Precipitation
Mostrando 25-36 de 3094 artigos, teses e dissertações.
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25. Arsenic and Other Elements Determination in Seawater Using Coprecipitation and Standard Mode Inductively Coupled Plasma Mass Spectrometry
The present work aims the determination of As, Co, Cr, Cu, Mn and Pb in seawater samples using coprecipitation extraction procedure before standard mode inductively coupled plasma mass spectrometry (ICP-MS) (no collision/reaction cell). The coprecipitation procedure is based on the precipitation of Mg(OH)2 from the reaction of the Mg2+ ions (present into the
J. Braz. Chem. Soc.. Publicado em: 2021-01
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26. 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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27. CLIMATE ZONING FOR THE CULTIVATION OF AFRICAN MAHOGANY SPECIES IN BRAZIL
ABSTRACT African mahogany is the common name given to different species of the genus Khaya. They are tree species native to the African continent, which have a wood quality that allows their noble use in making fine furniture, and in the civil and naval industries. Currently, African mahogany cultivation has received notoriety in Brazil and given its climati
CERNE. Publicado em: 2020-09
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28. PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC a
Quím. Nova. Publicado em: 20/07/2020
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29. Simultaneous Quantification of Plasma Catecholamines and Metanephrines by LC-MS/MS
The quantification of the low levels of catecholamines and metanephrines in biological fluids is important for clinical screening of pheochromocytoma/paraganglioma and diagnosis of overtraining syndrome in athletes. We introduce a novel, accurate and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of
J. Braz. Chem. Soc.. Publicado em: 2020-07
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30. PHYSICAL ANALYSIS OF REGIONALIZED FLOW AS AN AID IN THE IDENTIFICATION OF HYDROLOGICALLY HOMOGENEOUS REGIONS
ABSTRACT Regionalization is an important technique for estimating the flow of hydrographic sections with a lack of data. First, it is necessary to identify hydrologically homogeneous regions (HHRs), which are commonly validated via statistical analyses. Because this step is understood to be subjective, studies that contribute to a greater reliability in iden
Eng. Agríc.. Publicado em: 2020-06
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31. Exclusão pulmonar em neonatos - técnicas e o papel do ultrasom
ABSTRACT We analyzed the phenological responses of shrub-tree species of lowland deciduous (LDF) and submontane deciduous (SFD) forests in the Pantanal, and assessed their relationships with climatic factors at the community level and with strategies for seed dispersal. Vegetative and reproductive phenophases of 50 tree-shrub species were monitored monthly (
Rev. Bras. Anestesiol.. Publicado em: 2020-06
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32. Phenology and dispersal syndromes of woody species in deciduous forest fragments of the Pantanal in Mato Grosso do Sul State, Brazil
ABSTRACT We analyzed the phenological responses of shrub-tree species of lowland deciduous (LDF) and submontane deciduous (SFD) forests in the Pantanal, and assessed their relationships with climatic factors at the community level and with strategies for seed dispersal. Vegetative and reproductive phenophases of 50 tree-shrub species were monitored monthly (
Acta Bot. Bras.. Publicado em: 2020-06
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33. Zn2Al Layered Double Hydroxides Intercalated with Nitrate and p-Aminobenzoate as Ultraviolet Protective Agents in Low-Density Polyethylene Nanocomposites and Natural Insulating Oils
Zn2Al-Cl and Zn2Al-NO3 layered double hydroxides (LDHs) were synthesized through the fixed pH co-precipitation method and used as precursor materials for the intercalation of p-aminobenzoate through anion exchange reactions. Since chloride in Zn2Al-Cl was only partially exchanged with p-aminobenzoate, the phases Zn2Al-NO3 and Zn2Al-N -AB (nitrate exchanged w
J. Braz. Chem. Soc.. Publicado em: 2020-05
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34. CeαMn1-αO2 catalysts supported over γ-Al2O3 prepared by modified redox-coprecipitation methods for n-hexane combustion
A series of CeαMn1-αO2 catalysts supported on γ-alumina with various molar concentrations of Ce (α, from 0 to 0.90) was synthesized by coprecipitation, applying two different precipitating agents, namely, sodium hydroxide (method 1) and sodium carbonate (method 2), with the use of sodium permanganate as a redox agent for precipitation. XRD profiles of th
Quím. Nova. Publicado em: 2020-04
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35. Effect of titanium and nitrogen inoculation on the microstructure, mechanical properties and abrasive wear resistance of Hadfield Steels
Abstract The effect of titanium and nitrogen addition on Hadfield steels was investigated. In order to do this, two grades of steels were produced in terms of titanium and nitrogen addition. The final samples had their microstructure characterized and their mechanical properties were evaluated by uniaxial tensile and Charpy impact tests. Furthermore, the wea
REM, Int. Eng. J.. Publicado em: 2020-03
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36. Selective Entrapment of Pb2+ from Fresh Thunbergia laurifolia Leaves Extract and Thunbergia laurifolia Tea Extract
The leaves of Thunbergia laurifolia and its tea were extracted by water. The abilities to chelate heavy metal ions of the extracts were studied by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS). The results showed that the extracts exhibited high selectivity for Pb2+ chelation via a favourable-sele
J. Braz. Chem. Soc.. Publicado em: 2020-03