480 research outputs found

    Establishment of switchgrass in corn across a landscape gradient: Establishment, yield, and quality of biomass feedstock

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    Biofuel production in the United States is expected to offset a significant portion of current fuel use through continued use of corn (Zea mays L.) grain and increasingly from alternative feedstocks. Switchgrass (Panicum virgatum L.) is one such species with potential to be used as an alternative feedstock, but establishment is slow and requires long term commitment of land to reach maximum productivity. Switchgrass can be established while producing a corn crop using 2-4-D and atrazine herbicide and seeding switchgrass prior to corn planting, reducing the risk of producing switchgrass as a crop. Relative performance of both corn and switchgrass in the landscape can vary and can influence productivity. An experiment was conducted which examined performance of corn during establishment of `Cave-in-Rock\u27 and `Kanlow\u27 switchgrass, stand frequency in the following year, subsequent yield, and composition of harvested switchgrass biomass across a toposequence of landscape positions. Seeding switchgrass reduced yields from 11.6 Mg*ha-1 to 9.6 Mg*ha-1 and from 10.8 Mg*ha-1 to 8.3 Mg*ha-1, for grain and stover, respectively. Establishment stand frequencies were adequate in all landscape positions and frequencies ranging from 39 to 82 percent. Yield and cellulose concentration of subsequent year switchgrass biomass was greater for `Kanlow\u27. Nitrogen concentration was lower in `Kanlow\u27, but overall N removal was greater due to higher yield. Landscape position effect was demonstrated in the floodplain only, with floodplain position higher in total dry matter yield, ash content, N removal, and cellulose. Floodplain position biomass was lower in hemicellulose and total C. Switchgrass can be established in all landscape position when seeded prior to corn planting, subsequent composition of switchgrass varied by variety and landscape position. More years of data are needed to confirm these biomass quality differences between variety and landscape position

    ISU Student Organic Farm* – 2008 Field Season

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    The ISU Student Organic Farm had a good learning year. This is the third year of the farm at its current location and much is happening. Our perennials are now fully established and include red raspberries, strawberries, asparagus, and rhubarb. The 10 surviving fruit trees in their third year of establishment should now begin bearing. The wet spring caused a slow start but we were able to plant a variety of vegetables in our 24, 4 ft × 150 ft vegetable beds. Beds contained beans, peas, tomatoes, potatoes, eggplants, onions, various cucurbits, and various brassicas

    Farm-scale costs and returns for second generation bioenergy cropping systems in the US Corn Belt

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    While grain crops are meeting much of the initial need for biofuels in the US, cellulosic or second generation (2G) materials are mandated to provide a growing portion of biofuel feedstocks. We sought to inform development of a 2G crop portfolio by assessing the profitability of novel cropping systems that potentially mitigate the negative effects of grain-based biofuel crops on food supply and environmental quality. We analyzed farm-gate costs and returns of five systems from an ongoing experiment in central Iowa, USA. The continuous corn cropping system was most profitable under current market conditions, followed by a corn–soybean rotation that incorporated triticale as a 2G cover crop every third year, and a corn–switchgrass system. A novel triticale–hybrid aspen intercropping system had the highest yields over the long term, but could only surpass the profitability of the continuous corn system when biomass prices exceeded foreseeable market values. A triticale/sorghum double cropping system was deemed unviable. We perceive three ways 2G crops could become more cost competitive with grain crops: by (1) boosting yields through substantially greater investment in research and development, (2) increasing demand through substantially greater and sustained investment in new markets, and (3) developing new schemes to compensate farmers for environmental benefits associated with 2G crops

    Ejecta Evolution Following a Planned Impact into an Asteroid: The First Five Weeks

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    The impact of the DART spacecraft into Dimorphos, moon of the asteroid Didymos, changed Dimorphos' orbit substantially, largely from the ejection of material. We present results from twelve Earth-based facilities involved in a world-wide campaign to monitor the brightness and morphology of the ejecta in the first 35 days after impact. After an initial brightening of ~1.4 magnitudes, we find consistent dimming rates of 0.11-0.12 magnitudes/day in the first week, and 0.08-0.09 magnitudes/day over the entire study period. The system returned to its pre-impact brightness 24.3-25.3 days after impact through the primary ejecta tail remained. The dimming paused briefly eight days after impact, near in time to the appearance of the second tail. This was likely due to a secondary release of material after re-impact of a boulder released in the initial impact, through movement of the primary ejecta through the aperture likely played a role.Comment: 16 pages, 5 Figures, accepted in the Astrophysical Journal Letters (ApJL) on October 16, 202

    The Early Royal Society and Visual Culture

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    Recent studies have fruitfully examined the intersection between early modern science and visual culture by elucidating the functions of images in shaping and disseminating scientific knowledge. Given its rich archival sources, it is possible to extend this line of research in the case of the Royal Society to an examination of attitudes towards images as artefacts –manufactured objects worth commissioning, collecting and studying. Drawing on existing scholarship and material from the Royal Society Archives, I discuss Fellows’ interests in prints, drawings, varnishes, colorants, images made out of unusual materials, and methods of identifying the painter from a painting. Knowledge of production processes of images was important to members of the Royal Society, not only as connoisseurs and collectors, but also as those interested in a Baconian mastery of material processes, including a “history of trades”. Their antiquarian interests led to discussion of painters’ styles, and they gradually developed a visual memorial to an institution through portraits and other visual records.AH/M001938/1 (AHRC

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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