Use of the unique properties of fluoropolymers in the design of new,highly effective,ecologically friendly technologies for the fine purification of hydrogen halides and their aqueous solutions

A number of properties of fluoropolymers in aqueous solutions of hydrogen halides were investigated. The results enable fluoropolymers to be used in the purification of hydrogen halides and their aqueous solutions. The hydrophobicity of fluoropolymers and their diffusion permeability enable production of hydrogen halides of low moisture content. A second unit for hydroionic convection is based on hydroionic repulsion (determined by the hydrophobic properties of the fluoropolymer) and ionic elimination. The two units enable the highly effective, ecologically safe manufacture of highly pure hydrogen halides and their aqueous solutions to be carried out with minimum feedstock, cooling water, and power consumption. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1383–1387, 2001     

Mehraxiales mechanisches Ermüdungsmodell von Ultra‐Hochfestem Beton: Experimentelle und analytische Untersuchungen

Multiaxial Mechanical Model of Ultra‐High‐Performance Concrete The special and outstanding characteristics of ultra‐high‐performance concrete (UHPC) require the development of a multiaxial mechanical model for numerical investigations. With the three phases model it is possible to describe the behaviour of concrete from extremely brittle to more ductile using the characteristic development of the principal meridians, in particular the compressive meridian of the fracture surface. Furthermore, the anisotropic damage due to fatigue is considered in the principal‐stressarea by different grades of damage in relation to the tensile and the compressive meridian. In experimental investigations, the necessary parameters are determined to calibrate the three phases model for UHPC by specifying the principal meridians for static loading. In further dynamic investigations the parameters for an anisotropic damage model are determined for fatigue loading.     

Berechnung erdgedeckter Lagertanks nach Mang

Structural design of underground tanks by the method of Mang. For soil covered tanks, which lie by single bearing in a growed soil (“ditch” bearing) and the soil covers the tanks more than 1000 mm, the structural design by the method of Windels [1] is very economical. In [2] this method is described in detail and there is an extension for all practical load cases. For the other underground tanks the structural design is done by the method of Mang [3] and with the comments in [4]. This method is described in the following paper.     

Improved space-time coding for MIMO-OFDM wireless communications

Improved space-time coding for multiple-input multiple-output orthogonal frequency division multiplexing is studied for wireless systems using QPSK modulation for four transmit and four receive antennas. A 256-state code is shown to perform within 3 dB of outage capacity (and within 2 dB with perfect channel estimation), which is better than any other published result without using iterative decoding     

Book access, shared reading, and audio models: The effects of supporting the literacy learning of linguistically diverse students in school and at home.

Sixteen teachers and their 162 first-grade students participated in this study to explore the impact of book-rich classroom environments and home rereading, with and without an audio model, on reading motivation, comprehension, and fluency. Classrooms with both students who speak English as a second language and native English-speaking students were in 1 of 4 conditions: book-rich classroom environment, book-rich classroom environment and daily rereading of books at home, book-rich classroom environment and daily rereading of books with audiotapes at home, and unmodified reading instruction at school. There was enhanced comprehension for book-rich classrooms, both with and without a home component. Furthermore, home-based rereading increased students' reading motivation and promoted parental involvement. Use of audio models provided particular benefits for students learning to speak English. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The good, bad and ugly: distributed detection of a known signal in dependent Gaussian noise

Most results about quantized detection rely strongly on an assumption of independence among random variables. With this assumption removed, little is known. Thus, in this paper, Bayes-optimal binary quantization for the detection of a shift in mean in a pair of dependent Gaussian random variables is studied. This is arguably the simplest meaningful problem one could consider. If results and rules are to be found, they ought to make themselves plain in this problem. For certain problem parametrizations (meaning the signals and correlation coefficient), optimal quantization is achievable via a single threshold applied to each observation-the same as under independence. In other cases, one observation is best ignored or is quantized with two thresholds; neither behavior is seen under independence. Further, and again in distinction from the case of independence, it is seen that in certain situations, an XOR fusion rule is optimal, and in these cases, the implied decision rule is bizarre. The analysis is extended to the multivariate Gaussian problem.     

Evolution of dislocation structure in martensitic steels: the subgrain size as a sensor for creep strain and residual creep life

The results on the evolution of the dislocation structure in martensitic CrMoV-steels published by two research groups are shown to be consistent: The steady state dislocation spacings vary in inverse proportion to shear modulus normalized stress, the subgrains grow with strain at a rate which is determined by the initial subgrain size w₀, the steady state subgrain size w_∞ and the strain rate, independent of the composition of the material. At constant stress and temperature the strain ? and the subgrain size w are uniquely related by ? = ?_wln[log(w₀ / w_∞)/log(w / w_∞)] with ?_w = 0.12. Thus w can be used as a sensor for strain and, if the relation between strain and time is known, for the residual creep life.     

Zur sicheren Anwendung feuerverzinkter Stahlträger

Reliable application of hot dip zinc coated steel beams. Hot dip zinc coated steel beams as used e.g. for parking houses may be susceptible to cracking, with cracks along the beam axis starting from welds of partial end plate connections, in some cases also cracks at the bottom flange transverse to the beam axis occurred which propagated from local plastic deformations e.g. from cold forming for pre‐cambering the beams. The report describes the various causes interacting in the formation of the cracks according to the present state of knowledge and also gives tentative recommendations for the choice of material, structural detailing, fabrication and the hot dip coating process to avoid cracks in the future.