879 research outputs found

    The 'granite encapsulation' route to the safe disposal of Pu and other actinide

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    Waste actinides, including plutonium, present a long-term management problem and a serious security issue. Immobilisation in mineral or ceramic waste forms for interim storage is a widely proposed first step. The safest, most secure geological disposal for Pu is in very deep boreholes and we propose that the key step to combination of these immobilisation and disposal concepts is encapsulation of the waste form in cylinders of recrystallized granite. We discuss the underpinning science, focusing on experimental work, and consider implementation. Finally, we present and discuss analyses of zircon, UO2 and Ce-doped cubic zirconia from high pressure and temperature experiments in granitic melts that demonstrate the viability of this solution and that actinides can be isolated from the environment for millions, maybe hundreds of millions, of years

    Letter from B.E. Taylor to James B. Finley

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    Bezaleel Taylor writes to his grandfather James B. Finley. [Taylor is married to Finley\u27s granddaughter Catharine Rebecca Brooke (1824-1917), daughter of Elizabeth Finley and Rev. John Carrington Brooke]. Taylor wants to get into the business of selling books on commission. He seeks Finley\u27s input concerning the possibility of selling books through the Book Concern. Taylor has been elected mayor, but the position does not pay much. He needs more money to support his family. Brother James Taylor buried his little girl last week. Catharine and the children send their love. Abstract Number - 567https://digitalcommons.owu.edu/finley-letters/1863/thumbnail.jp

    Letter from B.E. Taylor to James B. Finley

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    Bezaleel Taylor writes to his grandfather James B. Finley. [Taylor is married to Finley\u27s granddaughter Catharine Rebecca Brooke (1824-1917), daughter of Elizabeth Finley and Rev. John Carrington Brooke]. Unfortunately, all members of the family have been sick with scarlet fever complicated by whooping cough. Francy has died (Minerva Francis Taylor, 1843-1849, died Feb. 27, 1849). Arvilla (Arvilla Ernestine Taylor, 1847-1929) and Clarybell (Eliza Clarabelle Taylor, 1845-1849) are both very ill. [Note: Clarabelle died a few weeks after the letter was written, March 28, 1849. See Ancestry.com]. Abstract Number - 439https://digitalcommons.owu.edu/finley-letters/1637/thumbnail.jp

    Letter from B.E. Taylor to James B. Finley

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    Bezaleel Taylor writes to his grandfather James B. Finley. [Taylor is married to Finley\u27s granddaughter Catharine Rebecca Brooke (1824-1917), daughter of Elizabeth Finley and Rev. John Carrington Brooke]. He reports on the status of the Methodist society in Hagerstown. Taylor writes about the new minister and the increasing interest in the church. Before the arrival of the new preacher there were difficulties and warfares within the society, and low attendance. The new minister is very well liked and things have greatly improved. He asks for Finley\u27s prayers. Abstract Number - 345https://digitalcommons.owu.edu/finley-letters/1543/thumbnail.jp

    Excavation at Aguas Buenas, Robinson Crusoe Island, Chile, of a gunpowder magazine and the supposed campsite of Alexander Selkirk, together with an account of early navigational dividers

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    Excavations were undertaken of a ruined building at Aguas Buenas, identified as an 18th-century Spanish gunpowder magazine. Evidence was also found for the campsite of an early European occupant of the island. A case is made that this was Alexander Selkirk, a castaway here from 1704 to 1709. Selkirk was the model for Defoe’s Robinson Crusoe. A detailed discussion is given of a fragment of copper alloy identifi ed as being from a pair of navigational dividers

    Vacuum polarization of a scalar field in wormhole spacetimes

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    An analitical approximation of for a scalar field in a static spherically symmetric wormhole spacetime is obtained. The scalar field is assumed to be both massive and massless, with an arbitrary coupling ξ\xi to the scalar curvature, and in a zero temperature vacuum state.Comment: 10 pages, RevTeX, two eps figure

    Influence of rate of inclusion of microalgae on the sensory characteristics and fatty acid composition of cheese and performance of dairy cows

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    Modification of milk and cheese fat to contain long-chain n-3 fatty acids (FA) by feeding microalgae (ALG) to dairy cows has the potential to improve human health, but the subsequent effect on the sensory attributes of dairy products is unclear. The objective was to determine the effect of feeding dairy cows different amounts of ALG that was rich in docosahexaenoic acid (DHA) on milk and cheese FA profile, cheese sensory attributes, and cow performance. Twenty Holstein dairy cows were randomly allocated to 1 of 4 dietary treatments in a 4 × 4 row and column design, with 4 periods of 28 d, with cheddar cheese production and animal performance measurements undertaken during the final 7 d of each period. Cows were fed a basal diet that was supplemented with ALG (Schizochytrium limancinum) at 4 rates: 0 (control, C), 50 (LA), 100 (MA), or 150 g (HA) of ALG per cow per day. We found that both milk and cheese fat content of DHA increased linearly with ALG feed rate and was 0.29 g/100 g FA higher in milk and cheese from cows fed HA compared with C. Supplementation with ALG linearly reduced the content of saturated FA and the ratio of n-6:n-3 FA in milk and cheese. Supplementation with ALG altered 20 out of the 32 sensory attributes, with a linear increase in cheese air holes, nutty flavor, and dry mouth aftertaste with ALG inclusion. Creaminess of cheese decreased with ALG inclusion rate and was positively correlated with saturated FA content. We also observed a quadratic effect on fruity odor, which was highest in cheese from cows fed HA and lowest in LA, and firmness and crumbliness texture, being highest in MA and lowest in HA. Supplementation with ALG had no effect on the dry matter intake, milk yield, or live weight change of the cows, with mean values of 23.1, 38.5, and 0.34 kg/d respectively, but milk fat content decreased linearly, and energy-corrected milk yield tended to decrease linearly with rate of ALG inclusion (mean values of 39.6, 38.4, 37.1, and 35.9 g/kg, and 41.3, 41.3, 40.5, and 39.4 kg/d for C, LA, MA, and HA, respectively). We conclude that feeding ALG to high-yielding dairy cows improved milk and cheese content of DHA and altered cheese taste but not cow performance, although milk fat content reduced as inclusion rate increased

    An observation of spin-valve effects in a semiconductor field effect transistor: a novel spintronic device

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    We present the first spintronic semiconductor field effect transistor. The injector and collector contacts of this device were made from magnetic permalloy thin films with different coercive fields so that they could be magnetized either parallel or antiparallel to each other in different applied magnetic fields. The conducting medium was a two dimensional electron gas (2DEG) formed in an AlSb/InAs quantum well. Data from this device suggest that its resistance is controlled by two different types of spin-valve effect: the first occurring at the ferromagnet-2DEG interfaces; and the second occuring in direct propagation between contacts.Comment: 4 pages, 2 figure

    Possible wormholes in a brane world

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    The condition R=0, where R is the four-dimensional scalar curvature, is used for obtaining a large class (with an arbitrary function of r) of static, spherically symmetric Lorentzian wormhole metrics. The wormholes are globally regular and traversable, can have throats of arbitrary size and can be both symmetric and asymmetric. These metrics may be treated as possible wormhole solutions in a brane world since they satisfy the vacuum Einstein equations on the brane where effective stress-energy is induced by interaction with the bulk gravitational field. Some particular examples are discussed.Comment: 7 pages, revtex4. Submitted to Phys. Rev.
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