2,077 research outputs found

    Interannual to Decadal Variability of Atlantic Water in the Nordic and Adjacent Seas

    Get PDF
    Warm salty Atlantic Water is the main source water for the Arctic Ocean and thus plays an important role in the mass and heat budget of the Arctic. This study explores interannual to decadal variability of Atlantic Water properties in the Nordic Seas area where Atlantic Water enters the Arctic, based on a reexamination of the historical hydrographic record for the years 1950-2009, obtained by combining multiple data sets. The analysis shows a succession of four multi-year warm events where temperature anomalies at 100m depth exceed 0.4oC, and three cold events. Three of the four warm events lasted 3-4 years, while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions. Three of the four warm events were accompanied by elevated salinities consistent with enhanced ocean transport into the Nordic Seas, with the exception of the event spanning July 1989-July 1993. Of the three cold events, two lasted for four years, while the third lasted for nearly 14 years. Two of the three cold events are associated with reduced salinities, but the cold event of the 1960s had elevated salinities. The relationship of these events to meteorological conditions is examined. The results show that local surface heat flux variations act in some cases to reinforce the anomalies, but are too weak to be the sole cause

    Phosphorus loss from soil to water.

    Get PDF
    End of Project ReportThe work described under this project covers field work on phosphorus(P) loss from soil to water under field conditions. In addition two International Workshops on P loss to water, held in Ireland in 1995 and 1998, are also covered under this project. The results indicate that P loss to water is a complex process and it is influenced by a number of factors, including hydrology of the soil, rates and timing of P application and soil P levels. Most work on this subject indicates that there is a positive relationship between soil test P levels and P loss to water. There is need for further work to establish the relative contribution of the different variables involved in P loss from soil to water for different soils and farming conditions. This should help provide answers to the most sustainable methods to minimise losses of P to water and ensure that agricultural production is compatible with good water quality.European Union Structural Funds (EAGGF

    An assessment of the long-term effects of three phosphorus fertiliser regimes on soil phosphorus and sward condition.

    Get PDF
    End of Project ReportA grazing trial using beef animals (mean weight 260 kg) was used to determine optimum soil phosphorus levels for dry stock farming. · The trial commenced in 1968. There were three fertiliser P treatments, 0, 15 and 30 kg P/ha applied annually. There were two stocking rates, 3300 and 2400 kg liveweight at turn out, respectively. Animals were rotationally grazed around six paddocks per treatment and stocking rates were reduced in June and September to match feed supply. The trial continued until 1998. ¸ Nitrogen was applied at a rate of 220 kg/ha per year to all treatments. ¹ Liveweight gains/ha/year were monitored annually. Soil P levels were monitored by sampling to 10 cm depth. º The distribution of phosphorus in the soil was recorded by analysing P levels at various depths from 0-2 mm to 100 cm. Botanical composition was recorded at the commencement of the trial and again in 1997. Phosphorus levels in herbage were also recorded. » An analysis of the liveweight gain data showed that for optimum output a Soil Index of 3 (Morgans P between 6.1 and 10.0 mg/l) is the target Soil P Index. ¼ Phosphorus recovery (as expressed by percentage of P fertiliser recovered in product) in the P30 treatments was low and was better in the P15 treatments. ½ The vast bulk of P accumulated near the surface of the soil, but there was some evidence of movement down the profile in the P30 treatment over a 30 year period. The soil P status influenced both the botanical composition of the sward and the P content in the herbage. The perennial ryegrass content declined on the zero P treatment, while there were no significant differences between the P15 and P30 treatments. The P concentration in the herbage in the zero P treatments were not sufficient for healthy growth of plants or animals.E u ropean Union Structural Funding (EAGGF

    Определение оптимальных параметров источника рентгеновского излучения на базе малогабаритного ускорителя электронов

    Get PDF
    Проведено моделирование спектров рентгеновского излучения, генерируемого электронами с энергией 4…10 МэВ в мишенях из различных материалов и разной толщины. Определены оптимальные параметры мишени-конвертора для использования ее в медицинских источниках монохроматического рентгеновского излучения на базе малогабаритных электронных ускорителей. Проведены оценки интенсивности излучения и сравнение источников на базе разных ускорителей

    Ex-situ evaluation of PTFE coated metals in a proton exchange membrane fuel cell environment

    Get PDF
    Metallic-based bipolar plates exhibit several advantages over graphite-based plates, including higher strength, lower manufacturing cost and better electrical conductivity. However, poor corrosion resistance and high interfacial contact resistance (ICR) are major challenges for metallic bipolar plates used in proton exchange membrane (PEM) fuel cells. Corrosion of metallic parts in PEM fuel cells not only increases the interfacial contact resistance but it can also decrease the proton conductivity of the Membrane Electrode Assembly (MEA), due to catalyst poisoning phenomena caused by corrosive products. In this paper, a composite coating of polytetrafluoroethylene (PTFE) was deposited on stainless steel alloys (SS304, SS316L) and Titanium (G-T2) via a CoBlast™ process. Corrosion resistance of the coated and uncoated metals in a simulated PEM fuel cell environment of 0.5 M H2SO4 + 2 ppm HF at 70 °C was evaluated using potentiodynamic polarisation. ICR between the selected metals and carbon paper was measured and used as an indicator of surface conductivity. Scanning Electron Microscopy (SEM), 3D microscopy, Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), and contact angle measurements were used to characterise the samples. The results showed that the PTFE coating improved the hydrophobicity and corrosion resistance but increased the ICR of the coated metals due to the unconductive nature of such coating. Thus, it was concluded that it is not fully feasible to use the PTFE alone for coating metals for fuel cell applications and a hybrid coating consisting of PTFE and a conductive material is needed to improve surface conductivity.Enterprise Irelan

    RAPPRESENTAZIONE IN CARTA DELLE CARATTERISTICHE DEI SENTIERI AI FINI DELLA MITIGAZIONE DEL RISCHIO GEOMORFOLOGICO

    Get PDF
    L’ambiente naturale di alcuni particolari ambiti geografici è in rapida evoluzione non solo per quanto riguarda le sue variabili, legate alle tendenze climatiche in atto, ma anche in relazione all’aumentata frequentazione turistica. La maggiore diffusione dei mezzi di risalita in montagna e di navigazione lungo le coste, rende possibile l’accesso anche a siti altrimenti difficilmente raggiungibili: ciò porta ad un contatto rapido e diretto con ambienti talvolta mutevoli in tempi brevi. La crescente richiesta di una maggiore conoscenza dell’ambiente naturale, che si esplica per lo più attraverso la frequentazione della rete sentieristica, implica la necessità di abbinare alle proposte di percorsi ed itinerari, note illustrative e carte tematiche di immediata lettura, che evidenzino sia i siti di interesse naturalistico - culturale sia le possibili situazioni di rischio e di difficoltà di percorrenza degli itinerari stessi. Esistono infatti alcuni elementi morfologici del territorio che di per sé non costituiscono una pericolosità in senso stretto ma che, a seconda delle capacità del fruitore, possono essere fonte indiretta di danno, in quanto rendono difficile l’attraversamento di alcuni punti specifici o la percorrenza di particolari tratti di sentiero. Contemporaneamente la stagionalità in alcune regioni climatiche e la variabilità meteorologica possono incrementare sia la pericolosità sia la vulnerabilità e di conseguenza il rischio per il frequentatore. Obiettivo del presente lavoro è quello di proporre una simbologia adeguata da inserire sulle carte dei sentieri, e più specificatamente su quelle geoturistiche, per una rapida e facile identificazione di specifiche situazioni riscontrabili lungo itinerari: questi simboli, che dovranno riferirsi solo alla percorribilità dell’itinerario e non alla valorizzazione naturalistica dello stesso, andranno rappresentati su base topografica separata, al fine di non appesantire la lettura dell’elaborato cartografico principale e dovranno fornire solo informazioni oggettive che saranno poi interpretate dal fruitore dell’itinerario. La simbologia e le note terranno conto sia delle caratteristiche costanti dei sentieri che degli elementi variabili, in funzione anche delle condizioni climatiche o stagionali, a seconda dei diversi ambienti interessati

    Increasing compliance with wearing a medical device in children with autism

    Full text link
    Health professionals often recommend the use of medical devices to assess the health, monitor the well-being, or improve the quality of life of their patients. Children with autism may present challenges in these situations as their sensory peculiarities may increase refusals to wear such devices. To address this issue, we systematically replicated prior research by examining the effects of differential reinforcement of other behavior (DRO) to increase compliance with wearing a heart rate monitor in 2 children with autism. The intervention increased compliance to 100% for both participants when an edible reinforcer was delivered every 90 s. The results indicate that DRO does not require the implementation of extinction to increase compliance with wearing a medical device. More research is needed to examine whether the reinforcement schedule can be further thinned

    The interactive effects of fertiliser nitrogen with dung and urine on nitrous oxide emissions in grassland

    Get PDF
    The authors wish to thank the Environmental Protection Agency for funding support under the Environmental Research Technological Development and Innovation programme and the Irish Department of Agriculture, Food and the Marine for funding support (Grant numbers RSF 13S430 and 11S138).peer-reviewedNitrous oxide (N2O) is an important and potent greenhouse gas (GHG). Although application of nitrogen (N) fertiliser is a feature of many grazing systems, limited data is available on N2O emissions in grassland as a result of the interaction between urine, dung and fertiliser N. A small plot study was conducted to identify the individual and interactive effects of calcium ammonium nitrate (CAN) fertiliser, dung and urine. Application of CAN with dung and urine significantly increased the mass of N2O-N emission. Importantly, the sum of N2O-N emitted from dung and CAN applied individually approximated the emission from dung and CAN fertiliser applied together, that is, an additive effect. However, in the case of urine and CAN applied together, the emission was more than double the sum of the emission from urine and CAN fertiliser applied individually, that is, a multiplicative effect. Nitrous oxide emissions from dung, urine and fertiliser N are typically derived individually and these individual emission estimates are aggregated to produce estimates of N2O emission. The presented findings have important implications for how individual emission factors are aggregated; they suggest that the multiplicative effect of the addition of CAN fertiliser to urine patches needs to be taken into account to refine the estimation of N2O emissions from grazing grasslands.The authors wish to thank the Environmental Protection Agency for funding support under the Environmental Research Technological Development and Innovation programme and the Irish Department of Agriculture, Food and the Marine for funding support (Grant numbers RSF 13S430 and 11S138)
    corecore