bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cold‐pool formation in a narrow valley
Authors: Vosper S. B. , Hughes J. K. , Lock A. P. , Sheridan P. F. , Ross A. N. , Jemmett‐Smith B. , Brown A. R. 
Published: June 2013

AbstractA numerical model simulation of the formation of a cold pool within a narrow valley during a clear calm night is presented. The results are compared with measurements made during the COLd air Pooling EXperiment (COLPEX). It is demonstrated that the model provides a realistic simulation of the observed cold pool. The cold pool begins to form approximately 1.5 hours before sunset, when the near‐surface air within the valley starts to cool more rapidly than the air on the surrounding hills. The model potential temperature budget is used to determine which physical processes are most important for the evolution of the cold pool. The results show that sheltering provided by the valley causes a turbulent heat ﬂux divergence over the lowest 5 m above the valley ﬂoor, which is large compared with the other terms in the budget. This causes relatively rapid cooling of the air adjacent to the ground. On the surrounding hills the turbulent heat ﬂux divergence is larger than in the valley, but the enhanced cooling this provides is approximately balanced by an almost equally large warming tendency from advection. The net eﬀect of these two terms is small compared with that in the valley and therefore the cooling rate is smaller. Above 5 m, the cooling in the valley is dominated by local transport of cold air away from the surface into the interior valley atmosphere.
A Copula Markov CUSUM Chart for Monitoring the Bivariate Auto‐correlated Binary Observations
Authors: Dokouhaki Pershang , Noorossana Rassoul 
Published: June 2013

Although in the statistical process control (SPC) literature, there are considerable number of researches related to the multivariates variables control charting (focusing on the variable quality characteristics), fewer investigations could be found regarding the multivariate attributes control charts (relying on the attribute quality characteristics). More specifically considering the multivariate attributes control charting, it would be more interesting to monitor the auto‐correlated data, since the real‐world processes usually include the data based on an auto‐correlation structure. Ignoring the auto‐correlation structure in developing a multivariate control chart increases the type I and type II errors simultaneously and consequently reduces the performance of the chart. The most important difficulty with developing multivariate attributes control charts is the absence of the joint distribution for the quality characteristics. This deficiency can be dispelled through the use of the copula approach for developing the joint distribution.In this paper, we use the Markov approach for modeling the auto‐correlated data. Then, the copula approach is used to make the joint distribution of two auto‐correlated binary data series. Finally, based on this joint distribution, we develop a cumulative sum (CUSUM) chart. Hence, the proposed chart is entitled the copula Markov CUSUM chart. The proposed control chart is compared with the most recent and effective existing one in the literature. Based on the average number of observations to signal (ANOS) measure, it is considered that the developed control chart performs better than the other one. In addition, a real case study related to two correlated diseases such as the Type 2 Diabetes Mellitus and the Obesity, in which each has an auto‐correlated structure, is investigated to verify the applicability of the control chart. Copyright © 2012 John Wiley & Sons, Ltd.
TiO2 Single Crystal with Four‐Truncated‐Bipyramid Morphology as an Efficient Photocatalyst for Hydrogen Production
Authors: Zhang Kai , Liu Qian , Wang Hui , Zhang Rubo , Wu Chunhui , Gong Jian Ru 
Published: June 2013

AbstractDiverse titanium dioxide (TiO2) nanostructures have attracted much attention recently due to their potential application in photocatalytic and photovoltaic fields. Here, the synthesis of a TiO2 single crystal with a novel four‐truncated‐bipyramid morphology is reported for the first time, produced by a simple hydrothermal method. Both peroxo titanic acid precursor and hydrofluoric acid capping agent are essential for the formation of this unique morphology. Moreover, the as‐prepared TiO2 photocatalyst exhibits excellent hydrogen production activity from an ethanol–water solution, which is attributed to exposure of both high‐energy {001} oxidative and low‐energy {101} reductive facets in an optimal ratio. The current findings will contribute greatly to development of more novel photocatalysts with controllable microscopic structures for hydrogen production.
Climate change regional review: Russia
Authors: Sharmina Maria , Anderson Kevin , Bows-Larkin Alice 
Published: June 2013

With climate change, an increasingly important focus of scientific and policy discourse, the Russian government has aimed to position the country as one of the leaders of the global process for addressing climate change. This article reviews a breadth of literature to analyze the politico‐economic situation in Russia with regard to international climate change negotiations, related domestic policies, societal attitudes, and climatic change impacts on Russia's territory. The analysis demonstrates how Russia has a pivotal role in influencing the future direction of international climate change mitigation and adaptation. Not only is Russia predisposed geographically to the impacts of climate change, but also it is a major emitter of greenhouse gases and a global supplier of fossil fuels, and remains a major force in international politics. This unique confluence of circumstances leaves Russia with a challenging dilemma. It can choose to acquiesce to short‐term political and economic considerations, adopt weak mitigation measures, and face potentially significant impacts. Or it can apply its considerable attributes and powers to initiate an epoch of international action to secure a low‐carbon climate‐resilient future. Although the former will see Russia subsumed into the international malaise on climate change, the latter may both quench the nation's ‘thirst for greatness’ and fill the void of international leadership. WIREs Clim Change 2013, 4:373–396. doi: 10.1002/wcc.236This article is categorized under:

Policy and Governance > National Climate Change Policy
Trans‐Disciplinary Perspectives > Regional Reviews
Trans‐Disciplinary Perspectives > National Reviews
A Bis(μ‐phenoxo)‐Bridged Dizinc Complex with Hydrolytic Activity
Authors: Mitra Mainak , Singh Reena , Pyrkosz‐Bulska Monika , Haukka Matti , Gumienna‐Kontecka Elzbieta , Nordlander Ebbe 
Published: June 2013

AbstractThe dinuclear complex [Zn2(papy)2]·2CH3OH [H2papy = N‐(2‐hydroxybenzyl)‐N‐(2‐picolyl)glycine] was synthesized and characterized. The crystal structure of the complex reveals that both ZnII ions are pentacoordinate with distorted pentagonal bipyramidal coordination arrangements. The phenoxyl groups of each ligand bridge the two metal atoms, whereas each carboxylate of the ligand is terminally bound to one ZnII ion. Potentiometric studies of the ZnII:H2papy system in a methanol/water mixture show the existence of a mononuclear species at lower pH; but at a pH above 5, a dimeric species starts to dominate and transforms further into a bis(μ‐phenoxo) bridged dizinc complex by deprotonation of phenolic hydrogen. A kinetic study of the hydrolysis of bis(2, 4‐dinitrophenyl)phosphate at different pH, catalyzed by complex 1, indicates a maximum rate at pH 9, where the bis(μ‐phenoxo)‐bridged dizinc species corresponding to 1 dominates in solution.
Characterization and statistical modeling of irregular porosity in carbon/carbon composites based on X‐ray microtomography data
Authors: Drach B. , Drach A. , Tsukrov I. 
Published: June 2013

AbstractStatistical analysis procedure is proposed to characterize volume, shape and orientation distribution of pores in chemical vapor infiltrated carbon/carbon composites. The microstructure data is provided by X‐ray microtomography. To characterize orientation distribution of pores, probability distribution functions of pore volume, orientation angles and principal moments of inertia are constructed. Based on this information, a statistically significant range of pore geometry parameters is determined for evaluation of their contribution to the effective elastic properties of the material. Using the design of experiment approach, a subset of 53 pores is selected for the finite element simulations. The results are analyzed to construct a 3‐factor stochastic model of a pore contribution to the overall elastic response based on its geometric parameters. It is determined that the non‐dimensionalized surface to volume ratio factor plays an important role for pores in this type of material. A 4‐factor model incorporating this ratio is proposed. The model is validated by direct finite element simulations for a set of 150 randomly selected pores not included in the initial subset. The accuracy of the proposed approach is compared with the traditionally used approximation of pores by equivalent ellipsoids.
On the dual‐mixed formulation for an exterior Stokes problem
Authors: Gatica G.N. , Hsiao G.C. , Meddahi S. , Sayas F.‐J. 
Published: June 2013

AbstractThis paper is concerned with a dual‐mixed formulation for a three dimensional exterior Stokes problem via boundary integral equation methods. Here velocity, pressure and stress are the main unknowns. Following a similar analysis given recently for the Laplacian, we are able to extend the classical Johnson & Nédélec procedure to the present case, without assuming any restrictive smoothness requirement on the coupling boundary, but only Lipschitz‐continuity. More precisely, after using the incompressibility condition to eliminate the pressure, we consider the resulting velocity‐stress approach with a Neumann boundary condition on an annular bounded domain, and couple the underlying equations with only one boundary integral equation arising from the application of the normal trace to the Green representation formula in the exterior unbounded region. As a result, we obtain a saddle point operator equation, which is then analyzed by the well‐known Babuška‐Brezzi theory: in particular, the well‐posedness of the formulation will be established.
High‐order finite volume schemes based on defect corrections
Authors: Filimon A. , Dumbser M. , Munz C.‐D. 
Published: June 2013

AbstractFor the approximation of steady state solutions, we propose an iterated defect correction approach to achieve higher‐order accuracy. The procedure starts with the steady state solution of a low‐order scheme, in general a second order one. The higher‐order reconstruction step is applied a posteriori to estimate the local discretization error of the lower‐order finite volume scheme. The defect is then used to iteratively shift the basic lower‐order scheme to the desired higher‐order accuracy given by the polynomial reconstruction. Hence, instead of solving the high‐order discrete equations the low‐order basic scheme is solved several times. This avoids that the high‐order reconstruction with a large stencil has to be implemented into an existing basic solver and can be seen as a non‐intrusive approach to higher‐order accuracy.
On the measurement of surface tension and contact angle
Authors: Miersemann E. 
Published: June 2013

AbstractWe propose a new method which combines experiments with numerical calculations to determine the capillary constant and the capillary contact angle. We measure the ascent of the liquid at the interior and at the exterior of a circular transparent tube. In contrast to known methods we do not assume that the contact angle is known. Assuming the interior contact angle is equal to the exterior angle, we find the capillary constant of the given liquid from the fact that the surface tensions of the interior and the exterior surfaces are equal. Dipping a cylindrical wire with constant circular cross section into a liquid with known surface tension we can determine the contact angle between the given liquid and the material from which the wire is made.
An extended Discontinuous Galerkin and Spectral Difference Method with modal filtering
Authors: Meister A. , Ortleb S. , Sonar T. , Wirz M. 
Published: June 2013

AbstractWe give a short overview of an extended Discontinuous Galerkin and Spectral Difference Method using PKD polynomials on triangular grids. A corresponding exponential filter is used to avoid oscillations near discontinuous solutions and to give some stabilization for nonsmooth testcases.
Properties and simplifications of constitutive time‐discretized elastoplastic operators
Authors: Sysala S. 
Published: June 2013

AbstractIn the paper, a general constitutive elastoplastic model for associated plasticity is investigated. The model is based on the thermodynamical framework with internal variables and can include basic plastic criteria with a combination of kinematic hardening and non‐linear isotropic hardening. The corresponding initial value constitutive elastoplastic problem is discretized by the implicit Euler method. The discretized one‐time‐step constitutive problem defines the elastoplastic operator, which is formulated by a simple generalization of a projection onto a convex set. Properties of the so‐called generalized projection are used for deriving basic properties of the elastoplastic operator like potentiality, monotonicity, Lipschitz continuity and local semismoothness. Further, hardening variables are eliminated from the projective definition of the elastoplastic operators, which yields relations among the models with hardening variables and the perfect plasticity model. Also a simplification of the operator for plastic criteria in eigenvalue forms is introduced. The simplifications are useful for a numerical implementation and can be used for deriving other properties like strong semismoothness of the elastoplastic operators for the classical plastic criteria or strong monotonicity of the stress‐strain operator for some models with hardening. The derived properties can be important for convergence analyses of Newton‐like methods and other mathematical and numerical analyses.
A novel method for the solution of the forward displacement problem of spherical parallel manipulators
Authors: Rodriguez J. , Ruggiu M. 
Published: June 2013

AbstractIn this paper, a novel method that solves the Forward displacement problem (FDP) of several common spherical parallel manipulators (SPMs) is presented. The method uses the quaternion algebra to express the FDP as a system of equations and the Dixon determinant procedure to construct univariate polynomials whose roots can be found either numerically or analytically. A case study is solved for a specific SPM, which satisfies certain geometric conditions, having 3 ‐ R(E)R architecture, with R denoting a revolute joint, E a planar motion generator and underlines indicating the actuated joint. In this case, the solutions of the system are obtained analytically by a symbolic method exploiting symmetries.
N‐Phase decagonal quasicrystalline circular inclusions under thermomechanical loadings
Authors: Wang X. , Schiavone P. 
Published: June 2013

AbstractIn this work a simple and effective method is proposed to solve the problem corresponding to plane strain deformations of an N‐phase decagonal quasicrystalline circular inclusion‐matrix system in which the circular inclusion is bonded to the surrounding matrix through (N‐2) co‐axial interphase layers. We consider three kinds of thermomechanical loadings: (i) the matrix is subjected to a remote uniform stress field; (ii) the composite undergoes a uniform temperature change; (iii) the matrix is subjected to a uniform heat flux at infinity. We find that it is sufficient to manipulate three 8 × 8 real matrices, a 5 × 5 real matrix, and another 4 × 4 real matrix to arrive at the complete temperature and thermoelastic fields within the circular inclusion and the surrounding matrix, irrespective of the number of interphase layers existing within the composite system. Our results clearly indicate that the existence of the intermediate interphase layer(s) mean that the internal stresses within the circular inclusion are: (i) sextic functions of the two coordinates x1 and x2 under the loading of a remote uniform stress field; (ii) quadratic functions of the two coordinates under the loading of a uniform temperature change; (iii) cubic functions of the two coordinates under the loading of a remote uniform heat flux. The design of neutral and harmonic coated circular inclusions is also discussed as an application of the derived solution. Our analysis suggests that a coated inclusion can be made neutral only to a remote isotropic phonon stress field; whereas it can be made harmonic to any remote uniform phonon stress field.
DNA elastic nonlinearities as multiple smooth combinations of soft and hard linear springs
Authors: Xiao H. 
Published: June 2013

AbstractDNA molecules perform biological functions via large elastic deformations and conformational changes in courses of their interactions with the cellular machinery. Adequate characterization of DNA elasticity is accordingly essential to an in‐depth understanding of DNA functions. Because of profound complexity, however, nonlinear features inherent in DNA elasticity remains to be uncovered in a direct, full sense and a unified, explicit characterization over the entire stretch range has been unavailable. Here it is suggested that DNA elastic nonlinearities may be understood by combining linear springs with high compliance and high rigidity. This finding uncovers the inherent geometrical feature in profound nonlinearities of DNA elasticity and leads to a unified, explicit force‐extension formula up to breaking. This formula reveals for the first time a complete set of characteristic constants for DNA elasticity and is shown to provide a unified characterization for both double‐ and single‐stranded DNA molecules. Results are presented in a straightforward, broad sense independent of any substructural details.
The undulatory motion of a chain of particles in a resistive medium in the case of a smooth excitation mode
Authors: Bolotnik N. , Pivovarov M. , Zeidis I. , Zimmermann K. 
Published: June 2013

AbstractThe motion of a chain of three identical bodies along a straight line in a dry‐friction medium is studied. The motion is excited and controlled by changing the distances between the bodies of the chain. An undulatory excitation mode is proposed, in which the distances between the adjacent bodies of the chain change periodically and the time histories of the distances in the pairs of adjacent bodies consecutively repeat each other with a constant time shift. It looks like a wave is running along the chain. The necessary and sufficient conditions for the system to be able to move from rest are established. For a specific excitation mode, in which the time histories of the distances between the bodies of the chain are defined as piecewise quadratic functions, a steady‐state motion of the system is studied for the case where the friction force is small in comparison with the force necessary for a body of the chain to be moved from a state of rest through a distance characterizing the amplitude of oscillations of adjacent bodies during the excitation period.
On localized modes of free vibrations of single‐walled carbon nanotubes embedded in nonhomogeneous elastic medium
Authors: Mikhasev G. 
Published: June 2013

AbstractFree axisymmetric vibrations of a single‐walled carbon nanotube (SWCNT) embedded in a nonhomogeneous elastic matrix are studied on the base of the nonlocal continuum shell theory. The effect of the surrounding elastic medium are considered using the Winkler‐type spring constant which is assumed to be variable along the tube axis. The tube may be prestressed by external tensile forces. The Flügge type shell equations, including the initial membrane hoop and axial stresses, are used as the governing ones. The constitutive equations are formulated by considering the small‐scale effects. Using the asymptotic approach, the SWCNT eigenmodes are constructed in the form of functions decreasing rapidly away from some “weakest” line which is assumed to be far from the tube edges. This study shows that introducing the small length scale parameter into the tube model allows to take into account inclusions in the surrounding elastic matrix which may results in the strong localization of some eigenmodes. The dependence of the natural frequencies and the power of the localization of the corresponding modes upon the constant of non‐locality, tensile stresses and the nanotube radius is analyzed.
Dimension reduction for models of pollutant transport with sedimentation
Authors: Limić N. , Starčević M. 
Published: June 2013

AbstractIn this paper we present a model for transport of substance with sedimentation governed by a water flow in a shallow basin. The model is developed by using a dimension reduction technique in an infinite layer. The concentration of substance is modeled by a 2D‐approximation, corrected in the vertical direction. In applications 2D‐models are often used in shallow basins as it was illustrated for instance in [Legović T., Limić N., Valković V., Estuar. Coast. Shelf Sci. 30, 619–654, (1990)]. Here we establish the acceptability criterion for the reduction, based on the mass conservation law. Thus we discuss the existence of solutions to the original 3D‐model and the deduced 2D‐model with L1 source terms. For the conclusion we prove that the relative error of sedimentation rates for the original and deduced model tends to zero as the distance from the source of substance tends to infinity.
Small‐amplitude grain boundaries of arbitrary angle in the Swift‐Hohenberg equation
Authors: Scheel A. , Wu Q. 
Published: June 2013

AbstractWe study grain boundaries in the Swift‐Hohenberg equation. Grain boundaries arise as stationary interfaces between roll solutions of different orientations. Our analysis shows that such stationary interfaces exist near onset of instability for arbitrary angles between the roll solutions. This extends prior work in [6] where the analysis was restricted to large angles, that is, weak bending near the grain boundary. The main new difficulty stems from possible interactions of the primary modes with other resonant modes. We generalize the normal form analysis in [6] and develop a singular perturbation approach to treat resonances.
Application of fractional order theory of thermoelasticity to a 1D problem for a half‐space
Authors: Sherief H.H. , Abd El‐Latief A.M. 
Published: June 2013

AbstractIn this work, we apply the fractional order theory of thermoelasticity to a 1D thermal shock problem for a half‐space. Laplace transform techniques are used. The predictions of the theory are discussed and compared with those for the coupled and generalized theories of thermoelasticity. Numerical results are computed and represented graphically for the temperature, displacement and stress distributions.
On uniqueness results for an elliptic‐parabolic‐system of partial differential equations arising in dynamic electrowetting
Authors: Fontelos M.A. , Grün G. 
Published: June 2013

AbstractWe prove regularity results and, as a consequence, uniqueness for a system of partial differential equations arising in the study of dynamic electrowetting phenomena and more general electrokinetic processes in three space dimensions. The system consists of Stokes equations coupled with equations for the motion of electric charges, Poisson equation for computing the electric field generated by such charges and a Cahn‐Hilliard equation for a phase field describing two fluids with different material parameters. The deduction and existence of weak solutions for this system was established in an earlier paper (Christof Eck et al., On a phase‐field model for electrowetting, Interfaces Free Bound. 11 (2), 259–290, (2009)).