bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regularization of diffusion tensor MRI via local coordinates
Authors: Gur Yaniv , Pasternak Ofer , Sochen Nir 
Published: December 2008

AbstractWe propose a novel framework for regularization of symmetric positive‐definite (SPD) tensors (e.g., diffusion tensors). This framework is based on differential geometry. The space of SPD matrices, Pn, is described as a Riemannian manifold that is parameterized via the Iwasawa coordinate system. Then, distances on Pn are measured in terms of a natural GL (n)‐invariant Riemannian metric. Using the Beltrami framework we construct a set of coupled geometric PDEs with respect to the Iwasawa coordinates. Then, by means of the gradient descent method these equations define the regularization flow over Pn. It appears to be that the local coordinate approach via that coordinate system results in very simple numerics that leads to fast convergence of the algorithm. We demonstrate the efficiency of this algorithm on real volumetric DTI datasets. Results of fibers tractography before and afterthe regularization process arepresented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the Lagrangian formulation of a Lane‐Emden‐type equation and double reduction
Authors: Khalique C Masood , Ntsime Pauline 
Published: December 2008

AbstractWe classify all Noether point symmetries of the Lane‐Emden‐type equation x y ″ + n y ′ + xνf (y) = 0 with respect to the standard Lagrangian L = 1/2 xny ′2 – xn +ν –1 ∫ f (y)dy for various functions f (y). We then obtain first integrals of the various cases which admit Noether point symmetries and obtain reduction to quadratures for these cases. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence and iterative approximation of solutions of some systems of variational inequalities and inclusions
Authors: Khan Syed Huzoorul H. , Kazmi K.R. 
Published: December 2008

AbstractIn 1968, Brézis [Ann. Inst. Fourier (Grenoble), 18(1) (1968) 115‐175] initiated the study of the existence theory of a class of variational inequalities later known as variational inclusions, using proximal‐point mappings due to Moreau [Bull. Soc. Math. France, 93 (1965) 273‐299]. Variational inclusions include variational, quasi‐variational, variational‐like inequalities as special cases.In 1985, Pang [Math. Prog. 31 (1985) 206‐219] showed that a variety of equilibrium models can be uniformly modelled as a variational inequality defined on the product sets equivalent to a system of variational inequalities and discuss the convergence of method of decomposition for system of variational inequalities.Motivated by the recent research work in this directions, we consider some systems of variational (‐like) inequalities and inclusions; develop the iterative algorithms for finding the approximate solutions and discuss their convergence criteria. Further, we study the sensitivity analysis of solution of the system of variational inclusions. The techniques and results presented here improve the corresponding techniques and results for the variational inequalities and inclusions in the literature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Boundary value problems in the theory of binary mixtures
Authors: Svanadze Merab 
Published: December 2008

AbstractIn this paper, the boundary value problems of steady oscillation (vibration) of the linear theory of thermoelasticity for binary mixtures are investigated by means of the boundary integral equation method (potential method). The uniqueness and existence theorems of solutions of the exterior boundary value problems by means potential method and multidimensional singular integral equations are proved. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotic limits of compressible Euler‐Maxwell system in plasma physics
Authors: Wang Shu 
Published: December 2008

AbstractIn this talk we will discuss asymptotic limit of compressible Euler‐Maxwell system in plasma physics. Some recent results about the convergence of compressible Euler‐Maxwell system to the incompressible Euler equations or incompressible e‐MHD equations will be given via the quasi‐neutral regime. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Connectedness of number theoretical tilings (dual tilings generated by Pisot units of degree 3 and 4)
Authors: Akiyama Shigeki , Gjini Nertila 
Published: December 2008

AbstractWe study the connectedness of Pisot dual tilings. It is shown that each tile generated by a Pisot unit of degree 3 is arcwise connected. However surprisingly, we found families of disconnected Pisot dual tiles of degree 4 which have infinitely many connected components. Also we give a simple necessary and sufficient condition for the connectedness of the Pisot dual tiles of degree 4. As a byproduct, we give a complete classification of the β expansion of 1 for quartic Pisot units. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of the R‐functions method to the solution of elliptic PDEs (Poster Presentation)
Authors: Gladkov Svyatoslav , Svendsen Bob 
Published: December 2008

AbstractIn the current work, the basics of the theory of R‐functions have been presented. Applications of this theory were shown on two model problems – Poisson equation and biharmonic equation – in complex two‐dimensional domains both with homogeneous Dirichlet boundary conditions. The solution is performed in conjunction with the Bubnov‐Galerkin method. As the basis for approximation tensor products of monomials were taken. The convergence study includes the comparison of current results with the standard finite element solution and the dependence of the number of coordinate functions on the relative error in the maximum‐norm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear mathematical model for intensive steel quenching and its analytical solution in closed form
Authors: Guseynov Sh.E. 
Published: December 2008

AbstractIn the present paper the nonlinear mathematical model for intensive steel quenching processes is considered. This model involves the hyperbolic heat conduction equation, the initial conditions and the Newton type nonlinear boundary conditions characterizing the boiling process on quenchant surface. The reduction of the original problem to the Volterra type nonlinear integral equation is the essence of offered approach. Besides, in the present work some analytical procedure for solving of obtained nonlinear equation is proposed. It is proved that this analytical procedure permits finding the unique solution of the original nonlinear model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analytical approach for some classes of coefficient inverse problems
Authors: Guseynov Sh.E. 
Published: December 2008

AbstractIn present work we consider some class of homogeneous one‐dimensional on spatial variable coefficient linear inverse problems of thermal conductivity in the bounded domain under. Offered approach allows reducing this class of inverse problems to the problems for the solving of the first kind Volterra linear integral equation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The numerical analysis and experimental researches of influence of triangular asperity's outline deviations after turning on the burnished product's technological quality
Authors: Kulakowska Agnieszka , Kukielka Leon 
Published: December 2008

AbstractThe paper concerns determination dependence of preparing inaccuracy surface after previous treatment on the state and properties of burnished article's surface layer (SL). The researches were realized in two stages. In the first one numerical analysis were made, and in the second one experimental verification of receiving results. The application in ANSYS was elaborated. It makes possible to analyze the influence of outline deviations of triangular asperity after turning on the surface roughness and the state of strains and stresses in SL after burnishing rolling. The variables in calculations are: height deviation of triangular asperity after turning Δht = 0.01 ÷ 0.04 [mm], and its distance deviation Δst = 0.05 ÷ 0.2 [mm] as well as the depth of burnishing a = 0.03 ÷ 0.39 [mm]. The results of experimental researches and numerical analysis cover in 5% confidence interval. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduction problems in multi‐scale systems dynamics
Authors: Kuzmina Lyudmila K. 
Published: December 2008

AbstractThe paper is devoted to the different aspects of mathematical modelling and qualitative analysis in dynamics of complex multi‐scale systems that are generated by applied problems of engineering practice. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear and linear instability of the Rossby‐Haurwitz wave
Authors: Skiba Yuri N. 
Published: December 2008

AbstractAs is known, the large‐scale dynamics of barotropic atmosphere can approximately be described by the nonlinear barotropic vorticity equation. It is also well known that the Rossby‐Haurwitz (RH) waves, being exact solutions to this equation, represent one of the main features of meteorological fields. Therefore the stability properties of the RH wave are of considerable interest for deeper understanding of the low‐frequency variability of the atmosphere. Many works has been devoted to the barotropic instability of flows on a beta‐plane and a sphere. However, mathematically, the nonlinear stability problem of the RH wave is still far from its complete solution. Indeed, some of the stability results have been obtained numerically, and hence, contain calculation errors. Severe truncation of perturbations used in the spectral stability analysis, though leads to interesting and useful conclusions, does not allow obtaining comprehensive results. The weak point of some analytical nonlinear instability studies consists in using inappropriate norms for perturbations. It should also be noted that a necessary condition for the linear instability of the RH wave was obtained only recently (Skiba, 2000).In the present work, the nonlinear stability of the RH wave in an ideal incompressible fluid on a rotating sphere is analytically studied. Let H(n) be a subspace of homogeneous spherical polynomials of degree n. Mathematically, a RH wave of degree n is the sum of a super‐rotating flow of subspace H(1) and a homogeneous spherical polynomial of subspace H(n). First, we derive a conservation law for arbitrary RH‐wave perturbations which asserts that any perturbation evolves in such a way that its kinetic energy E(t) and enstrophy q(t) decrease, remain constant or increase simultaneously. The law is used to divide all the perturbations into three invariant sets depending on the value of their mean spectral number k(t)=q(t)/E(t) introduced by Fjortoft (1953). These sets are denoted as M where k(t)¡n(n+1) (large‐scale perturbations), N where k(t)¿n(n+1) (small‐scale perturbations), and Z where k(t)=n(n+1) (boundary surface between the sets M and N). Note that Z includes one more invariant set, namely, the subspace H(n). The existence of invariant sets of perturbations allows us to study the RH wave instability in each set separately. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impulsive displacement of liquid in a pipe
Authors: Kleinstein Gerald G. 
Published: December 2008

AbstractThe solution of a viscous liquid, originally at rest in a pipe, which is set impulsively into motion by a pressure gradient is well known. Analyzing this solution shows that the displacement time – the time it takes to completely displace the liquid originally at rest in the pipe – falls primarily within an inviscid window. Assuming this result remains essentially unchanged when the displaced and displacing liquids are different we apply an inviscid analysis to determine the displacement time as a function of the density ratio of the liquids and the pressure difference. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Endangered species, real options, and forest management
Authors: Abdallah Skander Ben , Lasserre Pierre 
Published: December 2008

AbstractWe use a real option approach to determine optimally when a social planner has to stop or resume logging in situations where an endangered species relies on forest habitat for its survival, and that habitat evolves stochasticly. The model incorporates economic, ecological and social features, and is calibrated to generate an optimal forest management rule that balances the benefits from commercial forest exploitation with the risks of extinction facing the endangered species. For the reasonable parameters used in our application to the Rangifer tarandus caribou, an endangered species in Central Labrador (Canada), the policy of banning logging temporarily is quite attractive as it does not require long banning periods while it drastically reduces the extinction risk and increases forest value. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations on the wire sawing process
Authors: Liedke T. , Ams A. , Kuna M. 
Published: December 2008

AbstractThe wire sawing technology plays an important role on the manufacturing of thin discs out of brittle materials and is used for example in the solar‐ and microelectronic industry. The surface of a wire sawn disc shows a characteristic geometry, which suggests the influence of oscillations during the slicing process. In order to examine the process a distinct‐element‐model is used to simulate the motion and the interaction of the abrasive particles with the moving wire and the workpiece. The simulation shows interesting phenomena like clustering of particles and reacting forces to the wire, which could be one reason for the observed oscillations in the process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Function theoretical approach to anisotropic plane elasticity
Authors: Soldatov A. 
Published: December 2008

AbstractThe representation of general solutions of Lame system of plane elasticity is given with the help of so‐called Douglis analytic functions. Using integral representation of these functions the basic boundary value problems for Lame system are reduced to equivalent singular integral equations on the boundary. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of double stratification on MHD free convection with Soret and Dufour effects in a Darcian porous media
Authors: Tak S.S. , Lodha Arti 
Published: December 2008

AbstractThe heat and mass transfer characteristics of natural convection about a vertical surface embedded in a doubly stratified saturated porous medium subjected to a magnetic field is studied, taking into account the Dufour and Soret effects. It is found that the similarity solution exists for the case of uniform surface heat and mass flux conditions when the thermal and solutal stratification of the medium are assumed to have power function form x1/3. The resulting set of ordinary coupled nonlinear differential equations is solved numerically using shooting technique. Nusselt and Sherwood numbers are tabulated for various values of the involved parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stochastic Krylov subspace methods for flow in random porous media
Authors: Klie Hector , Rodriguez Adolfo , Wheeler Mary F. 
Published: December 2008

AbstractThe present work establishes a comparative analysis of two different Krylov‐based methods for assessing uncertainty in porous media flow applications. They are: (1) the stochastic reduced basis method (SRBM) and the (2) Krylov‐Karhunen‐Loeve moment equation (KKLME). The former relies on the construction of an orthogonal basis from which projectors may be realized to perform the uncertainty analysis on a lower‐dimensional space. The second approach relies on the idea of expressing input and corresponding outputs in terms of stochastic and perturbative polynomial expansions. By grouping terms and moments of the same order, the original stochastic equation is replaced by successive (and parallel) solutions of a set of deterministic equations. We provide a set of numerical experiments illustrating the capabilities of SRBM and KKLME against Monte Carlo simulations (MCS) on stationary permeability cases. We show that KKLME is superior to SRBM. Furthermore, KKLME appears to be also a more efficient alternative than MCS for non‐stationary permeability field distributions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation of hollow composite spheres with raspberry‐like structure based on hydrogen‐bonding interaction
Authors: Wang Junyou , Li Hao , Yang Xinlin 
Published: December 2008

AbstractThe hollow composite spheres with a raspberry‐like structure were prepared by a self‐assemble heterocoagulation based on the inter‐particle hydrogen‐bonding interaction between the amide groups of hollow poly (N,N′‐methylenebisacrylamide‐co‐N‐isopropyl acrylamide) (P(MBA‐co‐NIPAAm)) microspheres and the carboxylic acid groups of poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA)) nanoparticles, in which P(EGDMA‐co‐MAA) nanoparticle acted as the corona and the hollow P(MBA‐co‐NIPAAm) microsphere behaved as the core. The control coverage of the corona particles on the surface of hollow core microspheres of P(MBA‐co‐NIPAAm)/P(EGDMA‐co‐MAA) hollow composite sphere was studied in detail through adjustment of the mass ratio between the core and corona particles. The effect of the pH on the stability of the raspberry‐like hollow spheres was investigated. The polymer particles and the resultant heterocoagulated raspberry‐like hollow spheres were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous determination of three phytoecdysteroids in the roots of four medicinal plants from the genus Asparagus by HPLC
Authors: Wu Jia‐Jun , Cheng Ka‐Wing , Wang Hao , Ye Wen‐Cai , Li Edmund T. S. , Wang Mingfu 
Published: December 2008

AbstractIntroductionThe genus Asparagus is known to contain phytoecdysteroids that have been shown to exhibit many beneficial pharmacological properties such as improving lipid metabolism, modulating immunological responses, etc. Currently, knowledge about the contents of phytoecdysteroids in the roots of Asparagus species is limited and HPLC methods for their analyses are unsatisfactory.ObjectiveTo develop an HPLC method for the simultaneous determination of three phytoecdysteroids, 20‐hydroxyecdysone, ecdysone and ajugasterone C, in the roots of four Asparagus species.MethodologyReference standards of phytoecdysteroids were isolated from the roots of Asparagus filicinus by open column chromatography. HPLC analysis was performed on an Alltima C18 column with gradient elution using aqueous 0.2% formic acid solution containing 0.2% isopropanol and acetonitrile.ResultsAll calibration curves showed good linear correlation coefficients (r2 > 0.9994) within the tested ranges. Limits of detection (S/N = 3) and quantification (S/N = 10) for the three analytes were less than 2.7 and 9.9 ng, respectively. Intra‐ and inter‐day RSDs of retention times and peak areas were less than 2.61%. The recoveries were between 93.2 and 107.5%, and the RSDs were less than 3.83% for the root samples of A. filicinus.ConclusionThe HPLC method established is appropriate for the efficient quantitative and qualitative analyses of important phytoecdysteroids in Asparagus species. This study showed that A. filicinus is rich in phytoecdysteroids, especially 20‐hydroxyecdysone. However the three studied phytoecdysteroids were not detected in A. cochinchinensis, A. officinalis and A. setaceus. Copyright © 2008 John Wiley & Sons, Ltd.
Further examining the triangle tip: Improving support for students with emotional and behavioral needs
Authors: Kern Lee , Hilt‐Panahon Alexandra , Sokol Natalie G. 
Published: December 2008

AbstractStudents identified as having emotional and behavioral disorders (EBD) experience the poorest educational outcomes among any disability group. Although models of intervention and corresponding evidence‐based practices continue to advance, the promise of new approaches has failed to reach the general population of students with EBD. In this artice, we visit possible explanations for these continued poor outcomes. Breakdowns along several systems are discussed, including placement and related practices as well as the absence of individualized approaches. In addition, we offer suggestions for improvement. © 2008 Wiley Periodicals, Inc.
Compatibility of toluidine blue with laser microdissection and saturation labeling DIGE
Authors: Kirana Chandra , Ward Teresa , Jordan T. William , Rawson Pisana , Royds Janice , Shi Hong Jun , Stubbs Richard , Hood Kylie 
Published: December 2008

AbstractTissue fixation and staining protocols for laser microdissection are frequently not fully compatible with subsequent proteomic analysis. We compared the effect of three common histological stains (toluidine blue (TB), hemotoxylin, and hematoxylin and eosin (HE)) on tissue visualization, protein recovery, the saturation labeling reaction, and 2‐D electrophoresis. TB provided the best visualization of colorectal tumor tissue during laser microdissection (LMD) and had a comparable effect on protein recovery and the saturation labeling reaction with hematoxylin, provided a modified 2‐D clean‐up protocol was used. Eosin inhibited both protein recovery and the saturation labeling reaction.
Preparation of C60‐functionalized magnetic silica microspheres for the enrichment of low‐concentration peptides and proteins for MALDI‐TOF MS analysis
Authors: Chen Hemei , Qi Dawei , Deng Chunhui , Yang Penyuan , Zhang Xiangmin 
Published: December 2008

AbstractIn this work, for the first time, a novel C60‐functionalized magnetic silica microsphere (designated C60‐f‐MS) was synthesized by radical polymerization of C60 molecules on the surface of magnetic silica microspheres. The resulting C60‐f‐MS microsphere has magnetite core and thin C60 modified silica shell, which endow them with useful magnetic responsivity and surface affinity toward low‐concentration peptides and proteins. As a result of their excellent magnetic property, the synthesized C60‐f‐MS microspheres can be easily separated from sample solution without ultracentrifuge. The C60‐f‐MS microspheres were successfully applied to the enrichment of low‐concentration peptides in tryptic protein digest and human urine via a MALDI‐TOF MS analysis. Moreover, they were demonstrated to have enrichment efficiency for low‐concentration proteins. Due to the novel materials maintaining excellent magnetic properties and admirable adsorption, the process of enrichment and desalting is very fast (only 5 min), convenient and efficient. As it has been demonstrated in the study, newly developed fullerene‐derivatized magnetic silica materials are superior to those already available in the market. The facile and low‐cost synthesis as well as the convenient and efficient enrichment process of the novel C60‐f‐MS microspheres makes it a promising candidate for isolation of low‐concentration peptides and proteins even in complex biological samples such as serum, plasma, and urine or cell lysate.
Jacketed polymers: Controlled synthesis of mesogen‐jacketed polymers and block copolymers
Authors: Gao Long‐Cheng , Fan Xing‐He , Shen Zhi‐Hao , Chen Xiaofang , Zhou Qi‐Feng 
Published: December 2008

AbstractThe controlled radical polymerization of mesogen‐jacketed liquid crystalline polymers has triggered great interests in synthesis of complex structures as well as well‐defined linear homopolymers with controlled molecular weight and narrow molecular weight distributions. This review highlights the synthetic strategies of controlled radical polymerization of linear homopolymers, star polymers, superbranched polymers, graft polymers, block copolymers, star block copolymers, and so on. The employed living methods include nitroxide‐mediated radical polymerization and atom transfer radical polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 319–330, 2009