Density Matrices
Mostrando 1-12 de 53 artigos, teses e dissertações.
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1. Microplastics in Latin America Ecosystems: A Critical Review of the Current Stage and Research Needs
The ubiquity of microplastics ecosystems has gained global attention. In this context, Latin America, which is responsible for 8% of the world’s consumption of plastic material and has a small recycling rate (4.5%), does not have enough data on microplastics contamination in its environmental matrices. This systematic review analyzed 196 studies from 16 te
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Intercalation of Apocarotenoids from Annatto (Bixa orellana L.) into Layered Double Hydroxides
Synthetic conditions were evaluated to intercalate norbixin into layered double hydroxides (LDH). Norbixin was isolated from a hydrosoluble commercial annatto extract. LDH samples comprising M2+/Al3+ (M = Mg, Zn) were synthesized by coprecipitation and characterized by X-ray diffraction, thermal analysis coupled to mass spectrometry, vibrational spectroscopi
J. Braz. Chem. Soc.. Publicado em: 2020-11
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3. Effect of Propolis on Streptococcus mutans Biofilm Formation
Abstract Objective: To evaluate the susceptibility of S. mutans during growth as a biofilm in the presence of different concentrations of propolis. Material and Methods: Three different concentrations of ethanolic extract of propolis (10%, 5%, and 2.5%) were used to evaluate its potential to attenuate the biofilm formation of S. mutans (ATCC 25175) on micr
Pesqui. Bras. Odontopediatria Clín. Integr.. Publicado em: 13/01/2020
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4. Preparation of Syntactic Foams made from Green Polyethylene and Glass Microspheres: Morphological and Mechanical Characterization
Polymeric syntactic foams are composites made from the mixture of Hollow Glass Microspheres (HGM) and polymer matrices. One of their main characteristics is their low density and the production of these composites using a matrix derived from renewable sources potentiates their development without neglecting sustainability. In this paper , the properties of H
Mat. Res.. Publicado em: 11/11/2019
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5. Reuse of iron ore tailings in the production of geopolymer mortars
Abstract A great variety of silica and alumina-rich materials have been investigated in the production of alkaline activated binders (or geopolymers) with low environment impact, e.g. low CO2 emissions. Geopolymer mortars and concretes may be more environmentally friendly if not only Portland cement but also natural aggregates (sand, gravel) are replaced wit
REM, Int. Eng. J.. Publicado em: 16/09/2019
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6. Efecto de la adición de bentonita sobre las propiedades ópticas de diferentes materiales compuestos poliméricos
ABSTRACT In this work, composite materials were obtained by the incorporation of bentonite to biodegradable and synthetic polymeric matrices. Commercial (BE) and natural (BM) bentonite samples were employed, as well as three different polymeric matrices: thermoplastic corn starch (TPS), high density polyethylene (HDPE) and a poly(styrene-b-butadiene-b-styren
Matéria (Rio J.). Publicado em: 19/07/2018
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7. Pulse Eletrodeposition of Ni/nano-Al2O3 Composite Coatings on Cast Iron Cylinder Liner
Ni/nano-Al2O3 composite coating by pulse electrodeposition method has been used for coating on cast iron liner material. The hardness has been increased from 308 HV to 1050 HV through conventional Watts bath and by applying Taguchi's optimization technique with optimum parameters of pulse frequency 120 Hz, duty cycle 40% and peak current density 0.7A/cm2. Th
Mat. Res.. Publicado em: 26/03/2018
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8. Evaluation of bacterial diversity recovered from petroleum samples using different physical matrices
ABSTRACT Unraveling the microbial diversity and its complexity in petroleum reservoir environments has been a challenge throughout the years. Despite the techniques developed in order to improve methodologies involving DNA extraction from crude oil, microbial enrichments using different culture conditions can be applied as a way to increase the recovery of D
Braz. J. Microbiol.. Publicado em: 2016-09
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9. Nanocomposite of Poly(Lactic Acid)/Cellulose Nanocrystals: Effect of CNC Content on the Polymer Crystallization Kinetics
The barrier and mechanical properties of polymer matrices are affected by the polymer crystallization kinetics and the incorporation of nanoparticles can modify the nucleation density as well as the rate and mechanism of crystallization. In this study, a nanocomposite of poly(lactic acid) (PLA) containing cellulose nanocrystals (CNC) was prepared in order to
J. Braz. Chem. Soc.. Publicado em: 2016-05
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10. Physicochemical, Mechanical and Morphologic Characterization of Purple Banana Fibers
Weather conditions and the Brazilian fertile soil contribute to abundant natural resources in a wide variety of fiber types. These fibers have attracted interest in Materials Science area for such characteristics as: low cost, high elasticity modulus and renewability. In this context, the objective of this work was physical, chemical and morphological charac
Mat. Res.. Publicado em: 04/12/2015
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11. A Modified Computational Scheme for the Stochastic Perturbation Finite Element Method
Abstract A modified computational scheme of the stochastic perturbation finite element method (SPFEM) is developed for structures with low-level uncertainties. The proposed scheme can provide second-order estimates of the mean and variance without differentiating the system matrices with respect to the random variables. When the proposed scheme is used, it i
Lat. Am. j. solids struct.. Publicado em: 2015
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12. Effects of spatial and environmental factors on benthic a macroinvertebrate community
Interactions between terrestrial and aquatic systems influence the structure of river habitats and, consequently, affect their benthic macroinvertebrate composition. The aim of this study was to evaluate the effects of spatial and environmental variables (local physical and chemical variables of water and regional landscape characteristics) on the benthic ma
Zoologia (Curitiba). Publicado em: 12/09/2014