Quantum critical 5f-electrons avoid singularities in U(Ru,Rh)2Si2

We present specific heat measurements of 4% Rh-doped U(Ru,Rh)2Si2 at magnetic fields above the proposed metamagnetic transition field Hm~34 T, revealing striking similarities to the isotructural Ce analog CeRu2Si2, suggesting that strongly renormalized hybridized band models apply equally well to both systems. The vanishing bandwidths as H --> Hm are consistent with a putative quantum critical point close to Hm. The existence of a phase transition into an ordered phase in the vicinity of Hm for 4% Rh-doped U(Ru,Rh)2Si2, but not for CeRu2Si2, is consistent with a stronger super-exchange in the case of the U 5-f system, with irreversible processes at the transition revealing a strong coupling of the 5f orbitals to the lattice, most suggestive of orbital or electric quadrupolar order.Comment: 4 pages, 4 figure

Upland rice development under a no-tillage system as a function of gypsum and phosphorus.

the objective of this work was to determine the effect of the combination of gypsum applied to the soil surface without tillage and P applied in the sowing furrow on soil attributes and the plant height, number of panicles m-1 and grain yield of upland rice cultivated in an no-tillage system

Adubação a lanço sem incorporação na produtividade do feijão-comum.

O objetivo desse trabalho de pesquisa foi de determinar o efeito de doses de fertilizantes, distribuídos na superfície do solo sem incorporação, nos componentes de produção e produtividade de grãos da cultura do feijão-comum.CONAF

Bose-Einstein Condensation of S = 1 Ni spin degrees of freedom in NiCl2-4SC(NH2)2

It has recently been suggested that the organic compound NiCl$_2$-4SC(NH$_2$)$_2$ (DTN) exhibits Bose-Einstein Condensation (BEC) of the Ni spin degrees of freedom for fields applied along the tetragonal c-axis. The Ni spins exhibit 3D XY-type antiferromagnetic order above a field-induced quantum critical point at $H_{c1} \sim 2$ T. The Ni spin fluid can be characterized as a system of effective bosons with a hard-core repulsive interaction in which the antiferromagnetic state corresponds to a Bose-Einstein condensate (BEC) of the phase coherent $S = 1$ Ni spin system. We have investigated the the high-field phase diagram and the occurrence of BEC in DTN by means of specific heat and magnetocaloric effect measurements to dilution refrigerator temperatures. Our results indicate that a key prediction of BEC is satisfied; the magnetic field-temperature quantum phase transition line $H_c(T)-H_{c1} \propto T^\alpha$ approaches a power-law at low temperatures, with an exponent $\alpha = 1.47 \pm 0.06$ at the quantum critical point, consistent with the BEC theory prediction of $\alpha = 1.5$.Comment: 4 pages, 4 figure

Produtividade de grãos do feijoeiro comum em função da aplicação de N via foliar.

O objetivo do trabalho foi de determinar o efeito de doses e épocas de aplicação de nitrogênio via foliar na produtividade de grãos de duas cultivares de feijoeiro comum.CONAF

High-magnetic field lattice length changes in URu2Si2

We report high magnetic field (up to 45 T) c-axis thermal expansion and magnetostriction experiments on URu2Si2 single crystals. The sample length change associated with the transition to the hidden order phase becomes increasingly discontinous as the magnetic field is raised above 25 T. The re-entrant ordered phase III is clearly observed in both the thermal expansion and magnetostriction above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal-expansion is observed at the metamagnetic transition (B_M = 38 T) which is likely related to the existence of a quantum critical end point.Comment: 5 pages, 4 figures, to be published in PR

Efeito residual do herbicida imazapir + imazapique sobre as culturas de arroz, feijão, milho, soja e sorgo.

Objetivou-se com esse trabalho determinar os efeitos da mistura dos herbicidas imazapir + imazapique (IMZ+IMQ) no desenvolvimento das culturas de arroz de terras altas, feijoeiro comum, milho, soja e sorgo e correlacionar o desenvolvimento dessas plantas com a persistência desse produto no solo

Molecular markers applied to evaluation of environmental services in the araucaria forest in Southern Brazil.

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