260 research outputs found
Fermentation profile and microbial population in soybean silages with inoculant and powdered molasses
Fermentation profile and microbial population were assessed in soybean silages without any additive (control), with inoculant (I), with I + powdered molasses (I+M), and with powdered molasses only (M). Soybean plants were harvested at the R6 stage and ensiled in 2kg-capacity laboratory silos. The additives were added to the natural matter base of silages. The assessed fermentation periods were 1, 3, 7, 14, 28, and 56 days. A 4×6 factorial arrangement (4 additives × 6 fermentation periods) in a completely randomized design with 3 replicates was used. Lactic, acetic, and butyric acids concentrations were influenced by additives and periods (P< 0.05). It was observed higher lactic acid values to control silages, on the 56 th day. Lower average values of acetic and butyric acids were observed to I+M and M silages. It was observed quadratic effect to pH values with a reduction estimated of 0.5504, 0.5358, 0.6312 and 0.6680 units to pH values to control, I, I+M, and M silages in the first 10 days. A maximum lactic acid bacteria population was observed at the 28 th day of fermentation in silages with inoculant. The inoculant and powdered molasses improve the fermentation profile of soybean silages
Destruction of diagonal and off-diagonal long range order by disorder in two-dimensional hard core boson systems
We use quantum Monte Carlo simulations to study the effect of disorder, in
the form of a disordered chemical potential, on the phase diagram of the hard
core bosonic Hubbard model in two dimensions. We find numerical evidence that
in two dimensions, no matter how weak the disorder, it will always destroy the
long range density wave order (checkerboard solid) present at half filling and
strong nearest neighbor repulsion and replace it with a bose glass phase. We
study the properties of this glassy phase including the superfluid density,
energy gaps and the full Green's function. We also study the possibility of
other localized phases at weak nearest neighbor repulsion, i.e. Anderson
localization. We find that such a phase does not truly exist: The disorder must
exceed a threshold before the bosons (at weak nn repulsion) are localized. The
phase diagram for hard core bosons with disorder cannot be obtained easily from
the soft core phase diagram discussed in the literature.Comment: 7 pages, 10 eps figures include
CENTORI: a global toroidal electromagnetic two-fluid plasma turbulence code
A new global two-fluid electromagnetic turbulence code, CENTORI, has been
developed for the purpose of studying magnetically-confined fusion plasmas on
energy confinement timescales. This code is used to evolve the combined system
of electron and ion fluid equations and Maxwell equations in toroidal
configurations with axisymmetric equilibria. Uniquely, the equilibrium is
co-evolved with the turbulence, and is thus modified by it. CENTORI is
applicable to tokamaks of arbitrary aspect ratio and high plasma beta. A
predictor-corrector, semi-implicit finite difference scheme is used to compute
the time evolution of fluid quantities and fields. Vector operations and the
evaluation of flux surface averages are speeded up by choosing the Jacobian of
the transformation from laboratory to plasma coordinates to be a function of
the equilibrium poloidal magnetic flux. A subroutine, GRASS, is used to
co-evolve the plasma equilibrium by computing the steady-state solutions of a
diffusion equation with a pseudo-time derivative. The code is written in
Fortran 95 and is efficiently parallelized using Message Passing Interface
(MPI). Illustrative examples of output from simulations of a tearing mode in a
large aspect ratio tokamak plasma and of turbulence in an elongated
conventional aspect ratio tokamak plasma are provided.Comment: 9 figure
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