bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of intermittent loading on SCC behavior for an X70 pipeline steel in a near neutral pH solution
Authors: Wang Z. , Wang J. , Han E. , Ke W. 
Published: July 2007

AbstractThe influence of intermittent loading on stress corrosion cracking (SCC) behavior for an X70 pipeline steel was studied using slow strain rate tests (SSRT) in a near neutral pH soil solution at various applied potentials. The d.c. potential drop method was used to measure the crack initiation and propagation. The crack length at the cross section of the fractured sample was observed using scanning electron microscopy (SEM). The results showed that the crack initiation stress in solution was lower than the yield stress in air. SEM observation showed that the crack length was longer in intermittent loading than that in continuous loading. At anodic potential, the crack initiation stress was the lowest and the crack length was the longest. The crack kept growing during constant loading period.
Elasticity of Single Poly(amido amine) Dendrimers
Authors: Tomczak Nikodem , Vancso G. Julius 
Published: July 2007

AbstractAn atomic force microscope in the compression mode was used to probe the nanomechanical response of single dendrimeric molecules, as well as dendrimer aggregates adsorbed on silicon surface. The force‐compression behaviour of individual, generation 5 poly(amido amine) (PAMAM) dendrimers was described by a Hertzian model for the deformation of elastic bodies. The modulus values obtained ranged between 700 MPa (single dendrimers) and 150 MPa (dendrimer aggregates).magnified image
Temperature Dependence of Creep Behavior of PP–MWNT Nanocomposites
Authors: Ganß Martin , Satapathy Bhabani K. , Thunga Mahendra , Weidisch Roland , Pötschke Petra , Janke Andreas 
Published: July 2007

AbstractThe creep behavior of poly(propylene)–multi‐walled carbon nanotube (MWNT) composites has been studied with short term tensile creep tests at different temperatures and is discussed in relation to the structural characteristics determined by AFM, DSC, and polarized light microscopy. Master curves of creep compliance have been constructed using a time–temperature superposition (TTS) concept based on the William–Landel–Ferry (WLF) equation. The nanocomposites have shown an increase in creep compliance with increasing temperature as a consequence of temperature‐activated motion of the polymer chains. This is critically discussed in the light of activation enthalpy and other influencing factors such as polymer–nanotube interaction and thermal expansion coefficients following semi‐empirical approximations.magnified image
Surface Morphological Evolution of Ultrathin P4VP Films and Generation of Ordered Patterns on Graphite
Authors: Chen Dongzhong , Handa Hitesh , Wan Lei , Mao Guangzhao 
Published: July 2007

AbstractThe spin‐coated thin‐film morphology of poly(4‐vinylpyridine) has been studied by AFM; the dark lines or disks (circular holes) in the AFM height images correspond to the depressed regions. An epitaxy‐like “nano‐trench” pattern was observed in the noncrystalline polymer film deposited on the crystalline graphite substrate. The transition from surface‐templated to isotropic dewetting occurs during 3 nm of the film thickness increase. This study presents an example of ordered nanopatterns emerging from the chaotic spin‐coating process. The well‐defined “nano‐trench” morphology offers an opportunity for the study of the nanoconfinement effect and provides a unique means for surface patterning and nanolithography.magnified image
A finite element modified method of characteristics for convective heat transport
Authors: El‐Amrani Mofdi , Seaïd Mohammed 
Published: July 2007

AbstractWe propose a finite element modified method of characteristics for numerical solution of convective heat transport. The flow equations are the incompressible Navier‐Stokes equations including density variation through the Boussinesq approximation. The solution procedure consists of combining an essentially non‐oscillatory modified method of characteristics for time discretization with finite element method for space discretization. These numerical techniques associate the geometrical flexibility of the finite elements with the ability offered by modified method of characteristics to solve convection‐dominated flows using time steps larger than its Eulerian counterparts. Numerical results are shown for natural convection in a squared cavity and heat transport in the strait of Gibraltar. Performance and accuracy of the method are compared to other published data. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Convergence analysis of an approximation to miscible fluid flows in porous media by combining mixed finite element and finite volume methods
Authors: Amaziane Brahim , El Ossmani Mustapha 
Published: July 2007

AbstractThis article deals with development and analysis of a numerical method for a coupled system describing miscible displacement of one incompressible fluid by another through heterogeneous porous media. A mixed finite element (MFE) method is employed to discretize the Darcy flow equation combined with a conservative finite volume (FV) method on unstructured grids for the concentration equation. It is shown that the FV scheme satisfies a discrete maximum principle. We derive L∞ and BV estimates under an appropriate CFL condition. Then we prove convergence of the approximate solutions to a weak solution of the coupled system. Numerical results are presented to see the performance of the method in two space dimensions. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
FGFR3 protein expression and its relationship to mutation status and prognostic variables in bladder cancer
Authors: Tomlinson DC , Baldo O , Harnden P , Knowles MA 
Published: July 2007

AbstractFGFR3 is frequently activated by mutation in urothelial carcinoma (UC) and represents a potential target for therapy. In multiple myeloma, both over‐expression and mutation of FGFR3 contribute to tumour development. To define the population of UC patients who may benefit from FGFR‐targeted therapy, we assessed both mutation and receptor over‐expression in primary UCs from a population of new patients. Manual or laser capture microdissection was used to isolate pure tumour cell populations. Where present, non‐invasive and invasive components in the same section were microdissected. A screen of the region of the highest tumour stage in each sample yielded a mutation frequency of 42%. Mutations comprised 61 single and five double mutations, all in hotspot codons previously identified in UC. There was a significant association of mutation with low tumour grade and stage. Subsequently, non‐invasive areas from the 43 tumours with both non‐invasive and invasive components were analysed separately; 18 of these had mutation in at least one region, including nine with mutation in all regions examined, eight with mutation in only the non‐invasive component and one with different mutations in different regions. Of the eight with mutation in only the non‐invasive component, six were predicted to represent a single tumour and two showed morphological dissimilarity of fragments within the block, indicating the possible presence of distinct tumour clones. Immunohistochemistry showed over‐expression of FGFR3 protein in many tumours compared to normal bladder and ureteric controls. Increased expression was associated with mutation (85% of mutant tumours showed high‐level expression). Overall, 42% of tumours with no detectable mutation showed over‐expression, including many muscle‐invasive tumours. This may represent a non‐mutant subset of tumours in which FGFR3 signalling contributes to the transformed phenotype and which may benefit from FGFR‐targeted therapies. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
T and B lymphocyte depletion has a marked effect on the fibrosis of dystrophic skeletal muscles in the scid/mdx mouse
Authors: Farini A , Meregalli M , Belicchi M , Battistelli M , Parolini D , D'Antona G , Gavina M , Ottoboni L , Constantin G , Bottinelli R , Torrente Y 
Published: July 2007

AbstractAbnormal connective tissue proliferation following muscle degeneration is a major pathological feature of Duchenne muscular dystrophy (DMD), a genetic myopathy due to lack of the sarcolemmal dystrophin protein. Since this fibrotic proliferation is likely to be a major obstacle to the efficacy of future therapies, research is needed to understand and prevent the fibrotic process in order to develop an effective treatment. Murine muscular dystrophy (mdx) is genetically homologous to DMD, and histopatological alterations are comparable to those of the muscles of patients with DMD. To investigate the development of fibrosis, we bred the mdx mouse with the scid immunodepressed mouse and analysed fibrosis histologically; we used ELISA analysis to determine TGF‐β1 expression. Significant reduction of fibrosis and TGF‐β1 expression was found in the muscles of the scid/mdx mice. However, we observed similar centrally located nuclei, necrosis, muscle degeneration and muscle force compared to the mdx animals. These data demonstrate a correlation between the absence of B and T lymphocytes and loss of fibrosis accompanied by reduction of TGF‐β1, suggesting the importance of modulation of the immune system in DMD. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Poly(methyl methacrylate) Films Deposited via Non‐Equilibrium Atmospheric Pressure Plasma Polymerization Using Argon as Working Gas
Authors: Kasih Tota Pirdo , Kuroda Shin‐ichi , Kubota Hitoshi 
Published: July 2007

AbstractA non‐equilibrium atmospheric pressure plasma torch using argon (Ar) for sustaining plasma has been developed, and it was used to deposit plasma polymerized methyl methacrylate (PPMMA) films. The chemical structure and composition of the films obtained were examined by FT‐IR and XPS analyses. It was found that, when raising the concentration of vaporized monomer to a certain level into the plasma, the plasma transitioned from a filamentary to a glow‐like discharge, this resulting in a high retention of the monomer structure. Since the optical emission spectroscopy (OES) study of the plasma did not show any new excited species formed at higher concentrations of the monomer, it is clear that the fragmentation degree of the monomer in the plasma phase was quite low.magnified image
Coherent state path integral and super‐symmetry for condensates composed of bosonic and fermionic atoms
Authors: Mieck B. 
Published: July 2007

AbstractA super‐symmetric coherent state path integral on the Keldysh time contour is considered for bosonic and fermionic atoms which interact among each other with a common short‐ranged two‐body potential. We investigate the symmetries of Bose‐Einstein condensation for the equivalent bosonic and fermionic constituents with the same interaction potential so that a super‐symmetry results between the bosonic and fermionic components of super‐fields. Apart from the super‐unitary invarianceU(L|S) of the density terms, we specialize on the examination of super‐symmetries for pair condensate terms. Effective equations are derived for anomalous terms which are related to the molecular‐ and BCS‐ condensate pairs. A Hubbard‐Stratonovich transformation from ‘Nambu’‐doubled super‐fields leads to a generating function with super‐matrices for the self‐energy whose manifold is given by the orthosympletic super‐groupOsp(S,S| 2L). A nonlinear sigma model follows from the spontaneous breaking of the ortho‐symplectic super‐groupOsp(S,S| 2L) to the coset decompositionOsp(S,S| 2L) \U(L|S)⊗U(L|S). The invariant subgroupU(L|S) for the vacuum or background fields is represented by the density terms in the self‐energy whereas the super‐matrices on the coset spaceOsp(S,S| 2L) \U(L|S) describe the anomalous molecular and BCS‐ pair condensate terms. A change of integration measure is performed for the coset decompositionOsp(S,S| 2L) \U(L|S) ⊗U(L|S), including a separation of density and anomalous parts of the self‐energy with a gradient expansion for the Goldstone modes. The independent anomalous fields in the actions can be transformed by the inverse square root$\hat{G}_{Osp\backslash U}^{-1/2}$of the metric tensor ofOsp(S,S| 2L) \U(L|S) so that the non‐Euclidean integration measure with super‐Jacobi‐determinant$[{\rm SDET} (\hat{G}_{Osp\backslash U})]^{1/2}$can be removed from the coherent state path integral and Gaussian‐like integrations remain. The variations of the independent coset fields in the effective actions result in classical field equations for a nonlinear sigma model with the anomalous terms. The dynamics of the eigenvalues of the coset matrices is determined by Sine‐Gordon equations which have a similar meaning for the dynamics of the molecular‐ and BCS‐pair condensates as the Gross‐Pitaevskii equation for the coherent wave function in BEC phenomena.
Thermal evolution of small N–D complexes in deuterated dilute nitrides revealed by in‐situ high resolution X‐ray diffraction
Authors: Bisognin G. , De Salvador D. , Napolitani E. , Berti M. , Polimeni A. , Felici M. , Capizzi M. , Bais G. , Jabeen F. , Piccin M. , Rubini S. , Martelli F. , Franciosi A. 
Published: July 2007

AbstractIn this article we studied the thermal evolution of nitrogen–deuterium (N–D) complexes which form in dilute nitride GaAs1–x Nx alloys as a consequence of D irradiation. These complexes are particularly important and interesting because they lead to the electronic passivation of N and also because their formation is accompanied by a strain reversal (from tensile to compressive) of the as‐grown material. By collecting in‐situ high resolution X‐ray diffraction rocking‐curves during thermal annealing, we were able to monitor in real time the evolution of the lattice parameter (a) of the samples, demonstrating that two processes are involved in the dissolution of N–D clusters. During the first process a evolves from values larger than that of the GaAs substrate saturating at values very close to the GaAs one, while the second process, that starts at a higher temperature, leads to an almost complete recovery of the D‐free GaAs1–x Nx lattice parameter. By analizing the thermal evolution of a, we were able to extract information about the energetics of the two N–D complexes dissolution steps. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of stacking fault densities in 3C‐SiC crystals by diffuse X‐ray scattering
Authors: Boulle A. , Chaussende D. , Pecqueux F. , Conchon F. , Latu‐Romain L. , Masson O. 
Published: July 2007

AbstractThick 3C‐SiC single crystals grown by continuous‐feed physical vapor transport (CF‐PVT) are studied by high‐resolution X‐ray reciprocal space mapping. These crystals contain Shockley‐type stacking faults (SFs) lying in the {111} planes, which give rise to diffuse intensity streaks along the 〈111〉 directions. An approach is presented that allows to determine, in combination with the simulation of transverse scans, the SF density from the simulation of the diffuse intensity streaks. SF densities as low as 0.4 × 103 cm–1 could be detected in high‐quality CF‐PVT grown crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation by High Resolution X‐ray Diffraction of the local strains induced in Si by periodic arrays of oxide filled trenches
Authors: Eberlein M. , Escoubas S. , Gailhanou M. , Thomas O. , Micha J.‐S. , Rohr P. , Coppard R. 
Published: July 2007

AbstractHigh Resolution X‐ray Diffraction allows for the measurement of periodic strain fields in monocrystalline silicon and is non‐destructive. In this study a periodic strain field is induced in Si by SiO2 filled trenches (Shallow Trench Isolation process). The strain in Si is evaluated for different periods of the trench arrays namely from 2 μm to 0.2 μm. The periodic strain field gives rise to satellites in reciprocal space maps around the Si substrate peak. The intensity and envelope of these satellites depend on the local strain. The experimental reciprocal space maps are qualitatively compared with those computed from the elastic displacement field calculated with finite element modeling. When the array period decreases, a strong increase in local strain is observed. From 0.58 μm period and below, in addition to the Si substrate diffraction peak, a secondary diffraction peak representative of the strain in Si lines can be distinguished on reciprocal space maps. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray diffraction peaks from misfit dislocations in double‐ and triple‐crystal diffractometry
Authors: Kaganer Vladimir M. , Shalimov Artem , Bak‐Misiuk Jadwiga , Ploog Klaus H. 
Published: July 2007

AbstractWe propose a common description of the full widths at half maximum of X‐ray diffraction peaks obtained in different scans of triple‐crystal diffractometry and as well as for glancing incidence and glancing exit double‐crystal measurements. Calculations are compared with measurements of GaAs/Si(001) heteroepitaxial films. We show that the diffraction peak broadening is entirely due to random 60° misfit dislocations that provide only a minor part of the misfit relaxation. The remaining relaxation is due to periodic edge misfit dislocations that do not contribute to the peak broadening. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anomalous scattering and isomorphous replacement in X‐ray diffuse scattering holography
Authors: Kopecký Miloš , Kub Jiří , Busetto Edoardo , Lausi Andrea , Fábry Jan , Šourek Zbyněk 
Published: July 2007

AbstractTwo concepts of X‐ray diffuse scattering holography resulting in local atomic structure are presented. The first one uses the anomalous scattering near the absorption edge of a selected element. The second one is based on the variation of atomic scattering factor due to the isomorphous replacement of a selected atom in the structure by another one with different scattering properties. Feasibility of both concepts was demonstrated experimentally on a RbCl single crystal and GaMnAs epitaxial layer. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wide angle X‐ray dynamical diffraction by deformed crystals: recurrence relations
Authors: Pavlov K. M. , Paganin D. M. , Vine D. J. , Kirste L. 
Published: July 2007

AbstractDynamical wide‐angle multiwave X‐ray diffraction from a deformed crystal was considered, for the special case when no more than one strong reflection occurs at a time. The obtained set of equations can be transformed to the Takagi two‐beam approximation if the scattering vector is close to a vector of the reciprocal lattice. The new formalism was employed to obtain recurrence relations for the amplitude reflection coefficient corresponding to laterally homogeneous multilayer structures for the case of coplanar Bragg diffraction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pyroelectric‐piezoelectric related enhancement of the domain contrast on topographs performed using a coherent X‐ray beam in LiNbO3 at low temperature
Authors: Pernot Petra , Baruchel José 
Published: July 2007

AbstractLow‐temperature experiments (20–300 K) on a periodically poled lithium niobate using white‐beam section topography with a highly coherent X‐ray beam show a dramatic increase of the periodic contrast. This contrast produces as periodic black lines, with the period of the domains, and it occurs even for short sample‐to‐detector distances (10 cm). This behaviour suggests a new origin of the contrast, which adds to the room temperature one associated with the phase difference between the structure factors of inverted domains. We propose an explanation of the observed phenomenon at low temperatures, based on additional phase contrast between adjacent domains appearing due to their misorientation via the lattice parameter a modification that produces through the inverse piezoelectric effect. This effect results from the constant sign of the internal electric field present in the sample, and the sign variation, from one domain to the other, of the generated pyroelectric response, which increases substantially below 180 K. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time X‐ray reflectometry during thin‐film processing
Authors: Peverini L. , Kozhevnikov I. , Ziegler E. 
Published: July 2007

AbstractAn apparatus and a characterization technique have been developed at the ESRF beamline BM5 to investigate in‐situ the evolution of the morphology of a film using grazing incidence X‐ray reflectometry. The instrument is capable of measuring in‐situ and in real time the X‐ray intensity specularly and diffusely scattered from a rough thin film during various surfacing processes. The variation of the specular intensity as a function of the processing time, recorded simultaneously with each X‐ray scattering diagram, is analyzed to infer the film growth rate, the film density and the variation of roughness conformity during surface processing.The potential of the method is demonstrated for two particular cases: thin film deposition by magnetron sputtering and subsequent film etching by low energy ion bombardment. The paper describes some recent achievements and present examples of on‐line diagnostics for which real time in‐situ X‐rays reflectometry proves to be a unique probe. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time and in situ solidification of Al‐based alloys investigated by synchrotron radiation: a unique experimental set‐up combining radiography and topography techniques
Authors: Buffet A. , Reinhart G. , Schenk T. , Nguyen‐Thi H. , Gastaldi J. , Mangelinck‐Noël N. , Jung H. , Härtwig J. , Baruchel J. , Billia B. 
Published: July 2007

AbstractA unique experimental set‐up combining X‐ray radiography and topography has been recently developed at the ESRF. It allows direct observation of the solidification microstructure by these two complementary imaging techniques. This combined observation offers new possibilities, in particular for the investigation of strains, stresses and defect formation during directional solidification. In this paper we present in detail the experimental device and selected results obtained for two Al‐based alloys: Al–3.5 wt% Ni and β‐Al3Mg2. For the first time, we were able to characterize and quantify (by using topography) mechanical phenomena observed by radiography during the growth process. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synchrotron X‐ray Renninger scanning for studying strain in InAs/GaAs quantum dot system
Authors: Freitas Raul O. , Lamas Tomás E. , Quivy Andre A. , Morelhão Sérgio L. 
Published: July 2007

AbstractA systematic procedure for ultra‐precise lattice parameter determination using X‐ray Renninger scanning (XRS) is optimized and applied to probe the average in‐plane strain in series of samples representing the different stages of the growth process of single‐buried quantum dots (QDs). Covering InAs QDs growth on GaAs(001) substrates generates an expansive in‐plane strain that is related to the density of QDs. Rocking curves and atomic force microscopy are also used for a general qualitative analysis of the growths, as well as of the morphology and density of the QDs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analyzer‐based X‐ray phase contrast imaging with four bounce Si(444) monochromators at ELETTRA
Authors: Hönnicke M. G. , Rigon L. , Arfelli F. , Menk R.‐H. , Cusatis C. 
Published: July 2007

AbstractAn analyzer‐based X‐ray phase contrast imaging setup (ABI) based on four bounce Si(444) monochromators at 18 keV mounted at the SYRMEP beamline at Elettra is presented. The system was stable for the employed exposure times. Contrasts, visibility of the object edges and signal to noise ratio of the acquired images were studied. Simulation procedures of the images were also exploited. The results show that such setup can be used for high sensitivity (high contrast) experiments at Elettra. Also, due to intrinsic properties, this setup can be useful for future ultra‐small angle X‐ray scattering experiments. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)