10 research outputs found

    Comparative analysis of battery electric, hydrogen fuel cell and hybrid vehicles in a future sustainable road transport system

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    This paper compares battery electric vehicles (BEV) to hydrogen fuel cell electric vehicles (FCEV) and hydrogen fuel cell plug-in hybrid vehicles (FCHEV). Qualitative comparisons of technologies and infrastructural requirements, and quantitative comparisons of the lifecycle cost of the powertrain over 100,000 mile are undertaken, accounting for capital and fuel costs. A common vehicle platform is assumed. The 2030 scenario is discussed and compared to a conventional gasoline-fuelled internal combustion engine (ICE) powertrain. A comprehensive sensitivity analysis shows that in 2030 FCEVs could achieve lifecycle cost parity with conventional gasoline vehicles. However, both the BEV and FCHEV have significantly lower lifecycle costs. In the 2030 scenario, powertrain lifecycle costs of FCEVs range from 7360to7360 to 22,580, whereas those for BEVs range from 6460to6460 to 11,420 and FCHEVs, from 4310to4310 to 12,540. All vehicle platforms exhibit significant cost sensitivity to powertrain capital cost. The BEV and FCHEV are relatively insensitive to electricity costs but the FCHEV and FCV are sensitive to hydrogen cost. The BEV and FCHEV are reasonably similar in lifecycle cost and one may offer an advantage over the other depending on driving patterns. A key conclusion is that the best path for future development of FCEVs is the FCHEV.Fuel cell vehicle Electric vehicle Hybrid vehicle

    Techno-economic and behavioural analysis of battery electric, hydrogen fuel cell and hybrid vehicles in a future sustainable road transport system in the UK

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    This paper conducts a techno-economic study on hydrogen Fuel Cell Electric Vehicles (FCV), Battery Electric Vehicles (BEV) and hydrogen Fuel Cell plug-in Hybrid Electric Vehicles (FCHEV) in the UK using cost predictions for 2030. The study includes an analysis of data on distance currently travelled by private car users daily in the UK. Results show that there may be diminishing economic returns for Plug-in Hybrid Electric Vehicles (PHEV) with battery sizes above 20 kWh, and the optimum size for a PHEV battery is between 5 and 15 kWh. Differences in behaviour as a function of vehicle size are demonstrated, which decreases the percentage of miles that can be economically driven using electricity for a larger vehicle. Decreasing carbon dioxide emissions from electricity generation by 80% favours larger optimum battery sizes as long as carbon is priced, and will reduce emissions considerably. However, the model does not take into account reductions in carbon dioxide emissions from hydrogen generation, assuming hydrogen will still be produced from steam reforming methane in 2030.Fuel cell vehicle Electric vehicle Hybrid vehicle

    Enfermidades digitais em vacas de aptidão leiteira: associação com mastite clínica, metrites e aspectos epidemiológicos Foot diseases in dairy cows: association with clinical mastitis, metrites and predisposed factors

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    Utilizaram-se nesse estudo 5300 vacas de aptidão leiteira, provenientes de 80 propriedades rurais, que adotavam manejo intensivo ou semi-extensivo, com o objetivo de averiguar a existência de possível associação entre enfermidades digitais, mastite clínica e/ou metrite e identificar possíveis fatores de risco das enfermidades digitais. Em 325 (6,13%) vacas foram diagnosticados apenas enfermidades digitais, em 35 (0,66%) enfermidades digitais e mastite clínica, em 52 (0,98%) enfermidades digitais e metrite, em 28 (0,53%) enfermidades digitais, mastite clínica e metrite, em 128 (2,42%) apenas metrite, em 165 (3,11%) somente mastite clínica, e em 89 (1,68%) vacas metrite e mastite clínica. As mudanças bruscas na alimentação, o excesso de sujidades nas instalações, os pisos irregulares e abrasivos, a não utilização ou uso incorreto de pedilúvio, a falta de casqueamento preventivo, a ausência de quarentena, e a aquisição de animais sem a preocupação com o aspecto sanitário foram considerados os fatores de risco de maior ocorrência. Foi constatada diferença significativa entre a ocorrência de enfermidades digitais, mastite clínica e metrite, além de associação fraca entre tais enfermidades, concluindo-se que não houve relação expressiva entre enfermidades podais, mastite clínica e metrite em vacas lactantes.<br>With the objective to investigate a possible association between foot diseases, clinical mastitis and/or metritis and predisposing factors for foot diseases, 5300 dairy cows from 80 intensive and semi-intensive farms were used. In 325 (6.13%) cows only foot disease was diagnosed, in 35 (0.66%) foot disease and clinical mastitis, in 52 (0.98%) foot disease and metritis, in 28 (0.53%) foot disease, clinical mastitis and metritis, in 128 (2.42%) only metritis, in 165 (3.11%) only clinical mastitis, and in 89 (1.68%) cows metritis and clinical mastitis. Rapid changes in the diet, high exposure time of hoof horn to slurry and wet conditions, concrete floors, use of footbaths, low frequency of claw trimming, irregular quarantine, and no attention to health aspects during acquisition of the animals were considered as major risk factors for the occurrence of those diseases. The McNemar test for dependent samples showed significant statistical differences between the occurrence of foot disease, clinical mastitis and metritis, in spite of the poor association between those diseases. It was concluded that there was no expressive relationship between foot diseases, clinical mastitis and metritis in lactent cows

    Early intervention with high‐risk teenage mothers and their infants

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    DNA and Double-Stranded Oligonucleotides

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