1,802 research outputs found
Polymer Adsorption on Disordered Substrate
We analyze the recently proposed "pattern-matching" phase of a Gaussian
random heteropolymer adsorbed on a disordered substrate [S. Srebnik, A.K.
Chakraborty and E.I. Shakhnovich, Phys. Rev. Lett. 77, 3157 (1996)]. By mapping
the problem to that of a directed homopolymer in higher-dimensional random
media, we show that the pattern-matching phase is asymptotically weakly
unstable, and the large scale properties of the system are given by that of an
adsorbed homopolymer.Comment: 5 pages, RevTeX, text also available at http://matisse.ucsd.edu/~hw
A simplified mulesing crush
DURING the last two years Mr. Tom Flanigan, a mulesing contractor in a large area centred at Katanning, has performed the mules-tailstrip operation on many thousands of lambs and sheep
Education in the 'right' sense of the word: The quest for a balanced education at the Kansas State Agricultural College
Citation: Halpin, C. T. (2014). Education in the 'right' sense of the word: The quest for a balanced education at the Kansas State Agricultural College. Unpublished manuscript, Kansas State University, Manhattan, KS.Kirmser Undergraduate Research Award - Individual Non-Freshman category, grand prizeCharles SandersAfter the establishment of the Kansas State Agriculture College in accordance with the Morrill Act, there was significant disapproval for the scope of education at the school, in favor of a more "practical" agricultural education which came under the leadership of President Anderson. Although Anderson made significant efforts in advancing education, his moves were too radical, and the final direction of the college was determined when President George Fairchild successfully combined the practical and classical structures to provide a broad curriculum that did not ignore the importance of hands-on training, and in doing so, he built a model agricultural college for the nation
Sheep can be more profitable in the wheatbelt
TRADITIONALLY, wheatbelt farmers have looked upon sheep as being subsidiary, or at best, complementary to their main activity, wheat growing.
Because there has been a mistaken belief that clover would not grow, these farmers have depended upon native grasses and crop remains (stubble) for sheep feed, a practice which has put a limit to the number of sheep a property could support
Directed polymers in random media under confining force
The scaling behavior of a directed polymer in a two-dimensional (2D) random
potential under confining force is investigated. The energy of a polymer with
configuration is given by H\big(\{y(x)\}\big) = \sum_{x=1}^N \exyx
+ \epsilon \Wa^\alpha, where is an uncorrelated random potential
and \Wa is the width of the polymer. Using an energy argument, it is
conjectured that the radius of gyration and the energy fluctuation
of the polymer of length in the ground state increase as
and respectively with and for . A
novel algorithm of finding the exact ground state, with the effective time
complexity of \cO(N^3), is introduced and used to confirm the conjecture
numerically.Comment: 9 pages, 7 figure
How to identify twin-born lambs
IN the past few years it has become widely accepted that the ability to produce twin or multiple lambs is a heritable characteristic.
This means that breeding from sheep born as twins should give more multiple births and higher lambing percentages than breeding from sheep born as single lambs
Universal correlators and distributions as experimental signatures of 2+1 Kardar-Parisi-Zhang growth
We examine height-height correlations in the transient growth regime of the
2+1 Kardar-Parisi-Zhang (KPZ) universality class, with a particular focus on
the {\it spatial covariance} of the underlying two-point statistics,
higher-dimensional analog of the 1+1 KPZ Class Airy process. Making
comparison to AFM kinetic roughening data in 2d organic thin films, we use our
universal 2+1 KPZ spatial covariance to extract key scaling parameters for this
experimental system. Additionally, we explore the i) height, ii) local
roughness, and iii) extreme value distributions characteristic of these
oligomer films, finding compelling agreement in all instances with our
numerical integration of the KPZ equation itself. Finally, investigating
nonequilibrium relaxation phenomena exhibited by 2+1 KPZ Class models, we have
unearthed a universal KPZ ageing kinetics. In experiments with ample data in
the time domain, our 2+1 KPZ Euler {\it temporal covariance} will allow a
quick, independent estimate of the central KPZ scaling parameter.Comment: 6 Pages, 5 Figure
Comment on ``Nonuniversal Exponents in Interface Growth''
Recently, Newman and Swift[T. J. Newman and M. R. Swift, Phys. Rev. Lett.
{\bf 79}, 2261 (1997)] made an interesting suggestion that the strong-coupling
exponents of the Kardar-Parisi-Zhang (KPZ) equation may not be universal, but
rather depend on the precise form of the noise distribution. We show here that
the decrease of surface roughness exponents they observed can be attributed to
a percolative effect
Non-perturbative renormalization of the KPZ growth dynamics
We introduce a non-perturbative renormalization approach which identifies
stable fixed points in any dimension for the Kardar-Parisi-Zhang dynamics of
rough surfaces. The usual limitations of real space methods to deal with
anisotropic (self-affine) scaling are overcome with an indirect functional
renormalization. The roughness exponent is computed for dimensions
to 8 and it results to be in very good agreement with the available
simulations. No evidence is found for an upper critical dimension. We discuss
how the present approach can be extended to other self-affine problems.Comment: 4 pages, 2 figures. To appear in Phys. Rev. Let
Singularities of the renormalization group flow for random elastic manifolds
We consider the singularities of the zero temperature renormalization group
flow for random elastic manifolds. When starting from small scales, this flow
goes through two particular points and , where the average value
of the random squared potential turnes negative ($l^{*}$) and where
the fourth derivative of the potential correlator becomes infinite at the
origin ($l_{c}$). The latter point sets the scale where simple perturbation
theory breaks down as a consequence of the competition between many metastable
states. We show that under physically well defined circumstances $l_{c} to negative values does not
take place.Comment: RevTeX, 3 page
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