Stress corrosion cracking studies

This document reports on the activities for Task 17 of the U.S. DOE/UCCSN Cooperative Agreement Number DE-FC28-98NV12081. There are three subtasks in this Task, the experimental results, discussions, and conclusions of which are presented in the following sections. Data Sources and Electronic Data Control The Data Identification numbers for the data, graphs, and tables in this report, as submitted to the Data Management Database, are tabulated below. The table also includes the source files for the said data as well as the corresponding scientific notebooks where the data can be found. All data in the Q section of the report are qualified as the relevant notebooks have completed the Technical and QA review process

Environmental Effects on Corrosion Properties of Alloy 22

During the regulatory life of the Yucca Mountain High Level Nuclear Waste (HLNW) repository the primary engineered barrier that is to prevent release of radioactive material into the environment is proposed to be a Corrosion-Resistant Material (CRM) outer shell covering the Waste Package (WP) container. The current selection for the CRM is Alloy 22 (UNS N06022), a Ni-Cr-Mo-W-Fe alloy. Alloy 22 forms a defective chromic oxide passive film which results in excellent corrosion resistance; the presence of molybdenum in Alloy 22 offers corrosion resistance in reducing environments as well as oxidizing environments

Continue stress corrosion cracking/ electrochemical testing and model support

The work reported here is focused on measuring values for various model parameters for the General Corrosion Model (GCM). The objective of the UNR work is to obtain the parameter values under Quality Assurance protocols, so that the data can be incorporated into models that might be used to address licensing issues, for example. The derived kinetic parameters may be used in models for predicting the accumulation of general and localized corrosion damage to Alloy-22 canisters over the 10,000-year lifetime of the YM repository. The work focuses on obtaining data of the highest possible accuracy to derive kinetic parameters for the dominant processes in the growth and breakdown of passive films on Alloy-22. This work also forms the basis of Mr. Glen McMillion\u27s dissertation for the Ph.D. degree from the University of Nevada, which he is scheduled to complete at the end of 2004. This project has made significant progress and has produced important data since its inception in mid-FY2002: 1. All work has been performed under the control of the UCCSN Quality Assurance Program, which is approved by the DOE YMP. Data generated to date are being submitted to the Technical Data Archive (TDA). 2. Experimental apparatus specifically designed for this task has been built, thoroughly tested, and proven to generate high-accuracy data. 3. Data have been collected for approximately two-thirds of the first of three conditions identified in the experimental matrix developed in the Scientific Investigation Plan. 4. Data generated include cyclic polarization, electrochemical impedance spectroscopy (EIS), potentiostatic passive current density (Ip), and Ip transients in response to step changes in potential. Conditions for which these data have been generated are listed below. 5. Crevice corrosion of Alloy-22 has been observed and documented. 6. Significant variability of corrosion behavior and microstructure among mill-annealed specimens has been observed and documented

A theory of normed simulations

In existing simulation proof techniques, a single step in a lower-level specification may be simulated by an extended execution fragment in a higher-level one. As a result, it is cumbersome to mechanize these techniques using general purpose theorem provers. Moreover, it is undecidable whether a given relation is a simulation, even if tautology checking is decidable for the underlying specification logic. This paper introduces various types of normed simulations. In a normed simulation, each step in a lower-level specification can be simulated by at most one step in the higher-level one, for any related pair of states. In earlier work we demonstrated that normed simulations are quite useful as a vehicle for the formalization of refinement proofs via theorem provers. Here we show that normed simulations also have pleasant theoretical properties: (1) under some reasonable assumptions, it is decidable whether a given relation is a normed forward simulation, provided tautology checking is decidable for the underlying logic; (2) at the semantic level, normed forward and backward simulations together form a complete proof method for establishing behavior inclusion, provided that the higher-level specification has finite invisible nondeterminism.Comment: 31 pages, 10figure

Promptness and Bounded Fairness in Concurrent and Parameterized Systems

We investigate the satisfaction of specifications in Prompt Linear Temporal Logic (Prompt-LTL) by concurrent systems. Prompt-LTL is an extension of LTL that allows to specify parametric bounds onthe satisfaction of eventualities, thus adding a quantitative aspect to the specification language. We establish a connection between bounded fairness, bounded stutter equivalence, and the satisfaction of Prompt-LTL\X formulas. Based on this connection, we prove the first cutoff results for different classes of systems with a parametric number of components and quantitative specifications, thereby identifying previously unknown decidable fragments of the parameterized model checking problem

Phototriggered release of tetrapeptide AAPV from coumarinyl and pyrenyl cages

Ala-Ala-Pro-Val (AAPV) is a bioactive tetrapeptide that inhibits human neutrophil elastase (HNE), an enzyme involved in skin chronic inflammatory diseases like psoriasis. Caged derivatives of this peptide were prepared by proper N- and C-terminal derivatisation through a carbamate or ester linkage, respectively, with two photoactive moieties, namely 7-methoxycoumarin-2-ylmethyl and pyren-2-ylmethyl groups. These groups were chosen to assess the influence of the photosensitive group and the type of linkage in the controlled photorelease of the active molecule. The caged peptides were irradiated at selected wavelengths of irradiation (254, 300, and 350 nm), and the photolytic process was monitored by HPLC-UV. The results established the applicability of the tested photoactive groups for the release of AAPV, especially for the derivative bearing the carbamate-linked pyrenylmethyl group, which displayed the shortest irradiation times for the release at the various wavelengths of irradiation (ca. 4 min at 254 nm, 8 min at 300 nm and 46 min at 350 nm).Thanks are due to the Fundação para a Ciência e Tecnologia (FCT, Portugal) for financial support to the portuguese NMR network (PTNMR, Bruker Avance III 400- Univ. Minho), FCT and FEDER (European Fund for Regional Development)- COMPETE-QREN-EU for financial support through the Chemistry Research Centre of the University of Minho (Ref. UID/QUI/00686/2013 and UID/QUI/0686/2016). A PhD grant to A.M.S. (SFRH/BD/80813/2011) is also acknowledged.info:eu-repo/semantics/publishedVersio

Inclusion of maintenance energy improves the intracellular flux predictions of CHO

Chinese hamster ovary (CHO) cells are the leading platform for the production of biopharmaceuticals with human-like glycosylation. The standard practice for cell line generation relies on trial and error approaches such as adaptive evolution and high-throughput screening, which typically take several months. Metabolic modeling could aid in designing better producer cell lines and thus shorten development times. The genome-scale metabolic model (GSMM) of CHO can accurately predict growth rates. However, in order to predict rational engineering strategies it also needs to accurately predict intracellular fluxes. In this work we evaluated the agreement between the fluxes predicted by parsimonious flux balance analysis (pFBA) using the CHO GSMM and a wide range of 13C metabolic flux data from literature. While glycolytic fluxes were predicted relatively well, the fluxes of tricarboxylic acid (TCA) cycle were vastly underestimated due to too low energy demand. Inclusion of computationally estimated maintenance energy significantly improved the overall accuracy of intracellular flux predictions. Maintenance energy was therefore determined experimentally by running continuous cultures at different growth rates and evaluating their respective energy consumption. The experimentally and computationally determined maintenance energy were in good agreement. Additionally, we compared alternative objective functions (minimization of uptake rates of seven nonessential metabolites) to the biomass objective. While the predictions of the uptake rates were quite inaccurate for most objectives, the predictions of the intracellular fluxes were comparable to the biomass objective function.COMET center acib: Next Generation Bioproduction, which is funded by BMK, BMDW, SFG, Standortagentur Tirol, Government of Lower Austria and Vienna Business Agency in the framework of COMET - Competence Centers for Excellent Technologies. The COMET-Funding Program is managed by the Austrian Research Promotion Agency FFG; D.S., J.S., M.W., M.H., D. E.R. This work has also been supported by the PhD program BioToP of the Austrian Science Fund (FWF Project W1224)info:eu-repo/semantics/publishedVersio

‘Writing Now’

This chapter considers the themes and forms that characterise women’s writing in the new millennium. Post-9/11, self-representation has become a particularly urgent task for Muslim writers such as Monica Ali and Leila Aboulela. A concern with refugees, asylum seekers, and modern forms of slavery becomes increasingly prominent, not only in fiction – for example, Fadia Faqir’s My Name is Salma (2007) and Monica Ali’s In the Kitchen (2009) – but also in the theatre: Kay Adshead’s The Bogus Woman (2000), Sonja Linden’s Crocodile Seeking Refuge (2005), Christine Bacon’s Rendition Monologues (2008), Rukhsana Ahmad and Oladipo Agboluaje’s Footprints in the Sand (2008), Natasha Walter's Motherland (2008), and Gbemisola Ikumelo’s Next Door (2010). The impact of global capitalism, consumerism, and branding are explored in novels such as Scarlett Thomas’ Popco (2004), Ali Smith’s Girl Meets Boy (2007), and Winterson’s The Stone Gods (2007). Ageing is another major theme. Long a pre-occupation of Doris Lessing, it features also in Liz Jensen’s War Crimes for the Home (2002) and Alison Fell’s Tricks of the Light (2003). Anxieties about climate change and environmental apocalypse are addressed through dystopia in Maggie Gee’s The Ice People (1998) and The Flood (2004), Jeanette Winterson’s The Stone Gods (2007), Sarah Hall’s The Carhullen Army (2007), and Liz Jensen’s The Rapture (2009). Following Suniti Namjoshi’s pioneeringly collaborative Building Babel (1996), the use of multimedia in Maya Chowdhry’s digital poetry, Kate Pullinger’s ‘networked’ wikinovel Flight Paths (2005-), and the ‘visual novel’ (an interactive fiction game), gives literature an entirely new shape