192 resultados para Complexos de cobre


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This study aimed to evaluate and characterize the chemical properties of soil organic matter under two periodically flooded forest formations on the island of Marambaia, Rio de Janeiro. These formations differ on the degree of soil water saturation, caused by the influence of water table, and in the (F1) formation presents the water table nearer the surface compared to the (F2) formation. Samples were collected in layers from 0.00 to 0.05, 0.05-0.10 and 0.10-0.20 m. The soil properties evaluated were: pH, H+ + Al+ 3, Ca+2, Mg+2, Na+, K+, P, N, total organic carbon (TOC) and base saturation (V%), humin carbon fraction (C-HUM), carbon of humic acid fraction (HAF-C) and fulvic acid fraction carbon (FAF-C). Statistically higher pH values were observed for F1. In F2 there are higher values of Mg+2, P, N and V% value. Correlation was found between the concentrations of Mg+2, N, humic acid and fulvic acid with water table in F1, and water table in F2 with Na+ and K+. Fraction C-HUM was more representative of the total organic carbon, followed by C-HAF and C-FAF. The TOC levels were higher in F1. The C /N ratio was lower in F2, with values ranging between 9 and 12, and F1 were found higher values of this relationship, ranging from 9 to 15. Among the pathways of formation of organic soils in both areas it appears that the major route for organic matter accumulation is the inheritance route.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Clicar acesso eletrônico abaixo.

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Magnetic fields can be produced by natural magnets, artificial magnets, and by circulating electric currents in wires and solenoids. An interesting experiment to observe the interaction between the magnetic field and free charges in a conductor, a magnet falling inside a tube made of conductive materials. The slowing down of the magnet by the appearance of a field in the opposite direction to the original one (Lenz's Law) is function the number of free electrons in the conductor and the electrical properties of this. Based on this, the objective of this study is to analyze the relationship between the electrical properties of conductors, copper and aluminum, with magnetic force on a neodymium magnet-iron-boron magnet falling inside a copper tube and aluminum, positioned vertically. In performing this experiment, we observed that it is a demonstration of Lenz-Faraday’s Law

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The Cu-Au mine of Chapada is located in the municipality of Alto Horizonte, in the northwestern portion of Goiás state and is inserted in the geological context of the Brasilia Belt, specifically the Mara Rosa Magmatic Arc, which hosts important deposits of Au and Cu-Au. The rocks found in the study area belong mainly to the Volcano-Sedimentary Sequence of Mara Rosa and are composed of basic to acidic metavolcanic rocks, psammiticpellitic metasedimentary rocks, chemical rocks and also hydrothermal products. Late intrusions occur and are represented by pegmatitic dikes and tonalitic bodies. The ore deposit of the Chapada mine is formed predominantly by the chalcopyrite-pyritemagnetite association, where pyrite is the most abundant mineral. Through the structural mapping of the mining fronts, it was able to recognize three deformational phases (Dn, Dn +1, Dn +2). During the Dn phase, isoclinal recumbent folds were formed, in association with amphibolites facies metamorphism. Later, in phase Dn +1, there was formation of drag folds and intrafolial folds in association with retrograde metamorphism in the greenschist facies. The deformational phase Dn +2, in its turn, was responsible for late symmetrical folding of the foliation, with NS and EW axes, resulting in an interference pattern of the dome-and-basin type

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Trabalho trata da síntese e caracterização de quelatos inéditos de prata, paládio e platina contendo proteínas hidrolisadas da clara de ovo. A ideia consiste em preparar e utilizar quelatos metálicos contendo ligantes de origem natural, como metalofármacos. A pesquisa realizada pode ser dividida em três etapas. A primeira, referente à hidrólise e análise do hidrolisado proteico da clara de ovo. Diversos métodos e condições experimentais foram testadas a fim de se encontrar as condições de hidrólise mais adequadas (natureza da enzima, tempo, pH, temperatura, relação enzima:substrato) para a obtenção de aminoácidos livres e/ou pequenos peptídeos. A segunda parte consistiu na obtenção de compostos de coordenação de platina, prata e paládio contendo o hidrolisado proteico. Nessa etapa, diferentes rotas sintéticas e condições experimentais também foram utilizadas. Além disso, a espectroscopia vibracional no infravermelho foi utilizada nessa etapa para investigar as características estruturais (particularmente, os grupos funcionais presentes) dos compostos metálicos obtidos bem como da matéria prima utilizada (clara de ovo). Após inúmeras tentativas de síntese, três amostras promissoras, do ponto de vista da Química de Coordenação, foram obtidas, a saber, CO-Pd2, CO-Pd9 e CO-Ag3. Ensaios biológicos preliminares, que consistiu na terceira e última parte deste trabalho, foram realizados no sentido de avaliar a capacidade inibitória de crescimento das bactérias S. aureus e E. coli, através da determinação da Concentração Inibitória Mínima (CIM) dos compostos metálicos obtidos.

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Introduction: Tuberculosis (TB) is a granulomatous disease caused by Mycobacterium tuberculosis. The genus Mycobacteriumhas two different complexes: M. tuberculosis Complex and M. avium Complex. This is a global health epidemic and remains a major global health problem, besides, the clinical severity of TB is significantly higher in transplanted patients. The detection of these mycobacteria complexes in transplanted patients, by molecular methods, is fundamental for quick treatment of patients and can contribute for rapid and accuracy of diagnosis. Objective: To detect mycobacteria DNA of M. tuberculosis and M. avium Complexes in formalin fixed paraffin-embedded samples (FFPE) of two patients groups: non transplanted and transplanted. Materials and Methods: The study includes 40 FFPE biopsies separated in four groups: NTP – presence of epithelioid granuloma and positive ZN, non-transplanted patients – 9 samples; NTN - presence of epithelioid granuloma and negative ZN, non-transplanted patients – 10 samples; TP – positive ZN, transplanted patients – 9 samples; TN – negative ZN, transplanted patients – 7 samples. Sections were cut for DNA extraction. Samples were submitted to PCR for amplification of: a) β-actin, b) IS6110 insertion and c) IS1245 insertion. DNA evaluation was made by spectrophotometry and efficiency and PCR analysis was made by agarose gels under UV light. Results: In all samples processed, 97.1% were positive for human β-actin gene. In22.2% of NTP group were found the IS6110 insertion sequencebut the IS1245 wasn´t. In the NTN group was not found any sequence. In theTP group, 11.1% of the samples were positive for IS6110 and also 11,1% werepositive for IS1245. In the TN group, 14.3% of the samples were positive forIS6110 and for IS1245, 14.3% was also positive. Conclusion: Although factors such as DNA degradation after formalin fixation and paraffin embedding, were possible to detect DNA from the human gene ...

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The glassy carbon is a material with a huge technological evolution. Due to its lightness, biocompatibility and their thermal and electrical properties this material finds applications in several industrial fields such as electronics, medical, aerospace and chemical. In order to explore the conductive properties of glassy carbon for use as modified electrodes, the present work aims the processing of monolithic and reticulated glassy carbon with colloidal copper for use in electrochemical applications. First, the best parameters for the cure of furfuryl alcohol resin doped were established through viscosimetry measurements and pressurized differential scanning calorimetry. The analysis of the micrographs of the cured resins show that copper concentrations above 3% weight, generate higher porosity in the material. The characterizations of the monolithic and reticulated glassy carbon resulting from carbonization were performed by scanning electron microscopy (SEM), Raman and Electrochemical impedance spectroscopy, and although it was not possible to detect the presence of copper by SEM, the influence of these particles have been observed by Raman and FT-IR spectra and electrochemical behavior of the material. The decrease in conductivity of monolithic and reticulated glassy carbon in the presence of copper may be related to the defects caused by the presence of copper in the structure of the material.

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Nos últimos anos, a biotecnologia tem proporcionado avanços no desenvolvimento de biomateriais a serem utilizados como dispositivos médicos. Dentre esses dispositivos, podemos destacar aqueles que promovem a reparação tecidual e, também, a liberação controlada de fármacos. Partindo deste propósito, lentes de contato à base de celulose bacteriana (CB) foram desenvolvidas, visando o efeito curativo e reparativo para doenças da superfície ocular. A adição de ciclodextrinas (CDs) e fármacos, como o ciprofloxacino (CP) e o diclofenaco de sódio (DS) á essas lentes proporcionando propriedades terapêuticas e de liberação controlada dos fármacos. No entanto, para certificar-se do uso seguro desses compósitos pela indústria de dispositivos médicos, é necessário verificar se não possuem atividade citotóxica, genotóxica e/ou mutagênica. Sendo assim, a proposta do presente trabalho foi o desenvolvimento de uma adição eficaz de fármacos às lentes de contato de CB, para que sejam liberados de maneira controlada e, também, a verificação de sua biossegurança. Para essa verificação foram realizados ensaios in vitro de citotoxicidade (ensaio com o kit XTT e Sobrevivência Clonogênica), genotoxicidade (ensaio Cometa) e mutagenicidade (teste do Micronúcleo) com os respectivos. Após a análise estatística dos resultados foi possível verificar que o material CB-CP apresentou efeito citotóxico e os materiais CB-DS e CB-CD-DS apresentaram efeito citotóxico, genotóxico e mutagênico. Essa informação é fundamental para uma futura utilização segura desse biomaterial pela indústria de dispositivos médicos ...

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Um dos caminhos para identificar os contaminantes e seus efeitos em ecossistemas aquáticos é examinar a resposta de alguns organismos considerados bioindicadores. O presente projeto teve por objetivo avaliar a bioconcentração de cádmio e cobre pelo peixe de água doce Oreochromis niloticus (tilapia), visando, principalmente, estabelecer seu potencial bioindicador de contaminação destes metais em ambientes fluviais.Dentre os vários metais pesados passíveis de contaminação ambiental, o cobre um elemento essencial e o cádmio um elemento não essencial, são altamente tóxicos, mesmo em níveis de concentrações muito baixos e podem se elevar quanto maior for o nível trófico do organismo, podendo chegar ao homem em teores magnificados. Em condições laboratoriais, foram determinadas as toxicidades aguda de Cu, de Cd, e de Cu+Cd em tilápias em períodos de 24 á 96 horas de exposição. A partir dos resultados obtidos nos testes de toxicidade aguda, foi estabelecida a dose letal que levou a óbito metade da população (CL50). Os valores encontrados para o presente estudo foram: CL50-96h para cobre – 3,53 mg/L;CL50-96h pra cádmio – 20,13 mg/L;CL50-96h para cobre combinado ao cádmio – 1,36 mg/L. Foram avaliadas as concentrações dos referidos metais nos fígados e nas brânquias. O presente estudo mostra que em linhas gerais o fígado acumulou mais metal do que as brânquias, e que o processo de absorção do cobre é mais rápido do que o do cádmio para a espécie de peixe testada. Os resultados obtidos mostraram que o cobre foi mais tóxico do que o que o cádmio, entretanto, a combinação de ambos metais apresentou maior toxicidade

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This paper presents a study on the development of a manufacturing system of printed circuit boards through copper milling. An advantage of this system is the replacement of chemical processes by physical process presenting a sustainable solution. The paper uses programs that will generate G-code needed to establish the coordinates where the milling forms the tracks. After obtaining the code, it will be transformed into steps that will be sent through the serial port to the microcontroller and the serial communication control will be in software. After obtaining information the microcontroller will execute the movement of the stepper motors through their drivers, H-bridge, the microcontroller also drives the spindle motor responsible for rotating the grinding tool, using a driver with a optocoupler and TRIAC

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Solid-state compounds of general formula LnL3.nH2O, in wich Ln represents lanthanum, lanthanides and yttrium, L is ketoprofen, and n = 0,5 (Pr, Sm, Tb), 1 (La, Eu, Dy, Ho, Er, Tm, Lu) e 1,5 (Ce, Nd, Gd, Yb, Y) were synthesized. Simultaneous thermogravimetry-differential analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy and EDTA complexometry were employed to characterize these compounds. The TG-DTA and DSC curves provided information concerning the thermal behaviour and thermal decomposition of synthesized compounds. The experimental and theoretical infrared spectroscopic data suggested that ketoprofen acts as a bidentate ligand towards trivalent lanthanides and yttrium (III)