979 research outputs found
Technology requirements for advanced earth-orbital transportation systems, dual-mode propulsion
The application of dual-mode propulsion concepts to fully reusable single-stage-to-orbit (SSTO) vehicles is discussed. Dual-mode propulsion uses main rocket engines that consume hydrocarbon fuels as well as liquid hydrogen fuel. Liquid oxygen is used as the oxidizer. These engine concepts were integrated into transportation vehicle designs capable of vertical takeoff, delivering a payload to earth orbit, and return to earth with a horizontal landing. Benefits of these vehicles were assessed and compared with vehicles using single-mode propulsion (liquid hydrogen and oxygen engines). Technology requirements for such advanced transportation systems were identified. Figures of merit, including life-cycle cost savings and research costs, were derived for dual-mode technology programs, and were used for assessments of potential benefits of proposed technology activities. Dual-mode propulsion concepts display potential for significant cost and performance benefits when applied to SSTO vehicles
Technology requirements for advanced earth-orbital transportation systems: Summary report
Areas of advanced technology that are either critical or offer significant benefits to the development of future Earth-orbit transportation systems were identified. Technology assessment was based on the application of these technologies to fully reusable, single-state-to-orbit (SSTO) vehicle concepts with horizontal landing capability. Study guidelines included mission requirements similar to space shuttle, an operational capability beginning in 1995, and main propulsion to be advanced hydrogen-fueled rocket engines. The technical and economic feasibility of this class of SSTO concepts were evaluated as well as the comparative features of three operational take-off modes, which were vertical boost, horizontal sled launch, and horizontal take-off with subsequent inflight fueling. Projections of both normal and accelerated technology growth were made. Figures of merit were derived to provide relative rankings of technology areas. The influence of selected accelerated areas on vehicle design and program costs was analyzed by developing near-optimum point designs
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Fortunes of feminism: act four
Part of Fortunes of Feminism: A Roundtable on and with Nancy Fraser. Discussants: Jo Littler, Eric Fassin, Barbara Poggio, Nancy Frase
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Mrs Hinch, the rise of the cleanfluencer and the neoliberal refashioning of housework: Scouring away the crisis?
This article extends sociological and feminist accounts of housework by examining the social significance of the rise of the âcleanfluencerâ: online influencers who supply household cleaning and organization tips and modes of lifestyle aspiration via social media. We focus on âMrs Hinchâ; aka Sophie Hinchliffe from Essex, the âhomegrownâ Instagram star with 4.1 million followers who shares daily images and stories of cleaning and family life, and has a series of bestselling books, regular daytime TV appearances and supermarket tie-ins. We argue that, within neoliberal culture, housework is now often refashioned as a form of therapy for womenâs stressful lives: stresses that neoliberalism and patriarchy have both generated and compounded. The argument is developed through three sections. First, we locate Mrs Hinch in relation to longer classed, gendered and racialized histories of domestic labour and the figure of the âhousewifeâ, and the re-writing of domestic narratives to find new ways of ensuring womenâs willingness to participate in unpaid domestic labour. Second, we analyse the contradictions of cleanfluencing as a form of âdigital identity labourâ representing offline housework, which in this case is precarious and classed. Finally, drawing these themes together, we show how âHinchingâ recasts housework as part of a neoliberal therapeutic promise to âclean awayâ the instabilities, anxieties and threats of contemporary culture
Correspondence: No substantial long-term bias in the Cenozoic benthic foraminifera oxygen-isotope record
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Multi-Attribute SCADA-Specific Intrusion Detection System for Power Networks
The increased interconnectivity and complexity of supervisory control and data acquisition (SCADA) systems in power system networks has exposed the systems to a multitude of potential vulnerabilities. In this paper, we present a novel approach for a next-generation SCADA-specific intrusion detection system (IDS). The proposed system analyzes multiple attributes in order to provide a comprehensive solution that is able to mitigate varied cyber-attack threats. The multiattribute IDS comprises a heterogeneous white list and behavior-based concept in order to make SCADA cybersystems more secure. This paper also proposes a multilayer cyber-security framework based on IDS for protecting SCADA cybersecurity in smart grids without compromising the availability of normal data. In addition, this paper presents a SCADA-specific cybersecurity testbed to investigate simulated attacks, which has been used in this paper to validate the proposed approach
Engaging research ethics committees to develop an ethics and governance framework for best practices in genomic research and biobanking in Africa: the H3Africa model [Commentary]
In the past decade, there has been an increase in genomic research and biobanking activities in Africa. Research initiatives such as the Human Heredity and Health in Africa (H3Africa) Consortium are contributing to the development of scientific capacity and infrastructure to support these studies on the continent. Despite this growth, genomic research and biobanking have raised important ethical challenges for key research stakeholders, including members of research ethics committees. One of these is the limited ethical and regulatory frameworks to guide the review and conduct of genomic studies, particularly in Africa. This paper is a reflection on a series of consultative activities with research ethics committees in Africa which informed the development of an ethics and governance framework for best practices in genomic research and biobanking in Africa. The paper highlights the engagement process and the lessoned learned
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Mothers behaving badly: chaotic hedonism and the crisis of neoliberal social reproduction
This article focuses on the significance of the plethora of representations of mothers âbehaving badlyâ in contemporary anglophone media texts, including the films Bad Moms, Fun Mom Dinner and Bad Momâs Christmas, the book and online cartoons Hurrah for Gin and the recent TV comedy dramas Motherland, The Let Down and Catastrophe. All these media texts include representations of, first, mothers in the midst of highly chaotic everyday spaces where any smooth routine of domesticity is conspicuous by its absence; and second, mothers behaving hedonistically, usually through drinking and partying, behaviour that is more conventionally associated with men or women without children. After identifying the social type of the mother behaving badly (MBB), the article locates and analyses it in relation to several different social and cultural contexts. These contexts are: a neoliberal crisis in social reproduction marked by inequality and overwork; the continual if contested role of women as âfoundation parentsâ; and the negotiation of longer-term discourses of female hedonism. The title gestures towards a popular British sitcom of the 1990s, Men Behaving Badly, which popularized the idea of the ânew ladâ; and this article suggests that the new ladâs counterpart, the ladette, is mutating into the mother behaving badly, or the âlad momâ. Asking what work this figure does now, in a later neoliberal context, it argues that the mother behaving badly is simultaneously indicative of a widening and liberating range of maternal subject positions and symptomatic of a profound contemporary crisis in social reproduction. By focusing on the classed and racialised dynamics of the MBB â by examining who exactly is permitted to be hedonistic, and how â and by considering the MBBâs limited and partial imagining of progressive social change, the article concludes by emphasizing the urgency of creating more connections between such discourses and âparents behaving politicallyâ
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