Transition Metals
Mostrando 1-12 de 139 artigos, teses e dissertações.
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1. WSOC and Its Relationship with BC, Levoglucosan and Transition Metals in the PM2.5 of an Urban Area in the Amazon
Water-soluble organic carbon (WSOC) makes up a large mass fraction of the organic carbon in the aerosol and can influence important cloud processes in the atmosphere. The capacity of WSOC to form metallic complexes with transition metals is well known; however, its influence on the aerosol of urban areas in the Amazon region is not very well known. In this s
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Thermostimulated crystal structure transformation of the polymineral clay submicron particles
Abstract Changes in the structure of phyllosilicate microparticles of submicron fractions of polymineral clay with an average size of 290 nm, as well as changes in the positions of impurity ions of transition metals in the crystal lattice, were studied by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and high-resolution electron parama
Cerâmica. Publicado em: 2022
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3. Easily applicable protocol to formulate inks for extrusion-based 3D printing
Abstract 3D printing is a disruptive technology that is a key driver of the new industrial revolution. Among the various 3D printing methods, direct-ink-writing (DIW) takes a viscous ink material, extrudes it through a nozzle, and deposits it layer-by-layer to create 3D objects. DIW is a versatile method that can print ceramics, polymers, metals, living cell
Cerâmica. Publicado em: 2022
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4. Adsorption of Calcium(II), Cadmium(II) and Copper(II) Ions from Water by Prepared Silicon-Aluminum-Zirconium Oxide Using Sol-Gel Process
Ternary oxide silica-alumina-zirconia (SiO2/Al2O3/ZrO2) obtained by the sol-gel process was applied as novel adsorbent of ions in aqueous solution. Batch isotherms were performed using standard CuII, CdII and CaII solutions at variable pH and different concentrations. Adsorption capacity was best at weakly acidic pH. The maximum adsorption capacities were 2.
J. Braz. Chem. Soc.. Publicado em: 2021-07
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5. Theoretical Study of the Reactivity of Phenyl Radicals Toward Enol Acetates
Arylation reactions are an important class of reactions and allow the synthesis of natural and synthetic products. Despite the efficient, but high cost and toxic methodologies involving transition metals, radical arylations have gained importance after the advent of photoredox catalysis. Arylation of enol acetates is an important tool for obtaining aryl keto
J. Braz. Chem. Soc.. Publicado em: 2021-02
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6. Mitral Valve Replacement with Regent Aortic Valve in Severe Mitral Stenosis
Arylation reactions are an important class of reactions and allow the synthesis of natural and synthetic products. Despite the efficient, but high cost and toxic methodologies involving transition metals, radical arylations have gained importance after the advent of photoredox catalysis. Arylation of enol acetates is an important tool for obtaining aryl keto
Int. J. Cardiovasc. Sci.. Publicado em: 2021-02
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7. USO DA TEORIA DO FUNCIONAL DE DENSIDADE NA ANÁLISE DE SPIN CROSSOVER EM AULAS DE QUÍMICA INORGÂNICA
Spin crossover is a property found in some coordination compounds formed by the first series of transition metals with d4-d7 configuration. These complexes, when stimulated by an external factor (temperature, light, etc.), can be converted from their low spin states to high spin states, or vice versa. However, this issue is not addressed in the Inorganic Che
Quím. Nova. Publicado em: 2020-01
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8. Effect of Growth Velocity and Zn Content on Microhardness in Directionally Solidified Al-Zn Alloys
In this study, Al-xZn (x=1, 3, 5, 7, 10 and 20 wt. %) alloys were prepared using metals of 99.99% high purity in the vacuum atmosphere. These alloys were directionally solidified upward with a constant temperature gradient, G (10.3 K/mm) and different growth velocities (V) between 8.25 and 165 µm/s in the directional solidification apparatus. The experiment
Mat. Res.. Publicado em: 13/09/2018
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9. Influence of Small Content Elements Additions on the Glass Forming Ability of Zr-based Bulk Metallic Glasses Alloys
The present work reports investigation on the Glass Forming Ability (GFA) of Zr-based Bulk Metallic Glasses (BMG’s) by microalloying with early transition metals. GFA was measured as the amorphous fraction formed in samples with different diameters using optical microscopy (OM) and image analysis techniques. Samples with the highest GFA had their oxygen co
Mat. Res.. Publicado em: 06/09/2018
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10. Synthesis and characterization of lithiated nanostructures
ABSTRACT Regardless of the simple accumulation of ions in the crystal insertion sites, nanomaterials offer a new storage mechanism of lithium ions (Li+), these storage mechanisms are formed in the interfaces and inside of the nanopores. Such kinds of storage mechanisms have no effect on the structure of the electrode material. Consequently, the charge-discha
Matéria (Rio J.). Publicado em: 19/07/2018
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11. In vitro Evaluation of Oxidative Stress Caused by Fine Particles (PM2.5) Exhausted from Heavy-Duty Vehicles Using Diesel/Biodiesel Blends under Real World Conditions
In this work, the redox activity of fine diesel/biodiesel particulate matter (PM2.5) was studied in order to approach its toxicity from reactive oxygen species, due to adverse effects it may cause to human health. The oxidative potential was measured by the dithiothreitol (DTT) assay in order to study the relative contribution of water-soluble transition met
J. Braz. Chem. Soc.. Publicado em: 2018-06
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12. CO Tolerance and Stability of Proton Exchange Membrane Fuel Cells with Nafion® and Aquivion® Membranes and Mo-Based Anode Electrocatalysts
This work presents a CO tolerance study of PtMo/C (70:30, Pt:Mo) and Pt/MoO2-C anode catalysts on proton exchange membrane fuel cells (PEMFC) with Nafion® and Aquivion® ionomer membranes. Results denote improved activity for the hydrogen oxidation reaction (HOR) in the presence of CO on both anode catalysts at 85 ºC. Experiments of identical location tran
J. Braz. Chem. Soc.. Publicado em: 2018-05