798 research outputs found

    An investigation into miniature hydraulic actuation techniques for needle control on industrial knitting and sewing machines

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    The thesis is presented in four main parts: (1) the design and development of a hydraulic circular weft knitting machine; (2) the construction and testing of a hydraulic lockstitch sewing machine; (3) a detailed design study and analysis of pulse-generating rotary valves; (4) the design of a multi-feeder hydraulic circular weft knitting machine. Part 1 deals with the knitting machine aspect of the project consisting of verifying that a multi-actuator rotary valve system would operate with the desired time displacement profile, and in the correct sequence. This was then used as the basis for developing a ninety-six-needle, single feeder hydraulic circular weft knitting machine. This prototype machine was tested to obtain an assessment as to the advantages offered by hydraulic knitting techniques. Part 2 involved replacing the needle and thread take-up mechanisms of a lockstitch sewing machine, by two miniature hydraulic actuators, controlled by a rotary valve. The purpose of this machine was to prove that stitches could be formed successfully, thus demonstrating any beneficial features offered by hydraulic sewing devices. Part 3 deals with the detailed design study for pulse-generating rotary valves resulting from the previous applications. This valve was a new concept in valve technology and having established its definite potential, warranted the formation of a design procedure. The study outlines a method of optimising the torque required to rotate the bobbin by the construction of a mathematical model. Part 4 was concerned with designing a multi-feeder hydraulic circular weft knitting machine. This machine, controlled by an integrated actuator rotary collar valve to generate pulses, demonstrated how a series of twelve knitting time-displacement profiles could be created by ninety-six actuators positioned in a circular configuration. Thus, the research programme has been aimed at demonstrating how high speed motions, normally obtained by mechanical devices (cams, linkages) can be produced by miniature hydraulic actuation techniques. The feasibility of using these techniques has been verified by the building and testing of probably the first ever hydraulic knitting and sewing machines

    A new algorithm for recognizing the unknot

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    The topological underpinnings are presented for a new algorithm which answers the question: `Is a given knot the unknot?' The algorithm uses the braid foliation technology of Bennequin and of Birman and Menasco. The approach is to consider the knot as a closed braid, and to use the fact that a knot is unknotted if and only if it is the boundary of a disc with a combinatorial foliation. The main problems which are solved in this paper are: how to systematically enumerate combinatorial braid foliations of a disc; how to verify whether a combinatorial foliation can be realized by an embedded disc; how to find a word in the the braid group whose conjugacy class represents the boundary of the embedded disc; how to check whether the given knot is isotopic to one of the enumerated examples; and finally, how to know when we can stop checking and be sure that our example is not the unknot.Comment: 46 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTVol2/paper9.abs.htm

    Pedagogical judgement

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    A Study of the Structure and Associated Features of Sheep Mountain Anticline Big Horn County, Wyoming

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    A study was made of the joint sets developed within two stratigraphic units of significantly different ages in the Sheep Mountain region, Bighorn County, Wyoming, in an attempt to determine if any pre-Laramide orogeny existed in the area. The field methods used and the relationships exhibited between joint sets are discussed. From the data presented, no significant support of the premise is concluded

    The usability of climate information in sub-national planning in India, Kenya and Uganda: the role of social learning and intermediary organisations

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    Research on using climate information has often focused on the interaction between users and producers and the technical fit of information for real decision-making. However, due to resource and capacity constraints within both user and producer communities, this approach will not always be feasible or indeed necessary depending on the decisions at hand. These contexts have been relatively under-explored by scholars, and this paper provides an original empirical contribution using three case studies of sub-national governments in India, Kenya and Uganda. In the paper, we analyse how social learning supports changing the usability of climate information and the role of intermediary organisations in these processes. Firstly, the paper shows that intermediaries often choose to build the commitment to project aims rather than using climate information as an entry point to working on climate change, and this allows them to instigate challenging learning processes. Secondly, there are barriers to iterative processes and critical reflection with government stakeholders but these processes can gain traction when built into institutional practices such as formal M&E processes. Lastly, social learning can broaden the framing of climate change from a single sector issue to a multi-sectoral one. We conclude by arguing that bringing together scholarship on social learning with that on the usability of climate information can deepen understanding of the dynamic context in which the information becomes usable. The evidence from the case studies shows that learning processes can alter this context across scales

    Rabies elimination research: juxtaposing optimism, pragmatism and realism

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    More than 100 years of research has now been conducted into the prevention, control and elimination of rabies with safe and highly efficacious vaccines developed for use in human and animal populations. Domestic dogs are a major reservoir for rabies, and although considerable advances have been made towards the elimination and control of canine rabies in many parts of the world, the disease continues to kill tens of thousands of people every year in Africa and Asia. Policy efforts are now being directed towards a global target of zero human deaths from dog-mediated rabies by 2030 and the global elimination of canine rabies. Here we demonstrate how research provides a cause for optimism as to the feasibility of these goals through strategies based around mass dog vaccination. We summarize some of the pragmatic insights generated from rabies epidemiology and dog ecology research that can improve the design of dog vaccination strategies in low- and middle-income countries and which should encourage implementation without further delay. We also highlight the need for realism in reaching the feasible, although technically more difficult and longer-term goal of global elimination of canine rabies. Finally, we discuss how research on rabies has broader relevance to the control and elimination of a suite of diseases of current concern to human and animal health, providing an exemplar of the value of a ‘One Health’ approach

    How is museum lighting selected? An insight into current practice in UK museums

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    The results of a series of interviews with museum professionals on the subject of museum lighting specification and selection are reported, with the aim that this report should provide an insight into current practice. Specific attention is given to the usage of industry parameters (lux, CIE-Ra, CCT), and to investigating the level of ubiquity of light-emitting diode (LED) technology. It is found that the damage potential of lighting is considered most commonly in terms of lux dosage, that a minimum cut off in terms of CIE-Ra is used to specify lighting ‘quality’, and that LED usage is growing, primarily as a result of institution-wide energy use reduction drives

    Transition, action and education: redirecting pragmatist philosophy of education

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    Recent developments in contemporary pragmatist thought have the potential to help reshape our understandings of pragmatism in philosophy of education. We first survey the development of pragmatism as founded in experience, moving through linguistic pragmatism, to a newer –actionistic approach in conduct pragmatism. Conduct pragmatism prioritizes action over both experience and discursive thought in ways that can be central to educational activity and projects. Conduct pragmatism so conceived has the potential to alter and shift how philosophers of education relate to pragmatist thought and in the second section we outline some of these potentials. We indicate the possibilities for pragmatist philosophy of education to engage with diverse bodies of thought, moving away from an insular focus on one or two philosophers, and a diversity of locations where philosophy is active and conducted

    The impact of malaria parasites on dendritic cell–T cell interaction

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    Malaria is caused by apicomplexan parasites of the genus Plasmodium. While infection continues to pose a risk for the majority of the global population, the burden of disease mainly resides in Sub-Saharan Africa. Although immunity develops against disease, this requires years of persistent exposure and is not associated with protection against infection. Repeat infections occur due to the parasite's ability to disrupt or evade the host immune responses. However, despite many years of study, the mechanisms of this disruption remain unclear. Previous studies have demonstrated a parasite-induced failure in dendritic cell (DCs) function affecting the generation of helper T cell responses. These T cells fail to help B cell responses, reducing the production of antibodies that are necessary to control malaria infection. This review focuses on our current understanding of the effect of Plasmodium parasite on DC function, DC-T cell interaction, and T cell activation. A better understanding of how parasites disrupt DC-T cell interactions will lead to new targets and approaches to reinstate adaptive immune responses and enhance parasite immunity
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