16,487 research outputs found

    Estimation of pedigree errors in the UK dairy population using microsatellite markers and the impact on selection

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    The proportion of cows in the UK dairy herd whose sires were misidentified was estimated using DNA markers. Genetic marker genotypes were determined on 568 cows (from 168 milk samples and 400 hair samples) and 96 putative sires (from semen samples). The estimated pedigree error rate from the hair samples was 8.8%, and from the milk samples, 13.1%, giving an overall estimate of the error rate of 10%. This level of pedigree errors will have a relatively large impact on the efficiency of progeny testing and the accuracy of cow predicted breeding values. We predict a loss of response to selection of approximately 2 to 3% given this error rate

    Acidified and ultrafiltered recovered coagulants from water treatment works sludge for removal of phosphorus from wastewater

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    This study used a range of treated water treatment works sludge options for the removal of phosphorus (P) from primary wastewater. These options included the application of ultrafiltration for recovery of the coagulant from the sludge. The treatment performance and whole life cost (WLC) of the various recovered coagulant (RC) configurations have been considered in relation to fresh ferric sulphate (FFS). Pre-treatment of the sludge with acid followed by removal of organic and particulate contaminants using a 2kD ultrafiltration membrane resulted in a reusable coagulant that closely matched the performance FFS. Unacidified RC showed 53% of the phosphorus removal efficiency of FFS, at a dose of 20 mg/L as Fe and a contact time of 90 min. A longer contact time of 8 h improved performance to 85% of FFS. P removal at the shorter contact time improved to 88% relative to FFS by pre-acidifying the sludge to pH 2, using an acid molar ratio of 5.2:1 mol H+:Fe. Analysis of the removal of P showed that rapid phosphate precipitation accounted for >65% of removal with FFS. However, for the acidified RC a slower adsorption mechanism dominated; this was accelerated at a lower pH. A cost-benefit analysis showed that relative to dosing FFS and disposing waterworks sludge to land, the 20 year WLC was halved by transporting acidified or unacidified sludge up to 80 km for reuse in wastewater treatment. A maximum inter-site distance was determined to be 240 km above the current disposal route at current prices. Further savings could be made if longer contact times were available to allow greater P removal with unacidified RC

    Reuse of recovered coagulants in water treatment: An investigation on the effect coagulant purity has on treatment performance

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    Coagulant recovery offers many potential benefits to water treatment, by reducing chemical demand and waste production. The key obstacle to successful implementation is achieving the same levels of treatment quality and process economics as commercial coagulants. This study has evaluated the selectivity of pressure-filtration in the role of a low-cost coagulant recovery technology from waterworks sludge. The treatment performance of the purified recovered coagulant was directly compared to fresh and raw recovered coagulants. DOC and turbidity removal by recovered coagulants was close to that of commercial coagulants, indicating that coagulant can be successfully recovered and regenerated by acidifying waterworks sludge. However, performance was less consistent, with a much narrower optimum charge neutralisation window and 10ā€“30% worse removal performance under optimum conditions. This inferior performance was particularly evident for recovered ferric coagulants. The impact of this was confirmed by measuring THM formation potential and residual metals concentrations, showing 30ā€“300% higher THMFPs when recovered coagulants were used. This study confirms that pressure-filtration can be operated on an economically viable basis, in terms of mass flux and fouling. However, the selectivity currently falls short of the purity required for potable treatment, due to incomplete rejection of sludge contaminants

    Coagulant recovery and reuse for drinking water treatment

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    Coagulant recovery and reuse from waterworks sludge has the potential to significantly reduce waste disposal and chemicals usage for water treatment. Drinking water regulations demand purification of recovered coagulant before they can be safely reused, due to the risk of disinfection by-product precursors being recovered from waterworks sludge alongside coagulant metals. While several full-scale separation technologies have proven effective for coagulant purification, none have matched virgin coagulant treatment performance. This study examines the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies to attain virgin coagulant purity levels. The new suggested approach of alkali extraction of dissolved organic compounds (DOC) from waterworks sludge prior to acidic solubilisation of ferric coagulants provided the same 14:1 selectivity ratio (874 mg/L Fe vs. 61 mg/L DOC) to the more established size separation using ultrafiltration (1285 mg/L Fe vs. 91 mg/L DOC). Cation exchange Donnan membranes were also examined: while highly selective (2555 mg/L Fe vs. 29 mg/L DOC, 88:1 selectivity), the low pH of the recovered ferric solution impaired subsequent treatment performance. The application of powdered activated carbon (PAC) to ultrafiltration or alkali pre-treated sludge, dosed at 80 mg/mg DOC, reduced recovered ferric DOC contamination to <1 mg/L but in practice, this option would incur significant costs. The treatment performance of the purified recovered coagulants was compared to that of virgin reagent with reference to key water quality parameters. Several PAC-polished recovered coagulants provided the same or improved DOC and turbidity removal as virgin coagulant, as well as demonstrating the potential to reduce disinfection byproducts and regulated metals to levels comparable to that attained from virgin material

    Sunderland Software City: The Impact of a Collaborative Project to Develop the Software Industry within the North East of England

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    This paper uses a case study approach to evaluate the impact of a collaborative initiative within the North East of England which sets out to grow and sustain a software industry, based on the strengths of regional players. The project Sunderland Software City has the ambitious aim of developing the people, the infrastructure and the business and enterprise culture to create and sustain a software industry. This paper focuses upon the impact of the project, and presents some lessons learned to date

    Contemporary judgment on the growth of Hardyā€™s reputation as a novelist between 1971 and 1881

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    Thomas Hardy's first eight published novels appeared between 1871 and 1881, and were extensively reviewed by the London news papers and journals of opinion. The thesis is based mainly upon one hundred and twenty-six such reviews. Comparison of these reviews with the general standards employed in novel-reviewing and with the reception of eight contemporary works reveals the 'ordinariness' of Hardy's early books. His settings may be unusual in some cases, his style slightly bizarre, and some of his characters peculiar, but, unlike Meredith or James, he is not seen as blazing any new trails; unlike George Eliot he is not considered a writer of 'literature'; nor is he regarded as using the novel to convey a view of life, as did Gissing or Samuel Butler. Rather, the reviewers deal with him as they deal with Trollope or William Black, as one who writes fairly straightforwardly about fairly ordinary people and events. It is therefore not surprising to find some opinions that run counter to modern criticism: A Pair of Blue Eyes highly praised. The Trumpet-Major described as his masterpiece. The Return of the Native confusing the reviewers and arousing hostility, and even warm compliments for The Hand of Ethelberta and A Laodicean. Many reviewers were nevertheless perspicacious enough to realize that Hardy has extraordinary gifts: his ability to describe rural life and natural phenomena, his profound understanding of women's hearts his skill as a plot-maker. The reviewers generally admired and encouraged him at this stage of his development, and, in spite of finding the reviews confusing and even painful. Hardy may have had cause to be grateful to them, for they must have helped to create the following that enabled him to devote himself to his career as a novelist and to his calling to be a poet

    CCT, a Code to Automate the Design of Coupled Cavities

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    The CCT (Coupled Cavity Tuning) code automates the RF calculations and sizing of RF cavities for the CCL (Coupled Cavity Linac) structures of APT. It is planned to extend the code to the CCDTL (Coupled Cavity Drift Tube Linac). The CCT code controls the CCLFISH code, a member of the Poisson Superfish series of codes [1]. CCLFISH performs RF calculations and tunes the geometry of individual cavities, including an accelerating cavity (AC) and a coupling cavity (CC). CCT also relates the AC and CC by means of equations that describe the coupling slot between cavities. These equations account for the direct coupling, the next nearest neighbor coupling between adjacent AC's, and the frequency shifts in the AC and CC caused by the slot. Given design objectives of a coupling coefficient k, the pi/2 mode frequency, and the net frequency of the CC, the CCT code iterates to solve for the geometry of the AC and CC and the separation distance between them (this controls the slot size), satisfying the design objectives. The resulting geometry is used to automate CAD drawing preparation. The code can also be used in "as-designed" mode to calculate the frequencies and coupling of a specified configuration. An overview of the code is presented.Comment: Linac 2000, paper THB14, 3 pages, 3 figure

    Damage tolerant composite wing panels for transport aircraft

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    Commercial aircraft advanced composite wing surface panels were tested for durability and damage tolerance. The wing of a fuel-efficient, 200-passenger airplane for 1990 delivery was sized using grahite-epoxy materials. The damage tolerance program was structured to allow a systematic progression from material evaluations to the optimized large panel verification tests. The program included coupon testing to evaluate toughened material systems, static and fatigue tests of compression coupons with varying amounts of impact damage, element tests of three-stiffener panels to evaluate upper wing panel design concepts, and the wing structure damage environment was studied. A series of technology demonstration tests of large compression panels is performed. A repair investigation is included in the final large panel test

    Exploring Environmental-Economic Benefits from Agri-Industrial Diversification in the Sugar Industry: An Integrated Land Use and Value Chain Approach

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    The sugar industry in Queensland (Australia) is confronted with increasing economic pressure and environmental constraints. To explore whether agri-industrial diversification of the sugar industry provides a sustainable development pathway for the region, we develop a spatial environmental-economic approach that integrates a land use and value chain model with a hydrological model. Results indicate that agri-industrial diversification can lead to substantial increases in regional income, while at the same time increasing the resilience of a sugar industry facing decreasing sugar prices. Agri-industrial diversification drives land use diversification, which under current sugar prices does not lead to a reduction in sugarcane production. Water quality benefits from this land use diversification are mixed, and depend on the economic viability and erosion characteristics of the concerned production systems.spatial economics, environmental economics, value chains, agri-industries, water quality, Environmental Economics and Policy, Land Economics/Use, C6, O18, Q13, Q53,
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