background: the existence of some radionuclides in soil and some building materials produce a β-γ radiation field, which in some regions the exposure of these radionuclides to human is high. materials and methods: the air-absorbed dose, indoor and outdoor annual effective dose of soil and some building material samples (ceramic, granite, gypsum, etc.). the samples were collected from 35 differe...

background: knowledge of radioactivity levels in human diet is of particular concern for the estimation of possible radiological hazards to human health. however, very few surveys of radioactivity in food have been conducted in iran therefore the baseline values of the natural radionuclides concentration (40k, 226ra and 232th), and man made radionuclide, 137cs, were determined in twenty six sam...

This work describes experiments with quantum-degenerate atomic mixtures at ultracold temperatures, where quantum statistics determine macroscopic system properties. The first heteronuclear molecules at ultracold temperatures are formed in a quantum degenerate two-species Fermi-Fermi mixture on the repulsive side of a narrow s-wave Feshbach resonance. Elastic collisions in this mixture are inves...

Measurements of the potassium content of samples of food, performed with High Purity Germanium detectors, are presented in this paper. The potassium content was measured by identifying the 1460 keV photons produced in the decay of the isotope 40K. Samples were selected, for which a high potassium content was expected. The measurements confirmed the expectations qualitatively, but not always qua...

A finite-state method, based on leftmost longestmatch replacement, is presented for segmenting words into graphemes, and for converting graphemes into phonemes. A small set of hand-crafted conversion rules for Dutch achieves a phoneme accuracy of over 93%. The accuracy of the system is further improved by using transformation-based learning. The phoneme accuracy of the best system (using a larg...

The accumulation and distribution of 40K and 137Cs in tropical plant species were studied through measurements of gamma-ray spectra from mango, avocado, guava, pomegranate, chili pepper, papaya and manioc trees. Our goal was to infer their differences in the uptake and translocation of ions to the aboveground plant parts and to establish the suitability of using radiocaesium as a tracer for the...

We discuss a physical mechanism of a non-BCS nature which can stabilize a superconducting state in a strongly repulsive electronic system. By considering the two-dimensional Hubbard model with spatially modulated electron hoppings, we demonstrate how kinetic-energy frustration can lead to robust d-wave superconductivity at arbitrarily large on-site repulsion. This phenomenon should be observabl...

The time evolution of a dilute atomic boson-fermion mixture is studied at zero temperature, when the external magnetic field is brought close to a interspecies Feshbach resonance. On short time scales we find that before a collapse or phase separation of the mixture can occur, oscillations between fermionic atoms and heteronuclear molecules dominate the dynamics. Applying the model presented he...

In this paper we report measurements of 1/f noise in a crystalline metallic oxide with perovskite structure down to 4.2K. The results show existence of localized excitations with average activation energy ≈ 70-80 meV which produce peak in the noise at T ≈ 35-40K. In addition, it shows clear evidence of tunnelling type two-level-systems (as in glasses) which show up in noise measurements below 3...

Screen space rendering statistics were gathered from 150 3D objects, each modeled by between 2K and 40K triangles. While there is wide variance by individual object, the overall trend is that the distribution of triangles by screen size is roughly exponential in the direction of small triangles. From a subjective esthetics point of view, tessellations required 10K visible triangles per quarter ...