bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐angle wave instability and emergent shoreline shapes: 1. Modeling of sand waves, flying spits, and capes
Authors: Ashton Andrew D. , Murray A. Brad
Published: December 2006

Contrary to traditional findings, the deepwater angle of wave approach strongly affects plan view coastal evolution, giving rise to an antidiffusional “high wave angle” instability for sufficiently oblique deepwater waves (with angles between wave crests and the shoreline trend larger than the value that maximizes alongshore sediment transport, ∼45°). A one‐contour‐line numerical model shows that a predominance of high‐angle waves can cause a shoreline to self‐organize into regular, quasiperiodic shapes similar to those found along many natural coasts at scales ranging from kilometers to hundreds of kilometers. The numerical model has been updated from a previous version to include a formulation for the widening of an overly thin barrier by the process of barrier overwash, which is assumed to maintain a minimum barrier width. Systematic analysis shows that the wave climate determines the form of coastal response. For nearly symmetric wave climates (small net alongshore sediment transport), cuspate coasts develop that exhibit increasing relative cross‐shore amplitude and pointier tips as the proportion of high‐angle waves is increased. For asymmetrical wave climates, shoreline features migrate in the downdrift direction, either as subtle alongshore sand waves or as offshore‐extending “flying spits,” depending on the proportion of high‐angle waves. Numerical analyses further show that the rate that the alongshore scale of model features increases through merging follows a diffusional temporal scale over several orders of magnitude, a rate that is insensitive to the proportion of high‐angle waves. The proportion of high‐angle waves determines the offshore versus alongshore aspect ratio of self‐organized shoreline undulations.
High‐angle wave instability and emergent shoreline shapes: 2. Wave climate analysis and comparisons to nature
Authors: Ashton Andrew D. , Murray A. Brad
Published: December 2006

Recent research has revealed that the plan view evolution of a coast due to gradients in alongshore sediment transport is highly dependant upon the angles at which waves approach the shore, giving rise to an instability in shoreline shape that can generate different types of naturally occurring coastal landforms, including capes, flying spits, and alongshore sand waves. This instability merely requires that alongshore sediment flux is maximized for a given deepwater wave angle, a maximum that occurs between 35° and 50° for several common alongshore sediment transport formulae. Here we introduce metrics that sum over records of wave data to quantify the long‐term stability of wave climates and to investigate how wave climates change along a coast. For Long Point, a flying spit on the north shore of Lake Erie, Canada, wave climate metrics suggest that unstable waves have shaped the spit and, furthermore, that smaller‐scale alongshore sand waves occur along the spit at the same locations where the wave climate becomes unstable. A shoreline aligned along the trend of the Carolina Capes, United States, would be dominated by high‐angle waves; numerical simulations driven by a comparable wave climate develop a similarly shaped cuspate coast. Local wave climates along these simulated capes and the Carolina Capes show similar trends: Shoreline reorientation and shadowing from neighboring capes causes most of the coast to experience locally stable wave climates despite regional instability.
Nonstationary flow and nonergodic transport in random porous media
Authors: Darvini G. , Salandin P.
Published: December 2006

Transport processes taking place in natural formations are often characterized by the spatial nonstationarity of flow field and the nonergodic condition of solute spreading. The former may originate from statistical inhomogeneity of porous media properties or from the influence of boundary conditions as well as from conditioning procedures on measured data, while the latter is generally due to the finite size of the solute source. In real‐world applications these aspects sometimes dominate the transport phenomena, and known literature results based on statistical homogeneity and ergodicity assumptions cannot be properly applied. In this paper a method is proposed to handle different and concurrent causes of the flow field nonstationarity and to describe nonergodic transport of inert solutes by spatial moments in a domain of finite size. The goal is reached by expanding the steady state flow equation in Taylor series limited to the first‐order and by the recursive application of finite element (FE) method. The unknowns are the piezometric head mean values and its derivatives in respect to the fluctuating porous media hydraulic conductivity. From the latter the velocity statistics are derived on the basis of Darcy's law according to the first‐order approximation. By neglecting the pore‐scale dispersion the spatial moments of a solute plume are a posteriori obtained by a consistent Lagrangian analysis starting from the knowledge of the velocity field covariance matrices without any restriction regarding the statistical homogeneity of flow and/or ergodicity conditions. The proposed method is here applied to investigate the influence of boundary conditions on the solute transport developing in a limited domain. The results obtained from different test cases give a velocity field behavior in agreement with literature findings and allow us to define the nonergodic transport in bounded domains. The comparison of the results with some ad hoc developed Monte Carlo simulations ensures the applicability of the proposed approach at least to the small heterogeneity cases here considered.
Comparison of glacier‐inferred temperatures with observations and climate model simulations
Authors: Ren Diandong , Karoly David
Published: December 2006

A reconstructed temperature history for different regions of the globe was prepared by Oerlemans (2005) from length changes of 169 glaciers. In this study, we compare the glacier‐inferred temperature variations over 1900–1990 with observed and climate model simulated temperatures for the global average and for five regions: Southern Hemisphere, northwest America, Atlantic, Asia, and the Alps. There is reasonable agreement between the glacier‐inferred temperature trends and the observed temperature trends for the globe and in four of the five regions (except northwest America, NWAme). The trends for the globe and in these regions are significantly different from zero, cannot be explained by natural variability (again except for NWAme), and are consistent with the model‐simulated response to anthropogenic forcing in all regions. Hence, it is likely that the glacier length reductions are outside the range of natural variations and due in part to regional warming associated with increasing concentrations of greenhouse gases in the atmosphere.
Identifying instrumental and historical earthquake records in the SW Iberian margin using 210Pb turbidite chronology
Authors: Garcia‐Orellana Jordi , Gràcia Eulàlia , Vizcaino Alexis , Masqué Pere , Olid Carolina , Martínez‐Ruiz Francisca , Piñero Elena , Sanchez‐Cabeza Joan‐Albert , Dañobeitia Juanjo
Published: December 2006

Textural, mineralogical and geochemical analyses of near‐surface sediments from six different stations offshore SW Iberian Peninsula revealed the presence of thin detrital intervals corresponding to very fine‐grained turbidites. Precise dating of the two most recent sedimentary layers based on 210Pb and 137Cs geochronology provides ages of 1971 ± 3 AD and 1908 ± 8 AD. These ages correspond to high‐magnitude historical and instrumental earthquakes that occurred in the region: the 1969 Horseshoe Earthquake (Mw 8.0) and the 1909 Benavente Earthquake (Mw 6.0). Such a good correlation between turbidites and high‐magnitude (Mw > 6) historical and instrumental seismic events suggests that the record of mass transport deposits can also be used as a paleoseismic indicator in low‐convergence margins.
Mirror mode structures in the Jovian magnetosheath
Authors: Joy S. P. , Kivelson M. G. , Walker R. J. , Khurana K. K. , Russell C. T. , Paterson W. R.
Published: December 2006

Mirror mode waves are commonly observed in planetary magnetosheaths. Their magnetic signatures are often periodic but occasionally appear as intermittent increases of field magnitude (peaks) or as intermittent decreases (dips). We define quantitative mirror structure identification criteria and statistically analyze the distributions of the various forms. A survey of all the relevant magnetometer data in the Jovian magnetosheath reveals that mirror mode structures are present 61.5% of the time. Two‐thirds of the events include waves that are either quasi‐periodic or aperiodic, while 19% contain dips and 14% contain peaks. The amplitude and period of quasi‐periodic and periodic structures appear to increase as the residence time of the flowing plasma within the sheath increases. Peaks are primarily observed on the dayside in the high β plasmas of the middle magnetosheath. Dips are observed mostly in low β plasma near the magnetopause and on the flanks. A phenomenological model for the evolution of mirror structures that accounts for these observations has been developed. We propose that the mirror structures form near the bow shock and undergo an initial growth phase during which their amplitude increases linearly. Structures that dwell in anisotropic, high β plasma may saturate nonlinearly as described by Kivelson and Southwood [1996]. We interpret field magnitude peaks as the signatures of such nonlinear saturation. Finally, we ascribe the dip signatures to the process of stochastic decay of mirror structures as flow away from the subsolar point carries the structures into lower β plasma.
Magnetic petrology of variably retrogressed eclogites and amphibolites: A case study from the Hercynian basement of northern Sardinia (Italy)
Authors: Strada Eleonora , Talarico Franco Maria , Florindo Fabio
Published: December 2006

This study constitutes the first attempt to integrate rock magnetism and metamorphic petrology in the Hercynian basement of northern Sardinia. The investigation focused on the magnetic petrology of variably retrogressed eclogites and amphibolites from two suites of basic meta‐igneous rocks, which occur along a major tectonic line (Posada‐Asinara Line), within a medium‐grade (MG) and a high‐grade (HG) metamorphic complex. Consistent with petromagnetic results, HG metabasites contain variable amounts of monoclinic pyrrhotite (intergrown with rutile) and titanomagnetite (occurring as inclusions in garnet), abundant ilmenite (associated to secondary hornblende and with sphene ± low‐Ti‐magnetite rims), and rutile both as inclusions in ilmenite and as discrete grains. In MG metabasites, pyrrhotite is restricted to amphibolites of the Posada Valley area where it occurs as rare inclusions in garnet. All samples are characterized by variable amounts of ilmenite, rutile, and sphene which show the same microstructural features described in HG rocks. Microstructural evidence and geothermobarometric data indicate that (1) pyrrhotite and titanomagnetite likely formed prior to and remained stable during the eclogite facies metamorphic peak and (2) the growth of ilmenite and sphene can be attributed to the amphibolite facies retrogression, mainly due to model reactions such as garnet + omphacite + rutile + H2O → hornblende + plagioclase + ilmenite and amphibole + ilmenite + O2 → sphene + magnetite + quartz + H2O. The results from our combined petrological and petromagnetic study corroborate the hypothesis that significant volumes of mafic/ultramafic rocks, similar to some of the investigated outcrops, may account for the magnetic anomalies flanking the northeastern part of the Posada‐Asinara Line.
An examination of summertime cyclone transport processes during Intercontinental Chemical Transport Experiment (INTEX‐A)
Authors: Kiley Christopher M. , Fuelberg Henry E.
Published: December 2006

Warm conveyor belts (WCBs) are important mechanisms for transporting pollution during the cool season. These airstreams distribute surface emissions throughout the troposphere, playing a major role in the long‐range transport of chemical species. Previous efforts to understand the lofting of WCBs have not investigated the relative importance of vertical forcing. In this study, we use fine resolution model‐derived meteorological data, air parcel trajectories, flux calculations, and a diagnostic package for weather systems to perform a focused investigation of WCBs during the warm season INTEX‐A period. Lifting and transport mechanisms during INTEX‐A are compared to a well‐documented cool season WCB case in the literature. Results show that weak, midlatitude cyclones are capable of producing vertical transport as great or greater than much stronger cyclones. An analysis of forcing terms contributing to vertical motion reveals that the Laplacian of latent heat release is the primary contributor to vertical motion during some cases of INTEX‐A. The latent heating term is found to be greatest in areas of deep convection. This convection allows weak cyclones to produce WCB‐like transport. WCB pathways are similar for the cases studied. In each example, air which originates far south of the low in the warm sector ascends to the north and joins the upper level westerly flow northeast of the low center. Although the transport pathways are similar, the forcing mechanism and location of maximum vertical transport are found to exhibit strong case‐to‐case variability. When cyclone‐scale dynamics are relatively weak, widespread deep convection, especially south of the cyclone's center, is necessary to produce transport resembling a WCB.
Ozone production from the 2004 North American boreal fires
Authors: Pfister G. G. , Emmons L. K. , Hess P. G. , Honrath R. , Lamarque J.‐F. , Val Martin M. , Owen R. C. , Avery M. A. , Browell E. V. , Holloway J. S. , Nedelec P. , Purvis R. , Ryerson T. B. , Sachse G. W. , Schlager H.
Published: December 2006

We examine the ozone production from boreal forest fires based on a case study of wildfires in Alaska and Canada in summer 2004. The model simulations were performed with the chemistry transport model, MOZART‐4, and were evaluated by comparison with a comprehensive set of aircraft measurements. In the analysis we use measurements and model simulations of carbon monoxide (CO) and ozone (O3) at the PICO‐NARE station located in the Azores within the pathway of North American outflow. The modeled mixing ratios were used to test the robustness of the enhancement ratio ΔO3/ΔCO (defined as the excess O3 mixing ratio normalized by the increase in CO) and the feasibility for using this ratio in estimating the O3 production from the wildfires. Modeled and observed enhancement ratios are about 0.25 ppbv/ppbv which is in the range of values found in the literature and results in a global net O3 production of 12.9 ± 2 Tg O3 during summer 2004. This matches the net O3 production calculated in the model for a region extending from Alaska to the east Atlantic (9–11 Tg O3) indicating that observations at PICO‐NARE representing photochemically well aged plumes provide a good measure of the O3 production of North American boreal fires. However, net chemical loss of fire‐related O3 dominates in regions far downwind from the fires (e.g., Europe and Asia) resulting in a global net O3 production of 6 Tg O3 during the same time period. On average, the fires increased the O3 burden (surface −300 mbar) over Alaska and Canada during summer 2004 by about 7–9% and over Europe by about 2–3%.
Overview of the summer 2004 Intercontinental Chemical Transport Experiment–North America (INTEX‐A)
Authors: Singh H. B. , Brune W. H. , Crawford J. H. , Jacob D. J. , Russell P. B.
Published: December 2006

The INTEX‐A field mission was conducted in the summer of 2004 (1 July to 15 August 2004) over North America (NA) and the Atlantic in cooperation with multiple national and international partners as part of a consortium called ICARTT. The main goals of INTEX‐A were to (1) characterize the composition of the troposphere over NA, (2) characterize the outflow of pollution from NA and determine its chemical evolution during transatlantic transport, (3) validate satellite observations of tropospheric composition, (4) quantitatively relate atmospheric concentrations of gases and aerosols with their sources and sinks, and (5) investigate aerosol properties and their radiative effects. INTEX‐A primarily relied on instrumented DC‐8 and J‐31 aircraft platforms to achieve its objectives. The DC‐8 was equipped to measure detailed gas and aerosol composition and provided sufficient range and altitude capability to coordinate activities with distant partners and to sample the entire midlatitude troposphere. The J‐31 was specifically focused on radiative effects of clouds and aerosols and operated largely in the Gulf of Maine. Satellite products along with meteorological and 3‐D chemical transport model forecasts were integrated into the flight planning process. Intercomparisons were performed to quantify the accuracy of data and to create a unified data set. Satellite validation activities principally focused on Terra (MOPITT, MODIS, and MISR), Aqua (AIRS and MODIS) and Envisat (SCIAMACHY) to validate observations of CO, NO2, HCHO, H2O, and aerosol. Persistent fires in Alaska and NW Canada offered opportunities to quantify emissions from fires and study the transport and evolution of biomass burning plumes. Contrary to expectations, several pollution plumes of Asian origin, frequently mixed with stratospheric air, were sampled over NA. Quasi‐Lagrangian sampling was successfully carried out to study chemical aging of plumes during transport over the Atlantic. Lightning NOx source was found to be far larger than anticipated and provided a major source of error in model simulations. The composition of the upper troposphere was significantly perturbed by influences from surface pollution and lightning. Drawdown of CO2 was characterized over NA and its atmospheric abundance related to terrestrial sources and sinks. INTEX‐A observations provide a comprehensive data set to test models and evaluate major pathways of pollution transport over NA and the Atlantic. This overview provides a context within which the present and future INTEX‐A/ICARTT publications can be understood.
Abrupt wind regime changes in the North Atlantic Ocean during the past 30,000–60,000 years
Authors: López‐Martínez Constancia , Grimalt Joan O. , Hoogakker Babette , Gruetzner Jens , Vautravers Maryline J. , McCave I. Nicholas
Published: December 2006

The inputs of higher plants in Blake Outer Ridge (subtropical western North Atlantic) during marine isotope stage 3 (MIS3) have been recorded at high resolution by quantification of C23–C33 odd carbon numbered n‐alkanes and C20–C30 even carbon numbered n‐alkan‐1‐ols in sediment sections of Ocean Drilling Program Site 1060. The changes of these proxies at this open marine site are mainly related to eolian inputs. Their concentrations and fluxes exhibit major abrupt variations that are correlated with Dansgaard/Oeschger (D/O) patterns in Greenland ice cores. The ratios between interstadials and stadials range between 2 and 9 times. The intense flux increases in the D/O stadials are linked to strong enhancements of the westerly wind regime at these subtropical latitudes during stadials. The observed variation was paralleled by changes in wind‐blown dust and the polar circulation index in Greenland ice, which is in agreement with previously hypothesized atmospheric teleconnections between northern and middle‐low latitudes of the Northern Hemisphere. The close correspondence between sedimentary and ice core proxies is evidence that crossings of the glacial climate thresholds involved major reorganizations of the troposphere. The observed large rise in higher plant biomarkers indicates that climate stabilization in the D/O stadial conditions led to main increases in wind intensity.
Modelling and advanced understanding of unsteady‐state gas transfer in shaking bioreactors
Authors: Amoabediny Ghassem , Büchs Jochen
Published: December 2006

In shaken bioreactors equipped with a sterile closure (e.g. a cotton plug), a realistic understanding and estimation of gas transfer is advantageous to avoid oxygen limitation or carbon dioxide inhibition of a microbial culture. Therefore, in the present study, an unsteady‐state gas‐transfer model for shake flasks was developed and experimentally investigated for a wide range of gas‐transfer resistances (kplug). The introduced approach is based on the model of Henzler and co‐workers [Henzler and Schedel (1991) Bioprocess Eng. 7, 123–131; Mrotzek, Anderlei, Henzler and Büchs (2001) Biochem. Eng. J. 7, 107–112], which describe the spatially resolved gas partial pressures inside the sterile closure, affecting the local gas diffusion coefficients and convective Stefan flow. For further easy processing the resulting total mass‐transfer resistance (kplug) is described as a function of the mass flow through the sterile plug (OTRplug) by an empirical equation. This equation is introduced into a simulation model which calculates the gas partial pressures in the head space of the flask. Additionally, the gas‐transfer rates through the sterile closure and gas/liquid interface inside the flask is provided. Simulations indicate that neglecting the oxygen in the head space volume of the flask under initial conditions (simple steady‐state assumption) may lead to an underestimation of the oxygen transfer into the liquid phase. The extension of error depends on the conditions. A good agreement between the introduced unsteady‐state model and experimental results for the sulfite oxidation as a chemical model system confirmed the validity and usefulness of the proposed unsteady‐state approach.
Xenopus as a model to study alternative splicing in vivo
Authors: Méreau Agnes , Le Sommer Caroline , Lerivray Hubert , Lesimple Michelle , Hardy Serge
Published: December 2006

An increasing number of genes are being identified for which the corresponding mRNAs contain different combinations of the encoded exons. This highly regulated exon choice, or alternative splicing, is often tissue‐specific and potentially could differentially affect cellular functions. Alternative splicing is therefore not only a means to increase the coding capacity of the genome, but also to regulate gene expression during differentiation or development. To both evaluate the importance for cellular functions and define the regulatory pathways of alternative splicing, it is necessary to progress from the in vitro or ex vivo experimental models actually used towards in vivo whole‐animal studies. We present here the amphibian, Xenopus, as an experimental model highly amenable for such studies. The various experimental approaches that can be used with Xenopus oocytes and embryos to characterize regulatory sequence elements and factors are presented and the advantages and drawbacks of these approaches are discussed. Finally, the real possibilities for large‐scale identification of mRNAs containing alternatively spliced exons, the tissue‐specific patterns of exon usage and the way in which these patterns are modified by perturbing the relative amount of splicing factors are discussed.
Interface reactions and Kirkendall voids in metal organic vapor-phase epitaxy grown Cu(In,Ga)Se2 thin films on GaAs
Authors: Lei C. H. , Rockett A. A. , Robertson I. M. , Papathanasiou N. , Siebentritt S.
Published: December 2006

Cu ( In 1 − x Ga x ) Se 2 (CIGS) films were grown on (001) GaAs at 570 or 500°C by means of metal organic vapor-phase epitaxy. All films were Cu-rich [Cu∕(In+Ga)>1] with pseudomorphic Cu2Se second phase particles found only on the growth surface. During growth, diffusion of Ga from the substrate and vacancies generated by the formation of CIGS from Cu2Se at the surface occurred. The diffusion processes lead to the formation of Kirkendall voids at the GaAs/CIGS interface. Transmission electron microscopy and nanoprobe energy dispersive spectroscopy were used to analyze the diffusion and void formation processes. The diffusivity of Ga in CIGS was found to be relatively low. This is postulated to be due to a comparatively low concentration of point defects in the epitaxial films. A reaction model explaining the observed profiles and voids is proposed.
Time-of-arrival probabilities and quantum measurements
Authors: Anastopoulos Charis , Savvidou Ntina
Published: December 2006

In this paper we study the construction of probability densities for time of arrival in quantum mechanics. Our treatment is based upon the facts that (i) time appears in quantum theory as an external parameter to the system, and (ii) propositions about the time of arrival appear naturally when one considers histories. The definition of time-of-arrival probabilities is straightforward in stochastic processes. The difficulties that arise in quantum theory are due to the fact that the time parameter of the Schrödinger’s equation does not naturally define a probability density at the continuum limit, but also because the procedure one follows is sensitive on the interpretation of the reduction procedure. We consider the issue in Copenhagen quantum mechanics and in history-based schemes like consistent histories. The benefit of the latter is that it allows a proper passage to the continuous limit—there are, however, problems related to the quantum Zeno effect and decoherence. We finally employ the histories-based description to construct Positive-Operator-Valued-Measures (POVMs) for the time-of-arrival, which are valid for a general Hamiltonian. These POVMs typically depend on the resolution of the measurement device; for a free particle, however, this dependence cancels in the physically relevant regime and the POVM coincides with that of Kijowski.
Heterogeneous dynamics, ageing, and rejuvenating in van der Waals liquids
Authors: Merabia Samy , Long Didier
Published: December 2006

It has been shown over the past ten years that the dynamics close to the glass transition is strongly heterogeneous: fast domains coexist with domains three or four decades slower, the size of these regions being about 3nm at Tg. The authors extend here a model that has been proposed recently for the glass transition in van der Waals liquids. The authors describe in more details the mechanisms of the α relaxation in such liquids. It allows then to interpret physical ageing in van der Waals liquids as the evolution of the density fluctuation distribution towards the equilibrium one. The authors derive the expression of macroscopic quantities (volume, compliance, etc.). Numerical results are compared with experimental data (shape, times to reach equilibrium) for simple thermal histories (quenches, annealings). The authors explain the existence of a “Kovacs memory effect” and the temporal asymmetry between down jump and up jump temperatures experiments, even for systems for which there is no energy barriers. Their model allows also for calculating the evolution of small probe diffusion coefficients during ageing.
Multisample matrix-assisted laser desorption source for molecular beams of neutral peptides
Authors: Lupulescu C. , Abd El Rahim M. , Antoine R. , Barbaire M. , Broyer M. , Dagany X. , Maurelli J. , Rayane D. , Dugourd Ph.
Published: December 2006

We developed and tested a multisample laser desorption source for producing stable molecular beams of neutral peptides. Our apparatus is based on matrix-assisted laser desorption technique. The source consists of 96 different targets which may be scanned by a software control procedure. Examples of molecular beams of neutral peptides are presented, as well as the influence of the different source parameters on the jet.
Tuning of the magnetostrictive properties of CoFe2O4 by Mn substitution for Co
Authors: Bhame Shekhar D. , Joy P. A.
Published: December 2006

Marked changes in the magnetostriction of CoFe2O4 in the substitution of Mn for Co has been observed. The magnetostriction parallel to the applied field direction decreases with increasing Mn content, whereas the magnetostriction perpendicular to the field showed a marked increase for 10% of the Mn substitution. The observed magnetostrictive properties are correlated with the magnetic properties. The results suggest the possibility of tuning the magnetostrictive properties of cobalt ferrite for various applications by proper substitution.
Analytical coarse-grained description for polymer melts
Authors: Sambriski E. J. , Yatsenko G. , Nemirovskaya M. A. , Guenza M. G.
Published: December 2006

Starting from the Ornstein-Zernike equation the authors derive an analytical theory, at the level of pair correlation functions, which coarse grains polymer melts into liquids of interacting soft colloidal particles. Since it is analytical, the presented coarse-graining approach will be useful in developing multiscale modeling procedures to simulate complex fluids of macromolecules. The accuracy of the theory is tested by its capacity to reproduce the liquid structure, as given by the center-of-mass intermolecular total pair correlation function. The theory is found to agree well with the structure predicted by molecular dynamics simulations of the liquid described at the united atom level as well as by molecular dynamics simulations of the liquid of interacting colloidal particles. The authors perform simulations of the liquid of interacting colloidal particles having as input the potential obtained from their analytical total pair correlation function by enforcing the hypernetted-chain closure approximation. Tests systems are polyethylene melts of chains with increasing degrees of polymerization and polymer melts of chains with different chemical architectures. They also discuss the effect of adopting different conventional approximations for intra- and intermolecular monomer structure factors on the accuracy of the coarse-graining procedure, as well as the relevance of higher-order corrections to their expression.
Effect of Nd dopant on magnetic and electric properties of BiFeO3 thin films prepared by metal organic deposition method
Authors: Huang Fengzhen , Lu Xiaomei , Lin Weiwei , Wu Xiumei , Kan Yi , Zhu Jinsong
Published: December 2006

Polycrystalline Bi1−xNdxFeO3 (x=0–0.15) thin films were prepared on (111) Pt∕Ti∕SiO2∕Si substrates via metal organic deposition method. The effect of Nd dopant on the structural, electric, and magnetic properties was studied. It was found that the ferroelectric polarization and saturation magnetization of the films were enhanced by appropriate Nd doping due to the structural distortion and the suppressed cycloidal spin structure. Meanwhile, Nd-doped BiFeO3 thin films exhibited magnetic anisotropy because of the magnetocrystalline anisotropy.
Actuation of liquid crystal elastomers reprocessed with carbon nanoparticles
Authors: Chambers Martin , Zalar Boštjan , Remškar Maja , Žumer Slobodan , Finkelmann Heino
Published: December 2006

Liquid crystal elastomers are currently of great interest due to their large thermally stimulated changes in shape. Here the authors show that by using an existing network and conducting carbon nanoparticles dispersed in a solvent with high swelling capability, a surface integrated layer can be created. This layer allows the effective resistivity to be reduced from highly insulating to usable values for electrical actuation and withstands large changes in geometrical shape both in contraction and expansion. Utilizing a resistive “Joule” heating effect, the reprocessed system shows a 150% length change and can be cycled beyond 10kcycles.
Magnetoelectric gyration effect in Tb1−xDyxFe2−y∕Pb(Zr,Ti)O3 laminated composites at the electromechanical resonance
Authors: Dong Shuxiang , Zhai Junyi , Li J. F. , Viehland D. , Bichurin M. I.
Published: December 2006

A giant current-to-voltage (I-V) gyration effect was found in magnetostrictive Tb1−xDyxFe2−y and piezoelectric Pb(Zr,Ti)O3 laminated composites. An equivalent circuit theory was developed for magnetoelectric gyration, which predicted that I-V conversion is reduced by a frequency transfer function ZR(f) and that the maximum occurs at resonance. A giant conversion coefficient up to 2500V∕A was predicted and confirmed.
Double-layer resonant Brewster filters consisting of a homogeneous layer and a grating with equal refractive index
Authors: Wang Zhanshan , Sang Tian , Zhu Jingtao , Wang Li , Wu Yonggang , Chen Lingyan
Published: December 2006

In this letter, the double-layer resonant Brewster filters and their properties were presented, which consist of a homogenous layer with a refractive index equal to that of the grating. By tuning the thickness of the homogeneous layer, a multichannel resonant Brewster filter with thin grating thickness can be obtained. For this type of filters, the variety of the grating thickness almost did not change the resonance location, but had a distinct effect on the filter linewidth. By changing grating period or tuning incident angle, different linewidths can be obtained at the same resonance wavelength without losing the low-reflection sideband feature.
Optical properties of synthesized organic nanowires
Authors: Chen Yujie , Chen Xudong , Li Baojun , Yu Dingshan , He Zhiqiu , Li Guangji , Zhang Mingqiu
Published: December 2006

Organic nanowires have been synthesized by hydrothermal method. The functional groups in chemical structure of the organic nanowire have been characterized by Fourier-transform infrared spectrum. Optical properties of organic nanowires have been demonstrated by linear absorption, photoluminescence spectroscopy, and time-resolved photoluminescence spectroscopy. Two emission peaks at 3.91 and 3.3eV have been revealed by fluorescence spectrum at room temperature. For the emission peak at 3.3eV, a blueshift occurred when the temperature rises. Two time components have been observed in fluorescence dynamic process of the nanowire by time-resolved decay curve.
Resistance and sheet resistance measurements using electron beam induced current
Authors: Czerwinski A. , Płuska M. , Ratajczak J. , Szerling A. , Kątcki J.
Published: December 2006

A method for measurement of spatially uniform or nonuniform resistance in layers and strips, based on electron beam induced current (EBIC) technique, is described. High electron beam currents are used so that the overall resistance of the measurement circuit affects the EBIC signal. During the evaluation, the electron beam is scanned along the measured object, whose load resistance varies with the distance. The variation is compensated by an adjustable resistance within an external circuit. The method has been experimentally deployed for sheet resistance determination of buried regions of lateral confinements in semiconductor laser heterostructures manufactured by molecular beam epitaxy.
The American Treatment System for Adolescent Substance Abuse: Formidable Challenges, Fundamental Revisions, and Mechanisms for Improvements
Authors: Meyers Kathleen , McLellan A. Thomas
Published: December 2006

The purpose of this chapter is to discuss an additional complicating factor that impacts adolescent treatment and goes beyond the individual youth and his or her family: the service delivery system. These systems (e.g., educational institutions, health care, juvenile justice, and mental health systems) are complex environments that offer opportunities to identify, treat, and monitor adolescent substance abusers. However, the architecture and operating procedures of these systems often serve to inhibit access to needed services and to confuse or confound coordination of complementary service delivery across systems. The result can be formidable challenges to the identification and subsequent intervention and treatment of the adolescent who uses, abuses, or is dependent upon substances.

In the text that follows, we identify problems within the current “standard” system of care leading to failure to identify these adolescents, inadequate access to even basic substance abuse intervention for those identified, and failure to provide adequate amounts or types of services to those who do access the care system. We also present mechanisms for enhancements and conclude with a summary of three innovative approaches targeted to systems improvement.
The Role of Primary Care Physicians in Detection and Treatment of Adolescent Mental Health Problems
Authors: Romer Daniel , McIntosh Mary
Published: December 2006

This chapter presents research conducted as part of the Sunnylands Adolescent Mental Health Initiative (SAMHI) to determine primary care provider practices in identifying and referring adolescents for treatment of mental health problems.
No evidence of inbreeding avoidance in a polygynous ungulate: the reindeer (Rangifer tarandus)
Authors: Holand Øystein , Askim Kjartan R , Røed Knut H , Weladji Robert B , Gjøstein Hallvard , Nieminen Mauri
Published: December 2006

In polygynous species, mate choice is an integrated part of sexual selection. However, whether mate choice occurs independently of the genetic relatedness among mating pairs has received little attention, although inbreeding may have fitness consequences. We studied whether genetic relatedness influenced females' choice of partner in a highly polygynous ungulate—the reindeer (Rangifer tarandus)—in an experimental herd during two consecutive rutting seasons; the herd consisting of 75 females in 1999 and 74 females in 2000 was exposed to three 4.5-year-old adults and three 1.5-year-old young males, respectively. The females' distribution during peak rut was not influenced by their genetic relatedness with the dominant males of the mating groups. Further, genetic relatedness did not influence the actual choice of mating partner. We conclude that inbreeding avoidance through mating group choice as well as choice of mating partner, two interconnected processes of female mate choice operating at two different scales in space and time, in such a highly female-biased reindeer populations with low level of inbreeding may not occur.
Charles Scott Sherrington 1857-1952
Authors: Liddell Edward George Tandy
Published: December 2006

Charles Scott Sherrington was born on 27 November 1857 in Islington, where his mother was on a visit, and died at Eastbourne on 4 March 1952. For fifty-six years he was a considerable and influential contributor to knowledge of nervous reflex action and muscle management. His father was James Norton Sherrington of Caister, Great Yarmouth, who died when his children were small, there being two younger sons, both destined for the Law. After her first husband’s death the widow married Dr Caleb Rose of Ipswich. His stepfather’s influence was to extend all through Charles Sherrington’s life, for he was a good classical scholar and an archaeologist of note. The home at Edgehill House was a rendezvous for artists, the rooms being crammed with the works of David Cox, Cotman and others of the Norwich School. Many of them now hang in the Norwich Gallery. In later life, Charles was deeply appreciative of Vermeer. His interest in medicine doubtless came from his stepfather, and his mother made the home a true home in every aspect. As a schoolboy and in early life, Sherrington was an athlete of no mean order, playing soccer for his school, Ipswich Grammar School, to which he went in 1871. He played soccer for Ipswich Town, and in due time rugger for St Thomas’s Hospital and for Caius, and also rowed for his college. His vigorous game in the Caius scrum was long remembered by his contemporaries and he was made to admit, in after years, that he ought to have played half-back if only his eyesight had been better. At St Thomas’s, ‘We used to play football, rugby it was, on the Archbishop’s ground near the hospital, but it was very wet and rather dangerous’. Later on and until his marriage he was a pioneer of winter sports at Grindelwald. At Ipswich School, Thomas Ashe was a great inspiration to Sherrington and gave him a love of classics and the urge to travel. The headmaster at the time was H. A. Holden, editor of
Aristophanes
. Sherrington passed his preliminary examination in General Education at the Royal College of Surgeons of England in June 1875.
Frederick George Donnan, 1870-1956
Authors: Freeth Francis Arthur
Published: December 2006

This biography is compiled from the Personal Record which Donnan left with the Royal Society, the assistance of numerous pupils and friends, and from the recollections of the writer extending over a long period. Donnan was born on 5 September 1870 at Colombo, Ceylon, and was the second of a family consisting of two brothers and four sisters. His father was William Donnan, a merchant of Belfast, and his mother’s maiden name was Jane Ross Turnley Liggate she also being a native of Northern Ireland. Donnan’s uncle, Captain James Donnan, was ‘master attendant’, Colombo and Inspector of the Ceylon Pearl Fisheries, who received a C.M.G. on his retirement; his son, Donnan’s cousin, was a regular soldier who spent most of his life in India, retiring with the rank of Colonel in 1913, rejoining the Army in 1914, and dying of heat stroke in Mesopotamia. Donnan’s brother, William Dunlop Donnan, was a general medical practitioner (M.D. of the Queens University) of Belfast till his death in 1941. Donnan returning from Ceylon at the age of 3 had no recollections of that country at all and this must be considered in making any appreciation of him as a devoted Ulster patriot. Donnan was a bachelor, so particular and generous mention must be made of his two sisters Jane and Leonora (Nora) who played such an important and unobtrusive part in his life. Jane was his secretary at University College and later looked after the I.C.I. Research Associates working there; after his retirement she carried on with his correspondence. In these later years her eyesight began to fail and steadily worsened. She died only three days before her brother and they were cremated on the same day. On duty she was most intelligent and efficient and in private life had all the family charm.
Arthur George Tansley, 1871-1955
Authors: Godwin Harry
Published: December 2006

When he died in 1955 Sir Arthur Tansley had fortunately acceded to a standing request from the Council of the Royal Society for biographical information and in 1953 had supplied them with a typescript of what he called ‘factual biographical notes’. These were in fact a good deal better than ‘notes’, for they are carefully composed and constitute an excellent example of his own delightfully lucid and almost laconic style of writing. Since moreover that part of them which concerns his earliest school and university career is nearly unavailable from other directions, and contains his own characteristically objective comments upon the teachers and scientists of those days, it has seemed appropriate to derive this biography, up to the turn of the century and Tansley’s migration to Cambridge in 1906, almost directly from his own notes. This is signified below by the quotation marks and the concluding bracketed initials (A.G.T.). ‘Tansley was born on 15 August 1871, at 33 Regent Square, W.C., the only son of George Tansley and his wife, Amelia Lawrence. He had one sister, seven years older than himself. ‘[His father] was opposed to Arthur’s engaging in business, and very anxious that he should go to one of the old universities, for which George had the deepest respect and admiration. Arthur showed scientific leanings, especially towards botany, which had been stimulated by a member of the Working Men’s College—a wood turner by trade—who was an excellent and enthusiastic field botanist. From the age of 12 to 15 (1883-6) Arthur was at a preparatory school at Worthing where two successive masters were keen field naturalists, and their example fostered his attraction to field botany.
Guy Anstruther Knox Marshall, 1871-1959
Authors: Thompson William Robin
Published: December 2006

In his great ‘History of applied entomology’, published in 1930, Dr L. O. Howard, for many years the most distinguished leader in this field, remarks on the apparent inability of academic men to realize the scientific interest of entomological studies having any practical significance. This attitude, he suggests, is indicated clearly enough by the failure of the great scientific academies in various countries to elect economic entomologists, as such, to their fellowships. He points out that although Antonio Berlese and Filippa Silvestri in Italy were early elected to the Academy of the Lincei and Paul Marchal in France to the Academy of Sciences, this was due to their achievements in pure entomology, that is, as a branch of zoology. Dr Howard himself was not elected to the American National Academy until his 59th year. ‘I have a suspicion’, he adds, ‘that, if it had been thoroughly understood by the members of the academy that he’ (the writer) ‘was so pronouncedly utilitarian in his work and his views, he might have failed.’ This attitude has not greatly changed. It may even be said, that from the standpoint of the entomologist, it has changed rather for the worse. There was a time when the great Academies looked with interest on the work of the entomological taxonomists on which the whole structure of entomological science is erected. They are still interested in investigators who use insects as material in genetics, physiology or biochemistry; but they are, in general, little interested in the entomologist who devotes himself to insects as insects. Perhaps this attitude has not notably impeded the advance of entomology; but it does tend to separate the Academies in a rather regrettable way from one of the main currents of biological work in which their influence would be beneficial and from which they themselves might draw some useful lessons. It is therefore a pleasure to record that the Royal Society of London, by its election of Guy Marshall as a Fellow, in 1923, recognized the important part he had already played in the development of applied entomology in the Commonwealth and thus provided him, during the many years of active work that were to follow, with the strong backing the Fellowship of the Society carries. I suspect that the arguments for Marshall’s election were drawn from his research in pure entomology and had to do chiefly with his experiments in relation to the theory of mimicry; but I do not wish to stress this point, preferring for once to say, that the end justified the means.
William Hobson Mills, 1873-1959
Authors: Mann Frederick George , Maitland Peter
Published: December 2006

Although William Hobson Mills was born in London, on 6 July 1873, he was fundamentally a Lincolnshire man. His father, William Henry Mills, was an architect, whose biography is given inLincolnshire Leaders(p. 109), by C. A. Manning Press (Jarrolds 1894), and his mother, of maiden name Emily Wiles Quincey Hobson, was the daughter of William Hobson, the owner of one of the chief business houses in Spalding in Lincolnshire. Moreover, Mills’s parents moved to Spalding in the autumn of 1873, so that he became a Lincolnshire man in every respect other than that of his birthplace. Mills was educated first at Spalding Grammar School and then at Uppingham School. It was at Uppingham in the winter of 1890 that he had an accident whilst tobogganing in the snow, severing an Achilles tendon. Mills remarks in some brief biographical notes that this injury ‘limited his outdoor activities’: this was certainly true during his youth, but those who first met him in his middle age and found how vigorously he cycled and walked in his visits to the fens in search of plants and birds, would scarcely have realized that he suffered any handicap. He entered Jesus College, Cambridge, in October 1892 and read natural sciences. The injury to his foot, however, caused him to remain at home for the academic year 1893-1894. He returned to Cambridge in October 1894, and obtained a First Class in the Natural Sciences Tripos, Part I, in 1896, and in Part II (Chemistry) in 1897.