1,141 research outputs found

    Total productive maintenance implementation in the newspaper printing industry:an action research approach

    Get PDF
    The objective of Total Productive Maintenance (TPM) is to maximise plant and equipment effectiveness, to create a sense of ownership for operators, and promote continuous improvement through small group activities involving production, engineering and maintenance personnel. This paper describes and analyses a case study of TPM implementation at a newspaper printing house in Singapore. However, rather than adopting more conventional implementation methods such as employing consultants or through a project using external training, a unique approach was adopted based on Action Research using a spiral of cycles of planning, acting observing and reflecting. An Action Research team of company personnel was specially formed to undertake the necessary fieldwork. The team subsequently assisted with administering the resulting action plan. The main sources of maintenance and operational data were from interviews with shop floor workers, participative observation and reviews conducted with members of the team. Content analysis using appropriate statistical techniques was used to test the significance of changes in performance between the start and completion of the TPM programme. The paper identifies the characteristics associated with the Action Research method when used to implement TPM and discusses the applicability of the approach in related industries and processes

    Overview of Solid Target Studies for a Neutrino Factory

    Get PDF
    The UK pro­gramme of high power tar­get de­vel­op­ments for a Neu­tri­no Fac­to­ry is cen­tred on the study of high-Z ma­te­ri­als (tung­sten, tan­ta­lum). A de­scrip­tion of life­time shock tests on can­di­date ma­te­ri­als is given as part of the re­search into a solid tar­get so­lu­tion. A fast high cur­rent pulse is ap­plied to a thin wire of the sam­ple ma­te­ri­al and the life­time mea­sured from the num­ber of puls­es be­fore fail­ure. These mea­sure­ments are made at tem­per­a­tures up to ~2000 K. The stress on the wire is cal­cu­lat­ed using the LS-DY­NA code and com­pared to the stress ex­pect­ed in the real Neu­tri­no Fac­to­ry tar­get. It has been found that tan­ta­lum is too weak to sus­tain pro­longed stress at these tem­per­a­tures but a tung­sten wire has reached over 26 mil­lion puls­es (equiv­a­lent to more than ten years of op­er­a­tion at the Neu­tri­no Fac­to­ry). An ac­count is given of the op­ti­mi­sa­tion of sec­ondary pion pro­duc­tion from the tar­get and the is­sues re­lat­ed to mount­ing the tar­get in the muon cap­ture solenoid and tar­get sta­tion are dis­cussed

    Effects of rodent poisoning on Powelliphanta traversi

    Get PDF
    Rat predation is a threat to lowland Powelliphanta traversi (giant predatory land snail), and we have shown that ‘press’ poisoning of rodents (rats and mice) using brodifacoum baits significantly reduces rat abundance relative to non-poisoned areas. The effect on P. t. traversi was evident by the increase in population size, mainly due to adult migration, and a decrease in rat-damaged shells, for areas where rat predation occurs. A longer-term study is required to determine whether prolonged rat control benefits P. t. traversi recruitment. Mouse control was inadequate with use of brodifacoum baits. We document a concomitant rise in bird predation of P. traversi when rat abundance was reduced, suggesting that control of both is necessary to make real conservation gains. However, mortality related to other factors was more common than that caused by predators, possibly due to the habitat drying out periodically. We suggest that low recruitment rates, predator targeting of juveniles (i.e. blackbirds, song thrush and possibly mice and hedgehogs) and poor habitat conditions are the main threats to survival of lowland P. traversi

    Habitat use of Tradescantia fluminensis by Powelliphanta traversi

    Get PDF
    This study was initiated owing to concern that removal of the invasive ground cover, Tradescantia fluminensis, might adversely effect the rare, giant predatory land snail, Powelliphanta traversi. Of 18 sites surveyed in the Horowhenua District, seven sites provide habitat for P. traversi and do not contain Tradescantia. Five colonies of P. traversi are affected by Tradescantia, these are: Waiopehu Scenic Reserve, Prouse’s Bush, Kimberley Scenic Reserve, Ohau River Bush, and Hillas Covenant. Tradescantia infestation at these sites varies from heavy (Prouse’s Bush) to forest edge only (Hillas Covenant). Overall, Tradescantia affects a small proportion of snail habitat in the Horowhenua District. Our study of P. traversi at Prouse’s Bush, using harmonic radar to follow long-term movements and cotton tracks for short-term movements, indicates that this snail commonly occurs under Tradescantia, sometimes exclusively, and that many of the snails move regularly between leaf litter and this weed. Moreover, Tradescantia provides an important refuge for juvenile snails at Prouse’s Bush. Hence, removing Tradescantia from this site would have a detrimental impact on P. traversi. Graduated control of Tradescantia and concomitant replacement with native ground cover could be of mutual benefit to P. traversi and other ground-dwelling invertebrates

    Effects of removal of Tradescantia fluminensis on Powelliphanta traversi and other invertebrates

    Get PDF
    This study was initiated owing to concern that removal of the invasive ground cover weed Tradescantia fluminensis may adversely effect the rare giant predatory land snail Powelliphanta traversi. From field trials using hand removal and herbicide spraying, it was considered that graduated control of Tradescantia with concomitant replacement of native ground cover could be of benefit to P. traversi and other ground-dwelling invertebrates. Grazon® herbicide (active ingredient triclopyr) appears suitable for controlling Tradescantia at sites where P. t. traversi occurs, since the effects of triclopyr on ground-dwelling invertebrates in the field and first generation P. t. traversi in the laboratory were minimal. However, possible effects of triclopyr on subsequent P. t. traversi generations remain untested, and evidence from the literature suggests that there could be some detrimental effects. Similarly, the effects of triclopyr on the presumed earthworm prey of P. t. traversi remain untested

    Ostracods from freshwater and brackish environments of the Carboniferous of the Midland Valley of Scotland : the early colonization of terrestrial water bodies

    Get PDF
    The Mississippian Strathclyde Group of the Midland Valley of Scotland yields some of the earliest non-marine ostracods. The succession records shallow marine, deltaic, estuarine, lagoonal, lacustrine, fluvial and swamp environments representing a series of staging-posts between fully marine and limnetic settings. Macrofossils and ostracods are assigned to marine, marginal marine, brackish and freshwater environments based on their faunal assemblage patterns. Key brackish to freshwater ostracods are Geisina arcuata, Paraparchites circularis n. sp., Shemonaella ornata n. sp. and Silenites sp. A, associated with the bivalves Anthraconaia, Carbonicola, Cardiopteridium, Curvirimula, Naiadites, the microconchid ‘Spirorbis’, Spinicaudata and fish. Many Platycopina and Paraparchiticopina ostracods are interpreted as euryhaline, which corresponds with their occurrence in marine to coastal plain water bodies, and supports the ‘estuary effect’ hypothesis of non-marine colonization. The success of non-marine colonization by ostracods was dependent on the intrinsic adaptations of ostracod species to lower salinities, such as new reproductive strategies and the timing of extrinsic mechanisms to drive non-marine colonization, such as sea-level change. The genus Carbonita is the oldest and most common freshwater ostracod, and went on to dominate freshwater environments in the Late Palaeozoic

    Entanglement in bipartite generalized coherent states

    Full text link
    Entanglement in a class of bipartite generalized coherent states is discussed. It is shown that a positive parameter can be associated with the bipartite generalized coherent states so that the states with equal value for the parameter are of equal entanglement. It is shown that the maximum possible entanglement of 1 bit is attained if the positive parameter equals 2\sqrt{2}. The result that the entanglement is one bit when the relative phase between the composing states is π\pi in bipartite coherent states is shown to be true for the class of bipartite generalized coherent states considered.Comment: 10 pages, 4 figures; typos corrected and figures redrawn for better clarit

    Entanglement, quantum phase transition and scaling in XXZ chain

    Full text link
    Motivated by recent development in quantum entanglement, we study relations among concurrence CC, SUq_q(2) algebra, quantum phase transition and correlation length at the zero temperature for the XXZ chain. We find that at the SU(2) point, the ground state possess the maximum concurrence. When the anisotropic parameter Δ\Delta is deformed, however, its value decreases. Its dependence on Δ\Delta scales as C=C0C1(Δ1)2C=C_0-C_1(\Delta-1)^2 in the XY metallic phase and near the critical point (i.e. 1<Δ<1.31<\Delta<1.3) of the Ising-like insulating phase. We also study the dependence of CC on the correlation length ξ\xi, and show that it satisfies C=C01/2ξC=C_0-1/2\xi near the critical point. For different size of the system, we show that there exists a universal scaling function of CC with respect to the correlation length ξ\xi.Comment: 4 pages, 3 figures. to appear in Phys. Rev.
    corecore