Voltammetric determination of total iron in fuel ethanol using a 1,10 fenantroline/nafion carbon paste-modified electrode

This work presents a methodology for iron determination in fuel ethanol using a modified carbon paste electrode with 1.10 fenantroline/nafion. The electrochemical parameters were optimized for the proposed system and the voltammetric technique of square wave was employed for iron determination. An accumulation time of 5 minutes, such as a 100 mV of pulse magnitude (E(sw)) and frequency (f) of 25 Hz were used as optimized experimental conditions. The modified carbon paste electrode presented linear dependence of amperometric signal with iron concentration in a work range from 6.0x10(-6) until 2.0x10(-5) mol L(-1) of iron, exhibiting a linear correlation coefficient of 0.9884, a detection limit of 2.4 x10(-6) mol L(-1) (n = 3) and amperometric sensibility of 4.5x10(5) mu A/mol L(-1). Analytical curve method was used for iron determination at a commercial fuel sample. Flame atomic absorption spectroscopy was employed as comparative technique.

Utilização de um eletrodo de grafite-epóxi recoberto com [Zn(FEN)3][tetratris(4-clorofenil) borato]2 sensível a zinco(II) em meio 1,10-fenantrolina como eletrodo indicador em titulações potenciométricas de precipitação

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

Microbial transformation of cadina-4,10(15)-dien-3-one, aromadendr-1(10)-en-9-one and methyl ursolate by Mucor plumbeus ATCC 4740

The sesquiterpenes cadina-4,10(15)-dien-3-one (1) and aromadendr-1(10)-en-9-one (squamulosone) (14) along with the triterpenoid methyl ursolate (21) were incubated with the fungus Mucor plumbeus ATCC 4740. Substrates 1, 14 and ursolic acid (20) were isolated from the plant Hyptis verticillata in large quantities. M. plumbeus hydroxylated 1 at C-12 and C-14. When the iron content of the medium was reduced, however, hydroxylation at these positions was also accompanied by epoxidation of the exocyclic double bond. In total nine new oxygenated cadinanes have been obtained. Sesquiterpene 14 was converted to the novel 2α,13-dihydroxy derivative along with four other metabolites. Methyl ursolate (21) was transformed to a new compound, methyl 3β,7β,21β-trihydroxyursa-9(11),12-dien-28-oate (22). Two other triterpenoids, 3β,28-dihydroxyurs-12-ene (uvaol) (23) and 3β,28-bis(dimethylcarbamoxy)urs-12-ene (24) were not transformed by the micro-organism, however. © 2002 Elsevier Science Ltd. All rights reserved.

Modelagem espacial dinâmica aplicada ao estudo de movimentos de massa em uma região da serra do mar paulista, na escala de 1:10.000

Pós-graduação em Geociências e Meio Ambiente - IGCE

Síntese, caracterização e estudo de atividade biológica de complexos de prata(I) contendo ligantes baseados na 1,10-fenantrolina e tiouréia

Pós-graduação em Química - IQ

Mapeamento geológico-geomorfológico do Morro Azul na região de Limeira, SP, na escala 1:10 000

Geologic and geomorphologic mapping are important ways to characterize the environment, because they look to describe and diagnose landforms, identifying and understanding the morphogenetic processes, making it possible to comprehend the landscape dynamic. This work aimed to make a geological and geomorphological map, in a 1:10.000 scale, of the Morro Azul, the main elevation in the city of Limeira – SP, with the application of photogeological techniques and field descriptions. As final products are presented a geological-geomorphological map, a topographical profile, a slope map, beyond the main characteristics of the geological-geomorphological units of the area. This study presents itself as a preliminary work, and can serve as a subsidy to more specific works, such as geotechnics, environmental problems, among others

Il viaggio celeste di Paolo (2Cor 12,1-10). Particolarità e funzionalità di una forma di contatto con il soprannaturale

L’obiettivo principale di questa ricerca è quello di affrontare le questioni critiche poste all’esegesi da uno dei passi paolini più discussi. Grazie all’impiego delle categorie connesse all’esperienza religiosa, si vuole argomentare la possibilità di leggere il viaggio celeste in termini di modello culturale attraverso il quale interpretare un’esperienza di contatto con il soprannaturale. L’approccio individuato può consentire di rivalutare la funzione di tale narrazione non solo nel contesto di 2 Corinzi, bensì anche in relazione ai paralleli letterari di matrice tanto giudaica e protocristiana quanto greco-romana. Conseguenza di simile analisi ad ampio raggio è il riconoscimento dell’importanza attribuita da Paolo ad esperienze di questo tipo, come testimoniato da alcuni brani centrali delle sue lettere.

Atmospheric Implications for Formation of Clusters of Ammonium and 1−10 Water Molecules

A mixed molecular dynamics/quantum mechanics model has been applied to the ammonium/water clustering system. The use of the high level MP2 calculation method and correlated basis sets, such as aug-cc-pVDZ and aug-cc-pVTZ, lends confidence in the accuracy of the extrapolated energies. These calculations provide electronic and free energies for the formation of clusters of ammonium and 1−10 water molecules at two different temperatures. Structures and thermodynamic values are in good agreement with previous experimental and theoretical results. The estimated concentration of these clusters in the troposphere was calculated using atmospheric amounts of ammonium and water. Results show the favorability of forming these clusters and implications for ion-induced nucleation in the atmosphere.