bluuebunny/crossref_metadata_2025 huggingface dataset:
Martensitic transformations and damage: A combined phase field approach
Authors: Schmitt Regina , Kuhn Charlotte , Müller Ralf
Published: October 2015

A combined continuum phase field model for martensitic transformations and damage is introduced. The present approach considers the eigenstrain within the martensitic phase which leads in the surrounding material to both tensile and compressive stresses. The damage model needs to account for an appropriate differentiation thereof, since compressive stresses should not promote fracture. Interactions between micro crack propagation and the formation of the martensitic phases are studied in two dimensions. In agreement with experimental observations, martensite forms at the crack tip and influences the crack formation. For the numerical implementation finite elements are used while for the transient terms an implicit time integration scheme is employed. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Continuum modeling of material interfaces and surfaces based on molecular statics computations
Authors: Sievers Christian , Mosler Jörn
Published: October 2015

The effective macroscopic properties of a broad variety of different materials are defined by the properties of the involved material interfaces and surfaces. However, in contrast to classical bulk materials, the mechanical properties of material interfaces can usually only be determined indirectly. For that purpose, two different approaches are presented which allow to compute macroscopic properties of material interfaces based on molecular statics computations. While the first of those is based on the principle of energy equivalence, the second one relies on the principle of stress equivalence. The advantages and disadvantages of both frameworks are analyzed. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parallel solution of volume‐coupled multi‐field problems using an Abaqus‐PANDAS software interface
Authors: Schenke Maik , Ehlers Wolfgang
Published: October 2015

Numerical simulations have proven to be a powerful tool in several engineering disciplines, such as mechanical, civil and biomechanical engineering, and are thus widely used. However, the reliability of the simulations strongly relies on the governing material model. These models are usually developed in academic or industrial research projects and are implemented into dedicated software packages to proof their concepts. A transfer of these models from the research into a production‐related environment is often time consuming and prone to failures, and therefore a costly task.

The present work introduces a general interface between the research code PANDAS, which is a dedicated multi‐field finite‐element solver based on a monolithic solution strategy, and the commercial finite‐element package Abaqus. The coupling is based on the user‐defined element subroutine (UEL) of Abaqus. This procedure, on the one hand, allows for a straight‐forward embedding of the PANDAS material models into Abaqus. On the other hand, it provides, in comparison to the native UEL subroutine of Abaqus, a user‐friendly programming environment for user‐defined material models with an extended number of degrees of freedom. Furthermore, the coupling also supports the parallel‐analysis capabilities for large‐scale problems on high‐performance computing clusters.

The Abaqus‐PANDAS linkage can be applied to various coupled multi‐field problems. However, the present contribution addresses, in particular, volume‐coupled multi‐field problems as they arise when proceeding from the Theory of Porous Media (TPM) as a modelling framework. For instance, it can be used to model partially or fully saturated soils, or chemically or electro‐chemically driven swelling phenomena as they appear, for example, within hydrogels. Additionally, discontinuities, such as cracks, can be described for instance via phase‐field models or by the extended finite‐element method (XFEM). (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On electrostatic‐viscoelastic simulation of dielectric actuators
Authors: Schlögl Tristan , Leyendecker Sigrid
Published: October 2015

Describing and controlling the behaviour of dielectric elastomer actuated systems requires a suitable simulation model for the electro active polymers. This work is based on three dimensional finite elements to cover arbitrary actuator geometries. Maxwell's equations for electrostatics are coupled with the momentum balance by an electrostatic stress tensor. Time dependent quantities allow for a description of the deformation process depending on time. A potential energy function that is composed of Neo‐Hooke material behaviour, electric field energy and coupling terms covers the material properties. Viscoelastic effects are included and account for time dependent strains. A discrete version of Hamilton's principle leads to a structure preserving integration scheme for dielectric elastomers. The integration scheme is implemented in C++ and applied to examples. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Validation of a coupled FE‐model for the simulation of methane oxidation via thermal imaging
Authors: Thom Andrea , Ricken Tim , Bluhm Joachim , Widmann Renatus , Denecke Martin , Gehrke Tobias
Published: October 2015

To simulate the processes of methane oxidation in landfill cover layers, a new computational model was created. The purpose of the model is to allow a forecast on the performance of methanotrophic activity in landfill cover layers under changing environmental conditions. Therefore, a thermodynamic consistent model based on the well‐known Theory of Porous Media (TPM) combined with the mixture theory was developed, which analyzes the relevant gas productions of methane, oxygen and carbon dioxide. Diffusion, advection and conversion processes are considered as well as the energy production during methane oxidation. With the help of the thermal imaging technique a new experimental setup was developed in order to validate the coupled model in terms of the heat generation. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of ice under mechanical and thermal load
Authors: Urban Sten , Beitelschmidt Michael
Published: October 2015

The contact physics of the wheel‐rail contact of a railway vehicle under presence of water and ice at low temperatures is still not completely understood. For the investigation of the particular process in the contact zone a simulation is required, which is able to calculate the normal and tangential contact, the temperature field and the fluid‐structural interaction between wheel and rail at low temperatures under presence of snow and ice. For that purpose the behaviour of ice under wheel‐rail contact conditions is an important part. In this paper the thermal dynamic model of TSHIJOV [1], [3] for an adiabatic ice probe is updated by the new IAPWS equations of state for water [5] and ice phase Ih [4]. In a first approximation an ice specimen is loaded by specific wheel‐rail contact pressure distributions calculated by the half‐space formulation to clarify if phase transitions of ice can exist. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational Homogenization of Micromechanically Resolved Textile Materials
Authors: Mehnert Markus , Fillep Sebastian , Mergheim Julia , Steinmann Paul
Published: October 2015

This contribution deals with textile materials. On the macroscopic level textiles are characterized by a large area‐to‐thickness ratio, such that it is numerically efficient to treat the textile structure as a shell. To capture the contact behavior, fibers within a representative volume element are explicitly modeled by means of one dimensional beam elements on the microscopic level. A suitable, shell‐specific homogenization method is developed, which connects the homogeneous shell specific macro level to a fiber structured micro level. This contribution investigates the determination of the nonlinear constitutive behavior of textile materials. Selected examples for the macroscopic behavior of microscopic heterogeneous fiber structured materials are presented. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Clebsch transformation and its capabilities towards fluid and solid mechanics
Authors: Scholle Markus , Marner Florian
Published: October 2015

In fluid dynamics, Clebsch made use of the representation for the velocity field
$\vec u$
in terms of three potentials Φ, α, β in order to construct a first integral of the equations of motion in case of an inviscid flow with vortices. Apart from this, he received a self‐adjoint form of the equations allowing for deriving them from a variational formulation. In latter times the Clebsch transformation has been applied to different physical problems, for instance to baroclinic flow, Maxwell equations in classical electrodynamics [1], in Magnetohydrodynamics and even quantum theory within the context of a quantization of vortex tubes. Viscous flow, however, has not yet been formulated in terms of Clebsch variables to our best knowledge. It is the aim of this paper to demonstrate how Clebsch variables can be applied to viscous flow on the one hand, leading to a first integral of Navier‐Stokes equations as a first example. As a second example, solid mechanics is considered: by making use of an analogy between vortices in fluid flow on the one hand and dislocations in crystals on the other hand, a dynamic theory of dislocations can be established by using a certain modification of the Clebsch transformation. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An efficient numerical method for fully‐resolved particle simulations on high‐performance computers
Authors: Schneiders Lennart , Grimmen Jerry H. , Meinke Matthias , Schröder Wolfgang
Published: October 2015

A numerical method for fully‐resolved particle simulations on adaptively‐refined Cartesian meshes is presented. When the particle size is on the order of or smaller than the smallest scales of the carrier flow, fully resolving the particle surfaces on uniform Cartesian meshes results in a tremendous computational effort. This is circumvented by locally refining the mesh near the moving particle surfaces. A new dynamic load‐balancing strategy is described which enables the application of this approach to particulate turbulent flows on high‐performance computers. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulent boundary layer on a plate. Reynolds analogy and new formulations of the temperature defect law
Authors: Vigdorovich Igor
Published: October 2015

A consistent asymptotic theory describing hydrodynamic and thermal turbulent boundary layers on a flat plate in zero pressure gradient is developed. The fact that the flow depends on a limited number of governing parameters allows us to formulate algebraic closure conditions that relate the turbulent shear stress and turbulent heat flux to mean velocity and temperature gradients. As a result of an exact asymptotic solution of the boundary‐layer equations, the known laws of the wall for the velocity and temperature and the velocity and temperature defect laws as well as the expressions for the skin‐friction coefficient, Stanton number, and Reynolds‐analogy factor are obtained. The latter implies two new formulations for the temperature defect law one of which is completely similar to the velocity defect law and does not contain the Stanton number and the turbulent Prandtl number, and the other does not contain the skin‐friction coefficient. A heat‐transfer law is obtained that relates only thermal quantities. The theoretical conclusions agree well with experimental data. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear stability of a thin non‐isothermal droplet spreading on a rotating disk
Authors: Boettcher Konrad , Externbrink Timo
Published: October 2015

Previous works show that the linear stability of the contact line of an isothermal spreading droplet depends on the base state curvature of the free interface at the position of the unperturbed contact line [1]. Here the linear stability of a thin liquid droplet on a rotating disk is investigated, where the disk has a certain radial temperature profile and the ambient passive gas a constant temperature. It is shown that two different Marangoni effects influence the spreading beside centrifugal, gravitational, and capillary effects. The stability analysis prevails, that temperature gradients in the disk amplify some and damp other modes, while cooling the entire disk (or heating the gas) damps the growth rate of all modes and therefore seems to be an appropriate way to suppress the instability. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A comparison of viscoelastic and empirical rheological models in context of squeeze flows
Authors: Descher Stefan , Wünsch Olaf
Published: October 2015

This work compares the behavior of a Giesekus and Carreau‐Yasuda fluid in a squeeze flow between two circular plates. In order to do this the Carreau‐Yasuda model is fitted to the shear viscosity curve of the Giesekus model and the squeeze stress is compared over the process time. The investigations are performed numerically with a 2.5 dimensional wedge model. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptation and Enhancement of Generalized Polynomial Chaos for Industrial Applications
Authors: Glaser Philipp , Kosmas Petridis , Heuveline Vincent
Published: October 2015

This contribution presents ideas, how to adapt stochastic elements to industrial applications and reduce the number of simulations in comparison to Monte Carlo. Especially when the mathematical model equations are not known and just an input/output interface is given. For this so called black box model which can be generated by many simulation tools the generalized polynomial chaos based on the idea of Wiener [1], and extended by Xiu and Karniadakis [2] is a suitable technique. One main advantage of this concept can be seen in the ability to produce functional representations of stochastic variability. This yields in a reduction of the simulation number compared to classical methods and can intensified by using a sparse grids approach [3]. Looking at industrial applications the concept can be applied to a huge amount of systems. For example, components including electronic drives, fuel injection valves, and mechanical parts. As an example of use, a simplified model of a DC drive with six uncertain parameters is taken into account. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polynomial chaos approach for tuned bladed rotors with geometric modification
Authors: Koebelé‐Cousquer Maxime , Proppe Carsten
Published: October 2015

The paper presents a polynomial chaos approach for direct appoximation of cyclic modes of a tuned bladed rotor with all blades having the same randomly modified geometry. In order to validate this approach, accuracy of the approximation is evaluated for a simple rotor and is compared with other approximation methods, where eigenfrequencies and eigenvectors are obtained using polynomial approximation of structural matrices. The results show the good accuracy of the polynomial chaos approach. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polynomial Chaos and the Heave Motion of a Cylinder in Random Seas
Authors: Kreuzer Edwin , Solowjow Eugen
Published: October 2015

The stochastic equation of motion for a heaving cylinder subject to irregular sea waves is solved numerically with the polynomial chaos framework. Thereby, the stochastic forcing is expressed by a truncated Karhunen‐Loève expansion and the hydrodynamic radiation is formulated as a state space model. We obtain the mean and the variance of the cylinder heave motion. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Virtual process design on combined quasi‐static and high‐speed forming
Authors: Rozgić Marco , Kiliclar Yalin , Stiemer Marcus , Reese Stefanie
Published: October 2015

Sheet metal forming processes play a key role in a vast number of manufacturing cycles. The pursuit of novel approaches and enhancements of process chains is limited by the tremendous cost of experimental investigations. Hence, virtual process design is a suitable tool to overcome this limitation and to investigate new aspects of the processes via computer aided design. This work focuses on the optimization of a class of triggering pulses utilized in combined quasi‐static and electromagnetic high‐speed forming that avoid reverse currents. As typical example double exponential pulses are treated. Non‐linear, constrained optimization exploiting a LSDYNA simulation of the forming process is used to determine parameters defining a triggering current pulse, yielding an enhanced forming result, in terms of sharper drawing radii. A more detailed discussion of the method is presented in [1]. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robust Identification of Parametric Radiation Force Models via Impulse Response Fitting
Authors: Hatecke Hannes , Krüger Stefan
Published: October 2015

This paper presents a new identification method for obtaining parametric state‐space models for radiation force computation. These state‐space models can substitute the convolution integral in the equations of motion based on the impulse response function method. Thus, the method converts the integro‐differential equation to an ordinary differential equation which reduces the computational effort of radiation force computation significantly. The identification is performed in time‐domain which means that the retardation function is subject to fit. The method is verified by the application to a floating cylinder. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive FEM with goal‐oriented error estimation and an approximation of the dual problem for inelastic problems
Authors: Widany Kai‐Uwe , Mahnken Rolf
Published: October 2015

An approximation of the dual problem for goal‐oriented error estimation is derived, which preserves the numerical structure of the primal problem, usually found in standard finite element implementations for solid mechanics. For the error estimation we apply a higher‐order recovery procedure. An application to elasto‐plasticity is given. Numerical examples demonstrate the effectiveness of the procedure. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DAE‐formulation for optimal solutions of a multirate model
Authors: Pulch Roland , Kugelmann Bernd
Published: October 2015

A dynamical system including frequency modulated signals can be transformed into multirate partial differential algebraic equations. Optimal solutions are determined by a necessary condition. A method of lines yields a semi‐discretisation in the case of initial‐boundary value problems. We show that the resulting system can be written in a standard formulation of differential algebraic equations. Hence appropriate time integration schemes are available for a numerical solution. We present results for a test example modelling the electric circuit of a ring oscillator. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiobjective optimal control of fluid mixing
Authors: Ober‐Blöbaum Sina , Padberg‐Gehle Kathrin
Published: October 2015

In this contribution an efficient numerical method to solve multiobjective optimal control problems of fluid flow mixing governed by the advection equation is presented. To obtain well‐mixed behavior for non‐diffusive processes, the multi‐scale mixing of measure introduced in [1] is used in the formulation of the multiobjective optimal control problem. For the approximation of the Pareto set we combine reference point methods with an adjoint based optimization approach. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Harmonic Mistuning of Blisks
Authors: Pohle Linus , Panning‐von Scheidt Lars , Wallaschek Jörg
Published: October 2015

The paper describes a new method to calculate the maximum amplificationof blade vibrations of a bladed disk or blisk subject to manufacturing tolerances. Two effects of mistuned blisks are analyzed in this paper. The separation of two orthogonal nodal diameters are shown and described in detail. Furthermore, the excitation of more than one nodal diameter by only one engine order is discussed. If the eigenfrequencies of these nodal diameters are close together, the vibration amplitude of some blades increases. Based on a lumped‐mass model, it is shown which maximum amplitude can occur. The idea is to use a harmonic mistuning pattern to get the highest influence at small tolerances for one single nodal diameter. This influence is not exceeded by a randomly mistuned system and limits the maximum amplitude. The given analysis is validated by a common Monte‐Carlo simulation. On the other hand, a description of the excitation of other nodal diameters is given. Using these two effects, an absolute vibration maximum for a given mistuning limit can be calculated. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Applications of Approximation Theory to thermographic images in earthquake engineering
Authors: Cluni Federico , Costarelli Danilo , Minotti Anna Maria , Vinti Gianluca
Published: October 2015

In this paper we show some new applications of the approximation theory, by means of the multivariate sampling Kantorovich operators, to thermographic images in seismic engineering. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Edge detection based on fractional order differentiation and its application to railway track images
Authors: Telke Christian , Beitelschmidt Michael
Published: October 2015

Edge detection is one of the most fundamental necessities in image processing. Usally, edge detection algorithms are based on integer order differentiation operators. In many applications it is essential to perform a robust edge detection also to noisy input image data with low SNR as well. Thereby, integer based differentiation operators are often not leading to sufficient detection results. For this purpose an edge detector based on fractional order differentiation is introduced, which can significantly improve the detection performance to noisy images. Furthermore, a real application scenario of fractional order based edge detection is given within a modular railway track measurement system. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A fully meshless method for ‘gas – evaporating droplet’ flow modelling
Authors: Rybdylova Oyuna , Osiptsov Alexander N. , Sazhin Sergei S. , Begg Steven , Heikal Morgan
Published: October 2015

A meshless method for modelling two‐phase flows with phase transition is described. The method is based on consideration of three systems: viscous‐vortex blobs, thermal‐blobs and droplets; and can be applied for numerical simulation of 2D non‐isothermal flows of ‘gas‐evaporating droplets’ in the framework of the one‐way coupled two‐fluid approach. The carrier phase is viscous incompressible gas. The dispersed phase is presented by a cloud of identical spherical droplets, and, due to evaporation, the radius and mass of droplets are time dependent. The carrier phase parameters are calculated using the viscous‐vortex and thermal‐blob method; the dispersed phase parameters are calculated using the Lagrangian approach. Two applications have been considered: (i) a standard benchmark – Lamb vortex; (ii) a cold spray injected into a hot quiescent gas. In the latter problem three cases corresponding to three droplet sizes were investigated. The smallest droplets (of the three cases considered) are more readily entrained by the carrier phase and form ring‐like structures; the flow shows better mixing. Larger droplets evaporate less intensively. The medium sized droplets collect into two narrow bands stretched along the jet axis. The largest droplets form a two‐phase jet, which remains close to the jet axis. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Atomic Force Microscopy for investigating BaTiO3 and LiMn2O4 nanostructures based on Phase Field Approach
Authors: Thai Huy , Keip Marc‐André , Amanieu Hugues‐Yanis , Rosato Daniele , Schröder Jörg
Published: October 2015

Atomic Force Microscopy (AFM) probes the surface features of specimens using an extremely sharp tip scanning the sample surface while the force is applied. AFM is also widely used for investigating the electrically non‐conductive materials by applying an electric potential on the tip. Piezoresponse Force Microscopy (PFM) and Electrochemical Strain Microscopy (ESM) are variants of AFM for different materials. Both PFM and ESM signals are obtained by observing the displacement of the tip when applying electric fields during the scanning process. The PFM technique is based on converse piezoelectric effect of ferroelectrics and the ESM technique is based on electrochemical coupling in solid ionic conductors. In this work, two continuum‐mechanical formulations for simulation of PFM and ESM are discussed.

In the first model, for PFM simulation, a phase field approach based on the Allen‐Cahn equation for non‐conserved order parameters is employed for ferroelectrics. Here, the polarization vector is chosen as order parameter. Since ferroelectrics have highly anisotropic properties, this model accounts for transversely isotropic symmetry using an invariant formulation. The polarization switching behavior under the electric field will be discussed with some numerical examples.

In the simulation of ESM, we employ a constitutive model based on the work of Bohn et al. [8] for the modeling of lithium manganese dioxide LiMn2O4 (LMO). It simulates the deformation of the LMO particle according to an applied voltage and the evolution of lithium concentration after removing a DC pulse. The modeling results are compared to experimental data. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the full and block‐decoupling of nonlinear functions
Authors: Dreesen Philippe , Ishteva Mariya , Schoukens Johan
Published: October 2015

We review a method that decouples multivariate functions into linear combinations of a set of univariate (or simpler multivariate) functions of transformed variables. In this way the given nonlinear multiple‐input‐multiple‐output function is decoupled into a structure having simpler parallel internal branches that are linked by linear transformations to the original inputs and outputs. The procedure collects first‐order information by evaluating the Jacobian matrix of the given function in a set of points. These matrices are stacked into a three‐way tensor, whose decomposition reveals the decoupled representation. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In situ synthesis of nano‐assemblies of the high molecular weight ferrocene‐containing block copolymer via dispersion RAFT polymerization
Authors: Gao Chengqiang , Liu Chonggao , Zhou Heng , Wang Shuang , Zhang Wangqing
Published: October 2015

The in situ synthesis of the nano‐assemblies of the high molecular weight ferrocene‐containing block copolymer of poly(ethylene glycol)‐block‐poly(4‐vinylbenzyl ferrocenecarboxylate) (PEG‐b‐PVFC) via dispersion reversible addition‐fragmentation chain transfer (RAFT) polymerization was discussed. Taking the advantage of the accelerated polymerization rate of the dispersion RAFT polymerization, the nano‐objects of the well‐defined PEG‐b‐PVFC diblock copolymer with the polymerization degree (DP) of the ferrocene‐containing PVFC block up to 300 were prepared. It was found that the morphology of the PEG‐b‐PVFC diblock copolymer nano‐assemblies was dependent on the DP of the PEG and PVFC blocks, and nanospheres favorably formed in the case of the long PEG block and vesicles containing a thick and porous membrane were formed in the case of the short PEG block and long PVFC block, respectively. Our results demonstrate that the dispersion RAFT polymerization is an effective way to prepare the high molecular weight ferrocene‐containing block copolymer with interesting morphologies. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 900–909
Firewalls as artefacts of inconsistent truncations of quantum geometries
Authors: Germani Cristiano , Sarkar Debajyoti
Published: October 2015

In this paper we argue that a firewall is simply a manifestation of an inconsistent truncation of non‐perturbative effects that unitarize the semiclassical black hole. Namely, we show that a naive truncation of quantum corrections to the Hawking spectrum at order , inexorably leads to a “localised” divergent energy density near the black hole horizon. Nevertheless, in the same approximation, a distant observer only sees a discretised spectrum and concludes that unitarity is achieved by effects. This is due to the fact that instead, the correct quantum corrections to the Hawking spectrum go like . Therefore, while at a distance far away from the horizon, where , quantum corrections are perturbative, they do diverge close to the horizon, where . Nevertheless, these “corrections” nicely re‐sum so that correlations functions are smooth at the would‐be black hole horizon. Thus, we conclude that the appearance of firewalls is just a signal of the breaking of the semiclassical approximation at the Page time, even for large black holes.
Fe precipitation at the grain boundaries in Zn‐reacted Nd–Fe–B magnets: Experimental and first‐principles studies
Authors: Yang YuQi , Han BaoJun , Lu Zhao , Huang DongFang , Wang DongDong , Guo KeKe , Sun ZhiQiang , Zhou Yang , Li TaoTao
Published: October 2015

Traces of non‐magnetic atoms at the grain boundaries can effectively increase the coercivity of sintered Nd–Fe–B magnets. These atoms also have chance to occupy crystallographic Fe sites in NdFeB, which may force the unbound Fe to precipitate at the grain boundaries and thus destroy the nonmagnetic properties of the grain boundaries. In order to provide the thermodynamic evidences of Fe migration to the grain boundaries, one Zn diffusion reaction in NdFeB is investigated by scanning electron microscopy and energy‐dispersive X‐ray spectroscopy experiments, which confirm that 90 atomic percent of Fe is expelled to the grain boundaries. Magnetization measurements show that when Fe atoms precipitate at the grain boundaries, magnet's coercivity rapidly declines. The first‐principle calculations using linearized augmented plane wave method show that Zn atoms in 16k1, 8j2, and 4e sites have positive substitution energies and unfavorable for the Zn substitution at these sites, while the substitution energies are negative values and favorable for the Zn substitution at the sites of 8j1, 4c, and 16k2. Our experimental and theoretical calculations indicate that the doped atoms have significant effect on the formation of the Fe‐enriched layer at the grain boundary.
Theoretical performance analysis on transmission reserve table buffer with triage ranking for resource‐limited control networks
Authors: Fukazawa Taro , Yamada Tomohisa , Ninagawa Chuzo
Published: October 2015

Performance of the ‘transmission reserve table’ (TRT) buffer, which the authors recently proposed, is theoretically investigated. The buffer's triage ranking queuing was designed for resource‐limited control networks that are possibly exposed to a rush of control commands. Our previous study analyzed the performance of the TRT buffer by means of computer simulation. In this paper, we derive a stochastic analytical model for the TRT buffer and verify the model in comparison with computer simulations. Theoretical calculation demonstrates that the triage ranking of the TRT plays a crucial role in keeping the real‐timeness of the control network even in a rush of commands by our triage ranking mechanism. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Multi‐label emotion recognition of weblog sentence based on Bayesian networks
Authors: Wang Lei , Ren Fuji , Miao Duoqian
Published: October 2015

An increasing number of common users, in the Internet age, tend to express their emotions on the Web about everything they like or dislike. As a consequence, the number of all kinds of reviews, such as weblogs, production reviews, and news reviews, grows rapidly. This makes it difficult for people to understand the opinions of the reviews and obtain useful emotion information from such a huge number of reviews. Many scientists and researchers have attached more attention to emotion analysis of online information in the natural language processing field. Different from previous works, which just focused on the single‐label emotion analysis, this paper takes into account rich and delicate emotions and gives special regard to multi‐label emotion recognition for weblog sentences based on the Chinese emotion corpus (Ren‐CECps). Using the theory of Bayesian networks and probabilistic graphical model, the latent emotion variable and topic variable are employed to find out the complex emotions of weblog sentences. Our experimental results on the multi‐label emotion topic model demonstrate the effectiveness of the model in recognizing the polarity of sentence emotions. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Countercyclical energy and climate policy for the U.S.
Authors: Nemet Gregory F. , Grubler Arnulf , Kammen Daniel M.
Published: October 2015

Continuation of the U.S.’s historical pattern addressing energy problems only in times of crisis is unlikely to catalyze a transition to an energy system with fewer adverse social impacts. Instead, the U.S. needs to bolster support for energy innovation when the perceived urgency of energy‐related problems appears to be receding. Because of the lags involved in both the energy system and the climate system, decarbonizing the economy will require extraordinary persistence over decades. This need for sustained commitment is in contrast to the last several decades, which have been marked by volatility and cycles of boom and bust. In contrast to the often‐repeated phrase that one should ‘never let a good crisis go to waste,’ the U.S. needs to most actively foster energy innovation when aspects of energy and climate problems appear to be improving. We describe the rationale for a ‘countercyclical’ approach to energy and climate policy, which involves precommitment to a set of policies that go into effect once a set of trigger conditions are met. WIREs Clim Change 2016, 7:5–12. doi: 10.1002/wcc.369

This article is categorized under:

The Carbon Economy and Climate Mitigation > Policies, Instruments, Lifestyles, Behavior

Policy and Governance > National Climate Change Policy
Cancer Worry, Perceived Risk and Cancer Screening in First‐Degree Relatives of Patients with Familial Gastric Cancer
Authors: Li Jenny , Hart Tae L. , Aronson Melyssa , Crangle Cassandra , Govindarajan Anand
Published: October 2015

Currently, there is a lack of evidence evaluating the psychological impact of cancer‐related risk perception and worry in individuals at high risk for gastric cancer. We examined the relationships between perceived risk, cancer worry and screening behaviors among first‐degree relatives (FDRs) of patients with familial gastric cancer. FDRs of patients diagnosed with familial gastric cancer with a non‐informative genetic analysis were identified and contacted. Participants completed a telephone interview that assessed socio‐demographic information, cancer risk perception, cancer worry, impact of worry on daily functioning, and screening behaviors. Twenty‐five FDRs completed the telephone interview. Participants reported high levels of comparative and absolute cancer risk perception, with an average perceived lifetime risk of 54 %. On the other hand, cancer‐related worry scores were low, with a significant minority (12 %) experiencing high levels of worry. Study participants exhibited high levels of confidence (median = 70 %) in the effectiveness of screening at detecting a curable cancer. Participants that had undergone screening in the past showed significantly lower levels of cancer‐related worry compared to those that had never undergone screening. In conclusion, individuals at high‐risk for gastric cancer perceived a very high personal risk of cancer, but reported low levels of cancer worry. This paradoxical result may be attributed to participants’ high levels of confidence in the effectiveness of screening. These findings highlight the importance for clinicians to discuss realistic risk appraisals and expectations towards screening with unaffected members of families at risk for gastric cancer, in an effort to help mitigate anxiety and help with coping.
Thenmala Fault System, Southern India: Implication to Neotectonics
Authors: Praseeda E. , John Biju , Srinivasan C. , Singh Yogendra , Divyalakshmi K.S. , Samui Pijush
Published: October 2015

The Achankovil shear system is one of the major crustal scale structures in Peninsular India. This NW-SE trending shear zone stretches across the Western Ghats for a strike length of 120 km. A number of parallel lineaments demarcate this 15-20 km wide shear zone. Many studies were carried out to understand the origin and delineation of this structure. Low level seismicity reported in this region, however, does not suggest any relation with this shear zone and thus no significant study was carried out to understand its neotectonic behavior. However, there are a couple of faults identified in the southern end of this shear system viz., Thenmala and Thenmala south faults. Even though these faults were demarcated in hilly terrain of Western Ghats, its expression into the plain area east of the mountain terrain were not identified during the earlier studies. The present study however, delineated the signatures of these faults further in the southeast from satellite images. The traces of these faults are observed as multiple slip planes with varying deformation pattern. A group of N-S trending lineaments are also observed in hill ranges. Similarly, N-S trending long persistent vertical joints are observed in the plain area are free from displacement. The traces of NW-SE trending brittle faults observed in these areas crosscut all the joints including the N-S trending vertical ones. These observations suggest that the geomorphic signature associated with Thenmala lineaments may represent the youngest deformation (brittle) of the region.
Textural Characteristics of Sediments and Weathering in the Jhelum River Basin Located in Kashmir Valley, Western Himalaya
Authors: Mir Riyaz Ahmad , Jeelani Gh
Published: October 2015

This study presents a detailed textural and geochemical study of sediments of river Jhelum and its tributaries of Kashmir valley. The textural studies clearly established that the sediments were dominantly of medium grain size, moderately sorted and very positively skewed. The kurtosis suggested dominantly leptokurtic nature of sediments. The sediments were deposited under moderate to low energy conditions with dominant rolling processes. The statistical parameters showed little spatial as well as temporal variations. The observations are supported by the frequency curves and bivariate plots between various textural parameters, confirming the polymodal nature of sediments with dominant to moderate sand fraction. The bimodal and unimodal nature of the sediments was also present at certain locations. The major oxide elemental chemistry of the sediments indicated that the dominant elemental oxide was SiO2 followed by Al2O3 in all the sediments. The Chemical Index Alteration (CIA) and Resistant Index of Maturity (RM) reflected moderate weathering and immaturity of the sediments in the basin.
El aroma al evaluar el involucramiento del consumidor con un producto y su percepción de calidad
Authors: Arboleda Ana M. , Alonso Julio C.
Published: October 2015

Este estudio analiza en qué medida, usando el aroma como fuente de información de artículos como bolsos o maletines, el involucramiento del consumidor y la calidad percibida explican el precio percibido. El método es un diseño experimental intragrupo completo donde los sujetos evalúan 3 estímulos olfativos: cuero, cuero sintético y tela. Los resultados muestran que al emplear el involucramiento y la percepción de calidad como 2 perspectivas independientes y simultáneas al momento de evaluar el producto, el involucramiento no es relevante. Por lo tanto, es la variable calidad y no el involucramiento la que determina el precio percibido.
Mental disorders and transition to adult mental health services: A scoping review
Authors: Reale L. , Bonati M.
Published: October 2015

Background

Data are progressively accumulating regarding the transition to adult services.

Methods

A comprehensive search using the MEDLINE, Embase, PsycINFO, and Cochrane databases up until 16 March 2015 was conducted in order to summarize recent evidence on the transition from child to adult mental health services for patients with mental disorders. Authors extracted data and assessed study quality independently.

Results

The main findings of the 33 included studies were discussed taking into consideration four aspects: experiences of patients, carers, and clinicians, accounts of transition, current services models and protocols, and outcomes of transition. Of the 33 studies, 17 focused on a specific mental disorder: seven on attention deficit hyperactivity disorder, four on intellectual disability, three on eating disorders, two on serious emotional disorders and one on autism spectrum disorder. An attempt was also made to integrate the studies’ conclusions in order to improve transitional care.

Conclusions

The review reveals an evident need for longitudinal, controlled, health services research to identify and evaluate optimal service models with systematic and seamless transition protocols for patients with mental disorders requiring continuity of care into adult mental services.
Cognitive function and lifetime features of depression and bipolar disorder in a large population sample: Cross-sectional study of 143,828 UK Biobank participants
Authors: Cullen B. , Nicholl B.I. , Mackay D.F. , Martin D. , Ul-Haq Z. , McIntosh A. , Gallacher J. , Deary I.J. , Pell J.P. , Evans J.J. , Smith D.J.
Published: October 2015

Background

This study investigated differences in cognitive performance between middle-aged adults with and without a lifetime history of mood disorder features, adjusting for a range of potential confounders.

Methods

Cross-sectional analysis of baseline data from the UK Biobank cohort. Adults aged 40–69 (n = 143,828) were assessed using measures of reasoning, reaction time and memory. Self-reported data on lifetime features of major depression and bipolar disorder were used to construct groups for comparison against controls. Regression models examined the association between mood disorder classification and cognitive performance, adjusting for sociodemographic, lifestyle and clinical confounders.

Results

Inverse associations between lifetime history of bipolar or severe recurrent depression features and cognitive performance were attenuated or reversed after adjusting for confounders, including psychotropic medication use and current depressive symptoms. Participants with a lifetime history of single episode or moderate recurrent depression features outperformed controls to a small (but statistically significant) degree, independent of adjustment for confounders. There was a significant interaction between use of psychotropic medication and lifetime mood disorder features, with reduced cognitive performance observed in participants taking psychotropic medication.

Conclusions

In this general population sample of adults in middle age, lifetime features of recurrent depression or bipolar disorder were only associated with cognitive impairment within unadjusted analyses. These findings underscore the importance of adjusting for potential confounders when investigating mood disorder-related cognitive function.
Olanzapine or chlorpromazine plus lithium in first episode psychotic mania: An 8-week randomised controlled trial
Authors: Conus P. , Berk M. , Cotton S.M. , Kader L. , Macneil C. , Hasty M.K. , Hallam K. , Lambert M. , Murphy B.P. , McGorry P.D.
Published: October 2015

Background

Treatment strategies for mental disorders may vary according to illness stage. However no data currently exist to guide treatment in first episode psychotic mania. The aim of this study was to compare the safety and efficacy profile of chlorpromazine and olanzapine, as add-on to lithium, in patients with a first episode of psychotic mania, expecting better safety profile and adherence to olanzapine but similar efficacy for both treatments.

Methods

Data from 83 patients were collected in an 8-week randomised controlled trial on clinical variables, side effects, vital signs, and weight. Analyses of treatment differences over time were based on intent-to-treat principles. Kaplan-Meier estimated survival curves were used to analyse time-to-event data and mixed effects models repeated measures analysis of variance were used to determine treatment group differences over time on safety and efficacy measures.

Results

Ethics committee approval to delay informed consent procedure until recovery from the acute episode allowed the inclusion of 83 patients highly representative of those treated in the public sector. Contrary to our hypotheses, safety profile of both medications was similar. A signal for higher rate (P=.032) and earlier occurrence (P=.043) of mania remission was observed in the olanzapine group which did not survive correction for multiple comparisons.

Conclusions

Olanzapine and chlorpromazine have a similar safety profile in a uniquely representative cohort of patients with first episode psychotic mania. The possibility for a greater impact of olanzapine on manic symptoms leading to earlier remission of the episode needs exploration in a large sample.
MiR‐455‐3p regulates early chondrogenic differentiation via inhibiting Runx2
Authors: Zhang Zhiqi , Hou Changhe , Meng Fangang , Zhao Xiaoyi , Zhang Ziji , Huang Guangxin , Chen Weishen , Fu Ming , Liao Weiming
Published: October 2015

The expression of miR‐455‐3p has been shown to be up‐regulated in chondrogenesis of mesenchymal stem cell, but its role in different stages during chondrogenesis remains unknown. Here, we show that miR‐455‐3p is increased in ATDC5 cells from 0 d to 21 d, but rapidly decreases at 28 d, and a similar expression kinetic is detected in the development of mouse embryos. We show that miR‐455‐3p functions as an activator for early chondrogenic differentiation, most likely by inhibiting the expression of Runt‐related transcription factor 2 (Runx2) as indicated by luciferase reporter assays. In conclusion, miR‐455‐3p may activate early chondrogenesis by directly targeting Runx2.
Diversity and development of local inhibitory and excitatory neurons associated with dopaminergic nuclei
Authors: Morello Francesca , Partanen Juha
Published: October 2015

For regulation of voluntary movement and motivation the midbrain dopaminergic system receives input from a variety of brain regions. Often this input is mediated by local non‐dopaminergic neurons within or closely associated with the dopaminergic nuclei. In addition to the dopaminergic neurons, some of these non‐dopaminergic neurons also send functionally important output from the ventral midbrain to forebrain targets. The aim of this review is to introduce subtypes of GABAergic and glutamatergic neurons, which are located in the dopaminergic nuclei or the adjacent brainstem and are important for the regulation of the dopaminergic pathways. In addition, we discuss recent studies beginning to reveal mechanisms for their development, which may hold the key to understanding the diversity of these neurons.