Study of Resistive Micromegas in a Mixed Neutron and Photon Radiation Field

The Muon ATLAS Micromegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and gamma) high radiation field supplied by the Tandem accelerator, at the N.C.S.R. Demokritos in Athens. Monte-Carlo studies have been employed to study the effect of 5.5 MeV neutrons impinging on Micromegas detectors. The response of the Micromegas detectors on the photons originating from the inevitable neutron inelastic scattering on the surrounding materials of the experimental facility was also studied

Evidence for hadronic deconfinement in pˉ\bar{p}-p collisions at 1.8 TeV

We have measured deconfined hadronic volumes, $4.4 < V < 13.0$ fm$^{3}$, produced by a one dimensional (1D) expansion. These volumes are directly proportional to the charged particle pseudorapidity densities $6.75 < dN_{c}/d\eta < 20.2$. The hadronization temperature is $T = 179.5 \pm 5$ (syst) MeV. Using Bjorken's 1D model,the hadronization energy density is $\epsilon_{F} = 1.10 \pm 0.26$ (stat) GeV/fm$^{3}$ corresponding to an excitation of $24.8 \pm 6.2$ (stat) quark-gluon degrees of freedom.Comment: 15 pages, 3 figures, 2 table

Taxonomic Keys and Plates from The Myxomycetes

Digital work, reproduction of text and layout by Rojas Alvarado, Carlos y Lado Rodríguez, CarlosIn 1969, George W. Martin and Constantine J. Alexopoulos published a remarkable work on myxomycetes. Their monograph on this group of organisms became one of the references to the taxonomy and geographical distribution of the species in the world. The impact of this book was large, partially because they reviewed the previous works of Thomas Macbride (a large number of collections observed by Martin & Alexopoulos were collected by the former) and Arthur and Gulielma Lister (who sent European collections to the United States National Herbarium). In this manner, The Myxomycetes by Martin & Alexopoulos was in some ways, an update of the information already published in the books North American Slime-Moulds by Thomas Macbride (1922) and Monograph of the Mycetozoa by Arthur Lister (first edition in 1894). The original Martin & Alexopoulos The Myxomycetes book is found today in bookshelves of myxomycete researchers and institutional libraries around the world. It is the last worldwide monograph on myxomycetes. Despite being widely used for research purposes, the book has been out of print for many years and the younger generation of people interested in the fascinating world of myxomycetes has limited access to it. Both Macbride´s and Lister´s books have been rescued by the Biodiversity Heritage Library and can be accessed in digital format today, but The Myxomycetes by Martin & Alexopoulos is not available on the internet yet. Aware of that limitation, we obtained permission from the original publisher (University of Iowa Press) to create a digital version of the taxonomic keys and original plates contained in the book. Even though molecular techniques of myxomycete detection have been reshaping the nomenclature of the group in recent years and a number of binomials have changed over time, the original work published more than 50 years ago still offers important clues for taxonomic purposes. The drawings are much less detailed than those in Lister´s book, for example, but they are still useful for identification. However, they keys are comprehensive, detailed, and easy to use. We hope this digital compilation would contribute, even a little, to increase the access to scientific information in regions of the world where the original book has been difficult to read. We know it is not the same as having the actual book in your hands, but it is pretty close.Ministerio de Ciencia e Innovación de España/PGC2018-094660-B-I00//EspañaUCR::Sedes Regionales::Sede del Atlántico::Recinto de Paraíso::Finca Experimental Interdisciplinaria de Modelos Agroecológicos (FEIMA

Swiping more, committing less: Unraveling the links among dating app use, dating app success, and intention to commit infidelity

The present study was conducted to explore the cognitive processes linking people's perceptions of their mobile dating app experience and their intention to commit infidelity. Three hundred and ninety-five participants were recruited through a U.S. based university (44.6%) and MTurk (55.4%). Our results indicate that people's perceived success on a dating app was positively associated with their intention to commit infidelity through self-perceived desirability, and negatively associated with their intention to commit infidelity through perceived amount of available partners. These findings are discussed in light of theories of relational investment

Percolation approach to quark gluon plasma in high energy pp collisions

We apply continuum percolation to proton-proton collisions and look for the possible threshold to phase transition from confined nuclear matter to quark gluon plasma. Making the assumption that J/Psi suppression is a good signal to the transition, we discuss this phenomenon for pp collisions, in the framework of a dual model with strings.Comment: 8 pages, 3 figure

Polynomial Growth Harmonic Functions on Finitely Generated Abelian Groups

In the present paper, we develop geometric analytic techniques on Cayley graphs of finitely generated abelian groups to study the polynomial growth harmonic functions. We develop a geometric analytic proof of the classical Heilbronn theorem and the recent Nayar theorem on polynomial growth harmonic functions on lattices \mathds{Z}^n that does not use a representation formula for harmonic functions. We also calculate the precise dimension of the space of polynomial growth harmonic functions on finitely generated abelian groups. While the Cayley graph not only depends on the abelian group, but also on the choice of a generating set, we find that this dimension depends only on the group itself.Comment: 15 pages, to appear in Ann. Global Anal. Geo

Some implications of large impact craters and basins on Venus for terrestrial ringed craters and planetary evolution

Approximately 950 impact craters have been identified on the surface of Venus, mainly in Magellan radar images. From a combination of Earth-based Arecibo, Venera 15/1, and Magellan radar images, we have interpreted 72 as unequivocal peak-ring craters and four as multiringed basins. The morphological and structural preservation of these craters is high owing to the low level of geologic activity on the venusian surface (which is in some ways similar to the terrestrial benthic environment). Thus these craters should prove crucial to understanding the mechanics of ringed crater formation. They are also the most direct analogs for craters formed on the Earth in Phanerozoic time, such as Chicxulub. We summarize our findings to date concerning these structures

Measuring the Charged Particle Multiplicity with ALICE

The charged particle multiplicity distribution is one of the first measurements that ALICE will be able to perform. The knowledge of this basic property at a new energy is needed to configure Monte Carlo generators correctly with the aim of understanding the background of other, especially rare, processes including new physics. It allows to study the scaling behaviour and to verify model predictions. The unfolding of the measurement is a non-trivial task due to the finite precision and acceptance of the detector. Solutions are based on chi2 minimization or iteratively using Bayes' theorem. Both approaches to unfold the spectrum are presented. Furthermore, the capabilities of the SPD fast OR trigger are shown that enable physics at very high multiplicities.Comment: Proceedings of poster presentation at Quark Matter 2008, 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions in Jaipur, India; to be published in Indian Journal of Physics; 4 pages, 4 figure