On a damage-plasticity approach to model concrete failure

A damage-plasticity constitutive model for the description of fracture in plain concrete is presented. Two approaches, the local model comprising the adjustment of the softening modulus and the nonlocal model based on spatial averaging of history variables, are applied to the analysis of a concrete bar subjected to uniaxial tension and to a three-point bending test. The influence of mesh size and the decomposition into damage and plasticity components are discussed. It is shown that for the two examples studied, both approaches result in mesh-independent results. However, the nonlocal model, which relies on spatial averaging of history variables, exhibits sensitivity with respect to boundary conditions, which requires further studies.Comment: Revised version. Resubmitted to Engineering and Computational Mechanic

Computing Extensions of Linear Codes

This paper deals with the problem of increasing the minimum distance of a linear code by adding one or more columns to the generator matrix. Several methods to compute extensions of linear codes are presented. Many codes improving the previously known lower bounds on the minimum distance have been found.Comment: accepted for publication at ISIT 0

Experimental Implementation of a Codeword Stabilized Quantum Code

A five-qubit codeword stabilized quantum code is implemented in a seven-qubit system using nuclear magnetic resonance (NMR). Our experiment implements a good nonadditive quantum code which encodes a larger Hilbert space than any stabilizer code with the same length and capable of correcting the same kind of errors. The experimentally measured quantum coherence is shown to be robust against artificially introduced errors, benchmarking the success in implementing the quantum error correction code. Given the typical decoherence time of the system, our experiment illustrates the ability of coherent control to implement complex quantum circuits for demonstrating interesting results in spin qubits for quantum computing

Temperature and humidity profiles in the atmosphere from spaceborne lasers: A feasibility study

Computer simulations of the differential absorption lidar technique in a space craft for the purpose of temperature and humidity profiling indicate: (1) Current technology applied to O2 and H2O lines in the .7 to .8 micrometers wavelength band gives sufficiently high signal-to-noise ratios (up to 50 for a single pulse pair) if backscattering by aerosol particles is high, i.e. profiling accurate to 2 K for temperature and 10% for humidity should be feasible within the turbid lower troposphere in 1 km layers and with an averaging over approximately 100 pulses. (2) The impact of short term fluctuations in aerosol particle concentration is too big for a one laser system. Only a two laser system firing at a time lag of about 1 millisecond can surmount these difficulties. (3) The finite width of the laser line and the quasi-random shift of this line introduce tolerable, partly systematic errors

The politics of national diversity

On the consequences of the interplay between the diversity of ethnic, national, cultural and linguistic groupings in the Austro-Hungarian Empire

A theory of Austria

The present essay seeks, by way of the Austrian example, to make a contribution to what might be called the philosophy of the supranational state. More specifically, we shall attempt to use certain ideas on the philosophy of Gestalten as a basis for understanding some aspects of that political and cultural phenomenon which was variously called the Austrian Empire, the Habsburg Empire, the Danube Monarchy or Kakanien

On a three-dimensional lattice approach for modelling corrosion induced cracking and its influence on bond between reinforcement and concrete

The present work involves the discrete modelling of corrosion induced cracking and its influence on the bond between reinforcement and concrete. A lattice approach is used to describe the mechanical interaction of a corroding reinforcement bar, the surrounding concrete and the interface between steel reinforcement and concrete. The cross-section of the ribbed reinforcement bar is taken to be circular, assuming that the interaction of the ribs of the deformed reinforcement bar and the surrounding concrete is included in a cap-plasticity interface model. The expansion of the corrosion product is represented by an eigenstrain in the lattice elements forming the interface. The lattice modelling approach is applied to the analysis of corrosion induced cracking and its influence of the bond strength. The model capabilities are assessed by comparing results of analyses with those from unconfined pull-out tests reported in the literature. Future work will investigate the influence of the stiffness of interface elements and the effect of lateral confinement on corrosion induced cracking.Comment: Preprint of conference paper for Fracture Mechanics of Concrete and Concrete Structures, South Korea, 201

Quantum MDS Codes over Small Fields

We consider quantum MDS (QMDS) codes for quantum systems of dimension $q$ with lengths up to $q^2+2$ and minimum distances up to $q+1$. We show how starting from QMDS codes of length $q^2+1$ based on cyclic and constacyclic codes, new QMDS codes can be obtained by shortening. We provide numerical evidence for our conjecture that almost all admissible lengths, from a lower bound $n_0(q,d)$ on, are achievable by shortening. Some additional codes that fill gaps in the list of achievable lengths are presented as well along with a construction of a family of QMDS codes of length $q^2+2$, where $q=2^m$, that appears to be new.Comment: 6 pages, 3 figure