Retrofit Of A Steam Turbine With Dry Gas Seals.

LecturePg. 45-50The solution to a chronic utility problem, with a critical natural gas compression unit, at the Ammonia plant at Du Pont's Beaumont, Texas facility, is described. The most critical problem, chronic steam leakage from the turbine and subsequent oil system contamination, was corrected by the installation of noncontacting spiral groove seals. In addition, vibration problems caused by coupling lockup and subsequent premature coupling failure were solved by replacing the grease lubricated gear type coupling with a nonlubricated flexible coupling. A feature of the coupling is a keyed hub, designed for hydraulic removal. The turbine was sensitive to minor upsets and a rotordynamics study was done. The coupling and seal changes were both done at the same time. The unique features of these designs and measures taken to ensure proper application are addressed along with shop fabrication, field installation, and subsequent operation requirements. A description of project justification of reduced maintenance costs and avoided investments is also included

Viral factors in influenza pandemic risk assessment

The threat of an influenza A virus pandemic stems from continual virus spillovers from reservoir species, a tiny fraction of which spark sustained transmission in humans. To date, no pandemic emergence of a new influenza strain has been preceded by detection of a closely related precursor in an animal or human. Nonetheless, influenza surveillance efforts are expanding, prompting a need for tools to assess the pandemic risk posed by a detected virus. The goal would be to use genetic sequence and/or biological assays of viral traits to identify those non-human influenza viruses with the greatest risk of evolving into pandemic threats, and/or to understand drivers of such evolution, to prioritize pandemic prevention or response measures. We describe such efforts, identify progress and ongoing challenges, and discuss three specific traits of influenza viruses (hemagglutinin receptor binding specificity, hemagglutinin pH of activation, and polymerase complex efficiency) that contribute to pandemic risk

The Influence of Corporate Front-Group Stealth Campaigns

This research examined corporate front-group stealth campaigns. An experiment was conducted to examine the influence of front-group stealth campaigns on a variety of measures. It was anticipated that corporate front-group stealth campaigns, which feature names that mask the true interests of sponsors, positively affect public opinion, unless they are exposed as intentionally misleading, in which case they boomerang against sponsors. The experiment examined the potential of the inoculation strategy to preempt the influence of corporate front-group stealth campaigns. The pattern of results supported all of these expectations. Front-group stealth campaigns proved to be effective, at least in the short term. Front-group stealth campaigns eroded public attitudes toward the issue in question and boosted perceptions of the front group, but not the corporate sponsor. However, when front-group stealth campaigns were subsequently exposed, positive effects dissipated and perceptions of corporate sponsors boomeranged. Results revealed that inoculation can protect against the influence of front-group stealth campaigns.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Identification of a Novel Class of Farnesylation Targets by Structure-Based Modeling of Binding Specificity

Farnesylation is an important post-translational modification catalyzed by farnesyltransferase (FTase). Until recently it was believed that a C-terminal CaaX motif is required for farnesylation, but recent experiments have revealed larger substrate diversity. In this study, we propose a general structural modeling scheme to account for peptide binding specificity and recapitulate the experimentally derived selectivity profile of FTase in vitro. In addition to highly accurate recovery of known FTase targets, we also identify a range of novel potential targets in the human genome, including a new substrate class with an acidic C-terminal residue (CxxD/E). In vitro experiments verified farnesylation of 26/29 tested peptides, including both novel human targets, as well as peptides predicted to tightly bind FTase. This study extends the putative range of biological farnesylation substrates. Moreover, it suggests that the ability of a peptide to bind FTase is a main determinant for the farnesylation reaction. Finally, simple adaptation of our approach can contribute to more accurate and complete elucidation of peptide-mediated interactions and modifications in the cell

Light Microsopy Module, International Space Station Premier Automated Microscope

The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began science operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2015, if all goes as planned, five experiments will be completed: [1] Advanced Colloids Experiments with a manual sample base -3 (ACE-M-3), [2] the Advanced Colloids Experiment with a Heated Base -1 (ACE-H-1), [3] (ACE-H-2), [4] the Advanced Plant Experiment -03 (APEX-03), and [5] the Microchannel Diffusion Experiment (MDE). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] New York University: Paul Chaikin, Andrew Hollingsworth, and Stefano Sacanna, [2] University of Pennsylvania: Arjun Yodh and Matthew Gratale, [3] a consortium of universities from the State of Kentucky working through the Experimental Program to Stimulate Competitive Research (EPSCoR): Stuart Williams, Gerold Willing, Hemali Rathnayake, et al., [4] from the University of Florida and CASIS: Anna-Lisa Paul and Rob Ferl, and [5] from the Methodist Hospital Research Institute from CASIS: Alessandro Grattoni and Giancarlo Canavese

SN 2019ehk: A Double-peaked Ca-rich Transient with Luminous X-Ray Emission and Shock-ionized Spectral Features

We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in the star-forming galaxy M100 (d ≈ 16.2 Mpc) starting 10 hr after explosion and continuing for ~300 days. SN 2019ehk shows a double-peaked optical light curve peaking at t = 3 and 15 days. The first peak is coincident with luminous, rapidly decaying Swift-XRT–discovered X-ray emission (L_x ≈ 10⁴¹ erg s⁻¹ at 3 days; L_x ∝ t⁻³), and a Shane/Kast spectral detection of narrow Hα and He II emission lines (v ≈ 500 km s⁻¹) originating from pre-existent circumstellar material (CSM). We attribute this phenomenology to radiation from shock interaction with extended, dense material surrounding the progenitor star at r (0.1–1) × 10¹⁷ cm. The photometric and spectroscopic properties during the second light-curve peak are consistent with those of Ca-rich transients (rise-time of t_r = 13.4 ± 0.210 days and a peak B-band magnitude of M_B = −15.1 ± 0.200 mag). We find that SN 2019ehk synthesized (3.1 ± 0.11) × 10⁻² M_⊙ of ⁵⁶Ni and ejected M_(ej) = (0.72 ± 0.040) M⊙ total with a kinetic energy E_k = (1.8 ± 0.10) × 10⁵⁰ erg. Finally, deep HST pre-explosion imaging at the SN site constrains the parameter space of viable stellar progenitors to massive stars in the lowest mass bin (~10 M_⊙) in binaries that lost most of their He envelope or white dwarfs (WDs). The explosion and environment properties of SN 2019ehk further restrict the potential WD progenitor systems to low-mass hybrid HeCO WD+CO WD binaries

The International Companion to Scottish Poetry

A range of leading international scholars provide the reader with a comprehensive and innovative investigation of the extraordinary richness and diversity of Scotland\u2019s poetry. Addressing Languages and Chronologies, Poetic Forms, and Topics and Themes, this International Companion covers the entire subject from from the early Middle Ages to the modern day, and explores the connections, influences and interrelations between English, Gaelic, Latin, Old Norse and Scots verse. CONTENTS Series Editors\u2019 Preface Introduction (Carla Sassi) Part 1: Languages and Chronologies Early Celtic Poetry (to 1500) (Thomas Owen Clancy) Scots poetry in the Fourteenth and Fifteenth Centuries (R. D. S. Jack) Poetry in Latin (Roger Green) Poetry in the Languages and Dialects of Northern Scotland (Roberta Frank, Brian Smith) The Sixteenth and Seventeenth Centuries (S\uecm Innes, Alessandra Petrina) The Eighteenth Century (Ronald Black, Gerard Carruthers) The Nineteenth Century (Ian Duncan, Sheila Kidd) The Poetry of Modernity (1870\u20131950) (Emma Dymock, Scott Lyall) Contemporary Poetry (1950\u2013) (Attila D\uf3sa, Michelle Macleod) Part 2: Poetic Forms The Form of Scottish Gaelic poetry (William Gillies) Scots Poetic Forms (Derrick McClure) The Ballad in Scots and English (Suzanne Gilbert) Part 3: Topics and Themes Nature, Landscape and Rural Life (Louisa Gairn) Nation and Home (Carla Sassi, Silke Stroh) Protest and Politics (Wilson McLeod, Alan Riach) Love and Erotic Poetry (Peter Mackay) Faith and Religion (Meg Bateman, James McGonigal) Scottish Poetry as World Poetry (Paul Barnaby) The Literary Environment (Robyn Marsack) Endnotes Further Reading Notes on Contributors Index