Publicações - ciências exatas e da terra
|
DANTAS, AUGUSTO;
Aurora Trinidad Ramirez Pozo
Palavra-chave:
algoritmos evolutivos;
algoritmos bio-inspirados;
Aprendizado de Maquina;
meta-aprendizado
Áreas do conhecimento:
Ciências Exatas e da Terra; Metodologia e Técnicas da Computação; Inteligencia Artificial
resumo ...
|
|
Natalia Cristina Ortiz;
Cassius Tadeu Scarpin;
José Eduardo Pécora Junior;
Angel Ruiz
Palavra-chave:
Online scheduling;
Single Machine;
Setup dependent
Áreas do conhecimento:
Engenharias; Pesquisa Operacional; Programação Linear, Não-Linear, Mista e Dinâmica;
Ciências Exatas e da Terra; Ciência da Computação; Matemática da Computação; Modelos Analíticos e de Simulação
resumo ...
|
|
CECCON, JURANDIR;
Carlos Eduardo Duran Fernandez;
MONTENEGRO, MARCOS
Palavra-chave:
Gagliardo-Nirenberg inequalities;
Calculus of Variations;
Finsler geometry
Áreas do conhecimento:
Ciências Exatas e da Terra; Análise; Equações Diferenciais Parciais;
Ciências Exatas e da Terra; Matemática; Análise; Análise Funcional Não-Linear
resumo ...
Let M be a smooth compact manifold of dimension
$$n \ge 1$$
without boundary endowed with a volume form
$$\omega $$
and a fibrewise norm
$$\mathcal {N}:T^*M \rightarrow \mathbb {R}$$
. For any
$$p > q \ge 1$$
and corresponding interpolation parameter
$$\theta $$
, we prove that the optimal normed Nash inequality holds for any smooth function u on M,
$$\begin{aligned} \left( \int _M |u|^p\; \omega \right) ^{1/p \theta }\le & {} \left( N_{\mathrm{{opt}}} \left( \int _M \mathcal {N}^p(\mathrm{{d}}u)\; \omega \right) ^{1/p} \right. \\&+ \left. B\left( \int _M |u|^p\; \omega \right) ^{1/p} \right) \left( \int _M |u|^q\; \omega \right) ^{(1 - \theta )/\theta q} \end{aligned}$$
for some constant B, where
$$N_{\mathrm{{opt}}}$$
is the best possible constant. Its importance can be viewed from two perspectives. Firstly, this inequality is a powerful tool in the study of normed entropy and isoperimetrical inequalities on manifolds which have been established in the flat context by Gentil (J Funct Anal 202:591–599, 2003) and Cordero-Erausquin, Nazaret and Villani (Adv Math 182:307–332, 2004), , respectively. Secondly, this work introduces an appropriate framework to study Sobolev type inequalities on manifolds endowed with a very general way of measuring the involved quantities, instead of using the restricted Riemannian context.
|
|
BRANCHER, JOAO A;
BEGNINI, GILMAR J;
Ana Tereza Bittencourt Guimaraes;
DE ARAUJO, MELISSA R;
PIZZATTO, EDUARDO
Palavra-chave:
Attention deficit hyperactivity disorder;
Behavior,;
cárie;
Children;
Oral health
Áreas do conhecimento:
Ciências da Saúde; Farmacologia; Transmissão Neuromuscular;
Ciências Exatas e da Terra; Probabilidade e Estatística; Bioestatística
resumo ...
|
|
TIBIRIÇÁ, CARLOS EDUARDO J. A.;
LEITE, ISABEL P.;
BATISTA, TALITA V. V.;
FERNANDES, LUCIANO F.;
CHOMÉRAT, NICOLAS;
HERVE, FABIENNE;
HESS, PHILIPP;
Luiz Laureno Mafra Júnior
Palavra-chave:
harmful algae;
benthic microalgae;
toxic dinoflagellates;
ovatoxin;
Marine pollution;
plastic litter
Áreas do conhecimento:
Ciências Exatas e da Terra; Oceanografia Biológica; Interação entre os Organismos Marinhos e os Parâmetros Ambientais;
CIENCIAS_AGRARIAS; Recursos Pesqueiros e Engenharia de Pesca; Aqüicultura; Piscicultura;
Ciências Exatas e da Terra; Oceanografia; Oceanografia Química; Interações Químico-Biológicas/Geológicas das Substâncias Químicas da Água do Mar
resumo ...
Ostreopsis cf. ovata is a toxic marine benthic dinoflagellate responsible for harmful blooms affecting ecosystem and human health, mostly in the Mediterranean Sea. In this study we report the occurrence of a summer O. cf. ovata bloom in Currais, a coastal archipelago located on the subtropical Brazilian coast (~25° S). This bloom was very similar to Mediterranean episodes in many aspects: (a) field-sampled and cultivated O. cf. ovata cells aligned phylogenetically (ITS and LSU regions) along with Mediterranean strains; (b) the bloom occurred at increasing temperature and irradiance, and decreasing wind speed; (c) cell densities reached up to 8.0 × 104 cell cm−2 on fiberglass screen and 5.6 × 105 cell g−1 fresh weight on seaweeds; (d) and toxin profiles were composed mostly of ovatoxin-a (58%) and ovatoxin-b (32%), up to 35.5 pg PLTX-eq. cell−1 in total. Mussels were contaminated during the bloom with unsafe toxin levels (up to 131 µg PLTX-eq. kg−1). Ostreopsis cells attached to different plastic litter, indicating an alternate route for toxin transfer to marine fauna via ingestion of biofilm-coated plastic debris.
|
|
Barbara Maichak de Carvalho;
Henry Louis Spach;
André Martins Vaz dos Santos;
Alexandra Volpeto
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM,
v. 99,
p. 10-18,
2019
Palavra-chave:
In vitro digestion;
Sciaenidae;
shape;
trophic ecology
Áreas do conhecimento:
Ciências Exatas e da Terra; Oceanografia Biológica; Interação entre os Organismos Marinhos e os Parâmetros Ambientais
resumo ...
|
|
José Varalda;
DARTORA, C.A;
DE CAMARGO, P. C.;
DE OLIVEIRA, A. J. A.;
MOSCA, D. H.
Palavra-chave:
ceria;
cerium oxide;
Magnetic properties
Áreas do conhecimento:
Ciências Exatas e da Terra; Física; Física da Matéria Condensada; Materiais Magnéticos e Propriedades Magnéticas
resumo ...
Several experimental works currently demonstrate that metallic nano-oxides and carbon nanomaterials expected to be diamagnets, in fact, behave as ferromagnets at room temperature. More than scientifically intriguing, this unconventional and unexpected ferromagnetism pave the way for innovation products and novel nanotechnological applications, gathering the magnetism to interesting functionalities of these nanomaterials. Here, we investigate the non-conventional ferromagnetism observed at high temperatures in nanocrystalline cerium dioxide (CeO2or nanoceria) thin films that are optically transparent to visible light. Nanoceria exhibits several concrete applications in catalytic processes, photovoltaic cells, solid-state fuel cells, among others, which are mostly due to natural presence of oxygen vacancies and easy migration of the oxygen through the structure. The ferromagnetism in non-stoichiometric nanocrystaline ceria can be consistently described by ab initio electronic structure calculations, which support that oxygen vacancies cause the formation of magnetic moments and can provide a robust interconnectivity within magnetic polarons theoretical framework. Additionally, we present a conceptual model to account the oxygen transport to the non-conventional ferromagnetism at temperatures well above room temperature. The approach is complementary to the thermally-activated effective transfers of charge and spin around oxygen vacancy centers.
|
|
José Varalda;
DARTORA, C. A.;
DE CAMARGO, P. C.;
aDILSON J. A. DE OLIVEIRA;
Dante Homero Mosca
Palavra-chave:
ceria thin films;
CeO2;
magnetism;
vacancy migration;
Oxygen difusion
Áreas do conhecimento:
Ciências Exatas e da Terra; Física; Física da Matéria Condensada;
Ciências Exatas e da Terra; Física; Física da Matéria Condensada; Materiais Magnéticos e Propriedades Magnéticas
resumo ...
Several experimental works currently demonstrate that metallic nano-oxides and carbon nanomaterials expected to be diamagnets, in fact, behave as ferromagnets at room temperature. More than scientifically intriguing, this unconventional and unexpected ferromagnetism pave the way for innovation products and novel nanotechnological applications, gathering the magnetism to interesting functionalities of these nanomaterials. Here, we investigate the non-conventional ferromagnetism observed at high temperatures in nanocrystalline cerium dioxide (CeO2or nanoceria) thin films that are optically transparent to visible light. Nanoceria exhibits several concrete applications in catalytic processes, photovoltaic cells, solid-state fuel cells, among others, which are mostly due to natural presence of oxygen vacancies and easy migration of the oxygen through the structure. The ferromagnetism in non-stoichiometric nanocrystaline ceria can be consistently described by ab initio electronic structure calculations, which support that oxygen vacancies cause the formation of magnetic moments and can provide a robust interconnectivity within magnetic polarons theoretical framework. Additionally, we present a conceptual model to account the oxygen transport to the non-conventional ferromagnetism at temperatures well above room temperature. The approach is complementary to the thermally-activated effective transfers of charge and spin around oxygen vacancy centers.
|
|
Fernando de Ávila Silva;
Alexandre Kirilov
Palavra-chave:
Global Hypoellipticity;
Invariant Operators;
Kato?Rellich perturbations;
Low order perturbations
Áreas do conhecimento:
Ciências Exatas e da Terra; Análise; Equações Diferenciais Parciais;
Ciências Exatas e da Terra; Matemática; Análise; Equações Diferenciais Parciais
resumo ...
Analyzing the behavior at infinity of the sequence of eigenvalues given by matrix symbol of a invariant operator with respect to a fixed elliptic operator, we obtain necessary and sufficient conditions to ensure that perturbations of globally hypoelliptic operators continue to have this property. As an application, we recover classical results about perturbations of constant vector fields on the torus and extend them for more general classes of perturbations. Additionally, we construct examples of low order perturbations that destroy the global hypoellipticity, in the presence of diophantine phenomena
|
|
Carlos Eduardo Lunelli;
Duane Maciel Scremin;
Danilo Yokio Miyazaki;
Simone Adriane da Silva;
ZAWADZKI, SÔNIA F.
Palavra-chave:
Poli(ethylene therephthalate);
Chemical recycling;
polyurethanes;
Adhesives;
Properties evaluation
Áreas do conhecimento:
Ciências Exatas e da Terra; Química; Química Orgânica; Polímeros e Colóides;
Ciências Exatas e da Terra; Química; Química de Materiais
resumo ...
|
