational symmetry. Explicit fourth-order finite-difference schemes on general curvilinear coordinates, a multigrid V-cycle method, and an optimized low-storage, fourth-order Runge-Kutta method are employed. The method is first tested by computing the vortex breakdown of uniform fluid in a cylindrical container. Numerical solutions are then presented for swirling flows in various shapes of container with temperature difference and buoyancy force. Good agreement with previous studies is demonstrated in these example problems, and higher-order accuracy is confirmed. [ABSTRACT FROM AUTHOR]

It has long been established that marking accuracy in public examinations varies considerably among subjects and markers. This is unsurprising, given the diverse cognitive strategies that the marking process can entail, but what makes some questions harder to mark accurately than others? Are there distinct but subtle features of questions and their mark schemes that can affect accuracy? Such features could potentially contribute to a broad rationale for designating questions to markers according to personal expertise. The aim of this study was to identify question features that can distinguish those questions that are marked highly accurately from those that are marked less accurately. The study comprised an exploration of maths and physics questions from past GCSE examinations, which were marked in an experimental setting by groups of markers and yielded differing marking accuracies. The questions also varied in their difficulty for GCSE candidates, and in the cognitive strategies needed to mark them. Kelly's Repertory Grid technique and semi-structured interview schedules were used in meetings with highly experienced principal examiners, who had led the experimental marking of the questions. The data generated comprised ratings for each question on a number of question features (constructs). The ratings were analysed together with the marking accuracy data, enabling an investigation of possible relationships between each question feature and (i) marking accuracy, (ii) question difficulty for the candidate, and (iii) apparent cognitive marking strategy usage. For both subjects, marking accuracy was found to be related to various subject-specific question features, some of which were also related to question difficulty (for the candidate) and/or apparent marking strategy complexity. For both maths and physics, several other subject-specific question features were found to be unrelated to accuracy. Overall, the findings have potential implications for the management of markers and for question design. [ABSTRACT FROM AUTHOR]

An ‘alternate grid’ (GridAlt) technique is presented, which allows the different components of a general circulation model's governing equations to be computed on distinct grids chosen for that component or process. In the implementation presented here, the tendencies of state variables from the physical parametrizations are computed on a vertical grid with very fine resolution near the surface, whereas the remaining terms in the equations of motion are computed using an Eta coordinate with coarser vertical resolution. Results from a suite of aquaplanet experiments show that much of the benefit of increased vertical resolution in the whole model can be realized by enhancing the vertical resolution of the ‘physics grid’ using GridAlt. The benefit is realized in the fields which are computed directly in the physical parametrizations, and in the vertical structure of the relative humidity and mass streamfunction. Results from a suite of realistically configured simulations demonstrated an impact of GridAlt that was similar to its impact in the simplified simulations, as well as an improved response to El Niño Southern Oscillation forcing. It is concluded that the present implementation of GridAlt offers a practical way to allow GCMs to better capture the near-surface structure of the atmosphere. [ABSTRACT FROM AUTHOR]

A number of practical problems in physics can be solved by using accurate higher-order derivatives. Such derivatives can be obtained with automatic differentiation. However, one has to be concerned with the complexity of computing higher-order derivative tensors even for a modest order and number of independents. Initial experiments using univariate Taylor polynomials with interpolation and operator overloading with unrolled loops showed better runtimes than using other automatic differentiation tools. Motivated by these results, we developed the Rapsodia code generator that produces Fortran and C++libraries for the most common intrinsics. Here we explain the algorithmic approach, implementation, and present test results on a select set of applications. Further details on the Rapsodia tool, and an example for user extensions are given in the Appendix. [ABSTRACT FROM AUTHOR]

Quantum numbers and electron configurations form an important part of the general chemistry curriculum and textbooks. The objectives of this study are: (1) Elaboration of a framework based on the following aspects: (a) Origin of the quantum hypothesis, (b) Alternative interpretations of quantum mechanics, (c) Differentiation between an orbital and electron density, (d) Differentiation and comparison between classical and quantum mechanics, and (e) Introduction of quantum numbers based on electron density; (2) Formulation of five criteria based on the different aspects (a, b, c, d, and e), and (3) Evaluation of 55 freshman college-level general chemistry textbooks. Results obtained show: Criterion 1, none of the textbooks described satisfactorily that Planck's role in the origin of the quantum hypothesis was more at the level of an empirical adjustment, whereas Einstein provided the physical significance of the quantum hypothesis; Criterion 2, few textbooks (two satisfactory and four mentioned) included alternative interpretations of quantum mechanics (e.g., Bohm) and thus ignored that most theories are underdetermined by experimental evidence; Criterion 3, none of the textbooks described satisfactorily that orbitals are mathematical constructs and the shapes of the orbitals (s, p, d, f) are not derived from quantum mechanics but instead from electron density measurements; Criterion 4, although, quantum mechanics approaches classical mechanics as a limiting case, none of the textbooks presented a framework to facilitate transition in student understanding from classical to quantum mechanics (28 textbooks made a simple mention); and Criterion 5, few textbooks (one satisfactory, five mentioned) facilitated the introduction of quantum numbers based on experimental determination of electron density (photoelectron spectrum). It is concluded that the inclusion of these criteria in textbooks can facilitate students' conceptual understanding of quantum numbers and electron configurations. [ABSTRACT FROM AUTHOR]

Many of the explanations for girls' disinterest in physics focus on the role of the educational system in creating this situation. Here, we use evidence from free-choice science learning settings to study if this lack of interest is also expressed in non-school settings. Three sets of self-generated questions raised by children, adolescents and adults in the fields of biology and physics were used. The outcomes of this analysis show that the polar pattern previously described in school science settings, in which physics proves significantly less interesting to girls than to boys, while biology is of greater interest to girls than to boys, also appears in free-choice science learning settings. While boys develop an interest in physics with age, girls do not develop such an interest to the same degree. Thus, the initial gap in interest is probably not based on school-related causes, but its widening in later years probably is. A difference was also found between the genders in the type of information requested and in the motivation for raising the questions. Using topics that appeal to girls' interest as the context of science learning could prove beneficial in the process of mainstreaming science education. These topics can be identified using girls' spontaneous questions. [ABSTRACT FROM AUTHOR]

The article highlights various mathematical publications, professional activities and instructional resources. Part I of the Sibling Curves and Complex Roots traces the history of graphical representations of the complex zeros of function. It also includes two copies of complex Argand plane side by side, one for the domain of the function and the other for its range. The article about Leonhard Euler (1707-1783) by Graham Hoare provides an overview of his life and mathematics. In the "Mathematics and Physics," by Peter D. Lax, the author guides the reader on a tour of fruitful interaction between mathematics and physics.

A simplified model is used to estimate the energies of observed structures in the smectic B2 phase composed of bent-shaped molecules. An approximate twist solution connecting anticlinic antiferroelectric structure in the sample bulk with synclinic ferroelectric order induced at the sample surfaces by anchoring is proposed and the elastic and anchoring energies of this structure are determined. It is shown that uniform, twisted and partly twisted (mixed) anticlinic antiferroelectric structures can coexist with nearly the same energies. [ABSTRACT FROM AUTHOR]

Phase-field modelling is still a young discipline in condensed-matter physics, which established itself for the class of systems that can be characterised by domains of different phases separated by a distinct interface. Driven out of equilibrium, their dynamics result in the evolution of those interfaces which might develop into well defined-structures with characteristic length scales at the nano-, micro- or meso-scale. Since the material properties of such systems are to a large extent determined by those small-scale structures, acquiring a precise understanding of the mechanisms that drive the interfacial dynamics is a great challenge for scientists in this field. Phase-field modelling is an approach that allows this challenge to be tackled in a simulation-based manner. This review provides a critical overview of the conceptual background of the phase-field method, the most relevant fields of condensed-matter physics that have been approached using phase-field modelling, as well as the respective model formulations and the insight gained so far via their simulation and analysis. Moreover, we discuss directions of further development and the quality of the scientific contributions to be expected from those. [ABSTRACT FROM AUTHOR]

Thermodynamics, specifically energy and heat, is a major concept in the foundations of physics and physical science. To determine a strategy to teach thermodynamics meaningfully, the authors conducted classroom action research using interviews to determine secondary physics students' current conceptions of thermodynamics. On the basis of the findings, the authors developed and implemented a science unit to facilitate students' reconstructions of their ideas toward more scientifically appropriate concepts. The lessons, using a learning cycle strategy, and results of the pre- and post-interviews are presented. [ABSTRACT FROM AUTHOR]

Declining enrolment in the physical sciences at university is causing concern among higher education institutions, governments and industry. In response, renewed attention is being paid to the tertiary science background of school teachers, given their key role in both preparing and enthusing students for tertiary science study. A recent study, Who's teaching science?, has provided the first national picture of both the supply and tertiary qualifications of Australia's secondary school science teachers. While there is no shortage of teachers with strong grounding in the life sciences, schools are struggling to adequately staff senior science classes in Physics and Chemistry. This is a growing problem: large numbers of science teachers are set to retire, and many younger and early career teachers are expressing dissatisfaction with their careers. This paper highlights the findings most relevant for the university sector, and examines the policy implications, including those for the curriculum design of both science and teacher education programs. [ABSTRACT FROM AUTHOR]

A review is presented of recent work in the group utilising the DL_POLY molecular dynamics package. Simulations have been performed across several areas of polymer physics including the dynamics of polyethylene as a function of density and chain length, the rheology of trifunctional dendrimers, and penetrant diffusion with a macromolecular matrix. The methodology and conclusions of these investigations are reviewed. [ABSTRACT FROM AUTHOR]

This article describes the construction of a hierarchical taxonomy of metacognitive activities for the interpretation of thinking-aloud protocols of students in secondary education, who studied texts on history and physics. After testing an initial elaborate taxonomy on a restricted number of protocols by multiple raters, it appeared that the interrater correspondence was well below par. The categories in the taxonomy were too highly specified. Categories were combined and tested on new protocols in a cyclic fashion. The revised taxonomy was then used for coding 16 history protocols and 16 physics protocols. Frequencies of occurrence of metacognitive activities were obtained, as well as judgements of the quality of the metacognitive activities of the participants. There is a reasonable correlation between the frequency method and the quality method for coding thinking-aloud protocols. Also, there is a substantial covariation of the number of metacognitive activities across both tasks. [ABSTRACT FROM AUTHOR]

Activity coefficients (at 95.5  kPa) over the entire composition range are obtained for the binary mixtures formed by m- cresol with: bromobenzene and o -, m - and p -xylenes. A Swietoslawski-type ebulliometer is used to measure the bubble point temperatures necessary to determine the activity coefficients. Wilson equation is used to represent the measured liquid phase composition versus temperature data and the computed values of the vapor phase composition and activity coefficients are tabulated. [ABSTRACT FROM AUTHOR]

The experimental liquid–liquid equilibrium (LLE) data of the mixtures methanol  +2-butanone  +   n -alkane (C 10 –C 12 ) were studied at atmospheric pressure in the temperature range 268.15–298.15  K. The equilibrium compositions were measured by gas chromatography from samples splitted isothermally into a glass-stirred device and phase diagrams are reported at each temperature. The non-random two-liquid and universal quasichemical models were used to correlate the experimental tie-lines. A good fit has been obtained as a function of temperature for all the mixtures. The experimental results have been compared with the values predicted by the UNIFAC group contribution method and its modifications. Such predictions provide, however, a rather unsatisfactory description for the experimental results. [ABSTRACT FROM AUTHOR]

Densities and viscosities for the ternary liquid mixtures of water  +  ethylene glycol  +tetrahydrofuran, water  +  ethylene glycol  +  1,4-dioxane, water  +  ethylene glycol  +   N , N -dimethylformamide and water  +  ethylene glycol  +  dimethyl sulphoxide have been measured as a function of the composition at 298.15, 308.15 and 318.15  K. From the experimental measurements, viscosity deviations ( Δη ), antagonic index ( I A ) and excess molar volumes ( V E ) have been evaluated. The speeds of sound have been also measured and excess isentropic compressibilities () are calculated at 298.15  K. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding. [ABSTRACT FROM AUTHOR]

Ultrasonic and sonochemical reaction studies have been carried out by measuring ultrasonic velocities (ν) in the mixing of phenols like ortho -cresol with esters like ethyl acetate and iso amyl acetate as solvents. The ultrasonic velocities (ν) were measured using ultrasonic pulse echo overlap technique (model UX4400-M) on mixing of o -cresol with solvents at different temperatures. The results are interesting because increase in the acid content in the binary mixture decreases the ultrasonic velocity (ν). Another important feature is the effect of solvents like isoamyl acetate instead of ethyl acetate on the kinetic process. The reaction rate is larger with ethyl acetate as compared to the kinetic rate in isoamyl acetate. The variation of ultrasonic velocity (ν) in the binary mixtures of o -cresol–isoamyl acetate system with sonic waves is also studied and it has been found that the reaction rate decreases due to the passage of sonic waves through the medium. Arrhenious parameters have been computed for o -cresol–isoamyl acetate system. The free energy of activation (Δ F    # ) has been computed for o -cresol–ethyl acetate system. It is found that heat of activation ( E a ), entropy of activation (Δ S    # ) and free energy of activation (Δ F    # ) are quite in order for this process. [ABSTRACT FROM AUTHOR]

Experimental data of vapour–liquid equilibrium (VLE) for the binary systems tetrahydrofuran, or tetrahydropyran, or 2-methyl-tetrahydrofuran, or 2,5-dimethyl-tetrahydrofuran with bromocyclohexane have been measured in isobaric conditions at two pressures, 40.0 and 101.3  kPa. The equipment used was a dynamic recirculating still. The consistency of the measured VLE data has been tested with the Van Ness’ point-to-point method. The activity coefficients have been correlated with the mole fraction through Wilson, NRTL and UNIQUAC equations. [ABSTRACT FROM AUTHOR]

The aqueous solubility of non-steroidal anti-inflammatory drugs (NSAIDs) Ketoprofen, Ibuprofen, Diflunisal and Naproxen were measured in the presence of the Tween series surfactants at 37°C. Results showed that the solubility of NSAIDs in the Tween solutions was approximately proportional to Tween concentration; the ability of Tween series surfactants to solubilize NSAIDs in the present study was Tween-80  >  Tween-60  >  Tween-40  >  Tween-20; the order of increased solubility of NSAIDs in Tween series surfactants at a constant Tween series and concentration was Ibuprofen  >  Ketoprofen  >  Diflunisal  >  Naproxen. Under suitable conditions Tween series surfactants can be highly effective used to enhance the solubility of NSAIDs. [ABSTRACT FROM AUTHOR]

Isentropic compressibilities ( k s ) and deviation in isentropic compressibilities () have been determined from the measurements of ultrasonic sound velocity ( u ) and densities (ρ) for the ternary mixtures of N , N -dimethylformamide (DMF), and cyclohexanone with 1-propanol, 1-butanol, 1-pentanol and 1-hexanol at 303.15  K. The relative magnitude and sign of have been interpreted in terms of possible molecular interactions between the unlike molecules. The deviation in k ′ s values are negative throughout the range of volume fraction in all four ternary mixtures. [ABSTRACT FROM AUTHOR]

We show that two quite recent treatments of dislocation-mediated melting transitions result in the thermal energy associated with the melting temperature, T m , being expressed as a product of a volume factor and a combination of elastic constants times a lattice structure-dependent factor. We further show that the result for the latent heat of fusion L m obtained in one of these studies leads to the ratio L m / G Ω, where G is the shear modulus at melting and Ω the atomic volume, being a constant. Since the ratio of the vacancy formation energy to G Ω is also found to be roughly constant, we suggest that the factor G Ω at melting is crucial in determining the melting temperature, the latent heat of fusion and the vacancy formation energy and we comment on the reasons why this should be so. [ABSTRACT FROM AUTHOR]

Complementary methods were used to study one of the MHPOBC analogues: 4-(1-methylheptyloxycarbonyl)phenyl-4 ′ nonylbiphenyl-4-carboxylate (MHPNBC). The substance shows rich phase polymorphism. In addition to the para-, ferro- and antiferroelectric phases it exhibits three sub-phases (two ferri- and alpha sub-phase) and a highly ordered room temperature phase. Typical Goldstone mode in the whole temperature range of the SmC * phase and the soft mode in the vicinity of the SmC *– SmA * transition were observed in the dielectric spectra. In the phase two relaxation processes were found: the non-cancellation mode (NCM) and the reorientation around the short molecular axis (S-process). There is only one dielectric relaxation process observed in a highly ordered phase. It is most probably the NCM, whereas the S-process seems to be frozen out. [ABSTRACT FROM AUTHOR]

An analytic closed form for the second-order or fourth-order Markovian stochastic correlation of attosecond sum-frequency polarization beat (ASPB) can be obtained in the extremely Doppler-broadened limit. The homodyne detected ASPB signal is shown to be particularly sensitive to the statistical properties of the Markovian stochastic light fields with arbitrary bandwidth. The physical explanation for this is that the Gaussian-amplitude field undergoes stronger intensity fluctuations than a chaotic field. On the other hand, the intensity (amplitude) fluctuations of the Gaussian-amplitude field or the chaotic field are always much larger than the pure phase fluctuations of the phase-diffusion field. The field correlation has weakly influence on the ASPB signal when the laser has narrow bandwidth. In contrast, when the laser has broadband linewidth, the ASPB signal shows resonant-nonresonant cross correlation, and the sensitivities of ASPB signal to three Markovian stochastic models increase as time delay is increased. A Doppler-free precision in the measurement of the energy-level sum can be achieved with an arbitrary bandwidth. The advantage of ASPB is that the ultrafast modulation period 900 as can still be improved, because the energy-level interval between ground state and excited state can be widely separated. [ABSTRACT FROM AUTHOR]

An overview is presented of the notions of size-extensivity and size-consistency, which play an important role in the discussion of many-body methods in physics and chemistry. We also introduce the concept of generalized extensivity, which has been used before implicitly in the literature, and provide an operational definition, which can be tested numerically in a similar way as size-consistency. A numerical example illustrates the concept of generalized extensivity as applied to the EOM-CCSD, STEOM-CCSD and extended-STEOM-CCSD electronic structure methods for excited states. In another line of thought it is argued that algebraic proofs are often more easily constructed than diagrammatic proofs to demonstrate proper separation into non-interacting fragments. The algebraic line of reasoning is illustrated for single reference methods and applied to discuss separability properties for a variety of Hilbert space multi-reference coupled cluster methods. [ABSTRACT FROM AUTHOR]

This article should not be considered as an exhaustive review, but a presentation of some of both the author's other new results that show that water possesses features of solid state substances rather than statistical liquids. This appears in chemical transformations under low intensity forces, enormous times of relaxation, or memory effects. Besides infinite amount of structures constructed of water molecules including rods, helixes of different symmetry, rings, nets, plane structures compatible with lipid membrane, membrane channels, and fractal structures are shown which differ from the known crystallographic structures. [ABSTRACT FROM AUTHOR]

The introduction of the SVEA-96 Optima generation of advanced boiling water reactor fuel designs implies a further increment in complexity and heterogeneity that needs to be supported by accurate calculation tools. In order to take advantage of the improved economics offered by these modern fuel designs while simultaneously assuring safe and reliable reactor operation, both the reload design process and the online core monitoring procedures must be based on appropriate calculation methods. The modeling of transition cores involving the gradual introduction of these new fuel designs poses a severe challenge for the current core physics methods. Recognizing this, Westinghouse has engaged in a continuing process of improving its core physics calculation packages. This development program is supported by a comprehensive validation effort to demonstrate the accuracy and reliability of the improved methods as well as to identify areas requiring further development. The purpose of this paper is to summarize some of the results of this program. [ABSTRACT FROM AUTHOR]

Use of adaptive simulation is intended to improve the fidelity and robustness of important core attribute predictions such as core power distribution, thermal margins, and core reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e., in-core instrumentation readings, to adapt the simulation in a meaningful way. A meaningful adaption will result in high-fidelity and robust adapted core simulator models. To perform adaption, we propose an inverse theory approach in which the multitudes of input data to core simulators, i.e., reactor physics and thermal-hydraulic data, are to be adjusted to improve agreement with measured observables while keeping core simulator models unadapted. At first glance, devising such adaption for typical core simulators with millions of input and observables data would spawn not only several prohibitive challenges but also numerous disparaging concerns. The challenges include the computational burdens of the sensitivity-type calculations required to construct Jacobian operators for the core simulator models. Also, the computational burdens of the uncertainty-type calculations required to estimate the uncertainty information of core simulator input data present a demanding challenge. The concerns however are mainly related to the reliability of the adjusted input data. The methodologies of adaptive simulation are well established in the literature of data adjustment. We adopt the same general framework for data adjustment; however, we refrain from solving the fundamental adjustment equations in a conventional manner. We demonstrate the use of our so-called Efficient Subspace Methods (ESMs) to overcome the computational and storage burdens associated with the core adaption problem. We illustrate the successful use of ESM-based adaptive techniques for a typical boiling water reactor core simulator adaption problem. [ABSTRACT FROM AUTHOR]

Slip-stick vibration driven by friction is important in many applications, and to model it well enough to make reliable predictions requires detailed information about the underlying physical mechanisms of friction. To characterize the frictional behavior of an interface in the stick-slip regime requires measurements that themselves operate in the stick-slip regime. A novel methodology for measurements of this kind is presented, based on the excitation of a stretched string "bowed" with a rod that is coated with the friction material to be investigated. Measurements of the motion of the string allow the friction force and the velocity waveform at the contact point to be determined by inverse calculation. These friction results can be correlated with microscopic analysis of the wear track left in the coated surface. Results are presented using rosin as a friction material. These show that "sticking" involves some temperature dependent shear flow in the friction material, and that the exact definition of the states of "sticking" and "slipping" is by no means clear-cut. Friction force during slipping shows complex behavior, not well correlated with variations in sliding speed, so that other state variables such as temperature near the interface must play a crucial role. A new constitutive model for rosin friction, based on the repeated formation and healing of unstable shear bands, is suggested. [ABSTRACT FROM AUTHOR]

This paper reports the analysis of the resolution of a paper-and-pencil problem, by eight undergraduate students majoring in engineering (six) and physics (two) at the Pontifícia Universidade Católica do Rio Grande do Sul, in Porto Alegre, Brazil. The problem concerns kinetics of a rigid body, and the analysis was done in the light of Johnson-Laird’s mental models theory and Vergnaud’s conceptual fields theory. The problem-solving process has been investigated from the presentation of the problems’ variables and the pictures that followed it, up to the resolution itself. This investigation was carried out by analysing the knowledge-in-action that students have used as inferred from their written solutions and from what they said in semi-structured interviews. The findings of this analysis identified some characteristics in their answers that may help us to understand the processes used by students during the problem-solving task, with possible consequences for classroom procedures used by teachers. [ABSTRACT FROM AUTHOR]

This paper presents a critical analysis of data analysis requirements in physics tertiary entrance examinations. The setting is Western Australia. Common aspects of the questions asked over 14 years and changes in the questions since a major syllabus reform are identified. Similar changes in other jurisdictions are referenced. The data analysis questions reflect minimally the changes in emphasis in the reform syllabus. They imply science is unassailable laws and not science is inquiry. [ABSTRACT FROM AUTHOR]

This article describes an active learning method for the teaching of physical sciences and mathematics to engineers. After defining the challenges involved in the training of engineers, we shall describe the answers provided by our method, 'learning by doing' (named 'Apprentissage Par l'Action' in French), by introducing four key points: real-life simulation, the management of non-success, the result requirement and the different roles of the teachers. An assessment of this experience is carried out which emphasizes the factors paramount in the success of this pedagogical innovation. Similarities between our experience and other well-known methods such as problem-based learning, problem solving and, more generally, the concept of learning by doing coined by John Dewey in his philosophy of education, are mentioned. [ABSTRACT FROM AUTHOR]

This study applies the concept of cultural border (or boundary) crossing first introduced by Phelan et al. (1991) to the investigation of students' attitudes towards physics and to their choice of physics for A-level. A typology of border crossings is introduced and a number of possible crossings are hypothesized; for example, family background (parents' occupation and thinking style), low general school interest among family and peers, students' non-scientific perception of knowledge, their 'more-than-just-absorption' purposes of knowledge-acquisition and other value-related judgements. The quantitative methodology used here makes it possible to build regression models of students' attitudes and compare the possible impact of the border crossings with that of personality variables and teacher and teaching style characteristics. It is found that cultural border crossing factors are important predictors for attitudes towards physics as well as for choice of A-level physics in the Danish upper secondary school ('gymnasium'). [ABSTRACT FROM AUTHOR]

Dislocation properties have been studied in several Ll2 nickel-based alloys with high (Ni74Al26), medium (Ni3(Al, 0.25% Hf)), and low (Ni3Ga) antiphase boundary (APB) energies respectively, deformed in the temperature domain of the yield-stress anomaly. Several APB energies have been measured and compared with those found in the literature. The peak in the temperature variation of the strain-hardening coefficient has been correlated with the unlocking of incomplete Kear-Wilsdorf locks. The corresponding unlocking stresses, as well as the frequencies of octahedral-cube and cube-octahedral cross-slip, are strongly correlated with the respective fault energies. The local pinning of near-edge dislocations in cube planes appears essential for the observation of the yield-stress anomaly in alloys with high APB energies. [ABSTRACT FROM AUTHOR]

Diffraction is a cornerstone of optical physics and has implications for the design of all optical systems. The paper discusses the so-called 'non-diffracting' light field, commonly known as the Bessel beam. Approximations to such beams can be experimentally realized using a range of different means. The theoretical foundation of these beams is described and then various experiments that make use of Bessel beams are discussed: these cover a wide range of fields including non-linear optics, where the intense central core of the Bessel beam has attracted interest; short pulse non-diffracting fields; atom optics, where the narrow non-diffracting features of the Bessel beam are able to act as atomic guides and atomic confinement devices and optical manipulation, where the reconstruction properties of the beam enable new effects to be observed that cannot be seen with Gaussian beams. The intensity profile of the Bessel beam may offer routes to investigating statistical physics as well as new techniques for the optical sorting of particles. [ABSTRACT FROM AUTHOR]

Approximately thirty years ago archivists began formulating new models to guide archival collecting, creating a literature that continues to grow. In the mid-1980s, the introduction of the documentation strategy collection model put new emphasis on cooperation between repositories and among stakeholders. The model initially focused on the history of science, which has traditionally been poorly documented. Today, the documentation strategy model remains an essential tool in preserving the history of physics, astronomy, geophysics, and allied fields. The Center for History of Physics is using it to move beyond the records of academic science to develop strategies to preserve sources in the especially hard-to-document realms of government and corporate research. [ABSTRACT FROM AUTHOR]

The magnetic anisotropy energy (MAE) of 3 d transition-metal wires, stripes, and films is calculated self-consistently as a function of stripe width and film thickness. The magnetization-reorientation transitions in stripes are determined along the crossover from the mono-atomic one-dimensional chain to the two-dimensional monolayer. It is shown that the MAE oscillates as a function of stripe width and depends strongly on the considered transition metal. The reorientation transitions in Co films deposited on a highly polarizable substrate such as Pd are discussed. A local analysis of the layer-resolved MAEs provides new insights into the off-plane magnetization observed in Pd-capped Co films on Pd(111). The interfaces responsible for the stability of the off-plane easy axis are characterized microscopically. An unexpected internal magnetic structure of the Co-Pd interfaces is revealed in which the magnetic moments and spin-orbit interactions at Pd atoms play a crucial role. The nature of the reorientation transition from perpendicular to in-plane magnetization with increasing film thickness is studied by means of full-vectorial calculations. The existence of a spin-canted phase at intermediate film thickness is demonstrated. [ABSTRACT FROM AUTHOR]

In this combination of review and new science, we shall look at Density Functional Theory (DFT) and the Quantum Monte Carlo (QMC) method. For DFT, we shall (i) discuss the inadequacy of the Uniform Electron Gas model for chemistry (ii) examine Generalized Gradient Approximation (GGA) exchange functionals (iii) understand that they introduce left-right correlation for molecules (iv) argue that the functionals BLYP and OLYP are parameter-free for molecules (v) look at the 'remarkable' performance of these local functionals in the prediction of binding energies (vii) discuss hybrid functionals, and show how they can be improved through the introduction of an Ewald partitioning of 1/ r 12 , already examined by Hirao, Savin and Gill (viii) show that our new functional CAM-B3LYP offers good energetics as well as good charge transfer excitation energies, already shown by Hirao. For QMC, concentrating on the Diffusion Monte Carlo approach, we shall (i) relate the trial wavefunction to the transcorrelated wavefunction, and look again at the transcorrelated method, (ii) look at the nodal surfaces of the trial wavefunction, demonstrating in particular that the use of finite basis sets in the Hartree-Fock method necessarily introduces 'spurious' nodal features which probably cannot be ignored, (iii) argue that, now it is possible to perform Hartree-Fock calculations with slater-type basis sets, it is straightforwardly possible to obtain orbitals which obey the exact nuclear cusp conditions, (iv) therefore argue that these basis sets should be used in Monte Carlo studies. [ABSTRACT FROM AUTHOR]

Two new classes of non-iterative corrections to the ground- and excited-state energies obtained in the state-universal multi-reference coupled-cluster (SUMRCC) calculations have been developed using the multi-reference extension of the method of moments of coupled-cluster equations (MMCC) [K OWALSKI , K., and P IECUCH , P., 2001, J. molec. Struct. (THEOCHEM) , 547, 191]. In the first class of the configuration interaction (CI) corrected multi-reference MMCC (MRMMCC) approximations, the non-iterative corrections due to triply or triply and quadruply excited clusters are constructed with the help of multi-reference CI (MRCI) calculations employing the same active space as used in the SUMRCC calculations. In the second class of the completely renormalized (CR) SUMRCC methods, which can be viewed as the multi-reference extensions of the single-reference CR-CCSD(T) theory [K OWALSKI , K., and P IECUCH , P., 2000, J. chem. Phys. , 113, 18], the non-iterative corrections due to triply excited clusters are constructed with the help of the multi-reference many-body perturbation theory. In both cases, the non-iterative corrections due to higher-order clusters are added to the energies obtained with the SUMRCC method with singles and doubles. It is demonstrated that the newly developed corrections, including the CR-SUMRCC methods, offer considerable improvements in the SUMRCCSD results, reducing, in particular, the large errors in the SUMRCCSD results due to intruders. [ABSTRACT FROM AUTHOR]