Insulator phases of Bose-Fermi mixtures induced by next-neighbor interactions between fermions

We study a one-dimensional mixture of two-color fermions and scalar bosons at the hard-core limit, focusing on the effect that the next-neighbor interaction between fermions has on the zero-temperature ground state of the system for different fillings of each carrier. Exploring the parameters of the problem, we observed that the non-local interaction modifies the well-known mixed and spin-selective Mott insulators, and we also found the emergence of three unusual insulating states with peculiar charge density wave orderings, a fully out-of-phase density of carriers for bosonic half-filling, an insulator with the same bosonic and fermionic fillings, and a different spin-selective insulator where the bosonic filling matches the density of one kind of fermion. Modern cold-atom setups correspond to the ideal experimental setting where these incommensurable insulators can be observed.Comment: 11 pages, 9 figures. Comments are welcom

The number of P-vertices in a matrix with maximum nullity

Let T be a tree with n >= 2 vertices. Set 8(T) for the set of all real symmetric matrices whose graph is T. Let A is an element of S(T) and i is an element of {1, . . . , n}. We denote by A(i) the principal submatrix of A obtained after deleting the row and column i. We set m(A) (0) for the multiplicity of the eigenvalue zero in A (the nullity of A). When m(A(i)) (0) = m(A) (0) + 1, we say that i is a P-vertex of A. As usual, M(T) denotes the maximum nullity occurring of B is an element of S(T). In this paper we determine an upper bound and a lower bound for the number of P-vertices in a matrix A is an element of S(T) with nullity M(T). We also prove that if the integer b is between these two bounds, then there is a matrix E is an element of S(T) with b P-vertices and maximum nullity. (C) 2018 Elsevier Inc. All rights reserved.publishersversionpublishe

Desenvolvimento do feijoeiro sob o uso de biofertilizante e adubação mineral.

A produção intensiva de alimentos exige manejo adequado do solo para garantir a produtividade e a sustentabilidade ambiental. Uma das alternativas é a utilização de resíduos orgânicos no desenvolvimento das culturas, diminuindo a dependência de adubos minerais. Com o objetivo de avaliar o desenvolvimento da cultura de feijão (Phaseolus vulgaris L.), utilizando biofertilizante e adubação mineral, conduziu-se o experimento com seis tratamentos dispostos ao acaso, em esquema fatorial, em quatro blocos, com parcelas de 8,0 x 5,0 m. Os tratamentos sob solo cultivado com a cultura de feijão caracterizaram-se como: com e sem biofertilizante (CB e SB, respectivamente) e para a adubação mineral foram utilizadas a dose recomendada no plantio, ½ dose de adubação e sem adubação mineral (AM, 1/2AM, SAM). Adotaram-se práticas culturais convencionais para o preparo inicial do solo, e em seguida foi efetuada a aplicação de biofertilizante de origem bovina na dosagem de 100 m3 ha-1, com antecedência de três meses da semeadura. Foram avaliados os parâmetros massa da matéria seca acumulada na parte aérea da planta, área foliar e produtividade da cultura. Os resultados mostraram semelhanças entre as características analisadas, obtendo-se melhor desenvolvimento à cultura que recebeu biofertilizante

Geochemical characterization of the hydrous pyrolysis products from a recent cyanobacteria-dominated microbial mat

Hydrous pyrolysis experiments were performed on a recent microbial mat sample from Lagoa Vermelha, Brazil, to determine whether crude oil can be generated and expelled during artificial maturation of the Organic Matter (OM). The experiments were conducted at 280ºC, 330ºC and 350ºC during 20h. Two types of liquid pyrolysis products, assigned as free oil and bitumen, were isolated and analyzed. Free oil represents free organic phase released by hydrous pyrolysis, whereas bitumen was obtained by extraction from the solid pyrolysis residue with dichloromethane. Changes in the OM maturity were determined using Rock-Eval parameters and biomarker maturity ratios of original sample and pyrolysis products. Biomarker compositions of original sample extract and liquid pyrolysates were used for determination of dominant bacterial source. The yields of free oil and bitumen showed that a microbial mat OM has a high liquid hydrocarbons generation potential. Rock-Eval maturity parameters, biopolymer and biomarker compositions indicate a significant increase of the OM maturity during hydrous pyrolysis. At 280ºC the release of free, adsorbed and occluded compounds was observed; however, without a cracking of the OM. At 330ºC the generation of bitumen and free oil is mostly related to the OM cracking. The highest yield of free oil was recorded at this temperature. Distribution of biomarkers in the extract of original sample and liquid pyrolysates confirms cyanobacteria-dominated microbial mats, whereas the identification of long chain n-alkane series, with max