6,590 research outputs found
Sources of phosphorus trials. Miscellaneous trials.
I Sources of phosphorus work. Pasture trials - 77MT1 - New land (1977) continuous pasture trial, gravel. 80BA6 - Ley 1984. Serradella weeds and lupin regrowth, sand. 84N069 - New land (1984) pasture, gravel. Crop trials - 76WH9 - New land (1976) run down on one dressing of P W.L.S. 76WH10 - Young land Topdressed annually, biennially and once off. 76WH14 - Old land Topdressed anually and biennially. 76N4 - New land (1976) Topdressed annually biennially and once off, gravel. 84M63 - New land (1984) Once off dressing. Trials not sampled - 77WH2 - Old land Sources trial 77MT2 - Old land Sources trial II Miscellaneous trials. Maintenance P x S trials 65C5 and 65A1. Residual value of Phosphorus 78BA7. Grazing trial, Wooroloo 83PE35. Cultivation of Phosphorus availability 83BU1, 3 and 4 84MT7. Rates and times of nitrogen 84WH45. Ripping Trials - Residual effects 82WH2, 35 83WH28 and 31. Coarse organic matter for nitrogen: second crop effects 82N041, N17 and LG5
Global Alfven Eigenmodes in the H-1 heliac
Recent upgrades in H-1 power supplies have enabled the operation of the H-1
experiment at higher heating powers than previously attainable. A heating power
scan in mixed hydrogen/helium plasmas reveals a change in mode activity with
increasing heating power. At low power (<50 kW) modes with beta-induced Alfven
eigenmode (BAE) frequency scaling are observed. At higher power modes
consistent with an analysis of nonconventional Global Alfven Eigenmodes (GAEs)
are observed, the subject of this work. We have computed the mode continuum,
and identified GAE structures using the ideal MHD solver CKA and the
gyrokinetic code EUTERPE. An analytic model for ICRH-heated minority ions is
used to estimate the fast ion temperature from the hydrogen species. Linear
growth rate scans using a local flux surface stability calculation, LGRO, are
performed. These studies demonstrate growth from circulating particles whose
speed is significantly less than the Alfven speed, and are resonant with the
mode through harmonics of the Fourier decomposition of the strongly-shaped
heliac magnetic field. They reveal drive is possible with a small, hot
energetic tail of the hydrogen species. Local linear growth rate scans are also
complemented with global calculations from CKA and EUTERPE. These qualitatively
confirm the findings from the LGRO study, and show that the inclusion of finite
Larmor radius effects can reduce the growth rate by a factor of three, but do
not affect marginal stability. Finally, a study of damping of the global mode
with the thermal plasma is conducted, computing continuum, and the damping
arising from parallel electric fields. We find that continuum damping is of
order 0.1% for the configuration studied. The inclusion of resistivity lifts
the damping to 19%. Such large damping is consistent with experimental
observations that in absence of drive the mode decays rapidly (~0.1 ms).Comment: 18 pages, 15 figures, submitted 07/04/2017 to Plasma Physics and
Controlled Fusio
A statistical mechanics description of environmental variability in metabolic networks
Many of the chemical reactions that take place within a living cell are irreversible. Due to evolutionary pressures, the number of allowable reactions within these systems are highly constrained and thus the resulting metabolic networks display considerable asymmetry. In this paper, we explore possible evolutionary factors pertaining to the reduced symmetry observed in these networks, and demonstrate the important role environmental variability plays in shaping their structural organization. Interpreting the returnability index as an equilibrium constant for a reaction network in equilibrium with a hypothetical reference system, enables us to quantify the extent to which a metabolic network is in disequilibrium. Further, by introducing a new directed centrality measure via an extension of the subgraph centrality metric to directed networks, we are able to characterise individual metabolites by their participation within metabolic pathways. To demonstrate these ideas, we study 116 metabolic networks of bacteria. In particular, we find that the equilibrium constant for the metabolic networks decreases significantly in-line with variability in bacterial habitats, supporting the view that environmental variability promotes disequilibrium within these biochemical reaction system
Design and interpretation of cell trajectory assays
Cell trajectory data are often reported in the experimental cell biology literature to distinguish between different types of cell migration. Unfortunately, there is no accepted protocol for designing or interpreting such experiments and this makes it difficult to quantitatively compare different published datasets and to understand how changes in experimental design influence our ability to interpret different experiments. Here, we use an individual-based mathematical model to simulate the key features of a cell trajectory experiment. This shows that our ability to correctly interpret trajectory data is extremely sensitive to the geometry and timing of the experiment, the degree of motility bias and the number of experimental replicates. We show that cell trajectory experiments produce data that are most reliable when the experiment is performed in a quasi-one-dimensional geometry with a large number of identically prepared experiments conducted over a relatively short time-interval rather than a few trajectories recorded over particularly long time-intervals
Sources of phosphate trials. Miscellaneous trials
I. Sources of Phosphate Trials. Cropping Trials: (80BA6) - Deep sand, Badgingarra, Lupins. (77WH2) - Gravel, old land, WHRS, Wheat. (76WH9) - WLS, new land, WHRS, Wheat (1982). (76WH10) - WLS, young land, WHRS Wheat (1982). (77MT2) - Loamy gravel, old land, Mount Barker Oats. Pasture trials: (77MT1) - Loamy gravel, new land, Mount Barker. (77E1) - Sandy gravel, new land, Esperance. (77E4) – [78E4?] Sandy gravel, old land, Esperance. II. Miscellaneous Trials Long term trials. 66M30 - Super x stocking rate at Merredin. 48M/149 EX - Residual super trial at Merredin. 65A1, 65C5 and 69WH15 - Maintenance P x S trials. 75LG26 - Continuous cropping with super on heavy land. 81NO44 - Testing mineral fertilizer mixes. 78BA7 - Residual value of phosphorus, Badgingarra. Short term trials: 82BA2 - Tillage and placement of phosphorus on wheat and lupin. 82NO5 - Super x seed x defoliation x variety of sub clover. 82WH35 and 83WH31 - Deep ripping and nitrogen on wheat . 82WH2, 76WH9 and 81ME53 - Residual effects of ripping and compaction. 83WH10 - N and P on root growth of wheat and clover. 83BU1, 3 and 4 - Cultivation and soil phosphorus status. 83PE54 and 55 - Nutrient omission trials. 83PE35 - Pasture production at Wooroloo. 83LG62 - Rate of P on wheat. Soil test and reactive iron. 83NO3 - Rate of P on old land lupins
Towards a modeling of the time dependence of contact area between solid bodies
I present a simple model of the time dependence of the contact area between
solid bodies, assuming either a totally uncorrelated surface topography, or a
self affine surface roughness. The existence of relaxation effects (that I
incorporate using a recently proposed model) produces the time increase of the
contact area towards an asymptotic value that can be much smaller than
the nominal contact area. For an uncorrelated surface topography, the time
evolution of is numerically found to be well fitted by expressions of
the form [, where the exponent depends on
the normal load as , with close to 0.5. In
particular, when the contact area is much lower than the nominal area I obtain
, i.e., a logarithmic time increase of the
contact area, in accordance with experimental observations. The logarithmic
increase for low loads is also obtained analytically in this case. For the more
realistic case of self affine surfaces, the results are qualitatively similar.Comment: 18 pages, 9 figure
Two-dimensional photonic crystal polarizer
A novel polarizer made from two-dimensional photonic bandgap materials was
demonstrated theoretically. This polarizer is fundamentally different from the
conventinal ones. It can function in a wide frequency range with high
performance and the size can be made very compact, which renders it useful as a
micropolarizer in microoptics.Comment: 8 pages, RevTex, 4 figure
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