2,260 research outputs found
Influence of fallow enrichment with different leguminous tree species and of land preparation methods on following crop production.
Sensitive protein detection using an optical fibre long period grating sensor anchored with silica core gold shell nanoparticles
Copyright ©2014 Society of Photo-Optical Instrumentation Engineers.
This paper was published in the Proceedings of SPIE and is made available with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.An optical fibre long period grating (LPG), modified with a coating of silica gold (SiO2:Au) core/shell nanoparticles (NPs) deposited using the layer-by-layer (LbL) method, was employed for the development of a bio-sensor. The SiO2:Au NPs were electrostatically assembled onto the LPG with the aid of a poly(hydrochloride ammonium) (PAH) polycation layer. The LPG sensor operates at the phase matching turning point to provide the highest sensitivity. The SiO2:Au NPs were modified with biotin, which was used as a ligand for streptavidin (SV) detection. The sensing mechanism is based on the measurement of the refractive index change induced by the binding of the SV to the biotin. The lowest detected concentration of SV was 19 nM using an LPG modified with a 3 layer (PAH/SiO2:Au) thin film
SAT-based Explicit LTL Reasoning
We present here a new explicit reasoning framework for linear temporal logic
(LTL), which is built on top of propositional satisfiability (SAT) solving. As
a proof-of-concept of this framework, we describe a new LTL satisfiability
tool, Aalta\_v2.0, which is built on top of the MiniSAT SAT solver. We test the
effectiveness of this approach by demonnstrating that Aalta\_v2.0 significantly
outperforms all existing LTL satisfiability solvers. Furthermore, we show that
the framework can be extended from propositional LTL to assertional LTL (where
we allow theory atoms), by replacing MiniSAT with the Z3 SMT solver, and
demonstrating that this can yield an exponential improvement in performance
Incrementally Computing Minimal Unsatisfiable Cores of QBFs via a Clause Group Solver API
We consider the incremental computation of minimal unsatisfiable cores (MUCs)
of QBFs. To this end, we equipped our incremental QBF solver DepQBF with a
novel API to allow for incremental solving based on clause groups. A clause
group is a set of clauses which is incrementally added to or removed from a
previously solved QBF. Our implementation of the novel API is related to
incremental SAT solving based on selector variables and assumptions. However,
the API entirely hides selector variables and assumptions from the user, which
facilitates the integration of DepQBF in other tools. We present implementation
details and, for the first time, report on experiments related to the
computation of MUCs of QBFs using DepQBF's novel clause group API.Comment: (fixed typo), camera-ready version, 6-page tool paper, to appear in
proceedings of SAT 2015, LNCS, Springe
Density-Matrix-Power Functional: Performance for Finite Systems and the Homogeneous Electron Gas
An exchange correlation energy functional involving fractional power of the
one-body reduced density matrix [Phys. Rev. B {\bf 78}, 201103 (2008)] is
applied to finite systems and to the homogeneous electron gas. The performance
of the functional is assessed for the correlation and atomization energies of
the molecules contained in the G2 set and for the correlation energy of the
homogeneous electron gas. High accuracy is found for these two very different
types of systems.Comment: 4 figures 4 page
Interband mixing between two-dimensional states localized in a surface quantum well and heavy hole states of the valence band in narrow gap semiconductor
Theoretical calculations in the framework of Kane model have been carried out
in order to elucidate the role of interband mixing in forming the energy
spectrum of two-dimensional carriers, localized in a surface quantum well in
narrow gap semiconductor. Of interest was the mixing between the 2D states and
heavy hole states in the volume of semiconductor. It has been shown that the
interband mixing results in two effects: the broadening of 2D energy levels and
their shift, which are mostly pronounced for semiconductors with high doping
level. The interband mixing has been found to influence mostly the effective
mass of 2D carriers for large their concentration, whereas it slightly changes
the subband distribution in a wide concentration range.Comment: 12 pages (RevTEX) and 4 PostScript-figure
The violation of the Hund's rule in semiconductor artificial atoms
The unrestricted Pople-Nesbet approach for real atoms is adapted to quantum
dots, the man-made artificial atoms, under applied magnetic field. Gaussian
basis sets are used instead of the exact single-particle orbitals in the
construction of the appropriated Slater determinants. Both system chemical
potential and charging energy are calculated, as also the expected values for
total and z-component in spin states. We have verified the validity of the
energy shell structure as well as the Hund's rule state population at zero
magnetic field. Above given fields, we have observed a violation of the Hund's
rule by the suppression of triplets and quartets states at the 1p energy shell,
taken as an example. We also compare our present results with those obtained
using the LS-coupling scheme for low electronic occupations. We have focused
our attention to ground-state properties for GaAs quantum dots populated up to
forty electrons.Comment: 5 pages, 2 figures, submitted to Semic. Sci. Techno
Rede de recursos genéticos animais da Embrapa: espécies nativas com potencial econômico.
É previsto um grande aumento da população humana nas regiões em desenvolvimento do globo nos próximos anos. Tais regiões serão inevitavelmente demandadas por aumento na produção de alimentos. Espécies ainda não domesticadas ou semi-domesticadas possuem enorme potencial para alimentar o número crescente de pessoas do planeta. Ciente de tais desafios, a Embrapa inclui desde 2009 em sua Plataforma Nacional de conservação de Recursos Genéticos, os animais silvestres de interesse econômico. Coleções de animais, bancos de DNA e bancos de germoplasma são mantidos por unidades da empresa e por parceiros da rede, com vistas ao desenvolvimento do setor agropecuário em bases sustentáveis. A plataforma e suas redes de conservação de recursos genéticos propiciam pesquisas sobre as espécies conservadas, gerando uma notável quantidade de informações sobre o genótipo, o fenótipo e o potencial aproveitamento de tais animais em sistemas sustentáveis de produção, para benefício da população humana. Por seu caráter contínuo, a necessidade de captar recursos para manutenção das ações da plataforma é constante
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