Heat treatment study of the SiC/Ti-15-3 composite system

The oxidation and aging behaviors of a continuous fiber SiC/Ti-15V-3Cr-3Sn-3Al composite (SiC/Ti-15-3) were investigated. The aging characteristic of the composite were compared with those of the unreinforced Ti-15-3 matrix material, which was processed in the same manner as the composite. Various age hardened conditions of both the unreinforced matrix and the composite were evaluated by using optical microscopy, hardness measurements, and room temperature tensile tests (unreinforced matrix only). The Ti-15-3 material formed a thick surface oxide at temperature at or above 550 C when heat treated in air. The in situ composite matrix was softer than the unreinforced matrix for equivalent aging conditions. Both materials hardened to a maximum, then softened during overaging. The temperature at which peak aging occurred was approx. 450 C for both the in situ composite matrix and the unreinforced matrix. The room temperature elastic modulus and ultimate tensile strength of the unreinforced matrix varied as a function of aging treatment and paralleled the hardness behavior. The modulus and tensile strength showed little response to aging up to temperatures of 300 C; however, these properties increased after aging at 550 C. Aging at temperatures above 550 C resulted in a decrease in the modulus and tensile strength. The failure strain was a function of the precipitation state and of the amount of oxidation resulting from the heat treatment. Aging in air at the higher temperatures (greater than 550 C) caused the formation of a thick oxide layer and reduced the ductility. Aging in vacuum at these temperatures resulted in significantly higher ductilities. Long term exposures at 700 C caused the formation of a large grain boundary alpha-phase which reduced the ductility, even though the specimens were heat treated in vacuum

Counterfactual reasoning in strategy context : a theoretical investigation of the role of hindsight in strategic foresight

The purpose of this doctoral thesis is to deepen theoretical understanding of the role that hindsight plays in foresight. The thesis argues that the past is not an isolated static state, but one that is intimately connected with the future. However, there are several biases that influence our perceptions and conceptions of the past. These biases act as constraints on strategic learning by limiting our ability to understand the driving forces that emerge from the past, play out through the present and become critical uncertainties in the future. They can result in misperceptions about events or processes, and as such, may impair foresight methodologies such as scenario thinking. Such foresightful thinking flaws are characterised by a combination of hindsight biases and creeping determinism, which result in searching for information that corresponds to people's views about both the past and the future, logical path-dependencies, misaligned dominant logics, routines, recipes and paradigms, and over-confidence and defensive pessimism. Drawing on received research in psychology, the role of counter-to-factual reasoning as a heuristic is discussed and analysed as a possible antidote to foresightful thinking flaws. The judicious use of such a heuristic device as counterfactual reasoning, both as a sense-making process and as an analytical reasoning tool applied to the analysis of historical data, the thesis concludes, is a method for investigating and discovering the past and fortifying foresightful strategic thinking

Diatom and stable isotope records of late-Holocene lake ontogeny at Indrepollen, Lofoten, NW Norway: a response to glacio-isostasy and Neoglacial cooling

Borg Indrepollen is a coastal lake on the island of Vestvågøy, Lofoten, NW Norway. A sedimentary sequence spanning the last 4500 cal. yr BP was analysed for diatom, C/N and stable isotopes (δ13C and δ15 N). The record provides clear evidence of glacio-isostatic rebound in the Lofoten region. Five distinct lithostratigraphic-geochemical zones (I—V) and four major diatom zones (A—D) were identified. The early record (I—III, A—Biii; 4500—550 cal. yr BP) contains coarse sedimentary material and diatoms indicative of more marine conditions. The correlation between the isotopic data (high δ13C and low C/N) and trends in the biological data (marine/brackish flora) suggest the marine influence on the Indrepollen basin is a controlling factor of the source of organic material. The latter part of the record (IV, C; 550 cal. yr 550—226) indicates a transitional phase from marine-dominated diatom to brackish taxa and is coincident with a section of microlaminations in the core. The youngest zone (V, D; 226 cal. yr BP—present) is indicative of an isolated basin, with the deposition of fine sediments; freshwater diatom taxa dominate the biological record and δ13C are indicative of freshwater conditions. C/N suggests a shift to a terrestrial source of organic matter. The proxies show a transition from full marine conditions, when Indrepollen was a submerged fjord, to more freshwater, lacustrine conditions in the last 200 years. The record of land uplift from Borg Indrepollen mirrors changes in sedimentary records from across Northern Norway and relative sea-level curves for the region

Synthesizing scenario planning and industry recipes through an analysis of the Hollywood film industry

This paper creates a theoretical construct through the synthetization of industry recipes in the Hollywood film industry and scenario planning’s intuitive logics approach. It illustrates how the incumbent-challenger paradox coupled with the industry recipes framework can provide a robust scenario narrative. Through a multiple case study approach, an industry recipe is constructed, the industry recipe factors are identified. Then the intuitive logics approach is blended with the industry recipe factors through the creation of scenario recipe factors and represented in a theoretical framework. The underlying premise of the paper purports that exploration of the industry recipes framework can help advance the intuitive logic approach through narrative development

Celtic FC’s 1967 Lisbon Lions:Why the European Cup victory of the first club from Britain was a defining moment for the Irish diaspora in Scotland

In 1967, in Lisbon, Celtic Football Club, won the European Cup becoming the first club outside of Portugal, Spain and Italy to win it. The win was and is totemic for the Irish Catholic immigrant community in Scotland that has historically supported Celtic. We suggest the significance of the win reveals intersections of ethnicity, religion, nationalism, and the politics of ‘sectarianism’ in Scotland. During a period of discriminatory practices and attitudes towards Irish descended Catholics in Scotland, this iconic win for a Scottish based club born of Irish Catholics personified for this diaspora that (on one level) their day had arrived. This article explores the socio-cultural significance and legacy of ‘Lisbon 67ʹ for insider and outsider groups in Scotland. We reveal that soccer remains a central component of group memory connecting the past, present and future. We suggest Celtic’s win offered confidence and hope to a marginalized group within Scotland

Acetyl-CoA synthetase 2 promotes acetate utilization and maintains cancer cell growth under metabolic stress

A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment

Hamlet and the fall of the Berlin wall : the myth of interventionist Shakespeare performance

The critical reception of Heiner Müller’s 1990 Hamlet/Maschine at the Deutsches Theater in East Berlin epitomizes a trend of crediting GDR Shakespeare performance with political influence. Drawing on rehearsal notes and reviews, Oliver challenges the interventionist Shakespeare myth, contrasting the Deutsches Theater’s political involvement with the impact of its Hamlet production on events surrounding the fall of the Berlin Wall. Shakespeare’s capacity for political intervention at this point was limited by theater practitioners’ reliance on public funding, their close relationships with governmental authority, and an underlying distrust of the masses. Ultimately, GDR artists proved useful to the 1989 protest movement because they occupied a unique position at the interface of dissidence and power

Patient Harm Due to Diagnostic Error of Neuro-Ophthalmologic Conditions

PURPOSE: To prospectively examine diagnostic error of neuro-ophthalmic conditions and resultant harm at multiple sites. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: A total of 496 consecutive adult new patients seen at 3 university-based neuro-ophthalmology clinics in the United States in 2019 to 2020. METHODS: Collected data regarding demographics, prior care, referral diagnosis, final diagnosis, diagnostic testing, treatment, patient disposition, and impact of the neuro-ophthalmologic encounter. For misdiagnosed patients, we identified the cause of error using the Diagnosis Error Evaluation and Research (DEER) taxonomy tool and whether the patient experienced harm due to the misdiagnosis. MAIN OUTCOME MEASURES: The primary outcome was whether patients who were misdiagnosed before neuro-ophthalmology referral experienced harm as a result of the misdiagnosis. Secondary outcomes included appropriateness of referrals, misdiagnosis rate, interventions undergone before referral, and the primary type of diagnostic error. RESULTS: Referral diagnosis was incorrect in 49% of cases. A total of 26% of misdiagnosed patients experienced harm, which could have been prevented by earlier referral to neuro-ophthalmology in 97%. Patients experienced inappropriate laboratory testing, diagnostic imaging, or treatment before referral in 23%, with higher rates for patients misdiagnosed before referral (34% of patients vs. 13% with a correct referral diagnosis, P < 0.0001). Seventy-six percent of inappropriate referrals were misdiagnosed, compared with 45% of appropriate referrals (P < 0.0001). The most common reasons for referral were optic neuritis or optic neuropathy (21%), papilledema (18%), diplopia or cranial nerve palsies (16%), and unspecified vision loss (11%). The most common sources of diagnostic error were the physical examination (36%), generation of a complete differential diagnosis (24%), history taking (24%), and use or interpretation of diagnostic testing (13%). In 489 of 496 patients (99%), neuro-ophthalmology consultation (NOC) affected patient care. In 2% of cases, neuro-ophthalmology directly saved the patient's life or vision; in an additional 10%, harmful treatment was avoided or appropriate urgent referral was provided; and in an additional 48%, neuro-ophthalmology provided a diagnosis and direction to the patient's care. CONCLUSIONS: Misdiagnosis of neuro-ophthalmic conditions, mismanagement before referral, and preventable harm are common. Early appropriate referral to neuro-ophthalmology may prevent patient harm