Sample records for juhan judu peeter

  1. Book Reviews.

    ERIC Educational Resources Information Center

    International Journal of Early Childhood, 1994


    Reviews "La Educacion Preescolar: Desafio y Aventura" (Lavanchy Bobsien); "Working towards Better Childcare" (Peeters and Vandenbroeck, editors); "Children's Savings: A Study in the Development of Economic Behavior" (Sonuga-Barke and Webley); "Curvas de Crecimiento Estaturo-ponderal en Escolares" (Saez Crespo and others); and "Helping Bereaved…

  2. The Cartographic Representation of Linguistic Data. Discussion Papers in Geolinguistics Nos. 19-21. Selected Papers from a Geolinguistic Seminar (Le Pailly, France, September 10-13, 1992).

    ERIC Educational Resources Information Center

    Peeters, Yvo J. D., Ed.; Williams, Colin H., Ed.

    Papers from a conference on cartography in geolinguistics include: "The Political Importance of Visualisation of Language Contact" (Yvo J. D. Peeters); "Some Considerations on People and Boundaries" (Guy Heraud); "Geolinguistic Developments and Cartographic Problems" (Colin H. Williams, John E. Ambrose); "A Conceptual Home for Geolinguistics:…

  3. Comment on Turbulent Equipartition Theory of Toroidal Momentum Pinch

    SciTech Connect

    Hahm, T. S.; Diamond, P. H.; Gurcan, O. D.; Rewoldt, G.


    This response demonstrates that the comment by Peeters et al. contains an incorrect and misleading interpretation of our paper [Hahm et al., Phys. Plasmas 15, 055902 (2008)] regarding the density gradient dependence of momentum pinch and the turbulent equipartition (TEP) theory.

  4. "Build Me a Male Role Model!" A Critical Exploration of the Perceived Qualities/Characteristics of Men in the Early Years (0-8) in England

    ERIC Educational Resources Information Center

    Brownhill, Simon


    Young boys' "underachievement" and their disaffection with learning continue to dominate education agendas [Francis, B. 2006. "Stop That Sex Drive." "Times Educational Supplement" 30; Peeters, J. 2007. "Including Men in Early Childhood Education: Insights from the European Experience." "NZ Research…

  5. Bobcat (Felis rufus) ecology and management

    USGS Publications Warehouse

    Howell, Judd A.


    The bobcat (Felis rufus) is a medium sized predator in the family Felidae found exclusively in North America. Extensive natural history information is available and is summarized in several bibliographies and reviews (Sweeny and Poelker 1977, McCord and Cardoza 1982, Boddicker 1983, Anderson 1987, Rolley 1987). The bobcat is a spotted cat with a short white-tipped tail, small dark ear tufts and is about twice the size of the house cat (Felis domesticus) because of the bobcat’s longer bone structure (McCord and Cardoza 1982, Jameson and Peeters 1988). The bobcat weights between 5- 15 kg with males larger than females. TL 700- 1000, T 95-150, E (from crown) 60-75 (Jameson and Peeters 1988).

  6. Coupling the beam tracing code TORBEAM and the Fokker-Planck solver RELAX for fast electrons

    NASA Astrophysics Data System (ADS)

    Maj, O.; Poli, E.; Westerhof, E.


    In this paper the interface between the beam tracing code TORBEAM [Poli, Peeters and Pereverzev, Comp. Phys. Comm. 136, 90 (2001)] and the quasi-linear Fokker-Planck solver RELAX [Westerhof, Peeters and Schippers, Rijnhuizen Report No. RR 92-211 CA, 1992] is presented together with preliminary testing results for electron cyclotron waves in ITER plasmas and their effects on the electron distribution function. The resulting numerical package allows us to account for diffraction effects in the construction of the quasi-linear wave-particle diffusion operator. The coupling of the paraxial-WKB code TORBEAM to the ray-based code RELAX requires a reinterpretation of the paraxial wave field in terms of extended rays, which are addressed in details.

  7. Comment on 'Turbulent equipartition theory of toroidal momentum pinch' [Phys. Plasmas 15, 055902 (2008)

    SciTech Connect

    Peeters, A. G.; Angioni, C.; Strintzi, D.


    The comment addresses questions raised on the derivation of the momentum pinch velocity due to the Coriolis drift effect [A. G. Peeters et al., Phys. Rev. Lett. 98, 265003 (2007)]. These concern the definition of the gradient, and the scaling with the density gradient length. It will be shown that the turbulent equipartition mechanism is included within the derivation using the Coriolis drift, with the density gradient scaling being the consequence of drift terms not considered in [T. S. Hahm et al., Phys. Plasmas 15, 055902 (2008)]. Finally the accuracy of the analytic models is assessed through a comparison with the full gyrokinetic solution.

  8. Impact of the background toroidal rotation on particle and heat turbulent transport in tokamak plasmas

    SciTech Connect

    Camenen, Y.; Peeters, A. G.; Casson, F. J.; Hornsby, W. A.; Snodin, A. P.; Angioni, C.; Strintzi, D.


    Recent developments in the gyrokinetic theory have shown that, in a toroidal device, the Coriolis drift associated with the background plasma rotation significantly affects the small scale instabilities [A. G. Peeters et al., Phys. Rev. Lett. 98, 265003 (2007)]. The later study, which focuses on the effect of the Coriolis drift on toroidal momentum transport is extended in the present paper to heat and particle transport. It is shown numerically using the gyrokinetic flux-tube code GKW[A. G. Peeters and D. Strintzi, Phys. Plasmas 11, 3748 (2004)], and supported analytically, that the Coriolis drift and the parallel dynamics play a similar role in the coupling of density, temperature, and velocity perturbations. The effect on particle and heat fluxes increases with the toroidal rotation (directly) and with the toroidal rotation gradient (through the parallel mode structure), depends on the direction of propagation of the perturbation, increases with the impurity charge number and with the impurity mass to charge number ratio. The case of very high toroidal rotation, relevant to spherical tokamaks, is investigated by including the effect of the centrifugal force in a fluid model. The main effect of the centrifugal force is to decrease the local density gradient at the low field side midplane and to add an extra contribution to the fluxes. The conditions for which the inertial terms significantly affect the heat and particle fluxes are evidenced.

  9. On the nature of fermion-monopole supersymmetry

    NASA Astrophysics Data System (ADS)

    Plyushchay, M. S.


    It is shown that the generator of the nonstandard fermion-monopole supersymmetry uncovered by De Jonghe, Macfarlane, Peeters and van Holten, and the generator of its standard /N=1/2 supersymmetry have to be supplemented by their product operator to be treated as independent supercharge. As a result, the fermion-monopole system possesses the nonlinear /N=3/2 supersymmetry having the nature of the 3D spin-1/2 free particle's supersymmetry generated by the supercharges represented in a scalar form. Analyzing the supercharges' structure, we trace how under reduction of the fermion-monopole system to the spherical geometry the nonlinear /N=3/2 superalgebra comprising the Hamiltonian and the total angular momentum as even generators is transformed into the standard linear /N=1 superalgebra with the Hamiltonian to be the unique even generator.

  10. Nonlinear superconformal symmetry of a fermion in the field of a Dirac monopole

    NASA Astrophysics Data System (ADS)

    Leiva, Carlos; Plyushchay, Mikhail S.


    We study a longstanding problem of identification of the fermion-monopole symmetries. We show that the integrals of motion of the system generate a nonlinear classical Z2-graded Poisson, or quantum superalgebra, which may be treated as a nonlinear generalization of the osp(2|2)⊕su(2). In the nonlinear superalgebra, the shifted square of the full angular momentum plays the role of the central charge. Its square root is the even osp(2|2) spin generating the u(1) rotations of the supercharges. Classically, the central charge's square root has an odd counterpart whose quantum analog is, in fact, the same osp(2|2) spin operator. As an odd integral, the osp(2|2) spin generates a nonlinear supersymmetry of De Jonghe, Macfarlane, Peeters and van Holten, and may be identified as a grading operator of the nonlinear superconformal algebra.

  11. Gray Fox (Urocyon cinereoargenteus) ecology and management

    USGS Publications Warehouse

    Howell, Judd A.


    The gray fox (Urocyon cinereoargenteus) is a petite member of the family Canidae in the order Carnivora with a long muzzle and pointed ears (Samuel and Nelson 1982). The coat of the gray fox is silver gray across the back with significant amounts of rufus along the sides. This characteristic is often confused by people who see the flash of red and assume that the fox is a red fox (Vulpes vulpes). The gray fox has a black tipped tail with a dorsal black stripe that differentiates this species from the kit fox (Vulpes macrotis). The red fox has a white tipped tail. The gray fox weighs between 3-5 kg, occasionally to 7 kg. TL 800-1125, T 275-443, HF 100-150. (Jameson and Peeters 1988).

  12. Automatic vigilance: the attention-grabbing power of approach- and avoidance-related social information.


    Wentura, D; Rothermund, K; Bak, P


    The automatic processing of information was investigated, varying valence (positive vs. negative) and relevance (other-relevant traits [ORT] vs. possessor-relevant traits [PRT]; G. Peeters, 1983) of stimuli. ORTs denote unconditionally positive or negative consequences for persons in the social environment of the holder of the trait (e.g., honest, brutal) whereas PRTs denote unconditionally positive or negative consequences for the trait holder (e.g., happy, depressive). In 2 experiments using the Stroop paradigm, larger interference effects were found for ORTs than PRTs. This is due to the behavior-relatedness of ORTs. In a go/no-go lexical decision task (Experiment 3), participants either had to withdraw their finger from a pressed key (i.e., "avoid") or had to press a key (i.e., "approach") if a word was presented. Responses to negative ORTs were relatively faster in the withdraw condition, whereas positive ORTs were relatively faster in the press condition. PMID:10870906

  13. Low-volatility poly-oxygenates in the OH-initiated atmospheric oxidation of alpha-pinene: impact of non-traditional peroxyl radical chemistry.


    Vereecken, L; Müller, J F; Peeters, J


    Following new insights on non-traditional peroxyl radical chemistry, we present an update to our earlier OH-initiated alpha-pinene degradation mechanism (Peeters et al., Phys. Chem. Chem. Phys., 2001, 3, 5489), incorporating ring closure reactions and a fast H-shift isomerization in certain key peroxyl and oxy radical intermediates. These changes, affecting only a single branch of the comprehensive mechanism and based on extensive quantum-chemical and theoretical kinetic calculations, show significant formation, approximately 20% overall, of poly-oxygenated (hydro)peroxides in atmospheric conditions. These low-volatility compounds are expected to have a significant impact on aerosol formation, and are believed to be the high-mass product compounds observed in available experimental work. The proposed changes also affect the predicted acetone yield, matching the experimental data closely.

  14. Infrared spectra of interstellar deuteronated PAHs

    NASA Astrophysics Data System (ADS)

    Buragohain, Mridusmita; Pathak, Amit; Sarre, Peter


    Polycyclic Aromatic Hydrocarbon (PAH) molecules have emerged as a potential constituent of the ISM that emit strong features at 3.3, 6.2, 7.7, 8.6, 11.2 and 12.7 μm with weaker and blended features in the 3-20μm region. These features are proposed to arise from the vibrational relaxation of PAH molecules on absorption of background UV photons (Tielens 2008). These IR features have been observed towards almost all types of astronomical objects; say H II regions, photodissociation regions, reflection nebulae, planetary nebulae, young star forming regions, external galaxies, etc. A recent observation has proposed that interstellar PAHs are major reservoir for interstellar deuterium (D) (Peeters et al. 2004). According to the `deuterium depletion model' as suggested by Draine (2006), some of the Ds formed in the big bang are depleted in PAHs, which can account for the present value of D/H in the ISM. Hence, study of deuterated PAHs (PADs) is essential in order to measure D/H in the ISM.In this work, we consider another probable category of the large PAH family, i.e. Deuteronated PAHs (DPAH+). Onaka et al. have proposed a D/H ratio which is an order of magnitude smaller than the proposed value of D/H by Draine suggesting that if Ds are depleted in PAHs, they might be accommodated in large PAHs (Onaka et al. 2014). This work reports a `Density Functional Theory' calculation of large deuteronated PAHs (coronene, ovalene, circumcoronene and circumcircumcoronene) to determine the expected region of emission features and to find a D/H ratio that is comparable to the observational results. We present a detailed analysis of the IR spectra of these molecules and discuss the possible astrophysical implications.ReferencesDraine B. T. 2006, in ASP Conf. Ser. 348, Proc. Astrophysics in the Far Ultraviolet: Five Years of Discovery with FUSE, ed. G. Sonneborn, H. Moos, B-G Andersson (San Francisco, CA:ASP) 58Onaka T., Mori T. I., Sakon I., Ohsawa R., Kaneda H., Okada Y., Tanaka M

  15. Cavity Ringdown Spectroscopy and Kinetics of HO_2+HCHO: Detection of the ν_1 and {A}- {X} Bands of HOCH_2OOCAVITY Ringdown Spectroscopy and Kinetics of HO_2+HCHO: Detection of the ν_1 and {A}- {X} Bands of HOCH_2OO

    NASA Astrophysics Data System (ADS)

    Sprague, Matthew K.; Okumura, Mitchio; Sander, Stanley P.


    The reactions of HO_2 with carbonyl compounds are believed to be a sink for carbonyl compounds in the upper troposphere and lower stratosphere. These reactions proceed through a hydrogen bound intermediate before isomerizing. The reaction of HO_2 + formaldehyde (HCHO) serves as a prototype for this class of reactions, forming the isomerization product hydroxymethylperoxy (HOCH_2OO, HMP). Previous studies measured the spectrum and kinetics of HMP using either FTIR detection of the end products or direct detection of HMP by the unstructured tilde{B}-tilde{X} transition. Despite these studies, considerable uncertainty exists in the rate constant of HMP formation (±80%, 2σ). In this talk, we report the first detection of the ν_1 (OH stretch) and tilde{A}-tilde{X} electronic spectra of the HMP radical. The OH stretch spectrum is broad and featureless, while the tilde{A}(0)-tilde{X}(0) origin and combination band with the OOCO torsion tilde{A}(NOOCO=1)-tilde{X}(0) are rotationally resolved. Quantum chemistry calculations have been performed on both the tilde{A} and tilde{X} states as a function of the OOCO and HOCO dihedral angles to estimate the tilde{A}-tilde{X} transition frequency and to assess the coupling between the two torsional modes. We also present kinetics data showing the rates of production and destruction of HMP. I. Hermans, J. F. Muller, T. L. Nguyen, P. A. Jacobs, and J. Peeters. J. Phys. Chem. A 2005, 109, 4303. F. Su, J. G. Calvert, and J. H. Shaw J. Phys. Chem. 1979, 83, 3185. B. Veyret, R. Lesclaux, M. T. Rayez, J. C. Rayez, R. A. Cox, and G. K. Moortgat J. Phys. Chem. 1989, 93, 2368. J. P. Burrows, G. K. Moortgat, G. S. Tyndall, R. A. Cox, M. E. Jenkin, G. D. Hayman, and B. Veyret J. Phys. Chem. 1989, 93, 2375 S. P. Sander, B. J. Finlayson-Pitts, D. M. Golden, R. E. Huie, C. E. Kolb, M. J. Kurylo, M. J. Molina, et al. Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation Number 16, Jet Propulsion Laboratory, 2009 I

  16. Past changes of landscape due to increased dynamics of erosion processes in the Bezděz-Doksy region (Czech Republic)

    NASA Astrophysics Data System (ADS)

    Vysloužilová, Barbora; Dreslerová, Dagmar; Kozáková, Radka; Poništiak, Štefan; Chuman, Tomáš; Šefrna, Luděk


    This study broadens the archaeological research of the the Bezděz - Doksy region in Northern Bohemia, Czech Republic (Dreslerová et al., 2013). Extensive field works between 2008 and 2012 showed that the region has been settled since the La Tène period. Survey of the alluvial plain of the Robečský stream revealed a record of two intensive erosion episodes in the catchment. We suppose that the first episode may be connected to land use changes and the beginnings of agriculture at the site in the La Tène period. The second episode may be connected to the foundation of the medieval village of Okna, which came into existence in the vicinity of the La Tène settlement. The accelerated erosion of former albeluvisols (on loess) led to significant changes of landscape in the region. The aim of this contribution is to bring a reconstruction of soils, vegetation and relief at the site of Okna before the human occupancy and to detect landscape changes over the time. It focuses on the hypothesis that the accelerated soil erosion has been occurring at the site since the first anthropogenic influence like it is demonstrated by other studies in Europe (e.g. Leopold and Völkel, 2007; Boardman, 2013). An abrupt change of land use from forest to arable land is proved by palynological records. Simultaneously there are buried soil horizons and alluvial sediments which can be studied as geoarchives. The difficulties in reconstruction of relief and quantification of the historical erosion effects are faced by applying GIS and model approaches (Peeters et al., 2003). References Boardman, J., 2013. Soil Erosion in Britain: Updating the Record. Agriculture 3, 418-442. doi:10.3390/agriculture3030418 Dreslerová, D., Waldhauser, J., Abraham, V., Kočár, P., Křivánek, R., Meduna, P., Sádlo, J., 2013. The Bezděz - Doksy region (Northern Bohemia) in prehistory and the La Tène settlement at Okna (in Czech). Archeologické rozhledy LXV, 535-573. Leopold, M., Völkel, J., 2007

  17. The influence of the self-consistent mode structure on the Coriolis pinch effect

    SciTech Connect

    Peeters, A. G.; Camenen, Y.; Casson, F. J.; Hornsby, W. A.; Snodin, A. P.; Angioni, C.; Strintzi, D.


    This paper discusses the effect of the mode structure on the Coriolis pinch effect [A. G. Peeters, C. Angioni, and D. Strintzi, Phys. Rev. Lett. 98, 265003 (2007)]. It is shown that the Coriolis drift effect can be compensated for by a finite parallel wave vector, resulting in a reduced momentum pinch velocity. Gyrokinetic simulations in full toroidal geometry reveal that parallel dynamics effectively removes the Coriolis pinch for the case of adiabatic electrons, while the compensation due to the parallel dynamics is incomplete for the case of kinetic electrons, resulting in a finite pinch velocity. The finite flux in the case of kinetic electrons is interpreted to be related to the electron trapping, which prevents a strong asymmetry in the electrostatic potential with respect to the low field side position. The physics picture developed here leads to the discovery and explanation of two unexpected effects: First the pinch velocity scales with the trapped particle fraction (root of the inverse aspect ratio), and second there is no strong collisionality dependence. The latter is related to the role of the trapped electrons, which retain some symmetry in the eigenmode, but play no role in the perturbed parallel velocity.

  18. Influence of the centrifugal force and parallel dynamics on the toroidal momentum transport due to small scale turbulence in a tokamak

    SciTech Connect

    Peeters, A. G.; Camenen, Y.; Casson, F. J.; Hornsby, W. A.; Snodin, A. P.; Strintzi, D.; Angioni, C.


    The paper derives the gyro-kinetic equation in the comoving frame of a toroidally rotating plasma, including both the Coriolis drift effect [A. G. Peeters et al., Phys. Rev. Lett. 98, 265003 (2007)] as well as the centrifugal force. The relation with the laboratory frame is discussed. A low field side gyro-fluid model is derived from the gyro-kinetic equation and applied to the description of parallel momentum transport. The model includes the effects of the Coriolis and centrifugal force as well as the parallel dynamics. The latter physics effect allows for a consistent description of both the Coriolis drift effect as well as the ExB shear effect [R. R. Dominguez and G. M. Staebler, Phys. Fluids B 5, 3876 (1993)] on the momentum transport. Strong plasma rotation as well as parallel dynamics reduce the Coriolis (inward) pinch of momentum and can lead to a sign reversal generating an outward pinch velocity. Also, the ExB shear effect is, in a similar manner, reduced by the parallel dynamics and stronger rotation.

  19. Gyrokinetic theory and simulation of angular momentum transport

    SciTech Connect

    Waltz, R. E.; Staebler, G. M.; Candy, J.; Hinton, F. L.


    A gyrokinetic theory of turbulent toroidal angular momentum transport as well as modifications to neoclassical poloidal rotation from turbulence is formulated starting from the fundamental six-dimensional kinetic equation. The gyro-Bohm scaled transport is evaluated from toroidal delta-f gyrokinetic simulations using the GYRO code [Candy and Waltz, J. Comput. Phys. 186, 545 (2003)]. The simulations recover two pinch mechanisms in the radial transport of toroidal angular momentum: The slab geometry ExB shear pinch [Dominguez and Staebler, Phys. Fluids B 5, 387 (1993)] and the toroidal geometry 'Coriolis' pinch [Peeters, Angioni, and Strintzi, Phys. Rev. Lett. 98, 265003 (2007)]. The pinches allow the steady state null stress (or angular momentum transport flow) condition required to understand intrinsic (or spontaneous) toroidal rotation in heated tokamak without an internal source of torque [Staebler, Kinsey, and Waltz, Bull. Am. Phys. Soc. 46, 221 (2001)]. A predicted turbulent shift in the neoclassical poloidal rotation [Staebler, Phys. Plasmas 11, 1064 (2004)] appears to be small at the finite relative gyroradius (rho-star) of current experiments.

  20. Frequency bands of strongly nonlinear homogeneous granular systems.


    Lydon, Joseph; Jayaprakash, K R; Ngo, Duc; Starosvetsky, Yuli; Vakakis, Alexander F; Daraio, Chiara


    Recent numerical studies on an infinite number of identical spherical beads in Hertzian contact showed the presence of frequency bands [Jayaprakash, Starosvetsky, Vakakis, Peeters, and Kerschen, Nonlinear Dyn. 63, 359 (2011)]. These bands, denoted here as propagation and attenuation bands (PBs and ABs), are typically present in linear or weakly nonlinear periodic media; however, their counterparts are not intuitive in essentially nonlinear periodic media where there is a complete lack of classical linear acoustics, i.e., in "sonic vacua." Here, we study the effects of PBs and ABs on the forced dynamics of ordered, uncompressed granular systems. Through numerical and experimental techniques, we find that the dynamics of these systems depends critically on the frequency and amplitude of the applied harmonic excitation. For fixed forcing amplitude, at lower frequencies, the oscillations are large in amplitude and governed by strongly nonlinear and nonsmooth dynamics, indicating PB behavior. At higher frequencies the dynamics is weakly nonlinear and smooth, in the form of compressed low-amplitude oscillations, indicating AB behavior. At the boundary between the PB and the AB large-amplitude oscillations due to resonance occur, giving rise to collisions between beads and chaotic dynamics; this renders the forced dynamics sensitive to initial and forcing conditions, and hence unpredictable. Finally, we study asymptotically the near field standing wave dynamics occurring for high frequencies, well inside the AB. PMID:23944453

  1. Purification of rat liver particulate neutral ribonuclease and comparison of properties with pancreas and serum ribonucleases.

    PubMed Central

    Bartholeyns, J; Baudhuin, P


    Rat liver particulate neutral ribonuclease (EC was extensively purified (up to 40000-fold). It is shown to be an endonuclease, specific for pyrimidine bases, hydrolysing 5'-phosphate ester bonds. The enzyme specificity, Km, pH optimum, stability in acid medium and thermal stability at high temperature are the same as those of rat pancreatic and serum ribonucleases. Like pancreatic and serum neutral ribonucleases, the hepatic enzyme is sensitive to the liver natural inhibitor. This inhibitor was purified 8000-fold; its association with ribonuclease follows zero-order kinetics. These identical properties for ribonuclease of rat liver, pancreas and serum support the hypothesis [Bartholeyns, Peeters-Joris & Baudhuin (1975) Eur. J. Biochem. 60, 385-393] of an extrahepatic origin for the liver enzyme, the plasma ribonuclease of pancreatic origin being taken up by endocytosis in the liver. Neutral ribonuclease activity was detected in all rat organs investigated; its distribution among tissues is different from the distribution of the natural ribonuclear inhibitor. PMID:19011

  2. Diphthongs in the repopulated vowel space

    NASA Astrophysics Data System (ADS)

    Bogacka, Anna


    The study examined 8 British English diphthongs produced by Polish learners of English, testing the diphthongs' quality, duration, nasalization, and occurrence of glottal stops before the diphthongs. There were twelve conditions in which the diphthongs were tested: word-initial, word-final, before a voiced obstruent, before a voiceless obstruent, before a nasal consonant, and before a nasal consonant followed by a fricative, and each of these conditions was tested in a stressed and unstressed position. The diphthongs were tested in real words, embedded in sentences, controlled for the stress position, rhythmic units, and length. The sentences were read by 8 female and 8 male Polish learners of English and control subjects. The aim of the phonetic analysis done with Praat, and employing the methodologies used by Flege (1995) for SLA and Peeters (1991) and Jacewicz, Fujimara, and Fox (2003) for diphthongs, is to examine the shape of the restructured vowel space (Liljencrants and Lindblom 1972; Stevens 1989). The approach taken here is termed Vowel Space Repopulation to emphasize that the vowel space of Polish speakers of English is re-structured by new categories in complex ways which are not adequately captured by traditional notions such as ``transfer,'' ``interference,'' or ``interlanguage.''

  3. PREFACE: 21st Latin American Symposium on Solid State Physics (SLAFES XXI)

    NASA Astrophysics Data System (ADS)

    Aguiar, J. Albino


    Colombia e-mail: Professor Laura T Corredor Bohórquez Departamento de Física Universidade Federal de Pernambuco 50670-901 Recife PE Brazil e-mail: Professor Arkady Shanenko Departamento de Física Universidade Federal de Pernambuco 50670-901 Recife PE Brazil e-mail: Professor Renato F Jardim Instituto de Física Universidade de S\\~ao Paulo CP 66318 S\\~ao Paulo SP Brazil e-mail: Professor Francois Peeters Department Fysica Universiteit Antwerpen Groneneborgerlann 171 B-2020, Antwerpen Belgium e-mail: Organizing committee ChairmanCarlos Arturo Parra Vargas Proceedings EditorJosé Albino Aguiar Program ChairJairo Roa-Rojas SecretaryAura Janeth Barón González TreasurerArmando Sarmiento Santos Speaker ChairRafael González Hernández Fernando Naranjo Mayorga David A Landínez Téllez Jesús Oswaldo Morán José Sierra Ortega

  4. Decadal- to biennial scale variability of planktic foraminifera in the northeastern Arabian Sea during the last two millennia: evidence for winter monsoon forcing mechanisms

    NASA Astrophysics Data System (ADS)

    Munz, Philipp; Lückge, Andreas; Siccha, Michael; Kucera, Michal; Schulz, Hartmut


    The Asian monsoon system is controlling the hydrologic cycle, and thus the agricultural and economic prosperity of the worlds most densely populated region. Strong and moisture-laden winds from the southwest induce upwelling and significant productivity in the western Arabian Sea during boreal summer. During boreal winter, weaker dry and cold surface winds from the northeast nourish ocean productivity mainly in the northeastern Arabian Sea. Instrumental records spanning the last century are too short to understand how the monsoon system reacts to external forcing mechanisms and to accurately determine its natural variability. Compared to the summer monsoon component, the dynamics of the winter monsoon are virtually unknown, due to the lack of adequate archives that are affected only by winter conditions. Here we present a decadal- to biennial-scale resolution record of past winter monsoon variability over the last two millennia, based on census counts of planktic foraminifera from two laminated sediment cores collected offshore Pakistan. One shorter box core (SO90-39KG) spans the last 250 years with an average ~2-year resolution, whereas the longer piston core (SO130-275KL) spans the last 2,100 years with a 10-year resolution. We use Globigerina falconensis as a faunal indicator for winter conditions, a species that is most abundant during winter in the NE Arabian Sea (Peeters and Brummer, 2002; Schulz et al., 2002). Our results show that during the past 2,100 years G. falconensis varied with significant periodicities centered on ˜ 60, ˜ 53, ˜ 40, ˜ 34 and ˜ 29 years per cycle. Some of these periods closely match cycles that are known from proxy records of solar irradiance, suggesting a solar forcing on winter monsoon variability. During the past 250 years G. falconensis varied in correlation with the (11-year) Schwabe and the (22-year) Hale solar cycles. Furthermore, a significant ˜ 7 year cyclicity could indicate a teleconnection to the El Niño Southern

  5. The sensitivity of laser induced fluorescence instruments at low pressure to RO2 radicals and the use of this detection method to determine the yield of HO2 during OH-initiated isoprene oxidation

    NASA Astrophysics Data System (ADS)

    Heard, D. E.; Whalley, L. K.; Blitz, M. A.; Seakins, P. W.


    a dry air flow at variable positions along the flow-tube; Isoprene was added downstream of the lamp. Theoretical studies (Peeters et al., 2009) suggest an HO2 yield of 0.7 on a time-scale of a few seconds. Results from the recent laboratory studies will be discussed. Fuchs, H., Bohn, B., Hofzumahaus, A., Holland, F., Lu, K., Nehr, S., Rohrer, F., and Wahner, A.: Detection of HO2 by laser-induced fluorescence: Calibration and interferences from RO2 radicals, Atmos Meas Tech Discuss, 4, 1255-1302, 2011. Heard, D. E., and Pilling, M. J.: Measurement of OH and HO2 in the troposphere, Chem Rev, 103, 5163-5198, 2003. Peeters, J., Nguyen, T. L., and Vereecken, L.: HOx radical regeneration in the oxidation of isoprene, Phys Chem Chem Phys, 11, 5935-5939, 2009.

  6. Hydrophysical and hydrochemical features of Lake Issyk-Kul (Kyrgyzstan) as revealed by field survey of June, 2015

    NASA Astrophysics Data System (ADS)

    Zavialov, Peter; Makkaveev, Petr; Rimskiy-Korsakov, Nikolay; Alymkulov, Salmor; Izhitskiy, Alexander


    cycle. However, the vertical profiles of dissolved oxygen indicated that the most intense photosynthetic activity took place in the intermediate layers, while in the surface layer it was suppressed, hypothetically, by excessive insolation. The ionic salt content of the Issyk-Kul waters was essentially uniform throughout the water column, which points towards efficient mixing in the cold period. In summer season, temperature stratification was sufficiently strong to provide for significant reduction of dissolved oxygen and increase of nutrients in the bottom layer. Samples collected and analyzed for dissolved methane generally yielded low concentrations below 0.5 μl/l at the surface and 0.2 μl/l in the bottom layer, however, values as high as to 3.9 μl/l were documented in some samples corresponding to near-shore stations at depths of about 70 m. We also used a towed side-looking sonar to obtain detailed maps of bathymetric features, including the channels formed by ancient beds of the Tyup and the Dzhergalan Rivers. These channels are believed to represent important pathways for ventilated water and terrigenic substances penetrating into the deep central part of the lake following seasonal differential cooling on the eastern shelf (Peeters et al., 2003). Quantitative assessment of this plausible mechanism is subject to future work. References Oberhansli, H., and P. Molnar (2012) Climate evolution in Central Asia during the past few million years: A case study from Issyk-Kul. Scientific Drilling, 13, doi: 10.2204/iodp/sd.13.09.2011 Peeters F, Finger D, Hofer M, Brennwald M, Livingstone DM, Kipfer R (2003) Deep-water renewal in Lake Issyk-Kul driven by differential cooling. Limnol. and Oceanogr. 48: 1419- 1431.

  7. Hydroxyl Radical Regeneration in Isoprene Oxidation: the Upgraded Mechanism LIM1

    NASA Astrophysics Data System (ADS)

    Peeters, J.; Nguyen, S.; Nguyen, T.; Stavrakou, T.; Muller, J. J.


    Measured hydroxyl radical concentrations in isoprene-rich areas are much higher than predicted by existing chemical models, to the extent that the global oxidizing capacity of our atmosphere should be significantly revised upwards. The OH regeneration that clearly occurs in isoprene oxidation at low/moderate NO is attributed in the Leuven Isoprene Mechanism to novel, theoretically characterized chemical pathways (LIM0: Peeters et al. 2009; Peeters and Muller 2010). The key new features of LIM0 are (i) thermal equilibration of the labile beta-OH- and delta-OH-isoprenylperoxy isomers; (ii) 1,6-H shift isomerisation of the Z-delta-OH-peroxy isomers to yield hydroperoxy-methyl-butenals (HPALDs); (iii) fast photolysis of the HPALDs resulting overall in several OH radicals per HPALD. The OH-regeneration through photolabile HPALDs has recently found experimental support, but the peroxy isomerisation rate, HPALD yield and the extent of OH recycling are still uncertain (Crounse et al. 2011; Wolfe et al. 2012). In this work, the upgraded LIM1 mechanism is presented. Based on better levels of theory, the crucial equilibrium ratio of the isomerising Z-delta-OH-peroxys over the majority beta-OH-isoprenylperoxys had to be reduced by a factor of about 5 compared to LIM0, while the isomerisation rate of the Z-delta-OH-peroxys adopted from Taraborrelli et al. (2012) is about 3 times lower than in LIM0. The chemistry following the 1,6-H shift of the Z-delta-OH-peroxys is much expanded and extended. Firstly, LIM1 introduces other pathways beside HPALD formation following the Z-delta-OH-peroxy isomerisation, resulting likewise in OH recycling. This, together with the revised Z-delta-OH- equilibrium and isomerisation data above, affords a close model-reproduction of the HPALD and other product yields observed by Crounse et al. (2011). Secondly, LIM1 proposes new fast reactions of HO2 with the alpha-oxoketene products from the peroxy isomerisation routes; these reactions are shown to

  8. Hydroxyl radical regeneration in isoprene oxidation: upgraded mechanism LIM1

    NASA Astrophysics Data System (ADS)

    Peeters, Jozef; Son Nguyen, Vinh; Nguyen, Thanh Lam; Stravrakou, Trissevgeni; Muller, Jean-Francois


    The OH regeneration known to occur in isoprene oxidation at low/moderate NO is attributed in the Leuven Isoprene Mechanism to novel, theoretically characterized chemical pathways (LIM0: Peeters et al. 2009; Peeters and Muller 2010). Its key new features are (i) quasi-equilibration of the thermally labile beta-OH- and delta-OH-isoprenylperoxy isomers; (ii) 1,6-H shift isomerisation of the Z-delta-OH-peroxy isomers to yield hydroperoxy-methyl-butenals (HPALDs); (iii) fast photolysis of the HPALDs resulting overall in several OH radicals per HPALD. The OH-regeneration through photolabile HPALDs has recently found experimental support, but the peroxy isomerisation rate, HPALD yield and extent of OH recycling are still uncertain (Crounse et al. 2011; Wolfe et al. 2012). In this work, the upgraded LIM1 mechanism is presented. Based on much higher levels of theory that fully account for dispersion effects, the crucial equilibrium ratio of the isomerising Z-delta-OH-peroxys over the majority beta-OH-isoprenylperoxys is reduced by a factor ≈5 and the isomerisation rate of the Z-delta-OH-peroxys by a factor ≈1.5 compared to LIM0. The chemistry following the 1,6-H shift of the Z-delta-OH-peroxys is also much expanded and extended. Firstly, LIM1 introduces other pathways beside HPALD formation following the Z-delta-OH-peroxy isomerisation, but resulting likewise in OH recycling. This, together with the revised Z-delta-OH- equilibrium and isomerisation data above, affords a fair model-reproduction of the HPALD and other product yields observed by Crounse et al. (2011). Secondly, LIM1 proposes new fast reactions of HO2 with the alpha-oxoketene products from the peroxy isomerisation routes; these reactions are shown to efficiently convert HO2 into OH and are prime candidates for the unknown X + HO2 → OH + ... hydroxyl-recycling routes invoked in recent studies (Hofzumahaus et al.2009; Whalley et al. 2011). Modeling results using the IMAGES global CTM will be presented on

  9. Hydroxyl radical recycling in isoprene oxidation driven by hydrogen bonding and hydrogen tunneling: the upgraded LIM1 mechanism.


    Peeters, Jozef; Müller, Jean-François; Stavrakou, Trissevgeni; Nguyen, Vinh Son


    The Leuven isoprene mechanism, proposed earlier to aid in rationalizing the unexpectedly high hydroxyl radical (OH) concentrations in isoprene-rich, low-nitric-oxide (NO) regions ( Peeters ; et al. Phys. Chem. Chem. Phys . 2009 , 11 , 5935 ), is presented in an upgraded and extended version, LIM1. The kinetics of the crucial reactions in the proposed isoprene-peroxy radical interconversion and isomerization pathways are re-evaluated theoretically, on the basis of energy barriers computed at the much higher CCSD(T)/aug-cc-pVTZ//QCISD/6-311G(d,p) level of theory, and using multiconformer partition functions obtained at the M06-2X/6-311++G(3df,2p) level that, different from the B3LYP level used in our earlier work, accounts for the crucial London dispersion effects in the H-bonded systems involved. The steady-state fraction of the specific Z-δ-OH-peroxy radical isomers/conformers that can isomerize by a 1,6-H shift is shown to be largely governed by hydrogen-bond strengths, whereas their isomerization itself is found to occur quasi-exclusively by hydrogen atom tunneling. The isomer-specific Z-δ-OH-peroxy 1,6-H-shift rate coefficients are predicted to be of the order of 1 s(-1) at 298 K, but the experimentally accessible bulk rate coefficients, which have to be clearly distinguished from the former, are 2 orders of magnitude lower due to the very low Z-δ-OH-peroxy steady-state fractions that are only around or below 0.01 at low to moderate NO and depend on the peroxy lifetime. Two pathways subsequent to the peroxy radical 1,6-H shift are identified, the earlier predicted route yielding the photolabile hydroperoxy-methylbutenals (HPALDs), and a second, about equally important path, to dihydroperoxy-carbonyl peroxy radicals (di-HPCARP). Taking this into account, our predicted bulk peroxy isomerization rate coefficients are about a factor 1.8 higher than the available experimental results for HPALD production ( Crounse ; et al. Phys. Chem. Chem. Phys. 2011 , 13 , 13607

  10. Pedagogy with babies: perspectives of eight nursery managers

    PubMed Central

    Elfer, Peter; Page, Jools


    The last 30 years have seen a significant increase in babies attending nursery, with corresponding questions about the aims and organisation of practice. Research broadly agrees on the importance of emotionally consistent, sensitive and responsive interactions between staff and babies. Policy objectives for nursery and expectations of parents and staff give rise to different and sometimes conflicting aims for such interactions; for example attachments to staff, peer interactions or early learning. Research shows marked variations of pedagogy aims and organisation with babies in nurseries in different national and cultural contexts. It also demonstrates variation between nurseries in similar contexts and between staff in their beliefs and values about work with babies. This paper reports on an exploratory study of the beliefs, aspirations and approaches of eight managers concerning pedagogy with babies in two similar English local authorities. These managers spoke of the importance of being responsive to the concerns and priorities of parents, whilst being sensitive to the demands of the work on their staff. The main finding was of the contradictions and confusions managers felt were inherent in the work, arising from both conflicting policy objectives and personal beliefs and aspirations; sometimes their own and sometimes those of individual staff and parents. Urban, Vandenbroeck, Van Laere, Lazzari, and Peeters' [(2012). Towards competent systems in early childhood education and care. Implications for policy and practice. European Journal of Education, 47(4), 508–526.] concept of the ‘competent system’ is used to recommend a grounded approach to the development of a more culturally, socially and individually responsive pedagogy with babies than appears to exist at present. PMID:26692633

  11. Large effect of irradiance on hydrogen isotope fractionation of alkenones in Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    van der Meer, Marcel T. J.; Benthien, Albert; French, Katherine L.; Epping, Eric; Zondervan, Ingrid; Reichart, Gert-Jan; Bijma, Jelle; Sinninghe Damsté, Jaap S.; Schouten, Stefan


    The hydrogen isotopic (δD) composition of long-chain alkenones produced by certain haptophyte algae has been suggested as a potential proxy for reconstructing paleo sea surface salinity. However, environmental parameters other than salinity may also affect the δD of alkenones. We investigated the impact of the level of irradiance on hydrogen isotopic fractionation of alkenones versus growth water by cultivating two strains of the cosmopolitan haptophyte Emiliania huxleyi at different light intensities. The hydrogen isotope fractionation decreased by approximately 40‰ when irradiance was increased from 15 to 200 μmol photons m-2 s-1 above which it was relatively constant. The response is likely a direct effect of photosystem I and II activity as the relationship of the fractionation factor α versus light intensity can be described by an Eilers-Peeters photosynthesis model. This irradiance effect is in agreement with published δD data of alkenones derived from suspended particulate matter collected from different depths in the photic zone of the Gulf of California and the eastern tropical North Pacific. However, haptophyte algae tend to bloom at relatively high light intensities (>500 μmol photons m-2 s-1) occurring at the sea surface, at which hydrogen isotope fractionation is relatively constant and not affected by changes in light intensity. Alkenones accumulating in the sediment are likely mostly derived from these surface water haptophyte blooms, when the largest amount of biomass is produced. Therefore, the observed irradiance effect is unlikely to affect the applicability of the hydrogen isotopic composition of sedimentary long chain alkenones as a proxy for paleosalinity.

  12. Combining Ambient Measurements of OH Radicals and OH Reactivity in a Tropical Rainforest during the OP-3 Project: Resolving the Magnitude of the Missing OH Sources and Sinks

    NASA Astrophysics Data System (ADS)

    Whalley, L. K.; Edwards, P.; Furneaux, K. L.; Goddard, A.; George, I. J.; Evans, M. J.; Heard, D. E.; Team Op-3


    effect of 0.74 ppbv of NO. The model is unable to account for all of the OH reactivity; to simulate the OH reactivity a range of unmeasured sinks must be invoked. In general we believe that the simultaneous measurement of OH reactivity and OH concentration enables the separation of OH sources and sinks, allowing a more comprehensive test of our understanding of the radical chemistry occurring in this chemically complex environment. [1] J. Lelieveld, T. M. Butler, J. N. Crowley et al.: Nature, 2008, 452, p.737 - 740 [2] J. Peeters, T. L. Nguyen & L. Vereecken, PCCP, 2009, 11, p.5935 - 5939

  13. Unusually fast 1,6-h shifts of enolic hydrogens in peroxy radicals: formation of the first-generation C2 and C3 carbonyls in the oxidation of isoprene.


    Peeters, Jozef; Nguyen, Thanh Lam


    In a theoretical investigation using the CBS-QB3//UB3LYP/6-31+G** method supported by higher-level computations such as CBS-QB3//UQCISD/6-31+G**, the 1,6-H shifts of the enolic hydrogen in peroxy radicals of the type Z-HO-CH═CH-CH(2)-OO(•) were found to face exceptionally low energy barriers of only about 11 kcal mol(-1)--i.e., 6-9 kcal mol(-1) lower than the barriers for similar shifts of alkane hydrogens--such that they can proceed at unequaled rates of order 10(5) to 10(6) s(-1) at ambient temperatures. The unusually low barriers for enolic 1,6-H shifts in peroxy radicals, characterized here for the first time to our knowledge, are rationalized. As cases in point, the secondary peroxy radicals Z-HO-CH═C(CH(3))-CH(OO(•))-CH(2)OH (case A) and Z-HO-CH═CH-C(CH(3))(OO(•))-CH(2)OH (case B) derived from the primary Z-δ-hydroxy-peroxy radicals in the oxidation of isoprene, are predicted to undergo 1,6-H shifts of their enolic hydrogens at TST-calculated rates in the range 270-320 K of k(T)(A) = 5.4 × 10(-4) × T(5.04) × exp(-1990/T) s(-1) and k(T)(B) = 109 × T(3.13) × exp(-3420/T) s(-1), respectively, i.e., 2.0 × 10(6) and 6.2 × 10(4) s(-1), respectively, at 298 K, far outrunning in all relevant atmospheric and laboratory conditions their reactions with NO proposed earlier as their dominant pathways (Dibble J. Phys. Chem. A 2004, 108, 2199). These fast enolic-H shifts are shown to provide the explanation for the first-generation formation of methylglyoxal + glycolaldehyde, and glyoxal + hydroxyacetone in the oxidation of isoprene under high-NO conditions, recently determined by several groups. However, under moderate- and low-NO atmospheric conditions, the fast interconversion and equilibration of the various thermally labile, initial peroxy conformers/isomers from isoprene and the isomerization of the initial Z-δ-hydroxy-peroxy radicals, both recently proposed by us (Peeters et al. Phys. Chem. Chem. Phys. 2009, 11, 5935), are expected to

  14. Post-glacial coast development and human settling of the North European Ice Marginal Landscape (IML)

    NASA Astrophysics Data System (ADS)

    Bregman, I. Kant Baltic Federal State University, Kaliningrad, Russia, E. P. H.; Netherlands, Utrecht University, the; Druzhinina, I. Kant Baltic Federal State University, Kaliningrad, Russia, O. A.


    In North Europe, in the Ice Marginal Landscapes (IML) from the Netherlands to Estonia, human settling is in the Late-Pleistocene - Holocene strongly influenced by post-glacial relative coast development(MESO, 2010; SINCOS, 2002-2009; Machu, 2006-2009, IGCP project 346, CoPaF, 2009-2012) and glacio-isostasy. Geological processes like updoming and tectonic block displacements not only influenced sedimentation of river systems in delta's (e.g. Cohen, 2003), but influenced coastal development and human settling too in the North Sea area (e.g. Peeters, 2009; Hijma e.a., 2011) the Wadden areas (e.g. de Langen, 2011) and lagoons (e.g. Druzhinina, 2010). An overview of shoreline development at the distal side of the Late Glacial forbulge related to glaciological and geophysical processes however does not exist and coastal development models are also not correlated with human settling. Our project( 2012 - 2018) has the aim to describe the influence of shifting coast on the way of settling and living of ancient man in the IML. The main questions to be answered are as follow: (i) Is coast development influenced by glaciations a result of interaction between endo- and exogenic (glaciological-, geological-, and geophysical) forces in general and at the local scale of morphological elements? (ii) Did ancient man adept to changes in natural circumstances and what did that mean for his social behavior and economy? (iii) Were forms of human society and economy in the IML primarily dependent on the natural environment with regard to geophysical and geological differences and related to post-glacial response of the earth crust? Detailed integrated studying of "key-areas", with attention to deep geology, will allow to get new insight of the impact of post-glacial shoreline changes and history of man on the coast in the IML with focus on his past (history of relations) and future (impact of climate change. The project is an international project, with participation of institutes all

  15. Modeling serotonin uptake in the lung shows endothelial transporters dominate over cleft permeation

    PubMed Central

    Bassingthwaighte, James B.


    A four-region (capillary plasma, endothelium, interstitial fluid, cell) multipath model was configured to describe the kinetics of blood-tissue exchange for small solutes in the lung, accounting for regional flow heterogeneity, permeation of cell membranes and through interendothelial clefts, and intracellular reactions. Serotonin uptake data from the Multiple indicator dilution “bolus sweep” experiments of Rickaby and coworkers (Rickaby DA, Linehan JH, Bronikowski TA, Dawson CA. J Appl Physiol 51: 405–414, 1981; Rickaby DA, Dawson CA, and Linehan JH. J Appl Physiol 56: 1170–1177, 1984) and Malcorps et al. (Malcorps CM, Dawson CA, Linehan JH, Bronikowski TA, Rickaby DA, Herman AG, Will JA. J Appl Physiol 57: 720–730, 1984) were analyzed to distinguish facilitated transport into the endothelial cells (EC) and the inhibition of tracer transport by nontracer serotonin in the bolus of injectate from the free uninhibited permeation through the clefts into the interstitial fluid space. The permeability-surface area products (PS) for serotonin via the inter-EC clefts were ∼0.3 ml·g−1·min−1, low compared with the transporter-mediated maximum PS of 13 ml·g−1·min−1 (with Km = ∼0.3 μM and Vmax = ∼4 nmol·g−1·min−1). The estimates of serotonin PS values for EC transporters from their multiple data sets were similar and were influenced only modestly by accounting for the cleft permeability in parallel. The cleft PS estimates in these Ringer-perfused lungs are less than half of those for anesthetized dogs (Yipintsoi T. Circ Res 39: 523–531, 1976) with normal hematocrits, but are compatible with passive noncarrier-mediated transport observed later in the same laboratory (Dawson CA, Linehan JH, Rickaby DA, Bronikowski TA. Ann Biomed Eng 15: 217–227, 1987; Peeters FAM, Bronikowski TA, Dawson CA, Linehan JH, Bult H, Herman AG. J Appl Physiol 66: 2328–2337, 1989) The identification and quantitation of the cleft pathway conductance from these

  16. EVAPORISATION: a new vapor pressure model taking into account neighbour effects

    NASA Astrophysics Data System (ADS)

    Compernolle, Steven; Ceulemans, Karl; Muller, Jean-Francois


    pressure method can have a major impact on aerosol yield, considerably larger than the choice of activity coefficient model (Compernolle et al. 2009). M. Capouet and J.-F. Muller, Atm. Chem. Phys. 6, 1455-1467 (2006) M. Capouet, J.-F. Muller, K. Ceulemans, S. Compernolle, L. Vereecken and J. Peeters, J. Geophys. Res. 113, D02308 (2008) S. Compernolle, K. Ceulemans and J. Muller, Atm. Chem. Phys. 9, 1325-1388 (2009) S.H. Hilal, S.W. Karickhoff and L.A. Carreira , QSAR Comb. Sci. 22, 565-574 (2003) P.B. Myrdal and S.H. Yalkowsky, Ind. Eng. Chem. Res. 36, 2494-2499 (1997) Y. Nannoolal, J. Rarey and D. Ramjugernath, Fluid Phase Eq. 269, 117-133 (2008) B. Moller, J. Rarey and D. Ramjugernath, J. Mol. Liq. 143, 52-63 (2008)

  17. Towards a better understanding of isoprene emissions and chemistry above tropical forests with the TM5 model

    NASA Astrophysics Data System (ADS)

    van Geel, M. H. A.; Boersma, K. F.; Williams, J. E.; Huijnen, V.; van Noije, T. P. C.; VilÖGuerau de Arellano, J.; Parker, D. J.; Reeves, C. E.; Schlager, H.; Lichtenstern, M.; Murphy, J. G.; Mills, G.; Heard, D. E.; Ingham, T.; Commane, R.


    , TM5 overestimates HCHO by a factor 2. In line with previous studies we find that the TM5 model, as many other models, simulates insufficient OH over tropical forests, which results in too high isoprene concentrations, and an erroneous yield of HCHO from isoprene that would strongly bias the inversion. We are therefore implementing a number of recently proposed isoprene oxidation schemes to replace the standard TM5 CBM-IV isoprene + OH reaction. Preliminary results indicate that the epoxide-formation scheme proposed by Paulot et al. [2009] does not resolve discrepancies between the simulations and observations. We will discuss the success of the Leuven Isoprene Mechanism (LIM0) by Peeters et al. [2009], and the general implications of our findings for providing constraints on isoprene emissions in low-NOx regions.

  18. Effects of climate change on deep-water oxygen and winter mixing in a deep lake (Lake Geneva)

    NASA Astrophysics Data System (ADS)

    Schwefel, Robert; Alfred, Wüest; Damien, Bouffard


    Oxygen is the most important dissolved gas for lake ecosystems. Because low oxygen concentrations are an ongoing problem in many parts of the oceans and numerous lakes, oxygen depletion processes have been intensively studied over the last decades and were mainly attributed to high nutrient loads. Recently, climate-induced changes in stratification and mixing behavior were recognized as additional thread to hypolimnetic oxygen budgets in lakes and reservoirs [Matzinger et al., 2007; Zhang et al., 2015]. Observational data of Lake Geneva, a deep perialpine lake situated between France and Switzerland showed no decreasing trend in hypoxia over the last 43 years, despite an impressive reduction in nutrient input during this period. Instead, hypoxic conditions were predominantly controlled by deep mixing end of winter and in turn by winter temperatures. To test the sensitivity of Lake Geneva on future climate change and changes in water transparency, we simulated the hydrodynamics and temperature of Lake Geneva under varying conditions for atmospheric temperature and water clarity performed with the one-dimensional model SIMSTRAT [Goudsmit, 2002]. The results show, that the stratification in lakes is only weakly affected by changes in light absorption due to varying water quality. For conditions expected for the end of the century, a decrease in the annual mean deep convective mixing of up to 45 m is predicted. Also complete mixing events over the whole lake are less likely to occur. A change in the hypolimnetic oxygen concentration of up to 20% can thus be expected in the future. These results show, that changes in deep mixing have an equally strong impact as eutrophication on the deep-water oxygen development of oligomictic lakes and have to be considered in the prediction of the future development of lakes. References: Goudsmit, G. H., H. Burchard, F. Peeters, and A. Wüest (2002), Application of k-ɛ turbulence models to enclosed basins: The role of internal

  19. Global modelling of secondary organic aerosol from α-pinene oxidation using a parameterization based on a detailed chemical mechanism

    NASA Astrophysics Data System (ADS)

    Ceulemans, Karl; Müller, Jean-Francois; Compernolle, Steven; Stavrakou, Jenny


    sesquiterpenes we use two-product parameterizations based on smog chamber studies. Irreversible SOA formation due to polymerization of short-chained aldehydes (glyoxal, methylglyoxal, etc.) and direct emission of POA are also considered. Monoterpenes are estimated to contribute about 20-40 TgOA/year globally, i.e. a factor 2-4 higher than in previous modeling studies. This large contribution stems from the high SOA yields (of the order of 50% in atmospheric conditions) obtained using BOREAM at low NOx in the the oxidation of α-pinene by OH. These high yields result from the predicted formation of highly condensable polyfunctional compounds (e.g. hydroxy-dihydroperoxides). Possible uncertainties on these estimates will be discussed on the basis of sensitivity tests with the full mechanism. The calculated OA concentrations are compared with a large number of ground-based (IMPROVE, CARBOSOL, etc.) and aircraft (INTEX-A and ACE-1) measurements. Whereas a relatively good agreement is found over both Eastern and Western US, large OA underestimations are generally found over Europe, Africa and Asia. Possible causes will be discussed. Capouet, M. and J.-F. Müller, A group contribution method for estimating the vapour pressures of α-pinene oxidation products, Atmos. Chem. Phys., 6, 1455-1467, 2006. Capouet, M., J.-F. Müller, K. Ceulemans, S. Compernolle, L. Vereecken, J. Peeters, Modeling aerosol formation in α-pinene photooxidation experiments, J. Geophys. Res., 113, D02308, 2008. Ceulemans, K., S. Compernolle, J. Peeters, and J.-F. Müller, Evaluation of a detailed model of secondary aerosol formation from α-pinene against dark ozonolysis experiments, submitted to Atmos. Environ., 2009. Compernolle, S., K. Ceulemans, and J.-F. Müller, Influence of non-ideality on aerosol growth, Atmos. Chem. Phys., 9, 1325-1337, 2009. Odum, J. R., T. Hoffmann, F. Bowman, D. Collins, R. C. Flagan, and J. H. Seinfeld, Gas/particle partitioning and secondary organic aerosol AMFs, Environ. Sci

  20. Natural-Cause Mortality and Long-Term Exposure to Particle Components: An Analysis of 19 European Cohorts within the Multi-Center ESCAPE Project

    PubMed Central

    Hoek, Gerard; Raaschou-Nielsen, Ole; Stafoggia, Massimo; Andersen, Zorana Jovanovic; Weinmayr, Gudrun; Hoffmann, Barbara; Wolf, Kathrin; Samoli, Evangelia; Fischer, Paul H.; Nieuwenhuijsen, Mark J.; Xun, Wei W.; Katsouyanni, Klea; Dimakopoulou, Konstantina; Marcon, Alessandro; Vartiainen, Erkki; Lanki, Timo; Yli-Tuomi, Tarja; Oftedal, Bente; Schwarze, Per E.; Nafstad, Per; De Faire, Ulf; Pedersen, Nancy L.; Östenson, Claes-Göran; Fratiglioni, Laura; Penell, Johanna; Korek, Michal; Pershagen, Göran; Eriksen, Kirsten Thorup; Overvad, Kim; Sørensen, Mette; Eeftens, Marloes; Peeters, Petra H.; Meliefste, Kees; Wang, Meng; Bueno-de-Mesquita, H. Bas; Sugiri, Dorothea; Krämer, Ursula; Heinrich, Joachim; de Hoogh, Kees; Key, Timothy; Peters, Annette; Hampel, Regina; Concin, Hans; Nagel, Gabriele; Jaensch, Andrea; Ineichen, Alex; Tsai, Ming-Yi; Schaffner, Emmanuel; Probst-Hensch, Nicole M.; Schindler, Christian; Ragettli, Martina S.; Vilier, Alice; Clavel-Chapelon, Françoise; Declercq, Christophe; Ricceri, Fulvio; Sacerdote, Carlotta; Galassi, Claudia; Migliore, Enrica; Ranzi, Andrea; Cesaroni, Giulia; Badaloni, Chiara; Forastiere, Francesco; Katsoulis, Michail; Trichopoulou, Antonia; Keuken, Menno; Jedynska, Aleksandra; Kooter, Ingeborg M.; Kukkonen, Jaakko; Sokhi, Ranjeet S.; Vineis, Paolo; Brunekreef, Bert


    , Pershagen G, Eriksen KT, Overvad K, Sørensen M, Eeftens M, Peeters PH, Meliefste K, Wang M, Bueno-de-Mesquita HB, Sugiri D, Krämer U, Heinrich J, de Hoogh K, Key T, Peters A, Hampel R, Concin H, Nagel G, Jaensch A, Ineichen A, Tsai MY, Schaffner E, Probst-Hensch NM, Schindler C, Ragettli MS, Vilier A, Clavel-Chapelon F, Declercq C, Ricceri F, Sacerdote C, Galassi C, Migliore E, Ranzi A, Cesaroni G, Badaloni C, Forastiere F, Katsoulis M, Trichopoulou A, Keuken M, Jedynska A, Kooter IM, Kukkonen J, Sokhi RS, Vineis P, Brunekreef B. 2015. Natural-cause mortality and long-term exposure to particle components: an analysis of 19 European cohorts within the Multi-Center ESCAPE Project. Environ Health Perspect 123:525–533; PMID:25712504

  1. EDITORIAL: Focus on Graphene

    NASA Astrophysics Data System (ADS)

    Peres, N. M. R.; Ribeiro, Ricardo M.


    lattice models and quantum spin chains Mahdi Zarea and Nancy Sandler On the universal ac optical background in graphene V P Gusynin, S G Sharapov and J P Carbotte Heat conduction in graphene: experimental study and theoretical interpretation S Ghosh, D L Nika, E P Pokatilov and A A Balandin Calculation of the Raman G peak intensity in monolayer graphene: role of Ward identities D M Basko Electronic transport in bilayer graphene Mikito Koshino Magnetic Kronig-Penney model for Dirac electrons in single-layer graphene M Ramezani Masir, P Vasilopoulos and F M Peeters Electrical transport in high-quality graphene pnp junctions Jairo Velasco Jr, Gang Liu, Wenzhong Bao and Chun Ning Lau Local density of states and scanning tunneling currents in graphene N M R Peres, Ling Yang and Shan-Wen Tsai Gaps and tails in graphene and graphane B Dóra and K Ziegler Quasi-ferromagnet spintronics in the graphene nanodisc-lead system Motohiko Ezawa Range and correlation effects in edge disordered graphene nanoribbons Alessandro Cresti and Stephan Roche Remarks on the tight-binding model of graphene Cristina Bena and Gilles Montambaux

  2. Electrical control of spin in topological insulators

    NASA Astrophysics Data System (ADS)

    Chang, Kai


    by changing the gate voltage. It provides us a new way to control surface magnetism electrically. The gap opened by doped magnetic ions can lead to a short-range Bloembergen-Rowland interaction. The competition among the Heisenberg, Ising, and DM terms leads to rich spin configurations and an anomalous Hall effect on different lattices [4]. There are many proposals for quantum computation scheme are based on the spin in semiconductor quantum dots. Topological insulator quantum dots display a very different behavior with that of conventional semiconductor quantum dots [5]. In sharp contrast to conventional semiconductor quantum dots, the quantum states in the gap of the HgTe QD are fully spin-polarized and show ring-like density distributions near the boundary of the QD and optically dark. The persistent charge currents and magnetic moments, i.e., the Aharonov-Bohm effect, can be observed in such a QD structure. This feature offers us a practical way to detect these exotic ring-like edge states by using the SQUID technique. [0pt]Refs: [1] W. Yang, Kai Chang, and S. C. Zhang, Phys. Rev. Lett. 100, 056602 (2008); J. Li and Kai Chang, Appl. Phys. Lett. 95, 222110 (2009). [2] L. B. Zhang, Kai Chang, X. C. Xie, H. Buhmann and L. W. Molenkamp, New J. Phys. 12, 083058 (2010). [3] L. B. Zhang, F. Cheng, F. Zhai and Kai Chang, Phys. Rev. B 83 081402(R) (2011); Z. H. Wu, F. Zhai, F. M. Peeters, H. Q. Xu and Kai Chang, Phys, Rev. Lett. 106, 176802 (2011). [4] J. J. Zhu, D. X. Yao, S. C. Zhang, and Kai Chang, Phys. Rev. Lett. 106, 097201 (2011). [5] Kai Chang, and Wen-Kai Lou, Phys. Rev. Lett. 106, 206802 (2011).

  3. Using noble gases in the pore water of ocean sediments to characterize CH4 seepage off the coast of New Zealand

    NASA Astrophysics Data System (ADS)

    Tomonaga, Yama; Brennwald, Matthias S.; Kipfer, Rolf


    Newly developed analytical techniques to determine the abundances of noble gases in sediment pore water [1, 5] allow noble-gas concentrations and isotope ratios to be measured easily and routinely in unconsolidated lacustrine sediments [6, 7]. We applied these techniques for the first time to ocean sediments to investigate an active cold methane seepage system located in the South Pacific off the coast of New Zealand using 3He-4He ratios determined in the sediment pore water. Our results [8] show that more 3He-rich fluids are released in the vicinity of the Pacific-Australian subduction zone than at the forearc stations located closer to the New Zealand coast. However, the 3He-4He isotope signature in the sediment column indicates that only a minor part of the He emanating from deeper strata originates from a (depleted) mantle source. Hence, most He in the pore water is produced locally by the radioactive decay of U and Th in the sediment minerals or in the underlying crustal rocks. Such an occurrence of isotopically heavy crustal He also suggests that the source of the largest fraction of methane is a near-surface geochemical reservoir. This finding is in line with a previous δ13C study in the water column which concluded that the emanating methane is most likely of biological origin and is formed in the upper few meters of the sediment column [2]. The prevalence of isotopically heavy He agrees well with the outcome of other previous studies on island arc systems [3, 4] which indicate that the forearc regions are characterized by crustal He emission, whereas the volcanic arc region is characterized by the presence of mantle He associated with rising magma. References [1] Brennwald, M. S., Hofer, M., Peeters, F., Aeschbach-Hertig, W., Strassmann, K., Kipfer, R., and Imboden, D. M. (2003). Analysis of dissolved noble gases in the pore water of lacustrine sediments. Limnol. Oceanogr.: Methods 1, 51-62. [2] Faure, K., Greinert, J., Schneider von Deimling, J., Mc

  4. COST Action MP0806 'Particles in Turbulence': International Conference on Fundamentals, Experiments, Numeric and Applications

    NASA Astrophysics Data System (ADS)

    Abel, Markus; Bodenschatz, Eberhard; Toschi, Federico


    also like to thank the students from Potsdam University for their exquisite help. We are very thankful to Anita Peeters for her unwavering support and help in the organization of this particular event, as well as, for the efforts ensuring the smooth running of the COST Action 'Particles in turbulence'. Markus Abel, Eberhard Bodenschatz, Federico Toschi The PDF files of the conference program and conference poster are attached.

  5. Fullerenes, Organics and the Diffuse Interstellar Bands

    NASA Astrophysics Data System (ADS)

    Foing, Bernard H.


    ; [12] Krelowski, J. et al. 1999A&A 347, 235; [13] Sonnentrucker, P., Cami, J., Ehrenfreund, P., Foing, B. H. 1997 A&A 327, 1215; [14] Sonnentrucker, P., Foing, B. H., Breitfellner, M., Ehrenfreund, P. 1999 A&A 346, 936; [15] Cox, N. et al. 2007 A&A 470, 941; [16] Ehrenfreund, P. et al. 2002 ApJ 576 L117; [17] Ehrenfreund, P.; Foing, B. H. 1996 A&A 307 L25; [18] Sarre, P. J. et al. 1995 MNRAS.277 L41; [19] Cossart-Magos, C. & Leach, S. 1990 A&A 233, 559; [20] Cox, N. L., Ehrenfreund, P., Foing, B. H. et al. 2011 A&A 531, 25; [21] Cox, N. L., Boudin, N., Foing, B. H. et al. 2007 A&A 465, 899; [22] Ehrenfreund, P. & Charnley, S. 2000 ANRAA 38, 427; [23] Scarrott, S. M., Watkin, S., Miles, J. R., Sarre, P. J. 1992 MNRAS 255, 11; [25] Planck Collaboration, 2011 A&A 536 20 (Planck early results. XX.); [26] Ehrenfreund, P. et al. 1995 A&A 299; 213; [27] Ehrenfreund, P. & Foing, B. H 1995 P&SS 43, 1183; [28] van der Zwet, G. P., Allamandola, L. J. 1985 A&A 146 76; [29] Salama, F. et al. 1996 ApJ 458, 621; [30] Ruiterkamp, R. et al. 2005 A&A 432, 515; [31] Ruiterkamp, R. et al. 2002 A&A 390, 1153; [32] Vuong, M. H. & Foing, B. H 2000 A&A 363, L5; [33] Le Page, V. et al 2001 ApJS 132, 233; [34] Ehrenfreund, P et al. 2007 P&SS 55, 383; [35] Bryson, K. L., Peeters, Z., Salama, F., Foing, B., Ehrenfreund, P. et al. 2011 AdSpR 48, 1980; [36] Mattioda, A., Cook, A., Ehrenfreund, P. et al. 2012 AsBio 12, 841.

  6. Land - Ocean Climate Linkages and the Human Evolution - New ICDP and IODP Drilling Initiatives in the East African Rift Valley and SW Indian Ocean

    NASA Astrophysics Data System (ADS)

    Zahn, R.; Feibel, C.; Co-Pis, Icdp/Iodp


    enable us to establish the linkages between the ocean climatology of the SW Indian and terrestrial climates of Eastern Africa during key periods of global climate change. Combining the ICDP records of East African terrestrial climate at key hominin sites with IODP records of marine climate variability at the SE African continental margin will help to test if pulses of hominin evolutionary innovation were linked with periods of enhanced variability of local terrestrial environments and marine climatology of the Indian Ocean. * co-PIs of the ICDP initiative HSPDP are A.S. Cohen, R. Arrowsmith, A.K. Behrensmeyer, C. Feibel, R. Johnson, Z. Kubsa, D. Olago, R. Potts, R. Renaut * co-PIs of the IODP initiative SAFARI are R. Zahn, I. Hall, R. Schneider, M. Á. Bárcena, S. Barker, A. Biastoch, Chr. Charles, J. Compton, R. Cowling, P. Diz, L. Dupont, J.-A. Flores, S. Goldstein, S. Hemming, K. Holmgren, J. Lee-Thorp, G. Knorr, C. Lear, A. Mazaud, G. Mortyn, F. Peeters, B. Preu, R. Rickaby, J. Rogers, A. Rosell-Mele, Chr. Reason, V. Spiess, M. Trauth, G. Uenzelmann-Neben, S. Weldeab, P. Ziveri

  7. PREFACE: XXXth International Colloquium on Group Theoretical Methods in Physics (ICGTMP) (Group30)

    NASA Astrophysics Data System (ADS)

    Brackx, Fred; De Schepper, Hennie; Van der Jeugt, Joris


    Christophe Peeters, Deputy Mayor of the City of Ghent, was followed by a reception in the historical "Pacificatiezaal" of the City Hall. On Wednesday afternoon the participants had the opportunity to take a guided tour through medieval Ghent, admiring its wide range of monuments. The tour was followed by a much-appreciated boat trip exploring the canals and rivers of Ghent, all in sunny weather. On Thursday evening the conference banquet was held in the "Brasserie HA". Located in the Handelsbeurs Ghent. In the majestic banquet hall, the participants were not only treated to an exclusive dinner, but also to some fine piano music by Dmitry Gal'tsov and Richard Kerner. The conference was sponsored by: American Institute of Physics (AIP Publishing), Clay Mathematics Institute, Clifford Research Group - Faculty of Engineering and Architecture (Ghent Unviversity), Elsevier, Faculty of Sciences (Ghent University), Fonds de la Recherche Scientifique (FNRS), Foundation Compositio Mathematica, FWO Research Foundation - Flanders, International Association of Mathematical Physics, International Solvay Institutes, International Union of Pure and Applied Physics, National Science Foundation (USA) and Springer Birkhäuser. We would like to thank all our sponsors for their generous support. It took more than two years to organise a conference of such a size and importance. We express our gratitude to the International Advisory Committee for its help in selecting the plenary speakers and to the external members of the Organising Committee for their helpful suggestions and advice. We thank Wouter Dewolf for his devoted secretarial, administrative and organisational work and Vera Vanden Driessche for arranging the "Accompanying persons' programme". Finally, a big 'thank you' to all the local people (administrative and technical staff, research assistants and research students) for their devoted and tireless work in preparing and running the conference. Fred Brackx, Hennie De Schepper and Joris

  8. Preface

    NASA Astrophysics Data System (ADS)

    Benage, J. F.; Dufty, J. W.; Murillo, M. S.


    , Israel N W Ashcroft Cornell University, USA J Bollinger NIST, Boulder, USA J-M Caillol Université Paris XI, France D M Ceperley University of Illinois, USA G Chabrier Ecole Normale Supérieure de Lyon, France J Clerouin CEA Bruyeres-le-Chatel, France S das Sarma University of Maryland, USA A DeSilva University of Maryland, USA H DeWitt Lawrence Livermore National Laboratory, USA D Dubin University of California, USA J Dufty University of Florida, USA W Ebeling Humboldt University, Germany V Filinov Institute of High Temperature Physics, Russia M Fisher University of Maryland, USA V E Fortov Institute of High Temperature Physics, Russia K Golden University of Vermont, USA J-P Hansen Cambridge University, UK F Hensel Philipps-Universität, Germany G Kalman Boston College, USA W Kohn University of California, USA H Lowen University of Dusseldorf, Germany G Morfill Max Planck Institute of Extraterrestrial Physics, Germany D Neilson University of New South Wales, Australia G Patey University of British Columbia, Canada F Peeters University of Antwerp, Germany D Pines Los Alamos National Laboratory, USA G Roepke University of Rostock, Germany M Rosenberg University of California, USA Y Rosenfeld Negev Nuclear Research Center, Israel M Schlanges University of Greifswald, Germany G Senatore University of Trieste, France H Totsuji Okayama University, Japan J Weisheit Los Alamos National Laboratory, USA Obituary Forty years of plasma line broadening---in memory of Professor Charles Hooper Jr Our friend and colleague, Charles Hooper Jr, died on 5 May 2002 after a long illness and a valiant battle against it. This presentation is a brief look back at the issues in plasma line broadening over the past forty years, and the contributions to them by Chuck and his students. Chuck graduated from Dartmouth College in 1954. He served in the US Navy for two years before receiving a PhD from Johns Hopkins University in 1963. He then joined the faculty at the University of Florida where his