bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the impact of pre‐GPM microwave precipitation observations in the Goddard WRF ensemble data assimilation system
Authors: Chambon Philippe , Zhang Sara Q. , Hou Arthur Y. , Zupanski Milija , Cheung Samson 
Published: June 2013

AbstractThe forthcoming Global Precipitation Measurement (GPM) Mission will provide next‐generation precipitation observations from a constellation of satellites. Since precipitation by nature has large variability and low predictability at cloud‐resolving scales, the impact of precipitation data on the skills of mesoscale numerical weather prediction (NWP) is largely affected by the characterization of background and observation errors and the representation of nonlinear cloud/precipitation physics in an NWP data assimilation system.We present a data impact study on the assimilation of precipitation‐affected microwave (MW) radiances from a pre‐GPM satellite constellation using the Goddard WRF Ensemble Data Assimilation System (Goddard WRF‐EDAS). A series of assimilation experiments are carried out in a Weather Research Forecast (WRF) model domain of 9 km resolution in western Europe. Sensitivities to observation error specifications, background error covariance estimated from ensemble forecasts with different ensemble sizes, and MW channel selections are examined through single‐observation assimilation experiments. An empirical bias correction for precipitation‐affected MW radiances is developed based on the statistics of radiance innovations in rainy areas. The data impact is assessed by full data assimilation cycling experiments for a storm event that occurred in France in September 2010. Results show that the assimilation of MW precipitation observations from a satellite constellation mimicking GPM has a positive impact on the accumulated rain forecasts verified with surface radar rain estimates. The case‐study on a convective storm also reveals that the accuracy of ensemble‐based background error covariance is limited by sampling errors and model errors such as precipitation displacement and unresolved convective scale instability.
IDENTIFICATION OF FLUVIAL WOOD USING GOOGLE EARTH
Authors: Atha J. B. 
Published: June 2013

ABSTRACTFluvial wood has long been known to enhance stream complexity by creating aquatic habitat and by increasing complexity in channel hydraulics and morphology. Although the presence and dynamics of large wood in river floodplains have been studied in a multitude of settings due to its importance in monitoring and managing ecohydrologic systems, limitations occur when studying fluvial wood on a basin scale. I postulate that with the employment of Google Earth, satellite images may be used to identify large wood and measure floodplain width across broader spatial scales previously inhibited by expensive and incomplete geospatial data. In this study, large wood was correctly identified within the floodplain of the Queets River, Washington, USA, through Google Earth; however, correct identification within the wetted channel was only possible during low flow if at least 50% was above water level. Within the study area, fluvial channel widths are measured as well. Google Earth proves to be an effective tool to discern large wood across greater spatial scales if the high‐resolution imagery is available for the study area. Results of statistical analyses derived from the downstream hydraulic geometry of the river reveal that this channel is influenced by bankfull width, the orientation of the wood to the channel, and whether it is located on a bar or within the wetted channel. In addition, wood counts analyzed in the context of the geometry of the river indicate that the fluvial wood has an influence on overall channel behavior. Copyright © 2013 John Wiley & Sons, Ltd.
Network Imitation to Deal with Sociocultural Dilemmas in Acquisitions of Young, Innovative Firms
Authors: Öberg Christina 
Published: June 2013

AbstractThis article expands current acquisition literature to include sociocultural challenges on inter‐organizational levels following acquisitions of young, innovative firms. Socioculture here denotes network parties' shared values, belief systems, and practices. Three acquisitions illustrate their consequences. The young, innovative firms and their acquirers are part of different networks, have dissimilar motives for pursuing business, and work within different time frames. To potentially improve knowledge transfer and integration, the acquirer can learn from the innovative firm's network interactions; choose targets among its own network parties; organize its governance into a separate business unit; practice reverse value integration from the acquired party; and carefully promote practices that foster innovativeness. The article contributes to research on acquisitions of young, innovative firms through pointing to how values and practices are interlinked in networks, and how the imitation of the acquired party's network interaction may help to sustain its innovativeness and transfer knowledge between the acquirer and acquired party. © 2013 Wiley Periodicals, Inc.
A Marriage Metaphor Model for Sociocultural Integration in International Mergers and Acquisitions
Authors: Rottig Daniel 
Published: June 2013

AbstractThe purpose of this article is to gain a better understanding about the sociocultural integration process in international mergers and acquisitions (M&As) by developing a marriage metaphor model for these transactions. Building on the metaphor of M&As as “marriages” between organizations, the presented model suggests that the sociocultural integration process consists of three interrelated phases: the dating, mating, and creating periods. Extant research, however, focuses primarily on the pre‐M&A contingency and post‐M&A process periods, which correspond to the dating and creating phases, respectively, and treats these research streams in relative isolation. This paper attempts to integrate these streams of research in the contexts of M&As across cultures, and further sets out to shed light onto the third, underresearched closing period, which corresponds to the mating phase in the forwarded model. In so doing, this paper endeavors to propose a dynamic perspective of the sociocultural integration in international M&As to emphasize the interrelatedness and on‐going character of this three‐stage process. © 2013 Wiley Periodicals, Inc.
Ambivalent Perspectives: An Ethnographic Case Study of Ambivalence in Postacquisition Integration
Authors: Moore Fiona 
Published: June 2013

AbstractIn this article, I will draw upon Smelser's concept of ambivalence as a means of better understanding cultural factors in the integration of the Cowley Works automobile factory into the BMW Group. In doing so, I will be considering, first, how an integration of the concept of ambivalence improves understanding of conflict and consensus in mergers and acquisitions, second, how the use of ambivalence‐friendly methods, such as ethnography, can improve data gathering and analysis in such cases, and, finally, exploring how the concept of ambivalence allows the problematization of the role of the researcher, the preconceptions brought to the analysis, and the received wisdom or folk categories which permeate the study, as well as the practice, of business. I will conclude by considering some ways forward for the exploration of ambivalence in cross‐cultural management. © 2013 Wiley Periodicals, Inc.
1‐Alkyl‐2‐{(O‐Thioalkyl)Phenylazo}Imidazole Complexes of PbII and Their Photochromic Property
Authors: Saha Halder Shefali , Roy Suman , Kumar Mondal Tapan , Saha Rajat , Sinha Chittaranjan 
Published: June 2013

AbstractPbII complexes of 1‐alkyl‐2‐{(o‐thioalkyl)phenylazo}imidazole (SRaaiNR'), [Pb(SRaaiNR')2X2] were characterized by spectroscopic studies. The single‐crystal X‐ray structure of [Pb(SEtaaiNEt)2Cl2] (SEtaaiNEt = 1‐ethyl‐2‐{(o‐thioalkyl)phenylazo}imidazole) proved imidazolyl‐N and –SEt coordination forming unusual puckered eight member chelate rings. UV light irradiation of the complexes in DMF solution shows E‐to‐Z (E and Z refer to trans and cis‐configuration about –N=N–, respectively) photoisomerization of the coordinated azoimidazole. The rate of isomerization follows the sequence: [Pb(SRaaiNR')2Cl2] < [Pb(SRaaiNR')2Br2] < [Pb(SRaaiNR')2I2]. Quantum yields (φE→Z) and the activation energy (Ea) of the isomerization of the complexes are lower than observed for the free ligand. This can be explained by considering the molecular assembly and the thus observed increase in mass and rotor volume of the complexes. DFT and TDDFT calculations of optimized geometry could explained the spectral properties and photochromic activity.
Synthesis and Structure of Lanthanide Aryloxo Complexes and Their Polymerization Behavior for ϵ‐Caprolactone
Authors: Fang Lei , Yao Yingming , Zhang Yong , Shen Qi , Wang Yaorong 
Published: June 2013

AbstractProtic exchange reactions of bis(phenolate) lanthanide cyclopentadienyl complexes (C5H5)Ln(MBMP)(THF)2 [MBMP2– = 2,2′‐methylene‐bis(6‐tert‐butyl‐4‐methyl‐phenolate)] with a series of mono‐phenols (including 2,6‐dimethylphenol, 4‐tert‐butylphenol, and 4‐methoxyphenol) produce the lanthanide aryloxo complexes (MBMP)Ln(OC6H3‐Me2‐2,6)(DME)2 [Ln = La (1), Nd (2)], (MBMP)La(OC6H4‐tBu‐4)(DME)2 (3), [(MBMP)Nd(OC6H4‐tBu‐4)(THF)2]2 (4), and [(MBMP)Ln(OC6H4‐OMe‐4)(THF)2]2 [Ln = La (5), Nd (6)]. All of these complexes were well characterized by elemental analyses, IR spectra, and NMR in the cases of complexes 1, 3, and 5. The definitive molecule structures of complexes 1, 3, and 4 were determined by single‐crystal X‐ray diffraction. The catalytic behavior of complexes 1–6 for the ring‐opening polymerization of ϵ‐caprolactone was explored.
Modeling of consistent second‐order plate theories for anisotropic materials
Authors: Schneider P. , Kienzler R. , Böhm M. 
Published: June 2013

AbstractBy Fourier‐series expansion in thickness direction of the plate with respect to a basis of scaled Legendre polynomials, several equivalent (and therefore exact) two‐dimensional formulations of the three‐dimensional boundary‐value problem of linear elasticity in weak formulation for a plate with constant thickness are derived. These formulations are sets of countably many PDEs, which are power series in the squared plate parameter. For the special case of a homogeneous monoclinic material, we obtain an approximative plate theory in finitely many PDEs and unknown variables by the truncation approach of the uniform‐approximation technique. The PDE system is reduced to a scalar PDE expressed in the mid‐plane displacement. The resulting second‐order theory, considered as a first‐order theory, is equivalent to the classical Kirchhoff theory for the special case of an isotropic material and equivalent to Huber's classical theory for an actual monoclinic material. However it remains shear‐rigid as a second‐order theory. Therefore, it is modified by an a‐priori assumption to a theory for monoclinic materials, that presumes the former equivalences, considered as a first‐order theory, but is in addition equivalent to Kienzler's theory as a second‐order theory for the special case of isotropy, which implies further equivalences to established shear‐deformable theories, especially the Reissner‐Mindlin theory and Zhilin's plate theory. The presented new second‐order plate theory for monoclinic materials is finally a system of two coupled PDEs of differentiation order six in two variables.
Adaptive Gaussian particle method for the solution of the Fokker‐Planck equation
Authors: Scharpenberg M.D. , Lukáčová‐Medviová M. 
Published: June 2013

AbstractThe Fokker‐Planck equation describes the evolution of the probability density for a stochastic ordinary differential equation (SODE) or a deterministic ordinary differential equation (ODE) with stochastic initial values. A solution strategy for this partial differential equation (PDE) up to a relatively large number of dimensions is based on particle methods using Gaussians as basis functions. An initial probability density is decomposed into a sum of multivariate normal distributions and these are propagated according to the ODE. The decomposition as well as the propagation is subject to possibly large numerical errors due to the difficulty to control the spatial residual over the whole domain. In this paper a new particle method is derived, which allows a deterministic error control for the resulting probability density. It is based on global optimization and allows an adaption of an efficient surrogate model for the residual estimation.
On the ability of nanoindentation to measure anisotropic elastic constants of pyrolytic carbon
Authors: Gross T.S. , Timoshchuk N. , Tsukrov I.I. , Piat R. , Reznik B. 
Published: June 2013

AbstractWe used cube corner, Berkovich, cono‐spherical, and Vickers indenters to measure the indentation modulus of highly oriented bulk pyrolytic carbon both normal to and parallel to the plane of elastic isotropy. We compared the measurements with elastic constants previously obtained using strain gage methods and ultrasound phase spectroscopy. While no method currently exists to extract the anisotropic elastic constants from the indentation modulus, the method of Delafargue and Ulm (DU) [17] was used to predict the indentation modulus from the known elastic constants. The indentation modulus normal to the plane of isotropy was %sim; 20% higher than the DU predictions and was independent of indenter type. The indentation modulus parallel to the plane of isotropy was 2–3 times lower than DU predictions, was depth dependent, and was lowest for the cube corner indenter. We attribute the low indentation modulus to nanobuckling of the graphite‐like planes and the indenter type dependence to the impact of differing degree of transverse stress on the tendency toward nanobuckling.
Closed form solution for an annular elliptic crack around an elliptic rigid inclusion in an infinite solid
Authors: Singh B.M. , Rokne J.G. , Dhaliwal R.S. 
Published: June 2013

AbstractIn this paper we consider the problem of indentation of an elliptic crack by a rigid elliptic inclusion in anti‐plane shear mode. Making use of integral transforms the solution of the problem is reduced into triple integral equations with cosine kernels and weight functions. Closed form solution of the triple integral equations is obtained and also closed form expressions are obtained for the displacement component and the stress intensity factor.
Moving dislocations in finite plasticity: a topological approach
Authors: Hochrainer T. 
Published: June 2013

AbstractPlastic deformation of crystals is mostly mediated by the motion of dislocations. During the last two decades a lot of effort was directed towards including more knowledge about dislocations in continuum descriptions of plasticity. Promising approaches towards building continuum plasticity theories on averages of the behavior of many single dislocations have been formulated under the assumption of small deformations. In the current paper we derive the kinematics of single dislocations moving inside a dislocated crystal simultaneously deforming by the motion of other dislocations in the language of large deformation plasticity. The evolution equation of a single dislocation is connected to the formation of kinks and jogs due to cutting by other dislocations and is shown to parallel the evolution equation of the dislocation density tensor in finite deformation formulation. Implications for dislocation based modeling of plasticity are discussed.
Criteria for nonuniqueness of Riemann solutions to compressible duct flows
Authors: Han E. , Hantke M. , Warnecke G. 
Published: June 2013

AbstractThe Riemann solutions without vacuum states for compressible duct flows have been completely constructed in the paper [11]. However, the nonuniqueness of Riemann solutions due to a bifurcation of wave curves in state space is still an open problem. The purpose of this paper is to single out the physically relevant solution among all the possible Riemann solutions by comparing them with the numerical results of the axisymmetric Euler equations. Andrianov and Warnecke in [2] suggested using the entropy rate admissibility criterion to rule out the unphysical solutions. However, this criterion is not true for some test cases, i.e. the numerical result for axisymmetric three dimensional flows picks up an exact solution which does not satisfy the entropy rate admissibility criterion. Moreover, numerous numerical experiments show that the physically relevant solution is always located on a certain branch of the L–M curves.
Homogenization of the elastic properties of pyrolytic carbon based on an image processing technique
Authors: Böhlke T. , Langhoff T.‐A. , Lin S. , Gross T. 
Published: June 2013

AbstractIn this work, the linear elastic material properties of differently textured variants of pyrolytic carbon are homogenized from the submicro‐ to the micro‐scale. In high resolution transmission electron microscope (HRTEM) lattice fringe images, the microstructure of pyrolytic carbon manifests itself in terms of projections of graphene layers. According to their orientation distribution, different textures of pyrolytic carbon have been classified. Assuming a von Mises‐Fisher distribution for the spatial orientation of single graphene layers, the orientation distribution function of the projected layers in the image plane is analytically found to be a modified Struve function. For each pyrolytic carbon texture, Maximum‐likelihood estimates for the mean orientation and the concentration parameter of the von Mises‐Fisher distribution are obtained numerically. Hereby, Fourier transformation and appropriate filters are used to determine the probabilities for discrete orientations of the graphene layers directly from HRTEM images. First‐ and second‐order bounds of the linear elastic properties of pyrolytic carbon of the different textures are computed. Elastic constants of graphite and pyrolytic graphite have been used for modeling the elastic behavior of the graphene layers within a continuum mechanical setting. Due to the high anisotropy of all analyzed textures of pyrolytic carbon, the differences even between the second‐order bounds are quite large.
DGFEM for the analysis of airfoil vibrations induced by compressible flow
Authors: Česenek J. , Feistauer M. , Kosík A. 
Published: June 2013

AbstractThe subject of the paper is the numerical simulation of the interaction of two‐dimensional compressible viscous flow and a vibrating airfoil. A solid airfoil with two degrees of freedom performs rotation around an elastic axis and oscillations in the vertical direction. The numerical simulation consists of the solution of the Navier‐Stokes system by the discontinuous Galerkin method coupled with a system of nonlinear ordinary differential equations describing the airfoil motion. The time‐dependent computational domain and a moving grid are taken into account by the arbitrary Lagrangian‐Eulerian (ALE) formulation of the Navier‐Stokes equations. The developed method is robust with respect to the magnitude of the Mach number and Reynolds number. Its applicability is demonstrated by numerical experiments.
Is the one‐equation coupling of finite and boundary element methods always stable?
Authors: Of G. , Steinbach O. 
Published: June 2013

AbstractIn this paper we present a sufficient and necessary condition to ensure the ellipticity of the bilinear form which is related to the one‐equation coupling of finite and boundary element methods to solve a scalar free space transmission problem for a second order uniform elliptic partial differential equation in the case of general Lipschitz interfaces. This condition relates the minimal eigenvalue of the coefficient matrix in the bounded interior domain to the contraction constant of the shifted double layer integral operator which reflects the shape of the interface. This paper extends and improves earlier results [12] on sufficient conditions, but now includes also necessary conditions. Numerical examples confirm the theoretical results on the sharpeness of the presented estimates.
Unsteady magnetohydrodynamic free convection flow past an accelerated vertical plate with constant heat flux and heat generation or absorption
Authors: Narahari M. , Debnath L. 
Published: June 2013

AbstractThe unsteady free convection flow of an electrically conducting fluid past an accelerated infinite vertical plate with constant heat flux is investigated under the influence of uniform transverse magnetic field fixed relative to the fluid or to the plate in the presence of heat generation or absorption. Two important cases, (i) exponentially accelerated plate (EAP) and (ii) uniformly accelerated plate (UAP), have been considered. The governing partial differential equations have been solved analytically using the Laplace transform technique and closed form solutions are obtained for the velocity and temperature fields without any restriction. The effects of system parameters such as the Prandtl number, heat generation or absorption, Grashof number, and magnetic field parameter on the flow fields are analyzed through graphs and tables. Further, the solution of the problem involves inverse Laplace transforms of some new exponential forms and these formulas are provided.
Greedy‐based approximation of frequency‐weighted Gramian matrices for model reduction in multibody dynamics
Authors: Fehr J. , Fischer M. , Haasdonk B. , Eberhard P. 
Published: June 2013

AbstractThe method of elastic multibody systems is frequently used to describe the dynamical behavior of the mechanical subsystems in multi‐physics simulations. One important issue for the simulation of elastic multibody systems is the error‐controlled reduction of the flexible body's degrees of freedom. By the use of second order frequency‐weighted Gramian matrix based reduction techniques the distribution of the loads is taken into account a‐priori and very accurate models can be obtained within a predefined frequency range and even a‐priori error bounds are available. However, the calculation of the frequency‐weighted Gramian matrices requires high computational effort. Hence, appropriate approximation schemes have to be used to find the dominant eigenspace of these matrices. In the current contribution, the matrix integral needed for calculating the Gramian matrices is approximated by quadratures using integral kernel snapshots. The number and location of these snapshots have a strong influence on the reduction results. Sophisticated snapshot selection methods based on Greedy algorithms from the reduced basis methods are used to construct the optimal location of snapshot frequencies. The method can be viewed as an automatic determination of optimal frequency weighting and as an adaptive learning of quadrature rules. One ingredient of Greedy algorithms is the need of error measures. To gain computational advantage two different error estimators are derived and used in the Greedy algorithm instead of the absolute or relative error.
Exact and complete electro‐elastic field in a half‐space of piezoelectric medium with a charged surface electrode: Revisit
Authors: Li X.Y. 
Published: June 2013

AbstractThis note revisits the electro‐elastic coupling behaviors of a transversely isotropic piezoelectric half‐space with a charged surface electrode. A different idea is provided by employing the three‐dimensional (3D) general solution of electro‐elasticity as well as generalized potential theory method. Compared with the previous studies, the method in this study is very simple and straightforward. The potential theory method is successfully extended to non‐axisymmetric case and the electrode can be of any planar configuration. For a charged penny‐shaped electrode, exact and complete 3D analysis is conducted. The validity of the present solutions is achieved numerically and analytically via comparing with those in literature. Some phenomena, which have escaped the attention of previous researchers, are observed. The present solutions are of theoretic and practical significance to serve as benchmarks for numerical codes and simplified studies.