206 research outputs found

    Technology evaluation of heating, ventilation, and air conditioning for MIUS application

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    Potential ways of providing heating, ventilation, and air conditioning for a building complex serviced by a modular integrated utility system (MIUS) are examined. Literature surveys were conducted to investigate both conventional and unusual systems to serve this purpose. The advantages and disadvantages of the systems most compatible with MIUS are discussed

    Thirty four Galloway Lochs: bathymetry, water quality and surface sediment diatom assemblages

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    Bathymetric descriptions of thirty four Galloway lochs are given together with water quality data for 1983-85. Results of diatom analysis of surface sediment collected from each loch are presented in tabular form. Lake water pH is generally lower in November samples than in samples collected in summer months. Cation exchange, following deposition of sea salts on peaty catchments, is suggested as a partial winter period. cause of pH depression in the winter period. Where lakes are deep enough, summer thermal stratification usually occurs between 5 and 8 m depth. Floristic diversity of the periphyton component of surface sediment diatom assemblages is shown to increase generally with pH

    Lake sediment toxicity in the UK: the role of trace metals and persistent organic pollutants

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    The aim of this project was to determine sediment toxicities to the sediment-dwelling chironomid Chironomus riparius and the free-swimming cladoceran Daphnia magna using empirical measurements from ten lakes distributed both geographically across the UK and across a predicted toxicity quotient gradient

    Evaluating macrophytes as indicators of anthropogenic pressures in rivers in Ireland

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    Publication history: Accepted - 6 January 2021; Published online - 10 February 2021.The ability of macrophytes to indicate pressures in rivers was assessed by comparing metrics for nitrate (NO3), ammonia (NH4), soluble reactive phosphorus (SRP), dissolved oxygen saturation (DO), pH (PH) and siltation (SUBS) with direct estimates of the pressures at 810 sites in the Republic of Ireland, supplemented with General Linear Models (GLMs). The bivariate and rank correlation coefficients using the full data range and the first and fourth quartiles of the river pressures varied between 0.22 and - 0.39 for NO3 and DO; they were smaller or not significant for the other four metrics. The GLMs provided evidence for an independent association between NO3 and the nitrate concentration and SUBS and ammonia, indicating some specificity for these metrics. Discriminating sites in the first and fourth quartiles produced Type II errors between 37 (PH) and 69% (NH4), with a mean of 50. As the pressure-impact relationships are not precise enough (low correlation coefficients) that evidence from a single macrophyte metric is reliable, combining the metric with evidence from other biological groups at one site or from three or more sites may be the most useful approach.Environmental Protection Agency of Ireland - funding of the DETECT Project (2015-W-LS-9) Burnley Borough Council - funding to AB

    The long-term response of lake nutrient and chlorophyll concentrations to changes in nutrient loading in Ireland's largest lake, Lough Neagh

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    The long-term response of chlorophyll-a (chl-a) to changing lake water nutrient concentrations and increasing water temperature was investigated in Lough Neagh, a large, hypereutrophic lake in Northern Ireland. Trends in external and internal nutrient loading and their relation to lake nutrient concentrations were also established. Lake water concentrations of total P (TP) have increased since the 1990s but were not correlated with catchment inputs, which showed no trend. The characteristics of internal loading of P have changed since the mid-1990s, with an earlier and larger mass of P released from the sediments each summer. Catchment inputs of total oxidised N (NOx) decreased from the peak value of 10,186T/yr in 1995 to 5,396T/yr in 2011, coinciding with a reduction in lake water concentrations. External inputs and lake concentrations of NOx were highly correlated (R=0.88). Water temperature increased approximately 1C and was a predictor of variation in chl-a from 1974 to 2012. After the peak chl-a concentration in 1993, dissolved inorganic N (DIN) also became an important predictor, accounting for almost half of the 44% variance explained by a hierarchical partition model. Decreasing log (DIN:TP) ratios suggest that N limitation of chl-a has become more important in the lake recently

    Acidification in the Cairngorms and Lochnagar: a palaeoecological assessment

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    Sensitive lakes in areas of the United Kingdom with moderate to high sulphur deposition have been acidified since the middle of the nineteenth century- (Battarbee et al. 1988). Regions such as Galloway, south west Scotland (eg. Flower and Battarbee 1983, Flower et al. 1987), Wales (eg. Battarbee et al. 1988, Fritz et aL 1990), Cumbria (eg. Battarbee et al 1988, Atkinson and Haworth 1990), and Rannoch Moor in the central Scottish Highlands (eg. Flower et al 1988) have been affected. This study extends the geographical survey of lake acidification to the Caimgorm and Lochnagar regions of north east Scotland (Figure 1). The Caimgorms and Lochnagar are areas of considerable conservation value, forming the largest single area of land over 1000 m in the UK. The Caimgorm mountain plateau is a National Nature Reserve, noted for its alpine flora and fauna, whilst the Lochnagar range is a Scottish Wildlife Trust reserve. A secondary- aim of the study was to evaluate the 11land-use 11 hypothesis (eg. Rosenqvist 1977, 1978, 1981) as a mechanism for lake acidification by examining high altitude sites with no active land-management. Sites selected are all remote, lie above the tree line and have undisturbed catchments. Lochnagar and the Caimgorms are situated on sensitive granite geology (Kinniburgh and Edmunds 1986, Wells et al. 1986) in an area of moderate acid deposition (c. 0.95 g S yr-1 ). It can be predicted that sensitive lakes in this area (those having Ca2 + values of <60 μeq i-1 ) will have acidified (Battarbee 1989)

    Palaeoecological evaluation of the recent acidification of Welsh lakes: 1. Llyn Hir, Dyfed

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    Palaeoecological evaluation of the recent acidification of Lochnagar, Scotland

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    Lochnagar, a high altitude, relatively deep, come lake, lies on the Royal Deeside ESUHC of Balmoral, in an area which experiences moderate levels of acid deposition, The loch catchment comprises granite bedrock and is dominated by bare rock but overlain in places with blanket peals, Lochnagar may thus be considered potentially susceptible to acidification, The contemporary pH of the loch water is c. 5,0
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