Influence Of Continuous Precipitation Upon The Growth Kinetics Of The Cellular Reaction In An Al-Ag Alloy

The influence of the prior formation of a continuous precipitate upon the growth kinetics of the cellular reaction has been evaluated in an Al-17.9 wt. % Ag alloy. The continuous precipitate, in the form of intragranular plates of the γ′ transition phase, was shown to have reduced the upper bound of the driving force for the cellular reaction from the silver content of the untransformed alloy to that corresponding to the coherent solvus. When this reduction (≥ 98 %) is taken into account, the growth of cells is found to be controlled by cell boundary rather than by volume diffusion on the basis of both the Turnbull and the Cahn theories of the cellular reaction. Changing the mode of heat treatment from the usual quenching-and-aging to that of isothermal transformation reduces both the rate of growth of cells and the proportion of cellular structure formed by about an order of magnitude and increases the interlamellar spacing by 50-100%. These effects appear to result from a further decrease in the driving force. This decrease is attributed to a higher rate of introduction of misfit dislocations into the broad faces of the γ′ plates constituting the continuous precipitate, and thus to smaller values of the coherent solvus. © 1968

Understanding Anomalous Transport in Intermittent Maps: From Continuous Time Random Walks to Fractals

We show that the generalized diffusion coefficient of a subdiffusive intermittent map is a fractal function of control parameters. A modified continuous time random walk theory yields its coarse functional form and correctly describes a dynamical phase transition from normal to anomalous diffusion marked by strong suppression of diffusion. Similarly, the probability density of moving particles is governed by a time-fractional diffusion equation on coarse scales while exhibiting a specific fine structure. Approximations beyond stochastic theory are derived from a generalized Taylor-Green-Kubo formula.Comment: 4 pages, 3 eps figure

Classical and quantum partition bound and detector inefficiency

We study randomized and quantum efficiency lower bounds in communication complexity. These arise from the study of zero-communication protocols in which players are allowed to abort. Our scenario is inspired by the physics setup of Bell experiments, where two players share a predefined entangled state but are not allowed to communicate. Each is given a measurement as input, which they perform on their share of the system. The outcomes of the measurements should follow a distribution predicted by quantum mechanics; however, in practice, the detectors may fail to produce an output in some of the runs. The efficiency of the experiment is the probability that the experiment succeeds (neither of the detectors fails). When the players share a quantum state, this gives rise to a new bound on quantum communication complexity (eff*) that subsumes the factorization norm. When players share randomness instead of a quantum state, the efficiency bound (eff), coincides with the partition bound of Jain and Klauck. This is one of the strongest lower bounds known for randomized communication complexity, which subsumes all the known combinatorial and algebraic methods including the rectangle (corruption) bound, the factorization norm, and discrepancy. The lower bound is formulated as a convex optimization problem. In practice, the dual form is more feasible to use, and we show that it amounts to constructing an explicit Bell inequality (for eff) or Tsirelson inequality (for eff*). We give an example of a quantum distribution where the violation can be exponentially bigger than the previously studied class of normalized Bell inequalities. For one-way communication, we show that the quantum one-way partition bound is tight for classical communication with shared entanglement up to arbitrarily small error.Comment: 21 pages, extended versio

The Bulk Motion of Flat Edge-On Galaxies Based on 2MASS Photometry

We report the results of applying the 2MASS Tully-Fisher (TF) relations to study the galaxy bulk flows. For 1141 all-sky distributed flat RFGC galaxies we construct J, H, K_s TF relations and find that Kron $J_{fe}$ magnitudes show the smallest dispersion on the TF diagram. For the sample of 971 RFGC galaxies with V_{3K} < 18000 km/s we find a dispersion $\sigma_{TF}=0.42^m$ and an amplitude of bulk flow V= 199 +/-61 km/s, directed towards l=301 degr +/-18 degr, b=-2 degr +/-15 degr. Our determination of low-amplitude coherent flow is in good agreement with a set of recent data derived from EFAR, PSCz, SCI/SCII samples. The resultant two- dimensional smoothed peculiar velocity field traces well the large-scale density variations in the galaxy distributions. The regions of large positive peculiar velocities lie in the direction of the Great Attractor and Shapley concentration. A significant negative peculiar velocity is seen in the direction of Bootes and in the direction of the Local void. A small positive peculiar velocity (100 -- 150 km/s) is seen towards the Pisces-Perseus supercluster, as well as the Hercules - Coma - Corona Borealis supercluster regions.Comment: 10 pages, 5 figures. A&A/2003/3582 accepted 15.05.200

Peculiar Velocities of 3000 Spiral Galaxies from the 2MFGC Catalog

The 2MFGC catalog we have used contains 18020 galaxies selected from the extended objects in the 2MASS infrared sky survey as having apparent ratios of the axes b/a<0.3. Most of them are spiral galaxies of later morphological types whose disks are seen almost edge-on. The individual distances to the 2724 2MFGC galaxies with known rotation velocities and radial velocities are determined using a multiparameter infrared Tully-Fisher relation. A list of the distances and peculiar velocities of these galaxies is presented. The collective motion of the 2MFGC galaxies relative to the cosmic microwave background is characterized by a velocity V = 199 +- 37 km/s in the direction l = 304o +- 11o, b = -8o +- 8o. Our list is currently the most representative and uniform sample for analyzing non-Hubble motions of galaxies on a scale of ~100 Mpc.Comment: 12 pages, 5 figures, 1 table (here we present the beginning of the table as an illustration). Astrophysics, Vol. 49, No. 4, 2006. Original article submitted June 13, 2006. Translated from Astrofizika, Vol. 49, No. 4, pp. 527-540 (November 2006

Dark Matter and the CACTUS Gamma-Ray Excess from Draco

The CACTUS atmospheric Cherenkov telescope collaboration recently reported a gamma-ray excess from the Draco dwarf spheroidal galaxy. Draco features a very low gas content and a large mass-to-light ratio, suggesting as a possible explanation annihilation of weakly interacting massive particles (WIMPs) in the Draco dark-matter halo. We show that with improved angular resolution, future measurements can determine whether the halo is cored or cuspy, as well as its scale radius. We find the relevant WIMP masses and annihilation cross sections and show that supersymmetric models can account for the required gamma-ray flux. The annihilation cross section range is found to be not compatible with a standard thermal relic dark-matter production. We compute for these supersymmetric models the resulting Draco gamma-ray flux in the GLAST energy range and the rates for direct neutralino detection and for the flux of neutrinos from neutralino annihilation in the Sun. We also discuss the possibility that the bulk of the signal detected by CACTUS comes from direct WIMP annihilation to two photons and point out that a decaying-dark-matter scenario for Draco is not compatible with the gamma-ray flux from the Galactic center and in the diffuse gamma-ray background.Comment: 24 pages, 10 figures; version accepted for publication in JCA

Mapping all classical spin models to a lattice gauge theory

In our recent work [Phys. Rev. Lett. 102, 230502 (2009)] we showed that the partition function of all classical spin models, including all discrete standard statistical models and all Abelian discrete lattice gauge theories (LGTs), can be expressed as a special instance of the partition function of a 4-dimensional pure LGT with gauge group Z_2 (4D Z_2 LGT). This provides a unification of models with apparently very different features into a single complete model. The result uses an equality between the Hamilton function of any classical spin model and the Hamilton function of a model with all possible k-body Ising-type interactions, for all k, which we also prove. Here, we elaborate on the proof of the result, and we illustrate it by computing quantities of a specific model as a function of the partition function of the 4D Z_2 LGT. The result also allows one to establish a new method to compute the mean-field theory of Z_2 LGTs with d > 3, and to show that computing the partition function of the 4D Z_2 LGT is computationally hard (#P hard). The proof uses techniques from quantum information.Comment: 21 pages, 21 figures; published versio

Statistical Properties and Decay of Correlations for Interval Maps with Critical Points and Singularities

We consider a class of piecewise smooth one-dimensional maps with critical points and singularities (possibly with infinite derivative). Under mild summability conditions on the growth of the derivative on critical orbits, we prove the central limit theorem and a vector-valued almost sure invariance principle. We also obtain results on decay of correlations.Comment: 18 pages, minor revisions, to appear in Communications in Mathematical Physic

Quality of life in Type 1 (insulin-dependent) diabetic patients prior to and after pancreas and kidney transplantation in relation to organ function

Improvement of the quality of life in Type 1 (insulin-dependent) diabetic patients with severe late complications is one of the main goals of pancreas and/or kidney grafting. To assess the influences of these treatment modalities on the different aspects of the quality of life a cross-sectional study in 157 patients was conducted. They were categorized into patients pre-transplant without dialysis (n=29; Group A), pre-transplant under dialysis (n=44; Group B), post-transplant with pancreas and kidney functioning (n=31; Group C), post-transplant with functioning kidney, but insulin therapy (n=29; Group D), post-transplant under dialysis and insulin therapy again (n=15; Group E) and patients after single pancreas transplantation and rejection, with good renal function, but insulin therapy (n=9; Group F). All patients answered a mailed, self-administered questionnaire (217 questions) consisting of a broad spectrum of rehabilitation criteria. The results indicate a better quality of life in Groups C and D as compared to the other groups. In general the scores are highest in C, but without any significant difference to D. Impressive significant differences between C or D and the other groups were found especially in their satisfaction with physical capacity, leisure-time activities or the overall quality of life. The satisfaction with the latter is highest in C (mean±SEM: 4.0±0.2 on a 1 to 5-rating scale; significantly different from A: 3.1±0.1, B: 2.7±0.2 and E: 2.6±0.3; p<0.01), followed by D (3.8±0.2; significantly different from B and E; p<0.01). Group F shows a mean of 3.1±0.4, which is not significantly different from C. The percentages of patients in each group, who are not working: A: 38 %, B: 64 %, C: 74 %, D: 66 %, E: 87 % and F: 78 % indicate that there is no marked improvement in the vocational situation after successful grafting

Entanglement on mixed stabilizer states: normal forms and reduction procedures

Published versio