207 research outputs found

    UK Large-scale Wind Power Programme from 1970 to 1990: the Carmarthen Bay experiments and the Musgrove Vertical-Axis Turbines

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    This article describes the development of the Musgrove Vertical Axis Wind Turbine (VAWT) concept, the UK ‘Carmarthen Bay’ wind turbine test programme, and UK government’s wind power programme to 1990. One of the most significant developments in the story of British wind power occurred during the 1970s, 1980s, and 1990s, with the development of the Musgrove vertical axis wind turbine and its inclusion within the UK Government’s wind turbine test programme. Evolving from a supervisor’s idea for an undergraduate project at Reading University, the Musgrove VAWT was once seen as an able competitor to the horizontal axis wind systems that were also being encouraged at the time by both the UK government and the Central Electricity Generating Board, the then nationalised electricity utility for England and Wales. During the 1980s and 1990s the most developed Musgrove VAWT system, along with three other commercial turbine designs was tested at Carmarthen Bay, South Wales as part of a national wind power test programme. From these developmental tests, operational data was collected and lessons learnt, which were incorporated into subsequent wind power operations.http://dx.doi.org/10.1260/03095240677860621

    Regulation of abscisic acid concentration in leaves of field-grown pearl millet (Pennisetum americanum (L.) Leeke): the role of abscisic acid export

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    Diurnal changes in the ABA concn. in leaves of droughted, field-grown plants of P. americanum were not always correlated with changes in bulk leaf water potential. A rapid decline in ABA content of the leaves following its rise to a peak level in mid-morning, was observed in several time-course studies despite continued water stress. The possibility that the reduction in ABA in leaves was due to an elevated rate of its export was examined by measuring ABA concn. in developing panicles (possible sinks for leaf-produced ABA) and in leaves, and by comparing the amounts of ABA in ungirdled leaves and in leaves heat-girdled at the base of the lamina to block export. ABA concn. in panicles generally paralleled those in leaves, though the peak concn. of ABA in the morning in panicles occurred later than in the leaves in some samplings. Although girdling initially increased ABA concn., it did not prevent a subsequent fall which generally paralleled the decline observed in untreated leaves. The decrease in ABA that occurred despite the block to export and despite continuing stress was attributed to changes in the synthesis or metabolism of ABA within the leaf. The probable rate of export of ABA from leaves, calculated from the changes in its concn. due to girdling, was highest at the time of most rapid ABA accumulation and declined thereafter. The percentage export of recently assimilated C declined similarly. However, the probable absolute rate of export of photosynthate, computed from stomatal conductance and [14C]-export measurements, was not uniquely related to that of AB

    Metabolic control of embryonic dormancy in apple seed: seven decades of research

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    A biochemical mechanism for hybrid vigour

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