7,687 research outputs found
Quantum Communication Through an Unmodulated Spin Chain
We propose a scheme for using an unmodulated and unmeasured spin-chain as a
channel for short distance quantum communications. The state to be transmitted
is placed on one spin of the chain and received later on a distant spin with
some fidelity. We first obtain simple expressions for the fidelity of quantum
state transfer and the amount of entanglement sharable between any two sites of
an arbitrary Heisenberg ferromagnet using our scheme. We then apply this to the
realizable case of an open ended chain with nearest neighbor interactions. The
fidelity of quantum state transfer is obtained as an inverse discrete cosine
transform and as a Bessel function series. We find that in a reasonable time, a
qubit can be directly transmitted with better than classical fidelity across
the full length of chains of up to 80 spins. Moreover, the spin-chain channel
allows distillable entanglement to be shared over arbitrarily large distances.Comment: Much improved versio
Evaluation of advanced lift concepts and potential fuel conservation for short-haul aircraft
The effect of different field lengths, cruise requirements, noise level, and engine cycle characteristics on minimizing fuel consumption and minimizing operating cost at high fuel prices were evaluated for some advanced short-haul aircraft. The conceptual aircraft were designed for 148 passengers using the upper surface-internally blown jet flap, the augmentor wing, and the mechanical flap lift systems. Advanced conceptual STOL engines were evaluated as well as a near-term turbofan and turboprop engine. Emphasis was given to designs meeting noise levels equivalent to 95-100 EPNdB at 152 m (500 ft) sideline
Theory of adhesion: role of surface roughness
We discuss how surface roughness influence the adhesion between elastic
solids. We introduce a Tabor number which depends on the length scale or
magnification, and which gives information about the nature of the adhesion at
different length scales. We consider two limiting cases relevant for (a)
elastically hard solids with weak adhesive interaction (DMT-limit) and (b)
elastically soft solids or strong adhesive interaction (JKR-limit). For the
former cases we study the nature of the adhesion using different adhesive force
laws (, , where is the wall-wall separation). In
general, adhesion may switch from DMT-like at short length scales to JKR-like
at large (macroscopic) length scale. We compare the theory predictions to the
results of exact numerical simulations and find good agreement between theory
and the simulation results
Phosphorus Sources Trials
Pasture Trials 76BU1 New land pasture at Yallingupo Sand over laterite. 75N07B New land pasture at Chittering. Grave lo 76MT10 New land pasture at Mount Barker. Gravel. 77MT1 New land pasture at Mount Barkero Methods and particle size. Cropping Trials 76N4 New land - Phosphorus sources on barley - gravel sitee 76LG6 Short history - Phosphorus sources on barley - gravelly sande 76WH9 New land Phosphorus sources on wheat - loamy sands 77M016 - New land - Phosphorus sources on wheat - gravel ~ 3rd crop
Phosphorus Sources Trials
Pasture trials. 75N07B - New land pasture at Chittering – gravel. 76MT10 - New land pasture at Mt. Barker – gravel. 77MT1 - New land pasture at Mt. Barker – gravel. Methods and particle size.
Cropping trials 77MT2 - Old land at Mt. Barker - gravel – oats. 76WH10 - Young land at Wongan Hills - WLS – wheat. 76WH14 - Very old land at Wongan Hills - WLS – wheat. 77WH2 - Very old land at Wongan Hills - WLS – wheat. 77M016 - New land at New Norcia - gravel – wheat. 80BA6 - New land at Badgingarra - deep sand – lupins.
Trials not assessed in 1980. 76BU1 - New land pasture at Yallingup - sand over laterite. 76N4 - New land cropping at Newdegate – gravel. 76LG6 - Young land cropping at Newdegate - gravelly sand. 76WH9 - New land cropping at Wongan Hills – WLS
Nitrogen and phosphorus compound fertilisers
Nitrogen and phosphorus are two vitally important elements for plant growth which are deficient in most soils throughout Western Australia\u27s agricultural areas.
Both nitrogen and phosphorus can also be applied in appropriate compound fertilisers which can be drilled with the seed, thus making their handling much easier. However, excessively high rates can depress plant emergence and may lower crop yields
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