Triangle Percolation on the Grid

We consider a geometric percolation process partially motivated by recent work of Hejda and Kala. Specifically, we start with an initial set $X \subseteq \mathbb{Z}^2$, and then iteratively check whether there exists a triangle $T \subseteq \mathbb{R}^2$ with its vertices in $\mathbb{Z}^2$ such that $T$ contains exactly four points of $\mathbb{Z}^2$ and exactly three points of $X$. In this case, we add the missing lattice point of $T$ to $X$, and we repeat until no such triangle exists. We study the limit sets $S$, the sets stable under this process, including determining their possible densities and some of their structure.Comment: 31 pages, 27 figures (including appendix

Scholarship Series: KSU Faculty Showcase

Kennesaw State University School of Music presents Faculty Showcase, a KSU School of Music Scholarship Series concert.https://digitalcommons.kennesaw.edu/musicprograms/1534/thumbnail.jp

Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment

Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl) succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O-2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and naphthalene), W-cofactor-containing enzymes for reductive dearomatization of benzoyl-CoA (class II benzoyl-CoA reductase) in obligate anaerobes and addition of water to acetylene, fermentative formation of cyclohexanecarboxylate from benzoate, and methanogenic degradation of hydrocarbons

The Discovery Potential of a Super B Factory

The Proceedings of the 2003 SLAC Workshops on flavor physics with a high luminosity asymmetric e+e- collider. The sensitivity of flavor physics to physics beyond the Standard Model is addressed in detail, in the context of the improvement of experimental measurements and theoretical calculations.Comment: 476 pages. Printed copies may be obtained by request to [email protected] . arXiv admin note: v2 appears to be identical to v

Redox control of sulfur degassing in silicic magmas

International audienceExplosive eruptions involve mainly silicic magmas in which sulfur solubility and diffusivity are low. This inhibits sulfur exsolution during magma uprise as compared to more mafic magmas such as basalts. Silicic magmas can nevertheless liberate large quantities of sulfur as shown by the monitoring of SO2 in recent explosive silicic eruptions in arc settings, which invariably have displayed an excess of sulfur relative to that calculated from melt degassing. If this excess sulfur is stored in a fluid phase, it implies a strong preference of sulfur for the fluid over the melt under oxidized conditions, with fluid/melt partition coefficients varying between 50 and 2612, depending on melt composition. Experimentally determined sulfur partition coefficients for a dacite bulk composition confirm this trend and show that in volcanic eruptions displaying excess gaseous sulfur, the magmas were probably fluid-saturated at depth. The experiments show that in more reduced silicic magmas, those coexisting only with pyrrhotite, the partition coefficient decreases dramatically to values around 1, because pyrrhotite locks up nearly all the sulfur of the magma. Reevaluation of the sulfur yields of some major historical eruptions in the light of these results shows that for oxidized magmas, the presence of 1-5 wt % fluid may indeed account for the differences observed between the petrologic estimate of the sulfur yield and that constrained from ice core data. Explosive eruptions of very large magnitude but involving reduced and cool silicic magmas, such as the Toba or the Bishop events, release only minor amounts of sulfur and could have consequently negligible long-term (years to centuries) atmospherical effects. This redox control on sulfur release diminishes as the melt composition becomes less silicic and as temperature increases, because both factors favor more efficient melt sulfur degassing owing to the increased diffusivity of sulfur in silicate melts under such conditions

Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}$and correspond to an integrated luminosity of$4.6\;{\rm f}{{{\rm b}}^{-1}}$. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum${{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}$and pseudorapidity$|\eta |\lt 1.9$, is measured to be${{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV