bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biotransformation of three aromadendrane‐type sesquiterpenoids by Aspergillus wentii
Authors: Miyazawa Mitsuo , Takahashi Tomohiko , Sakata Kazuki , Horibe Isao 
Published: April 2008

AbstractBACKGROUND: The biotransformation of sesquiterpenoids, which are a large class of naturally occurring compounds, using microorganisms as a biocatalyst to produce useful novel organic compounds was investigated. The biotransformation of sesquiterpenoids, (+)‐aromadendrene (1), (−)‐alloaromadendrene (2) and (+)‐ledene (3) has been investigated using Aspergillus wentii as a biocatalyst.Results: Compound 1 was converted to (−)‐(10S,11S)‐10,13,14‐trihydroxyaromadendrane (4). Compound 2 was converted to (+)‐(1S,11S)‐1,13‐dihydroxyaromadendrene (5) and (−)‐5,11‐epoxycadin‐1(10)‐en‐14‐ol (6). Compound 3 was converted to compound 6, (+)‐(10R,11S)‐10,13‐dihydroxyaromadendr‐1‐ene (7) and (+)‐(10S,11S)‐10,13‐dihydroxyaromadendr‐1‐ene (8). The structure of the metabolic products has been elucidated on the basis of their spectral data.CONCLUSION: Compound 1 gave only one product that was hydroxylated at C‐10, C‐13 and C‐14. By contrast, compounds 2 and 3 gave a number of products, one of which was common. The differences in oxidation of 1–3 are due to the configuration of the C‐1 position. Compounds 4–8 were new compounds. Copyright © 2008 Society of Chemical Industry
High‐flow priapism complicating ischemic priapism following iatrogenic laceration of the dorsal artery during a Winter procedure
Authors: Bertolotto Michele , Ciampalini Sandro , Martingano Paola , Mucelli Fabio Pozzi 
Published: April 2008

AbstractWe report a case of a patient who developed high‐flow priapism following a Winter procedure performed for the treatment of low‐flow ischemic priapism. During the creation of bilateral cavernosal–glandular shunts, the tip of the left dorsal artery was accidentally lacerated. A fistula developed through the shunt between the torn artery and the cavernosal sinusoids of the tip of the left corpus cavernosum. Gray‐scale and Doppler sonography and angiography allowed diagnosis and guided the therapeutic approach. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
One‐step preparation of hybrid materials of polyacrylamide networks and gold nanoparticles
Authors: Song Yonghai , Li Zhiqiang , Wang Li , Yao Yong , Chen Chuangye , Cui Kang 
Published: April 2008

AbstractHybrid materials of polyacrylamide networks and gold nanoparticles were prepared by directly heating an aqueous solution containing HAuCl4, acrylamide, N,N′‐methylenebis‐acrylamide, and sodium sulfite (Na2SO3). Acrylamide, N,N′‐methylenebis‐acrylamide, and Na2SO3 were used as monomers, crosslinking agent, and initiator, respectively. In the process of polyacrylamide network synthesis, HAuCl4 was reduced by acrylamide and Na2SO3 into gold nanoparticles and adsorbed on the produced polyacrylamide networks. Transmission electron microscopy proved that the size of gold nanoparticles was in the range of 3–10 nm. Atomic force microscopy showed that the gold nanoparticles homogeneously dispersed into the polyacrylamide networks matrix. The hybrid materials as absorbents may be useful in healthcare, communication technology, building industry, chromatography, water purification, and agriculture. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
A Characterization of the degree sequences of 2‐trees
Authors: Bose Prosenjit , Dujmović Vida , Krizanc Danny , Langerman Stefan , Morin Pat , Wood David R. , Wuhrer Stefanie 
Published: April 2008

AbstractA graph G is a 2‐tree if G = K3, or G has a vertex v of degree 2, whose neighbors are adjacent, and G/ v is a 2‐ tree. A characterization of the degree sequences of 2‐trees is given. This characterization yields a linear‐time algorithm for recognizing and realizing degree sequences of 2‐trees. © 2008 Wiley Periodicals, Inc. J Graph Theory 58:191‐209, 2008
Disjoint quasi‐kernels in digraphs
Authors: Heard Scott , Huang Jing 
Published: April 2008

AbstractA quasi‐kernel in a digraph is an independent set of vertices such that any vertex in the digraph can reach some vertex in the set via a directed path of length at most two. Chvátal and Lovász proved that every digraph has a quasi‐kernel. Recently, Gutin et al. raised the question of which digraphs have a pair of disjoint quasi‐kernels. Clearly, a digraph has a pair of disjoint quasi‐kernels cannot contain sinks, that is, vertices of outdegree zero, as each such vertex is necessarily included in a quasi‐kernel. However, there exist digraphs which contain neither sinks nor a pair of disjoint quasi‐kernels. Thus, containing no sinks is not sufficient in general for a digraph to have a pair of disjoint quasi‐kernels. In contrast, we prove that, for several classes of digraphs, the condition of containing no sinks guarantees the existence of a pair of disjoint quasi‐kernels. The classes contain semicomplete multipartite, quasi‐transitive, and locally semicomplete digraphs. © 2008 Wiley Periodicals, Inc. J Graph Theory 58:251‐260, 2008
Raman study on electrochemical lithium insertion into multiwalled carbon nanotubes
Authors: Kim Yoong Ahm , Kojima Masashito , Muramatsu Hiroyuki , Shimamoto Daisuke , Hayashi Takuya , Endo Morinobu , Terrones Mauricio , Dresselhaus Mildred S. 
Published: April 2008

AbstractWe have carried out in situ Raman studies during the electrochemical insertion of lithium ions (Li+) into pristine and thermally treated multiwalled carbon nanotubes (MWNTs). We found an improved structural integrity as well as the removal of defects in the thermally treated tubes. The different Li+ insertion behaviors above 0.5 V in as‐grown and thermally treated tubes could be explained by the presence of defects on the outer surface of the tubes. No change of Raman spectra from 2.8 to 0.8 V is characterized by the coverage of Li+ on the outer surface of tubes, whereas the upshift of G band and the absence of a separated G band below 0.75 V indicate the formation of diluted graphite intercalation below the stage‐2 phase (LiC12). Copyright © 2008 John Wiley & Sons, Ltd.
Thermophysical properties of compressor oils for refrigerating plant
Authors: Semenyuk Yury V. , Sechenyh Vitaly V. , Zhelezny Vitaly P. , Skripov Pavel V. 
Published: April 2008

AbstractIn the present study, an accurate experimental information for the widely used commercial refrigerating compressor oils ONF 46, ACD 100 FY, Azmol, FR 32, XC 15, XC 40 and WF 15A is presented. Experimental data on the capillary constant, surface tension, density, refractive index and kinematic viscosity at the temperature range from 293 to 353 K for seven commercial compressor oils are reported. In addition, the experimental data on the isobaric heat capacity at temperature range from 288 to 393 K, the vapor pressure at liquid‐saturated curve and average molecular weight for four commercial compressor oils are firstly presented in the paper. The data obtained are fitted by few‐constant correlations. Based on results obtained, the values of pseudocritical temperature for the compressor oils have been determined. Copyright © 2008 John Wiley & Sons, Ltd.
Stationary phases for hydrophilic interaction chromatography, their characterization and implementation into multidimensional chromatography concepts
Authors: Jandera Pavel 
Published: April 2008

AbstractHydrophilic interaction chromatography (HILIC) is becoming increasingly popular for separation of polar samples on polar columns in aqueous‐organic mobile phases rich in organic solvents (usually ACN). Silica gel with decreased surface concentration of silanol groups, or with chemically bonded amino‐, amido‐, cyano‐, carbamate‐, diol‐, polyol‐, or zwitterionic sulfobetaine ligands are used as the stationary phases for HILIC separations, in addition to the original poly(2‐sulphoethyl aspartamide) strong cation‐exchange HILIC material. The type of the stationary and the composition of the mobile phase play important roles in the mixed‐mode HILIC retention mechanism and can be flexibly tuned to suit specific separation problems. Because of excellent mobile phase compatibility and complementary selectivity to RP chromatography, HILIC is ideally suited for highly orthogonal 2‐D LC‐LC separations of complex samples containing polar compounds, such as peptides, proteins, oligosaccharides, drugs, metabolites and natural compounds. This review attempts to present an overview of the HILIC separation systems, possibilities for their characterization and emerging HILIC applications in 2‐D off‐line and on‐line LC‐LC separations of various samples, in combination with RP and other separation modes.
Misalignment effects on steady‐state and dynamic behaviour of compliant journal bearings lubricated with couple stress fluids
Authors: Boucherit Hamid , Lahmar Mustapha , Bou‐Said Benyebka 
Published: April 2008

AbstractThis work concerns the steady‐state and dynamic analysis of misaligned compliant journal bearings considering the effects of couple stresses arising from the lubricant blended with polymer additives. Based on the Stokes micro‐continuum theory, a modified form of the Reynolds equation is derived. The displacement field at the fluid film–bearing liner interface due to pressure forces is determined using the elastic thin liner model. The effects of the misalignment and the couple stress parameters on static and dynamic performances such as pressure distribution, load‐carrying capacity, power loss, side leakage flow, misalignment moment, critical mass and whirl frequency are presented and discussed. Copyright © 2008 John Wiley & Sons, Ltd.
A parameterisation of impact laws in perfect multi‐contact collisions
Authors: Aeberhard U. , Glocker Ch. 
Published: April 2008

AbstractImpacts in rigid multibody systems cause instantaneous jumps in the generalised velocities. Naturally, the velocity after impact depends on the chosen impact law. An impact law should fulfil kinematic, kinetic as well as energy restrictions. In this paper, we study the domain of possible post‐impact velocities for arbitrary impact laws. For single‐contact collisions, this domain is at most one‐dimensional but the domain becomes higher dimensional in the multi‐contact case. The domain of possible post‐impact velocities is a compact convex subset of the tangent space to the configuration manifold. Using a complete canonical parameterisation, the post‐impact velocity of all impact laws can be addressed. For instance, the impact law corresponding to maximal dissipation as well as Newtons (extended) impact law are examples of incomplete canonical parameterisations. These impact laws are not complete as non‐local impact effects are not addressed. Here, we try to find a complete canonical parameterisation which covers non‐local impact effects. Moreover, the relationship between symmetries and conservation laws in this context will be elucidated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differential topology methods for shape description
Authors: Biasotti Silvia , Giorgi Daniela , Patané Giuseppe 
Published: April 2008

AbstractDifferential topology, and specifically Morse theory, provides a suitable setting for formalizing and solving several problems related to shape analysis. In this field, we discuss how a shape can be analyzed according to the properties of a real function defined on it (e.g., harmonic fields or laplacian eigenfunctions), and how these properties can be stored in compact and informative descriptors. We refer to Reeb graphs, that encode the configuration of level sets and critical points of the function
Asymptotics for the potential in a periodic network with localized defects
Authors: Bonnetier Eric , Sista Sivaji Ganesh 
Published: April 2008

AbstractWe consider a network of conductors built on the lattice h Z2 and study how the potential is affected by a localized interior defect. We derive an asymptotic expansion of the difference between the potential of the perturbed network and that of an ideal, defect‐free network. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A stall‐delay model for rotating blades
Authors: Dumitrescu Horia , Cardos Vladimir 
Published: April 2008

AbstractThe paper is aimed at describing a fundamental phenomenon: the effect of rotation on the inboard blade boundary layer on a wind turbine. The three‐dimensional incompressible steady momentum integral boundary‐layer equations are used to predict the boundary‐layer growth and limiting streamline angles on the blade surface for both attached and separating flow. The chordwise skin friction coefficient is used to identify boundary layer separation and shear layer reattachment locations. The nature of flow near the axis of rotation is discussed and the physical mechanism associated with 3‐D and rotational effects is identified. A semi‐empirical correction law for the lift coefficient based on 2‐D airfoil data is established. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of non‐viscous liquid pinch off using a coupled level set boundary integral method
Authors: Garzon Maria , Sethian James A. , Gray Len 
Published: April 2008

AbstractThe pinch off of an inviscid fluid column is described using a potential flow model with capillary forces. The interface velocity is obtained via a Galerkin boundary integral method for the 3D axisymmetric Laplace equation, whereas the interface location and the velocity potential on the free boundary are both approximated using level set techniques on a fixed domain. The algorithm is validated computing the Raleigh‐Taylor instability for liquid columns which provides an analytical solution for short times. The simulations show the time evolution of the fluid tube and the algorithm is capable of handling pinch‐off and after pinch‐off events. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Validation for turbulent mixing simulations
Authors: Glimm James , Jin Hyeonseong 
Published: April 2008

AbstractWe compare simulation studies of acceleration driven mixing (the Rayleigh‐Taylor instability) to laboratory experiments. Good agreement is obtained for variables describing the large scale aspects of the mixing process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal control of constrained time lag systems: Necessary conditions and numerical treatment
Authors: Göllmann Laurenz , Kern Daniela , Maurer Helmut 
Published: April 2008

AbstractWe consider retarded optimal control problems with constant delays in state and control variables under mixed controlstate inequality constraints. First order necessary optimality conditions in the form of Pontryagin's minimum principle are presented and discussed as well as numerical methods based upon discretization techniques and nonlinear programming. The minimum principle for the considered problem class leads to a boundary value problem which is retarded in the state dynamics and advanced in the costate dynamics. It can be shown that the Lagrange multipliers associated with the programming problem provide a consistent discretization of the advanced adjoint equation for the delayed control problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Higher‐order energy consistent time integrators for nonlinear thermoviscoelastodynamics
Authors: Groß Michael , Betsch Peter 
Published: April 2008

AbstractAn advantage of the temporal fe method is that higher‐order accurate time integrators can be constructed easily. A further important advantage is the inherent energy consistency if applied to equations of motion. The temporal fe method is therefore used to construct higher‐order energy‐momentum conserving time integrators for nonlinear elastodynamics (see Ref. [1]). Considering finite motions of a flexible solid body with internal dissipation, an energy consistent time integration is also of great advantage (see the references [2, 3]). In this paper, we show that an energy consistent time integration is also advantageous for dynamics with dissipation arising from conduction of heat as well as from a viscous material. The energy consistency is preserved by using a new enhanced hybrid Galerkin (ehG) method. The obtained numerical schemes satisfy the energy balance exactly, independent of their accuracy and the used time step size. This guarantees numerical stability. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective transport properties for flashing ratchets using homogenization theory
Authors: Latorre Juan C. , Kramer Peter R. , Pavliotis Grigorios A. 
Published: April 2008

AbstractWe study effective transport properties of Brownian motor models of molecular motors. The effective drift and diffusivity can be calculated by solving cell problems, given explicitly by homogenization theory. We briefly describe how this approach is equivalent to theWang‐Peskin‐Elston (WPE) [3] numerical algorithm for calculating effective transport properties of flashing ratchets. For an on‐off flashing ratchet we examine the optimization of the Peclet number as a function of the free parameters of the system. We also present a numerical method for solving the cell equations for a flashing ratchet with Gaussian multiplicative noise. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A high order finite volume method for the 2D shallow water equation
Authors: Messerschmidt Bettina 
Published: April 2008

AbstractIn this paper, we give a brief introduction into two numerical flux functions in the context of Finite Volume Schemes on unstructured grids of theoretically arbitrary high order, namely the well‐ known ADER‐ and the new STE‐ Scheme. We will emphasize in particular the differences with regard to computing time. Further we give an example comparing the results of the schemes applied for the first time to the 2D Shallow Water Equation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scaling dynamics for solvable coagulation equations with dust and gel
Authors: Menon Govind , Pego Robert L. 
Published: April 2008

AbstractWe study limiting behavior of rescaled size distributions that evolve by Smoluchowski's rate equations for coagulation, with rate kernel K=2, x+y or xy. We find that the dynamics naturally extend to probability distributions on the half‐line with zero and infinity appended, representing populations of clusters of zero and infinite size. The “scaling attractor” (set of subsequential limits) is compact and has a Levy‐Khintchine‐type representation that linearizes the dynamics and allows one to establish several signatures of chaos. In particular, for any given solution trajectory, there is a dense family of initial distributions (with the same initial tail) that yield scaling trajectories that shadow the given one for all time. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Continuous solutions of some boundary layer problem
Authors: Dreglea Aliona I. , Sidorov Nikolay A. 
Published: April 2008

AbstractThe continuous solutions for BVP of third order nonlinear differential equations appears in [1] mathematical model of the melt spinning process. The existence theorem is proved for such BVP. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the structure of phase spaces in Synergetic Inter‐Representation Network
Authors: Sugimoto Takeshi 
Published: April 2008

AbstractExchanging ideas and concepts among people can be handled with by so‐called Synergetic Inter‐Representation Network, which is described by n ‐dimensional ordinary differential equations with cubic nonlinearity. The novel find is the fact that the basic equation set is transformed to a set of n ‐dimensional Lotka‐Volterra equations. This discovery allows us to scrutinize the existence and stability of the fixed points: (1) The origin is an unstable fixed point; (2) The single representation survival, for example (0, 0, …, λj /C, …, 0), is a stable fixed point; (3) The coexistence of several representations exists as a saddle point. If all of these exist, the number of the saddle points is 2n – n – 1. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling of various methods for the investigation of the morphology of blends of natural rubber and polybutadiene
Authors: Portal J. , Carrot C. , Majeste J.C. , Cocard S. , Pelissier V. , Baran K. , Anselme‐Bertrand I. 
Published: April 2008

AbstractThe aim of this work is to develop a set of experimental methods to investigate the morphology of blends of two immiscible elastomers, namely natural rubber (NR) and polybutadiene (PB). Selective extraction, dynamic mechanical spectroscopy in the melt, and transmission electron microscopy (TEM) were used to get information on the structure of unfilled and uncured blends. 1,2‐dichloroethane and 4‐methyl‐2‐pentanone (MIBK) were employed to dissolve selectively NR and PB in specific conditions to assess the continuity of the phases. In oscillatory shear flow at low frequencies and low volume fractions of the minor phase, the storage modulus shows an excess of elasticity that increases with the dispersed phase content. At higher concentration of the minor phase, the elasticity decreases in relation to the morphology. Samples were also ultra cryo‐microtomed and then analyzed by TEM. The superposition of the three methods highlights the existence of a phase‐inversion point for these systems. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Recycled and virgin LDPE as rheology modifiers of lithium lubricating greases: A comparative study
Authors: Martín‐Alfonso J.E. , Valencia C. , Sánchez M.C. , Franco J.M. , Gallegos C. 
Published: April 2008

AbstractIn this work, a new application for recycled low‐density polyethylene (LDPE), as rheology modifier of standard lithium lubricating grease formulations, was studied. The effectiveness of this additive was compared with that achieved with a virgin LDPE. With this aim, both types of polymers were added to the formulation during the manufacturing process of greases, following the same standard protocol, to reinforce the role of the thickening agent, the lithium 12‐hidroxystearate. The effect that both lithium soap and LDPE concentrations exert on the rheology of lubricating grease formulations and its relationship with grease microstructure were discussed. Lubricating greases were rheologically characterized through small‐amplitude oscillatory shear and viscous flow measurements. In addition to these, scanning electron microscopy observations and mechanical stability tests were also carried out. In all cases, an increase in soap concentration yields higher values of apparent viscosity and linear viscoelasticity functions. On the other hand, the values of the rheological functions obtained for recycled LDPE‐based lubricating greases are, in general, higher than those obtained for virgin LDPE‐based grease formulations. However, the structural skeleton developed in greases containing recycled LDPE demonstrates less resistance to severe working conditions, showing lower mechanical stability than virgin LDPE‐based grease formulations. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers