bluuebunny/crossref_metadata_2025_split huggingface dataset:
A second‐order accurate difference scheme for the two‐dimensional Burgers' system
Authors: Xu Pei‐Pei , Sun Zhi‐Zhong 
Published: March 2008

AbstractIn this article, a Crank‐Nicolson‐type finite difference scheme for the two‐dimensional Burgers' system is presented. The existence of the difference solution is shown by Brouwer fixed‐point theorem. The uniqueness of the difference solution and the stability and L2 convergence of the difference scheme are proved by energy method. An iterative algorithm for the difference scheme is given in detail. Furthermore, a linear predictor–corrector method is presented. The numerical results show that the predictor–corrector method is also convergent with the convergence order of two in both time and space. At last, some comments are provided for the backward Euler scheme. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
The method of fundamental solutions with eigenfunctions expansion method for 3D nonhomogeneous diffusion equations
Authors: Young D.L. , Chen C.H. , Fan C.M. , Shen L.H. 
Published: March 2008

AbstractAfter the successful applications of the combination of the method of fundamental solutions (MFS), the method of particular solutions (MPS), and the eigenfunctions expansion method (EEM) to solve 2D homogeneous and nonhomogeneous diffusion equations by Young et al. (Young et al., Numer Meth Part Differ Equat 22 (2006), 1173), this article intends to extend the same fundamental concepts to calculate more challenging 3D nonhomogeneous diffusion equations. The nonhomogeneous diffusion equations with time‐independent source terms and boundary conditions are analyzed by the proposed meshless MFS‐MPS‐EEM model. Nonhomogeneous diffusion equation in any complex domains can be decomposed into a Poisson equation and a homogeneous diffusion equation by the principle of linear superposition. This approach is proved to be far better off than solutions by using classic method of separation of variables with inefficient multisummation of very sophisticated series expansion from special functions, which can only limit to treat very simple 3D geometries such as cube, cylinder, or sphere. Poisson equation is solved by using the MPS‐MFS model, in which the source term in the Poisson equation is first handled by the MPS based on the compactly‐supported radial basis functions and the Laplace equation is solved by the MFS. On the other hand, by utilizing the EEM, the homogeneous diffusion equation is first transformed into a Helmholtz equation, which is then solved by the MFS together with the technique of singular value decomposition (SVD) to acquire the eigenvalues and eigenfunctions. After the eigenfunctions are obtained, we can synthesize the diffusion solutions like the orthogonal Fourier series expansions but with only one summation for the series even for multidimensional problems. Numerical results for four case studies of 3D homogeneous and nonhomogeneous diffusion problems show good agreement with the analytical and other numerical solutions, such as finite element method (FEM). Thus, the present numerical scheme has provided a promising meshfree numerical approach to solve 3D nonhomogeneous diffusion equations with time‐independent source terms and boundary conditions for very irregular domains. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Most low‐level microsatellite instability in colorectal cancers can be explained without an elevated slippage rate
Authors: Graham T , Halford S , Page KM , Tomlinson IPM 
Published: March 2008

AbstractMany cancers show a low level of microsatellite slippage and are labelled MSI‐L (microsatellite instability—low). However, it is unclear whether this slippage can be attributed to some underlying genetic change that results in a mutator phenotype, analogous to mismatch repair deficiency in MSI‐H cancers, or whether the apparent instability is the result of relatively frequent normal somatic slippage. Here, we have used a mathematical model of microsatellite slippage during cancer growth to estimate the degree of microsatellite slippage expected in a cancer due to normal somatic slippage. We compared the model to the slippage observed in 42 non‐MSI‐H cancers that were macro‐dissected into four distinct regions and genotyped at N = 9 microsatellite loci. When the slippage rate was set at µ = 10−5 per locus per division, ten cancers showed a level of slippage in at least one region that was too severe to be expected from normal somatic slippage alone, suggesting that these cancers had acquired MSI‐L. Only one of these ten cancers had putative MSI‐L in all four regions. When we considered a slightly higher slippage rate of µ = 5 × 10−5, none of the cancers showed a degree of slippage that could not be reasonably explained by normal somatic slippage. Counting the number of ‘unstable’ loci was a poor indicator of putative MSI‐L status. We conclude that most low‐level microsatellite instability in colorectal cancers can be explained without requiring an elevated slippage rate during neoplastic development, and hence there is little evidence for a discrete MSI‐L group of cancers. Putative MSI‐L status is indicated by the presence of at least one locus that has multiple alleles that differ by at least five motif repeats from the germline. If an underlying genetic change does cause MSI‐L, it appears to be a relatively uncommon event that occurs late in oncogenesis. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Experimental characterization of the impact‐damage tolerance of a cross‐ply graphite‐fiber/epoxy laminate
Authors: Wu Xiang‐Fa , Ghoshal Goutam , Kartashov Mikhail , Aslan Zuleyha , Turner Joseph A. , Dzenis Yuris A. 
Published: March 2008

AbstractIn this study, the impact‐damage tolerance of a graphite‐fiber/epoxy composite laminate is studied by examining the correlation between the impact force and the resulting delamination area in the laminate. The cross‐ply [02/902/02]s composite laminate was made of thermosetting P7051S‐20Q‐1000 prepregs (Toray Composites America). A Hopkinson pressure bar (HPB) was employed to create the impulsive loading with varying magnitude. Transient impact force, displacement, impact power, and transmitted impact energy were calculated using the transient signals recorded from the strain gage mounted on the HPB. Impulsive loads with controllable magnitude were used to induce delamination damage with varying size in the composite samples. Nondestructive evaluation based on a novel ultrasonic pulse‐echo reflector technique was used successfully for characterizing the delamination areas in the thin composite samples with thickness ∼2 mm. The present experimental results indicate that there exists a very good linear correlation between the impact force (e.g. the peak force, impact impulse, peak impact power, and the transmitted impact energy of the first impact force pulse exerted by the HPB) and the delamination area of the composite samples. This correlation can be used to determine the threshold of the impact force that initiates the delamination damage in the composite laminate. In contrast to the weight‐drop test, the present experimental method successfully examined the impact damage tolerance of polymer matrix composites (PMCs) subjected to impulsive loading with very high force magnitude and ultra short duration such as the typical ballistic impact. The present method and results can be used for the study of impact damage tolerance of PMCs with varying lay‐ups and interface modifications. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Effect of Attapulgite filler on the properties of Nylon‐6
Authors: Subramani Chandramouleeswaran , Jamnik Vijay S. , Mhaske S.T. 
Published: March 2008

AbstractNylon‐6/Attapulgite (ATP) composites were prepared by melt blending in a twin screw extruder. Nylon‐6/ATP composites were tested for its mechanical, rheological, thermal and morphological properties. The results have shown drastic improvement in the flexural modulus by 74% at the loading level of 4% of ATP. The tensile strength was also increased at the 3–4% loadings of ATP. The impact strength was doubled even at the 2% loading of ATP. The strength and stiffness of Nylon‐6/ATP composites were both improved significantly in the presence of attapulgite. In addition, the incorporation of ATP gave rise to the increase in the storage modulus. The extensional viscosities were studied and found to increase as the loading level was increased. Scanning electron microscopy (SEM) was used to assess the clay morphology and the dispersion of the attapulgite. SEM revealed the addition of attapulgite showed fibrillar structure of Nylon‐6/ATP composite. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Preparation of a xanthate‐terminated dextran by click chemistry: Application to the synthesis of polysaccharide‐coated nanoparticles via surfactant‐free ab initio emulsion polymerization of vinyl acetate
Authors: Bernard Julien , Save Maud , Arathoon Benoit , Charleux Bernadette 
Published: March 2008

AbstractStable monodisperse poly(vinyl acetate) (PVAc) submicronic latex particles were synthesized by ab initio batch emulsion polymerization using a dextran derivative from renewable resource as an efficient steric stabilizer. The dextranend‐functionalized by a xanthate moiety was synthesized by Huisgen's 1,3‐dipolar cycloaddition (click chemistry). It was applied as a macromolecular RAFT (reversible addition fragmentation chain transfer) agent in surfactant‐free emulsion polymerization of vinyl acetate to form in situ an amphiphilic block copolymer able to efficiently stabilize the latex particles. The method afforded the preparation of high solids content (27%) latices coated by dextran. Both the kinetic study and the molar mass analyses confirmed the involvement of the dithiocarbonate group in the emulsion polymerization process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2845–2857, 2008
Precise Measurement of the Size of Nanoparticles by Dynamic Light Scattering with Uncertainty Analysis
Authors: Takahashi Kayori , Kato Haruhisa , Saito Takeshi , Matsuyama Shigetomo , Kinugasa Shinichi 
Published: March 2008

AbstractDynamic light scattering (DLS) is a powerful technique for the sizing of nanoparticles and characterization of their properties in the liquid phase. However, the precision of this technique remains unclear and therefore, in the current work, the precision of the DLS technique for sizing polystyrene latex suspensions and the uncertainty of the DLS data are estimated. Precise measurements of the short time correlation function at seven scattering angles and five different concentrations are performed for four kinds of polystyrene latex suspensions with diameters of 30–100 nm. The extrapolations of apparent diffusion coefficients to infinite dilution and to lower angles yield more precise values than those obtained at one angle and one concentration. The extrapolated particle size measured by DLS is compared to the size determined by a differential mobility analyzer (DMA) in air. Before the comparison, the intensity‐averaged size measured by DLS is recalculated to the number‐averaged size in the case of DMA from the particle size distribution. After the recalculation, consistent values of mean particle diameter are found to be between those obtained by DLS and DMA within the estimated uncertainties.
Particle Size Classification of Glass Particles Using Aerodynamic Jet Vectoring
Authors: Humes Zachary E. , Smith Barton L. 
Published: March 2008

AbstractAn experimental demonstration of a new, non‐contact particle characterization technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows–flows that are a fraction of the jet flow rate–to sharply change the direction of a planar, particle‐laden jet. As the jet is vectored, particles present in the flow experience a resultant drag force, dependent upon their size, that balances inertia. Since this balance determines the particle's trajectory, vectoring the flow leads to a separation of particles downstream. This simple, low‐pressure‐drop sorting technique classifies particles with less risk of damage or contamination than currently available sorting devices.Particles from 10–40 μm and 2.5 times the density of water have been sorted to an accuracy of 1.5 μm. Sorting of heavy particles such as these is accomplished at very low speeds, reducing the tendency of damage to the particles. Lighter particles are sorted at higher speeds. Particles from 5–40 μm and 0.6 times the density of water were sorted to an accuracy of 6.6 μm. AVPS is also shown to be capable of concentrating aerosols. Our measurements indicate that an air sample containing water‐like particles can be concentrated by a factor of 10 using AVPS.
Lag effect of particulate air pollution on lung function in children
Authors: Min Jin‐Young , Min Kyoung‐Bok , Cho Sung‐Il , Paek Domyung 
Published: March 2008

AbstractWe assessed the relationship between particle air pollution and changes in lung function in children as measured by spirometry over time. Data were collected from air pollution and family health examinations of 181 subjects, aged 9–19 years, in a Korean community. The children performed lung function tests, and their height and weight were measured. Their parents responded to an interview regarding the children's history of disease. Data on air pollution were obtained from the Environmental Management Corporation, which is part of the Korean Ministry of the Environment. We found evidence that the declines in forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) were significantly associated with the PM10 concentration for 37–60 hr preceding the lung function tests. The associations were consistent in the two‐pollutant models. Our findings suggest that exposure to PM10 may increase the risk of adverse health effects in children with respiratory symptoms or diseases. Pediatr Pulmonol. 2008; 43:476–480. © 2008 Wiley‐Liss, Inc.
The effect of gadolinium addition on the surface structure of Bi2O3–GeO2 glasses and vitroceramics
Authors: Simon V. , Ponta O. , Simon S. , Udvar D. A. , Neumann M. 
Published: March 2008

AbstractHeavy metal oxide glasses and vitroceramics belonging to the Bi2O3–GeO2–Gd2O3 system are investigated. The changes induced by heat treatment in the elemental composition on sample surfaces are related to the local order changes. O 1s and Bi 4f core level X‐ray photoelectron spectra evidence the local order changes caused by gadolinium addition to the Bi2O3–GeO2 matrix and by partial crystallisation of the precursor glass samples. The addition of gadolinium to the Bi2O3–GeO2 glass matrix leads to a reduction of the number of bridging oxygens and a depolymerisation of the glass structure. The number of bridging oxygens increases on heat treatment of the samples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
White‐beam synchrotron topographic characterization of antiparallel 180° domains in MgO doped near‐stoichiometric LiNbO3
Authors: Gao Lei , Wang Ji Yang , Liu Hong , Hu Xiao Bo , Zhu Pei Ping , Tian Yu Lian , Huang Wan Xia 
Published: March 2008

AbstractThe Czochralski grown MgO‐doped near‐stoichiometric LiNbO3 (N‐SLN) crystals have been investigated by using white‐beam synchrotron radiation topography. It was found that quasi‐periodic antiparallel 180° domains appeared frequently in y ‐cut (10$ \bar 1 $0) slice. Due to the different structure factors between positive and negative domains, at the wavelengths near the absorption edge of Nb atom, antiparallel 180° domains in MgO‐doped N‐SLN were revealed by anomalous scattering and the domain boundaries were visible by black‐white contrast from positive and negative domains. In the case of occurrence of anomalous scattering the ratio of |F (0006)|2 to |F (000$ \bar 6 $)|2 was calculated. The mechanisms of this quasi‐periodic domain inversion and the growth characteristics in MgO‐doped N‐SLN are also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ag‐YBCO compounds as thermoelectric material
Authors: Rodríguez J. E. 
Published: March 2008

AbstractIn order to improve their thermoelectric properties, the transport properties of polycrystalline YBa2Cu3O7–δ (YBCO) perovskites were modified by partial substitutions of Cu by silver atoms and by submitting the samples to a thermal process at 600 °C. The Seebeck coefficient S (T), electrical resistivity ρ (T) and thermal conductivity κ (T) were measured in the temperature range between 77 K and 300 K. The Seebeck coefficient in all samples is positive in the measured temperature range and its magnitude increases with the Ag content from 30 μV/K to 130 μV/K. The behavior of the electrical resistivity changes from semiconducting to metallic as the Ag doping increases; its magnitude is always less than 0.9 mΩ cm. The thermal conductivity shows a weak linear temperature behavior and its magnitude decreases with Ag doping, which suggest that Ag atoms are efficient phonon‐scattering centers. In all samples κ (T) is less than 5 W/K m and in highly doped samples it reaches values close to 3.5 W/K m. From S (T), ρ (T) and κ (T) data the dimensionless thermoelectric figure of merit ZT (T) and the thermoelectric power factor PF(T) were calculated; these parameters reach maximum values close to 0.4 and 60 μW/K2cm, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DFT studies on structure, mechanics and phase behavior of magnetic shape memory alloys: Ni2MnGa
Authors: Özdemir Kart S. , Uludog˘an M. , Karaman I. , Çag˘ın T. 
Published: March 2008

AbstractMagnetic shape memory alloys (MSMAs) are the smart materials which can undergo a reversible structural phase transition when a magnetic field is applied. The experimentally most studied MSMA, Ni2MnGa, undergoes a martensitic phase transition from a high temperature cubic phase to a low temperature tetragonal phase. In this work, a detailed study of structure, magnetic and mechanical properties of Ni2MnGa in these phases were performed using density functional theory (DFT). The predicted lattice constant, bulk modulus, magnetic moments and elastic constants of the initial L21 structure are in good agreement with experimental results and previous calculations. We report the martensitic phase at c /a = 1.26 for non‐modulated and c /a = 0.93 for 5M modulated structures which are consistent with the experiments. Analysis of electronic density of states showed that the double minority spin peak appeared at the Fermi level is due to the hybridization of Ga 4p and Ni 3d states. The peaks in the minority spin in the cubic structure reverse their order during martensitic transformation. The elastic constants of martensitic phases were also calculated to encourage measurements of these quantities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective dielectric response of nanostructured layers
Authors: Wormeester Herbert , Kooij E. Stefan , Poelsema Bene 
Published: March 2008

AbstractThe Maxwell Garnett effective medium theory was originally developed for a very small volume fraction of metal particles in a transparent medium. In contrast to the bulk situation, it can be applied to high coverages for thin metal particulate films and predicts the plasmon resonance energy accurately in contrast to the Bruggeman effective medium theory. The comparison of the Maxwell Garnett approach to a more rigorous analysis of particulate films with the Thin Island Film theory shows that also the plasma energy of the plasmon resonance is very accurately obtained with the simple effective medium theory. Also a quite accurate splitting of the resonance energy through particle interaction is obtained. However, interband transitions and the optical coupling of the layer with the effective medium response to the substrate lead to substantial differences compared to the dipole approximation of the rigorous Thin Island Film theory. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Etching‐back of uniaxially strained silicon on insulator investigated by spectroscopic ellipsometry
Authors: Himcinschi C. , Singh R. , Moutanabbir O. , Scholz R. , Reiche M. , Christiansen S. H. , Gösele U. , Zahn D. R. T. 
Published: March 2008

AbstractSpectroscopic Ellipsometry was employed to study the etching process of uniaxially strained Si (sSi) layers obtained by direct wafer bonding of Si wafers in a mechanically bent state followed by thinning one of the Si wafers, the donor wafer, by the smart‐cut process, keeping the other, the handle wafer intact. The smart‐cut process requires a high dose hydrogen implantation into the donor wafer prior to bonding. As a result of the implantation conditions a ∼600 nm uniaxially sSi layer could be transferred onto the handle wafer. In order to thin down and smooth the surface damage of the transferred layer induced by the implantation and splitting process, the samples were dipped in a solution of tetra‐methyl ammonium hydroxide (TMAH). The thicknesses of the transferred sSi layers determined from ellipsometry were in good agreement with those obtained from Transmission Electron Microscopy (TEM), while the roughness values were matching those obtained from Atomic Force Microscopy (AFM). The etching rate has also been determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Depolarizing Mueller matrices: how to decompose them?
Authors: Ossikovski R. , Anastasiadou M. , Ben Hatit S. , Garcia‐Caurel E. , De Martino A. 
Published: March 2008

AbstractThe various decompositions of depolarizing Mueller matrices into products of basic optical devices, i.e. retarders, diattenuators and depolarizers, are critically revisited and discussed. Both classic as well as recently proposed factorizations are reviewed. Physical and calculation aspects such as depolarization and matrix singularity are comparatively addressed. The problems of physical realizability and matrix filtering are treated in connection with the sum decomposition of a depolarizing Mueller matrix. Experimental matrices are factorized using the different decompositions and physically interpreted. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rayleigh–Mie scattering ellipsometry as an in situ diagnostic for the production of “smart nanoparticles”
Authors: Weiß Raphaela , Hong Suk‐Ho , Ränsch Jens , Winter Jörg 
Published: March 2008

AbstractWe have utilised in situ Rayleigh–Mie scattering ellipsometry to analyse the growth process of amorphous hydrogenated carbon nitride (a‐C:H:N) nanoparticles synthesised in a plasma of nitrogen and acetylene. The validity of the measurements is shortly discussed. The complex refractive indices in dependence of the particle radius are carefully determined and compared with a‐C:H(:N) films which are deposited under similar conditions and analysed via multiple wavelength ellipsometry. Internal structures of the nanoparticles are then deduced from the change of optical constants during the growth. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)