Water Chemistry
Mostrando 1-12 de 230 artigos, teses e dissertações.
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1. Synthesis of Triazoles by Electro-Assisted Click Reaction Using a Copper Foil Electrode
This paper presents an innovative pathway for the synthesis of triazoles using the well-known “click chemistry” assisted by the electrochemical oxidation of metallic Cu0. The click reaction is used to couple a wide range of biological interest compounds. In this case, faster and less polluting methods for a biological environment was achived by in situ C
J. Braz. Chem. Soc.. Publicado em: 2021-07
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2. Different scales determine the occurrence of aquatic macrophyte species in a tropical stream
ABSTRACT Distributions of aquatic macrophyte species are commonly associated with water chemistry characteristics. However, other environmental factors that can lead to the occurrence of aquatic plants in lotic ecosystems, such as dynamic habitats linked to the surrounding landscape, have been underestimated. This study aims to evaluate landscape features th
Acta Bot. Bras.. Publicado em: 2021-03
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3. CHLORDECONE ADSORPTION ON FUNCTIONALIZED ACTIVATED CARBONS: COMPUTATIONAL CHEMISTRY AS A TOOL FOR UNDERSTANDING THE ADSORPTION PROCESS
Chlordecone (CLD) has been used as a pesticide for a long time to control the proliferation of various insects in tropical countries like the French West Indies. CLD was included in 2009 in the list of persistent organic pollutants (POPs) by the Stockholm Convention, prohibiting its production and use worldwide. Thus, its removal from water and soils is a sa
Quím. Nova. Publicado em: 2021-02
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4. Synthesis and Antioxidant and Antimicrobial Properties of β-Hydroxy Sulfides, Sulfoxides, and Sulfones Derived from Cardanol and Glycerol Derivatives
Natural and synthetic sulfur-bearing organic compounds have many applications in medicinal chemistry. This article reports the preparation of amphiphilic β-hydroxy sulfides, sulfoxides, and sulfones derived from cardanol and glycerol. Thiolysis of cardanol epoxide 3 with various thiols (4a-4j) in ethanol or water yielded the corresponding β-hydroxy sulfide
J. Braz. Chem. Soc.. Publicado em: 2020-12
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5. Extratos de Lilium sp., Agapanthus sp. e Hydrangea sp.: comportamento como indicadores naturais em diferentes faixas de pH
This experimental activity proposes the use of lily (Lilium sp.), agapanthus (Agapanthus sp.) and hydrangea (Hydrangea sp.) extracts to investigate the colorimetric profile of each extract between pH 1-14. Water, ethanol and ethanol/HCl 1% (w/w) were used as extractive solvents. Among the flowers tested, the extracts of orange lily and burnt yellow lily were
Quím. Nova. Publicado em: 2020-02
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6. INTERAÇÕES INTERMOLECULARES E O FENÔMENO DA SOLUBILIDADE: EXPLICAÇÕES DE GRADUANDOS EM QUÍMICA
The present study investigated the use of intermolecular interaction concepts by freshman chemistry students during general chemistry classes, explaining some of the solubility phenomenon. For this purpose, classes on the topic in question were monitored and two tests were asking for explanations for the difference in solubility of oxygen and carbon dioxide
Quím. Nova. Publicado em: 2020-01
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7. Films Formed on Carbon Steel in Sweet Environments - A Review
Corrosion of carbon steel pipelines in sweet environments has been extensively researched on oil and natural gas exploration and production in order to obtain efficient corrosion mitigation methods. Although the consequences of corrosion are known, the cause and mechanism by which a certain phenomenon occurs are still not well understood. Sweet corrosion is
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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8. FOTOCATÁLISE MEDIADA POR TiO2 NO ESTADO NANOPARTICULADO: REVISÃO DA REATIVIDADE PELO CONCEITO DE TRAPS E ALGUMAS APLICAÇÕES EM QUÍMICA ANALÍTICA
TiO2 has been used as a white pigment and studied since the first decades of the XX century for the undesirable chalking of outdoor paintings exposed to sunlight. Since the first report of Honda and Fujishima (1972) of the water splitting by the harvesting of sunlight on a n-type single crystal TiO2 electrode, the engagement of researchers with the field has
Quím. Nova. Publicado em: 02/05/2019
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9. 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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10. Together yet separate: variation in soil chemistry determines differences in the arboreal-shrub structure of two contiguous rupestrian environments
ABSTRACT Rupestrian landscapes are characterized by vegetation mosaics comprised of different plant communities and strongly linked to environmental filters. These environments are nutrient-impoverished, and possess water retention deficits and high solar exposure. This study aimed to determine whether chemical properties of the soil shape the arboreal-shrub
Acta Bot. Bras.. Publicado em: 02/07/2018
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11. MEASURING THE CONDUCTIVITY OF VERY DILUTE ELECTROLYTE SOLUTIONS, DROP BY DROP
Undergraduate experiments on ionic conductivity are common practice in general chemistry and advanced physical chemistry laboratories. Often, the conductivities are measured for solutions prepared for various salts, in a range of concentrations, and the relationship between solution conductivity and concentration is interpreted in terms of the Kohlrausch law
Quím. Nova. Publicado em: 2018-07
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12. EXPERIMENTO COM ABACATE, BORRA DE CAFÉ, LICURI E LEITE DE COCO PARA EXTRAÇÃO DE ÓLEO, PRODUÇÃO DE BIODIESEL E ANÁLISE ESPECTRAL
An undergraduate organic chemistry experiment for oil extraction and biodiesel production using alternative biomass was developed, whereby oils of avocado, coconut and spent coffee grounds were obtained and submitted to transesterification reaction with CH3OH under NaOH catalysis. Avocado and coffee oils were obtained by typical extraction and coconut oil wa
Quím. Nova. Publicado em: 2018-06