ALBERT

Description:    The effect of strain accumulation in the InAs/In x Ga 1− x As quantum dots (QDs) system was studied in this work. It was found that strain in the In x Ga 1− x As layer accumulation in the QD layer. This effect resulted in a dramatic reduction of growth mode transition thickness of the QD layer. For InAs/In 0.25 Ga 0.75 As QDs, critical thickness is measured to be as low as 1.08 ML. The experimental results in this work highlight the importance of strain accumulation in the design and fabrication of QD-based devices with metamorphic buffer layer involved. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6482-1 Authors Lu Wang, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Meicheng Li, School of Renewable Energy, North China Electric Power University, Beijing, 102206 China Wenxin Wang, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Haitao Tian, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Zhigang Xing, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Min Xiong, School of Material Science and Technology, Harbin Institute of Technology, Harbin, China Liancheng Zhao, School of Material Science and Technology, Harbin Institute of Technology, Harbin, China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The strong influence of laser polarization on the orientation and shape of femtosecond-laser-induced self-organized nanostructures (‘ripples’, LIPSS) still constitutes an open question, taking into account that the laser electric field is present only at the first step of electronic excitation. Based on the explanation of similar structures generated during ion sputtering, we present a theoretical model indicating a possible explanation for this phenomenon. Our model shows that a directional asymmetry in the pattern can result from a spatial asymmetry of the initial excitation, induced e.g. by a corresponding distribution of excited-electron kinetic energies. Numerical simulation of this model yields typical patterns which are compared to experimental observations under appropriate conditions. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6472-3 Authors Juergen Reif, Experimental Physics II/Materials Science, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Olga Varlamova, Experimental Physics II/Materials Science, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Sergej Varlamov, Statistical Physics and Nonlinear Dynamics, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Michael Bestehorn, Statistical Physics and Nonlinear Dynamics, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The preparation of chlorine-, bromine-, and iodine-terminated silicon surfaces (Si(111):Cl, Br, and I) using atomically flat Si(111)-(1×1):H is described. The halogenated surfaces were obtained by photochemically induced radical substitution reactions with the corresponding dihalogen in a Schlenk tube by conventional inert gas chemistry. The nucleophilic substitution of the Si-Cl functionality with the Grignard reagent (CH 3 MgCl) resulted in the unreconstructed methylated Si(111)-(1×1):CH 3 surface. The halogenated and methylated silicon surfaces were characterized by Fourier transform infrared (FTIR) spectroscopy and laser-induced desorption of monolayers (LIDOM). Calibration of the desorption temperature via analysis of time-of-flight (TOF) distributions as a function of laser fluence allowed the determination of the originally emitted neutral fragments by TOF mass spectrometry using electron-impact ionization. The halogens were desorbed atomically and as SiX n (X = Cl, Br) clusters. The methyl groups mainly desorbed as methyl and ethyl fragments and a small amount of + SiCH 3 . Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6483-0 Authors Nils Salingue, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany Peter Hess, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    This paper investigates the flow field near three intersecting shock waves appearing in steady Mach reflection. Results of numerical computations reveal a “von Neumann Paradox”—like feature for weak shock waves, in which the flow field between the reflected and the Mach stem is smooth with no distinct slip flow region and changes rather smoothly. An analytical solution of the Navier–Stokes equations constructed using a polar–coordinate system gives a flow field with the same properties as the numerical simulation. Content Type Journal Article Pages 1-6 DOI 10.1007/s00193-011-0329-8 Authors A. Sakurai, Tokyo Denki University, Kanda, Tokyo, Japan M. Tsukamoto, Tokyo Denki University, Kanda, Tokyo, Japan D. Khotyanovsky, Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia M. Ivanov, Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia Journal Shock Waves Online ISSN 1432-2153 Print ISSN 0938-1287

Description:    The propagation and attenuation of an initial shock wave through a mm-scale channel of circular cross-section over lengths up to 2,000 diameters is examined as a model problem for the scaling of viscous effects in compressible flows. Experimental wave velocity measurements and pressure profiles are compared with existing data and theoretical predictions for shock attenuation at large scales and low pressures. Significantly more attenuation is observed than predicted based on streamtube divergence. Simulations of the experiment show that viscous effects need to be included, and the boundary layer behavior is important. A numerical model including boundary layer and channel entrance effects reproduces the wave front velocity measurements, provided a boundary layer transition model is included. A significant late-time pressure rise is observed in experiments and in the simulations. Content Type Journal Article Pages 1-11 DOI 10.1007/s00193-011-0330-2 Authors J. M. Austin, Department of Aerospace Engineering, University of Illinois, Urbana, IL 61801, USA D. J. Bodony, Department of Aerospace Engineering, University of Illinois, Urbana, IL 61801, USA Journal Shock Waves Online ISSN 1432-2153 Print ISSN 0938-1287

Description: Erratum to: The Role of Tortuosity in Upscaling Content Type Journal Article Pages 1-3 DOI 10.1007/s11242-011-9787-9 Authors Francisco J. Valdés-Parada, Area de Ingeniería en Recursos Energéticos, Universidad Autónoma Metropolitana-Iztapalapa, Mexico, D.F. 09340, Mexico Mark L. Porter, EES-14, MS D462, Los Alamos National Laboratory, Los Alamos, NM 87545, USA Brian D. Wood, School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USA Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description: A modified predictor-corrector scheme combining with the depth gradient method (DGM) and the weighted average flux (WAF) method has been presented to solve the one-dimensional shallow water equations with source terms. Approximate solutions in the predictor step are obtained by the DGM with piecewise-linear reconstructions in each cell volume. The source terms can then be calculated directly by these predicted values at the corresponding half-time step. In the corrector step, the TVD version of the WAF method is applied to calculate the numerical fluxes at the same half-time step for each cell face. The accuracy of numerical solutions is shown by applying the method to solve various test cases in both steady and unsteady problems with and without source terms. It shows that the numerical results are in good agreement with the existing analytical solutions as well as experimental data in some test cases.

Description: Based on the iterated statistically multiscale analysis (SMSA), we present the convergence of the equivalent mechanical parameters (effective moduli), obtain the error result, and prove the symmetric, positive and definite property of the equivalent mechanical parameters tensor computed by the finite element method. The numerical results show the proved results and illustrate that the SMSA-FE algorithm is a rational method for predicting the equivalent mechanical parameters of the composite material with multiscale random grains. In conclusion, we discuss the future work for the inhomogeneous composite material with multiscale random grains.

Description: In the present note, we study slant and hemislant submanifolds of an LP-cosymplectic manifold which are totally umbilical. We prove that every totally umbilical proper slant submanifold M of an LP-cosymplectic manifold M¯ is either totally geodesic or if M is not totally geodesic in M¯ then we derive a formula for slant angle of M. Also, we obtain the integrability conditions of the distributions of a hemi-slant submanifold, and then we give a result on its classification.

Description: One of the main methods to reduce the production costs is waste recycling which is the most important challenge for the future. Cotton wastes collected from ginning process have desirable properties which could be used during spinning process. The purpose of this study was to develop predictive models of breaking strength and mass irregularity (CVm%) of cotton waste rotor-spun yarns containing cotton waste collected from ginning process by using the artificial neural network trained with backpropagation algorithm. Artificial neural network models have been developed based on rotor diameter, rotor speed, navel type, opener roller speed, ginning waste proportion and yarn linear density as input parameters. The parameters of artificial neural network model, namely, learning, and momentum rate, number of hidden layers and number of hidden processing elements (neurons) were optimized to get the best predictive models. The findings showed that the breaking strength and mass irregularity of rotor spun yarns could be predicted satisfactorily by artificial neural network. The maximum error in predicting the breaking strength and mass irregularity of testing data was 8.34% and 6.65%, respectively.

Description:    We have demonstrated spatially selective modification of the magnetic properties of transparent iron-oxide-doped glass by femtosecond- (fs-) laser irradiation and subsequent annealing. A near-infrared fs-laser beam with a wavelength of 775 nm was focused 1 mm below the surfaces of glass samples. This produces absorption peaks due to the formation of hole-trap centers in the irradiated region. Transparency was recovered after annealing at 450°C. A ferrimagnetic component was observed in the M–H curve even at room temperature, whereas the diamagnetic component dominated in the M–H curve of the as-prepared glass sample. This indicates that fs-laser irradiation enhanced the magnetization in the irradiated area. The irradiated and annealed glass sample also exhibited superparamagnetic blocking in the temperature dependence of the magnetization with a blocking temperature higher than room temperature. This change in magnetism is presumably due to local crystallization of ferrimagnetic nanoparticles, such as magnetite, induced by fs-laser irradiation and annealing. The magnetic and optical properties of glass that had been annealed but not irradiated by a fs-laser beam remained unchanged. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6485-y Authors Seisuke Nakashima, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Koji Sugioka, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Katsumi Midorikawa, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description: The possibility of condensation of electron pairs has been established by Yang and Coleman. Recent observations of Bose-Einstein condensate (BEC) of alkali atoms, containing odd number of electrons, require some explanation, which also must be based on a correct permutational symmetry of a system, containing different types of fermions. In the framework of the same reduced density matrix formalism, it is proved that aggregates (atoms), containing even number 2f of fermions, can be condensed only in a mixed quantum state in contrast to elementary bosons because a natural occupation number λ is proved to be strictly smaller than their total sum. If fermions are absent in aggregates the reduction of sum of λ to one term becomes possible. The upper bound λ_{max} for a macroscopic ensemble of n aggregates, built of m different sorts of fermions is shown to be m^1[((2f-1)!!)^3 A/(2f)!!B]^{1/2} where A is the number of all possible aggregates in a system, B is the number of ways to form a given composition of an aggregate from 2f-fermions of m sorts; n is a macroscopic greatest common devisor of fermion numbers of all sorts. The bound λ_{max} increases as n^{f}, while sum of λ grows as n^{2f}. The evenness of the total number of fermions 2f in an aggregate is a necessary and sufficient condition for BEC formation. In particular, the number N of neutrons in neutral atom must be even because of the integrity of f=Z+N/2. The extreme type wave function is built, for which λ is arbitrary close to n^{f} that proves the sufficiency of this criterion. The occupation maximum is achieved when pairs of fermions (identical or different) are condensed independently. The possibility of condensation of bound aggregates only (atoms) is shown arising from nonoverlapping of wave functions of electron relative coordinates of different atoms. This conclusion is based on separation of the centers' of mass motion, which are proved behaving like a bosonic gas. The remaining product of identical atomic wave functions of relative coordinates, which determine main properties of condensate ingredients, is shown not requiring further antisymmetrization that makes condensation possible. Content Type Journal Article Pages 127-142 DOI 10.3233/JCM-2011-0370 Authors M. Mestechkin, 12773 Seabreeze Farms Dr. # 33, San Diego, CA 92130, USA. E-mail: mestechkinmm@gmail.com Journal Journal of Computational Methods in Science and Engineering Online ISSN 1875-8983 Print ISSN 1472-7978 Journal Volume Volume 11 Journal Issue Volume 11, Number 3 / 2011

Description: The present work consists to elaborate a computing program able to generate a Delaunay unstructured triangular meshes around the complex configurations applied in aerodynamics, like airfoil of aircraft, multi-elements airfoils, nacelle, fuselage, etc... While basing on the Delaunay criterion, again called 'in-circle criterion' of the hollow circle that means no point is inside a circle circumscribes a triangle of the mesh. The initial mesh can be set up by joining the trailing-edge point of the airfoil to all the outer boundary points, the surface mesh points for the airfoil are then introduced one at a time, and the internal nodes of the O-mesh generated by using a sequence of conformal transformation of Von Karman Trefftz through the whole domain of the out-flow. Each time a new point is introduced, the triangles failing the 'Delaunay criterion' are located using the tree-search algorithm, forming a convex cavity named 'Delaunay cavity'. These triangles will be broken and will be replaced by new triangles while connecting this new point to each of the points at vertices of this cavity. This generated a new triangulation and the algorithm repeats this process with the next new point until succeed to a Delaunay mesh. A Laplacian filter is used to reposition the mesh points in order to have a regular mesh clever to be exploited by the numerical methods: finite volume method or finite element method. Content Type Journal Article Pages 143-158 DOI 10.3233/JCM-2011-0372 Authors Toufik Zebbiche, University SAAD Dahleb of Blida, BP 270, Blida 09000, Algeria Nasreddine Hamdi, University Amar TELIDJI of Laggouat, BP 37, Lagouat 03000, Algeria Journal Journal of Computational Methods in Science and Engineering Online ISSN 1875-8983 Print ISSN 1472-7978 Journal Volume Volume 11 Journal Issue Volume 11, Number 3 / 2011

Description: We study tubular surfaces in Euclidean 3-space satisfying some equations in terms of the Gaussian curvature, the mean curvature, the second Gaussian curvature, and the second mean curvature. This paper is a completion of Weingarten and linear Weingarten tubular surfaces in Euclidean 3-space.

Description:    In this paper, we demonstrate that cubic gadolinium oxide is paramagnetic and follows the Curie–Weiss law from 20 K to room temperature for particles size comprised between 3.5 and 60 nm. The largest particles (60 nm) possess the macroscopic behaviour of Gd oxide with a Néel temperature, T N , close to 18 K (Gd oxide is antiferromagnetic below T N , paramagnetic above). Then size-induced effects can be encountered only for particles smaller than 60 nm. We find that the finite-size scaling model used for describing the size evolution of the antiferro/paramagnetic transition is valid for sizes comprised between 3.5 and 35 nm with parameters in excellent agreement with those usually found for antiferromagnetic materials. The correlation length (3.6 nm) is of the order of magnitude of a few lattice parameters and the critical exponent λ is found equal to 1.3, a value very close to that predicted by the three dimensional Heisenberg model ( λ =1.4). Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6492-z Authors B. Mutelet, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France N. Keller, GEMAC, UMR 8635 CNRS, Université de Versailles-St-Quentin, 45, avenue des Etats-Unis, 78035 Versailles Cedex, France S. Roux, UTINAM, UMR 6213 CNRS, Université de Franche-Comté, 25030 Besanon Cedex, France M. A. Flores-Gonzales, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France F. Lux, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France M. Martini, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France O. Tillement, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France C. Billotey, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France M. Janier, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France C. Villiers, INSERM U823, Institut Albert Bonniot, Rond Point de la Chantourne, 38574 La Tronche, France Ghenadie Novitchi, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard, 3 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France Dominique Luneau, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard, 3 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France P. Perriat, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Pore networks can be extracted from 3D rock images to accurately predict multi-phase flow properties of rocks by network flow simulation. However, the predicted flow properties may be sensitive to the extracted pore network if it is small, even though its underlying characteristics are representative. Therefore, it is a challenge to investigate the effects on flow properties of microscopic rock features individually and collectively based on small samples. In this article, a new approach is introduced to generate from an initial network a stochastic network of arbitrary size that has the same flow properties as the parent network. Firstly, we characterise the realistic parent network in terms of distributions of the geometrical pore properties and correlations between these properties, as well as the connectivity function describing the detailed network topology. Secondly, to create a stochastic network of arbitrary size, we generate the required number of nodes and bonds with the correlated properties of the original network. The nodes are randomly located in the given network domain and connected by bonds according to the strongest correlation between node and bond properties, while honouring the connectivity function. Thirdly, using a state-of-the-art two-phase flow network model, we demonstrate for two samples that the rock flow properties (capillary pressure, absolute and relative permeability) are preserved in the stochastic networks, in particular, if the latter are larger than the original, or the method reveals that the size of the original sample is not representative. We also show the information that is necessary to reproduce the realistic networks correctly, in particular the connectivity function. This approach forms the basis for the stochastic generation of networks from multiple rock images at different resolutions by combining the relevant statistics from the corresponding networks, which will be presented in a future publication. Content Type Journal Article Pages 1-23 DOI 10.1007/s11242-011-9792-z Authors Z. Jiang, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK M. I. J. van Dijke, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK K. Wu, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK G. D. Couples, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK K. S. Sorbie, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK J. Ma, Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, EH14 4AS UK Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description:    Surface ablation of a dielectric material (fused silica) by single femtosecond pulses is studied as a function of pulse duration (7–450 fs) and applied fluence ( F th 〈 F 〈10 F th ). We show that varying the pulse duration gives access to high selectivity (with resolution ∼10 nm) for axial removal of matter but does not influence the transverse ablation selectivity, which only depends on the normalized applied fluence F / F th . The ablation efficiency is shown to be inversely dependent on the pulse duration and saturates with respect to the applied fluence earlier at ultra-short pulse durations (≤30 fs). The deduced optimal fluence F opt corresponding to the highest ablation efficiency for each pulse width defines two regimes of laser application. Below F opt , the removed material depth can be accurately adjusted in a large range (∼40–200 nm) as a function of the applied fluence and the morphology of the ablated pattern almost reproduces the Gaussian beam distribution. Above F opt , the material removal depth tends to saturate and the morphology of the ablated pattern evolves to a top-hat distribution. The coupled evolution of depth and morphology is related to the dynamics of formation of dense plasma at the surface of the material, acting as an ultra-fast optical shutter. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6469-y Authors O. Utéza, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France N. Sanner, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France B. Chimier, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France A. Brocas, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France N. Varkentina, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France M. Sentis, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France P. Lassonde, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada F. Légaré, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada J. C. Kieffer, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    An energy source produced by a TEA CO 2 laser operated at 10.6 μm primarily was considered as a key essential in this paper to describe the energy conversion process in air-breathing laser propulsion in the round. Some secondary factors were ignored when three independent modules, a ray transmission module, an energy source term module and a fluid mechanics module, were established by a simultaneous laser radiation transportation equation and a fluid mechanics equation set-up. The incident laser beam after being reflected by the optical system or transmitted by it was simulated based on a certain geometrical optics method named ray tracing. Thus, coherent superimposition could be avoided when describing the laser beam focusing process, and so could the solving process of the laser wave equation at the non-paraxial condition. The calculated results were in good agreement with those of theoretical analysis and experiments. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6479-9 Authors Yanji Hong, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Junling Song, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Cunyan Cui, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Qian Li, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Engineering design of thermal quality clothing is a promising solution by applying multi-disciplinary knowledge to achieve the design and production of clothing with desirable thermal functions. In this paper, a special simulation-based and lifestyle-oriented CAD system is introduced to help the user in engineering design of thermal quality clothing. The engineering-oriented simulation models endowed with explicit data availability arose from the material parameters that are the key issue for engineering application. To offer an easy-to-use tool, this system is implemented with a lifestyle-oriented design procedure. It can facilitate the designers to quickly implement design and simulate on the wearing scenario, and evaluate and optimize their design. Due to the design of thermal quality clothing can be achieved without making physical prototypes, it is able to speed up the design cycle and reduce the design and development cost. Content Type Journal Article Pages 1-17 DOI 10.1007/s00366-011-0224-z Authors Aihua Mao, School of Computer Science and Engineering, South China University of Technology, Guangzhou, 510006 China Jie Luo, Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China Yi Li, Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China Ruomei Wang, School of Information Science and Technology, Sun Yat-Sen University, Guangzhou, 510006 China Guiqing Li, School of Computer Science and Engineering, South China University of Technology, Guangzhou, 510006 China Yueping Guo, Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China Journal Engineering with Computers Online ISSN 1435-5663 Print ISSN 0177-0667

Description:    Understanding the mechanical properties of ancient paintings is a major issue for conservation and restoration. One strategy is to measure the mechanical properties of reconstructed paints: however, the aging process is poorly known, so it is also desirable to measure mechanical properties directly on ancient paint samples. Using nanoindentation, we have characterized submillimetric samples recovered from restoration of two Van Gogh paintings and compared the results with reconstructed paint samples. We demonstrate that the reduced modulus and hardness of historical paints can be measured at a very local scale, even differentiating between each paint layer. Our reconstructed paint samples exhibit elastic moduli comparable to values of the literature, but the values measured on the two 19th century paint samples are found to be significantly larger. Similarly, the compositional dependence of the elastic modulus is consistent with literature results for our reconstructed samples while our preliminary results for ancient samples do not readily fall into the same pattern. These results all point out to a significant impact of long term aging, in a manner which is difficult to predict in our present state of understanding. They demonstrate that nanoindentation is a very adequate tool to improve our knowledge of art paint mechanics and aging. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6486-x Authors Johanna Salvant, Laboratoire du Centre de Recherche et de Restauration des Musées de France (C2RMF), CNRS UMR 171, Palais du Louvre, 14, Quai François Mitterrand, Paris, 75001 France Etienne Barthel, Laboratoire CNRS/Saint-Gobain “Surface du Verre et Interfaces”, UMR 125, 39, Quai Lucien Lefranc, BP 135, Aubervilliers Cedex, 93303 France Michel Menu, Laboratoire du Centre de Recherche et de Restauration des Musées de France (C2RMF), CNRS UMR 171, Palais du Louvre, 14, Quai François Mitterrand, Paris, 75001 France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The effect of HfO 2 on phase change characteristics of Sb 2 Te 3 films for phase change memory (PCM) applications was investigated by in situ temperature dependence of electrical resistance measurement, X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. It is shown that HfO 2 inhibited the crystallization of the amorphous Sb 2 Te 3 films, which improved the long-term stability of metastable amorphous phase. Memory devices based on Sb 2 Te 3 –HfO 2 composite films with HfO 2 concentrations of 10 at.% and 15 at.% were successfully fabricated and characterized. The 15 at.% HfO 2 -based memory device exhibited lower reset voltage and power consumption compared with the 10 at.% HfO 2 - and Ge 2 Sb 2 Te 5 -based ones. The endurances exceeded 1.6×10 5 and 2.2×10 5 SET–RESET cycles for 10 at.% and 15 at.% HfO 2 -based memory devices, respectively, and the resistance ratio between RESET and SET states achieved two orders of magnitude for both memory devices. The Sb 2 Te 3 –HfO 2 composite films, especially with HfO 2 concentration of 15 at.%, could be one of the most promising materials for application in PCM devices. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6478-x Authors Yegang Lu, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Sannian Song, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Zhitang Song, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Kun Ren, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Bo Liu, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Songlin Feng, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description: The aim of the current research is to propose a new generation of automated guided vehicle systems for alleviating the collision states in material handling systems where the automated guided vehicles movements are allowed to be both unidirectional and bidirectional. The objective function is to maximize the average annual profit in an FMS system using a simulation method. Despite several researches done in this field, this criterion has been studied rarely. The current study includes some new changes in AGV design for preventing some common problems such as congestions and deadlocks based on real profits/costs analysis in a flexible manufacturing system. For this reason, some experiments have been carried out to study the effects of several empty vehicle dispatching rules on average annual profit. The results show that the proposed framework is efficient and robust enough for industrial environments.

Description: We analyze a previous paper by S. T. Mohyud-Din and M. A. Noor (2007) and show the mistakes in it. Then, we demonstrate a more efficient method for solving fourth-order boundary value problems.

Description: A simple lexisearch algorithm that uses path representation method for the asymmetric traveling salesman problem (ATSP) is proposed, along with an illustrative example, to obtain exact optimal solution to the problem. Then a data-guided lexisearch algorithm is presented. First, the cost matrix of the problem is transposed depending on the variance of rows and columns, and then the simple lexisearch algorithm is applied. It is shown that this minor preprocessing of the data before the simple lexisearch algorithm is applied improves the computational time substantially. The efficiency of our algorithms to the problem against two existing algorithms has been examined for some TSPLIB and random instances of various sizes. The results show remarkably better performance of our algorithms, especially our data-guided algorithm.

Description: The 2-DOF controllable close-chain linkage mechanism is investigated in this paper. Based on the characteristics of the multi-DOF nonlinear coupling dynamic equation of the system established by the finite element method, an analytic method of multiple-scales Newmark is presented after thinking about the method of perturbation and the method of numerical analysis. Firstly, the first-order approximate solution of the dynamic responses of the system at the time of t is calculated by the multiple scales method. Then, taken the first-order approximate solution as the initialization of the generalized coordinate of the system, the stable dynamic response of the system is obtained by the implicit Newmark method. The simulation and experimental results are given in the end. The studies indicate that the method of multiple-scales Newmark is correct and practicable to study the dynamic characteristics of such kind of multi-DOF nonlinear coupling system.

Description:    We investigated the ejection dynamics of triazene polymer layers in the thickness range of 40 nm to 600 nm upon nanosecond laser ablation at a wavelength of 532 nm. The ablation is due to laser-induced thermal degradation of a small part of the polymer in contact with the silicon substrate. The subsequent dynamics of the flying polymer layer are measured with sub-nanosecond time resolution. The evaluation of the initial velocity for different film thicknesses gives insight into the energy transfer process during the acceleration of the films. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6500-3 Authors P. Frank, University of Konstanz, 78457 Konstanz, Germany J. Shaw-Stewart, Laboratory for Functional Polymers, EMPA, Swiss Federal Laboratories for Material Testing and Research, Überlandstrasse 129, 8600 Dübendorf, Switzerland T. Lippert, General Energy Research Department, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland J. Boneberg, University of Konstanz, 78457 Konstanz, Germany P. Leiderer, University of Konstanz, 78457 Konstanz, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description: A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

Description: Cerebral aneurysms are local expansions of blood vessel walls in the brain blood system. The rupture of an aneurysm is a very severe event associated with a high rate of mortality. When cerebral aneurysms are detected, clinicians need to decide if operation is required. The risk of aneurysm rupture is then compared to the risks associated with the medical intervention. In the present paper, a probabilistic framework for a mechanically based rupture risk assessment of cerebral aneurysms is proposed. The method is based on the assumption that the strength of aneurysmal tissues can be described by a statistical distribution. A structural analysis of the aneurysm in question is performed, and the maximum stress experienced by the aneurysm is compared to the strength distribution. The proposed model was compared with clinical results for ruptured aneurysms in terms of rupture density and accumulated rupture risk as a function of aneurysm size. The model was able to reproduce the clinical results well. The proposed framework may potentially be used under in vivo conditions to predict the risk of rupture for diagnosed aneurysms.

Description:    Spontaneous nanostructure formations on roughened and smooth silicon surface by the femtosecond laser irradiation with the repetition rate of 100 kHz were systematically studied. In addition to the widely accepted so-called coarse ripple, which has the period analogous to the wavelength of the laser beam and aligns perpendicularly to the electric field of the incident laser beam, the ripple which has the period similar to the wavelength of the incident laser beam but aligns parallel to the electric field of the laser beam was observed on the roughened surface for the lower fluence and the higher number of pulse irradiation. Furthermore, the ensemble of dots formed by the enhancement of the local electric field was found on the roughened surface. This structure is preferentially formed around the scratches aligned perpendicularly to the electric field of the laser beam. These novel nanostructures are considered to be peculiar to the femtosecond laser irradiation and open the possibilities for precise control of the spontaneous nanostructure formation by femtosecond laser irradiation. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6490-1 Authors Takuro Tomita, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Ryota Kumai, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Hidenori Nomura, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Shigeki Matsuo, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Shuichi Hashimoto, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Ken Morita, Center for Frontier Research of Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Toshiro Isu, Center for Frontier Research of Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We present a study of the temperature non-homogeneities induced by millisecond laser annealing in advanced CMOS technologies at die level. Because of the design, the device layout at the wafer surface introduces during this anneal significant spatial variations of optical absorption and heat transfer that can induce temperature non-uniformities over the die, often called ‘pattern effects’. These temperature variations are becoming a major issue, since they are the origin of significant device properties dispersion. A complete optical and thermal simulation set has been developed to estimate the temperature variations induced by the topologies at the wafer surface during the laser anneal process. The modelling has been validated by either a comparison with another software or reflectometry and electrical measurements on real structures. This work demonstrates that the temperature variations are caused either by optical coupling or by thermal properties dispersion present at the wafer surface at the anneal step. Finally, we demonstrate that the impact of the thin-film interferences and diffraction phenomena is the critical issue for these pattern effects. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6467-0 Authors A. Colin, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France P. Morin, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France F. Cacho, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France H. Bono, LETI, CEA-Grenoble, 17 Rue des Martyrs, 38054 Grenoble Cedex 9, France R. Beneyton, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France D. Mathiot, InESS, CNRS and Université de Strasbourg, BP 20 CR, 23 rue de Loess, 67037 Strasbourg Cedex 2, France E. Fogarassy, InESS, CNRS and Université de Strasbourg, BP 20 CR, 23 rue de Loess, 67037 Strasbourg Cedex 2, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A micro-crack in silicon was experimentally investigated by using a combination of transmission electron microscopy and geometric phase analysis. The strain fields of the crack tip, with scales of a few tens of nanometers, were mapped. The crack tip dislocation emission and stress relief by dislocation generation around a crack tip can be proved. And, the strain field of an edge dislocation was compared with the Peierls–Nabarro dislocation model at the scale of a dislocation width. We show that the Peierls–Nabarro model is the appropriate theoretical model to describe the deformation fields of the dislocation core. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6488-8 Authors C. W. Zhao, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Y. M. Xing, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China P. C. Bai, College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China J. J. Li, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Q. L. Liu, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Y. G. Du, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China M. H. Liu, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thin films of the n-type, organic semiconductor PDI-8CN 2 were thermally evaporated on two different dielectric surfaces and their optical and morphological properties investigated using Variable Angle Spectroscopic Ellipsometry (VASE) and Atomic Force Microscopy (AFM), respectively. The two dielectric surfaces used were SiO 2 and a plasma polymer derived from the non-synthetic monomer linalyl acetate. The characterisations were performed in order to assess the viability of plasma polymerised linalyl acetate (PLA) thin films as dielectric layers in future Organic Field-Effect Transistor (OFET) devices. These studies resulted in determination of the optical profiles (refractive index and extinction coefficient) in the UV-Vis band of PDI-8CN 2 grown on SiO 2 and an observation of uniaxial anisotropy in the organic semiconductor. This information is useful for the design of opto-electronic devices using PDI-8CN 2 layers. Variations in morphological properties and small variations optical properties were found when the PDI-8CN 2 films were grown on PLA layers, and attributed to the change in surface chemistry between dielectrics. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6487-9 Authors L. J. Anderson, Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville, QLD 4811 Australia M. V. Jacob, Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville, QLD 4811 Australia M. Barra, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy F. V. Di Girolamo, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy A. Cassinese, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thermophysical properties of liquid alloys are usually difficult to measure, especially for high melting point and reactive alloys. In this work, the surface tensions of superheated and undercooled liquid Ti 55 Al 45 , Ti 50 Al 45 Nb 5 and Ti 45 Al 45 Nb 10 alloys are determined by using oscillating drop method under electromagnetic levitation state. The experimental results of Ti–Al and Ti–Al–Nb alloys display linear temperature dependence. The maximum undercoolings of 259 (0.143 T L ), 268 (0.146 T L ) and 275 K (0.147 T L ) are respectively achieved for these three alloys. Furthermore, the viscosities of liquid Ti 55− x Al 45 Nb x alloys are also derived from the experimental results. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6491-0 Authors K. Zhou, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China H. P. Wang, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China J. Chang, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China B. Wei, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We present an object-oriented framework, named DOOLINES , for non-linear static and dynamic analyses of slender marine structures which often appear in offshore structures employed in the petroleum and gas industries as, among others, flexible risers, steel catenary risers, umbilicals, floating hoses, and mooring lines. DOOLINES allows the rapid development of tailored, modular, reusable and extensible large-size systems, being itself extensible. These properties, along with the ease of use of our framework, are assessed by means of case studies. Code examples are provided. Content Type Journal Article Pages 1-11 DOI 10.1007/s00366-011-0226-x Authors Eduardo S. S. da Silveira, Laboratório de Computação Científica e Visualização, Universidade Federal de Alagoas, Campus A. C. Simões, Av. Lourival de Melo Mota S/N, Tabuleiro do Martins, 57072-970 Maceió, AL, Brazil Eduardo N. Lages, Laboratório de Computação Científica e Visualização, Universidade Federal de Alagoas, Campus A. C. Simões, Av. Lourival de Melo Mota S/N, Tabuleiro do Martins, 57072-970 Maceió, AL, Brazil Fábio M. G. Ferreira, Laboratório de Computação Científica e Visualização, Universidade Federal de Alagoas, Campus A. C. Simões, Av. Lourival de Melo Mota S/N, Tabuleiro do Martins, 57072-970 Maceió, AL, Brazil Journal Engineering with Computers Online ISSN 1435-5663 Print ISSN 0177-0667

Description: We optimize geometries of various self-similar transport networks using a three-step strategy based on the entransy theory. Using this optimization method, we obtained optimal relationships of geometric parameters of T-shape networks for fluid flow, heat conduction, convective heat transfer, and other transport phenomena. Some optimization results agree well with the existing theories or experimental data. The optimized transport network structure depends strongly on the optimization objective and the constraints, so that both the maximum heat transfer effect and minimum flow resistance cannot be satisfied at the same time.

Description: This paper discusses the problem of determining an unknown source which depends only on one variable for the modified Helmholtz equation. This problem is ill-posed in the sense that the solution (if it exists) does not depend continuously on the data. The regularization solution is obtained by the simplified Tikhonov regularization method. Convergence estimate is presented between the exact solution and the regularization solution. Moreover, numerical results are presented to illustrate the accuracy and efficiency of this method.

Description:    We consider the effects of rotation in a mushy layer being cast from a vertical surface where the effects of Coriolis acceleration, gravity and centrifugal effects are included. It is demonstrated that the Coriolis acceleration and gravity play a passive role in convection and are excluded from the stability criteria. The stability criteria is presented as the critical centrifugal Rayleigh numbers referenced for locations far away (start of solidification) and close to (nearing end of solidification) the axis or rotation. Content Type Journal Article Pages 1-10 DOI 10.1007/s11242-011-9790-1 Authors S. Govender, Corporate Specialist Gas Turbines, Generation Business Engineering, ESKOM Holdings Ltd., Maxwell Drive Sunninghill, Johannesburg, 2000 South Africa Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description:    The onset of thermal convection in a two-dimensional porous box is investigated analytically. One of the two lateral boundaries is in contact with a hydrostatic reservoir, where the saturating fluid can flow freely in and out. This open boundary is thermally insulating, but with the buoyancy of the fluid taken into account. For the second lateral wall, we study five different options for the boundary conditions. This leads to five different eigenvalue problems for the onset of convection. These five solutions are compared with the known solutions where the buoyancy along open sidewalls is neglected (Tyvand 2002 ). Content Type Journal Article Pages 1-18 DOI 10.1007/s11242-011-9791-0 Authors Heidi S. Nygård, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, 1432 Norway Peder A. Tyvand, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, 1432 Norway Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description:    Image-based network modeling has become a powerful tool for modeling transport in real materials that have been imaged using X-ray computed micro-tomography (XCT) or other three-dimensional imaging techniques. Network generation is an essential part of image-based network modeling, but little quantitative work has been done to understand the influence of different network structures on modeling. We use XCT images of three different porous materials (disordered packings of spheres, sand, and cylinders) to create a series of four networks for each material. Despite originating from the same data, the networks can be made to vary over two orders of magnitude in pore density, which in turn affects network properties such as pore-size distribution and pore connectivity. Despite the orders-of-magnitude difference in pore density, single-phase permeability predictions remain remarkably consistent for a given material, even for the simplest throat conductance formulas. Detailed explanations for this beneficial attribute are given in the article; in general, it is a consequence of using physically representative network models. The capillary pressure curve generated from quasi-static drainage is more sensitive to network structure than permeability. However, using the capillary pressure curve to extract pore-size distributions gives reasonably consistent results even though the networks vary significantly. These results provide encouraging evidence that robust network modeling algorithms are not overly sensitive to the specific structure of the underlying physically representative network, which is important given the variety image-based network-generation strategies that have been developed in recent years. Content Type Journal Article Pages 1-29 DOI 10.1007/s11242-011-9789-7 Authors Pradeep Bhattad, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA Clinton S. Willson, Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, USA Karsten E. Thompson, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description:    Low salinity water injections for oil recovery have shown seemingly promising results in the case of clay-bearing sandstones saturated with asphaltic crude oil. Reported data showed that low salinity water injection could provide up to 20% pore volume (PV) of additional oil recovery for core samples and up to 25% PV for reservoirs in near wellbore regions, compared with brine injection at the same Darcy velocity. The question remains as to whether this additional recovery is also attainable in reservoirs. The answer requires a thorough understanding of oil recovery mechanism of low salinity water injections. Numerous hypotheses have been proposed to explain the increased oil recovery using low salinity water, including migration of detached mixed-wet clay particles with absorbed residual oil drops, wettability alteration toward increased water-wetness, and emulsion formation. However, many later reports showed that a higher oil recovery associated with low salinity water injection at the common laboratory flow velocity was neither necessarily accompanied by migration of clay particles, nor necessarily accompanied by emulsion. Moreover, increased water-wetness has been shown to cause the reduction of oil recovery. The present study is based on both experimental and theoretical analyses. Our study reveals that the increased oil recovery is only related to the reduction of water permeability due to physical plugging of the porous network by swelling clay aggregates or migrating clay particles and crystals. At a fixed apparent flow velocity, the value of negative pressure gradient along the flow path increases as the water permeability decreases. Some oil drops and blobs can be mobilized under the increased negative pressure gradient and contribute to the additional oil recovery. Based on the revealed mechanism, we conclude that low salinity water injection cannot be superior to brine injection in any clay-bearing sandstone reservoir at the maximum permitted injection pressure. Through our study of low salinity water injection, the theory of tertiary oil recovery has been notably improved. Content Type Journal Article Pages 1-30 DOI 10.1007/s11242-011-9788-8 Authors Y. Li, Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071, USA Journal Transport in Porous Media Online ISSN 1573-1634 Print ISSN 0169-3913

Description: A generalized version of the Leslie-Gower predator-prey model that incorporates the prey population structure is introduced. Our results show that the inclusion of (age) structure in the prey population does not alter the qualitative dynamics of the model; that is, we identify sufficient conditions for the ‘‘trapping’’ of the dynamics in a biological compact set—albeit the analysis is a bit more challenging. The focus is on the study of the boundedness of solutions and identification of sufficient conditions for permanence. Sufficient conditions for the local stability of the nonnegative equilibria of the model are also derived, and sufficient conditions for the global attractivity of positive equilibrium are obtained. Numerical simulations are used to illustrate our results.

Description: The rotordynamics and fluid dynamics of a turbo-machine considering the effect of fluid-solid interaction (FSI) are numerically investigated using finite element software ADINA. The iterative method is adopted in computation of coupled fields of displacement and fluid. What distinguishes the present study from previous ones is the use of ADINA's rotational meshes and the FSI interface that separates the rotor surface from its surrounding fluid. The rotor's center orbit and frequency response as well as the transient fluid dynamics are obtained with various axial flow speeds. By including real rotating motion of the rotor, this paper presents a better way to solve complicated rotordynamic problems of turbo-machines that are operated in FSI circumstances.

Description:    Existing non-Gaussian closure method is usually applied to non-linear systems with white noise excitation only. But random vibration of vehicle is excited by correlated road spectrum. To solve vibration responses of a non-linear automotive suspension system, the non-Gaussian closure solution procedure is improved by introducing an additional subsystem which described by a simple differential equation to the vehicle model. A car model with two degrees of freedom against three different types of damping is analyzed based on this proposed method. Some important parameters such as acceleration response, relative loads between the wheel and the road, and passing-through frequency of suspension system were calculated effectively. Content Type Journal Article Pages 1-11 DOI 10.1007/s10010-011-0142-7 Authors Fengrong Bi, School of Mechanical Engineering, Tianjin University, 300072 Tianjin, China S. Jack Hu, Department of Mechanical Engineering, The University of Michigan, Ann Arbor, MI 48109, USA Baoan Song, School of Mechanical Engineering, Hebei University of Technology, 300132 Tianjin, China Journal Forschung im Ingenieurwesen Online ISSN 1434-0860 Print ISSN 0015-7899

Description: We consider Liénard type and frequency-damped oscillator equations. Integrating factors and the associated first integrals are derived from the method to compute λ-symmetries and the associated reduction algorithm. The knowledge of a λ-symmetry of the equation permits the determination of an integrating factor or a first integral by means of coupled first-order linear systems of partial differential equations. We will compare our results with those gained by the other methods.

Description:    Compressible Mooney–Rivlin theory has been used to model hyperelastic solids, such as rubber and porous polymers, and more recently for the modeling of soft tissues for biomedical tissues, undergoing large elastic deformations. We propose a solution procedure for Lagrangian finite element discretization of a static nonlinear compressible Mooney–Rivlin hyperelastic solid. We consider the case in which the boundary condition is a large prescribed deformation, so that mesh tangling becomes an obstacle for straightforward algorithms. Our solution procedure involves a largely geometric procedure to untangle the mesh: solution of a sequence of linear systems to obtain initial guesses for interior nodal positions for which no element is inverted. After the mesh is untangled, we take Newton iterations to converge to a mechanical equilibrium. The Newton iterations are safeguarded by a line search similar to one used in optimization. Our computational results indicate that the algorithm is up to 70 times faster than a straightforward Newton continuation procedure and is also more robust (i.e., able to tolerate much larger deformations). For a few extremely large deformations, the deformed mesh could only be computed through the use of an expensive Newton continuation method while using a tight convergence tolerance and taking very small steps. Content Type Journal Article Pages 1-13 DOI 10.1007/s00366-011-0225-y Authors Suzanne M. Shontz, Department of Computer Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA Stephen A. Vavasis, Department of Combinatorics and Optimization, University of Waterloo, Waterloo, ON N2L 3G1, Canada Journal Engineering with Computers Online ISSN 1435-5663 Print ISSN 0177-0667

Description:    Hierarchical ZnO (zinc oxide) nanostructures composed with nano-sheet and micro-flower structures (made from the nano-sheet) have been generated on tinfoil substrate via a chemical bath deposition process. Benefiting from an inherent distinct lattice constant compared with commonly used glass or other kinds of substrate, the tinfoil substrate played an important role on the formation of the hierarchical ZnO nanostructures. The resulting hierarchical ZnO surface shows excellent superhydrophobicity and extremely low water rolling angle after being modified with spin coating Teflon. The flexible and superhydrophobic characteristics of such fabricated substrate will be beneficial for applications requiring bendable and lightweight superhydrophobic substrates. In addition, the multifunctional properties of ZnO nanostructures are expected to broaden the applications to electronic and optical applications. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6493-y Authors Jun Wu, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Jun Xia, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Chen Jing, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Wei Lei, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Bao-ping Wang, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thin films of silicon carbide (SiC) have been prepared by means of pulsed laser deposition (PLD) on sapphire (Al 2 O 3 ) and Si(100) substrates with a Nd-YAG laser 1064 nm. We achieved the growth of cubic silicon carbide (3C-SiC) films at the temperatures of 650°C from a SiC target in vacuum. The as-deposited films are morphologically and structurally characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The use of off-axis PLD method placing the sample at 90° with respect to the target leads to a good quality smooth film. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6494-x Authors G. Monaco, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy D. Garoli, Physical Department “G. Galilei”, University of Padova, Via Marzolo 8, Padova, Italy M. Natali, CNR-ICIS Corso Stati Uniti 4, Padova, Italy M. G. Pelizzo, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy P. Nicolosi, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description: The aim of this paper is, in accordance with efficient web search service operation objectives, to propose enhancements to the sophistication of the functionality that can be offered by search engine services. A meta-search third-party result ranking mechanism is proposed, which is capable of adapting over the continuous changes that occur on the web, providing in parallel personalized information acquisition considering the user's navigation behaviour. Transparency is achieved for both personalization and web evolution adaptation mechanisms, requiring virtually none effort from the user's part. In essence, the proposed meta search engine rates, re-organises and combines the results acquired from search services for a specific user information resource request in accordance with a weighted combination of a performance related factor (tightly related to the ranking of the web result as given by the search engine service) and a reliability related factor (corresponding to the user satisfaction stemming from the specific web result that he/she browses), while the performance of each search engine with respect to adequately adapting to the web evolution is taken into account. For the evaluation of the web results reliability, a collaborative reputation mechanism is utilized, which helps estimating their quality and predicting their future usability, taking into account their past performance in consistently satisfying user expectations. A set of results indicative of the efficiency of our proposed scheme is provided. The Internet search services used were Google, MSN and Yahoo! Content Type Journal Article Pages 109-124 DOI 10.3233/JCM-2011-0368 Authors Malamati Louta, University of Western Macedonia, Department of Informatics and Telecommunications Engineering, Kozani, Greece Ioannis Anagnostopoulos, University of Central Greece, Department of Computer Science and Biomedical Informatics, Lamia, Greece Ilias Maglogiannis, University of Central Greece, Department of Computer Science and Biomedical Informatics, Lamia, Greece Angelos Michalas, Technological Educational Institute of Western Macedonia, Department of Informatics and Computer Technology GR-52100, Kastoria, Greece Journal Journal of Computational Methods in Science and Engineering Online ISSN 1875-8983 Print ISSN 1472-7978 Journal Volume Volume 11 Journal Issue Volume 11, Number 3 / 2011

Description: 'Motion' and intention that are involved in the perception of musical structure combined with mirror neuron (MN) system activation are studied in this article. The mechanism of MN involved in the perception of musical structures is seen as a means for cueing the learner on `known' factors that can be used for his/her knowledge scaffolding. To explore such relationships, EEG recordings, and especially the Mu-rhythm in the premotor cortex that relates to the activation of MN, were acquired and explored. Three experiments were designed to provide the auditory and visual stimuli to a group of subjects, including both musicians and non-musicians. The acquired signals, after appropriate averaging in the time domain, were analyzed in frequency and bifrequency domains, using spectral and bispectral analysis, respectively. Experimental results have shown that an intention – related activity shown in musicians could be associated with Mu – rhythm suppression. Moreover, an underlying ongoing function appearing in the transition from heard sound to imagined sound could be revealed in the bispectrum domain. A Mu-rhythm modulation provoked by the MNs could cause bispectral fluctuations, especially when visual stimulation is combined with an auditory one for the case of musicians. These results pave the way for further exploitation of the role of MNs in music and, in general, knowledge perception. Content Type Journal Article Pages 91-107 DOI 10.3233/JCM-2011-0367 Authors Panagiotis Doulgeris, Aristotle University of Thessaloniki, Faculty of Technology, Department of Electrical and Computer Engineering, GR – 541 24, Thessaloniki, Greece Stelios Hadjidimitriou, Aristotle University of Thessaloniki, Faculty of Technology, Department of Electrical and Computer Engineering, GR – 541 24, Thessaloniki, Greece Konstantinos Panoulas, Aristotle University of Thessaloniki, Faculty of Technology, Department of Electrical and Computer Engineering, GR – 541 24, Thessaloniki, Greece Leontios Hadjileontiadis, Aristotle University of Thessaloniki, Faculty of Technology, Department of Electrical and Computer Engineering, GR – 541 24, Thessaloniki, Greece Stavros Panas, Aristotle University of Thessaloniki, Faculty of Technology, Department of Electrical and Computer Engineering, GR – 541 24, Thessaloniki, Greece Journal Journal of Computational Methods in Science and Engineering Online ISSN 1875-8983 Print ISSN 1472-7978 Journal Volume Volume 11 Journal Issue Volume 11, Number 3 / 2011

Description: Content Type Journal Article Category Preface Pages 89-90 DOI 10.3233/JCM-2011-0366 Authors Dimitris Kanellopoulos Sotiris Kotsiantis Panagiotis Pintelas Journal Journal of Computational Methods in Science and Engineering Online ISSN 1875-8983 Print ISSN 1472-7978 Journal Volume Volume 11 Journal Issue Volume 11, Number 3 / 2011

Description:    Die Festigkeitshypothesen und Fließflächen aus den klassischen Kursen der Mechanik (die Normalspannungshypothese, die Modelle nach von Mises und Tresca) reichen oft nicht aus, das tatsächliche Verhalten von Bauteilen unter Belastung zu erfassen. Deshalb werden in der Literatur weitere Modelle mit einem oder mehreren Parametern vorgeschlagen. Diese Modelle beschränken allerdings die Geometrien der zulässigen Formen der Flächen im Spannungsraum. In dieser Arbeit wird ein auf die Zugspannung normiertes Druck-Torsion-Diagramm vorgestellt, in dem sich die Modelle inkompressiblen Materialverhaltens miteinander vergleichen lassen. Mit diesem Diagramm wird der Begriff der Symmetrie der Fläche in der π -Ebene verdeutlicht. Die konvexen Flächen inkompressiblen Materialverhaltens sind im Diagramm durch zwei Modelle extremaler Fließfiguren beschränkt. Auf der Basis von verallgemeinerten Modellen (Radcig-Modell und konvexe Kombination der Modelle von Sayir und Haythornthwaite) wird die minimale Anzahl der Parameter für die Abbildung konvexen Formen inkompressiblen Materialverhaltens diskutiert. Wegen der Komplexität werden diese Modelle für die Praxis nicht empfohlen. Daneben wird ein so genanntes geometrisch-mechanisches Modell mit zwei Parametern vorgeschlagen, das mehrere konvexe Formen beinhaltet. Durch die Variation der Potenz der Spannung in diesem Modell wird versucht, einen maximalen Bereich an konvexen Lösungen im Druck-Torsion-Diagramm zu erhalten. Die Analyse von Fließflächen ist mit der Berechnung der Konvexitätsgrenzen verbunden. Bei der analytischen Überprüfung der Konvexität wird von einer Formel von Betten-Troost ausgegangen. Einige Restriktionen, denen die Konvexität unterliegt, werden mit dieser Formel jedoch nicht erkannt. Eine Nachrechnung der Formel von Betten-Troost hat zu zusätzlichen Termen geführt. Da die Einschränkungen bei der Herleitung der Formel nicht bekannt sind, wird hier mit der korrigierten Gleichung gearbeitet. Um kompressibles Materialverhalten beschreiben zu können, wird die erste Spannungsinvariante in die Modellgleichungen eingeführt. In Abhängigkeit von der vorhandenen Potenzen der Vergleichsspannung in den Modellgleichungen werden drei einfache Transformationen vorgeschlagen, die die Anwendung der Modelle deutlich vereinfachen. Bei dieser Vorgehensweise erübrigt sich die Überprüfung der Konvexität in den Meridianschnitten. Content Type Journal Article Pages 1-20 DOI 10.1007/s10010-011-0135-6 Authors A. Bolchoun, Deutsches Kunstoff-Institut Darmstadt, Schloßgartenstr. 6, 64289 Darmstadt, Deutschland V. A. Kolupaev, Deutsches Kunstoff-Institut Darmstadt, Schloßgartenstr. 6, 64289 Darmstadt, Deutschland H. Altenbach, Lehrstuhl Technische Mechanik, Otto-von-Guericke-Universität-Magdeburg, 39106 Magdeburg, Deutschland Journal Forschung im Ingenieurwesen Online ISSN 1434-0860 Print ISSN 0015-7899

Description:    An investigation into a three-dimensional, curved shock wave interacting with a three-dimensional, curved boundary layer on a slender body is presented. Three different nose profiles mounted on a cylindrical body were tested in a supersonic wind tunnel and numerically simulated by solving the Navier–Stokes equations. The conical and hemispherical nose profiles tested were found to generate shock waves of sufficient strength to separate the boundary layer on the cylinder, while the shock wave generated by the ogival profile did not separate the boundary layer. For the separated flow, separation was found to occur predominantly on the windward side of the cylinder with the lee-side remaining shielded from the direct impact of the incident shock wave. A thickening of the boundary layer on the lee-side of all the profiles was observed, and in the conical and hemispherical cases this leads to the re-formation of the incident shock wave some distance away from the surface of the cylinder. A complex reflection pattern off the shock wave/boundary layer interaction (SWBLI) was also identified for the separated flow cases. For comparative purposes, an inviscid simulation was performed using the hemispherical profile. Significant differences between the viscous and inviscid results were noted including the absence of a boundary layer leading to a simplified shock wave reflection pattern forming. The behaviour of the incident shock wave on the lee-side of the cylinder was also affected with the shock wave amalgamating on the surface of the cylinder instead of away from the surface as per the viscous case. Test data from the wind tunnel identified two separation lines present on the cylindrical surface of the hemispherical SWBLI generator. The pair of lines were not explicitly evident in the original CFD simulations run, but were later identified in a high-resolution simulation. Content Type Journal Article Pages 1-16 DOI 10.1007/s00193-011-0322-2 Authors S. Mowatt, Flow Research Unit, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa B. Skews, Flow Research Unit, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa Journal Shock Waves Online ISSN 1432-2153 Print ISSN 0938-1287

Description:    GaN is a promising material not only for electronic devices but also for photocatalysts. Synthesis of GaN nanocrystal is a key issue to improve performance for these applications. In the present study, GaN nanocrystallites have been synthesized by pulsed laser ablation (PLA), where safe and inactive pure N 2 gases were used as reactive background gases. The third harmonics beam of a Q -switched Nd:YAG laser (355 nm, 10 mJ/pulse, 4 J/(cm 2 pulse)) was used to ablate a sintered high purity GaN target. The deposition substrates were not heated. It was clarified that the formed GaN nanoparticles contained a hexagonal system with the wurtzite structure. The diameter of the nanocrystallites was about 10 nm, and showed only little dependence on the background gas pressure, while the porosity of the assembly of nanocrystallites and content of GaN nanocrystallites in the assembly increased with background gas pressure. Highly porous nanometer-sized GaN film obtained at higher gas pressure is considered to be candidate structures for the photocatalysts. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6438-5 Authors Takehito Yoshida, Department of Mechanical Engineering, Anan National College of Technology, Anan, Tokushima 774-0017, Japan Soichiro Kakumoto, Department of Physics, Konan University, Kobe, 658-8501 Japan Akira Sugimura, Department of Physics, Konan University, Kobe, 658-8501 Japan Ikurou Umezu, Department of Physics, Konan University, Kobe, 658-8501 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Laser Spinning is a new technique that has been shown to quickly produce amorphous inorganic nanofibers from bulk material under atmospheric conditions. This technique employs a high power laser to melt a small volume of the precursor material while a supersonic gas jet provokes its rapid elongation and cooling, producing long micro- and nanofibers within a range of diameters. In this work, the quantity of the fibers produced and the distribution of their diameters are measured and statistically analyzed for different operating conditions. The advance speed of the laser beam over the precursor material is experimentally demonstrated to be the most influencing factor on the diameter of the fibers. Other variables of the process, such as assist gas pressure, were found to have less influence. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6415-z Authors O. Dieste, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain F. Quintero, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain J. Pou, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain F. Lusquiños, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain A. Riveiro, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The resonant transmission peaks in the asymmetric and symmetric multilayer narrowband transmission filters are theoretically investigated based on the transfer matrix method. In an asymmetric filter there exists only one resonant peak within the photonic band gap, and its position can be changed when the design wavelength is varied. In a symmetric filter, it is found that there are two resonant peaks. Using Bloch wave approximation, an investigation of these two resonant peaks has been made, and they are shown to correspond to the symmetric and antisymmetric field solutions in the defect layer. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6434-9 Authors Tsung-Wen Chang, Graduate Institute of Electro-Optical Engineering, Chang Gung University, Tao-Yuan, 333 Taiwan Tzong-Jer Yang, Department of Electrical Engineering, Chunghua University, Hsinchu, 300 Taiwan Zheng-Hui Wang, Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, 116 Taiwan Chien-Jang Wu, Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, 116 Taiwan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description: Many problems with control theory have led to investigations into switched systems. One of the most urgent problems related to the analysis of the dynamics of switched systems is the stability problem. The stability of a switched system can be ensured by a common Lyapunov function for all switching modes under an arbitrary switching law. Finding a common Lyapunov function is still an interesting and challenging problem. The purpose of the present paper is to prove the stability of equilibrium in a certain class of nonlinear switched systems by introducing a common Lyapunov function; the Lyapunov function is based on generalized Kullback–Leibler divergence or Csiszár's I-divergence between the state and equilibrium. The switched system is useful for finding positive solutions to linear algebraic equations, which minimize the I-divergence measure under arbitrary switching. One application of the stability of a given switched system is in developing a new approach to reconstructing tomographic images, but nonetheless, the presented results can be used in numerous other areas.