1,343 research outputs found
Effect of sodium bicarbonate and sodium bentonite on digestion and rumen fermentation characteristics of forage sorghum silage-based diets fed to growing steers
One percent sodium bicarbonate (NaHCo3) increased intake of a 50% silage - 50% grain diet, but had no effect on intake of a full-feed sorghum silage diet. The addition of concentrate (rolled milo) slightly lowered rumen pH and decreased acid detergent fiber (ADF) and starch digestion. NaHC03 had no effect on digestibility, but 2% bentonite lowered digestibility of NDF and ADF. Neither compound affected rumen fermentation characteristics.; Dairy Day, 1985, Kansas State University, Manhattan, KS, 1985
Order Parameter Description of the Anderson-Mott Transition
An order parameter description of the Anderson-Mott transition (AMT) is
given. We first derive an order parameter field theory for the AMT, and then
present a mean-field solution. It is shown that the mean-field critical
exponents are exact above the upper critical dimension. Renormalization group
methods are then used to show that a random-field like term is generated under
renormalization. This leads to similarities between the AMT and random-field
magnets, and to an upper critical dimension for the AMT. For
, an expansion is used to calculate the critical
exponents. To first order in they are found to coincide with the
exponents for the random-field Ising model. We then discuss a general scaling
theory for the AMT. Some well established scaling relations, such as Wegner's
scaling law, are found to be modified due to random-field effects. New
experiments are proposed to test for random-field aspects of the AMT.Comment: 28pp., REVTeX, no figure
Universality Class of Thermally Diluted Ising Systems at Criticality
The universality class of thermally diluted Ising systems, in which the
realization of the disposition of magnetic atoms and vacancies is taken from
the local distribution of spins in the pure original Ising model at
criticality, is investigated by finite size scaling techniques using the Monte
Carlo method. We find that the critical temperature, the critical exponents and
therefore the universality class of these thermally diluted Ising systems
depart markedly from the ones of short range correlated disordered systems. Our
results agree fairly well with theoretical predictions previously made by
Weinrib and Halperin for systems with long range correlated disorder.Comment: 7 pages, 6 figures, RevTe
Hall effect in the marginal Fermi liquid regime of high-Tc superconductors
The detailed derivation of a theory for transport in quasi-two-dimensional
metals, with small-angle elastic scattering and angle-independent inelastic
scattering is presented. The transport equation is solved for a model Fermi
surface representing a typical cuprate superconductor. Using the small-angle
elastic and the inelastic scattering rates deduced from angle-resolved
photoemission experiments, good quantitative agreement with the observed
anomalous temperature dependence of the Hall angle in optimally doped cuprates
is obtained, while the resistivity remains linear in temperature. The theory is
also extended to the frequency-dependent complex Hall angle
On the critical behavior of disordered quantum magnets: The relevance of rare regions
The effects of quenched disorder on the critical properties of itinerant
quantum antiferromagnets and ferromagnets are considered. Particular attention
is paid to locally ordered spatial regions that are formed in the presence of
quenched disorder even when the bulk system is still in the paramagnetic phase.
These rare regions or local moments are reflected in the existence of spatially
inhomogeneous saddle points of the Landau-Ginzburg-Wilson functional. We derive
an effective theory that takes into account small fluctuations around all of
these saddle points. The resulting free energy functional contains a new term
in addition to those obtained within the conventional perturbative approach,
and it comprises what would be considered non-perturbative effects within the
latter. A renormalization group analysis shows that in the case of
antiferromagnets, the previously found critical fixed point is unstable with
respect to this new term, and that no stable critical fixed point exists at
one-loop order. This is contrasted with the case of itinerant ferromagnets,
where we find that the previously found critical behavior is unaffected by the
rare regions due to an effective long-ranged interaction between the order
parameter fluctuations.Comment: 16 pp., REVTeX, epsf, 2 figs, final version as publishe
The effect of rare regions on a disordered itinerant quantum antiferromagnet with cubic anisotropy
We study the quantum phase transition of an itinerant antiferromagnet with
cubic anisotropy in the presence of quenched disorder, paying particular
attention to the locally ordered spatial regions that form in the Griffiths
region. We derive an effective action where these rare regions are described in
terms of static annealed disorder. A one loop renormalization group analysis of
the effective action shows that for order parameter dimensions the rare
regions destroy the conventional critical behavior. For order parameter
dimensions the critical behavior is not influenced by the rare regions,
it is described by the conventional dirty cubic fixed point. We also discuss
the influence of the rare regions on the fluctuation-driven first-order
transition in this system.Comment: 6 pages RevTe
The Anderson-Mott Transition as a Random-Field Problem
The Anderson-Mott transition of disordered interacting electrons is shown to
share many physical and technical features with classical random-field systems.
A renormalization group study of an order parameter field theory for the
Anderson-Mott transition shows that random-field terms appear at one-loop
order. They lead to an upper critical dimension for this model.
For the critical behavior is mean-field like. For an
-expansion yields exponents that coincide with those for the
random-field Ising model. Implications of these results are discussed.Comment: 8pp, REVTeX, db/94/
The power of invalidating communication: Receiving invalidating feedback predicts threat-related emotional, physiological, and social responses
© 2016 Guilford Publications, Inc. Previous studies have found that communicating acceptance and understanding (validation) enhances the recipient's psychological and physiological wellbeing compared with receiving nonunderstanding feedback (invalidation). Yet, such studies have not established whether it is validation or absence of invalidation that is beneficial. This study examined the social, physiological, and emotional effects of validating and invalidating feedback in more detail, by employing a control group. Ninety healthy volunteers were randomly allocated to receive validating, invalidating, or no feedback during a series of stressor tasks. Self-report ratings, psychophysiological measurements and social engagement behaviors were recorded. While there were no significant differences between validated and control participants, invalidated participants showed increased physiological and psychological arousal on several measures and reduced social engagement behaviors compared with the other two groups. the relevance of these findings for understanding adverse effects of invalidation during clinical interactions is discussed
Non-Universal Power Law of the "Hall Scattering Rate" in a Single-Layer Cuprate Bi_{2}Sr_{2-x}La_{x}CuO_{6}
In-plane resistivity \rho_{ab}, Hall coefficient, and magnetoresistance (MR)
are measured in a series of high-quality Bi_{2}Sr_{2-x}La_{x}CuO_{6} crystals
with various carrier concentrations, from underdope to overdope. Our crystals
show the highest T_c (33 K) and the smallest residual resistivity ever reported
for Bi-2201 at optimum doping. It is found that the temperature dependence of
the Hall angle obeys a power law T^n with n systematically decreasing with
increasing doping, which questions the universality of the Fermi-liquid-like
T^2 dependence of the "Hall scattering rate". In particular, the Hall angle of
the optimally-doped sample changes as T^{1.7}, not as T^2, while \rho_{ab}
shows a good T-linear behavior. The systematics of the MR indicates an
increasing role of spin scattering in underdoped samples.Comment: 4 pages, 5 figure
Sliding Luttinger liquid phases
We study systems of coupled spin-gapped and gapless Luttinger liquids. First,
we establish the existence of a sliding Luttinger liquid phase for a system of
weakly coupled parallel quantum wires, with and without disorder. It is shown
that the coupling can {\it stabilize} a Luttinger liquid phase in the presence
of disorder. We then extend our analysis to a system of crossed Luttinger
liquids and establish the stability of a non-Fermi liquid state: the crossed
sliding Luttinger liquid phase (CSLL). In this phase the system exhibits a
finite-temperature, long-wavelength, isotropic electric conductivity that
diverges as a power law in temperature as . This two-dimensional
system has many properties of a true isotropic Luttinger liquid, though at zero
temperature it becomes anisotropic. An extension of this model to a
three-dimensional stack exhibits a much higher in-plane conductivity than the
conductivity in a perpendicular direction.Comment: Revtex, 18 pages, 8 figure
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