Laser Spectroscopy
Mostrando 1-12 de 265 artigos, teses e dissertações.
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1. A química analítica aplicada aos estudos de pigmentos rupestres: uma revisão
Instrumental advances have been employed in the study of archeological remains such as prehistoric rupestrians paintings with the objective of chemically characterizing them in order to reconstruct the cultural technologies of a prehistoric human group and/or to support conservation science studies. The analytical techniques most commonly used in archaeometr
Química Nova. Publicado em: 2022
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2. Calibration Strategies Applied to Laser-Induced Breakdown Spectroscopy: A Critical Review of Advances and Challenges
Over the years, laser-induced breakdown spectroscopy (LIBS) has been reported in the literature as an alternative to traditional methods of analysis, becoming well established among spectroanalytical techniques. LIBS is a technique widely used for qualitative approaches; however, it is necessary considerable effort for use in quantitative analysis, mainly du
J. Braz. Chem. Soc.. Publicado em: 2020-12
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3. Direct Analysis of Human Hair Before and After Cosmetic Modification Using a Recent Data Fusion Method
The cosmetic modification of hair is a very common procedure used to mask or cover evidence at a crime scene. Deoxyribonucleic acid (DNA) tests are expensive and require good-quality collection of samples and a database profile. To overcome these challenges, direct analysis was performed on a large set of hair strands collected from individuals, denoted orig
J. Braz. Chem. Soc.. Publicado em: 2020-01
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4. HYDROXYAPATITE - CARBON NANOTUBE COMPOSITES FOR DRUG DELIVERY APPLICATIONS
Abstract The aim of this study was the synthesis of composites containing hydroxyapatite (Hap) or silicon substituted hydroxyapatite (HapSi), carboxyl functionalized carbon nanotubes (fMWCNT) and gelatin (G) in different ratios. Ibuprofen (IBU) was chosen as a model drug for the formulation of extended-release dosage forms. The obtained composites were chara
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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5. Electrochemical Behavior During the Zirconium Conversion Coating Formation on AISI 1006 Steel
This study investigated a conversion coating based on hexafluorozirconic acid solution on cold-rolled (AISI 1006) steel sheets, in situ, at different pH values and immersion times. Electrochemical characterization was carried out by electrochemical impedance spectroscopy (EIS) with hexafluorozirconic acid bath as the electrolyte. Laser scanning confocal micr
Mat. Res.. Publicado em: 12/09/2019
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6. Synthesis and Characterization of Fluorescent PVA/PVAc-Rodhamine Microspheres
Fluorescent polymeric microspheres are used in a wide range of biomedical and technological applications, including blood flow determination, screening, flow visualization, flow tracing, medical imaging, fluorescence microscopy and flow cytometry among others. Rhodamine 6G (R6G) is a lipophilic cationic dye, which is among the most stable organic fluorophore
Mat. Res.. Publicado em: 02/09/2019
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7. Mineralogical and gemological characterization of emerald crystals from Paraná deposit, NE Brazil: a study of mineral chemistry, absorption and reflectance spectroscopy and thermal analysis
Abstract The Paraná deposit, located at Southwestern Rio Grande do Norte state, in Brazil, is one of the few emerald deposits found at Borborema Province. The mineralization occurs in phlogopite schists and actinolite-phlogopite schists associated with pegmatites and albitites within the Portalegre Shear Zone. Unlike other well-known Brazilian emerald depos
Braz. J. Geol.. Publicado em: 22/08/2019
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8. LASER INDUCED-BREAKDOWN SPECTROSCOPY (LIBS): HISTÓRICO, FUNDAMENTOS, APLICAÇÕES E POTENCIALIDADES
This review attempts to present a broad view of the technique laser-induced breakdown spectroscopy (LIBS), since its origin, fundamentals, sample preparation strategies, use of chemometric tools for data processing, the advantages and limitations with regard to qualitative and quantitative analysis, aplications and future trends as an analytical technique th
Quím. Nova. Publicado em: 18/07/2019
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9. Combination of Multi-Energy Calibration (MEC) and Laser-Induced Breakdown Spectroscopy (LIBS) for Dietary Supplements Analysis and Determination of Ca, Mg and K
This study describes the application of laser-induced breakdown spectroscopy (LIBS) for the direct determination of Ca, K and Mg in powdered dietary supplements. Multi-energy calibration (MEC) method was applied to obtain a calibration curve. With MEC, it was possible to observe spectral interferences and select adequate emission lines from LIBS. For Ca and
J. Braz. Chem. Soc.. Publicado em: 2019-04
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10. Structural and Optical Properties of GaN Thin Films Grown on Si (111) by Pulsed Laser Deposition
In this work we present results and analysis concerning the processing and characterization of Gallium Nitride (GaN) thin films (TF) grown on Si (111) substrates by pulsed laser deposition technique (PLD), which were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and Raman spectroscopy (RS). The GaN films show
Mat. Res.. Publicado em: 14/01/2019
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11. Damping of Fe-Al Alloy Electrodeposited in an Ionic Liquid
Iron-Aluminium alloys were produced by the electro-deposition of iron-aluminium on a copper substrate. The electro-deposition process was done in the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO. A solution of (0.2 M FeCl2 + 2.75 M AlCl3)/ [Py1,4] TfO was used at a temperature of T=363 K because this mixture is solid at roo
Mat. Res.. Publicado em: 11/10/2018
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12. Qualitative and Quantitative Chemical Investigation of Orthopedic Alloys by Combining Wet Digestion, Spectroanalytical Methods and Direct Solid Analysis
In this study, two laser-based techniques, laser-induced breakdown spectroscopy (LIBS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) were used for analytical signal evaluation of Ti, Al, and V and investigation of possible harmful elements eventually present as minor elements in Ti alloys. Due to the lack of certified reference
J. Braz. Chem. Soc.. Publicado em: 2018-04