bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic force and scanning electron microscopy of atmospheric particles
Authors: Barkay Zahava , Teller Amit , Ganor Eliezer , Levin Zev , Shapira Yoram 
Published: October 2005

AbstractAtomic force microscopy (AFM) and scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS) have been used for both morphological and elemental mass analysis study of atmospheric particles. As part of the geometrical particle analysis, and in addition to the traditional height profile measurement of individual particles, AFM was used to measure the volume relative to the projection area for each particle separately, providing a particle shape model. The element identification was done by the EDS analysis, and the element mass content was calculated based on laboratory calibration with particles of known composition. The SEM–EDS mass measurements from two samples collected at 150 and 500 m above the surface of the Mediterranean Sea were found to be similar to mass calculations derived from the AFM volume measurements. The AFM results show that the volume of most of the aerosols that were identified as soluble marine sulfate and nitrate aerosol particles can be better estimated using cylindrical shapes than spherical or conical geometry. Microsc. Res. Tech. 68:107–114, 2005. © 2005 Wiley‐Liss, Inc.
A method for finding the station where climatic trends are most representative for a region
Authors: Huth Radan 
Published: October 2005

AbstractA method is proposed to identify the station where trends in several climatic elements are most representative for a whole region. It is based on principal component analysis of trend magnitudes. The most representative is the station at which the distance of principal component scores from zero is the smallest. The method is applied to seasonal and annual means of 10 climatic elements at 20 stations in the Czech Republic. It succeeds in finding stations outlying because of their inhomogeneity or mountain‐summit position. The degree of representativeness of stations varies considerably among seasons. The trends in individual climatic elements at the most representative station are usually close to the trends in the spatial mean, but on some occasions, they considerably differ from each other. Copyright © 2005 Royal Meteorological Society.
Structural characterization of blends containing both PVDF and natural rubber latex
Authors: Simoes R. D. , Job A. E. , Chinaglia D. L. , Zucolotto V. , Camargo‐Filho J. C. , Alves N. , Giacometti J. A. , Oliveira O. N. , Constantino C. J. L. 
Published: October 2005

AbstractFilms containing different volumes of latex of natural rubber (NR) in a fixed mass of poly (vinylidene fluoride) (PVDF) powder were fabricated by compressing under annealing a mixture of both materials without using any solvent. This is an important issue keeping in mind that these films have to be used in the future as biomaterials in different applications once the solvents that are used to dissolve the PVDF become toxic to human. The films with different percentage of latex in PVDF were characterized using micro‐Raman scattering and Fourier transform infrared absorption (FTIR) spectroscopies, thermomechanical techniques using thermogravimetry (TG), differential scanning calorimetry (DSC), dynamical‐mechanical analysis (DMA) and scanning electron microscopy (SEM). The results showed that the latex of NR and PVDF do not interact chemically, leading to the formation of a polymeric blend with high thermal stability and mechanical properties suitable for applications involving bone (prostheses, for instance). Besides, the results recorded using the micro‐Raman technique revealed that for a fixed amount of PVDF the higher the amount of latex in the blend, the better the miscibility between both materials. Copyright © 2005 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering (SERS) of random silver or gold particle arrays on aminodextran‐coated polystyrene beads
Authors: Siiman Olavi , Ledis Stephen 
Published: October 2005

AbstractCitrate and/or chemically modified aminodextran (Amdex) SERS bands were detected from silver particle‐Amdex‐polystyrene (PS) beads either as singlets or small clusters, prepared by reaction between aqueous silver nitrate, Amdex‐coated PS beads, and aqueous sodium citrate solution. However, citrate on individual silver or gold particles of the same size was not detected with 633‐nm excitation. SERS of dyes such as rhodamine 6 G was readily observed on individual silver particles or on the gold beads. Three distinct modes of citrate/modified‐Amdex binding to the silver particle‐Amdex‐PS beads were characterized: (1) exchangeable citrate bound through one or more carboxylate groups—citrate could be washed away with H2O or D2O; displaced by successively greater concentrations of R6G; or squeezed out mechanically by applying the pressure of a second coverslip on top of a droplet of bead suspension; (2) nonexchangeable Amdex bound to silver via a primary alcoholate ion of oxidized, glutaraldehyde‐cross‐linked Amdex; and (3) nonexchangeable oxidized Amdex bound to silver via carboxylate group(s) but with H/D exchangeable alcohol hydrogen atom. That oxidation of the glucopyranose residues of Amdex on PS beads had taken place by Ag(I) as silver nitrate in aqueous solution to split out carboxylate groups was first identified from their characteristic vibrational modes in the SERS spectra of colloidal silver suspensions. Minimum amplification factors for (R6G on Ag)/(R6G on Au) with 633‐nm excitation were estimated as 1 × 1015/1 × 1011. An extra SERS enhancement of about 1000‐fold due to multiplicity of metal particles per bead was included. Copyright © 2005 John Wiley & Sons, Ltd.
Gold‐polymer nanocomposites: studies of their optical properties and their potential as SERS substrates
Authors: Giesfeldt Kathleen S. , Connatser R. Maggie , De Jesús Marco A. , Dutta Pampa , Sepaniak Michael J. 
Published: October 2005

AbstractPolymer‐nanometallic‐particle composites have demonstrated technological potential owing to their unique optical and electrical properties. In this article, we report on composites prepared via physical vapor deposition of gold metal onto pliable polydimethylsiloxane (PDMS) polymer. Rapid Au diffusion and nanometallic‐particle formation in a phase‐separated surface layer of the PDMS creates unique tunable sub‐surface‐based composites. The rate of deposition and average Au thickness can be manipulated to tune the optical properties, which are studied by visible wavelength optical extinction spectrometry and surface‐enhanced Raman scattering (SERS). DC conductivity measurements were made during Au deposition to study percolation conditions for the materials and depth profiling was performed by X‐ray photoelectron spectrometry (XPS). This work presents the use of Au‐PDMS nanocomposites in combination with a sample translation technique (STT) for the improved SERS qualitative and quantitative analysis. This translation approach considerably improves the reproducibility and the sensitivity of the technique by minimizing the thermal and photolytic effects inherent in SERS. The Au‐PDMS nanocomposites exhibit an affinity for amine and nitro‐based compounds that are biologically relevant and point toward the potential for being used as substrates for biologically based SERS experiments. Sample Raman spectra with the nanocomposite under STT‐SERS conditions are included. Copyright © 2005 John Wiley & Sons, Ltd.
Accessing Chain Length Dependent Termination Rate Coefficients of Methyl Methacrylate (MMA) via the Reversible Addition Fragmentation Chain Transfer (RAFT) Process
Authors: Johnston‐Hall Geoffrey , Theis Alexander , Monteiro Michael J. , Davis Thomas P. , Stenzel Martina H. , Barner‐Kowollik Christopher 
Published: October 2005

AbstractSummary: The RAFT‐CLD‐T methodology is demonstrated to be not only applicable to 1‐substituted monomers such as styrene and acrylates, but also to 1,1‐disubstituted monomers such as MMA. The chain length of the terminating macromolecules is controlled by CPDB in MMA bulk free radical polymerization at 80 °C. The evolution of the chain length dependent termination rate coefficient, k, was constructed in a step‐wise fashion, since the MMA/CPDB system displays hybrid behavior (between conventional and living free radical polymerization) resulting in initial high molecular weight polymers formed at low RAFT agent concentrations. The obtained CLD of kt in MMA polymerizations is compatible with the composite model for chain length dependent termination. For the initial chain‐length regime, up to a degree of polymerization of 100, kt decreases with α (in the expression k = k · i−α) being close to 0.65 at 80 °C. At chain lengths exceeding 100, the decrease is less pronounced (affording an α of 0.15 at 80 °C). However, the data are best represented by a continuously decreasing non‐linear functionality implying a chain length dependent α.
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Qigong exercise for the symptoms of Parkinson's disease: A randomized, controlled pilot study
Authors: Schmitz‐Hübsch Tanya , Pyfer Derek , Kielwein Karin , Fimmers Rolf , Klockgether Thomas , Wüllner Ullrich 
Published: October 2005

AbstractIrrespective of limited evidence, not only traditional physiotherapy, but also a wide array of complementary methods are applied by patients with Parkinson's disease (PD). We evaluated the immediate and sustained effects of Qigong on motor and nonmotor symptoms of PD, using an add‐on design. Fifty‐six patients with different levels of disease severity (mean age/standard deviation [SD], 63.8/7.5 years; disease duration 5.8/4.2 years; 43 men [76%]) were recruited from the outpatient movement disorder clinic of the Department of Neurology, University of Bonn. We compared the progression of motor symptoms assessed by Unified Parkinson's Disease Rating Scale motor part (UPDRS‐III) in the Qigong treatment group (n = 32) and a control group receiving no additional intervention (n = 24). Qigong exercises were applied as 90‐minute weekly group instructions for 2 months, followed by a 2 months pause and a second 2‐month treatment period. Assessments were carried out at baseline, 3, 6, and 12 months. More patients improved in the Qigong group than in the control group at 3 and 6 months (P = 0.0080 at 3 months and P = 0.0503 at 6 months; Fisher's exact test). At 12 months, there was a sustained difference between groups only when changes in UPDRS‐III were related to baseline. Depression scores decreased in both groups, whereas the incidence of several nonmotor symptoms decreased in the treatment group only. © 2005 Movement Disorder Society
Anticholinesterase effect on motor kinematic measures and brain activation in Parkinson's disease
Authors: Mentis Marc J. , Delalot Dominique , Naqvi Hassan , Gordon Mark F. , Gudesblatt Mark , Edwards Christine , Donatelli Luke , Dhawan Vijay , Eidelberg David 
Published: October 2005

AbstractAnticholinesterase (AChE) drugs are being prescribed off label for nonmotor symptoms in Parkinson's disease (PD). Theoretically, these drugs can impair motor function. A small literature suggests AChE therapy has little effect on clinical motor evaluation; however, no study has made objective motor kinematic measures or evaluated brain function. We hypothesized that even if clinical examination was normal in PD patients on dopamine therapy, (1) sensitive kinematic measures would be abnormal during AChE therapy or (2) normal kinematic measures would be maintained by compensatory brain activation. We carried out a randomized, double‐blind, placebo‐controlled trial of 8 weeks donepezil (10 mg/day) in 17 PD subjects. Subjects carried out a computerized motor task during a positron emission tomography (PET) scan before starting the drug and again after 8 weeks of donepezil or placebo. Kinematic measures of motor function and PET scans were analyzed to compare the effects of donepezil and placebo. Neither placebo nor donepezil altered motor kinematic measures. Furthermore, movement integrity while on donepezil was maintained without compensatory brain activity. Donepezil 10 mg/day can be given for nonmotor symptoms in PD without adverse motor effects or compensatory brain activity. © 2005 Movement Disorder Society
REM sleep behavior disorder, hallucinations, and cognitive impairment in Parkinson's disease
Authors: Sinforiani Elena , Zangaglia Roberta , Manni Raffaele , Cristina Silvano , Marchioni Enrico , Nappi Giuseppe , Mancini Francesca , Pacchetti Claudio 
Published: October 2005

AbstractThe objective of this study was to evaluate the relationship between REM sleep behavior disorder (RBD), hallucinations, and cognitive impairment in Parkinson's disease (PD). One hundred and ten PD patients, divided into three groups (without RBD or hallucinations; with RBD but no hallucinations; with RBD and hallucinations), were submitted to neuropsychological evaluation. The group without RBD and hallucinations showed normal neuropsychological tests when compared to normal controls. The group with hallucinations was characterized by a more severe cognitive impairment affecting both short‐ and long‐term memory, logical abilities, and frontal functions, while the RBD‐only group presented frontal impairment. The hypothesis that RBD in PD can be considered a risk factor not only of the hallucinations but also of more severe and diffuse cognitive abnormalities needs to be strengthened through a longitudinal evaluation. © 2005 Movement Disorder Society
On the ‘one and one‐half dimensional’ relativistic Vlasov–Maxwell system
Authors: Glassey Robert , Schaeffer Jack 
Published: October 2005

AbstractThe time evolution of a collisionless plasma is studied in the case when the Viasov density ƒ is a function of the time, one space variable and two velocity variables. The electromagnetic fields E, B also have a special structure, and the magnetic field B is non‐trivial. It is shown that smooth, consistent initial values generate a uniquc smooth global solution.
An improved boundary element method for the charge density of a thin electrified plate in ℝ3
Authors: Ervin V. J. , Stephan E. P. , El‐Seoud S. Abou 
Published: October 2005

AbstractA weakly singular integral equation of the first kind on a plane surface piece Γ is solved approximately via the Galerkin method. The determination of the solution of this integral equation (with the single‐layer potential) is a classical problem in physics, since its solution represents the charge density of a thin, electrified plate Γ loaded with some given potential. Using piecewise constant or piecewise bilinear boundary elements we derive asymptotic estimates for the Galerkin error in the energy norm and analyse the effect of graded meshes. Estimates in lower order Sobolev norms are obtained via the Aubin–Nitsche trick. We describe in detail the numerical implementation of the Galerkin method with both piecewise‐constant and piecewise‐linear boundary elements. Numerical experiments show experimental rates of convergence that confirm our theoretical, asymptotic results.
An asymptotic‐numerical approach to the coronal loop problem
Authors: Verhulst F. , Zegeling P. A. 
Published: October 2005

AbstractThe coronal loop problem is characterized by mixed boundary conditions and the loop length condition, which is global. Using singular perturbation methods one can identify and construct two boundary layers at the base of the loop.Extending this to a combined asymptotic‐numerical treatment it is possible to construct two static solutions satisfying the same conditions; this unusual feature arises from the presence of the first boundary layer, which corresponds with a steep temperature gradient and an energy balance dominated by conduction and radiation losses.
The transient behaviour of multidimensional PN‐diodes in low injection
Authors: Schmeiser Christian , Unterreiter Andreas 
Published: October 2005

AbstractAn initial boundary value problem modelling the transient behaviour of a pn‐junction semiconductor diode is simplified by formal asymptotics, where the scaled minimal Debye length and the scaled intrinsic number are considered as small parameters. The implicit assumption on the biasing situation is that of low injection. The simplified model is shown to be equivalent to an integral relation between the evolution of the current and of the contact voltage. A simple switching application is governed by a non‐linear Volterra integral equation for the current. This equation is shown to possess a unique solution globally in time converging to the unique steady state.
Non‐linear parabolic problem associated with the penetration of a magnetic field into a substance
Authors: Long Nguyen Thanh , Alain Pham Ngoc Dinh 
Published: October 2005

AbstractWe study the following initial and boundary value problem:
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In section 1, with u0 in L2(Ω), f continuous such that f(u) + ϵ non‐decreasing for ϵ positive, we prove the existence of a unique solution on (0,T), for each T > 0. In section 2 it is proved that the unique soluition u belongs to L2(0, T; H ∩ H2) ∩ L∞(0, T; H) if we assume u0 in H and f in C1(ℝ,ℝ). Numerical results are given for these two cases.
Modelling of dynamic networks of thin elastic plates
Authors: Lagnese J. E. , Leugering G. 
Published: October 2005

AbstractThe purpose of this paper is to derive junction conditions for networks of thin elastic plates and to analyse the dynamic equations of such networks. Junction conditions for networks of Kirchhoff plates and networks of Reissner–Mindlin plates are derived based on geometric considerations of the deformation at a junction. It is proved that the dynamic system which describes the Reissner–Mindlin network is well‐posed is an appropriate energy space. It is further established that the Kirchhoff network is obtained in the limit of the Reissner–Mindlin network as the shear moduli go to infinity.
A normal crack in an elastic half‐space with stress‐free surface
Authors: Martin P. A. , Päivärinta L. , Rempel S. 
Published: October 2005

AbstractThe problem of an elastic half‐space with stress‐free surface and a crack of arbitrary shape with prescribed displacements or tractions is reduced to an equivalent system of integral equations on the crack. For a pressurized crack in a plane perpendicular to the free surface, a scalar integral equation is derived. In properly chosen function spaces, unique solvability of the integral equation and regularity of solutions for regular data are proven.
Classical solutions of two‐dimensional stokes problems on non‐smooth domains. Part 1: The radon integral operators
Authors: Lubuma Jean Mbaro‐Saman 
Published: October 2005

AbstractThe applicability of the Neumann indirect method of potentials to the Dirichlet and Neumann problems for the two‐dimensional Stokes operator on a non‐smooth boundary Γ is subject to two kinds of sufficient and/or necessary conditions on Γ. The first one, occurring in electrostatic, is equivalent to the boundedness onC(Γ) of the velocity double‐layer potentialWas well as to the existence of jump relations of potentials. The second condition, which forces Γ to be a simple rectifiable curve and which, compared to the Laplacian, is a stronger restriction on the corners of Γ, states that the Fredholm radius ofWis greater than 2. Under these conditions, the Radon boundary integral equations defined by the above‐mentioned jump relations are solvable by the Fredholm theory; the double‐ (for Dirichlet) and the single‐ (for Neumann) layer potentials corresponding to their solutions are classical solutions of the Stokes problems.
An Lq‐theory for weak solutions of the stokes system in exterior domains
Authors: Farwig R. , Simader C. G. , Sohr H. 
Published: October 2005

AbstractWe introduce a new concept for weak solutions in Lq‐spaces, 1 < q < ∞, of the Stokes system in an exterior domain Ω ⊂ ℝn, n ⩾ 2. Defining the variational formulation in the homogeneous Sobolev space \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop H\limits^.{_{0}}^{1,q} (\Omega )^n = \{ u \in L_{1{\rm oc}}^q (\overline \Omega )^n;\nabla u \in L^q (\Omega )^{n^2 },u\left| {_{\partial \Omega } = 0} \right.\},$\end{document} we prove existence and uniqueness of weak solutions for an arbitrary external force and a prescribed divergence g = div u. On the other hand, solutions in the sense of distributions which are defined by taking test functions only in C(Ω)n are not unique if q > n/(n−1). In this case, a hidden boundary condition related to the force exerted on the body may be imposed to single out a unique solution.
The existence of solutions of a general boundary value problem for the divergence
Authors: Schwarz G. 
Published: October 2005

AbstractThis paper is concerned with the question of necessary and sufficient conditions to find a vector field V∈ Γ(TM) solving the equation div V = Φ under inhomogeneous boundary conditions V|∂M = Z|∂M with Z∈ Γ (TM) An existence and regularity result is given for an arbitrary Riemannian manifold with boundary, M. The proof is based on the Hodge theory of differential forms.
Bifurcations of strongly non‐linear self‐excited oscillations
Authors: Doelman Arjen , Verhulst Ferdinand 
Published: October 2005

AbstractPerturbation of a single‐degree‐of‐freedom conservative oscillator leads to the emergence and vanishing of periodic solutions and to various types of self‐excited oscillations. Using techniques from dynamical systems theory, in particular a certain Poincaré map, we establish the presence of Hopf bifurcations, various types of homoclinic bifurcations and saddle‐node bifurcations of the associated Poincaré map. The corresponding bifurcation sets in parameter space are computed explicitly by perturbation methods. The theory is applied to the generalized van der Pol and the generalized Rayleigh oscillator, and to the case of a non‐linear spring attached to a conveyor belt.
An elementary proof of the exponential blow‐up for semi‐linear wave equations
Authors: Takamura Hiroyuki 
Published: October 2005

AbstractThis paper deals with the upper bound of the life span of classical solutions to □u = ∣u∣p, u∣t = 0 = εφ(x), ut∣t=0 = εψ(x) with the critical power of p in two or three space dimensions. Zhou has proved that the rate of the upper bound of this life span is exp(ε−p(p−1)). But his proof, especially the two‐dimensional case, requires many properties of special functions. Here we shall give simple proofs in each space dimension which are produced by pointwise estimates of the fundamental solution of □. We claim that both proofs are done in almost the same way.
Global existence, uniqueness and asymptotic behaviour of solutions of the Wigner–Poisson and Schrödinger‐Poisson systems
Authors: Illner Reinhard , Zweifel Paul F. , Lange Horst 
Published: October 2005

AbstractWe prove global existence and uniqueness of classical solutions of the Wigner–Poisson and Schrödinger–Poisson systems of equations for both repulsive and attractive potentials. In the repulsive case, we prove decay estimates for the particle density, the potential and the solutions.
Stability and instability in adiabatic shearing motions of incompressible fluids
Authors: Jiang Song 
Published: October 2005

AbstractWe investigate the effect of temperature dependence of the viscosity on the stability of the adiabatic shearing flows of an incompressible Newtonian viscous fluid between two parallel plates. When the viscosity strongly decreases with temperature, the shearing flow caused by a steady motion of the upper plate (steady shearing) becomes unstable, while the shearing flow caused by a time‐dependent body force is found to be stable.