1,575 research outputs found
Crop management in rows.
Trial 87M71
Effect of row spacing and stubble retention on the yield of wheat.
Location: Merredin Research Station.
Treatments, site management and results from 1987, 1988 and 1989 have been described in previous experimental summaries. Four row spacings (9, 18, 27 and 36 cm) are compared in either burnt or stubble retained plots, on a red brown earth on the Merredin Research Station. There are six replicates laid out in a randomised block design.
Trial 90ME32
Effect of row spacing and variety on the yield of wheat.
Location: duplex site at Crooks (see 1989 Experimental Summary)
This trial was carried out on the duplex soil site at Crooks (see 1989 Experimental Summary); in 1990, the wheat crop was sown after lupins, and aimed to look at the interaction between row spacing and variety of wheat. Varieties which differ in their canopy characteristics might be expected to differ in the rate at which they develop ground cover, and might therefore influence the partitioning of ET between soil evaporation and crop transpiration. The varieties Kuhn (low tillering, small leaf area) and Aroona (higher tillering, larger leaf area) were compared at row spacings of 9, 18 and 36 cm
Methane Fluxes from a High Intensity Seep Area west of Crimea, Black Sea
Methane seepage is a wide-spread phenomenon in the Black Sea with an increase in density and intensity west of the Crimea in the Paleo Dnepr area between 70 and 250m water depth. Within the EU funded project CRIMEA we studied the impact of high intensity seeps on the methane distribution in the water column and its possible transport into the atmosphere. Here we present data which allow flux calculations of free methane from an area of 1 by 1.23 miles between 80 and 95m water depth. Our calculations are based on direct and hydroacoustic flux measurements of single seeps or small-scaled seep areas (several m2); the spatial extrapolation of these fluxes use the very strong correlation between the bubble seep occurrence and a high backscattering seafloor; the temporal variability of bubble release was detected via the lander-based hydroacoustic system GasQuant.More than 1000 bubbling seep sites were identified during two cruises in 2003 and 2004 by hydroacoustic water column surveys. The hydroacoustic detection of bubbles uses the strong backscattering of the free gas phase caused by the great impedance difference of bubbles in water (equivalent to the detection of fish and their swim bladder). In echograms, bubble streams or even single bubbles can be detected, traced and used for special analyses such as bubble rising speed, bubble size and shrinking rates. Because of the flare-like appearance of bubble streams in echograms we call these features ’flares’.Parallel multi beam mapping allowed the detection of the seafloor morphology together with the spatial backscatter intensity of the seafloor. The combination of flare occurrences with high backscatter areas provided a very good correlation. Normalized, the backscatter ranged from -12.5 to 7.1 dB for an area of 4.23 km2. All seep positions plott in areas with more than -2.7 dB, which is almost the entire area of investigation (95.8 %). However, 75% of the flares occur within only 20.1% of the area, half of the flares occur in only 9.2% and 25% even occur in only 3.8% of the area with backscattering values above 2.4 dB. This correlation allows to predict and extrapolate active bubble seeps even without direct or hydroacoustic observations.One reason for the high backscattering seafloor are patches of carbonate cemented seafloor (formed via AOM) which typically occurs just below bright white Beggiatoa mats. In addition, high resolution seismic studies with a 5kHz sub-bottom profiler clearly show a shallow gas front in normally 3m sediment depth. In those areas where strong gas front reflectors dome up and reach the seafloor surface the backscatter values and flare density are the highest. This clearly shows that the bubbles released are fed from shallow gas which also might have an impact on the physical properties of the seafloor and its backscatter behaviour. Seeps in lower or even very low backscatter areas possibly indicate a rather young or weak activity which did not (so far) cause a remarkable carbonate cementation detectable during multi beam surveys.However, the backscatter data are the base for our spatial flux calculations which use direct bubble trapping to distinguish the flux rate from one single seep hole and hydroacoustic methods for small seep areas of several m2. Direct bubble flux measurements were performed with the submersible JAGO by trapping the bubbles with a funnel. Fluxes vary between 0.55 and 1.44 ml/s (or 1.98 to 5.18 l/h at in situ volume; or 0.24 to 0.64 mmol/s). Subsequent GC-based gas analyses onboard confirmed that the gas phase consists exclusively of methane. Visual observations by JAGO and towed camera systems showed bubble diameters between 1 and 15mm with typical sizes between 3 and 7mm. Together with bubble rising speeds of typically 25cm/s both attributes are in very good agreement with detailed hydroacoustic measurements using a dual frequency scientific echo sounder EK500 (120 and 38kHz). Flux estimat
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Caustic leaching of high-level radioactive tank sludge: A critical literature review
The Department of Energy (DOE) must treat and safely dispose of its radioactive tank contents, which can be separated into high-level waste (HLW) and low-level waste (LLW) fractions. Since the unit costs of treatment and disposal are much higher for HLW than for LLW, technologies to reduce the amount of HLW are being developed. A key process currently being studied to reduce the volume of HLW sludges is called enhanced sludge washing (ESW). This process removes, by water washes, soluble constituents such as sodium salts, and the washed sludge is then leached with 2--3 M NaOH at 60--100 C to remove nonradioactive metals such as aluminum. The remaining solids are considered to be HLW while the solutions are LLW after radionuclides such as {sup 137}Cs have been removed. Results of bench-scale tests have shown that the ESW will probably remove the required amounts of inert constituents. While both experimental and theoretical results have shown that leaching efficiency increases as the time and temperature of the leach are increased, increases in the caustic concentration above 2--3 M will only marginally improve the leach factors. However, these tests were not designed to validate the assumption that the caustic used in the ESW process will generate only a small increase (10 Mkg) in the amount of LLW; instead, the test conditions were selected to maximize leaching in a short period and used more water and caustic than is planned during full-scale operations. Even though calculations indicate that the estimate for the amount of LLW generated by the ESW process appears to be reasonable, a detailed study of the amount of LLW from the ESW process is still required. If the LLW analysis indicates that sodium management is critical, then a more comprehensive evaluation of the clean salt process or caustic recycle would be needed. Finally, experimental and theoretical studies have clearly demonstrated the need for the control of solids formation during and after leaching
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Caustic leaching of high-level radioactive tank sludge: A critical literature review
The Department of Energy (DOE) must treat and safely dispose of its radioactive tank contents, which can be separated into high-level waste (HLW) and low-level waste (LLW) fractions. Since the unit costs of treatment and disposal are much higher for HLW than for LLW, technologies to reduce the amount of HLW are being developed. A key process currently being studied to reduce the volume of HLW sludges is called enhanced sludge washing (ESW). This process removes, by water washes, soluble constituents such as sodium salts, and the washed sludge is then leached with 2--3 M NaOH at 60--100 C to remove nonradioactive metals such as aluminum. The remaining solids are considered to be HLW while the solutions are LLW after radionuclides such as {sup 137}Cs have been removed. Results of bench-scale tests have shown that the ESW will probably remove the required amounts of inert constituents. While both experimental and theoretical results have shown that leaching efficiency increases as the time and temperature of the leach are increased, increases in the caustic concentration above 2--3 M will only marginally improve the leach factors. However, these tests were not designed to validate the assumption that the caustic used in the ESW process will generate only a small increase (10 Mkg) in the amount of LLW; instead the test conditions were selected to maximize leaching in a short period and used more water and caustic than is planned during full-scale operations. Even though calculations indicate that the estimate for the amount of LLW generated by the ESW process appears to be reasonable, a detailed study of the amount of LLW from the ESW process is still required. If the LLW analysis indicates that sodium management is critical, then a more comprehensive evaluation of the clean salt process or caustic recycle would be needed. Finally, experimental and theoretical studies have clearly demonstrated the need for the control of solids formation during and after leaching
Motivation as a predictor of outcomes in school-based humanistic counselling
Recent years have seen a growth in the provision of counselling within UK secondary schools, and research indicates that it is associated with significant reductions in psychological distress. However, little is known about the moderators and mediators of positive therapeutic benefit. In the field of adult mental health, motivation has been found to be one of the strongest predictors of therapeutic outcomes, and it was hypothesised that this may also be a predictor of outcomes for young people in school-based counselling services. To assess the relationship between young people’s motivation for counselling and its effectiveness within a secondary school setting. Eighty-one young people (12 - 17 years old) who attended school-based humanistic counselling services in Scotland. Clients completed a measure of motivation for counselling at the commencement of their therapeutic work and a measure of psychological wellbeing at the commencement and termination of counselling. Motivation for counselling was not found to be significantly related to outcomes. The results indicate that the association between motivation and outcomes may be weaker in young people as compared with adults. However, a number of design factors may also account for the non-significant findings: insufficient participants, marginal reliability of the motivation measure and social desirability effects
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Tank Focus Area pretreatment activities
Plans call for the high-level wastes to be retrieved from the tanks and immobilized in a stable waste form suitable for long-term isolation. Chemistry and chemical engineering operations are required to retrieve the wastes, to condition the wastes for subsequent steps, and to reduce the costs of the waste management enterprise. Pretreatment includes those processes between retrieval and immobilization, and includes preparation of suitable feed material for immobilization and separations to partition the waste into streams that yield lower life-cycle costs. Some of the technologies being developed by the Tank Focus Area (TFA) to process these wastes are described. These technologies fall roughly into three areas: (1) solid/liquid separation (SLS), (2) sludge pretreatment, and (3) supernate pretreatment
BAR-PLUS: the Bologna Annotation Resource Plus for functional and structural annotation of protein sequences
We introduce BAR-PLUS (BAR+), a web server for functional and structural annotation of protein sequences. BAR+ is based on a large-scale genome cross comparison and a non-hierarchical clustering procedure characterized by a metric that ensures a reliable transfer of features within clusters. In this version, the method takes advantage of a large-scale pairwise sequence comparison of 13 495 736 protein chains also including 988 complete proteomes. Available sequence annotation is derived from UniProtKB, GO, Pfam and PDB. When PDB templates are present within a cluster (with or without their SCOP classification), profile Hidden Markov Models (HMMs) are computed on the basis of sequence to structure alignment and are cluster-associated (Cluster-HMM). Therefrom, a library of 10 858 HMMs is made available for aligning even distantly related sequences for structural modelling. The server also provides pairwise query sequence–structural target alignments computed from the correspondent Cluster-HMM. BAR+ in its present version allows three main categories of annotation: PDB [with or without SCOP (*)] and GO and/or Pfam; PDB (*) without GO and/or Pfam; GO and/or Pfam without PDB (*) and no annotation. Each category can further comprise clusters where GO and Pfam functional annotations are or are not statistically significant. BAR+ is available at http://bar.biocomp.unibo.it/bar2.0
An assessment of the precision and confidence of aquatic eddy correlation measurements
The quantification of benthic fluxes with the aquatic eddy correlation (EC) technique is based on simultaneous measurement of the current velocity and a targeted bottom water parameter (e. g., O-2, temperature). High-frequency measurements (64Hz) are performed at a single point above the seafloor using an acoustic Doppler velocimeter (ADV) and a fast-responding sensor. The advantages of aquatic EC technique are that 1) it is noninvasive, 2) it integrates fluxes over a large area, and 3) it accounts for in situ hydrodynamics. The aquatic EC has gained acceptance as a powerful technique; however, an accurate assessment of the errors introduced by the spatial alignment of velocity and water constituent measurements and by their different response times is still needed. Here, this paper discusses uncertainties and biases in the data treatment based on oxygen EC flux measurements in a large-scale flume facility with well-constrained hydrodynamics. These observations are used to review data processing procedures and to recommend improved deployment methods, thus improving the precision, reliability, and confidence of EC measurements. Specifically, this study demonstrates that 1) the alignment of the time series based on maximum cross correlation improved the precision of EC flux estimations; 2) an oxygen sensor with a response time of <0.4 s facilitates accurate EC fluxes estimates in turbulence regimes corresponding to horizontal velocities <11 cm s(-1); and 3) the smallest possible distance (<1 cm) between the oxygen sensor and the ADV's sampling volume is important for accurate EC flux estimates, especially when the flow direction is perpendicular to the sensor's orientation
A Very Intense Neutrino Super Beam Experiment for Leptonic CP Violation Discovery based on the European Spallation Source Linac: A Snowmass 2013 White Paper
Very intense neutrino beams and large neutrino detectors will be needed in
order to enable the discovery of CP violation in the leptonic sector. We
propose to use the proton linac of the European Spallation Source currently
under construction in Lund, Sweden to deliver, in parallel with the spallation
neutron production, a very intense, cost effective and high performance
neutrino beam. The baseline program for the European Spallation Source linac is
that it will be fully operational at 5 MW average power by 2022, producing 2
GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade
the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron
production and 14 pulses/s for neutrino production. Furthermore, because of the
high current required in the pulsed neutrino horn, the length of the pulses
used for neutrino production needs to be compressed to a few s with the
aid of an accumulator ring. A long baseline experiment using this Super Beam
and a megaton underground Water Cherenkov detector located in existing mines
300-600 km from Lund will make it possible to discover leptonic CP violation at
5 significance level in up to 50% of the leptonic Dirac CP-violating
phase range. This experiment could also determine the neutrino mass hierarchy
at a significance level of more than 3 if this issue will not already
have been settled by other experiments by then. The mass hierarchy performance
could be increased by combining the neutrino beam results with those obtained
from atmospheric neutrinos detected by the same large volume detector. This
detector will also be used to measure the proton lifetime, detect cosmological
neutrinos and neutrinos from supernova explosions. Results on the sensitivity
to leptonic CP violation and the neutrino mass hierarchy are presented.Comment: 28 page
Beam instrumentation for the Tevatron Collider
The Tevatron in Collider Run II (2001-present) is operating with six times
more bunches and many times higher beam intensities and luminosities than in
Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and
the never-ending luminosity upgrade campaign. We present the overall picture of
the Tevatron diagnostics development for Run II, outline machine needs for new
instrumentation, present several notable examples that led to Tevatron
performance improvements, and discuss the lessons for future colliders
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