Desenvolvimento de um código computacional para simulação e análise de espectros atômicos

The aim of this work was the development a computer code for simulation and analysis of atomic spectra from databases constructed from the literature. There were created four routines that can be useful for spectroscopic studies in the atomic processes of laser isotope separation. In the first routine, Possible Transitions, the program checks the possible electron transitions from an energy level of the atom present in the database considering the selection rules for an electric dipole transition. The second routine, Locator Transitions, checks the possible electronic transitions within a user-specified spectral region. The routine Spectra Simulator creates simulated spectra using the graphical application gnuplot through lorentzian curve and finally, the routine Electronic Temperature determines the temperature of electronic excitation of the atom, thought the Boltzmann Plot Method. To test the reliability of the program there were obtained experimental emission spectra of a hollow cathode discharge of dysprosium and argon as a buffer gas. The hollow cathode discharge has been subjected to different values of operating currents and pressure of inert gas. The spectra obtained were treated with the assistance of program routines developed (Transition Locator and Spectra Simulator) and temperatures electronic excitation of the atoms of dysprosium in the different discharge conditions were calculated (routine Electronic Temperature). The results showed that the electronic excitation temperature of the neutral dysprosium atoms in the hollow cathode discharge increases with increasing current applied to the cathode and also by increasing the gas pressure buffer. The determination coefficients, R2, obtained by the Electronic Temperature routine using the linear adjust of the Boltzmann Plot Method were greater... (Complete abstract click electronic access below)

Espectrometria de massa para análise isotópica dos bio-elementos

Mass spectrometry is an analytical technique widely used in several areas of academic research. It allows the knowledge of the information about the micro-world of atoms leading to significant advances in science today. The analysis of stable isotopes of carbon, hydrogen, oxygen, nitrogen and sulfur, also known as bio-elements, shows itself as a major area of interest in using the proposed method. The development of techniques and equipment coupled with mass spectrometry promises to deliver even greater progress in this field, in particular, for the biological sciences and related areas. The pyrolytic method in reduction of organic compounds at high temperatures provides simultaneous isotopic analysis of bio-elements H and O, by the gases released, H2 and CO after the pyrolitic process, significantly reducing analysis time and the amount of material to sample. This paper presents a review of mass spectrometry with its basic principles of operation, and pyrolytic method for reducing compounds at temperatures above 1400 ° C for isotopic analysis of bio-elements

Diodo planar orgânico Schottky: construção e caracterização

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Expansão térmica de nanotubos de carbono de duas camadas

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Fracionamento de mercúrio em amostras de tecido muscular de peixes coletados na área de influência do AHE Jirau - Bacia do rio Madeira utilizando estratégias metaloproteômicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Glicerina na alimentação de cordeiros Ile de France em terminação

Pós-graduação em Zootecnia - FCAV

Efeito do tamanho de partícula na ensilabilidade e no valor nutritivo de silagens de cana-de-açúcar para bovinos de corte

Pós-graduação em Zootecnia - FCAV

Estudos sobre a aplicação do pentacloreto de nióbio na síntese de derivados de 4-aril-3,4-di- hidrocumarinas

Coumarin is a natural active compound that can be found in many plants. The coumarins have many properties such as bronchodilator, anti-inflammatory, antioxidant, anticoagulant, antibiotics, immunomodulatory, antimicrobial and antiviral, thus, they are widely used in medical applications. More recently the coumarin derivatives have attracted the interest of many research groups in the field of new materials, for example the possibility of their use as sensitizers in dye-sensitized solar cells (DSSC) and lasers. The MCRs are defined as a process in which three or more reactants are combined in the same reaction pot, resulting in products with good structural complexity a single step, in addition to economy of atoms and selectivity and is a very important feature in modern synthetic methodology. In this work we investigated the use of niobium pentachloride as catalyst of the multicomponent reactions between phenolic derivatives, various aromatic aldehydes and β-diester derivatives in the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives. The reactions were carried out at room temperature, under inert atmosphere (N2), using dichloromethane anhydrous (CH2 Cl2) as solvent, with a reaction time of most 120 hours. The products were isolated by column chromatography on silica gel and submitted to spectrometric and spectroscopic analysis. The results show that NbCl5 is an excellent agent for promoting the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives through multicomponent reactions, obtaining yields varying from 45 to 95%

Síntese de tetra-hidropiridinas por meio de reações multicomponentes

Multicomponent Reactions are defined as reactions between three or more reagents in a single reaction step in the same reaction vial, forming a product that includes the majority of atoms and structural characteristics of the reagents. Thus these reactions save time and energy. One of the ways to improve the yield and reaction time of a multicomponent reaction is to use different catalysts, an example of catalyst that shows great potential and has been studied in recent years is the molecular iodine is known to be a Lewis acid with high catalytic power. The functionalized piperidines, also known as tetrahydropyridines, are alkaloids that have pharmacological potential, this is due to the piperidine ring present in many natural product structures with muscarinic activity, nicotine, analgesic, antipsychotic, anti-proliferative, among others. In this paper we describe studies about on the application of molecular iodine (I2) in the multicomponent reaction between aniline derivatives, benzaldehyde and β-ketoester (methyl acetoacetate) for the synthesis of functionalized piperidines and the synthesis of a corresponding piperidone by acid hydrolysis. Data analysis allowed us to demonstrate the efficacy of molecular iodine in the synthesis of functionalized piperidines, obtaining results with yields 44-87% and short reaction time of 8 to 24 hours, and the efficacy of acid hydrolysis of enamine in the structure of the tetrahydropyridine derivative in a yield of 81%

Controle da porosidade e das características ácido-base de óxidos mistos derivados da hidrotalcita para aplicação em catálise

Pós-graduação em Química - IQ

Equipamento para realização de ensaios de tração confinada e aquecida em geossintéticos

Pós-graduação em Engenharia Civil - FEIS

Fotocatálise heterogênea de enterococcus faecalis e pseudomonas aeruginosa desencadeada pela ação da luz UV e branca em espátulas com revestimento de nanopartículas TiO2 e Ag

Nanotechnology, the science of minuscule, has developed products which are able t o manipulate atoms and molecules that could be applied in the sterilization process of dental instruments. Objetives: The objective of the present study was to evaluate the self-cleaning action of TiO2 and Ag nanoparticles coating on dental instruments by the photocataliys process under UV and visible light irradiation. Material and method: Microbiologic tests were done using dental cement spatulas coated with TiO2 and Ag nanoparticles (one or three layers), and contaminated with 10 mcrl of Pseudomonas aeruginosa and Enterococcus faecalis, respectively. After contamination, they were exposed to ultraviolet light and visible light for 120 minutes. Next, they were transferred to and stored in test tubes with BHI (Brain Heart Infusion) and incubated in 35 to 37 °C. Checking times for bacterial growth and for control and retrieval tests were done at: 24, 48, 72 and 96 hours. Result: The Pseudomonas aeruginosa was inactive after 120 minutes of ultraviolet light irradiation, thus confirming the heterogeneous photocatalytic activity of TiO2 and Ag. The Pseudomonas aeruginosa was not inactivated under visible light irradiation and the Enterococcus faecalis was not inactivated under UV and visible light irradiation of the dental cement spatulas coated with TiO2 and Ag nanoparticles in the readings to 96 hours, showing bacterial growth. Conclusion: There were no influence of one or three layers of TiO2 and Ag nanoparticles coating of the spatulas in the results. The heterogeneous photocatalysis activity of TiO2 and Ag under UV light irradiation was confirmed for Pseudomonas aeruginosa but not under visible light. Enterococcus faecalis did not confirmed the photocatalytics activity of TiO2 and Ag under UV light irradiation and visible lights irradiation.

Implicações da disponibilidade de espaço no confinamento de bovinos de corte

Pós-graduação em Zootecnia - FCAV

Multiplicação de Diaphorina citri e de Candidatus Liberibacter asiaticus em híbridos de citros indicados como porta-enxerto

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Chemical and Fatty acid composition of different cuts cooked or uncooked from yearling bulls fed oil sources

This study evaluated the chemical and lipid composition of uncooked or cooked loin (Longissimus thoracis) and rump (Biceps femoris) in samples of 2.54 cm thick from 35 carcasses of Nellore young bulls finished in feedlot for 96 days and slaughtered at an average weight of 532.17 ± 30.25 kg and 24 months of age. The rump had the lowest level of protein and ash (18.57 and 0.90%, respectively) and the highest level of ether extract compared to loin (3.37 and 1.90%, respectively). Higher levels of cholesterol were found in rump compared to loin (40.91 e 30.93 mg 100 g-1, respectively). The uncooked loin showed lower content of saturated fatty acids and higher content of polyunsaturated fatty acids. The best values for the omega-6: omega-3 ratio was observed in the uncooked beef. In the present study, the loin was healthier due to the higher amount of polyunsaturated fatty acids compared to rump. Cooking the meat decreases the levels of polyunsaturated fatty acids, omega-3, omega-6 and the omega-6: omega-3 ratio.