Ramond-Ramond Fields, Fractional Branes and Orbifold Differential K-Theory

We study D-branes and Ramond-Ramond fields on global orbifolds of Type II string theory with vanishing H-flux using methods of equivariant K-theory and K-homology. We illustrate how Bredon equivariant cohomology naturally realizes stringy orbifold cohomology. We emphasize its role as the correct cohomological tool which captures known features of the low-energy effective field theory, and which provides new consistency conditions for fractional D-branes and Ramond-Ramond fields on orbifolds. We use an equivariant Chern character from equivariant K-theory to Bredon cohomology to define new Ramond-Ramond couplings of D-branes which generalize previous examples. We propose a definition for groups of differential characters associated to equivariant K-theory. We derive a Dirac quantization rule for Ramond-Ramond fluxes, and study flat Ramond-Ramond potentials on orbifolds.Comment: 46 pages; v2: typos correcte

Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics

Application of pixe method to coal analysis

In many countries coal is used to a great scale for energy production. Determination of contents of different elements in coal, provide data for predicting the environmental impact of burning coals Additionally, the coal composition play very important role in the selection of method of coal gasification1/ Analysis of coal samples with proton irradiation offers possibilities of fast determination of content of both major and trace elements2/ The additional advantage of the PIXE method consists here in the fact that the matrix element, coal is outside of the detection range. In the present paper the results of elemental analysis of 47 coal samples from several Polish mines are presented

Thermographic diagnostics of the gums

W artykule przedstawiono zagadnienie dotyczące wykorzystania kamer termowizyjnych do bezinwazyjnych badań stomatologicznych. Badania wstępne przeprowadzono dla kilku osób, dokonując pomiarów rozkładu promieniowania temperaturowego w obrębie dziąsła. Analiza wyników badań wykazała zmiany przepływu krwi w dziąśle, co oznacza, iż badania te mogą być pomocne w monitorowaniu przejściowych procesów zapalnych dziąseł. Ważnym zagadnieniem jest jednak dobór odpowiedniej metodyki przeprowadzania tych pomiarów.One of the modern methods used in medicine are thermographic research. Since periodontal tissues are among the most vascularized in the human body, the use of a high-sensitivity thermal imaging camera would allow non-invasive assessment and early detection of pathological changes in the gum [2, 3]. The aim of the study was to evaluate the hemodynamic changes within the gums during orthodontic treatment using thermography research. The examination covered several generally healthy people aged 10-13 years, who were undergoing orthodontic treatment. Thermographic research concerned the incisors of the upper dental arch with clinically healthy periodontium. A cooled, high sensitivity thermal camera FLIR X6580sc was used for investigations. Based on the performed research and analysis of the results, it can be concluded that in the case of measurements taken after about 5 minutes from the initial test there cannot be observed any changes in the average temperature. However, these changes are visible after about 20 minutes after the application of orthodontic forces. Namely, the observed increase in the average temperature was about 1,5 C, which indicated the hemodynamic changes within the gums. Based on the obtained results it can be concluded that the thermographic research may be helpful in monitoring the transition of inflammatory processes through the gum in the treatment with permanent braces. However, the selection of an appropriate methodology for conducting these measurements is a very important issue