199 research outputs found

    The cyclic stress-strain behavior of PWA 1480 at 650 deg C

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    The monotonic plastic flow behavior of several single crystal nickel-base, superalloys has been shown to vary significantly with crystallographic orientation. In the present study, the cyclic plastic flow response of one such alloy, PWA 1480, was examined at 650 deg C in air. Single crystal specimens aligned near several crystallographic directions were tested in fully reversed, total-strain-controlled low cycle fatigue tests at a frequency of 0.1 Hz. The cyclic stress-strain response and general cyclic hardening behavior was analyzed as a function of crystallographic orientation and inelastic strain range

    Variability of Optical Counterparts in the Chandra Galactic Bulge Survey

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    We present optical lightcurves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey. Using data from the Mosaic-II instrument on the Blanco 4m Telescope at CTIO, we gathered time-resolved photometric data on timescales from ∼2\sim2 hr to 8 days over the 34\frac{3}{4} of the X-ray survey containing sources from the initial GBS catalog. Among the lightcurve morphologies we identify are flickering in interacting binaries, eclipsing sources, dwarf nova outbursts, ellipsoidal variations, long period variables, spotted stars, and flare stars. 87%87\% of X-ray sources have at least one potential optical counterpart. 24%24\% of these candidate counterparts are detectably variable; a much greater fraction than expected for randomly selected field stars, which suggests that most of these variables are real counterparts. We discuss individual sources of interest, provide variability information on candidate counterparts, and discuss the characteristics of the variable population.Comment: Accepted for publication in the Astrophysical Journal Supplement

    A metamorphic inorganic framework that can be switched between eight single-crystalline states

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    The design of highly flexible framework materials requires organic linkers, whereas inorganic materials are more robust but inflexible. Here, by using linkable inorganic rings made up of tungsten oxide (P8W48O184) building blocks, we synthesized an inorganic single crystal material that can undergo at least eight different crystal-to-crystal transformations, with gigantic crystal volume contraction and expansion changes ranging from −2,170 to +1,720 Å3 with no reduction in crystallinity. Not only does this material undergo the largest single crystal-to-single crystal volume transformation thus far reported (to the best of our knowledge), the system also shows conformational flexibility while maintaining robustness over several cycles in the reversible uptake and release of guest molecules switching the crystal between different metamorphic states. This material combines the robustness of inorganic materials with the flexibility of organic frameworks, thereby challenging the notion that flexible materials with robustness are mutually exclusive

    A morphological model for sexing nestling peregrine falcons (Falco Peregrinus Macropus) verified through genetic analysis

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    Adult peregrine falcons (Falco peregrinus macropus) have monotypic plumage and display strong reversed sexual dimorphism, with females significantly larger than males. Reversed sexual dimorphism is measurable among nestlings in the latter stages of their development and can therefore be used to differentiate between sexes. In the early stages of development, however, nestlings cannot be sexed with any degree of certainty because morphological differentiation between the sexes is not well developed. During this study we developed a model for sexing younger nestlings based on genetic analysis and morphometric data collected as part of a long-term banding study of this species. A discriminant function model based on morphological characteristics was developed for determining the sex of nestlings (n = 150) in the field and was shown to be 96.0% accurate. This predictive model was further tested against an independent morphometric dataset taken from a second group of nestlings (n = 131). The model correctly allocated sex to 96.2% of this second group of nestlings. Sex can reliably be determined (98.6% accurate) for nestlings that have a wing length of at least 9 cm using this model. Application of this model, therefore, allows the banding of younger nestlings and, as such, significantly increases the period of time over which banding can occur. Another important implication of this model is that by banding nestlings earlier, they are less likely to jump from the nest, therefore reducing the risk of injury to both the brood and the bander.<br /

    The relationship work of sexual intimacy in long-term heterosexual and LGBTQ partnerships

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    Sex is perceived as crucial to relationship success. This article reveals how sexual intimacy is part of the relationship work that couples ordinarily complete to sustain their partnerships over time. It problematizes the binary logics of good–bad sex, female–male desire, and homo–heterosexual difference and shows how fluctuations of desire and/or sexual capacity are managed by couples through intimate knowledge. Findings presented here derive from a multiple methods study with 50 long-term heterosexual and LGBTQ partnerships. I demonstrate how the absence of normative sexual scripts enables queer couples to more readily manage sexual discrepancies. Gendered differences and inequalities persist within many heterosexual relationships while reflexivity and increased openness characterizes queer coupledom. Women and LGBTQ couples are more inclined to deploy humour to diffuse difficult situations and in this context gay men are akin to women more so than heterosexual men

    Unsettling lesbian motherhood: Critical reflections over a generation (1990-2015)

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    This article explores how advancements in equality rights combine with attitudinal changes in UK society and LGBTQ communities to impact on the experience of lesbian mothers over a generation. The author reflects on ordinary moments where sexuality and relationships become meaningful and situate emotions at the heart of analytical enquiry because it is through emotional interactions that micro–macro networks of relations intersect. Autobiography is combined with original data from empirical research to provide analytical entry points, which aims to advance understanding and also facilitate reflection on how we understand and come to know queer parenthood. Whilst there are now many routes into lesbian motherhood and the stigma of queer kinship is diminishing, this article demonstrates the need to problematize the prevailing narratives of coupledom that are emerging and tease apart the conflation of temporal progression, progressive rights and narratives of progress

    Family Trouble: Heteronormativity, emotion work and queer youth mental health

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    Conflict with the family about sexual orientation and gender diversity is a key risk factor associated with poor mental health in youth populations. Findings presented here derive from a UK study that employed an interdisciplinary critical mental health approach that de-pathologized emotional distress and conceptualised families as social and affective units that are created through everyday practices. Our aim was to explore how family relationships foster, maintain or harm the mental health and wellbeing of LGBTQ+ youth. Data were generated through exploratory visual, creative and digital qualitative methods in two phases. Phase 1 involved digital/paper emotion maps and interviews with LGBTQ+ youth aged 16-25 (n=12) and family member/mentor interviews (n=7). Phase 2 employed diary methods and follow-up interviews (n=9). The data analytic strategy involved three stages: individual case analysis; cross-sectional thematic analysis; and metainterpretation. We found that family relationships impacted on queer youth mental health in complex ways that were related to the establishment of their autonomous queer selves, the desire to remain belonging to their family and the need to maintain a secure environment. The emotion work involved in navigating identity, belonging and security was made difficult because of family heteronormativity, youth autonomy and family expectations and had a stark impact on queer youth mental health and wellbeing. Improving the mental health of LGBTQ+ youth requires a much deeper understanding of the emotionality of family relationships and the difficulties negotiating these as a young person

    Predictive runtime code scheduling for heterogeneous architectures

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    Heterogeneous architectures are currently widespread. With the advent of easy-to-program general purpose GPUs, virtually every re- cent desktop computer is a heterogeneous system. Combining the CPU and the GPU brings great amounts of processing power. However, such architectures are often used in a restricted way for domain-speci c appli- cations like scienti c applications and games, and they tend to be used by a single application at a time. We envision future heterogeneous com- puting systems where all their heterogeneous resources are continuously utilized by di erent applications with versioned critical parts to be able to better adapt their behavior and improve execution time, power con- sumption, response time and other constraints at runtime. Under such a model, adaptive scheduling becomes a critical component. In this paper, we propose a novel predictive user-level scheduler based on past performance history for heterogeneous systems. We developed sev- eral scheduling policies and present the study of their impact on system performance. We demonstrate that such scheduler allows multiple appli- cations to fully utilize all available processing resources in CPU/GPU- like systems and consistently achieve speedups ranging from 30% to 40% compared to just using the GPU in a single application mode.Postprint (published version

    Risky business: a single-centre cross-sectional analysis of calculated cardiovascular risk in patients with primary aldosteronism and essential hypertension

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    Objectives Primary aldosteronism (PA), the most common endocrine cause of hypertension, is associated with a higher risk of cardiovascular disease (CVD) than blood pressure (BP)-matched essential hypertension (EH). We aimed to compare the calculated risks of CVD in patients who had hypertension with PA or EH using CVD risk calculators, hypothesising that they will fail to recognise the increased CVD risk in PA. Design Cross-sectional analysis. Setting An endocrine hypertension service in Victoria, Australia. Participants Patients who had hypertension without CVD referred for the investigation of hypertension. Outcome measures Calculated 5-year or 10-year CVD risk as predicted by the National Vascular Disease Prevention Alliance (NVDPA) algorithm, Framingham Risk Score, Pooled Cohort Equations and QRISK3. Results Those with PA (n=128) and EH (n=133), did not differ significantly in their calculated CVD risks with the NVDPA algorithm (moderate-to- high 5-year risk 36/100 vs 45/99, p=0.17); the Framingham Risk Score (median 10-year risk 7.72% (4.43%–12.95%) vs 6.84% (3.85%– 10.50%), p=0.14); the Pooled Cohort Equations (median 10-year risk 9.45% (4.36%–15.37%) vs 7.90% (2.09%– 14.73%), p=0.07); and QRISK3 (median 10-year risk 11.31% (7.22%–20.29%) vs 12.47% (5.10%–19.93%), p=0.51). Similarities persisted on regression analyses accounting for systolic BP. Conclusions CVD risk algorithms do not reflect the increased risk of CVD in patients with PA, and likely underestimate the true risk of CVD among those with PA. Screening for PA, in addition to using the CVD risk algorithm in patients who had hypertension, may facilitate the targeted treatment of PA and minimisation of cardiovascular risk in affected individuals.Pravik Solanki, Stella May Gwini, Renata Libianto, Genevieve Gabb, Jimmy Shen, Morag J Young, Peter J Fuller, Jun Yan
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