Design of an Apparatus to Detect Small Changes in the Mass of Rotational Machine Components

In this study, an apparatus was designed to detect changes on the order of grams in the mass of test samples subject to accelerations approaching 275g. The apparatus incorporated a surface speedometer, displacement transducer and on-board data-logging device in order to correlate mass loss events with changes in rotational speed and acceleration. An accessory was also designed to allow for on-board video recording to validate the findings and to better understand the mechanics of mass loss events. Such mass loss events are of interest for high-speed rotating machinery (e.g., manufacturing equipment, turbine rotors and automotive drivetrains), where material can build up and be dislodged, or other mass loss events can occur that currently cannot be measured directly. Results of such a design will allow for identification of mass loss in service for improved equipment diagnostics and control

Quasi-particle model for lattice QCD: quark-gluon plasma in heavy ion collisions

We propose a quasi-particle model to describe the lattice QCD equation of state for pure SU(3) gauge theory in its deconfined state, for $T \ge 1.5T_c$. The method involves mapping the interaction part of the equation of state to an effective fugacity of otherwise non-interacting quasi-gluons. We find that this mapping is exact. Using the quasi-gluon distribution function, we determine the energy density and the modified dispersion relation for the single particle energy, in which the trace anomaly is manifest. As an application, we first determine the Debye mass, and then the important transport parameters, {\it viz}, the shear viscosity, $\eta$ and the shear viscosity to entropy density ratio, $\eta/{\mathcal S}$. We find that both $\eta$ and $\eta/{\mathcal S}$ are sensitive to the interactions, and that the interactions significantly lower both $\eta$ and $\eta/\mathcal S$.Comment: 10 pages, 8 figures, epj class file, version accepted for publication in Euro. Phys.J

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Beam-target helicity asymmetry e in K0 Λ and K0 Σ0 photoproduction on the neutron

We report the first measurements of the E beam-target helicity asymmetry for the γ - n - →K0Λ and K0Σ0 channels in the energy range 1.70≤W≤2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin I=0 and I=1 photocoupling transition amplitudes in pseudoscalar meson photoproduction

Glycoconjugates: Overview and strategy

This chapter focuses on glycoconjugates. The practical application of mass spectrometric techniques to the difficult task of complete structural elucidation of oligosaccharides, polysaccharides, and glycoconjugates has been influenced strongly by instrument development—namely, gas-liquid chromatography/mass spectrometry, soft ionization, and high-field magnets. First, methylation linkage analysis developed principally because of the first working interface between a gas-liquid chromatograph and a mass spectrometer (GC/MS) which was assembled by Ragnar Ryhage at the Karolinska Institute in Stockholm on what would become the LKB-9000 instrument. The two-stage molecular separator, which constituted this interface, was ingenious and enabled online mass spectrometric analysis of gas-liquid chromatography effluents. The synergy of an on-line chromatographic and mass spectrometric system was astounding and still constitutes one of the most powerful analytical tools for volatiles. The chapter provides a valuable text for those who intend to acquire a background in mass spectrometry related to carbohydrate chemistry and provides a surprisingly rich lesson for those who believe that carbohydrate mass spectrometry began with fast atom bombardment ionization (FAB)-MS methods. © 1990, Elsevier Inc. All rights reserved

Phosphorous-containing glycosphingolipids

Two main classes of glycosphingolipids are also phospholipids: these comprise the inositol-containing glycophosphosphingolipids (GPSL) and phosphonoglycosphingolipids (PNGSL), containing carbon-phosphorous bonds. Both are unique forms of acidic cell membrane glycosphingolipids. THe GPSL are represented rather ubiquitously in plants, yeast and fungi, and possibly in protozoans, but not in higher animals. The PNGSL have thus far only been found in marine invertebrates, chiefly Aplysia. Despite the possibility that large numbers of novel and unknown structures exist in these two large classes of glycosphingolipids, relatively little structural, biosynthetic and functional work has been accomplished. What is known about GPSLs and PNGSLs will be the subject of this review. © 1986