Physical Chemistry
Mostrando 1-12 de 236 artigos, teses e dissertações.
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1. Oxigênio no contexto da COVID-19: o que sabemos sobre a molécula que respiramos e o papel central da química
OXYGEN IN THE COVID-19 CONTEXT: WHAT WE KNOW ABOUT THE MOLECULE WE BREATHE AND THE CENTRAL ROLE OF CHEMISTRY. In this work, the role of chemistry in the coronavirus disease 2019 (COVID-19) pandemic is highlighted through the medical oxygen supply crises in Brazil, as an example of oxygen utility in health. Starting from oxygen chemical characterization, the
Química Nova. Publicado em: 2022
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2. NORBORNADIENO: SÍNTESE E APLICAÇÕES
Bicyclo[2.2.1]hepta-2,5-diene or norbornadiene (NBD) is a bicyclic hydrocarbon molecule used in many fields of chemistry since its first synthesis in 1950. NBD is the precursor of Aldrin, an agrochemical that was commonly used as an insecticide until the end of the XX century. Norbornadiene is capable of interconverting into its isomer, quadricyclane (QC), b
Química Nova. Publicado em: 2022
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3. Diesel-Like Biofuels Production Using Fatty Waste
According to the waste-to-energy (WTE) valorization and circular economy principles, the use of waste oil and grease (WOG) for obtaining biofuels shows the tendency towards sustainability, makes the interest in green chemistry, and the development of environmentally friendly processes grow. Three different fatty wastes (from the fat trap of a sewage station,
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Lignin-modified road marking paint: weathering aging studies
Abstract The accelerated artificial aging with ultraviolet radiation, viscosity, density, no-pick-up time, flexibility, and abrasion resistance of lignin-modified road marking paint were evaluated. The addition of lignin did not cause significant changes in the physical chemistry, flexibility and no-pick-time test compared to the precursor paint. The additio
REM, Int. Eng. J.. Publicado em: 2021-06
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5. WILHELM OSTWALD PARA ALÉM DO ANTIATOMISMO
The Baltic German chemist Wilhelm Ostwald (1853-1932) had his scientific prestige eclipsed in the history of chemistry due to his rejection to atomic theory, which suggests the permanence of the whig interpretation on history of chemistry in the narratives about him. In this paper, we intend to present elements on Ostwald’s biography far from his role in t
Quím. Nova. Publicado em: 2021-02
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6. On Democritean Rhysmos
Abstract: In Metaphysics A.4 (985b4-19 ENT#091;DK67 A6ENT#093;), Aristotle provides crucial information about fundamental aspects of the chemistry and microphysics of the atomic theory of Leucippus and Democritus of Abdera. Besides the plenum and the void, which he identifies as the elements of the atomic theory, he presents what he himself names as differen
Rev. Archai. Publicado em: 26/09/2019
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7. Apatite multi-generations in the Três Estradas Carbonatite, Southern Brazil: physical and chemistry meaning and implications to phosphate ore quality
Abstract Carbonatites were recently discovered in Southern Brazil, which increased the interest to evaluate the economic potential of these uncommon rocks, especially the Três Estradas Carbonatite. Carbonates are the dominant minerals of fresh rock followed by apatite, but the weathering process makes apatite abundant. We focused on apatite from the carbona
Braz. J. Geol.. Publicado em: 01/07/2019
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8. UMA AULA DE WALTHER NERNST NO BRASIL
Walther Hermann Nernst is known to have established the basis for the third law of thermodynamics and also as one of the founders of the modern physical chemistry. For his work in chemical thermodynamics, he was awarded the Nobel Prize in chemistry, in 1920. An important fact about this scientist life, not always realized, was his stay in Brazil, in 1914, fo
Quím. Nova. Publicado em: 02/05/2019
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9. RM1 Semiempirical Model: Chemistry, Pharmaceutical Research, Molecular Biology and Materials Science
In this review, we show improvements to the semiempirical quantum chemical method RM1 and present a wide range of its applications as reported by researchers of various areas, such as theoretical, organic, physical, analytical, and inorganic chemistry, as well as their interfaces with medicinal chemistry, biology, and materials science. Success of RM1 is see
J. Braz. Chem. Soc.. Publicado em: 2019-04
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10. Equipartition of energy, Avogadro law and ratio of specific heats
Abstract The equipartition of energy in its simplest form, which is related to the translational motion of the molecules of a gas, was announced independently by Waterston in 1845 and by Clausius in 1857. In its more general form, it was formulated by Maxwell in 1860. Together with the relation between pressure and translational motion, given by the kinetic
Rev. Bras. Ensino Fís.. Publicado em: 18/02/2019
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11. Limnology of shallow lakes of the semi-arid Central Pampa of Argentina
Resumo Objetivo No Pampa Central da Argentina, há três regiões fitogeográficas criadas pela diminuição da precipitação vinda do oeste. Essa região possui um grande número de lagos sendo a maioria desses temporários com hidroperíodos definidos por ciclos climáticos, embora alterados pela ação antrópica. Alguns desses lagos foram estudados co
Acta Limnol. Bras.. Publicado em: 18/02/2019
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12. Mass Spectrometry Study of Ammonia Formed During Plasma Nitrocarburizing and Nitriding Processes
In this work, we used mass spectrometry to investigate ammonia (NH3) formed during the nitrocarburizing and nitriding processes of α-Fe sintered and low alloy steel by using d.c. glow discharges in different N2/H2/CH4 gas concentration mixtures. Experiments were conducted using two different configurations: one to collect and analyze species probed primaril
Mat. Res.. Publicado em: 16/07/2018