Aplicações de um potencial reativo no estudo da interação entre moléculas e superfícies bidimensionais

In materials science, the search for technological improvements have become one of the main subject of study of researchers. This is especially true in the case of materials with reduced sizes, in the nanometer scale. Important phenomena to be studied in these cases are the desorption and adsorption on two-dimensional materials, such as graphene. These phenomena are of great importance in the study of interactions between organic films, synthesis or catalysis of reactions on surfaces and even in the creation of nanoscale devices [1, 2, 3, 4]. Between the most important topics related to these phenomena are the storage of gases in low-dimensional systems and the study of nanostructured fuel cells or batteries. In this context we used two different parametrizations for the reactive force field ReaxFF to study the potential barriers and reaction barriers of our system. First we made a study about the Reaction Barriers and Energy Barriers for bonds between graphene and the following atoms: sulfur, fluorine, hydrogen, nitrogen and oxygen. It is important to have this information in order to make it possible to understand how these atoms react with the graphene sheet. Subsequently, we calculate reaction barriers for mixed structures where fluorine is a fixed element bonded to graphene and other element is simultaneously bonded to graphene. This other element (N, O, H or S) is varied in its possible relative positions (ortho, meta and para in relation to fluorine in either: the same side and in the opposite side of the graphene membrane)

Estudo de temperatura de plasma de álcool através de espectroscopia de emissão natural radical C2*

Non-intrusive methods of diagnosis, such as spectral analysis of the radiation emitted by the system, have been used as a viable alternative for determining the temperature of combustion systems. Among them, the determination of temperature by natural emission spectroscopy has the advantage of requiring relatively simple experimental devices. Once Chemiluminescent species are formed directly in the excited state, the collection and recording of radiation emission spectrum is enough to determine the temperature (CARINHANA, 2008). In this study we used the process of making direct comparisons between the experimental spectra obtained in the laboratory from the plasma of alcohol, and the theoretical spectra plotted from a computer program developed at the IEAv. The objective was to establish a fast and reliable method to measure the rotational temperature of the radical C2*. The results showed that the temperature of the plasma, which in turn can be taken as the rotational temperature of the system, is proportional to the pressure. The temperature values ranged from ca. 2300 ~ 2500 K at a pressure of 19 mmHg to 3100 ~ 3500 K for the pressure of 46 mmHg. The temperature values are somewhat smaller when we consider the theoretical spectrum as a Lorentzian curve. The overlap of the spectra was better when using the profile curve, but still were not exactly superimposed. The solution to improve the overlap of the theoretical with the experimental spectra is the use of a curve that has the convolution of two profiles analyzed: Lorentzian and Gaussian. This curve is called the Voigt profile, which will also be implemented by programmers and studied in a next work

Espectroscopia de infravermelho e suas aplicações

Infrared spectroscopy (IR spectroscopy) explores the infrared region of the electromagnetic spectrum. Like any other spectroscopic technique, it can be used to identify a compound or the composition of investigate a sample. Spectroscopy (IR) is a very important technique in qualitative chemical analysis, widely used in the chemistry of natural products, organic synthesis and transformations. In this work we study of the theoretical foundations of infrared spectroscopy, the different vibration modes, experimental techniques, and the identification and characterization of solids. Were studied as applications: their use in thermograph and remote sensing satellites

Investigação da fase de carga ordenada em sistemas orgânicos quase-unidimensionais

In the eld of synthetical materials, often called in the literature as organic/molecular conductors or charge-transfer salts, the most prominient examples are the quasi onedimensional systems (TMTTF)2X and (TMTSF)2X, where TMTTF, TMTSF and X refers to tetrametiltetratiafuvaline, tetrametiltetraselenafuvaline and a monovalent anion (X = PF6

Controle da dinâmica caótica do oscilador de morse forçado

In this work, the dissociation dynamics of heteronuclear diatomic molecules is investigated by means of the classical driven Morse oscillator. The interaction of the molecule and the laser field is represented through the product of the molecule dipole function and the electric field of the laser. This interaction may lead to the breaking of the chemical bound, that is, to the dissociation of the molecule. The work was developed in two parts. In the first part, we studied the dissociation as a function of the range of the permanent dipole. In the second part, we maximized the dissociation probability manipulating the parameters of the external field. We have observed that the dissociation can be controlled by means of variations of parameters associated with the range of the permanent dipole

Florística e fitossociologia de comunidades arbóreas em contato savana-floresta, Parque Estadual de Porto Ferreira (PEPF), Porto Ferreira, SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da infestação de macrófitas aquáticas na comunidade planctônica em um viveiro de piscicultura

Pós-graduação em Microbiologia Agropecuária - FCAV

Associação da ocorrência de formigas (Hymenoptera: Formicidae) com atributos do solo e da vegetação em um domínio do cerrado à nordeste do estado do maranhão, Brasil

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Características de atributos do solo em ambientes da região Sul do estado do Amazonas

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Síntese e caracterização de hidrogéis de amido retrogradado e goma gelana utilizados como matriz em sistemas de liberação cólon específica de fármacos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Schinus Terebinthifolius raddi: estudo farmacognóstico e investigação da atividade biológica de extratos e frações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do porta-enxerto, da configuração de extração e do período de maturação no teor de limonina e na aceitação sensorial do suco de laranja Pêra-Rio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparo e caracterização de nanopartículas lipídicas sólidas como sistema carreador conjunto para os herbicidas atrazina e simazina visando futuras aplicações em agricultura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alterações no equilíbrio ácido-base em equinos submetidos à prova de três tambores ou à competição de enduro de 160 Km

Pós-graduação em Medicina Veterinária - FCAV

Physical-chemical characterization and wet milling yield of four maize hybrids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)