Výsledky vyhledávání - "Helion Vargas"

Akademický článek

Characterization of Cuban and Brazilian natural zeolites by photoacoustic spectroscopy and electron paramagnetic resonance

Autor: ARLEM LARA-BERNAL, MARCELO G. DA SILVA, LEONARDO MOTA, ERNESTO MARÍN, THALLIS C. CORDEIRO, EDSON C. DA SILVA, DANIEL A. VIANA, HELION VARGAS, JOSÉ CARLOS POLIDORO, MARISA BEZERRA DE MELLO-MONTE

Publikováno v: Anais da Academia Brasileira de Ciências, Vol 94, Iss 1 (2022)

Abstract This report describes the photoacoustic and electron paramagnetic resonance investigations of Brazilian and Cuban zeolites. Photoacoustic optical absorption measurements indicate the presence of iron (Fe 3 +) ions with their respective trans

Externí odkaz: https://doaj.org/article/6c6ad35f1969484cbee80ba44ec4459f

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Akademický článek

Detection of Greenhouse Gas Precursors from Diesel Engines Using Electrochemical and Photoacoustic Sensors

Autor: Aline Rocha, Layse Campos, Laisa Brasil, Guilherme Lima, Marcelo Sthel, Maria Castro, Geórgia Mothé, Helion Vargas

Publikováno v: Sensors, Vol 10, Iss 11, Pp 9726-9741 (2010)

Atmospheric pollution is one of the worst threats to modern society. The consequences derived from different forms of atmospheric pollution vary from the local to the global scale, with deep impacts on climate, environment and human health. Several g

Externí odkaz: https://doaj.org/article/30d46258a0504f94a28b51e2ab2ee93d

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Akademický článek

A Sulfur Hexafluoride Sensor Using Quantum Cascade and CO2 Laser-Based Photoacoustic Spectroscopy

Autor: Helion Vargas, Delson Schramm, Marcelo da Silva, Mila Rocha, Marcelo Sthel, Guilherme Lima, András Miklós

Publikováno v: Sensors, Vol 10, Iss 10, Pp 9359-9368 (2010)

The increase in greenhouse gas emissions is a serious environmental problem and has stimulated the scientific community to pay attention to the need for detection and monitoring of gases released into the atmosphere. In this regard, the development o

Externí odkaz: https://doaj.org/article/a90ea721e64f4b4d952bb249f8821b11

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Akademický článek

Nutrient release by a Brazilian sedimentary zeolite

Autor: Marisa B.M. Monte, Antonieta Middea, Paulo R.P. Paiva, Alberto C.C. Bernardi, Nélio G.A.M. Rezende, Milton Baptista-Filho, Marcelo G. Silva, Helion Vargas, Helio S. Amorim, Fernando de Souza-Barros

Publikováno v: Anais da Academia Brasileira de Ciências, Vol 81, Iss 4, Pp 641-653 (2009)

This report describes the characterization of a sedimentary occurrence from the Parnaíba Basin, Brazil, containing the zeolite stilbite intertwined with smectitic clay mineral. The head samples from different sites present a wide content range of th

Externí odkaz: https://doaj.org/article/c3d69aa047da4b659e42b1c13a0184f7

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Akademický článek

Determination of thermal diffusivity in papaya pulp as a function of maturation stage Determinação da difusividade térmica da polpa de mamão em função do estádio de maturação

Autor: Savio Figueira Corrêa, Maximiliano Silva de Souza, Talita Pereira, Gustavo Verçosa de Lima Alves, Jurandi Gonçalves de Oliveira, Marcelo Gomes da Silva, Helion Vargas

Publikováno v: Revista Brasileira de Fruticultura, Vol 30, Iss 3, Pp 611-615 (2008)

In order to determine the penetration of the thermal wave in the papaya fruit pulp (Carica papaya L.), cv. Golden, thermal diffusivity of the pulp was obtained measuring temperature at four different depths. Measurements were carried out initially wi

Externí odkaz: https://doaj.org/article/5179120a430e4a2aa8b6de9050c7c430

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Akademický článek

Thermal properties of WC-10 wt. (%) Co alloys

Autor: Francisco de Assis Léo Machado, Márcio Ferreira Rodrigues, Helion Vargas, Marcello Filgueira, Roberto da Trindade Faria Júnior

Publikováno v: Materials Research, Vol 11, Iss 1, Pp 37-41 (2008)

In this article, photothermal techniques were used in order to determine some thermal properties: diffusivity, conductivity, effusivity and specific heat capacity of WC-10 wt. (%) Co six samples subjected to different sintering processes. The samples

Externí odkaz: https://doaj.org/article/10b87a26e44c4d00b8cf7ba49512f06c

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Akademický článek

Water and vapor permeability at different temperatures of poly (3-Hydroxybutyrate) dense membranes

Autor: Luiz H. Poley, Marcelo G. da Silva, Helion Vargas, Marcelo O. Siqueira, Rubén Sánchez

Publikováno v: Polímeros, Vol 15, Iss 1, Pp 22-26 (2005)

Polyhydroxyalkanoates (PHAs) are polymers produced from renewable resources with biodegradability and biocompatibility, being therefore attractive for medical and pharmaceutical purposes. Poly (3-hydroxybutyrate) (PHB) is the most important polymer o

Externí odkaz: https://doaj.org/article/0d33cf2e022a444c882ca7a4d4708a6d

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Conjunto de bobinas para medidas da susceptibilidade magnetica a temperatura do H4 liquido

Autor: Helion Vargas

Publikováno v: Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo (USP)
instacron:USP

Conjunto de bobinas para medidas da susceptibilidade magnética a temperatura do H4 liquido Set of coils for measuring the magnetic susceptibility to temperature of liquid H4

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cb5b634f39b0d9178ea433e8f6aaa36a
https://doi.org/10.11606/d.43.1967.tde-06062022-124345

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Investigation of phase transitions in vegetable oils through temperature-dependent optical measurements: supercooling effect

Autor: T. C. Cordeiro, A. B. Rangel, Helion Vargas, F. A. F. Menezes, E. C. da Silva

Publikováno v: Journal of Thermal Analysis and Calorimetry. 143:27-33

Measurements of the phase transitions in vegetable oils such as coconut, palm (fruit), palm kernel (from the seeds), macauba (Acrocomia aculeata) and its biodiesel have been taken through temperature-dependent optical transmittance. Room-temperature

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::e0a73503a588c16ea87c7b1b2f1205e7
https://doi.org/10.1007/s10973-019-09168-7

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Characterization of Cuban and Brazilian natural zeolites by photoacoustic spectroscopy and electron paramagnetic resonance

Publikováno v: Anais da Academia Brasileira de Ciências, Volume: 94, Issue: 1, Article number: e20200512, Published: 31 JAN 2022
Anais da Academia Brasileira de Ciências, Vol 94, Iss 1 (2022)
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA-Alice)
Empresa Brasileira de Pesquisa Agropecuária (Embrapa)
instacron:EMBRAPA
Anais da Academia Brasileira de Ciências v.94 n.1 2022
Anais da Academia Brasileira de Ciências
Academia Brasileira de Ciências (ABC)
instacron:ABC

This report describes the photoacoustic and electron paramagnetic resonance investigations of Brazilian and Cuban zeolites. Photoacoustic optical absorption measurements indicate the presence of iron (Fe 3 +) ions with their respective transition ban

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::176a2dba1ae1f904dd293921a696a431
https://pubmed.ncbi.nlm.nih.gov/35107514

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