Continuum Moment Equations on the Lattice

An analysis is given as to why one can not directly evaluate continuum moment equations, i.e., equations involving powers of the position variable times charge, current, or energy/momentum operators, on the lattice. I examine two cases: a three point function evaluation of the nucleon magnetic moment and a four point function (charge overlap) evaluation of the pseudoscalar charge radius.Comment: 9 pages; 1 ps figur

Channeling of Charged Particles Through Periodically Bent Crystals: on the Possibility of a Gamma Laser

We discuss radiation generated by positrons channeling in a crystalline undulator. The undulator is produced by periodically bending a single crystal with an amplitude much larger than the interplanar spacing. Different approaches for bending the crystal are described and the restrictions on the parameters of the bending are established. We present the results of numeric calculations of the spectral distributions of the spontaneous emitted radiation and estimate the conditions for stimulated emission. Our investigations show that the proposed mechanism provides an efficient source for high energy photons, which is worth to be studied experimentally.Comment: contributed to the conference ``Fundamental and Applied Aspects of Modern Physics'' in Luederitz, Namibia, 200

Beauty, elegance, grace, and sexiness compared

Beauty is the single most frequently and most broadly used aesthetic virtue term. The present study aimed at providing higher conceptual resolution to the broader notion of beauty by comparing it with three closely related aesthetically evaluative concepts which are likewise lexicalized across many languages: elegance, grace(fulness), and sexiness. We administered a variety of questionnaires that targeted perceptual qualia, cognitive and affective evaluations, as well as specific object properties that are associated with beauty, elegance, grace, and sexiness in personal looks, movements, objects of design, and other domains. This allowed us to reveal distinct and highly nuanced profiles of how a beautiful, elegant, graceful, and sexy appearance is subjectively perceived. As aesthetics is all about nuances, the fine-grained conceptual analysis of the four target concepts of our study provides crucial distinctions for future research

Tunable Field Induced Superconductivity

We investigate the transport properties of a thin superconducting Al layer covering a square array of magnetic dots with out-of-plane magnetization. A thorough characterization of the magnetic properties of the dots allowed us to fine-tune their magnetic state at will, hereby changing the influence of the dots on the superconductor in a continuous way. We show that even though the number of vortex-antivortex pairs discretely increases with increasing the magnetization of the dots, no corresponding discontinuity is observed in the resistance of the sample. The evolution of the superconducting phase boundary as the magnetic state of the dots is swept permits one to devise a fully controllable and erasable field induced superconductor

Automatic telemetry checkout system

Telemetry checkout station is designed to automatically perform measurements on the vehicle telemetry. Its features include real-time digitizing and computer controlled station setup, data processing, and self-check. The station can handle a wide variety of automatic tests by changing its computer programs

Technical note: A significance test for data-sparse zones in scatter plots

Data-sparse zones in scatter plots of hydrological variables can be of interest in various contexts. For example, a well-defined data-sparse zone may indicate inhibition of one variable by another. It is of interest therefore to determine whether data-sparse regions in scatter plots are of sufficient extent to be beyond random chance. We consider the specific situation of data-sparse regions defined by a linear internal boundary within a scatter plot defined over a rectangular region. An Excel VBA macro is provided for carrying out a randomisation-based significance test of the data-sparse region, taking into account both the within-region number of data points and the extent of the region. Example applications are given with respect to a rainfall time series from Israel and also to validation scatter plots from a seasonal forecasting model for lake inflows in New Zealand

Excited states in Richardson pairing model: `probabilistic' approach

Richardson equations can be mapped on the classical electrostatic problem in two dimensions. We have recently suggested a new analytical approach to these equations in the thermodynamical limit, which is based on the `probability' of the system of charges to be in a given configuration at the effective temperature equal to the interaction constant. In the present paper, we apply this approach to excited states of the Richardson pairing model. We focus on the equally-spaced situation and address arbitrary fillings of the energy layer, where interaction acts. The `partition function' for the classical problem on the plane, which is given by Selberg-type integral, is evaluated exactly. Three regimes for the energy gap are identified, which can be treated as the dilute regime of pairs, BCS regime, and dilute regime of holes.Comment: 14 pages, 1 figur