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Sample records for ideal atomic centre

  1. The virtual atomic and molecular data centre (VAMDC) consortium

    NASA Astrophysics Data System (ADS)

    Dubernet, M. L.; Antony, B. K.; Ba, Y. A.; Babikov, Yu L.; Bartschat, K.; Boudon, V.; Braams, B. J.; Chung, H.-K.; Daniel, F.; Delahaye, F.; Del Zanna, G.; de Urquijo, J.; Dimitrijević, M. S.; Domaracka, A.; Doronin, M.; Drouin, B. J.; Endres, C. P.; Fazliev, A. Z.; Gagarin, S. V.; Gordon, I. E.; Gratier, P.; Heiter, U.; Hill, C.; Jevremović, D.; Joblin, C.; Kasprzak, A.; Krishnakumar, E.; Leto, G.; Loboda, P. A.; Louge, T.; Maclot, S.; Marinković, B. P.; Markwick, A.; Marquart, T.; Mason, H. E.; Mason, N. J.; Mendoza, C.; Mihajlov, A. A.; Millar, T. J.; Moreau, N.; Mulas, G.; Pakhomov, Yu; Palmeri, P.; Pancheshnyi, S.; Perevalov, V. I.; Piskunov, N.; Postler, J.; Quinet, P.; Quintas-Sánchez, E.; Ralchenko, Yu; Rhee, Y.-J.; Rixon, G.; Rothman, L. S.; Roueff, E.; Ryabchikova, T.; Sahal-Bréchot, S.; Scheier, P.; Schlemmer, S.; Schmitt, B.; Stempels, E.; Tashkun, S.; Tennyson, J.; Tyuterev, Vl G.; Vujčić, V.; Wakelam, V.; Walton, N. A.; Zatsarinny, O.; Zeippen, C. J.; Zwölf, C. M.

    2016-04-01

    The Virtual Atomic and Molecular Data Centre (VAMDC) Consortium is a worldwide consortium which federates atomic and molecular databases through an e-science infrastructure and an organisation to support this activity. About 90% of the inter-connected databases handle data that are used for the interpretation of astronomical spectra and for modelling in many fields of astrophysics. Recently the VAMDC Consortium has connected databases from the radiation damage and the plasma communities, as well as promoting the publication of data from Indian institutes. This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for scientific research. It is noted that the VAMDC Consortium strongly advocates that authors of research papers using data cite the original experimental and theoretical papers as well as the relevant databases. .

  2. Strategic Leadership of Teaching and Learning Centres: From Reality to Ideal

    ERIC Educational Resources Information Center

    Palmer, Stuart; Holt, Dale; Challis, Di

    2011-01-01

    This paper reports on the third phase of a study of Australian Teaching and Learning Centres to identify factors that contribute to the effective strategic leadership of Centres. Focus groups at 10 Australian universities included 66 respondents, providing a diverse range of perspectives, from students to members of the university executive.…

  3. Exact spatial density of ideal Bose atoms in a one-dimensional harmonic trap

    NASA Astrophysics Data System (ADS)

    Cheng, Ze

    2016-05-01

    We have proposed an exact analytical solution to the problem of Bose–Einstein condensation (BEC) of harmonically trapped, one-dimensional, and ideal atoms. It is found that the number of atoms in vapor is characterized by an analytical function, which involves a q -digamma function in mathematics. We employ the q -digamma function to calculate the spatial density n(z;T, N) of ideal Bose atoms in a one-dimensional harmonic trap. The first main finding in this paper is that when Bose atoms are in the normal state, the density profile exhibits Friedel oscillations. The second main finding is that when Bose atoms are in the BEC state, the density profile exhibits a sharp peak with extremely narrow width. The third main finding is that the central peak of the spatial density is a monotonically increasing function of the number of atoms N but is a monotonically decreasing function of temperature T.

  4. Updates to the Virtual Atomic and Molecular Data Centre

    NASA Astrophysics Data System (ADS)

    Hill, Christian; Tennyson, Jonathan; Gordon, Iouli E.; Rothman, Laurence S.; Dubernet, Marie-Lise

    2014-06-01

    The Virtual Atomic and Molecular Data Centre (VAMDC) has established a set of standards for the storage and transmission of atomic and molecular data and an SQL-based query language (VSS2) for searching online databases, known as nodes. The project has also created an online service, the VAMDC Portal, through which all of these databases may be searched and their results compared and aggregated. Since its inception four years ago, the VAMDC e-infrastructure has grown to encompass over 40 databases, including HITRAN, in more than 20 countries and engages actively with scientists in six continents. Associated with the portal are a growing suite of software tools for the transformation of data from its native, XML-based, XSAMS format, to a range of more convenient human-readable (such as HTML) and machinereadable (such as CSV) formats. The relational database for HITRAN1, created as part of the VAMDC project is a flexible and extensible data model which is able to represent a wider range of parameters than the current fixed-format text-based one. Over the next year, a new online interface to this database will be tested, released and fully documented - this web application, HITRANonline2, will fully replace the ageing and incomplete JavaHAWKS software suite.

  5. Constructing the "Ideal" Family for Family-Centred Practice: Challenges for Delivery

    ERIC Educational Resources Information Center

    Dodd, Jenny; Saggers, Sherry; Wildy, Helen

    2009-01-01

    Family-centred practice positions families as the key decision-makers, central to and experts in the wants and needs of their child. This paper discusses how families interviewed for a Western Australian study describe their relationships with a range of allied health professionals in the paediatric disability sector. The allied health…

  6. The Ideal and Real Gas Heat Capacity of Potassium Atoms at High Temperatures

    NASA Astrophysics Data System (ADS)

    Biolsi, Louis; Biolsi, Michael

    2016-04-01

    The ideal gas heat capacity, Cp, of potassium atoms is calculated to high temperatures using statistical mechanics. Since there are a large number of electronic energy levels in the partition function (Boltzmann sum) below the first ionization potential, the partition function and Cp will become very large as the temperature increases unless the number of energy levels contributing to the partition function is constrained. Two primary categories of arguments are used to do this. First, at high temperatures, the increased size of the atoms constrains the sum (Bethe method). Second, an argument based on the existence of interacting charged species at higher temperatures is used to constrain the sum (ionization potential lowering method). When potassium atoms are assumed to constitute a real gas that obeys the virial equation of state, the lowest non-ideal contribution to Cp depends on the second derivative of the second virial coefficient, B( T), which depends on the interaction potential energy curves between two potassium atoms. When two ground-state (2{S}) atoms interact, they can follow either of the two potential energy curves. When a 2{S} atom interacts with an atom in the first electronically excited (2{P}) state, they can follow any of the eight potential energy curves. The values of B( T) for the ten states are determined, then averaged, and used to calculate the nonideal contribution to Cp.

  7. Atomic and Molecular Databases, VAMDC (Virtual Atomic and Molecular Data Centre)

    NASA Astrophysics Data System (ADS)

    Dubernet, Marie-Lise; Zwölf, Carlo Maria; Moreau, Nicolas; Awa Ba, Yaya; VAMDC Consortium

    2015-08-01

    The "Virtual Atomic and Molecular Data Centre Consortium",(VAMDC Consortium, http://www.vamdc.eu) is a Consortium bound by an Memorandum of Understanding aiming at ensuring the sustainability of the VAMDC e-infrastructure. The current VAMDC e-infrastructure inter-connects about 30 atomic and molecular databases with the number of connected databases increasing every year: some databases are well-known databases such as CDMS, JPL, HITRAN, VALD,.., other databases have been created since the start of VAMDC. About 90% of our databases are used for astrophysical applications. The data can be queried, retrieved, visualized in a single format from a general portal (http://portal.vamdc.eu) and VAMDC is also developing standalone tools in order to retrieve and handle the data. VAMDC provides software and support in order to include databases within the VAMDC e-infrastructure. One current feature of VAMDC is the constrained environnement of description of data that ensures a higher quality for distribution of data; a future feature is the link of VAMDC with evaluation/validation groups. The talk will present the VAMDC Consortium and the VAMDC e infrastructure with its underlying technology, its services, its science use cases and its etension towards other communities than the academic research community.

  8. Bose-Einstein condensation of photons in an ideal atomic gas

    NASA Astrophysics Data System (ADS)

    Kruchkov, Alex; Slyusarenko, Yurii

    2013-07-01

    We study peculiarities of Bose-Einstein condensation of photons that are in thermodynamic equilibrium with atoms of noninteracting gases. General equations of the thermodynamic equilibrium of the system under study are obtained. We examine solutions of these equations in the case of high temperatures, when the atomic components of the system can be considered as nondegenerated ideal gases of atoms, and the photonic component can form a state with the Bose condensate. Transcendental equation for transition temperature and expression for the density of condensed photons in the considered system are derived. We also obtain analytical solutions of the equation for the critical temperature in a number of particular cases. The existence of two regimes of Bose condensation of photons, which differ significantly in nature of transition temperature dependence on the total density of photons pumped into the system, is revealed. In one case, this dependence is a traditional fractional-power law, and in another one it is the logarithmic law. Applying numerical methods, we determine boundaries of existence and implementation conditions for different regimes of condensation depending on the physical parameters of the system under study. We also show that for a large range of physical systems that are in equilibrium with photons (from ultracold gases of alkali metals to certain types of ideal plasma), the condensation of photons should occur according to the logarithmic regime.

  9. Electromagnetic Shifts of Energy Levels of a Hydrogen Atom in Idealized Cavities.

    NASA Astrophysics Data System (ADS)

    Burzan, Dragisa

    Available from UMI in association with The British Library. Requires signed TDF. Energy level shifts are evaluated for the 2p-2s transition for a hydrogen atom in various confining geometries with idealized perfectly conducting metallic boundaries in all cases. The minimal coupling Hamiltonian formalism is employed in the non-relativistic approximation in the Coulomb gauge to calculate the level shifts. Bethe's work for the Lamb shift in free space for the hydrogen atom is used as the model for working out the transverse level shifts in the various confining geometries. The Stark effect arising from the interaction of an atom with its image in the metal is used to evaluate the longitudinal level shift. The analysis is carried out by first quantizing the electro-magnetic field in a general cavity after a discussion is presented in the introduction of the relation of this work to that of other authors on related topics. The theory is then developed in detail in the various special confining geometries starting with case of the parallelopiped and its limiting cases of two plates and one plate respectively. The confining geometries of a finite and infinite cylinder are considered next followed by that of sphere. Detailed numerical results are presented in each of the various special cases with graphs and tables after extensive computation. The conclusions of the thesis are summarized separately.

  10. Site occupancy of interstitial deuterium atoms in face-centred cubic iron

    PubMed Central

    Machida, Akihiko; Saitoh, Hiroyuki; Sugimoto, Hidehiko; Hattori, Takanori; Sano-Furukawa, Asami; Endo, Naruki; Katayama, Yoshinori; Iizuka, Riko; Sato, Toyoto; Matsuo, Motoaki; Orimo, Shin-ichi; Aoki, Katsutoshi

    2014-01-01

    Hydrogen composition and occupation state provide basic information for understanding various properties of the metal–hydrogen system, ranging from microscopic properties such as hydrogen diffusion to macroscopic properties such as phase stability. Here the deuterization process of face-centred cubic Fe to form solid-solution face-centred cubic FeDx is investigated using in situ neutron diffraction at high temperature and pressure. In a completely deuterized specimen at 988 K and 6.3 GPa, deuterium atoms occupy octahedral and tetrahedral interstitial sites with an occupancy of 0.532(9) and 0.056(5), respectively, giving a deuterium composition x of 0.64(1). During deuterization, the metal lattice expands approximately linearly with deuterium composition at a rate of 2.21 Å3 per deuterium atom. The minor occupation of the tetrahedral site is thermally driven by the intersite movement of deuterium atoms along the ‹111› direction in the face-centred cubic metal lattice. PMID:25256789

  11. Virtual Atomic and Molecular Data Centre: Level 3 Service and Future Prospects

    NASA Astrophysics Data System (ADS)

    Dubernet, M. L.; Rixon, G.; Doronin, M.; VAMDC Collaboration

    2015-03-01

    The Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu) is an international Consortium that has created an interoperable e-science infrastructure for the exchange of atomic and molecular data. The VAMDC defines standards for the exchange of atomic and molecular data, develop reference implementation of those standards, deploys registries of internet resources (yellow pages), designs user applications in order to meet the user needs, builds data access layers above databases to provide unified outputs from these databases, cares about asynchronous queries with workflows and connects its infrastructure to the grid. The paper describes the current service deployment of the VAMDC data infrastructure across our registered databases and the key features of the current infrastructure.

  12. Calibration of a new experimental chamber for PIXE analysis at the Accelerator Facilities Division of Atomic Energy Centre Dhaka (AECD)

    NASA Astrophysics Data System (ADS)

    Hassan, Md. Taufique; Shariff, Md. Asad; Hossein, Amzad; Abedin, Md. Joynal; Fazlul Hoque, A. K. M.; Chowdhuri, M. S.

    2015-05-01

    A new experimental chamber has been installed at the 3 MV Van de Graaff Accelerator Facilities Division in the Atomic Energy Centre, Dhaka, to perform different Ion Beam Analysis (IBA) techniques. The calibration of this new setup for Particle Induced X-ray Emission (PIXE) technique has been done using a set of thin MicroMatter standards and GUPIX (PIXE spectrum analysis software), which is explicated in this paper. The effective thicknesses of the beryllium window of the X-ray detector and of the different absorbers used were determined. For standardization, the so called instrumental constant H (product of detector solid angle and the correction factor for the setup) as function of X-ray energy were determined and stored inside the GUPIX library for further PIXE analysis.

  13. Atomic structure of Zr-Cu glassy alloys and detection of deviations from ideal solution behavior with Al addition by x-ray diffraction using synchrotron light in transmission

    NASA Astrophysics Data System (ADS)

    Georgarakis, K.; Yavari, A. R.; Louzguine-Luzgin, D. V.; Antonowicz, J.; Stoica, M.; Li, Y.; Satta, M.; LeMoulec, A.; Vaughan, G.; Inoue, A.

    2009-05-01

    The atomic structure of Zr-Cu binary amorphous alloys was studied using real space pair distribution functions derived from x-ray diffraction. The structure can be modeled by an ideal solution approximation because of relatively weak Cu-Zr atomic interactions. Addition of Al to Zr-Cu metallic glasses modifies the atomic structure in the short and medium range order because of the strongly attractive interaction between Al and Zr atoms. These interactions generate strong deviations from the ideal solution behavior.

  14. A molecular dynamics study of the effect of thermal boundary conductance on thermal transport of ideal crystal of n-alkanes with different number of carbon atoms

    NASA Astrophysics Data System (ADS)

    Rastgarkafshgarkolaei, Rouzbeh; Zeng, Yi; Khodadadi, J. M.

    2016-05-01

    Phase change materials such as n-alkanes that exhibit desirable characteristics such as high latent heat, chemical stability, and negligible supercooling are widely used in thermal energy storage applications. However, n-alkanes have the drawback of low thermal conductivity values. The low thermal conductivity of n-alkanes is linked to formation of randomly oriented nano-domains of molecules in their solid structure that is responsible for excessive phonon scattering at the grain boundaries. Thus, understanding the thermal boundary conductance at the grain boundaries can be crucial for improving the effectiveness of thermal storage systems. The concept of the ideal crystal is proposed in this paper, which describes a simplified model such that all the nano-domains of long-chain n-alkanes are artificially aligned perfectly in one direction. In order to study thermal transport of the ideal crystal of long-chain n-alkanes, four (4) systems (C20H42, C24H50, C26H54, and C30H62) are investigated by the molecular dynamics simulations. Thermal boundary conductance between the layers of ideal crystals is determined using both non-equilibrium molecular dynamics (NEMD) and equilibrium molecular dynamics (EMD) simulations. Both NEMD and EMD simulations exhibit no significant change in thermal conductance with the molecular length. However, the values obtained from the EMD simulations are less than the values from NEMD simulations with the ratio being nearly three (3) in most cases. This difference is due to the nature of EMD simulations where all the phonons are assumed to be in equilibrium at the interface. Thermal conductivity of the n-alkanes in three structures including liquid, solid, and ideal crystal is investigated utilizing NEMD simulations. Our results exhibit a very slight rise in thermal conductivity values as the number of carbon atoms of the chain increases. The key understanding is that thermal transport can be significantly altered by how the molecules and the

  15. Ideal MHD

    NASA Astrophysics Data System (ADS)

    Freidberg, Jeffrey P.

    2014-06-01

    1. Introduction; 2. The ideal MHD model; 3. General properties of ideal MHD; 5. Equilibrium: one-dimensional configurations; 6. Equilibrium: two-dimensional configurations; 7. Equilibrium: three-dimensional configurations; 8. Stability: general considerations; 9. Alternate MHD models; 10. MHD stability comparison theorems; 11. Stability: one-dimensional configurations; 12. Stability: multi-dimensional configurations; Appendix A. Heuristic derivation of the kinetic equation; Appendix B. The Braginskii transport coefficients; Appendix C. Time derivatives in moving plasmas; Appendix D. The curvature vector; Appendix E. Overlap limit of the high b and Greene-Johnson stellarator models; Appendix F. General form for q(y); Appendix G. Natural boundary conditions; Appendix H. Upper and lower bounds on dQKIN.

  16. MeCaSDa and ECaSDa: Methane and ethene calculated spectroscopic databases for the virtual atomic and molecular data centre

    NASA Astrophysics Data System (ADS)

    Ba, Yaye Awa; Wenger, Christian; Surleau, Romain; Boudon, Vincent; Rotger, Maud; Daumont, Ludovic; Bonhommeau, David A.; Tyuterev, Vladimir G.; Dubernet, Marie-Lise

    2013-11-01

    Two spectroscopic relational databases, denoted MeCaSDa and ECaSDa, have been implemented for methane and ethene, and included in VAMDC (Virtual Atomic and Molecular Data Centre, http://portal.vamdc.eu/vamdc_portal/home.seam). These databases collect calculated spectroscopic data from the accurate analyses previously performed for the electronic ground state of methane, ethene, and some of their isotopologues: 12CH4, 13CH4, and 12C2H4. Both infrared absorption and Raman scattering lines are included. The polyad structures are reported and the transitions are precisely described by their energy, their intensity and the full description of the lower and upper states involved in the transitions. The relational schemas of ECaSDa and MeCaSDa databases are equivalent and optimised to enable the better compromise between data retrieval and compatibility with the XSAMS (XML Schema for Atoms, Molecules, and Solids) format adopted within the VAMDC European project.

  17. Sex Education and Ideals

    ERIC Educational Resources Information Center

    de Ruyter, Doret J.; Spiecker, Ben

    2008-01-01

    This article argues that sex education should include sexual ideals. Sexual ideals are divided into sexual ideals in the strict sense and sexual ideals in the broad sense. It is argued that ideals that refer to the context that is deemed to be most ideal for the gratification of sexual ideals in the strict sense are rightfully called sexual…

  18. CH_4, C_2H_4, SF_6 and CF_4 Calculated Spectroscopic Databases for the Virtual Atomic and Molecular Data Centre

    NASA Astrophysics Data System (ADS)

    Boudon, Vincent; Wenger, Christian; Surleau, Romain; Louviot, Maud; Faye, Mbaye; Rotger, Maud; Daumont, Ludovic; Bonhommeau, David A.; Tyuterev, Vladimir; Ba, Yaye Awa; Dubernet, Marie-Lise

    2014-06-01

    Two spectroscopic relational databases, denoted MeCaSDa and ECaSDa, have been implemented for methane and ethene, and included in VAMDC (Virtual Atomic and Molecular Data Centre, http://portal.vamdc.eu/vamdc_portal/home.seam) [1]. These databases collect calculated spectroscopic data from the accurate analyses previously performed for the electronic ground state of methane, ethene, and some of their isotopologues: 12CH_4, 13CH_4, and 12C_2H_4 [2]. Both infrared absorption and Raman scattering lines are included. The polyad structures are reported and the transitions are precisely described by their energy, their intensity and the full description of the lower and upper states involved in the transitions. Very recently, we also built on the same model two new databases, named SHeCaSDa and TFMeCaSDa for the SF_6 and CF_4 greenhouse gas molecules, respectively. The relational schemas of these four databases are equivalent and optimized to enable the better compromise between data retrieval and compatibility with the XSAMS (XML Schema for Atoms, Molecules, and Solids) format adopted within the VAMDC European project. [1] Y. A. Ba, Ch. Wenger et al., J. Quant. Spectrosc. Radiat. Transfer, 130, 62 (2013). [2] M.-L. Dubernet, V. Boudon et al., J. Quant. Spectrosc. Radiat. Transfer, 111, 2151 (2010).

  19. CH(4), C(2)H(4), SF(6) and CF(4) Calculated Spectroscopic Databases for the Virtual Atomic and Molecular Data Centre

    NASA Astrophysics Data System (ADS)

    Boudon, V.; Wenger, Ch.; Surleau, R.; Louviot, M.; Faye, M.; Rotger, M.; Daumont, L.; Bonhommeau, D. A.; Tyuterev, Vl. G.; Ba, Y. A.; Dubernet, M.-L.

    2014-06-01

    Two spectroscopic relational databases, denoted MeCaSDa and ECaSDa, have been implemented for methane and ethene, and included in the VAMDC (Virtual Atomic and Molecular Data Centre, http://portal.vamdc.eu/vamdc portal/home.seam)1. These databases collect calculated spectroscopic data from the accurate analyses previously performed for the electronic ground state of methane, ethene, and some of their isotopologues: 12CH4, 13CH4, and 12C2H4 2. Both infrared absorption and Raman scattering lines are included. The polyad structures are reported and the transitions are precisely described by their energy, their intensity, and the full description of the lower and upper states involved in the transitions. Very recently, we also built on the same model two new databases, named SHeCaSDa and TFMeCaSDa for the SF6 and CF4 greenhouse gas molecules, respectively. The relational schemas of these four databases are equivalent and optimized to enable the better compromise between data retrieval and compatibility with the XSAMS (XML Schema for Atoms, Molecules, and Solids) format adopted within the VAMDC European project.

  20. Force correcting atom centred potentials for generalised gradient approximated density functional theory: Approaching hybrid functional accuracy for geometries and harmonic frequencies in small chlorofluorocarbons

    NASA Astrophysics Data System (ADS)

    Anatole von Lilienfeld, O.

    2013-08-01

    Generalised gradient approximated (GGA) density functional theory (DFT) typically overestimates polarisability and bond-lengths, and underestimates force constants of covalent bonds. To overcome this problem we show that one can use empirical force correcting atom centred potentials (FCACPs), parametrised for every nuclear species. Parameters are obtained through minimisation of a penalty functional that explicitly encodes hybrid DFT forces and static polarisabilities of reference molecules. For hydrogen, fluorine, chlorine and carbon the respective reference molecules consist of H2, F2, Cl2 and CH4. The transferability of this approach is assessed for harmonic frequencies in a small set of chlorofluorocarbon molecules. Numerical evidence, gathered for CF4, CCl4, CCl3F, CCl2F2, CClF3, ClF, HF, HCl, CFH3, CF2H2, CF3H, CHCl3, CH2Cl2 and CH3Cl indicates that the GGA+FCACP level of theory yields harmonic frequencies that are significantly more consistent with hybrid DFT values, as well as slightly reduced molecular polarisability.

  1. Ideals and Category Typicality

    ERIC Educational Resources Information Center

    Kim, ShinWoo; Murphy, Gregory L.

    2011-01-01

    Barsalou (1985) argued that exemplars that serve category goals become more typical category members. Although this claim has received support, we investigated (a) whether categories have a single ideal, as negatively valenced categories (e.g., cigarette) often have conflicting goals, and (b) whether ideal items are in fact typical, as they often…

  2. Quaternions and ideal flows

    NASA Astrophysics Data System (ADS)

    Eshraghi, H.; Gibbon, J. D.

    2008-08-01

    After a review of some of the recent works by Holm and Gibbon on quaternions and their application to Lagrangian flows, particularly the incompressible Euler equations and the equations of ideal MHD, this paper investigates the compressible and relativistic Euler equations using these methods.

  3. "Waveguidability" of idealized jets

    NASA Astrophysics Data System (ADS)

    Manola, Iris; Selten, Frank; Vries, Hylke; Hazeleger, Wilco

    2013-09-01

    It is known that strong zonal jets can act as waveguides for Rossby waves. In this study we use the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis data to analyze the connection between jets and zonal waves at timescales beyond 10 days. Moreover, a barotropic model is used to systematically study the ability of idealized jets to trap Rossby wave energy ("waveguidability") as a function of jet strength, jet width, and jet location. In general, strongest waveguidability is found for narrow, fast jets. In addition, when the stationary wave number is integer, a resonant response is found through constructive interference. In Austral summer, the Southern Hemispheric jet is closest to the idealized jets considered and it is for this season that similar jet-zonal wave relationships are identified in the ECMWF reanalysis data.

  4. Ideal Integrating Bolometer

    NASA Technical Reports Server (NTRS)

    Kogut, A.; DiPirro, M.; Moseley, S. H.

    2004-01-01

    We describe a new "ideal integrator" bolometer as a prototype for a new generation of sensitive, flexible far-IR detectors suitable for use in large arrays. The combination of a non-dissipative sensor coupled with a fast heat switch provides breakthrough capabilities in both sensitivity and operation. The bolometer temperature varies linearly with the integrated infrared power incident on the detector, and may be sampled intermittently without loss of information between samples. The sample speed and consequent dynamic range depend only on the heat switch reset cycle and can be selected in software. Between samples, the device acts as an ideal integrator with noise significantly lower than resistive bolometers. Since there is no loss of information between samples, the device is well-suited for large arrays. A single SQUID readout could process an entire column of detectors, greatly reducing the complexity, power requirements, and cost of readout electronics for large pixel arrays.

  5. Defining the ideal femtosecond laser capsulotomy

    PubMed Central

    Packer, Mark; Teuma, E Valas; Glasser, Adrian; Bott, Steven

    2015-01-01

    Purpose We define the ideal anterior capsulotomy through consideration of capsular histology and biomechanics. Desirable qualities include preventing posterior capsular opacification (PCO), maintaining effective lens position (ELP) and optimising capsular strength. Methods Laboratory study of capsular biomechanics and literature review of histology and published clinical results. Results Parameters of ideal capsulotomy construction include complete overlap of the intraocular lens to prevent PCO, centration on the clinical approximation of the optical axis of the lens to ensure concentricity with the capsule equator, and maximal capsular thickness at the capsulotomy edge to maintain integrity. Conclusions Constructing the capsulotomy centred on the clinical approximation of the optical axis of the lens with diameter 5.25 mm optimises prevention of PCO, consistency of ELP and capsular strength. PMID:25829488

  6. Capturing Medical Students’ Idealism

    PubMed Central

    Smith, Janice K.; Weaver, Donna B.

    2006-01-01

    PURPOSE Students’ idealism and desire to work with underserved populations decline as they progress from preclinical training through clerkships and residency. With an increasingly diverse population and increasing health disparities, academic health centers need to incorporate changes in their curricula to train socially responsible and idealistic physicians. International electives can provide valuable learning experiences to help achieve these goals. METHODS Sixty-six preclinical medical students at the University of Texas Medical Branch participated in an international elective from 1997 to 2005. After 1 week of didactics, they spent 3 weeks as part of a multidisciplinary medical team in rural Nicaragua. Postelective questionnaires were administered. From students’ responses, we identified common learning themes and grouped them under the categories of attitudes, awareness, and skills. Limitations included a self-selection bias, lack of a control group, and limited follow-up. RESULTS After the elective, students had an increased interest in volunteerism, humanitarian efforts, and working with underserved populations both in the United States and abroad, as well as more compassion toward the underserved. Students also reported a heightened awareness of social determinants of health and public health, and a broadened global perspective, as well as increased self-awareness. CONCLUSIONS Our findings illustrate that a well-structured, mentored experience in international health can have a positive impact on preclinical students’ attitudes, including their compassion, volunteerism, and interest in serving under-served populations, all measures of idealism. PMID:17003160

  7. Quasi-Ideal Memory System.

    PubMed

    Sun, Junwei; Shen, Yi

    2015-07-01

    The definition for ideal memory system is so strict that some physical elements cannot exist in the real world. In this paper, an ideal memory system can be extended to generate 15 different kinds of quasi-ideal memory systems, which are included in memory systems as its special cases and are different from ideal memory system. For a system to be a quasi-ideal memory system, it should show three unique fingerprints: 1) the pinched hysteretic loop of a quasi-ideal memory system must be odd symmetrical in the plane; 2) the pinched hysteretic loop of a quasi-ideal memory system must be "self-crossing"; and 3) the slope of tangent line for the pinched hysteresis loop must be strictly monotone in a given period. PMID:25204007

  8. Space Sciences and Idealism

    NASA Astrophysics Data System (ADS)

    Popov, M.

    Erwin Schrodinger suggested that " Scientific knowledge forms part of the idealistic background of human life", which exalted man from a nude and savage state to true humanity [Science and Humanism, Cambridge, 1961, p9]. Modern space sciences an space exploration are a brilliant demonstration of the validity of Schrodinger's thesis on Idealism. Moreover, Schrodingers thesis could be considered also as a basic principle for the New Educational Space Philosophical Project "TIMAEUS"."TIMAEUS" is not only an attempt to to start a new dialogue between Science, the Humanities and Religion; but also it is an origin of the cultural innovations of our so strange of globilisation. TIMAEUS, thus, can reveal Idealism as something more fundamental , more refined, more developed than is now accepted by the scientific community and the piblic. TIMAEUS has a significant cultural agenda, connected with the high orbital performance of the synthetic arts, combining a knowledge of the truly spiritual as well as the universal. In particular, classical ballet as a synthetic art can be a new and powerful perfector and re-creator of the real human, real idealistic, real complex culture in orbit. As is well known, Carlo Blasis, the most important dance theorist of the 19t h .century, made probably the first attempts to use the scientific ideas of Leonardo da Vinci and Isaac Newton for the understanding of the gravitational nature of balance and allegro in ballet. In particular Blasis's idea of the limited use of the legs in classical dance realised by the gifted pupils of Enrico Cecchetti - M.Fokine, A.Pavlova and V.Nijinsky, with thinkable purity and elegance of style. V.Nijinsky in his remarkable animation of the dance of two dimensional creatures of a Euclidean flat world (L'Apres Midi d'un Faune,1912) discovered that true classical dance has some gravitational limits. For example, Nijinsky's Faunes and Nymphs mut use running on the heels (In accordance with "Partitura" 1916); they

  9. Science Learning Centres Roundup

    ERIC Educational Resources Information Center

    Education in Science, 2010

    2010-01-01

    The national network of Science Learning Centres aims to raise the quality of science teaching from Key Stage 1 through post-16 (ages 5-19). Short courses are provided locally through the regional Science Learning Centres and longer, more intensive programmes are available at the National Science Learning Centre in York. There are a growing number…

  10. Uncountably Generated Ideals of Functions

    ERIC Educational Resources Information Center

    Sury, B.

    2011-01-01

    Maximal ideals in the ring of continuous functions on the closed interval [0, 1] are not finitely generated. This is well-known. What is not as well-known, but perhaps should be, is the fact that these ideals are not countably generated although the proof is not harder! We prove this here and use the result to produce some non-prime ideals in the…

  11. Thermal stability of idealized folded carbyne loops.

    PubMed

    Cranford, Steven W

    2013-01-01

    Self-unfolding items provide a practical convenience, wherein ring-like frames are contorted into a state of equilibrium and subsequently  pop up' or deploy when perturbed from a folded structure. Can the same process be exploited at the molecular scale? At the limiting scale is a closed chain of single atoms, used here to investigate the limits of stability of such folded ring structures via full atomistic molecular dynamics. Carbyne is a one-dimensional carbon allotrope composed of sp-hybridized carbon atoms. Here, we explore the stability of idealized carbyne loops as a function of chain length, curvature, and temperature, and delineate an effective phase diagram between folded and unfolded states. We find that while overall curvature is reduced, in addition to torsional and self-adhesive energy barriers, a local increase in curvature results in the largest impedance to unfolding. PMID:24252156

  12. Be Ye Perfect? Religious Ideals in Education

    ERIC Educational Resources Information Center

    de Ruyter, Doret J.

    2006-01-01

    This article explores the meaning of "religious ideals" and their possible role in education. "Religious ideals" are defined as ideals that acquire meaning due to a belief in transcendence or a divine being. Two kinds of religious ideals are being distinguished, namely ideals that are constituted by a belief in a transcendent being and ideals that…

  13. Dimensional Analysis Using Toric Ideals: Primitive Invariants

    PubMed Central

    Atherton, Mark A.; Bates, Ronald A.; Wynn, Henry P.

    2014-01-01

    Classical dimensional analysis in its original form starts by expressing the units for derived quantities, such as force, in terms of power products of basic units etc. This suggests the use of toric ideal theory from algebraic geometry. Within this the Graver basis provides a unique primitive basis in a well-defined sense, which typically has more terms than the standard Buckingham approach. Some textbook examples are revisited and the full set of primitive invariants found. First, a worked example based on convection is introduced to recall the Buckingham method, but using computer algebra to obtain an integer matrix from the initial integer matrix holding the exponents for the derived quantities. The matrix defines the dimensionless variables. But, rather than this integer linear algebra approach it is shown how, by staying with the power product representation, the full set of invariants (dimensionless groups) is obtained directly from the toric ideal defined by . One candidate for the set of invariants is a simple basis of the toric ideal. This, although larger than the rank of , is typically not unique. However, the alternative Graver basis is unique and defines a maximal set of invariants, which are primitive in a simple sense. In addition to the running example four examples are taken from: a windmill, convection, electrodynamics and the hydrogen atom. The method reveals some named invariants. A selection of computer algebra packages is used to show the considerable ease with which both a simple basis and a Graver basis can be found. PMID:25436774

  14. Elastin: a representative ideal protein elastomer.

    PubMed Central

    Urry, D W; Hugel, T; Seitz, M; Gaub, H E; Sheiba, L; Dea, J; Xu, J; Parker, T

    2002-01-01

    During the last half century, identification of an ideal (predominantly entropic) protein elastomer was generally thought to require that the ideal protein elastomer be a random chain network. Here, we report two new sets of data and review previous data. The first set of new data utilizes atomic force microscopy to report single-chain force-extension curves for (GVGVP)(251) and (GVGIP)(260), and provides evidence for single-chain ideal elasticity. The second class of new data provides a direct contrast between low-frequency sound absorption (0.1-10 kHz) exhibited by random-chain network elastomers and by elastin protein-based polymers. Earlier composition, dielectric relaxation (1-1000 MHz), thermoelasticity, molecular mechanics and dynamics calculations and thermodynamic and statistical mechanical analyses are presented, that combine with the new data to contrast with random-chain network rubbers and to detail the presence of regular non-random structural elements of the elastin-based systems that lose entropic elastomeric force upon thermal denaturation. The data and analyses affirm an earlier contrary argument that components of elastin, the elastic protein of the mammalian elastic fibre, and purified elastin fibre itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension. PMID:11911774

  15. Centres of excellence.

    PubMed

    Watson, J M

    1980-05-16

    The present Government may not be enthusiastic about health centres. But Dr Joyce M. Watson, of Glasgow University Department of General Practice and based at Woodside Health Centre in Glasgow, writes with enthusiasm of their advantages for the practice of medicine and the care of patients. PMID:10247174

  16. Detonation Failure in Ideal and Non-Ideal Explosives

    NASA Astrophysics Data System (ADS)

    Haskins, Peter J.; Cook, Malcolm D.

    2007-12-01

    In this paper we revisit and extend the classic treatment of detonation failure developed by Eyring et al. [1]. We recently published a development of this theory [2] in which a pressure dependant rate law was substituted for the Arrhenius temperature dependant law originally considered. Here we show that by assuming a 2-component rate law based upon a temperature dependant ignition phase and a pressure dependant growth phase we are able to rationalise the very different failure characteristics (critical diameter and velocity decrement at failure) of ideal and non-ideal explosives.

  17. Dementia and the person-centred care approach.

    PubMed

    McGreevy, Jessica

    2015-10-01

    Approaches to care that focus solely on biomedical needs are still rife in dementia; however, a person-centred approach is emerging that focuses on 'seeing the person'. This article explores the literature on person-centred dementia care to determine if it is an ideal rather than a reality. The background to the development of person-centred care is presented with reference to policies in place in the UK. Using the setting of long-term care, the journey of people with dementia is explored at diagnosis, living well and end of life. PMID:26402212

  18. Idealism and materialism in perception.

    PubMed

    Rose, David; Brown, Dora

    2015-01-01

    Koenderink (2014, Perception, 43, 1-6) has said most Perception readers are deluded, because they believe an 'All Seeing Eye' observes an objective reality. We trace the source of Koenderink's assertion to his metaphysical idealism, and point to two major weaknesses in his position-namely, its dualism and foundationalism. We counter with arguments from modern philosophy of science for the existence of an objective material reality, contrast Koenderink's enactivism to his idealism, and point to ways in which phenomenology and cognitive science are complementary and not mutually exclusive. PMID:26492727

  19. Pretoria Centre Reaches Out

    NASA Astrophysics Data System (ADS)

    Bosman, Olivier

    2014-08-01

    On 5 July 2014 six members of the Pretoria Centre of ASSA braved the light pollution of one of the shopping malls in Centurion to reach out to shoppers a la John Dobson and to show them the moon, Mars and Saturn. Although the centre hosts regular monthly public observing evenings, it was felt that we should take astronomy to the people rather than wait for the people to come to us.

  20. Chemical Laws, Idealization and Approximation

    ERIC Educational Resources Information Center

    Tobin, Emma

    2013-01-01

    This paper examines the notion of laws in chemistry. Vihalemm ("Found Chem" 5(1):7-22, 2003) argues that the laws of chemistry are fundamentally the same as the laws of physics they are all "ceteris paribus" laws which are true "in ideal conditions". In contrast, Scerri (2000) contends that the laws of chemistry are…

  1. Temperature and the Ideal Gas

    ERIC Educational Resources Information Center

    Daisley, R. E.

    1973-01-01

    Presents some organized ideas in thermodynamics which are suitable for use with high school (GCE A level or ONC) students. Emphases are placed upon macroscopic observations and intimate connection of the modern definition of temperature with the concept of ideal gas. (CC)

  2. Convex analysis and ideal tensegrities

    NASA Astrophysics Data System (ADS)

    Maceri, Franco; Marino, Michele; Vairo, Giuseppe

    2011-11-01

    A theoretical framework based on convex analysis is formulated and developed to study tensegrity structures under steady-state loads. Many classical results for ideal tensegrities are rationally deduced from subdifferentiable models in a novel mechanical perspective. Novel energy-based criteria for rigidity and pre-stressability are provided, allowing to formulate numerical algorithms for computations.

  3. [Harmony--idea and ideal].

    PubMed

    Scharfetter, C

    1996-03-01

    The concept of the whole as an ideal of gestalt and value is sketched. In the concrete situation of healer and patient a multiperspective approach rather than a realization of wholeness has to be enough, taking into account somatic, physiological, intraindividual-psychological, interpersonal-social and transpersonal aspects of personalities in diagnosis and treatment. PMID:8900879

  4. Dimensional analysis using toric ideals: primitive invariants.

    PubMed

    Atherton, Mark A; Bates, Ronald A; Wynn, Henry P

    2014-01-01

    Classical dimensional analysis in its original form starts by expressing the units for derived quantities, such as force, in terms of power products of basic units [Formula: see text] etc. This suggests the use of toric ideal theory from algebraic geometry. Within this the Graver basis provides a unique primitive basis in a well-defined sense, which typically has more terms than the standard Buckingham approach. Some textbook examples are revisited and the full set of primitive invariants found. First, a worked example based on convection is introduced to recall the Buckingham method, but using computer algebra to obtain an integer [Formula: see text] matrix from the initial integer [Formula: see text] matrix holding the exponents for the derived quantities. The [Formula: see text] matrix defines the dimensionless variables. But, rather than this integer linear algebra approach it is shown how, by staying with the power product representation, the full set of invariants (dimensionless groups) is obtained directly from the toric ideal defined by [Formula: see text]. One candidate for the set of invariants is a simple basis of the toric ideal. This, although larger than the rank of [Formula: see text], is typically not unique. However, the alternative Graver basis is unique and defines a maximal set of invariants, which are primitive in a simple sense. In addition to the running example four examples are taken from: a windmill, convection, electrodynamics and the hydrogen atom. The method reveals some named invariants. A selection of computer algebra packages is used to show the considerable ease with which both a simple basis and a Graver basis can be found. PMID:25436774

  5. Preoccupied with the Self: Towards Self-Responsible, Enterprising, Flexible and Self-Centred Subjectivity in Education

    ERIC Educational Resources Information Center

    Brunila, Kristiina; Siivonen, Päivi

    2016-01-01

    In the neoliberal order, the ideal self is self-responsible, enterprising, flexible and self-centred. Regarding this ideal we argue that the rise of therapisation in society, and in education, particularly, links both the therapeutic and enterprising discourses. The article examines how these discourses jointly produce and legitimate the ideal,…

  6. Cylindrical magnets and ideal solenoids

    NASA Astrophysics Data System (ADS)

    Derby, Norman; Olbert, Stanislaw

    2010-03-01

    Both wire-wound solenoids and cylindrical magnets can be approximated as ideal azimuthally symmetric solenoids. We present an exact solution for the magnetic field of an ideal solenoid in an easy to use form. The field is expressed in terms of a single function that can be rapidly computed by means of a compact efficient algorithm, which can be coded as an add-in function to a spreadsheet, making field calculations accessible to introductory students. These expressions are not only accurate but are also as fast as most approximate expressions. We demonstrate their utility by simulating the dropping of a cylindrical magnet through a nonmagnetic conducting tube and comparing the calculation with data obtained from experiments suitable for an undergraduate laboratory.

  7. Representation of Ideal Magnetohydrodynamic Modes

    SciTech Connect

    Roscoe B. White

    2013-01-15

    One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through δ Β = ∇ X (xi X B) ensures that δ B • ∇ ψ = 0 at a resonance, with ψ labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation δ Β = ∇ X αB. These two representations are equivalent, but the vanishing of δ B • ∇ψ at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in xi to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed

  8. Ideal and incompressible fluid dynamics

    NASA Astrophysics Data System (ADS)

    Oneill, M. E.; Chorlton, F.

    An introductory treatment of fluid mechanics theory, emphasizing mathematical methods and techniques, is given. Basic mathematical techniques of flow analysis are outlined in connection with viscous and inviscid flows, compressible and incompressible flows, and ideal flows. Among the specific flow problems addressed are: the kinematics of fluids in motion; equations of motion in boundary layer flows; and the stream functions for two-dimensional flows. Methods for analyzing wave motion in rectangular and cylindrical tanks are also described.

  9. Lidar Calibration Centre

    NASA Astrophysics Data System (ADS)

    Pappalardo, Gelsomina; Freudenthaler, Volker; Nicolae, Doina; Mona, Lucia; Belegante, Livio; D'Amico, Giuseppe

    2016-06-01

    This paper presents the newly established Lidar Calibration Centre, a distributed infrastructure in Europe, whose goal is to offer services for complete characterization and calibration of lidars and ceilometers. Mobile reference lidars, laboratories for testing and characterization of optics and electronics, facilities for inspection and debugging of instruments, as well as for training in good practices are open to users from the scientific community, operational services and private sector. The Lidar Calibration Centre offers support for trans-national access through the EC HORIZON2020 project ACTRIS-2.

  10. Flexibility mechanisms in ideal zeolite frameworks.

    PubMed

    Treacy, M M J; Dawson, C J; Kapko, V; Rivin, I

    2014-02-13

    Zeolites are microporous crystalline aluminosilicate materials whose atomic structures can be usefully modelled in purely mechanical terms as stress-free periodic trusses constructed from rigid corner-connected SiO4 and AlO4 tetrahedra. When modelled this way, all of the known synthesized zeolite frameworks exhibit a range of densities, known as the flexibility window, over which they satisfy the framework mechanical constraints. Within the flexibility window internal stresses are accommodated by force-free coordinated rotations of the tetrahedra about their apices (oxygen atoms). We use rigidity theory to explore the folding mechanisms within the flexibility window, and derive an expression for the configurational entropic density throughout the flexibility window. By comparison with the structures of pure silica zeolite materials, we conclude that configurational entropy associated with the flexibility modes is not a dominant thermodynamic term in most bulk zeolite crystals. Nevertheless, the presence of a flexibility window in an idealized hypothetical tetrahedral framework may be thermodynamically important at the nucleation stage of zeolite formation, suggesting that flexibility is a strong indicator that the topology is realizable as a zeolite. Only a small fraction of the vast number of hypothetical zeolites that are known exhibit flexibility. The absence of a flexibility window may explain why so few hypothetical frameworks are realized in nature. PMID:24379426

  11. Incident and Emergency Centre of the IAEA.

    PubMed

    Baciu, Florian; Buglova, Elena; Martincic, Rafael; Spiegelberg Planer, Rejane; Stern, Warren; Winkler, Guenther

    2010-06-01

    The Incident and Emergency Centre of the International Atomic Emergency Agency is the global focal point for preparedness, event reporting, and response to nuclear and radiological incidents and emergencies irrespective of their cause. The Centre continuously works to develop standards and guidance for strengthening Member States' preparedness; develops practical tools and training programs to assist Member States in promptly applying the standards and guidance; and organizes a variety of training events and exercises. The Centre evaluates national plans and assists in their development; facilitates effective communication between countries; develops response procedures; and supports national exercises. The Centre provides access to multiple information resources; assesses trends that may influence crisis and consequence management plans and response; and develops and continuously enhances methodology for identifying conditions needed for early warning and response. The Centre provides around-the-clock assistance to Member States in dealing with nuclear and radiological events, including security related events through timely and efficient services and the provision of a coordinated international response to such emergencies. PMID:20445379

  12. Piecewise lexsegment ideals in exterior algebras

    NASA Astrophysics Data System (ADS)

    Shakin, D. A.

    2005-02-01

    The problem of describing the Hilbert functions of homogeneous ideals of an exterior algebra over a field containing a fixed monomial ideal I is considered. For this purpose the notion of a piecewise lexsegment ideal in an exterior algebra is introduced generalizing the notion of a lexsegment ideal. It is proved that if I is a piecewise lexsegment ideal, then it is possible to describe the Hilbert functions of the homogeneous ideals containing I in a way similar to that suggested by Kruskal and Katona for the situation I=0. Moreover, a generalization of the extremal properties of lexsegment ideals is obtained (the inequality for the Betti numbers).

  13. On fuzzy ideals of BL-algebras.

    PubMed

    Meng, Biao Long; Xin, Xiao Long

    2014-01-01

    In this paper we investigate further properties of fuzzy ideals of a BL-algebra. The notions of fuzzy prime ideals, fuzzy irreducible ideals, and fuzzy Gödel ideals of a BL-algebra are introduced and their several properties are investigated. We give a procedure to generate a fuzzy ideal by a fuzzy set. We prove that every fuzzy irreducible ideal is a fuzzy prime ideal but a fuzzy prime ideal may not be a fuzzy irreducible ideal and prove that a fuzzy prime ideal ω is a fuzzy irreducible ideal if and only if ω(0) = 1 and |Im(ω)| = 2. We give the Krull-Stone representation theorem of fuzzy ideals in BL-algebras. Furthermore, we prove that the lattice of all fuzzy ideals of a BL-algebra is a complete distributive lattice. Finally, it is proved that every fuzzy Boolean ideal is a fuzzy Gödel ideal, but the converse implication is not true. PMID:24892085

  14. Maple Leaf Outdoor Centre.

    ERIC Educational Resources Information Center

    Maguire, Molly; Gunton, Ric

    2000-01-01

    Maple Leaf Outdoor Centre (Ontario) has added year-round outdoor education facilities and programs to help support its summer camp for disadvantaged children. Schools, youth centers, religious groups, and athletic teams conduct their own programs, collaborate with staff, or use staff-developed programs emphasizing adventure education and personal…

  15. Winnipeg Centre Project.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    The Winnipeg Centre Project is a field-based, work-study program that attempts to create more appropriate education for the inner-city child. Sponsored by the Planning and Research Branch of the Department of Colleges and Universities Affairs and administered by Brandon University in consultation with the Winnipeg School Division, the project is…

  16. Wycheproof Education Centre.

    ERIC Educational Resources Information Center

    Sweetnam and Godfrey, Melbourne (Australia).

    The Wycheproof township in New South Wales (Australia) is the regional center for a grain farming community. The Wycheproof Education Centre was formed by the merger of a separate primary and secondary school (on one site with existing buildings), into a single governing body that is educationally structured into junior, middle, and senior…

  17. Implementing Responsibility Centre Budgeting

    ERIC Educational Resources Information Center

    Vonasek, Joseph

    2011-01-01

    Recently, institutes of higher education (universities) have shown a renewed interest in organisational structures and operating methodologies that generate productivity and innovation; responsibility centre budgeting (RCB) is one such process. This paper describes the underlying principles constituting RCB, its origin and structural elements, and…

  18. The GSO Data Centre

    NASA Astrophysics Data System (ADS)

    Paletou, F.; Glorian, J.-M.; Génot, V.; Rouillard, A.; Petit, P.; Palacios, A.; Caux, E.; Wakelam, V.

    2015-12-01

    Hereafter we describe the activities of the Grand Sud-Ouest Data Centre operated for INSU (CNRS) by the OMP--IRAP and the Université Paul Sabatier in Toulouse, in a collaboration with the OASU--LAB in Bordeaux and OREME--LUPM in Montpellier.

  19. Detonation Failure in Ideal and Non-Ideal Explosives

    NASA Astrophysics Data System (ADS)

    Haskins, P. J.; Cook, M. D.

    2007-06-01

    In this paper we revisit and extend the classic treatment of detonation failure developed by Eyring et. al. [1]. We recently published a development of this theory [2] in which a pressure dependant rate law was substituted for the Arrhenius temperature dependant law originally considered. Here we show that by assuming a 2-component rate law based upon a temperature dependant ignition phase and a pressure dependant growth phase we are able to rationalise the very different failure characteristics (critical diameter and velocity decrement at failure) of ideal and non-ideal explosives. [1] Eyring, H., Powell, R.E., Duffy, G.H., and Parlin, R.B., ``The stability of detonation,'' Chem. Rev. 45, 69-181 (1949). [2] Haskins, P.J., Cook, M.D., and Wood, A.D., ``On the dependence of critical diameter and velocity decrement at failure on the burn law,'' in proceedings of the 33rd International Pyrotechnics Seminar, Fort Collins, Co, USA, 385-391 (2006).

  20. Numerical Simulations for Ideal Magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Dai, Wenlong

    An approximate Riemann solver needed in a high -order Godunov-type scheme for ideal MHD is developed in this thesis. The Riemann solver consists of the initial guess, the calculation of the two fast shock speeds and post-shock states, the performance of two possible rotations, the calculation of the two slow shock speeds and post-shock states, and the improvement of the initial guess. The Riemann solver includes all the discontinuities in ideal MHD. The extension of the Piecewise Parabolic Method in ideal MHD is presented based on the Riemann solver. The code starts from a set of normal physical variables. A cubic polynomial is used to interpolate each of Riemann invariants. The values of those physical variables at edges of computational zones are obtained through the interpolated Riemann invariants. The monotonicity constraint is applied to those point values of physical variables. A parabola is used for the internal structure of a zone. The set of time-averaged fluxes is calculated by the Riemann solver. The conserved quantities are updated by adding the net flux advected into each zone. After the dynamical step in a Lagrangian grid, the conserved quantities are mapped onto a fixed Eulerian grid. The two-dimensional scheme is built upon the technique of dimension splitting. The scheme is applied to wave steepening, propagation of shocks, various shock tube problems, the penetration of a solar wind filament, and MHD shock interactions with a cloud. The results of these applications show that the scheme has the principal advantages of a Godunov-type scheme, i.e., the robust operation in the presence of very strong discontinuities, thin shock fronts with little attendant noise generation, and thin contact and tangential discontinuities.

  1. Chemical Laws, Idealization and Approximation

    NASA Astrophysics Data System (ADS)

    Tobin, Emma

    2013-07-01

    This paper examines the notion of laws in chemistry. Vihalemm ( Found Chem 5(1):7-22, 2003) argues that the laws of chemistry are fundamentally the same as the laws of physics they are all ceteris paribus laws which are true "in ideal conditions". In contrast, Scerri (2000) contends that the laws of chemistry are fundamentally different to the laws of physics, because they involve approximations. Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34-50, 2000) agree that the laws of chemistry are operationally different to the laws of physics, but claim that the distinction between exact and approximate laws is too simplistic to taxonomise them. Approximations in chemistry involve diverse kinds of activity and often what counts as a scientific law in chemistry is dictated by the context of its use in scientific practice. This paper addresses the question of what makes chemical laws distinctive independently of the separate question as to how they are related to the laws of physics. From an analysis of some candidate ceteris paribus laws in chemistry, this paper argues that there are two distinct kinds of ceteris paribus laws in chemistry; idealized and approximate chemical laws. Thus, while Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34--50, 2000) are correct to point out that the candidate generalisations in chemistry are diverse and heterogeneous, a distinction between idealizations and approximations can nevertheless be used to successfully taxonomise them.

  2. Obese people's perceptions of the thin ideal.

    PubMed

    Couch, Danielle; Thomas, Samantha L; Lewis, Sophie; Blood, R Warwick; Holland, Kate; Komesaroff, Paul

    2016-01-01

    The media play a key role in promoting the thin ideal. A qualitative study, in which we used in depth interviews and thematic analysis, was undertaken to explore the attitudes of 142 obese individuals toward media portrayals of the thin ideal. Participants discussed the thin ideal as a social norm that is also supported through the exclusion of positive media portrayals of obese people. They perceived the thin ideal as an 'unhealthy' mode of social control, reflecting on their personal experiences and their concerns for others. Participants' perceptions highlighted the intersections between the thin ideal and gender, grooming and consumerism. Participants' personal responses to the thin ideal were nuanced--some were in support of the thin ideal and some were able to critically reflect and reject the thin ideal. We consider how the thin ideal may act as a form of synoptical social control, working in tandem with wider public health panoptical surveillance of body weight. PMID:26685706

  3. Measurement of optical Feshbach resonances in an ideal gas.

    PubMed

    Blatt, S; Nicholson, T L; Bloom, B J; Williams, J R; Thomsen, J W; Julienne, P S; Ye, J

    2011-08-12

    Using a narrow intercombination line in alkaline earth atoms to mitigate large inelastic losses, we explore the optical Feshbach resonance effect in an ultracold gas of bosonic (88)Sr. A systematic measurement of three resonances allows precise determinations of the optical Feshbach resonance strength and scaling law, in agreement with coupled-channel theory. Resonant enhancement of the complex scattering length leads to thermalization mediated by elastic and inelastic collisions in an otherwise ideal gas. Optical Feshbach resonance could be used to control atomic interactions with high spatial and temporal resolution. PMID:21902391

  4. Imagining the ideal dairy farm.

    PubMed

    Cardoso, Clarissa S; Hötzel, Maria José; Weary, Daniel M; Robbins, Jesse A; von Keyserlingk, Marina A G

    2016-02-01

    Practices in agriculture can have negative effects on the environment, rural communities, food safety, and animal welfare. Although disagreements are possible about specific issues and potential solutions, it is widely recognized that public input is needed in the development of socially sustainable agriculture systems. The aim of this study was to assess the views of people not affiliated with the dairy industry on what they perceived to be the ideal dairy farm and their associated reasons. Through an online survey, participants were invited to respond to the following open-ended question: "What do you consider to be an ideal dairy farm and why are these characteristics important to you?" Although participants referenced social, economic, and ecological aspects of dairy farming, animal welfare was the primary issue raised. Concern was expressed directly about the quality of life for the animals, and the indirect effect of animal welfare on milk quality. Thus participants appeared to hold an ethic for dairy farming that included concern for the animal, as well as economic, social, and environmental aspects of the dairy system. PMID:26709190

  5. Representation of ideal magnetohydrodynamic modes

    SciTech Connect

    White, R. B.

    2013-02-15

    One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through {delta}B(vector sign)={nabla} Multiplication-Sign ({xi}(vector sign) Multiplication-Sign B(vector sign)) ensures that {delta}B(vector sign){center_dot}{nabla}{psi}=0 at a resonance, with {psi} labelling an equilibrium flux surface. Also useful for the analysis of guiding center orbits in a perturbed field is the representation {delta}B(vector sign)={nabla} Multiplication-Sign {alpha}B(vector sign). These two representations are equivalent, but the vanishing of {delta}B(vector sign){center_dot}{nabla}{psi} at a resonance is necessary but not sufficient for the preservation of field line topology, and a indiscriminate use of either perturbation in fact destroys the original equilibrium flux topology. It is necessary to find the perturbed field to all orders in {xi}(vector sign) to conserve the original topology. The effect of using linearized perturbations on stability and growth rate calculations is discussed.

  6. Measuring explosive non-ideality

    SciTech Connect

    Souers, P C

    1999-02-17

    The sonic reaction zone length may be measured by four methods: (1) size effect, (2) detonation front curvature, (3) crystal interface velocity and (4) in-situ gauges. The amount of data decreases exponentially from (1) to (4) with there being almost no gauge data for prompt detonation at steady state. The ease and clarity of obtaining the reaction zone length increases from (1) to (4). The method of getting the reaction zone length, , is described for the four methods. A measure of non-ideality is proposed: the reaction zone length divided by the cylinder radius. N = /R{sub o}. N = 0 for true ideality. It also decreases with increasing radius as it should. For N < 0.10, an equilibrium EOS like the JWL may be used. For N > 0.10, a time-dependent description is essential. The crystal experiment, which measures the particle velocity of an explosive-transparent material interface, is presently rising in importance. We examine the data from three experiments and apply: (1) an impedance correction that transfers the explosive C-J particle velocity to the corresponding value for the interface, and (2) multiplies the interface time by 3/4 to simulate the explosive speed of sound. The result is a reaction zone length comparable to those obtained by other means. A few explosives have reaction zones so small that the change of slope in the particle velocity is easily seen.

  7. Studies on crystal structures, active-centre geometry and depurinating mechanism of two ribosome-inactivating proteins.

    PubMed Central

    Huang, Q; Liu, S; Tang, Y; Jin, S; Wang, Y

    1995-01-01

    Two ribosome-inactivating proteins, trichosanthin and alpha-momorcharin, have been studied in the forms of complexes with ATP or formycin, by an X-ray-crystallographic method at 1.6-2.0 A (0.16-0.20 nm) resolution. The native alpha-momorcharin had been studied at 2.2 A resolution. Structures of trichosanthin were determined by a multiple isomorphous replacement method. Structures of alpha-momorcharin were determined by a molecular replacement method using refined trichosanthin as the searching model. Small ligands in all these complexes have been recognized and built on the difference in electron density. All these structures have been refined to achieve good results, both in terms of crystallography and of ideal geometry. These two proteins show considerable similarity in their three-dimensional folding and to that of related proteins. On the basis of these structures, detailed geometries of the active centres of these two proteins are described and are compared with those of related proteins. In all complexes the interactions between ligand atoms and protein atoms, including hydrophobic forces, aromatic stacking interactions and hydrogen bonds, are found to be specific towards the adenine base. The relationship between the sequence conservation of ribosome-inactivating proteins and their active-centre geometry was analysed. A depurinating mechanism of ribosome-inactivating proteins is proposed on the basis of these results. The N-7 atom of the substrate base group is proposed to be protonated by an acidic residue in the active centre. Images Figure 1 PMID:7619070

  8. SPOT4 Management Centre

    NASA Technical Reports Server (NTRS)

    Labrune, Yves; Labbe, X.; Roussel, A.; Vielcanet, P.

    1994-01-01

    In the context of the CNES SPOT4 program CISI is particularly responsible for the development of the SPOT4 Management Centre, part of the SPOT4 ground control system located at CNES Toulouse (France) designed to provide simultaneous control over two satellites. The main operational activities are timed to synchronize with satellite visibilities (ten usable passes per day). The automatic capability of this system is achieved through agenda services (sequence of operations as defined and planned by operator). Therefore, the SPOT4 Management Centre offers limited, efficient and secure human interventions for supervision and decision making. This paper emphasizes the main system characteristics as degree of automation, level of dependability and system parameterization.

  9. Elderly Care Centre

    NASA Astrophysics Data System (ADS)

    Wagiman, Aliani; Haja Bava Mohidin, Hazrina; Ismail, Alice Sabrina

    2016-02-01

    The demand for elderly centre has increased tremendously abreast with the world demographic change as the number of senior citizens rose in the 21st century. This has become one of the most crucial problems of today's era. As the world progress into modernity, more and more people are occupied with daily work causing the senior citizens to lose the care that they actually need. This paper seeks to elucidate the best possible design of an elderly care centre with new approach in order to provide the best service for them by analysing their needs and suitable activities that could elevate their quality of life. All these findings will then be incorporated into design solutions so as to enhance the living environment for the elderly especially in Malaysian context.

  10. SPOT4 Management Centre

    NASA Astrophysics Data System (ADS)

    Labrune, Yves; Labbe, X.; Roussel, A.; Vielcanet, P.

    1994-11-01

    In the context of the CNES SPOT4 program CISI is particularly responsible for the development of the SPOT4 Management Centre, part of the SPOT4 ground control system located at CNES Toulouse (France) designed to provide simultaneous control over two satellites. The main operational activities are timed to synchronize with satellite visibilities (ten usable passes per day). The automatic capability of this system is achieved through agenda services (sequence of operations as defined and planned by operator). Therefore, the SPOT4 Management Centre offers limited, efficient and secure human interventions for supervision and decision making. This paper emphasizes the main system characteristics as degree of automation, level of dependability and system parameterization.

  11. Computational Methods for Ideal Magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Kercher, Andrew D.

    Numerical schemes for the ideal magnetohydrodynamics (MHD) are widely used for modeling space weather and astrophysical flows. They are designed to resolve the different waves that propagate through a magnetohydro fluid, namely, the fast, Alfven, slow, and entropy waves. Numerical schemes for ideal magnetohydrodynamics that are based on the standard finite volume (FV) discretization exhibit pseudo-convergence in which non-regular waves no longer exist only after heavy grid refinement. A method is described for obtaining solutions for coplanar and near coplanar cases that consist of only regular waves, independent of grid refinement. The method, referred to as Compound Wave Modification (CWM), involves removing the flux associated with non-regular structures and can be used for simulations in two- and three-dimensions because it does not require explicitly tracking an Alfven wave. For a near coplanar case, and for grids with 213 points or less, we find root-mean-square-errors (RMSEs) that are as much as 6 times smaller. For the coplanar case, in which non-regular structures will exist at all levels of grid refinement for standard FV schemes, the RMSE is as much as 25 times smaller. A multidimensional ideal MHD code has been implemented for simulations on graphics processing units (GPUs). Performance measurements were conducted for both the NVIDIA GeForce GTX Titan and Intel Xeon E5645 processor. The GPU is shown to perform one to two orders of magnitude greater than the CPU when using a single core, and two to three times greater than when run in parallel with OpenMP. Performance comparisons are made for two methods of storing data on the GPU. The first approach stores data as an Array of Structures (AoS), e.g., a point coordinate array of size 3 x n is iterated over. The second approach stores data as a Structure of Arrays (SoA), e.g. three separate arrays of size n are iterated over simultaneously. For an AoS, coalescing does not occur, reducing memory efficiency

  12. (Fuzzy) Ideals of BN-Algebras

    PubMed Central

    Walendziak, Andrzej

    2015-01-01

    The notions of an ideal and a fuzzy ideal in BN-algebras are introduced. The properties and characterizations of them are investigated. The concepts of normal ideals and normal congruences of a BN-algebra are also studied, the properties of them are displayed, and a one-to-one correspondence between them is presented. Conditions for a fuzzy set to be a fuzzy ideal are given. The relationships between ideals and fuzzy ideals of a BN-algebra are established. The homomorphic properties of fuzzy ideals of a BN-algebra are provided. Finally, characterizations of Noetherian BN-algebras and Artinian BN-algebras via fuzzy ideals are obtained. PMID:26125050

  13. Can Chemistry Teachers' Centres Survive?

    ERIC Educational Resources Information Center

    Garforth, F. M.

    1972-01-01

    The difficulties faced by the Hull Chemistry Teachers' Centre in England are discussed. The lack of finances and time, as well as organizational difficulties in relationship with Science Centres and universities are among the problems. (TS)

  14. Pulsatile flow through idealized trabeculae

    NASA Astrophysics Data System (ADS)

    Battista, Nicholas; Miller, Laura

    2013-11-01

    Trabeculae begin to form in the human developing heart for Reynolds numbers on the order of 10. Other hearts, such as the squid heart, have trabeculae for Re on the order of 10 and larger. The effect of trabeculae on the flow in this range of Re is not well understood. In this study, computational fluid dynamics is used to quantify the effects of Reynolds number and idealized trabeculae height on the resulting flows. An adaptive and parallelized version of the immersed boundary method (IBAMR) is used to solve the fluid-structure interaction problem. We see the formation of vortices depends upon Re and trabeculae height. We then explore how the periodicity of the flow effects vortex formation and shear patterns. This is important because it is thought that these dynamic processes are important to the generation of shear at the endothelial surface layer and strains at the epithelial layer, which will aid in proper development and functionality.

  15. Irreversibility in an ideal fluid

    NASA Astrophysics Data System (ADS)

    Jenkins, Alejandro

    2014-11-01

    When a real fluid is expelled quickly from a tube, it forms a jet separated from the surrounding fluid by a thin, turbulent layer. On the other hand, when the same fluid is sucked into the tube, it enters from all directions, forming a sink-like flow. We show that, even for the ideal flow described by the time-reversible Euler equation, an experimenter who only controls the pressure in a pump attached to the tube would see jets form in one direction exclusively. The asymmetry between outflow and inflow therefore does not depend on viscous dissipation, but rather on the experimenter's limited control of initial and boundary conditions. This illustrates, in a rather different context from the usual one of thermal physics, how irreversibility may arise in systems whose microscopic dynamics are fully reversible.

  16. [The ideal body: media pedagogy].

    PubMed

    Ribeiro, Rubia Guimarães; da Silva, Karen Schein; Kruse, Maria Henriqueta Luce

    2009-03-01

    We present enunciations that circulate in the media regarding the body, discussing the ways in which the speeches related with the maintenance of health and aesthetics invest in its improvement. Therefore, we used the Caderno Vida, a weekly insert of Zero Hora, for we understand it as owner of a proper speech that has the power of subjectivate people The analysis is part of Cultural Studies and it is based on the ideas of Michel Foucault. The methodological strategy used was the speech analysis of subjects about body care. The periodical questions its readers using speeches that point to beauty health and success The constructed categories were: how is the ideal body, what to do to have such body and why we must have this body Balanced feeding, practice of regular physical activities and the accomplishment of plastic surgeries are recommendations recurrently found in weekly inserts. PMID:19653558

  17. Universal behavior in ideal slip

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Ferrante, John; Smith, John R.

    1991-01-01

    The slip energies and stresses are computed for defect-free crystals of Ni, Cu, Ag, and Al using the many-atom approach. A simple analytical expression for the slip energies is obtained, leading to a universal form for slip, with the energy scaled by the surface energy and displacement scaled by the lattice constant. Maximum stresses are found to be somewhat larger than but comparable with experimentally determined maximum whisker strengths.

  18. Recharging Our Sense of Idealism: Concluding Thoughts

    ERIC Educational Resources Information Center

    D'Andrea, Michael; Dollarhide, Colette T.

    2011-01-01

    In this article, the authors aim to recharge one's sense of idealism. They argue that idealism is the Vitamin C that sustains one's commitment to implementing humanistic principles and social justice practices in the work of counselors and educators. The idealism that characterizes counselors and educators who are humanistic and social justice…

  19. The DESY Grid Centre

    NASA Astrophysics Data System (ADS)

    Haupt, A.; Gellrich, A.; Kemp, Y.; Leffhalm, K.; Ozerov, D.; Wegner, P.

    2012-12-01

    DESY is one of the world-wide leading centers for research with particle accelerators, synchrotron light and astroparticles. DESY participates in LHC as a Tier-2 center, supports on-going analyzes of HERA data, is a leading partner for ILC, and runs the National Analysis Facility (NAF) for LHC and ILC in the framework of the Helmholtz Alliance, Physics at the Terascale. For the research with synchrotron light major new facilities are operated and built (FLASH, PETRA-III, and XFEL). DESY furthermore acts as Data-Tier1 centre for the Neutrino detector IceCube. Established within the EGI-project DESY operates a grid infrastructure which supports a number of virtual Organizations (VO), incl. ATLAS, CMS, and LHCb. Furthermore, DESY hosts some of HEP and non-HEP VOs, such as the HERA experiments and ILC as well as photon science communities. The support of the new astroparticle physics VOs IceCube and CTA is currently set up. As the global structure of the grid offers huge resources which are perfect for batch-like computing, DESY has set up the National Analysis Facility (NAF) which complements the grid to allow German HEP users for efficient data analysis. The grid infrastructure and the NAF use the same physics data which is distributed via the grid. We call the conjunction of grid and NAF the DESY Grid Centre. In the contribution to CHEP2012 we will in depth discuss the conceptional and operational aspects of our multi-VO and multi-community Grid Centre and present the system setup. We will in particular focus on the interplay of Grid and NAF and present experiences of the operations.

  20. Practicing Identity: A Crafty Ideal?

    NASA Astrophysics Data System (ADS)

    Brysbaert, A.; Vetters, M.

    This paper focuses on the materialization of technological practices as a form of identity expression. Contextual analyses of a Mycenaean workshop area in the Late Bronze Age citadel of Tiryns (Argolis, Greece) are presented to investigate the interaction of different artisans under changing socio-political and economic circumstances. The case study indicates that although certain technological practices are often linked to specific crafts, they do not necessarily imply the separation of job tasks related to the working of one specific material versus another. Shared technological practices and activities, therefore, may be a factor in shaping cohesive group identities of specialized artisans. Since tracing artisans' identities is easier said than done on the basis of excavated materials alone, we employ the concepts of multiple chaînes opératoires combined with cross-craft interactions as a methodology in order to retrieve distinctive sets of both social and technological practices from the archaeological remains. These methodological concepts are not restricted to a specific set of steps in the production cycle, but ideally encompass reconstructing contexts of extraction, manufacture, distribution and discard/reuse for a range of artefacts. Therefore, these concepts reveal both technological practices, and, by contextualising these technological practices in their spatial layout, equally focus on social contacts that would have taken place during any of these actions. Our detailed contextual study demonstrates that the material remains when analysed in their entirety are complementary to textual evidence. In this case study they even form a source of information on palatial spheres of life about which the fragmentary Linear B texts, so far, remain silent.

  1. [The primary healthcare centres].

    PubMed

    Brambilla, Antonio; Maciocco, Gavino

    2014-04-01

    The central attributes of primary care are: first contact (accessibility), longitudinality (person- focused preventive and curative care overtime), patient-oriented comprehensiveness and coordination (including navigation towards secondary and tertiary care). Besides taking care of the needs of the individuals, primary health care teams are also looking at the community, especially when addressing social determinants of health. The rationale for the benefits for primary care for health has been found in: 1) greater access to needed services; 2) better quality of care; 3) a greater focus on prevention; 4) early management of health problems; 5) organizing and delivering high quality care for chronic non-communicable diseases. This paper describes the role of primary healthcare centres in strengthening community primary services and in reducing health inequalities. Furthemore, the experiences of Regional Health Services from Tuscany and Emilia-Romagna are discussed, with a brief overview of the literature. PMID:24770539

  2. Quantum transport in ultracold atoms

    NASA Astrophysics Data System (ADS)

    Chien, Chih-Chun; Peotta, Sebastiano; di Ventra, Massimiliano

    2015-12-01

    Ultracold atoms confined by engineered magnetic or optical potentials are ideal to study phenomena otherwise difficult to realize or probe in the solid state, thanks to the ability to control the atomic interaction strength, number of species, density and geometry. Here, we review quantum transport phenomena in atomic gases that mirror and can either better elucidate or show fundamental differences with respect to those observed in mesoscopic and nanoscopic systems. We discuss the significant progress in transport experiments in atomic gases, the similarities and differences between transport in cold atoms and in condensed matter systems, and survey theoretical predictions that are difficult to verify in conventional set-ups.

  3. Inherent contradictions in the ego ideal.

    PubMed

    Dendy, Errol B

    2010-10-01

    The author puts forth a concept of the ego ideal as the fantasied self that the child believes will bring it gratification and happiness. He then shows how the ego ideal's content evolves through the various stages of psychosexual development in accordance with its mission. A picture emerges of an ego ideal in inherent conflict because it is shaped by contradictory wishes, as well as contradictory fantasies of how to make those wishes come true. A section on romantic love points to a second contradiction within the ego ideal, beyond its contradictory content: a contradiction of aim. PMID:21141785

  4. Ideal and Nonideal Reasoning in Educational Theory

    ERIC Educational Resources Information Center

    Jaggar, Alison M.

    2015-01-01

    The terms "ideal theory" and "nonideal theory" are used in contemporary Anglophone political philosophy to identify alternative methodological approaches for justifying normative claims. Each term is used in multiple ways. In this article Alison M. Jaggar disentangles several versions of ideal and nonideal theory with a view to…

  5. Ideals as Anchors for Relationship Experiences

    PubMed Central

    Frye, Margaret; Trinitapoli, Jenny

    2016-01-01

    Research on young-adult sexuality in sub-Saharan Africa typically conceptualizes sex as an individual-level risk behavior. We introduce a new approach that connects the conditions surrounding the initiation of sex with subsequent relationship well-being, examines relationships as sequences of interdependent events, and indexes relationship experiences to individually held ideals. New card-sort data from southern Malawi capture young women’s relationship experiences and their ideals in a sequential framework. Using optimal matching, we measure the distance between ideal and experienced relationship sequences to (1) assess the associations between ideological congruence and perceived relationship well-being, (2) compare this ideal-based approach to other experience-based alternatives, and (3) identify individual- and couple-level correlates of congruence between ideals and experiences in the romantic realm. We show that congruence between ideals and experiences conveys relationship well-being along four dimensions: expressions of love and support, robust communication habits, perceived biological safety, and perceived relationship stability. We further show that congruence is patterned by socioeconomic status and supported by shared ideals within romantic dyads. We argue that conceiving of ideals as anchors for how sexual experiences are manifest advances current understandings of romantic relationships, and we suggest that this approach has applications for other domains of life. PMID:27110031

  6. Maintaining ideal body weight counseling sessions

    SciTech Connect

    Brammer, S.H.

    1980-10-09

    The purpose of this program is to provide employees with the motivation, knowledge and skills necessary to maintain ideal body weight throughout life. The target audience for this program, which is conducted in an industrial setting, is the employee 40 years of age or younger who is at or near his/her ideal body weight.

  7. Kirkwood-Buff integrals for ideal solutions

    NASA Astrophysics Data System (ADS)

    Ploetz, Elizabeth A.; Bentenitis, Nikolaos; Smith, Paul E.

    2010-04-01

    The Kirkwood-Buff (KB) theory of solutions is a rigorous theory of solution mixtures which relates the molecular distributions between the solution components to the thermodynamic properties of the mixture. Ideal solutions represent a useful reference for understanding the properties of real solutions. Here, we derive expressions for the KB integrals, the central components of KB theory, in ideal solutions of any number of components corresponding to the three main concentration scales. The results are illustrated by use of molecular dynamics simulations for two binary solutions mixtures, benzene with toluene, and methanethiol with dimethylsulfide, which closely approach ideal behavior, and a binary mixture of benzene and methanol which is nonideal. Simulations of a quaternary mixture containing benzene, toluene, methanethiol, and dimethylsulfide suggest this system displays ideal behavior and that ideal behavior is not limited to mixtures containing a small number of components.

  8. Students' ideals for nursing older people in practice.

    PubMed

    Alabaster, Erica S

    2006-06-01

    Aim.  Drawing on research exploring nursing students' experiences of working with older people, this paper aims to demonstrate how context and culture can impact on the realization of their ideals. Background.  The principles underpinning individualized and person-centred approaches to care resonate with those focal to gerontologic nursing. Restrictive contexts of care and pervasive workplace cultures render nurses unable to deliver care in accord with these. Design and method.  This interpretive study was informed by phenomenological-hermeneutic theory. A purposive sample (n = 10) was recruited from a single educational institution. Data were generated in two phases using loosely structured interviews and supplementary activity. Themes explicating their experiences were identified via systematized detailed analysis and issues pertaining to nursing students' orientation towards older people cut across these. Findings and discussion.  Students perceived that older people were prone to depersonalization and marginalization, so sought to show respect by coming to know individuals, form human connections with them and personalize care accordingly. Giving respect, promoting personhood, asserting reciprocal identity and maintaining dignity were prominent features of this but were often frustrated by practices and cultures encountered in mainstream settings. Conclusions.  Nursing students' approaches to older people are contextual and reflect elements of person-centred ideology. Their attempts upholding their ideals are liable to be subverted by workplace norms. Preparatory education should address these, assist students to learn how to attend to personhood in restrictive environments and offer targeted placements in age-specific and non-acute services. Relevance to clinical practice.  Demographic trends mean that working with older people has increased significance for nurses in most settings. Person-centredness is seen as beneficial for older people but

  9. Correlation of ideal and actual shear strengths of metals with their friction properties

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1981-01-01

    The relation between the ideal and actual shear strengths and friction properties of clean metals in contact with clean diamond, boron nitride, silicon carbide, manganese-zinc ferrite, and the metals themselves in vacuum is discussed. An estimate of the ideal shear strength for metals is obtained from the shear modulus, the repeat distance of atoms in the direction of shear of the metal, and the interplanar spacing of the shearing planes. The coefficient of friction for metals is shown to be correlated with both the ideal and actual shear strength of metals. The higher the strength of the metal, the lower the coefficient of friction occurs.

  10. Patient-centred care: making cancer treatment centres accountable.

    PubMed

    Zucca, Alison; Sanson-Fisher, Rob; Waller, Amy; Carey, Mariko

    2014-07-01

    Patient-centred care is argued to be an essential component in the delivery of quality health and cancer care. This manuscript discusses the need to generate credible data which indicates the quality of patient-centred care provided by cancer treatment centres. Patient-centred care covers six domains including physical comfort; emotional support; respect for patients' preferences and values; integration and coordination; involvement of family and friends; and the provision of information, communication and education to enable patients to understand and make informed decisions about their care. First, we identify priority areas within each domain. Next, we propose three questions that should be asked of every patient across the six domains of patient-centred care. The first question explores whether patients were specifically asked by a healthcare provider at the cancer treatment centre about their concerns, values and preferences. Research indicates that it cannot be assumed that clinicians are aware of patient's needs or preferences in these six areas. Second, if the answer from the patient suggests that they would like assistance, then it would be expected that this would be offered. Thirdly, if the patient indicates that they would like such assistance and it is provided, then it might be expected that the patient would report that the provided assistance did relieve their suffering, or the assistance provided was consistent with their preferences, needs and values. Regular measurement and reporting of these aspects of patient-centred cancer care has the potential to identify deficits and inequities in care delivery, allow for comparisons across treatment centres and stimulate an improvement in the patient-centred care provided to cancer patients. PMID:24696084

  11. CMCC Data Distribution Centre

    NASA Astrophysics Data System (ADS)

    Aloisio, Giovanni; Fiore, Sandro; Negro, A.

    2010-05-01

    The CMCC Data Distribution Centre (DDC) is the primary entry point (web gateway) to the CMCC. It is a Data Grid Portal providing a ubiquitous and pervasive way to ease data publishing, climate metadata search, datasets discovery, metadata annotation, data access, data aggregation, sub-setting, etc. The grid portal security model includes the use of HTTPS protocol for secure communication with the client (based on X509v3 certificates that must be loaded into the browser) and secure cookies to establish and maintain user sessions. The CMCC DDC is now in a pre-production phase and it is currently used only by internal users (CMCC researchers and climate scientists). The most important component already available in the CMCC DDC is the Search Engine which allows users to perform, through web interfaces, distributed search and discovery activities by introducing one or more of the following search criteria: horizontal extent (which can be specified by interacting with a geographic map), vertical extent, temporal extent, keywords, topics, creation date, etc. By means of this page the user submits the first step of the query process on the metadata DB, then, she can choose one or more datasets retrieving and displaying the complete XML metadata description (from the browser). This way, the second step of the query process is carried out by accessing to a specific XML document of the metadata DB. Finally, through the web interface, the user can access to and download (partially or totally) the data stored on the storage device accessing to OPeNDAP servers and to other available grid storage interfaces. Requests concerning datasets stored in deep storage will be served asynchronously.

  12. An orthotropic source of thermal atoms

    SciTech Connect

    Dinneen, T.; Ghiorso, A.; Gould, H.

    1995-07-01

    A source of thermal atoms that emits 100% of its atoms into a narrow beam with small angular divergence is described. It uses both surface ionization and surface neutralization in conjunction with electric fields to selectively emit a highly directional (orthotropic) beam of neutral atoms. The ion recycling process can be modulated electronically and lends itself to scanning. This orthotropic source is ideal for the efficient use of rare atomic species, well suited for atomic clocks, essential in the efficient delivery of radioactive atoms to optical traps, and has potential to produce ultra high intensity beams of stable atoms.

  13. Predicting film genres with implicit ideals.

    PubMed

    Olney, Andrew McGregor

    2012-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  14. Predicting Film Genres with Implicit Ideals

    PubMed Central

    Olney, Andrew McGregor

    2013-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  15. The ideal strength and mechanical hardness of solids

    SciTech Connect

    Krenn, Christopher

    2000-04-01

    Relationships between intrinsic mechanical hardness and atomic-scale properties are reviewed, Hardness scales closely and linearly with shear modulus for a given class of material (covalent, ionic or metallic). A two-parameter fit and a Peierls-stress model produce a more universal scaling relationship, but no model can explain differences in hardness between the transition metal carbides and nitrides. Calculations of ''ideal strength'' (defined by the limit of elastic stability of a perfect crystal) are proposed. The ideal shear strengths of fcc aluminum and copper are calculated using ab initio techniques and allowing for structural relaxation of all five strain components other than the imposed strain. The strengths of Al and Cu are similar (8-9% of the shear modulus), but the geometry of the relaxations in Al and Cu is very different. The relaxations are consistent with experimentally measured third-order elastic constants. The general thermodynamic conditions of elastic stability that set the upper limits of mechanical strength are derived. The conditions of stability are shown for cubic (hydrostatic), tetragonal (tensile) and monoclinic (shear) distortions of a cubic crystal. The implications of this stability analysis to first-principles calculations of ideal strength are discussed, and a method to detect instabilities orthogonal to the direction of the applied stress is identified. The relaxed ideal shear and tensile strengths of bcc tungsten are also calculated using ab initio techniques and are favorably compared to recent nano-indentation measurements. The {l_brace}100{r_brace} tensile strength (29.5 GPa) is governed by the Bain instability. The shear strengths in the weak directions on {l_brace}110{r_brace}, {l_brace}112{r_brace}, and {l_brace}123{r_brace} planes are very nearly equal ({approx} 18 GPa) and occur at approximately the same strain (17-18%). This isotropy is a function of the linear elastic isotropy for shear in directions containing {l

  16. The ideal strength and mechanical hardness of solids

    NASA Astrophysics Data System (ADS)

    Krenn, Christopher Robert

    2000-10-01

    Relationships between intrinsic mechanical hardness and atomic-scale properties are reviewed. Hardness scales closely and linearly with shear modulus for a given class of material (covalent, ionic or metallic). A two-parameter fit and a Peierls-stress model produce a more universal scaling relationship, but no model can explain differences in hardness between the transition metal carbides and nitrides. Calculations of "ideal strength" (defined by the limit of elastic stability of a perfect crystal) are proposed. The ideal shear strengths of fcc aluminum and copper are calculated using ab initio techniques and allowing for structural relaxation of all five strain components other than the imposed strain. The strengths of Al and Cu are similar (8-9% of the shear modulus), but the geometry of the relaxations in Al and Cu is very different. The relaxations are consistent with experimentally measured third-order elastic constants. The general thermodynamic conditions of elastic stability that set the upper limits of mechanical strength are derived. The conditions of stability are shown for cubic (hydrostatic), tetragonal (tensile) and monoclinic (shear) distortions of a cubic crystal. The implications of this stability analysis to first-principles calculations of ideal strength are discussed, and a method to detect instabilities orthogonal to the direction of the applied stress is identified. The relaxed ideal shear and tensile strengths of bcc tungsten are also calculated using ab initio techniques and are favorably compared to recent nano-indentation measurements. The {100} tensile strength (29.5 GPa) is governed by the Bain instability. The shear strengths in the weak directions on {110}, {112}, and {123} planes are very nearly equal (≈18 GPa) and occur at approximately the same strain (17-18%). This isotropy is a function of the linear elastic isotropy for shear in directions containing <111> in bcc and of the atomic configurations of energetic saddle points

  17. Minister unveils new nanotech centres

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2009-06-01

    Three new nanotechnology research centres are to be set up in France as part of a €70m government plan to help French companies in the sector. Researchers at the new centres, which will be located in Grenoble, Saclay (near Paris) and Toulouse, will be encouraged to collaborate with industry to develop new nanotech-based products. Dubbed NANO-INNOV, the new plan includes €46m for two new buildings at Saclay, with the rest being used to buy new equipment at the three centres and to fund grant proposals from staff to the French National Research Agency (ANR).

  18. Single atom electrochemical and atomic analytics

    NASA Astrophysics Data System (ADS)

    Vasudevan, Rama

    In the past decade, advances in electron and scanning-probe based microscopies have led to a wealth of imaging and spectroscopic data with atomic resolution, yielding substantial insight into local physics and chemistry in a diverse range of systems such as oxide catalysts, multiferroics, manganites, and 2D materials. However, typical analysis of atomically resolved images is limited, despite the fact that image intensities and distortions of the atoms from their idealized positions contain unique information on the physical and chemical properties inherent to the system. Here, we present approaches to data mine atomically resolved images in oxides, specifically in the hole-doped manganite La5/8Ca3/8MnO3, on epitaxial films studied by in-situ scanning tunnelling microscopy (STM). Through application of bias to the STM tip, atomic-scale electrochemistry is demonstrated on the manganite surface. STM images are then further analyzed through a suite of algorithms including 2D autocorrelations, sliding window Fourier transforms, and others, and can be combined with basic thermodynamic modelling to reveal relevant physical and chemical descriptors including segregation energies, existence and strength of atomic-scale diffusion barriers, surface energies and sub-surface chemical species identification. These approaches promise to provide tremendous insights from atomically resolved functional imaging, can provide relevant thermodynamic parameters, and auger well for use with first-principles calculations to yield quantitative atomic-level chemical identification and structure-property relations. This research was sponsored by the Division of Materials Sciences and Engineering, BES, DOE. Research was conducted at the Center for Nanophase Materials Sciences, which also provided support and is a DOE Office of Science User Facility.

  19. Ideals and Realities of the Olympic Games

    ERIC Educational Resources Information Center

    Hibler, Richard W.

    1976-01-01

    With the growth of professionalism and the emphasis on money in sports, modern society is losing sight of the ideals of style and grace that were of primary importance in the early Olympic games. nJD)

  20. Sahaja: an Indian ideal of mental health.

    PubMed

    Neki, J S

    1975-02-01

    Sahaja is an Indian ideal of mental and spiritual health that has received special emphasis in the Sikh scriptures--especially, the Adi Granth. Since the concept of sahaja has long been associated with mystical thought and practice, its description has become shrouded in peculiar esoteric terminologies. It is the purpose of this communication to divest sahaja of its esoteric, mystic connotations and to redefine it as a mental health ideal in the context of contemporary conditions. PMID:1114187

  1. Guiding center equations for ideal magnetohydrodynamic modes

    SciTech Connect

    White, R. B.

    2013-04-15

    Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through {delta}B-vector={nabla} Multiplication-Sign ({xi}-vector Multiplication-Sign B-vector), however, perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories, the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement {xi}-vector are derived which preserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

  2. Guiding Center Equations for Ideal Magnetohydrodynamic Modes

    SciTech Connect

    Roscoe B. White

    2013-02-21

    Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through δ~B = ∇ X (ξ X B) however perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement ξ are derived which perserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

  3. The Statistical Mechanics of Ideal MHD Turbulence

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    2003-01-01

    Turbulence is a universal, nonlinear phenomenon found in all energetic fluid and plasma motion. In particular. understanding magneto hydrodynamic (MHD) turbulence and incorporating its effects in the computation and prediction of the flow of ionized gases in space, for example, are great challenges that must be met if such computations and predictions are to be meaningful. Although a general solution to the "problem of turbulence" does not exist in closed form, numerical integrations allow us to explore the phase space of solutions for both ideal and dissipative flows. For homogeneous, incompressible turbulence, Fourier methods are appropriate, and phase space is defined by the Fourier coefficients of the physical fields. In the case of ideal MHD flows, a fairly robust statistical mechanics has been developed, in which the symmetry and ergodic properties of phase space is understood. A discussion of these properties will illuminate our principal discovery: Coherent structure and randomness co-exist in ideal MHD turbulence. For dissipative flows, as opposed to ideal flows, progress beyond the dimensional analysis of Kolmogorov has been difficult. Here, some possible future directions that draw on the ideal results will also be discussed. Our conclusion will be that while ideal turbulence is now well understood, real turbulence still presents great challenges.

  4. Contemporary design for 'landmark' centre.

    PubMed

    2009-08-01

    As one of the UK's largest builders of healthcare facilities, construction company Morgan Ashurst is accustomed to delivering complex, challenging hospital projects. The construction of a new oncology centre at Musgrove Park Hospital, Taunton for Taunton and Somerset NHS Foundation Trust-- said to be the first new stand-alone radiotherapy centre to be built in the UK for almost 20 years--was no exception. Health Estate Journal reports. PMID:19711668

  5. RTEMS Centre - Support and Maintenance Centre to RTEMS Operating System

    NASA Astrophysics Data System (ADS)

    Silva, H.; Constantino, A.; Freitas, D.; Coutinho, M.; Faustino, S.; Mota, M.; Colaço, P.; Sousa, J.; Dias, L.; Damjanovic, B.; Zulianello, M.; Rufino, J.

    2009-05-01

    RTEMS CENTRE - Support and Maintenance Centre to RTEMS Operating System is a joint ESA/Portuguese Task Force initiative to develop a support and maintenance centre to the Real-Time Executive for Multiprocessor Systems (RTEMS). This paper gives a high level visibility of the progress, the results obtained and the future work in the RTEMS CENTRE [6] and in the RTEMS Improvement [7] projects. RTEMS CENTRE started officially in November 2006, with the RTEMS 4.6.99.2 version. A full analysis of RTEMS operating system was produced. The architecture was analysed in terms of conceptual, organizational and operational concepts. The original objectives [1] of the centre were primarily to create and maintain technical expertise and competences in this RTOS, to develop a website to provide the European Space Community an entry point for obtaining support (http://rtemscentre.edisoft.pt), to design, develop, maintain and integrate some RTEMS support tools (Timeline Tool, Configuration and Management Tools), to maintain flight libraries and Board Support Packages, to develop a strong relationship with the World RTEMS Community and finally to produce some considerations in ARINC-653, DO-178B and ECSS E-40 standards. RTEMS Improvement is the continuation of the RTEMS CENTRE. Currently the RTEMS, version 4.8.0, is being facilitated for a future qualification. In this work, the validation material is being produced following the Galileo Software Standards Development Assurance Level B [5]. RTEMS is being completely tested, errors analysed, dead and deactivated code removed and tests produced to achieve 100% statement and decision coverage of source code [2]. The SW to exploit the LEON Memory Management Unit (MMU) hardware will be also added. A brief description of the expected implementations will be given.

  6. Complete quantum control of exciton qubits bound to isoelectronic centres.

    PubMed

    Éthier-Majcher, G; St-Jean, P; Boso, G; Tosi, A; Klem, J F; Francoeur, S

    2014-01-01

    In recent years, impressive demonstrations related to quantum information processing have been realized. The scalability of quantum interactions between arbitrary qubits within an array remains however a significant hurdle to the practical realization of a quantum computer. Among the proposed ideas to achieve fully scalable quantum processing, the use of photons is appealing because they can mediate long-range quantum interactions and could serve as buses to build quantum networks. Quantum dots or nitrogen-vacancy centres in diamond can be coupled to light, but the former system lacks optical homogeneity while the latter suffers from a low dipole moment, rendering their large-scale interconnection challenging. Here, through the complete quantum control of exciton qubits, we demonstrate that nitrogen isoelectronic centres in GaAs combine both the uniformity and predictability of atomic defects and the dipole moment of semiconductor quantum dots. This establishes isoelectronic centres as a promising platform for quantum information processing. PMID:24875932

  7. Force-induced chemical reactions on the metal centre in a single metalloprotein molecule

    NASA Astrophysics Data System (ADS)

    Zheng, Peng; Arantes, Guilherme M.; Field, Martin J.; Li, Hongbin

    2015-06-01

    Metalloproteins play indispensable roles in biology owing to the versatile chemical reactivity of metal centres. However, studying their reactivity in many metalloproteins is challenging, as protein three-dimensional structure encloses labile metal centres, thus limiting their access to reactants and impeding direct measurements. Here we demonstrate the use of single-molecule atomic force microscopy to induce partial unfolding to expose metal centres in metalloproteins to aqueous solution, thus allowing for studying their chemical reactivity in aqueous solution for the first time. As a proof-of-principle, we demonstrate two chemical reactions for the FeS4 centre in rubredoxin: electrophilic protonation and nucleophilic ligand substitution. Our results show that protonation and ligand substitution result in mechanical destabilization of the FeS4 centre. Quantum chemical calculations corroborated experimental results and revealed detailed reaction mechanisms. We anticipate that this novel approach will provide insights into chemical reactivity of metal centres in metalloproteins under biologically more relevant conditions.

  8. Reality television and the muscular male ideal.

    PubMed

    Dallesasse, Starla L; Kluck, Annette S

    2013-06-01

    Although researchers have examined the negative effects of viewing reality television (RTV) on women's body image, this research has not been extended to men. Exploring the extent to which RTV depicts men who embody the muscular ideal may enhance our understanding of the potential influence of this media genre. We explored the extent to which RTV depicted men who embodied the muscular ideal using a quantitative content analysis. Based on binomial tests, the primary male cast members of programs airing on networks popular among young adult men during the Fall 2009 broadcast season were more muscular, with lower levels of body fat, than average U.S. men. The chest-to-waist and shoulder-to-waist ratios of these cast members did not differ as a function of program type (i.e., reality drama, endurance, and romance). Young men who view RTV programs included in the present study would be exposed to an unrepresentative muscular ideal. PMID:23523084

  9. Topological photonic crystal with ideal Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on symmetry analysis, we show that a minimal number of symmetry-related Weyl points can be realized in time-reversal invariant photonic crystals. We propose to realize these ``ideal'' Weyl points in modified double-gyroid photonic crystals, which is confirmed by our first-principle photonic band-structure calculations. Photonic crystals with ideal Weyl points are qualitatively advantageous in applications such as angular and frequency selectivity, broadband invisibility cloaking, and broadband 3D-imaging.

  10. Analysis of an idealized Stirling thermocompressor

    SciTech Connect

    Kornhauser, A.A.

    1996-12-31

    A thermocompressor uses thermal energy to increase the pressure of a fluid without the intermediate production of mechanical work. The thermocompressor described here is essentially a cold-connected Gamma Stirling engine with the power cylinder replaced by inlet and discharge check valves. It is analyzed based on assumptions similar to those made in the analysis of an ideal Stirling engine. The analysis gives closed form predictions for thermocompressor thermal efficiency, volumetric efficiency, and non-dimensional heat input as functions of pressure and temperature ratio. It is also used to compare thermocompressor performance to that of an ideal Otto engine-driven mechanical compressor.

  11. Ideal light concentrators with reflector gaps

    DOEpatents

    Winston, Roland

    1980-01-01

    A cylindrical or trough-like radiant energy concentration and collection device is provided. The device includes an energy absorber, a glazing enveloping the absorber and a reflective wall. The ideal contour of the reflective wall is determined with reference to a virtual absorber and not the actual absorber cross section.

  12. Street Children Draw the Ideal Person.

    ERIC Educational Resources Information Center

    DiCarlo, Margaret A.; And Others

    Forty-three adolescents (11-16 years of age) attending a health care program, Project Alternatives, for "street children" in Tegucigalpa, Honduras, drew randomly assigned pictures of either the ideal man or woman, engaged in some activity. These drawings were compared to samples from adolescents in various parts of the world to assess the global…

  13. Real vs. Ideal Self Discrepancy in Bulimics.

    ERIC Educational Resources Information Center

    Kosak, Karen

    Bulimia is an eating disorder prevalent among young women, characterized by binge eating episodes followed by purging with subsequent depressive moods and self-deprecating thoughts. To determine whether bulimic women exhibit a greater discrepancy between their perceived and ideal selves than do nonbulimics, three samples of women were assessed.…

  14. The Heat Capacity of Ideal Gases

    ERIC Educational Resources Information Center

    Scott, Robert L.

    2006-01-01

    The heat capacity of an ideal gas has been shown to be calculable directly by statistical mechanics if the energies of the quantum states are known. However, unless one makes careful calculations, it is not easy for a student to understand the qualitative results. Why there are maxima (and occasionally minima) in heat capacity-temperature curves…

  15. Water: The Ideal Early Learning Environment

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    2008-01-01

    Bathtubs and swimming pools provide the ideal learning environment for people with special needs. For young preschool children, the activities that take place through water can help them develop physical fitness, facilitate motor development, reinforce perceptual-motor ability, encourage social development, and enhance self-esteem and confidence.…

  16. Ideal orifice pulse tube refrigerator performance

    NASA Technical Reports Server (NTRS)

    Kittel, P.

    1992-01-01

    The recent development of orifice pulse tube refrigerators has raised questions as to what limits their ultimate performance. Using an analogy to the Stirling cycle refrigerator, the efficiency (cooling power per unit input power) of an ideal orifice pulse tube refrigerator is shown to be T1/T0, the ratio of the cold temperature to the hot temperature.

  17. Idleness and the Ideal of the Gentlemen.

    ERIC Educational Resources Information Center

    Wagner, Ann

    1985-01-01

    The conceptual and cultural background for Puritan opposition to idleness are examined. Also included is a review of the educational ideals portrayed in the sixteenth-century "courtesy literature" (intended for instruction of the aristocracy). A likely source for Puritan views is England rather than New England. (RM)

  18. Axisymmetric ideal MHD stellar wind flow

    NASA Technical Reports Server (NTRS)

    Heinemann, M.; Olbert, S.

    1978-01-01

    The ideal MHD equations are reduced to a single equation under the assumption of axisymmetric flow. A variational principle from which the equation is derivable is given. The characteristics of the equation are briefly discussed. The equation is used to rederive the theorem of Gussenhoven and Carovillano.

  19. The World Grant Ideal and Engagement Scholarship

    ERIC Educational Resources Information Center

    Fitzgerald, Hiram E.; Simon, Lou Anna K.

    2012-01-01

    Michigan State University President Lou Anna Simon's concept of the world grant ideal is grounded in three core values: quality, inclusiveness, and connectivity. These core values fuel the 21st-century imperative to build sustainable global prosperity. They represent an affirmation of the Morrill Act of 1862 in the context of a global society and…

  20. Home Management Textbooks and the "Ideal" Family.

    ERIC Educational Resources Information Center

    Williams, Sue W.; Nickols, Sharon Y.

    1981-01-01

    Content analysis of systematically selected paragraphs of the three major textbooks used in teaching college-level home management courses was used to examine the hypothesis that they portray, and implicitly endorse, an ideal family type. Implications of the findings for home economists and family practitioners are discussed. (Author/CT)

  1. Developing Ideal Student and Residency Programs.

    ERIC Educational Resources Information Center

    Selvin, Gerald J.

    1993-01-01

    The Veterans Administration (VA) is a primary educator of optometry students, with each college of optometry being affiliated with at least one VA hospital. Ideally, fourth-year optometry students rotate through a specific VA facility for about 12 weeks. Guidelines are designed to provide optimum care in a rich learning environment. (MSE)

  2. How Is the Ideal Gas Law Explanatory?

    ERIC Educational Resources Information Center

    Woody, Andrea I.

    2013-01-01

    Using the ideal gas law as a comparative example, this essay reviews contemporary research in philosophy of science concerning scientific explanation. It outlines the inferential, causal, unification, and erotetic conceptions of explanation and discusses an alternative project, the functional perspective. In each case, the aim is to highlight…

  3. Derivation of the Ideal Gas Law

    ERIC Educational Resources Information Center

    Laugier, Alexander; Garai, Jozsef

    2007-01-01

    Undergraduate and graduate physics and chemistry books usually state that combining the gas laws results in the ideal gas law. Leaving the derivation to the students implies that this should be a simple task, most likely a substitution. Boyle's law, Charles's law, and the Avogadro's principle are given under certain conditions; therefore, direct…

  4. The ideal Kolmogorov inertial range and constant

    NASA Technical Reports Server (NTRS)

    Zhou, YE

    1993-01-01

    The energy transfer statistics measured in numerically simulated flows are found to be nearly self-similar for wavenumbers in the inertial range. Using the measured self-similar form, an 'ideal' energy transfer function and the corresponding energy flux rate were deduced. From this flux rate, the Kolmogorov constant was calculated to be 1.5, in excellent agreement with experiments.

  5. Liquid atomization

    NASA Astrophysics Data System (ADS)

    Bayvel, L.; Orzechowski, Z.

    The present text defines the physical processes of liquid atomization, the primary types of atomizers and their design, and ways of measuring spray characteristics; it also presents experimental investigation results on atomizers and illustrative applications for them. Attention is given to the macrostructural and microstructural parameters of atomized liquids; swirl, pneumatic, and rotary atomizers; and optical drop sizing methods, with emphasis on nonintrusive optical methods.

  6. Questioning Centre-Periphery Platforms

    ERIC Educational Resources Information Center

    Postiglione, Gerard A.

    2005-01-01

    How much is hegemony and how much is self-determination in the higher education systems in Southeast Asia? This paper argues that while the question of centre and periphery is still relevant to the analysis of international university systems, the analytical frameworks from which it has arisen may lose viability in the long term. Southeast Asian…

  7. Ideal photon number amplifier and duplicator

    NASA Technical Reports Server (NTRS)

    Dariano, G. M.

    1992-01-01

    The photon number-amplification and number-duplication mechanism are analyzed in the ideal case. The search for unitary evolutions leads to consider also a number-deamplification mechanism, the symmetry between amplification and deamplification being broken by the integer-value nature of the number operator. Both transformations, amplification and duplication, need an auxiliary field which, in the case of amplification, turns out to be amplified in the inverse way. Input-output energy conservation is accounted for using a classical pump or through frequency-conversion of the fields. Ignoring one of the fields is equivalent to considering the amplifier as an open system involving entropy production. The Hamiltonians of the ideal devices are given and compared with those of realistic systems.

  8. Non-ideal solution thermodynamics of cytoplasm.

    PubMed

    Ross-Rodriguez, Lisa U; Elliott, Janet A W; McGann, Locksley E

    2012-10-01

    Quantitative description of the non-ideal solution thermodynamics of the cytoplasm of a living mammalian cell is critically necessary in mathematical modeling of cryobiology and desiccation and other fields where the passive osmotic response of a cell plays a role. In the solution thermodynamics osmotic virial equation, the quadratic correction to the linear ideal, dilute solution theory is described by the second osmotic virial coefficient. Herein we report, for the first time, intracellular solution second osmotic virial coefficients for four cell types [TF-1 hematopoietic stem cells, human umbilical vein endothelial cells (HUVEC), porcine hepatocytes, and porcine chondrocytes] and further report second osmotic virial coefficients indistinguishable from zero (for the concentration range studied) for human hepatocytes and mouse oocytes. PMID:23840923

  9. Regular shock refraction in planar ideal MHD

    NASA Astrophysics Data System (ADS)

    Delmont, P.; Keppens, R.

    2010-03-01

    We study the classical problem of planar shock refraction at an oblique density discontinuity, separating two gases at rest, in planar ideal (magneto)hydrodynamics. In the hydrodynamical case, 3 signals arise and the interface becomes Richtmyer-Meshkov unstable due to vorticity deposition on the shocked contact. In the magnetohydrodynamical case, on the other hand, when the normal component of the magnetic field does not vanish, 5 signals will arise. The interface then typically remains stable, since the Rankine-Hugoniot jump conditions in ideal MHD do not allow for vorticity deposition on a contact discontinuity. We present an exact Riemann solver based solution strategy to describe the initial self similar refraction phase. Using grid-adaptive MHD simulations, we show that after reflection from the top wall, the interface remains stable.

  10. Ideal transparent conductors for full spectrum photovoltaics

    NASA Astrophysics Data System (ADS)

    Yu, Kin Man; Mayer, Marie A.; Speaks, Derrick T.; He, Hongcai; Zhao, Ruying; Hsu, L.; Mao, Samuel S.; Haller, E. E.; Walukiewicz, Wladek

    2012-06-01

    In current technologies, state-of-the-art transparent conducting oxides exhibit good conductivity (˜5 × 103 S/cm) and transparency up to only λ ˜ 1000 nm, restricting the use of such thin films to photovoltaics that are not utilizing the infrared part of the solar spectrum. We have found that among metal oxides, high electron mobility CdO satisfies the essential requirements for a low resistance and high infrared transmission transparent contact. With appropriate intentional doping, we have achieved ideal uncompensated CdO with extremely high conductivity (>104 S/cm) and an excellent transmission window in the range from 400 to >1500 nm, making this material an ideal TCO for photovoltaics with low band gap absorbers.

  11. Computational methods for ideal compressible flow

    NASA Technical Reports Server (NTRS)

    Vanleer, B.

    1983-01-01

    Conservative dissipative difference schemes for computing one dimensional flow are introduced, and the recognition and representation of flow discontinuities are discussed. Multidimensional methods are outlined. Second order finite volume schemes are introduced. Conversion of difference schemes for a single linear convection equation into schemes for the hyperbolic system of the nonlinear conservation laws of ideal compressible flow is explained. Approximate Riemann solvers are presented. Monotone initial value interpolation; and limiters, switches, and artificial dissipation are considered.

  12. VH-1: Multidimensional ideal compressible hydrodynamics code

    NASA Astrophysics Data System (ADS)

    Hawley, John; Blondin, John; Lindahl, Greg; Lufkin, Eric

    2012-04-01

    VH-1 is a multidimensional ideal compressible hydrodynamics code written in FORTRAN for use on any computing platform, from desktop workstations to supercomputers. It uses a Lagrangian remap version of the Piecewise Parabolic Method developed by Paul Woodward and Phil Colella in their 1984 paper. VH-1 comes in a variety of versions, from a simple one-dimensional serial variant to a multi-dimensional version scalable to thousands of processors.

  13. Preserving idealism in global health promotion.

    PubMed

    Franco-Paredes, Carlos; Zeuli, Julia; Hernández-Ramos, Isabel; Santos-Preciado, Jose I

    2010-12-01

    If the field of global health is to evolve in the second decade of the new millennium, we need to revive the idealistic spirit and by using the lens of health equity work toward improved health status around the world. Morality and empathy are considered by-products of our evolutionary history as a human species. Idealism may be a trait that we may choose to preserve in our modern evolutionary history. PMID:21513081

  14. The Ideal Man and Woman According to University Students

    ERIC Educational Resources Information Center

    Weinstein, Lawrence; Laverghetta, Antonio V.; Peterson, Scott A.

    2009-01-01

    The present study determined if the ideal man has changed over the years and who and what the ideal woman is. We asked students at Cameron University to rate the importance of character traits that define the ideal man and woman. Subjects also provided examples of famous people exemplifying the ideal, good, average, and inferior man and woman. We…

  15. Word recognition using ideal word patterns

    NASA Astrophysics Data System (ADS)

    Zhao, Sheila X.; Srihari, Sargur N.

    1994-03-01

    The word shape analysis approach to text recognition is motivated by discoveries in psychological studies of the human reading process. It attempts to describe and compare the shape of the word as a whole object without trying to segment and recognize the individual characters, so it bypasses the errors committed in character segmentation and classification. However, the large number of classes and large variation and distortion expected in all patterns belonging to the same class make it difficult for conventional, accurate, pattern recognition approaches. A word shape analysis approach using ideal word patterns to overcome the difficulty and improve recognition performance is described in this paper. A special word pattern which characterizes a word class is extracted from different sample patterns of the word class and stored in memory. Recognition of a new word pattern is achieved by comparing it with the special pattern of each word class called ideal word pattern. The process of generating the ideal word pattern of each word class is proposed. The algorithm was tested on a set of machine printed gray scale word images which included a wide range of print types and qualities.

  16. Non-Ideal Behavior in Solvent Extraction

    SciTech Connect

    Peter Zalupski

    2011-09-01

    This report presents a summary of the work performed to meet FCR&D level 3 milestone M31SW050801, 'Complete the year-end report summarizing FY11 experimental and modeling activities.' This work was carried out under the auspices of the Non-Ideality in Solvent Extraction Systems FCR&D work package. The report summarizes our initial considerations of potential influences that non-ideal chemistry may impose on computational prediction of outcomes in solvent extraction systems. The report is packaged into three separate test cases where a robustness of the prediction by SXFIT program is under scrutiny. The computational exercises presented here emphasize the importance of accurate representation of both an aqueous and organic mixtures when modeling liquid-liquid distribution systems. Case No.1 demonstrates that non-ideal behavior of HDEHP in aliphatic diluents, such as n-dodecane, interferes with the computation. Cases No.2 and No.3 focus on the chemical complexity of aqueous electrolyte mixtures. Both exercises stress the need for an improved thermodynamic model of an aqueous environment present in the europium distribution experiments. Our efforts for year 2 of this project will focus on the improvements of aqueous and non-aqueous solution models using fundamental physical properties of mixtures acquired experimentally in our laboratories.

  17. Principles for designing ideal protein structures

    PubMed Central

    Koga, Nobuyasu; Tatsumi-Koga, Rie; Liu, Gaohua; Xiao, Rong; Acton, Thomas B.; Montelione, Gaetano T.; Baker, David

    2013-01-01

    Unlike random heteropolymers, natural proteins fold into unique ordered structures. Understanding how these are encoded in amino-acid sequences is complicated by energetically unfavourable non-ideal features—for example kinked α-helices, bulged β-strands, strained loops and buried polar groups—that arise in proteins from evolutionary selection for biological function or from neutral drift. Here we describe an approach to designing ideal protein structures stabilized by completely consistent local and non-local interactions. The approach is based on a set of rules relating secondary structure patterns to protein tertiary motifs, which make possible the design of funnel-shaped protein folding energy landscapes leading into the target folded state. Guided by these rules, we designed sequences predicted to fold into ideal protein structures consisting of α-helices, β-strands and minimal loops. Designs for five different topologies were found to be monomeric and very stable and to adopt structures in solution nearly identical to the computational models. These results illuminate how the folding funnels of natural proteins arise and provide the foundation for engineering a new generation of functional proteins free from natural evolution. PMID:23135467

  18. EAC: The European Astronauts Centre

    NASA Astrophysics Data System (ADS)

    Ripoll, Andres

    The newly established European Astronauts Centre (EAC) in Cologne represents the European Astronauts Home Base and will become a centre of expertise on European astronauts activities. The paper gives an overview of the European approach to man-in-space, describes the European Astronauts Policy and presents the major EAC roles and responsibilities including the management of selection, recruitment and flight assignment of astronauts; the astronauts support and medical surveillance; the supervision of the astronauts' non-flight assignments; crew safety; the definition of the overall astronauts training programme; the scheduling and supervision of the training facilities; the implementation of Basic Training; the recruitment, training and certification of instructors, and the interface to NASA in the framework of the Space Station Freedom programme. An overview is given on the organisation of EAC, and on the European candidate astronauts selection performed in 1991.

  19. The Notting Dale Urban Studies Centre

    ERIC Educational Resources Information Center

    Webb, Chris; Lynas, Sue

    1976-01-01

    Founded in 1974, the Centre is one of the most intensively used resource centres in the United Kingdom. Adults and students from elementary to college level use its facilities to learn about the urban environment. (BD)

  20. Interacting Ions in Biophysics: Real is not Ideal

    PubMed Central

    Eisenberg, Bob

    2013-01-01

    Ions in water are important throughout biology, from molecules to organs. Classically, ions in water were treated as ideal noninteracting particles in a perfect gas. Excess free energy of each ion was zero. Mathematics was not available to deal consistently with flows, or interactions with other ions or boundaries. Nonclassical approaches are needed because ions in biological conditions flow and interact. The concentration gradient of one ion can drive the flow of another, even in a bulk solution. A variational multiscale approach is needed to deal with interactions and flow. The recently developed energetic variational approach to dissipative systems allows mathematically consistent treatment of the bio-ions Na+, K+, Ca2+, and Cl− as they interact and flow. Interactions produce large excess free energy that dominate the properties of the high concentration of ions in and near protein active sites, ion channels, and nucleic acids: the number density of ions is often >10 M. Ions in such crowded quarters interact strongly with each other as well as with the surrounding protein. Nonideal behavior found in many experiments has classically been ascribed to allosteric interactions mediated by the protein and its conformation changes. The ion-ion interactions present in crowded solutions—independent of conformation changes of the protein—are likely to change the interpretation of many allosteric phenomena. Computation of all atoms is a popular alternative to the multiscale approach. Such computations involve formidable challenges. Biological systems exist on very different scales from atomic motion. Biological systems exist in ionic mixtures (like extracellular and intracellular solutions), and usually involve flow and trace concentrations of messenger ions (e.g., 10−7 M Ca2+). Energetic variational methods can deal with these characteristic properties of biological systems as we await the maturation and calibration of all-atom simulations of ionic mixtures and

  1. Atomic polarizabilities

    SciTech Connect

    Safronova, M. S.; Mitroy, J.; Clark, Charles W.; Kozlov, M. G.

    2015-01-22

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.

  2. Centre Selection for Clinical Trials and the Generalisability of Results: A Mixed Methods Study

    PubMed Central

    Gheorghe, Adrian; Roberts, Tracy E.; Ives, Jonathan C.; Fletcher, Benjamin R.; Calvert, Melanie

    2013-01-01

    Background The rationale for centre selection in randomised controlled trials (RCTs) is often unclear but may have important implications for the generalisability of trial results. The aims of this study were to evaluate the factors which currently influence centre selection in RCTs and consider how generalisability considerations inform current and optimal practice. Methods and Findings Mixed methods approach consisting of a systematic review and meta-summary of centre selection criteria reported in RCT protocols funded by the UK National Institute of Health Research (NIHR) initiated between January 2005-January 2012; and an online survey on the topic of current and optimal centre selection, distributed to professionals in the 48 UK Clinical Trials Units and 10 NIHR Research Design Services. The survey design was informed by the systematic review and by two focus groups conducted with trialists at the Birmingham Centre for Clinical Trials. 129 trial protocols were included in the systematic review, with a total target sample size in excess of 317,000 participants. The meta-summary identified 53 unique centre selection criteria. 78 protocols (60%) provided at least one criterion for centre selection, but only 31 (24%) protocols explicitly acknowledged generalisability. This is consistent with the survey findings (n = 70), where less than a third of participants reported generalisability as a key driver of centre selection in current practice. This contrasts with trialists’ views on optimal practice, where generalisability in terms of clinical practice, population characteristics and economic results were prime considerations for 60% (n = 42), 57% (n = 40) and 46% (n = 32) of respondents, respectively. Conclusions Centres are rarely enrolled in RCTs with an explicit view to external validity, although trialists acknowledge that incorporating generalisability in centre selection should ideally be more prominent. There is a need to operationalize

  3. Communicating astronomy by the Unizul Science Centre

    NASA Astrophysics Data System (ADS)

    Beesham, A.; Beesham, N.

    2015-03-01

    The University of Zululand, situated along the east coast of KwaZulu-Natal, has a thriving Science Centre (USC) situated in the developing port city of Richards Bay. Over 30 000 learners visit the centre annually, and it consists of an exhibition area, an auditorium, lecture areas and offices. The shows consist of interactive games, science shows, competitions, quizzes and matriculation workshops. Outreach activities take place through a mobile science centre for schools and communities that cannot visit the centre.

  4. Statistical Theory of the Ideal MHD Geodynamo

    NASA Technical Reports Server (NTRS)

    Shebalin, J. V.

    2012-01-01

    A statistical theory of geodynamo action is developed, using a mathematical model of the geodynamo as a rotating outer core containing an ideal (i.e., no dissipation), incompressible, turbulent, convecting magnetofluid. On the concentric inner and outer spherical bounding surfaces the normal components of the velocity, magnetic field, vorticity and electric current are zero, as is the temperature fluctuation. This allows the use of a set of Galerkin expansion functions that are common to both velocity and magnetic field, as well as vorticity, current and the temperature fluctuation. The resulting dynamical system, based on the Boussinesq form of the magnetohydrodynamic (MHD) equations, represents MHD turbulence in a spherical domain. These basic equations (minus the temperature equation) and boundary conditions have been used previously in numerical simulations of forced, decaying MHD turbulence inside a sphere [1,2]. Here, the ideal case is studied through statistical analysis and leads to a prediction that an ideal coherent structure will be found in the form of a large-scale quasistationary magnetic field that results from broken ergodicity, an effect that has been previously studied both analytically and numerically for homogeneous MHD turbulence [3,4]. The axial dipole component becomes prominent when there is a relatively large magnetic helicity (proportional to the global correlation of magnetic vector potential and magnetic field) and a stationary, nonzero cross helicity (proportional to the global correlation of velocity and magnetic field). The expected angle of the dipole moment vector with respect to the rotation axis is found to decrease to a minimum as the average cross helicity increases for a fixed value of magnetic helicity and then to increase again when average cross helicity approaches its maximum possible value. Only a relatively small value of cross helicity is needed to produce a dipole moment vector that is aligned at approx.10deg with the

  5. Hamiltonian description of the ideal fluid

    SciTech Connect

    Morrison, P.J.

    1994-01-01

    Fluid mechanics is examined from a Hamiltonian perspective. The Hamiltonian point of view provides a unifying framework; by understanding the Hamiltonian perspective, one knows in advance (within bounds) what answers to expect and what kinds of procedures can be performed. The material is organized into five lectures, on the following topics: rudiments of few-degree-of-freedom Hamiltonian systems illustrated by passive advection in two-dimensional fluids; functional differentiation, two action principles of mechanics, and the action principle and canonical Hamiltonian description of the ideal fluid; noncanonical Hamiltonian dynamics with examples; tutorial on Lie groups and algebras, reduction-realization, and Clebsch variables; and stability and Hamiltonian systems.

  6. Continuum damping of ideal toroidal Alfven eigenmodes

    SciTech Connect

    Zhang, X.D.; Zhang, Y.Z.; Mahajan, S.M.

    1993-08-01

    A perturbation theory based on the two dimensional (2D) ballooning transform is systematically developed for ideal toroidal Alfven eigenmodes (TAEs). A formula, similar to the Fermi golden rule for decaying systems in quantum mechanics, is derived for the continuum damping rate of the TAE; the decay (damping) rate is expressed explicitly in terms of the coupling of the TAE to the continuum spectrum. Numerical results are compared with previous calculations. It is found that in some narrow intervals of the parameter m{cflx {epsilon}} the damping rate varies very rapidly. These regions correspond precisely to the root missing intervals of the numerical solution by Rosenbluth et al.

  7. Broken symmetry in ideal magnetohydrodynamic turbulence

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1993-01-01

    A numerical study of the long-time evolution of a number of cases of inviscid, isotropic, incompressible, three-dimensional fluid, and magneto-fluid turbulence has been completed. The results confirm that ideal magnetohydrodynamic turbulence is non-ergodic if there is no external magnetic field present. This is due essentially to a canonical symmetry being broken in an arbitrary dynamical representation. The broken symmetry manifests itself as a coherent structure, i.e., a non-zero time-averaged part of the turbulent magnetic field. The coherent structure is observed, in one case, to contain about eighteen percent of the total energy.

  8. "The Scientific Method" as Myth and Ideal

    NASA Astrophysics Data System (ADS)

    Woodcock, Brian A.

    2014-10-01

    "The Scientific Method" as it has been portrayed in popular and introductory contexts has been declared a myth. The variation that one finds in introductory presentations of "The Scientific Method" is explained by the fact that there is no canonical account among historians and philosophers of science. What, in particular, is wrong with "The Scientific Method"? This essay provides a fairly comprehensive survey of shortcomings of "The Scientific Method". Included are corrections to several misconceptions that often accompany such presentations. Rather than treating "The Scientific Method" as a useful approximation or an ideal, the myth should be discarded. Lessons can be learned for introductory pedagogical contexts from considering the shortcomings of the myth.

  9. New approach to nonrelativistic ideal magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Banerjee, Rabin; Kumar, Kuldeep

    2016-07-01

    We provide a novel action principle for nonrelativistic ideal magnetohydrodynamics in the Eulerian scheme exploiting a Clebsch-type parametrisation. Both Lagrangian and Hamiltonian formulations have been considered. Within the Hamiltonian framework, two complementary approaches have been discussed using Dirac's constraint analysis. In one case the Hamiltonian is canonical involving only physical variables but the brackets have a noncanonical structure, while the other retains the canonical structure of brackets by enlarging the phase space. The special case of incompressible magnetohydrodynamics is also considered where, again, both the approaches are discussed in the Hamiltonian framework. The conservation of the stress tensor reveals interesting aspects of the theory.

  10. Arsenic-terminated Ge(111): An ideal 1 x 1 surface

    SciTech Connect

    Bringans, R.D.; Uhrberg, R.I.G.; Bachrach, R.Z.; Northrup, J.E.

    1985-07-29

    Arsenic interaction with the Ge(111) surface results in the replacement of the outer Ge layer with an As layer. This system has a 1 x 1 symmetry and the calculated positions of the As atoms are very close to the positions expected from bulk bond lengths. Ge(111):As is thus a model ideal surface and a comparison is made of an experimental and a theoretical determination of its fully occupied surface band.

  11. Nonlinear electrophoresis of ideally polarizable particles

    NASA Astrophysics Data System (ADS)

    Figliuzzi, Bruno; Chan, Wai Hong Ronald; Buie, Cullen R.

    2013-11-01

    We focus in this presentation on the nonlinear electrophoresis of ideally polarizable particles. At high applied voltages, significant ionic exchanges occur between the EDL which surrounders the particle and the bulk solution. In this situation, the velocity field, the electric potential and the ionic concentration at the immediate vicinity of the particle are described by a complicated set of coupled nonlinear partial differential equations. These equations are classically considered in the limit of a weak applied field, which enables further analytical progress (Khair and Squires, Phys. Fluids, 2010). However, in the general case, the equation governing the electrophoretic motion of the particle must be solved numerically. In this study, we rely on a numerical approach to determine the electric potential, ionic concentration and velocity field in the bulk solution surrounding the particle. The numerical simulations use a pseudo-spectral which was used successfully by Chu and Bazant to determine the electric potential and the ionic concentration around an ideally polarizable metallic sphere (Physical Review E, 2006). Our numerical model also incorporates the steric model developed by Kilic et al. in 2007 to account for crowding effects in the electric double layer.

  12. The Statistical Mechanics of Ideal Homogeneous Turbulence

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    2002-01-01

    Plasmas, such as those found in the space environment or in plasma confinement devices, are often modeled as electrically conducting fluids. When fluids and plasmas are energetically stirred, regions of highly nonlinear, chaotic behavior known as turbulence arise. Understanding the fundamental nature of turbulence is a long-standing theoretical challenge. The present work describes a statistical theory concerning a certain class of nonlinear, finite dimensional, dynamical models of turbulence. These models arise when the partial differential equations describing incompressible, ideal (i.e., nondissipative) homogeneous fluid and magnetofluid (i.e., plasma) turbulence are Fourier transformed into a very large set of ordinary differential equations. These equations define a divergenceless flow in a high-dimensional phase space, which allows for the existence of a Liouville theorem, guaranteeing a distribution function based on constants of the motion (integral invariants). The novelty of these particular dynamical systems is that there are integral invariants other than the energy, and that some of these invariants behave like pseudoscalars under two of the discrete symmetry transformations of physics, parity, and charge conjugation. In this work the 'rugged invariants' of ideal homogeneous turbulence are shown to be the only significant scalar and pseudoscalar invariants. The discovery that pseudoscalar invariants cause symmetries of the original equations to be dynamically broken and induce a nonergodic structure on the associated phase space is the primary result presented here. Applicability of this result to dissipative turbulence is also discussed.

  13. Ideal fermion delocalization in Higgsless models

    SciTech Connect

    Chivukula, R. Sekhar; Simmons, Elizabeth H.; He, Hong-Jian; Kurachi, Masafumi; Tanabashi, Masaharu

    2005-07-01

    In this note we examine the properties of deconstructed Higgsless models for the case of a fermion whose SU(2) properties arise from delocalization over many sites of the deconstructed lattice. We derive expressions for the correlation functions and use these to establish a generalized consistency relation among correlation functions. We discuss the form of the W boson wavefunction and show that if the probability distribution of the delocalized fermions is appropriately related to the W wavefunction, then deviations in precision electroweak parameters are minimized. In particular, we show that this ''ideal fermion delocalization'' results in the vanishing of three of the four leading zero-momentum electroweak parameters defined by Barbieri et al. We then discuss ideal fermion delocalization in the context of two continuum Higgsless models, one in Anti-deSitter space and one in flat space. Our results may be applied to any Higgsless linear moose model with multiple SU(2) groups, including those with only a few extra vector bosons.

  14. Modeling of non-ideal aluminized explosives

    SciTech Connect

    Fried, L E; Howard, W M; Souers, P C

    1999-06-01

    We have implemented a Wood-Kirkwood kinetic detonation model based on multi-species equations of state and multiple reaction rate laws. Finite rate laws are used for the slowest chemical reactions, while other reactions are given infinite rates and are kept in constant thermodynamic equilibrium. Within the context of WK theory, we study the chemical interaction between Al and HMX detonation products in non-ideal explosives. We develop a kinetic rate law for the combustion of Al in a condensed detonation that depends on the pressure and the detonation product gases. We use a Murnaghan form for the equation of state of the solid and liquid Al and Al{sub 2}O{sub 3}. We find that we can replicate experimental detonation velocities for HMX/Al composites to within a few percent for a wide range of aluminum content. We discuss the uncertainties in our model and the implications of our results on the modeling of other non-ideal explosives.

  15. Simple Waves in Ideal Radiation Hydrodynamics

    SciTech Connect

    Johnson, B M

    2008-09-03

    In the dynamic diffusion limit of radiation hydrodynamics, advection dominates diffusion; the latter primarily affects small scales and has negligible impact on the large scale flow. The radiation can thus be accurately regarded as an ideal fluid, i.e., radiative diffusion can be neglected along with other forms of dissipation. This viewpoint is applied here to an analysis of simple waves in an ideal radiating fluid. It is shown that much of the hydrodynamic analysis carries over by simply replacing the material sound speed, pressure and index with the values appropriate for a radiating fluid. A complete analysis is performed for a centered rarefaction wave, and expressions are provided for the Riemann invariants and characteristic curves of the one-dimensional system of equations. The analytical solution is checked for consistency against a finite difference numerical integration, and the validity of neglecting the diffusion operator is demonstrated. An interesting physical result is that for a material component with a large number of internal degrees of freedom and an internal energy greater than that of the radiation, the sound speed increases as the fluid is rarefied. These solutions are an excellent test for radiation hydrodynamic codes operating in the dynamic diffusion regime. The general approach may be useful in the development of Godunov numerical schemes for radiation hydrodynamics.

  16. Ideal fermion delocalization in Higgsless models

    NASA Astrophysics Data System (ADS)

    Chivukula, R. Sekhar; Simmons, Elizabeth H.; He, Hong-Jian; Kurachi, Masafumi; Tanabashi, Masaharu

    2005-07-01

    In this note we examine the properties of deconstructed Higgsless models for the case of a fermion whose SU(2) properties arise from delocalization over many sites of the deconstructed lattice. We derive expressions for the correlation functions and use these to establish a generalized consistency relation among correlation functions. We discuss the form of the W boson wavefunction and show that if the probability distribution of the delocalized fermions is appropriately related to the W wavefunction, then deviations in precision electroweak parameters are minimized. In particular, we show that this “ideal fermion delocalization” results in the vanishing of three of the four leading zero-momentum electroweak parameters defined by Barbieri et al. We then discuss ideal fermion delocalization in the context of two continuum Higgsless models, one in Anti-deSitter space and one in flat space. Our results may be applied to any Higgsless linear moose model with multiple SU(2) groups, including those with only a few extra vector bosons.

  17. An ideal sealed source life-cycle

    SciTech Connect

    Tompkins, Joseph Andrew

    2009-01-01

    we have today. This regulation created a new regulatory framework seen as promising at the time. However, now they recognize that, despite the good intentions, the NIJWP/85 has not solved any source disposition problems. The answer to these sealed source disposition problems is to adopt a philosophy to correct these regulatory issues, determine an interim solution, execute that solution until there is a minimal backlog of sources to deal with, and then let the mechanisms they have created solve this problem into the foreseeable future. The primary philosophical tenet of the ideal sealed source life cycle follows. You do not allow the creation (or importation) of any source whose use cannot be justified, which cannot be affordably shipped, or that does not have a well-delinated and affordable disposition pathway. The path forward dictates that we fix the problem by embracing the Ideal Source Life cycle. In figure 1, we can see some of the elements of the ideal source life cycle. The life cycle is broken down into four portions, manufacture, use, consolidation, and disposition. These four arbitrary elements allow them to focus on the ideal life cycle phases that every source should go through between manufacture and final disposition. As we examine the various phases of the sealed source life cycle, they pick specific examples and explore the adoption of the ideal life cycle model.

  18. Sensing data centres for energy efficiency.

    PubMed

    Liu, Jie; Terzis, Andreas

    2012-01-13

    Data centres are large energy consumers today, and their consumption is expected to increase further, driven by the growth in cloud services. The large monetary cost and the environmental impact of this consumption have motivated operators to optimize data centre management. We argue that one of the underlying reasons for the low-energy utilization is the lack of visibility into a data centre's highly dynamic operating conditions. Wireless sensor networks promise to remove this veil of uncertainty by delivering large volumes of data collected at high spatial and temporal fidelities. The paper summarizes data centre operations in order to describe the parameters that a data centre sensing network should collect and motivate the challenges that such a network faces. We present technical approaches for the problems of data collection and management and close with an overview of a data centre genome, an end-to-end data centre sensing system. PMID:22124086

  19. Perceptual centres in speech - an acoustic analysis

    NASA Astrophysics Data System (ADS)

    Scott, Sophie Kerttu

    Perceptual centres, or P-centres, represent the perceptual moments of occurrence of acoustic signals - the 'beat' of a sound. P-centres underlie the perception and production of rhythm in perceptually regular speech sequences. P-centres have been modelled both in speech and non speech (music) domains. The three aims of this thesis were toatest out current P-centre models to determine which best accounted for the experimental data bto identify a candidate parameter to map P-centres onto (a local approach) as opposed to the previous global models which rely upon the whole signal to determine the P-centre the final aim was to develop a model of P-centre location which could be applied to speech and non speech signals. The first aim was investigated by a series of experiments in which a) speech from different speakers was investigated to determine whether different models could account for variation between speakers b) whether rendering the amplitude time plot of a speech signal affects the P-centre of the signal c) whether increasing the amplitude at the offset of a speech signal alters P-centres in the production and perception of speech. The second aim was carried out by a) manipulating the rise time of different speech signals to determine whether the P-centre was affected, and whether the type of speech sound ramped affected the P-centre shift b) manipulating the rise time and decay time of a synthetic vowel to determine whether the onset alteration was had more affect on P-centre than the offset manipulation c) and whether the duration of a vowel affected the P-centre, if other attributes (amplitude, spectral contents) were held constant. The third aim - modelling P-centres - was based on these results. The Frequency dependent Amplitude Increase Model of P-centre location (FAIM) was developed using a modelling protocol, the APU GammaTone Filterbank and the speech from different speakers. The P-centres of the stimuli corpus were highly predicted by attributes of

  20. Optimal shortcuts for atomic transport in anharmonic traps

    NASA Astrophysics Data System (ADS)

    Zhang, Qi; Muga, J. G.; Guéry-Odelin, D.; Chen, Xi

    2016-06-01

    We design fast trap trajectories to transport cold atoms in anharmonic traps, combining invariant-based inverse engineering, perturbation theory, and optimal control theory. Among the ideal trajectories for harmonic traps, we choose the ones that minimize the anharmonic energy.

  1. Maria Goeppert Mayer: atoms, molecules and nuclear shells

    SciTech Connect

    Johnson, K.E.

    1986-09-01

    The mathematical physicist's early work in atomic and molecular physics, and her unfamiliarity with the ''fashions'' in nuclear physics, gave her the ideal preparation for solving the puzzle of the nuclear ''magic numbers.''

  2. Achieving ideal breast aesthetics with autologous reconstruction

    PubMed Central

    2015-01-01

    Achieving ideal breast aesthetic has become a top priority for women considering breast reconstruction following mastectomy. The use of autologous tissue is generally regarded as providing the most natural results because donor tissues quality and consistency is similar to that of the native breast. There are several donor sites that are particularly useful for autologous reconstruction that include the abdomen, gluteal region, posterior thorax, and the thigh. Traditional and microsurgical techniques can be used. Shaping is a critical component and involves a basic understanding of the footprint, conus, and skin envelope. This manuscript will review many aspects of breast shaping in-order to achieve aesthetically pleasing results in a predictable manner. PMID:26005645

  3. Ideal ballooning modes in axisymmetric mirror machines

    SciTech Connect

    Baldwin, D.E.; McNamara, B.; Willmann, P.

    1980-12-15

    A simple code is described that finds marginally stable (..omega../sup 2/ = 0) ballooning-type MHD modes, localized about a field line in an axisymmetric, open-ended, plasma confinement device. The equations are based on a lower bound for the perturbed energy delta W, derived by W. Newcomb from the ideal MHD energy principle, and are cast in the form of a Ricatti equation for the first derivative of the eigenfunction, with the open boundary conditions that this derivative vanish at the plasma boundary down each field line. The input to the code is the two-dimensional shape of a field line, the field strength B(s), and parameters to define pressure profiles throughout the system. The objective is to find the highest plasma pressures for which the given line is MHD-stable.

  4. Symmetry transforms for ideal magnetohydrodynamics equilibria.

    PubMed

    Bogoyavlenskij, Oleg I

    2002-11-01

    A method for constructing ideal magnetohydrodynamics (MHD) equilibria is introduced. The method consists of the application of symmetry transforms to any known MHD equilibrium [ O. I. Bogoyavlenskij, Phys. Rev. E. 62, 8616, (2000)]. The transforms break the geometrical symmetries of the field-aligned solutions and produce continuous families of the nonsymmetric MHD equilibria. The method of symmetry transforms also allows to obtain MHD equilibria with current sheets and exact solutions with noncollinear vector fields B and V. A model of the nonsymmetric astrophysical jets outside of their accretion disks is developed. The total magnetic and kinetic energy of the jet is finite in any layer c(1)

  5. Positron kinetics in an idealized PET environment.

    PubMed

    Robson, R E; Brunger, M J; Buckman, S J; Garcia, G; Petrović, Z Lj; White, R D

    2015-01-01

    The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the 'gas-phase' assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations. PMID:26246002

  6. How is the Ideal Gas Law Explanatory?

    NASA Astrophysics Data System (ADS)

    Woody, Andrea I.

    2013-07-01

    Using the ideal gas law as a comparative example, this essay reviews contemporary research in philosophy of science concerning scientific explanation. It outlines the inferential, causal, unification, and erotetic conceptions of explanation and discusses an alternative project, the functional perspective. In each case, the aim is to highlight insights from these investigations that are salient for pedagogical concerns. Perhaps most importantly, this essay argues that science teachers should be mindful of the normative and prescriptive components of explanatory discourse both in the classroom and in science more generally. Giving attention to this dimension of explanation not only will do justice to the nature of explanatory activity in science but also will support the development of robust reasoning skills in science students while helping them understand an important respect in which science is more than a straightforward collection of empirical facts, and consequently, science education involves more than simply learning them.

  7. Ideal magnetohydrodynamic interchanges in low density plasmas

    SciTech Connect

    Huang Yimin; Goel, Deepak; Hassam, A.B.

    2005-03-01

    The ideal magnetohydrodynamic equations are usually derived under the assumption V{sub A}<

  8. IDEAL Symposium on the East African Lakes

    NASA Astrophysics Data System (ADS)

    Johnson, T. C.; Kelts, K.; Lehman, J. T.; Wuest, A.

    A vast array of interdisciplinary problems presented by the African Great Lakes were highlighted at the International Symposium on the Limnology, Climatology and Paleoclimatology of the East African Lakes, organized by the International Decade for the East African Lakes (IDEAL) February 17-21 in Jinja, Uganda. Approximately 125 scientists attended from North America, Europe, Africa, and New Zealand. Jinja is located on the northern shore of Lake Victoria at the head-waters of the Nile and is the site of the host institution for the symposium, the Uganda Freshwater Fisheries Research Organization (UFFRO). The conveners of the symposium were Tom Johnson of Duke University, George Kitaka of UNESCO-ROSTA, and Eric Odada of the University of Nairobi.

  9. Review of Idealized Aircraft Wake Vortex Models

    NASA Technical Reports Server (NTRS)

    Ahmad, Nashat N.; Proctor, Fred H.; Duparcmeur, Fanny M. Limon; Jacob, Don

    2014-01-01

    Properties of three aircraft wake vortex models, Lamb-Oseen, Burnham-Hallock, and Proctor are reviewed. These idealized models are often used to initialize the aircraft wake vortex pair in large eddy simulations and in wake encounter hazard models, as well as to define matched filters for processing lidar observations of aircraft wake vortices. Basic parameters for each vortex model, such as peak tangential velocity and circulation strength as a function of vortex core radius size, are examined. The models are also compared using different vortex characterizations, such as the vorticity magnitude. Results of Euler and large eddy simulations are presented. The application of vortex models in the postprocessing of lidar observations is discussed.

  10. Positron kinetics in an idealized PET environment

    PubMed Central

    Robson, R. E.; Brunger, M. J.; Buckman, S. J.; Garcia, G.; Petrović, Z. Lj.; White, R. D.

    2015-01-01

    The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the ‘gas-phase’ assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations. PMID:26246002

  11. An ideal glass transition in supercooled water?

    NASA Astrophysics Data System (ADS)

    Sciortino, F.; Chen, S. H.; Gallo, P.; Tartaglia, P.

    Analyzing recent molecular dynamics simulations in deeply supercooled liquid states, we have found that the single particle dynamics in water can be interpreted in terms of Mode Coupling Theory, in its so-called ideal formulation. In this paper we review such evidence and discuss the relevance of this finding for the debated thermodynamic behavior of supercooled water. The experimental apparent power-law behavior of the transport coefficients in water, diverging or going to zero at the so-called Angell temperature could indeed be interpreted as a kinetic, as distinct from thermodynamic, phenomena. This finding removes the need of a thermodynamic singularity for the explanation of the anomalies of liquid water. We also comment on the development of a significant harmonic dynamics on cooling the liquid, which could indicate a transition from a fragile to a strong behavior in liquid water.

  12. Positron kinetics in an idealized PET environment

    NASA Astrophysics Data System (ADS)

    Robson, R. E.; Brunger, M. J.; Buckman, S. J.; Garcia, G.; Petrović, Z. Lj.; White, R. D.

    2015-08-01

    The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the ‘gas-phase’ assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations.

  13. Ideal distributed Bragg reflectors and resonators

    SciTech Connect

    Harvey, R.J.

    1988-05-17

    The method of designing an ideal distributed-Bragg reflector for a microwave waveguide is described comprising the steps of: selecting a signal waveform for propagation as a symmetric traveling wave within the reflector; and determining those surfaces which do not interfere with the symmetric traveling wave having a transverse magnetic polarization by solving the equation sin(k/sub y/Y)=sin(ky..delta..)sinP(k/sub x/x) for horizontally aligned surfaces and the equation sin(k/sub x/x)=sin(k/sub x/..delta..)sin/sup r/(k/sub y/Y) for vertically aligned surfaces; where k/sub y/ is the transverse wave number, k/sub x/ is the axial wave number, p=ky/kx, r=kx,ky, and ..delta.. is set equal to the amplitude of the corrugation, being the transverse spacing at a surface boundary between adjacent horizontally aligned surfaces.

  14. IDEAL: A methology for developing information systems

    NASA Technical Reports Server (NTRS)

    Evers, Ken H.; Bachert, Robert F.

    1988-01-01

    As a result of improved capabilities obtained through current computer technologies, application programs and expert systems, Enterprises are being designed or upgraded to be highly integrated and automated information systems. To design or modify Enterprises, it is necessary to first define what functions are to be performed within the Enterprise, identify which functions are potential candidates for automation, and what automated or expert systems are available, or must be developed, to accomplish the selected function. Second, it is necessary to define and analyze the informational requirements for each function along with the informational relationships among the functions so that a database structure can be established to support the Enterprise. To perform this type of system design, an integrated set of analysis tools is required to support the information analysis process. The IDEAL (Integrated Design and Engineering Analysis Languages) methodology provides this integrated set of tools and is discussed.

  15. Broken Ergodicity in Ideal, Homogeneous, Incompressible Turbulence

    NASA Technical Reports Server (NTRS)

    Morin, Lee; Shebalin, John; Fu, Terry; Nguyen, Phu; Shum, Victor

    2010-01-01

    We discuss the statistical mechanics of numerical models of ideal homogeneous, incompressible turbulence and their relevance for dissipative fluids and magnetofluids. These numerical models are based on Fourier series and the relevant statistical theory predicts that Fourier coefficients of fluid velocity and magnetic fields (if present) are zero-mean random variables. However, numerical simulations clearly show that certain coefficients have a non-zero mean value that can be very large compared to the associated standard deviation. We explain this phenomena in terms of broken ergodicity', which is defined to occur when dynamical behavior does not match ensemble predictions on very long time-scales. We review the theoretical basis of broken ergodicity, apply it to 2-D and 3-D fluid and magnetohydrodynamic simulations of homogeneous turbulence, and show new results from simulations using GPU (graphical processing unit) computers.

  16. Nonlinear electrophoresis of ideally polarizable particles

    NASA Astrophysics Data System (ADS)

    Figliuzzi, B.; Chan, W. H. R.; Moran, J. L.; Buie, C. R.

    2014-10-01

    We focus in this paper on the nonlinear electrophoresis of ideally polarizable particles. At high applied voltages, significant ionic exchange occurs between the electric double layer, which surrounds the particle, and the bulk solution. In addition, steric effects due to the finite size of ions drastically modify the electric potential distribution in the electric double layer. In this situation, the velocity field, the electric potential, and the ionic concentration in the immediate vicinity of the particle are described by a complicated set of coupled nonlinear partial differential equations. In the general case, these equations must be solved numerically. In this study, we rely on a numerical approach to determine the electric potential, the ionic concentration, and the velocity field in the bulk solution surrounding the particle. The numerical simulations rely on a pseudo-spectral method which was used successfully by Chu and Bazant [J. Colloid Interface Sci. 315(1), 319-329 (2007)] to determine the electric potential and the ionic concentration around an ideally polarizable metallic sphere. Our numerical simulations also incorporate the steric model developed by Kilic et al. [Phys. Rev. E 75, 021502 (2007)] to account for crowding effects in the electric double layer, advective transport, and for the presence of a body force in the bulk electrolyte. The simulations demonstrate that surface conduction significantly decreases the electrophoretic mobility of polarizable particles at high zeta potential and at high applied electric field. Advective transport in the electric double layer and in the bulk solution is also shown to significantly impact surface conduction.

  17. Idealized simulations of sting jet cyclones

    NASA Astrophysics Data System (ADS)

    Baker, L. H.; Gray, S. L.; Clark, P. A.

    2012-04-01

    An idealized modeling study of sting-jet cyclones is presented. Sting jets are descending mesoscale jets that occur in some extratropical cyclones and produce localized regions of strong low-level winds in the frontal fracture region. Moist baroclinic lifecycle (LC1) simulations are performed with modifications to produce cyclones resembling observed sting-jet cyclones. Two jets exist in the control idealized cyclone that descend into the frontal fracture region and result in strong winds near to the top of the boundary layer; one of these satisfies the criteria for a sting jet, the other is associated with the warm front. Sensitivity experiments show that both these jets are robust features. The sting jet strength (measured by maximum low-level wind speed or descent rate) increases with the cyclone growth rate; growth rate increases with increasing basic-state zonal jet maximum or decreasing basic-state tropospheric static stability. The two cyclones with the weakest basic-state static stability have by far the strongest sting jets, with descent rates comparable to those observed. Evaporative cooling contributes up to 20% of the descent rate in these sting jets compared with up to 4% in the other sting jets. Conditional symmetric instability (CSI) release in the cloud head also contributes to the sting jet, although there is less extensive CSI than in observed cases. The robustness of the sting jets suggests that they could occur frequently in cyclones with frontal fracture; however, they are unlikely to be identified unless momentum transport through the boundary layer leads to strong surface wind gusts.

  18. On controlling nonlinear dissipation in high order filter methods for ideal and non-ideal MHD

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Sjogreen, B.

    2004-01-01

    The newly developed adaptive numerical dissipation control in spatially high order filter schemes for the compressible Euler and Navier-Stokes equations has been recently extended to the ideal and non-ideal magnetohydrodynamics (MHD) equations. These filter schemes are applicable to complex unsteady MHD high-speed shock/shear/turbulence problems. They also provide a natural and efficient way for the minimization of Div(B) numerical error. The adaptive numerical dissipation mechanism consists of automatic detection of different flow features as distinct sensors to signal the appropriate type and amount of numerical dissipation/filter where needed and leave the rest of the region free from numerical dissipation contamination. The numerical dissipation considered consists of high order linear dissipation for the suppression of high frequency oscillation and the nonlinear dissipative portion of high-resolution shock-capturing methods for discontinuity capturing. The applicable nonlinear dissipative portion of high-resolution shock-capturing methods is very general. The objective of this paper is to investigate the performance of three commonly used types of nonlinear numerical dissipation for both the ideal and non-ideal MHD.

  19. Atomic supersymmetry

    NASA Technical Reports Server (NTRS)

    Kostelecky, V. Alan

    1993-01-01

    Atomic supersymmetry is a quantum-mechanical supersymmetry connecting the properties of different atoms and ions. A short description of some established results in the subject are provided and a few recent developments are discussed including the extension to parabolic coordinates and the calculation of Stark maps using supersymmetry-based models.

  20. Atomic Calligraphy

    NASA Astrophysics Data System (ADS)

    Imboden, Matthias; Pardo, Flavio; Bolle, Cristian; Han, Han; Tareen, Ammar; Chang, Jackson; Christopher, Jason; Corman, Benjamin; Bishop, David

    2013-03-01

    Here we present a MEMS based method to fabricate devices with a small number of atoms. In standard semiconductor fabrication, a large amount of material is deposited, after which etching removes what is not wanted. This technique breaks down for structures that approach the single atom limit, as it is inconceivable to etch away all but one atom. What is needed is a bottom up method with single or near single atom precision. We demonstrate a MEMS device that enables nanometer position controlled deposition of gold atoms. A digitally driven plate is swept as a flux of gold atoms passes through an aperture. Appling voltages on four comb capacitors connected to the central plate by tethers enable nanometer lateral precision in the xy plane over 15x15 sq. microns. Typical MEMS structures have manufacturing resolutions on the order of a micron. Using a FIB it is possible to mill apertures as small as 10 nm in diameter. Assuming a low incident atomic flux, as well as an integrated MEMS based shutter with microsecond response time, it becomes possible to deposit single atoms. Due to their small size and low power consumption, such nano-printers can be mounted directly in a cryogenic system at ultrahigh vacuum to deposit clean quench condensed metallic structures.

  1. Examples for Non-Ideal Solution Thermodynamics Study

    ERIC Educational Resources Information Center

    David, Carl W.

    2004-01-01

    A mathematical model of a non-ideal solution is presented, where it is shown how and where the non-ideality manifests itself in the standard thermodynamics tableau. Examples related to the non-ideal solution thermodynamics study are also included.

  2. Why Education in Public Schools Should Include Religious Ideals

    ERIC Educational Resources Information Center

    de Ruyter, Doret J.; Merry, Michael S.

    2009-01-01

    This article aims to open a new line of debate about religion in public schools by focusing on religious ideals. The article begins with an elucidation of the concept "religious ideals" and an explanation of the notion of reasonable pluralism, in order to be able to explore the dangers and positive contributions of religious ideals and their…

  3. Promoting Spiritual Ideals through Design Thinking in Public Schools

    ERIC Educational Resources Information Center

    Tan, Charlene; Wong, Yew-Leong

    2012-01-01

    Against a backdrop of the debates on religious education in public or state schools, we argue for the introduction of "spiritual ideals" into the public school curriculum. We distinguish our notion of spiritual ideals from "religious ideals" as conceptualised by De Ruyter and Merry. While we agree with De Ruyter and Merry that ideas drawn from…

  4. Moral Identity as Moral Ideal Self: Links to Adolescent Outcomes

    ERIC Educational Resources Information Center

    Hardy, Sam A.; Walker, Lawrence J.; Olsen, Joseph A.; Woodbury, Ryan D.; Hickman, Jacob R.

    2014-01-01

    The purposes of this study were to conceptualize moral identity as moral ideal self, to develop a measure of this construct, to test for age and gender differences, to examine links between moral ideal self and adolescent outcomes, and to assess purpose and social responsibility as mediators of the relations between moral ideal self and outcomes.…

  5. Liquid atomization

    SciTech Connect

    Walzel, P. )

    1993-01-01

    A systematic review of different liquid atomizers is presented, accompanied by a discussion of various mechanisms of droplet formation in a gas atmosphere as a function of the liquid flow-regime and the geometry of the atomizer. Equations are presented for the calculation of the mean droplet-diameter. In many applications, details of the droplet size distribution are, also, important, e.g., approximate values of the breadth of the droplet formation are given. The efficiency of utilization of mechanical energy in droplet formation is indicated for the different types of atomizers. Atomization is used, in particular, for the following purposes: (1) atomization of fuels; (2) making granular products; (3) carrying out mass-transfer operations; and (4) coating of surfaces.

  6. Nuclear Science Centre, New Delhi

    SciTech Connect

    Mehta, G.; Potukuchi, P.; Roy, A.

    1995-08-01

    Argonne is collaborating with the Nuclear Science Centre (NSC), New Delhi, to develop a new type of superconducting accelerating structure for low-velocity heavy ions. A copper model has been evaluated and tests on the niobium prototype are currently in progress. Some technical details of this project are described in the Superconducting Linac Development section of this report. All funding for the prototype has come from the NSC, and they have also stationed two staff members at ATLAS for the past two years to gain experience and work on this project. Additional NSC personnel visited ATLAS for extended periods during 1994 for electronics and cryogenics experience and training. Two NSC staff members are scheduled to spend several months at ANL during 1995 to continue tests and developments of the prototype resonators and to initiate fabrication of the production models for their linac project.

  7. Ideal Spintronics in Molecule-Based Novel Organometallic Nanowires.

    PubMed

    Sun, Qilong; Dai, Ying; Ma, Yandong; Wei, Wei; Yu, Lin; Huang, Baibiao

    2015-01-01

    With the purpose of searching for new intriguing nanomaterial for spintronics, a series of novel metalloporphyrin nanowires (M-PPNW, M = Cr, Mn, Fe, Co, Ni, Cu and Zn) and hybrid nanowires fabricated by metalloporphyrin and metal-phthalocyanine (M-PCNW) are systematically investigated by means of first-principles calculations. Our results indicate that the transition metal atoms (TMs) embedded in the frameworks distribute regularly and separately, without any trend to form clusters, thus leading to the ideally ordered spin distribution. Except for the cases embedded with Ni and Zn, the others are spin-polarized. Remarkably, the Mn-PPNW, Mn-PCNW, MnCu-PPNW, MnCr-PCNW, and MnCu-PCNW frameworks all favor the long-ranged ferromagnetic spin ordering and display half-metallic nature, which are of greatest interest and importance for electronics and spintronics. The predicted Curie temperature for the Mn-PCNW is about 150 K. In addition, it is found that the discrepancy in magnetic coupling for these materials is related to the competition mechanisms of through-bond and through-space exchange interactions. In the present work, we propose not only two novel sets of 1D frameworks with appealing magnetic properties, but also a new strategy in obtaining the half-metallic materials by the combination of different neighboring TMs. PMID:26239021

  8. Ideal Spintronics in Molecule-Based Novel Organometallic Nanowires

    NASA Astrophysics Data System (ADS)

    Sun, Qilong; Dai, Ying; Ma, Yandong; Wei, Wei; Yu, Lin; Huang, Baibiao

    2015-08-01

    With the purpose of searching for new intriguing nanomaterial for spintronics, a series of novel metalloporphyrin nanowires (M-PPNW, M = Cr, Mn, Fe, Co, Ni, Cu and Zn) and hybrid nanowires fabricated by metalloporphyrin and metal-phthalocyanine (M-PCNW) are systematically investigated by means of first-principles calculations. Our results indicate that the transition metal atoms (TMs) embedded in the frameworks distribute regularly and separately, without any trend to form clusters, thus leading to the ideally ordered spin distribution. Except for the cases embedded with Ni and Zn, the others are spin-polarized. Remarkably, the Mn-PPNW, Mn-PCNW, MnCu-PPNW, MnCr-PCNW, and MnCu-PCNW frameworks all favor the long-ranged ferromagnetic spin ordering and display half-metallic nature, which are of greatest interest and importance for electronics and spintronics. The predicted Curie temperature for the Mn-PCNW is about 150 K. In addition, it is found that the discrepancy in magnetic coupling for these materials is related to the competition mechanisms of through-bond and through-space exchange interactions. In the present work, we propose not only two novel sets of 1D frameworks with appealing magnetic properties, but also a new strategy in obtaining the half-metallic materials by the combination of different neighboring TMs.

  9. Polyprotein of GB1 is an ideal artificial elastomeric protein

    NASA Astrophysics Data System (ADS)

    Cao, Yi; Li, Hongbin

    2007-02-01

    Naturally occurring elastomeric proteins function as molecular springs in their biological settings and show mechanical properties that underlie the elasticity of natural adhesives, cell adhesion proteins and muscle proteins. Constantly subject to repeated stretching-relaxation cycles, many elastomeric proteins demonstrate remarkable consistency and reliability in their mechanical performance. Such properties had hitherto been observed only in naturally evolved elastomeric proteins. Here we use single-molecule atomic force microscopy techniques to demonstrate that an artificial polyprotein made of tandem repeats of non-mechanical protein GB1 has mechanical properties that are comparable or superior to those of known elastomeric proteins. In addition to its mechanical stability, we show that GB1 polyprotein shows a unique combination of mechanical features, including the fastest folding kinetics measured so far for a tethered protein, high folding fidelity, low mechanical fatigue during repeated stretching-relaxation cycles and ability to fold against residual forces. These fine features make GB1 polyprotein an ideal artificial protein-based molecular spring that could function in a challenging working environment requiring repeated stretching-relaxation. This study represents a key step towards engineering artificial molecular springs with tailored nanomechanical properties for bottom-up construction of new devices and materials.

  10. Ideal Spintronics in Molecule-Based Novel Organometallic Nanowires

    PubMed Central

    Sun, Qilong; Dai, Ying; Ma, Yandong; Wei, Wei; Yu, Lin; Huang, Baibiao

    2015-01-01

    With the purpose of searching for new intriguing nanomaterial for spintronics, a series of novel metalloporphyrin nanowires (M-PPNW, M = Cr, Mn, Fe, Co, Ni, Cu and Zn) and hybrid nanowires fabricated by metalloporphyrin and metal-phthalocyanine (M-PCNW) are systematically investigated by means of first-principles calculations. Our results indicate that the transition metal atoms (TMs) embedded in the frameworks distribute regularly and separately, without any trend to form clusters, thus leading to the ideally ordered spin distribution. Except for the cases embedded with Ni and Zn, the others are spin-polarized. Remarkably, the Mn-PPNW, Mn-PCNW, MnCu-PPNW, MnCr-PCNW, and MnCu-PCNW frameworks all favor the long-ranged ferromagnetic spin ordering and display half-metallic nature, which are of greatest interest and importance for electronics and spintronics. The predicted Curie temperature for the Mn-PCNW is about 150 K. In addition, it is found that the discrepancy in magnetic coupling for these materials is related to the competition mechanisms of through-bond and through-space exchange interactions. In the present work, we propose not only two novel sets of 1D frameworks with appealing magnetic properties, but also a new strategy in obtaining the half-metallic materials by the combination of different neighboring TMs. PMID:26239021

  11. The network of WHO Collaborating Centres in Occupational Health and the role of maritime centres.

    PubMed

    Kortum, Evelyn; Fingerhut, Marilyn A

    2003-01-01

    The WHO Network of Collaborating Centres in Occupational Health comprises 70 Collaborating Centres. Four of these Centres are specialised in Maritime Occupational Health and they are situated in Poland, Germany, Denmark and the Ukraine. All Collaborating Centres follow the mandate of the Occupational Health Programme in WHO, which is the Global Strategy on Occupational Health for All. Collaborating Centres in Maritime Occupational Health cover a specific group of workers who are exposed to different work environments than workers on land. They are often not at all or only insufficiently covered by any health services. The Collaborating Centres in Maritime Occupational Health provide an excellent example of international collaboration. PMID:14974788

  12. AXIS-SVO Data Centre Creation

    NASA Astrophysics Data System (ADS)

    Ceballos, M. Teresa

    We present the process followed to create the AXIS-SVO Data Centre at the Instituto de Física de Cantabria under the standards of the Virtual Observatory using the publication tools elaborated by the ESA-VO team at the European Space Astronomy Centre (ESAC). The current content of this Data Centre is a sample of optical spectra which are part of the AXIS-XMS sample, based on observations of the XMM-Newton X-ray observatory.

  13. Bangalore looks to new interdisciplinary science centre

    NASA Astrophysics Data System (ADS)

    Ramachandran, Ramaseshan

    2008-09-01

    A new centre to boost interdisciplinary research in India is being established in Bangalore - India's IT and software capital. The International Centre for Theoretical Sciences (ICTS) will be led by Spenta Wadia, a theoretical physicist from the Tata Institute of Fundamental Research (TIFR) in Mumbai, which is setting up the new centre. He expects construction of the ICTS, the first of its kind in India, to start by November 2009.

  14. Atomic resolution holography.

    PubMed

    Hayashi, Kouichi

    2014-11-01

    Atomic resolution holography, such as X-ray fluorescence holography (XFH)[1] and photoelectron holography (PH), has the attention of researcher as an informative local structure analysis, because it provides three dimensional atomic images around specific elements within a range of a few nanometers. It can determine atomic arrangements around a specific element without any prior knowledge of structures. It is considered that the atomic resolution holographic is a third method of structural analysis at the atomic level after X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). As known by many researchers, XRD and XAFS are established methods that are widespread use in various fields. XRD and XAFS provide information on long-range translational periodicities and very local environments, respectively, whereas the atomic resolution holography gives 3D information on the local order and can visualize surrounding atoms with a large range of coordination shells. We call this feature "3D medium-range local structure observation".In addition to this feature, the atomic resolution holography is very sensitive to the displacement of atoms from their ideal positions, and one can obtain quantitative information about local lattice distortions by analyzing reconstructed atomic images[2] When dopants with different atomic radii from the matrix elements are present, the lattices around the dopants are distorted. However, using the conventional methods of structural analysis, one cannot determine the extent to which the local lattice distortions are preserved from the dopants. XFH is a good tool for solving this problem.Figure 1 shows a recent achievement on a relaxor ferroelectric of Pb(Mg1/3Nb2/3)O3 (PMN) using XFH. The structural studies of relaxor ferroelectrics have been carried out by X-ray or neutron diffractions, which suggested rhombohedral distortions of their lattices. However, their true pictures have not been obtained, yet. The Nb Kα holograms showed

  15. The International Centre for Theoretical Physics

    NASA Astrophysics Data System (ADS)

    Hussain, Faheem

    2008-07-01

    This talk traces in brief the genesis of the Abdus Salam International Centre for Theoretical Physics, Trieste, as one of Prof. Abdus Salam's major achievements. It outlines why Salam felt the necessity for establishing such a centre to help physicists in the developing world. It situates the founding of the Centre within Salam's broader vision of the causes of underdevelopment and of science as an engine for scientific, technological, economic and social development. The talk reviews the successes and failures of the ICTP and gives a brief overall view of the current status of the Centre.

  16. Demonstration of asymmetric electron conduction in pseudosymmetrical photosynthetic reaction centre proteins in an electrical circuit

    PubMed Central

    Kamran, Muhammad; Friebe, Vincent M.; Delgado, Juan D.; Aartsma, Thijs J.; Frese, Raoul N.; Jones, Michael R.

    2015-01-01

    Photosynthetic reaction centres show promise for biomolecular electronics as nanoscale solar-powered batteries and molecular diodes that are amenable to atomic-level re-engineering. In this work the mechanism of electron conduction across the highly tractable Rhodobacter sphaeroides reaction centre is characterized by conductive atomic force microscopy. We find, using engineered proteins of known structure, that only one of the two cofactor wires connecting the positive and negative termini of this reaction centre is capable of conducting unidirectional current under a suitably oriented bias, irrespective of the magnitude of the bias or the applied force at the tunnelling junction. This behaviour, strong functional asymmetry in a largely symmetrical protein–cofactor matrix, recapitulates the strong functional asymmetry characteristic of natural photochemical charge separation, but it is surprising given that the stimulus for electron flow is simply an externally applied bias. Reasons for the electrical resistance displayed by the so-called B-wire of cofactors are explored. PMID:25751412

  17. Ideal MHD properties for proposed noncircular tokamaks

    SciTech Connect

    Helton, F.J.; Greene, J.M.

    1986-10-01

    We obtain Double Dee, TFXC-C, Big Dee, and JET equlibria which are optimized with respect to both shape and current profile for stability to ideal MHD modes. With a wall reasonably far from the plasma surface we find that the external kink constrains q/sub 1/ to be above two, where q/sub 1/ is the plasma surface value of the safety factor, and the ballooning mode limits the value of ..beta... Then a relevant stable ..beta.. value for the Double Dee reactor design is over 7%. Such a Double Dee equilibrium is not in a separated second stability region and thus does not have a problem with accessibility. A relevant stable ..beta.. value for the TFCX-C reactor design is over 6%. Equivalent relevant stable ..beta.. values for the Big Dee (17%) and JET (7%) are included for calibration purposes. We compare these relevant stable ..beta.. values with the ..beta..'s determined by two recent scaling laws.

  18. In Pursuit of a More Ideal Hohlraum

    NASA Astrophysics Data System (ADS)

    Baker, Kevin; Thomas, Cliff; Baumann, Ted; Berger, Richard; Biener, Monika; Callahan, Debbie; Celliers, Peter; Elsner, Fred; Felker, Sean; Hamza, Alex; Hinkel, Denise; Huang, Haibo; Jones, Oggie; Landen, Nino; Milovich, Jose; Moody, John; Nikroo, Abbas; Olson, Rick; Strozzi, David

    2015-11-01

    Current hohlraum designs have a number of issues which are detrimental to achieving ignition; including LPI, CBET, hot electrons, non-ideal spectral emission(gold M-Band) and wall motion leading to implosions with large symmetry swings. We are undertaking a campaign on the NIF to address many of these issues through the use of thin wall liners. We will present a comparison between three experiments, a gold hohlraum, a copper-lined hohlraum and a zinc oxide foam-lined hohlraum and discuss our future experimental plans which will utilize very low density foam liners, ~ 10 mg/cc, and low gas fill densities, <0.6 mg/cc. This combination is predicted in simulations to greatly reduce the expansion of the gold wall leading to reduced symmetry swings, result in large reductions in LPI(SBS, SRS and 2Wpe) and eliminate gold m-band emission. The removal of the gold m-band spectra reduces the ablator-fuel instability growth and allows the use of undoped or less doped capsules which in turn reduces the ablation front growth factors leading to a more stable implosion. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  19. Dust Resuspension due to Idealized Foot Motion

    NASA Astrophysics Data System (ADS)

    Sheth, Ritesh

    2005-11-01

    The air quality is affected by amount and types of particulate contaminants that are suspended in the air. The resuspension phenomena occur through two mechanisms: mechanical, where kinetic energy is transferred through direct contact from an impacting body or a vibrating surface, and aerodynamic, where dust particles are resuspended by the flow disturbance generated by the body. In this presentation we focus on aerodynamic resuspension of particles caused by walking. The foot movement is idealized and is either towards or away from a floor without touching it. As a first approach, a 15 cm diameter disk having the equivalent area to that of a human foot is used. The ``foot'' movement is driven vertically by a linear servo motor that controls the velocity, acceleration, stroke and deceleration (a typical vertical velocity is 0.5-1.0 m/s). A thin layer of dust is spread on a table relative to which the disk is allowed to move up and down. Flow visualizations show that both the upward and downward movements of the disk play an important role in the dust resuspension. A clear effect of radial jet and vortex dynamics on the particle resuspension is observed during the downward motion. In the wake of the rising disk, the particles were entrained upwards as a starting ring vortex formed. Quantitative PIV measurements will be performed to help further analyze the flow structure of this flow configuration.

  20. Ideal bulk pressure of active Brownian particles

    NASA Astrophysics Data System (ADS)

    Speck, Thomas; Jack, Robert L.

    2016-06-01

    The extent to which active matter might be described by effective equilibrium concepts like temperature and pressure is currently being discussed intensely. Here, we study the simplest model, an ideal gas of noninteracting active Brownian particles. While the mechanical pressure exerted onto confining walls has been linked to correlations between particles' positions and their orientations, we show that these correlations are entirely controlled by boundary effects. We also consider a definition of local pressure, which describes interparticle forces in terms of momentum exchange between different regions of the system. We present three pieces of analytical evidence which indicate that such a local pressure exists, and we show that its bulk value differs from the mechanical pressure exerted on the walls of the system. We attribute this difference to the fact that the local pressure in the bulk does not depend on boundary effects, contrary to the mechanical pressure. We carefully examine these boundary effects using a channel geometry, and we show a virial formula for the pressure correctly predicts the mechanical pressure even in finite channels. However, this result no longer holds in more complex geometries, as exemplified for a channel that includes circular obstacles.

  1. Ideal Tearing in the Hall Regime

    NASA Astrophysics Data System (ADS)

    Pucci, F.; Velli, M.; Tenerani, A.

    2015-12-01

    Magnetic reconnection is generally believed to be the mechanism thatexplains explosive events in astrophysical plasmas, such as flares inthe solar corona, substorms. One of the main questions which remainsconcerns how magnetic reconnection may account for the fast magneticenergy conversion to kinetic and thermal energies. Recently it hasbeen shown by Pucci and Velli (2014) that, assuming that currentsheets scales as different powers of the magnetic Reynolds number S,the growth rate of the tearing mode instability in current sheetsincreases as the sheets thin and, once the thickness reaches a scalinga/L ˜ S-1/3, the time scale for the instability to develop becomesof the order of the Alfvén time. In Hall reconnection, dispersivewaves introduced by the Hall effect make the energy release ratesfaster. This effect becomes important to the collisional tearing modeinstability when the thickness of magnetic reversal layer iscomparable to the ion inertia length, where Hall currents produce athree-dimensional quadrupole structure of magnetic field. Here wepresent a linear study aiming to show how an "ideal tearing mode" isachieved when Hall effects are included, including scaling laws forsheet aspect ratios and growth rates.

  2. Ideal timing of orchiopexy: a systematic review.

    PubMed

    Chan, Emily; Wayne, Carolyn; Nasr, Ahmed

    2014-01-01

    The ideal management of cryptorchidism is a highly debated topic within the field of pediatric surgery. The optimal timing of orchiopexy is particularly unclear, as existing literature reports mixed recommendations. The aim of this study was to determine, based on a systematic review, the most favorable age at which orchiopexy should be performed. We conducted a systematic search of MEDLINE, Embase, CINAHL, and the Cochrane Library to find relevant articles. Two researchers quality assessed each study using the following tools: AMSTAR (systematic reviews), Jadad (RCTs), and MINORS (non-RCTs). We developed a conclusion based on the highest quality studies. We found one relevant systematic review, one RCT, and 30 non-RCTs. Fertility potential was greatest when orchiopexy was performed before 1 year of age. Additionally, orchiopexy before 10–11 years may protect against the increased risk of testicular cancer associated with cryptorchidism. Orchiopexy should not be performed before 6 months of age, as testes may descend spontaneously during the first few months of life. The highest quality evidence recommends orchiopexy between 6 and 12 months of age. Surgery during this timeframe may optimize fertility potential and protect against testicular malignancy in children with cryptorchidism. PMID:24232174

  3. Ideal bulk pressure of active Brownian particles.

    PubMed

    Speck, Thomas; Jack, Robert L

    2016-06-01

    The extent to which active matter might be described by effective equilibrium concepts like temperature and pressure is currently being discussed intensely. Here, we study the simplest model, an ideal gas of noninteracting active Brownian particles. While the mechanical pressure exerted onto confining walls has been linked to correlations between particles' positions and their orientations, we show that these correlations are entirely controlled by boundary effects. We also consider a definition of local pressure, which describes interparticle forces in terms of momentum exchange between different regions of the system. We present three pieces of analytical evidence which indicate that such a local pressure exists, and we show that its bulk value differs from the mechanical pressure exerted on the walls of the system. We attribute this difference to the fact that the local pressure in the bulk does not depend on boundary effects, contrary to the mechanical pressure. We carefully examine these boundary effects using a channel geometry, and we show a virial formula for the pressure correctly predicts the mechanical pressure even in finite channels. However, this result no longer holds in more complex geometries, as exemplified for a channel that includes circular obstacles. PMID:27415318

  4. Ideal near-field thermophotovoltaic cells

    NASA Astrophysics Data System (ADS)

    Molesky, Sean; Jacob, Zubin

    2015-05-01

    We ask the question, what are the ideal characteristics of a near-field thermophotovoltaic cell? Our search leads us to a reformulation of near-field radiative heat transfer in terms of the joint density of electronic states of the emitter-absorber pair in the thermophotovoltaic system. This form reveals that semiconducting materials with narrowband absorption spectra are critical to the energy-conversion efficiency. This essential feature is unavailable in conventional bulk semiconductor cells but can be obtained using low-dimensional materials. Our results show that the presence of matched van Hove singularities resulting from quantum confinement in the emitter and absorber of a thermophotovoltaic cell boosts both the magnitude and spectral selectivity of radiative heat transfer, dramatically improving energy-conversion efficiency. We provide a model near-field thermophotovoltaic system design making use of this idea by employing the van Hove singularities present in carbon nanotubes. Shockley-Queisser analysis shows that the predicted heat transfer characteristics of this model device are fundamentally better than existing thermophotovoltaic designs. Our work paves the way for the use of quantum dots, quantum wells, two-dimensional semiconductors, semiconductor nanowires, and carbon nanotubes as future materials for thermophotovoltaic cells.

  5. Engaging distortions: are we idealizing marriage?

    PubMed

    Bonds-Raacke, J M; Bearden, E S; Carriere, N J; Anderson, E M; Nicks, S D

    2001-03-01

    The present study was an investigation of the premarital status of engagement in terms of relationship satisfaction and marital expectations using the Evaluation and Nurturing Relationship Issues, Communication and Happiness (ENRICH) Marital Satisfaction Scale (EMS) and its two subscales of Idealistic Distortion (ID) and Marital Satisfaction (MS) (D. G. Fournier, D. H. Olson, & J. M. Druckman, 1983). There were 104 students (23 men and 81 women), of which 15 were married, 19 were engaged, and 70 had extended dating relationships. On average, participants had been in the relationship for 3.8 years, and the mean age was 22 years. Results demonstrated that individuals engaged to be married had significantly higher idealistic distortion scores (M = 86.89) than did either married individuals (M = 56.67) or those in extended dating relationships (M = 61.19). Finally, a negative relation was found between length of relationships and marital satisfaction subscores. Results are discussed in light of factors contributing to such idealized thinking. PMID:11403340

  6. Acting Atoms.

    ERIC Educational Resources Information Center

    Farin, Susan Archie

    1997-01-01

    Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)

  7. Newton's Atom

    NASA Astrophysics Data System (ADS)

    Chaney, Andrea; Espinosa, James; Espinosa, James

    2006-10-01

    At the turn of the twentieth century, physicists and chemists were developing atomic models. Some of the phenomena that they had to explain were the periodic table, the stability of the atom, and the emission spectra. Niels Bohr is known as making the first modern picture that accounted for these. Unknown to much of the physics community is the work of Walter Ritz. His model explained more emission spectra and predates Bohr's work. We will fit several spectra using Ritz's magnetic model for the atom. The problems of stability and chemical periodicity will be shown to be challenges that this model has difficulty solving, but we will present some potentially useful adaptations to the Ritzian atom that can account for them.

  8. Kinetic Atom.

    ERIC Educational Resources Information Center

    Wilson, David B.

    1981-01-01

    Surveys the research of scientists like Joule, Kelvin, Maxwell, Clausius, and Boltzmann as it comments on the basic conceptual issues involved in the development of a more precise kinetic theory and the idea of a kinetic atom. (Author/SK)

  9. Ideal thermodynamic processes of oscillatory-flow regenerative engines will go to ideal stirling cycle?

    NASA Astrophysics Data System (ADS)

    Luo, Ercang

    2012-06-01

    This paper analyzes the thermodynamic cycle of oscillating-flow regenerative machines. Unlike the classical analysis of thermodynamic textbooks, the assumptions for pistons' movement limitations are not needed and only ideal flowing and heat transfer should be maintained in our present analysis. Under such simple assumptions, the meso-scale thermodynamic cycles of each gas parcel in typical locations of a regenerator are analyzed. It is observed that the gas parcels in the regenerator undergo Lorentz cycle in different temperature levels, whereas the locus of all gas parcels inside the regenerator is the Ericson-like thermodynamic cycle. Based on this new finding, the author argued that ideal oscillating-flow machines without heat transfer and flowing losses is not the Stirling cycle. However, this new thermodynamic cycle can still achieve the same efficiency of the Carnot heat engine and can be considered a new reversible thermodynamic cycle under two constant-temperature heat sinks.

  10. Nonlinear filtering and limiting in high order methods for ideal and non-ideal MHD

    NASA Technical Reports Server (NTRS)

    Yee,H. C.; Sjogreen, B.

    2004-01-01

    The various filtering mechanisms and base scheme options of the newly developed adaptive numerical dissipation control in spatially high order filter schemes for the ideal and non-ideal magnetohydrodynamics (MHD) equations are investigated. These filter schemes are applicable to complex unsteady MHD high-speed shock/shear/turbulence problems. They also provide a natural and efficient way for the minimization of Div(B) numerical error. The type of spatial base scheme to be used in conjunction with our filter idea is very general. For example, spectral, compact and non-compact spatially central finite difference schemes are possible candidates. The adaptive numerical dissipation mechanism consists of automatic detection of different flow features as distinct sensors to signal the appropriate type and amount of numerical dissipation/filter where needed and to leave the rest of the region free from numerical dissipation contamination. The numerical dissipation considered consists of high order linear dissipation for the suppression of high frequency oscillation and the nonlinear dissipative portion of high-resolution shock-capturing methods for discontinuity capturing. The applicable nonlinear dissipative portion of high-resolution shock-capturing methods is also very general. The objective of this paper is to investigate the performance of using compact and non-compact central base schemes in conjunction with three commonly used types of nonlinear numerical dissipation for both the ideal and non-ideal MHD. This extended abstract shows the performance of three nonlinear filters in conjunction with a sixth-order non-compact spatial central base scheme. In the final paper, the high order compact spatial central base scheme will be illustrated and compared with the non-compact base scheme. The reason for the investigation of the high order compact spatial central base scheme over the non-compact base scheme is to evaluate if additional accuracy can be gained in regions of

  11. European guidelines for the accreditation of Sleep Medicine Centres.

    PubMed

    Pevernagie, Dirk

    2006-06-01

    This document describes guidelines for accreditation of Sleep Medicine Centres in Europe. These guidelines are the result of a consensus procedure, in which representatives of the European Sleep Research Society (ESRS) and representatives of different European National Sleep Societies (ENSS) were involved. The information obtained during different rounds of consultation was gathered and processed by the members of the Steering Committee of the ESRS. The scope of the guidelines is to define the characteristics of multidisciplinary Sleep Medicine Centres (SMCs), in terms of requirements regarding staff, operational procedures and logistic facilities. Accreditation of SMCs is proposed to be the responsibility of the individual ENSS. The Accreditation Guidelines may thus be considered an instrument for the national societies to develop new or standardize existing accreditation questionnaires, as well as procedures for visiting the site, drafting the accreditation report, and finally, granting the accreditation. The Accreditation Guidelines are meant to be a line of action, that ideally should be followed as close as possible, but that may be subject to certain exceptions, depending on local customs or regulations. PMID:16704580

  12. Star Formation and Dynamics in the Galactic Centre

    NASA Astrophysics Data System (ADS)

    Mapelli, Michela; Gualandris, Alessia

    The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the vicinity of a supermassive black hole (SMBH). Despite the hostile environment, several tens of early-type stars populate the central parsec of our Galaxy. A fraction of them lie in a thin ring with mild eccentricity and inner radius ˜ 0.04 pc, while the S-stars, i.e. the ˜ 30 stars closest to the SMBH ( lesssim 0.04 pc), have randomly oriented and highly eccentric orbits. The formation of such early-type stars has been a puzzle for a long time: molecular clouds should be tidally disrupted by the SMBH before they can fragment into stars. We review the main scenarios proposed to explain the formation and the dynamical evolution of the early-type stars in the GC. In particular, we discuss the most popular in situ scenarios (accretion disc fragmentation and molecular cloud disruption) and migration scenarios (star cluster inspiral and Hills mechanism). We focus on the most pressing challenges that must be faced to shed light on the process of star formation in the vicinity of a SMBH.

  13. Cold Atoms

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    This chapter and the following one address collective effects of quantum particles, that is, the effects which are observed when we put together a large number of identical particles, for example, electrons, helium-4 or rubidium-85 atoms. We shall see that quantum particles can be classified into two categories, bosons and fermions, whose collective behavior is radically different. Bosons have a tendency to pile up in the same quantum state, while fermions have a tendency to avoid each other. We say that bosons and fermions obey two different quantum statistics, the Bose-Einstein and the Fermi-Dirac statistics, respectively. Temperature is a collective effect, and in Section 5.1 we shall explain the concept of absolute temperature and its relation to the average kinetic energy of molecules. We shall describe in Section 5.2 how we can cool atoms down thanks to the Doppler effect, and explain how cold atoms can be used to improve the accuracy of atomic clocks by a factor of about 100. The effects of quantum statistics are prominent at low temperatures, and atom cooling will be used to obtain Bose-Einstein condensates at low enough temperatures, when the atoms are bosons.

  14. Athletic-ideal and thin-ideal internalization as prospective predictors of body dissatisfaction, dieting, and compulsive exercise.

    PubMed

    Homan, Kristin

    2010-06-01

    Although internalization of the thin ideal has been extensively researched and is now regarded as a risk factor for eating disturbance, endorsement of the firm, athletic body ideal has received only minimal attention. This short-term longitudinal study explored whether internalization of two aspects of the current cultural ideal (thinness and athleticism) prospectively predicted three potentially deleterious outcomes: body dissatisfaction, dieting, and compulsive exercise. Undergraduate women (N=231) completed self-report measures at the beginning of the academic year and again 7 months later (N=156 at Time 2). Athletic-ideal internalization predicted change in compulsive exercise over the 7-month study period but not body dissatisfaction or dieting; thin-ideal internalization predicted change in all three outcomes. When both internalization measures were tested simultaneously, neither contributed unique variance. Results suggest that athletic-ideal internalization is not as detrimental as thin-ideal internalization. PMID:20226748

  15. The European NEO Coordination Centre

    NASA Astrophysics Data System (ADS)

    Perozzi, E.; Borgia, B.; Micheli, M.

    An operational approach to NEO (Near-Earth Object) hazard monitoring has been developed at European level within the framework of the Space Situational Awareness Program (SSA) of the European Space Agency (ESA). Through federating European assets and profiting of the expertise developed in European Universities and Research Centers, it has been possible to start the deployment of the so-called SSA NEO Segment. This initiative aims to provide a significant contribution to the worldwide effort to the discovery, follow-up and characterization of the near-Earth object population. A major achievement has been the inauguration in May 2013 of the ESA NEO Coordination Centre located at ESRIN (Frascati, Italy). The goal of the NEOCC Precursor Service operations is twofold: to make available updated information on the NEO population and the associated hazard and to contribute to optimize the NEO observational efforts. This is done by maintaining and improving a Web Portal publicly available at http://neo.ssa.esa.int and by performing follow-up observations through a network of collaborating telescopes and facilities. An overview of the SSA-NEO System and a summary of the first two years of NEOCC operations is presented.

  16. Family Life and Developmental Idealism in Yazd, Iran.

    PubMed

    Abbasi-Shavazi, Mohammad Jalal; Askari-Nodoushan, Abbas

    2012-01-01

    BACKGROUND: This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern families, that modern families help to produce modern societies, and that modern family change is to be expected. OBJECTIVE: We examine the extent to which developmental idealism has been disseminated in Iran. We also investigate predictors of the dissemination of developmental idealism. METHODS: We use survey data collected in 2007 from a sample of women in Yazd, a city in Iran. We examine the distribution of developmental idealism in the sample and the multivariate predictors of developmental idealism. RESULTS: We find considerable support for the expectation that many elements of developmental idealism have been widely disseminated. Statistically significant majorities associate development with particular family attributes, believe that development causes change in families, believe that fertility reductions and age-at-marriage increases help foster development, and perceive family trends in Iran headed toward modernity. As predicted, parental education, respondent education, and income affect adherence to developmental idealism. CONCLUSIONS: Developmental idealism has been widely disseminated in Yazd, Iran and is related to social and demographic factors in predicted ways. COMMENTS: Although our data come from only one city, we expect that developmental idealism has been widely distributed in Iran, with important implications for family and demographic behavior. PMID:22942772

  17. Family Life and Developmental Idealism in Yazd, Iran

    PubMed Central

    Abbasi-Shavazi, Mohammad Jalal; Askari-Nodoushan, Abbas

    2012-01-01

    BACKGROUND This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern families, that modern families help to produce modern societies, and that modern family change is to be expected. OBJECTIVE We examine the extent to which developmental idealism has been disseminated in Iran. We also investigate predictors of the dissemination of developmental idealism. METHODS We use survey data collected in 2007 from a sample of women in Yazd, a city in Iran. We examine the distribution of developmental idealism in the sample and the multivariate predictors of developmental idealism. RESULTS We find considerable support for the expectation that many elements of developmental idealism have been widely disseminated. Statistically significant majorities associate development with particular family attributes, believe that development causes change in families, believe that fertility reductions and age-at-marriage increases help foster development, and perceive family trends in Iran headed toward modernity. As predicted, parental education, respondent education, and income affect adherence to developmental idealism. CONCLUSIONS Developmental idealism has been widely disseminated in Yazd, Iran and is related to social and demographic factors in predicted ways. COMMENTS Although our data come from only one city, we expect that developmental idealism has been widely distributed in Iran, with important implications for family and demographic behavior. PMID:22942772

  18. GCSS Idealized Cirrus Model Comparison Project

    NASA Technical Reports Server (NTRS)

    Starr, David OC.; Benedetti, Angela; Boehm, Matt; Brown, Philip R. A.; Gierens, Klaus; Girard, Eric; Giraud, Vincent; Jakob, Christian; Jensen, Eric; Khvorostyanov, Vitaly; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The GCSS Working Group on Cirrus Cloud Systems (WG2) is conducting a systematic comparison and evaluation of cirrus cloud models. This fundamental activity seeks to support the improvement of models used for climate simulation and numerical weather prediction through assessment and improvement of the "process" models underlying parametric treatments of cirrus cloud processes in large-scale models. The WG2 Idealized Cirrus Model Comparison Project is an initial comparison of cirrus cloud simulations by a variety of cloud models for a series of idealized situations with relatively simple initial conditions and forcing. The models (16) represent the state-of-the-art and include 3-dimensional large eddy simulation (LES) models, two-dimensional cloud resolving models (CRMs), and single column model (SCM) versions of GCMs. The model microphysical components are similarly varied, ranging from single-moment bulk (relative humidity) schemes to fully size-resolved (bin) treatments where ice crystal growth is explicitly calculated. Radiative processes are included in the physics package of each model. The baseline simulations include "warm" and "cold" cirrus cases where cloud top initially occurs at about -47C and -66C, respectively. All simulations are for nighttime conditions (no solar radiation) where the cloud is generated in an ice supersaturated layer, about 1 km in depth, with an ice pseudoadiabatic thermal stratification (neutral). Continuing cloud formation is forced via an imposed diabatic cooling representing a 3 cm/s uplift over a 4-hour time span followed by a 2-hour dissipation stage with no cooling. Variations of these baseline cases include no-radiation and stable-thermal-stratification cases. Preliminary results indicated the great importance of ice crystal fallout in determining even the gross cloud characteristics, such as average vertically-integrated ice water path (IWP). Significant inter-model differences were found. Ice water fall speed is directly

  19. Promotion in Call Centres: Opportunities and Determinants

    ERIC Educational Resources Information Center

    Gorjup, Maria Tatiana; Valverde, Mireia; Ryan, Gerard

    2008-01-01

    Purpose: The purpose of this paper is to examine the quality of jobs in call centres by focusing on the opportunities for promotion in this sector. More specifically, the research questions focus on discovering whether promotion is common practise in the call centre sector and on identifying the factors that affect this.…

  20. The European standards of Haemophilia Centres

    PubMed Central

    Giangrande, Paul; Calizzani, Gabriele; Menichini, Ivana; Candura, Fabio; Mannucci, Pier Mannuccio; Makris, Michael

    2014-01-01

    Introduction The European haemophilia community of professionals and patients has agreed on the principles of haemophilia care to address comprehensive optimal delivery of care which is nowadays scattered throughout Europe. Many of the health facilities call themselves Haemophilia Centres despite their variation in size, expertise and services provided. Only a small number of countries have Haemophilia Centre accreditation systems in place. Methods In the framework of the European Haemophilia Network project, following an inclusive process of stakeholder involvement, the European Guidelines for the certification of haemophilia centres have been developed in order to set quality standards for European Haemophilia Centres and criteria for their certification. Results The Guidelines define the standards and criteria for the designation of two levels of care delivery: European Haemophilia Treatment Centres, providing local routine care, and European Haemophilia Comprehensive Care Centres, providing specialised and multi-disciplinary care and functioning as tertiary referral centres. Additionally, they define standards about general requirements, patient care, provision of an advisory service and establishment of network of clinical and specialised services. Conclusions The implementation of the European Guidelines for the certification of Haemophilia Centres will contribute to the reduction of health inequalities through the standardisation of quality of care in European Union Member States and could represent a model to be taken into consideration for other rare disease groups. PMID:24922293

  1. The Press Research Centre, 1956-1976.

    ERIC Educational Resources Information Center

    Press Research Centre, Krakow (Poland).

    In 1956, the Press Research Centre was established in Cracow, Poland by a group of journalists and publishers, for the purpose of instituting press research that would have practical applications. The aims of the Centre were to conduct studies on the history of the Polish press, the contemporary press, press readership, and editorial techniques.…

  2. The European Centre for Leisure and Education

    ERIC Educational Resources Information Center

    Convergence, 1969

    1969-01-01

    Supported by UNESCO, the European Centre for Leisure and Education is an establishment of the Czechoslovak Academy of Sciences. The task of the Centre lies in the search for common trends of leisure and education in Europe, involving four types of activity: research, editorial, bibliographic, and documentary. It has sponsored conferences, and has…

  3. The Irish Centre for Talented Youth

    ERIC Educational Resources Information Center

    Gilheany, Sheila

    2005-01-01

    Conducting potency tests on penicillin, discussing rocket technology with a NASA astronaut, analysing animal bone fragments from medieval times, these are just some of the activities which occupy the time of students at The Irish Centre for Talented Youth. The Centre identifies young students with exceptional academic ability and then provides…

  4. Large proximal ureteral stones: Ideal treatment modality?

    PubMed Central

    Kadyan, B.; Sabale, V.; Mane, D.; Satav, V.; Mulay, A.; Thakur, N.; Kankalia, S. P.

    2016-01-01

    Background and Purpose: Ideal treatment modality for patients with large impacted proximal ureteral stone remains controversial. We compared laparoscopic transperitoneal ureterolithotomy (Lap-TPUL) and semirigid ureteroscopy for large proximal ureteric stones to evaluate their efficacy and safety. Patients and Methods: From November 2012 to December 2014, we enrolled 122 patients with large (≥1.5 cm) proximal ureteral stone in the study. Patients were randomly divided into two groups: Group A (60 patients), retrograde ureteroscopic lithotripsy using a semirigid ureteroscope; Group B (62 patients), transperitoneal LU (Lap-TPUL). Results: The overall stone-free rate was 71.6% and 93.5% for Group A and Group B respectively (P = 0.008). Auxiliary procedure rate was higher in Group A than in Group B (27.3% vs. 5.6%). The complication rate was 11.2% in Group B versus 25% in Group A. Mean procedure time was higher in laparoscopy group as compared to ureterorenoscopy (URS) groups (84.07 ± 16.80 vs. 62.82 ± 12.71 min). Hospital stay was 4.16 ± 0.67 days in laparoscopy group and 1.18 ± 0.38 days in URS group (P < 0.0001). Conclusion: Laparoscopic transperitoneal ureterolithotomy is a minimally invasive, safe and effective treatment modality and should be recommended to all patients of impacted large proximal stones, which are not amenable to URS or extracorporeal shock-wave lithotripsy or as a primary modality of choice especially if patient is otherwise candidate for open surgery. PMID:27141190

  5. Idealized Computational Models for Auditory Receptive Fields

    PubMed Central

    Lindeberg, Tony; Friberg, Anders

    2015-01-01

    We present a theory by which idealized models of auditory receptive fields can be derived in a principled axiomatic manner, from a set of structural properties to (i) enable invariance of receptive field responses under natural sound transformations and (ii) ensure internal consistency between spectro-temporal receptive fields at different temporal and spectral scales. For defining a time-frequency transformation of a purely temporal sound signal, it is shown that the framework allows for a new way of deriving the Gabor and Gammatone filters as well as a novel family of generalized Gammatone filters, with additional degrees of freedom to obtain different trade-offs between the spectral selectivity and the temporal delay of time-causal temporal window functions. When applied to the definition of a second-layer of receptive fields from a spectrogram, it is shown that the framework leads to two canonical families of spectro-temporal receptive fields, in terms of spectro-temporal derivatives of either spectro-temporal Gaussian kernels for non-causal time or a cascade of time-causal first-order integrators over the temporal domain and a Gaussian filter over the logspectral domain. For each filter family, the spectro-temporal receptive fields can be either separable over the time-frequency domain or be adapted to local glissando transformations that represent variations in logarithmic frequencies over time. Within each domain of either non-causal or time-causal time, these receptive field families are derived by uniqueness from the assumptions. It is demonstrated how the presented framework allows for computation of basic auditory features for audio processing and that it leads to predictions about auditory receptive fields with good qualitative similarity to biological receptive fields measured in the inferior colliculus (ICC) and primary auditory cortex (A1) of mammals. PMID:25822973

  6. Idealized computational models for auditory receptive fields.

    PubMed

    Lindeberg, Tony; Friberg, Anders

    2015-01-01

    We present a theory by which idealized models of auditory receptive fields can be derived in a principled axiomatic manner, from a set of structural properties to (i) enable invariance of receptive field responses under natural sound transformations and (ii) ensure internal consistency between spectro-temporal receptive fields at different temporal and spectral scales. For defining a time-frequency transformation of a purely temporal sound signal, it is shown that the framework allows for a new way of deriving the Gabor and Gammatone filters as well as a novel family of generalized Gammatone filters, with additional degrees of freedom to obtain different trade-offs between the spectral selectivity and the temporal delay of time-causal temporal window functions. When applied to the definition of a second-layer of receptive fields from a spectrogram, it is shown that the framework leads to two canonical families of spectro-temporal receptive fields, in terms of spectro-temporal derivatives of either spectro-temporal Gaussian kernels for non-causal time or a cascade of time-causal first-order integrators over the temporal domain and a Gaussian filter over the logspectral domain. For each filter family, the spectro-temporal receptive fields can be either separable over the time-frequency domain or be adapted to local glissando transformations that represent variations in logarithmic frequencies over time. Within each domain of either non-causal or time-causal time, these receptive field families are derived by uniqueness from the assumptions. It is demonstrated how the presented framework allows for computation of basic auditory features for audio processing and that it leads to predictions about auditory receptive fields with good qualitative similarity to biological receptive fields measured in the inferior colliculus (ICC) and primary auditory cortex (A1) of mammals. PMID:25822973

  7. The role of the sexual assault centre.

    PubMed

    Eogan, Maeve; McHugh, Anne; Holohan, Mary

    2013-02-01

    Sexual Assault Centres provide multidisciplinary care for men and women who have experienced sexual crime. These centres enable provision of medical, forensic, psychological support and follow-up care, even if patients chose not to report the incident to the police service. Sexual Support Centres need to provide a ring-fenced, forensically clean environment. They need to be appropriately staffed and available 24 hours a day, 7 days a week to allow prompt provision of medical and supportive care and collection of forensic evidence. Sexual Assault Centres work best within the context of a core agreed model of care, which includes defined multi-agency guidelines and care pathways, close links with forensic science and police services, and designated and sustainable funding arrangements. Additionally, Sexual Assault Centres also participate in patient, staff and community education and risk reduction. Furthermore, they contribute to the development, evaluation and implementation of national strategies on domestic, sexual and gender-based violence. PMID:22975433

  8. New Zealand Earthquake Forecast Testing Centre

    NASA Astrophysics Data System (ADS)

    Gerstenberger, Matthew C.; Rhoades, David A.

    2010-08-01

    The New Zealand Earthquake Forecast Testing Centre is being established as one of several similar regional testing centres under the umbrella of the Collaboratory for the Study of Earthquake Predictability (CSEP). The Centre aims to encourage the development of testable models of time-varying earthquake occurrence in the New Zealand region, and to conduct verifiable prospective tests of their performance over a period of five or more years. The test region, data-collection region and requirements for testing are described herein. Models must specify in advance the expected number of earthquakes with epicentral depths h ≤ 40 km in bins of time, magnitude and location within the test region. Short-term models will be tested using 24-h time bins at magnitude M ≥ 4. Intermediate-term models and long-term models will be tested at M ≥ 5 using 3-month, 6-month and 5-year bins, respectively. The tests applied will be the same as at other CSEP testing centres: the so-called N test of the total number of earthquakes expected over the test period; the L test of the likelihood of the earthquake catalogue under the model; and the R test of the ratio of the likelihoods under alternative models. Four long-term, three intermediate-term and two short-term models have been installed to date in the testing centre, with tests of these models commencing on the New Zealand earthquake catalogue from the beginning of 2008. Submission of models is open to researchers worldwide. New models can be submitted at any time. The New Zealand testing centre makes extensive use of software produced by the CSEP testing centre in California. It is envisaged that, in time, the scope of the testing centre will be expanded to include new testing methods and differently-specified models, nonetheless that the New Zealand testing centre will develop in parallel with other regional testing centres through the CSEP international collaborative process.

  9. Atomic research

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Connatser, Robert; Cothren, Bobby; Johnson, R. B.

    1993-01-01

    Work performed by the University of Alabama in Huntsville's (UAH) Center for Applied Optics (CAO) entitled Atomic Research is documented. Atomic oxygen (AO) effects on materials have long been a critical concern in designing spacecraft to withstand exposure to the Low Earth Orbit (LEO) environment. The objective of this research effort was to provide technical expertise in the design of instrumentation and experimental techniques for analyzing materials exposed to atomic oxygen in accelerated testing at NASA/MSFC. Such testing was required to answer fundamental questions concerning Space Station Freedom (SSF) candidate materials and materials exposed to atomic oxygen aboard the Long-Duration Exposure Facility (LDEF). The primary UAH task was to provide technical design, review, and analysis to MSFC in the development of a state-of-the-art 5eV atomic oxygen beam facility required to simulate the RAM-induced low earth orbit (LEO) AO environment. This development was to be accomplished primarily at NASA/MSFC. In support of this task, contamination effects and ultraviolet (UV) simulation testing was also to be carried out using NASA/MSFC facilities. Any materials analysis of LDEF samples was to be accomplished at UAH.

  10. Actuated atomizer

    NASA Technical Reports Server (NTRS)

    Tilton, Charles (Inventor); Weiler, Jeff (Inventor); Palmer, Randall (Inventor); Appel, Philip (Inventor)

    2008-01-01

    An actuated atomizer is adapted for spray cooling or other applications wherein a well-developed, homogeneous and generally conical spray mist is required. The actuated atomizer includes an outer shell formed by an inner ring; an outer ring; an actuator insert and a cap. A nozzle framework is positioned within the actuator insert. A base of the nozzle framework defines swirl inlets, a swirl chamber and a swirl chamber. A nozzle insert defines a center inlet and feed ports. A spool is positioned within the coil housing, and carries the coil windings having a number of turns calculated to result in a magnetic field of sufficient strength to overcome the bias of the spring. A plunger moves in response to the magnetic field of the windings. A stop prevents the pintle from being withdrawn excessively. A pintle, positioned by the plunger, moves between first and second positions. In the first position, the head of the pintle blocks the discharge passage of the nozzle framework, thereby preventing the atomizer from discharging fluid. In the second position, the pintle is withdrawn from the swirl chamber, allowing the atomizer to release atomized fluid. A spring biases the pintle to block the discharge passage. The strength of the spring is overcome, however, by the magnetic field created by the windings positioned on the spool, which withdraws the plunger into the spool and further compresses the spring.

  11. Moral rules, moral ideals, and use-inspired research.

    PubMed

    Kovac, Jeffrey

    2007-06-01

    Moral rules provide the baseline for ethics, proscribing unacceptable behavior; moral ideals inspire us to act in ways that improve the human condition. Whatever the moral ideals for pure research, science has a practical side so it is important to find a moral ideal to give guidance to more applied research. This article presents a moral ideal for use-inspired research based on Norman Care's idea of shared-fate individualism This ideal reflects the observation that all human lives, both present and future are tightly coupled and, as a result, research projects should be chosen, where possible, with the goal of service to others. Together with the ideals of the habit of truth and the gift economy, shared-fate individualism provides the basis for a humane ethics of science. PMID:17717730

  12. The Canadian Astronomy Data Centre

    NASA Astrophysics Data System (ADS)

    Ball, Nicholas M.; Schade, D.; Astronomy Data Centre, Canadian

    2011-01-01

    The Canadian Astronomy Data Centre (CADC) is the world's largest astronomical data center, holding over 0.5 Petabytes of information, and serving nearly 3000 astronomers worldwide. Its current data collections include BLAST, CFHT, CGPS, FUSE, Gemini, HST, JCMT, MACHO, MOST, and numerous other archives and services. It provides extensive data archiving, curation, and processing expertise, via projects such as MegaPipe, and enables substantial day-to-day collaboration between resident astronomers and computer specialists. It is a stable, powerful, persistent, and properly supported environment for the storage and processing of large volumes of data, a condition that is now absolutely vital for their science potential to be exploited by the community. Through initiatives such as the Common Archive Observation Model (CAOM), the Canadian Virtual Observatory (CVO), and the Canadian Advanced Network for Astronomical Research (CANFAR), the CADC is at the global forefront of advancing astronomical research through improved data services. The CAOM aims to provide homogeneous data access, and hence viable interoperability between a potentially unlimited number of different data collections, at many wavelengths. It is active in the definition of numerous emerging standards within the International Virtual Observatory, and several datasets are already available. The CANFAR project is an initiative to make cloud computing for storage and data-intensive processing available to the community. It does this via a Virtual Machine environment that is equivalent to managing a local desktop. Several groups are already processing science data. CADC is also at the forefront of advanced astronomical data analysis, driven by the science requirements of astronomers both locally and further afield. The emergence of 'Astroinformatics' promises to provide not only utility items like object classifications, but to directly enable new science by accessing previously undiscovered or intractable

  13. Big Surveys, Big Data Centres

    NASA Astrophysics Data System (ADS)

    Schade, D.

    2016-06-01

    Well-designed astronomical surveys are powerful and have consistently been keystones of scientific progress. The Byurakan Surveys using a Schmidt telescope with an objective prism produced a list of about 3000 UV-excess Markarian galaxies but these objects have stimulated an enormous amount of further study and appear in over 16,000 publications. The CFHT Legacy Surveys used a wide-field imager to cover thousands of square degrees and those surveys are mentioned in over 1100 publications since 2002. Both ground and space-based astronomy have been increasing their investments in survey work. Survey instrumentation strives toward fair samples and large sky coverage and therefore strives to produce massive datasets. Thus we are faced with the "big data" problem in astronomy. Survey datasets require specialized approaches to data management. Big data places additional challenging requirements for data management. If the term "big data" is defined as data collections that are too large to move then there are profound implications for the infrastructure that supports big data science. The current model of data centres is obsolete. In the era of big data the central problem is how to create architectures that effectively manage the relationship between data collections, networks, processing capabilities, and software, given the science requirements of the projects that need to be executed. A stand alone data silo cannot support big data science. I'll describe the current efforts of the Canadian community to deal with this situation and our successes and failures. I'll talk about how we are planning in the next decade to try to create a workable and adaptable solution to support big data science.

  14. Atom Interferometry

    SciTech Connect

    Kasevich, Mark

    2008-05-08

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton's constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gyroscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be used to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  15. Atom Interferometry

    SciTech Connect

    Mark Kasevich

    2008-05-07

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  16. Atom Interferometry

    ScienceCinema

    Mark Kasevich

    2010-01-08

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  17. Engineering the Ideal Gigapixel Image Viewer

    NASA Astrophysics Data System (ADS)

    Perpeet, D. Wassenberg, J.

    2011-09-01

    Despite improvements in automatic processing, analysts are still faced with the task of evaluating gigapixel-scale mosaics or images acquired by telescopes such as Pan-STARRS. Displaying such images in ‘ideal’ form is a major challenge even today, and the amount of data will only increase as sensor resolutions improve. In our opinion, the ideal viewer has several key characteristics. Lossless display - down to individual pixels - ensures all information can be extracted from the image. Support for all relevant pixel formats (integer or floating point) allows displaying data from different sensors. Smooth zooming and panning in the high-resolution data enables rapid screening and navigation in the image. High responsiveness to input commands avoids frustrating delays. Instantaneous image enhancement, e.g. contrast adjustment and image channel selection, helps with analysis tasks. Modest system requirements allow viewing on regular workstation computers or even laptops. To the best of our knowledge, no such software product is currently available. Meeting these goals requires addressing certain realities of current computer architectures. GPU hardware accelerates rendering and allows smooth zooming without high CPU load. Programmable GPU shaders enable instant channel selection and contrast adjustment without any perceptible slowdown or changes to the input data. Relatively low disk transfer speeds suggest the use of compression to decrease the amount of data to transfer. Asynchronous I/O allows decompressing while waiting for previous I/O operations to complete. The slow seek times of magnetic disks motivate optimizing the order of the data on disk. Vectorization and parallelization allow significant increases in computational capacity. Limited memory requires streaming and caching of image regions. We develop a viewer that takes the above issues into account. Its awareness of the computer architecture enables previously unattainable features such as smooth

  18. Converging cylindrical shocks in ideal magnetohydrodynamics

    SciTech Connect

    Pullin, D. I.; Mostert, W.; Wheatley, V.; Samtaney, R.

    2014-09-15

    We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R=√(μ{sub 0}/p{sub 0}) I/(2 π) where I is the current, μ{sub 0} is the permeability, and p{sub 0} is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The

  19. Converging cylindrical shocks in ideal magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Pullin, D. I.; Mostert, W.; Wheatley, V.; Samtaney, R.

    2014-09-01

    We consider a cylindrically symmetrical shock converging onto an axis within the framework of ideal, compressible-gas non-dissipative magnetohydrodynamics (MHD). In cylindrical polar co-ordinates we restrict attention to either constant axial magnetic field or to the azimuthal but singular magnetic field produced by a line current on the axis. Under the constraint of zero normal magnetic field and zero tangential fluid speed at the shock, a set of restricted shock-jump conditions are obtained as functions of the shock Mach number, defined as the ratio of the local shock speed to the unique magnetohydrodynamic wave speed ahead of the shock, and also of a parameter measuring the local strength of the magnetic field. For the line current case, two approaches are explored and the results compared in detail. The first is geometrical shock-dynamics where the restricted shock-jump conditions are applied directly to the equation on the characteristic entering the shock from behind. This gives an ordinary-differential equation for the shock Mach number as a function of radius which is integrated numerically to provide profiles of the shock implosion. Also, analytic, asymptotic results are obtained for the shock trajectory at small radius. The second approach is direct numerical solution of the radially symmetric MHD equations using a shock-capturing method. For the axial magnetic field case the shock implosion is of the Guderley power-law type with exponent that is not affected by the presence of a finite magnetic field. For the axial current case, however, the presence of a tangential magnetic field ahead of the shock with strength inversely proportional to radius introduces a length scale R=sqrt{μ _0/p_0} I/(2 π ) where I is the current, μ0 is the permeability, and p0 is the pressure ahead of the shock. For shocks initiated at r ≫ R, shock convergence is first accompanied by shock strengthening as for the strictly gas-dynamic implosion. The diverging magnetic field

  20. Review of CERN Data Centre Infrastructure

    NASA Astrophysics Data System (ADS)

    Andrade, P.; Bell, T.; van Eldik, J.; McCance, G.; Panzer-Steindel, B.; Coelho dos Santos, M.; Traylen and, S.; Schwickerath, U.

    2012-12-01

    The CERN Data Centre is reviewing strategies for optimizing the use of the existing infrastructure and expanding to a new data centre by studying how other large sites are being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote data centres. This paper gives the details on the project's motivations, current status and areas for future investigation.

  1. Studying of barrier height and ideality factor relation in the nano sized Au-n type Si Schottky diodes

    NASA Astrophysics Data System (ADS)

    Yeganeh, M. A.; Mamedov, R. K.; Rahmatallahpur, Sh.

    2011-07-01

    The results of formation of the operating potential barrier height ( Φв) of inhomogeneous Schottky diodes (SD) in view of an additional electric field in the near contact region of the semiconductor and features of its dependence on the external applied voltage are presented. A correlation, between SD heterogeneity and dependence between potential barrier height ( Φв) and ideality factor ( n), is presented. Using conducting probe atomic force microscope (CP-AFM) techniques, it is shown that Au/n-Si diodes consist of sets of parallel-connected and cooperating nano diodes with the contact surfaces sizes in the order of 100-200 nm. The effective Φв and ideality factors of the SD have been obtained from the current-voltage ( I- V) characteristics, which were measured using a CP-AFM along a contact surface. It was experimentally shown that the forward and reverse part of I- V characteristics and their effective Φв and ideality factors of the identically fabricated nano-SD differ from diode to diode. The Φв for the nano-SD has ranged from 0.565 to 0.723 eV and ideality factor from 1.11 to 1.98. No correlation can be found between the Φв and ideality factor. The Φв distribution obtained from the I- V characteristics has been fitted by a Gaussian function but the ideality factor distribution could not be fitted by a Gaussian function.

  2. Structure characterisation method for ideal and non-ideal twisted plywoods.

    PubMed

    Aguilar Gutierrez, Oscar F; Rey, Alejandro D

    2014-12-21

    The twisted plywood architecture, known as the Bouligand structure, is a ubiquitous biological and synthetic fibrous composite structure, analogous to that of cholesteric liquid crystals. Twisted plywoods can show ideal or non-ideal structures and are formed via equilibrium or non-equilibrium liquid crystal self-assembly processes. A key to the structure characterisation of plywood films is the specification of the local and global helix vector h(x) and pitch p(x) of the cholesteric order. Previous extensive work demonstrated that oblique cuts of the plywood give rise to arc-patterns that depend both on the unknown incision angle α and the unknown pitch p(x), thus making the precise 3D cholesteric reconstruction ambiguous. In this paper we present an efficient method based on geometric modelling and new visualization software that determines unambiguously the cholesteric pitch under spatially homogeneous and heterogeneous conditions. The method is applied to films that display two-pitch and spatially non-homogenous structures, as sometimes observed under equilibrium and non-equilibrium self-assembly. The method can be extended to other biological materials such as cornea-like, cylindrical, and various cuticle plywoods. PMID:25342518

  3. Towards Human-Centred Design

    NASA Astrophysics Data System (ADS)

    Bannon, Liam J.

    The field of HCI has evolved and expanded dramatically since its origin in the early 1980’s. The HCI community embraces a large community of researchers and practitioners around the world, from a variety of disciplinary backgrounds in the human and social sciences, engineering and informatics, and more recently, the arts and design disciplines. This kaleidoscope of cultures and disciplines as seen at INTERACT Conferences provides a rich pool of resources for examining our field. Applications are increasingly exploring our full range of sensory modalities, and merging the digital and physical worlds. WiFi has opened up a huge design space for mobile applications. A focus on usability of products and services has been complemented by an emphasis on engagement, enjoyment and experience. With the advent of ubiquitous computing, and the emergence of “The Internet of Things”, new kinds of more open infrastructures make possible radically new kinds of applications. The sources of innovation have also broadened, to include human and social actors outside of the computing and design organizations. The question is to what extent is our mainstream thinking in the HCI field ready for the challenges of this Brave New World? Do the technological and social innovations that we see emerging require us to re-shape, or even, re-create, our field, or is it a case of a more gradual evolution and development of that which we already know? In this closing Keynote, I will provide a perspective on the evolution and development of the HCI field, looking backwards as well as forwards, in order to determine what are some of the changes of significance in the field. This “broad-brush” approach to what I term “ human-centred design” will be complemented by the examination of specific projects and applications, to help anchor some of the discussion. Areas such as user-centred design, participatory design, computer-supported cooperative work and learning, and interaction design, in

  4. The quantum mechanical two-Coulomb-centre problem in the Dirac equation framework

    NASA Astrophysics Data System (ADS)

    Reity, O. K.; Lazur, V. Yu; Katernoha, A. V.

    2002-01-01

    The asymptotic expansions (at small and large internuclear distances R) of the eigenvalues (potential curves) E(R) of the two-Coulomb-centre problem are obtained. The Dirac equation with an axially symmetrical potential, not allowing complete separation of variables, is solved analytically by the Wentzel-Kramers-Brillouin approach and boundary-layer method. In the framework of this scheme, the relativistic two-Coulomb-centre wavefunction is constructed. The first two terms of the asymptotic (at large internuclear distance) behaviour of the exchange interaction potential for an ion with an atom are calculated.

  5. Two-level trap model of BEC in an ideal gas

    NASA Astrophysics Data System (ADS)

    Dorfman, Konstantin; Kocharovsky, Vitaly; Kocharovsky, Vladimir

    2009-04-01

    We consider a two-energy-level trap with arbitrary degeneracy of an upper level and find an analytical solution for the condensate statistics in a mesoscopic ideal gas with arbitrary number of atoms and any temperature, including a critical region. The solution is a cut-off negative binomial distribution that tends to a cut-off gamma distribution in the thermodynamic limit. We show how to model BEC in real traps by BEC in the two-level or three-level traps.

  6. Ideal superspin glass behaviour in a random-close-packed ensemble of maghemite nanoparticles

    NASA Astrophysics Data System (ADS)

    De Toro, J. A.; Lee, S. S.; Mathieu, R.; Normile, P. S.; Salazar, D.; Cheong, J. L.; Muñiz, P.; Riveiro, J. M.; Hillenkamp, M.; Tamion, A.; Tournus, F.; Nordblad, P.

    2014-06-01

    Highly uniform (8 nm) bare maghemite nanoparticles were pressed into a disc with a volume fraction close to the characteristic filling factor of random-close-packed ensembles of spherical particles. We review the ideal superspin glass behaviour exhibited by this material, including an onset of the absorption component of the ac susceptibility at the freezing transition as sharp (in a normalized temperature scale) as those observed in atomic spin glasses, narrow memory dips in the zero-field cooled magnetization, and a spin-glass characteristic field-dependence of the susceptibility. Critical exponents were extracted from static and dynamic scaling analysis.

  7. Your Ideal Silhouette. Courseware Evaluation for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Tierney, Margaret S.; And Others

    This courseware evaluation rates the "Your Ideal Silhouette" program developed by Your Image, Inc. This program (not contained in this document) uses the computer to identify figure faults and illustrate personalized corrective style lines to achieve the ideal silhouette. Part A describes the program in terms of subject area (textiles and…

  8. Teachers' Ethnotheories of the "Ideal Student" in Five Western Cultures

    ERIC Educational Resources Information Center

    Harkness, Sara; Blom, Marjolijn; Oliva, Alfredo; Moscardino, Ughetta; Zylicz, Piotr Olaf; Bermudez, Moises Rios; Feng, Xin; Carrasco-Zylicz, Agnieszka; Axia, Giovanna; Super, Charles M.

    2007-01-01

    This paper explores teachers' ethnotheories of the "ideal student" in five western societies: Italy, The Netherlands, Poland, Spain, and the US. Quantitative and qualitative methods are used to derive culture-specific profiles of the "ideal student" as described by kindergarten and primary school teachers in semi-structured interviews (sample n's…

  9. Intelligibility of reverberant noisy speech with ideal binary masking.

    PubMed

    Roman, Nicoleta; Woodruff, John

    2011-10-01

    For a mixture of target speech and noise in anechoic conditions, the ideal binary mask is defined as follows: It selects the time-frequency units where target energy exceeds noise energy by a certain local threshold and cancels the other units. In this study, the definition of the ideal binary mask is extended to reverberant conditions. Given the division between early and late reflections in terms of speech intelligibility, three ideal binary masks can be defined: an ideal binary mask that uses the direct path of the target as the desired signal, an ideal binary mask that uses the direct path and early reflections of the target as the desired signal, and an ideal binary mask that uses the reverberant target as the desired signal. The effects of these ideal binary mask definitions on speech intelligibility are compared across two types of interference: speech shaped noise and concurrent female speech. As suggested by psychoacoustical studies, the ideal binary mask based on the direct path and early reflections of target speech outperforms the other masks as reverberation time increases and produces substantial reductions in terms of speech reception threshold for normal hearing listeners. PMID:21973369

  10. A Generalized Deduction of the Ideal-Solution Model

    ERIC Educational Resources Information Center

    Leo, Teresa J.; Perez-del-Notario, Pedro; Raso, Miguel A.

    2006-01-01

    A new general procedure for deriving the Gibbs energy of mixing is developed through general thermodynamic considerations, and the ideal-solution model is obtained as a special particular case of the general one. The deduction of the Gibbs energy of mixing for the ideal-solution model is a rational one and viewed suitable for advanced students who…