A5048768137- Nonlinear Optical Materials Research
- Synthesis and biological activity
- Essential Oils and Antimicrobial Activity
- Bee Products Chemical Analysis
- Microwave Dielectric Ceramics Synthesis
- Graphene research and applications
- Molecular spectroscopy and chirality
- Ferroelectric and Piezoelectric Materials
- Advanced Condensed Matter Physics
- Molecular Junctions and Nanostructures
- Iron-based superconductors research
- Phytochemicals and Antioxidant Activities
- X-ray Diffraction in Crystallography
- Analytical chemistry methods development
- Crystal structures of chemical compounds
- Solid-state spectroscopy and crystallography
- Crystallography and molecular interactions
- Agricultural and Food Sciences
- Phytochemistry and Biological Activities
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Chemometric Analyses
- Crystallization and Solubility Studies
- Synthesis and Characterization of Heterocyclic Compounds
- Magnetic and transport properties of perovskites and related materials
- Heavy Metals in Plants
Universidade Federal de Mato Grosso
2013-2023
Universidade Federal de Mato Grosso do Sul
2021
Universidade Federal de Alagoas
2019
Universidade Federal de Rondônia
2019
Universidade Federal do Ceará
2001-2004
Abstract Single‐crystal samples of L ‐histidine hydrochloride monohydrate (LHICL), C 6 H 9 N 3 O 2 ·HCl·H O, were studied by Raman spectroscopy at temperatures ranging from 295 to 40 K over the spectral range 20–3400 cm −1 . A tentative assignment bands is given. The effect temperature change on vibrational spectrum discussed. behavior spectra, in particular emergence new modes low‐wavenumber region, indicates that LHICL undergoes a structural phase transition between 140 and 110 K. There...
Abstract Measurements of ecosystem gas exchange, meteorology, and hydrology (rainfall soil moisture) were used to assess the seasonal patterns of, controls on, average diel (24 h) net CO2 exchange (NEE), evapotranspiration (E), bulk canopy water vapor conductance (Gc) a tropical transitional (ecotonal) forest in Brazilian Amazon. Diel trends E NEE almost completely explained by variation photosynthetic photon flux density (QPPFD), while QPPFD response varied little over annual cycle,...
We study the energy gap opening in electronic spectrum of graphene bilayers caused by asym- metric doping. Both substitutional impurities (boron acceptors and nitrogen donors) adsorbed potassium donors are considered. The evolution with dopant concentration is compared to situation which asymmetry between layers induced an external electric field. effects similar that field, but behave quite differently, showing smaller band gaps a large sensitivity disorder sublattice occupation.
We have performed x-ray, electrical resistivity, and Raman scattering measurements in ${\mathrm{La}}_{0.70}{\mathrm{Sr}}_{0.30}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{3}$ manganites, with x varying from 0 to 0.40. The appearance of new peaks the spectra as Fe content increases is attributed either otherwise forbidden modes that become active due symmetry breaking effect or phonon density states features, which arise a disorder-induced phenomenon. softening some...
This work aimed to characterize the biochar produced from residues of coconut fruit and evaluate how it might beneficially alter retention capacity water nutrients in soils with a sandy texture. The was retort furnace later analyzed determine its chemical physical characteristics. Experiments analyze potential for were performed PVC columns filled 400 mm depth, upper 300 receiving treatments that consisted 0, 1, 2, 3, 4, 5% (p p-1) mixed soil. For nutrient experiment, addition...
Iron sulfides are promising candidates for the next generation of rechargeable lithium-ion battery materials. Motivated thereby, we present a detailed study correlation- and doping-induced electronic reconstruction in troilite. Based on local-density-approximation plus dynamical-mean-field-theory, stress importance multi-orbital Coulomb interactions concert with first-principles band structure calculations consistent understanding intrinsic Mott-Hubbard insulating state FeS. We explore...
Abstract A possible structural change in Sr 0.66 Ba 0.34 Nb 2 O 6 single‐crystal fibers when the temperature decreases from 295 to 10 K was investigated by dielectric constant measurements and Raman spectroscopy. An anomaly observed loss factor is associated with variation intensity wavenumber of certain modes. We observe that relative low modes has a singular behavior for y ( xz ) ȳ scattering geometry. high‐wavenumber band disappears lowered geometry shifts higher zz These observations can...
Polarized Raman spectra of L-arginine hydrochloride monohydrated single crystal in nine different scattering geometries the two irreducible representations factor group C2 were studied at room temperature. The experimental wavenumber values are compared with those obtained from ab-initio calculation and assignment bands to respective molecular vibrations is also given. Finally, a discussion related previously reported phase transition undergone by low temperature furnished.
A Raman study of structural changes in the Zr-rich PbZr1-xTixO3 (PZT) system under hydrostatic pressures up to 5.0 GPa is presented. We observe that externally applied pressure induces several phase transitions PZT ceramics among phases with orthorhombic (AO), rhombohedral low-temperature (RLT), and high-temperature (RHT) symmetries (all found at ambient room temperature). Each compositions investigated (0.02⩽x⩽0.14) exhibits a high-pressure (OI') symmetry. further report detailed dependence...
This paper describes the study of two alkaloids extracted from Pilocarpus Microphyllus (Rutaceae): pilosine and epiisopilosine. These substances have potential application in treatment several diseases. In this work FT-Raman FT-IR spectra epiisopilosine were investigated at 300 K. Vibrational wavenumber wave vector been predicted using density functional theory (B3LYP) calculations with 6-31 G(d,p) basis set. A comparison experiment, allowed us to assign most normal modes crystals.
We present a detailed study of correlation- and pressure-induced electronic reconstruction in hexagonal iron monosulfide, system which is widely found meteorites one the components Earth's core. Based on perusal experimental data, we stress importance multi-orbital electron-electron interactions concert with first-principles band structure calculations for consistent understanding its intrinsic Mott–Hubbard insulating state. explain anomalous nature insulator-metal-insulator transition seen...
Abstract This work aimed to develop and characterize edible films made with cassava starch buriti oil in a factorial scheme verify the effect of interaction between these factors on physical properties. The experiment was developed an entirely randomized design 2 × 3 scheme. They were prepared six different formulations evaluating thickness, water solubility, moisture, activity, chromaticiy ( C *), total color difference (Δ E opacity light transmittance, tensile strength elongation at break,...