bluuebunny/crossref_metadata_2025 huggingface dataset:
A non‐conventional discontinuous Lagrangian for viscous flow
Authors: Scholle Markus , Marner Florian
Published: October 2016

Although many attempts for finding a variational formulation of Navier‐Stokes equations have been made, a Lagrangian for viscous flow has not been established yet. An auspicious suggestion was made by Scholle [1] by extending Seliger and Whitham's Lagrangian [2] with additional terms ending up with some partial success: on the one hand, the phenomenon ‘viscosity’ occurs in a qualitatively correct manner, on the other hand the equations of motion resulting from the variation of Hamilton's principle differ from Navier‐Stokes equations and therefore, their solutions reveal noticeable quantitative differences to those of Navier‐Stokes equations. In this paper the Lagrangian [1] is modified by applying an innovative idea by Anthony [3], motivated by the reformulation of the Lagrangian in terms of complex fields, which can also be understood as the inversion of Madelungs idea [4] of reformulating the complex Schrödinger's equation into a hydrodynamic form. The prize one has to pay is that the resulting Lagrangian is discontinuous and therefore the mathematical treatment of the related variational problem challenging. Furthermore, an additional parameter, ω0, has to be introduced. However, it is demonstrated that Navier‐Stokes equations are recovered by the limit ω0 → ∞, whereas the case of finite ω0 can be interpreted as a generalization towards non‐equilibrium thermodynamics [3]. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flow‐induced anisotropic viscosity in short fiber reinforced polymers
Authors: Bertóti Róbert , Böhlke Thomas
Published: October 2016

The commonly used flow models for fiber reinforced polymers often neglect the flow induced mechanical anisotropy of the suspension. With an increasing fiber volume fraction, this plays, however, an important role. There are some models which count on this effect, they are, however, phenomenological and require a fitted model parameter. In this paper, a micromechanically based constitutive law is proposed which considers the flow induced anisotropic viscosity of the fiber suspension. The introduced viscosity tensor can handle arbitrary anisotropy of the fluid‐fiber mixture depending on the actual fiber orientation distribution. A homogenization method for unidirectional structures in contribution with orientation averaging is used to determine the effective viscosity tensor. The motion of rigid ellipsoidal fibers induced by the flow of the matrix material is described by Jeffery's equation. A numerical implementation of the introduced model is applied to representative flow modes. The calculated stress values are analyzed in transient and stationary flow cases. They show a less pronounced anisotropic viscous behaviour in every investigated case compared to the results obtained by the use of the Dinh‐Armstrong constitutive law. The reason for the qualitative difference is that the presented model depends on the complete orientation information, while the other one is linear in the fourth‐order fiber orientation tensor. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling and Simulation of Food Foams
Authors: Gladbach Katharina , Delgado Antonio , Rauh Cornelia
Published: October 2016

The rheological behaviour of protein solutions containing bubbles at rest, but particularly during fluid mechanical transport is not sufficiently investigated yet. Protein foams have a great importance in food production because of their special sensory properties. A suspension that contains bubbles in a Newtonian liquid exhibits inherently a complex rheological behaviour, such as elastic effects, a shear‐ and time‐dependent viscosity and normal stress differences. The deformation state of the bubbles in a suspension subjected to a steady shear is a function of the gas volume fraction ϕ and the capillary number NCa. In the present article, material equations for protein solutions with gas volume fractions ϕ ≤ 0.75 and small bubble deformations, i. e. NCa ≪ 1, are analysed and further developed. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Void dynamics in lead‐free Sn‐Ag‐Cu solder joints
Authors: Werner Marek , Reppel Thomas , Weinberg Kerstin
Published: October 2016

As a result of thermal and mechanical loading of Sn‐Ag‐Cu solder joints pores, flaws and voids may nucleate and grow. Such void nucleation is studied here by means of a phase‐field approach which accounts for the decomposition of the solder into phases described by its concentration c. In this investigation, the void growth results from boundary inward flux only, effects due to grain size and interstitials are not involved, cf. [1].

The free energy functional is approximated by a second order Taylor expansion and thus composed of a bulk free energy density and a Ginzburg‐type gradient term. The bulk free energy density ϕ follows a classical Ginzburg‐Landau double‐well potential. The gradient‐energy coefficient κ depends on ϕ and is calculated similar to [2]. Experimental data have been adapted for the modeling of the temporal evolution of the concentration of voids located on a square domain in 2D. The simulation is based on a B‐spline finite element analysis. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
From CAA to CFD
Authors: Akkermans R.A.D. , Bernicke P. , Ewert R. , Dierke J.
Published: October 2016

In this contribution, an application of a computational aeroacoustic code as a hybrid Zonal LES tool is presented. The here used hybrid approach is based on a novel implementation of the Non‐Linear Perturbation Equations extended with fluctuating viscous terms, denoted as “Overset” since a perturbation analysis is performed on top of a background flow. The extension to LES is demonstrated with isotropic decaying turbulence, where the expected temporal decay and scaling of the reference DNS data is recovered with the LES employing a classical Smagorinsky model. Furthermore, a conceptual approach is presented that describes the investigation of sound sources with application to trailing‐edge noise. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drag reduction via wall‐normal oscillations in turbulent flat plate boundary layer flow at very high Reynolds number
Authors: Albers Marian , Meysonnat Pascal S. , Schröder Wolfgang
Published: October 2016

The effects of wall‐normal single point oscillations in turbulent boundary layers at very high Reynolds number are investigated by numerical simulation. The impact on the friction drag and on the turbulent structures is analyzed. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bayesian calibration of model coefficients for a simulation of flow over porous material involving SVM classification
Authors: Friedman Noémi , Kumar Pradeep , Zander Elmar , Matthies Hermann G.
Published: October 2016

In this contribution the identification of the model coefficients of a novel turbulent flow model over porous media is concerned. The flow is modeled with a volume and Reynolds averaged compressible Navier‐Stokes equations approach. The main focus of this contribution is to calibrate the model coefficients starting from expert prior knowledge by incorporating DNS data of the velocity field and the Reynolds stresses. For the inverse problem general Polynomial Chaos Expansions (gPCE) based surrogate model was used. To avoid the identification of nonphysical coefficient setups, these parametric regions were filtered out by identifying a decision boundary by the support vector machine binary classification. The machinery of the Markov Chain Monte Carlo (MCMC) was used for the data assimilation combined with a nonlinear Minimum Mean Square Estimator (MMSE) for speeding up the convergence of the random walk of the MCMC. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Experimental Design to Identify the Average Stress‐Strain Response in Short Fiber‐Reinforced Plastics
Authors: Ospald Felix , Herzog Roland
Published: October 2016

We show how to use optimal experimental design methods for the parameter identification of short fiber reinforced plastic (SFRP) materials. The experimental data is given by computer simulations of representative volume elements (RVE) of the SFRP material. The experiments are designed such that a minimal number of RVE simulations is required and that the model response attains a minimal variance for a class of strains and fiber orientations. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stochastic upscaling of heterogeneous materials
Authors: Sarfaraz Muhammad Sadiq , Rosić Bojana , Matthies Hermann G.
Published: October 2016

We propose a probabilistic strategy to upscale the material spatial variability from fine to coarse scale. To implement this idea in a numerical framework, we consider the coarse‐scale as stochastic, i. e. its material properties are considered uncertain and modeled as random variables/fields. Numerical examples are shown to demonstrate the applicability of proposed approach. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An impulse control approach for optimal maintenance scheduling of a gas turbine
Authors: Gröger Michael
Published: October 2016

Today gas turbine outages are determined by one global life counter and deterministic life times. In the future the gas turbine will be equipped with multiple life counters for outage determination. Therefore we present an impulse control approach which takes the probabilistic nature of the damage mechanism into account to calculate an optimized maintenance schedule. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling, simulation and optimization of an elastic structure under moving loads
Authors: Kimmerle Sven‐Joachim
Published: October 2016

We consider an elastic structure that is subject to moving loads representing e.g. heavy trucks on a bridge or a trolley on a crane beam. A model for the quasi‐static mechanical behaviour of the structure is derived, yielding a coupled problem involving partial differential equations (PDE) and ordinary differential equations (ODE). The problem is simulated numerically and validated by comparison with a standard formula used in engineering. We derive an optimal policy for passing over potentially fragile bridges. In general, our problem class leads to optimal control problems subject to coupled ODE and PDE. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The One‐Shot Method in SU2
Authors: Kusch Lisa , Gauger Nicolas R.
Published: October 2016

For PDE‐constrained optimization tasks the one‐shot approach is well‐suited. The solution of the state equation is augmented with an adjoint solver to provide approximate reduced derivatives that can be used in an optimization iteration to change the design. In this paper different one‐shot strategies for SU2 are implemented and tested for aerodynamic shape optimization in the open‐source multi‐physics package SU2 to extend the choice of optimization algorithms. These include the application of the one‐shot approach when considering additional constraints apart from the state equation. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Frequency based preconditioning and smoothing for shape optimization
Authors: Kusch Jonas , Gauger Nicolas R. , Müller Siegfried , Schmidt Stephan
Published: October 2016

In this paper, we present a smoothing technique which can be understood as a Quasi‐Newton method. The idea of this preconditioner is that it approximates the symbol of the inverse Hessian, which has smoothing behavior. This symbol is derived analytically for the Stokes equations and investigated numerically for a flow with a Reynolds number of 80. The resulting symbol is then approximated by differential operators, which will lead to a method similar to Sobolev Smoothing. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An efficient optimization method for mechanical shells considering cut‐outs
Authors: Dienemann Robert , Schumacher Axel
Published: October 2016

In this contribution an optimization method for shell structures is presented. This method was developed in order to perform a simultaneous optimization of the shape and position of the mid surface and a topology optimization to introduce cut‐outs. A topology optimization method for continuum structures is combined with a manufacturing constraint for deep drawable sheet metals. It is shown, how more than a million design variables can be handled efficiently using a mathematical optimization algorithm for the design update and the finite element method for the structural simulation. © 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Using Local Spectral Information in Domain Decomposition Methods – A Brief Overview in a Nutshell
Authors: Klawonn Axel , Kühn Martin , Rheinbach Oliver
Published: October 2016

For second‐order elliptic partial differential equations large discontinuities in the coefficients yield ill‐conditioned stiffness matrices. The convergence of domain decomposition methods (DDM) can be improved by incorporating (numerically computed) local eigenvectors into the coarse space. Different adaptive coarse spaces for DDM have been constructed and used successfully. For two‐level Schwarz, FETI‐1 and BDD methods, adaptive coarse spaces with a rigorous theoretical basis are known for 2D and 3D. Although successfully in use for almost a decade, a theory for adaptive coarse spaces for FETI‐DP and BDDC was lacking. While the problem was recently settled for 2D, the estimate for the 3D adaptive algorithm required improved coarse spaces. We give an brief overview of the literature, i. e., the different known approaches, and show numerical results for a specific adaptive FETI‐DP method in 3D, where the condition number bound could only recently be proven. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ℋ‐matrix techniques for approximating large covariance matrices and estimating its parameters
Authors: Litvinenko Alexander , Genton Marc , Sun Ying , Keyes David
Published: October 2016

In this work the task is to use the available measurements to estimate unknown hyper‐parameters (variance, smoothness parameter and covariance length) of the covariance function. We do it by maximizing the joint log‐likelihood function. This is a non‐convex and non‐linear problem. To overcome cubic complexity in linear algebra, we approximate the discretised covariance function in the hierarchical (ℋ‐) matrix format. The ℋ‐matrix format has a log‐linear computational cost and storage O(knlogn), where rank k is a small integer. On each iteration step of the optimization procedure the covariance matrix itself, its determinant and its Cholesky decomposition are recomputed within ℋ‐matrix format. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A non symmetric FVM‐BEM coupling method
Authors: Erath Christoph , Of Günther , Sayas Francisco‐Javier
Published: October 2016

We consider the prototype model for flow and transport of a concentration in porous media in an interior domain and couple it with a diffusion process in the corresponding unbounded exterior domain. To guarantee mass conservation and stability with respect to dominating convection also for a discrete solution we introduce a non symmetric coupling of the vertex‐centered finite volume method (FVM) and the boundary element method (BEM). BEM approximates the unbounded exterior problem which avoids truncation of the domain. One can also interpret that the (unbounded) exterior problem “replaces” the boundary conditions of the interior problem. We aim to provide a first rigorous analysis of the discrete system for different model parameters; existence and uniqueness, convergence, and a priori estimates. Numerical examples illustrate the strength of the chosen method which is computational cheaper than the previous three field FVM‐BEM couplings. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive FEM for NURBS Surface Shells
Authors: Weise Michael
Published: October 2016

The application of shell theories in the finite element method (FEM) requires a description of the shell midsurface geometry and its derivatives. Modern computer aided design software uses non‐uniform rational B‐splines (NURBS) for geometry description. We give some insights on how to implement adaptive FEM for NURBS surface Naghdi shells. A speciality is the incorporation of tangential vectors with continuous directions, but jumping lengths. Such vectors may occur when NURBS surfaces are combined. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Snapshot location for POD in control of a linear heat equation
Authors: Alla Alessandro , Gräßle Carmen , Hinze Michael
Published: October 2016

In the present work, we study the approximation of a distributed optimal control problem for a linear heat equation with model order reduction based on Proper Orthogonal Decomposition (POD‐MOR). We show that snapshot location for control problems is crucial in model reduction. For the determination of the time instances (snapshot locations) we utilize an a‐posteriori error control concept which is based on a reformulation of the optimality system of the underlying optimal control problem as a second order in time and fourth order in space elliptic system. Finally, we present a numerical test to illustrate our approach. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How not to discretize the control
Authors: Wachsmuth Daniel , Wachsmuth Gerd
Published: October 2016

In this short note, we address the discretization of optimal control problems with higher order polynomials. We develop a necessary and sufficient condition to ensure that weak limits of discrete feasible controls are feasible for the original problem. We show by means of a simple counterexample that a naive discretization by higher order polynomials can lead to non‐feasible limits of sequences of discrete solutions. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Simulation of Air Flow in Model Room
Authors: Ćoćić Aleksandar , Brajović Mladen , Lečić Milan
Published: October 2016

Efficient, and appropriate indoor air environment is important issue in building design. Air flow patterns which are formed in the room are mainly depended on its geometrical parameters. Investigation of flow patterns are performed on a relatively simple geometry of model room, with a small obstacle (partition) in it. There are several interesting flow phenomena which are present in the model room: flow through sudden geometry expansion, stagnation flow with lateral boundaries, flow over the obstacle, etc. Since the air velocities are low, it is assumed that flow is incompressible. Numerical calculations of these patterns have been done using RANS modeling approach. For all calculations an extended version of open‐source CFD software OpenFOAM was used. Several turbulence models have been used for RANS approach, with special attention on their performance in capturing unsteady flow phenomena. Comparison of obtained numerical results and available experimental results for mean velocities shown good agreement. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A small‐gain approach to networked control systems with asynchronous communication
Authors: Geiselhart R. , Borgers D.P. , Heemels W.P.M.H.
Published: October 2016

The aim of this work is to give a procedure to compute an ISS Lyapunov function (ISS ‐ input‐to‐state stability) for a large‐scale networked control system (NCS) in which sensors, controllers and actuators are connected via multiple communication networks that operate asynchronously, [1]. The main idea is that the NCS is modeled as an interconnection of controlled subsystems and (hybrid) error systems, for which local ISS Lyapunov functions can be derived from the underlying medium access control (MAC) protocol systematically. The application of a small‐gain result leads to the construction of an ISS Lyapunov function for the whole NCS. In particularly, maximally allowable transfer intervals (MATIs) and maximally allowable delays (MADs) for each communication network can be computed that are directly related to the ISS gains and convergence rates. In this respect, tradeoffs between the quality‐of‐control (QoC) of the whole NCS and the quality‐of‐service (QoS) of the communication networks become explicit. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Observer Design based on Constant‐Input Observability for DAEs
Authors: Küsters Ferdinand , Trenn Stephan , Wirsen Andreas
Published: October 2016

For differential‐algebraic equations (DAEs) an observability notion is considered which assumes the input to be unknown and constant. Based on this, an observer design is proposed. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solving Differential Matrix Equations using Parareal
Authors: Köhler Martin , Lang Norman , Saak Jens
Published: October 2016

Differential matrix equations appear in many applications like optimal control of partial differential equations, balanced truncation model order reduction of linear time varying systems and many more. Here, we will focus on differential Riccati equations (DRE). Solving such matrix‐valued ordinary differential equations (ODE) is a highly time consuming process. We present a Parareal based algorithm applied to Rosenbrock methods for the solution of the matrix‐valued differential Riccati equations. Considering problems of moderate size, direct matrix equation solvers for the solution of the algebraic Lyapunov equations arising inside the time intgration methods are used. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Model order reduction of dynamic skeletal muscle models
Authors: Mordhorst Mylena , Wirtz Daniel , Röhrle Oliver
Published: October 2016

Forward‐dynamics simulations of three‐dimensional continuum‐mechanical skeletal muscle models are a complex and computationally expensive problem. Considering a fully dynamic modelling framework based on the theory of finite elasticity is challenging as the muscles' mechanical behaviour requires to consider a highly nonlinear, viscoelastic and incompressible material behaviour. The governing equations yield a nonlinear second‐order differential algebraic equation (DAE), which represents a challenge to model order reduction (MOR) techniques. This contribution shows the results of the offline phase that could be obtained so far by applying a combination of the proper orthogonal decomposition (POD) and the discrete empirical interpolation method (DEIM). (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Higher‐order conformal decomposition finite element method
Authors: Omerović Samir , Fries Thomas‐Peter
Published: October 2016

Numerical simulations of structures using higher‐order finite elements is still a challenging task, in particular for domains with curved boundaries. A new higher‐order accurate approach is proposed, combining the advantages of the classical p‐FEM with embedded domain methods. Boundaries and/or interfaces are described implicitly using the level set method. In the elements cut by the zero level set, an automatic decomposition into interface aligned, i. e. conforming sub‐elements is realized. Transfinite mappings are utilized to construct higher‐order sub‐elements by mappings of reference elements to the two sides of the boundary or interface. It is shown that although the resulting sub‐elements are not always well‐shaped, optimal convergence rates are possible. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity Analysis of the Design Parameters for the Calibration of Cable‐driven Parallel Robots
Authors: Reicherts Sebastian , Blume Sebastian , Reichert Christopher , Schramm Dr.‐Ing. Dr. h.c. Dieter
Published: October 2016

Uncertainties in the kinematic parameters like the pulley positions take a major influence onto the force capability of a cable‐driven parallel robot. For that purpose this paper describes a calibration method to estimate exactly the underlying kinematic parameters. As the kinematic is influenced by a variety of different parameter, the calibration can be very complex and time consuming. In this approach, a sensitivity analysis of a cable‐driven parallel robot is presented to simplify and enhance the calibration. The results are discussed and the further steps are introduced. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐adaptive multirate generalized‐structure additively partitioned Runge‐Kutta schemes for mechanical fluid‐structure interaction
Authors: Bremicker‐Trübelhorn Sascha , Ortleb Sigrun
Published: October 2016

We extend the multirate GARK approach by Günther and Sandu [1, 2] to the case of non‐constant micro steps per macro step to be able to cover time adaptivity, arriving at our so‐called TAMGARK scheme and derive order conditions for arbitrary non‐constant micro step sizes. The TAMGARK scheme is applied to the classical piston problem [3] to study the interaction between the piston and inviscid fluid flow in one spatial dimension. We demonstrate the functionality of the chosen time‐adaptation strategy and the ability of the overall scheme to preserve the order of the basic schemes. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Cheeger constant of a quantum graph
Authors: Kennedy James B. , Mugnolo Delio
Published: October 2016

We review the theory of Cheeger constants for graphs and quantum graphs and their present and envisaged applications. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bounds on the Non‐real Spectrum of a Singular Indefinite Sturm‐Liouville Operator on ℝ
Authors: Behrndt Jussi , Schmitz Philipp , Trunk Carsten
Published: October 2016

A simple explicit bound on the absolute values of the non‐real eigenvalues of a singular indefinite Sturm‐Liouville operator on the real line with the weight function sgn(·) and an integrable, continuous potential q is obtained. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localic Krull dimension
Authors: Bezhanishvili Guram , Bezhanishvili Nick , Lucero‐Bryan Joel , van Mill Jan
Published: October 2016

We shall define localic Krull dimension for topological spaces. In particular, a space X has the localic Krull dimension n if n is the greatest number such that X can be mapped, via a continuous and open map, onto the n‐chain seen as an Alexandroff space. We shall discuss the applications of this concept in obtaining topological completeness results in modal logic. We shall also show how the localic Krull dimension is related to the Krull dimension in ring theory. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complexity of a knot invariant
Authors: Brooke‐Taylor Andrew , Miller Sheila
Published: October 2016

The algebraic structures called quandles constitute a complete invariant for tame knots. However, determining when two quandles are isomorphic is an empirically hard problem, so there is some dissatisfaction with quandles as knot invariants. We have confirmed this apparent difficulty, showing within the framework of Borel reducibility that the general isomorphism problem for quandles is as complex as possible. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Invitation to Infinitary Computability
Authors: Carl Merlin
Published: October 2016

In the last two decades, various machine models of computability have been generalized to work in the transfinite. I will give an overview of these models, some of the main results concerning them and some reasons why studying them is of interest outside of foundational considerations. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simple formulas defining complicated sets
Authors: Lücke Philipp
Published: October 2016

We consider the question whether large cardinal axioms imply that certain complicated sets cannot be defined by simple formulas. More precisely, we ask whether the existence of larger large cardinals is compatible with the existence of a well‐ordering of the real numbers that is definable by a Σ1‐formula that uses a single ordinal as a parameter. This note presents results by Ralf Schindler, Philipp Schlicht and the author showing that the existence of a well‐ordering of the reals that is definable by a Σ1‐formula with parameter ω1 is compatible with the existence of a Woodin cardinal and incompatible with the existence of a Woodin cardinal with a measurable cardinal above it. Moreover, a similar result holds for Σ1‐formulas using certain large cardinals as a parameter. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Moreau‐type Variational Integrator
Authors: Capobianco Giuseppe , R. Eugster Simon
Published: October 2016

In this paper we derive a variational integrator for nonsmooth mechanical systems by discretizing the principle of virtual action with finite elements in time. After the discretization with local finite elements, the constitutive laws for the contact forces are introduced as in Moreau's time stepping scheme. This derivation shows exemplary how variational integrators for systems with frictional unilateral constraints can be derived. The long‐time energy behavior of the presented scheme is compared with the behavior of Moreau's stepping scheme on an example system. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of applications within the reviewing service zbMATH
Authors: Kühnemund Andreas
Published: October 2016

Zentralblatt MATH (zbMATH) is the world's most comprehensive and longest‐running abstracting and reviewing service in pure and applied mathematics. The database contains more than 3.6 million bibliographic entries, starting from the 18th century. The presentation during the DMV/GAMM meeting gave a short introduction to the search engine with emphasis on selected fields of applied mathematics. This is a shortened version of the talk without details about the database itself. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure Dependence of Fe‐Co Hydroxides on Fe/Co Ratio and Their Application for Supercapacitors
Authors: Jiang Liyang , Sui Yanwei , Qi Jiqiu , Chang Yuan. , He Yezeng , Meng Qingkun , Wei Fuxiang , Sun Zhi , Jin Yunxue
Published: October 2016

Fe‐Co hydroxides with different Fe/Co atomic ratios grown on nickel foams are synthesized by one‐step electrochemical deposition. The prepared samples are characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. It was found that the influence of initial Fe/Co ratios in the precursor solutions on the structure and electrochemical performance of electrodeposited products is significant. Fe(OH)3 shows particle shape with average diameter of 200 nm. With addition of Co ions, frame‐like structure consisting of smaller particles is formed for Fe‐Co hydroxides. Based on the morphology of Co(OH)2, it is deduced that Co(OH)2 serves as a network former constructing a tridimensional frame network structure. Fe‐Co hydroxide with Fe/Co ratio of 1:1 exhibits two types of structure features: nanoflake‐like network structure overall and nanoparticle structure with numerous mesoporous microscopically. As the supercapacitor electrode materials, the as‐prepared Fe‐Co hydroxide electrode with Fe/Co ratio of 1:1 exhibits highest specific capacitance of 2255.6 F g−1 at the current density of 1 A g−1 and also shows good cycling performance of 73.5% capacity retention at current density of 10 A g−1 after 2000 cycles. This work provides a facile method to produce promising Fe‐Co hydroxide electrode materials with high performance for supercapacitors.
Exploratory Population PK Analysis of Dupilumab, a Fully Human Monoclonal Antibody Against IL‐4Rα, in Atopic Dermatitis Patients and Normal Volunteers
Authors: Kovalenko P , DiCioccio AT , Davis JD , Li M , Ardeleanu M , Graham NMH , Soltys R
Published: October 2016

An exploratory population pharmacokinetic model for functional dupilumab was developed. Data from healthy volunteers and patients with atopic dermatitis (AD) receiving intravenous or subcutaneous doses were integrated. The data included 197 participants (2,518 measurements of dupilumab in serum) from six phase I and II studies. The data were analyzed using stochastic approximation expectation‐maximization and importance sampling methods. The best structural model was a two‐compartment model with parallel linear and Michaelis–Menten elimination from the central compartment. Estimated parameters were: central volume 2.74 L, elimination rate 0.0459 d−1, central‐to‐peripheral rate 0.0652 d−1, peripheral‐to‐central rate 0.129 d−1, bioavailability 60.7%, maximal target‐mediated elimination rate 0.968 mg/L/d, and Michaelis–Menten constant 0.01 mg/L. Body weight was a significant covariate of the central volume. No gender effect was observed when controlling for weight. No differences between healthy volunteers and patients with AD were found. The model adequately described dupilumab pharmacokinetics for intravenous and subcutaneous routes of administration.
Development of diffuse alveolar damage after initiation of Nijutsuto
Authors: Kato Motoyasu , Sasaki Shinichi , Izumi Hiroshi , Uekusa Toshimasa , Tominaga Shigeru , Takahashi Kazuhisa
Published: October 2016

Chinese traditional medicine, Nijutsuto, is used to treat patients with frozen shoulder and osteoarthritis. Herbal medicine is often linked to the development of interstitial lung disease. An 83‐year‐old Japanese man with osteoarthritis who was on Nijutsuto was admitted to our hospital with dyspnoea and severe cough after 2 weeks from initiation of Nijutsuto. A chest computed tomography scan on admission showed diffuse ground glass opacity with traction bronchiectasis. Thus, he was diagnosed with Nijutsuto‐induced interstitial lung disease, and was treated with a high dose of methylprednisolone and cyclophosphamide. However, the patient died of respiratory failure 2 weeks after admission. The patient was definitively diagnosed with diffuse alveolar damage by pathological autopsy. Nijutsuto contains Radix Scutellariae, which is considered to be the cause of interstitial lung disease. Chinese traditional medicine containing both Radix Scutellariae and Licorice should be carefully used because of its potential role in the development of diffuse alveolar damage.
Characterization of high‐aspect‐ratio periodic structures by X‐ray photoelectron spectroscopy
Authors: McEleney Kevin , Bruce Jared P. , Freund Michael S.
Published: October 2016

X‐ray photoelectron spectroscopy (XPS) is a powerful surface characterization technique often relied on for quantification of surface species and coverages. Investigation of silicon microrods, considered a model for high‐aspect‐ratio structures, at different angles with respect to substrate normal was determined to have a significant impact on the relative sensitivity of surface‐bound species on rods relative to the base substrate. Comparison between planar silicon and microrod arrays demonstrates that the angular dependence is complicated and that careful studies must optimize conditions to differentiate between surfaces. In addition, the use of reverse angle resolved XPS, where the substrate is turned away from the X‐ray source, is shown to assist in simplifying the spectrum by removing underlying signal from the substrate near the base. Copyright © 2016 John Wiley & Sons, Ltd.
Observation of surface contamination layer by X‐ray reflectometry (XRR) analyses
Authors: Kim Chang Soo , Jeon Hyeon‐Gu , Jung Young , Choi Minhyuk , O Byungsung , Kim Ki‐Hong
Published: October 2016

Ultra‐thin HfO2 films of 3.5, 5.0, and 8.0 nm nominal thicknesses were prepared, respectively, on silicon substrates by using atomic layer deposition method. Through the analyses of X‐ray reflectometry (XRR), X‐ray photoelectron spectroscopy, and transmission electron microscopy for HfO2 films with and without sample cleaning, the effects of surface contamination on XRR curve and film thickness were investigated, and contamination layer was observed and the thickness of the layer was determined. X‐ray photoelectron spectroscopy results indicated that the amount of surface contamination varied considerably because of the surface cleaning. XRR curve shapes and the positions of thickness fringes changed and the thickness from Fourier analyses of the curves were different for the same sample due to the different surface contamination. Contamination layer of about 1 nm thickness was observed by Fourier analysis of XRR curve. Simulation for XRR curve showed the best fit to data when contamination layer of about 1 nm thickness was considered, and the result was consistent with that of the Fourier analysis. Copyright © 2016 John Wiley & Sons, Ltd.
Probe the Binding Mode of Aristololactam‐β‐D‐glucoside to Phenylalanine Transfer RNA in Silico
Authors: Xiao Xingqing , Zhao Binwu , Yang Li , Liang Xiaodong , Ren Yingqian
Published: October 2016

Understanding the interactions of drug molecules with biomacromolecules at a micro‐scale level is essential to design potent drugs for the treatments of human genome diseases. To unravel the mechanism of binding of aristololactam‐β‐D‐glucoside (ADG) and phenylalanine transfer RNA (tRNAPhe), an integrated computational strategy combining quantum mechanics (QM) calculation, molecular docking and atomistic molecular dynamics (MD) simulation was present in this work. QM calculations were performed to derive the partial charges of ADG, molecular docking was used to determine the binding poses of ADG on the tRNAPhe, and atomistic MD simulations were conducted to examine the thermal stability of five predicted binding poses for the complex of ADG and the tRNAPhe. The binding free energies of the five complexes were then calculated using the molecular mechanics/generalized born surface area approach with the variable internal dielectric constant model. By comparing computed affinities and experimentally‐measured values in the binding free energy, we identified a most likely binding structure of ADG and the tRNAPhe. Further analysis of energy of the ADG‐tRNA complex revealed that the aristololactam of ADG provides binding specificity to the tRNAPhe, and the D‐glucoce contributes to the affinity for binding with the tRNAPhe.
Insights into Mechanistic and Synergistic Aspects of Novel Synthetic Short Cationic Antibacterial Peptides
Authors: Mittal Sherry , Maurya Indresh K. , Kaur Sarabjit , Swami Anuradha , Jain Rahul , Wangoo Nishima , Sharma Rohit K.
Published: October 2016

Two series of short cationic antimicrobial peptides (CAMPs) in which modification of the imidazole ring of histidine by bulkier alkyl substituents was done using regiospecific and radical‐mediated alkylation. The synthesized CAMPs were evaluated for their antibacterial efficacy using different bacterial strains. In particular, CAMP 11 i was found to be most active against L. monocytogenes and other CAMPs such as 10 e and 11 g exhibited moderate activity against S. aureus.The most active compounds were tested against Hek‐293 and HeLa cells with active CAMPs 11 i and 11 g with calculation of selectivity index against the L. monocytogenesand S. aureus, respectively as compared to mammalian cells. The SEM studies were also performed which confirmed the disruption of cell wall of treated bacteria using CAMP 11 i at its MIC concentration. The selectivity of active peptides towards bacterial cells in comparison to mammalian cells was checked using tryptophan quenching studies on small unilamellar vesicles. The results were found to be perfectly in corroboration with the differences between bacterial and mammalian cell membrane composition, thereby, indicating that these peptides kill the bacterial cells via conjugation with the cell membrane. Synergy studies of CAMPs in combination with known clinical antibacterial drugs against L. monocytogenes further displayed enhanced antibacterial efficacy.
Electrochemical Reduction of CO2 to CO by a Co‐N‐C Electrocatalyst and PEM Reactor at Ambient Conditions
Authors: Ogihara Hitoshi , Maezuru Tomomi , Ogishima Yuji , Yamanaka Ichiro
Published: October 2016

Selective electrochemical reduction of CO2 to CO was studied using a new electrocatalyst and a gas‐electrolysis cell utilized a polymer‐electrolyte‐membrane (PEM) reactor. A selective and active electrocatalyst was prepared by partial pyrolysis of electrocatalyst precursor of Co‐4,4′‐dimethyl‐2,2’‐bipyridine (4,4’‐dmbpy) supported on Ketjenblack (KB). A heat‐treatment temperature of the Co‐4,4’‐dmbpy/KB significantly influenced on its electrocatalytic activity and 573∼673 K treatments were suitable for a selective CO2 reduction. A high performance of CO formation (331 μmol h−1 cm−2, 217 TOF(Co) h−1) at 20 mA cm−2 with 72 % faradic efficiency was performed by using the optimized Co‐4,4’‐dmbpy/KB electrocatalyst at –0.75 V (SHE) and 273 K. Electrochemical silent Co species in CV studies promoted electrochemical reduction of CO2 to CO.
NH3 Competitive Adsorbed FTIR: A Potential Method to Investigate the Confined Species‐Acidic Sites Interaction in SAPO‐34 Catalyst
Authors: Hu Bing , Wang Dakang , Gao Simeng , Zhang Xiangwen , Mao Guoliang , Wang Baohui , Luo Mingjian
Published: October 2016

NH3 competitive adsorbed FTIR method is proposed for investigating the interaction between confined species and acidic sites. Results indicate aromatic cations formed in SAPO‐34 cages. The cations have much higher extinction coefficient than the corresponding aromatics. They cause the new absorbance bands between 1300 and 1700 cm−1. The absorbance bands at 1615 and 1607 cm−1 are related to the vibration of strengthened C=C bonds of aromatic cations. The area of these two bands can be used to quantify the amount of confined species. The band at 1650 cm−1 is a sign of the formation of phenanthrene derivatives and pyrene.
Effectivity and economical aspects for agile quality assurance in large enterprises
Authors: Poth Alexander
Published: October 2016

The transition from a classical to an agile software development procedure needs a structured and strategic roll out to realize the expected benefits of the transition phase. Quality assurance as part of the software development has also to be designed to realize its targets of the agile transition for adequate project and program quality assurance. Besides effectivity the economic aspects have to be implemented also in a value‐driven agile product quality assurance. This tension between effectivity and economy will be shown on the example of the Volkswagen group IT. The transition is mapped to the SPI Manifesto to demonstrate the currency in 2009 of the established values and principles for software process improvement.
The detection of spina bifida at 11–13+6 weeks' gestation
Authors: Borg Michael
Published: October 2016

Prenatal detection of spina bifida during a 12‐week ultrasound can be a complex diagnosis. Spina bifida is a condition characterised by failure of the neural tube to form during embryological development, and the early manifestations in the head and spine may be detected on ultrasound. A good understanding of the characteristic intracranial ultrasound signs within the first trimester, such as the intracranial translucency, cisterna magna and aqueduct of Sylvius will allow for greater awareness and detection of spina bifida at this gestation. Other markers such as biparietal diameter, transverse abdominal diameter, brain stem to occiput bone and frontomaxillary facial angle have been shown to greatly increase the detection of such a condition. Recent advances in technology such as 3D sonography and transvaginal scanning have greatly increased visualisation and provided greater confidence in detection. At present, there is no formal direction put forward from major ultrasound bodies for the detection, at this gestation; however, bodies such as ISUOG have created awareness. Future developments suggest that the visualisation of the intracranial translucency and aqueduct of Sylvius will become a standard practice while scanning at this gestation.
Inclusion/Exclusion as the Missing Link. A Luhmannian Analysis of Loneliness Among Older People
Authors: Schirmer Werner , Michailakis Dimitris
Published: October 2016

This article contributes to the interdisciplinary study of loneliness among older people with some insights based on Luhmann's systems theory. We argue that loneliness is a consequence of the way society includes/excludes people. In contrast to traditional societies, modern society forces people to act as individuals. In order to prevent loneliness, individuals themselves must search for membership in functionally diffuse collectivities (couple relations, friendships, communities). Luhmann's theory provides the framework to integrate the findings of empirical research. We claim that older people are more prone to loneliness for three reasons: first, after retirement they lose their performance role, which limits access to informal communities. Second, because they suffer from illness, impairment and a lack of resources more often than younger people, their access to functionally diffuse collectivities is impeded. Finally, because of structural and semantic changes in the family system, older people often find themselves at the margins of families. Copyright © 2016 John Wiley & Sons, Ltd.
Modern Techniques of Surface Science
Authors: Woodruff D. Phil
Published: October 2016

This fully revised, updated and reorganised third edition provides a thorough introduction to the characterisation techniques used in surface science and nanoscience today. Each chapter brings together and compares the different techniques used to address a particular research question, including how to determine the surface composition, surface structure, surface electronic structure, surface microstructure at different length scales (down to sub-molecular), and the molecular character of adsorbates and their adsorption or reaction properties. Readers will easily understand the relative strengths and limitations of the techniques available to them and, ultimately, will be able to select the most suitable techniques for their own particular research purposes. This is an essential resource for researchers and practitioners performing materials analysis, and for senior undergraduate students looking to gain a clear understanding of the underlying principles and applications of the different characterisation techniques used in the field today.
Detecting and Responding to Alien Plant Incursions
Authors: Wilson John R. , Panetta F. Dane , Lindgren Cory
Published: October 2016

Ecologists, land managers and policymakers continue to search for the most effective ways to manage biological invasions. An emerging lesson is that proactive management can limit negative impacts, reduce risks and save money. This book explores how to detect and respond to alien plant incursions, summarising the most current literature, providing practical recommendations and reviewing the conditions and processes necessary to achieve prevention, eradication and containment. Chapter topics include assessing invasiveness and the impact of alien plants, how to improve surveillance efforts, how to make timely management decisions, and how legislation and strategic planning can support management. Each chapter includes text boxes written by international experts that discuss topical issues such as spatial predictive modelling, costing invasions, biosecurity, biofuels, and dealing with conflict species.
The Politics of Environmental Performance
Authors: Jahn Detlef
Published: October 2016

As the world faces the prospect of climate change, nuclear disasters, and water scarcity, it is clear that environmental degradation is an increasingly serious challenge with economic and social consequences. In this book, Detlef Jahn analyzes political processes in a macro-comparative study in order to estimate the role of politics in the field of environmental performance in 21 OECD countries. His model demonstrates various styles of politics used to combat environmental degradation. He finds that economic and environmental performance are still closely linked, and that moving towards a service society does not by itself solve the environmental challenge. The close relationship of these areas was made strikingly clear in the economic crisis of the new millennium. He argues that economic globalization fosters environmental deterioration, and undermines efforts in domestic politics and international coordination to improve the environmental record.