Carbon Content
Mostrando 1-12 de 850 artigos, teses e dissertações.
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1. Preparation of Silicon Oxycarbide (SiCO) Ceramics from Different Polymer Architectures and Assessment on the Performance as Electrodic Materials for Voltammetric Sensing of Antioxidant Phenolic Compounds
Silicon oxycarbide (SiCO) ceramics obtained from polymer pyrolysis and with varied carbon contents were prepared and evaluated as new electrodic materials for sensing of tert butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants. Three polymers were synthesized varying molecular architecture and aromatic carbon groups, followed by pyrolysi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Role of the reducing agent in tungsten extraction by chlorination with chlorine from an ore enriched by physical means
Abstract The effect of three reducing agents (sulphur dioxide, pyrite and carbon) on tungsten extraction from a scheelite-wolframite concentrate with chlorine gas was assessed. A low-grade ore (0.9% w/w WO3) was collected in the San Martín department, San Luis Province, Argentina, and subsequently enriched by physical means (65.73% w/w WO3). The minerals id
REM - International Engineering Journal. Publicado em: 2022
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3. An alternative energy generation from charcoal produced from Brazilian pine (Araucaria angustifolia (Bert.) O. Ktze) seed residues
The perspective is that the energy demand will grow in the coming decades worldwide. The search for renewable energy sources is urgent and necessary. Residual biomass may be a promising source of raw material for obtaining bioenergy. Thus, this research sought to evaluate the energetic and physicochemical properties of residues from the seeds of Brazilian pi
Química Nova. Publicado em: 2022
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4. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
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5. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06
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6. Evaluation of the combined addition of aluminum lactate and calcium carbonate to alumina-based castables
Abstract Calcium aluminate cement (CAC) can induce the development of high green mechanical strength to refractory castables in a short period of time (24 h). However, the production of this hydraulic binder is energy-intensive and releases a large content of carbon dioxide (CO2), which adds to global warming. Thus, aiming to develop an alternative binding s
Cerâmica. Publicado em: 2021-06
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7. Analysis of carbonation and hydration of BOF steel slag for application as railway ballast
Abstract The reutilization of waste is a valuable alternative for the preservation of natural resources and the environment. In this sense, Basic Oxygen Furnace (BOF) steel slag is one of the most residues generated in steel the industry. It is estimated that for each ton of steel produced, about 150 kg of steel slag is generated in the BOF process. Generall
REM, Int. Eng. J.. Publicado em: 2020-12
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8. Carbon stock and organic fractions in soil under monoculture and Sorghum bicolor–Urochloa ruziziensis intercropping systems
ABSTRACT The use of no-till conservationist agricultural systems as well as intercropping in the Cerrado biome are practices that increase soil organic matter (SOM) due to the deposition of straw. This study aimed to quantify the carbon stock and organic fractions of a latosol under off-season monoculture (Sorghum bicolor and Urochloa ruziziensis) and interc
Bragantia. Publicado em: 2020-09
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9. Estatística Cardiovascular – Brasil 2020
ABSTRACT The use of no-till conservationist agricultural systems as well as intercropping in the Cerrado biome are practices that increase soil organic matter (SOM) due to the deposition of straw. This study aimed to quantify the carbon stock and organic fractions of a latosol under off-season monoculture (Sorghum bicolor and Urochloa ruziziensis) and interc
Arq. Bras. Cardiol.. Publicado em: 2020-09
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10. SIMULATING CROP YIELD, SOIL NITROGEN, AND ORGANIC CARBON IN NO-TILLAGE CROP SEQUENCES IN A SUBTROPICAL CLIMATE IN BRAZIL
ABSTRACT Brazil stands out worldwide for its high grain production in areas of direct sowing. The objective of this study was to simulate and assess the relationship of soil organic carbon content and nitrogen, crop yield, and biomass of two crop sequences under the no-tillage system in a subtropical region of São Paulo, Brazil, using CSM-CROPGRO-Soybean an
Eng. Agríc.. Publicado em: 2020-08
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11. Chemical and Spectroscopic Characteristics of Anthrosol (Amazonian Dark Earth) and Surrounding Soil from the Brazilian Amazon Forest: Evaluation of Mineral and Organic Matter Content by Depth
The chemical and spectroscopic characteristics of soil organic matter (SOM) isolated from Amazonian dark earth (ADE) and surrounding soil (SR) were evaluated according to the soil depth. The results showed opposite trends for the soils. While ADE featured SOM with a greater aromatic condensation degree and greater hydrophobicity in the top layer, the SR show
J. Braz. Chem. Soc.. Publicado em: 2020-08
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12. Application of Mixture Design Using Diluted Acid for Extraction of Inorganic Components in Fruits of Casearia fasciculata and Determination by ICP OES: Evaluation by PCA and HCA
This study is the first to propose the simultaneous quantification of 10 elements in fruits of Casearia fasciculata by inductively coupled plasma optical emission spectrometry (ICP OES). A method of digestion using dilute nitric acid was optimized by mixture design for extraction of elements in the seed, peel, and pulp of Casearia fasciculata cultivated in t
J. Braz. Chem. Soc.. Publicado em: 2020-06