3,200 research outputs found

    Tile drainage for increased production

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    Organized drainage districts in Iowa include approximately 6 million acres of land, representing an original investment of over $75,000,000. There are 18,519 miles of public drainage improvements (ditches, tile lines and levees). There is no record of the immense amount of private drainage work which has been done in Iowa, but it probably is far greater in extent and is more evenly spread over the state than the public drainage improvement. In spite of this, many thousands of acres of crops were lost or badly damaged in 1942 and 1943 because of inadequate drainage. Production of food can be increased by bringing into production much low, level and fertile Iowa land which is not being farmed because it is too wet. Efficiency in production also can be increased. Countless seepy hillsides in the rolling sections of the state are unproductive and interfere greatly with field operation of equipment

    Variables associated with performance of an active limb movement following within-session instruction in people with and people without low back pain

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    Modification of a movement pattern can be beneficial in decreasing low back pain (LBP) symptoms. There is variability, however, in how well people are able to modify performance of a movement. What has not been identified is the factors that may affect a person’s ability to modify performance of a movement. We examined factors related to performance of active hip lateral rotation (HLR) following standardized instructions in people with and people without LBP. Data were collected during performance of HLR under 3 conditions: passive, active, and active instructed. In people with LBP, motion demonstrated during the passive condition (r=0.873, P<0.001), motion demonstrated during the active condition (r=0.654, P=0.008), and gender (r=0.570, P=0.027) were related to motion demonstrated during the active-instructed condition. Motion demonstrated during the passive condition explained 76% (P<0.001) of the variance in motion demonstrated during the active-instructed condition. A similar relationship did not exist in people without LBP. The findings of the study suggest that it may be important to assess motion demonstrated during passive HLR to determine how difficult it will be for someone with LBP to modify the performance of HLR. Prognosis should be worst for those who display similar movement patterns during passive HLR and active-instructed HLR

    Nitrogen balance and urine, serum and plasma composition of growing pigs fed on raw or heat-treated field peas (Pisum sativum)

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    Experiments were conducted to determine the effect of heating field peas (Pisum sativum) on the N balance and urine, serum and plasma composition of growing pigs. In the first experiment, four diets containing raw field peas (cv. Wirrega) or field peas heated to 150° (cv. Wirrega), 165° (cv. Wirrega) or 150° (cv. Dundale) for 15 min respectively were formulated to contain 1.15 g ileal digestible N/MJ digestible energy (DE) and 0.36 g lieal digestible lysine/MJ DE in a sugar-based diet. Digestibility estimates were based on those for the Dundale cultivar of field peas used in previous experiments. Total urine and faeces collection from eight pigs was conducted over two 7 d collection periods with a 7 d diet change-over period. Serial blood sampling from the external jugular vein was conducted on the final day of each collection period. There was no significant difference (P < 0.05) in the N balance or apparent biological value of the field-pea treatments. Pigs fed on diets containing peas heated to 150° (cv. Wirrega) or 165° (cv. Wirrega) had a significantly lower (P < 0.01) daily output of urea and uric acid in the urine, and depressed serum protein and serum urea concentrations. Plasma lysine concentration and daily urine lysine output were not significantly different (P < 0.05) in pigs fed on heated peas. Protein excretion in the urine of pigs fed on diets containing peas heated to 165° increased 3–7 times (depending on estimation technique) the level observed in pigs fed on diets containing raw peas. A second experiment was conducted to determine the apparent ileal digestibility of N and amino acids in cv. Wirrega field peas. This study revealed that N digestibility (0.44) and lysine digestibility (0.35) in peas heated to 165° were significantly lower than the cv. Dundale estimates (0.57 and 062 respectively) used in diet formulations. The depressed serum and urine variables in pigs fed on heated peas were attributed to overestimation of digestibility. The results exemplify the fact that it is not possible to draw general conclusions as to the effects of heat on any particular protein concentrate. Variability in N balance experiments and problems associated with urine analysis are suggested as likely reasons for the current study not reflecting poor utilization of ileal digestible lysine from heat-treated field peas. Despite considerable variation in the results, it is possible that a large proportion of non-utilizable amino acids in heated field peas may be excreted from the pig via the urine in the form of a protein

    Pilot-Scale Continuous-Flow Hydrothermal Liquefaction of Filamentous Fungi

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    This study examined the potential of using the filamentous fungus Rhizopus oligosporus as a feedstock for hydrothermal liquefaction (HTL). The fungal biomass, cultivated in thin stillage from a corn ethanol plant, was processed at pilot-scale using a 1.5-L capacity continuous-flow HTL system. HTL operating conditions of 300–400 °C at 27 MPa for 12–30 min were tested. Biocrude yields ranging from 48.2 to 60.9% were obtained. At low reaction temperatures (300 °C), yields as high as 59.9% could still be achieved. Aside from the least severe reaction condition studied (300 °C, 12 min), neither the yield nor elemental composition of the biocrude was significantly impacted by residence time or temperature, as is typically seen with batch reactors. Similarities in the biochemical and elemental composition between R. oligosporus and microalgae resulted in biocrude yields that were comparable to those previously reported for continuous-flow systems using microalgae. These findings demonstrate the viability of using fungal biomass as a feedstock for the HTL process, and they show that lower temperatures can be used at pilot-scale while still achieving maximal yields

    Language motivation in a reconfigured Europe: access, identity, autonomy

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    In this paper, I propose that we need to develop an appropriate set of conceptual tools for examining motivational issues pertaining to linguistic diversity, mobility and social integration in a rapidly changing and expanding Europe. I begin by drawing on research that has begun to reframe the concept of integrative motivation in the context of theories of self and identity. Expanding the notion of identity, I discuss the contribution of the Council of Europe's European Language Portfolio in promoting a view of motivation as the development of a plurilingual European identity and the enabling of access and mobility across a multilingual Europe. Next, I critically examine the assumption that the individual pursuit of a plurilingual identity is unproblematic, by highlighting the social context in which motivation and identity are constructed and embedded. To illuminate the role of this social context, I explore three inter-related theoretical frameworks: poststructuralist perspectives on language motivation as 'investment'; sociocultural theory; and theories of autonomy in language education. I conclude with the key message that, as with autonomy, language motivation today has an inescapably political dimension of which we need to take greater account in our research and pedagogical practice

    The mass of the neutron star in Vela X-1 and tidally induced non-radial oscillations in GP Vel

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    We report new radial velocity observations of GP Vel/HD77581, the optical companion to the eclipsing X-ray pulsar Vela X-1. Using data spanning more than two complete orbits of the system, we detect evidence for tidally induced non-radial oscillations on the surface of GP Vel, apparent as peaks in the power spectrum of the residuals to the radial velocity curve fit. By removing the effect of these oscillations (to first order) and binning the radial velocities, we have determined the semi-amplitude of the radial velocity curve of GP Vel to be K_o=22.6+/-1.5 km/s. Given the accurately measured semi-amplitude of the pulsar's orbit, the mass ratio of the system is 0.081+/-0.005. We are able to set upper and lower limits on the masses of the component stars as follows. Assuming GP Vel fills its Roche lobe then the inclination angle of the system, i=70.1+/-2.6 deg. In this case we obtain the masses of the two stars as M_x=2.27 +/-0.17 M_sun for the neutron star and M_o=27.9+/-1.3 M_sun for GP Vel. Conversely, assuming the inclination angle is i=90 deg, the ratio of the radius of GP Vel to the radius of its Roche lobe is beta=0.89+/-0.03 and the masses of the two stars are M_x=1.88+/-0.13 M_sun and M_o=23.1+/-0.2 M_sun. A range of solutions between these two sets of limits is also possible, corresponding to other combinations of i and beta. In addition, we note that if the zero phase of the radial velocity curve is allowed as a free parameter, rather than constrained by the X-ray ephemeris, a significantly improved fit is obtained with an amplitude of 21.2+/-0.7 km/s and a phase shift of 0.033+/-0.007 in true anomaly. The apparent shift in the zero phase of the radial velocity curve may indicate the presence of an additional radial velocity component at the orbital period.Comment: Accepted for publication in Astronomy & Astrophysic

    Reappraising David Livingstone's The Geographical Tradition:A Quarter of a Century On

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    The information, practices and views in this article are those of the author(s) and do not necessarily reflect the opinion of the Royal Geographical Society (with IBG). © 2019 Royal Geographical Society (with the Institute of British Geographers). The quarter of a century since the publication of David Livingstone's The Geographical Tradition in 1992 provides an apt moment to reflect on the book's theses, lacunae, and legacies, and to take stock of the ways in which its provocations and reception might instruct the wider project of rendering the discipline's history. In framing this themed intervention, we engage the assertion that contextualisers need contextualising; there exists scope to heighten awareness of the location within time, space and culture from which contextualist historiographies of geography are written. We call attention to the meaning and implications of the particular and situated contextualist methodology mobilised and executed in The Geographical Tradition
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