Tetra-μ-acetato-κ4 O:O′;κ3 O,O′:O;κ3 O:O,O′-bis­[(acetato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)europium(III)]

In the title centrosymmetric dinuclear complex, [Eu2(CH3CO2)6(C12H8N2)2], the EuIII atom is nine-coordinated by two N atoms from a 1,10-phenanthroline ligand and seven O atoms from five acetate ligands (two bidentate, three monodentate). The crystal structure is stabilized by π–π stacking inter­actions between the pyridine and benzene rings of adjacent mol­ecules, with a centroid–centroid distance of 3.829 (2) Å

Entropic Upper Bound on Gravitational Binding Energy

We prove that the gravitational binding energy {\Omega} of a self gravitating system described by a mass density distribution {\rho}(x) admits an upper bound B[{\rho}(x)] given by a simple function of an appropriate, non-additive Tsallis' power-law entropic functional Sq evaluated on the density {\rho}. The density distributions that saturate the entropic bound have the form of isotropic q-Gaussian distributions. These maximizer distributions correspond to the Plummer density profile, well known in astrophysics. A heuristic scaling argument is advanced suggesting that the entropic bound B[{\rho}(x)] is unique, in the sense that it is unlikely that exhaustive entropic upper bounds not based on the alluded Sq entropic measure exit. The present findings provide a new link between the physics of self gravitating systems, on the one hand, and the statistical formalism associated with non-additive, power-law entropic measures, on the other hand

Optical properties of polydisperse submicrometer aggregates of sulfur-containing zinc oxide consisting of spherical nanocrystallites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Spherical microparticles formed by agglomerated spherical nanocrystals of sulfur-containing ZnO were prepared by homogeneous precipitation of ZnS followed by thermal treatment under an air atmosphere. The samples were characterized by thermogravimetry (TG), X-ray diffraction (XRD) and Raman, UV-Vis diffuse reflectance (DRS) and photoluminescence (PL) spectroscopies. The particle morphologies were observed by transmission and scanning electron microscopies (TEM and SEM), showing that spherical microparticles of sulfur-containing ZnO are formed by aggregates of 25 nm spherical nanocrystallites. XRD and TEM results show the presence of ZnO and ZnS phases for short time thermal treatments and only the ZnO wurtzite phase for longer thermal treatments. The presence of Zn-S bonds in sulfur-containing zinc oxide decreases the ZnO band gap energy as verified by DRS, probably due to a valence band offset.354902908Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Towards predicting liquid fuel physicochemical properties using molecular dynamics guided machine learning models

Accurate determination of fuel properties of complex mixtures over a wide range of pressure and temperature conditions is essential to utilizing alternative fuels. The present work aims to construct cheap-to-compute machine learning (ML) models to act as closure equations for predicting the physical properties of alternative fuels. Those models can be trained using the database from MD simulations and/or experimental measurements in a data-fusion-fidelity approach. Here, Gaussian Process (GP) and probabilistic generative models are adopted. GP is a popular non-parametric Bayesian approach to build surrogate models mainly due to its capacity to handle the aleatory and epistemic uncertainties. Generative models have shown the ability of deep neural networks employed with the same intent. In this work, ML analysis is focused on two particular properties, the fuel density and diffusion, but it can also be extended to other physicochemical properties. This study explores the versatility of the ML models to handle multi-fidelity data. The results show that ML models can predict accurately the fuel properties of a wide range of pressure and temperature conditions.The research leading to these results had received funding from the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) through Programa de Recursos Humanos (PRH) under the PRH 8 - Mechanical Engineering for the Efficient Use of Biofuels, grant agreement numbers F0A5.EDDE.B5C0.3BCB and 2B61.4F5C.A83B.A713.Peer ReviewedPostprint (published version

Areas of natural occurrence of melipona scutellaris Latreille, 1811(Hymenoptera: Apidae) in the state of Bahia, Brazil.

The bee Melipona scutellaris is considered the reared meliponine species with the largest distribution in the North and Northeast regions of Brazil, with records from the state of Rio Grande do Norte down to the state of Bahia. Considering the importance of this species in the generation of income for family agriculture and in the preservation of areas with natural vegetation, this study aimed at providing knowledge on the distribution of natural colonies of M. scutellaris in the state of Bahia. Literature information, interviews with stinglessbee beekeepers, and expeditions were conducted to confirm the natural occurrence of the species. A total of 102 municipalities showed records for M. scutellaris, whose occurrence was observed in areas ranging from sea level up to 1,200-meter height. The occurrence of this species in the state of Bahia is considered to be restricted to municipalities on the coastal area and the Chapada Diamantina with its rainforests. Geographic coordinates, elevation, climate and vegetation data were obtained, which allowed a map to be prepared for the area of occurrence in order to support conservation and management policies for the species

COPPER FRACTIONATION IN PROTEINS FROM PLASMA, MUSCLE AND LIVER OF NILE TILAPIA

COPPER FRACTIONATION IN PROTEINS FROM PLASMA, MUSCLE AND LIVER OF NILE TILAPIA. Copper fractionation in plasma, muscle and liver of Nile tilapia was performed after protein separation by 2D-PAGE. SR XRF analysis indicated the presence of copper in three protein spots of plasma, and in two protein spots of muscle and liver, respectively. Copper ions were found to be distributed mostly in proteins that had a molar mass of less than 54 kDa and greater than 13 kat and a pI in the 5.3-9.3 range. The copper concentration bound to these proteins was determined by GFAAS which showed concentrations in the 1.20-4.82 mg g(-1) range.35349349