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Sample records for karin persson waller

  1. Superculture? Thoughts Prompted by Roland S. Persson's Essay

    ERIC Educational Resources Information Center

    Tebbs, Trevor J.

    2012-01-01

    The author finds Roland S. Persson's (2012a) paper to be timely, fascinating, important and powerful. At risk of mixing metaphors, it provides much food for thought and a penetrating lens through which all those vested in the optimal realisation of human potential would be prudent to review their own perceptions, boundaries of belief and…

  2. Drawings of fossils by Robert Hooke and Richard Waller

    PubMed Central

    Kusukawa, Sachiko

    2013-01-01

    The drawings of fossils by Robert Hooke and Richard Waller that were the basis of the engravings in Hooke's Posthumous works (1705) are published here for the first time. The drawings show that both Hooke and Waller were proficient draftsmen with a keen eye for the details of petrified objects. These drawings provided Hooke with a polemic edge in making the case for the organic origins of ‘figured stones’.

  3. 832 Karin: Absence of rotational spectral variations

    NASA Astrophysics Data System (ADS)

    Vernazza, Pierre; Rossi, Alessandro; Birlan, Mirel; Fulchignoni, Marcello; Nedelcu, Alin; Dotto, Elisabetta

    2007-11-01

    832 Karin is the largest member of the young Karin cluster that formed 5.75±0.05 Myr ago in the outer main belt. Surprisingly, recent near-IR spectroscopy measurements [Sasaki, T., Sasaki, S., Watanabe, J., Sekiguchi, T., Yoshida, F., Kawakita, H., Fuse, T., Takato, N., Dermawan, B., Ito, T., 2004. Astrophys. J. 615 (2), L161-L164] revealed that Karin's surface shows different colors as a function of rotational phase. It was interpreted that 832 Karin shows us the reddish space-weathered exterior surface of the parent body as well as an interior face, which has not had time to become space-weathered. This result is at odds with recent results including seismic and geomorphic modeling, modeling of the Karin cluster formation and measurements of the space weathering rate. Consequently, we aimed to confirm/infirm this surprising result by sampling Karin's spectrum well throughout its rotation. Here, we present new visible (0.45-0.95 μm) and near-infrared (0.7-2.5 μm) spectroscopic observations of 832 Karin obtained in January and April 2006, covering most of Karin's longitudes. In the visible range, we find that Karin shows no rotational spectral variations. Similarly, we find that Karin exhibits very little (to none) spectral variations with rotation in the near-IR range. Our results imply that 832 Karin has a homogeneous surface, in terms of composition and surface age. Our results also imply that the impact that generated the family refreshed entirely Karin's surface, and probably the surfaces of all members.

  4. Culture, Globalisation and the Study of Giftedness: Reflections on Persson's Analysis and Recommendations for Future Research

    ERIC Educational Resources Information Center

    Foreman, Jennifer; Renzulli, Joseph

    2012-01-01

    Dr. Persson's (2012a) target article addresses a number of key points that will greatly impact the study of giftedness, gifted education, and talent development in the "flat" world of the 21st century and beyond. Research in these areas needs to continually reflect upon changes in the social world outside its narrow purview to validate its…

  5. Multiple Scattering Debye-Waller Factors for Arsenate

    NASA Astrophysics Data System (ADS)

    Kim, E.; Chen, N.; Arthur, Z.; Warner, J.; Demopoulos, G. P.; Rowson, J. W.; Jiang, D. T.

    2013-04-01

    Debye-Waller factors for the As-O-O triangular multiple scattering paths within the arsenate in Na2HAsO4·7H2O are evaluated in terms of magnitude ratio with respect to the Debye-Waller factor of the nearest neighbour As-O shell (σ2As-0-0/σ2As-0). The arsenates are studied under two different levels of distortion from an ideal tetrahedron, i.e. a relatively high distortion in the powder form and a nearly ideal tetrahedron in an aqueous solution at pH 14. The Debye-Waller factor ratio σ2As-0-0/σ2As-0) is found to be 2.0 and 1.9 for the powder and liquid sample, respectively, appearing to be insensitive to the distortion of the arsenate tetrahedron.

  6. Maxine Waller: The Making of a Community Organizer.

    ERIC Educational Resources Information Center

    Lewis, Helen Matthews

    1990-01-01

    Maxine Waller describes how concern for the children of Ivanhoe (Virginia) led her to become president of the Civic League. The Civic League has mobilized the town to renovate buildings and create a riverside park, promoted business ventures, and sponsored adult education classes and an oral history project. (SV)

  7. Risk, Russian-roulette and lotteries: Persson and Savulescu on moral enhancement.

    PubMed

    Gunson, Darryl; McLachlan, Hugh

    2013-11-01

    The literature concerning the possibility and desirability of using new pharmacological and possible future genetic techniques to enhance human characteristics is well-established and the debates follow some well-known argumentative patterns. However, one argument in particular stands out and demands attention. This is the attempt to tie the moral necessity of moral enhancement to the hypothesised risks that allowing cognitive enhancement will bring. According to Persson and Savulescu, cognitive enhancement should occur only if the risks they think it to poses are mitigated by moral enhancement. By this they mean the compulsory and universal amplification of the disposition of altruism and the inflation of our sense of fairness, by chemical and/or genetic means. Their claim is important, intriguing and unsettling. This paper focuses on three central, but relatively neglected, features of their argument. First, there is a pernicious ambiguity in the language of 'risk' used by Persson and Savulescu where they tend to conflate 'risk' and 'uncertainty'. Second, their use of the lottery analogy to render their position more plausible is unconvincing. It tends to distort rather than illuminate the relevant considerations. Third, Persson and Savulescu do not adequately take into account the social and individual benefits that enhancing cognition could have. If they did, it would be apparent that those benefits alone would outweigh the considerations used to justify accompanying CE with ME.

  8. Debye-Waller coefficient of heavily deformed nanocrystalline iron.

    PubMed

    Scardi, P; Rebuffi, L; Abdellatief, M; Flor, A; Leonardi, A

    2017-04-01

    Synchrotron radiation X-ray diffraction (XRD) patterns from an extensively ball-milled iron alloy powder were collected at 100, 200 and 300 K. The results were analysed together with those using extended X-ray absorption fine structure, measured on the same sample at liquid nitrogen temperature (77 K) and at room temperature (300 K), to assess the contribution of static disorder to the Debye-Waller coefficient (Biso). Both techniques give an increase of ∼20% with respect to bulk reference iron, a noticeably smaller difference than reported by most of the literature for similar systems. Besides good quality XRD patterns, proper consideration of the temperature diffuse scattering seems to be the key to accurate values of the Debye-Waller coefficient. Molecular dynamics simulations of nanocrystalline iron aggregates, mapped on the evidence provided by XRD in terms of domain size distribution, shed light on the origin of the observed Biso increase. The main contribution to the static disorder is given by the grain boundary, while line and point defects have a much smaller effect.

  9. Debye–Waller coefficient of heavily deformed nanocrystalline iron1

    PubMed Central

    Abdellatief, M.

    2017-01-01

    Synchrotron radiation X-ray diffraction (XRD) patterns from an extensively ball-milled iron alloy powder were collected at 100, 200 and 300 K. The results were analysed together with those using extended X-ray absorption fine structure, measured on the same sample at liquid nitrogen temperature (77 K) and at room temperature (300 K), to assess the contribution of static disorder to the Debye–Waller coefficient (B iso). Both techniques give an increase of ∼20% with respect to bulk reference iron, a noticeably smaller difference than reported by most of the literature for similar systems. Besides good quality XRD patterns, proper consideration of the temperature diffuse scattering seems to be the key to accurate values of the Debye–Waller coefficient. Molecular dynamics simulations of nanocrystalline iron aggregates, mapped on the evidence provided by XRD in terms of domain size distribution, shed light on the origin of the observed B iso increase. The main contribution to the static disorder is given by the grain boundary, while line and point defects have a much smaller effect. PMID:28381974

  10. Revealing Additional Dimensions of Globalisation and Cultural Hegemony: A Response to Roland S. Persson's Call for Cultural Sensitivity in Gifted Studies

    ERIC Educational Resources Information Center

    Ambrose, Don

    2012-01-01

    In this commentary, the author finds the interdisciplinary approach of Roland S. Persson's (2012a) target article refreshing. Persson's (2012a) additional emphases on ethnocentricity, cultural bias and strong threads of influence from the global economy also are helpful. They shed light on some strong contextual influences that shape the…

  11. An "Immanent" Social Class Effect on Participation in Higher Education? A Rejoinder to Harrison and Waller

    ERIC Educational Resources Information Center

    Noble, John; Davies, Peter

    2010-01-01

    This article responds to criticisms, put forward by Harrison and Waller in this issue, of an earlier paper by Noble and Davies. In particular, we argue that our interpretation of earlier quantitative research is correct, that Harrison and Waller have misconstrued the purpose of our previous paper and the analysis it contains, and that they…

  12. An "Immanent" Social Class Effect on Participation in Higher Education? A Rejoinder to Harrison and Waller

    ERIC Educational Resources Information Center

    Noble, John; Davies, Peter

    2010-01-01

    This article responds to criticisms, put forward by Harrison and Waller in this issue, of an earlier paper by Noble and Davies. In particular, we argue that our interpretation of earlier quantitative research is correct, that Harrison and Waller have misconstrued the purpose of our previous paper and the analysis it contains, and that they…

  13. The Black American Press and the New Manifest Destiny: The Waller Affair

    ERIC Educational Resources Information Center

    Woods, Randall B.

    1977-01-01

    In 1895 the United States and France became involved in a dispute concerning the arrest and imprisonment of one John L. Waller, a black American who dared to challenge French imperialism in Madagascar. The black press, perhaps at the height of its power and influence, reacted vigorously to Waller and his goals, and to the Cleveland…

  14. Monte Carlo simulation of an anharmonic Debye-Waller factor to the T(4) order.

    PubMed

    Wang, Kun Lun; Huang, Xian Bin; Li, Jing; Xu, Qiang; Dan, Jia Kun; Ren, Xiao Dong

    2017-03-01

    In an increasing number of cases the harmonic approximation is incommensurate with the quality of Bragg diffraction data, while results of the anharmonic Debye-Waller factor are not typically available. This paper presents a Monte Carlo computation of a Taylor expansion of an anharmonic Debye-Waller factor with respect to temperature up to the fourth order, where the lattice was a face-centred cubic lattice and the atomic interaction was described by the Lennard-Jones potential. The anharmonic Debye-Waller factor was interpreted in terms of cumulants. The results revealed three significant points. Firstly, the leading term of anharmonicity had a negative contribution to the Debye-Waller factor, which was confirmed by Green's function method. Secondly, the fourth-order cumulants indicated a non-spherical probability density function. Thirdly, up to the melting point of two different densities, the cumulants up to the fourth order were well fitted by the Taylor expansion up to T(4), which suggested that the Debye-Waller factor may be calculated by perturbation expansion up to the corresponding terms. In conclusion, Monte Carlo simulation is a useful approach for calculating the Debye-Waller factor.

  15. An experimental 'Life' for an experimental life: Richard Waller's biography of Robert Hooke (1705).

    PubMed

    Moxham, Noah

    2016-03-01

    Richard Waller's 'Life of Dr Robert Hooke', prefixed to his edition of Hooke's Posthumous Works (1705), is an important source for the life of one of the most eminent members of the early Royal Society. It also has the distinction of being one of the earliest biographies of a man of science to be published in English. I argue that it is in fact the first biography to embrace the subject's natural-philosophical work as the centre of his life, and I investigate Waller's reasons for adopting this strategy and his struggle with the problem of how to represent an early experimental philosopher in print. I suggest that Waller eschews the 'Christian philosopher' tradition of contemporary biography - partly because of the unusually diverse and fragmentary nature of Hooke's intellectual output - and draws instead upon the structure of the Royal Society's archive as a means of organizing and understanding Hooke's life. The most quoted phrase from Waller's biography is that Hooke became 'to a crime close and reserved' in later life; this essay argues that Waller's biographical sketch was fashioned in order to undo the effects of that reserve. In modelling his approach very closely on the structure of the society's records he was principally concerned with making Hooke's work and biography accessible, intelligible and useful to the fellowship in a context familiar to them, a context which had provided the institutional framework for most of Hooke's adult life. I argue that Waller's 'Life' was also intended to make the largest claims for Hooke's intellectual standing that the author dared in the context of the enmity between Hooke and Isaac Newton once the latter became president of the Royal Society. However, I also adduce fresh manuscript evidence that Waller actually compiled, but did not publish, a defence of Hooke's claim to have discovered the inverse square law of gravity, allowing us to glimpse a much more assertive biography of Hooke than the published version.

  16. John Dewey and the Question of Race: The Fight for Odell Waller

    ERIC Educational Resources Information Center

    Stack, Sam F., Jr.

    2009-01-01

    In an attempt to better understand the complexity of American racism and democracy, this paper explores racism through the plight of an African American sharecropper, Odell Waller, and the reaction and involvement of John Dewey, America's most liberal democratic philosopher of the 20th century. This exploration delves into the nature of American…

  17. John Dewey and the Question of Race: The Fight for Odell Waller

    ERIC Educational Resources Information Center

    Stack, Sam F., Jr.

    2009-01-01

    In an attempt to better understand the complexity of American racism and democracy, this paper explores racism through the plight of an African American sharecropper, Odell Waller, and the reaction and involvement of John Dewey, America's most liberal democratic philosopher of the 20th century. This exploration delves into the nature of American…

  18. Willard Waller's Sociology of Teaching Reconsidered: "What Does Teaching Do to Teachers?"

    ERIC Educational Resources Information Center

    Pajak, Edward F.

    2012-01-01

    Willard Waller's (1932/1976) classic account of what teaching does to teachers is examined through the lens of psychoanalytic theory in conjunction with Ovid's myth of Narcissus. Parallel themes within the two texts are analyzed and interpreted as suggesting that narcissistic psychological processes played a part in distorting teachers'…

  19. Willard Waller's Sociology of Teaching Reconsidered: "What Does Teaching Do to Teachers?"

    ERIC Educational Resources Information Center

    Pajak, Edward F.

    2012-01-01

    Willard Waller's (1932/1976) classic account of what teaching does to teachers is examined through the lens of psychoanalytic theory in conjunction with Ovid's myth of Narcissus. Parallel themes within the two texts are analyzed and interpreted as suggesting that narcissistic psychological processes played a part in distorting teachers'…

  20. Who invented the dichotomous key? Richard Waller's watercolors of the herbs of Britain.

    PubMed

    Griffing, Lawrence R

    2011-12-01

    On 27 March 1689, Richard Waller, Fellow and Secretary of the Royal Society presented his "Tables of the English Herbs reduced to such an order, as to find the name of them by their external figures and shapes" to his assembled colleagues at a meeting of the Royal Society. These tables were developed for the novice by being color images, composed in pencil and watercolor, of selected plants and their distinguishing characteristics. The botanical watercolors for the tables are now a Turning-the-Pages document online on the website of the Royal Society. However, for the past 320 years, the scientific context for the creation of these outstanding botanical watercolors has remained obscure. These tables were developed by Waller as an image-based dichotomous key, pre-dating by almost 100 years the text-based dichotomous keys in the first edition of Flora Française (1778) by Jean Baptiste Lamarck, who is generally given priority for the development of the dichotomous key. How these large folio images were arranged to illustrate a dichotomous key is unknown, but an arrangement based on Waller's description is illustrated here as leaf-ordering for the separate hierarchical clusters (tables). Although only 24 species of watercolored dicot herbs out of a total of 65 in the set of watercolors (the others being monocots) are used in these tables, they are a "proof of concept", serving as models upon which a method is based, that of using a key composed of dichotomous choices for aiding identification.

  1. Mature and Fresh Surfaces on New-Born Asteroid Karin

    NASA Astrophysics Data System (ADS)

    Sasaki, S.; Sasaki, T.; Watanabe, J.; Sekiguchi, T.; Yoshida, F.; Ito, T.; Kawakita, H.; Fuse, T.; Takato, N.; Dermawan, B.

    2004-11-01

    We report a near-infrared (J, H, and K bands) spectroscopy of the brightest asteroid 832 Karin among the Karin cluster group, which was formed by collisional breakup only 5.8 million years ago. The spectroscopic observation was performed by the Subaru telescope with Cooled Infrared Spectrograph and Camera for OHS (CISCO) on 2003 September 14. To obtain a wide range spectrum, grisms named zJ (0.88-1.40 micron), JH (1.06-1.82 micron), and wK (1.85-2.51 micron) were used. We obtained 3 sets of spectra corresponding to the rotational phase 0.30-0.34, 0.35-0.38, and 0.45-0.50 in comparison with lightcurve observations. Near infrared (0.9-1.4micron) reflectance slope of the 1st set was twice as steep as that of later spectra. The range, where the most significant spectral change was detected, was observed both by zJ and JH bands. Gradual change of the spectral slope is detected through zJ(1st) - JH(1st) - zJ(2nd) - JH(2nd) data . We verified that spectra of a reference star SAO165395 (zJ) were not changed before the 1st set and after the 2nd set of Karin observation, which should remove the possibility that the spectral change was caused by instrumental or atmospheric (and hour angle) effect through the observation of the 1st set and the 2nd set of Karin. For different rotational phases of Karin, we derived different spectra such as a reddened spectrum like that of S-type asteroid and an un-reddened spectrum like that of ordinary chondrite. Karin would be an impact fragment which not only has new surface but also preserves old surface. Probably it would be one of cone-shaped fragments at low-velocity impact forming Karin cluster group. Our result supports the idea that S-type asteroids are parent bodies of ordinary chondrites.

  2. Slow wave conduction patterns in the stomach: from Waller's foundations to current challenges.

    PubMed

    Cheng, L K

    2015-02-01

    This review provides an overview of our understanding of motility and slow wave propagation in the stomach. It begins by reviewing seminal studies conducted by Walter Cannon and Augustus Waller on in vivo motility and slow wave patterns. Then our current understanding of slow wave patterns in common laboratory animals and humans is presented. The implications of slow wave arrhythmic patterns that have been recorded in animals and patients suffering from gastroparesis are discussed. Finally, current challenges in experimental methods and techniques, slow wave modulation and the use of mathematical models are discussed. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  3. Thermodynamic properties of semiconductor compounds studied based on Debye-Waller factors

    NASA Astrophysics Data System (ADS)

    Van Hung, Nguyen; Toan, Nguyen Cong; Ba Duc, Nguyen; Vuong, Dinh Quoc

    2015-08-01

    Thermodynamic properties of semiconductor compounds have been studied based on Debye-Waller factors (DWFs) described by the mean square displacement (MSD) which has close relation with the mean square relative displacement (MSRD). Their analytical expressions have been derived based on the statistical moment method (SMM) and the empirical many-body Stillinger-Weber potentials. Numerical results for the MSDs of GaAs, GaP, InP, InSb, which have zinc-blende structure, are found to be in reasonable agreement with experiment and other theories. This paper shows that an elements value for MSD is dependent on the binary semiconductor compound within which it resides.

  4. X-ray absorption Debye-Waller factors from ab initio molecular dynamics

    NASA Astrophysics Data System (ADS)

    Vila, F. D.; Lindahl, V. E.; Rehr, J. J.

    2012-01-01

    An ab initio equation of motion method is introduced to calculate the temperature-dependent mean-square vibrational amplitudes σ2 which appear in the Debye-Waller factors in x-ray absorption, x-ray scattering, and related spectra. The approach avoids explicit calculations of phonon modes, and is based instead on calculations of the displacement-displacement time correlation function from ab initio density functional theory molecular dynamics simulations. The method also yields the vibrational density of states and thermal quantities such as the lattice free energy. Illustrations of the method are presented for a number of systems and compared with other methods and experiment.

  5. Measurement of coherent Debye-Waller factor in in vivo deuterated C-phycocyanin by inelastic neutron scattering.

    PubMed

    Bellissent-Funel, M C; Filabozzi, A; Chen, S H

    1997-04-01

    Quasielastic neutron scattering measurements of dry and 35% D2O hydrated amorphous protein powder of C-phycocyanin were made as a function of temperature ranging from 313K down to 100K. The protein is grown from blue-green algae cultured in D2O and is deuterated up to 99%. The scattering is thus dominated by coherent scattering. Within the best energy resolution of the time-of-flight instrument, which is 28 mueV FWHM, the scattering appears entirely elastic. For this reason we are able to extract a coherent Debye-Waller factor by making an independent measurement of the static structure factor. We observe a considerable difference in the q dependence of the Debye-Waller factor between the dry and hydrated proteins; furthermore, there is an interesting temperature dependence of the Debye-Waller factor that is quite different from that predicted for dense hard-sphere liquids.

  6. A Surrogate for Debye-Waller Factors from Dynamic Stokes Shifts

    PubMed Central

    Zhong, Qin; Johnson, Jerainne; Aamer, Khaled A.; Tyagi, Madhusudan

    2011-01-01

    We show that the short-time behavior of time-resolved fluorescence Stokes shifts (TRSS) are similar to that of the intermediate scattering function obtained from neutron scattering at q near the peak in the static structure factor for glycerol. This allows us to extract a Debye-Waller (DW) factor analog from TRSS data at times as short as 1 ps in a relatively simple way. Using the time-domain relaxation data obtained by this method we show that DW factors evaluated at times ≥ 40 ps can be directly influenced by α relaxation and thus should be used with caution when evaluating relationships between fast and slow dynamics in glassforming systems. PMID:21701673

  7. Measuring Order and the Debye-Waller Factor for Porous Arrays

    NASA Astrophysics Data System (ADS)

    Kaatz, Forrest; Bultheel, Adhemar; Egami, Takeshi

    2007-03-01

    We derive methods that explain how to quantify the amount of order in ``ordered'' and ``highly ordered'' porous arrays. Ordered arrays from bee honeycomb and several from the general field of nanoscience are compared. Accurate measures of the order in porous arrays are made using the discrete radial distribution function (RDF) and the Debye-Waller Factor (DWF) from 2-D discrete Fourier transforms calculated from the real-space data using MATLAB routines. Nanoporous anodized aluminum oxide, hexagonal arrays from functional materials, hexagonal arrays from nanosphere lithography, and arrays from block copolymer lithography (all taken from the literature) are compared to two-dimensional model systems. The DWF is normalized to the first harmonic and depends on N, the number of peaks in the fit for these finite arrays. We optimize N to the classical model for the DWF as a fit to reciprocal space K^2.

  8. Search for anisotropy in the Debye-Waller factor of HCP solid (4)He.

    PubMed

    Barnes, Ashleigh L; Hinde, Robert J

    2016-02-28

    The properties of hexagonal close packed (hcp) solid (4)He are dominated by large atomic zero point motions. An accurate description of these motions is therefore necessary in order to accurately calculate the properties of the system, such as the Debye-Waller (DW) factors. A recent neutron scattering experiment reported significant anisotropy in the in-plane and out-of-plane DW factors for hcp solid (4)He at low temperatures, where thermal effects are negligible and only zero-point motions are expected to contribute. By contrast, no such anisotropy was observed either in earlier experiments or in path integral Monte Carlo (PIMC) simulations of solid hcp (4)He. However, the earlier experiments and the PIMC simulations were both carried out at higher temperatures where thermal effects could be substantial. We seek to understand the cause of this discrepancy through variational quantum Monte Carlo simulations utilizing an accurate pair potential and a modified trial wavefunction which allows for anisotropy. Near the melting density, we find no anisotropy in an ideal hcp (4)He crystal. A theoretical equation of state is derived from the calculated energies of the ideal crystal over a range of molar volumes from 7.88 to 21.3 cm(3), and is found to be in good qualitative agreement with experimental data.

  9. Limits of metastability in amorphous ices: the neutron scattering Debye-Waller factor.

    PubMed

    Amann-Winkel, Katrin; Löw, Florian; Handle, Philip H; Knoll, Wiebke; Peters, Judith; Geil, Burkhard; Fujara, Franz; Loerting, Thomas

    2012-12-21

    Recently, it became clear that relaxation effects in amorphous ices play a very important role that has previously been overlooked. The thermodynamic history of amorphous samples strongly affects their transition behavior. In particular, well-relaxed samples show higher thermal stability, thereby providing a larger window to investigate their glass transitions. We here present neutron scattering experiments using fixed elastic window scans on relaxed forms of amorphous ice, namely expanded high density amorphous ice (eHDA), a variant of low density amorphous ice (LDA-II) and hyperquenched glassy water (HGW). These amorphous ices are expected to be true glassy counterparts of deeply supercooled liquid water, therefore fast precursor dynamics of structural relaxation are expected to appear below the calorimetric glass transition temperature. The Debye-Waller factor shows a very weak sub-T(g) anomaly in some of the samples, which might be the signature of such fast precursor dynamics. However, we cannot find this behavior consistently in all samples at all reciprocal length scales of momentum transfer.

  10. Detection of the YORP Effect for Small Asteroids in the Karin Cluster

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Nesvorný, D.; Vokrouhlický, D.

    2016-06-01

    The Karin cluster is a young asteroid family thought to have formed only ≃ 5.75 Myr ago. The young age can be demonstrated by numerically integrating the orbits of Karin cluster members backward in time and showing the convergence of the perihelion and nodal longitudes (as well as other orbital elements). Previous work has pointed out that the convergence is not ideal if the backward integration only accounts for the gravitational perturbations from the solar system planets. It improves when the thermal radiation force known as the Yarkovsky effect is accounted for. This argument can be used to estimate the spin obliquities of the Karin cluster members. Here we take advantage of the fast growing membership of the Karin cluster and show that the obliquity distribution of diameter D≃ 1{--}2 km Karin asteroids is bimodal, as expected if the YORP effect acted to move obliquities toward extreme values (0° or 180°). The measured magnitude of the effect is consistent with the standard YORP model. The surface thermal conductivity is inferred to be 0.07-0.2 W m-1 K-1 (thermal inertia ≃ 300{--}500 J m-2 K-1 s{}-1/2). We find that the strength of the YORP effect is roughly ≃ 0.7 of the nominal strength obtained for a collection of random Gaussian spheroids. These results are consistent with a surface composed of rough, rocky regolith. The obliquity values predicted here for 480 members of the Karin cluster can be validated by the light-curve inversion method.

  11. Detection of the YORP effect for small asteroids in the Karin family

    NASA Astrophysics Data System (ADS)

    Nesvorny, David; Carruba, Valerio; Vokrouhlicky, David

    2016-10-01

    The Karin family formed by a collisional breakup of a ~40-km parent asteroid only 5.75 Myr ago. The young age can be demonstrated by numerically integrating the orbits of Karin family members backward in time and showing the convergence of orbital elements. Previous work has pointed out that the convergence is not ideal if the backward integration only accounts for the gravitational perturbations from the Solar System planets. It improves when the thermal radiation force known as the Yarkovsky effect is accounted for. This method can be used to estimate the spin obliquities of Karin family members. Here we show that the obliquity distribution of diameter D=1-2 km asteroids in the Karin family is bimodal, as expected if the YORP effect acted to move obliquities toward extreme values (0 or 180 deg). The measured magnitude of the effect is consistent with the standard YORP model. Specifically, the strength of the YORP effect is inferred to be roughly 70% of the nominal YORP strength obtained for a collection of random Gaussian spheroids. The surface thermal conductivity is found to be 0.07-0.2 W/m/K (thermal inertia 300-500 in the SI units). These results are consistent with surfaces composed of rough and rocky regolith. The obliquity values predicted here for 480 members of the Karin cluster can be validated by the lightcurve inversion method. In broader context, the bimodal distribution of obliquities in the Karin cluster can be thought as an initial stage of dynamical evolution that later leads to a characteristically bi-lobed distribution of family members in the semimajor axis (e.g., Eos, Merxia or Erigone families).

  12. Monte Carlo Simulation Using Johnson Potential on Gd-Mg Alloy for Debye-Waller Factor and Debye Temperature

    NASA Astrophysics Data System (ADS)

    Chitra, S.; Ramachandran, K.

    Monte Carlo simulation (MCS) on the thermal properties in Gd-Mg alloy becomes essential as there are only limited experiments available. A realistic Johnson potential is used to workout the specific heats for various temperatures and hence the Debye temperature. The results from the present simulation technique are very well compared with our shell model calculation. The need of better X-ray measurements for Debye-Waller factor and Debye temperature other than the measurements of Subadhra and Sirdeshmukh, is discussed in detail.

  13. Records of wells, drillers' logs, water-level measurements, and chemical analyses of ground water in Brazoria, Fort Bend, and Waller counties, Texas, 1985-89

    USGS Publications Warehouse

    Locke, Glenn L.

    1991-01-01

    Data for water wells and ground water in Brazoria, Fort Bend, and Waller Counties were collected during 1985-89 by the U.S. Geological Survey. This report presents a compilation of records for 32 wells in Brazoria County, 19 wells in Fort Bend County, and 16 wells in Waller County. Drillers' logs for 65 wells, water levels for 85 wells, chemical analyses of water for 9 wells, and water levels and chemical analyses of water from previously inventoried wells also are presented in this report.

  14. Testing the Deployment Repeatability of a Precision Deployable Boom Prototype for the Proposed SWOT Karin Instrument

    NASA Technical Reports Server (NTRS)

    Agnes, Gregory S.; Waldman, Jeff; Hughes, Richard; Peterson, Lee D.

    2015-01-01

    NASA's proposed Surface Water Ocean Topography (SWOT) mission, scheduled to launch in 2020, would provide critical information about Earth's oceans, ocean circulation, fresh water storage, and river discharge. The mission concept calls for a dual-antenna Ka-band radar interferometer instrument, known as KaRIn, that would map the height of water globally along two 50 km wide swaths. The KaRIn antennas, which would be separated by 10 meters on either side of the spacecraft, would need to be precisely deployable in order to meet demanding pointing requirements. Consequently, an effort was undertaken to design build and prototype a precision deployable Mast for the KaRIn instrument. Each mast was 4.5-m long with a required dilitation stability of 2.5 microns over 3 minutes. It required a minimum first mode of 7 Hz. Deployment repeatability was less than +/- 7 arcsec in all three rotation directions. Overall mass could not exceed 41.5 Kg including any actuators and thermal blanketing. This set of requirements meant the boom had to be three times lighter and two orders of magnitude more precise than the existing state of the art for deployable booms.

  15. Atomic disorder of Li0.5Ni0.5O thin films caused by Li doping: estimation from X-ray Debye–Waller factors

    PubMed Central

    Yang, Anli; Sakata, Osami; Yamauchi, Ryosuke; Kumara, L. S. R.; Song, Chulho; Katsuya, Yoshio; Matsuda, Akifumi; Yoshimoto, Mamoru

    2015-01-01

    Cubic type room-temperature (RT) epitaxial Li0.5Ni0.5O and NiO thin films with [111] orientation grown on ultra-smooth sapphire (0001) substrates were examined using synchrotron-based thin-film X-ray diffraction. The 11 and 22 rocking curves including six respective equivalent reflections of the Li0.5Ni0.5O and NiO thin films were recorded. The RT B 1 factor, which appears in the Debye–Waller factor, of a cubic Li0.5Ni0.5O thin film was estimated to be 1.8 (4) Å2 from its 11 and 22 reflections, even though the Debye model was originally derived on the basis of one cubic element. The corresponding Debye temperature is 281 (39) K. Furthermore, the B 2 factor in the pseudo-Debye–Waller factor is proposed. This parameter, which is evaluated using one reflection, was also determined for the Li0.5Ni0.5O thin film by treating Li0.5Ni0.5O and NiO as ideal NaCl crystal structures. A structural parameter for the atomic disorder is introduced and evaluated. This parameter includes the combined effects of thermal vibration, interstitial atoms and defects caused by Li doping using the two Debye–Waller factors. PMID:26664345

  16. Anharmonic correlated Debye model high-order expanded interatomic effective potential and Debye-Waller factors of bcc crystals

    NASA Astrophysics Data System (ADS)

    Van Hung, Nguyen; Hue, Trinh Thi; Khoa, Ha Dang; Vuong, Dinh Quoc

    2016-12-01

    High-order expanded interatomic effective potential and Debye-Waller factors (DWFs) for local vibrational amplitudes in X-ray absorption fine structure (XAFS) of bcc crystals have been studied based on the anharmonic correlated Debye model. DWFs are presented in terms of cumulant expansion up to the fourth order and the many-body effects are taken into account in the present one-dimensional model based on the first shell near neighbor contribution approach used in the derivations of the anharmonic effective potential and XAFS cumulants where Morse potential is assumed to describe the single-pair atomic interaction. Analytical expressions for the dispersion relation, correlated Debye frequency and temperature and four first temperature-dependent XAFS cumulants have been derived based on the many-body perturbation approach. Thermodynamic properties and anharmonic effects in XAFS of bcc crystals described by the obtained cumulants have been in detail discussed. The advantage and efficiency of the present theory are illustrated by good agreement of the numerical results for Mo, Fe and W with experiment.

  17. Effect of Particle Size and Lattice Strain on the Debye-Waller Factors of Silicon Carbide Nanoparticles.

    PubMed

    Purushotham, E

    2016-03-01

    Nano Silicon Carbide (SiC) particles have been produced by ball milling process. The sample was taken 0, 10, 20, 30, 40 and 50 hours of milling. The resulting nanoparticle powders were characterized by X-ray diffraction measurements. The high-energy ball milling of SiC after 50 hours resulted in particle size of about 24 nm. The Debye temperature, mean-square amplitudes of vibration, Debye-Waller factor, particle size, and lattice strain and vacancy formation of energies of SiC nanoparticles prepared by ball mill have been obtained from X-ray integrated intensities. The integrated intensities have been measured with a Philips CWU 3710 X-ray powder diffractometer fitted with a scintillation counter using filtered CuKα radiation at room temperature and have been corrected for thermal diffuse scattering. The X-ray Debye temperatures obtained in the present investigation has been used to estimate the vacancy formation energies for SiC nanoparticles.

  18. Direct in situ thermometry: Variations in reciprocal-lattice vectors and challenges with the Debye-Waller effect.

    PubMed

    Cremons, Daniel R; Flannigan, David J

    2016-02-01

    Conventional in situ transmission electron microscopy (TEM) enables the atomic-scale study of dynamic materials processes on millisecond time scales. Specimen holders capable of being heated to over 1000°C have provided insight into myriad processes, including nanoscale thermal transport, structural phase transitions, and catalytic reactions. In order for such studies to be accurate and precise, direct determination of the specimen temperature - rather than the heating-element temperature - is critical. Further, such methods should be versatile in that any temperature across a wide range may be measured, irrespective of single-indicator properties specific to the specimen (e.g., first-order phase transition, melting point, etc.). Here, we describe a rigorous approach to direct, in situ thermometry of TEM specimens that exploits lattice thermal expansion and the resultant decrease in diffraction-vector magnitude in reciprocal space. Via sub-pixel measurement of reciprocal-lattice-vector magnitudes, picometer increases in lattice parameters are measured over a continuous temperature range and compared to those expected from the coefficient of thermal expansion. Statistical treatment of several experimental trials conducted on nanostructured aluminum thin films shows excellent agreement with both theory and (indirect) measurement of the in situ heating holder. Additionally, we illustrate how uncontrolled, thermally-induced variation in single-crystal orientation leads to modulation of the excitation error and, therefore, the Bragg-spot intensities resulting in a convolution of heating and tilting effects, thus complicating temperature determination via the Debye-Waller effect. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A spectral model for irradiated silicates: application to asteroid 832 Karin

    NASA Astrophysics Data System (ADS)

    Brunetto, R.; Vernazza, P.; Marchi, S.; Birlan, M.; Fulchignoni, M.; Orofino, V.; Strazzulla, G.

    We define a new approach to space weathering of airless bodies, and include its effect in the Shkuratov model. We start from recent results of ion irradiation experiments (60-400 keV) of meteorites and silicates; we find that the reddening and darkening process (in the range 0.3-2.5 microns) mainly affects the continuum of reflectance spectra (parameterized by a Cs coefficient), but it does not significantly affect the position or relative intensities of the mafic silicate absorption features. The Cs coefficient is strongly related with the number of displacements per unit area (damage parameter); we consequently obtain an exposure time curve, and corresponding astrophysical timescales. We apply this new description of space weathering to model observed spectra of asteroid 832 Karin, in the 0.4-2.4 microns spectral region. The obtained exposure time is slightly lower than the age of the impact and collisional breakup which originated the Karin asteroidal family, i.e. about 5.75 My.

  20. Onboard Interferometric SAR Processor for the Ka-Band Radar Interferometer (KaRIn)

    NASA Technical Reports Server (NTRS)

    Esteban-Fernandez, Daniel; Rodriquez, Ernesto; Peral, Eva; Clark, Duane I.; Wu, Xiaoqing

    2011-01-01

    An interferometric synthetic aperture radar (SAR) onboard processor concept and algorithm has been developed for the Ka-band radar interferometer (KaRIn) instrument on the Surface and Ocean Topography (SWOT) mission. This is a mission- critical subsystem that will perform interferometric SAR processing and multi-look averaging over the oceans to decrease the data rate by three orders of magnitude, and therefore enable the downlink of the radar data to the ground. The onboard processor performs demodulation, range compression, coregistration, and re-sampling, and forms nine azimuth squinted beams. For each of them, an interferogram is generated, including common-band spectral filtering to improve correlation, followed by averaging to the final 1 1-km ground resolution pixel. The onboard processor has been prototyped on a custom FPGA-based cPCI board, which will be part of the radar s digital subsystem. The level of complexity of this technology, dictated by the implementation of interferometric SAR processing at high resolution, the extremely tight level of accuracy required, and its implementation on FPGAs are unprecedented at the time of this reporting for an onboard processor for flight applications.

  1. Wrongful death claims. Harriton v Stephens. [2002] NSWSC 461. Edwards v Blomeley. [2002] NSWSC 460. Waller v James [2002] NSWSC 462.

    PubMed

    Devereux, John

    2002-11-01

    Studdert J in all three cases went to great length to summarise the global judicial position of "wrongful life" claims. He did not, however, examine in great length how or whether "wrongful life" claims or "wrongful birth" claims are reconcilable with tort and common law principles. Although the cases identify the difficulty in assessing and quantifying damages, they do not directly address the strict legal principles which apply in the assessment of damages. The main conclusion of the three judgments was that no duty of care is owed to the plaintiff in these circumstances and, even if a duty could be established, the impossibility of quantifying damages and public policy considerations warrant the rejection of such a claim: "thus conscience does make cowards of us all." The significance of the decisions cannot be understand. The decisions deny recognition of "wrongful life" claims in circumstances where a disabled person has incurred injuries en ventre sa mere (in the mother's womb) as a result of infections contracted by a plaintiff's mother or genetic material passed on by a plaintiff's parents. Some countries have now legislated for the abolition of "wrongful life and birth" suits. In January 2002 the French legislature passed a Bill overturning the "wrongful life" decision of the Cour de Cassation in Perruche (17 November 2000). As the issue now falls for ultimate determination by the French Senate, the French pro-life movement continues to lobby for the prohibition of "wrongful birth" suits as well. Furthermore, eight States in the United States have prohibited either one or both actions and the State of Michigan prohibited both actions in 2001. It is likely that all three cases will be appealed. The appeal in Harriton will re-examine the viability of a "wrongful life" claim in Australia whereas the cases of Edwards and Waller still need to determine the "wrongful birth" claims brought by the plaintiffs' parents. It is likely that the latter two cases will

  2. An alternative explanation of the change in T-dependence of the effective Debye-Waller factor at T(c) or T(B).

    PubMed

    Ngai, K L; Habasaki, J

    2014-09-21

    The cusp-like temperature dependence of the Debye-Waller factor or non-ergodicity parameter f(Q)(T) at some temperature T(c) above T(g) found by experiments in several fragile glassformers has been considered as critical evidence for validity of the ideal Mode Coupling Theory (MCT). A comprehensive review of experimental data of f(Q)(T) and beyond brings out various problems of the MCT predictions. For example, the molten salt, 0.4Ca(NO3)2-0.6KNO3 (CKN), was the first glassformer measured by neutron scattering to verify the cusp-like behavior of f(Q)(T) at T(c) predicted by ideal MCT. While the fits of the other scaling laws of MCT to viscosity, light scattering, and dielectric relaxation data all give T(c) in the range from 368 to 375 K, there is no evidence of cusp-like behavior of f(Q)(T) at T(c) from more accurate neutron scattering data obtained later on by Mezei and Russina [J. Phys.: Condens. Matter 11, A341 (1999)] at temperatures below 400 K. In several molecular glass-formers, experiments have found at temperatures below T(c) that [1-f(Q)(T)] is manifested as nearly constant loss (NCL) in the frequency dependent susceptibility. The NCL persists down to below T(g) and is not predicted by the ideal MCT. No clear evidence of the change of T-dependence of f(Q)(T) at any T(c) was found in intermediate and strong glassformers, although ideal MCT does not distinguish fragile and strong glassformers in predicting the critical behavior of f(Q)(T) a priori. Experiments found f(Q)(T) changes T-dependence not only at T(c) but also at the glass transition temperature T(g). The changes of T-dependence of f(Q)(T) at T(c) and T(g) are accompanied by corresponding changes of dynamic variables and thermodynamic quantities at T(B) ≈ T(c) and at T(g). The dynamic variables include the relaxation time τ(α)(T), the non-exponentiality parameter n(T), and the generalized fragility m(T) of the structural α-relaxation. The thermodynamic quantities are the free volume deduced

  3. An alternative explanation of the change in T-dependence of the effective Debye-Waller factor at T{sub c} or T{sub B}

    SciTech Connect

    Ngai, K. L.; Habasaki, J.

    2014-09-21

    The cusp-like temperature dependence of the Debye-Waller factor or non-ergodicity parameter f{sub Q}(T) at some temperature T{sub c} above T{sub g} found by experiments in several fragile glassformers has been considered as critical evidence for validity of the ideal Mode Coupling Theory (MCT). A comprehensive review of experimental data of f{sub Q}(T) and beyond brings out various problems of the MCT predictions. For example, the molten salt, 0.4Ca(NO{sub 3}){sub 2}-0.6KNO{sub 3} (CKN), was the first glassformer measured by neutron scattering to verify the cusp-like behavior of f{sub Q}(T) at T{sub c} predicted by ideal MCT. While the fits of the other scaling laws of MCT to viscosity, light scattering, and dielectric relaxation data all give T{sub c} in the range from 368 to 375 K, there is no evidence of cusp-like behavior of f{sub Q}(T) at T{sub c} from more accurate neutron scattering data obtained later on by Mezei and Russina [J. Phys.: Condens. Matter 11, A341 (1999)] at temperatures below 400 K. In several molecular glass-formers, experiments have found at temperatures below T{sub c} that [1−f{sub Q}(T)] is manifested as nearly constant loss (NCL) in the frequency dependent susceptibility. The NCL persists down to below T{sub g} and is not predicted by the ideal MCT. No clear evidence of the change of T-dependence of f{sub Q}(T) at any T{sub c} was found in intermediate and strong glassformers, although ideal MCT does not distinguish fragile and strong glassformers in predicting the critical behavior of f{sub Q}(T) a priori. Experiments found f{sub Q}(T) changes T-dependence not only at T{sub c} but also at the glass transition temperature T{sub g}. The changes of T-dependence of f{sub Q}(T) at T{sub c} and T{sub g} are accompanied by corresponding changes of dynamic variables and thermodynamic quantities at T{sub B} ≈ T{sub c} and at T{sub g}. The dynamic variables include the relaxation time τ{sub α}(T), the non-exponentiality parameter n(T), and

  4. KaRIN: an Instrument for Measuring High-Resolution Sea-Surface Topography and Fresh Water Extent, Stage, and Slope

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Moller, D.; Enjolras, V.

    2006-12-01

    Traditional nadir profiling altimeters, such as Topex, Jason, or IceSat, are incaple of fully sampling the space- time signatures of both ocean mesoscale and submesoscale phenomena and changes in river discharge. To overcome this limitation, we present an instrument concept, the Ka-band Radar Interferometer (KaRIN), which is able to provide the appropriate space-time sampling to sample these phenomena with a height and slope accuracy suitable to resolve topographic signatures for both ocean and land hydrology applications. Although ocean and hydrlogic applications are quite different, the required sampling characteristics are similar. Both applications require global coverage up to high latitudes (78deg). Measurement of ocean mesoscale and submesoscale phenomena requires a temporal revisit time on the order of 10 days and a height accuracy of about 2cm over a spatial scale of 2km. The sampling of river discharge requires an approximately weekly revisit time, an ability to image water bodies (to determine extent) with a spatial resolution of 100m, a height accuracy better than 10cm and a slope accuracy of 1cm/1km, after averaging over a river area equivalent to 1km x 1km. The similarity in measurement requirements allows for the possibility of meeting both ocean and hydrology requirements with a single instrument. The KaRIN instrument builds on the interferometric SAR concept demonstrated by the NASA Shuttle Radar Topography Mission (SRTM), and the Wide-Swath Ocean Altimeter concept, which was studied by NASA as a potential complement to the Ocean Surface Topography Mission (OSTM). Two major modifications are made to these systems to achieve the desired performance: the spatial sampling requirement implies that full synthetic aperture must be used. Second, achieving the desired height and slope accuracy with a realizable spaceborne instrument requires using a Ka-band (0.8 cm wavelength) radar at near nadir incidence. To validate the science performance of the

  5. VizieR Online Data Catalog: Class 0 sources continuum subtracted UV-tables (Persson+, 2016)

    NASA Astrophysics Data System (ADS)

    Persson, M. V.; Harsono, D.; Tobin, J. J.; van Dishoeck, E. F.; Joergensen, J. K.; Murillo, N.; Lai, S.-P.

    2016-03-01

    This dataset contains the continuum subtracted UV-tables, in UVFITS format written by GILDAS MAPPING for the sources NGC 1333 IRAS 2A (203GHz), NGC 1333 IRAS 4A (335GHz), NGC 1333 IRAS 4B (203GHz), and VLA 1623 (219GHz). (2 data files).

  6. Debye-Waller factor in solid He-4 at sub-Kelvin temperatures

    NASA Astrophysics Data System (ADS)

    Blackburn, Elizabeth; Goodkind, John M.; Sinha, Sunil K.; Hudis, Jacob; Broholm, Collin; van Duijn, Joost; Down, Richard; Kirichek, Oleg; Frost, Chris D.

    2007-03-01

    The recent observation by Kim and Chan [Science 305 (2204) 1941] of a transition at low temperatures (˜ 200 mK) in the hcp-phase of solid helium has re-opened interest in the old question of supersolidity. The nature of the low-temperature phase remains in question, and to investigate this in more detail, we have measured the density distribution of He-4 nuclei in crystals of He-4 with a molar volume of 21.3 cm^3 down to 140 mK. We find no evidence for any changes in the vicinity of the transition. Treating the material as a traditional crystal, we have extracted the mean square displacement for the nuclei and find anisotropy between the in- and out-of-plane motions. Our values are in agreement with previous work at higher temperatures.

  7. Elastic and inelastic diffraction of fast atoms, Debye-Waller factor, and Mössbauer-Lamb-Dicke regime

    NASA Astrophysics Data System (ADS)

    Roncin, Philippe; Debiossac, Maxime

    2017-07-01

    The diffraction of fast atoms at crystal surfaces is ideal for a detailed investigation of the surface electronic density. However, instead of sharp diffraction spots, most experiments show elongated streaks characteristic of inelastic diffraction. This paper describes these inelastic profiles in terms of individual inelastic collisions with surface atoms taking place along the projectile trajectory and leading to vibrational excitation of the local Debye oscillator. A quasielastic regime where only one inelastic event contributes is identified as well as a mixed quantum-classical regime where several inelastic collisions are involved. These regimes describe a smooth evolution of the scattering profiles from sharp spots to elongated streaks merging progressively into the classical diffusion regime.

  8. Path-integral approach to Debye-Waller factors in EXAFS, EELS and XPD for cubic and quartic anharmonic potentials.

    PubMed

    Miyanaga, T; Suzuki, T; Fujikawa, T

    2000-03-01

    In this paper thermal effects in extended X-ray absorption fine structure (EXAFS) and X-ray photoelectron diffraction (XPD) due to atomic vibration in cubic and quartic potentials are studied by use of Feynman's path-integral approach. This approach can be applied to strongly anharmonic systems where the cumulant analyses break down. It is closely related to the well known classical approach which is only valid at high temperature. The phase of the thermal factor plays an important role both in EXAFS and XPD analyses for the asymmetric potential with strong anharmonicity. At low temperature the cumulant expansion up to the second order for the thermal damping function agrees well with the self-consistent result, but up to higher orders should be taken into account for the phase function. At high temperature the result from self-consistent calculations shows the characteristic behaviour: the thermal damping function is negative in the high-k region for both strongly and weakly anharmonic systems. The cumulant approximation cannot reproduce this behaviour. For the strongly anharmonic systems the quantum result shows qualitatively different behaviour from the classical approximation at low temperature: the former does not show the negative values even in the high-k region, while the latter shows the phase inversion in the amplitude.

  9. The Ironic Hypocrisy of Killing: How Sanctioned Counterinsurgency Policies of the Philippine War Ends in the Court-Martial of Major Littleton Waller

    DTIC Science & Technology

    2013-04-01

    white suits and collars ” would have to be replaced with stricter tactics. 25 Major John Henry Parker was one of these officers in the Philippines... white man’s burden”, a phrase referring to the innate moral responsibility of the Anglo-Saxon to uplift the entire human race. 17 One general...gratuitously, they were nonetheless of brutal consequence to the Philippine people. While soldiers were court-martialed for crimes in the

  10. KARIN: The Ka-Band Radar Interferometer for the Proposed Surface Water and Ocean Topography (SWOT) Mission

    NASA Technical Reports Server (NTRS)

    Esteban-Fernandez, Daniel; Peral, Eva; McWatters, Dalia; Pollard, Brian; Rodriguez, Ernesto; Hughes, Richard

    2013-01-01

    Over the last two decades, several nadir profiling radar altimeters have provided our first global look at the ocean basin-scale circulation and the ocean mesoscale at wavelengths longer than 100 km. Due to sampling limitations, nadir altimetry is unable to resolve the small wavelength ocean mesoscale and sub-mesoscale that are responsible for the vertical mixing of ocean heat and gases and the dissipation of kinetic energy from large to small scales. The proposed Surface Water and Ocean Topography (SWOT) mission would be a partnership between NASA, CNES (Centre National d'Etudes Spaciales) and the Canadian Space Agency, and would have as one of its main goals the measurement of ocean topography with kilometer-scale spatial resolution and centimeter scale accuracy. In this paper, we provide an overview of all ocean error sources that would contribute to the SWOT mission.

  11. KARIN: The Ka-Band Radar Interferometer for the Proposed Surface Water and Ocean Topography (SWOT) Mission

    NASA Technical Reports Server (NTRS)

    Esteban-Fernandez, Daniel; Peral, Eva; McWatters, Dalia; Pollard, Brian; Rodriguez, Ernesto; Hughes, Richard

    2013-01-01

    Over the last two decades, several nadir profiling radar altimeters have provided our first global look at the ocean basin-scale circulation and the ocean mesoscale at wavelengths longer than 100 km. Due to sampling limitations, nadir altimetry is unable to resolve the small wavelength ocean mesoscale and sub-mesoscale that are responsible for the vertical mixing of ocean heat and gases and the dissipation of kinetic energy from large to small scales. The proposed Surface Water and Ocean Topography (SWOT) mission would be a partnership between NASA, CNES (Centre National d'Etudes Spaciales) and the Canadian Space Agency, and would have as one of its main goals the measurement of ocean topography with kilometer-scale spatial resolution and centimeter scale accuracy. In this paper, we provide an overview of all ocean error sources that would contribute to the SWOT mission.

  12. 75 FR 47637 - Prohibited Transaction Exemptions and Grant of Individual Exemptions Involving: 2010-23, D-11500...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... FURTHER INFORMATION CONTACT: Ms. Karin Weng of the Department, telephone (202) 693-8557. (This is not a... INFORMATION CONTACT: Ms. Karin Weng of the Department, telephone (202) 693-8557. (This is not a...

  13. 78 FR 19599 - Approval and Promulgation of Implementation Plans; Texas; Reasonably Available Control Technology...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ..., Harris, Liberty, Montgomery and Waller counties. Specifically, we are finalizing our proposed approval of... number where Bend, Galveston, document begins]. Harris, Liberty, Montgomery and Waller Counties, TX. NOX..., Fort page number where Bend, Galveston, document begins]. Harris, Liberty, Montgomery and Waller...

  14. The Debate on Dominant Culture and Cultural Imperialism

    ERIC Educational Resources Information Center

    Anchan, John P.

    2012-01-01

    In this commentary, the author reviews in depth Roland S. Persson's (2012a) target article. According to him Persson (2012a) presents a convincing argument as he wove through examples and explanations. The idea of superculture connects well with the established neocolonial literature and the North-South/Centre-Periphery debate. From general to…

  15. A Catalyst for Charting a Path to Research Validity in the Field of Gifted Education

    ERIC Educational Resources Information Center

    Sisk, Dorothy A.

    2012-01-01

    Roland S. Persson's (2012a) article addresses a concern that many educators have stressed in their theoretical models, namely the importance of the interaction between the individual and the environment, and the impact of culture on not only values and beliefs, but on behaviour. As Persson (2012a) points out these models all have merit, but he…

  16. Evaluation of Low-Pressure Drop Antimicrobial and Hybrid Air Filters

    DTIC Science & Technology

    2006-09-01

    Pass Bioaerosol Removal Efficiencies of a Room Air Cleaner,” Karin K. Foarde, James T. Hanley, David S. Ensor , Peter Roessler Aerosol Science...Karin K. Foarde, James T. Hanley, Alan C. Veeck ASHRAE Journal 52-58 (2000) “Determine the Efficacy of Antimicrobial Treatments of Fibrous...Air Filters,” Karin K. Foarde, James T. Hanley ASHRAE Transactions: Research 4429 (RP-909): 156–170. “Development of a Method for Measuring Single

  17. Tackling important issues in Europe.

    PubMed

    de Lange, Karin

    2014-06-14

    Forthcoming animal health legislation, antimicrobial resistance and corporate practice were all discussed at the recent general assembly of the Federation of Veterinarians of Europe. Karin de Lange reports.

  18. Voluntary moral enhancement and the survival-at-any-cost bias.

    PubMed

    Rakić, Vojin

    2014-04-01

    I discuss the argument of Persson and Savulescu that moral enhancement ought to accompany cognitive enhancement, as well as briefly addressing critiques of this argument, notably by John Harris. I argue that Harris, who believes that cognitive enhancement is largely sufficient for making us behave more morally, might be disposing too easily of the great quandary of our moral existence: the gap between what we do and what we believe is morally right to do. In that regard, Persson and Savulescu's position has the potential to offer more. However, I question Persson and Savulescu's proposal of compulsory moral enhancement (a conception they used to promote), proposing the alternative of voluntary moral enhancement.

  19. Air Force Command and Control Intelligence, Surveillance, Reconnaissance Center (AFC2ISRC) Environmental Assessment

    DTIC Science & Technology

    2005-08-01

    Japanese honeysuckle, Virginia creeper, poison ivy, muscadine grape and lespedeza, and high tide bush. Exotic species, such as privet are also...Virginia. January. _________. 2004a. Three Headquarters Site Selection Study. Final Submittal. Prepared by Waller , Todd & Sadler Architects...Inc. July. _________. 2004b. AFC2ISRC Charette Report / Customer Concept Document. Final Submittal. Prepared by Waller , Todd & Sadler

  20. The Inner Workings of Ovarian Cancer

    SciTech Connect

    Rodland, Karin

    2016-06-29

    New research identifies critical proteins present in the tumors of women with ovarian cancer. Karin Rodland discusses the work led by PNNL and Johns Hopkins researchers, working with collaborators across the nation.

  1. The Inner Workings of Ovarian Cancer

    ScienceCinema

    Rodland, Karin

    2016-11-02

    New research identifies critical proteins present in the tumors of women with ovarian cancer. Karin Rodland discusses the work led by PNNL and Johns Hopkins researchers, working with collaborators across the nation.

  2. 78 FR 45903 - Native American Housing Assistance and Self-Determination Act of 1996: Negotiated Rulemaking...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    .... Annette Bryan, Executive Director, Puyallup Nation Housing Authority, Tacoma, Washington. Heather Cloud, Representative, Ho-Chunk Nation, Black River Falls, Wisconsin. Gary Cooper, Executive Director, Cherokee Nation..., Gardnerville, Nevada. Karin Lee Foster, Legal Counsel, Yakama Nation Housing Authority, Toppenish, Washington...

  3. FVE must continue to be active, says outgoing president.

    PubMed

    de Lange, Karin

    2015-08-01

    Karin de Lange reports from the recent general assembly of the Federation of Veterinarians of Europe, where issues on the agenda included proposed European regulations on animal health and veterinary medicines.

  4. Libraries in Florida: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/florida.html Libraries in Florida To use the sharing features on ... please enable JavaScript. Atlantis JFK Medical Center MEDICAL LIBRARY 5301 S. Congress Ave. Att: Karin H. Pancake Atlantis, ...

  5. Moral bioenhancement and agential risks: Good and bad outcomes.

    PubMed

    Torres, Phil

    2017-09-18

    In Unfit for the Future, Ingmar Persson and Julian Savulescu argue that our collective existetial predicment is unprecedentedly dangerous due to climate change and terrorism. Given these global risks to human prosperity and survival, Persson and Savulescu argue that we should explore the radical possibility of moral bioenhancement in addition to cognitive enhancement. In this article, I argue that moral bioenhancements could nontrivially exacerbate the threat posed by certain kinds of malicious agents, while reducing the threat of other kinds. This introduces a previously undiscussed complication to Persson and Savulescu's proposal. In the final section, I present a novel argument for why moral bioenhancement should either be compulsory or not be made available to the public at all. © 2017 John Wiley & Sons Ltd.

  6. Research Needs in Business Education.

    ERIC Educational Resources Information Center

    D'Onofrio, Marianne J., Ed.; And Others

    1990-01-01

    Set of five articles includes "Introduction" (D'Onofrio); "Teaching Higher-Order Thinking Skills" (Maxam); "Research Questions in Teaching Software" (Franz, Waller); "Research in International Business Education" (Blockhus); and "The Knowledge Worker and Computer Technology" (Graf). (JOW)

  7. Congress and SDIO, 1983-1989.

    DTIC Science & Technology

    1992-01-31

    34polite but negative," Proxmire feared that they and the Japanese would feel denied the protection of the U.S. nuclear deterrent and that they might be...28 Douglas Waller , James Bruce, and Douglas Cook, "SDI: Progress and Challenges" (Staff report submitted to Senators William Proxmire, J. Bennett...for FY 1988. Pt. 2, 174. 35 Douglas C. Waller , James T. Bruce, and Douglas M. Cook, The Strategic Defense Initiative: Progress and Challenges

  8. Non-chromate, Zero-VOC Coatings for Steel Substrates on Army and Navy Aircraft and Ground Vehicles

    DTIC Science & Technology

    2012-08-01

    Austin Minter Anniston Army Depot Anniston AL Department of Engineering Quality. Coordinate processing of Stryker Demonstrations, and phosphate... Anniston Army Depot – Patty Dodson 3) Demonstration of Non-chromate primer and ZVOC Topcoat Cherry Point – Jacob Waller ESTCP WP 200906...Sealers Anniston Army Depot – Patty Dodson 3) Demonstration of Non-chromate primer and ZVOC Topcoat Cherry Point – Jacob Waller ESTCP WP 200906

  9. IFLA General Conference, 1990. Division of Collections and Services: Section of Acquisition and Exchange; Section of Interlending and Document Delivery, Section of Serial Publications. Booklet 5.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    The 25 papers in this collection were presented at the meetings of three sections of the Division of Collections and Services and a workshop: (1) "Survey of International Exchange of Non-Official Publications: Progress Report" (Ulla Hojsgaard); (2) "Buying Media for Everyone: Public Library Acquisition in Scandinavia" (Tove Persson); (3) "The…

  10. Description of Mixed-Phase Clouds in Weather Forecast and Climate Models

    DTIC Science & Technology

    2013-09-30

    Ocean Sciences and Atmospheric Measurement Techniques ( Copernicus Scientific Publishing). Some of this work is also including other data, from e.g...MT, T. Mauritsen, M. Shupe, I. Brooks, P. Persson, C. Birch, C. Leck, A. Sirevaag, and M. Nicolaus , 2011: A transitioning Arctic surface energy budget

  11. In the Shadows of Dominant Cultures: The Elusive Definition of Giftedness

    ERIC Educational Resources Information Center

    Polyzoi, Eleoussa; Haydey, Donna Copsey

    2012-01-01

    In this commentary, the authors contend that Persson's (2012a) paper, Cultural Variation and Dominance in a Globalised Knowledge-Economy: Towards a Culture-Sensitive Research Paradigm in the Science of Giftedness, lacks conciseness in defining the connections between the significance of cultural dominance and the definition of giftedness. However,…

  12. On Universals, Cultural Variations and Individual Uniqueness: Throwing down the Gauntlet in Giftedness Research

    ERIC Educational Resources Information Center

    Garces-Bacsal, Rhoda Myra

    2012-01-01

    Roland S. Persson's (2012a) piece is extremely comprehensive, timely and very relevant especially in light of a growing appreciation of cultural diversity and the emergence of a global community--which is an inevitable offshoot of globalisation that goes beyond world economy and international markets. It covers multiple themes; ranging from…

  13. Nanodevice for Imaging Normal Stress Distribution With Application in Sensing Texture and Feel’ by Touching

    DTIC Science & Technology

    2004-12-01

    M.C. Schlamp, A.P. Alivisatos, Light-emitting Diodes made from Cadmium Selenide Nanocrystals and Semiconducting Polymer, Nature, 370, 354-357 (1994...from Cadmium Selenide Nanocrystal, Nature, 389, 699-701 (1997). 11. S.H.M. Persson, L. Olofsson, L. Gunnarsson, Appl. Phys. Lett., 74, 2546 (1999

  14. Cooled Ion Frequency Standard (FY81).

    DTIC Science & Technology

    1981-01-01

    Spectroscopy, Jasper , Canada, Wayne M. Itano. 11. Gordon Conf. on Atomic Physics, Wolfeboro, N. H., D. J. Wineland. * 5 Miscellaneous A. All FY81 funds will be...Frequency Metrology Using Laser Cooled Ions." F. L. Walls and Karl Persson NRL $40 k Development of Hydrogen Discharge Source capable of operation in vacuum

  15. Critique of Cultural Variation and Dominance in a Globalised Knowledge-Economy: Towards a Culture-Sensitive Research Paradigm in the Science of Giftedness

    ERIC Educational Resources Information Center

    Harris, Carole Ruth

    2012-01-01

    Persson's (2012a) article is concerned with giftedness research in the light of cultural bias with a view to cultural dominance that derives from ethnocentricity. He questions the validity of current research that appears to ignore or sidestep cultural difference and proposes that an agenda for amelioration of such bias lies in greater awareness…

  16. The Scenic Route Is Not Always the Most Informative

    ERIC Educational Resources Information Center

    Freeman, Joan

    2012-01-01

    Roland S. Persson's (2012a) argument is that there is a dominant research culture in the field of gifts and talents, which must of necessity distort research and practice in cultures which are different. He ties this to the dominance of the global economy and points to the need for more cross-cultural studies. In this commentary, the author points…

  17. Basic Framework to Understand Identity Development in a Multicultural Context

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.; Valdez, Gilbert

    2012-01-01

    In the lead article, Persson (2012a) focuses on salient issues that have not as yet been addressed by others, and which are relevant, and germane. With the advent of the Internet and web and e-mail, conversation and discussion among scholars have increased tremendously. At the current time, researchers are able to share their data, their thoughts…

  18. Some Thoughts on "Cultural Variation and Dominance in a Globalised Knowledge-Economy"

    ERIC Educational Resources Information Center

    Yang, Yang; Gentry, Marcia

    2012-01-01

    To view giftedness research in a global context is an important and desirable attempt. Roland S. Persson (2012a), in the target article entitled Cultural Variation and Dominance in a Globalised Knowledge-Economy: Towards a Cultural-Sensitive Research Paradigm in the Science of Giftedness, delivers thought-provoking views in the cultural influences…

  19. East-West Cultural Bias and Creativity: We Are Alike and We Are Different

    ERIC Educational Resources Information Center

    Kaufman, James C.; Lan, Lan

    2012-01-01

    Persson (2012a) correctly raises the question of how cultural biases may impact giftedness research. He alludes to East-West differences in perceptions of creativity and ways that the collectivist-individualistic approaches may lead to differences in creativity perception. In this commentary, the authors discuss different approaches, and attempt…

  20. Critique of Cultural Variation and Dominance in a Globalised Knowledge-Economy: Towards a Culture-Sensitive Research Paradigm in the Science of Giftedness

    ERIC Educational Resources Information Center

    Harris, Carole Ruth

    2012-01-01

    Persson's (2012a) article is concerned with giftedness research in the light of cultural bias with a view to cultural dominance that derives from ethnocentricity. He questions the validity of current research that appears to ignore or sidestep cultural difference and proposes that an agenda for amelioration of such bias lies in greater awareness…

  1. IFLA General Conference, 1990. Division of Collections and Services: Section of Acquisition and Exchange; Section of Interlending and Document Delivery, Section of Serial Publications. Booklet 5.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    The 25 papers in this collection were presented at the meetings of three sections of the Division of Collections and Services and a workshop: (1) "Survey of International Exchange of Non-Official Publications: Progress Report" (Ulla Hojsgaard); (2) "Buying Media for Everyone: Public Library Acquisition in Scandinavia" (Tove Persson); (3) "The…

  2. A Malignant Oligarchy: Progenitors Govern the Behavior of Oligodendrogliomas

    PubMed Central

    Pei, Yanxin; Wechsler-Reya, Robert J.

    2010-01-01

    Recent studies have suggested that brain tumors arise from neural stem cells, and are maintained by stem-like tumor-initiating cells (TICs). In this issue of Cancer Cell Persson et al. report that oligodendrogliomas, unlike malignant astrocytomas, originate from – and are propagated by – cells that resemble oligodendrocyte progenitors. PMID:21156279

  3. A malignant oligarchy: progenitors govern the behavior of oligodendrogliomas.

    PubMed

    Pei, Yanxin; Wechsler-Reya, Robert J

    2010-12-14

    Recent studies have suggested that brain tumors arise from neural stem cells and are maintained by stem-like tumor-initiating cells (TICs). In this issue of Cancer Cell, Persson et al. report that oligodendrogliomas, unlike malignant astrocytomas, originate from-and are propagated by-cells that resemble oligodendrocyte progenitors. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Basic Framework to Understand Identity Development in a Multicultural Context

    ERIC Educational Resources Information Center

    Shaughnessy, Michael F.; Valdez, Gilbert

    2012-01-01

    In the lead article, Persson (2012a) focuses on salient issues that have not as yet been addressed by others, and which are relevant, and germane. With the advent of the Internet and web and e-mail, conversation and discussion among scholars have increased tremendously. At the current time, researchers are able to share their data, their thoughts…

  5. The Scenic Route Is Not Always the Most Informative

    ERIC Educational Resources Information Center

    Freeman, Joan

    2012-01-01

    Roland S. Persson's (2012a) argument is that there is a dominant research culture in the field of gifts and talents, which must of necessity distort research and practice in cultures which are different. He ties this to the dominance of the global economy and points to the need for more cross-cultural studies. In this commentary, the author points…

  6. Operationalizing Economics for Counterinsurgency and Stability Operations

    DTIC Science & Technology

    2009-05-01

    Press, 2004. Besley , Timothy J., and Torsten Persson. The Incidence of Civil War: Theory and Evidence. Cambridge, MA: National Bureau of Economic...183-201. Tyson, Ann Scott . “Standard Warfare May Be Eclipsed by Nation-Building.” Washington Post, October 5, 2008. 53

  7. The challenge of ecological restoration

    Treesearch

    John A. Stanturf

    2012-01-01

    Recent estimates by the World Conservation Union (IUCN) and World Resources Institute (WRI) suggest that over 2 billion ha of forests are degraded and in need of restoration. Goren Persson, former prime minister of Sweden, proposed the formation of a Global Restoration council to implement the Bonn Challenge to restore 150 million ha of degraded forests by 2020. The...

  8. On Universals, Cultural Variations and Individual Uniqueness: Throwing down the Gauntlet in Giftedness Research

    ERIC Educational Resources Information Center

    Garces-Bacsal, Rhoda Myra

    2012-01-01

    Roland S. Persson's (2012a) piece is extremely comprehensive, timely and very relevant especially in light of a growing appreciation of cultural diversity and the emergence of a global community--which is an inevitable offshoot of globalisation that goes beyond world economy and international markets. It covers multiple themes; ranging from…

  9. Dynamic compensation, parameter identifiability, and equivariances

    PubMed Central

    2017-01-01

    A recent paper by Karin et al. introduced a mathematical notion called dynamical compensation (DC) of biological circuits. DC was shown to play an important role in glucose homeostasis as well as other key physiological regulatory mechanisms. Karin et al. went on to provide a sufficient condition to test whether a given system has the DC property. Here, we show how DC can be formulated in terms of a well-known concept in systems biology, statistics, and control theory—that of parameter structural non-identifiability. Viewing DC as a parameter identification problem enables one to take advantage of powerful theoretical and computational tools to test a system for DC. We obtain as a special case the sufficient criterion discussed by Karin et al. We also draw connections to system equivalence and to the fold-change detection property. PMID:28384175

  10. Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films

    NASA Astrophysics Data System (ADS)

    Chase, T.; Trigo, M.; Reid, A. H.; Li, R.; Vecchione, T.; Shen, X.; Weathersby, S.; Coffee, R.; Hartmann, N.; Reis, D. A.; Wang, X. J.; Dürr, H. A.

    2016-01-01

    We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.

  11. Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films

    SciTech Connect

    Chase, T.; Trigo, M.; Reid, A. H.; Dürr, H. A.; Li, R.; Vecchione, T.; Shen, X.; Weathersby, S.; Coffee, R.; Hartmann, N.; Wang, X. J.; Reis, D. A.

    2016-01-25

    We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.

  12. Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films

    SciTech Connect

    Chase, T.; Trigo, M.; Reid, A. H.; Li, R.; Vecchione, T.; Shen, X.; Weathersby, S.; Coffee, R.; Hartmann, N.; Reis, D. A.; Wang, X. J.; Dürr, H. A.

    2016-01-25

    We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.

  13. 78 FR 24226 - Notice of Proposed Information Collection: Comment Request; FHA TOTAL (Technology Open to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... URBAN DEVELOPMENT Notice of Proposed Information Collection: Comment Request; FHA TOTAL (Technology Open... Officer, Department of Housing and Urban Development, 451 7th Street SW., Washington, DC 20410, Room 9120...: Karin B. Hill, Director, Office of Single Family Program Development, Department of Housing and...

  14. Schools That Succeed: How Educators Marshal the Power of Systems for Improvement

    ERIC Educational Resources Information Center

    Chenoweth, Karin

    2017-01-01

    Informed by years of research and on-the-ground reporting, "Schools That Succeed" is Karin Chenoweth's most inspiring and compelling book yet--an essential read for educators who seek to break the stubborn connection between academic achievement and socioeconomic status. Chenoweth draws on her decade-long journey into neighborhood…

  15. 75 FR 38557 - Application Nos. and Proposed Exemptions; D-11489, Morgan Stanley & Co., Incorporated; L-11609...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... should state: (1) The name, address, and telephone number of the person making the comment or request... fiduciary who is Independent of Morgan Stanley. 10. The proposed exemption contains a number of safeguards... CONTACT: Ms. Karin Weng of the Department, telephone (202) 693-8557. (This is not a toll-free number...

  16. 75 FR 51979 - Narrow Woven Ribbons with Woven Selvedge from the People's Republic of China: Amended Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ..., published price lists, official import statistics and customs data, and information obtained from interested...: Amended Final Determination of Sales at Less Than Fair Value AGENCY: Import Administration, International... CONTACT: Karine Gziryan, AD/CVD Operations, Office 4, Import Administration, International Trade...

  17. Epistemic Practices and Object Relations in Professional Work

    ERIC Educational Resources Information Center

    Nerland, Monika; Jensen, Karen

    2012-01-01

    Professional practice is embedded in complex dynamics of knowledge that are present within, but reach beyond, local work. Knowledge is generated from a manifold of sources, and further developed and circulated in professional communities as practitioners are confronted with non-routine problems. Drawing on the work of Karin Knorr Cetina and her…

  18. 77 FR 6809 - Center for Scientific Review; Notice of Closed Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-09

    ...: Jacinta Bronte-Tinkew, Ph.D., Scientific Review Officer, Center for Scientific Review, National Institutes..., CA 94115. Contact Person: Karin F Helmers, Ph.D., Scientific Review Officer, Center for Scientific... Street, San Francisco, CA 94115. Contact Person: Melinda Jenkins, Ph.D., Scientific Review Officer...

  19. Persistent Discourses in Physics Education: Gender Neutrality and the Gendering of Competence

    ERIC Educational Resources Information Center

    Gonsalves, Allison

    2014-01-01

    In her article, Karin Due presents us with a contradiction in physics: the construction of physics as a symbolically masculine discipline alongside a simultaneous discourse of the "gender-neutrality" of the discipline. Due's article makes an important contribution to the study of the gendering of physics practices, particularly in…

  20. The Role of Shared Knowledge in Science: The Failure of the Constructivist Programme in the Sociology of Science.

    ERIC Educational Resources Information Center

    Freudenthal, Gad

    1984-01-01

    Discusses various aspects of contructivism, focusing on the work of Karin Knorr-Cetina. Indicates that an internal critique of Knorr's arguments for the relativist program in the sociology highlights the role of shared knowledge in science and that Knorr's analysis produces new insights concerning the necessity and nature of scientific consensus.…

  1. Astronaut C. Michael Foale is briefed on use of Sky Genie

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut C. Michael Foale, STS-63 mission specialist, is briefed on the use of Sky Genie device by Karin L. Porter. The device would aid in emergency egress operations aboard a troubled Space Shuttle. Porter, an employee of Rockwell International, helps train astronauts in egress procedures at JSC's Shuttle mockup and integration laboratory.

  2. Targeted Approach to Overcoming Treatment Resistance in Advanced Prostate Cancer

    DTIC Science & Technology

    2013-07-01

    therapy -­‐resistant   prostate   cancer  cells  and  in  combination   therapy  (SOW...treatment resistance in advanced prostate cancer PRINCIPAL INVESTIGATOR: Dr. Karin Scarpinato CONTRACTING ORGANIZATION: Georgia Southern...SUPPLEMENTARY NOTES 14. ABSTRACT The purpose of this project is to determine if rescinnamine is effective against prostate cancer and

  3. Psycholinguistics and Foreign Language Learning. Papers from a Conference (Stockholm, Sweden and Abo, Finland, October 25-26, 1982). Meddelanden fran Stiftelsens for Abo Akademi Forskningsinstitut Nr.86.

    ERIC Educational Resources Information Center

    Ringbom, Hakan, Ed.

    At irregular intervals, beginning in 1977, Swedish-Finnish conferences on contrastive and applied linguistics have been arranged in Stockholm and Turko/Abo. This volume presents most of the papers given at the 1982 conference. Papers include: "Free Recall of Mixed Language Lists. Error Patterns in Bilingual Memory" (Karin Aronsson, Anja Metsola,…

  4. Response to Elwood, M. et al., Comment on: Maternal Exposure to Domestic Hair Cosmetics and Occupational Endocrine Disruptors Is Associated with a Higher Risk of Hypospadias in the Offspring. Int. J. Environ. Res. Public Health 2017, 14, 27.

    PubMed

    Haraux, Elodie; Braun, Karine; Buisson, Philippe; Stéphan-Blanchard, Erwan; Devauchelle, Camille; Ricard, Jannick; Boudailliez, Bernard; Tourneux, Pierre; Gouron, Richard; Chardon, Karen

    2017-09-15

    Dear Editor, Thank you for inviting us to reply to a "Comment" paper to our published paper "Maternal Exposure to Domestic Hair Cosmetics and Occupational Endocrine Disruptors Is Associated with a Higher Risk of Hypospadias in the Offspring" (Authors: Elodie Haraux, Karine Braun, Philippe Buisson, Erwan Stéphan-Blanchard, Jannick Ricard, Camille Devauchelle, Bernard Boudailliez, Pierre Tourneux, Richard Gouron, Karen Chardon).[...].

  5. Astronaut C. Michael Foale is briefed on use of Sky Genie

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut C. Michael Foale, STS-63 mission specialist, is briefed on the use of Sky Genie device by Karin L. Porter. The device would aid in emergency egress operations aboard a troubled Space Shuttle. Porter, an employee of Rockwell International, helps train astronauts in egress procedures at JSC's Shuttle mockup and integration laboratory.

  6. Persistent Discourses in Physics Education: Gender Neutrality and the Gendering of Competence

    ERIC Educational Resources Information Center

    Gonsalves, Allison

    2014-01-01

    In her article, Karin Due presents us with a contradiction in physics: the construction of physics as a symbolically masculine discipline alongside a simultaneous discourse of the "gender-neutrality" of the discipline. Due's article makes an important contribution to the study of the gendering of physics practices, particularly in…

  7. Field Evaluations of Topical Arthropod Repellents in North, Central, and South America

    DTIC Science & Technology

    2014-09-01

    percent protection when compared to Ultrathon. 982 JOURNAL OF MEDICAL ENTOMOLOGY Vol. 51, no. 5 inces of Toledo , Cayo, and Stann Creek than in the...and Russell King (Ministry of Health, Belize), and Victor López-Sifuentes and Karin Es- cobedo-Vargas (NAMRU-6) for their Þeld assistance and

  8. "Like-Me" Simulation as an Effective and Cognitively Plausible Basis for Social Robotics

    DTIC Science & Technology

    2009-02-24

    havior of teams from observation. In: RoboCup 2002: robot soccer world cup, Fukuoka, Japan 25. Karin-D’Arcy MR, Povinelli DJ (2002) Do chimpanzees...2001) Building a multimodal human-robot interface. IEEE Intel Syst 16:16–20 41. Povinelli DJ, Eddy TJ (1994) The eyes as a window: what young

  9. The Role of Tumor Associated Macrophage in Recurrent Growth of Tumor Stem Cell

    DTIC Science & Technology

    2012-09-01

    Sica . Macrophage polarization: tumor-associated macrophages as a paradigm for polarized M2 mononuclear phagocytes. Trends Immunol. 23: 549-555...2002 3. Alberto Mantovani, Paola Allavena1, Antonio Sica and Frances Balkwill. Cancer-related inflammation. Nature. 454: 436-444, 2008 4. Karin E. de

  10. 75 FR 70019 - Notice of Submission of Proposed Information Collection to OMB; Emergency Comment Request...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... CFR 4001.408 detail the requirements pertinent to HUD's single family mortgage insurance programs, i.e... mortgagees to mortgagors who are at risk of losing their homes to foreclosure. The new FHA-insured mortgages... FURTHER INFORMATION CONTACT: Karin Hill, Director, Office of Single Family Program Development, Department...

  11. Governance and Foreign Aid Allocation

    DTIC Science & Technology

    2006-07-01

    policies (North 1990, Williamson 1991 , World Bank 1993, etc.). These advances highlighted the importance of the strategic behaviors of governments...1990, Williamson 1991 , World Bank 1993, Persson and Tabellini 1990), roles of markets and governments (Commander et al 1996), role of human...widespread debt crisis in developing countries. The declining trend was more pronounced during 1991 -1997 with an absolute decline in net ODA flows from

  12. Parameterizing Surface Fluxes in the Arctic

    DTIC Science & Technology

    2001-09-01

    Precision Solar pyranometers (PSP) at a 5 second sampling interval (Persson et al., 2001). Each sensor was located 1.5-2.0 meters above the surface...their heights, thicknesses and types all significantly affect the radiation balance There is a strong relationship between the presence of clouds...limited to the region of drift. Only cloud base height is available and there is no coinciding data set that provides thickness measurements for the

  13. Adhesive contact of rough surfaces: comparison between numerical calculations and analytical theories.

    PubMed

    Carbone, G; Scaraggi, M; Tartaglino, U

    2009-09-01

    The authors have employed a numerical procedure to analyse the adhesive contact between a soft elastic layer and a rough rigid substrate. The solution to the problem, which belongs to the class of the free boundary problems, is obtained by calculating Green's function which links the pressure distribution to the normal displacements at the interface. The problem is then formulated in the form of a Fredholm integral equation of the first kind with a logarithmic kernel. The boundaries of the contact area are calculated by requiring the energy of the system to be stationary. This methodology has been employed to study the adhesive contact between an elastic semi-infinite solid and a randomly rough rigid profile with a self-affine fractal geometry. We show that, even in the presence of adhesion, the true contact area still linearly depends on the applied load. The numerical results are then critically compared with the predictions of an extended version of Persson's contact mechanics theory, which is able to handle anisotropic surfaces, as 1D interfaces. It is shown that, for any given load, Persson's theory underestimates the contact area by about 50% in comparison with our numerical calculations. We find that this discrepancy is larger than for 2D rough surfaces in the case of adhesionless contact. We argue that this increased difference might be explained, at least partially, by considering that Persson's theory is a mean-field theory in spirit, so it should work better for 2D rough surfaces rather than for 1D rough surfaces. We also observe that the predicted value of separation is in agreement with our numerical results as well as the exponents of the power spectral density of the contact pressure distribution and of the elastic displacement of the solid. Therefore, we conclude that Persson's theory captures almost exactly the main qualitative behaviour of the rough contact phenomena.

  14. Training Grant in Epidemiology and Prevention of Breast Cancer

    DTIC Science & Technology

    2005-07-01

    Persson 1. hormone levels after menopause and subsequent breast cancer. J Nat] Breast-cancer risk following long-term oestrogen - and oestrogen ...and the preparation of a short grant proposal to examine the relationship between childhood adiposity and concentrations of sex hormones in girls. Ms...advisor, Dr. Susan Hankinson, on analyses on sex steroid hormones , prolactin II, and breast cancer incidence. She will is second author on two papers

  15. Contact mechanics for layered materials with randomly rough surfaces.

    PubMed

    Persson, B N J

    2012-03-07

    The contact mechanics model of Persson is applied to layered materials. We calculate the M function, which relates the surface stress to the surface displacement, for a layered material, where the top layer (thickness d) has different elastic properties than the semi-infinite solid below. Numerical results for the contact area as a function of the magnification are presented for several cases. As an application, we calculate the fluid leak rate for laminated rubber seals.

  16. Democratic Values and Support for Militant Politics: Evidence from a National Survey of Pakistan

    DTIC Science & Technology

    2012-11-27

    Dalton 1994; Persson and Tabbellini 2009), better governance ( Almond and Verba 1963), and economic growth (Huntington 1984). Drawing on this tradition, a...the Pakistan Muslim League) are Kashmiri. Many products , such as cooking oil, are sold and marketed under the brand name “Kashmir.” The notion of...characterization of “Hindu” oppression is sustainable for many Pakistanis. 8 Azad is the adjective corresponding to the noun azadi. 10   a legitimate

  17. Testing a Readable Writing Approach to Text Revision.

    ERIC Educational Resources Information Center

    Duffy, Thomas M.; Kabance, Paula

    1982-01-01

    The present findings imply that a readability formula is not an effective writing production criterion, even when the writer does not deliberately write to the formula. Comprehensibility of text might be better controlled through the proper use of the transformer concept (MacDonald-Ross and Waller). (Author/PN)

  18. 75 FR 54420 - Notice of Final Federal Agency Actions on US 290/Hempstead Corridor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ...) in Harris County, Texas. Those actions grant licenses, permits, and approvals for the project...: US 290 from FM 2920 to IH 610 in Harris County; FHWA Project Reference Number: FHWA-TX-EIS-07-01-F... 610 and Sam Houston Tollway. It will begin in northwestern Harris County at FM 2920 near Waller, TX...

  19. Judge Advocates in Vietnam: Army Lawyers in Southeast Asia 1959-1975

    DTIC Science & Technology

    2003-01-01

    Ibid., 688-89. 6. Prugh, Law at War, 51. 7. Ibid., 53. 8. Ibid., 59. 9. The first female judge advocate in Vietnam, Maj. Ann Wansley , served at U.S. Army...33-34, 84 Waller, Col. James C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Wansley , Maj. Ann

  20. 40 CFR 52.2309 - Emissions inventories.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .../Galveston (HGA), Beaumont/Port Arthur (BPA), El Paso (ELP), and Dallas/Fort Worth (DFW) ozone nonattainment... and includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller.../Galveston areas. (f) The Texas Natural Resource Conservation Commission submitted a revision to the State...

  1. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... area consists of Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller... requesting that the Houston/Galveston and Beaumont/Port Arthur ozone nonattainment areas be granted an... NOX control requirements of sections 182(f) and 182(b) of the Clean Air Act for the Houston/Galveston...

  2. 40 CFR 52.2309 - Emissions inventories.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../Galveston (HGA), Beaumont/Port Arthur (BPA), El Paso (ELP), and Dallas/Fort Worth (DFW) ozone nonattainment... and includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller.../Galveston areas. (f) The Texas Natural Resource Conservation Commission submitted a revision to the State...

  3. 40 CFR 52.2309 - Emissions inventories.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .../Galveston (HGA), Beaumont/Port Arthur (BPA), El Paso (ELP), and Dallas/Fort Worth (DFW) ozone nonattainment... and includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller.../Galveston areas. (f) The Texas Natural Resource Conservation Commission submitted a revision to the State...

  4. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... area consists of Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller... requesting that the Houston/Galveston and Beaumont/Port Arthur ozone nonattainment areas be granted an... NOX control requirements of sections 182(f) and 182(b) of the Clean Air Act for the Houston/Galveston...

  5. 40 CFR 52.2309 - Emissions inventories.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .../Galveston (HGA), Beaumont/Port Arthur (BPA), El Paso (ELP), and Dallas/Fort Worth (DFW) ozone nonattainment... and includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller.../Galveston areas. (f) The Texas Natural Resource Conservation Commission submitted a revision to the State...

  6. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... area consists of Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller... requesting that the Houston/Galveston and Beaumont/Port Arthur ozone nonattainment areas be granted an... NOX control requirements of sections 182(f) and 182(b) of the Clean Air Act for the Houston/Galveston...

  7. 40 CFR 52.2308 - Area-wide nitrogen oxides (NOX) exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... area consists of Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller... requesting that the Houston/Galveston and Beaumont/Port Arthur ozone nonattainment areas be granted an... NOX control requirements of sections 182(f) and 182(b) of the Clean Air Act for the Houston/Galveston...

  8. TRIHALOMETHANE LEVELS IN HOME TAP WATER AND SEMEN QUALITY

    EPA Science Inventory

    Trihalomethane Levels in Home Tap Water and Semen Quality
    Laura Fenster, 1 Kirsten Waller, 2 Gayle Windham, 1 Tanya Henneman, 2 Meredith Anderson, 2 Pauline Mendola, 3 James W. Overstreet, 4 Shanna H. Swan5

    1California Department of Health Services, Division of Environm...

  9. 76 FR 65758 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ..., SIFMA and Sullivan & Cromwell. \\9\\ See letters from ABA, NYC Bar, Patrick, Saxony, SIFMA and Sullivan & Cromwell. Some commenters asserted the proposed 85 percent limitation was an arbitrary ``one size fits all..., Mick & Associates, Network 1, Patrick, REISA, Saxony, Secore & Waller, SIFMA, Sullivan & Cromwell and...

  10. The Race Issue in Mississippi Politics; A Content Analysis of Campaign Discourse in Mississippi's 1971 Gubernatorial Campaign.

    ERIC Educational Resources Information Center

    King, Emma Lou

    Racial attitudes were an issue in the 1972 Mississippi gubernatorial campaign between Charles Evers and William Waller. This conclusion is supported by test evidence consisting of content analysis of candidate speeches, news coverage of speeches in the form of direct quotations, printed issue position papers, and printed campaign advertising. A…

  11. SHORTER MENSTRUAL CYCLES ASSOCIATED WITH CHLORINATION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    Shorter Menstrual Cycles Associated with Chlorination by-Products in Drinking Water.
    Gayle Windham, Kirsten Waller, Meredith Anderson, Laura Fenster, Pauline Mendola, Shanna Swan. California Department of Health Services.

    In previous studies of tap water consumption we...

  12. STRAIN COMPARISON IN PREGNANT RATS OF ENDOCRINE RESPONSE TO BROMODICHLOROMETHANE: A DRINKING WATER DISINFECTION BY-PRODUCT

    EPA Science Inventory

    Bromodichloromethane (BDCM), a trihalomethane, is a by-product of the chlorination of drinking water. In an epidemiological study, consumption of drinking water with high levels of BDCM was associated with an increased risk of spontaneous abortion in pregnant women (Waller et al....

  13. Relationship of Purported Measures of Pathological and Nonpathological Dissociation to Self-Reported Psychological Distress and Fantasy Immersion

    ERIC Educational Resources Information Center

    Levin, Ross; Spei, Ekaterina

    2004-01-01

    In order to investigate both the psychometric structure of the Dissociative Experiences Survey (DES) and the discriminant validity of the DES-Taxon (Waller, Putnam, & Carlson, 1996) as a specific marker of pathological dissociation, 376 non-clinical community based respondents completed the DES and a battery of psychopathology and imaginative…

  14. The Effect of a Coronary Artery Risk Evaluation Program on the Serum Lipid Values of a Selected Military Population

    DTIC Science & Technology

    1991-05-01

    platelet aggregation, or thrombosis (Waller, 1988). Reduced myocardial perfusion lowers the oxygen tension shifting metabolism from an aerobic to an...health outcomes were achieved by the participants. In addition, many persons later recounted how they eagerly sought out other supplemental information

  15. Relationship of Purported Measures of Pathological and Nonpathological Dissociation to Self-Reported Psychological Distress and Fantasy Immersion

    ERIC Educational Resources Information Center

    Levin, Ross; Spei, Ekaterina

    2004-01-01

    In order to investigate both the psychometric structure of the Dissociative Experiences Survey (DES) and the discriminant validity of the DES-Taxon (Waller, Putnam, & Carlson, 1996) as a specific marker of pathological dissociation, 376 non-clinical community based respondents completed the DES and a battery of psychopathology and imaginative…

  16. Testing a Readable Writing Approach to Text Revision.

    ERIC Educational Resources Information Center

    Duffy, Thomas M.; Kabance, Paula

    1982-01-01

    The present findings imply that a readability formula is not an effective writing production criterion, even when the writer does not deliberately write to the formula. Comprehensibility of text might be better controlled through the proper use of the transformer concept (MacDonald-Ross and Waller). (Author/PN)

  17. Culture and Leadership in Educational Administration: A Historical Study of What Was and What Might Have Been

    ERIC Educational Resources Information Center

    Bates, Richard

    2006-01-01

    This paper examines the consequences for school leadership of the abandonment of Waller's insights into the school as a social organism and the embracing of the cult of efficiency as the foundation for the analysis of school culture. Tracing the separation of conception from execution, leadership from teaching, administration from education…

  18. 29 CFR 784.106 - Relationship of employee's work to the named operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Trade Winds, Inc., 289 F. 2d 278; see also Waller v. Humphreys, 133 F. 2d 193 and McComb v. Consolidated... is also possible for an employee to come within the exemption provided by section 13(a)(5) or section...

  19. 75 FR 15391 - Approval and Promulgation of Air Quality Implementation Plans; Texas; Revision to Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... tanks, transport vessels and marine vessels in the Houston/Galveston/Brazoria (HGB) 1997 8-hour ozone... and Waller counties. Specifically, this revision subjects owners or operators of VOC storage tanks... the revision pursuant to section 110 and part D of the Clean Air Act (CAA). DATES: Written...

  20. Stretching the boundaries

    NASA Astrophysics Data System (ADS)

    2012-08-01

    Tom Waller of swimwear manufacturer Speedo's global research and development facility, Aqualab, talked to Nature Materials about the competitive sporting goods industry and the technology behind their new racing system that will be put to the test at the 2012 Olympic Games in London.

  1. Forest statistics for Southeast Texas counties - 1986

    Treesearch

    William H. McWilliams; Daniel F. Bertelson

    1986-01-01

    These tables were derived from data obtained during a 1986 inventory of 22 counties comprising the Southeast Unit of Texas (fig. 1). Grimes, Leon, Madison, and Waller counties have been added to the Southeastern Unit since the previous inventory if 1975. All comparisons of the 1975 and 1986 forest statistics made in this Bulletin account for this change. The data on...

  2. TRIHALOMETHANE LEVELS IN HOME TAP WATER AND SEMEN QUALITY

    EPA Science Inventory

    Trihalomethane Levels in Home Tap Water and Semen Quality
    Laura Fenster, 1 Kirsten Waller, 2 Gayle Windham, 1 Tanya Henneman, 2 Meredith Anderson, 2 Pauline Mendola, 3 James W. Overstreet, 4 Shanna H. Swan5

    1California Department of Health Services, Division of Environm...

  3. CHLORINATION BY-PRODUCTS IN DRINKING WATER AND MENSTRUAL CYCLE FUNCTION

    EPA Science Inventory

    Chlorination by-Products in Drinking Water and Menstrual Cycle Function

    Gayle C. Windham1, Kirsten Waller2, Meredith Anderson2, Laura Fenster1, Pauline Mendola3, Shanna Swan4

    1California Department of Health Services, Division of Environmental and Occupational Disea...

  4. 75 FR 1814 - Manufacturer of Controlled Substances; Notice of Registration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ... Center for Natural Products Research-NIDA MProject, University of Mississippi, 135 Coy Waller Lab Complex... determined that the registration of National Center for Natural Products Research-NIDA MProject to... time. DEA has investigated National Center for Natural Products Research-NIDA MProject to ensure...

  5. 76 FR 8777 - Manufacturer of Controlled Substances; Notice of Registration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... for Natural Products Research-NIDA MProject, University of Mississippi, 135 Coy Waller Lab Complex... registration of National Center for Natural Products Research-NIDA MProject to manufacture the listed basic... National Center for Natural Products Research-NIDA MProject to ensure that the company's registration...

  6. CHLORINATION BY-PRODUCTS IN DRINKING WATER AND MENSTRUAL CYCLE FUNCTION

    EPA Science Inventory

    Chlorination by-Products in Drinking Water and Menstrual Cycle Function

    Gayle C. Windham1, Kirsten Waller2, Meredith Anderson2, Laura Fenster1, Pauline Mendola3, Shanna Swan4

    1California Department of Health Services, Division of Environmental and Occupational Disea...

  7. SHORTER MENSTRUAL CYCLES ASSOCIATED WITH CHLORINATION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    Shorter Menstrual Cycles Associated with Chlorination by-Products in Drinking Water.
    Gayle Windham, Kirsten Waller, Meredith Anderson, Laura Fenster, Pauline Mendola, Shanna Swan. California Department of Health Services.

    In previous studies of tap water consumption we...

  8. The Role of the Buffalo Soldiers during the Spanish-American War

    DTIC Science & Technology

    1992-01-01

    Albert M. Jones Timothy Breen Berry F. Taylor Thomas P. Ledgwidge John Mulisn Harman H. Wynkoop James M. Dean Edward C. Waller G. Roland Fortescue... Leary 0. Hunt, LeRoy R. Houston, Robert C. James, Frank W. Johnson, Charles Johnson, Harry F. Johnson, Lewis L. Kehoe, Michael J. Keim, Amandus

  9. TIME TO PREGNANCY IN RELATION TO TOTAL TRIHALOMETHANE LEVELS IN TAP WATER

    EPA Science Inventory

    Time to pregnancy in relation to total trihalomethane levels in tap water
    Shanna H. Swan, Cuirong Ren, Gayle C. Windham, Laura Fenster, Kirsten Waller. (University of Missouri and California Department of Health Services).

    We have previously reported increased risks o...

  10. Brokenhearts: Dissolution of Romantic Relationships.

    ERIC Educational Resources Information Center

    Meeker, F. B.; La Fong, Carl

    Results of an investigation examining the dissolution of romantic relationships are analyzed. Men and women (N=105) who had ended romantic relationships were surveyed in structured individual interviews. Commonalities and differences in respondents' perceptions of the experience were examined. Specific tests were made of a corollary to Waller's…

  11. The Role of Personality in the Selection of a Major: With and without Vocational Self-Efficacy and Interests

    ERIC Educational Resources Information Center

    Larson, Lisa M.; Wu, Tsui Feng; Bailey, Donna C.; Gasser, Courtney E.; Bonitz, Verena S.; Borgen, Fred H.

    2010-01-01

    The purpose of this study is to examine the role of personality traits measured by the Multidimensional Personality Questionnaire (MPQ; [Tellegen, 2000] and [Tellegen and Waller, 2008]) in selecting educational majors. Personality traits were examined alone, and with the combination of Holland's hexagonal confidence domains, as measured by the…

  12. What Doth It Profit? The Study of Mountain Religion.

    ERIC Educational Resources Information Center

    Salstrom, Paul; And Others

    1990-01-01

    Five papers examine mountain religion, focusing on Jeff Todd Titon's book, "Powerhouse of God: Speech, Chant, and Song in an Appalachian Baptist Church." Discussants include Paul Salstrom; Deborah Vansau McCauley; Howard Dorgan; Altina Waller; and Charles T. Davis. Titon responds, explaining his views and study of religion. (TES)

  13. Locating the Extrema of Fungible Regression Weights

    ERIC Educational Resources Information Center

    Waller, Niels G.; Jones, Jeff A.

    2009-01-01

    In a multiple regression analysis with three or more predictors, every set of alternate weights belongs to an infinite class of "fungible weights" (Waller, Psychometrica, "in press") that yields identical "SSE" (sum of squared errors) and R[superscript 2] values. When the R[superscript 2] using the alternate weights is a fixed value, fungible…

  14. Locating the Extrema of Fungible Regression Weights

    ERIC Educational Resources Information Center

    Waller, Niels G.; Jones, Jeff A.

    2009-01-01

    In a multiple regression analysis with three or more predictors, every set of alternate weights belongs to an infinite class of "fungible weights" (Waller, Psychometrica, "in press") that yields identical "SSE" (sum of squared errors) and R[superscript 2] values. When the R[superscript 2] using the alternate weights is a fixed value, fungible…

  15. An experimental investigation of the elastic scattering of He and H 2 from Ag(111)

    NASA Astrophysics Data System (ADS)

    Horne, James M.; Yerkes, Steven C.; Miller, David R.

    1980-03-01

    Experimental diffraction probabilities for 63 meV He and 66 meV H 2 scattering from Ag(111) along the <112¯> direction are reported. Debye-Waller experiments for the He/Ag(111) system yield a mean well depth of 9.3 meV and an effective surface Debye temperature of 253 K.

  16. TIME TO PREGNANCY IN RELATION TO TOTAL TRIHALOMETHANE LEVELS IN TAP WATER

    EPA Science Inventory

    Time to pregnancy in relation to total trihalomethane levels in tap water
    Shanna H. Swan, Cuirong Ren, Gayle C. Windham, Laura Fenster, Kirsten Waller. (University of Missouri and California Department of Health Services).

    We have previously reported increased risks o...

  17. STRAIN COMPARISON IN PREGNANT RATS OF ENDOCRINE RESPONSE TO BROMODICHLOROMETHANE: A DRINKING WATER DISINFECTION BY-PRODUCT

    EPA Science Inventory

    Bromodichloromethane (BDCM), a trihalomethane, is a by-product of the chlorination of drinking water. In an epidemiological study, consumption of drinking water with high levels of BDCM was associated with an increased risk of spontaneous abortion in pregnant women (Waller et al....

  18. Proceedings of the Electronics Manufacturing Seminar (13th Annual) Held at China Lake, California on 1-3 March 1989

    DTIC Science & Technology

    1989-03-01

    123 Daniel Weinberger Santa Barbara Research Center Goleta, CA Lessons Learned from... Barbara M. Waller, Patrick S. Barry, and W. Mike Wolverton Defense Systems and Electronics Group, Texas Instruments, Inc. Dallas, Texas ABSTRACT...121 NWC TP 6986 EMPF TR 0007 LASER ROBOTIC WORK CELL by Daniel Weinberger Program Manager Santa Barbara Research Center Goleta, California ABSTRACT A

  19. Blacks in Pop Music: A Short Story.

    ERIC Educational Resources Information Center

    Rickelman, Melinda

    1991-01-01

    A short history of black pop music includes artists who have changed pop music or culture and highlights from the 1920s into the 1980s, from Fats Waller to Michael Jackson. In black pop music, there is a direct line of influence from the sharecropper to the current Top 40. (SLD)

  20. Radiological Weapons of Terror

    DTIC Science & Technology

    1999-04-01

    The Defense Initiative of the 1990s.” Science Vol. 267, 24 February 1995, p. 1099 32 Waller, Douglas “Nuclear Ninjas ” Time Vol 147, 8 January 1996, p... Ninjas ” Time, Vol 147, 8 January 1996, pp. 38-41 Watson, Dale. “Statement of Dale Watson, Chief, International Terrorism Section, National Security

  1. Effects of Local Artificial Defects in Multifilamentary Coated Conductors With Patterned Links (Postprint)

    DTIC Science & Technology

    2012-02-01

    1994. 18A. P. Zhuravel , A. G. Sivakov, O. G. Turutanov, A. N. Omelyanchouk, S. M. Anlage, A. Lukashenko, A. V. Ustinov, and D. Abraimov, Low Temp...D. C. Larbalestier, A. P. Zhuravel , and A. V. Ustinov, Appl. Phys. Lett. 85, 2568 2004. 21L. B. Wang, G. You, K. R. Barraca, K. Waller, J. M

  2. Blacks in Pop Music: A Short Story.

    ERIC Educational Resources Information Center

    Rickelman, Melinda

    1991-01-01

    A short history of black pop music includes artists who have changed pop music or culture and highlights from the 1920s into the 1980s, from Fats Waller to Michael Jackson. In black pop music, there is a direct line of influence from the sharecropper to the current Top 40. (SLD)

  3. A Phenomenological Model for Circadian and Sleep Allostatic Modulation of Plasma Cortisol Concentration

    DTIC Science & Technology

    2012-09-25

    decreased morning awakening salivary cortisol . Psychoneuroendo- crinology 29: 1184–1191, 2004. 2. Balbo M, Leproult R, Van Cauter E. Impact of sleep and...A phenomenological model for circadian and sleep allostatic modulation of plasma cortisol concentration David Thorsley,1 Rachel Leproult,2,3 Karine...2012 Thorsley D, Leproult R, Spiegel K, Reifman J. A phenomenological model for circadian and sleep allostatic modulation of plasma cortisol

  4. Review of National Work Programme on the Long Term Effects of Sustained High G on the Cervical Spine (Analyse du programme de travail national : les effets long terme sur la colonne cervicale d’un nombre de G lev et prolong )

    DTIC Science & Technology

    2008-12-01

    Prof. Karin Harms-Ringdahl, PhD, RPT Karolinska Institutet Department of Neurobiology, Care Sciences, and Society Division of Physiotherapy 23100...Äng Karolinska Institutet Department of Neurobiology, Care Sciences, and Society Division of Physiotherapy Alfred Nobels Allé 23100 SE-14183...report is in preparation. The RAF has an ongoing project (from August 2006 to September 2007) determining the need for physiotherapy for aircrew on the

  5. Equitable PERSTEMPO - The Challenge for Long-Term Deployed Armed Forces

    DTIC Science & Technology

    2003-04-07

    substantial impact on the operational effectiveness of the Bundeswehr of the future.  Rudolf Scharping Former Federal Minister of Defense The vision...Federal Minister of Defense, Rudolf Scharping, initiated a new force planning by means of the so-called "Cornerstones Paper" on 01 June 2000, the Chief of...Annex 1) 77 Rainer Marr, Timea Biro, and Karin Steiner , Vereinbarkeit von Familie und Beruf des Soldaten – Moeglichkeiten und Grenzen einer

  6. Perspectives on Positioning, Interaction, and Learning in Small-Group Discussion: Possibilities for Extending the Analytic Lens

    ERIC Educational Resources Information Center

    Kittleson, Julie M.; Wilson, Rachel E.

    2014-01-01

    In this forum piece, we respond to Karin Due's study of social dynamics in groups of students in physics class and gender issues that play out in this context. We discuss two threads that appear in Due's paper: one pertains to patterns of talk within groups and how these patterns open up possibilities for learning, the other pertains to…

  7. Bridging Ends to Means: Achieving a Viable Peace in Afghanistan

    DTIC Science & Technology

    2010-04-01

    Afghanistan ‟s social fabric. Analysts, for example, have drawn parallels between Taliban and Lebanon’s Hezbollah, a social and political movement that... Justice in Afghanistan edited by Antonio Donini, Norah Niland and Karin Wermester. Kumarian Press, 2004. United Nation Office on Drugs and Crime...AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY Bridging Ends to Means Achieving a Viable Peace in Afghanistan

  8. Defining "Weapons of Mass Destruction"

    DTIC Science & Technology

    2006-01-01

    Series Editor Stephen D. Carey, Research Associate Sarah L. Carlson, Research Project Specialist Robertson S. Gile, Research Associate Creighton hottinger...adopted February 13, 1947. For a history of the CCA, see Bernhard G. Bechhoefer, Postwar Negotiations for Arms Control (Washington, DC: The...Research Fellow RiChaRD a. Love Research Fellow KaRiN D. LioN Occasional Paper Series Editor Stephen D. Carey, Research Associate Sarah L. Carlson, Research

  9. 2011 AFMS Medical Research Symposium Held in National Harbor, Maryland on August 2-4, 2011. Volume 2: Enroute Care and Expeditionary Medicine Track

    DTIC Science & Technology

    2011-08-01

    Theater Hospital, Ballad Air Base, Iraq. (2006). Perspectives in vascular surgery and endovascular therapy_ 18:2, 91-99 Rasmussen, T., Woodson, J...LeppaniemiA (2002) Vascular Trauma: A 40 year Experience with Extremity Vascular Emphasis. Scandavian Journal of Surgery 91: 109-126, 2002 lHch, NM...Josh Walker Lena Napohlano Molly Tilley StephAn NOI1.h PaulileParl< C•rdlology EducatioriTraining Vascular Surgery Karin Hawkins John Mechtel TOdCI

  10. CPTAC Investigators Discuss Research Insights and Perspectives as part of ASBMB Journal Club - 12 Nov | Office of Cancer Clinical Proteomics Research

    Cancer.gov

    On Wednesday, November 12, 2014 from 2:00 PM to 3:00 PM EST, Daniel Liebler, PhD (Vanderbilt University) and Karin Rodland, PhD (Pacific Northwestern National Laboratory) and Ruedi Aebersold, PhD (Swiss Federal Institute of Technology) will share their research insight as part of the ASBMB Journal Club.  Both Doctors Liebler and Rodland are Principal Investigators in the NCI’s Clinical Proteomic Tumor Analysis Consortium.

  11. 2011 Special Operations Forces Industry Conference

    DTIC Science & Technology

    2011-05-19

    Forces Industry Conference Tampa, FL May 17-19, 2011 Agenda TUESDAY, MAY 17, 2011 BUSINESS OPPORTUNITIES SESSION Small Business and TILO Mrs...00 AM - 9:30 AM Small Business and TILO Ballrooms A-C  mrs. Karin Fones, Program support specialist, technology and Industry...531 Actions • Goal 31% • Achieved 45.6% • Industry Meetings – Hosted 89 Visits • TILO Engagements – FY10: 566 Requests, 115 Events, 1,014

  12. Perspectives on Positioning, Interaction, and Learning in Small-Group Discussion: Possibilities for Extending the Analytic Lens

    ERIC Educational Resources Information Center

    Kittleson, Julie M.; Wilson, Rachel E.

    2014-01-01

    In this forum piece, we respond to Karin Due's study of social dynamics in groups of students in physics class and gender issues that play out in this context. We discuss two threads that appear in Due's paper: one pertains to patterns of talk within groups and how these patterns open up possibilities for learning, the other pertains to…

  13. Case Study: South Texas Veterans Health Care System’s Communication Center

    DTIC Science & Technology

    2008-07-14

    Department Center and School BLDG 2841 MCCS-HFB (Army-Baylor Program in Health and Business Administration) 3151 Scott Road, Suite 1411 Fort Sam Houston...Program in Healthcare and Business Administration, Fort Sam Houston, TX to Andrew M. Welch, MHA, FACHE, Preceptor and Karin Waugh Zucker, MA, JD...noticeable improvement on no-show rates ( Hashim , Franks, & Fiscella, 2001). Telephone reminders are a very effective method of increasing attendance to

  14. Videogame-Based Training Success: The Impact of Trainee Characteristics - Year 2

    DTIC Science & Technology

    2006-07-01

    Technical Report 1188 Videogame -Based Training Success: The Impact of Trainee Characteristics - Year 2 Karin A. Orvis George Mason University...from... to) July2006 Final December 2004-March 2006 4. TITLE AND SUBTITLE 5a. CONTRACT OR GRANT NUMBER Videogame -Based Training Success: The Impact of...Matter POC: James Belanich 14. ABSTRACT (Maximum 200 words): Personal computer (PC)-based videogames are emerging as an increasingly popular training

  15. What is Informal Learning and What are its Antecedents? An Integrative and Meta-Analytic Review

    DTIC Science & Technology

    2014-07-01

    Christopher P. Cerasoli George M. Alliger Jamie S. Donsbach The Group for Organizational Effectiveness John E. Mathieu University of...Christopher P. Cerasoli, George M. Alliger , Jamie S. Donsbach; John E. Mathieu; Scott I. Tannenbaum; Karin A. Orvis 5c. PROJECT NUMBER...What are its Antecedents? An Integrative and Meta-Analytic Review Christopher P. Cerasoli, George M. Alliger Jamie S. Donsbach The Group for

  16. ASBMB Journal Club - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    On Wednesday, November 12, 2014 from 2:00 PM to 3:00 PM EST, Daniel Liebler, PhD (Vanderbilt University) and Karin Rodland, PhD (Pacific Northwestern National Laboratory) and Ruedi Aebersold, PhD (Swiss Federal Institute of Technology) will share their research insight as part of the ASBMB Journal Club.  Both Doctors Liebler and Rodland are Principal Investigators in the NCI’s Clinical Proteomic Tumor Analysis Consortium.

  17. Suppression of fluorescence phonon sideband from nitrogen vacancy centers in diamond nanocrystals by substrate effect.

    PubMed

    Zhao, Hong-Quan; Fujiwara, Masazumi; Takeuchi, Shigeki

    2012-07-02

    Substrates effect is observed on the suppression of the phonon sideband from nitrogen vacancy (NV) centers in 50nm diamond nanocrystals at cryogenic temperatures. As a quantitative parameter of the population of phonon sidebands, the Debye-Waller factor is estimated from fluorescence spectra on glass, silicon, and silica-on-silicon substrates. Fluorescence spectra of negatively charged NV centers in nanodiamonds on silica-on-silicon substrates have average and maximum Debye-Waller factors of 12.7% (which is about six times greater than that of samples on glass substrates) and 19.3%, respectively. This effect is expected to be very important for future applications of NV centers in quantum information science and nanosensing.

  18. In-situ X-ray diffraction studies of the phase transformations and structural states of B2, R and B19′ phases in Ti{sub 49.5}Ni{sub 50.5} alloy

    SciTech Connect

    Ostapenko, Marina G.; Meisner, Ludmila L.; Lotkov, Aleksandr I. Gudimova, Ekaterina Y.; Zakharova, Margarita A.

    2015-10-27

    The martensitic transformation, Debye–Waller factor, mean-square atomic displacements and the coefficient of thermal expansion on cooling of the Ti{sub 49.5}Ni{sub 50.5} shape memory alloy were examined using in-situ X-ray diffraction. It was revealed B2→R (T{sub R} ≡ T = 273 ± 10 K) along with B2→B19’ (M{sub s} ≡ T = 273 ± 10 K) transitions occur. It was found that Debye–Waller factor and mean-square displacement of B2 phase undergo significant increase as functions of temperature when phase transition B2→R and B2→B19’ take place. The analysis of the thermal expansion coefficient of the B2 phase indicates that the value of a increases almost linearly while cooling.

  19. Direct measurement of non-equilibrium phonon occupations in femtosecond laser heated Au films

    NASA Astrophysics Data System (ADS)

    Chase, Tyler; Trigo, Mariano; Reid, Alexander; Li, Renkai; Vecchione, Theodore; Shen, Xiaozhe; Weathersby, Stephen; Coffee, Ryan; Hartmann, Nick; Reis, David; Wang, Xijie; Durr, Hermann

    We use ultrafast electron diffraction to detect the temporal evolution of phonon populations in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. We show from the increase of the diffuse scattering intensity that the population of phonon modes near the X and K points in the Au fcc Brillouin zone grows with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average. We find that thermalization continues within the initially non-equilibrium phonon distribution after 10 ps. The observed momentum dependent timescale of phonon populations is in contrast to what is usually predicted in a two-temperature model.

  20. On the nature of a glassy state of matter in a hydrated protein: Relation to protein function.

    PubMed

    Teeter, M M; Yamano, A; Stec, B; Mohanty, U

    2001-09-25

    Diverse biochemical and biophysical experiments indicate that all proteins, regardless of size or origin, undergo a dynamic transition near 200 K. The cause of this shift in dynamic behavior, termed a "glass transition," and its relation to protein function are important open questions. One explanation postulated for the transition is solidification of correlated motions in proteins below the transition. We verified this conjecture by showing that crambin's radius of gyration (Rg) remains constant below approximately 180 K. We show that both atom position and dynamics of protein and solvent are physically coupled, leading to a novel cooperative state. This glassy state is identified by negative slopes of the Debye-Waller (B) factor vs. temperature. It is composed of multisubstate side chains and solvent. Based on generalization of Adam-Gibbs' notion of a cooperatively rearranging region and decrease of the total entropy with temperature, we calculate the slope of the Debye-Waller factor. The results are in accord with experiment.

  1. Identification of Surface Debye Temperature of an Alkanethiol Self Assembled Monolayer on Au(111) by Low Energy Helium Diffraction

    NASA Astrophysics Data System (ADS)

    West, Joshua; Camillone, Nicholas, III; Schwartz, Peter

    2005-03-01

    Using Low Energy Atomic Diffraction (LEAD), a nonperturbative and totally unpenetrating surface characterization technique, we have conducted measurements on the surface of self assembling monolayers (SAMs) of decanethiol on a Au(111) surface. Debye-Waller attenuation measurements were taken for substrate temperatures from 14.5 K to 110 K. For the lowest substrate temperatures, thermal Debye-Waller attenuation decreased consistent with a surface Debye temperature of about 100 K. The excellent order demonstrated by these particular data provided high resolution to six orders of the hexagonal peak (corresponding to the rt3 x rt3 thiol mesh). These data from higher order diffraction peaks allows us to more precisely measure the lateral thermal vibration of the terminal methyl groups, which is considerably less than previously reported

  2. Predictability Studies Using Adjoint Methods

    DTIC Science & Technology

    2000-09-30

    Hewson, P.H. Hildebrand, D . Jorgensen, R.H. Langland, Y. Lemaitre, P. Mascart, J.A. Moore, P.O.G. Persson, F . Roux, M.A. Shapiro, C. Snyder, Z. Toth...initial-time, leading 40-day SVs were used as proxies for the leading forward Lyapunov vectors (LVs), following Reynolds and Errico (1999). Our focus...data sets and high- level community connectivity for this program. REFERENCES Reynolds, C.A., R. M. Errico , 1999: On the Convergence of Singular

  3. Nanotribology and Nanoscale Friction

    SciTech Connect

    Guo, Yi; Qu, Zhihua; Braiman, Yehuda; Zhang, Zhenyu; Barhen, Jacob

    2008-01-01

    Tribology is the science and technology of contacting solid surfaces in relative motion, including the study of lubricants, lubrication, friction, wear, and bearings. It is estimated that friction and wear cost the U.S. economy 6% of the gross national product (Persson, 2000). For example, 5% of the total energy generated in an automobile engine is lost to frictional resistance. The study of nanoscale friction has a technological impact in reducing energy loss in machines, in microelectromechanical systems (MEMS), and in the development of durable, low-friction surfaces and ultra-thin lubrication films.

  4. Infrared recombination lines of hydrogen from young objects in the southern Galactic plane

    NASA Technical Reports Server (NTRS)

    Beck, Sara C.; Fischer, Jacqueline; Smith, Howard A.

    1991-01-01

    Near infrared recombination lines of hydrogen are observed in twelve young objects in the southern Galactic plane. The sample includes Herbig-Haro objects and IRAS dark-cloud point sources from the 1987 catalog of Persson and Campbell. In four of the IRAS sources two or three infrared lines are measured, and their intensity ratios are consistent with models of optically thick ionized winds. The intrinsic line shapes, retrieved from maximum-entropy deconvolutions, indicate gas velocities of 100 km/s or more as expected from ionized winds. These sources are apparently embedded pre-main-sequence objects with outflows. They include some of the brightest known YSOs.

  5. A search for T Tauri stars and related objects: Archival photometry of candidate variables in V733 Cep field

    NASA Astrophysics Data System (ADS)

    Jurdana-Šepić, R.; Poljančić Beljan, I.

    Searching for T Tauri stars or related early type variables we carried out a BVRI photometric measurements of five candidates with positions within the field of the pre-main sequence object V733 Cephei (Persson's star) located in the dark cloud L1216 near to Cepheus OB3 Association: VES 946, VES 950, NSV 14333, NSV 25966 and V385 Cep. Their magnitudes are determined on the plates from Asiago Observatory historical photographic archive exposed 1971 - 1978. We provide finding charts for program stars and comparison sequence stars, magnitude estimations, magnitude mean values and BVR_cI_c light curves of program stars.

  6. Contact mechanics for poroelastic, fluid-filled media, with application to cartilage.

    PubMed

    Persson, B N J

    2016-12-21

    I study a simple contact mechanics model for a poroelastic, fluid-filled solid squeezed against a rigid, randomly rough substrate. I study how the fluid is squeezed out from the interface, and how the area of contact, and the average interfacial separation, change with time. I present numerical results relevant for a human cartilage. I show that for a fluid filled poroelastic solid the probability of cavitation (and the related wear as the cavities implode), and dynamical scraping (defined below and in Hutt and Persson, J. Chem. Phys. 144, 124903 (2016)), may be suppressed by fluid flow from the poroelastic solid into the (roughness induced) interfacial gap between the solids.

  7. Contact mechanics and rubber friction for randomly rough surfaces with anisotropic statistical properties

    NASA Astrophysics Data System (ADS)

    Carbone, G.; Lorenz, B.; Persson, B. N. J.; Wohlers, A.

    2009-07-01

    In this paper we extend the theory of contact mechanics and rubber friction developed by one of us (B.N.J. Persson, J. Chem. Phys. 115, 3840 (2001)) to the case of surfaces with anisotropic surface roughness. As an application we calculate the viscoelastic contribution to the rubber friction. We show that the friction coefficient may depend significantly on the sliding direction, while the area of contact depends weakly on the sliding direction. We have carried out experiments for rubber blocks sliding on unidirectionally polished steel surfaces. The experimental data are in a good qualitative agreement with the theory.

  8. Human Immunodeficiency Virus (HIV) Infections; Strain and Type Variations; Diagnosis and Prevention.

    DTIC Science & Technology

    1992-10-26

    Thorstensson, R, Chiodi , F, and Norrby, E: Hyperimmune antisera against synthetic peptides representing the glycoprotein of human immunodeficiency virus...Syndr, 5:177-187, 1992. 19. Barbas III, C F, Bj6rling E, Chiodi , F, Dunlop, N, Cababa, D, Jones T M, Zebedee, S L, Persson, M A A, Nara, P L, Norrby E...20. Chiodi , F, Keys, B, Albert, J, Hagberg, L, Lundeberg, J, Uhldn M, Feny6, E M, and Norkrans, G. HIV-1 is present in the cerebrospinal fluid of the

  9. Emerging Trends in the Sea State of the Beaufort and Chukchi Seas

    DTIC Science & Technology

    2016-07-06

    j , Peter Guest k , Ted Maksym l , Peter Wadhams m , Chris Fairall n , o , Ola Persson n , o , Martin Doble p , Hans Graber q , Bjoern Lund r ...Centre for Medium-Range Weather Forecasts, Redding, UK a r t i c l e i n f o Article history: Received 29 September 2015 Revised 18 February 2016...Accepted 29 February 2016 Available online 6 July 2016 Keywords: Sea ice Arctic Ocean Ocean surface waves a b s t r a c t The sea state of the

  10. Detection of the O I 11287 A line in the Seyfert 1 galaxy I ZW 1

    NASA Astrophysics Data System (ADS)

    Rudy, Richard J.; Rossano, George S.; Puetter, R. C.

    1989-07-01

    This paper reports a detection of the infrared 11287 A transition of neutral oxygen in the Seyfert 1 galaxy I Zw 1. The observed strength of the feature is 6.5 x 10 to the -14th erg/sq cm sec. When this value is compared to the flux of O I 8446A measured by Persson and McGregor (1985), the ratio of the photon fluxes is unity, to within the measurement uncertainties. This is a direct confirmation that the broad permitted O I lines observed in Seyfert 1 galaxies and quasars arise through fluorescent excitation by Lyman Beta.

  11. Contact mechanics for poroelastic, fluid-filled media, with application to cartilage

    NASA Astrophysics Data System (ADS)

    Persson, B. N. J.

    2016-12-01

    I study a simple contact mechanics model for a poroelastic, fluid-filled solid squeezed against a rigid, randomly rough substrate. I study how the fluid is squeezed out from the interface, and how the area of contact, and the average interfacial separation, change with time. I present numerical results relevant for a human cartilage. I show that for a fluid filled poroelastic solid the probability of cavitation (and the related wear as the cavities implode), and dynamical scraping (defined below and in Hutt and Persson, J. Chem. Phys. 144, 124903 (2016)), may be suppressed by fluid flow from the poroelastic solid into the (roughness induced) interfacial gap between the solids.

  12. Infrared recombination lines of hydrogen from young objects in the southern Galactic plane

    NASA Technical Reports Server (NTRS)

    Beck, Sara C.; Fischer, Jacqueline; Smith, Howard A.

    1991-01-01

    Near infrared recombination lines of hydrogen are observed in twelve young objects in the southern Galactic plane. The sample includes Herbig-Haro objects and IRAS dark-cloud point sources from the 1987 catalog of Persson and Campbell. In four of the IRAS sources two or three infrared lines are measured, and their intensity ratios are consistent with models of optically thick ionized winds. The intrinsic line shapes, retrieved from maximum-entropy deconvolutions, indicate gas velocities of 100 km/s or more as expected from ionized winds. These sources are apparently embedded pre-main-sequence objects with outflows. They include some of the brightest known YSOs.

  13. Effective Hamiltonian for a microwave billiard with attached waveguide.

    PubMed

    Stöckmann, H-J; Persson, E; Kim, Y-H; Barth, M; Kuhl, U; Rotter, I

    2002-06-01

    In a recent work the resonance widths in a microwave billiard with attached waveguide were studied in dependence on the coupling strength [E. Persson et al., Phys. Rev. Lett. 85, 2478 (2000)], and resonance trapping was experimentally found. In the present paper an effective Hamiltonian is derived that depends exclusively on billiard and waveguide geometry. Its eigenvalues give the poles of the scattering matrix provided that the system and environment are defined adequately. Further, we present the results of resonance trapping measurements where, in addition to our previous work, the position of the slit aperture within the waveguide was varied. Numerical simulations with the derived Hamiltonian qualitatively reproduce the experimental data.

  14. Proceedings of the Annual Electronics Manufacturing Seminar (12th) Held in China Lake, California on 17-19 February 1988

    DTIC Science & Technology

    1988-02-01

    and edentify by block number) FIELD GROUP SUB-GROUP Aging effects Automated inspection 09 01 Artificial intelligence Cleaning 3 05/08 Automated cleaning...Assistant Secretary of the Navy for Shipbuilding and Logistics Washington, DC Artificial Intelligence in the Manufacturing Environment: Expert...Measuring Solderabitity, Connection Technology , February 1987 Fenawire, D.L.; Wolverton, W.M.; Spitz, D .; Burkett, A.; Russell, W.; and Waller, B

  15. Water-level altitudes in the Jasper Aquifer, greater Houston area, Texas, January-February 2001

    USGS Publications Warehouse

    Coplin, L.S.; Lanning-Rush, Jennifer

    2002-01-01

    This report, prepared in cooperation with the Harris-Galveston Coastal Subsidence District, is the second annual report that depicts water-level altitudes in the Jasper aquifer in the greater Houston area (Montgomery County and parts of Harris, Grimes, Walker, and Waller Counties). The first water-level-altitude map for the Jasper aquifer in the area published by the U.S. Geological Survey (Coplin, 2001) depicts water levels in wells measured in spring 2000.

  16. Water-level altitudes in wells completed in the Jasper aquifer, greater Houston area, Texas, Spring 2000

    USGS Publications Warehouse

    Coplin, L.S.

    2001-01-01

    This report, prepared in cooperation with the Harris-Galveston Coastal Subsidence District, presents a map showing the approximate water-level altitudes in spring 2000 in wells completed in the Jasper aquifer (back of page). The most recent previously published water-level-altitude map for the Jasper aquifer in the region is by Popkin (1971). The study area includes Montgomery County and parts of Harris, Waller, Grimes, and Walker Counties.

  17. Fictitious sources in X-ray optics of defect crystals

    SciTech Connect

    Punegov, V.I.; Yurkin, V.M.

    1994-11-01

    Using the formalism of fictitious sources, X-ray Laue diffraction in a wedge-shaped defect crystal is analyzed. Expressions for the aperture and period of interference are obtained. These parameters are shown to depend on the degree of perfection (the static Debye-Waller factor) of a periodic structure. A criterion for the interference pattern contrast with allowance for coherently and diffusely scattered intensity is given. 5 refs., 2 figs.

  18. The History of the U.S. Coast Guard’s Deepwater Program and Evolution of the Acquisions Directorate

    DTIC Science & Technology

    2014-12-15

    3013233PCA009 LT Kevin Hertzler, USCG LT Brian Waller, USCG Dr. Syed Adeel Ahmed University of New Orleans, College of Engineering 2000 Lakeshore...Drive New Orleans, LA 70148 USCG Deputy Commandant of Mission Support Mary Fuata 2703 Martin Luther King AVE SE Washington DC 20593 DCMS-81...ownership of modernization, later referred to as fleet recapitalization. The Coast Guard created the Acquisitions Directorate (CG-9) which was a new

  19. Diffuse inelastic scattering of atoms from surfaces

    SciTech Connect

    Manson, J.R.; Celli, V.

    1989-02-15

    We consider the large-angle diffuse scattering of thermal-energy atoms by defects or adsorbates on a surface. We obtain the Debye-Waller factor for the thermal attenuation of the incoherent elastic peak. When the Debye exponent is small, the diffuse inelastic contribution is dominated by the single-phonon exchange, and is proportional to the frequency distribution function of the defect or adsorbate. We discuss its magnitude compared to the multiphonon background.

  20. Technical Communication--Taking the User into Account.

    DTIC Science & Technology

    1981-08-01

    performance task is Influenced by media formats which differed in design according to the Educational Cognitive Style (ECS) preference of the user/reader...individual and the variables influencing him/her as an active processor of information (Waller, 1977). If we are to understand and facilitate...Technical Communications distinctive modes of apprehending, storing, transforming, and using information. As such, their influence extends to a variety

  1. Massachusetts Institute of Technology Defense and Arms Control Studies Program

    DTIC Science & Technology

    1995-01-01

    the 1995 General James H. Doolittle dinner and workshop, an event DACS cosponsored with the Olin Institute of Strategic Studies at Harvard and the...several prominent analysts of the war participated in the all day event which was held on April 19, 1995. Our keynote speakers were Lieutenant General...Calvin Waller, who was General Schwartzkoff’s deputy, and Lieutenant General Thomas Kelly, who was head of operations on the Joint Staff during the war

  2. Structural Studies on Varicella Zoster Virus

    DTIC Science & Technology

    1990-08-20

    syndromes, varicella or chickenpox and zoster or shingles (Waller and Stoddard, 1952) . The name "varicella" is derived from "variola" (for smallpox...the trunk. "Shingles" is derived from the equivalent latin verb "cingere" while " chickenpox " may be from the old English word "glean" - "itch...history of infectious disease, there has been confusion between smallpox and chickenpox (not helped by some of the nomenclature discussed above). Now

  3. Electron energy loss spectroscopy equation for spectra with overlapping oscillations and its solution by a regularization method

    NASA Astrophysics Data System (ADS)

    Olga, Nemtsova; Bakieva, Olga

    2016-02-01

    The integral equation of EELFS spectra with the overlapping oscillations for two-component systems is proposed. To solve this equation Tikhonov's regularization method with the iterative procedure is applied. The atomic pair correlation functions of the investigated objects are obtained from the experimental EELFS spectra of Cu50Ni50 and Cu50Mn50 alloys by using Tikhonov's regularization method. The experimental results agree well with the known crystallographic data (partial interatomic distances, coordination numbers and Debye-Waller factors).

  4. Entropically Stabilized Local Dipole Formation in Lead Chalcogenides

    DTIC Science & Technology

    2010-12-17

    structural modulations are helpful in produc- ing low thermal conductivity and, therefore, high thermoelectric figures of merit (4, 8). Such studies...Waller effects (12) from increased thermal motion; however, the extent of the changes is extraordinarily large. In Fig. 1, D and E, we show the PDFs at 15...like that in ferroelectrically distorted lone-pair–active Pb2+ compounds such as PbTiO3 (14). The off-centered ions are disordered 1Condensed Matter

  5. Estimation and Specification Error in Item Response Theory.

    DTIC Science & Technology

    1983-10-01

    of Educational Psychology Chicago, IL 60611 210 Education Bldg. University of Illinois 1 Mr. Robert McKinley Champaign, IL 61801 American College...Waller Department of Educational Psychology University of Wisconsin—Milwaukee Milwaukee, WI 53201 1 Dr. Brian Waters HumRRO 300 North Washington...Bonn 2 WEST GERMANY 1 Dr. Bruce Williams Department of Educational Psychology University of Illinois Urbana, IL 61801 1 Dr. Wendy Yen CTB/McGraw

  6. The structure of nickel and indium oxide thin films from EXAFS data

    NASA Astrophysics Data System (ADS)

    Bets, V.; Zamozdiks, T.; Lusis, A.; Purans, J.; Bausk, N.; Sheromov, M.

    1987-11-01

    The structure of nickel oxide and indium oxide doped by tin films prepared by reactive magnetron sputtering has been studied by the EXAFS method. It has been found that the nickel oxide thin film has a microcrystalline structure with significant disorder proved by the increase of the Debye-Waller factor and the sharp decrease of peak amplitudes. The indium oxide thin film has a noticeable structural disorder due to 8% tin dopping.

  7. Earth observation taken by the Expedition 28 crew

    NASA Image and Video Library

    2011-09-08

    ISS028-E-045031 (8 Sept. 2011) --- This panoramic view of Texas, the Gulf of Mexico and surrounding area was photographed by one of the Expedition 28 crew members aboard the International Space Station. Big smoke near the Red River is from the Magnolia/Longview complex of fires; the fire just northwest of Houston (right center) is the Waller fire. A great deal of thicker smoke haze can be spotted coming from indeterminate sources.

  8. Novel Osteoinductive Photo-cross-linkable Chitosan-lactide-fibrinogen Hydrogels Enhance Bone Regeneration in Critical Size Segmental Bone Defects

    DTIC Science & Technology

    2014-08-01

    the elasticity of the co- polymer networks , due to the effect of intermolecular hydrogen bonds between hydroxyl and amino groups of chitosan -lactide...4563-8. 22. Jiang B, Waller TM, Larson JC, Appel AA, Brey EM. Fibrin-loaded porous poly ( ethylene glycol ) hydrogels as scaffold materials for...and properties of a pH/temperature-responsive carboxymethyl chitosan / poly (N-isopropylacrylamide) semi -IPN hydrogel for oral delivery of drugs

  9. Air Traffic Controller Scanning and Eye Movements in Search of Information - A Literature Review

    DTIC Science & Technology

    1989-03-01

    The second category has been referred to as point of regard or point of gaze measurement. This includes photographic methods and oculometric methods...altitude and rates of response (i.e., turn rate). This was a very small sample study involving only seven test pilots. The oculometric data could not only...altitude. Using the oculometric data led Waller et al. (1982) to conclude that when you allow an operator a choice of informa-t-i-on sources you may

  10. [G. Baglivi and scientific European community between rationalism and enlightenment].

    PubMed

    Toscano, A

    2000-01-01

    The Baglivi Correspondence, kept in the Waller Collection at the University Library of Uppsala, has been published in Italy for the first time in 1999. This Correspondence kept in Sweden provides new information about the scientific Italian culture between the second half of the seventeenth century and the beginning of the eighteenth. Moreover, it provides important knowledge on the diffusion the Baglivi's work in the scientific European context at that time.

  11. Concept Mapping in Strategy-Based Technical Instruction: Impact on Text Recall and Procedural Performance

    DTIC Science & Technology

    1990-07-01

    Armbruster & Anderson, 1984; Dansereau, et al., 1979; Holley et al., 1979; Novak & Gowin , 1984). Little is known however about whether the efficacy of...In T. M. Duffy, & R. Waller, (Eds.), Designing usable texts. Orlando, FL: Academic Press, 179-212. Lambiotte, J. G., Dansereau, D. F., Hythecker, V . I...Manuscript under editorial review. Larson, C. 0., Dansereau, D. F., Hythecker, V . I., O’Donnell, A. M., Young, M. D., Lambiotte, J. G., & Rocklin, T. R

  12. Long-Term Performance Analysis of GIOVE Clocks

    DTIC Science & Technology

    2010-11-01

    Francisco Gonzalez, Stefano Binda European Space Agency, ESA- ESTEC , Noordwijk , The Netherlands pierre.waller@esa.int Daniel Rodriguez, Guillermo...ADDRESS(ES) European Space Agency, ESA- ESTEC , Noordwijk , The Netherlands 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME...European Frequency and Time Forum (EFTF), 13-16 April 2010, Noordwijk , The Netherlands. [6] J. Camparo, 2004, “Frequency Equilibration and the Light

  13. The Victims of Terrorism: An Assessment of Their Influence and Growing Role in Policy, Legislation, and the Private Sector

    DTIC Science & Technology

    2007-01-01

    provides families in the New York area with tickets to sporting and cultural events in addition to sponsoring mentoring programs that include...Arabic language, religion, and culture (GJG, undated). Much of GJG’s research is outsourced to the Mann and Mairone Group, a subset of the Chicago...French Passenger Jet Bombing,” 2004). The UK Bali Bombing Victims Group, led by Jocelyn Waller, who lost her son in the 2002 nightclub bombings, has

  14. Complexity: A Cognitive Barrier to Defense Systems Acquisition Management

    DTIC Science & Technology

    2001-01-01

    observer’s role was central to America’s preeminent nine- teenth century philosopher, Charles Sand- ers Peirce , who wrote about the triadic relationship...science education even today. The ideas of Boscovich and Peirce re- garding the role of the observer resurfaced with the emergence of systems science...simultaneously is well known (Waller, 1982; Miller, 1956; Simon , 1974; Warfield, 1988). The tendency is to underconceptualize interrelationships, thereby

  15. "small problems, Big Trouble": An Art and Science Collaborative Exhibition Reflecting Seemingly small problems Leading to Big Threats

    NASA Astrophysics Data System (ADS)

    Waller, J. L.; Brey, J. A.

    2014-12-01

    "small problems, Big Trouble" (spBT) is an exhibition of artist Judith Waller's paintings accompanied by text panels written by Earth scientist Dr. James A. Brey and several science researchers and educators. The text panels' message is as much the focus of the show as the art--true interdisciplinarity! Waller and Brey's history of art and earth science collaborations include the successful exhibition "Layers: Places in Peril". New in spBT is extended collaboration with other scientists in order to create awareness of geoscience and other subjects (i.e. soil, parasites, dust, pollutants, invasive species, carbon, ground water contaminants, solar wind) small in scale which pose significant threats. The paintings are the size of a mirror, a symbol suggesting the problems depicted are those we increasingly need to face, noting our collective reflections of shared current and future reality. Naturalistic rendering and abstract form in the art helps reach a broad audience including those familiar with art and those familiar with science. The goal is that gallery visitors gain greater appreciation and understanding of both—and of the sober content of the show as a whole. "small problems, Big Trouble" premiers in Wisconsin April, 2015. As in previous collaborations, Waller and Brey actively utilize art and science (specifically geoscience) as an educational vehicle for active student learning. Planned are interdisciplinary university and area high school activities linked through spBT. The exhibition in a public gallery offers a means to enhance community awareness of and action on scientific issues through art's power to engage people on an emotional level. This AGU presentation includes a description of past Waller and Brey activities: incorporating art and earth science in lab and studio classrooms, producing gallery and museum exhibitions and delivering workshops and other presentations. They also describe how walking the paths of several past earth science

  16. Adhesive contact of randomly rough surfaces

    NASA Astrophysics Data System (ADS)

    Pastewka, Lars; Robbins, Mark

    2012-02-01

    The contact area, stiffness and adhesion between rigid, randomly rough surfaces and elastic substrates is studied using molecular statics and continuum simulations. The surfaces are self-affine with Hurst exponent 0.3 to 0.8 and different short λs and long λL wavelength cutoffs. The rms surface slope and the range and strength of the adhesive potential are also varied. For parameters typical of most solids, the effect of adhesion decreases as the ratio λL/λs increases. In particular, the pull-off force decreases to zero and the area of contact Ac becomes linear in the applied load L. A simple scaling argument is developed that describes the increase in the ratio Ac/L with increasing adhesion and a corresponding increase in the contact stiffness [1]. The argument also predicts a crossover to finite contact area at zero load when surfaces are exceptionally smooth or the ratio of surface tension to bulk modulus is unusually large, as for elastomers. Results that test this prediction will be presented and related to the Maugis-Dugdale [2] theories for individual asperities and the more recent scaling theory of Persson [3]. [1] Akarapu, Sharp, Robbins, Phys. Rev. Lett. 106, 204301 (2011) [2] Maugis, J. Colloid Interface Sci. 150, 243 (1992) [3] Persson, Phys. Rev. Lett. 74, 75420 (2006)

  17. Molecular dynamics study of contact mechanics: contact area and interfacial separation from small to full contact

    NASA Astrophysics Data System (ADS)

    Yang, Chunyan; Persson, Bo

    2008-03-01

    We report a molecular dynamics study of the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. We study the contact area and the interfacial separation from small contact (low load) to full contact (high load). For small load the contact area varies linearly with the load and the interfacial separation depends logarithmically on the load [1-4]. For high load the contact area approaches to the nominal contact area (i.e., complete contact), and the interfacial separation approaches to zero. The present results may be very important for soft solids, e.g., rubber, or for very smooth surfaces, where complete contact can be reached at moderate high loads without plastic deformation of the solids. References: [1] C. Yang and B.N.J. Persson, arXiv:0710.0276, (to appear in Phys. Rev. Lett.) [2] B.N.J. Persson, Phys. Rev. Lett. 99, 125502 (2007) [3] L. Pei, S. Hyun, J.F. Molinari and M.O. Robbins, J. Mech. Phys. Sol. 53, 2385 (2005) [4] M. Benz, K.J. Rosenberg, E.J. Kramer and J.N. Israelachvili, J. Phy. Chem. B.110, 11884 (2006)

  18. The Issues of Freedom and Happiness in Moral Bioenhancement: Continuing the Debate With a Reply to Harris Wiseman.

    PubMed

    Rakić, Vojin

    2017-10-05

    During the previous years, Harris Wiseman has devoted substantial attention to my stance on voluntary moral bioenhancement. He argued that he has been influenced by that position, but nonetheless criticized it. I haven't replied to his criticisms yet and wish to do so now. One of the reasons is to avoid my position being misrepresented. By replying to Wiseman's criticisms, I also wish to clarify those issues in my standpoint that might have given rise to some of the misinterpretations. With the same purpose in mind, I will demarcate my concept of voluntary moral bioenhancement from related standpoints, in particular from Persson and Savulescu's notion of compulsory moral bioenhancement that, as I argued, diminishes our freedom (of the will). Furthermore, I will consider the possibility of adding another essential element to my position-one that I have not discussed in my earlier publications. It is designed to propose a novel explanation of why humans would be motivated to opt for voluntary moral bioenhancement if its outcome is not a lowering of the likelihood of "Ultimate Harm" (as defined by Persson and Savulescu) or a milder form of self-destruction of humanity. This explanation will be based on the conception that an increase in happiness, rather than Ultimate Harm prevention, might be the grounding rationale for moral bioenhancement.

  19. The Misfortunes of Moral Enhancement.

    PubMed

    Azevedo, Marco Antonio

    2016-10-01

    In Unfit for the Future, Ingmar Persson and Julian Savulescu present a sophisticated argument in defense of the imperative of moral enhancement. They claim that without moral enhancement, the future of humanity is seriously compromised. The possibility of ultimate harm, caused by a dreadful terrorist attack or by a final unpreventable escalation of the present environmental crisis aggravated by the availability of cognitive enhancement, makes moral enhancement a top priority. It may be considered optimistic to think that our present moral capabilities can be successfully improved by means of moral education, moral persuasion, and fear of punishment. So, without moral enhancement, drastic restrictions on human freedom would become the only alternative to prevent those dramatic potential outcomes. In this article, I will try to show that we still have reason to be less pessimistic and that Persson & Savulescu's arguments are fortunately unconvincing. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Regulation of the Prostate Cancer Tumor Microenvironment

    DTIC Science & Technology

    2015-04-01

    Science 317(5834), 124-127 (2007). 7. Naugler, W.E., Sakurai, T., Kim , S., Maeda, S., Kim , K., Elsharkawy, A.M., Karin, M. Gender disparity in liver...Elizabeth M. Peek ,1 Wang Song,2 Hanwei Zhang,3 Jiaoti Huang,4 and Arnold I. Chin1,3,5,6* 1Molecular Biology Institute, UCLA, Los Angeles, California...M. Peek and Wang Song made an equal contribution to this manuscript. The authors have nothing to disclose. Correspondence to: Arnold I. Chin, MD

  1. Radiation-Induced Immune Modulation in Prostate Cancer

    DTIC Science & Technology

    2006-01-01

    Research Society, Denver, CO, 2004. Dörthe Schaue, Yu-Pei Liao, Begonya Comin-Anduix, Antoni Ribas , Annelies Debucquoy, Karin Haustermans, and William H...Submitted, 2006. Schaue, D., Y. Liao, B. Comin-Anduix, A. Ribas , D.C. Altieri, A. Debucquoy, K. Haustermans and W.H. McBride: The Effect of Radiation...Comin-Anduix, A. Ribas , D.C. Altieri, A. Debucquoy, K. Haustermans and W.H. McBride: The Effect of Radiation Therapy on Tumor-Specific Immune Responses

  2. The Role of NF-kB in Normal and Transformed Mammary Epithelium.

    DTIC Science & Technology

    1998-08-01

    aAN has been constructed by standard molecular cloning techniques. The plasmid is called pBLG-AN. The avian IiB- aAN has been used successfully in...Mercurio, F., DiDonato, J., Rosette, C., and Karin, M. 1992. Molecular cloning and characterization of a novel Rel/NF-id3 family member displaying...reaching a peak during lactation. Using Dr. Clark’s pBJ41 construct, a transgene bearing the human NFKB2 cDNA has been constructed by standard molecular

  3. Order parameters from image analysis: a honeycomb example

    NASA Astrophysics Data System (ADS)

    Kaatz, Forrest H.; Bultheel, Adhemar; Egami, Takeshi

    2008-11-01

    Honeybee combs have aroused interest in the ability of honeybees to form regular hexagonal geometric constructs since ancient times. Here we use a real space technique based on the pair distribution function (PDF) and radial distribution function (RDF), and a reciprocal space method utilizing the Debye-Waller Factor (DWF) to quantify the order for a range of honeycombs made by Apis mellifera ligustica. The PDFs and RDFs are fit with a series of Gaussian curves. We characterize the order in the honeycomb using a real space order parameter, OP 3 , to describe the order in the combs and a two-dimensional Fourier transform from which a Debye-Waller order parameter, u, is derived. Both OP 3 and u take values from [0, 1] where the value one represents perfect order. The analyzed combs have values of OP 3 from 0.33 to 0.60 and values of u from 0.59 to 0.69. RDF fits of honeycomb histograms show that naturally made comb can be crystalline in a 2D ordered structural sense, yet is more ‘liquid-like’ than cells made on ‘foundation’ wax. We show that with the assistance of man-made foundation wax, honeybees can manufacture highly ordered arrays of hexagonal cells. This is the first description of honeycomb utilizing the Debye-Waller Factor, and provides a complete analysis of the order in comb from a real-space order parameter and a reciprocal space order parameter. It is noted that the techniques used are general in nature and could be applied to any digital photograph of an ordered array.

  4. Communication: Relationship between solute localization and diffusion in a dynamically constrained polymer system

    NASA Astrophysics Data System (ADS)

    Saylor, David M.; Jawahery, Sudi; Silverstein, Joshua S.; Forrey, Christopher

    2016-07-01

    We investigate the link between dynamic localization, characterized by the Debye-Waller factor, , and solute self-diffusivity, D, in a polymer system using atomistic molecular dynamics simulations and vapor sorption experiments. We find a linear relationship between lnD and 1/ over more than four decades of D, encompassing most of the glass formation regime. The observed linearity is consistent with the Langevin dynamics in a periodically varying potential field and may offer a means to rapidly assess diffusion based on the characterization of dynamic localization.

  5. Vibrational, optical and structural studies of an amorphous Se(0.90)S(0.10) alloy produced by mechanical alloying.

    PubMed

    Machado, K D; Sanchez, D F; Maciel, G A; Brunatto, S F; Mangrich, A S; Stolf, S F

    2009-05-13

    The local atomic order of an amorphous Se(0.90)S(0.10) alloy produced by mechanical alloying was studied by x-ray diffraction and extended x-ray absorption fine structure (EXAFS) data obtained at three temperatures, T = 300, 200 and 30 K. From the cumulant analysis of the EXAFS data, structural properties such as average interatomic distances, average coordination numbers, Debye-Waller factors and anharmonicity, given by the third cumulant, were obtained. The results found indicate that there is alloying at an atomic level, and Se-S pairs are more disordered and distorted than Se-Se ones due to the milling process.

  6. Atom scattering from surface Einstein modes

    SciTech Connect

    Manson, J.R.

    1988-04-15

    We consider the scattering of thermal-energy atoms by a surface with a dilute coverage of adsorbates having a dispersionless Einstein vibrational mode. We show that the diffuse elastic scattered intensity has a Debye-Waller-type thermal attenuation only at low temperatures, and at large temperatures the attenuation saturates to a much weaker form. Similar thermal attenuation behavior occurs for the diffuse inelastic intensities. For an ordered adsorbate layer there is also a diffuse elastic intensity which increases with temperature at small temperatures.

  7. The material dependence of temperature measurement resolution in thermal scanning electron microscopy

    SciTech Connect

    Wu, Xiaowei; Hull, Robert

    2013-03-18

    Thermal scanning electron microscopy is a recently developed temperature mapping technique based on thermal diffuse scattering in electron backscatter diffraction in a scanning electron microscope. It provides nano-scale and non-contact temperature mapping capabilities. Due to the specific temperature sensitive mechanism inherent to this technique, the temperature resolution is highly material dependent. A thorough investigation of what material properties affect the temperature resolution is important for realizing the inherent temperature resolution limit for each material. In this paper, three material dependent parameters-the Debye-Waller B-factor temperature sensitivity, backscatter yield, and lattice constant-are shown to control the temperature resolution.

  8. Coverage-dependent quantum versus classical scattering of thermal neon atoms from Li/Cu(100).

    PubMed

    Maclaren, D A; Huang, C; Levi, A C; Allison, W

    2008-09-07

    We show that subtle variations in surface structure can enhance quantum scattering and quench atom-surface energy transfer. The scattering of thermal energy neon atoms from a lithium overlayer on a copper substrate switches between a classical regime, dominated by multiphonon interactions, and a quantum regime, dominated by elastic diffraction. The transition is achieved by simple tailoring of the lithium coverage and quantum scattering dominates only in the narrow coverage range of theta=0.3-0.6 ML. The results are described qualitatively using a modified Debye-Waller model that incorporates an approximate quantum treatment of the adsorbate-substrate vibration.

  9. Local structural study of doped-ceria by EXAFS spectroscopy

    SciTech Connect

    Shirbhate, S. C.; Acharya, S. A.; Yadav, A. K.; Sagdeo, A. P.; Jha, S. N.

    2016-05-23

    In the present work, Structural and Local structural study of Sm, Gd doped and Sm-Gd co-doped ceria system has been studied by Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). These ceria based systems are synthesized by hydrothermal synthesis route. Fluorite structure is confirmed by X-ray diffraction (XRD) and data is well fitted using Rietveld refinement by Full-Prof suite. Local structural changes in terms of coordination with surrounding, inter atomic distances and Debye Waller factor of nearest neighbor and next nearest neighbor has been discussed.

  10. Disorder and complexity in the atomic structure of the perfect icosahedral alloy of Al-Pd-Mn

    SciTech Connect

    de Boissieu, M.; Stephens, P. ); Boudard, M.; Janot, C. ); Chapman, D.L. ); Audier, M. )

    1994-05-30

    The atomic structure of the perfect Al-Pd-Mn icosahedral phase has been studied on single grain samples. Using anomalous x-ray diffraction close to the Pd edge, the partial structure factor [ital F][sub Pd] has been extracted. In the six-dimensional description of its structure, we find that the atomic surface cannot be described by an object with a sharp boundary. A phason Debye-Waller term has been introduced to fully account for the data. It is interpreted as resulting from random phason disorder and nonsphericity of the atomic surfaces.

  11. The Impact of the Defense Industry Consolidation on the Aerospace Industry

    DTIC Science & Technology

    2006-03-01

    Markets, School of Economics, University of Nottingham, May 2000. 9. Demski, Joel S. and Robert P. Magee. “A Perspective on Accounting for Defense...Takuji. “What Do the Purified Solow Residuals Tell Us about Japan’s Lost Decade?” Monetary and Economic Studies: 113-148 (February 2005). 26. Kim... Robert E. Waller. “Consolidation of the U.S. Defense Industrial Base: Impact on Research Expenditures,” Acquisition Review Quarterly, 9: 143-150 (Spring

  12. Quasi-elastic neutron scattering studies of protein dynamics

    SciTech Connect

    Rorschach, H.E.

    1993-05-25

    Results that shed new light on the study of protein dynamics were obtained by quasi-elastic neutron scattering. The triple axis instrument H-9 supplied by the cold source was used to perform a detailed study of the quasi-elastic spectrum and the Debye-Waller factor for trypsin in powder form, in solution, and in crystals. A preliminary study of myoglobin crystals was also done. A new way to view the results of quasi-elastic scattering experiments is sketched, and the data on trypsin are presented and analyze according to this new picture.

  13. Quasi-elastic neutron scattering studies of protein dynamics. Progress report, November 1, 1992--May 25, 1993

    SciTech Connect

    Rorschach, H.E.

    1993-05-25

    Results that shed new light on the study of protein dynamics were obtained by quasi-elastic neutron scattering. The triple axis instrument H-9 supplied by the cold source was used to perform a detailed study of the quasi-elastic spectrum and the Debye-Waller factor for trypsin in powder form, in solution, and in crystals. A preliminary study of myoglobin crystals was also done. A new way to view the results of quasi-elastic scattering experiments is sketched, and the data on trypsin are presented and analyze according to this new picture.

  14. Local structural study of doped-ceria by EXAFS spectroscopy

    NASA Astrophysics Data System (ADS)

    Shirbhate, S. C.; Yadav, A. K.; Acharya, S. A.; Sagdeo, A. P.; Jha, S. N.

    2016-05-01

    In the present work, Structural and Local structural study of Sm, Gd doped and Sm-Gd co-doped ceria system has been studied by Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). These ceria based systems are synthesized by hydrothermal synthesis route. Fluorite structure is confirmed by X-ray diffraction (XRD) and data is well fitted using Rietveld refinement by Full-Prof suite. Local structural changes in terms of coordination with surrounding, inter atomic distances and Debye Waller factor of nearest neighbor and next nearest neighbor has been discussed.

  15. Review of the highlights of X-ray studies of liquid metal surfaces

    SciTech Connect

    Pershan, P. S.

    2014-12-14

    X-ray studies of the interface between liquid metals and their coexisting vapor are reviewed. After a brief discussion of the few elemental liquid metals for which the surface Debye-Waller effect is sufficiently weak to allow measurement, this paper will go on to discuss the various types of surface phenomena that have been observed for liquid metal alloys. These include surface adsorption, surface freezing, surface aggregation of nm size atomic clusters, and surface chemistry that leads to new 3D crystalline phases.

  16. Slow Wave Conduction Patterns in the Stomach: From Waller’s Foundations to Current Challenges

    PubMed Central

    2015-01-01

    This review provides an overview of our understanding of motility and slow wave propagation in the stomach. It begins by reviewing seminal studies conducted by Walter Cannon and Augustus Waller on in vivo motility and slow wave patterns. Then our current understanding of slow wave patterns in common laboratory animals and humans is presented. The implications of slow wave dysrhythmic patterns that have been recorded in animals and patients suffering from gastroparesis are discussed. Finally, current challenges in experimental methods and techniques, slow wave modulation and the use of mathematical models are discussed. PMID:25313679

  17. Electron-Ion Equilibration in Ultrafast Heated Graphite

    NASA Astrophysics Data System (ADS)

    White, T. G.; Hartley, N. J.; Borm, B.; Crowley, B. J. B.; Harris, J. W. O.; Hochhaus, D. C.; Kaempfer, T.; Li, K.; Neumayer, P.; Pattison, L. K.; Pfeifer, F.; Richardson, S.; Robinson, A. P. L.; Uschmann, I.; Gregori, G.

    2014-04-01

    We have employed fast electrons produced by intense laser illumination to isochorically heat thermal electrons in solid density carbon to temperatures of ˜10 000 K. Using time-resolved x-ray diffraction, the temperature evolution of the lattice ions is obtained through the Debye-Waller effect, and this directly relates to the electron-ion equilibration rate. This is shown to be considerably lower than predicted from ideal plasma models. We attribute this to strong ion coupling screening the electron-ion interaction.

  18. Making babies without sex: the law and the profits.

    PubMed

    Annas, G J

    1984-12-01

    The author reviews scientific and societal developments in artificial reproductive technologies during the past year in the U.S., the United Kingdom, and Australia. Successful births resulted from surrogate embryo transfer and from transfer of an embryo following in vivo fertilization. Recommendations on social policy were made by Australia's Waller Committee, Britain's Warnock Committee, and U.S. congressional hearings. Annas stresses the need to define parenthood and restrict commercialization of childbearing through the enactment of legislation, the promulgation of guidelines for sound clinical practice, and the establishment of an interdisciplinary body to monitor developments and the need for further regulation.

  19. Procurements by the Non-Acoustic Anti-Submarine Warfare Program Through the Environmental Technologies Laboratory

    DTIC Science & Technology

    1994-06-14

    Audit Program Director, (703) 692-3179 (DSN 222-3179), or Ms. Kimberley A. Caprio , Audit Project Manager, (703) 692-3024 (DSN 222-3024). Copies of the...LITY. ASN (RD&AVO IAFX &A DEPUTYr ASS ISTANV SECRE’TAY OF TE9E Allh FORCE (CONTFOAC.TIN1) , SAF/AQC DI ±T rPHOC.IrJTýfl4Ew T LICY. AS!-, RMi1 I.,70 SAZWI...Stephenson Kimberley A. Caprio Stephanie F. Mandel Ira C. Gebler Lisa M. Waller Velma L. Booker

  20. Communication: Relationship between solute localization and diffusion in a dynamically constrained polymer system.

    PubMed

    Saylor, David M; Jawahery, Sudi; Silverstein, Joshua S; Forrey, Christopher

    2016-07-21

    We investigate the link between dynamic localization, characterized by the Debye-Waller factor, 〈u(2)〉, and solute self-diffusivity, D, in a polymer system using atomistic molecular dynamics simulations and vapor sorption experiments. We find a linear relationship between lnD and 1/〈u(2)〉 over more than four decades of D, encompassing most of the glass formation regime. The observed linearity is consistent with the Langevin dynamics in a periodically varying potential field and may offer a means to rapidly assess diffusion based on the characterization of dynamic localization.

  1. Rubber friction on road surfaces: Experiment and theory for low sliding speeds

    NASA Astrophysics Data System (ADS)

    Lorenz, B.; Oh, Y. R.; Nam, S. K.; Jeon, S. H.; Persson, B. N. J.

    2015-05-01

    We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

  2. Is moral bioenhancement dangerous?

    PubMed

    Drake, Nicholas

    2016-01-01

    In a recent response to Persson and Savulescu's Unfit for the Future, Nicholas Agar argues that moral bioenhancement is dangerous. His grounds for this are that normal moral judgement should be privileged because it involves a balance of moral subcapacities; moral bioenhancement, Agar argues, involves the enhancement of only particular moral subcapacities, and thus upsets the balance inherent in normal moral judgement. Mistaken moral judgements, he says, are likely to result. I argue that Agar's argument fails for two reasons. First, having strength in a particular moral subcapacity does not necessarily entail a worsening of moral judgement; it can involve strength in a particular aspect of morality. Second, normal moral judgement is not sufficiently likely to be correct to be the standard by which moral judgements are measured.

  3. General contact mechanics theory for randomly rough surfaces with application to rubber friction.

    PubMed

    Scaraggi, M; Persson, B N J

    2015-12-14

    We generalize the Persson contact mechanics and rubber friction theory to the case where both surfaces have surface roughness. The solids can be rigid, elastic, or viscoelastic and can be homogeneous or layered. We calculate the contact area, the viscoelastic contribution to the friction force, and the average interface separation as a function of the sliding speed and the nominal contact pressure. We illustrate the theory with numerical results for the classical case of a rubber block sliding on a road surface. We find that with increasing sliding speed, the influence of the roughness on the rubber block decreases to the extent that only the roughness of the stiff counter face needs to be considered.

  4. Fluid dynamics at the interface between contacting elastic solids with randomly rough surfaces.

    PubMed

    Persson, B N J

    2010-07-07

    We study fluid dynamics at the interface between elastic solids with randomly rough surfaces. The contact mechanics model of Persson is used to take into account the elastic interaction between the solid walls, and the Bruggeman effective medium theory to account for the influence of the disorder on the fluid flow. We calculated the flow tensor which determines the pressure flow factor and, for example, the leak rate of static seals. It is shown how the perturbation treatment of Tripp can be extended to arbitrary order in the ratio between the root-mean-square roughness amplitude and the average interfacial surface separation. We introduce a matrix D(ζ), determined by the surface roughness power spectrum, which can be used to describe the anisotropy of the surface at any magnification ζ. Results are presented for the asymmetry factor γ(ζ) (generalized Peklenik number) for grinded steel and sandblasted PMMA surfaces. © 2010 IOP Publishing Ltd

  5. Raman scattering from molecular conduction junctions: Charge transfer mechanism

    NASA Astrophysics Data System (ADS)

    Oren, Michal; Galperin, Michael; Nitzan, Abraham

    2012-03-01

    We present a model for the charge transfer contribution to surface-enhanced Raman spectroscopy (SERS) in a molecular junction. The model is a generalization of the equilibrium scheme for SERS of a molecule adsorbed on a metal surface [B. N. J. Persson. Chem. Phys. Lett.CHPLBC0009-261410.1016/0009-2614(81)85441-3 82, 561 (1981)]. We extend the same physical consideration to a nonequilibrium situation in a biased molecular junction and to nonzero temperatures. Two approaches are considered and compared: a semiclassical approach appropriate for nonresonance Raman scattering, and a quantum approach based on the nonequilibrium Green's function method. Nonequilibrium effects on this contribution to SERS are demonstrated with numerical examples. It is shown that the semiclassical approach provides an excellent approximation to the full quantum calculation as long as the molecular electronic state is outside the Fermi window, that is, as long as the field-induced charge transfer is small.

  6. Simple contact mechanics model of the vertebrate cartilage.

    PubMed

    Persson, B N J; Kovalev, A; Gorb, S N

    2017-09-27

    We study a simple contact mechanics model of the vertebrate cartilage, which includes (bulk) osmotic effects. The surface roughness power spectrum of a pig cartilage is obtained from the measured surface topography. Using the Reynolds equations with fluid flow factors, calculated using the Persson contact mechanics theory and the Bruggeman effective medium theory, we show how the area of contact and the average interfacial separation change with time. We found that in most cases the contact area percolates, resulting in islands of confined fluid which carry most of the external load. Most importantly, we find that the pressure in the area of real contact is nearly independent of the external load, and well below 1 MPa. This allows the surfaces in the area of "real contact", to be separated (at nanometer range separation distance) by osmotic repulsion, resulting in a very small (breakloose) friction force observed even after a long time of stationary contact.

  7. Rubber friction on road surfaces: Experiment and theory for low sliding speeds

    SciTech Connect

    Lorenz, B.; Persson, B. N. J.; Oh, Y. R.; Nam, S. K.; Jeon, S. H.

    2015-05-21

    We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

  8. Rubber friction on road surfaces: Experiment and theory for low sliding speeds.

    PubMed

    Lorenz, B; Oh, Y R; Nam, S K; Jeon, S H; Persson, B N J

    2015-05-21

    We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

  9. Genetic therapy, person-regarding reasons and the determination of identity.

    PubMed

    Elliot, Robert

    1997-04-01

    It has been argued, for example by Ingmar Persson, that genetic therapy performed on a conceptus does not alter the identity of the person that develops from it, even if we are essentially persons. If this claim is true then there can be person-regarding reasons for performing genetic therapy on a conceptus. Here it is argued that such person-regarding reasons obtain only if we are not essentially persons but essentially animals. This conclusion requires the defeat of the origination theory, which says that personal identity is determined by the identity of the foetus from which one originates. It is argued that the origination theory is false in the special case relevant to performing genetic therapy on a conceptus for person-regarding reasons.

  10. Surface coupling effects on contact mechanics: contact area and interfacial separation between an elastic solid and a hard substrate with randomly rough, self-affine fractal surfaces

    NASA Astrophysics Data System (ADS)

    Feshanjerdi, M.; Masoudi, A. A.; Khorrami, M.

    2016-12-01

    The objective of this study is to investigate both the contact area and the interfacial separation between two surfaces. Both surfaces are considered to be rough, one of them being elastic and the other one hard. The work is based on an extended version of Persson's model of contact mechanics to study the behavior of the contact area, the interfacial separation and the pressure distribution. The results are compared with the case merely the hard substrate is rough. It is seen that introducing a roughness in the elastic surface decreases the real contact, if the surfaces are uncorrelated. A positive (negative) correlation increases (decreases) the real contact. A reverse pattern occurs for the width of the pressure distribution, as well as the interfacial separation (at equal pressures).

  11. Rubber friction and tire dynamics.

    PubMed

    Persson, B N J

    2011-01-12

    We propose a simple rubber friction law, which can be used, for example, in models of tire (and vehicle) dynamics. The friction law is tested by comparing numerical results to the full rubber friction theory (Persson 2006 J. Phys.: Condens. Matter 18 7789). Good agreement is found between the two theories. We describe a two-dimensional (2D) tire model which combines the rubber friction model with a simple mass-spring description of the tire body. The tire model is very flexible and can be used to accurately calculate μ-slip curves (and the self-aligning torque) for braking and cornering or combined motion (e.g. braking during cornering). We present numerical results which illustrate the theory. Simulations of anti-blocking system (ABS) braking are performed using two simple control algorithms.

  12. Insight into a reversible energy transfer system.

    PubMed

    Gao, Ming Xuan; Zou, Hong Yan; Gao, Peng Fei; Liu, Yue; Li, Na; Li, Yuan Fang; Huang, Cheng Zhi

    2016-09-15

    Resonance energy transfer (RET) processes have wide applications; these processes involve a unidirectional energy transfer from a particular donor to a particular acceptor. Here, we report a plasmonic resonance energy transfer (PRET), which occurs from the surface of gold nanoparticles to fluorescent organic dyes, and coexists with a nanometal surface energy transfer (NSET) that operates in the reverse direction. The coexistence of both PRET and NSET in opposite directions means that the roles of both donor and acceptor can be interchanged, which could be identified by using spectrofluorometric measurements and light scattering dark field microscopic imaging. The experimental data could be further theoretically supported using Persson and Lang's model, the quasi-static approximation and finite-difference time-domain simulation. Moreover, disruption of the PRET process by altering the energy transfer pairs suggests that interactions occur inside the reversible energy transfer system, which manifest by increasing the fluorescence quenching efficiency of the NSET process.

  13. Continuum mechanics at the atomic scale: Insights into non-adhesive contacts using molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Solhjoo, Soheil; Vakis, Antonis I.

    2016-12-01

    Classical molecular dynamics (MD) simulations were performed to study non-adhesive contact at the atomic scale. Starting from the case of Hertzian contact, it was found that the reduced Young's modulus E* for shallow indentations scales as a function of, both, the indentation depth and the contact radius. Furthermore, the contact of two representative rough surfaces was investigated: one multi-asperity, Greenwood-Williamson-type (GW-type) rough surface — where asperities were approximated as spherical caps — and a comparable randomly rough one. The results of the MD simulations were in agreement for both representations and showed that the relative projected contact areas Ar p c were linear functions of nominal applied pressures, even after the initiation of plastic deformation. When comparing the MD simulation results with the corresponding continuum GW and Persson models, both continuum models were found to overestimate the values of Ar p c relative to the MD simulation results.

  14. Preventing ultimate harm as the justification for biomoral modification.

    PubMed

    Murphy, Timothy F

    2015-06-01

    Most advocates of biogenetic modification hope to amplify existing human traits in humans in order to increase the value of such traits as intelligence and resistance to disease. These advocates defend such enhancements as beneficial for the affected parties. By contrast, some commentators recommend certain biogenetic modifications to serve social goals. As Ingmar Persson and Julian Savulescu see things, human moral psychology is deficient relative to the most important risks facing humanity as a whole, including the prospect of Ultimate Harm, the point at which worthwhile life is forever impossible on the planet. These risks can be mitigated, they say, by enhancing moral psychology in novel ways. Persson and Savulescu argue that some parents should modify the underlying biogenetics of their children's moral psychology, if such measures were safe and effective, but they admit these interventions may not decouple humanity from Ultimate Harm. Neither are these modifications the only options, they concede, for addressing risks to humanity. Even with these concessions, saving humanity from itself is a fairly poor reason to modify the moral psychology of children. In most ways, adults would be better candidates, morally speaking, for modifications of psychology. Even then, there is no direct link between morally enhanced human beings and the hoped-for effect of better protection from Ultimate Harm. Asserting a general duty of all to contribute to the avoidance of Ultimate Harm is a better moral strategy than intervening in the moral psychology of some, even though meeting that duty may involve substantial interference with the free exercise of one's interests.

  15. Parametric autoexcitation of magnetic droplet soliton perimeter modes

    NASA Astrophysics Data System (ADS)

    Xiao, D.; Tiberkevich, V.; Liu, Y. H.; Liu, Y. W.; Mohseni, S. M.; Chung, S.; Ahlberg, M.; Slavin, A. N.; Åkerman, J.; Zhou, Yan

    2017-01-01

    Recent experiments performed in current-driven nanocontacts with strong perpendicular anisotropy have shown that spin-transfer torque can drive self-localized spin waves [W. H. Rippard, A. M. Deac, M. R. Pufall, J. M. Shaw, M. W. Keller, S. E. Russek, G. E. W. Bauer, and C. Serpico, Phys. Rev. B 81, 014426 (2010), 10.1103/PhysRevB.81.014426; S. M. Mohseni, S. R. Sani, J. Persson, T. N. A. Nguyen, S. Chung, Y. Pogoryelov, and J. Åkerman, Phys. Status Solidi RRL 5, 432 (2011)], 10.1002/pssr.201105375, that above a certain intensity threshold can condense into a nanosized and highly nonlinear dynamic state known as a magnetic droplet soliton [S. M. Mohseni, S. R. Sani, J. Persson, T. N. A. Nguyen, S. Chung, Y. Pogoryelov, P. K. Muduli, E. Iacocca, A. Eklund, R. K. Dumas, S. Bonetti, A. Deac, M. A. Hoefer, and J. Åkerman, Science 339, 1295 (2013)], 10.1126/science.1230155. Here we demonstrate analytically, numerically, and experimentally that at sufficiently large driving currents and for a spin polarization direction tilted away from the normal to a nanocontact plane, the circular droplet soliton can become unstable against the excitations in the form of periodic deformations of its perimeter. We also show that these perimeter excitation modes (PEMs) can be excited parametrically when the fundamental droplet soliton precession frequency is close to the double frequency of one of the PEMs. As a consequence, with increasing magnitude of a bias magnetic field the PEMs with progressively higher indices and frequencies can be excited. Full qualitative and partly quantitative agreement with experiment confirm the presented theoretical picture.

  16. Misfit strain of oxygen precipitates in Czochralski silicon studied with energy-dispersive X-ray diffraction

    SciTech Connect

    Gröschel, A. Will, J.; Bergmann, C.; Magerl, A.

    2014-06-21

    Annealed Czochralski Silicon wafers containing SiO{sub x} precipitates have been studied by high energy X-ray diffraction in a defocused Laue setup using a laboratory tungsten tube. The energy dispersive evaluation of the diffracted Bragg intensity of the 220 reflection within the framework of the statistical dynamical theory yields the static Debye-Waller factor E of the crystal, which gives access to the strain induced by the SiO{sub x} precipitates. The results are correlated with precipitate densities and sizes determined from transmission electron microscopy measurements of equivalent wafers. This allows for the determination of the constrained linear misfit ε between precipitate and crystal lattice. For samples with octahedral precipitates the values ranging from ε = 0.39 (+0.28/−0.12) to ε = 0.48 (+0.34/−0.16) indicate that self-interstitials emitted into the matrix during precipitate growth contribute to the lattice strain. In this case, the expected value calculated from literature values is ε = 0.26 ± 0.05. Further, the precise evaluation of Pendellösung oscillations in the diffracted Bragg intensity of as-grown wafers reveals a thermal Debye-Waller parameter for the 220 reflection B{sup 220}(293 K) of 0.5582 ± 0.0039 Å{sup 2} for a structure factor based on spherically symmetric scattering contributions.

  17. Abandoning the common law: medical negligence, genetic tests and wrongful life in the Australian High Court.

    PubMed

    Faunce, Thomas; Jefferys, Susannah

    2007-05-01

    The Australian High Court recently found that the common law could allow parents to claim tortious damages when medical negligence was proven to have led to the birth of an unplanned, but healthy, baby (Cattanach v Melchior (2003) 215 CLR 1). In Harriton v Stephens (2006) 80 ALJR 791; [2006] HCA 15 and Waller v James; Waller v Hoolahan (2006) 80 ALJR 846; [2006] HCA 16 the High Court in a six-to-one decision (Kirby J dissenting) decided that no such claim could be made by a child when medical negligence in failing to order an in utero genetic test caused the child severe disability. In an era when almost all pregnancies will soon require patented fetal genetic tests as part of the professional standard of care, the High Court, by barring so-called "wrongful life" (better termed "wrongful suffering") claims, may have created a partial immunity from suit for their corporate manufacturers and the doctors who administer them. What lessons can be learnt from this case about how the Australian High Court is, or should be, approaching medical negligence cases and its role as guardian of the Australian common law?

  18. Pushing the limits of crystallography

    PubMed Central

    Wolny, Janusz; Buganski, Ireneusz; Kuczera, Pawel; Strzalka, Radoslaw

    2016-01-01

    A very serious concern of scientists dealing with crystal structure refinement, including theoretical research, pertains to the characteristic bias in calculated versus measured diffraction intensities, observed particularly in the weak reflection regime. This bias is here attributed to corrective factors for phonons and, even more distinctly, phasons, and credible proof supporting this assumption is given. The lack of a consistent theory of phasons in quasicrystals significantly contributes to this characteristic bias. It is shown that the most commonly used exponential Debye–Waller factor for phasons fails in the case of quasicrystals, and a novel method of calculating the correction factor within a statistical approach is proposed. The results obtained for model quasiperiodic systems show that phasonic perturbations can be successfully described and refinement fits of high quality are achievable. The standard Debye–Waller factor for phonons works equally well for periodic and quasiperiodic crystals, and it is only in the last steps of a refinement that different correction functions need to be applied to improve the fit quality. PMID:27980514

  19. Disorder effects on EXAFS modeling for catalysts working at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Sun, Xueping; Sun, Fanfei; Sun, Zhihu; Chen, Jing; Du, Xianlong; Wang, Jianqiang; Jiang, Zheng; Huang, Yuying

    2017-08-01

    In-situ X-ray absorption fine structure spectroscopy (XAFS) has been widely used to study the structure around active site of catalysts at elevated pressures and temperatures for decades. However, methods of XAFS data analysis can vary significantly, depending on the disorder degree of the material system investigated. In this work, in-situ XAFS was explored to investigate the structural evolutions of the industry CuO/ZnO/Al2O3 catalyst for methanol synthesis at elevated temperatures in nitrogen (N2) atmosphere. Due to the large Debye-Waller factor, data analysis using the conventional Gaussian mode resulted in erroneously contracted Cu-Cu bond distances which made the conventional Gaussian mode invalid in this system. To account for the deviation from harmonic behavior, the cumulant expansion technique was used to correct the error in the bond contraction, and the frequency pattern could be fully reproduced by considering cumulants up to C3. In order to elucidate the contributions of the structure and thermal components to the Debye-Waller factors, the Einstein method was also used to analyze the data that provides a straightforward proof regarding the effect of the temperature on the in-situ XAFS experiment.

  20. Structure determination from XAFS using high-accuracy measurements of x-ray mass attenuation coefficients of silver, 11 keV-28 keV, and development of an all-energies approach to local dynamical analysis of bond length, revealing variation of effective thermal contributions across the XAFS spectrum.

    PubMed

    Tantau, L J; Chantler, C T; Bourke, J D; Islam, M T; Payne, A T; Rae, N A; Tran, C Q

    2015-07-08

    We use the x-ray extended range technique (XERT) to experimentally determine the mass attenuation coefficient of silver in the x-ray energy range 11 kev-28 kev including the silver K absorption edge. The results are accurate to better than 0.1%, permitting critical tests of atomic and solid state theory. This is one of the most accurate demonstrations of cross-platform accuracy in synchrotron studies thus far. We derive the mass absorption coefficients and the imaginary component of the form factor over this range. We apply conventional XAFS analytic techniques, extended to include error propagation and uncertainty, yielding bond lengths accurate to approximately 0.24% and thermal Debye-Waller parameters accurate to 30%. We then introduce the FDMX technique for accurate analysis of such data across the full XAFS spectrum, built on full-potential theory, yielding a bond length accuracy of order 0.1% and the demonstration that a single Debye parameter is inadequate and inconsistent across the XAFS range. Two effective Debye-Waller parameters are determined: a high-energy value based on the highly-correlated motion of bonded atoms (σ(DW) = 0.1413(21) Å), and an uncorrelated bulk value (σ(DW) = 0.1766(9) Å) in good agreement with that derived from (room-temperature) crystallography.

  1. Order Parameters for Two-Dimensional Networks

    NASA Astrophysics Data System (ADS)

    Kaatz, Forrest; Bultheel, Adhemar; Egami, Takeshi

    2007-10-01

    We derive methods that explain how to quantify the amount of order in ``ordered'' and ``highly ordered'' porous arrays. Ordered arrays from bee honeycomb and several from the general field of nanoscience are compared. Accurate measures of the order in porous arrays are made using the discrete pair distribution function (PDF) and the Debye-Waller Factor (DWF) from 2-D discrete Fourier transforms calculated from the real-space data using MATLAB routines. An order parameter, OP3, is defined from the PDF to evaluate the total order in a given array such that an ideal network has the value of 1. When we compare PDFs of man-made arrays with that of our honeycomb we find OP3=0.399 for the honeycomb and OP3=0.572 for man's best hexagonal array. The DWF also scales with this order parameter with the least disorder from a computer-generated hexagonal array and the most disorder from a random array. An ideal hexagonal array normalizes a two-dimensional Fourier transform from which a Debye-Waller parameter is derived which describes the disorder in the arrays. An order parameter S, defined by the DWF, takes values from [0, 1] and for the analyzed man-made array is 0.90, while for the honeycomb it is 0.65. This presentation describes methods to quantify the order found in these arrays.

  2. Structural Physics of Bee Honeycomb

    NASA Astrophysics Data System (ADS)

    Kaatz, Forrest; Bultheel, Adhemar; Egami, Takeshi

    2008-03-01

    Honeybee combs have aroused interest in the ability of honeybees to form regular hexagonal geometric constructs since ancient times. Here we use a real space technique based on the pair distribution function (PDF) and radial distribution function (RDF), and a reciprocal space method utilizing the Debye-Waller Factor (DWF) to quantify the order for a range of honeycombs made by Apis mellifera. The PDFs and RDFs are fit with a series of Gaussian curves. We characterize the order in the honeycomb using a real space order parameter, OP3, to describe the order in the combs and a two-dimensional Fourier transform from which a Debye-Waller order parameter, u, is derived. Both OP3 and u take values from [0, 1] where the value one represents perfect order. The analyzed combs have values of OP3 from 0.33 to 0.60 and values of u from 0.83 to 0.98. RDF fits of honeycomb histograms show that naturally made comb can be crystalline in a 2D ordered structural sense, yet is more `liquid-like' than cells made on `foundation' wax. We show that with the assistance of man-made foundation wax, honeybees can manufacture highly ordered arrays of hexagonal cells.

  3. Leaps in the Dark - The making of scientific reputations

    NASA Astrophysics Data System (ADS)

    Waller, John

    2004-12-01

    In Leaps in the Dark , John Waller presents another collection of revelations from the world of science. He considers experiments in which the scientists' awareness was not perhaps as keen as they might have claimed in retrospect; he investigates the jealousy and opposition that scientific ideas can provoke; he celebrates the scientists who were wrong, but for very good reasons; and he demonstrates how national interest can affect scientists and their theories. The result is an entertaining and highly readable re-examination of scientific discoveries and reputations from the Renaissance to the twentieth century. The tales in Leaps in the Dark range across a wide historical field, from a seventeenth-century witch-finder, Joseph Glanvill, to Sir Robert Watson-Watt, the self-proclaimed 'Father of radar'. Each story underscores the rich, fascinating complexity of scientific discovery. Writing in a clear and engaging style, and skilfully weaving history in with the science, John Waller brings these scientists to life, illustrating how their work and their discoveries influenced their careers and the wider world around them.

  4. Vibrational properties of nanocrystals from the Debye Scattering Equation

    SciTech Connect

    Scardi, P.; Gelisio, L.

    2016-02-26

    One hundred years after the original formulation by Petrus J.W. Debije (aka Peter Debye), the Debye Scattering Equation (DSE) is still the most accurate expression to model the diffraction pattern from nanoparticle systems. A major limitation in the original form of the DSE is that it refers to a static domain, so that including thermal disorder usually requires rescaling the equation by a Debye-Waller thermal factor. The last is taken from the traditional diffraction theory developed in Reciprocal Space (RS), which is opposed to the atomistic paradigm of the DSE, usually referred to as Direct Space (DS) approach. Besides being a hybrid of DS and RS expressions, rescaling the DSE by the Debye-Waller factor is an approximation which completely misses the contribution of Temperature Diffuse Scattering (TDS). The present work proposes a solution to include thermal effects coherently with the atomistic approach of the DSE. Here, a deeper insight into the vibrational dynamics of nanostructured materials can be obtained with few changes with respect to the standard formulation of the DSE, providing information on the correlated displacement of vibrating atoms.

  5. On the nature of a glassy state of matter in a hydrated protein: Relation to protein function

    PubMed Central

    Teeter, M. M.; Yamano, A.; Stec, B.; Mohanty, U.

    2001-01-01

    Diverse biochemical and biophysical experiments indicate that all proteins, regardless of size or origin, undergo a dynamic transition near 200 K. The cause of this shift in dynamic behavior, termed a “glass transition,” and its relation to protein function are important open questions. One explanation postulated for the transition is solidification of correlated motions in proteins below the transition. We verified this conjecture by showing that crambin's radius of gyration (Rg) remains constant below ≈180 K. We show that both atom position and dynamics of protein and solvent are physically coupled, leading to a novel cooperative state. This glassy state is identified by negative slopes of the Debye-Waller (B) factor vs. temperature. It is composed of multisubstate side chains and solvent. Based on generalization of Adam-Gibbs' notion of a cooperatively rearranging region and decrease of the total entropy with temperature, we calculate the slope of the Debye-Waller factor. The results are in accord with experiment. PMID:11572978

  6. Some Improvements in Confidence Intervals for Standardized Regression Coefficients.

    PubMed

    Dudgeon, Paul

    2017-03-13

    Yuan and Chan (Psychometrika 76:670-690, 2011. doi: 10.1007/S11336-011-9224-6 ) derived consistent confidence intervals for standardized regression coefficients under fixed and random score assumptions. Jones and Waller (Psychometrika 80:365-378, 2015. doi: 10.1007/S11336-013-9380-Y ) extended these developments to circumstances where data are non-normal by examining confidence intervals based on Browne's (Br J Math Stat Psychol 37:62-83, 1984. doi: 10.1111/j.2044-8317.1984.tb00789.x ) asymptotic distribution-free (ADF) theory. Seven different heteroscedastic-consistent (HC) estimators were investigated in the current study as potentially better solutions for constructing confidence intervals on standardized regression coefficients under non-normality. Normal theory, ADF, and HC estimators were evaluated in a Monte Carlo simulation. Findings confirmed the superiority of the HC3 (MacKinnon and White, J Econ 35:305-325, 1985. doi: 10.1016/0304-4076(85)90158-7 ) and HC5 (Cribari-Neto and Da Silva, Adv Stat Anal 95:129-146, 2011. doi: 10.1007/s10182-010-0141-2 ) interval estimators over Jones and Waller's ADF estimator under all conditions investigated, as well as over the normal theory method. The HC5 estimator was more robust in a restricted set of conditions over the HC3 estimator. Some possible extensions of HC estimators to other effect size measures are considered for future developments.

  7. Vibrational properties of nanocrystals from the Debye Scattering Equation

    DOE PAGES

    Scardi, P.; Gelisio, L.

    2016-02-26

    One hundred years after the original formulation by Petrus J.W. Debije (aka Peter Debye), the Debye Scattering Equation (DSE) is still the most accurate expression to model the diffraction pattern from nanoparticle systems. A major limitation in the original form of the DSE is that it refers to a static domain, so that including thermal disorder usually requires rescaling the equation by a Debye-Waller thermal factor. The last is taken from the traditional diffraction theory developed in Reciprocal Space (RS), which is opposed to the atomistic paradigm of the DSE, usually referred to as Direct Space (DS) approach. Besides beingmore » a hybrid of DS and RS expressions, rescaling the DSE by the Debye-Waller factor is an approximation which completely misses the contribution of Temperature Diffuse Scattering (TDS). The present work proposes a solution to include thermal effects coherently with the atomistic approach of the DSE. Here, a deeper insight into the vibrational dynamics of nanostructured materials can be obtained with few changes with respect to the standard formulation of the DSE, providing information on the correlated displacement of vibrating atoms.« less

  8. Local structure and vibrational properties of alpha-Pu, alpha-Uand the alpha-U charge density wave

    SciTech Connect

    Nelson, E.J.; Allen, P.G.; Blobaum, K.J.M.; Wall, W.A.; Booth, C.H.

    2004-08-10

    The local atomic environment and vibrational properties of atoms in monoclinic pure {alpha}-plutonium as well as orthorhombic pure a-uranium and its low-temperature charge-density-wave (CDW) modulation are examined by extended x-ray absorption fine structure spectroscopy (EXAFS). Pu L{sub III}-edge and U L{sub III}-edge EXAFS data measured at low temperatures verify the crystal structures of {alpha}-U and {alpha}-Pu samples previously determined by x-ray diffraction and neutron scattering. Debye-Waller factors from temperature-dependent EXAFS measurements are fit with a correlated Debye model. The observed Pu-Pu bond correlated Debye temperature of {theta}{sub cD}({alpha}-Pu) = 162 {+-} 5 K for the pure {alpha}-Pu phase agrees with our previous measurement of the correlated Debye temperature of the gallium-containing {alpha}{prime}-Pu phase in a mixed phase 1.9 at% Ga-doped {alpha}{prime}-Pu/{delta}-Pu alloy. The temperature dependence of the U-U nearest neighbor Debye-Waller factor exhibits a sharp discontinuity in slope near T{sub CDW} = 43 K, the transition temperature at which the charge-density wave (CDW) in {alpha}-U condenses from a soft phonon mode along the (100) direction. Our measurement of the CDW using EXAFS is the first observation of the structure of the CDW in polycrystalline {alpha}-U. The different temperature dependence of the Debye-Waller factor for T < T{sub CDW} can be modeled by the change in bond length distributions resulting from condensation of the charge density wave. For T > T{sub CDW}, the observed correlated Debye temperature of {theta}{sub cD}({alpha}-U) = 199 {+-} 3 K is in good agreement with other measurements of the Debye temperature for polycrystalline {alpha}-U. CDW structural models fit to the {alpha}-U EXAFS data support a squared CDW at the lowest temperatures, with a displacement amplitude of {var_epsilon} = 0.05 {+-} 0.02 {angstrom}.

  9. Local Structure and Vibrational Properties of alpha-Pu, alpha-U, and the alpha-U Charge Density Wave

    SciTech Connect

    Nelson, E J; Allen, P G; Blobaum, K M; Wall, M A; Booth, C H

    2004-08-10

    The local atomic environment and vibrational properties of atoms in monoclinic pure {alpha}-plutonium as well as orthorhombic pure {alpha}-uranium and its low-temperature charge-density-wave (CDW) modulation are examined by extended x-ray absorption fine structure spectroscopy (EXAFS). Pu L{sub III}-edge and U L{sub III}-edge EXAFS data measured at low temperatures verify the crystal structures of {alpha}-U and {alpha}-Pu samples previously determined by x-ray diffraction and neutron scattering. Debye-Waller factors from temperature-dependent EXAFS measurements are fit with a correlated Debye model. The observed Pu-Pu bond correlated Debye temperature of {theta}{sub cD}({alpha}-Pu) = 162 {+-} 5 K for the pure {alpha}-Pu phase agrees with our previous measurement of the correlated Debye temperature of the gallium-containing {alpha}'-Pu phase in a mixed phase 1.9 at% Ga-doped {alpha}'-Pu/{delta}-Pu alloy. The temperature dependence of the U-U nearest neighbor Debye-Waller factor exhibits a sharp discontinuity in slope near T{sub CDW} = 43 K, the transition temperature at which the charge-density wave (CDW) in {alpha}-U condenses from a soft phonon mode along the (100) direction. Our measurement of the CDW using EXAFS is the first observation of the structure of the CDW in polycrystalline {alpha}-U. The different temperature dependence of the Debye-Waller factor for T < T{sub CDW} can be modeled by the change in bond length distributions resulting from condensation of the charge density wave. For T > T{sub CDW}, the observed correlated Debye temperature of {theta}{sub cD}({alpha}-U) = 199 {+-} 3 K is in good agreement with other measurements of the Debye temperature for polycrystalline {alpha}-U. CDW structural models fit to the {alpha}-U EXAFS data support a squared CDW at the lowest temperatures, with a displacement amplitude of {var_epsilon} = 0.05 {+-} 0.02 {angstrom}.

  10. Persistent discourses in physics education: gender neutrality and the gendering of competence

    NASA Astrophysics Data System (ADS)

    Gonsalves, Allison

    2014-06-01

    In her article, Karin Due presents us with a contradiction in physics: the construction of physics as a symbolically masculine discipline alongside a simultaneous discourse of the "gender-neutrality" of the discipline. Due's article makes an important contribution to the study of the gendering of physics practices, particularly in group dynamics, and how this serves to simultaneously reinforce the two competing discourses of physics as a masculine discipline, and the discourse of physics as a gender neutral discipline. Due also suggests that an implication of this contradiction is a limited number of available positions for girls in physics compared to those available to boys. I wish to take up this observation and discuss how available positions for boys and girls in physics are related quite closely to two other concepts discussed in Due's article: competence and recognition.

  11. Perspectives on positioning, interaction, and learning in small-group discussion: possibilities for extending the analytic lens

    NASA Astrophysics Data System (ADS)

    Kittleson, Julie M.; Wilson, Rachel E.

    2014-06-01

    In this forum piece, we respond to Karin Due's study of social dynamics in groups of students in physics class and gender issues that play out in this context. We discuss two threads that appear in Due's paper: one pertains to patterns of talk within groups and how these patterns open up possibilities for learning, the other pertains to ways in which gender is constructed within groups and made visible via discourse. Our comments are intended to provide alternative ways of thinking about such issues. We hope to provide insight into how to deepen analyses of group dynamics and gender because research in both areas is important in terms of understanding how social contexts support and/or constrain learning, gender identity, and the like.

  12. Alois Alzheimer: A Hundred Years after the Discovery of the Eponymous Disorder

    PubMed Central

    Tagarelli, Antonio; Piro, Anna; Tagarelli, Giuseppe; Lagonia, Paolo; Quattrone, Aldo

    2006-01-01

    The familiar term “Alzheimer’s disease” was coined by Emil Kraepelin to honour his pupil, Alois Alzheimer. However, little is known about the life of the man after whom this important and well-known disease was termed. On the centennial of the discovery of Alzheimer’s disease, it is appropriate to report some aspects of the life and scientific work of Alois Alzheimer. The authors contacted all the libraries of the Universities where Alzheimer studied and/or worked to receive any original material regarding Alois Alzheimer. This review is based for a most part on an original biography written by Konrad and Urlike Maurer after the interviews to Alzheimer’s nieces, Hildegard Koeppen, Ilse Lieblein, Bärbel Lippert, Karin Weiβ, and his nephew, Rupert Finsterwalder. The authors obtained this biography from the Central Library of Medicine in Koeln. PMID:23674983

  13. The Nordic Tradition of Caring Science: The Works of Three Theorists.

    PubMed

    Arman, Maria; Ranheim, Albertine; Rydenlund, Kenneth; Rytterström, Patrik; Rehnsfeldt, Arne

    2015-10-01

    The Nordic tradition of caring science has had a significant influence on healthcare research, healthcare education and clinical development in the Nordic countries from 1990 to the present. Theoretical contributions from the professors and scientists Katie Eriksson, Kari Martinsen and Karin Dahlberg form the basis for this paper. The tradition has established a paradigm of ethics, ontology and epistemology for the caring science domain. Short introductions present the scientific background of Eriksson, Martinsen, and Dahlberg, and show how interpretive teamwork has led to the formation of an intertwining of the essential qualities of the theories. The synthesis emphasizes caring science as a human science, and views caring as a natural phenomenon where the patient's world, vulnerability, health, and suffering are primary. In the art and act of caring, relationships and dialogue are essential; they provide parameters where caring becomes visible in its absence. © The Author(s) 2015.

  14. Neutron interferometer crystallographic imperfections and gravitationally induced quantum interference measurements

    NASA Astrophysics Data System (ADS)

    Heacock, B.; Arif, M.; Haun, R.; Huber, M. G.; Pushin, D. A.; Young, A. R.

    2017-01-01

    Dynamical diffraction leads to an interesting, unavoidable set of interference effects for neutron interferometers. This experiment studies the interference signal from two and three successive Bragg diffractions in the Laue geometry. We find that intrinsic Bragg-plane misalignment in monolithic, "perfect" silicon neutron interferometers is relevant between successive diffracting crystals, as well as within the Borrmann fan for typical interferometer geometries. We show that the dynamical phase correction employed in the Colella, Overhauser, and Werner gravitationally induced quantum interference experiments is attenuated by slight, intrinsic misalignments between diffracting crystals, potentially explaining the long-standing 1% discrepancy between theory and experiment. This systematic may also impact precision measurements of the silicon structure factor, affecting previous and future measurements of the Debye-Waller factor and neutron-electron scattering length as well as potential fifth-force searches. For the interferometers used in this experiment, Bragg planes of different diffracting crystals were found to be misaligned by 10 to 40 nrad.

  15. Electron phonon effects on the direct band gap in semiconductors: LCAO calculations

    NASA Astrophysics Data System (ADS)

    Olguín, D.; Cardona, M.; Cantarero, A.

    2002-06-01

    Using a perturbative treatment of the electron-phonon interaction, we have studied the effect of phonons on the direct band gap of conventional semiconductors. Our calculations are performed in the framework of the tight-binding linear combination of atomic orbitals (LCAO) approach. Within this scheme we have calculated the temperature and isotopic mass dependence of the lowest direct band gap of several semiconductors with diamond and zincblende structure. Our results reproduce the overall trend of available experimental data for the band gap as a function of temperature, as well as give correctly the mass dependence of the band gap on isotopic. A calculation of conduction band intervalley deformation potentials is also reported. Finally, calculated Debye-Waller factors are compared with X-ray and EXAFS experimental results.

  16. Speciation of Gold Nanoparticles by Ex Situ Extended X-ray Absorption Fine Structure and X-ray Absorption Near Edge Structure.

    PubMed

    Giorgetti, Marco; Aquilanti, Giuliana; Ballarin, Barbara; Berrettoni, Mario; Cassani, Maria Cristina; Fazzini, Silvia; Nanni, Daniele; Tonelli, Domenica

    2016-07-05

    A combined X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) methodology is here presented on a series of partially and fully reduced Au(III) samples. This allows monitoring the relative fraction of Au(III) and Au(0) in the studied samples, displaying a consistent and independent outcome. The strategy followed is based, for the first time, on two structural models that can be fitted simultaneously, and it evaluates the correlation among strongly correlated parameters such as coordination number and the Debye-Waller factor. The results of the present EXAFS and XANES approach can be extended to studies based on X-ray absorption spectroscopy experiments for the in situ monitoring of the formation of gold nanoclusters.

  17. Confirmatory and exploratory factor analysis of the distress tolerance scale (DTS) in a clinical sample of eating disorder patients.

    PubMed

    Raykos, Bronwyn C; Byrne, Susan M; Watson, Hunna

    2009-12-01

    A confirmatory factor analysis of the factor structure of the Distress Tolerance Scale (DTS) created by Corstorphine et al. [Corstorphine, E., Mountford, V., Tomlinson, S., Waller, G., & Meyer, C. (2007). Distress tolerance in the eating disorders. Eating Behaviors, 8, 91-97.] was conducted to assess whether the scale's purported three factors emerged in a clinical sample of patients with a DSM-IV diagnosed eating disorder. The original three-factor model was generally considered to be a poor fit for the data. Subsequent exploratory factor analysis indicated that a better fit emerged using a four-factor structure. Significant associations were observed between behavioral avoidance of positive affect and eating disorder psychopathology. Implications for use of the DTS with eating disorder patients are discussed.

  18. Water-level changes 2000-2004 in the Chicot and Evangeline Aquifers, Houston-Galveston Region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.

    2004-01-01

    This report depicts 2000–2004 water-level changes in the Chicot and Evangeline aquifers in the Houston-Galveston region (figs. 1 and 2). The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District and the Fort Bend Subsidence District. The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979 and separate similar annual reports for the Fort Bend subregion since 1990. Beginning with 2002, the separate annual reports were combined into one report.

  19. Approximate changes in water levels in wells completed in the Chicot and Evangeline aquifers, 1977-94 and 1993-94, and measured compaction, 1973-93, in the Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Coplin, L.S.; Santos, Horacio X.

    1994-01-01

    This report is one in a series of reports that depict water-level changes since 1977 and compaction of subsurface material since 1973.  The report was prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, and presents maps showing the approximate changes in water levels in wells completed in the Chicot and Evangeline aquifers, 1977-94 and 1993-94 (figs. 1-4), extensometer site locations (fig. 5), and measured compaction, 1973-93 (fig. 6), in the Houston-Galveston region.  Water-level change maps were prepared previously by Kasmarek and others (1993).  The Houston-galveston region includes Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  20. Water-level altitudes in wells completed in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas, January-February 1992, 1993, and 1994

    USGS Publications Warehouse

    Kasmarek, M.C.

    1997-01-01

    This report depicts annual water-level altitudes for 3 consecutive years in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the city of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 1992 and 1994. The most recent previously published water-level-altitude maps (and water-level-change maps) for the two aquifers in the region are by Kasmarek and others (1997). The Houston-Galveston region includes Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  1. Approximate changes in water levels in wells completed in the Chicot and Evangeline aquifers, 1977-93 and 1992-93, and measured compaction, 1973-92, in the Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Coplin, L.S.; Campodonico, Al

    1993-01-01

    This report is one in a series of reports that depict water-level changes since 1977 and compaction of subsurface material since 1973.  The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District and the City of Houston, and presents maps showing the approximate changes in water levels in wells completed in the Chicot and Evangeline aquifers, 1977-93 and 1992-93 (figs. 1-4), and measured compaction, 1973-92 (figs. 5 and 6), in the Houston-Galveston region.  The Houston-Galveston region includes Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  2. Approximate changes in water levels in wells completed in the Chicot and Evangeline aquifers, 1977-92 and 1991-92, and measured compaction, 1973-91 in the Houston-Galveston region, Texas.

    USGS Publications Warehouse

    Kasmarek, Mark C.; Barbie, Dana L.; Campodonico, Al

    1992-01-01

    This report is one in a series of reports that depict water-level changes since 1977 and compaction of subsurface material since 1973.  The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District and the City of Houston, and presents maps showing the approximate changes in water-levels in wells completed in the Chicot and Evangeline aquifers, 1977-92 and 1991-92 (figs. 1-4), and measured compations, 1973-91 (figs. 5 and 6), in the Houston-Galveston region.  The Houston-Galveston region includes Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  3. Xafs Studies of Transition Metal And Halogen Biomaterials in Invertebrate Tools

    SciTech Connect

    Tao, Y.; Shokes, J.E.; Scott, R.A.; Nesson, M.H.; Schofield, R.M.S.

    2009-06-04

    A significant fraction of arthropods, as well as some worms and members of other phyla, contain extraordinary amounts of transition metals (Mn, Fe, Cu, Zn) and halogens (Cl, Br, I) in their hardened tools (jaws, claws, fangs, stings, etc.). Bulk Zn EXAFS differs for different kinds of tools, whereas Br appears to occupy a common environment in different tools. Zn binding to histidine is observed for most samples but bulk Zn EXAFS is likely to sample a mixture of Zn coordination environments. Principal Component Analysis (PCA) suggests the presence of three main Zn coordination components. The similar Br EXAFS in widely different tools indicates that Br-phenyl is the dominant form, suggesting the presence of brominated aromatic amino acid-derived organic components in these biomaterials. Calculated Debye-Waller factors are used to simulate EXAFS when model compound data are unavailable.

  4. Zinc cysteine active sites of metalloproteins: A density functional theory and x-ray absorption fine structure study

    NASA Astrophysics Data System (ADS)

    Dimakis, Nicholas; Farooqi, Mohammed Junaid; Garza, Emily Sofia; Bunker, Grant

    2008-03-01

    Density functional theory (DFT) and x-ray absorption fine structure (XAFS) spectroscopy are complementary tools for the biophysical study of active sites in metalloproteins. DFT is used to compute XAFS multiple scattering Debye Waller factors, which are then employed in genetic algorithm-based fitting process to obtain a global fit to the XAFS in the space of fitting parameters. Zn-Cys sites, which serve important functions as transcriptional switches in Zn finger proteins and matrix metalloproteinases, previously have proven intractable by this method; here these limitations are removed. In this work we evaluate optimal DFT nonlocal functionals and basis sets for determining optimal geometries and vibrational densities of states of mixed ligation Zn(His)4-n(Cys)n sites. Theoretical results are compared to experimental XAFS measurements and Raman spectra from the literature and tabulated for use.

  5. Molecular dynamics of an α-helical polypeptide: Temperature dependence and deviation from harmonic behavior

    PubMed Central

    Levy, Ronald M.; Perahia, David; Karplus, Martin

    1982-01-01

    The mean square amplitudes of atomic fluctuations for a polypeptide (decaglycine) α-helix evaluated from molecular dynamics simulations at seven temperatures between 5 and 300 K are compared with analytic harmonic results and with experimental values. Above 100 K the harmonic approximation significantly underestimates the amplitudes of the displacements. Analysis of the time dependence of the fluctuations shows that low-frequency modes (<75 cm-1) dominate the atomic fluctuations and that there is a contribution with a very long relaxation time (>10 ps). Quantum corrections to the amplitude of the fluctuations are found to be small above 50 K. The mean square amplitudes obtained from the molecular dynamics simulations are compared with the values derived from x-ray temperature (Debye-Waller) factors for metmyoglobin (80, 250, and 300 K) and ferrocytochrome c (300 K). PMID:16593164

  6. Hydrologic data for urban studies in the Austin, Texas, metropolitan area, 1979

    USGS Publications Warehouse

    Slade, R.M.; Dorsey, M.E.; Gordon, J.D.; Mitchell, R.N.; Gaylord, J.L.

    1981-01-01

    This report contains rainfall and runoff data collected during the 1979 water year for the Austin, Texas, metropolitan area. In 1975, the program was expanded to include the collection of water-quality data. In 1978, the program was expanded to include a groundwater resources study of the south Austin metropolitan area in the Balcones fault zone. The information will be useful in determining the extent to which progressive urbanization will affect the yeild and mode of occurrence of storm runoff. The major streams in the study area are the Colorado River, Onion Creek, Barton Creek, Walnut Creek, Bull Creek, Boggy Creek, Shoal Creek, Williamson Creek, Slaughter Creek, Bear Creek, and Waller Creek. Detailed rainfall-runoff computations are presented for eight storm periods during the 1979 water year. Water-quality data for sites in the Austin metropolitan area are also given in this report. (USGS)

  7. Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction.

    PubMed

    Sokolowski-Tinten, K; Shen, X; Zheng, Q; Chase, T; Coffee, R; Jerman, M; Li, R K; Ligges, M; Makasyuk, I; Mo, M; Reid, A H; Rethfeld, B; Vecchione, T; Weathersby, S P; Dürr, H A; Wang, X J

    2017-09-01

    We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

  8. Adult age differences in the ability to mentally transform object and body stimuli.

    PubMed

    Devlin, Anna L; Wilson, Peter H

    2010-11-01

    Cognitive neuroscience literature suggests a strong dissociation between the ability to mentally transform object and body stimuli (Hegarty & Waller, 2004). However, little is known about how this ability changes with age. This dissociation was explored in 20 younger (19-24 years) and 20 older (65-87 years) adults. Mental rotation of object stimuli was demonstrated for both age groups, suggesting that the neuro-cognitive network involved with performing (object-based) mental transformations is relatively preserved in older age. Compared to young adults, older adults displayed the greatest decline in performance efficiency for the whole-body task. The authors propose that an age-related decline in the integrity of body-schema information may account for this change.

  9. Neutral Silicon-Vacancy Center in Diamond: Spin Polarization and Lifetimes

    NASA Astrophysics Data System (ADS)

    Green, B. L.; Mottishaw, S.; Breeze, B. G.; Edmonds, A. M.; D'Haenens-Johansson, U. F. S.; Doherty, M. W.; Williams, S. D.; Twitchen, D. J.; Newton, M. E.

    2017-09-01

    We demonstrate optical spin polarization of the neutrally charged silicon-vacancy defect in diamond (SiV0 ), an S =1 defect which emits with a zero-phonon line at 946 nm. The spin polarization is found to be most efficient under resonant excitation, but nonzero at below-resonant energies. We measure an ensemble spin coherence time T2>100 μ s at low-temperature, and a spin relaxation limit of T1>25 s . Optical spin-state initialization around 946 nm allows independent initialization of SiV0 and NV- within the same optically addressed volume, and SiV0 emits within the telecoms down-conversion band to 1550 nm: when combined with its high Debye-Waller factor, our initial results suggest that SiV0 is a promising candidate for a long-range quantum communication technology.

  10. The influence of social anxiety on the body checking behaviors of female college students.

    PubMed

    White, Emily K; Warren, Cortney S

    2014-09-01

    Social anxiety and eating pathology frequently co-occur. However, there is limited research examining the relationship between anxiety and body checking, aside from one study in which social physique anxiety partially mediated the relationship between body checking cognitions and body checking behavior (Haase, Mountford, & Waller, 2007). In an independent sample of 567 college women, we tested the fit of Haase and colleagues' foundational model but did not find evidence of mediation. Thus we tested the fit of an expanded path model that included eating pathology and clinical impairment. In the best-fitting path model (CFI=.991; RMSEA=.083) eating pathology and social physique anxiety positively predicted body checking, and body checking positively predicted clinical impairment. Therefore, women who endorse social physique anxiety may be more likely to engage in body checking behaviors and experience impaired psychosocial functioning. Published by Elsevier Ltd.

  11. Vibrational dynamics and surface structure of Bi(111) from helium atom scattering measurements.

    PubMed

    Mayrhofer-Reinhartshuber, M; Tamtögl, A; Kraus, P; Rieder, K H; Ernst, W E

    2012-03-14

    The Bi(111) surface was studied by elastic scattering of helium atoms at temperatures between 118 and 423 K. The observed diffraction patterns with clear peaks up to third order were used to model the surface corrugation using the eikonal approximation as well as the GR method. Best fit results were obtained with a rather large corrugation height compared to other surfaces with metallic character. The corrugation shows a slight enhancement of the surface electron density in between the positions of the surface atoms. The vibrational dynamics of Bi(111) were investigated by measurements of the Debye-Waller attenuation of the elastic diffraction peaks and a surface Debye temperature of (84 ± 8) K was determined. A decrease of the surface Debye temperature at higher temperatures that was recently observed on Bi nanofilms could not be confirmed in the case of our single-crystal measurements.

  12. Gastro-intestinal nematode infection in lambs — A model based on climatic indices for forecasting peak pasture larval contamination

    NASA Astrophysics Data System (ADS)

    Paton, G.

    1987-06-01

    The parasite Ostertagia circumcincta is the primary cause of parasitic gastro-enteritis in lambs during their first season at grass. The life-cycle of this nematode parasite involves the development and survival of the free-living stages on pasture. Accordingly the pasture is the site of deposition, development and transmission of infection and meteorological factors affecting the pasture will affect the parasites. In this paper two empirical models for forecasting the timing of the “summer wave” of infective larvae on pasture are presented. These models are similar in form to that described by Starr and Thomas (1980) but involve different approaches to assessing the temperature and moisture components of the daily index value. Further, using the prediction model described by Paton, Thomas and Waller (1984) as an investigative tool, certain tentative suggestions are made as to a general fundamental weakness of empirical index methods.

  13. Relationship of purported measures of pathological and nonpathological dissociation to self-reported psychological distress and fantasy immersion.

    PubMed

    Levin, Ross; Spei, Ekaterina

    2004-06-01

    In order to investigate both the psychometric structure of the Dissociative Experiences Survey (DES) and the discriminant validity of the DES-Taxon (Waller, Putnam, & Carlson, 1996) as a specific marker of pathological dissociation, 376 non-clinical community based respondents completed the DES and a battery of psychopathology and imaginative involvement self-report measures. The DES was scored for both the Taxon and the DES-Absorption subscale. A DES subscale purported to tap normative dissociative processes. The two DES subscales demonstrated substantial overlap, both with each other (r = .80) and with the self-report measures with both DES scales comparably associated with high levels of psychological distress. Both DES subscales were also associated with elevated levels of "normative" imaginative involvement (fantasy proneness, absorption, daydreaming immersion). We conclude that both DES scales are largely indistinguishable from each other in relation to other self-report measures of psychopathology and fantasy access.

  14. Ethics and new reproductive technologies: an international review of committee statements.

    PubMed

    Walters, LeRoy

    1987-06-01

    Walters examines the statements of advisory committees in eight countries on new practices involving human reproduction: clinical in vitro fertilization; surrogate motherhood; and human embryo research. He analyzes the positions taken by the committees on the general acceptability of the new technologies, as well as on specific issues involved in assisted human reproduction. In chronological order, the statements examined are those of the U.S. Ethics Advisory Board; the Waller committee in Victoria, Australia; a South Australian committee; the Demack committee in Queensland; Britain's Council for Science and Society; Britain's Warnock committee; a Tasmania, Australia, committee; the Ontario Law Reform Commission; Australia's Family Law Council; West Germany's Benda committee; the American Fertility Society; a Western Australia committee; the Dutch Health Council; and the National Ethics Committee of France.

  15. Vibron Solitons and Soliton-Induced Infrared Spectra of Crystalline Acetanilide

    NASA Astrophysics Data System (ADS)

    Takeno, S.

    1986-01-01

    Red-shifted infrared spectra at low temperatures of amide I (C=O stretching) vibrations of crystalline acetanilide measured by Careri et al. are shown to be due to vibron solitons, which are nonlinearity-induced localized modes of vibrons arising from their nonlinear interactions with optic-type phonons. A nonlinear eigenvalue equation giving the eigenfrequency of stationary solitons is solved approximately by introducing lattice Green's functions, and the obtained result is in good agreement with the experimental result. Inclusion of interactions with acoustic phonons yields the Debye-Waller factor in the zero-phonon line spectrum of vibron solitons, in a manner analogous to the case of impurity-induced localized harmonic phonon modes in alkali halides.

  16. Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction

    PubMed Central

    Sokolowski-Tinten, K.; Shen, X.; Zheng, Q.; Chase, T.; Coffee, R.; Jerman, M.; Li, R. K.; Ligges, M.; Makasyuk, I.; Mo, M.; Reid, A. H.; Rethfeld, B.; Vecchione, T.; Weathersby, S. P.; Dürr, H. A.; Wang, X. J.

    2017-01-01

    We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels. PMID:28795080

  17. Influence of the chemical nature of implanted ions on the structure of a silicon layer damaged by implantation

    SciTech Connect

    Shcherbachev, K. D. Voronova, M. I.; Bublik, V. T.; Mordkovich, V. N. Pazhin, D. M.; Zinenko, V. I.; Agafonov, Yu. A.

    2013-12-15

    The influence of the implantation of silicon single crystals by fluorine, nitrogen, oxygen, and neon ions on the distribution of strain and the static Debye-Waller factor in the crystal lattice over the implanted-layer depth has been investigated by high-resolution X-ray diffraction. The density depth distribution in the surface layer of native oxide has been measured by X-ray reflectometry. Room-temperature implantation conditions have ensured the equality of the suggested ranges of ions of different masses and the energies transferred by them to the target. It is convincingly shown that the change in the structural parameters of the radiation-damaged silicon layer and the native oxide layer depend on the chemical activity of the implanted ions.

  18. General laws of X-ray reflection from rough surfaces: II. Conformal roughness

    NASA Astrophysics Data System (ADS)

    Kozhevnikov, I. V.

    2012-07-01

    Is shown that, if the expansions of the Debye-Waller formulas for the reflection and total scattering coefficients in the roughness height σ are limited to terms of order σ2, these expressions are valid for any layered inhomogeneous medium with conformal (depth-periodic) roughness and for any distribution function of the roughness heights if the roughness correlation length along the surface is sufficiently large. The advantages of measuring the total reflection coefficient, which characterizes the total intensity of radiation (both specularly reflected and diffusively scattered) directed by a rough surface back into vacuum, for solving the inverse problem of X-ray reflectometry (i.e., the reconstruction of the permittivity profile from a measured reflection curve) are discussed.

  19. Resuscitation great. Willem Einthoven: the development of the human electrocardiogram.

    PubMed

    Cajavilca, Christian; Varon, Joseph

    2008-03-01

    The electrocardiogram is one of the most commonly used diagnostic tools in healthcare. This ingenious device was developed and created in the early 1900s by Willem Einthoven, MD, PhD after studying the mechanisms of electromagnetism and Waller's capillary electrometer. Einthoven dedicated most of his research and clinical activities to improve the early versions of the electrical current recording medical devices. Einthoven's most notable invention was the string galvanometer which we now know as the electrocardiogram. Although the idea of using the string galvanometer as a diagnostic tool faced opposition by scientists and physicians of his time, he remained convinced of the potential of his machine to improve patient care. Einthoven's string galvanometer subsequently became the standard diagnostic tool for recognition and differentiation of heart conditions through the interpretation of cardiac waves, and has become standard practice in the field of resuscitation. In 1924, Einthoven received the Nobel Prize in Medicine for his development of the string galvanometer.

  20. The origins of electrocardiography in Poland.

    PubMed

    Gryglewski, Ryszard W

    2015-06-01

    The progress of science and technology in the 19(th) century enabled better understanding of the electrical activity that occurs during a heartbeat. However, it was only the construction and introduction of the galvanometer that cleared the way for appropriate experimental and clinical studies. Marey, Waller, Wenckebach, Einthoven, and Pardee are just examples of the world's pioneers of electrocardiography. Polish researchers, including Cybulski, Eiger, Rzętkowski, Surzycki, and Latkowski, also contributed to the development of this area of study. The following article is a review aiming to reconstruct the origins of electrocardiography in Poland, both as a measurement method used in experiments and as a diagnostic tool in clinical studies conducted in the years preceding the outbreak of World War I.

  1. A Mössbauer spectroscopy study of the conformational dynamics of native membrane proteins

    NASA Astrophysics Data System (ADS)

    Aleksandrov, A. Yu.; Novakova, A. A.; Semin, B. K.

    1987-07-01

    In a Mössbauer study of non-dehydrated membrane proteins from thermophilic green-blue algae we observed the behavior of the “narrow” and “broad” lines of their Mössbauer spectra during the heating from 80 to 270 K and found that the behavior of the full area SF under the spectrum resembles that of the Debye-Waller factor and that quadrupole splitting decreases drastically, from Δ = 0.7 mm/s to Δ ≈ 0, as the temperature is increased from 220 to 270 K. The mathematical treatment of the spectra and decomposition into three components corresponding to thermal, diffusional and conformational motions enabled us to explain the temperature-dependent changes in the spectra.

  2. The Effect of Boron Addition on the Atomic Structure and Microwave Magnetic Properties of FeGaB Thin Films

    SciTech Connect

    Gao, J.; Yang, A; Chen, Y; Kirkland, J; Lou, J; Sun, N; Vittoria, C; Harris, V

    2009-01-01

    Varying amounts of boron were added to the host FeGa alloy to investigate its impact upon local atomic structure and magnetic and microwave properties. The impact of B upon the local atomic structure in FeGaB films was investigated by extended x-ray absorption fine structure (EXAFS) analysis. The EXAFS fitting results revealed a contraction of lattice parameters with the introduction of B. The Debye-Waller factor determined from EXAFS fitting increases as a function of boron addition and abruptly changes during the structural evolution from crystalline to amorphous that occurs near 9% B. Upon the onset of this transition the static and microwave magnetic properties became exceptionally soft, with values of coercivity and ferromagnetic linewidth reducing to less than 1 Oe and 25 Oe, respectively.

  3. The effect of boron addition on the atomic structure and microwave magnetic properties of FeGaB thin films

    NASA Astrophysics Data System (ADS)

    Gao, Jinsheng; Yang, Aria; Chen, Yajie; Kirkland, J. P.; Lou, Jing; Sun, Nian X.; Vittoria, Carmine; Harris, Vincent G.

    2009-04-01

    Varying amounts of boron were added to the host FeGa alloy to investigate its impact upon local atomic structure and magnetic and microwave properties. The impact of B upon the local atomic structure in FeGaB films was investigated by extended x-ray absorption fine structure (EXAFS) analysis. The EXAFS fitting results revealed a contraction of lattice parameters with the introduction of B. The Debye-Waller factor determined from EXAFS fitting increases as a function of boron addition and abruptly changes during the structural evolution from crystalline to amorphous that occurs near 9% B. Upon the onset of this transition the static and microwave magnetic properties became exceptionally soft, with values of coercivity and ferromagnetic linewidth reducing to less than 1 Oe and 25 Oe, respectively.

  4. Temperature effect on the 002 structure factor of ternary Ga{sub 1-x}In{sub x}As crystals

    SciTech Connect

    Titantah, J. T.; Lamoen, D.; Schowalter, M.; Rosenauer, A.

    2007-08-15

    In this work, we study the effect of relaxation of the atomic positions and lattice parameter of mixed Ga{sub 1-x}In{sub x}As systems on the 002 electron atomic scattering amplitudes (ASA). The ASAs are shown to vary strongly with lattice parameter but to be indistinguishable for different In concentrations when the lattice parameter is held fixed. The resulting relationship between ASA and lattice parameter is then used in a finite temperature, zero pressure Monte Carlo relaxation of the mixed crystal. The consequence of the use of this atomic scattering amplitude is a reduction of the structure factor, leading to an increase of the In concentration at which the 002 structure factor vanishes. This method directly includes the effect of temperature on the ASA and on the structure factors and therefore does not require an explicit knowledge of the Debye-Waller factor.

  5. Fungible weights in logistic regression.

    PubMed

    Jones, Jeff A; Waller, Niels G

    2016-06-01

    In this article we develop methods for assessing parameter sensitivity in logistic regression models. To set the stage for this work, we first review Waller's (2008) equations for computing fungible weights in linear regression. Next, we describe 2 methods for computing fungible weights in logistic regression. To demonstrate the utility of these methods, we compute fungible logistic regression weights using data from the Centers for Disease Control and Prevention's (2010) Youth Risk Behavior Surveillance Survey, and we illustrate how these alternate weights can be used to evaluate parameter sensitivity. To make our work accessible to the research community, we provide R code (R Core Team, 2015) that will generate both kinds of fungible logistic regression weights. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  6. LLE (Laboratory for Laser Energetics) review

    SciTech Connect

    Kumpan, S.A.

    1990-01-01

    This volume of the LLE Review, covering the period April--June 1990, contains articles in two main sections, Progress in Laser Fusion and Advanced Technology Developments. The first article presents the theoretical interpretation of the glass-ablator cryogenic-implosion experiments recently conducted on OMEGA. It is followed by an article describing the analysis of neutron time-of-flight data taken during DT and DD experiments; and a discussion of the improvements to laser diagnostics that now provide for precise control of the OMEGA laser is given. This paper contains a report on the development of transparent conductive coatings for KDP crystals, and a discussion of the study of the transient-surface Debye-Waller effect in materials irradiated with an ultrafast laser.

  7. Stochastic model for protein flexibility analysis.

    PubMed

    Xia, Kelin; Wei, Guo-Wei

    2013-12-01

    Protein flexibility is an intrinsic property and plays a fundamental role in protein functions. Computational analysis of protein flexibility is crucial to protein function prediction, macromolecular flexible docking, and rational drug design. Most current approaches for protein flexibility analysis are based on Hamiltonian mechanics. We introduce a stochastic model to study protein flexibility. The essential idea is to analyze the free induction decay of a perturbed protein structural probability, which satisfies the master equation. The transition probability matrix is constructed by using probability density estimators including monotonically decreasing radial basis functions. We show that the proposed stochastic model gives rise to some of the best predictions of Debye-Waller factors or B factors for three sets of protein data introduced in the literature.

  8. The origins of electrocardiography in Poland

    PubMed Central

    2015-01-01

    The progress of science and technology in the 19th century enabled better understanding of the electrical activity that occurs during a heartbeat. However, it was only the construction and introduction of the galvanometer that cleared the way for appropriate experimental and clinical studies. Marey, Waller, Wenckebach, Einthoven, and Pardee are just examples of the world's pioneers of electrocardiography. Polish researchers, including Cybulski, Eiger, Rzętkowski, Surzycki, and Latkowski, also contributed to the development of this area of study. The following article is a review aiming to reconstruct the origins of electrocardiography in Poland, both as a measurement method used in experiments and as a diagnostic tool in clinical studies conducted in the years preceding the outbreak of World War I. PMID:26336508

  9. The Invalidating Childhood Environment Scale (ICES): psychometric properties and relationship to borderline personality symptomatology.

    PubMed

    Robertson, Christopher D; Kimbrel, Nathan A; Nelson-Gray, Rosemery O

    2013-06-01

    The objective of this study was to examine the psychometric properties of the Invalidating Childhood Environment Scale (ICES; Mountford, Corstorphine, Tomlinson, & Waller, 2004), a measure designed to retrospectively assess exposure to parental invalidation. The ICES was administered to a sample of female college students along with measures of parental bonding and borderline personality disorder (BPD) symptomatology. In contrast with previous findings, the ICES demonstrated excellent internal consistency within a nonclinical sample. It also correlated in the predicted directions with measures of parental bonding and BPD symptomatology. Taken together, these findings suggest that the ICES is a promising retrospective measure of parental invalidation. They also provide some support for the hypothesized link between parental invalidation and BPD symptomatology and suggest that additional research with clinical samples is needed.

  10. Sourcing and Communicating Cosmic Narratives -- A Role for the IAU?

    NASA Astrophysics Data System (ADS)

    Waller, William Howard

    2015-08-01

    Communicating astronomy critically depends on crafting competent and engaging stories. IAU Commission 55 has an opportunity to take the lead in exploring and celebrating astronomical narratives. Possibilities include an online "Astro Tales" publication of astronomical stories by IAU members for the general public (that complements the trade-oriented CAP), "Profiles in Astronomy" that feature interviews with IAU members, forums featuring exceptional science communicators and their cosmic stories, writing competitions for students, and an awards program. Through some version of these endeavors, the IAU could become a major arbiter of astronomical information and outreach worldwide. In this session, Dr. Waller will use his online journal "The Galactic Inquirer" at http://galacticinquirer.net as an exemplar and encourage input from participants.

  11. Which spatial abilities and strategies predict males' and females' performance in the object perspective test?

    PubMed

    Meneghetti, Chiara; Pazzaglia, Francesca; De Beni, Rossana

    2012-08-01

    The present study aimed to investigate whether different spatial abilities and strategies sustain perspective-taking (PT) performance in males and females. The PT task used was the Object Perspective Test (OPT, Kozhevnikov and Hegarty in Mem Cogn 29:745-756, 2001; Hegarty and Waller in Intelligence 32:175-191, 2004). A sample of 40 males and 40 females completed the OPT and several other visuo-spatial tasks and questionnaires. Multiple regression analysis showed that OPT performance was predicted positively by a spatial imagery preference and negatively by the specific use of mental rotation strategy (i.e. turning the sheet of paper). Gender interacted with the Embedded Figure Test (EFT), a spatial visualization task, since high EFT scores only positively predicted the OPT results in males. Overall, our results show that OPT performance is sustained by specific spatial abilities and strategies modulated, at least in part, by gender.

  12. Temperature measurements of shocked crystals by use of nanosecond X-ray diffraction

    SciTech Connect

    Murphy, William J.; Higginbotham, Andrew; Wark, Justin S.; Park, Nigel

    2007-12-12

    Over the past few years we have been pioneering the use of sub-nanosecond X-ray diffraction to determine the phase and compression of shocked crystals. It is well known that the deviation of atoms from their ideal lattice sites due to thermal motion reduces the integrated intensity within diffraction peaks - the so-called Debye-Waller effect, and thus it is pertinent to investigate whether line ratios might be sufficiently sensitive to be used as a viable temperature diagnostic. Clearly the matter is not completely straight-forward, as the Debye frequency of a solid also varies under compression. In our initial investigations we have calculated the ratios of intensities of high-order reflections assuming various forms of the Grueneisen parameter, and have also compared these results with those obtained from Molecular Dynamics simulations. Given the photon energies of nanosecond X-ray pulses that can currently be produced, we comment on the experimental feasibility of the technique.

  13. A summary of the low angle x-ray atomic scattering factors which have been measured by the critical voltage effect in High Energy Electron Diffraction (HEED)

    SciTech Connect

    Fox, A.G.; Fisher, R.M.

    1987-08-01

    A tabulated summary of all the accurate (/approximately/0.1%) low-angle x-ray atomic scattering (form) factors which have been determined by the systematic critical voltage technique in HEED is presented. For low atomic number elements (Z/approx lt/40) the low angle form factors can be significantly different to best free atom values, and so the best band structure calculated and/or x-ray measured form factors consistent with the critical voltage measurements are also indicated. At intermediate atomic numbers Zapprox. =40..-->..50 only the very low-angle form factors appear to be different to the best free atom values, and even then only by a small amount. For heavy elements (Z/approx lt/70) the best free atom form factors appear to agree very closely with the critical voltage measured values and so, in this case, critical voltage measurements give very accurate measurements of Debye-Waller factors. 48 refs.

  14. Flat-ramp vs. convex-concave thrust geometries in a deformable hanging wall: new insights from analogue modeling experiments

    NASA Astrophysics Data System (ADS)

    Almeida, Pedro; Tomas, Ricardo; Rosas, Filipe; Duarte, Joao; Terrinha, Pedro

    2015-04-01

    Different modes of strain accommodation affecting a deformable hanging-wall in a flat-ramp-flat thrust system were previously addressed through several (sandbox) analog modeling studies, focusing on the influence of different variables, such as: a) thrust ramp dip angle and friction (Bonini et al, 2000); b) prescribed thickness of the hanging-wall (Koy and Maillot, 2007); and c) sin-thrust erosion (compensating for topographic thrust edification, e.g. Persson and Sokoutis, 2002). In the present work we reproduce the same experimental procedure to investigate the influence of two different parameters on hanging-wall deformation: 1) the geometry of the thrusting surface; and 2) the absence of a velocity discontinuity (VD) that is always present in previous similar analogue modeling studies. Considering the first variable we use two end member ramp geometries, flat-ramp-flat and convex-concave, to understand the control exerted by the abrupt ramp edges in the hanging-wall stress-strain distribution, comparing the obtain results with the situation in which such edge singularities are absent (convex-concave thrust ramp). Considering the second investigated parameter, our motivation was the recognition that the VD found in the different analogue modeling settings simply does not exist in nature, despite the fact that it has a major influence on strain accommodation in the deformable hanging-wall. We thus eliminate such apparatus artifact from our models and compare the obtained results with the previous ones. Our preliminary results suggest that both investigated variables play a non-negligible role on the structural style characterizing the hanging-wall deformation of convergent tectonic settings were such thrust-ramp systems were recognized. Acknowledgments This work was sponsored by the Fundação para a Ciência e a Tecnologia (FCT) through project MODELINK EXPL/GEO-GEO/0714/2013. Pedro Almeida wants to thank to FCT for the Ph.D. grant (SFRH/BD/52556/2014) under the

  15. The effect of the exchange-correlation functional on H{sub 2} dissociation on Ru(0001)

    SciTech Connect

    Wijzenbroek, M.; Kroes, G. J.

    2014-02-28

    The specific reaction parameter (SRP) approach to density functional theory (DFT) has enabled a chemically accurate description of reactive scattering experiments for activated H{sub 2}–metal systems (H{sub 2} + Cu(111) and Cu(100)), but its application has not yet resulted in a similarly accurate description of non-activated or weakly activated H{sub 2}-metal systems. In this study, the effect of the choice of the exchange-correlation functional in DFT on the potential energy surface and dynamics of H{sub 2} dissociation on Ru(0001), a weakly activated system, is investigated. In total, full potential energy surfaces were calculated for over 20 different functionals. The functionals investigated include functionals incorporating an approximate description of the van der Waals dispersion in the correlation functional (vdW-DF and vdW-DF2 functionals), as well as the revTPSS meta-GGA. With two of the functionals investigated here, which include vdW-DF and vdW-DF2 correlation, it has been possible to accurately reproduce molecular beam experiments on sticking of H{sub 2} and D{sub 2}, as these functionals yield a reaction probability curve with an appropriate energy width. Diffraction probabilities computed with these two functionals are however too high compared to experimental diffraction probabilities, which are extrapolated from surface temperatures (T{sub s}) ⩾ 500 K to 0 K using a Debye–Waller model. Further research is needed to establish whether this constitutes a failure of the two candidate SRP functionals or a failure of the Debye–Waller model, the use of which can perhaps in future be avoided by performing calculations that include the effect of surface atom displacement or motion, and thereby of the experimental T{sub s}.

  16. EXAFS and XANES investigation of (Li, Ni) codoped ZnO thin films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Mino, Lorenzo; Gianolio, Diego; Bardelli, Fabrizio; Prestipino, Carmelo; Senthil Kumar, E.; Bellarmine, F.; Ramanjaneyulu, M.; Lamberti, Carlo; Ramachandra Rao, M. S.

    2013-09-01

    Ni doped, Li doped and (Li, Ni) codoped ZnO thin films were successfully grown using a pulsed laser deposition technique. Undoped and doped ZnO thin films were investigated using extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES). Preliminary investigations on the Zn K-edge of the undoped and doped ZnO thin films revealed that doping has not influenced the average Zn-Zn bond length and Debye-Waller factor. This shows that both Ni and Li doping do not appreciably affect the average local environment of Zn. All the doped ZnO thin films exhibited more than 50% of substitutional Ni, with a maximum of 77% for 2% Ni and 2% Li doped ZnO thin film. The contribution of Ni metal to the EXAFS signal clearly reveals the presence of Ni clusters. The Ni-Ni distance in the Ni0 nanoclusters, which are formed in the film, is shorter with respect to the reference Ni metal foil and the Debye-Waller factor is higher. Both facts perfectly reflect what is expected for metal nanoparticles. At the highest doping concentration (5%), the presence of Li favors the growth of a secondary NiO phase. Indeed, 2% Ni and 5% Li doped ZnO thin film shows %Nisub = 75 ± 11, %Nimet = 10 ± 8, %NiO = 15 ± 8. XANES studies further confirm that the substitutional Ni is more than 50% in all the samples. These results explain the observed magnetic properties.

  17. Comparative surface dynamics of amorphous and semicrystalline polymer films

    PubMed Central

    Becker, James S.; Brown, Ryan D.; Killelea, Daniel R.; Yuan, Hanqiu; Sibener, S. J.

    2011-01-01

    The surface dynamics of amorphous and semicrystalline polymer films have been measured using helium atom scattering. Time-of-flight data were collected to resolve the elastic and inelastic scattering components in the diffuse scattering of neutral helium atoms from the surface of a thin poly(ethylene terephthalate) film. Debye–Waller attenuation was observed for both the amorphous and semicrystalline phases of the polymer by recording the decay of elastically scattered helium atoms with increasing surface temperature. Thermal attenuation measurements in the specular scattering geometry yielded perpendicular mean-square displacements of 2.7•10-4 Å2 K-1 and 3.1•10-4 Å2 K-1 for the amorphous and semicrystalline surfaces, respectively. The semicrystalline surface was consistently ∼15% softer than the amorphous across a variety of perpendicular momentum transfers. The Debye–Waller factors were also measured at off-specular angles to characterize the parallel mean-square displacements, which were found to increase by an order of magnitude over the perpendicular mean-square displacements for both surfaces. In contrast to the perpendicular motion, the semicrystalline state was ∼25% stiffer than the amorphous phase in the surface plane. These results were uniquely accessed through low-energy neutral helium atom scattering due to the highly surface-sensitive and nonperturbative nature of these interactions. The goal of tailoring the chemical and physical properties of complex advanced materials requires an improved understanding of interfacial dynamics, information that is obtainable through atomic beam scattering methods. PMID:20713734

  18. HI--line Observations of Low Surface Brightness Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Thomas, D. L.; Taylor, C. L.; Brinks, E.; Skillman, E. D.

    1995-12-01

    We present HI--line observations of low--surface brightness (LSB) dwarf galaxies to survey their nearby environment (r <= 100 kpc) for HI bright companions. It is possible that star formation histories in dwarf galaxies can be strongly affected by interactions with nearby companions. If massive star formation can be triggered by galaxy--galaxy interactions, then the absence of such interactions likely explains the lack of star formation in LSB dwarf galaxies relative to their high surface brightness counterparts (HII galaxies). Taylor et al. (1995, ApJS, 99, 427) surveyed a sample of HII galaxies and found that 60% of the sample had nearby HI companions. In our sample of 18 LSB galaxies, we found that only 22% had companions detectable in HI. Furthermore, we find that the peak column densities for the LSB sample are all below {10(21) } HI atoms cm(-2) . This is below the empirically established level needed for star formation to occur in dwarf galaxies as discussed by Skillman (1987, in Star Formation in Galaxies, ed. C.J. Lonsdale Persson (NASA Conf. Pub. CP--2466), p.263), Kennicutt (1989, ApJ, 344, 685), van der Hulst et al. (1993, AJ, 106, 548), and Taylor et al. (1994, AJ, 107, 971).

  19. A new young stellar object in the S 187 complex: Photometry and spectroscopy

    NASA Astrophysics Data System (ADS)

    Zavagno, A.; Deharveng, L.; Caplan, J.

    1994-01-01

    We report the discovery in the S 187 complex of a young stellar object with an optical counterpart. High resolution spectroscopy in the red and near infrared indicates that this object is a pre-main-sequence star. In the red, the spectrumis dominated by a very bright H-alpha line with a total width (wing to wing) greater than 1000 km/s. This line exhibits a special type of P Cygni profile (Beal's Type III). The object's near infrared spectrum is dominated by the Ca II triplet emission at 8498 A, 8542 A, and 8662 A; these lines are broad and optically thick. Numerous Fe I and Fe II emission lines are observed also, B, V, R, I, H, K, and L magnitudes of the object, as well as its H-alpha luminosity, indicate that it is probably a Herbig late Be or early Ae star. It presents many characteristics of the 'outflow group' of Herbig stars identified by Hamann & Persson (1992B); it is very similar, both in luminosity and geometry, to the well-known young stellar objects V645 Cyh and R Mon.

  20. Site Testing at the Mexican National Astronomical Observatory in San Pedro Martir

    NASA Astrophysics Data System (ADS)

    Costero, R.; Echevarria, J.; Tapia, M.

    1996-05-01

    Measurements on the local seeing have been carried out during two and a half yea rs (March 29, 1992 to October 7, 1994), over a total of 378 nights. The Site Tes ting Telescope (STT) from the Steward Observatory yields a median seeing of 0.61 arcsec and a first quartile of 0.50 arcsec. Additional measurements with the Carnegie Monitor (CM), many of them done simultaneously with the STT, yield almost identical results. The Micro--Thermal Array (MTA), also from Steward Observatory, show that the seeing size decreases about 0.1 arcsec at 15 meters above the ground. The seeing does not show any dependence on wind velocity or direction, at least for wind velocities smaller than 40 kilometers per hour. We will present the details of these results. The participation of several persons in this project is here acknowledge, especially that of R. Cromwell and N. Wolf, from Steward Observatory, and S.E. Persson and D.M. Carr, from The Observatories of the Carnegie Institution of Washington.

  1. ADENOVIRUS INTERACTION WITH ITS CELLULAR RECEPTOR CAR.

    SciTech Connect

    HOWITT,J.; ANDERSON,C.W.; FREIMUTH,P.

    2001-08-01

    The mechanism of adenovirus attachment to the host cell plasma membrane has been revealed in detail by research over the past 10 years. It has long been known that receptor binding activity is associated with the viral fibers, trimeric spike proteins that protrude radially from the vertices of the icosahedral capsid (Philipson et al. 1968). In some adenovirus serotypes, fiber and other virus structural proteins are synthesized in excess and accumulate in the cell nucleus during late stages of infection. Fiber protein can be readily purified from lysates of cells infected with subgroup C viruses, for example Ad2 and Ad5 (Boulanger and Puvion 1973). Addition of purified fiber protein to virus suspensions during adsorption strongly inhibits infection, indicating that fiber and intact virus particles compete for binding sites on host cells (Philipson et al. 1968; Hautala et al. 1998). Cell binding studies using purified radiolabeled fiber demonstrated that fiber binds specifically and with high affinity to the cell plasma membrane, and that cell lines typically used for laboratory propagation of adenovirus have approximately 10{sup 4} high-affinity receptor sites per cell (Persson et al. 1985; Freimuth 1996). Similar numbers of high-affinity binding sites for radiolabeled intact virus particles also were observed (Seth et al. 1994).

  2. 'It [HIV] is part of the relationship': exploring communication among HIV-serodiscordant couples in South Africa and Tanzania.

    PubMed

    Rispel, Laetitia C; Cloete, Allanise; Metcalf, Carol A; Moody, Kevin; Caswell, Georgina

    2012-01-01

    In many sub-Saharan African countries, a high proportion of people living with HIV are in long-term serodiscordant relationships. This paper explores how HIV serodiscordance shapes communication among couples in long-term HIV-serodiscordant relationships. A total of 36 couples were purposively recruited through healthcare providers and civil society organisations in South Africa (26) and Tanzania (10). We explored couples' portrayal of living in a serodiscordant relationship by conducting semi-structured interviews with each partner separately, followed by a joint interview with both partners. Using an adaptation of Persson's model on sero-silence and sero-sharing, we categorised coping style as 'sero-silent' if partners reported that they did not talk much with each other about issues related to their serodiscordant status or as 'sero-sharing' if they portrayed HIV as being an issue which they dealt with together. Some couples exhibited features of both coping styles and, at times, partners differed in their ways of coping.

  3. Critical Velocity for Stick-Slip Motion of an Elastic Block

    NASA Astrophysics Data System (ADS)

    Luan, Binquan; Robbins, Mark

    2003-03-01

    Molecular dynamics simulations are used to study stick-slip motion of an elastic slider over a rigid substrate covered by a thin film. We study the variation of force with time and the critical velocity vc above which steady sliding is observed as a function of the mass M, size, geometry and stiffness of the slider. The results resolve a controversy over the relationship between vc and M. When the cross-section of the slider is independent of height above the contact, vc becomes independent of M as M increases.^1 However, when the cross-section rises with distance from the contact, as in the Surface Force Apparatus,^2 the stiffness is dominated by regions near the contact. In this case, the slider is effectively rigid and vc decreases as M-1/2 as predicted by Robbins and Thompson.^3 ^1B. N. J. Persson, Sliding Friction: Physical Principles and Applications (Springer, Berlin, 1998). ^2M. L. Gee, P. M. McGuiggan, J. N. Israelachvili and A. M. Homola, J. Chem. Phys. 93, 1895 (1990). ^3M. O. Robbins and P. A. Thompson, Science 253, 916 (1991).

  4. Elastic contact mechanics: percolation of the contact area and fluid squeeze-out.

    PubMed

    Persson, B N J; Prodanov, N; Krick, B A; Rodriguez, N; Mulakaluri, N; Sawyer, W G; Mangiagalli, P

    2012-01-01

    The dynamics of fluid flow at the interface between elastic solids with rough surfaces depends sensitively on the area of real contact, in particular close to the percolation threshold, where an irregular network of narrow flow channels prevails. In this paper, numerical simulation and experimental results for the contact between elastic solids with isotropic and anisotropic surface roughness are compared with the predictions of a theory based on the Persson contact mechanics theory and the Bruggeman effective medium theory. The theory predictions are in good agreement with the experimental and numerical simulation results and the (small) deviation can be understood as a finite-size effect. The fluid squeeze-out at the interface between elastic solids with randomly rough surfaces is studied. We present results for such high contact pressures that the area of real contact percolates, giving rise to sealed-off domains with pressurized fluid at the interface. The theoretical predictions are compared to experimental data for a simple model system (a rubber block squeezed against a flat glass plate), and for prefilled syringes, where the rubber plunger stopper is lubricated by a high-viscosity silicon oil to ensure functionality of the delivery device. For the latter system we compare the breakloose (or static) friction, as a function of the time of stationary contact, to the theory prediction.

  5. Tracking changes in natural organic carbon character during artificial infiltration using flourescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Köhler, Stephan J.; Lavonen, Elin; McCleaf, Philip; Hummel, Angelica; Berggren Kleja, Dan; Johansson, Per-Olof

    2016-04-01

    In many Nordic countries more than half of the drinking water is produced using surface water. Artificial infiltration allows increasing water withdrawal from groundwater but may not be sustainable during longer periods. Here we report results from a one year study on changes in dissolved organic carbon concentration (DOC) and DOC character along the whole infiltration area starting with the stream water until the drinking water plant raw water intake. Both DOC, fluorescence spectroscopy and LC-OCD are used to understand the observed changes in the aquatic phase. Large seasonal changes close to the infiltration basin contrasts with stable conditions further away. Selective removal of terrestrial type of DOC is coherent using both analytical techniques. A simple empirical relationship between Humic like material and absorbance developed elsewhere also holds in this system (Köhler et al 2016). Fluorescence is a fast and promising tool for tracking changes in natural organic carbon character during artificial infiltration. References Stephan J. Köhler, Elin Lavonen, Alexander Keucken, Philippe Schmitt-Kopplin, Tom Spanjer and Kenneth Persson. Upgrading coagulation with hollow-fibre nanofiltration for improved organic matter removal during surface water treatment Water research (2016) 89:232-240.

  6. The role of the roughness spectral breadth in elastic contact of rough surfaces

    NASA Astrophysics Data System (ADS)

    Yastrebov, Vladislav A.; Anciaux, Guillaume; Molinari, Jean-François

    2017-10-01

    We study frictionless and non-adhesive contact between elastic half-spaces with self-affine surfaces. Using a recently suggested corrective technique, we ensure an unprecedented accuracy in computation of the true contact area evolution under increasing pressure. This accuracy enables us to draw conclusions on the role of the surface's spectrum breadth (Nayak parameter) in the contact area evolution. We show that for a given normalized pressure, the contact area decreases logarithmically with the Nayak parameter. By linking the Nayak parameter with the Hurst exponent (or fractal dimension), we show the effect of the latter on the true contact area. This effect, undetectable for surfaces with poor spectral content, is quite strong for surfaces with rich spectra. Numerical results are compared with analytical models and other available numerical results. A phenomenological equation for the contact area growth is suggested with coefficients depending on the Nayak parameter. Using this equation, the pressure-dependent friction coefficient is deduced based on the adhesive theory of friction. Some observations on Persson's model of rough contact, whose prediction does not depend on Nayak parameter, are reported. Overall, the paper provides a unifying picture of rough elastic contact and clarifies discrepancies between preceding results.

  7. Surface-enhanced photocycle studied in a single photoreceptor protein molecule

    NASA Astrophysics Data System (ADS)

    Kalkan, Kaan; Xie, Aihua

    2009-03-01

    Photoactive yellow protein (PYP) functions as a blue light sensor for bacterial vision (phototaxis). The photocycle of PYP is initiated by the absorption of a blue photon (absorption peak at 446 nm) by its para-coumaric acid (pCA) chromophore. The photon energy is stored in the pCA through photoisomerization which is subsequently transferred to the rest of the protein through a series of conformational states, finally leading to its partial unfolding (signaling). The present work captures the distinct conformational changes of PYP at the single molecule level, during the execution of its photocycle. In particular, the present work employs surface-enhanced Raman scattering (SERS) active substrates and non-resonant excitation at 514 nm. As we confirm with regular Raman spectroscopy, the photocycle of PYP cannot be excited under 514 nm irradiation. On the contrary, 514 nm photons can excite the photocycle when PYP is adsorbed on silver, as we evidence from single molecule as well as ensemble-averaged SERS. In this case, the optical absorption of PYP shows a dramatic broadening (full width at half maximum shifting from 0.4 to 0.9 eV) such that electronic excitation can occur significantly at 514 nm. Therefore, the origin of the observed ``surface-enhanced photocycle'' is understood to be of the same as ``chemical enhancement'' in SERS in view of the ``adsorbate-induced resonance states'' model (Persson, 1993).

  8. HESS Opinions "On forecast (in)consistency in a hydro-meteorological chain: curse or blessing?"

    NASA Astrophysics Data System (ADS)

    Pappenberger, F.; Cloke, H. L.; Persson, A.; Demeritt, D.

    2011-01-01

    Flood forecasting increasingly relies on Numerical Weather Prediction (NWP) forecasts to achieve longer lead times (see Cloke et al., 2009; Cloke and Pappenberger, 2009). One of the key difficulties that is emerging in constructing a decision framework for these flood forecasts is when consecutive forecasts are different, leading to different conclusions regarding the issuing of forecasts, and hence inconsistent. In this opinion paper we explore some of the issues surrounding such forecast inconsistency (also known as "jumpiness", "turning points", "continuity" or number of "swings"; Zoster et al., 2009; Mills and Pepper, 1999; Lashley et al., 2008). We begin by defining what forecast inconsistency is; why forecasts might be inconsistent; how we should analyse it; what we should do about it; how we should communicate it and whether it is a totally undesirable property. The property of consistency is increasingly emerging as a hot topic in many forecasting environments (for a limited discussion on NWP inconsistency see Persson, 2011). However, in this opinion paper we restrict the discussion to a hydro-meteorological forecasting chain in which river discharge forecasts are produced using inputs from NWP. In this area of research (in)consistency is receiving recent interest and application (see e.g., Bartholmes et al., 2008; Pappenberger et al., 2011).

  9. Determining the Locations of Brown Dwarfs in Young Star Clusters

    NASA Technical Reports Server (NTRS)

    Porter, Lauren A.

    2005-01-01

    Brown dwarfs are stellar objects with masses less than 0.08 times that of the Sun that are unable to sustain nuclear fusion. Because of the lack of fusion, they are relatively cold, allowing the formation of methane and water molecules in their atmospheres. Brown dwarfs can be detected by examining stars' absorption spectra in the near-infrared to see whether methane and water are present. The objective of this research is to determine the locations of brown dwarfs in Rho Ophiuchus, a star cluster that is only 1 million years old. The cluster was observed in four filters in the near-infrared range using the Wide-Field Infra-Red Camera (WIRC) on the 100" DuPont Telescope and Persson's Auxiliary Nasymith Infrared Camera (PANIC) on the 6.5-m Magellan Telescope. By comparing the magnitude of a star in each of the four filters, an absorption spectrum can be formed. This project uses standard astronomical techniques to reduce raw frames into final images and perform photometry on them to obtain publishable data. Once this is done, it will be possible to determine the locations and magnitudes of brown dwarfs within the cluster.

  10. Vibrational properties of a Li -- OH complex in ZnO

    NASA Astrophysics Data System (ADS)

    Martin, K. R.; Blaney, P. M.; Shi, G. A.; Stavola, M.; Fowler, W. B.

    2006-03-01

    Considerable interest has developed on the potential use of II-VI oxides as electronic and optical materials. In several cases alkali atoms have been suggested as dopants. We report on the theoretical and experimental investigation of infrared and vibrational properties of a Li-OH complex in ZnO. Earlier infrared experiments[1] revealed a broad OH-like band centered at 3577.3 cm-1 (12K), with full width at half maximum ranging from 0.4 cm-1 (12K) to 41.3 cm-1 (300K) and a corresponding shift in peak position of - 29 cm-1, suggesting a significant coupling of the OH stretch with other modes. We have performed similar experiments on the OD version of this defect and have theoretically investigated[2,3] the coupling of these stretch modes to other modes. The lack of a significant isotope dependence of the resulting parameters suggests that the defect couples to the host rather than the large-amplitude motion of the H or D itself. 1. L. E. Halliburton et al., J. Appl. Phys. 96, 7168 (2004). 2. B. N. J. Persson and R. Ryberg, Phys. Rev. B 32, 3586 (1985). [3] M. Budde et al., Phys. Rev. B 63, 195203 (2001).

  11. Determining the Locations of Brown Dwarfs in Young Star Clusters

    NASA Technical Reports Server (NTRS)

    Porter, Lauren A.

    2005-01-01

    Brown dwarfs are stellar objects with masses less than 0.08 times that of the Sun that are unable to sustain nuclear fusion. Because of the lack of fusion, they are relatively cold, allowing the formation of methane and water molecules in their atmospheres. Brown dwarfs can be detected by examining stars' absorption spectra in the near-infrared to see whether methane and water are present. The objective of this research is to determine the locations of brown dwarfs in Rho Ophiuchus, a star cluster that is only 1 million years old. The cluster was observed in four filters in the near-infrared range using the Wide-Field Infra-Red Camera (WIRC) on the 100" DuPont Telescope and Persson's Auxiliary Nasymith Infrared Camera (PANIC) on the 6.5-m Magellan Telescope. By comparing the magnitude of a star in each of the four filters, an absorption spectrum can be formed. This project uses standard astronomical techniques to reduce raw frames into final images and perform photometry on them to obtain publishable data. Once this is done, it will be possible to determine the locations and magnitudes of brown dwarfs within the cluster.

  12. Surface topography and contact mechanics of dry and wet human skin.

    PubMed

    Kovalev, Alexander E; Dening, Kirstin; Persson, Bo N J; Gorb, Stanislav N

    2014-01-01

    The surface topography of the human wrist skin is studied by using optical and atomic force microscopy (AFM) methods. By using these techniques the surface roughness power spectrum is obtained. The Persson contact mechanics theory is used to calculate the contact area for different magnifications, for the dry and wet skin. The measured friction coefficient between a glass ball and dry and wet skin can be explained assuming that a frictional shear stress σf ≈ 13 MPa and σf ≈ 5 MPa, respectively, act in the area of real contact during sliding. These frictional shear stresses are typical for sliding on surfaces of elastic bodies. The big increase in friction, which has been observed for glass sliding on wet skin as the skin dries up, can be explained as result of the increase in the contact area arising from the attraction of capillary bridges. Finally, we demonstrated that the real contact area can be properly defined only when a combination of both AFM and optical methods is used for power spectrum calculation.

  13. Physical analysis of the state- and rate-dependent friction law. II. Dynamic friction

    NASA Astrophysics Data System (ADS)

    Baumberger, T.; Berthoud, P.; Caroli, C.

    1999-08-01

    We report an extensive study of dynamic friction at nonlubricated multicontact interfaces between nominally flat bodies, rough on the micrometer scale, made of identical polymer glasses. This work, which complements a previous study of static friction on the same systems, has been performed at temperatures ranging from 20 °C to close below the glass transitions. The data are analyzed within the framework of the Rice-Ruina state- and rate-dependent friction model. We show that this phenomenology is equivalent to a generalized Tabor decomposition of the friction force into the product of an age-dependent load-bearing area and of a velocity-strengthening interfacial shear stress. Quantitative analysis of this latter term leads to associate velocity strengthening with thermal activation of basic dynamical units of nanometer dimensions. We interpret our results with the help of a model due to Persson, in which shear is localized in a nanometer-thick interfacial adhesive layer, pinned elastically at a low shear level. Sliding proceeds via uncorrelated depinning of ``nanoblocks'' which constitute the layer. It is the competition between the drive-induced loading of these blocks up to their depinning stress and the thermally activated premature depinning events which leads to the velocity-strengthening contribution to the interfacial strength. In our interpretation, friction therefore appears as the localized elastoplastic response of a confined amorphous interfacial layer.

  14. Wavelength Scaling of High-Harmonic Yield: Threshold Phenomena and Bound State Symmetry Dependence

    NASA Astrophysics Data System (ADS)

    Starace, Anthony F.; Frolov, M. V.; Manakov, N. L.

    2008-05-01

    Using our recent description of harmonic generation (HG) in terms of a system's complex quasienergy [1], we analyze the harmonic power PδE(λ) (over a fixed interval, δE, of harmonic energies) as a function of wavelength and show that it reproduces the wavelength scaling predicted recently by two groups of authors [2, 3] based on solutions of the time-dependent Schr"odinger equation: PδE(λ)˜&-xcirc;, where x 5-6. Furthermore, the oscillations of PδE(λ) on a fine λ scale found in Ref. [3] are then shown to have a quantum origin, involving threshold phenomena within a system of interacting ionization and HG channels. Our results are also shown to be sensitive to the bound state wave function's symmetry. [1] M.V. Frolov, A.V. Flegel, N.L. Manakov, and A.F. Starace, Phys. Rev. A 75, 063407 (2007). [2] J. Tate, T. Auguste, H.G. Muller, P. Salières, P. Agostini, and L.F. DiMauro, Phys. Rev. Lett.98, 013901 (2007). [3] K. Schiessl, K.L. Ishikava, E. Persson, and J. Burgd"orfer, Phys. Rev. Lett.99, 253903 (2007).

  15. Ab initio calculations of correlated electron dynamics in ultrashort pulses

    NASA Astrophysics Data System (ADS)

    Feist, Johannes

    2010-03-01

    The availability of ultrashort and intense light pulses on the femtosecond and attosecond timescale promises to allow to directly probe and control electron dynamics on their natural timescale. A crucial ingredient to understanding the dynamics in many-electron systems is the influence of electron correlation, induced by the interelectronic repulsion. In order to study electron correlation in ultrafast processes, we have implemented an ab initio simulation of the two-electron dynamics in helium atoms. We solve the time-dependent Schr"odinger equation in its full dimensionality, with one temporal and five spatial degrees of freedom in linearly polarized laser fields. In our computational approach, the wave function is represented through a combination of time-dependent close coupling with the finite element discrete variable representation, while time propagation is performed using an Arnoldi-Lanczos approximation with adaptive step size. This approach is optimized to allow for efficient parallelization of the program and has been shown to scale linearly using up to 1800 processor cores for typical problem sizes. This has allowed us to perform highly accurate and well- converged computations for the interaction of ultrashort laser pulses with He. I will present some recent results on using attosecond and femtosecond pulses to probe and control the temporal structure of the ionization process. This work was performed in collaboration with Stefan Nagele, Renate Pazourek, Andreas Kaltenb"ack, Emil Persson, Barry I. Schneider, Lee A. Collins, and Joachim Burgd"orfer.

  16. Temperature dependences of line widths and peak positions of optical absorption peaks due to localized vibration of hydrogen Si

    NASA Astrophysics Data System (ADS)

    Suezawa, M.; Fukata, N.; Saito, M.; Yamada-Kaneta, H.

    2001-12-01

    We studied the temperature dependences of line widths and peak positions of optical absorptions due to the hydrogen bound to point defects and acceptors in Si. Specimens were prepared from floating-zone-grown Si crystals of high-purity and of p-type, doped with group III acceptors. They were doped with H by heating at 1300°C in H 2 gas followed by quenching. The former specimen was then irradiated with 3 MeV electrons at RT to form complexes of H and point defects and the latter specimens were annealed at 150°C to form H-acceptor pairs. We measured their optical absorption spectra by an FT-IR spectrometer in the temperature range of 6 K and RT. Peaks due to localized vibrational modes of H bound to acceptors and point defects were well fitted with Lorentzian line shapes. The temperature dependences of those line widths and peak positions were analyzed with the dephasing model proposed by Persson and Ryberg.

  17. The hysteretic contribution of friction for the polished rubber on the concrete surface

    NASA Astrophysics Data System (ADS)

    Feshanjerdi, M.; Khorrami, M.; Masoudi, A. A.; Razzaghi Kashani, M.

    2017-02-01

    The rubber friction coefficient, and the contact area during stationary sliding is calculated, for the contact of a polished rubber block and a concrete surface, when both surfaces are rough. The calculation is based on an extended version of Persson's contact mechanics theory. Compared to only the substrate being rough, when both of the surfaces are rough but their cross correlation is zero, the friction coefficient is larger. Introducing a positive correlation decreases the friction coefficient, while introducing a negative correlation increases the friction coefficient. To support these theoretical arguments, some experiments have been performed. We have produced roughness on the rubber surface, using abrasive paper, and measured the surface topographies for the concrete and the polished rubber surfaces. The auto spectral density functions for the both surfaces have been calculated, and the rubber viscoelastic modulus mastercurve has been obtained. We have measured the rubber friction at different sliding velocities, when the rubber surfaces are rough and smooth, and compared it to the theoretical results. It is seen that when the rubber surface is rough, the rubber friction coefficient is larger compared to the case the rubber surface is smooth. The theoretical results are in good agreement with experimental observation.

  18. Extremely red objects in the fields of high redshift radio galaxies

    NASA Technical Reports Server (NTRS)

    Persson, S. E.; Mccarthy, P. J.; Dressler, Alan; Matthews, Keith

    1993-01-01

    We are engaged in a program of infrared imaging photometry of high redshift radio galaxies. The observations are being done using NICMOS2 and NICMOS3 arrays on the DuPont 100-inch telescope at Las Campanas Observatory. In addition, Persson and Matthews are measuring the spectral energy distributions of normal cluster galaxies in the redshift range 0 to 1. These measurements are being done with a 58 x 62 InSb array on the Palomar 5-m telescope. During the course of these observations we have imaged roughly 20 square arcminutes of sky to limiting magnitudes greater than 20 in the J, H, and K passbands (3 sigma in 3 square arcseconds). We have detected several relatively bright, extremely red, extended objects during the course of this work. Because the radio galaxy program requires Thuan-Gunn gri photometry, we are able to construct rough photometric energy distributions for many of the objects. A sample of the galaxy magnitudes within 4 arcseconds diameter is given. All the detections are real; either the objects show up at several wavelengths, or in subsets of the data. The reddest object in the table, 9ab'B' was found in a field of galaxies in a rich cluster at z = 0.4; 9ab'A' lies 8 arcseconds from it.

  19. Elucidating the contact mechanics of aluminum silicon surfaces with Green's function molecular dynamics

    NASA Astrophysics Data System (ADS)

    Campañá, Carlos; Müser, Martin H.; Denniston, Colin; Qi, Yue; Perry, Thomas A.

    2007-12-01

    We study the contact mechanics of a flat, elastic wall pressed against a rigid substrate with Green's function molecular dynamics. The substrate's height profiles are parametrized from atomic force microscope topography measurements of two different aluminum-silicon alloys. In both samples, roughness lives on disparate length scales, i.e., on relatively large scales defined by size and mean separation of load-bearing silicon particles and on much smaller scales associated with the roughness on top of individual particles. The major differences between the two alloys are their silicon content and the typical silicon particle geometry. These differences lead to quite different stress distributions on both mesoscale and microscale in our calculations. A common feature is that the stress distribution decays exponentially for large stresses σ and not like a Gaussian. Persson's contact mechanics theory is generalized to the case where contact can only occur on silicon particles. This generalization predicts relatively accurate microscopic mean square stresses, however, it fails to predict accurate numbers for mean square stresses on the mesoscopic scales. Local overlap models are not accurate either, because they fail to describe the contact morphology.

  20. Spin-polarized currents and noise in normal-metal/superconductor junctions with Yu-Shiba-Rusinov impurities

    NASA Astrophysics Data System (ADS)

    Persson, Daniel; Shevtsov, Oleksii; Löfwander, Tomas; Fogelström, Mikael

    2016-10-01

    Conventional superconductors disordered by magnetic impurities demonstrate physical properties that are drastically different from their pristine counterparts. In our previous work [D. Persson et al., Phys. Rev. B 92, 245430 (2015), 10.1103/PhysRevB.92.245430], we explored the spectral and thermodynamic properties of such systems for two extreme cases: completely random and ferromagnetically aligned impurity magnetic moments. Here we consider the transport properties of these systems and show that they have a potential to be used in superconducting spintronic devices. Each magnetic impurity contributes a Yu-Shiba-Rusinov (YSR) bound state to the spectrum, residing at subgap energies. Provided the YSR states form metallic bands, we demonstrate that the tunneling current carried by these states can be highly spin polarized when the impurities are ferromagnetically ordered. The spin polarization can be switched by tuning the bias voltage. Moreover, even when the impurity spins are completely uncorrelated, one can still achieve almost 100 % spin polarization of the current, if the tunnel interface is spin active. We compute electric current and noise, varying parameters of the interface between tunneling and fully transparent regimes, and analyze the relative role of single-particle and Andreev reflection processes.

  1. Seine estuary modelling and AirSWOT measurements validation

    NASA Astrophysics Data System (ADS)

    Chevalier, Laetitia; Lyard, Florent; Laignel, Benoit

    2013-04-01

    In the context of global climate change, knowing water fluxes and storage, from the global scale to the local scale, is a crucial issue. The future satellite SWOT (Surface Water and Ocean Topography) mission, dedicated to the surface water observation, is proposed to meet this challenge. SWOT main payload will be a Ka-band Radar Interferometer (KaRIn). To validate this new kind of measurements, preparatory airborne campaigns (called AirSWOT) are currently being designed. AirSWOT will carry an interferometer similar to Karin: Kaspar-Ka-band SWOT Phenomenology Airborne Radar. Some campaigns are planned in France in 2014. During these campaigns, the plane will fly over the Seine River basin, especially to observe its estuary, the upstream river main channel (to quantify river-aquifer exchange) and some wetlands. The present work objective is to validate the ability of AirSWOT and SWOT, using a Seine estuary hydrodynamic modelling. In this context, field measurements will be collected by different teams such as GIP (Public Interest Group) Seine Aval, the GPMR (Rouen Seaport), SHOM (Hydrographic and Oceanographic Service of the Navy), the IFREMER (French Research Institute for Sea Exploitation), Mercator-Ocean, LEGOS (Laboratory of Space Study in Geophysics and Oceanography), ADES (Data Access Groundwater) ... . These datasets will be used first to validate locally AirSWOT measurements, and then to improve a hydrodynamic simulations (using tidal boundary conditions, river and groundwater inflows ...) for AirSWOT data 2D validation. This modelling will also be used to estimate the benefit of the future SWOT mission for mid-latitude river hydrology. To do this modelling,the TUGOm barotropic model (Toulouse Unstructured Grid Ocean model 2D) is used. Preliminary simulations have been performed by first modelling and then combining to different regions: first the Seine River and its estuarine area and secondly the English Channel. These two simulations h are currently being

  2. Spectro-dynamical asteroid families in the main belt

    NASA Astrophysics Data System (ADS)

    Bus, S.

    2014-07-01

    Spectral observations of collisionally-derived asteroid families continue to provide strong evidence that the surfaces of members from each family are spectrally homogeneous. This apparent homogeneity provides motivation to use new approaches in combining physical observations, such as spectral colors or albedo, with orbital parameters for the identification of family members and interlopers (e.g. [1,2]). The work described here uses the combined Sloan Digital Sky Survey colors (fourth release of the SDSS Moving Object Catalog [3]) and proper orbital elements from the Asteroids-Dynamics Site (AstDyS [4]) for 39,147 asteroids with semimajor axes between 2.1 and 3.2 au to search for ''spectro-dynamical'' families. The analysis is designed to identify groupings of asteroids that form statistically significant peaks in number density compared to the background population for a fixed spectral color distribution. A number of techniques from multivariate analysis are folded together and have been calibrated to accommodate asteroid families of different size, shape, and number density. In the final phase of the analysis, the number density for asteroids within a given spectral range is represented by 2-dimensional contour slices through proper-element space, and a visual inspection is made to confirm the reality of each grouping. Some families show evidence of complex structure that may be indicative of multiple collisional events over the history of the family. An example of this is the Karin family, which is located within the older, much larger Koronis family [5]. While both families are composed of asteroids classified as S-types, there is a significant color difference between the Koronis and Karin asteroids that is used to distinguish between members of the two families. In the same way, the Vesta family appears to be comprised of two distributions of asteroids that are offset in proper-element space and exhibit a statistically significant difference in the shape of

  3. New insights on the Karoo shale gas potential from borehole KZF-1 (Western Cape, South Africa)

    NASA Astrophysics Data System (ADS)

    Campbell, Stuart A.; Götz, Annette E.; Montenari, Michael

    2016-04-01

    A study on world shale reserves conducted by the Energy Information Agency (EIA) in 2013 concluded that there could be as much as 390 Tcf recoverable reserves of shale gas in the southern and south-western parts of the Karoo Basin. This would make it the 8th-largest shale gas resource in the world. However, the true extent and commercial viability is still unknown, due to the lack of exploration drilling and modern 3D seismic. Within the framework of the Karoo Research Initiative (KARIN), two deep boreholes were drilled in the Eastern and Western Cape provinces of South Africa. Here we report on new core material from borehole KZF-1 (Western Cape) which intersected the Permian black shales of the Ecca Group, the Whitehill Formation being the main target formation for future shale gas production. To determine the original source potential for shale gas we investigated the sedimentary environments in which the potential source rocks formed, addressing the research question of how much sedimentary organic matter the shales contained when they originally formed. Palynofacies indicates marginal marine conditions of a stratified basin setting with low marine phytoplankton percentages (acritarchs, prasinophytes), good AOM preservation, high terrestrial input, and a high spores:bisaccates ratio (kerogen type III). Stratigraphically, a deepening-upward trend is observed. Laterally, the basin configuration seems to be much more complex than previously assumed. Furthermore, palynological data confirms the correlation of marine black shales of the Prince Albert and Whitehill formations in the southern and south-western parts of the Karoo Basin with the terrestrial coals of the Vryheid Formation in the north-eastern part of the basin. TOC values (1-6%) classify the Karoo black shales as promising shale gas resources, especially with regard to the high thermal maturity (Ro >3). The recently drilled deep boreholes in the southern and south-western Karoo Basin, the first since the

  4. Willem Einthoven and the birth of clinical electrocardiography a hundred years ago.

    PubMed

    Barold, S Serge

    2003-01-01

    The first electrocardiogram (ECG) from the intact human heart was recorded with a mercury capillary electrometer by Augustus Waller in May 1887 at St. Mary's Hospital, London. The tracings were poor and exhibited only 2 distorted deflections. Willem Einthoven (1860-1927) who was professor of physiology at the University of Leiden, The Netherlands, began his studies of the ECG with the mercury capillary electrometer, and improved its distortion mathematically so that he was finally able to register a good representation of the ECG before the beginning of the twentieth century. He later further improved ECG recordings with the introduction of a string galvanometer of his design. Einthoven published his first article about the string galvanometer in 1901, followed by a more detailed description in 1903 which included a report of ECGs taken with the new instrument. The year 2002 marks the centennial of Willem Einthoven's first recording of the ECG in a clinically applicable fashion with the string galvanometer. The clinical use of Einthoven's immobile equipment required transtelephonic transmission of the ECG from the physiology laboratory to the clinic at the Academic Hospital about a mile away as documented in the 1906 paper on the "télécardiogramme". This report contained a wealth of ECG patterns and arrhythmias. Einthoven developed a system of electrocardiographic standardization that continues to be used all over the world and introduced the triaxial bipolar system with 3 limb leads and thus established uniformity of the recording process. Einthoven also conceived the famous equilateral triangle with leads I, II, and III at its sides and the calculation of the electrical axis (in the frontal plane) depicted as a single vector with an arrow at the center of the triangle. Einthoven recognized the great potential importance of the ECG as a diagnostic and investigative tool and his achievements made him the founder of modern electrocardiography. He was awarded the

  5. Cross linking molecular systems to form ultrathin dielectric layers

    NASA Astrophysics Data System (ADS)

    Feng, Danqin

    Dehydrogenation leads to cross linking of polymer or polymer like formation in very different systems: self-assembled monolayers and in closo -carboranes leading to the formation of semiconducting and dielectric boron carbide. We find evidence of intermolecular interactions for a self-assembled monolayer (SAM) formed from a large molecular adsorbate, [1,1';4',1"-terphenyl]-4,4"-dimethanethiol, from the dispersion of the molecular orbitals with changing the wave vector k and from the changes with temperature. With the formation self assembled molecular (SAM) layer, the molecular orbitals hybridize to electronic bands, with indications of significant band dispersion of the unoccupied molecular orbitals. Although organic adsorbates and thin films are generally regarded as "soft" materials, the effective Debye temperature, indicative of the dynamic motion of the lattice normal to the surface, can be very high, e.g. in the multilayer film formed from [1,1'-biphenyl]-4,4'-dimethanethiol (BPDMT). Depending on molecular orientation, the effective Debye temperature can be comparable to that of graphite due to the 'stiffness' of the benzene rings, but follows the expected Debye-Waller behavior for the core level photoemission intensities with temperature. This is not always the case. We find that a monomolecular film formed from [1,1';4',1"-terphenyl]-4,4"-dimethanethiol deviates from Debye-Waller temperature behavior and is likely caused by temperature dependent changes in molecular orientation. We also find evidence for the increase in dielectric character with polymerization (cross-linking) in spite of the decrease in the HOMO-LUMO gap upon irradiation of TPDMT. The changes in the HOMO-LUMO gap, with cross-linking, are roughly consistent with the band dispersion. The decomposition and cross-linking processes are also accompanied by changes in molecular orientation. The energetics of the three isomeric carborane cage compounds [ closo-1,2-orthocarborane, closo-1

  6. Scientists Outline Volcanic Ash Risks to Aviation

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-01-01

    The ash clouds that belched out of Iceland's Eyjafjallajökull volcano last spring and dispersed over much of Europe, temporarily paralyzing aviation, were vast smoke signal warnings about the hazard that volcanic ash poses for air traffic around the world. At a 15 December news briefing at the AGU Fall Meeting in San Francisco, two experts with the U.S. Geological Survey (USGS) presented an overview of the damage airplanes can sustain from rock fragment- and mineral fragment-laden ash, an update on efforts to mitigate the hazard of ash, and an outline of further measures that are needed to address the problem. Between 1953 and 2009, there were 129 reported encounters of aircraft with volcanic ash clouds, according to a newly released USGS document cited at the briefing. The report, “Encounters of aircraft with volcanic ash clouds: A compilation of known incidents, 1953-2009,” by Marianne Guffanti, Thomas Casadevall, and Karin Budding, indicates that 26 encounters involved significant damage to the airplanes; nine of those incidents resulted in engine shutdown during flight. The report, which does not focus on the effects on airplanes of cumulative exposure to dilute ash and does not include data since 2009, indicates that “ash clouds continue to pose substantial risks to safe and efficient air travel globally.”

  7. An Infrared Radiative Transfer Parameterization For A Venus General Circulation Model

    NASA Astrophysics Data System (ADS)

    Eymet, Vincent; Fournier, R.; Lebonnois, S.; Bullock, M. A.; Dufresne, J.; Hourdin, F.

    2006-09-01

    A new 3-dimensional General Circulation Model (GCM) of Venus'atmosphere is curently under development at the Laboratoire de Meteorologie Dynamique, in the context of the Venus-Express mission. Special attention was devoted to the parameterization of infrared radiative transfer: this parameterization has to be both very fast and sufficiently accurate in order to provide valid results over extented periods of time. We have developped at the Laboratoire d'Energetique a Monte-Carlo code for computing reference radiative transfer results for optically thick inhomogeneous scattering planetary atmospheres over the IR spectrum. This code (named KARINE) is based on a Net-Exchange Rates formulation, and uses a k-distribution spectral model. The Venus spectral data, that was compiled at the Southwest Research Institute, accounts for gaseous absorption and scattering, typical clouds absorption and scattering, as well as CO2 and H2O absorption continuums. We will present the Net-Exchange Rates matrix that was computed using the Monte-Carlo approach. We will also show how this matrix has been used in order to produce a first-order radiative transfer parameterization that is used in the LMD Venus GCM. In addition, we will present how the proposed radiative transfer model was used in a simple convective-radiative equilibrium model in order to reproduce the main features of Venus' temperature profile.

  8. Extended Solar System Structures Observed by WISE

    NASA Astrophysics Data System (ADS)

    Sykes, Mark V.; Masci, Frank; Cutri, Roc; Walker, Russell; Mainzer, Amy; Bauer, James; Stevenson, Rachel; Tricarico, Pasquale

    2014-11-01

    Extended structures associated with recent asteroid collisions and comets were detected by the Infrared Astronomical Satellite, which conducted the first survey of the thermal emission of the sky in 1983. Twenty-seven years later, the Wide-field Infrared Survey Explorer (WISE), conducted a more sensitive survey of the sky at wavelengths spanning the shorter IRAS bandpasses and detected many of these same structures. Initial identifications include asteroid dust bands associated with collisions giving rise to the Karin and Beagle clusters within the Koronis and Themis asteroid families, respectively. An additional pair of bands is associated with the collision giving rise to the Veritas asteroid family. Comet trails associated with short-period comets have also been observed. Type 2 trails, detected by IRAS and possibly associated with asteroid collisions within the past few thousand years, have yet to be identified. Because WISE is significantly more sensitive than IRAS in the mid-infrared, it has detected some trails extending much further over their orbits and will greatly expand the catalog of trails detected in addition to those observed by IRAS and Spitzer (the latter by targeted observations). WISE and the yet more sensitive NEOCAM survey telescope will provide important insights into the recent collisional history of the asteroid belt and the nature and evolution of comets.

  9. Evaluation of New Fluorescent Lipophosphoramidates for Gene Transfer and Biodistribution Studies after Systemic Administration

    PubMed Central

    Belmadi, Nawal; Berchel, Mathieu; Denis, Caroline; Berthe, Wilfried; Sibiril, Yann; Le Gall, Tony; Haelters, Jean-Pierre; Jaffres, Paul-Alain; Montier, Tristan

    2015-01-01

    The objective of lung gene therapy is to reach the respiratory epithelial cells in order to deliver a functional nucleic acid sequence. To improve the synthetic carrier’s efficacy, knowledge of their biodistribution and elimination pathways, as well as cellular barriers faced, depending on the administration route, is necessary. Indeed, the in vivo fate guides the adaptation of their chemical structure and formulation to increase their transfection capacity while maintaining their tolerance. With this goal, lipidic fluorescent probes were synthesized and formulated with cationic lipophosphoramidate KLN47 (KLN: Karine Le Ny). We found that such formulations present constant compaction properties and similar transfection results without inducing additional cytotoxicity. Next, biodistribution profiles of pegylated and unpegylated lipoplexes were compared after systemic injection in mice. Pegylation of complexes led to a prolonged circulation in the bloodstream, whereas their in vivo bioluminescent expression profiles were similar. Moreover, systemic administration of pegylated lipoplexes resulted in a transient liver toxicity. These results indicate that these new fluorescent compounds could be added into lipoplexes in small amounts without perturbing the transfection capacities of the formulations. Such additional properties allow exploration of the in vivo biodistribution profiles of synthetic carriers as well as the expression intensity of the reporter gene. PMID:26540038

  10. The role of IL-17 signaling in regulation of the liver-brain axis and intestinal permeability in Alcoholic Liver Disease

    PubMed Central

    Ma, Hsiao-Yen; Xu, Jun; Liu, Xiao; Zhu, Yunheng; Gao, Bin; Karin, Michael; Tsukamoto, Hidekazu; Jeste, Dilip V.; Grant, Igor; Roberts, Amanda J; Contet, Candice; Geoffroy, Cedric; Zheng, Binhai; Brenner, David; Kisseleva, Tatiana

    2016-01-01

    Alcoholic liver disease (ALD) progresses from a normal liver, to steatosis, steatohepatitis, fibrosis and hepatocellular carcinoma (HCC). Despite intensive studies, the pathogenesis of ALD is poorly understood, in part due to a lack of suitable animal models which mimic the stages of ALD progression. Furthermore, the role of IL-17 in ALD has not been evaluated. We and others have recently demonstrated that IL-17 signaling plays a critical role in development of liver fibrosis and cancer. Here we summarize the most recent evidence supporting the role of IL-17 in ALD. As a result of a collaborative effort of Drs. Karin, Gao, Tsukamoto and Kisseleva, we developed several improved models of ALD in mice: 1) chronic-plus-binge model that mimics early stages of steatohepatitis, 2) intragastric ethanol feeding model that mimics alcoholic steatohepatitis and fibrosis, and 3) diethylnitrosamine (DEN)+alcohol model that mimics alcoholic liver cancer. These models might provide new insights into the mechanism of IL-17 signaling in ALD and help identify novel therapeutic targets. PMID:27239399

  11. A simplified density functional theory method for investigating charged adsorbates on an ultrathin, insulating film supported by a metal substrate.

    PubMed

    Scivetti, Ivan; Persson, Mats

    2014-04-02

    A simplified density functional theory (DFT) method for investigating charged adsorbates on an ultrathin, insulating film supported by a metal substrate is developed and presented. This new method is based on a previous DFT development that uses a perfect conductor (PC) model to approximate the electrostatic response of the metal substrate, while the film and the adsorbate are both treated fully within DFT (Scivetti and Persson 2013 J. Phys.: Condens. Matter 25 355006). The missing interactions between the metal substrate and the insulating film in the PC approximation are modelled by a simple force field (FF). The parameters of the PC model and the force field are obtained from DFT calculations of the film and the substrate, here shown explicitly for a NaCl bilayer supported by a Cu(100) surface. In order to obtain some of these parameters and the polarizability of the force field, we have to include an external, uniformly charged plane in the DFT calculations, which has required the development of a periodic DFT formalism to include such a charged plane in the presence of a metal substrate. This extension and implementation should be of more general interest and applicable to other challenging problems, for instance, in electrochemistry. As illustrated for the gold atom on the NaCl bilayer supported by a Cu(100) surface, our new DFT-PC-FF method allows us to handle different charge states of adsorbates in a controlled and accurate manner with a considerable reduction of the computational time. In addition, it is now possible to calculate vertical transition and reorganization energies for the charging and discharging of adsorbates that cannot be obtained by current DFT methodologies that include the metal substrate. We find that the computed vertical transition energy for charging of the gold adatom is in good agreement with experiments.

  12. Modeling the evolution of ice deuteration during the formation of low-mass protostars

    NASA Astrophysics Data System (ADS)

    Taquet, Vianney; Charnley, Steven; Cordiner, Martin

    2013-07-01

    Extremely large deuteration of several molecules has been observed around low-mass proto- stars for a decade. New observations performed with the Herschel Space Observatory or with ground- based interferometers have allowed astronomers to derive the D/H ratio of water, giving contrasting results (between less than 1e-3 to a few percents; Coutens et al. 2012, Persson et al. 2013, Visser et al. 2013, Taquet et al. 2013a). In previous studies, we have successfully reproduced the high deuteration of water derived by Coutens et al. (2012) with typical molecular cloud conditions and a low value for the H2 ortho/para ratio (opr < 1e-3; Taquet et al. 2013b). However, this result contrasts with the long timescale needed to decrease the H2 opr from its statistical value of 3 and, therefore, the non-detection of DCO+ towards interstellar clouds outside dense cores (see Pagani et al. 2011). In this poster, we study the time-dependent and spatial evolutions of the H2 opr and the ice deuteration in the early-stages of low-mass star formation. For this purpose, we coupled our gas-grain astrochemical model (Taquet et al. 2012) with a simple dynamical model of core collapse leading to the formation of a central protostar (Whitworth & Ward-Thompson 2001). We present the first results of this work and show that we can reproduce the deuteration of various molecules both in prestellar cores and Class 0 protostars. In pre stellar cores, the deuteration of interstellar ices is limited to the few outermost layers. In Class 0 protostars, the deuteration of various molecules decreases with the age of the protostar and could explain the difference in the observations presented above.

  13. Theory of substrate-directed heat dissipation for single-layer graphene and other two-dimensional crystals

    NASA Astrophysics Data System (ADS)

    Ong, Zhun-Yong; Cai, Yongqing; Zhang, Gang

    2016-10-01

    We present a theory of the phononic thermal (Kapitza) resistance at the interface between graphene or another single-layer two-dimensional (2D) crystal (e.g., MoS2) and a flat substrate, based on a modified version of the cross-plane heat transfer model by Persson, Volokitin, and Ueba [J. Phys.: Condens. Matter 23, 045009 (2011), 10.1088/0953-8984/23/4/045009]. We show how intrinsic flexural phonon damping is necessary for obtaining a finite Kapitza resistance and also generalize the theory to encased single-layer 2D crystals with a superstrate. We illustrate our model by computing the thermal boundary conductance (TBC) for bare and SiO2-encased single-layer graphene and MoS2 on a SiO2 substrate, using input parameters from first-principles calculation. The estimated room temperatures TBC for bare (encased) graphene and MoS2 on SiO2 are 34.6 (105) and 3.10 (5.07) MWK -1m-2 , respectively. The theory predicts the existence of a phonon frequency crossover point, below which the low-frequency flexural phonons in the bare 2D crystal do not dissipate energy efficiently to the substrate. We explain within the framework of our theory how the encasement of graphene with a top SiO2 layer introduces new low-frequency transmission channels, which significantly reduce the graphene-substrate Kapitza resistance. We emphasize that the distinction between bare and encased 2D crystals must be made in the analysis of cross-plane heat dissipation to the substrate.

  14. High Resolution Far Infrared Fourier Transform Spectroscopy of the NH_2 Radical.

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, M. A.; Pirali, O.; Balcon, D.; Vervloet, M.

    2011-06-01

    First identified toward Sgr B2, the NH_2 radical has recently been detected in the interstellar medium by the HIFI instrument on board of Herschel. Despite the fact that this radical has not been detected in brown dwarfs and exoplanets yet, it is already included in physical and chemical models of those environments (temperature higher than 2000 K expected in several objects). Its detection in those objects will depend on the existence of a reliable high temperature and high resolution spectroscopic database on the NH_2 radical.The absorption spectrum of NH_2 has been recorded between 15 and 700 Cm-1 at the highest resolution available using the Bruker IFS125HR Fourier transform interferometer connected to the far infrared AILES beamline at SOLEIL (R=0.001 Cm-1). The radical was produced by an electrical discharge (DC) through a continuous flow of NH_3 and He using the White-type discharge cell developped on the beamline (optical path: 24m). Thanks to the brilliance of the synchrotron radiation, more than 700 pure rotational transitions of NH_2 have been identified with high N values (NMax=25) in its fundamental and first excited vibrational modes. By comparison to the previous FT spectroscopic study on that radical in the FIR spectral range, asymmetric splitting as well as fine and hyperfine structure have been resolved for several transitions. E. F. Van Dishoeck, D. J. Jansen, P. Schilke, T. G. Phillips The Astrophysical Journal 416, L83-L86 (1993) C. M. Persson, J. H. Black, J. Cernicharo et al. Astronomy and Astrophysics 521, L45 (2010) K. Lodders and B. Fegley, Jr Icarus 155, 393-424 (2002) I. Morino and K. Kawaguchi Journal of Molecular Spectroscopy 182, 428-438 (1997)

  15. A Receding Halo Sub-structure Towards Norma

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Sukanya

    2016-01-01

    We present results from follow-up spectroscopic observations of clustered Cepheid candidates identified from K-band light curves towards the Norma constellation (Chakrabarti et al. 2015), as well as others that we have found more recently. The average radial velocity of these stars is ~ 200 km/s, which is large and distinct from that of the Galaxy's stellar disk. These objects at l ~ -27 and b ~ -1 are therefore halo stars; using the period-luminosity relation of Type I Cepheids, they are at ~ 90 kpc. While the spectra do not have sufficient S/N to independently determine the metallicity and spectral type of the stars, there is a clear correspondence between the observed Brackett series lines in these observations and in known Type I Cepheids. Distances determined from the K-band period-luminosity relation (Matsunaga et al. 2013) and the 3.6 μm period-luminosity relation (Scowcroft et al. 2011) agree closely, and I-band observations have confirmed the periods of these sources. The extinction corrected J - Ks colors of these sources are comparable to known Type I Cepheids (Persson et al. 2004). The observed radial velocity of these stars agrees with predictions from dynamical models (Chakrabarti & Blitz 2009). If these stars are indeed members of the predicted dark-matter dominated dwarf galaxy that perturbed the outer HI disk of the Milky Way, this would represent the first application of Galactoseismology. These observations also challenge models of the Galactic halo. Young Cepheid variables are unexpected in models of the Galactic halo, though star formation due to infall of gas-rich dwarf galaxies may well produce a small population of yet undiscovered Cepheids in the outer halo.

  16. Velocity transition in the crack growth dynamics of filled elastomers: Contributions of nonlinear viscoelasticity.

    PubMed

    Morishita, Yoshihiro; Tsunoda, Katsuhiko; Urayama, Kenji

    2016-04-01

    The crack growth dynamics of the carbon-black (CB) filled elastomers is studied experimentally and analyzed while focusing on both kinetics and crack tip profiles. The CB amounts are varied to change the mechanical properties of the elastomers. Static crack growth measurements simultaneously reveal the discontinuous-like transition of the crack growth rate v between the "slow mode" (v≈10^{-5}-10^{-3} m/s) and "fast mode" (v≈10^{-1}-10^{2} m/s) in a narrow range of the input tearing energy Γ and the accompanying changes in the crack tip profiles from blunt to sharp shapes. The crack tip profiles are characterized by two specific parameters, i.e., the deviation δ from the parabolic profile and the opening displacement a in the loading direction. The analysis based on the linear and weakly nonlinear elasticity theories of fracture dynamics demonstrates that the Γ dependence of δ and a is simply classified into three groups depending on the mode (slow or fast) and the magnitudes of δ, independent of CB volume fractions. The theories well explain the results in the slow and fast modes with small magnitudes of δ, while they fail to describe the data in the fast mode with large magnitudes of δ, where the contributions of the strong nonlinearity and/or energy dissipation become significant. The correlation between a power-law relationship Γ∼v^{α} observed in the fast mode and the linear viscoelasticity spectrum is also discussed. The correlation in elastomers with low CB volume fractions is quantitatively explained by the theory of Persson and Brener [Phys. Rev. E 71, 036123 (2005)PLEEE81539-375510.1103/PhysRevE.71.036123], whereas the deviation from the theory becomes appreciable for elastomers with higher CB volume fractions which exhibit strong nonlinear viscoelasticity.

  17. S(H)2 reaction vs hydrogen abstraction/expulsion in methyl radical-methylsilane reactions: effects of prereactive complex formation.

    PubMed

    Norberg, Daniel; Shiotani, Masaru; Lunell, Sten

    2008-02-14

    A quantum chemical study has been undertaken to elucidate the cause of the recently observed S(H)2 reaction between the deuterated methyl radical (*CD3) and methylsilane (SiD3CH3) following the photolysis of CD3I. [Komaguchi, K.; Norberg, D.; Nakazawa, N.; Shiotani, M.; Persson, P.; Lunell, S. Chem. Phys. Lett. 2005, 410, 1-5.] It is found that the backside S(H)2 mechanism may proceed favorably for C-Si-C angles deviating with up to 40 degrees from linearity. The competitive hydrogen abstraction reaction is predicted to be active in the range of 90 degrees

  18. Teeth mobility measurement: a laser vibrometry approach.

    PubMed

    Castellini, P; Scalise, L; Tomasini, E P

    1998-10-01

    This work presents a new technique based on the assessment of the mobility degree through the application of dynamic loads and the measurement of the tooth displacement with a laser Doppler vibrometer. Measurements of the mobility degree have been made, up to now, by the application of static loads and the measurement of the consequent displacement. The results obtained with the measurement technique proposed by Muhlemann (1967) have been validated by O'Leary et al. (1964) and by Persson and Sweson (1980). This approach, however, has not been clinically disseminated both because of the high cost of the equipment and, above all, because of the difficulty in performing the measurements. The ratio between the maximum of the tooth displacement and the input force peak has been considered as the mobility degree index. Dynamic loads have been applied and measured on teeth, with a small hammer and a load cell. The consequent displacement of tooth has been measured with a Laser Doppler vibrometer that allows easy to use and versatile noncontact measurements with high accuracy and sensitivity (< 0.1 mm/sec). An introductory in vitro study has been carried out on real teeth extracted and mounted on structures with different-stiffness silicone cast (stiffness of the support is one of the parameters responsible for teeth mobility), in order to evaluate the technique. An in vivo study has also been carried out on different teeth of a healthy patient. It is possible to observe the agreement between the O'Leary results and ones obtained in this work. The practicality of the procedure has also been demonstrated. Good correspondence between data available in literature and results obtained has been demonstrated. The use of the technique here proposed could allow having a deeper knowledge of the behavior of the periodontal teeth system: the tooth mobility under dynamic loads. With this new technique, it will be possible to quickly measure a pathological mobility of the tooth, before

  19. Approach to voxel-based carbon stock quanticiation using LiDAR data in tropical rainforest, Brunei

    NASA Astrophysics Data System (ADS)

    Kim, Eunji; Piao, Dongfan; Lee, Jongyeol; Lee, Woo-Kyun; Yoon, Mihae; Moon, Jooyeon

    2016-04-01

    Forest is an important means to adapt climate change as the only carbon sink recognized by the international community (KFS 2009). According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), Agriculture, Forestry, and Other Land Use (AFOLU) sectors including forestry contributed 24% of total anthropogenic emissions in 2010 (IPCC 2014; Tubiello et al. 2015). While all sectors excluding AFOLU have increased Greenhouse Gas (GHG) emissions, land use sectors including forestry remains similar level as before due to decreasing deforestation and increasing reforestation. In earlier researches, optical imagery has been applied for analysis (Jakubowski et al. 2013). Optical imagery collects spectral information in 2D. It is difficult to effectively quantify forest stocks, especially in dense forest (Cui et al. 2012). To detect individual trees information from remotely sensed data, Light detection and ranging (LiDAR) has been used (Hyyppäet al. 2001; Persson et al. 2002; Chen et al. 2006). Moreover, LiDAR has the ability to actively acquire vertical tree information such as tree height using geo-registered 3D points (Kwak et al. 2007). In general, however, geo-register 3D point was used with a raster format which contains only 2D information by missing all the 3D data. Therefore, this research aimed to use the volumetric pixel (referred as "voxel") approach using LiDAR data in tropical rainforest, Brunei. By comparing the parameters derived from voxel based LiDAR data and field measured data, we examined the relationships between them for the quantification of forest carbon. This study expects to be more helpful to take advantage of the strategic application of climate change adaption.

  20. Velocity transition in the crack growth dynamics of filled elastomers: Contributions of nonlinear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Morishita, Yoshihiro; Tsunoda, Katsuhiko; Urayama, Kenji

    2016-04-01

    The crack growth dynamics of the carbon-black (CB) filled elastomers is studied experimentally and analyzed while focusing on both kinetics and crack tip profiles. The CB amounts are varied to change the mechanical properties of the elastomers. Static crack growth measurements simultaneously reveal the discontinuous-like transition of the crack growth rate v between the "slow mode" (v ≈10-5-10-3 m/s) and "fast mode" (v ≈10-1-102 m/s) in a narrow range of the input tearing energy Γ and the accompanying changes in the crack tip profiles from blunt to sharp shapes. The crack tip profiles are characterized by two specific parameters, i.e., the deviation δ from the parabolic profile and the opening displacement a in the loading direction. The analysis based on the linear and weakly nonlinear elasticity theories of fracture dynamics demonstrates that the Γ dependence of δ and a is simply classified into three groups depending on the mode (slow or fast) and the magnitudes of δ , independent of CB volume fractions. The theories well explain the results in the slow and fast modes with small magnitudes of δ , while they fail to describe the data in the fast mode with large magnitudes of δ , where the contributions of the strong nonlinearity and/or energy dissipation become significant. The correlation between a power-law relationship Γ ˜vα observed in the fast mode and the linear viscoelasticity spectrum is also discussed. The correlation in elastomers with low CB volume fractions is quantitatively explained by the theory of Persson and Brener [Phys. Rev. E 71, 036123 (2005), 10.1103/PhysRevE.71.036123], whereas the deviation from the theory becomes appreciable for elastomers with higher CB volume fractions which exhibit strong nonlinear viscoelasticity.

  1. GLOBIN-5-Dependent O2 Responses Are Regulated by PDL-1/PrBP That Targets Prenylated Soluble Guanylate Cyclases to Dendritic Endings

    PubMed Central

    Soltesz, Zoltan; Oda, Shigekazu; Zelmanovich, Veronica; Abergel, Zohar

    2014-01-01

    Aerobic animals constantly monitor and adapt to changes in O2 levels. The molecular mechanisms involved in sensing O2 are, however, incompletely understood. Previous studies showed that a hexacoordinated globin called GLB-5 tunes the dynamic range of O2-sensing neurons in natural C. elegans isolates, but is defective in the N2 lab reference strain (McGrath et al., 2009; Persson et al., 2009). GLB-5 enables a sharp behavioral switch when O2 changes between 21 and 17%. Here, we show that GLB-5 also confers rapid behavioral and cellular recovery from exposure to hypoxia. Hypoxia reconfigures O2-evoked Ca2+ responses in the URX O2 sensors, and GLB-5 enables rapid recovery of these responses upon re-oxygenation. Forward genetic screens indicate that GLB-5's effects on O2 sensing require PDL-1, the C. elegans ortholog of mammalian PrBP/PDE6δ protein. In mammals, PDE6δ regulates the traffic and activity of prenylated proteins (Zhang et al., 2004; Norton et al., 2005). PDL-1 promotes localization of GCY-33 and GCY-35, atypical soluble guanylate cyclases that act as O2 sensors, to the dendritic endings of URX and BAG neurons, where they colocalize with GLB-5. Both GCY-33 and GCY-35 are predicted to be prenylated. Dendritic localization is not essential for GCY-35 to function as an O2 sensor, but disrupting pdl-1 alters the URX neuron's O2 response properties. Functional GLB-5 can restore dendritic localization of GCY-33 in pdl-1 mutants, suggesting GCY-33 and GLB-5 are in a complex. Our data suggest GLB-5 and the soluble guanylate cyclases operate in close proximity to sculpt O2 responses. PMID:25505325

  2. Theoretical assessment of renal autoregulatory mechanisms.

    PubMed

    Sgouralis, Ioannis; Layton, Anita T

    2014-06-01

    A mathematical model of renal hemodynamics was used to assess the individual contributions of the tubuloglomerular feedback (TGF) mechanism and the myogenic response to glomerular filtration rate regulation in the rat kidney. The model represents an afferent arteriole segment, glomerular filtration, and a short loop of Henle. The afferent arteriole model exhibits myogenic response, which is activated by hydrostatic pressure variations to induce changes in membrane potential and vascular muscle tone. The tubule model predicts tubular fluid and Cl(-) transport. Macula densa Cl(-) concentration is sensed as the signal for TGF, which acts to constrict or dilate the afferent arteriole. With this configuration, the model afferent arteriole maintains stable glomerular filtration rate within a physiologic range of perfusion pressure (80-180 mmHg). The contribution of TGF to overall autoregulation is significant only within a narrow band of perfusion pressure values (80-110 mmHg). Model simulations of ramp-like perfusion pressure perturbations agree well with findings by Flemming et al. (Flemming B, Arenz N, Seeliger E, Wronski T, Steer K, Persson PB. J Am Soc Nephrol 12: 2253-2262, 2001), which indicate that changes in vascular conductance are markedly sensitive to pressure velocity. That asymmetric response is attributed to the rate-dependent kinetics of the myogenic mechanism. Moreover, simulations of renal autoregulation in diabetes mellitus predict that, due to the impairment of the voltage-gated Ca(2+) channels of the afferent arteriole smooth muscle cells, the perfusion pressure range in which single-nephron glomerular filtration rate remains stable is reduced by ~70% and that TGF gain is reduced by nearly 40%, consistent with experimental findings.

  3. The Far-UV Albedo of the Moon Determined from Dayside LAMP Observations

    NASA Astrophysics Data System (ADS)

    Bullock, Mark A.; Retherford, K. D.; Gladstone, R.; Greathouse, T. K.; Mandt, K. E.; Hendrix, A. R.; Feldman, P. D.; Miles, P. F.; Egan, A. F.

    2013-10-01

    The Lyman Alpha Mapping Project (LAMP) onboard the Lunar Reconnaissance Orbiter (LRO) has been recording far-UV photons reflected from the lunar surface almost continuously since December 2009 (Gladstone et al., 2010). One photon at a time, LAMP builds up spectra from 575 to 1965 Å with a resolution of 26 Å. We will present 3 years of accumulated LAMP lunar dayside spectral maps and derive the lunar geometric albedo spectrum for a range of phase angles. These LAMP observations can thus be used to reconstruct the lunar far-UV photometric function and refine photometric models of the lunar surface (Hapke, 1963; Lucke et al., 1976). We will also compare LAMP lunar dayside albedo with the albedo from 820-1840 Å obtained by the Hopkins Ultraviolet Telescope (HUT) on the March 1995 Astro-2 Space Shuttle mission (Henry et al., 1995). The improved lunar photometric functions from our analysis of LAMP albedo spectra will enable a better quantitative assessment of how phase angle and composition affect the Moon’s reflectance in the far-UV. Gladstone, G. R., Stern, S. A., Retherford, K. D., Black, R. K., Slater, D. C., Davis, M. W., Versteeg, M. H., Persson, K. B., Parker, J. W., Kaufmann, D. E., Egan, A. F., Greathouse, T. K., Feldman, P. D., Hurley, D., Pryor, W. R., Hendrix, A. R., 2010. LAMP: The lyman alpha mapping project on NASA's lunar reconnaissance orbiter mission. Space Science Reviews. 150, 161-181. Hapke, B. W., 1963. A theoretical photometric function for the lunar surface. Journal of Geophysical Research. 68, 4571-4586. Henry, R. C., Feldman, P. D., Kruk, J. W., Davidsen, A. F., Durrance, S. T., 1995. Ultraviolet Albedo of the Moon with the Hopkins Ultraviolet Telescope. The Astrophysical Journal Letters. 454, L69. Lucke, R. L., Henry, R. C., Fastie, W. G., 1976. Far-ultraviolet albedo of the moon. The Astronomical Journal. 81, 1162-1169.

  4. 210Pb dating

    USGS Publications Warehouse

    Swarzenski, Peter W.

    2014-01-01

    Roughly fifty years ago, a small group of scientists from Belgium and the United States, trying to better constrain ice sheet accumulation rates, attempted to apply what was then know about environmental lead as a potential geochronometer. Thus Goldberg (1963) developed the first principles of the 210Pb dating method, which was soon followed by a paper by Crozaz et al. (1964), who examined accumulation history of Antarctic snow using 210Pb. Shortly thereafter, Koide et al. (1972, 1973) adapted this technique to unravel sediment deposition and accumulation records in deep-sea environments. Serendipitously, they chose to work in a deep basin off California, where an independent and robust age model had already been developed. Krishanswami et al. (1971) extended the use of this technique to lacustrine deposits to reconstruct depositional histories of lake sediment, and maybe more importantly, contaminant inputs and burial. Thus, the powerful tool for dating recent (up to about one century old) sediment deposits was established and soon widely adopted. Today almost all oceanographic or limnologic studies that address recent depositional reconstructions employ 210Pb as one of several possible geochronometers (Andrews et al., 2009; Gale, 2009; Baskaran, 2011; Persson and Helms, 2011). This paper presents a short overview of the principles of 210Pb dating and provides a few examples that illustrate the utility of this tracer in contrasting depositional systems. Potential caveats and uncertainties (Appleby et al., 1986; Binford, 1990; Binford et al., 1993; Smith, 2001; Hancock et al., 2002) inherent to the use and interpretation of 210Pb-derived age-models are also introduced. Recommendations as to best practices for most reliable uses and reporting are presented in the summary.

  5. Emergence: A Planetarium and Art Gallery Collaboration Between Artist, Astronomer, and Musician

    NASA Astrophysics Data System (ADS)

    Beaver, J.; Waller, J. B.; Turner, M.

    2011-09-01

    We describe an unusual planetarium program and art gallery exhibition that premiered in Menasha, Wisconsin. Emergence combines fine art and improvisational music with astronomy and physics. The authors, Judith Baker Waller, John Beaver, and Matt Turner, are, respectively, artist, astronomer, and musician. All three acted as partners in planning and executing the final production. The overall goal of Emergence is to use art, music, and natural science each as a point of departure to learn about the others, and to explore the interaction between humans and the natural world and the differences and commonalities between art, science, and music. Of particular interest, the planetarium portion includes techniques that are, so far as we know, unique. Each night the show is different, the details chosen randomly, but always according to the same theoretical scheme. Various elements are parameterized, the show varying with time according to subroutines that dictate the overall pacing and look, but with details always chosen randomly according to prearranged probabilities. We believe that some of these techniques could be of interest to others who wish to explore the unique possibilities of the planetarium as educational performance space. We argue that this provides a useful format for collaborations between artist and scientist, as scientific content can be delivered in a way that is consistent with the concerns of the artist. We describe some of the approaches taken toward these ends in Emergence, and some of the lessons learned about the process of collaboration between a scientist, a visual artist and a performing artist.

  6. Graphene on Ni(111): Electronic Corrugation and Dynamics from Helium Atom Scattering

    PubMed Central

    2015-01-01

    Using helium atom scattering, we have studied the structure and dynamics of a graphene layer prepared in situ on a Ni(111) surface. Graphene/Ni(111) exhibits a helium reflectivity of ∼20% for a thermal helium atom beam and a particularly small surface electron density corrugation ((0.06 ± 0.02) Å peak to peak height). The Debye–Waller attenuation of the elastic diffraction peaks of graphene/Ni(111) and Ni(111) was measured at surface temperatures between 150 and 740 K. A surface Debye temperature of θD = (784 ± 14) K is determined for the graphene/Ni(111) system and θD = (388 ± 7) K for Ni(111), suggesting that the interlayer interaction between graphene and the Ni substrate is intermediary between those for strongly interacting systems like graphene/Ru(0001) and weakly interacting systems like graphene/Pt(111). In addition we present measurements of low frequency surface phonon modes on graphene/Ni(111) where the phonon modes of the Ni(111) substrate can be clearly observed. The similarity of these findings with the graphene/Ru(0001) system indicates that the bonding of graphene to a metal substrate alters the dynamic properties of the graphene surface strongly and is responsible for the high helium reflectivity of these systems. PMID:26617683

  7. Design rules for rational control of polymer glass formation behavior and mechanical properties with small molecular additives

    NASA Astrophysics Data System (ADS)

    Mangalara, Jayachandra Hari; Simmons, David

    Small molecule additives have long been employed to tune polymers' glass formation, mechanical and transport properties. For example, plasticizers are commonly employed to suppress polymer Tg and soften the glassy state, while antiplasticizers, which stiffen the glassy state of a polymer while suppressing its Tg, are employed to enhance protein and tissue preservation in sugar glasses. Recent literature indicates that additives can have a wide range of possible effects, but all of these have not been clearly understood and well appreciated. Here we employ molecular dynamics simulations to establish design rules for the selection of small molecule additives with size, molecular stiffness, and interaction energy chosen to achieve targeted effects on polymer properties. We furthermore find that a given additive's effect on a polymer's Tg can be predicted from its Debye-Waller factor via a function previously found to describe nanoconfinement effects on the glass transition. These results emphasize the potential for a new generation of targeted molecular additives to contribute to more targeted rational design of polymers. We acknowledge the Keck Foundation and the Ohio Supercomputing Center for financial and computational support of this effort, respectively.

  8. Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al0.15Ga0.85N

    NASA Astrophysics Data System (ADS)

    Magalhães, S.; Fialho, M.; Peres, M.; Lorenz, K.; Alves, E.

    2016-04-01

    In this work radial symmetric x-ray diffraction scans of Al0.15Ga0.85N thin films implanted with Tm ions were measured to determine the lattice deformation and crystal quality as functions of depth. The alloys were implanted with 300 keV Tm with 10° off-set to the sample normal to avoid channelling, with fluences varying between 1013 Tm cm-2 and 5  ×  1015 Tm cm-2. Simulations of the radial 2θ-ω scans were performed under the frame of the dynamical theory of x-ray diffraction assuming Gaussian distributions of the lattice strain induced by implantation defects. The structure factor of the individual layers is multiplied by a static Debye-Waller factor in order to take into account the effect of lattice disorder due to implantation. For higher fluences two asymmetric Gaussians are required to describe well the experimental diffractograms, although a single asymmetric Gaussian profile for the deformation is found in the sample implanted with 1013 Tm cm-2. After thermal treatment at 1200 °C, the crystal quality partially recovers as seen in a reduction of the amplitude of the deformation maximum as well as the total thickness of the deformed layer. Furthermore, no evidence of changes with respect to the virgin crystal mosaicity is found after implantation and annealing.

  9. Low clouds in central California

    NASA Image and Video Library

    2017-09-28

    Low clouds filled California’s Central Valley in late January, 2015. Such winter fog is considered a common phenomenon, and can be so dense that it snarls traffic, causes fender-benders, and can make symptoms worse in those with respiratory disease. At the same time, the moist winter fog helps keep temperatures low in the rich agricultural region by reflecting sunlight and keeping the ground from warming, which helps keep the abundant fruit and nut trees dormant, allowing for bountiful harvests. Scientific studies have reported that winter fogs (also called Thule fogs) are occurring less frequently in the Central Valley. One study, by Dennis Baldocchi and Eric Waller, was published in May, 2014. It finds that since 1981 the number of fog days between November and February has decreased by 46 percent. The severe drought that California has experienced in recent years may also have decreased the number of fog events even more since 2012. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured this true-color image on January 24, 2015. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  10. Sample thickness effect of thermal vibration correction within X-ray dynamical theory for germanium-doped silicon

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Will, Johannes; Dong, Peng; Yang, Deren

    2017-03-01

    As of today, highly germanium doped Czochralski silicon crystals are used in applications. However, it is not clear how a germanium content in the range of 1018 atoms/cm3 influences the oxygen precipitation behavior, which is highly relevant for the gettering potential of the wafer. In this context, high energy X-ray diffraction is a promising tool to monitor real-time the strain introduced by the oxygen agglomeration and growth. Nevertheless, in particular, in the dynamical limit of X-ray diffraction and at elevated temperatures, the strain originating from the precipitation process has to be clearly distinguished from the intensity contribution of thermal vibrations. In Laue geometry, dynamical effects can even lead to an increment of the integrated intensity with temperature completely unexpected in the kinematical limit, where temperature is tackled solely by a Debye-Waller factor. In the following, an approach is presented allowing us to completely correct the influence of thermal vibrations in the dynamical limit. This approach is applied to undoped and highly germanium doped silicon crystals, clearly revealing an enhanced inventory of grown-in precipitates with germanium doping and suggesting a morphological transformation towards a phase of higher strain of the grown-in precipitates in the range between room temperature and 800 °C.

  11. Carrier relaxation and lattice heating dynamics in silicon revealed by femtosecond electron diffraction.

    PubMed

    Harb, Maher; Ernstorfer, Ralph; Dartigalongue, Thibault; Hebeisen, Christoph T; Jordan, Robert E; Miller, R J Dwayne

    2006-12-21

    We report on the use of femtosecond electron diffraction to resolve the dynamics of electron-phonon relaxation in silicon. Nanofabricated free-standing membranes of polycrystalline silicon were excited below the damage threshold with 387 nm light at a fluence of 5.6 mJ/cm2 absorbed (corresponding to a carrier density of 2.2 x 10(21) cm(-3)). The diffraction pattern was captured over a range of delay times with a time resolution of 350 fs. All of the detected Bragg peaks exhibited intensity loss with a time constant of less than 2 ps. Beyond the initial decay, there was no further change in the diffracted intensity up to 700 ps. We find that the loss of intensity in the diffracted orders is accounted for by the Debye-Waller effect on a time scale indicative of a thermally driven process as opposed to an electronically driven one. Furthermore, the relaxation time constant is consistent with the excitation regime where the phonon emission rate is reduced due to carrier screening.

  12. Effective cross section for scattering from a quasi-stationary state and Einstein relations in the quantum theory of radiation

    SciTech Connect

    Shekhtman, V.L.

    1995-12-01

    A theoretical investigation of the correlation between the resonance scattering from a quasi-stationary state and the Einstein relations in the quantum theory of radiation was carried out. On the basis of the Einstein relations, the mode-averaged value of the total scattering cross section at the frequency of the resonance maximum was obtained in the general form. With allowance for radiative, vibronic, transverse, and inhomogeneous widths of a zero-phonon line, relations were obtained that permit the oscillator strength of a resonance electronic transition to be found from measurements of the absorption cross section at the resonance frequency and the half-width of the absorption spectral line. The relations depend on the shape of the absorption spectrum. The cases of the Lorentzian, Gaussian, and Voigt line shapes were considered. Using the E-2A transitions in an optically excited ruby as an example, the cross section of the phonon resonance scattering from impurity centers in crystals with a sufficiently large value of the Debye-Waller factor, e{sup {minus}2M}{ge} 0.5, was considered. The results can be applied in phonon spectroscopy. The main results are interpreted in detail in terms of the Bohr spectroscopic correspondence principle. A new derivation is given of the Ladenburg formula relating the transition probabilities and the dispersion constants. 23 refs., 1 fig.

  13. Water-level altitudes 1998, water-level changes 1977-98 and 1997-98, and compaction 1973-97 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Coplin, L.S.

    1998-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 1998 and approximate water-level changes in wells from 1977 to 1998 and from 1997 to 1998, a map showing extensometer site locations, and graphs showing measured compaction of subsurface material at selected sites from 1973 to 1997. The most recent previously published water-level-altitude maps and water-level-change maps for the two aquifers in the region are by Kasmarek and others (1997). The Houston-Galveston region comprises Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  14. Water-level altitudes 2001, water-level changes 1977-2001 and 2000-2001, and compaction 1973-2000 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Coplin, L.S.; Houston, Natalie A.; Brown, Dexter W.

    2001-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 2001 (figs 1,4) and approximate water-level changes in wells from 1977 to 2001 and from 2000 to 2001 (figs 2,3,5,6), a map showing extensometer site locations (fig. 7), and graphs showing measured compaction of subserface material at selected sites from 1973 to 2000 (fig. 8). The most recent previously published water-level-altitude maps and water-level-change maps for the two aquifers in the region are by Coplin and Santos. (2000). The Houston-Galveston region comprises Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  15. Water-level altitudes 1999, water-level changes 1977-99 and 1998-99, and compaction 1973-98 in the Chicot and Evangeline aquifers; Houston-Galveston region, Texas

    USGS Publications Warehouse

    Coplin, L.S.; Santos, H.X.; East, J.W.

    1999-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 1999 and approximate water-level changes in wells from 1977 to 1999 and from 1998 to 1999, a map showing extensometer site locations, and graphs showing measured compaction of subsurface material at selected sites from 1973 to 1998. The most recent previously published water-level-altitude maps and water-level-change maps for the two aquifers in the region are by Coplin (1998). The Houston-Galveston region comprises Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  16. Water-level altitudes 2000, water-level changes 1977-2000 and 1999-2000 and compaction 1973-99 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Coplin, L.S.; Santos, Horacio X.

    2000-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline aquifers showing the approximate water-level altitudes in wells in 2000 and approximate water-level changes in wells from 1977 to 2000 and from 1999 to 2000, a map showing extensometer site locations, and graphs showing measured compaction of subsurface material at selected sites from 1973 to 1999. The most recent previously published water-level-altitude maps and water-level-change maps for the two aquifers in the region are by Coplin and other (1999). The Houston-Galveston region comprises Harris and Galveston Counties and adjacent parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties.

  17. Water-level changes 1977-87, 1987-95, and 1995-2000 in the Chicot and Evangeline Aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Lanning-Rush, Jennifer

    2002-01-01

    This report depicts long-term water-level changes in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District and the Fort Bend Subsidence District. For the Chicot and Evangeline aquifers, maps show approximate water-level changes for the periods 1977 to 1987 (figs. 1 and 4), 1987 to 1995 (figs. 2 and 5), and 1995 to 2000 (figs. 3 and 6). Nineteen seventy-seven was the first year that water levels in a network of wells were measured and water-levelaltitude maps made for the Chicot and Evangeline aquifers. Nineteen eighty-seven, 1995, and 2000 were years in which land-surface altitudes throughout Harris, Galveston, and Fort Bend Counties were releveled using spirit leveling (1987) and Global Positioning Satellite technology (1995 and 2000); thus the selection of those years for the maps. The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979 and separate similar annual reports for the Fort Bend subregion since 1990. Beginning with 2002, the separate annual reports were combined into one report.

  18. [On the first studies of electrophysiology].

    PubMed

    de Micheli, Alfredo

    2011-01-01

    A historical outline of the evolution of electrophysiology from the eighteenth century is shortly presented. Topics concerning the so called animal electricity starting from the observations on descharges of Torpedo fish until Bolognese Galvani's researches on the frogs are exposed. The points of view of their oppositionists also are examined. These ones, leaded by the physicist Alessandro Volta, professor in the University of Pavia, believed that electricity detected by galvanists was not inherent to animal but was due to the action of the metallic conductors present in the circuit: contact electricity. Only towards the middle of the nineteenth century the physicist Carlo Matteucci attained to demonstrate the existente of the real animal electricity in form of injury current. It was possible to determine that quantitatively thanks to the capillary electrometer built in 1872 by the French physicist Gabriel Lippmann. This instrument was used by the English physiologist Waller in order to obtain the primitive electrocardiographic tracings in humans (1887). At beginnings of the twentieth century, the Dutch professor Willem Einthoven, of the University of Leiden, introduced his string galvanometer which permitted to allow the modern electrocardiography. So it was possible to record the electrical potentials of myocardial cells, first in vitro, later in isolated and perfused heart, son after in dog's heart in situ and finally in human heart. Therefore now it is possible to effectuate endocardial and epicardial mappings, indispensable in order to diagnose and treat the cardiac arrhythmias.

  19. High precision electronic charge density determination for L10-ordered γ-TiAl by quantitative convergent beam electron diffraction

    NASA Astrophysics Data System (ADS)

    Sang, Xiahan; Kulovits, Andreas; Wang, Guofeng; Wiezorek, Jörg

    2012-12-01

    Low order structure and Debye-Waller (DW) factors for tetragonal L10-ordered γ-TiAl were measured simultaneously using quantitative convergent beam electron diffraction. The high precision and accuracy (largest error <0.5%) measurements allowed the construction of charge density difference maps from full sets of structure and DW factors, suitable for validation of first principles density functional theory (DFT) calculation results. Comparison of the experimentally determined charge density distribution with theoretical DFT predictions shows excellent qualitative agreement in this study. The three-dimensional charge density representations indicate a large electron charge localisation centred about the tetrahedral site at ¼, ¼, ¼, which is coordinated by two Ti atoms at 0, 0, 0 and ½, ½, 0 and two Al atoms at ½, 0, ½ and 0, ½, ½, respectively. Compared to experimental data, the DFT calculations based on full-potential linearised augmented plane wave (LAPW) method (implemented in WIEN2K) were found to quantitatively overestimate charge density between Ti-Ti second nearest neighbour atoms. Moreover, the results from the DFT method based on the projector-augmented wave (PAW) method and a plane wave basis set (implemented in VASP) were found to differ appreciably from both the experimental and LAPW-DFT results, implying that the PAW approach may not accurately describe the bonding in the intermetallic systems with 3 d electrons, such as γ-TiAl.

  20. Anomalous structural behavior in the metamagnetic transition of FeRh thin films from a local viewpoint

    NASA Astrophysics Data System (ADS)

    Wakisaka, Yuki; Uemura, Yohei; Yokoyama, Toshihiko; Asakura, Hiroyuki; Morimoto, Hiroyuki; Tabuchi, Masao; Ohshima, Daiki; Kato, Takeshi; Iwata, Satoshi

    2015-11-01

    The metamagnetic transition in FeRh thin films has been investigated via temperature-dependent x-ray-absorption fine-structure spectroscopy in order to gain correlations between magnetization and local electronic and geometric structures. According to the Fe and Rh K -edge x-ray-absorption near-edge structure (XANES), strong hybridization between Fe and Rh was revealed to exist. This Fe-Rh hybridization was observed to decrease during the phase transition from the antiferromagnetic (AFM) to ferromagnetic (FM) phases from the systematic change in the Fe K -edge XANES. In addition, only the Debye-Waller factor of the Fe-Fe pair in the AFM phase was observed to be considerably enhanced when compared with that in the FM phase, which was ascribed to local structural fluctuation inherent in the AFM phase. By considering the different features of the exchange interactions in Fe-Rh and Fe-Fe, this anomalous behavior is interpreted as being consistent with the recent theoretical study proposing the local fluctuations of spin and structure. Therefore, we consider that the local spin and Fe-Fe distance fluctuations play an important role in driving the metamagnetic transition, whereas the Fe-Rh hybridization correlates with the static stability of each magnetic phase.

  1. The aromatic residues Trp and Phe have different effects on the positioning of a transmembrane helix in the microsomal membrane.

    PubMed

    Braun, P; von Heijne, G

    1999-07-27

    We have examined the effect of Trp and Phe residues on the positioning of a poly-Leu transmembrane helix relative to the microsomal membrane by employing a previously described "glycosylation mapping" technique [Nilsson, I. M., Sääf, A., Whitley, P., Gafvelin, G., Waller, C., and von Heijne, G. (1998) J. Mol. Biol. 284, 1165-1175]. Both Trp and Phe tend to push the transmembrane helix into the membrane when inserted in positions flanking the poly-Leu stretch, and Trp (but not Phe) pulls the transmembrane helix toward the lipid-water interface when inserted inside the poly-Leu segment. Thus, the preference of Trp for the lipid-water interface previously suggested on the basis of biophysical studies of model peptides can also be observed for a bona fide transmembrane helix in a biological membrane. We further show that a sufficiently long poly-Trp segment functions as an efficient stop-transfer sequence during protein translocation across the microsomal membrane, despite the preference of Trp residues for the lipid-water interface region.

  2. Delineating the construct network of the Personnel Reaction Blank: associations with externalizing tendencies and normal personality.

    PubMed

    Blonigen, Daniel M; Patrick, Christopher J; Gasperi, Marianna; Steffen, Benjamin; Ones, Deniz S; Arvey, Richard D; Baumgartl, Viviane de Oliveira; do Nascimento, Elizabeth

    2011-03-01

    Integrity testing has long been utilized in personnel selection to screen for tendencies toward counterproductive workplace behaviors. The construct of externalizing from the psychopathology literature represents a coherent spectrum marked by disinhibitory traits and behaviors. The present study drew on a sample of male and female undergraduates to examine the construct network of the Personnel Reaction Blank (PRB; H. G. Gough, R. D. Arvey, & P. Bradley, 2004), a measure of integrity, in relation to externalizing as well as normal-range personality constructs assessed by the Multidimensional Personality Questionnaire (MPQ; A. Tellegen & N. G. Waller, 2008). Results revealed moderate to strong associations between several PRB scales and externalizing, which were largely accounted for by MPQ traits subsumed by Negative Emotionality and Constraint. After accounting for MPQ traits in the prediction of externalizing, a modest predictive increment was achieved when adding the PRB scales, particularly biographical indicators from the Prosocial Background subscale. The findings highlight externalizing as a focal criterion for scale development in the integrity testing literature and help delineate the construct network of the PRB within the domains of personality and psychopathology.

  3. Atomic structure and phason modes of the Sc-Zn icosahedral quasicrystal.

    PubMed

    Yamada, Tsunetomo; Takakura, Hiroyuki; Euchner, Holger; Pay Gómez, Cesar; Bosak, Alexei; Fertey, Pierre; de Boissieu, Marc

    2016-07-01

    The detailed atomic structure of the binary icosahedral (i) ScZn7.33 quasicrystal has been investigated by means of high-resolution synchrotron single-crystal X-ray diffraction and absolute scale measurements of diffuse scattering. The average atomic structure has been solved using the measured Bragg intensity data based on a six-dimensional model that is isostructural to the i-YbCd5.7 one. The structure is described with a quasiperiodic packing of large Tsai-type rhombic triacontahedron clusters and double Friauf polyhedra (DFP), both resulting from a close-packing of a large (Sc) and a small (Zn) atom. The difference in chemical composition between i-ScZn7.33 and i-YbCd5.7 was found to lie in the icosahedron shell and the DFP where in i-ScZn7.33 chemical disorder occurs on the large atom sites, which induces a significant distortion to the structure units. The intensity in reciprocal space displays a substantial amount of diffuse scattering with anisotropic distribution, located around the strong Bragg peaks, that can be fully interpreted as resulting from phason fluctuations, with a ratio of the phason elastic constants K 2/K 1 = -0.53, i.e. close to a threefold instability limit. This induces a relatively large perpendicular (or phason) Debye-Waller factor, which explains the vanishing of 'high-Q perp' reflections.

  4. Atomic structure and phason modes of the Sc–Zn icosahedral quasicrystal

    PubMed Central

    Yamada, Tsunetomo; Takakura, Hiroyuki; Euchner, Holger; Pay Gómez, Cesar; Bosak, Alexei; Fertey, Pierre; de Boissieu, Marc

    2016-01-01

    The detailed atomic structure of the binary icosahedral (i) ScZn7.33 quasicrystal has been investigated by means of high-resolution synchrotron single-crystal X-ray diffraction and absolute scale measurements of diffuse scattering. The average atomic structure has been solved using the measured Bragg intensity data based on a six-dimensional model that is isostructural to the i-YbCd5.7 one. The structure is described with a quasiperiodic packing of large Tsai-type rhombic triacontahedron clusters and double Friauf polyhedra (DFP), both resulting from a close-packing of a large (Sc) and a small (Zn) atom. The difference in chemical composition between i-ScZn7.33 and i-YbCd5.7 was found to lie in the icosahedron shell and the DFP where in i-ScZn7.33 chemical disorder occurs on the large atom sites, which induces a significant distortion to the structure units. The intensity in reciprocal space displays a substantial amount of diffuse scattering with anisotropic distribution, located around the strong Bragg peaks, that can be fully interpreted as resulting from phason fluctuations, with a ratio of the phason elastic constants K 2/K 1 = −0.53, i.e. close to a threefold instability limit. This induces a relatively large perpendicular (or phason) Debye–Waller factor, which explains the vanishing of ‘high-Q perp’ reflections. PMID:27437112

  5. Long-time mean-square displacements in proteins.

    PubMed

    Vural, Derya; Hong, Liang; Smith, Jeremy C; Glyde, Henry R

    2013-11-01

    We propose a method for obtaining the intrinsic, long-time mean square displacement (MSD) of atoms and molecules in proteins from finite-time molecular dynamics (MD) simulations. Typical data from simulations are limited to times of 1 to 10 ns, and over this time period the calculated MSD continues to increase without a clear limiting value. The proposed method consists of fitting a model to MD simulation-derived values of the incoherent intermediate neutron scattering function, I(inc)(Q,t), for finite times. The infinite-time MSD, , appears as a parameter in the model and is determined by fits of the model to the finite-time I(inc)(Q,t). Specifically, the is defined in the usual way in terms of the Debye-Waller factor as I(Q,t=∞)=exp(-Q(2)/3). The method is illustrated by obtaining the intrinsic MSD of hydrated lysozyme powder (h=0.4 g water/g protein) over a wide temperature range. The intrinsic obtained from data out to 1 and to 10 ns is found to be the same. The intrinsic is approximately twice the value of the MSD that is reached in simulations after times of 1 ns which correspond to those observed using neutron instruments that have an energy resolution width of 1 μeV.

  6. Power Evaluation of Focused Cluster Tests.

    PubMed

    Puett, Rc; Lawson, Ab; Clark, Ab; Hebert, Jr; Kulldorff, M

    2010-09-01

    Many statistical tests have been developed to assess the significance of clusters of disease located around known sources of environmental contaminants, also known as focused disease clusters. The majority of focused-cluster tests were designed to detect a particular spatial pattern of clustering, one in which the disease cluster centers around the pollution source and declines in a radial fashion with distance. However, other spatial patterns of environmentally related disease clusters are likely given that the spatial dispersion patterns of environmental contaminants, and thus human exposure, depend on a number of factors (i.e., meteorology and topography). For this study, data were simulated with five different spatial patterns of disease clusters, reflecting potential pollutant dispersion scenarios: 1) a radial effect decreasing with increasing distance, 2) a radial effect with a defined peak and decreasing with distance, 3) a simple angular effect, 4) an angular effect decreasing with increasing distance and 5) an angular effect with a defined peak and decreasing with distance. The power to detect each type of spatially distributed disease cluster was evaluated using Stone's Maximum Likelihood Ratio Test, Tango's Focused Test, Bithell's Linear Risk Score Test, and variations of the Lawson-Waller Score Test. Study findings underscore the importance of considering environmental contaminant dispersion patterns, particularly directional effects, with respect to focused-cluster test selection in cluster investigations. The effect of extra variation in risk also is considered, although its effect is not substantial in terms of the power of tests.

  7. Many-body effects on the zero-point renormalization of diamond: a frozen-phonons approach

    NASA Astrophysics Data System (ADS)

    Antonius, Gabriel; Poncé, Samuel; Cô; té, Michel; Gonze, Xavier

    2013-03-01

    Electron-phonon interaction has a sizeable effect on the electronic structure of materials. Even at zero temperature, the zero-point renormalization (ZPR) can reduce the band gap of insulators by several hundreds of meV. The method of choice to compute this effect is based on the AHC theory, performing perturbative calculations with DFT wavefunctions and energies, possibly with a scissor shift. However, previous studies suggest that inclusion of many-body effects might change substantially the DFT electron-phonon coupling coefficients. We study the ZPR of the optical band gap of diamond, using a frozen-phonons method. This allows us to perform G0W0 and self-consistent quasi-particle GW calculations on the distorted lattice, thus including many-body effects in the electron-phonon coupling coefficients. The frozen-phonons method also allows us to study other neglected components of the AHC theory, such as the non-diagonal Debye-Waller term, and the anharmonic effects.

  8. Progress in the Theory and Interpretation of X-ray Absorption Spectra

    NASA Astrophysics Data System (ADS)

    Rehr, J. J.

    2002-03-01

    There has been dramatic progress in recent years in the understanding of x-ray absorption spectra (XAS) [1]. For example, modern real space multiple scattering theory has yielded a quantitative treatment of the extended fine structure in XAS. Crucial in the theory is a treatment of electronic excited states including many-body effects such as inelastic losses and Debye-Waller factors. These developments have led to ab initio codes which permit an interpretation of the spectra in terms of geometrical and electronic properties of materials [2]. Indeed, the availability of such codes has revolutionized experimental investigations based on synchrotron radiation x-ray sources. Algorithmic improvements have recently made possible fast, parallel calculations of the near edge structure (XANES) [3], and approximate treatments of local field effects and many-body amplitude factors. Related techniques have been applied to several other spectroscopies, e.g., anomalous x-ray scattering, x-ray magnetic circular dichroism, and photoelectron diffraction [4]. [1] J. J. Rehr and R. C. Albers, Rev. Mod. Phys. 72, 621 (2000); [2] A. L. Ankudinov, B. Ravel, J.J. Rehr, and S. Conradson, Phys. Rev. B 58, 7565 (1998); [3] A. L. Ankudinov, C. E. Bouldin, J. J. Rehr, J. Sims, and H. Hung, Phys. Rev. B, in press (2002); [4] F. J. Garcia de Abajo, M. A. Van Hove, C. S. Fadley, Phys. Rev. B 63, 075404 (2001).

  9. Brief report: adolescents' co-rumination with mothers, co-rumination with friends, and internalizing symptoms.

    PubMed

    Waller, Erika M; Rose, Amanda J

    2013-04-01

    The current research examined co-rumination (extensively discussing, rehashing, and speculating about problems) with mothers and friends. Of interest was exploring whether adolescents who co-ruminate with mothers were especially likely to co-ruminate with friends as well as the interplay among co-rumination with mothers, co-rumination with friends, and anxious/depressed symptoms. Early- to mid-adolescents (N = 393) reported on co-rumination and normative self-disclosure with mothers and friends and on their internalizing symptoms in this cross-sectional study. Co-rumination with mothers (but not normative self-disclosure) was concurrently associated with adolescents' co-rumination with friends. In addition, the relation between co-rumination with mothers and adolescents' anxious/depressed symptoms reported previously (Waller & Rose, 2010) became non-significant when co-rumination with friends was statistically controlled. This suggests that the relation between friendship co-rumination and anxious/depressed symptoms may help explain the relation between mother-child co-rumination and anxious/depressed symptoms. Potential implications for promoting adolescents' well-being are discussed. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  10. X-ray absorption investigation of local structural disorder in Ni1-xFex (x=0.10, 0.20, 0.35, and 0.50) alloys

    DOE PAGES

    Zhang, Fuxiang X.; Jin, Ke; Zhao, Shijun; ...

    2017-04-27

    Defect energetics in structural materials has long been recognized to be affected by specific alloy compositions. Significantly enhanced radiation resistance has recently been observed in concentrated solid-solution alloys. However, the link between local structural disorder and modified defect dynamics in solid solutions remains unclear. To reveal the atomic-level lattice distortion, the local structures of Ni and Fe in Ni1-xFex (x=0.1, 0.2, 0.35 and 0.5) solid solution alloys were measured with extended X-ray absorption fine structure (EXAFS) technique. The lattice constant and the first-neighbor distances increase with the increase of Fe content in the solid solutions. EXAFS measurements have revealed thatmore » the bond length of Fe with surrounding atoms is 0.01-0.03 larger than that of Ni in the alloy systems. Debye-Waller factor of the Fe-Fe bonds in all the systems is also slightly larger than that of the Ni-Ni bond. EXAFS fitting suggests that the local structural disorder is enhanced with the addition of Fe elements in the solid solution. The local bonding environments from ab initio calculation are in good agreement with the experimental results, which suggest that the Fe has a larger first-neighbor bonding distance than that of Ni, and thus Ni atom inside the Ni-Fe solid solution alloys undergoes compressive strain.« less

  11. Modeling the interactions of phthalocyanines in water: from the Cu(II)-tetrasulphonate to the metal-free phthalocyanine.

    PubMed

    Martín, Elisa I; Martínez, Jose M; Sánchez Marcos, Enrique

    2011-01-14

    A quantum and statistical study on the effects of the ions Cu(2+) and SO(3)(-) in the solvent structure around the metal-free phthalocyanine (H(2)Pc) is presented. We developed an ab initio interaction potential for the system CuPc-H(2)O based on quantum chemical calculations and studied its transferability to the H(2)Pc-H(2)O and [CuPc(SO(3))(4)](4-)-H(2)O interactions. The use of the molecular dynamics technique allows the determination of energetic and structural properties of CuPc, H(2)Pc, and [CuPc(SO(3))(4)](4-) in water and the understanding of the keys for the different behaviors of the three phthalocyanine (Pc) derivatives in water. The inclusion of the Cu(2+) cation in the Pc structure reinforces the appearance of two axial water molecules and second-shell water molecules in the solvent structure, whereas the presence of SO(3)(-) anions implies a well defined hydration shell of about eight water molecules around them making the macrocycle soluble in water. Debye-Waller factors for axial water molecules have been obtained in order to examine the potential sensitivity of the extended x-ray absorption fine structure technique to detect the axial water molecules.

  12. Pr2M2O7 (M=Zr, Hf) local and crystal structure changes in a fluorite-pyrochlore phase transition.

    NASA Astrophysics Data System (ADS)

    Menushenkov, A. P.; Popov, V. V.; Gaynanov, B. R.; Zubavichus, Ya V.

    2016-09-01

    The formation of nanocrystal powders of Pr2M2O7 (M=Zr, Hf) compounds upon calcinations up to 1400°C has been investigated by using of X-ray absorption fine structure (XAFS) spectroscopy combined with X-ray powder diffraction (XRD). The structure ordering upon calcination was estimated independently from XRD and EXAFS data. It was found that the phase transition fluorite-pyrochlore occurs at calcination temperature in the range of 900-1000°C. The appearance of the ordered pyrochlore structure at calcination temperatures above 1000°C was manifested as splitting of the first oxygen coordination shell of the local praseodymium environment and supported by a sharp reduction of the Debye-Waller factor values of interatomic bonds. Besides we observed the L3 -Hf X-ray absorption near edge line shape splitting with increasing of annealing temperature of amorphous precursor due to crystal field influence in high ordered pyrochlore-type structure.

  13. Vibrational neutron spectroscopy of collagen and model polypeptides.

    PubMed Central

    Middendorf, H D; Hayward, R L; Parker, S F; Bradshaw, J; Miller, A

    1995-01-01

    A pulsed source neutron spectrometer has been used to measure vibrational spectra (20-4000 cm-1) of dry and hydrated type I collagen fibers, and of two model polypeptides, polyproline II and (prolyl-prolyl-glycine)10, at temperatures of 30 and 120 K. the collagen spectra provide the first high resolution neutron views of the proton-dominated modes of a protein over a wide energy range from the low frequency phonon region to the rich spectrum of localized high frequency modes. Several bands show a level of fine structure approaching that of optical data. The principal features of the spectra are assigned. A difference spectrum is obtained for protein associated water, which displays an acoustic peak similar to pure ice and a librational band shifted to lower frequency by the influence of the protein. Hydrogen-weighted densities of states are extracted for collagen and the model polypeptides, and compared with published calculations. Proton mean-square displacements are calculated from Debye-Waller factors measured in parallel quasi-elastic neutron-scattering experiments. Combined with the collagen density of states function, these yield an effective mass of 14.5 a.m.u. for the low frequency harmonic oscillators, indicating that the extended atom approximation, which simplifies analyses of low frequency protein dynamics, is appropriate. PMID:8527680

  14. Chladni's law for vibrating plates

    NASA Astrophysics Data System (ADS)

    Rossing, Thomas D.

    1982-03-01

    The normal vibrational modes of free circular plates can be classified according to the number of nodal diameters m and the number of nodal circles n. Chladni observed that the addition of one nodal circle raised the frequency f about the same amount as adding two nodal diameters, and Rayleigh pointed out that f is proportional to (m+2n)2 for large f. Waller, however, concluded that the number of nodal diameters necessary to raise the frequency as much as a nodal circle varies from two to five. We have examined data on the vibrations of flat and non-flat circular plates and fitted their vibration frequencies to the relationship f = c(m+bn)k. By proper choice of c it is possible to satisfy Chladni's law (b = 2, k = 2) over quite a wide range of frequency in flat plates. Non-flat plates such as cymbals and bells, require different choices of b and k. A brief history of Chladni patterns, and suggestions for observing and demonstrating the vibrational modes of plates are included (AIP).

  15. Surface Structure of Bi(111) from Helium Atom Scattering Measurements. Inelastic Close-Coupling Formalism.

    PubMed

    Kraus, P; Tamtögl, A; Mayrhofer-Reinhartshuber, M; Apolloner, F; Gösweiner, Ch; Miret-Artés, S; Ernst, W E

    2015-07-30

    Elastic and inelastic close-coupling (CC) calculations have been used to extract information about the corrugation amplitude and the surface vibrational atomic displacement by fitting to several experimental diffraction patterns. To model the three-dimensional interaction between the He atom and the Bi(111) surface under investigation, a corrugated Morse potential has been assumed. Two different types of calculations are used to obtain theoretical diffraction intensities at three surface temperatures along the two symmetry directions. Type one consists of solving the elastic CC (eCC) and attenuating the corresponding diffraction intensities by a global Debye-Waller (DW) factor. The second one, within a unitary theory, is derived from merely solving the inelastic CC (iCC) equations, where no DW factor is necessary to include. While both methods arrive at similar predictions for the peak-to-peak corrugation value, the variance of the value obtained by the iCC method is much better. Furthermore, the more extensive calculation is better suited to model the temperature induced signal asymmetries and renders the inclusion for a second Debye temperature for the diffraction peaks futile.

  16. The ultraviolet imaging telescope: Instrument and data characteristics

    NASA Astrophysics Data System (ADS)

    Stecher, Theodore P.; Ultraviolet Imaging Telescope Team

    1997-05-01

    The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro Observatory on the Space Shuttle Columbia in December 1990 (see Figure 1) and again on the Space Shuttle Endeavour in March 1995. Ultraviolet (1200-3300 Å) images of a wide variety of astronomical objects were detected with UV image intensifiers and recorded on photographic film. Typical angular resolutions were 2-3 arcsec over a 40 arcmin field of view. The reduced and calibrated images from the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. UIT's design, operation, data reduction, and calibration are described in detail in Stecher et al. (1997), including a comprehensive description of the data characteristics. This publication provides UIT data users with information for understanding and using the data, as well as guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film. Further information on the Astro missions and the UIT science program is available at the following website http://fondue.gsfc.nasa.gov/UIT/UIT_HomePage.html and in an educational slideset that is available from the Astronomical Society of the Pacific (Waller & Offenberg 1994).

  17. Electron-phonon coupling and surface Debye temperature of Bi2Te3 (111) from helium atom scattering

    NASA Astrophysics Data System (ADS)

    Tamtögl, Anton; Kraus, Patrick; Avidor, Nadav; Bremholm, Martin; Hedegaard, Ellen M. J.; Iversen, Bo B.; Bianchi, Marco; Hofmann, Philip; Ellis, John; Allison, William; Benedek, Giorgio; Ernst, Wolfgang E.

    2017-05-01

    We have studied the topological insulator Bi2Te3 (111) by means of helium atom scattering. The average electron-phonon coupling λ of Bi2Te3 (111) is determined by adapting a recently developed quantum-theoretical derivation of the helium scattering probabilities to the case of degenerate semiconductors. Based on the Debye-Waller attenuation of the elastic diffraction peaks of Bi2Te3 (111), measured at surface temperatures between 110 and 355 K , we find λ to be in the range of 0.04 -0.11 . This method allows us to extract a correctly averaged λ and to address the discrepancy between previous studies. The relatively modest value of λ is not surprising even though some individual phonons may provide a larger electron-phonon interaction. Furthermore, the surface Debye temperature of Bi2Te3 (111) is determined as ΘD=(81 ±6 ) K . The electronic surface corrugation was analyzed based on close-coupling calculations. By using a corrugated Morse potential a peak-to-peak corrugation of 9% of the lattice constant is obtained.

  18. Graphene on Ni(111): Electronic Corrugation and Dynamics from Helium Atom Scattering.

    PubMed

    Tamtögl, Anton; Bahn, Emanuel; Zhu, Jianding; Fouquet, Peter; Ellis, John; Allison, William

    2015-11-19

    Using helium atom scattering, we have studied the structure and dynamics of a graphene layer prepared in situ on a Ni(111) surface. Graphene/Ni(111) exhibits a helium reflectivity of ∼20% for a thermal helium atom beam and a particularly small surface electron density corrugation ((0.06 ± 0.02) Å peak to peak height). The Debye-Waller attenuation of the elastic diffraction peaks of graphene/Ni(111) and Ni(111) was measured at surface temperatures between 150 and 740 K. A surface Debye temperature of θD = (784 ± 14) K is determined for the graphene/Ni(111) system and θD = (388 ± 7) K for Ni(111), suggesting that the interlayer interaction between graphene and the Ni substrate is intermediary between those for strongly interacting systems like graphene/Ru(0001) and weakly interacting systems like graphene/Pt(111). In addition we present measurements of low frequency surface phonon modes on graphene/Ni(111) where the phonon modes of the Ni(111) substrate can be clearly observed. The similarity of these findings with the graphene/Ru(0001) system indicates that the bonding of graphene to a metal substrate alters the dynamic properties of the graphene surface strongly and is responsible for the high helium reflectivity of these systems.

  19. Parallel calculations of vibrational properties in complex materials: negative thermal expansion and elastic inhomogeneity

    NASA Astrophysics Data System (ADS)

    Vila, F. D.; Rehr, J. J.

    Effects of thermal vibrations are essential to obtain a more complete understanding of the properties of complex materials. For example, they are important in the analysis and simulation of x-ray absorption spectra (XAS). In previous work we introduced an ab initio approach for a variety of vibrational effects, such as crystallographic and XAS Debye-Waller factors, Debye and Einstein temperatures, and thermal expansion coefficients. This approach uses theoretical dynamical matrices from which the locally-projected vibrational densities of states are obtained using a Lanczos recursion algorithm. In this talk I present recent improvements to our implementation, which permit simulations of more complex materials with up to two orders of magnitude larger simulation cells. The method takes advantage of parallelization in calculations of the dynamical matrix with VASP. To illustrate these capabilities we discuss two problems of considerable interest: negative thermal expansion in ZrW2O8; and local inhomogeneities in the elastic properties of supported metal nanoparticles. Both cases highlight the importance of a local treatment of vibrational properties. Supported by DOE Grant DE-FG02-03ER15476, with computer support from DOE-NERSC.

  20. Re-evaluation of the diagnosis of porphyria cutanea tarda in Admiral Sir Francis Beaufort

    PubMed Central

    Peters, T J; Levell, N J

    2010-01-01

    Objectives Two biographies of Admiral Francis Beaufort (1774–1857) have stated that, aged 20–25 years, he suffered from porphyria cutanea tarda (PCT) that was ‘cured’ following severe blood loss during a naval skirmish. We have examined the evidence concerning the nature of his skin disease. Design Primary records, most notably Beaufort's correspondence with his family, his journals and his father's diaries were sought out and analysed. Setting This case report is discussed in the context of 18th-century naval medicine and concepts and treatment of skin disease. Results The description of his lesions, their age of onset, their progression and response to treatment, particularly topical tar and associated features are quite inconsistent with a diagnosis of PCT. His mother, Mary Waller Beaufort (1739–1821), consulted Dr Robert Darwin in 1803 about a painful skin disease affecting her legs. Detailed description of the lesions and a contemporary diagnosis are not available but possible diagnoses include chronic psoriasis and stasis eczema. Conclusions A more tenable diagnosis is that Francis Beaufort had chronic plaque psoriasis remitted by bed rest and convalescence in the sunny Mediterranean climate with cessation of alcohol consumption and improved nutrition as well as topical and oral medications. PMID:21103105

  1. Low-temperature semiconductor band-gap thermal shifts: T4 shifts from ordinary acoustic and T2 from piezoacoustic coupling

    NASA Astrophysics Data System (ADS)

    Allen, Philip B.; Nery, Jean Paul

    2017-01-01

    At low temperature, the experimental gap of silicon decreases as Eg(T ) =Eg(0 ) -A T4 . The main reason is electron-phonon renormalization. The physics behind the T4-power law is more complex than has been realized. Renormalization at low T by intraband scattering requires a nonadiabatic treatment in order to correctly include acoustic phonons and avoid divergences from piezoacoustic phonon interactions. The result is an unexpected low T term Eg(0 ) +A'Tp with positive coefficient A', and power p =4 for nonpiezoelectric materials, and power p =2 for piezoelectric materials. The acoustic phonons in piezoelectric semiconductors generate a piezoelectric field, modifying the electron-phonon coupling. However, at higher T , thermally excited acoustic phonons of energy ℏ vsq and intraband excitation energies ɛq-ɛ0=ℏ2q2/2 m* become comparable in size. Above this temperature, the low q and higher q intraband acoustic phonon contributions to Tp rapidly cancel, leaving little thermal effect. Then the contribution from interband scattering by acoustic phonons is dominant. This has the power law T4 for both nonpiezoelectric and piezoelectric semiconductors. The shift can then have either sign, but usually reduces the size of gaps as T increases. It arises after cancellation of the T2 terms that appear separately in Debye-Waller and Fan parts of the acoustic phonon interband renormalization. The cancellation occurs because of the acoustic sum rule.

  2. X-ray-absorption fine-structure studies of superconducting Tl2CaBa2Cu2Ox thin films

    NASA Astrophysics Data System (ADS)

    Dimarzio, D.; Wiesmann, H.; Chen, D. H.; Heald, S. M.

    1990-07-01

    Superconducting Tl-Ca-Ba-Cu-O thin films have been prepared by the technique of reactive magnetron sputtering using targets of Tl, Ca-Ba, and Cu. Three films with different quality superconducting transitions were fabricated and analyzed. X-ray-absorption fine-structure measurements were performed on the Cu K edge in order to determine orientation, bond lengths, number of nearest neighbors, and relative disorder as a function of the quality of their superconducting transition. Magnetically oriented powder samples of the appropriate superconducting phase were used for comparison. X-ray-absorption near-edge results reveal increasing CuO2 plane orientation parallel to the substrate as the quality of the superconducting transition improved, consistent with x-ray-diffraction data. Extended x-ray-absorption fine-structure (EXAFS) measurements also show this trend. EXAFS gives a Cu-O(1) bond length of 1.92+/-0.01 Å for all three films, and all three samples exhibit an increasing Debye-Waller disorder factor consistent with the deterioration in the quality of their superconducting transitions.

  3. Doping induced structural changes in colloidal semiconductor nanowires.

    PubMed

    Kandel, Krishna Prasad; Pietsch, Ullrich; Li, Zhen; Oztürk, Ozgül Kurtulus

    2013-03-28

    Undoped and Mn(2+)-doped CdSe nanowires (NWs) grown by a solution-liquid-solid (SLS) method using Bi nanocatalysts have been studied by X-ray powder diffraction measurements. Except for heavily doped nanowires no measurable changes in nanowire lattice parameters were observed. The lattice parameter of heavily doped nanowires shrinks by about 0.5% compared with the undoped ones, which corresponds to a doping concentration of 1.6%. For the other samples no change in lattice parameter is measured referring to a doping level much below 1%. Real structural parameters of nanowires were found to vary as a function of doping level, such as the zinc blende to wurtzite ratio, the static Debye-Waller factor, axial strain, and the number of stacking faults. Compared with the undoped nanowires the overall perfection is slightly improved for low doping but deteriorates drastically for higher doping. Our results highlight the importance of controlling the dopant concentration during the preparation of doped nanostructures.

  4. Application of molecular dynamics simulations for structural studies of carbon nanotubes.

    PubMed

    Bródka, A; Kołoczek, J; Burian, A

    2007-01-01

    Molecular dynamics studies based on the Brenner-Tersoff second-generation reactive empirical bond order potential and the Lennard-Jones carbon-carbon potential for intra- and inter-layer interactions have been performed for carbon nanotubes. These potentials reproduce reasonably the carbon-carbon distances and inter-layer spacing. The structure factors and the reduced radial distribution functions computed from the cartesian coordinates, resulting from energy minimisation and molecular dynamics simulations at 2 K and 300 K have been obtained for two models of two- and five-wall carbon nanotubes containing defects in the form of five and seven membered carbon rings. The results of computations have been compared with experimental data obtained from neutron and X-ray diffraction. The energy relaxation and the molecular dynamics simulations at 2 K and 300 K with appropriate values of the Debye-Waller factor lead practically to the same results which are in a good agreement with the experimental data indicating that molecular dynamics reproduce all structure features of the investigated carbon nanotubes together with thermal oscillations. Possible applications of this approach for other carbon nanotubes and related materials have been also discussed.

  5. Experimental evidence for an absorbing phase transition underlying yielding of a soft glass

    NASA Astrophysics Data System (ADS)

    Nagamanasa, K. Hima; Gokhale, Shreyas; Sood, A. K.; Ganapathy, Rajesh

    2014-03-01

    A characteristic feature of solids ranging from foams to atomic crystals is the existence of a yield point, which marks the threshold stress beyond which a material undergoes plastic deformation. In hard materials, it is well-known that local yield events occur collectively in the form of intermittent avalanches. The avalanche size distributions exhibit power-law scaling indicating the presence of self-organized criticality. These observations led to predictions of a non-equilibrium phase transition at the yield point. By contrast, for soft solids like gels and dense suspensions, no such predictions exist. In the present work, by combining particle scale imaging with bulk rheology, we provide a direct evidence for a non-equilibrium phase transition governing yielding of an archetypal soft solid - a colloidal glass. The order parameter and the relaxation time exponents revealed that yielding is an absorbing phase transition that belongs to the conserved directed percolation universality class. We also identified a growing length scale associated with clusters of particles with high Debye-Waller factor. Our findings highlight the importance of correlations between local yield events and may well stimulate the development of a unified description of yielding of soft solids.

  6. Impact of Air Pollution on California Central Valley Fog Frequency

    NASA Astrophysics Data System (ADS)

    Gray, E.; Baldocchi, D. D.; Goldstein, A. H.

    2015-12-01

    Throughout the 20th century, trends in California Central Valley fog frequency have changed dramatically without explanation. While episodes of dense radiation fog, known regionally as Tule Fog, increased steadily from 1930-1970, analysis from both ground and remote sensing measurements confirm a 46-50% reduction in fog days in the last 30 years (Baldocchi and Waller, 2014, Herkes et al., 2014). The dominant hypotheses suggest that the recent decline in radiation fog can be explained by the rising temperatures associated with climate change or urban heat island effect. This assertion fails to explain the significant increase in Central Valley fog midcentury. Here we instead assert that changes in air pollution, rather than climate, better support this upward then downward temporal trend. Automobile use greatly increased emissions of nitrogen oxide (NOx) midcentury, followed by a large decrease in vehicle emissions due to statewide regulation from 1980 to present. In the Central Valley, NOx from automobile emissions contributes to the formation ammonium nitrate (NH4NO3), the dominant hygroscopic aerosol in the valley's wintertime boundary layer that can act as cloud condensation nuclei (CCN) necessary for fog droplet formation. Thus, changes in air pollution not only affect the number of CCN, but may also impact the density and persistence of fog episodes. Using NOAA meteorological records throughout the twentieth century, we will show the correlation between fog frequency, air pollution, and climatic drivers. We conclude that fog trends are closely correlated with changes in air pollution, rather than solely climate change.

  7. Thickness-dependent electron–lattice equilibration in laser-excited thin bismuth films

    DOE PAGES

    Sokolowski-Tinten, K.; Li, R. K.; Reid, A. H.; ...

    2015-11-19

    Electron–phonon coupling processes determine electronic transport properties of materials and are responsible for the transfer of electronic excess energy to the lattice. With decreasing device dimensions an understanding of these processes in nanoscale materials is becoming increasingly important. We use time-resolved electron diffraction to directly study energy relaxation in thin bismuth films after optical excitation. Precise measurements of the transient Debye–Waller-effect for various film thicknesses and over an extended range of excitation fluences allow to separate different contributions to the incoherent lattice response. While phonon softening in the electronically excited state is responsible for an immediate increase of the r.m.s.more » atomic displacement within a few hundred fs, 'ordinary' electron–phonon coupling leads to subsequent heating of the material on a few ps time-scale. Moreover, the data reveal distinct changes in the energy transfer dynamics which becomes faster for stronger excitation and smaller film thickness, respectively. The latter effect is attributed to a cross-interfacial coupling of excited electrons to phonons in the substrate.« less

  8. Biotin Transport and Accumulation by Cells of Lactobacillus plantarum II. Kinetics of the System

    PubMed Central

    Waller, James R.; Lichstein, Herman C.

    1965-01-01

    Waller, James R. (University of Cincinnati, Cincinnati, Ohio), and Herman C. Lichstein. Biotin transport and accumulation by cells of Lactobacillus plantarum. II. Kinetics of the system. J. Bacteriol. 90:853–856. 1965.—Bound biotin-saturated cells of Lactobacillus plantarum accumulated free biotin by a time-dependent process exhibiting substrate saturation phenomena in the presence and absence of glucose. Apparent Km and Vmax values determined in the presence and absence of glucose, respectively, from Lineweaver-Burk plots were found to be 31.5 and 7.72 mμm (Km) and 9.72 and 3.26 μμmoles per mg per min (Vmax). Free biotin transport per se appeared to be an energy-independent, mediated process, whereas the accumulation of large intracellular vitamin concentrations was energy-dependent. Internal free biotin was quantitatively converted to bound biotin. The rate and extent of bound biotin formation was slower than free biotin uptake, and dependent upon intracellular free biotin levels up to a saturating concentration. PMID:5847806

  9. Diversity and coverage of structural sublibraries selected using the SAGE and SCA algorithms.

    PubMed

    Reynolds, C H; Tropsha, A; Pfahler, L B; Druker, R; Chakravorty, S; Ethiraj, G; Zheng, W

    2001-01-01

    It is often impractical to synthesize and test all compounds in a large exhaustive chemical library. Herein, we discuss rational approaches to selecting representative subsets of virtual libraries that help direct experimental synthetic efforts for diverse library design. We compare the performance of two stochastic sampling algorithms, Simulating Annealing Guided Evaluation (SAGE; Zheng, W.; Cho, S. J.; Waller, C. L.; Tropsha, A. J. Chem. Inf. Comput. Sci. 1999, 39, 738-746.) and Stochastic Cluster Analysis (SCA; Reynolds, C. H.; Druker, R.; Pfahler, L. B. Lead Discovery Using Stochastic Cluster Analysis (SCA): A New Method for Clustering Structurally Similar Compounds J. Chem. Inf. Comput. Sci. 1998, 38, 305-312.) for their ability to select both diverse and representative subsets of the entire chemical library space. The SAGE and SCA algorithms were compared using u- and s-optimal metrics as an independent assessment of diversity and coverage. This comparison showed that both algorithms were capable of generating sublibraries in descriptor space that are diverse and give reasonable coverage (i.e. are representative) of the original full library. Tests were carried out using simulated two-dimensional data sets and a 27 000 compound proprietary structural library as represented by computed Molconn-Z descriptors. One of the key observations from this work is that the algorithmically simple SCA method is capable of selecting subsets that are comparable to the more computationally intensive SAGE method.

  10. Retrospective reports of parenting received in their families of origin: relationships to adult attachment in adult children of alcoholics.

    PubMed

    Kelley, Michelle L; Nair, Veena; Rawlings, Tanaya; Cash, Thomas F; Steer, Kate; Fals-Stewart, William

    2005-09-01

    The present study examined general and romantic attachment and parenting students received in their families of origin among 401 college students who resided with an alcohol-abusing parent prior to age 16 years as compared to those who did not reside with alcohol-abusing parents. Participants completed the Children's Report of Parent Behavior Instrument [Schludermann, E. and Schludermann, S. (1970). Children's Report of Parent Behavior Inventory (CRPBI). Canada: University of Manitoba], Experiences in Close Relationships--Revised [Fraley, R. C., Waller, N. G., and Brennan, K. G. (2000). An item response theory analysis of self-report measures of adult attachment. Journal of Personality and Social Psychology, 78, 350-365], Relationship Scale Questionnaire [Griffin, D. W. and Bartholomew, K. (1994). Models of the self and other: Fundamental dimensions underlying measures of adult attachment. Journal of Personality and Social Psychology, 67, 430-445], and the Children of Alcoholics Screening Test [Jones, J. W. (1983). The Children of Alcoholics Screening Test: Test manual. Chicago: Camelot]. Young adults who met criteria for ACOAs reported more anxious and avoidant behavior in romantic relationships and a more fearful style of general adult attachment. Parenting behavior in one's family of origin predicted anxious behavior in romantic relationships and a fearful overall style of attachment, whereas being an ACOA and parenting in one's family of origin predicted avoidant behavior in romantic relationships.

  11. Commensurability and stability in nonperiodic systems

    PubMed Central

    Fasano, Y.; De Seta, M.; Menghini, M.; Pastoriza, H.; de la Cruz, F.

    2005-01-01

    We have investigated the response of 3D Bi2Sr2CaCu2O8 vortex structures to a weak perturbation induced by 2D Fe pinning structures acting on one extremity of vortex lines. The pinning patterns were nano-engineered at the sample surface by means of either a Bitter decoration of the vortex lattice or electron-beam lithography. The commensurability conditions between 2D rigid pinning potentials and 3D elastic structures with short-range positional and long-range orientational correlation have been experimentally determined. When the 2D potential is a replica of the nonperiodic vortex structure an amplification of its interaction with the vortex structure takes place. This effect is detected only for the first matching field, becoming negligible for other matching fields. On the other hand, a periodic 2D perturbation is shown to transform the nonperiodic Bragg glass-like structure into an Abrikosov crystal with an effective Debye–Waller factor. PMID:16576763

  12. Electrocardiographic intricacies clarified by echocardiography--should the electrocardiogram be interpreted echocardiographically?

    PubMed

    Ker, James

    2012-07-12

    During the past century the electrocardiogram (ECG) has established itself as an integral part of the cardiovascular examination. Since the first direct recordings of cardiac potentials by Waller in 1887, to the invention of the string galvanometer by Willem Einthoven in 1901, to use in the clinic by 1910, the electrocardiogram has become the most widely used clinical tool in the diagnosis of virtually every type of heart disease. Currently up to 20 million ECGs are performed annually in the United States alone. However, in this era of readily available echocardiography, an important caveat in the interpretation of the electrocardiogram has emerged: variants of intracardiac structures which might mimic disease on the ECG. In this perspective various structural variants of intracardiac structures, specifically variants of papillary muscles and subaortic muscular bands, will be shown, together with their associated electrocardiographic changes, mimicking disease. It is concluded that in this era of readily available echocardiography, the electrocardiogram should be interpreted echocardiographically in instances where intricate variations are seen on the surface electrocardiogram. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Personality influences on change in smoking behavior.

    PubMed

    Welch, David; Poulton, Richie

    2009-05-01

    To investigate associations between personality traits in early adulthood (and changes in them) and change in smoking status. Prospective, longitudinal study of a general-population birth cohort. We measured smoking at ages 18, 26, and 32, and personality at ages 18 and 26 using the Multidimensional Personality Questionnaire (Tellegen & Waller, in press). We assessed personality's ability to predict future smoking, and assessed how changes in personality traits relate to change in smoking status. Higher aggression and alienation at age 18 predicted smoking at 26; higher self-control and traditionalism at age 18 predicted nonsmoking at 26; and higher alienation at age 26 predicted persistence of smoking to age 32. Personality change between 18 and 26 was associated with change in smoking behavior; those who stopped smoking decreased more than others in negative emotionality and increased more in constraint. These findings suggest that interventions fostering personality change may be effective in reducing smoking and indicate appropriate targets for such antismoking interventions in young people. In particular, high alienation predicted smoking persistence, perhaps due to resistance to existing antismoking messages; we discuss approaches that may overcome this.

  14. Simulation of the EXAFS and Raman spectra of InxGa1-xN utilizing the equation of motion routine of FEFF8.

    NASA Astrophysics Data System (ADS)

    Katsikini, M.; Pinakidou, F.; Paloura, E. C.; Arvanitidis, J.; Ves, S.; Reinholz, U.; Papadomanolaki, E.; Iliopoulos, E.

    2016-05-01

    A combined analysis of EXAFS and Raman spectra is applied for the study of InxGa1-xN alloys with 0.3Waller factor (DWF). The static disorder component of the DWFs was obtained by fitting the Ga and In K-edge EXAFS spectra. The analysis revealed that the nearest neighbor distances of the 1st and 2nd shell deviate from the values predicted by the law of Vegard and the virtual crystal approximation. The static disorder in the first nearest neighboring shell (In-N and Ga-N) is null whereas in the cation-cation neighboring shells the static component is generally smaller than the vibrational.

  15. Delineating the Construct Network of the Personnel Reaction Blank: Associations with Externalizing Tendencies and Normal Personality

    PubMed Central

    Blonigen, Daniel M.; Patrick, Christopher J.; Gasperi, Marianna; Steffen, Benjamin; Ones, Deniz S.; Arvey, Richard D.; de Oliveira Baumgartl, Viviane; do Nascimento, Elizabeth

    2010-01-01

    Integrity testing has long been utilized in personnel selection to screen for tendencies toward counterproductive workplace behaviors. The construct of externalizing from the psychopathology literature represents a coherent spectrum marked by disinhibitory traits and behaviors. The present study used a sample of male and female undergraduates to examine the construct network of the Personnel Reaction Blank (PRB; Gough, Arvey, & Bradley, 2004), a measure of integrity, in relation to externalizing as well as normal-range personality constructs assessed by the Multidimensional Personality Questionnaire (MPQ; Tellegen & Waller, 2008). Results revealed moderate to strong associations between several PRB scales and externalizing, which were largely accounted for by MPQ traits subsumed by Negative Emotionality and Constraint. After accounting for MPQ traits in the prediction of externalizing, a modest predictive increment was achieved when adding the PRB scales, particularly biographical indicators from the Prosocial Background subscale. The findings highlight externalizing as a focal criterion for scale development in the integrity testing literature, and help delineate the construct network of the PRB within the domains of personality and psychopathology. PMID:21171783

  16. Modeling the interactions of phthalocyanines in water: From the Cu(II)-tetrasulphonate to the metal-free phthalocyanine

    NASA Astrophysics Data System (ADS)

    Martín, Elisa I.; Martínez, Jose M.; Marcos, Enrique Sánchez

    2011-01-01

    A quantum and statistical study on the effects of the ions Cu^{2+} and SO3- in the solvent structure around the metal-free phthalocyanine (H2Pc) is presented. We developed an ab initio interaction potential for the system CuPc-H2O based on quantum chemical calculations and studied its transferability to the H2Pc-H2O and [CuPc(SO3)4]^{4-}-H2O interactions. The use of the molecular dynamics technique allows the determination of energetic and structural properties of CuPc, H2Pc, and [CuPc(SO3)4]^{4-} in water and the understanding of the keys for the different behaviors of the three phthalocyanine (Pc) derivatives in water. The inclusion of the Cu^{2+} cation in the Pc structure reinforces the appearance of two axial water molecules and second-shell water molecules in the solvent structure, whereas the presence of SO3{}^- anions implies a well defined hydration shell of about eight water molecules around them making the macrocycle soluble in water. Debye-Waller factors for axial water molecules have been obtained in order to examine the potential sensitivity of the extended x-ray absorption fine structure technique to detect the axial water molecules.

  17. Ab initio calculation of optical constants from visible to x-ray energies

    NASA Astrophysics Data System (ADS)

    Prange, M. P.; Rivas, G.; Ankudinov, A. L.; Rehr, J. J.

    2004-03-01

    We present a semi-automated approach for ab initio calculations of optical constants of materials from the visible to the hard x-ray energies. The approach is based on a generalization of the real space Green's formalism implemented in the FEFF8 spectroscopy code to include optical spectra. The method includes self-consistent potentials, core-hole and self-energy effects, inelastic losses and a full- or high order multiple-scattering. The procedure is based on calculations of the imaginary part of the dielectric function ɛ2 summed over all edges, from which other optical constants are derived using Kramers-Kronig transforms and analytical relations. These constants include the complex index of refraction, the real part of the dielectric function, and energy loss spectra. In contrast to standard atomic tables, the calculations include solid-state corrections, such as fine structure, Debye-Waller factors, lifetime broadening, etc. Typical results for several materials are presented and compared with experiment.

  18. Psychopathic Personality Traits and Environmental Contexts: Differential Correlates, Gender Differences, and Genetic Mediation

    PubMed Central

    Hicks, Brian M.; Carlson, Marie D.; Blonigen, Daniel M.; Patrick, Christopher J.; Iacono, William G.; MGue, Matt

    2011-01-01

    Theorists have speculated that primary psychopathy (or Factor 1 affective-interpersonal features) is prominently heritable whereas secondary psychopathy (or Factor 2 social deviance) is more environmentally determined. We tested this differential heritability hypothesis using a large adolescent twin sample. Trait-based proxies of primary and secondary psychopathic tendencies were assessed using Multidimensional Personality Questionnaire (MPQ; Tellegen & Waller, 2008) estimates of Fearless Dominance and Impulsive Antisociality, respectively (Benning et al., 2005). The environmental contexts of family, school, peers, and stressful life events were assessed using multiple raters and methods. Consistent with prior research, MPQ Impulsive Antisociality was robustly associated with each environmental risk factor, and these associations were significantly greater than those for MPQ Fearless Dominance. However, MPQ Fearless Dominance and Impulsive Antisociality exhibited similar heritability, and genetic effects mediated the associations between MPQ Impulsive Antisociality and the environmental measures. Results were largely consistent across male and female twins. We conclude that gene-environment correlations rather than main effects of genes and environments account for the differential environmental correlates of primary and secondary psychopathy. PMID:22452762

  19. Groundwater environmental tracer data collected from the Chicot, Evangeline, and Jasper aquifers in Montgomery County and adjacent counties, Texas, 2008

    USGS Publications Warehouse

    Oden, Timothy D.

    2011-01-01

    The Gulf Coast aquifer system is the primary water supply for Montgomery County in southeastern Texas, including part of the Houston metropolitan area and the cities of Magnolia, Conroe, and The Woodlands Township, Texas. The U.S. Geological Survey, in cooperation with the Lone Star Groundwater Conservation District, collected environmental tracer data in the Gulf Coast aquifer system, primarily in Montgomery County. Forty existing groundwater wells screened in the Gulf Coast aquifer system were selected for sampling in Montgomery County (38 wells), Waller County (1 well), and Walker County (1 well). Groundwater-quality samples, physicochemical properties, and water-level data were collected once from each of the 40 wells during March-September 2008. Groundwater-quality samples were analyzed for dissolved gases and the environmental tracers sulfur hexafluoride, chlorofluorocarbons, tritium, helium-4, and helium-3/tritium. Water samples were collected and processed onsite using methods designed to minimize changes to the water-sample chemistry or contamination from the atmosphere. Replicate samples for quality assurance and quality control were collected with each environmental sample. Well-construction information and environmental tracer data for March-September 2008 are presented.

  20. Research on long-time self-irradiation of alloy δ-Pu 242-Ga

    NASA Astrophysics Data System (ADS)

    Somenkov, V. A.; Blanter, M. S.; Glazkov, V. P.; Laushkin, A. V.; Orlov, V. K.

    2011-06-01

    Self-irradiation of Pu-Ga alloy was studied by neutron diffraction, which provided information about the crystalline structure and yielded mean-square atom displacements < u2> from the Debye-Waller factor. The measurements were performed at room temperature using the sample based on the isotope Pu 242 with low neutron absorption cross-section to which the short-living isotope Pu 238 (1.4%) was added to accelerate self-irradiation. This composition of the sample sped up the aging processes by the factor of four and allowed us to obtain the maximum equivalent time of 23.5 years. Fcc structure remains the same throughout this interval. The changes in < u2> due to static displacements occur in two stages, viz. a relatively rapid growth (roughly by 50%) over the first 5-6 equivalent years and slow decline during 6-23 equivalent years making a close approach to the initial values. The latter stage has not been described in the literature. It can be explained by the confluence of point defects into helium bubbles and dislocation loops accumulated over time.

  1. A New Probe of the Molecular Gas Content in Galaxies: Application to M101

    NASA Technical Reports Server (NTRS)

    Smith, D. A.; Allen, R. J.; Bohlin, R. C.; Nicholson, N.; Stecher, T. P.

    1999-01-01

    Studies of nearby spiral galaxies suggest that photodissociation regions (PDRs) are capable of producing the observed large--scale distribution of HI (Allen et al.- 1997, and references therein). The column density of HI in a PDR is fundamentally linked to the amount of far--ultraviolet (FUV) emission produced by nearby young stars and the local molecular gas volume density. Measurements of the HI column density and the FUV emission associated with PDRs thus provide a new probe of the molecular gas distribution in nearby galaxies. Advantages of this method include its insensitivity to assumptions about the CO/{\\rm H2} conversion factor or the gas temperature. We discuss the application of this method to M101. The HI column density and FUV emission have been measured for 35 PDRs from VLA data (Braun 1997) and Ultraviolet Imaging Telescope data (Waller et al.-1997). We derive volume densities ranging from n-100 {\\rm cm(exp -3)} in the central HI--poor regions of M101 to n -3000 {\\rm cm(exp -3)} in the HI--rich periphery of the galaxy.

  2. Mössbauer Effect in Hemoglobin and Some Iron-Containing Biological Compounds

    PubMed Central

    Gonser, U.; Grant, R. W.

    1965-01-01

    The Mössbauer effect in Fe57 has been used to study the molecules, hemoglobin, O2-hemoglobin, CO2-hemoglobin, and CO-hemoglobin (within red cells) and the molecules, hemin and hematin (in the crystalline state). Quadrupole splittings and isomeric shifts observed in the Mössbauer spectra of these molecules are tabulated. The temperature dependence of the quadrupole splitting and relative recoil-free fraction for hemoglobin with different ligands has been investigated. An estimate of the Debye-Waller factor in O2-hemoglobin at 5°K is 0.83. An asymmetry in the quadrupole splitting observed in hemoglobin is attributed to a directional dependence of the recoil-free fraction which establishes the sign of the electric field gradient in the molecule and indicates that the lowest lying d orbital of the Fe atoms is |xy>. This asymmetry indicates that the iron atoms in hemoglobin are vibrating farther perpendicular to the heme planes than parallel to them, and, in fact, the ratio of the mean square displacements perpendicular and parallel to the heme planes in hemoglobin is ≈5.5 at 5°K. The temperature dependence of the quadrupole splitting in hemoglobin has been used to estimate a splitting between the lowest lying iron atom d orbitals of ≈420 cm-1. PMID:5884013

  3. Thermodynamic and structural properties of phospholipid langmuir monolayers on hydrosol surfaces.

    PubMed

    Wiegart, Lutz; Struth, Bernd; Tolan, Metin; Terech, Pierre

    2005-08-02

    Measurements of Langmuir pressure/area isotherms, rheology, grazing incidence X-ray diffraction (GIXD), and grazing incidence diffuse X-ray scattering out of the specular plane (GIXOS) have been used to investigate the influence of a hydrosol containing charged mineral nanoparticles on the thermodynamic and structural properties of a DPPC monolayer. The mineral adsorption layer that is formed via electrostatic interaction underneath the lipid layer alters the thermodynamic properties of the phospholipid monolayer in terms of maximal achievable compression, compressibility, and phase behavior. Modifications appear in the latter case as a coolinglike effect. Rheology measurements of the bulk viscoelastic properties revealed a stabilizing effect of the transient bulk network on the surfactant layer. The lipid chain lattice is found to be reorganized and adapted to the internal atomic structure of the mineral particles. A model for the superposition of Bragg rods from the lipid chains and the minerals is applied to separate these scattering contributions. In the vicinity of the mineral particles, the (2) reflection for DPPC on a liquid substrate was found, indicating strongly suppressed fluctuations at the surface. An estimation of the Debye-Waller factor associated with the lipid layer organization is used to quantify the damping of fluctuations within the lipid matrix due to the rigidifying and stabilizing effect of the mineral particles.

  4. "Your feet's too big": an inquiry into psychological and symbolic meanings of the foot.

    PubMed

    Zerbe, K J

    1985-01-01

    The foot is a highly cathected appendage that is commonly singled out as the brunt of humorous or derisive remarks, as if it embodies repugnance and disgust. Attitudes toward the foot are overdetermined, bearing the imprint of man's early linguistic patterns and individual dynamics. This article suggests that feet are symbolic because they bear the feelings derived from earlier separations, good and bad object representations, collective memories, and genital representations. The foot's role as symbol of both the male and female genitals, repository of badness, symbol of passivity, initiator of movement, and site of self-mutilation have been briefly reviewed. As Fats Waller rhapsodizes that the "feet's too big," he finds a convenient way to displace his symbiotic and erotic anxieties vis-à-vis women. Similarly, patients who come for psychiatric treatment and psychotherapy frequently make references to their feet or use them in specific ways. An understanding of this type of communication can often provide insight into individual dynamics and enhance treatment. The weight placed on these communications depends, of course, on the vicissitudes of the previous therapeutic work as well as on the particular problems of the patient.

  5. Pressure and chemical substitution effects in the local atomic structure of BaFe2As2

    NASA Astrophysics Data System (ADS)

    Granado, E.; Mendonça-Ferreira, L.; Garcia, F.; Azevedo, G. De M.; Fabbris, G.; Bittar, E. M.; Adriano, C.; Garitezi, T. M.; Rosa, P. F. S.; Bufaiçal, L. F.; Avila, M. A.; Terashita, H.; Pagliuso, P. G.

    2011-05-01

    The effects of K and Co substitutions and quasihydrostatic applied pressure (P<9 GPa) in the local atomic structure of BaFe2As2, Ba(Fe0.937Co0.063)2As2 and Ba0.85K0.15Fe2As2 superconductors were investigated by extended x-ray absorption fine structure (EXAFS) measurements in the As K absorption edge. The As-Fe bond length is found to be slightly reduced (≲0.01 Å) by both Co and K substitutions, without any observable increment in the corresponding Debye-Waller factor. Also, this bond is shown to be compressible [κ=3.3(3)×10-3 GPa-1]. The observed contractions of As-Fe bond under pressure and chemical substitutions are likely related with a reduction of the local Fe magnetic moments, and should be an important tuning parameter in the phase diagrams of the Fe-based superconductors.

  6. Brief Report: Adolescents' Co-Rumination with Mothers, Co-Rumination with Friends, and Internalizing Symptoms

    PubMed Central

    Rose, Amanda J.

    2013-01-01

    The current research examined co-rumination (extensively discussing, rehashing, and speculating about problems) with mothers and friends. Of interest was exploring whether adolescents who co-ruminate with mothers were especially likely to co-ruminate with friends as well as the interplay among co-rumination with mothers, co-rumination with friends, and anxious/depressed symptoms. Early- to mid-adolescents (N = 393) reported on co-rumination and normative self-disclosure with mothers and friends and on their internalizing symptoms in this cross-sectional study. Co-rumination with mothers (but not normative self-disclosure) was concurrently associated with adolescents' co-rumination with friends. In addition, the relation between co-rumination with mothers and adolescents' anxious/depressed symptoms reported previously (Waller & Rose, 2010) became non-significant when co-rumination with friends was statistically controlled. This suggests that the relation between friendship co-rumination and anxious/depressed symptoms may help explain the relation between mother-child co-rumination and anxious/depressed symptoms. Potential implications for promoting adolescents' well-being are discussed. PMID:23398818

  7. Structural instability in BaZrO3 crystals: Calculations and experiment

    NASA Astrophysics Data System (ADS)

    Lebedev, A. I.; Sluchinskaya, I. A.

    2013-09-01

    The phonon spectrum of cubic barium zirconate is calculated from first principles using the density functional theory. An unstable R 25 phonon mode observed in the phonon spectrum indicates an instability of the BaZrO3 structure with respect to the oxygen octahedra rotations. It is shown that the symmetry of the ground-state structure of the crystal is I4/ mcm. The local structure of BaZrO3 is studied by the EXAFS spectroscopy at the Ba L III absorption edge at 300 K to search for the instability predicted by calculations. Anomalously high values of the Debye-Waller factor for the Ba-O atomic pairs (σ{1/2} ˜ 0.015 Å2) are attributed to the appearance of this structural instability. The average amplitude of the octahedra rotations caused by thermal vibrations is estimated from the measured σ{1/2} value to be ˜4° at 300 K. The closeness of the calculated energies of various distorted phases resulting from the condensation of the R 25 mode suggests a possible formation of the structural glass state in BaZrO3 as the temperature is lowered. It explains the origin of the disagreement between the results of calculations and diffraction experiments.

  8. [A history of the electrocardiogram].

    PubMed

    Johansson, B W

    2001-01-01

    The discoveries by Galvani and Volta of electricity and its effects fascinated the intellectual world, but it was not until 1856 that Köllicker and Müller discovered that the heart muscle could produce electric activity. Muirhead in London recorded the first electrocardiogram (ECG) in man in 1869 or 1870 with a siphon instrument and Waller in 1887 with a capillary electrometer. Einthoven's string galvanometer was a breakthrough. As early as five years after his publication Einthoven introduced "Le Télecardiograme" in 1906 by which a cable connected his instrument to a hospital one and a half kilometres away. The string galvanometer produced precise ECG recordings but it was like the opera primadonnas of the time, voluminous and unpredictable. Rune Elmqvist developed the direct-writing inkjet recorder, first demonstrated at the Congress of Cardiology in Paris, 1950. Ohnell's studies of preexcitation, to which the WPW-syndrome belongs, were important. After the initial focus on arrhythmias, ECG became more and more used in the diagnosis of myocardial ischaemia and coronary heart disease. To refine this diagnosis the hypoxaemia (breathing air with low oxygen content) test, as well as the exercise test and other stress tests were introduced. Vectorcardiography displays the spatial movements of the electrical forces generated by the heart. Long-term ECG registration with a portable tape recorder is important both for the diagnosis of arrhythmias and myocardial ischaemia. Foetal and comparative ECG have provided important clinical and scientific information.

  9. Surface Structure of Bi(111) from Helium Atom Scattering Measurements. Inelastic Close-Coupling Formalism

    PubMed Central

    2015-01-01

    Elastic and inelastic close-coupling (CC) calculations have been used to extract information about the corrugation amplitude and the surface vibrational atomic displacement by fitting to several experimental diffraction patterns. To model the three-dimensional interaction between the He atom and the Bi(111) surface under investigation, a corrugated Morse potential has been assumed. Two different types of calculations are used to obtain theoretical diffraction intensities at three surface temperatures along the two symmetry directions. Type one consists of solving the elastic CC (eCC) and attenuating the corresponding diffraction intensities by a global Debye–Waller (DW) factor. The second one, within a unitary theory, is derived from merely solving the inelastic CC (iCC) equations, where no DW factor is necessary to include. While both methods arrive at similar predictions for the peak-to-peak corrugation value, the variance of the value obtained by the iCC method is much better. Furthermore, the more extensive calculation is better suited to model the temperature induced signal asymmetries and renders the inclusion for a second Debye temperature for the diffraction peaks futile. PMID:26257838

  10. Comparisons of American, Israeli, Italian and Mexican physicians and nurses on the total and factor scores of the Jefferson scale of attitudes toward physician-nurse collaborative relationships.

    PubMed

    Hojat, Mohammadreza; Gonnella, Joseph S; Nasca, Thomas J; Fields, Sylvia K; Cicchetti, Americo; Lo Scalzo, Alessandra; Taroni, Francesco; Amicosante, Anna Maria Vincenza; Macinati, Manuela; Tangucci, Massimo; Liva, Carlo; Ricciardi, Gualtiero; Eidelman, Shmuel; Admi, Hanna; Geva, Hana; Mashiach, Tanya; Alroy, Gideon; Alcorta-Gonzalez, Adelina; Ibarra, David; Torres-Ruiz, Antonio

    2003-05-01

    This cross-cultural study was designed to compare the attitudes of physicians and nurses toward physician-nurse collaboration in the United States, Israel, Italy and Mexico. Total participants were 2522 physicians and nurses who completed the Jefferson Scale of Attitudes Toward Physician-Nurse Collaboration (15 Likert-type items, (Hojat et al., Evaluation and the Health Professions 22 (1999a) 208; Nursing Research 50 (2001) 123). They were compared on the total scores and four factors of the Jefferson Scale (shared education and team work, caring as opposed to curing, nurses, autonomy, physicians' dominance). Results showed inter- and intra-cultural similarities and differences among the study groups providing support for the social role theory (Hardy and Conway, Role Theory: Perspectives for Health Professionals, Appelton-Century-Crofts, New York, 1978) and the principle of least interest (Waller and Hill, The Family: A Dynamic Interpretation, Dryden, New York, 1951) in inter-professional relationships. Implications for promoting physician-nurse education and inter-professional collaboration are discussed.

  11. Bond length variation in Zn substituted NiO studied from extended X-ray absorption fine structure

    NASA Astrophysics Data System (ADS)

    Singh, S. D.; Poswal, A. K.; Kamal, C.; Rajput, Parasmani; Chakrabarti, Aparna; Jha, S. N.; Ganguli, Tapas

    2017-06-01

    Bond length behavior for Zn substituted NiO is determined through extended x-ray absorption fine structure (EXAFS) measurements performed at ambient conditions. We report bond length value of 2.11±0.01 Å for Zn-O of rock salt (RS) symmetry, when Zn is doped in RS NiO. Bond length for Zn substituted NiO RS ternary solid solutions shows relaxed behavior for Zn-O bond, while it shows un-relaxed behavior for Ni-O bond. These observations are further supported by first-principles calculations. It is also inferred that Zn sublattice remains nearly unchanged with increase in lattice parameter. On the other hand, Ni sublattice dilates for Zn compositions up to 20% to accommodate increase in the lattice parameter. However, for Zn compositions more than 20%, it does not further dilate. It has been attributed to the large disorder that is incorporated in the system at and beyond 20% of Zn incorporation in the cubic RS lattice of ternary solid solutions. For these large percentages of Zn incorporation, the Ni and the Zn atoms re-arrange themselves microscopically about the same nominal bond length rather than systematically increase in magnitude to minimize the energy of the system. This results in an increase in the Debye-Waller factor with increase in the Zn concentration rather than a systematic increase in the bond lengths.

  12. The mediating role of anger in the relationship between PTSD symptoms and impulsivity.

    PubMed

    Contractor, Ateka A; Armour, Cherie; Wang, Xin; Forbes, David; Elhai, Jon D

    2015-03-01

    Research indicates a significant relationship between posttraumatic stress disorder (PTSD) and anger (Olatunji, Ciesielski, & Tolin, 2010; Orth & Wieland, 2006). Individuals may seek urgent coping to deal with the distress of anger, which is a mobilizing and action-oriented emotion (Novaco & Chemtob, 2002); possibly in the form of impulsive actions consistent with impulsivity's association with anger (Milligan & Waller, 2001; Whiteside & Lynam, 2001). This could be 1 of the explanations for the relationship between PTSD and impulsivity (Kotler, Julian, Efront, & Amir, 2001; Ledgerwood & Petry, 2006). The present study assessed the mediating role of anger between PTSD (overall scores and subscales of arousal and negative alterations in mood/cognitions) and impulsivity, using gender as a covariate of impulsivity. The PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), Dimensions of Anger Reaction scale-5, and the UPPS Impulsivity Scale were administered to a sample of 244 undergraduate students with a trauma history. Results based on 1000 bootstrapped samples indicated significant direct effects of PTSD (overall and 2 subscales) on anger, of anger on impulsivity, and of PTSD (overall and 2 subscales) on impulsivity. Further, anger significantly mediated the relationship between PTSD (overall and 2 subscales) and impulsivity, consistent with the hypothesized models. Results suggest that impulsivity aims at coping with distressing anger, possibly explaining the presence of substance usage, and other impulsive behaviors in people with PTSD. Further, anger probably serves as a mobilizing and action-oriented emotion coupled with PTSD symptoms.

  13. Nanoscale heat transport from Ge hut, dome, and relaxed clusters on Si(001) measured by ultrafast electron diffraction

    SciTech Connect

    Frigge, T. Hafke, B.; Tinnemann, V.; Krenzer, B.; Horn-von Hoegen, M.

    2015-02-02

    The thermal transport properties of crystalline nanostructures on Si were studied by ultra-fast surface sensitive time-resolved electron diffraction. Self-organized growth of epitaxial Ge hut, dome, and relaxed clusters was achieved by in-situ deposition of 8 monolayers of Ge on Si(001) at 550 °C under UHV conditions. The thermal response of the three different cluster types subsequent to impulsive heating by fs laser pulses was determined through the Debye-Waller effect. Time resolved spot profile analysis and life-time mapping was employed to distinguish between the thermal response of the different cluster types. While dome clusters are cooling with a time constant of τ = 150 ps, which agrees well with numerical simulations, the smaller hut clusters with a height of 2.3 nm exhibit a cooling time constant of τ = 50 ps, which is a factor of 1.4 slower than expected.

  14. Clinicians' judgments of clinical utility: a comparison of the DSM-IV with dimensional models of general personality.

    PubMed

    Lowe, Jennifer Ruth; Widiger, Thomas A

    2009-06-01

    Clinical utility, or the usefulness of a diagnostic system in clinical practice, has been identified as a potential limitation of alternative dimensional models of personality disorder, such as the five-factor model (FFM; McCrae & Costa, 1990), the Temperament and Character Inventory (TCI; Cloninger, 2000), the Multidimensional Personality Questionnaire (MPQ; Tellegen & Waller, 1987), and the Shedler & Westen Assessment Procedure-200 (SWAP-200; Shedler & Westen, 1998). Both proponents of and opponents to dimensional models of personality disorder have suggested that their clinical utility be assessed in preparation for DSM-V (e.g., Rounsaville et al., 2002; First et al., 2002; Verheul, 2005; First, 2005). Samuel & Widiger (2006) found the FFM to have significantly greater clinical utility than the existing diagnostic categories. In the current study, 1,572 practicing psychologists were asked to describe one of three cases using the DSM-IV and the constructs of one of four alternative dimensional models (FFM, TCI, MPQ, SWAP). Clinicians then rated each model on six aspects of clinical utility. Results indicate that clinicians find dimensional models to be higher in clinical utility than the DSM-IV on five of the six aspects of clinical utility, but not significantly different from each other. Implications of these findings are discussed.

  15. Structure of interfaces in GaN/AlN and Ge/Si multilayered heterosystems by XAFS spectroscopy

    NASA Astrophysics Data System (ADS)

    Erenburg, S. B.; Trubina, S. V.; Zhuravlev, K. S.; Malin, T. V.; Zinovyev, V. A.; Dvurechenskii, A. V.; Kuchinskaya, P. A.; Kvashnina, K. O.

    2016-11-01

    III-nitride heterostructures in the form of multilayered quantum wells (MQWs) or quantum dots (QDs) and interacting Ge QDs (“quantum molecules”) are promising candidates for high-speed intersubband (ISB) optical devices relying on the quantum confinement of electrons. Microstructural parameters (interatomic distances, coordination numbers, and Debye-Waller factors) were determined by means of EXAFS spectroscopy based on the Synchrotron Radiation, and the relationship between the variations in these parameters and the morphology of superlattices and symmetric assembles of QDs were established. The EXAFS technique has been used to study the local structure of thin hexagonal GaN/AlN MQWs grown by ammonia MBE at different temperatures. It is shown that the heterointerface intermixing leads to a decrease in the Ga-Al interatomic distance and the Ga-Ga coordination number in MQWs. The degree of intermixing in the boundary layers rises from 30% to 40% with increase of the growth temperature from 795 to 895 °C. It was found that in the first phase of quantum molecules growth Ge atoms concentration is 25%. With further growth (deposition of the base layers) Ge concentration increases up to 35-45%, depending on the temperature (from 610 to 550 °C) of deposition.

  16. Line Edge Roughness and Cross Sectional Characterization of Sub-50 nm Structures Using Critical Dimension Small Angle X-ray Scattering

    SciTech Connect

    Wang Chengqing; Jones, Ronald L.; Lin, Eric K.; Wu Wenli; Ho, Derek L.; Villarrubia, John S.; Choi, Kwang-Woo; Clarke, James S.; Roberts, Jeanette; Bristol, Robert; Bunday, Benjamin

    2007-09-26

    The need to characterize line edge and line width roughness in patterns with sub-50 nm critical dimensions challenges existing platforms based on electron microscopy and optical scatterometry. The development of x-ray based metrology platforms provides a potential route to characterize a variety of parameters related to line edge roughness by analyzing the diffracted intensity from a periodic array of test patterns. In this study, data from a series of photoresist line/space patterns featuring programmed line width roughness are measured by critical dimension small angle x-ray scattering (CD-SAXS). For samples with designed periodic roughness, CD-SAXS provides the wavelength and amplitude of the periodic roughness through satellite diffraction peaks. For real world applications, the rate of decay of intensity, termed an effective 'Debye-Waller' factor in CD-SAXS, provides an overall measure of the defects of the patterns. CD-SAXS data are compared to values obtained from critical dimension scanning electron microscopy (CD-SEM). Correlations between the techniques exist, however significant differences are observed for the current samples. A tapered cross sectional profile provides a likely explanation for the observed differences between CD-SEM and CD-SAXS measurements.

  17. The effect of attachment insecurity in the development of eating disturbances across gender: the role of body dissatisfaction.

    PubMed

    Koskina, Nefeli; Giovazolias, Theodoros

    2010-01-01

    The present study examined the effects of insecure attachment on the development of negative body image as a contributing factor to the development of disturbed eating patterns in male and female university students. Participants were nonclinical male (n = 100) and female (n = 381) university students. Administering self-report questionnaires, the authors assessed demographic information (gender, age), anthropometric data (Body Mass Index [BMI], age), romantic attachment (ECRS-R; R. C. Fraley, N. G. Waller, & K. A. Brennan, 2000), body dissatisfaction (BSQ), and disturbed eating (EAT-26). The authors found body dissatisfaction to fully mediate the relationship between attachment anxiety and disordered eating in women. Body dissatisfaction mediated anxious attachment and dieting in men. In addition, attachment avoidance had a direct impact on eating behaviors for both genders, without the mediation of any variables measured in this study. The findings of the present study suggest that the anxiety and avoidance dimensions of attachment insecurity affect eating behaviors differently, and the effects are different across genders. The authors discuss results in the context of therapeutic interventions design.

  18. High-resolution Valence and Core Excitation Spectra via First-Principles Calculations and Experiment

    NASA Astrophysics Data System (ADS)

    Shirley, Eric; Fossard, F.; Gilmore, K.; Hug, G.; Kas, J. J.; Rehr, J. J.; Vila, F.

    We calculate the optical and C K-edge near edge spectra of crystalline and molecular C60 measured with high-resolution electron energy-loss spectroscopy. The calculations are carried out using at least three different methods: Bethe-Salpeter calculations using the NIST Bethe-Salpeter Equation solver (NBSE) in the valence and OCEAN (Obtaining Core Excitation with Ab initio methods and NBSE) suite [Gilmore et al., Comp. Phys. Comm., (2015)]; excited-core-hole calculations using XCH [D. Prendergast and G. Galli, Phys. Rev. Lett. 96, 215502 (2006)]; and constrained occupancy using StoBe (Stockholm-Berlin core-excitation code) [StoBe-deMon version 3.0, K. Hermann et al. (2009)]. They include self-energy effects, lifetime-damping, and Debye-Waller effects. A comparison of spectral features to those observed illustrates the sensitivity of certain features to computation details (e.g., self-energy corrections and core-hole screening). This may point to limitations of various approximations, e.g. in conventional BSE paradigm and/or the incomplete treatment of vibrational effects. Supported in part by DOE BES Grant DE-FG03-97ER45623 (JJR, JJK, FV).

  19. Application of maximum entropy method for the study of electron density distribution in SrS, BaS and PuS using powder X-ray data

    NASA Astrophysics Data System (ADS)

    Saravanan, R.

    2006-06-01

    A study of the electronic structure of the three sulphides, SrS, BaS and PuS has been carried out in this work, using the powder X-ray intensity data from JCPDS powder diffraction data base. The statistical approach, MEM (maximum entropy method) is used for the analysis of the data for the electron density distribution in these materials and an attempt has been made to understand the bonding between the metal atom and the sulphur atom. The mid-bond electron density is found to be maximum for PuS among these three sulphides, being 0.584 e/Å^3 at 2.397 Å. SrS is found to have the lowest electron density at the mid-bond (0.003 e/Å^3) at 2.118 Å from the origin leaving it more ionic than the other two sulphides studied in this work. The two-dimensional electron density maps on (1 0 0) and (1 1 0) planes and the one-dimensional profiles along the bonding direction [1 1 1] are used for these analyses. The overall and individual Debye-Waller factors of atoms in these systems have also been studied and analyzed. The refinements of the observed X-ray data were carried out using standard softwares and also a routine written by the author.

  20. Comparing two alternative measures of general personality in the assessment of psychopathy: a test of the NEO PI-R and the MPQ.

    PubMed

    Gaughan, Eric T; Miller, Joshua D; Pryor, Lauren R; Lynam, Donald R

    2009-08-01

    This study examined the interrelations between two measures of personality, the Revised NEO Personality Inventory (NEO PI-R; P. T. Costa & R. R. McCrae, 1992) and the Multidimensional Personality Questionnaire (MPQ; Tellegen & Waller, 2008), and their relations with psychopathy in a sample of undergraduates. Results revealed good convergence between conceptually related personality traits; however, the NEO PI-R facets accounted for more variance in the MPQ subscales (mean R(2)=.49) than did MPQ subscales in NEO PI-R facets (mean R(2)=.35). Both accounted for substantial proportions of variance in psychopathy scores, although the NEO PI-R accounted for larger proportions and manifested greater incremental validity when using the broader domains of each measure; the differences decreased when the narrower facets/subscales were used. The results suggest that, although both measures assess psychopathy-related traits, the NEO PI-R provides a more complete description because of its assessment of interpersonal antagonism and the central role of this construct in psychopathy.

  1. Extended x-ray absorption fine structure in Ga1-xMnxN/SiC films with high Mn content

    NASA Astrophysics Data System (ADS)

    Sancho-Juan, O.; Martínez-Criado, O.; Cantarero, A.; Garro, N.; Salomé, M.; Susini, J.; Olguín, D.; Dhar, S.; Ploog, K.

    2011-05-01

    In this study, the local atomic structure of highly homogeneous Ga1-xMnxN alloy films (0.03Waller factor does not show a significant trend as Mn content increases, which suggests the presence of short-range disorder in the GaN lattice. Ab initio calculations of the structural parameter for two different Mn concentrations are consistent with the experimental results.

  2. Diffraction Studies of the Atomic Vibrations of Bulk and Surface Atoms in the Reciprocal and Real Spaces of Nanocrystalline SiC

    NASA Technical Reports Server (NTRS)

    Stelmakh, S.; Grzanka, E.; Weber, H.-P.; Vogel, S.; Palosz, B.; Palosz, B.

    2004-01-01

    To describe and evaluate the vibrational properties of nanoparticles it is necessary to distinguish between the surface and the core of the particles. Theoretical calculations show that vibrational density of states of the inner atoms of nanograins is similar to bulk material but shifted to higher energies which can be explained by the fact that the gain core is stressed (hardened) due to the presence of internal pressure. Theoretical calculations also show that there is a difference between vibrational properties of a crystal lattice of the grain interior in isolated particles and in a dense (sintered) nanocrystalline material. This is probably due to a coupling of the modes inside the grains via the grain boundaries in dense nanocrystalline bodies. We examined strains present in the surface shell based on examination of diamond and Sic nanocrystals in reciprocal (Bragg-type scattering) and real (PDF analysis) space analysis of neutron diffraction data. Recently we examined the atomic thermal motions in nanocrystalline Sic based on the assumption of a simple Einstein model for uncorrelated atomic notions. According to this model, the Bragg intensity is attenuated as a function of scattering angle by the Debye-Waller factor. Based on this assumption overall temperature factors were determined from the Wilson plots.

  3. Hydrogeologic characterization of the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas

    USGS Publications Warehouse

    Shah, Sachin D.; Houston, Natalie A.; Braun, Christopher L.

    2007-01-01

    Introduction The Brazos River alluvium aquifer underlies the Brazos River in Texas from Bosque County to Fort Bend County. The aquifer, one of 21 minor aquifers in the State, supplies water for irrigation, domestic, stock, and commercial use. The Brazos River alluvium aquifer likely will become more important in the future as demand for water increases statewide. A thorough understanding of the hydrogeology of the alluvium aquifer will be the foundation for future studies in the area. During October 2006-April 2007, the U.S. Geological Survey, in cooperation with the Texas Water Development Board, conducted a study to delineate the altitude of the top, altitude of the base, and thickness of the Brazos River alluvium aquifer, and to compile and summarize available hydraulic property (specific capacity, transmissivity, and hydraulic conductivity) data. A digital elevation model was used as the altitude of the top of the aquifer. The altitude of the base of the aquifer was generated using data from wells. The study area encompasses the Brazos River alluvium aquifer in parts of Bosque, Hill, McLennan, Falls, Robertson, Milam, Brazos, Burleson, Grimes, Washington, Waller, Austin, and Fort Bend Counties and a 1.5-mile-wide lateral buffer adjacent to the aquifer. The results of this study will be used by the Texas Water Development Board for input into a ground-water availability model.

  4. Long-time mean-square displacements in proteins

    NASA Astrophysics Data System (ADS)

    Vural, Derya; Hong, Liang; Smith, Jeremy C.; Glyde, Henry R.

    2013-11-01

    We propose a method for obtaining the intrinsic, long-time mean square displacement (MSD) of atoms and molecules in proteins from finite-time molecular dynamics (MD) simulations. Typical data from simulations are limited to times of 1 to 10 ns, and over this time period the calculated MSD continues to increase without a clear limiting value. The proposed method consists of fitting a model to MD simulation-derived values of the incoherent intermediate neutron scattering function, Iinc(Q,t), for finite times. The infinite-time MSD, , appears as a parameter in the model and is determined by fits of the model to the finite-time Iinc(Q,t). Specifically, the is defined in the usual way in terms of the Debye-Waller factor as I(Q,t=∞)=exp(-Q2/3). The method is illustrated by obtaining the intrinsic MSD of hydrated lysozyme powder (h=0.4 g water/g protein) over a wide temperature range. The intrinsic obtained from data out to 1 and to 10 ns is found to be the same. The intrinsic is approximately twice the value of the MSD that is reached in simulations after times of 1 ns which correspond to those observed using neutron instruments that have an energy resolution width of 1 μeV.

  5. Comparison of EBSD patterns simulated by two multislice methods.

    PubMed

    Liu, Q B; Cai, C Y; Zhou, G W; Wang, Y G

    2016-10-01

    The extraction of crystallography information from electron backscatter diffraction (EBSD) patterns can be facilitated by diffraction simulations based on the dynamical electron diffraction theory. In this work, the EBSD patterns are successfully simulated by two multislice methods, that is, the real space (RS) method and the revised real space (RRS) method. The calculation results by the two multislice methods are compared and analyzed in detail with respect to different accelerating voltages, Debye-Waller factors and aperture radii. It is found that the RRS method provides a larger view field of the EBSD patterns than that by the RS method under the same calculation conditions. Moreover, the Kikuchi bands of the EBSD patterns obtained by the RRS method have a better match with the experimental patterns than those by the RS method. Especially, the lattice parameters obtained by the RRS method are more accurate than those by the RS method. These results demonstrate that the RRS method is more accurate for simulating the EBSD patterns than the RS method within the accepted computation time. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  6. Quantitative first-principles calculations of valence and core excitation spectra of solid C60

    NASA Astrophysics Data System (ADS)

    Fossard, F.; Hug, G.; Gilmore, K.; Kas, J. J.; Rehr, J. J.; Vila, F. D.; Shirley, E. L.

    2017-03-01

    We present calculated valence and C 1 s near-edge excitation spectra of solid C60 and experimental results measured with high-resolution electron energy-loss spectroscopy. The near-edge calculations are carried out using three different methods: solution of the Bethe-Salpeter equation (BSE) as implemented in the ocean suite (Obtaining Core Excitations with Ab Initio methods and the NIST BSE solver), the excited-electron core-hole approach, and the constrained-occupancy method using the Stockholm-Berlin core excitation code, StoBe. The three methods give similar results and are in good agreement with experiment, though the BSE results are the most accurate. The BSE formalism is also used to carry out valence level calculations using the NIST BSE solver. Theoretical results include self-energy corrections to the band gap and bandwidths, lifetime-damping effects, and Debye-Waller effects in the core excitation case. A comparison of spectral features to those observed experimentally illustrates the sensitivity of certain features to computational details, such as self-energy corrections to the band structure and core-hole screening.

  7. Using Sentinel-2A multispectral imagery to explore for deep groundwater resources in the Ceres-Tankwa Karoo, Western Cape, South Africa: Significance for the 'water-energy(-food) nexus' in an arid region

    NASA Astrophysics Data System (ADS)

    Hartnady, Chris; Wise, Edward; Hartnady, Michael; Olianti, Camille; Hay, E. Rowena

    2017-04-01

    warming and increasing water scarcity in semi-arid regions, deep artesian groundwater systems provide a long-term solution to future demands for water, food and power. In contrast to shale-gas development, which competes for the scarce water resource and poses a substantial pollution threat, an alternative, synergistic and conjunctive development of solar energy, specifically Concentrating Solar Power plants facilitated by the deep artesian groundwater resource, is envisaged for the Ceres-Tankwa and other parts of the Southern Karoo, in a proposed "Sores-Kamma (Sun-Water) Initiative". In this effort, Sentinel-2A-based lithological mapping is integrated with a new digital elevation model, providing geomorphometry and morphotectonic interpretations, and with the systematic monitoring of surface- and groundwater fluxes using a conjunction of radar satellite, Global Navigation Satellite Systems and microgravity approaches. Reference De Kock, M.O., Beukes, N.J., Götz, A.E., Cole, D., Birch, A., Withers, A. and Van Niekerk, H.S. 2016. Open file progress report on exploration of the southern Karoo Basin through CIMERA-KARIN borehole KZF-1 in the Tankwa Karoo, Witzenberg (Ceres) District. 12 pp. Available online at http://www.cimera.co.za/index.php/karin-feedback

  8. Multiverse: Increasing Diversity in Earth and Space Science Through Multicultural Education

    NASA Astrophysics Data System (ADS)

    Peticolas, L. M.; Raftery, C. L.; Mendez, B.; Paglierani, R.; Ali, N. A.; Zevin, D.; Frappier, R.; Hauck, K.; Shackelford, R. L., III; Yan, D.; Thrall, L.

    2015-12-01

    Multiverse at the University of California, Berkeley Space Sciences Laboratory provides earth and space science educational opportunities and resources for a variety of audiences, especially for those who are underrepresented in the sciences. By way of carefully crafted space and earth science educational opportunities and resources, we seek to connect with people's sense of wonder and facilitate making personal ties to science and the learning process in order to, ultimately, bring the richness of diversity to science and make science discovery accessible for all. Our audiences include teachers, students, education and outreach professionals, and the public. We partner with NASA, the National Science Foundation, scientists, teachers, science center and museum educators, park interpreters, and others with expertise in reaching particular audiences. With these partners, we develop resources and communities of practice, offer educator workshops, and run events for the public. We will will present on our pedagogical techniques, our metrics for success, and our evaluation findings of our education and outreach projects that help us towards reaching our vision: We envision a world filled with science literate societies capable of thriving with today's technology, while maintaining a sustainable balance with the natural world; a world where people develop and sustain the ability to think critically using observation and evidence and participate authentically in scientific endeavors; a world where people see themselves and their culture within the scientific enterprise, and understand science within the context that we are all under one sky and on one Earth. Photo Caption: Multiverse Team Members at our Space Sciences Laboratory from left to right: Leitha Thrall, Daniel Zevin, Bryan Mendez, Nancy Ali, Igor Ruderman, Laura Peticolas, Ruth Paglierani, Renee Frappier, Rikki Shackelford, Claire Raftery, Karin Hauck, and Darlene Yan.

  9. Using trees to remediate tritium contaminated groundwater: a modeling and tracer study.

    SciTech Connect

    Rebel, Karin, Theodora

    2004-01-01

    Rebel, Karin, T. 2004. Using trees to remediate tritium contaminated groundwater: a modeling and tracer study. Ph.D Dissertation. Cotnell University. Ithaca, New York. 174 pp. Abstract: We have developed a spatially explicit model of water and tritium fluxes in the vadose zone in order to simulate water uptake and subsurface lateral movement in coniferous and mixed hardwood - coniferous forests on Coastal Plain soils of the southern United States. These Coastal Plain soils are characteristically sand overlying slowly permeable clays found at depths of 30 to 200 cm, and can form temporarily saturated, unconfined aquifers. Ten hectares of the modeled watershed was periodically irrigated with tritium enriched water. We used the tritium enriched water as a tracer to validate the model. The model was used to optimize irrigation, to evaluate the amount of tritium entering the atmosphere due to evapotranspiration and to quantify water and tritium fluxes in texture contrast soils. Using tritium as a tracer, we have studied how tree species and canopy position effect water and solutes uptake from different parts of the soil profile. We clipped branches to obtain leaf water from over-and understory laurel oak (Quercus Laurifolia) and over- and understory pine (Pinus elliottii and Pinus taeda), which was then analyzed for tritium. We found that for early successional trees (Pinus spp.) and trees in the overstory proportionally more water was taken up from deeper in the soil compared to the hardwoods or trees in the understory, which took up proportionally more water from the soil surface. These differences are important for understanding competition for resources within a forest and in predicting the hydrologic response to forest management practices such as thinning.

  10. NASA Tech Briefs, December 2011

    NASA Technical Reports Server (NTRS)

    2011-01-01

    Topics covered include: 1) SNE Industrial Fieldbus Interface; 2) Composite Thermal Switch; 3) XMOS XC-2 Development Board for Mechanical Control and Data Collection; 4) Receiver Gain Modulation Circuit; 5) NEXUS Scalable and Distributed Next-Generation Avionics Bus for Space Missions; 6) Digital Interface Board to Control Phase and Amplitude of Four Channels; 7) CoNNeCT Baseband Processor Module; 8) Cryogenic 160-GHz MMIC Heterodyne Receiver Module; 9) Ka-Band, Multi-Gigabit-Per-Second Transceiver; 10) All-Solid-State 2.45-to-2.78-THz Source; 11) Onboard Interferometric SAR Processor for the Ka-Band Radar Interferometer (KaRIn); 12) Space Environments Testbed; 13) High-Performance 3D Articulated Robot Display; 14) Athena; 15) In Situ Surface Characterization; 16) Ndarts; 17) Cryo-Etched Black Silicon for Use as Optical Black; 18) Advanced CO2 Removal and Reduction System; 19) Correcting Thermal Deformations in an Active Composite Reflector; 20) Umbilical Deployment Device; 21) Space Mirror Alignment System; 22) Thermionic Power Cell To Harness Heat Energies for Geothermal Applications; 23) Graph Theory Roots of Spatial Operators for Kinematics and Dynamics; 24) Spacesuit Soft Upper Torso Sizing Systems; 25) Radiation Protection Using Single-Wall Carbon Nanotube Derivatives; 26) PMA-PhyloChip DNA Microarray to Elucidate Viable Microbial Community Structure; 27) Lidar Luminance Quantizer; 28) Distributed Capacitive Sensor for Sample Mass Measurement; 29) Base Flow Model Validation; 30) Minimum Landing Error Powered-Descent Guidance for Planetary Missions; 31) Framework for Integrating Science Data Processing Algorithms Into Process Control Systems; 32) Time Synchronization and Distribution Mechanisms for Space Networks; 33) Local Estimators for Spacecraft Formation Flying; 34) Software-Defined Radio for Space-to-Space Communications; 35) Reflective Occultation Mask for Evaluation of Occulter Designs for Planet Finding; and 36) Molecular Adsorber Coating

  11. Well-ordered science and Indian epistemic cultures: toward a polycentered history of science.

    PubMed

    Ganeri, Jonardon

    2013-06-01

    This essay defends the view that "modern science," as with modernity in general, is a polycentered phenomenon, something that appears in different forms at different times and places. It begins with two ideas about the nature of rational scientific inquiry: Karin Knorr Cetina's idea of "epistemic cultures," and Philip Kitcher's idea of science as "a system of public knowledge," such knowledge as would be deemed worthwhile by an ideal conversation among the whole public under conditions of mutual engagement. This account of the nature of scientific practice provides us with a new perspective from which to understand key elements in the philosophical project of Jaina logicians in the seventh, eighth, and ninth centuries C.E. Jaina theory seems exceptionally well targeted onto two of the key constituents in the ideal conversation--the classification of all human points of view and the representation of end states of the deliberative process. The Buddhist theory of the Kathāvatthu contributes to Indian epistemic culture in a different way: by supplying a detailed theory of how human dialogical standpoints can be revised in the ideal conversation, an account of the phenomenon Kitcher labels "tutoring." Thus science in India has its own history, one that should be studied in comparison and contrast with the history of science in Europe. In answer to Joseph Needham, it was not 'modern science' which failed to develop in India or China but rather non-well-ordered science, science as unconstrained by social value and democratic consent. What I argue is that this is not a deficit in the civilisational histories of these countries, but a virtue.

  12. Lunar and Planetary Science XXXVI, Part 18

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Topics discussed include: PoDS: A Powder Delivery System for Mars In-Situ Organic, Mineralogic and Isotopic Analysis Instruments Planetary Differentiation of Accreting Planetesimals with 26Al and 60Fe as the Heat Sources Ground-based Observation of Lunar Surface by Lunar VIS/NIR Spectral Imager Mt. Oikeyama Structure: First Impact Structure in Japan? Central Mounds in Martian Impact Craters: Assessment as Possible Perennial Permafrost Mounds (Pingos) A Further Analysis of Potential Photosynthetic Life on Mars New Insight into Valleys-Ocean Boundary on Mars Using 128 Pixels per Degree MOLA Data: Implication for Martian Ocean and Global Climate Change; Recursive Topography Based Surface Age Computations for Mars: New Insight into Surficial Processes That Influenced Craters Distribution as a Step Toward the Formal Proof of Martian Ocean Recession, Timing and Probability; Laser-induced Breakdown Spectroscopy: A New Method for Stand-Off Quantitative Analysis of Samples on Mars; Milk Spring Channels Provide Further Evidence of Oceanic, >1.7-km-Deep Late Devonian Alamo Crater, Southern Nevada; Exploration of Martian Polar Residual Caps from HEND/ODYSSEY Data; Outflow Channels Influencing Martian Climate: Global Circulation Model Simulations with Emplaced Water; Presence of Nonmethane Hydrocarbons on Pluto; Difference in Degree of Space Weathering on the Newborn Asteroid Karin; Circular Collapsed Features Related to the Chaotic Terrain Formation on Mars; A Search for Live (sup 244)Pu in Deep-Sea Sediments: Preliminary Results of Method Development; Some Peculiarities of Quartz, Biotite and Garnet Transformation in Conditions of Step-like Shock Compression of Crystal Slate; Error Analysis of Remotely-Acquired Mossbauer Spectra; Cloud Activity on Titan During the Cassini Mission; Solar Radiation Pressure and Transient Flows on Asteroid Surfaces; Landing Site Characteristics for Europa 1: Topography; and The Crop Circles of Europa.

  13. Lunar and Planetary Science XXXVI, Part 18

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Topics discussed include: PoDS: A Powder Delivery System for Mars In-Situ Organic, Mineralogic and Isotopic Analysis Instruments Planetary Differentiation of Accreting Planetesimals with 26Al and 60Fe as the Heat Sources Ground-based Observation of Lunar Surface by Lunar VIS/NIR Spectral Imager Mt. Oikeyama Structure: First Impact Structure in Japan? Central Mounds in Martian Impact Craters: Assessment as Possible Perennial Permafrost Mounds (Pingos) A Further Analysis of Potential Photosynthetic Life on Mars New Insight into Valleys-Ocean Boundary on Mars Using 128 Pixels per Degree MOLA Data: Implication for Martian Ocean and Global Climate Change; Recursive Topography Based Surface Age Computations for Mars: New Insight into Surficial Processes That Influenced Craters Distribution as a Step Toward the Formal Proof of Martian Ocean Recession, Timing and Probability; Laser-induced Breakdown Spectroscopy: A New Method for Stand-Off Quantitative Analysis of Samples on Mars; Milk Spring Channels Provide Further Evidence of Oceanic, >1.7-km-Deep Late Devonian Alamo Crater, Southern Nevada; Exploration of Martian Polar Residual Caps from HEND/ODYSSEY Data; Outflow Channels Influencing Martian Climate: Global Circulation Model Simulations with Emplaced Water; Presence of Nonmethane Hydrocarbons on Pluto; Difference in Degree of Space Weathering on the Newborn Asteroid Karin; Circular Collapsed Features Related to the Chaotic Terrain Formation on Mars; A Search for Live (sup 244)Pu in Deep-Sea Sediments: Preliminary Results of Method Development; Some Peculiarities of Quartz, Biotite and Garnet Transformation in Conditions of Step-like Shock Compression of Crystal Slate; Error Analysis of Remotely-Acquired Mossbauer Spectra; Cloud Activity on Titan During the Cassini Mission; Solar Radiation Pressure and Transient Flows on Asteroid Surfaces; Landing Site Characteristics for Europa 1: Topography; and The Crop Circles of Europa.

  14. Plastic matters: an analytical procedure to evaluate the degradability of contemporary works of art.

    PubMed

    Lazzari, Massimo; Ledo-Suárez, Ana; López, Thaïs; Scalarone, Dominique; López-Quintela, M Arturo

    2011-03-01

    The most significant results concerning a chemical study to evaluate the degradability of polymeric components in four contemporary works of art, partially or completely realized in plastics, are presented and discussed in this paper. The procedure applied is mainly based on the use of Fourier transform IR and UV-vis spectroscopies and pyrolysis-gas chromatography/mass spectrometry, and consists of the following steps: (1) compositional analysis of the artworks, with particular attention to components which may have a negative effect on the overall ageing; (2) evaluation of the actual state of conservation; (3) investigation of the accelerated ageing of reference polymer samples; and (4) monitoring of the natural ageing of the artworks. On such a basis, the following could be concluded. Stage Evidence by Loris Cecchini is made of poly(ether urethane) elastomer which contains a high amount of phthalates. Their exudation gives a sticky appearance to the artwork and their removal during ageing is the main cause of the loss of flexibility. The latex used by Andrés Pinal for tailoring Traxe de Home is a natural polyisoprene, whose oxidative degradation accounts for the extensive deterioration and yellowing of the artwork. The plaster sculptures of 3D Bodyscans 1:9 by Karin Sander are coated with an aliphatic epoxy resin. Its oxidation with formation of amides is the cause of the surface yellowing. The adhesive used by Dario Villalba for Tierra, Ladrillo y Agua is a commercial poly(vinyl acetate). Simulated photoageing suggests a fast deterioration due to deacetylation and cross-linking, which possibly is the main reason for the actual detachment of debris from the support.

  15. Surface heterogeneity of small asteroids

    NASA Astrophysics Data System (ADS)

    Sasaki, Sho

    A rubble pile model of asteroid origin would predict averaged rather homogeneous surface of an asteroid. Previous spacecraft observations (mostly S-type asteroids) did not show large color/albedo variation on the surface. Vesta would be exceptional since HST observation suggested that its surface should be heterogeneous due to the impact excavation of the interior. As for a young asteroid (832) Karin (age being 5Ma), Sasaki et al. (2004) detected variation of infrared spectra which could be explained by the difference of the space weathering degree. They discussed the possibility of the survival of the old surface. However, the variation was not confirmed by later observation (Chapman et al., 2007; Vernazza et al., 2007). Recent observation of a small (550m) asteroid Itokawa by Hayabusa spacecraft revealed that Itokawa is heterogeneous in color and albedo although the overall rocky structure is considered as a rubble pile (Saito et al., 2006). The color difference can be explained by the difference of weathering degree (Ishiguro et al., 2008). The heterogeneity could be explained by mass movement caused by rapid rotation from YORP effect (Scheeres et al., 2007) or seismic shaking (Sasaki, 2006). Probably small silicate asteroids without significant regolith could have heterogeneous in color and albedo. On large asteroids (˜ a few 10km), regolith reaccumulation should have covered the underlying heterogeneity. References: Chapman, C. R. et al (2007) Icarus, 191, 323-329 Ishiguro, M. et al. (2008) MAPS, in press. Saito, J. et al. (2006) Science, 312, 1341-1344 Sasaki, S. (2006) in Spacecraft Reconnaissance of Asteroid and Comet Interiors Sasaki, T. et al (2004) Astrophys. J. 615, L161-L164 Scheeres, D. J. (2007) Icarus 188, 425-429 Vernazza, P. et al. (2007) Icarus 191, 330-336.

  16. Defining the Flora Family: Reflectance Properties and Age

    NASA Astrophysics Data System (ADS)

    Dykhuis, Melissa J.; Molnar, Lawrence A.; Van Kooten, Samuel J; Greenberg, Richard

    2014-05-01

    The Flora family resides in the densely populated inner main belt, bounded in semimajor axis by the ν6 secular resonance and the Jupiter 3:1 mean motion resonance. The presence of several large families that overlap dynamically with the Floras (e.g. the Vesta, Baptistina, and Nysa-Polana families), and the removal of a significant fraction of Floras via the nearby ν6 resonance have historically complicated the Flora family's distinction in both proper orbital elements and reflectance properties. Here we use orbital information from AstDyS, color information from SDSS, and albedo information from WISE, to obtain the characteristic orbital and reflectance properties of the Floras, by sampling the core of the family in multidimensional phase space. We find the characteristic Flora SDSS colors to be a* = 0.127 ± 0.012 and i-z = -0.038 ± 0.008; the characteristic Flora albedo is pV = 0.295 ± 0.006. These properties allow us to select a high-purity sample of Floras with similar orbital and reflectance properties as required for a detailed dynamical study. We then use the young Karin family, for which we have an age determined via direct backward integration of members' orbits, to calibrate the Yarkovsky drift rates for the Flora family without having to estimate the Floras' material properties. The size-dependent dispersion of the Flora members in semimajor axis (the "V" plot) then yields an age for the family of 940+160-120 My. We discuss the effects on our age estimate of two independent processes that both introduce obliquity variations among the family members on short (My) timescales: 1) the capture of Flora members in spin-orbit resonance, and 2) YORP-driven obliquity variation through YORP cycles. Accounting for these effects does not significantly change the age determination.

  17. 2012 Aspen Winter Conference New Paradigms for Low-Dimensional Electronic Materials, February 5-10, 2012

    SciTech Connect

    Moore, Joel; Rabe, Karin; Nayak, Chetan; Troyer, Matthias

    2012-05-01

    Aspen Center for Physics Project Summary DOE Budget Period: 10/1/2011 to 9/30/2012 Contract # DE-SC0007479 New Paradigms for Low-Dimensional Electronic Materials The 2012 Aspen Winter Conference on Condensed Matter Physics was held at the Aspen Center for Physics from February 5 to 10, 2012. Seventy-four participants from seven countries, and several universities and national labs attended the workshop titled, New Paradigms for Low-Dimensional Electronic Materials. There were 34 formal talks, and a number of informal discussions held during the week. Talks covered a variety of topics related to DOE BES priorities, including, for example, advanced photon techniques (Hasan, Abbamonte, Orenstein, Shen, Ghosh) and predictive theoretical modeling of materials properties (Rappe, Pickett, Balents, Zhang, Vanderbilt); the full conference schedule is provided with this report. The week's events included a public lecture (Quantum Matters given by Chetan Nayak from Microsoft Research) and attended by 234 members of the public, and a physics caf© geared for high schoolers that is a discussion with physicists conducted by Kathryn Moler (Stanford University) and Andrew M. Rappe (University of Pennsylvania) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by Joel Moore (University of California Berkeley), Chetan Nayak (Microsoft Research), Karin Rabe (Rutgers University), and Matthias Troyer (ETH Zurich). Two organizers who did not attend the conference were Gabriel Aeppli (University College London & London Centre for Nanotechnology) and Andrea Cavalleri (Oxford University & Max Planck Hamburg).

  18. Whither Cometary Dust?

    NASA Astrophysics Data System (ADS)

    Lisse, Carey M.

    2010-10-01

    In this paper I will discuss recent findings that have important implications for our understanding of the formation and evolution of primitive solar system dust, including: - Nesvorny et al. (2010), following up on their dynamical analyses of the zodiacal dust bands as sourced by the breakup of the Karin (5Mya) and Veritas (8Mya) asteroid families, argue that over 90% of the interplanetary dust cloud at 1 AU comes from JFC comets with near-circularized, low inclination orbits. This implies that the noted IPD collections of anhydrous and hydrous dust particles are likely to be from Oort cloud and JFC comets, respectively, not from asteroids and comets as thought in the past. Hydrous dust particles from comets like 85P/Wild2 and 9P/Tempel 1 would be consistent with results from the STARDUST and Deep Impact experiments. - Estimates of the dust particle size distributions (PSDs) in the comae of 85P/Wild2 (Green et al. 2004, 2007) and 73P/SW-3 (Sitko et al. 2010, Vaubaillon & Reach 2010) and in the trails of comets (Reach et al. 2007) have broken power law structure, with a plateau enhancement of particles of 1 mm - 1 cm in size. This size is also the size of most chondritic inclusions, and the predicted size range of the "aggregational barrier", where collisions between dust particles become destructive. - Studies of the albedo and polarization properties of cometary dust (Kolokolova et al. 2007) suggest there are 2 major groupings, one with low scattering capability and one with high. While these families could possibly have been explained by systematics in the PSDs of the emitted dust, independent work by Lisse et al. (2008) on the mineralogy of a number of highly dusty comets has shown evidence for one family of comets with highly crystalline dust and another with highly amorphous dust.

  19. Bringing radical behaviorism to revolutionary Brazil and back: Fred Keller's Personalized System of Instruction and Cold War engineering education.

    PubMed

    Akera, Atsushi

    2017-09-12

    This article traces the shifting epistemic commitments of Fred S. Keller and his behaviorist colleagues during their application of Skinnerian radical behaviorism to higher education pedagogy. Building on prior work by Alexandra Rutherford and her focus on the successive adaptation of Skinnerian behaviorism during its successive applications, this study utilizes sociologist of science Karin Knorr Cetina's concept of epistemic cultures to more precisely trace the changes in the epistemic commitments of a group of radical behaviorists as they shifted their focus to applied behavioral analysis. The story revolves around a self-paced system of instruction known as the Personalized System of Instruction, or PSI, which utilized behaviorist principles to accelerate learning within the classroom. Unlike Skinner's entry into education, and his focus on educational technologies, Keller developed a mastery-based approach to instruction that utilized generalized reinforcers to cultivate higher-order learning behaviors. As it happens, the story also unfolds across a rather fantastic political terrain: PSI originated in the context of Brazilian revolutionary history, but circulated widely in the U.S. amidst Cold War concerns about an engineering manpower(sic) crisis. This study also presents us with an opportunity to test Knorr Cetina's conjecture about the possible use of a focus on epistemic cultures in addressing a classic problem in the sociology of science, namely unpacking the relationship between knowledge and its social context. Ultimately, however, this study complements another historical case study in applied behavioral analysis, where a difference in outcome helps to lay out the range of possible shifts in the epistemic commitments of radical behaviorists who entered different domains of application. The case study also has some practical implications for those creating distance learning environments today, which are briefly explored in the conclusion. © 2017 Wiley

  20. Size and Age Dependence of Koronis Family Colors

    NASA Astrophysics Data System (ADS)

    Molnar, L. A.

    2011-10-01

    The ancient and massive Koronis family now has four identified subfamilies (asteroid families made by the breakup of fragments of the ancient collision), with ages running from 5.7 to 290 My. This presents unique opportunities to explore space weathering processes, along with dynamical processes such as collisions and binary formation and destruction. Analysis of family members with accurate SDSS measurements shows a correlation of average subfamily color with age that for the first time is highly statistically significant. Yet Thomas et al. (2011) report a size dependence of the colors of the ancient family that demands caution when comparing subfamilies with differing size distributions. Reanalyis of the Thomas et al. data show the reported break near asteroid diameter 5 km is not significant. However, analysis of the much more extensive SDSS data set show a significant break past diameter 2.5 km, with smaller objects systematically bluer. The break is not present in the Karin subfamily (the youngest at 5.7 My), but is already fully developed in the Eriphyla subfamily (only 220 My). The reddening trend with age remains even when comparing only asteroids of similar size, confirming the presence of space weathering phenomena. The meaning of the trend with size is not immediately clear. We consider briefly the strengths and weaknesses of several interpretations of the bluer colors for small objects: 1) those objects receive more jolts from random collisions capable of shaking the regolith and exposing fresh material beneath; 2) those objects receive more jolts from the cycle of fission and recombination driven by YORP; and 3) the lower gravity on those objects retains regolith less well.

  1. Heparanase and a synthetic peptide of heparan sulfate-interacting protein recognize common sites on cell surface and extracellular matrix heparan sulfate.

    PubMed

    Marchetti, D; Liu, S; Spohn, W C; Carson, D D

    1997-06-20

    Heparanase is an endo-beta-D-glucuronidase that degrades the glycosaminoglycan chains of heparan sulfate (HS) proteoglycans at specific sites. Elevated levels of heparanase are associated with the metastatic potential of melanoma and other types of tumor cells. We previously reported heparanase degradation of cell surface HS subpopulations of the human adenocarcinoma cell line RL95. In the present study, heparanase activity was examined on RL95 cell surface HS subpopulations in the presence of a synthetic peptide (CRPKAKAKAKAKDQTK) of heparin/heparan sulfate-interacting protein (HIP; Liu, S., Smith, S. E., Julian, J., Rohde, L. H., Karin, N. J., and Carson, D. D. (1996) J. Biol. Chem. 271, 11817-11823). Heparanase digestion generated HS fragments from cell surface- or extracellular matrix-derived HS of approximately 25 and 9 kDa, respectively. In contrast, HS of various size classes isolated from proteoglycans secreted or released by RL95 and endothelial cells in culture were not susceptible to heparanase digestion. Incubation of heparanase-containing melanoma cellular extracts or partially purified heparanase preparations with cell surface- or ECM-derived HS and HIP peptide, but not a scrambled sequence of this peptide or other HS-binding proteins present in ECM, completely inhibited heparanase action. Conversely, predigestion of cell surface HS with either heparanase-containing cellular extracts or with secreted or partially purified heparanase destroyed binding to HIP peptide. Preincubation of HS with HIP peptide prevented subsequent heparanase digestion. Collectively, these data demonstrate that HIP peptide and heparanase recognize specific, common motifs within HS chains at cell surfaces and in ECM and may mutually modulate HS-dependent activities.

  2. Identification of SLF1 as a new copper homeostasis gene involved in copper sulfide mineralization in Saccharomyces cerevisiae.

    PubMed Central

    Yu, W; Farrell, R A; Stillman, D J; Winge, D R

    1996-01-01

    In Saccharomyces cerevisiae, at least 12 genes are important for cells to propagate in medium containing elevated concentrations of copper salts (J. Welch, S. Fogel, C. Buchman, and M. Karin, EMBO J. 8:255-260, 1989). Complementation studies were carried out on a copper-sensitive mutation (cup14) from this group. A new yeast gene, designated SLF1, was identified as a multicopy suppressor of the cup14 mutation. Slf1 is important for the physiological process of copper sulfide (CuS) mineralization on the surface of cells cultured in medium containing copper salts. CuS mineralization causes the cells to turn brown. Disruption of SLF1, which is located close to the telomere region of chromosome IV, leads to limited copper sensitivity, and the resulting cells lack the normal brownish coloration when grown in CuSO4-containing medium. Overproduction of Slf1 in wild-type cells confers superresistance to CuSO4 and enhances the coloration of cells cultured in the presence of CuSO4. Upon addition of KCN to Cu-grown cells, the brownish coloration was bleached instantly, and copper ions were solubilized. These data are consistent with Slf1-dependent accumulation of CuS complexes on the cell surface. Disruption of SFL1 also results in loss of the ability of yeast cells to deplete Cu but not Cd ions from the growth medium, whereas overexpression enhances Ca depletion ability and the resulting deposition of CuS particles. It is proposed that Slfl participates in a copper homeostasis pathway, distinct from the Cup1 detoxification system, that leads to sulfide generation and CuS biomineralization on the cell surface. This process may coordinate with the Cup1 pathway at different copper concentrations to prevent copper-induced toxicity. PMID:8628314

  3. A New Solar System Dust Band

    NASA Astrophysics Data System (ADS)

    Espy, Ashley J.; Dermott, S. F.; Kehoe, T. J.; Jayaraman, S.

    2007-10-01

    The relative proportions of asteroidal and cometary material in the zodiacal cloud is an evolving debate. The determination of the asteroidal component is constrained through the study of the dust bands (the fine-structure component superimposed on the broad background cloud), since they have been confidently linked to specific, young, asteroid family disruptions in the main belt. These disruptions represent recent injections of dust into the cloud and thus hold the key to determining at least a minimum value of the asteroidal contribution. There are currently known to be three dust band pairs, one at approximately 10 degrees corresponding to the Veritas family and two central band pairs near the ecliptic, one of which corresponds to the Karin cluster of the Koronis family. However, through careful co-adding of almost all the pole-to-pole intensity scans in the mid infrared wavebands of the IRAS data set, a new solar system dust band has been found at approximately 17 degrees inclination. We think this is a confirmation of the M/N partial band pair suggested by Sykes (1988). The new dust band appears to be mostly, yet not completely formed, which we attribute to the young age of the likely sources. We will present dynamical modeling of the new band which allows us to determine the most likely source and amount of cross-sectional area of dust in the band. This is turn allows us to put constraints on the size of the precursor and amount of dust contributed by this source to the background cloud. Since the band is incomplete, the dynamics of the distribution of the node will allow us to put loose constraints on the time of formation of this band and compare with the ages of the potential sources. This work is funded by NASA GSRP.

  4. Evidence from IRAS for a very young, partially formed dust band

    NASA Astrophysics Data System (ADS)

    Espy, Ashley J.; Dermott, Stanley F.; Kehoe, Thomas J. J.; Jayaraman, Sumita

    2009-02-01

    The relative proportions of asteroidal and cometary materials in the zodiacal cloud is an ongoing debate. The determination of the asteroidal component is constrained through the study of the Solar System dust bands (the fine-structure component superimposed on the broad background cloud), since they have been confidently linked to specific, young, asteroid families in the main belt. The disruptions that produce these families also result in the injection of dust into the cloud and thus hold the key to determining at least a minimum value for the asteroidal contribution to the zodiacal cloud. There are currently known to be at least three dust band pairs, one at approximately 9.35° associated with the Veritas family and two central band pairs near the ecliptic, one of which is associated with the Karin subcluster of the Koronis family. Through careful co-adding of almost all the pole-to-pole intensity scans in the mid-infrared wavebands of the Infrared Astronomical Satellite (IRAS) data set, we find strong evidence for a partial Solar System dust band, that is, a very young dust band in the process of formation, at approximately 17° latitude. We think this is a confirmation of the M/N partial band pair first suggested by Sykes [1988. IRAS observations of extended zodiacal structures. Astrophys. J. 334, L55-L58]. The new dust band appears at some but not all ecliptic longitudes, as expected for a young, partially formed dust band. We present preliminary modeling of the new, partial dust band which allows us to put constraints on the age of the disruption event, the inclination and node of the parent body at the time of disruption, and the quantity of dust injected into the zodiacal cloud.

  5. Blood Cadmium Levels and Incident Cardiovascular Events during Follow-up in a Population-Based Cohort of Swedish Adults: The Malmö Diet and Cancer Study

    PubMed Central

    Barregard, Lars; Sallsten, Gerd; Fagerberg, Björn; Borné, Yan; Persson, Margaretha; Hedblad, Bo; Engström, Gunnar

    2015-01-01

    é Y, Persson M, Hedblad B, Engström G. 2016. Blood cadmium levels and incident cardiovascular events during follow-up in a population-based cohort of Swedish adults: the Malmö Diet and Cancer Study. Environ Health Perspect 124:594–600; http://dx.doi.org/10.1289/ehp.1509735 PMID:26517380

  6. AN IMAGING AND SPECTROSCOPIC STUDY OF FOUR STRONG Mg II ABSORBERS REVEALED BY GRB 060418

    SciTech Connect

    Pollack, L. K.; Prochaska, J. X.; Chen, H.-W.; Bloom, J. S.

    2009-08-20

    We present results from an imaging and spectroscopic study of four strong Mg II absorbers of W(2796) {approx}> 1 A revealed by the afterglow of GRB 060418 at z{sub GRB} = 1.491. These absorbers, at z = 0.603, 0.656, 1.107, and z {sub GRB}, exhibit large ion abundances that suggest neutral gas columns characteristic of damped Ly{alpha} systems. The imaging data include optical images obtained using Low-Resolution Imaging Spectrometer (LRIS) on the Keck I telescope and using Advanced Camera for Surveys on board Hubble Space Telescope, and near-infrared H-band images obtained using Persson's Auxiliary Nasmyth Infrared Camera on the Magellan Baade Telescope and K'-band images obtained using NIRC2 with laser guide star adaptive optics on the Keck II telescope. These images reveal six distinct objects at {delta} {theta} {approx}< 3.''5 of the afterglow's position, two of which exhibit well-resolved mature disk morphology, one shows red colors, and three are blue compact sources. Follow-up spectroscopic observations using LRIS confirm that one of the disk galaxies coincides with the Mg II absorber at z = 0.656. The observed broadband spectral energy distributions of the second disk galaxy and the red source indicate that they are associated with the absorbers at z = 0.603 and z = 1.107, respectively. These results show that strong Mg II absorbers identified in gamma-ray burst (GRB) afterglow spectra are associated with typical galaxies of luminosity {approx}0.1 - 1 L{sub *} at impact parameter of {rho} {approx}< 10 h {sup -1} kpc. The close angular separation would preclude easy detections toward a bright quasar. Finally, we associate the remaining three blue compact sources with the GRB host galaxy, noting that they are likely star-forming knots located at projected distances of {rho} = 2 - 12 h {sup -1} kpc from the afterglow. At the afterglow's position, we derive a 2{sigma} upper limit to the underlying star-formation rate intensity of 0.0074 M{sub sun} yr{sup -1} kpc

  7. A long-term photometric study of the FU Orionis star V 733 Cephei

    NASA Astrophysics Data System (ADS)

    Peneva, S. P.; Semkov, E. H.; Munari, U.; Birkle, K.

    2010-06-01

    Context. The FU Orionis candidate V733 Cep was discovered by Roger Persson in 2004. The star is located in the dark cloud L1216 close to the Cepheus OB3 association. Because only a small number of FU Orionis stars have been detected to date, photometric and spectral studies of V733 Cep are of great interest. Aims: The studies of the photometrical variability of PMS stars are very important to the understanding of stellar evolution. The main purpose of our study is to construct a long-time light curve of V733 Cep. On the basis of BVRI monitoring we also study the photometric behavior of the star. Methods: We gather data from CCD photometry and archival photographic plates. The photometric BVRI data (Johnson-Cousins system) that we present were collected from June 2008 to October 2009. To facilitate transformation from instrumental measurements to the standard system, fifteen comparison stars in the field of V733 Cep were calibrated in BVRI bands. To construct a historical light curve of V733 Cep, a search for archival photographic observations in the Wide-Field Plate Database was performed. As a result, 192 photographic plates containing the field of V733 Cep were found. Some plates were analyzed at our request to estimate the magnitude of V733 Cep. Results: Our photometric study confirms the affiliation of V733 Cep to the group of FU Orionis objects. An outburst in the optical and a slow rise in brightness during the period 1971-1993 are well documented. During the period 1993-2004, V733 Cep exhibited its maximum brightness and the amplitude of the observed outburst exceeded 4.5 m (R). The BVRI photometric data imply that from February 2007 to October 2009, a slow decrease in brightness of V733 Cep was observed. The observed color evolution of V-I index also suggest that V733 Cep is currently fading. The long-time light curve of V733 Cep is similar to the light curves of other FU Orionis objects.

  8. Hreels Studies of Surface Phonons in ALUMINUM/SILICON(111) and in High-Temperature Superconductors

    NASA Astrophysics Data System (ADS)

    Akavoor, Prasad Raman

    High Resolution Electron Energy Loss Spectroscopy (HREELS) studies have been performed on different ordered structures formed when Al is deposited on Si(111)-7 times 7 and annealed. These structures are (sqrt{3}timessqrt{3 })R30^circ, (sqrt {7}timessqrt{7})R19.1^ circ and 7 times 7-Al. Several phonons have been measured for the first time. For the sqrt{3} times sqrt{3} structure, loss peaks at 16 +/- 2, 32.3, 42.2 and 69.2 meV are found in the specular spectra (q = 0). Of these, the 32.3 and 69.2 meV phonons had been predicted by theory based on force-constant matrix calculations. Off -specular measurements have also been made in the overline {Gamma K} direction of the surface Brillouin zone (SBZ). Two simple lattice dynamical models are presented which explain most of the data. The models use force constants taken from an ab initio electronic structure calculation of Northrup. For other structures, phonon losses have been found and tentatively identified. In the last part of this thesis, we report measurements of surface optical phonons on high Tc superconductors. For Bi_2Sr_2CaCu _2O_{8+delta } (Bi2212), in addition to peaks near 50 and 80 meV (400 and 645 cm^{-1}) which have been previously observed, our loss spectra exhibit a new peak at 26 meV (210 cm^{-1} ). The temperature dependence of these peaks in the range between 45 K and 146 K is found to be rather weak. The 50 and 80 meV peaks shift to lower energy by approximately 1.5 meV over this range. Two interpretations of the data, one based on the work of Persson and Demuth and the other based on comparison to optical data are presented. Phonons have also been measured on Bi _2Sr_2CuO _{6+delta} (Bi2201). Bi2201 samples exhibit similar phonon structure as Bi2212. This is consistent with optical measurements. Search for the superconducting gap was done but no evidence of the gap was found in our spectra in contrast to some earlier EELS work.

  9. Delineating Potential Quick-clay Areas Using High-resolution Seismic Methods: Towards a 3D Model of an Area Prone to Slide in SW Sweden

    NASA Astrophysics Data System (ADS)

    Salas Romero, S.; Malehmir, A.; Snowball, I.

    2015-12-01

    , Krawzyck C, Gurk M, Ismail N, Polom U, Persson L (2013) Geophysical assessment and geotechnical investigation of quick-clay landslides—a Swedish case study. Near Surface Geophysics, 11, 341-350

  10. Prey consumption by the juvenile soles, Solea solea and Solea senegalensis, in the Tagus estuary, Portugal

    NASA Astrophysics Data System (ADS)

    Vinagre, C.; Cabral, H. N.

    2008-06-01

    The soles Solea solea and Solea senegalensis are marine flatfish that use coastal and estuarine nursery grounds, which generally present high food availability, refuge from predators and favourable conditions for rapid growth. Two important nursery grounds for these species juveniles have been identified in the Tagus estuary, one in the upper part of the estuary (nursery A) and another in the south bank (nursery B). While S. solea is only present at the uppermost nursery area, S. senegalensis is present at both nurseries. Although they are among the most important predators in these nursery grounds, there are no estimates on their food consumption or on the carrying capacity of the system for soles. The Elliott and Persson [1978. The estimation of daily rates of food consumption for fish. Journal of Animal Ecology 47, 977-993] model was used to estimate food consumption of both species juveniles in both nursery areas, taking into account gastric evacuation rates (previously determined) and 24 h sampling surveys, based on beam-trawl catches carried out every 3 h, in the summer of 1995. Monthly beam trawls were performed to determine sole densities over the summer. Density estimates and daily food consumption values were used to calculate total consumption over the summer period. Sediment samples were taken for the estimation of prey densities and total biomass in the nursery areas. Daily food consumption was lower for S. solea (0.030 g wet weight d -1) than for S. senegalensis (0.075 g wet weight d -1). It was concluded that thermal stress may be an important factor hindering S. solea's food consumption in the warmer months. Total consumption of S. solea over the summer (90 days) was estimated to be 97 kg (wet weight). Solea senegalensis total consumption in nursery A was estimated to be 103 kg, while in nursery B it was 528 kg. Total prey biomass estimated for nursery A was 300 tonnes, while for nursery B it was 58 tonnes. This suggests that food is not a limiting

  11. The Key Role of Nuclear-Spin Astrochemistry

    NASA Astrophysics Data System (ADS)

    Le Gal, Romane; Herbst, Eric; Xie, Changjian; Guo, Hua; Talbi, Dahbia; Muller, Sebastien; Persson, Carina

    2017-06-01

    Thanks to the new spectroscopic windows opened by the recent generation of telescopes, a large number of molecular lines have been detected. In particular, nuclear-spin astrochemistry has gained interest owing to numerous ortho-to-para ratio (OPR) measurements for species including H_3^+, CH_2, C_3H_2, H_2O, NH_3, NH_2, H_2S, H_2CS, H_2O^+ and H_2Cl^+. Any multi-hydrogenated species can indeed present different spin configurations, if some of their hydrogen nuclei are identical, and the species thus exist in distinguishable forms, such as ortho and para. In thermal equilibrium, OPRs are only functions of the temperature and since spontaneous conversion between ortho and para states is extremely slow in comparison with typical molecular cloud lifetimes, OPRs were commonly believed to reflect a ``formation temperature''. However, observed OPRs are not always consistent with their thermal equilibrium values, as for the NH_3 and NH_2 cases. It is thus crucial to understand how interstellar OPRs are formed to constrain the information such new probes can provide. This involves a comprehensive analysis of the processes governing the interstellar nuclear-spin chemistry, including the formation and possible conversions of the different spin symmetries both in the gas and solid phases. If well understood, OPRs might afford new powerful astrophysical diagnostics on the chemical and physical conditions of their environments, and in particular could trace their thermal history. In this context, observations of non-thermal values for the OPR of the radical NH_2 toward four high-mass star-forming regions, and a 3:1 value measured for the H_2Cl^+ OPR toward diffuse and denser gas, led us to develop detailed studies of the mechanisms involved in obtaining such OPRs with the aid of quasi-classical trajectory calculations. We will present these new promising results, improving our understanding of the interstellar medium. Persson et al. 2016, A&A, 586, A128, Neufeld et al. 2016, Ap

  12. Influence of chemical substitution on the photoluminescence of Sr{sub (1−x)}Pb{sub x}WO{sub 4} solid solution

    SciTech Connect

    Hallaoui, A.; Taoufyq, A.; Arab, M.; Bakiz, B.; Benlhachemi, A.; Bazzi, L.; Villain, S.; Valmalette, J-C.; Guinneton, F.; Gavarri, J-R.

    2015-07-15

    The solid solution Sr{sub 1−x}Pb{sub x}WO{sub 4} based on luminescent tungstates SrWO{sub 4} and PbWO{sub 4} has been synthesized by solid-state reaction for all compositions 0≤x≤1. Using Rietveld method, the structural data of all polycrystalline samples have been refined and crystal cell parameters exhibited a linear behavior as a function of x. All substituted structures are of scheelite type. Scanning electron microscopy showed that a high level of crystallization characterized the samples, with modifications in sizes and shapes depending on composition x. Infrared and Raman spectroscopy have been performed to characterize the evolution of vibrational modes with substitution rate. Finally, a systematic study of luminescence under X-ray excitation has been performed: in the composition range x=0.2 to 0.4, intensities of emission exhibited increased values. The luminescence profiles have been interpreted in terms of four Gaussian components, two of them depending on substitution rate. - Graphical abstract: Photoluminescence under X-ray excitation of Sr{sub 1−x}Pb{sub x}WO{sub 4} solid solution: (left) decomposition of emission large band into four components for composition x=0.3; (right) variation of total emission intensity with composition x. - Highlights: • Structural study of solid solution Sr{sub 1−x}Pb{sub x} WO{sub 4} using Rietveld analyses. • Variation of Debye–Waller factor with composition x, disorder parameter. • Existence of four components of luminescence under X-ray excitation. • Effect of substitution of Sr by Pb on two components, due to Pb–O–W interactions. • Enhancement of luminescence intensity in a specific composition range.

  13. Mode localization in the cooperative dynamics of protein recognition.

    PubMed

    Copperman, J; Guenza, M G

    2016-07-07

    The biological function of proteins is encoded in their structure and expressed through the mediation of their dynamics. This paper presents a study on the correlation between local fluctuations, binding, and biological function for two sample proteins, starting from the Langevin Equation for Protein Dynamics (LE4PD). The LE4PD is a microscopic and residue-specific coarse-grained approach to protein dynamics, which starts from the static structural ensemble of a protein and predicts the dynamics analytically. It has been shown to be accurate in its prediction of NMR relaxation experiments and Debye-Waller factors. The LE4PD is solved in a set of diffusive modes which span a vast range of time scales of the protein dynamics, and provides a detailed picture of the mode-dependent localization of the fluctuation as a function of the primary structure of the protein. To investigate the dynamics of protein complexes, the theory is implemented here to treat the coarse-grained dynamics of interacting macromolecules. As an example, calculations of the dynamics of monomeric and dimerized HIV protease and the free Insulin Growth Factor II Receptor (IGF2R) domain 11 and its IGF2R:IGF2 complex are presented. Either simulation-derived or experimentally measured NMR conformers are used as input structural ensembles to the theory. The picture that emerges suggests a dynamical heterogeneous protein where biologically active regions provide energetically comparable conformational states that are trapped by a reacting partner in agreement with the conformation-selection mechanism of binding.

  14. Mode localization in the cooperative dynamics of protein recognition

    NASA Astrophysics Data System (ADS)

    Copperman, J.; Guenza, M. G.

    2016-07-01

    The biological function of proteins is encoded in their structure and expressed through the mediation of their dynamics. This paper presents a study on the correlation between local fluctuations, binding, and biological function for two sample proteins, starting from the Langevin Equation for Protein Dynamics (LE4PD). The LE4PD is a microscopic and residue-specific coarse-grained approach to protein dynamics, which starts from the static structural ensemble of a protein and predicts the dynamics analytically. It has been shown to be accurate in its prediction of NMR relaxation experiments and Debye-Waller factors. The LE4PD is solved in a set of diffusive modes which span a vast range of time scales of the protein dynamics, and provides a detailed picture of the mode-dependent localization of the fluctuation as a function of the primary structure of the protein. To investigate the dynamics of protein complexes, the theory is implemented here to treat the coarse-grained dynamics of interacting macromolecules. As an example, calculations of the dynamics of monomeric and dimerized HIV protease and the free Insulin Growth Factor II Receptor (IGF2R) domain 11 and its IGF2R:IGF2 complex are presented. Either simulation-derived or experimentally measured NMR conformers are used as input structural ensembles to the theory. The picture that emerges suggests a dynamical heterogeneous protein where biologically active regions provide energetically comparable conformational states that are trapped by a reacting partner in agreement with the conformation-selection mechanism of binding.

  15. Water-level altitudes 2003 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973–2015 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, M.C.; Lanning-Rush, Jennifer

    2004-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, and the Fort Bend Subsidence District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2003, water-level changes from 2002 to 2003, approximate water-level changes from 1990 to 2003, approximate water-level changes from 1977 to 2003, and lines of zero water-level change for selected intervals beginning with 1977–82 (figs. 1,2,3,4,5,6,7,8, 9-10). For the Jasper aquifer, maps show approximate water-level altitudes in 2003 and water-level changes from 2002 to 2003 and 2000 to 2003 (figs. 11,12, 13). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2002 (fig. 15).The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2003 altitude and change maps for the three aquifers are included in this report.

  16. Water-level altitudes 2002 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2001 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Coplin, L.S.; Lanning-Rush, Jennifer

    2002-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, and the Fort Bend Subsidence District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2002, water-level changes from 2001 to 2002, approximate water-level changes from 1977 to 2002, lines of zero water-level change for intervals increasing in 5-year increments beginning with 1977–82, and approximate water-level changes from 1990 to 2002 (in the Fort Bend subregion [Fort Bend County and adjacent areas]) (figs. 1–10). For the Jasper aquifer, maps show approximate water-level altitudes in 2002 and water-level changes from 2001 to 2002 and 2000 to 2002 (figs. 11–13). The report also contains a map showing extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at selected sites from 1973 or later to 2001 (fig. 15). The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and separate annual reports of same for the Fort Bend subregion since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. This year (2002), the altitude and change maps for the three aquifers are in this report.

  17. Experimental and theoretical study of rotationally inelastic diffraction of H2(D2) from methyl-terminated Si(111)

    NASA Astrophysics Data System (ADS)

    Nihill, Kevin J.; Hund, Zachary M.; Muzas, Alberto; Díaz, Cristina; del Cueto, Marcos; Frankcombe, Terry; Plymale, Noah T.; Lewis, Nathan S.; Martín, Fernando; Sibener, S. J.

    2016-08-01

    Fundamental details concerning the interaction between H2 and CH3-Si(111) have been elucidated by the combination of diffractive scattering experiments and electronic structure and scattering calculations. Rotationally inelastic diffraction (RID) of H2 and D2 from this model hydrocarbon-decorated semiconductor interface has been confirmed for the first time via both time-of-flight and diffraction measurements, with modest j = 0 → 2 RID intensities for H2 compared to the strong RID features observed for D2 over a large range of kinematic scattering conditions along two high-symmetry azimuthal directions. The Debye-Waller model was applied to the thermal attenuation of diffraction peaks, allowing for precise determination of the RID probabilities by accounting for incoherent motion of the CH3-Si(111) surface atoms. The probabilities of rotationally inelastic diffraction of H2 and D2 have been quantitatively evaluated as a function of beam energy and scattering angle, and have been compared with complementary electronic structure and scattering calculations to provide insight into the interaction potential between H2 (D2) and hence the surface charge density distribution. Specifically, a six-dimensional potential energy surface (PES), describing the electronic structure of the H2(D2)/CH3-Si(111) system, has been computed based on interpolation of density functional theory energies. Quantum and classical dynamics simulations have allowed for an assessment of the accuracy of the PES, and subsequently for identification of the features of the PES that serve as classical turning points. A close scrutiny of the PES reveals the highly anisotropic character of the interaction potential at these turning points. This combination of experiment and theory provides new and important details about the interaction of H2 with a hybrid organic-semiconductor interface, which can be used to further investigate energy flow in technologically relevant systems.

  18. X-ray dynamical diffraction from multilayer Laue lenses with rough interfaces

    SciTech Connect

    Yan Hanfei

    2009-04-15

    A modeling approach for x-ray dynamical diffraction from multilayer Laue lenses (MLLs) with rough interfaces is developed. Although still based on the principle of the distorted-wave Born approximation (DWBA), this model is formulated from the perspective of the physical scattering process, very different from the conventional DWBA formalism. Using this model, one can study x-ray scattering from rough interfaces in the regime of Fresnel diffraction and in the case of absorptive samples, for example, x-ray dynamical diffraction from MLLs with rough interfaces, which is hard to handle in the framework of the conventional DWBA. Theoretical simulations for various MLLs with rough interfaces are conducted. It is found that interfacial roughness results in a decrease in the local diffraction intensity, where the attenuation factor is a function of the root-mean-square (rms) roughness versus the local zone width ratio. This study shows that if all zones possess an identical rms roughness value that is less than half of the outmost MLL zone width, the focal broadening effect due to roughness is almost unnoticeable, provided that the mean position of the interface does not deviate from the required zone plate law. A further study shows that uncorrelated interfacial roughness can be treated the same as interfacial diffusion, in which case a roughness factor similar to the ''Debye-Waller factor'' can be used, and the pseudo-Fourier coefficients of the susceptibility function for an MLL [H. F. Yan et al., Phys. Rev. B 76, 115438 (2007)] have to be multiplied by this factor.

  19. Vibrational dynamics and band structure of methyl-terminated Ge(111)

    SciTech Connect

    Hund, Zachary M.; Nihill, Kevin J.; Sibener, S. J.; Campi, Davide; Bernasconi, M.; Wong, Keith T.; Lewis, Nathan S.; Benedek, G.

    2015-09-28

    A combined synthesis, experiment, and theory approach, using elastic and inelastic helium atom scattering along with ab initio density functional perturbation theory, has been used to investigate the vibrational dynamics and band structure of a recently synthesized organic-functionalized semiconductor interface. Specifically, the thermal properties and lattice dynamics of the underlying Ge(111) semiconductor crystal in the presence of a commensurate (1 × 1) methyl adlayer were defined for atomically flat methylated Ge(111) surfaces. The mean-square atomic displacements were evaluated by analysis of the thermal attenuation of the elastic He diffraction intensities using the Debye-Waller model, revealing an interface with hybrid characteristics. The methyl adlayer vibrational modes are coupled with the Ge(111) substrate, resulting in significantly softer in-plane motion relative to rigid motion in the surface normal. Inelastic helium time-of-flight measurements revealed the excitations of the Rayleigh wave across the surface Brillouin zone, and such measurements were in agreement with the dispersion curves that were produced using density functional perturbation theory. The dispersion relations for H-Ge(111) indicated that a deviation in energy and lineshape for the Rayleigh wave was present along the nearest-neighbor direction. The effects of mass loading, as determined by calculations for CD{sub 3}-Ge(111), as well as by force constants, were less significant than the hybridization between the Rayleigh wave and methyl adlayer librations. The presence of mutually similar hybridization effects for CH{sub 3}-Ge(111) and CH{sub 3}-Si(111) surfaces extends the understanding of the relationship between the vibrational dynamics and the band structure of various semiconductor surfaces that have been functionalized with organic overlayers.

  20. How Accurately Can Extended X-ray Absorption Spectra Be Predicted from First Principles? Implications for Modeling the Oxygen-Evolving Complex in Photosystem II.

    PubMed

    Beckwith, Martha A; Ames, William; Vila, Fernando D; Krewald, Vera; Pantazis, Dimitrios A; Mantel, Claire; Pécaut, Jacques; Gennari, Marcello; Duboc, Carole; Collomb, Marie-Noëlle; Yano, Junko; Rehr, John J; Neese, Frank; DeBeer, Serena

    2015-10-14

    First principle calculations of extended X-ray absorption fine structure (EXAFS) data have seen widespread use in bioinorganic chemistry, perhaps most notably for modeling the Mn4Ca site in the oxygen evolving complex (OEC) of photosystem II (PSII). The logic implied by the calculations rests on the assumption that it is possible to a priori predict an accurate EXAFS spectrum provided that the underlying geometric structure is correct. The present study investigates the extent to which this is possible using state of the art EXAFS theory. The FEFF program is used to evaluate the ability of a multiple scattering-based approach to directly calculate the EXAFS spectrum of crystallographically defined model complexes. The results of these parameter free predictions are compared with the more traditional approach of fitting FEFF calculated spectra to experimental data. A series of seven crystallographically characterized Mn monomers and dimers is used as a test set. The largest deviations between the FEFF calculated EXAFS spectra and the experimental EXAFS spectra arise from the amplitudes. The amplitude errors result from a combination of errors in calculated S0(2) and Debye-Waller values as well as uncertainties in background subtraction. Additional errors may be attributed to structural parameters, particularly in cases where reliable high-resolution crystal structures are not available. Based on these investigations, the strengths and weaknesses of using first-principle EXAFS calculations as a predictive tool are discussed. We demonstrate that a range of DFT optimized structures of the OEC may all be considered consistent with experimental EXAFS data and that caution must be exercised when using EXAFS data to obtain topological arrangements of complex clusters.

  1. Magnetic and structural properties of nanostructured Fe–20Al–2Cr powder mixtures

    SciTech Connect

    Zerniz, N.; Azzaza, S.; Chater, R.; Abbas, H.; Bououdina, M.; Bouchelaghem, W.

    2015-02-15

    Nanostructured Fe–20Al–2Cr (wt.%) powders have been prepared using high energy planetary ball-mill. Changes in structural, morphological and magnetic properties of the powders during mechanical alloying (MA) and during subsequent annealing have been examined by X-ray diffraction, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The observed structural and microstructural changes have been related to several processes occurring during MA. After MA, the material becomes significantly disordered and refines to nanoscale grain sizes (~ 14 nm). The obtained bcc α-Fe(Al,Cr) solid solution shows a ferromagnetic behavior. Upon subsequent annealing at 400 °C, α-Fe{sub 2}O{sub 3} and spinel oxides are formed at the surface of particles, while structural defects disappeared as Fe(Al,Cr) solid solution becomes more ordered and grain growth occurs. The saturation magnetization (Ms) shows lower values after annealing, attributed to the formation of metal oxides with low magnetic moment. - Graphical abstract: Display Omitted - Highlights: • Nanostructured Fe–Al–Cr powders were prepared by MA. • Careful analysis of the XRD patterns by using the Rietveld refinement • The lattice distortion is evidenced by the increase of both the lattice parameter and the static Debye Waller parameter. • Annealing at 400 °C stabilizes the microstructure at the nanometer range and leads to the formation of Fe{sub 3}O{sub 4} and Fe{sub 2}O{sub 3} oxides. • Both the milled and annealed samples are ferromagnetic.

  2. Long-time mean-square displacements in proteins

    SciTech Connect

    Vural, Derya; Hong, Liang; Smith, Jeremy C.; Glyde, Henry R.

    2013-11-08

    We propose a method for obtaining the intrinsic, long-time mean square displacement (MSD) of atoms and molecules in proteins from finite-time molecular dynamics (MD) simulations. Typical data from simulations are limited to times of 1 to 10 ns, and over this time period the calculated MSD continues to increase without a clear limiting value. The proposed method consists of fitting a model to MD simulation-derived values of the incoherent intermediate neutron scattering function, Iinc(Q,t), for finite times. The infinite-time MSD, r2 , appears as a parameter in the model and is determined by fits of the model to the finite-time Iinc(Q,t). Specifically, the r2 is defined in the usual way in terms of the Debye-Waller factor as I(Q,t = ∞) = exp( –Q2 r2 /3). The method is illustrated by obtaining the intrinsic MSD r2 of hydrated lysozyme powder (h = 0.4 g water/g protein) over a wide temperature range. The intrinsic r2 obtained from data out to 1 and to 10 ns is found to be the same. In conclusion, the intrinsic r2 is approximately twice the value of the MSD that is reached in simulations after times of 1 ns which correspond to those observed using neutron instruments that have an energy resolution width of 1 μeV.

  3. Anisotropy in the thermal hysteresis of resistivity and charge density wave nature of single crystal SrFeO3-δ: X-ray absorption and photoemission studies.

    PubMed

    Hsieh, S H; Solanki, R S; Wang, Y F; Shao, Y C; Lee, S H; Yao, C H; Du, C H; Wang, H T; Chiou, J W; Chin, Y Y; Tsai, H M; Chen, J-L; Pao, C W; Cheng, C-M; Chen, W-C; Lin, H J; Lee, J F; Chou, F C; Pong, W F

    2017-12-01

    The local electronic and atomic structures of the high-quality single crystal of SrFeO3-δ (δ~0.19) were studied using temperature-dependent x-ray absorption and valence-band photoemission spectroscopy (VB-PES) to investigate the origin of anisotropic resistivity in the ab-plane and along the c-axis close to the region of thermal hysteresis (near temperature for susceptibility maximum, Tm~78 K). All experiments herein were conducted during warming and cooling processes. The Fe L 3,2-edge X-ray linear dichroism results show that during cooling from room temperature to below the transition temperature, the unoccupied Fe 3d e g states remain in persistently out-of-plane 3d 3z(2)-r(2) orbitals. In contrast, in the warming process below the transition temperature, they change from 3d 3z(2)-r(2) to in-plane 3d x(2)-y(2) orbitals. The nearest-neighbor (NN) Fe-O bond lengths also exhibit anisotropic behavior in the ab-plane and along the c-axis below Tm. The anisotropic NN Fe-O bond lengths and Debye-Waller factors stabilize the in-plane Fe 3d x(2)-y(2) and out-of-plane 3d 3z(2)-r(2) orbitals during warming and cooling, respectively. Additionally, a VB-PES study further confirms that a relative band gap opens at low temperature in both the ab-plane and along the c-axis, providing the clear evidence of the charge-density-wave nature of SrFeO3-δ (δ~0.19) single crystal.

  4. Validation of reference genes for normalization of qPCR gene expression data from Coffea spp. hypocotyls inoculated with Colletotrichum kahawae.

    PubMed

    Figueiredo, Andreia; Loureiro, Andreia; Batista, Dora; Monteiro, Filipa; Várzea, Vítor; Pais, Maria Salomé; Gichuru, Elijah K; Silva, Maria Céu

    2013-09-28

    Coffee production in Africa represents a significant share of the total export revenues and influences the lives of millions of people, yet severe socio-economic repercussions are annually felt in result of the overall losses caused by the coffee berry disease (CBD). This quarantine disease is caused by the fungus Colletotrichum kahawae Waller and Bridge, which remains one of the most devastating threats to Coffea arabica production in Africa at high altitude, and its dispersal to Latin America and Asia represents a serious concern. Understanding the molecular genetic basis of coffee resistance to this disease is of high priority to support breeding strategies. Selection and validation of suitable reference genes presenting stable expression in the system studied is the first step to engage studies of gene expression profiling. In this study, a set of ten genes (S24, 14-3-3, RPL7, GAPDH, UBQ9, VATP16, SAND, UQCC, IDE and β-Tub9) was evaluated to identify reference genes during the first hours of interaction (12, 48 and 72 hpi) between resistant and susceptible coffee genotypes and C. kahawae. Three analyses were done for the selection of these genes considering the entire dataset and the two genotypes (resistant and susceptible), separately. The three statistical methods applied GeNorm, NormFinder, and BestKeeper, allowed identifying IDE as one of the most stable genes for all datasets analysed, and in contrast GADPH and UBQ9 as the least stable ones. In addition, the expression of two defense-related transcripts, encoding for a receptor like kinase and a pathogenesis related protein 10, were used to validate the reference genes selected. Taken together, our results provide guidelines for reference gene(s) selection towards a more accurate and widespread use of qPCR to study the interaction between Coffea spp. and C. kahawae.

  5. Glass transition of polymers in bulk, confined geometries, and near interfaces

    NASA Astrophysics Data System (ADS)

    Napolitano, Simone; Glynos, Emmanouil; Tito, Nicholas B.

    2017-03-01

    When cooled or pressurized, polymer melts exhibit a tremendous reduction in molecular mobility. If the process is performed at a constant rate, the structural relaxation time of the liquid eventually exceeds the time allowed for equilibration. This brings the system out of equilibrium, and the liquid is operationally defined as a glass—a solid lacking long-range order. Despite almost 100 years of research on the (liquid/)glass transition, it is not yet clear which molecular mechanisms are responsible for the unique slow-down in molecular dynamics. In this review, we first introduce the reader to experimental methodologies, theories, and simulations of glassy polymer dynamics and vitrification. We then analyse the impact of connectivity, structure, and chain environment on molecular motion at the length scale of a few monomers, as well as how macromolecular architecture affects the glass transition of non-linear polymers. We then discuss a revised picture of nanoconfinement, going beyond a simple picture based on interfacial interactions and surface/volume ratio. Analysis of a large body of experimental evidence, results from molecular simulations, and predictions from theory supports, instead, a more complex framework where other parameters are relevant. We focus discussion specifically on local order, free volume, irreversible chain adsorption, the Debye–Waller factor of confined and confining media, chain rigidity, and the absolute value of the vitrification temperature. We end by highlighting the molecular origin of distributions in relaxation times and glass transition temperatures which exceed, by far, the size of a chain. Fast relaxation modes, almost universally present at the free surface between polymer and air, are also remarked upon. These modes relax at rates far larger than those characteristic of glassy dynamics in bulk. We speculate on how these may be a signature of unique relaxation processes occurring in confined or heterogeneous polymeric

  6. Changing epidemiology of injury-related pediatric mortality in a rural state: implications for injury control.

    PubMed

    Rausch, T K; Sanddal, N D; Sanddal, T L; Esposito, T J

    1998-12-01

    To document the current epidemiology of pediatric injury-related deaths in a rural state and evaluate changes over time. Retrospective review of injury-related deaths in children less than 15 years of age. Data were obtained from death certificates and coroner, autopsy, prehospital, and hospital records. Analysis was done of the mechanism of injury, age, sex, race, location of incident, toxicology, and safety device use. Comparisons with analogous data collected from an earlier time period were made. The state of Montana, from October 1989 to September 1992. Deaths per 100,000 population, intentionality of injury, mechanism of injury, use of protective devices, and comparisons with previous data (1980-1985) collected by Baker and Waller (Childhood injury: State by state mortality facts. Baltimore: Johns Hopkins Injury Prevention Center, 1989;148-152). Of 121 patients reviewed, 56% were male and 44% were female. Mean age was 7.0 years (median, 8.0). Eighty-one percent of patients were Caucasian, and 16% were Native American. The leading cause of injury was motor vehicle crashes, which was followed by drowning, unintentional firearm injuries, deaths related to house fires, homicides, and suicides. Overall, 87% of injuries were unintentional and 13% were intentional, with 62% of these suicides and 38% homicides. When considered independently of intent, firearm-related injuries ranked second. Earlier data showed motor vehicle crashes ranking second, unintentional firearm injuries seventh, and homicide fourth. Comparison of death rates per 100,000 people for the two time periods showed increases in suicide deaths (3.2 vs 0.8) and unintentional firearm injury deaths (2.3 vs 0.6). The epidemiology of rural pediatric injury-related deaths has changed. Deaths related to suicide and firearms have increased. Violent deaths related to injuries caused by firearms are at a magnitude approaching all other causes. These findings have implications for public health education and

  7. Understanding the changes in ductility and Poisson's ratio of metallic glasses during annealing from microscopic dynamics

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Ngai, K. L.; Wang, W. H.

    2015-07-01

    In the paper K. L. Ngai et al., [J. Chem. 140, 044511 (2014)], the empirical correlation of ductility with the Poisson's ratio, νPoisson, found in metallic glasses was theoretically explained by microscopic dynamic processes which link on the one hand ductility, and on the other hand the Poisson's ratio. Specifically, the dynamic processes are the primitive relaxation in the Coupling Model which is the precursor of the Johari-Goldstein β-relaxation, and the caged atoms dynamics characterized by the effective Debye-Waller factor f0 or equivalently the nearly constant loss (NCL) in susceptibility. All these processes and the parameters characterizing them are accessible experimentally except f0 or the NCL of caged atoms; thus, so far, the experimental verification of the explanation of the correlation between ductility and Poisson's ratio is incomplete. In the experimental part of this paper, we report dynamic mechanical measurement of the NCL of the metallic glass La60Ni15Al25 as-cast, and the changes by annealing at temperature below Tg. The observed monotonic decrease of the NCL with aging time, reflecting the corresponding increase of f0, correlates with the decrease of νPoisson. This is important observation because such measurements, not made before, provide the missing link in confirming by experiment the explanation of the correlation of ductility with νPoisson. On aging the metallic glass, also observed in the isochronal loss spectra is the shift of the β-relaxation to higher temperatures and reduction of the relaxation strength. These concomitant changes of the β-relaxation and NCL are the root cause of embrittlement by aging the metallic glass. The NCL of caged atoms is terminated by the onset of the primitive relaxation in the Coupling Model, which is generally supported by experiments. From this relation, the monotonic decrease of the NCL with aging time is caused by the slowing down of the primitive relaxation and β-relaxation on annealing, and

  8. The adsorption of H2 on Fe(111) studied by thermal energy atom scattering

    NASA Astrophysics Data System (ADS)

    Jiang, P.; Zappone, M.; Bernasek, S. L.

    1993-11-01

    The interaction of H2 with Fe(111) has been studied by thermal energy atom scattering (TEAS). The specularly scattered He intensity as a function of hydrogen coverage exhibits a concave drop in scattered He intensity up to 30% coverage, followed by a plateau and another drop in intensity at 80% coverage. A model has been developed to account for this data which assumes three adsorption sites for H on Fe(111), in analogy with the three desorption peaks seen in temperature-programmed desorption (TPD). The adsorption sites have not been definitely assigned, but are labeled ``deep-hollow,'' ``shallow-hollow,'' and ``on-top.'' Competitive adsorption into the deep-hollow and shallow-hollow sites is assumed to account for the initial concavity of the data. Adsorption into on-top sites only becomes significant at 80% coverage. Effective cross sections and reflectivities for the three sites have been obtained for θi=60° and 40°. When a H saturated surface is heated, the scattered He intensity decreases upon heating from 173 to 240 K, at which point desorption has already begun. This drop in intensity is not completely explicable by a Debye-Waller attenuation. It is proposed to be due to a shift in population of the adsorbed H to more exposed, on-top sites, in accord with a Boltzmann distribution of adsorption sites. The scattered He intensity increases upon further heating from 240 to 400 K, corresponding to the desorption of recombined H2 from the surface. Comparison of the He/H/Fe(111) system is made with the He/H/Pt(111) and He/H/Fe(110) systems.

  9. Methods for presenting and visualising electrocardiographic data: From temporal signals to spatial imaging.

    PubMed

    Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George; Guldenring, Daniel

    2013-01-01

    The electrocardiogram (ECG) is a recording of the electrical activity of the heart. It is commonly used to non-invasively assess the cardiac activity of a patient. Since 1938, ECG data has been visualised as 12 scalar traces (known as the standard 12-lead ECG). Although this is known as the standard approach, there has been a myriad of alternative methods proposed to visualise ECG data. The purpose of this paper is to provide an overview of these methods and to introduce the field of ECG visualisation to early stage researchers. A scientific purpose is to consider the future of ECG visualisation within routine clinical practice. This paper structures the different ECG visualisation methods using four categories, i.e. temporal, vectorial, spatial and interactive. Temporal methods present the data with respect to time, vectorial methods present data with respect to direction and magnitude, spatial methods present data in 2D or 3D space and interactive methods utilise interactive computing to facilitate efficient interrogation of ECG data at different levels of detail. Spatial visualisation has been around since its introduction by Waller and vector based visualisation has been around since the 1920s. Given these approaches have already been given the 'test of time', they are unlikely to be replaced as the standard in the near future. Instead of being replaced, the standard is more likely to be 'supplemented'. However, the design and presentation of these ECG visualisation supplements need to be universally standardised. Subsequent to the development of 'standardised supplements', as a requirement, they could then be integrated into all ECG machines. We recognise that without intuitive software and interactivity on mobile devices (e.g. tablet PCs), it is impractical to integrate the more advanced ECG visualisation methods into routine practice (i.e. epicardial mapping using an inverse solution). Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Helium atom diffraction measurements of the surface structure and vibrational dynamics of CH(3)-Si(111) and CD(3)-Si(111) surfaces.

    PubMed

    Becker, James S; Brown, Ryan D; Johansson, Erik; Lewis, Nathan S; Sibener, S J

    2010-09-14

    The surface structure and vibrational dynamics of CH(3)-Si(111) and CD(3)-Si(111) surfaces were measured using helium atom scattering. The elastic diffraction patterns exhibited a lattice constant of 3.82 Å, in accordance with the spacing of the silicon underlayer. The excellent quality of the observed diffraction patterns, along with minimal diffuse background, indicated a high degree of long-range ordering and a low defect density for this interface. The vibrational dynamics were investigated by measurement of the Debye-Waller attenuation of the elastic diffraction peaks as the surface temperature was increased. The angular dependence of the specular (θ(i)=θ(f)) decay revealed perpendicular mean-square displacements of 1.0×10(-5) Å(2) K(-1) for the CH(3)-Si(111) surface and 1.2×10(-5) Å(2) K(-1) for the CD(3)-Si(111) surface, and a He-surface attractive well depth of ∼7 meV. The effective surface Debye temperatures were calculated to be 983 K for the CH(3)-Si(111) surface and 824 K for the CD(3)-Si(111) surface. These relatively large Debye temperatures suggest that collisional energy accommodation at the surface occurs primarily through the Si-C local molecular modes. The parallel mean-square displacements were 7.1×10(-4) and 7.2×10(-4) Å(2) K(-1) for the CH(3)-Si(111) and CD(3)-Si(111) surfaces, respectively. The observed increase in thermal motion is consistent with the interaction between the helium atoms and Si-CH(3) bending modes. These experiments have thus yielded detailed information on the dynamical properties of these robust and technologically interesting semiconductor interfaces.

  11. Personality traits of problem gamblers with and without alcohol dependence.

    PubMed

    Lister, Jamey J; Milosevic, Aleks; Ledgerwood, David M

    2015-08-01

    A large proportion of individuals with gambling disorder also present with a history of alcohol dependence, but few studies have directly examined the relationship between these two conditions. This study's primary and secondary aims were to 1) examine the relationship of personality traits to co-occurring lifetime (current/past) alcohol dependence status, while 2) accounting for differences in gambling characteristics and co-occurring psychiatric disorders among problem/pathological gamblers recruited from the community. Problem/pathological gamblers (N=150) completed measures of personality traits and gambling characteristics (e.g., gambling severity, gambling involvement, delayed discounting of monetary rewards), and were clinically interviewed for co-occurring psychiatric disorders. A co-occurring lifetime diagnosis of alcohol dependence (n=61, 40.7%) was associated with lower personality scores for Control, Well-Being, Achievement, Traditionalism, and Harm Avoidance, as well as higher scores for Alienation (Tellegen & Waller, 1994) in bivariate analyses. Problem/pathological gamblers with lifetime alcohol dependence reported greater lifetime gambling severity, greater past-year gambling involvement, steeper delayed discounting, and a greater likelihood of current and lifetime substance dependence, lifetime antisocial personality disorder, and current unipolar mood disorders. Multivariate analyses indicated that lower Control, Traditionalism, and Well-Being and a co-occurring lifetime substance dependence diagnosis best accounted for a co-occurring lifetime alcohol dependence diagnosis in problem/pathological gamblers. Problem/pathological gamblers with co-occurring lifetime alcohol dependence demonstrate addictive behavior across multiple domains and report a personality style characterized by hopelessness, impaired control, and resistance to externally-motivated treatment approaches. Implications for the treatment of these complex cases are discussed

  12. Vibrational dynamics and band structure of methyl-terminated Ge(111)

    NASA Astrophysics Data System (ADS)

    Hund, Zachary M.; Nihill, Kevin J.; Campi, Davide; Wong, Keith T.; Lewis, Nathan S.; Bernasconi, M.; Benedek, G.; Sibener, S. J.

    2015-09-01

    A combined synthesis, experiment, and theory approach, using elastic and inelastic helium atom scattering along with ab initio density functional perturbation theory, has been used to investigate the vibrational dynamics and band structure of a recently synthesized organic-functionalized semiconductor interface. Specifically, the thermal properties and lattice dynamics of the underlying Ge(111) semiconductor crystal in the presence of a commensurate (1 × 1) methyl adlayer were defined for atomically flat methylated Ge(111) surfaces. The mean-square atomic displacements were evaluated by analysis of the thermal attenuation of the elastic He diffraction intensities using the Debye-Waller model, revealing an interface with hybrid characteristics. The methyl adlayer vibrational modes are coupled with the Ge(111) substrate, resulting in significantly softer in-plane motion relative to rigid motion in the surface normal. Inelastic helium time-of-flight measurements revealed the excitations of the Rayleigh wave across the surface Brillouin zone, and such measurements were in agreement with the dispersion curves that were produced using density functional perturbation theory. The dispersion relations for H-Ge(111) indicated that a deviation in energy and lineshape for the Rayleigh wave was present along the nearest-neighbor direction. The effects of mass loading, as determined by calculations for CD3-Ge(111), as well as by force constants, were less significant than the hybridization between the Rayleigh wave and methyl adlayer librations. The presence of mutually similar hybridization effects for CH3-Ge(111) and CH3-Si(111) surfaces extends the understanding of the relationship between the vibrational dynamics and the band structure of various semiconductor surfaces that have been functionalized with organic overlayers.

  13. A unified description of crystalline-to-amorphous transitions

    SciTech Connect

    Lam, N.Q.; Okamoto, P.R.; Devanathan, R. |; Meshii, M.

    1993-07-01

    Amorphous metallic alloys can now be synthesized by a variety of solid-state processes demonstrating the need for a more general approach to crystalline-to-amorphous (c-a) transitions. By focusing on static atomic displacements as a measure of chemical and topological disorder, we show that a unified description of c-a transformations can be based on a generalization of the phenomenological melting criterion proposed by Lindemann. The generalized version assumes that melting of a defective crystal occurs whenever the sum of thermal and static mean-square displacements exceeds a critical value identical to that for melting of the defect-free crystal. This implies that chemical or topological disorder measured by static displacements is thermodynamically equivalent to heating, and therefore that the melting temperature of the defective crystal will decrease with increasing amount of disorder. This in turn implies the existence of a critical state of disorder where the melting temperature becomes equal to a glass-transition temperature below which the metastable crystal melts to a glass. The generalized Lindemann melting criterion leads naturally to an interpretation of c-a transformations as defect-induced, low-temperature melting of critically disordered crystals. Confirmation of this criterion is provided by molecular-dynamics simulations of heat-induced melting and of defect-induced amorphization of intermetallic compounds caused either by the production of Frenkel pairs or anti-site defects. The thermodynamic equivalence between static atomic disorder and heating is reflected in the identical softening effects which they have on elastic properties and also in the diffraction analysis of diffuse scattering from disordered crystals, where the effect of static displacements appears as an artificially-enlarged thermal Debye-Waller factor. Predictions of this new, unified approach to melting and amorphization are compared with available experimental information.

  14. A new model to perform electrophysiological studies in the early embryonic mouse heart.

    PubMed

    Kornblum, Anna; Pillekamp, Frank; Matzkies, Matthias; Fleischmann, Bernd; Bonnemeier, Hendrik; Schunkert, Heribert; Brockmeier, Konrad; Hescheler, Jürgen; Reppel, Michael

    2013-01-01

    The first electrocardiograms (ECGs) have been recorded with a capillary electrometer in the late 19(th) century by John Burdon Sanderson and Augustus Waller. In 1903 Willem Einthoven used the much more sensitive string galvanometer and was awarded Nobel Price in Medicine for this discovery. Though the physical principles of that era are still in use, there have been many advances but also challenges in cardiac electrophysiology over the last decades. One challenge is to record electrocardiograms of rather small animals such as mice and even smaller organisms such as their embryos. As mice belong to the most routinely used laboratory animals it is important to better understand their physiology and specific diseases. We therefore aimed to study whether it is feasible to measure electrical activities of embryonic mouse hearts. For our studies we used substrate-integrated Microelectrode Arrays combined with newly developed stimulation electrodes to perform electrophysiological studies in these hearts. The system enabled us to perform ECG-like recordings with atrio-ventricular (anterograde) and ventriculo-atrial (retrograde) stimulation. The functional separation of atria and ventricles, indicated by a stable atrio-ventricular conduction time, occurred clearly earlier than the morphological separation. Electrical stimulation induced a reversible prolongation of the anterograde and retrograde conduction up to atrio-ventricular conduction blocks at higher frequencies. These results yield new insight into functional aspects of murine cardiac development, and may help as a new diagnostic tool to uncover the functional and electrophysiological background of embryonic cardiac phenotypes of genetically altered mice. Copyright © 2013 S. Karger AG, Basel.

  15. Centennial of the string galvanometer and the electrocardiogram.

    PubMed

    Fisch, C

    2000-11-15

    This article is a review of the history of the string galvanometer and of the electrocardiogram (ECG) on the occasion of the centennial of the instrument. Einthoven most likely developed the string galvanometer prior to 1901, the date of the first publication. The galvanometer made electrocardiography practical creating a new branch of medicine and even a new industry. In 1791 Galvani, in 1842 Mateucci and in 1855 Kolliker and Muller recorded, using the nerve muscle preparation, contraction of injured muscle, contraction of muscle when laid across a beating heart, and occasionally two contractions. In 1872 Lippmann introduced the capillary manometer. Using the capillary manometer Waller recorded for the first time from body surface voltage changes generated by the heart. Einthoven and Lewis dominated the early years of electrocardiography. The former made his contributions by 1913 while Lewis continued the studies of arrhythmias until 1920. The period following 1920 was influenced largely by Wilson. None did as much to advance ECG knowledge as did Wilson. The interest shifted to the theory of the ECG, abnormalities of wave form and of ECG leads. A major contribution of the ECG is in evaluation of ischemic heart disease and cardiac arrhythmias. Issues facing electrocardiography in the year 2000 include a shortage of experienced electrocardiographers, the advent of new noninvasive procedures and, paradoxically, wide acceptance of the ECG by the medical profession. The role of the computer in analysis of the clinical ECG is limited. The technique, while reasonably reliable for analysis of the normal tracing and some ECG waveforms, has serious limitations when applied to arrhythmias. The early hopes for "stand-alone" programs are yet to be realized.

  16. Distinct patterns of glycosylation of colligin, a collagen-binding glycoprotein, and SPARC (osteonectin), a secreted Ca2+-binding glycoprotein. Evidence for the localisation of colligin in the endoplasmic reticulum.

    PubMed

    Hughes, R C; Taylor, A; Sage, H; Hogan, B L

    1987-02-16

    Mouse parietal endoderm PYS cells were labelled with [2-3H]mannose for 16-24 h. Colligin, an Mr-47000 collagen-binding protein, and SPARC, a Mr-43000 protein, highly homologous to the Ca2+-binding protein osteonectin, were isolated from labelled cell extracts and culture medium respectively. Glycopeptides obtained by exhaustive digestion with pronase were analysed by lectin-affinity, ion-exchange, and gel-filtration chromatography and by paper chromatography of high-mannose oligosaccharides after endo H release. The results show that the N-linked carbohydrate chains of colligin are exclusively the high-mannose type, of which (Man)8(GlcNAc)2 and (Man)9(GlcNAc)2 make up 77%. This carbohydrate structure provides strong evidence that colligin is a component of the endoplasmic reticulum, and argues against a role in cell-surface interactions. By contrast to colligin, SPARC secreted by PYS cells contains predominantly a diantennary complex type of chain containing a variable number of sialic acid and core-substituted fucose residues. Similar glycosylation patterns to those discussed above were seen in colligin isolated from primary mouse embryonic parietal endoderm cells and the murine 3T3 cell line, and in SPARC secreted by bovine corneal endothelial cells. Unlike the type-IV-collagen-binding glycoprotein studied by Dennis, J., Waller, C. and Schirrmacher, V. [J. Cell Biol. 99, 1416-1423 (1984)], removal of N-linked oligosaccharides from colligin had no effect on its binding to native type IV collagen.

  17. EXAFS Studies and Microwave Magnetic Properties of FeGaB Thin Films and FeCuZr Ball-Milled Alloys

    NASA Astrophysics Data System (ADS)

    Gao, Jinsheng

    X-ray absorption fine structure (XAFS) is a spectroscopic technique which can investigate the physical and chemical structure of materials at the atomic scale. X-rays are applied in this technique to be near and above the binding energy of a particular core electronic level of a particular atomic species. Over the last decades, XAFS has emerged as a highly informative probe of the local structure around selected atomic species in solids, liquids, and molecular gases. It offers both element specificity and local structure sensitivity. Foremost among its strengths are its ability to probe the local atomic environments of different elements in the sample by selecting the corresponding incident X-ray energy. In the first part of this thesis, FeGaB alloys, which are of value as soft magnetic materials having relatively large magnetostriction coefficient, were fabricated in which varying amounts of boron were added to the host FeGa alloy to investigate its impact upon local atomic structure and magnetic and microwave properties. The impact of B upon the local atomic structure in FeGaB films were investigated by extended X-ray absorption fine structure (EXAFS) analysis. EXAFS fitting results revealed a contraction of lattice parameters with the introduction of B. The Debye-Waller factor determined from EXAFS fitting gradually increases as a function of boron addition and abruptly increases during the structural evolution from crystalline to amorphous. Upon the onset of this transition the static and microwave magnetic properties became exceptionally softer, with values of coercivity and ferromagnetic linewidth reducing dramatically. In the second part of this thesis, metastable alloys of the composition FeCuZr were synthesized by high energy ball milling and measured by EXAFS . The fitting results demonstrate that nanocrystalline or amorphous alloys have been obtained depending on the Zr content.

  18. Water-level altitudes 2004 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2003 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Lanning-Rush, Jennifer

    2004-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2004, water-level changes from 2003 to 2004, approximate water-level changes from 1977 to 2004, and approximate water-level changes from 1990 to 2004 (figs. 1, 2, 3, 4, 5, 6, 7, 8). For the Jasper aquifer, maps show approximate water-level altitudes in 2004 and water-level changes from 2003 to 2004 and 2000 to 2004 (figs. 9, 10, 11). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 12) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2003 (fig. 13). The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2004 water-level-altitude and water-level-change maps for the three aquifers are included in this report.

  19. Water-level altitudes 2006 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2005 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Houston, Natalie A.; Brown, Dexter W.

    2006-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2006, water-level changes from 2005 to 2006, and approximate water-level changes from 2001 to 2006, from 1990 to 2006, and from 1977 to 2006 (figs. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10). For the Jasper aquifer, maps show approximate water-level altitudes in 2006 and water-level changes from 2005 to 2006 and 2000 to 2006 (figs. 11, 12, 13). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2005 (fig. 15).The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2006 water-level-altitude and water-level-change maps for the three aquifers are included in this report.

  20. Water-level altitudes 2005 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2004 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Houston, Natalie A.

    2005-01-01

    This report is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The Houston-Galveston region comprises Harris, Galveston, Fort Bend, Waller, and Montgomery Counties and adjacent parts of Brazoria, Grimes, Walker, San Jacinto, Liberty, and Chambers Counties. The report was prepared in cooperation with the Harris-Galveston Coastal Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District. For the Chicot and Evangeline aquifers, maps show approximate water-level altitudes in 2005, water-level changes from 2004 to 2005, and approximate water-level changes from 2000 to 2005, from 1990 to 2005, and from 1977 to 2005 (figs. 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10). For the Jasper aquifer, maps show approximate water-level altitudes in 2005 and water-level changes from 2004 to 2005 and 2000 to 2005 (figs. 11, 12, and 13). The report also contains a map showing borehole extensometer (well equipped with compaction monitor) site locations (fig. 14) and graphs showing measured compaction of subsurface material at these sites from 1973 or later to 2004 (fig. 15).The U.S. Geological Survey (USGS) has published annual reports of water-level altitudes and water-level changes for the Chicot and Evangeline aquifers in the Houston-Galveston region since 1979; and annual reports of same for the Fort Bend subregion (Fort Bend County and adjacent areas) since 1990. The USGS published its first water-level-altitude map for the Jasper aquifer in the greater Houston area (primarily Montgomery County) in 2001. The 2005 water-level-altitude and water-level-change maps for the three aquifers are included in this report.