7,579 research outputs found
Acumulo de biomassa seca em cana-de-açúcar RB 92579 em função da manutenção de diferentes níveis de palhada sobre o solo.
On The Existence of Roton Excitations in Bose Einstein Condensates: Signature of Proximity to a Mott Insulating Phase
Within the last decade, artificially engineered Bose Einstein Condensation
has been achieved in atomic systems. Bose Einstein Condensates are superfluids
just like bosonic Helium is and all interacting bosonic fluids are expected to
be at low enough temperatures. One difference between the two systems is that
superfluid Helium exhibits roton excitations while Bose Einstein Condensates
have never been observed to have such excitations. The reason for the roton
minimum in Helium is its proximity to a solid phase. The roton minimum is a
consequence of enhanced density fluctuations at the reciprocal lattice vector
of the stillborn solid. Bose Einstein Condensates in atomic traps are not near
a solid phase and therefore do not exhibit roton minimum. We conclude that if
Bose Einstein Condensates in an optical lattice are tuned near a transition to
a Mott insulating phase, a roton minimum will develop at a reciprocal lattice
vector of the lattice. Equivalently, a peak in the structure factor will appear
at such a wavevector. The smallness of the roton gap or the largeness of the
structure factor peak are experimental signatures of the proximity to the Mott
transition.Comment: 4 pages, 5 figure
Análise conjuntural da cultura do arroz nas regiões brasileiras.
O presente trabalho teve por objetivo analisar e demonstrar o movimento migratório da cultura do arroz em termos de área plantada e volume de produção nas regiões Norte, Nordeste, Centro-Oeste, Sudeste e Sul do Brasil nas safras de 1978/79, 1988/89, 1998/1999 e 2008/2009
Desenvolvimento do software Adubapasto 1.0 para recomendação de adubação para sistemas de pastejo intensivo.
Noncommutative spaces, the quantum of time and the Lorentz symmetry
We introduce three space-times that are discrete in time and compatible with
the Lorentz symmetry. We show that these spaces are no commutative, with
commutation relations similar to the relations of the Snyder and Yang spaces.
Furthermore, using a reparametrized relativistic particle we obtain a
realization of the Snyder type spaces and we construct an action for them.Comment: 8 pages, to appear in PR
Probing the single-particle character of rotational states in F using a short-lived isomeric beam
A beam containing a substantial component of both the ,
ns isomeric state of F and its , 109.77-min ground
state has been utilized to study members of the ground-state rotational band in
F through the neutron transfer reaction , in inverse kinematics.
The resulting spectroscopic strengths confirm the single-particle nature of the
13/2 band-terminating state. The agreement between shell-model
calculations, using an interaction constructed within the shell, and our
experimental results reinforces the idea of a single-particle/collective
duality in the descriptions of the structure of atomic nuclei
Estudo de compostos de valor agregado presentes no resíduo gerado após o processo de microfiltração do açaí.
Effect of enzymatic treatment, shear stress and temperature on the rheological behavior of blackberry (Rubus spp.) juice.
- …