Chemical Signal
Mostrando 1-12 de 363 artigos, teses e dissertações.
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1. APRESENTAÇÃO - História Antiga: Diferentes Perspectivas
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
Rev. Bras. Hist.. Publicado em: 2020-08
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2. Evaluation of the Oxidation Degradation Process of Biodiesel via 1H NMR Spectroscopy
Biodiesel is a suitable alternative to replace the petro-diesel. The biodiesel is formed by unsaturated esters easily degraded by interferences of oxygen, temperature, contact with metals or contaminants. The aim of this research was to investigate the biodiesel degradation process via 1H nuclear magnetic resonance (NMR) spectroscopy, observing the olefinic,
J. Braz. Chem. Soc.. Publicado em: 2020-08
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3. Chemically-Activated Biochar from Ricinus communis L. Cake and Their Potential Applications for the Voltammetric Assessment of Some Relevant Environmental Pollutants
Biochar is a rich-carbon material highly functionalized, which allows the use as electrodes modifier for preconcentration and voltammetric determination of several species. This work describes a castor cake biochar production and chemical activation with different reaction conditions using HNO3 and/or H2O2. Biochar samples were characterized using scanning e
J. Braz. Chem. Soc.. Publicado em: 2020-05
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4. EVALUATION OF SILICA NANOPARTICLE COLLOIDAL STABILITY WITH A FIBER OPTIC QUASI-ELASTIC LIGHT SCATTERING SENSOR
Abstract Colloidal silica is an important biocompatible, inert and non-toxic material for imaging, therapy, and drug delivery biomedical applications. In this context, the evaluation of colloidal suspensions and their stabilities by a Fiber Optic Quasi-Elastic Light Scattering sensor is proposed. Two different silica nanoparticles were prepared and character
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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5. IDENTIFICAÇÃO DE ADULTERANTES DE BIODIESEL METÍLICO DE CRAMBE EM MISTURAS COM DIESEL, USANDO FT-MIR E CARTAS DE CONTROLE MULTIVARIADAS BASEADAS NO SINAL ANALÍTICO LÍQUIDO
Adulterants in biodiesel/diesel blends modifies its physical and chemical properties. In this work, Fourier Transform Mid-Infrared spectrometry (FT-MIR) and multivariate control charts based on Net Analyte Signal (NAS) were used to monitor the quality of Crambe methyl biodiesel in relation to the biodiesel content and the presence of adulterants. The calibra
Quím. Nova. Publicado em: 2020-01
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6. The effectiveness of eugenol against cisplatin-induced ototoxicity
Resumo Introdução: A ototoxicidade refere-se ao dano celular ou comprometimento da função da orelha interna associado a qualquer agente terapêutico ou substância química e ainda representa o principal efeito colateral que restringe o uso da cisplatina. Objetivo: O objetivo deste estudo foi realizar uma investigação bioquímica, funcional e histopa
Braz. j. otorhinolaryngol.. Publicado em: 13/12/2019
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7. A New Electrochemical Platform Based on a Polyurethane Composite Electrode Modified with Magnetic Nanoparticles Coated with Molecularly Imprinted Polymer for the Determination of Estradiol Valerate in Different Matrices
A polyurethane composite electrode modified with magnetic nanoparticles (mag; Fe3O4) coated with molecularly imprinted polymers (MIPs) was developed for the electrochemical determination of estradiol valerate. Chemical and morphological analyses of the mag-MIP were performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (E
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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8. Unusual effect of chemical communication on social aggression in juvenile cichlid fish Cichlasoma paranaense (Cichliformes: Cichlidae)
RESUMO Algumas espécies de peixes são organizadas socialmente e apresentam uma ordem de rank social que é alcançada por meio de interações agressivas. Após o estabelecimento da hierarquia, essas espécies comunicam seu rank por diversas pistas sensoriais, essa comunicação é adaptativa, pois reduz os efeitos prejudiciais das lutas físicas. Peixes c
Neotrop. ichthyol.. Publicado em: 27/06/2019
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9. Determination of the Antioxidant Capacity of Red Fruits by Miniaturized Spectrophotometry Assays
Natural sources with high antioxidant capacity represent an interesting potential to prevent or minimize the oxidative stress that causes many chronic diseases. The antioxidant capacity of red fruits (strawberry and cherry) was evaluated by miniaturized spectrophotometric methods 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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10. Effects of in-office bleaching agent combined with different desensitizing agents on enamel
Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initi
J. Appl. Oral Sci.. Publicado em: 08/11/2018
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11. Cloning and expression of an endoglucanase gene from the thermotolerant fungus Aspergillus fumigatus DBiNU-1 in Kluyveromyces lactis
Abstract An intronless endoglucanase from thermotolerant Aspergillus fumigatus DBINU-1 was cloned, characterized and expressed in the yeast Kluyveromyces lactis. The full-length open reading frame of the endoglucanase gene from A. fumigatus DBiNU-1, designated Cel7, was 1383 nucleotides in length and encoded a protein of 460 amino acid residues. The predicte
Braz. J. Microbiol.. Publicado em: 2018-09
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12. Development of a Novel and Simple Electroanalytical Procedure for the Determination of Copper in Biofuel Employing a Sensor Based on Vulcan Functionalized with Carbazone
A novel and simple electroanalytical method for the determination of Cu2+ in biodiesel samples by stripping voltammetric analysis was developed. The method employs a carbon paste electrode (CPE) modified with Vulcan carbon, previouly functionalized with carbazone (CBZ). The CPE/Vulcan-CBZ sensor promoted a significant increase in the analytical signal obtain
J. Braz. Chem. Soc.. Publicado em: 2018-04