Behavior and Breakdown of Higher-Order Fermi-Pasta-Ulam-Tsingou Recurrences

We investigate numerically the existence and stability of higher-order recurrences (HoRs), including super-recurrences, super-super-recurrences, etc., in the alpha and beta Fermi-Pasta-Ulam-Tsingou (FPUT) lattices for initial conditions in the fundamental normal mode. Our results represent a considerable extension of the pioneering work of Tuck and Menzel on super-recurrences. For fixed lattice sizes, we observe and study apparent singularities in the periods of these HoRs, speculated to be caused by nonlinear resonances. Interestingly, these singularities depend very sensitively on the initial energy and the respective nonlinear parameters. Furthermore, we compare the mechanisms by which the super-recurrences in the two model's breakdown as the initial energy and respective nonlinear parameters are increased. The breakdown of super-recurrences in the beta-FPUT lattice is associated with the destruction of the so-called metastable state and hence is associated with relaxation towards equilibrium. For the alpha-FPUT lattice, we find this is not the case and show that the super-recurrences break down while the lattice is still metastable. We close with comments on the generality of our results for different lattice sizes

The Explanatory and Predictive Power of Non Two-Stage-Probability Theories of Decision Making Under Ambiguity

Representing ambiguity in the laboratory using a Bingo Blower (which is transparent and not manipulable) and asking the subjects a series of allocation questions (which are more efficient than pairwise choice questions), we obtain data from which we can estimate by maximum likelihood methods (with explicit assumptions about the errors made by the subjects) a significant subset of the empirically relevant models of behaviour under ambiguity, and compare their relative explanatory and predictive abilities. Our results suggest that not all recent models of behaviour represent a major improvement in explanatory and predictive power, particularly the more theoretically sophisticated ones.Alpha Model, Ambiguity, Bingo Blower, Choquet Expected Utility, Contraction Model, Rank Dependent Expected Utility, Subjective Expected Utility,Vector Expected Utility.

Sun direction detection system

One of the detectors is an illumination detector consisting of two spaced apart elongated strips with a strip of cadmium sulphide (Cds) deposited therebetween. Whenever the line image impinges the CdS strip, the resistance between the two other strips is relatively low, while being high when the line image is outside the field of view of the illumination detector. Also included is a sun angle detector which consists of a vapor deposited resistor strip connected at one end to plus 10v and at the other end to minus 10v. Spaced apart from the resistor strip is an elongated strip of low resistance material acting as an output strip, with a CdS strip between the two strips. When the line image is within the field of view of the sun angle detector, the output voltage at the output strip depends on the position of the line image across the sun angle detector

The Explanatory and Predictive Power of Non Two-Stage-Probability Theories of Decision Making Under Ambiguity

Representing ambiguity in the laboratory using a Bingo Blower (which is transparent and not manipulable) and asking the subjects a series of allocation questions (which are more efcient than pairwise choice questions), we obtain data from which we can estimate by maximum likelihood methods (with explicit assumptions about the errors made by the subjects) a signicant subset of the empirically relevant models of behaviour under ambiguity, and compare their relative explanatory and predictive abilities. Our results suggest that not all recent models of behaviour represent a major improvement in explanatory and predictive power, particularly the more theoretically sophisticated ones.Alpha Model, Ambiguity, Bingo Blower, Choquet Expected Utility, Contraction Model, Rank Dependent Expected Utility, Subjec tive Expected Utility,Vector Expected Utility.

Magnetic relaxation of type II superconductors in a mixed state of entrapped and shielded flux

The magnetic relaxation has been investigated in type II superconductors when the initial magnetic state is realized with entrapped and shielded flux (ESF) contemporarily. This flux state is produced by an inversion in the magnetic field ramp rate due to for example a magnetic field overshoot. The investigation has been faced both numerically and by measuring the magnetic relaxation in BSCCO tapes. Numerical computations have been performed in the case of an infinite thick strip and of an infinite slab, showing a quickly relaxing magnetization in the first seconds. As verified experimentally, the effects of the overshoot cannot be neglected simply by cutting the first 10-100 seconds in the magnetic relaxation. On the other hand, at very long times, the magnetic states relax toward those corresponding to field profiles with only shielded flux or only entrapped flux, depending on the amplitude of the field change with respect to the full penetration field of the considered superconducting samples. In addition, we have performed numerical simulations in order to reproduce the relaxation curves measured on the BSCCO(2223) tapes; this allowed us to interpret correctly also the first seconds of the $M(t)$ curves.Comment: 9 pages, 12 figures submit to PR

The Singing Insects of Michigan

Excerpt: The so-called singing insects are all those that make loud, rhythmical noises. They include members of three groups of Orthoptera (Gryllidae, Tettigoniidae, and Acridoidea) and one family of Homoptera (Cicadidae). There are about 300 noisy species in these four groups in eastern North America, perhaps a thousand in all of North America, and 25-30 thousand in the entire world. Only about 1000 of the world species have been studied in any detail, mostly in North America, Europe, Japan, and Australia

Methodology for estimation of total body composition in laboratory mammals

A standardized dissection and chemical analysis procedure was developed for individual animals of several species in the size range mouse to monkey (15 g to 15 kg). The standardized procedure permits rigorous comparisons to be made both interspecifically and intraspecifically of organ weights and gross chemical composition in mammalian species series, and was applied successfully to laboratory mice, hamsters, rats, guinea pigs, and rabbits, as well as to macaque monkeys. The procedure is described in detail

Effect of Stand Density on Behavior of Leaf Area Prediction Models for Eastern White Pine (Pinus strobus L.) in Maine

There is little debate within the forest science community that leaf area (LA, the surface area of live foliage) or leaf area index (LAI, the total surface area of live foliage per unit of ground area) are important variables, central to enhancing the understanding of forest growth and many forest ecosystem processes. The ability to accurately measure LA1 has become a research priority and has resulted in various methods of estimation for a variety of species and regions. In this study LA estimation models for Pinus strobus L. were developed, tested, and compared across a wide range of densities for both thinned and unthinned stands in the Penobscot River Valley of central Maine. Test plots were located within a 52-year-old plantation. Direct LA1 estimations from litterfall were used to compare the indirect estimations of below-canopy light interception and various allometric models. Four treelevel models were developed through non-linear regression and compared at both treelevel and stand-level. Two models utilized sapwood area at breast height (SAbh) as a predictor variable and two non-sapwood models were based on basal area and a modified live-crown ratio (BA*mLCR). When compared to litterfall, LA1 measurements from light interception data yielded underestimates and overestimates in thinned and unthinned sites, respectively. However, the treatment-specific bias was masked when pooling the data and a relatively strong relationship with litterfall existed ( R ~ = 0.68). Among the allometric models, the SAbh models performed best showing no bias across stand densities. Estimations from BA*mLCR were in agreement with both litterfall and sapwood models within unthinned sites, but were biased, providing overestimations for thinned plots. The apparent bias in LA1 estimation from BA*mLCR was caused by the model\u27s high sensitivity to the limited range of large trees sampled for equation development. Basal area at breast height was particularly influential. However, when sapwood-derived coefficients were used, an adjusted BA*mLCR equation performed well across the range of stand densities and provided accurate LA1 estimations when referenced to litterfall and sapwood-based estimations