996 resultados para corn yield


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This study examines the performance of digital ink-jet printing on cationized cotton treated with polyepichlorohydrin-dimethylamine (PECH-amine). The results show that the color yield of ink-jet printing with reactive inks on cationic modified cotton is much greater than that on untreated cotton. The effect on the increase of color yield by cationic modification is greater than that by preparation with alkali, urea, and thickener. The reason for this is that introducing positively charged sites increases dye uptake and dye fixation on cationized cotton. The results also show that cationic modification with PECH-amine decreases the rub fastness but increases the wash fastness of the treated cotton.

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Regression analysis has shown that recovery rates are determined by a variety of conditions at the time of default. These conditions can be broken into five major categories: (1) a security's seniority within the capital structure of the defaulting firm, (2) the type of default event, (3) firm-specific factors, (4) industry-specific factors, and (5) macroeconomic factors. Expectations of these inputs determine the expected recovery rate if default were to occur, thereby determining credit ratings and security prices. Although it is widely understood how recovery rate estimates influence credit rating assignments (the higher the expected recovery rate, the higher the assigned credit rating), no research, to the best of my knowledge, has investigated the reasons why higher rated securities recover more than lower rated securities in the event of default. Specifically, this paper will empirically investigate why securities originally rated investment grade, fallen angels, recover more than securities originally rated high yield in the event of default.

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Culture-based fish yield in non-perennial reservoirs of Sri Lanka was related to reservoir morphometry and stocking density. The reservoirs were stocked mainly with fingerlings of one Chinese and three Indian major carp species, common carp, Cyprinus carpio L., and the genetically improved farmed tilapia strain of Nile tilapia, Oreochromis niloticus (L.), at four pre-determined species combinations and a range of stocking densities [SD (fingerlings ha−1)]. Twenty-three reservoirs were harvested successfully at the end of the culture period of 2002–2003. Basic limnological and morphometric parameters, including shoreline development (DL) and shoreline area ratio (RLA), were estimated for each of the 23 reservoirs. Bray–Curtis similarity and non-metric multidimensional scaling using mean values of limnological data revealed that reservoirs could be ordinated into two major clusters, one with intact sample distribution due to similar trophic characteristics and the other with scattered sample distribution. Reservoirs in the cluster with similar trophic characteristics showed significant correlation (P < 0.05) between RLA and total fish yield (Y). A multiple regression equation, Y = −693 + 4810 RLA + 0.484 SD, was generated to estimate fish harvest in relation to SD.

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The indentation slope curve from a spherical indentation on elastic-plastic materials is examined. By comparing it with that of an linear elastic material of the same elastic properties, we found that the start point of plastic yielding for an elastic-plastic material can be easily located from the indentation slope curve. Based on this analysis, a simple but effective method is proposed to measure the plastic yield stress of very small samples from a spherical nano-indentation slope curve.

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A well designed runner and feeding system should produce castings with minimal defects and low pour weight. This thesis investigates how the filling regime and solidification of the mould influences defects in the castings produced from that mould. Design guidelines to reduce such defects are proposed and tested. An existing shrinkage fault in a Grey Iron disc brake casting is simulated using a commercial finite-difference computer program. Three criteria are used to predict the defect and the effect of changes to the feeder geometry. Critical Fraction Solidification analysis is used to determine whether the feeder remains in liquid contact with the casting during solidification and this approach is shown to correctly predict the presence or absence of porosity* The feeder block is extended below the ingate of the casting to improve liquid contact between the casting and feeder without significantly increasing the feeder mass. Plant trials confirm the change to the feeder eliminates the porosity defect. The runner system and mould venting for a thin walled Ductile Iron casting are investigated. Trials show that by setting the total mould vent area to be greater than the net ingate area of the castings, the cold-shut frequency is halved. A method for runner system design based on peak linear flow velocity in the runner during mould filling is proposed. A new pressurised runner system produces castings with significantly fewer defects and reduced pour weight when runner areas are designed to maintain peak velocity below 1 m/s. Peak velocity and magnesium levels are demonstrated to be critical factors in the elimination of cold-shut defects. A pressurised runner system is also shown to isolate inclusion defects from castings more effectively than an unpressurised system. From this work, a technique is proposed which allows the yield of an existing runner and feeder system for iron castings to be improved with confidence in the results.

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C60 has been shown to give increased sputter yields and, hence, secondary ions when used as a primary particle in SIMS analysis. In addition, for many samples, there is also a reduction in damage accumulation following continued bombardment with the ion beam. In this paper, we report a study of the impact energy (up to 120 keV) of C60 on the secondary ion yield from a number of samples with consideration of any variation in yield response over mass ranges up to m/z 2000. Although increased impact energy is expected to produce a corresponding increase in sputter yield/rate, it is important to investigate any increase in sample damage with increasing energy and, hence, efficiency of the ion beams. On our test samples including a metal, along with organic samples, there is a general increase in secondary ion yield of high-mass species with increasing impact energy. A corresponding reduction in the formation of low-mass fragments is also observed. Depth profiling of organic samples demonstrates that when using C60, there does not appear to be any increase in damage evident in the mass spectra as the impact energy is increased.

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The effects of animal species (AS; Angora goats, Merino sheep, mixed-grazed goats and sheep at the ratio of 1:1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on the liveweight, body condition score, carcass yield and mortality of goats and sheep were determined in a replicated experiment on improved annual temperate pastures in southern Australia from 1981 to 1984. The pattern of liveweight change was similar for both species with growth from pasture germination in autumn until maturation in late spring followed by weight loss. In winter, sheep grew faster than goats (65 versus 10 g/day, P < 0.05). In mixed-grazed treatments between November and December goats either grew when sheep were losing weight or goats lost less weight than sheep (P < 0.01). Both AS (P < 0.001) and SR (P < 0.001) affected liveweight of sheep and an AS SR interaction (P <  0.05) affected liveweight of goats. Mixed-grazed sheep were heavier than separately grazed sheep at all SR with a mean difference at 10 and 12.5/ha of 4.6 kg. Mixed-grazed goats at 10/ha were heavier than separately grazed goats from the end of the second year of the experiment, but at 12.5/ha, separately grazed goats maintained an advantage over mixed-grazed goats, with a 9.4-kg mean difference in December (P < 0.05). Body condition scores of goats and sheep declined with increasing SR; they were highest in late spring and were highly correlated with liveweight (r2 > 0.8). Both AS and SR affected (P < 0.001) carcass weight and GR tissue depth as a direct result of differences in liveweight. Adjusting for differences in carcass weight negated AS effects on GR tissue depth. The carcass weights of sheep and goats increased by similar amounts for each 1-kg increase in liveweight. Mortality of sheep (3.1% p.a.) was unaffected by AS or SR. An AS SR interaction indicated mortality of separately grazed goats at 12.5/ha and mixed-grazed goats at 10 and 12.5/ha were higher (P < 0.05) than all other goat (29 versus 9%) and sheep treatments, primarily because of increased susceptibility to cold stress. Disease prevalence differed between sheep and goats. Mixed grazing of Merino sheep and Angora goats produced complementary and competitive effects depending upon the SR. Goats used summer pasture better but winter pasture less well for liveweight gain than sheep. Angora goats should not be grazed alone or mixed grazed with sheep on annual temperate pastures at SR greater than that recommended for Merino sheep and the evidence indicates a lower SR will reduce risks associated with mortality.

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In general, rock masses are inhomogeneous, discontinuous media composed of rock material and naturally occurring discontinuities such as joints, fractures and bedding planes. Because of these features, the strength of rock masses is notoriously difficult to assess. Nonetheless, many criteria have been proposed for estimating rock mass strength. Based on the finite element upper and lower bound limit analysis methods, this study examined two empirical yield criteria for rock masses, the Hoek-Brown failure criterion (2002) and the Douglas criterion (2002). The comparisons showed that very different results may be obtained using the same input parameters. Therefore, it is interesting to discuss the source of these differences.